GB2353738A

GB2353738A - Catalytic converter

Info

Publication number: GB2353738A
Application number: GB0015471A
Authority: GB
Inventors: Branko Richard Babic
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-21
Filing date: 2000-06-21
Publication date: 2001-03-07
Anticipated expiration: 2020-06-21
Also published as: GB0015471D0; GB2353738B

Abstract

A catalytic converter having a casing 1 housing which has an inlet 2 and an outlet 3 for the flow of exhaust gases therethrough and a plurality of catalyst coated plates provided within the casing. The plates have a series of apertures 6 the flow of gas therethrough and the plates are arranged so that the apertures 6 in one plate are offset from the apertures 6 in an adjacent plate. Hence, as gas flows through the plates, it passes through one plate and impinges on the surface of the adjacent plate. The plates may either be flat plates, (this enhances turbulence between the plates) or they may have protrusions for example cone shaped or pyramid protrusions which allow smoother gas flow characteristics. The converter may have a single chamber or alternatively a converter design with three chambers all comprising such plates is described. This three-chamber configuration is capable of five-way catalysis. The principles of the catalytic converter can also be applied to a mixing component which may be used in spray cans or industrial mixing systems. The technology can be extended to provide very efficient heat exchangers, such as radiators and coolers.

Description

2353738 Cataljc Convefters This invention relates to catalytic.

converters, to be used partic-udarly In the eNliaust sy-stems of automobiles, jets and other vehicles. The iriverition is equdly applicable to &-,ed power generating svstems.

A main problem in catalytic conversion is that insufficient molecular contact occurs between the catalyst and the reactive species. A main aim of the prescmt. invention is to overcome this problein.

nie present invention in a first aspect provides a catalytic converter cornprisiRg a casing having ail inlet and an outlet for the floN of exhaust gas therethrough, and a plurality of catalyst coated plates pro,. rided vrithin. the casing substantially transverse to the gas flow, the said plates having a series of apertures therein for the flovT of gas therethrough, wherein the said plates are so arranged that the apertu,res in one plate are offset fiTom the apertures in an. adjacent plate.

The plates may have flat surfaces so that the gas flow through the aperwres in -the one plate will impact against the adjacent plate and thus fonn gas turbulence and. vortices between the plates, thus increasing the catalytic action between the gas flow and. the catalyst coating on the plates.

However, the plates may also be provided with a plurality of protrusions on their surface closest to the 11ilet. The protrusions may be cone shaped or triangular. 'n-ds so-called smoothi flow converter design does not induce turbulence, but deflects the impacting media with minimum disruption to the flow characteristics wl-@st maintaining direct impact characteristics.

Preferably, the plates axe made froin a so-called low density material wherein particles of a first material are suspended in a second inaterial, arid said first material has a lower density than said second material.

The discs may also be made ftom a second material which has a plurality of air vacuoles. The preferred size and. distribution of the air vacuoles is the same for that of the first material with a lower density.

-Me plates are preferably of cerarnic material and a.e coated s.?lth aily suitable catalyst, but can. be made ftorn suitable rnetal.. 'lli.e plates compn.se a material compn.ses a substantially ho.m..)gen-ek)ils miXture of expanded polystyrene, ex.foliated clays or glass or some other sintable material, with a ceramic.Tnatrix, wherem the size of ex.fo[i.ated particles within. the matrix is not more than about 1 mm m diameter, and is preferably not more than. ',/-. rrim in diameter; such a material preferably contains, as an example only, al-)out'c01,/ (for example, typically from 70% to 00% particles) expanded polystyrene.

The present invention in a second aspect accordingly provides a plate for a catalytic. converter, which comprises as an example only, an expanded polystyrelie/ceramic 1.natrLx material as defined in the previous paragraph.

In thl- first and second aspects of the invention as defined above the plates will normally be of circular crosssection, but could be of different cross -sectional shape such as ellipsoidal, rectangular or even cylindrical with perforated cylinders sliding inside each othei. to provide a working unit. The preferred shape is deternillied by. its application.

Such an expanded polystyren.e'C--ramlc maffi\ material can also be used to line the inside walls of the easing of the catalytic converter according to the first aspect of the invention, to retain heat in the easing arid thus assist in achiein.:,- an optimum worldn,:, temperature in the catalytic converter.

ZD b Existing technology can also be used. to retain heat in the chamber, in combination with the plates substrate.

-Ihus the present invention may provide a catalytic converter to the easing of which is applied an expanded polystyr,-n-.,lceran-ilc matrix material as defined above. The expanded polystyrene in die material may be wholly or partially replacCed by cork or suitable cellWo5e, andlor the ceramic matrix may be a clay such as cordierite, as,,vffl be deschbed iri. more de-tail subsequently.

nic use of the designed ceramic matrix material to lie the inside of the catalytic converter ewsingretains heat and raises the temperature of the catalytic chamber more quickly. than covering the outside of the chainber with such material. 7he fact that the new catalyst design starts to function within a matter of seconds arid achieves its optimum working temperature quickly increases the the heat v,;idi the designed cerain' of die improved catalyst. Tills is aclUeved by retaining 1 10 matrix.material and Teducina the mass of thematrix of such materials.

j-ne ceramic plates can atso I)e made of the expanded polystyrene/ceramic matrix matenal., as previously stated, and by using- extremely small ex. foliated beads vith the ceramic matrix, a. thin plate section can be achieved. Because this material is an extremely poor conductor of heat the temperature reaches the optimum worldrig range ven, quickly- The impact of the exhaust gases with the catalyst covered. surface is increased. because the apertures in adjacent plates are offset so that as the gas emerges out of the plat-, apertures it has to change direction to enter the apertures of the next catalyst covered plate. n-ds change of direction causes vortex formation and improves the miscibility of exhaust gases. The offset aperture design. also has the effect of causing the exhaust gases emerging from the apertures of the platee to impact on the adacent following 1 1 plate surface where it interacts widi the catalyst.- Given that the catalyst can only acMeve its effect if the gas comes into contact Nith the catalysing elements, then the formation of voitices will be essential if -die size of the catalyst chamber is to be reduced.

J"he miscibilityof exhaust gases can be fuither enhanced by the size and directionof apertures in. the plates. Different. methods to induu more violent interplate vortex formation are available and another way of achieving ths is to provide raised lip sections at the ends of the apertures, at the downstream side of the plate. The eMct of the lip is to cause a local pressure gradient in the immediate region of the exit -end of the apertures. This pressure difference induces vortex formation in the flowing gases and acl-deves the required gas miscibihty and. impact of the circulating gases with the walls of the catalyst coated plates. Ms space is a passive space aTea where gas exchange takes place by diffusion rather than &eect turbulence.

The effectiveness of the catalyst could beincreased by covermg the whole plate surface with the catalytic elements. Given the low voluine of gas in contact with -die catalyst and the short time the gases spend within the apertures, then the interplate catalyst covered surfaces would give higher conversion rates. This would reduce the size of the chamber arid increase efficiericy and may require less catalytic element to achieve purification of exhaust gases.

C1ven that the catalyst only needs to be one atom deep to achieve its effect, then the metal vaporisation and condensation technique would give a more cost effective method of depositing, catalyston the base material.

-M-- concept of providing variable pressure gradients the chamber can be achieved by the provision oflarger and smaller diameter apeiftires in the catalyst plates. This design has the efl,ct of inducing d' ring press-Lire 2Tadients and therefore proVidin differential pressure gradients Iffe. g 1 - t in between the plates of the chamber. The effect of these variable pressures is to increase the vortex formation in sizze and speed. This occurs because gases respond immediately to changes in pres.suie. The- increase of vortex formation increases the rate at -v,,liich the gases are mixed in the interplatee space. iM-temat.- large and sinall diameter apertures also provides a variation in pressure gradient within the chamber.

A further way to provide an ilicrease in die vortex formation is to provide chamiels sAlithin the plate mass, atthe do,,nsiTearn side ofth.e plate, to!puirjp".dic gases around the interplate space. TIds puirip system designi, irivolving no moving parts. 1S worked by. the reduced pressure,,jiddn the aperture,-,. The flowing gases reduce the pressure at. the channel exit and the higher pressure at the channel. entrance causes a. current of gas through. the channel. movement of gas increases the rate of vortex fon-nation in the interplate space.

The- above principles can bee generally used, for gas/liqiiid systems to provide an exceptionally W efficient method of miscibility. The principles can be used to mix fbr example petrol and air mixtures, gas mixftires, hqtiid mixtiires and other fluid substances where "no moving parC mig systems are desirable. Any situation where moving fluid mixtures need to be mixed can be subjected W 1 to the described systems to cause mixing of thee constituents.

As a homogeniser of fluid/gas systems such as fuel and air, the vortex achon. reduces the size of the fuel droplets. In combustion Iengines the oxidation of such hornogeffiser fuel in the cylinder is much faster and more effective because the size of the fuel droplets is so small. This efficiency of combustion isuseful in other ap ir plications i icludingjet engines where the oxidation of fuel would occur in the combustion chamber. delivering maximum thrust. The provision of pre-heating the fuel air mixture would further add to fast oxidation of combustibles.

5' J-hare is a presure gradient by'Virtue of the fact that, as the exhaust val,..7e opens, the corribusted I gases escape into tbernanifold. As the c- in 1. 1 In y1i der empties there is a taili off of combusted gases to befallovred by another high. pressure pulse from the exhaust cycle of thenext cylinder in line. '17his pressure difference further helps to create vortex form ation within the catalc chamber.

In the case of t1e catalyst the induction of violent vortex formation is essential in. order to ensure that aU the exhaust gases come in. contact with the catalytic -elements. This feature. of the invention improves the rate of exhaust gas dissociation and reduces the size of tile catalytic chamber.

Given that the chamber has to reach a temperature of some 4501C to fimction. at its optii-nLu-n. then the closer the catalyst is situated to the engine exhaust the more quicidy the workirig temperature is achieved. 'Me consti uction of the new catalyst also acts as a silencer given that there is a physical barrier -to sound energ C y fi-om one plate to the next. 'Me reflected so-and eneiT y dissipates releasing energm decreasing order froin one plate to the next.

y as heat M Experiments have shown a direct relationship bet,.veen surface area and conversion rates of exhaust species. The aj.M of the design. is to provide themaximurn surface area that can be coated with the catalytic elements and allovv worldric, gaseous throughput. Tbe back pressure induced by the impedance and &ag on. the moving gases can. have an adverse effect on the working of the ve"hicle engine if it becomes too high. An. optimum arrangement is therefore established for each engine.

The plate design has established a system of interfaces that the exhaust gases have to interact with before they can move ftirther down tie chamber. The forvrard plate has an arrangement of apertures that are specifically aligned. in a regular arrangement. The folloNring plate has an offset similar arrangement of aperaires presenting a surface to impede the 1-novelnellt of exhaust gases.

Gas-Is migratirig through the aperture of the fonvaxd plate impact on the surface of the second plate, come ito contactwith the catalyst covered surface and underg;o conversion. 71ieiiiipactiig gas rebounds to fonn turbulence and vortexes that circulates the gases in the interplate space. 7he entire plate surface is covered with catalysilkg elements so that the circulating gases iinpacting on the downstream side of the forward plate undqgo further conversion. The gases move through the 11 11 apertures in the second plate, come in contact with the catalyst covered surface arid undergo further oxidation/reduction [c, emerge and repeat the process on a tILUd plate. The process continGes throughout the catalyser cliarnber.

Plates can be selectively coated with chosen catalysing, elements so that differentspecies are converted by selected coatings on chosen plates. The coating can be con ventiona coats, or electrolytic or vapor deposition ofthel desired coatings. Alterriatively the whole assembly can be dipped into the soltitions.

The design feature of the plate is the size of the plate and the thickness of the plate. The size and number of apertures in the plate, which can be of any optimised size or shape, is important in relation to the volw-iie of gas that can traverse the plate.

The siz.- of the plate, le. its diameter, isrelated to the engine capacity. The. larger the cubic capacity of the sum of the cylindersthegreater the diameter of the plale. In an cases the size of tile apertures arid the inter-aperture solid surface is related. The smaller the capacity of the eng-ine the sirialler the diameter of die plate components. Parallel arrarigernents of chambers can be established to split the total volumetric output of the erngine into smaller parallel volumetric throughputs for each. chamber. A design. of "in serles!! chambers with gate valves is possible, for very low volumetn.i.c throughput also facilitating higher volumetric tliroughpilts.

Preferably. the plates Will have a. diameter from 9c..-m to 21 em.

An optimum arrangement of number of aperttires and the surface area 1S calculated for each engine type. In general an optimum are a, ofthe sum of the apertures in the plate, is allowed for a given cubic capaclt,,,,' of the engine or system the catalyst is designed for. Drag induced by the tiirbifience and vortex formations is taken into account.

Preferably, the apertures have a diameter in the range, from I inin to 31111-n.

More preferably, the nearest ectges of ajacciii apertures are separated by a distance from 0.5mm to 2.0inin.

The tl-iicljiess of the ph ate gives the length of the aperture traversingthe plate. This dimension is important in rriaintaining. the turbulence of the exhaustgases. Generally and depending on the diameter of the aperture, lamina flow of a ga.s in a tube develops according to speci-fic enteri.a. '111.e object in determining the thickness ofthe plate is to provide a. length. of aperture in. which preferably lamina flow cannotoccur. Complex conditions are experienced within the catalytic converter chamber. In smaller apertures larnma flow is established within the fLrst centimeter of the aperture length. The design of the plate in this case would be- a thickness of plate that was less than one centimeter and preferably halfthe distance, or less, than required for lamina flow to be -established. Mixing of exhaust gases is therefore generated even within the apertures traversing the plate body. In apertures main flow is apparent at about the distance of the radius of the ape"e. and can be related to the speed of gas traversffig the plate. Preferably, the plates have a tlu.'clcjiess of greater than or equal to 21nin. More preferably, the plates have a thickiiess in the range fl-om 4inm to 6i-ni-n Ideally, the thickness of the plates should be greater than the radius of their apertures., nic diameter of the aperture is related to the pressure drop exerted by eases traversing the plate apertures.

The interplate spacing does not appear to correlate significantly to the rate of conversion of the exhaust gases. 'I'lie plate spacing is determined by the prevailing requirements that in.duce maxirmirn turbulence formation for the given engine size.

Preferably, there are from 10 to 15 plates.

Practically, 2 plates form the minirnum ftirbulent flow configniation.

Th- plate catalytic converter obviates one of the inain problems induced by catalysers of other designs. 'Re problem ofu'icreased back pressure duce to the diag of laminated flowing gas-Is is removed by the plate design because the apertures are of a very short length. The spacings between the plate induce vortex formations, that are optimised according to the capacity of the engine. The nattire of the distal opening of the traversing aperture also induces vortex forniation in addition to the vortex formation due to the pressure difference Inthe interplate space and within the aperture. 'I'lic size of the plates can be ajusted to provide the desired gaseous throughput to minirrilse the back pressure induced by the catalyser.

The above pressure measurements in. the prototype gave remarkably low pressure drops. Measurements on the 10Omm diameter plates with 5 plate configuration, mounted on a 2.33 liter engine, gave an. exceptionally low manometer reading of,,-lisplaced water.

t) Pressure drops of tl-ds low order open up the possibility of adding buffer plates in fi-,--)nt ofthe catalysing plates that assist o3Kidation/reduction of pollutants. The buffer plates are coated Mth chemical compounds that absorb/convertIprevent components that poison or inactivate. catalysing elements. The catalysing elements in tl-ds case remain fresh and achieve verV high conversion rates.

In the quest for total catalysis the filither conversion of the hydrocarbon species is assisted by the pumping of highly heated air into the cataly-de chamber. The active component in this case is the 21 % oxygen contained in the air. At the relatively lugh temperature of the combustion engine, oxidation of exhaust gases is assisted by. injection of pre-heated air.

The pre-heated air cc, Uld be specifically pie-licated by a variety of means to high temperature or indirectly heated by forcing the air to circulate overflic enclosed irianifold section, to be puniped into the adjacent catalyser members. The pumping of exhaust gases could pro,,i.de negative pressure conditions at the exhaust valves.

Ilie exhaust gases reaching the catalyser chamber are very depleted in the available o\ygen for the oxidation of the hydrocarbon species. The pumping of highly heated oxygenated air into the exhaust system w-W oxidise the components once the temperature exceeds the dissociation energy of the species in question. 'Mis technique is particularly advantageous in situations such as diesel exhaust gases oxidation. Given suitable conditions the carbon residues can be oxidised fiffly. The provision J of an after-burner chamber rich in oxygen is advantageous to total catalysis.

The plates are preferably to be made from the expanded polystyrene/ceramic matrix matenal previously described. This material is a clay matrix -with an expanded polystyrene bead/corl-,lceHulose dusL e.g. saw dust, straw dust, milled cellulose flour, exfohatrz,.d hydrocarbon synihetic materials, etc, constituent that provides measured sized organic particles that are coated 1 11 with a suitable material or clay product. As the end product, in this case plates, are fiTed, the organic particles oxidise to carbon dioXide and water leaving behind a vacuole filled mAth air. Such highly aerated compowids have remarkably hnv heat conducting properfies, and retair, most of the heat, fto.m the hot gases, on the surface of the catalysing plate- Thi.s property of the material raises the temperature of the plate surface, to optirnurn catalysing temperatures in seconds. 'fhe crucial component of the material is the s.1ze of the vacuoles. Ideally the vaclioles shodid be '/;, mm to powder in diameter.

For the catalyfic plate design ffie matrix is en.111saged to be the well established clay substrate material called cordierite. This substrate material aerated as described. proVides a suitable substrate material for 15 plate manufacture in the new catalytic converter design. The method of providing the measured air sacs or vacuoles is dependant on the availability of suitable matellials. If inorganic materials are preferred because of the increased deiisit,, of the plat-Is. then inorganic exfoliated perlit.- or vermiculite can be used. A inixturle of high alurnina cement clay with the above could proNdde a suitable matrix material for various applications.

These very useful exfoliated materials are particularly useful in the manufacture of cordicritc clay products that e-xhibit very low coefficient of expansion. The cordiente, perlile, vermiculite combinations provide an inorgan:ically based aerated clay inaterial that is exceptionally useful in the ceramic industry, because the addition of aerated compounds to cordierite and other clays w'hen in sufficiently high. concentrations impaTts, exceptional thermal shock properties to the product.

The catalytic chamber can be made.1n. a. number ofv-,,ays but conventi, anal technology can be used to house the plate design, The plates can of course be made from metal substrates.

Extensive testing of the plate vortex inducM''-:Ir design for catalytic convert.-rapplications suggests a complex relationship between concentrations of oxygen, temperature and oxidatiorVreduction chemical reactions that occux i catalytic converters. Optimum conditions have to be created for best conversion rates of selected species.

Because NOx reduction occurs best when low oxKgen levels are present in the exhaust gas a preferentially low (lambda, air/fael ratio) value is required for NOx conversion, is a ratio of fuel air mixture that is ideally set at 1.

k v 1lie oxidation of CO and the hydrocarbon species, and indeed the solid carbon. paT.tcles &s obviously I I T1 vironment-s.

seen in. some fiiels, e.g. diesel, are best achievedat hig i levels, ie. ioxygen ich- en i Because of tfie above contra.,diction of best conditions for conversion rates the industry selects optimum conditions that provide overa_11 best conversion rates for the whole of the ---zhaust gas. These conditions fall short of ideal conversion conditions for individual species so that catalytic conversion is never ideal for arry given species.

To overcome these disadvantages a double chamber catalytic conveiter may be provided, cornprising a first and a second chaniber.. both chambers having a plurality of plates ivith aperb-1res, the plates being arranged so that the apertures on one plate are offset frorn the adjacent plate, the first chamber being at the inlet side of the converter and the second chamber being at the outlet side of the converter, the fust chaniber having an atmosphere vitli a relatively low oxygen content and the second chamber having an atmosplierevath a relatively high oxygen content.

The plate design allows for an anterior chairiber to work at low oxygen levels for the NOx I conversion.. J-his chamber designed as already described will be subject to catalysis as the exhaust gas emerge out of the cylinder at low oNygen. level.. In situation-, such. as re-circulated diesel. exhaust gas engines the levels of oxygen in the exha ust will. be at suitable levels forTNOx conversion.

As the partially catalysed exhaust g as, virtuallyexhaust Nox free, enter the second charnber they are subject to pre-heated air injection to provide a second ideal set of conversion conditions. T-he high oxygen environnient at the proposed temperature, is optirnised to prolVide hydrocarbon dissociation.

These temperatures are in the rajgge of about 650'C. These, oxKgen in excess, preferenLial conditions for CO and HC conversion willgive vep er y high conv sion rales, parlicularly of the HC species silice the HC are lon1sed at high temperature. Tons v/ill add the further factor in the exhaust species being electrostatically attracted iii[c) reactive proximity. Ms will 11riprove k:ineiic momentum Interaction required for a successfal chemical. reacti.o.n. 'The electrostatically charged plates can also be employed to IMprove the interaction between the species.

A buffier plate comprising a small aperture, and if advantageous, tin oxide or other catalyst covered, b I plate has the -effect of impedirig the flow of exhaust gas so as to build up the pressure in the anterior U pait of the chamber. 'Mis has die effect of distribuffiig the e-Jiaust lgases M die anterior pall of die convertersc) that the exhaiist gases flow evenly over the folloWInjg catalyst covered plates. The flin, oxide itself has catalysing properties as well as pollutant absorbing capacity, c.a. of lead. '[lie g coating can. be a pollutant absorbing matenial.

Catal,;sis at the e,.laust end of the combustion engines can be assisted by eliminating sorne- of the 1 pollutants at the widation stage- of the combustion process.

Althlough the positioning of the plate homogeniser between the carburettor and the intake manifold is likely to exercise its inain advantage on the fael consumption, it will nevertheless reduce the total amount of pollutants because of improved oxidation of fael witlffii the cylinder. Nod-ffiig can be done. about the NOx component and there will abways be some CO.. HC and C, particularly as the engines age. Catalysis will therefore continue to be required at the post-combustion stage.

Other methods of inducing exhaustg" impact with catalyst covered surfaces are available, in accordance with the present invention, and in order to improve the rate of irripact there irlay. be used a stainless steel wre wool mesh. The steel inesh fomis a dense network. of impeding barriers to the rnigrating gases. Given the spaces available to the moving gases on a molecular basis the spaces between the metal wool elements provide aflice passage thiough the chamber.

In one arrangement, one plate of a pair of adjacent plates sandwiches a. mass of wire wool inbetween a plate of another pair of plates. This subchamber has stainless steel wire wool covered with for example one of the platinum group catalytic elements. This design facility allows the gases to disperse under pressure and mix before entering the next similar sandwich of wre wool. The exhaust gases are further catalysed and. pass on through the next open space to enter a firther subchamber containing wire wool covered iwith a flirther catalytic element that degrades other gases within the catalyst.

The number of sandwiched sub-chamber components can vary depending on the amount of gas that has to be converted and the pressures involved. The back pressure of file exhaust gases can be controlled by varying the density of the wire wool elernents.

The usefulness of the Wire wool franic,,orl.. is that the gases -:tie foreed to cliange direction and collide 1,rith the catalyst covered surfaces. Only at a collision between a gas molecifle and tfle catalytic element can a dissociation reaction take place. 1.7he i c wool d 1 Alir es gn therefore forces the gas to ftequently cli.a-nge direction,, mixing, forming vorticesin beh,ee. n the sre 7scol. elements as Z- Z thegas passes OVeT the mre c,..mponen.t. 'lle diameterand shape of element determine d the amount of'vortex formation and catalytic. cl-enlent a gas can contact as it passes through. the sub chamber.

Because there is a great deal of contact between the gas and the catalytic elements in these designs, conversion of gases can be ael-d.-), p-d sooner than conventional catalytic convei-ter designs.

Many arrangements are possible and in practice it may be more converjent to simply i-niX all the individual catalyst covered strands of stainless steel wool into a inass that would simply fill the catalytic chamber, without also providing offset plates in accordance wth themain aspect of the invention. To ensure that all the exhaust gasesinteract W1.1h. specific catalytic elements, subchambers containing a specific element per chamber may be provided.

Further ways to force the exhaust gases to impact on the catalyst covered surfaces nithin the catalyser chamber is to iise catalyst covered spheres of various si7es andmateriials, As an example hollow glass spheres of various diameters are packed into the three sepa-rate chambers. 111e e> haiist gases are thenforced to change d]IC.cfion as they impact on. the sphere slirface, the flowing gases are dissociated as they impact onto thecatalytic surface, hollow spheres are used because the substrate heats up more quicIdy to the optimum temperature than solid spheres. Cordierite material spheres can be used. for thee above design. In an alternative arrangement the whole chamber Can be filled -mfl7i a miX ofcatalyst covered hollow spheres made- with the designed matrLY,. Contact betweell catalytic elements and tliC gases is very low in thts desig-n.

A similar effect can be achieved by c.oatig crushed cl. iker/clay products,porecIaLi/ceraiiiic and the Ece into chwiks the size of TA),1deli is determined by the amount of gas that has to flow through the catalysed chamber. Infilis case the exhaust gases impact -,.ritli the catalyst covered surface and dissociate into envirorimentally acceptable end products. As the gases pass over the crushed material the drag on the flowing gases causes the gases to vortex into a variety of vortices the size of which is determined by. the amount of gas inoving in a given volume.

1 11 The mixing effect achieved by the pluralitx y of plates of the catalytic converter, ma.Y also be applied toother mixing systems. Therefore, in a third aspect, the present.im, entionprovides a mixinc, component comprising a plurality of parallel plates, the said plate,-, hakling a senesof aperhires therein for the flow of a fluid or gas medhim therethrough., wherein. said plates are arranged so that tic apertures of one plate are offset from the apertures 3,11 theao-jacent plate so that the flow of the medium through the apeitures In one plate will Unpact against the adjacent plate.

The rnixirg component of the third aspect of the present invention may be used for spray cans. Currently. ball be;I11ings afee used to stir the mixtue in spray cans pnor to sprwring. Therefore, in a fourth aspect, thle present invention provides a spray can comprising a mixing component comprisuig a pluralit,, of parallel plates, -ffie said plates having a series of apertures therein for the flow of a fluid or gas medium theretluougl-4 wherein. said plates arel arranged so that the apertures of one plate are offset fi-om the apertures in the adjacent plate so that the flow of the medium through the apertures in one plate w-M impact against the adjacent plate and tIUS forms turbulence and N.!ortices between the plates.

The above mixing component can also be used in industrial mixing systems, A; here the components to be mixed,be they grains, s uspensions, mixt1ires, fluids, gases are passed through. the plates. Therefore, in a fifth aspect, the present invention provides an. industrial mixer comprising a mi:Ning component comprising a single plate or a pluralit of parallel plates, the said plates having a series of apeftures therein for &ie flow of a fluid. or gas medium therethrough., wherein said plates are arranged so that the apertures of one plate are offset from the apertures in the adjacent plat-- so that the flow of the medium dirough the apertures in one plate will impact against the adjacent plate and this forms turbulence and vortices between the plates. A single plate design can also be used.

The mi:xer of the fifth aspect of the present invention has no niovirlg part,.

In a sixth aspect, the presentinvention. provides a. heat transfer device comprising a plurality of parallel plates, the said plates having a series of apertures therein for the flow of a flLiid or gas 11 medium therethrough, wherein side plates are arranged so that the apertuxes of one plate are offset from the apeAures in the adjacent plate so that the gas flow of the medium through the apertures in one plate inipacts aglst the adjacent plate. The device earl be configured as a radiator or a cooler.

Ilie i-nvelition Will be filither deschbed, by way of example only, with reference to the accompanyin.

1 Y 9 Figure 1 is a side viewof a preflerred embodiment of a. catalytic coriverter according to the invention...

Figure I a is a side view of a t-,,plcal e,,ihai-i,,t system of a road vehicle.

F' ures 2 and 3 are end of an ad. acent pair of ecrainic plates used in the catalytic converter 19 shown in figure 1, Figure 4 is a schematic side view fflustrafingtlie gas flow through plates of the catalytic converter sho,v,vn infigure l., Figure 5 is simil.a-r to Figure 4, showing a modifi-ed form of the plates of the cataly-fic converter, Figure 6 is a view similar to figuies, 4 and 5, but showng a flirther modified form of the plates, Figure 7 shows a modified trailing edge design for gaseous flow.

Figure 8 is a side view of another eeXample of a catalytic converter according to the ffivention; Figure 9,,zhows a scheniatic view a two chamber conveitel for four way catalysis, Figure 10 shows a catalytic converter with steel wool inserted between the plates, F ure 11 shows a schematic view of a. plate of a catalytic converter with protruding cone sections kg 1 - to provide sinooth flow deflection., r-,igure 12 shows a schematic of a plate smooth flow plates assembly; Figure 13 sho ws a schematic of a catalytic converter invith rectangular holes in plates, plan.,i.ew-, Figure 14 sliosAs a schemalic of a catalytic converter movable section to maximise speed of throil_ghpiit.

shows a schematic of a cat.al,,t.ic converter with gate vaIve, Figure 16 shows,,,[ schematic of a four way catalytic, converter with two cha-rnberssTdtll pre-heated, air., Figure 17 shows a schematic of a catalytic converter with a smooth flow cone- design obviating dead. space, Figure 18 shows a schematic of a cone plate, cross section, cone and tail end. of a catalytic converter, Figure 19 shows aschematic of a cross section of off-set cone design side view; Figure 20 shows a schematic of a plan view otT--set cone design plate.

Fi c 21 shows a schematic of a box design catalyser, igur Figure 22 shows a schematic of a secdon view of box catalyser., Figure 23 shows a schematic of a fiv.- way catalyser three chamber design; Figure 24 schematic showing volumetric. throughput, thick arrow fastest speed., Figure25 schematic ofjet engine exhaust; Figure'26 schematic showing restriction of gas exhaust flow, and Figure 271 schematic showing second combustion chairiber in 'et en ine exhaust.

j g Figure 28 schematic showing the buffer plate.

Figure 29scheinatic shokg a disc of a heal exchanger -.,dtli counterflow, (lesi.c-,il disc.

Figure 30 schematic side-,dev of exchanger disc.

Figure 31 schematic of a heat exchanger assembly.

Fgurc-, 32 schematic of a heat (exchanger appliance.

Figure 33 schematic of a fusion chamber disc deSign.

Fig-Lire 34 schematic of ffision chamber heat exchange assembly.

Thee catalylic converter shown in figure 1 comprises a me-tal casHig 1, preferably of stainless steel, having an inlet 2 and an outlet 3 for the flow of exhaust gas therethrough, and is intended to be fitted into the exhaust systern of an automobile or engin.e assembly.

The casing 1 is lined. with a material 4 which comprises a substantially homogeneous niLxtur(z,. of expanded polystyrene with a ceramic matrix, wherein the size of the polystyrene particles within the matiix is not more tharl about 1 mm in diameter, and is preferably from about nim to dust in dia.ineter, and whereirl the rnatenal preferably contains about 80% expanded polystyrene. In all cases it may be prepared to use other exfoliateid matena]s and there are suitable exfoliated clays such as perlite, vermiculite, silicate materials etc. Such a lining rnatenal retains heatin the easing 1 and thus assistsin. achieving an optimum working temperature in the catal-y-h.e converter.

There are arranged in the easing 1, across the flow of the exhaust gas th-ethrougti, a plurality of catalyst coated plates 5 each having therein a series of apertures 6 for the flow of gas through the plates. Adjacent plates 5 are arranged. with respect to each other. so that the ap-rftires 6 in one plate are axially offiset from the apert-ures in the adjacent plate, and as a consequence the gas flow through the apertwes in the on,e plate will impact against the adjacent plate and thus form gas turbulence and vortices between the ad acent plates, thus increasing the catalytic action bebnreeji the gas flow and the catalyst coating on the plates.

Mat is, the offsetting, of the apertures 6 in the adjacent plates 5 interrupts die flow of gases and causes!hem to eddy and collide frequently with the catalyst surfaces of the plates. Such an improved distribution of the exhaust gases withill the easing of the catalytic converter will dramatically improve the conversion rate of the gases- and thus reduce the arnount of catalytic material needed.

Fig la, demonstrates schernatically chambers intend- ., the possible proposed siting of the. vanous -d for the FIVE W'AY catalytic conversion of hydrocarbon fuel, end products. 7"1i- iiiaj-dfold is attached to the engine block, the fist chamber is heated to a high temperature- and uses up the available oxygen to oxidise the non conibpst--d hydrocarbons. caiton monoxide. and carbonaceous, paiticulates. As the oxygen level is reduced the reaction-- become cemp- ltve and the third order reactions occur to strip the nitrogen oXides of!heir oxygen i.esulke,' in reduction chemistly to reduce the oxides of nitrogen, to leave 1-atrog-cri gas in a molecularstate.

In the second chamber in line flirther down the exhaust system preheated air is added to further oxidise any remaining hydrocarbon, carbon and carbon monoxide. Four Way catalyses 15 achieved by thIs stage of the clean up process.

In the third chamber oxides of sulphur are created to cc)nveri.die,,; ulphur conipounds inloharmless non acidic components.

Figures 2 and 3 are end views of a pair of adjacent plates 5, the apertures 6 of which are axially offset as described above.

Figures 4 iflustrates. the gas flow through and betw, een. the plate 5 of the catalytic converter shown in. figure 1, and reference numeral 7 indicates the vortices thus produced. Flosvever, as shown in. fi.gure 5, the plates 5 are modified in. that alternate apertures 6a therein have a different diameter than that. of the apertures 6b therebetween, and the exhaust gases will move faster through the narrow apertur-es 6b than through the wder apertures 6a. Dos-mstrearn of Tie plates 5, vai-ymg interplate pressures induce violent vortex fonnation, which increases contact with the catalytic elements and the rate- of disassociation of the exhaust gases.

In the modified embodiment shmmi in figure 6, the do-,7,..iistreaiii ends of the plates 5 are provided - the pressure of the with raised lips 8 around th.e apertures 6, as shmmi. Such raised lips 8 changI riio,dlig gases,, and vorteX fomiation is assisted by induced pressure difference and gaseous collision.

In the further modifled embodiment shown in fl. ures -1 and 8, the downstream ends of the plates 5 9 are provided with channels 9 shaped as sho,,%in. As best seen in figure 1, the gas exiting the channels at (-)peilUgs 9a has reduced pressure due le),as suction pro,ldcd by the nio,ijig gas M the aperture 6 (Induces suction. at the channel. entrance 9b).

Figure 9 shows wiother embodiment of a catalytic converter wherein. preheated air enters through one or more i-Tilets 10, arranged between flist and second chambers 11 and 1.2 of the catalytic converter.

The two chamber system shown in figure 0 is. designed to provide selective o-,,ddatioiVrediiction conditions, as previously desenbed. That is, NOx reduction occurs in the oxygen depleted first chamber 11 of the converter. The second chamber 12 has additional pre-heated air pumped in tlirough the irilets 10 to provide ideal oxygen-nch conditions for the oxidation of the carbonaccous, hydrocarbon and CO components. This catalyser design should be particularly suitable for diesel exhaust purification. The pre-heated air should be at a sufficiently high temperature to iduce dissociation of the hydrocarbon components inthe exhaust. In this way ions are fonned, toincrease the chance of the vanous component species coming into reactive proximity.

Figure 9 also illustrates die provision of buffer plates 13 positioned in front of the main plates 5, not only to absorb any heavy metal impurities, but also to act as a pressure distribufin.g means that. ensiires, an. even distribution of the exhaust gases passing through. the catalyser. The buffer plate.13 should be designed to prk),,ide the optimum back pressure for a specific enginc, and the surn of the back pressure incluced by the main plates 5 should not exceed the back pressure characteristic of the bu fler plate. Sec figurc 28.

The plates 5 may be coated with any suitable catalyst, and in the preferred. embodiment of the Y invention the plates 5 comprise the same exfoliated additive/ceramic matrix material that constitutes the material 4 used to lie the casing 1.

In another embodiment of the catalytic converter of the invention (not illustrated). adjacent pairs of Plates 5 have their apertures 6 axially offset as previously described, and the spaces between ajacent pairs of plates are ffiled mrdi for example stainless steel wool. coated with a suitable catalyst. It is envisaged that the distance between ajacent pairs of plates wffi be greater than the interplate gap between the plates of each pair. Glass, clay products, ceramics, porcelain, or treated clinker, coated with suitable catalyst, could be used instead of th(z-, cataly'st coated stainless steel voc)l, In for exarnple specialist catalyst designs. See fig ire 10. 91 Precise measurements on, conversion. rates are being chelated. Early results.ftom the original photoggraphic plate assembly indicate astonishing data. 'rhis substrate had. not been --,)ptimlsed and contains only 5% of the surface area, when compared to the standaid 400 cell substrates. 7he conversion rate of this design, which contains only 5% catalysing elements when compared. to the conventional substrates, is 90% efficient. Results are available for conversion rate, stLidied at the Johnson Matthey Laboratories, Royston. The work was conducted. to confirm the fact that very small quantities of precious metals have to be used to achieve effective catalysis with the plate concept. Conventional catalysers do not work when such low amounts of precious metals are used.

For marLy reasons metal substrates are desirable. All the plate and othersubstrateS can be made from suitable inetals. C-jiven the usefulness of the low density material concept. it would increase the useftilriess of metal substrates to make tlie plaies out of low density metal substrates. 'nie addition of exfoliated additives -to metal matrixes decreases the total mass of -the metal of choice, by a very considerable margin. It may be necessary to manufacture the low density metal composites Linder wi inert atmosphere since many of the available additives willoxidise at the high temperabir.es.-required to melt. some of the steel compounds that may be selected.

Many ways of provi.,-Eng vacuotes of the rightsize are available. Prevailing conditions determine the choice of the additive to be used to provide the solid particle for vacuole formation.

In all cases the size of the vacuoles as already described should be very small. The size of the vacuole determines to a considerable extent the load bearing properties of the findshed. product. Since all the materials as described in the "Styrocrete Patent.Application", GB 2 340 125 A, have very large quantities of additives (95% and less) the structural properties of such metal composites are very dependant on the size of the vacuole. The quantity of additive determines the properties of the fuiished material. Products made from metal matrixes of very low densities are therefore possible as described above that will require much less heat crierg-N, to achieve "light off' temperatures in catalytic converters. 'niere are many odier uses for such low density metal composites. 'nie density of these "aerated" inetal composite materials are less than 1 and will therefore float in water.

Fiirther research has indicated a possibility that. solid particles can impacton the plateSUTfUC 'wIth such- force that a possibility exists th. at the coatin s covenng the plates can be darnaged. The solid 9 particles, most likely to cause such impact damage are small pieces of.metal ftom theworlang parts of the engine and other solid matter found in. the exhaust systems.

A solid pa-rticle traNielling down the elybaust pipe- N-U adopt a central position in the mass of tlie flow. As this area of moving gases IS at the mwdmurn velocity any solid pieces of niaten -a tend to impact wiffi mayjmum momentum with the plate surface.

To protect the plates covered with catalytic elements steel wool can be positioned at the f6i ward end of the converter assembly-. An optirnised sandwich design is the airli that provides the required level of back pressure but also provides a filter for the solid matter in the exhaustpas. The Mter in fact acts as a barrier Lo particles. The sandwich of stainless steel or ceranfic or some offier suitable felt like material acts as a sieve for solid particles thal could dairiage t1le. catalyst covered surface by iinpactiig oil the plate surface. The above sandwich. is designed to remove from the flowing gases solid inaterials which could damage -die catalyst covered surface. -An inlierent problein with this concept and indeedNrith all substrate-, acting as traps is that they can block up and.incapacitate the converter.

As indicated in. Fig 10 the filter sandwich can be covered with. catalysing elements. Itcanbe arranged in combination vith other wool sandwich designs 14, or as a part of perforated. plate assembly. The way the forward buffer plate 13 is perforated, has an important effect on the gas distribution in. the chamber. Fig 28 shows a buffer plate which has a. distribution of small holes in the center of the flow of impacting gas wU cause back pressure. As the distance from the center of the plate increases the holes become larger. The rate of the increase in tlie hole size is directly related to the pressure distribution curve desired for the volwnetric thiroughput of the system in hand. The parabolic pressure curve induced by the above perforated buffer plat-, design lias the effect of distributing the mo i mass of gas evenly througliout die forwa:rd end of the 111119 chamber. 'nie effect of Lllis gas distribution is to pIovide a relatively even flow of gas across the whole of the chamber.

The Fluid Dynamic Computations liave confirmed the exticirie turbulence Induced by the Styrocat plate desic-ni. Having reduced the amount of space available to the traversi L- ses the back 11 mg ga pressure induced by the turbulence is higher than conventional lainina flow catalytic converters. The back pressure inducecd by the impedance and diag, On th.C.M.01,6111 have an adN'CT-,e effect on n g gases can the workikg of the eng-gine if it'becomes too higb. An optimum arrangementis. therefore established for each engine.

Engineers are concerned at increased back pressure exerted by the system and have expressed preference for lower back pressure designs.

The Styiocat desLgn had. at all times concentrated. at inducing maximum tLirbulence, vortexing and. molecular contact with the catalyst covered surface. The CFD modeling (conducted at the Arvin Cheswick Laboratories, Warton) has shown that indeed there is. In the design complete molecular collision with the catalyst covered surface. The rebouriding molecules create a great deal of turbulence which increases the back pressure to a value higher than conventional laminar flow catalysers. TItis specific design ficature was established lo, overcome the very serious problem of gases close to the %A)alls of the tubular substrate designs move at an ex[remely slow rate and the level of contact between the catalysing elements arid the exdiaust gases, is therefore very small. Very large 11 1. 1 11 surface areas have to be created to achieve the required conversion rates.

The deliberate induction. of turbulence by fOTC1ng the moving gases in. the chamber to impact on a solid surface at. night angles to the flov,, induces h:igher than desirable levels of back pressure. J.he induction of back pressure is a feature of geometric factors. "Thekinetics of mo'VIT12. 1 particles suffer a maximum displacement when the interaction between two solid components occurs at right angles. To mfi-dmise the displacement of such solid. members, interactions at acute angles are advantageous. Gases on the molecular level behave in the same way solid particles behave when impacting on surfaces.

In the Styiocat plate design a modification in the gleemetry of the solid surface can be designed to give acute angle of incidence thatwili reduce turbulence to a minii-num. Reduced turbulence is reflected in direct reduction in back pressure characteristics of the assembly.

For the cone or wedge configurations see Fkg 11. In this case the surface area on which the moving gases Unpact is increased but the turbulence is reduced. Turbulence can be optimised by varying the 1 11 rou-01ness of the wash coat or the surface of the cone material or by renio"'ing sections of the top 11 cones to the i.Cq=ed level. Fig 11 represents the cone designi with,,(:,, cdoiis.aiat can be specified to provide increasing degrees of turbulence. Section 1 of the pyramid design is the apex of the cone. When this section. is removed florn the design a given arnount of turbulence is generated by theflat silrtace presentedto the fl,)5711112 mass of gas. The arroxs indicate the direefi.,,)nDf the flowing gas over the catalyst covered pyramidal sections. As section 16 is removed in an. alternative desIgn, the amount of tuibulence, increases, and continues to increase as flirther sections 17, 18, 19, 20 are removed in modified designs. In designs where section 2M is established maximum turbulence is acMeved but less than the flat plate design 5 as in Fig 23 The back-,vash areas 22, at the "base" of the cone design 15, figure 11, or flat plate configuration 5 as in Fig 4, creale sta& volumes of vortexirisr gases that exchange particles and gases by "diff-tision" rather than. direct flow of gases. 'Tubules, through the ZI 11 body-, see Fig 8, 9a & 9b as ah-eady specified can promote gas movenientin this aica of the plate.

I The CIHD Work has confirmed the theoretical expectations and the working prototype obsen,edbeha,Oor, of the turbulent flow characteristics of the plate design catalyser. A large number of possible geometric variab ons can. be specified to give the desired parameters to the incident -exhaust gases. Turbulence can be reduced by forcing the gases to impinge on the, catalyst covered surface at an acute angle. The cone shape is the simplest design to present such an acute angle, g&oMeiiy to the incident gases. A variety of wedges can also be designed to give the desired back pressure characteristics.

The exceptional effectiveness of the plate design -enforcing the flowing materials to impact on the catalyst covered surface, indicates the usefulness of breaking up the mass of the flowing material into small volumes. The given volume is forced independently of the mass of gas toiripact on a given surface. In d-Lis parceling of flovfirig matter the bulk of the gas is prevented from exerting an influence in any given locality. The smaller the voluiries of material isolated and forced to move through the aperture in the plate or plate the more effective the pressure induced movement becomes.

For less critical gaseous or fluad flow, alternative arrangements are possible inkvhich the apertures in the plates or plates are larger than the holes in the plate-,-,. The holes in the plates of ivhatever shape the design requires, can be long rectangular or short rectangular openings in the plates that allow a larger mass of gas to traverse the plate. This design is particularly useful for the higher dscosity masses than the exhaust gases of hydrocarbon combustion.

The sections are shaped in such a way that the pitched section of the leading plate as illustrated by example only in Fig 12 & 13, and numbered items 15 displaces the flowing - I)A ICY - material sideways to empty into the holes 6 Fill 12, bet,.,een the pitched section and fiov I - towards the next plate 11i the assembly. The gases moving through the apertures Ill the leading plate are forced to Impact On the folloi?,,i plate, pitched sections 15, Fi,, 12.

11 Ing ig The flo'WML, mass interacts with the surface covered viith the catalytic elements and inoves on down the pitched section to emerge through the holes in the plate c.g. itein 6 Fig 12. Fig 13 represents, the plan,riew of Fig 122.

11 - - The prevailing conditions determine the actualsape, size and configuration of the substrate. In Fig 12, the pitched configuration. is exempli.fied in cross secti.on to illustrate as an example only, the relationship betiveen the plates or plates. The holes of xvIi.atever size or shape in the leading plate are akmed in such a way that the apex of the following plate is offset and. situated. directly about the center of the hole of the leading plate. In thds way and given that gases and fluids travel in straight lines through the holes., impact on the pitched sections of the trailing inclined member. Excellent, displacement of the moving mass occurs arid the design lends itself to many uses M liquid containment applications, mudguards beiiig just one such exaniple. tU- the moving mass iriteracts. vith the surface of the pitch eld sections.

Fig 12 further illustrates a possible interlocking design in NA,hich the substance of the plate peripher - is so designed that odd numbcr plates have a recessed section.23 into Much fit. y the projections of the structural locking pieces 24, designed on even nwribered plates. In the above way the crucial offiset arrangement of leading and trailing c is ensured.

plat s The above design by exampleonly, demonstrates the recesses section in member 23, of odd numbered plates 5 and the raised sections 24 of even numbered plates 5. The interlocking sections 23 and 24 ensure that the assembly of the substrate is precisely aligried. A. proper alignment of plates in the substi-ate is crucial. to assemblies proper function. Members, 15 in Fig 12 channel moving gases into the substratevia holes 6.

The mass of the plate is the grid like design of tic pitched roof like sections of the plates or plates circumvented by the solid interlocldngsections 7 of the various designs, In sections that have a large span pillar like projections can be specified to give support to the vaTious members.

Ric pitched design see Fig 13, is particularly iisefid Ln maintaining sinooth flow conditions within the substrale. assembly. Sino,,,.)di flol. 7 conditions iriduce less back pressure than turbulent Gow.

The long, rectangular hole designi can of course dosi ed to induce turbulent flow. In 11 gn this design the solid sections are flat. '['he roof like structure is omitted so that. the flat plate sections are aligned M the offiset rnanner, to force the gases to impact on the surface of the following plates. Severe turbulence is induced by this design and 1S usefid in situation which require a high rate of Tnlxmg.

The catalyser design is therefore open to a considerable amount of specific tailoring to meet the prevailing requirements. The various long rectangular hole designs are proving useful in the more viscous applications as no moving part mixers of fluid materials exist.

71.1e need to create maximum turbulence m the catalytic converter in order to achieve high miscibility, of the exhaust species creates a high backpressure in the catalyser chamber. High back pressures are undesirable in some types of engines and in order to compensate for theincrease in pressure the plate design concept is particularly useful in as much that the plates can be aligned m a nwriber of possible ways.

For catalytic converters which require very low back pressure the plate design is arranged in a horizontal attitude in which the plates are assembled one on. top of another see Fig 13. 11e holes of the leadingplate are so ali ed that as the moving gas, emerges TWI koi it of the hole it. impacts on asolid surtace of the following plate. The induced turbulence rniXes the gases in a -iole.nt manner before they proceed to the next hole in, the fcllow,- plate. The process is repeated throughout the catalytic chamber.

In the flat catalyser arrangement the exhaust gases enter the catalyser via the inlet 2, see Fi - int g 14 and are channel d' o the space 25 above the plates. Here- the gasess, are distributed throughout the space above the plates to fdl the space and migrate downwards through the plates. The gases eemeerge to fill the similar space 26 at the distal end of the chaniber and from there to move out of the chamber via the outlet 3. Tlie gases ale contained and channeled -uj-d,-bree ona y wi i the catal ser body 1. The odd - 1 ti E thin v 1 plate 5 and even plates al.e arranged so that the offset hole arrangement 6 is established.

The gas rnoves in the direction of the arrows and the movable sliding valve 2-7 vanes (lie siZe of the aritenor chamber. The valve is inoved by a variety of niewls blit basically the'.

the through flow the furlher back the valve, slides.!lie valve arrangement therefore provides ameans whereby, the size of the chamber can be increased or deereased.

The honizonlal plate design is assembled in. such away that. the moving gaseshave to move &iroiigh the holes in the plates. All peripheries are solid and. tie plate bodies can be- supported by regular Dillar structures that give structural support to the plate assembly. 7he exhaust gases enter space- 2 to disperse across plate and migrate through the holes 6 in the plate. The gases impact on the catalyst covered surface of the following plate, undergo catalysis, and change dilection of flow M the interplate space 8 to repeat the procedure through plates - 5 and repeat the procedure throughout the catalyser. The gas emerges into the space below the plates arid flow in, direction 26. From her- the gases flow to the posterior end of the catalyser chamber and out of the 1 systern 3 via the catalyser outlet. Catalysis of exhaust gases occuis as the gases coiric into contact Mth the catalyst covered surfaces oil rout tlirough the chamber arid in the space therein.

A number of possible arrangement,-, can be specifi.ed.dth this design. In situations,vhere maximum vortexing is required at low engine revolutions a two chamber arrangement can be used.

The size of the anterior chamber can be varied. by means of the abovesliding valve 27. or other suitable means. Constant pressure chambers can be achieved by this concept. In such a case the mming gases are restricted to the anterior chamber at low revolutions so that the gases are moving at a high velocit-y. through the forward. chamber. As thee revolutions of the engine increase the VOluille of exhaust gases increases the pressure in the forward chamber to override the pressure sensitive valve.

In a flirther modification and as an example- only a gate valve is established. 'When the pressure of inoving gases exceedstlie set Irilt, the gate valve '218 is forced open to allow gases 29 to enter the second chamber. Heretlie gases move m a similar manner as in the forward chamber, to enierge into space below the plates and flosn? In direction 26. The gases continue out of the chamber via outlet 3. llie gas moves unidirectionally from 25, '19, 26 and out via 3. Mechanical, electrical ormagnetic assemblies canbe used to control the gatemechanisrn.

The size of the plate can in this way be controlled to give th.e.maximum turbulence and optimum back pressures. Large plates have smaller back pressures. By reducing the size of the plate the turbulence is increased to give better mixing of gases.

Further modifications is made- to the design as seen in Fig 15, a gate valve is provided to increase the surface area of the plate as the volumetric fluoughput increases. A firther amangement allows the design of Fig 14. to be used for four way catalysis see Fig 16. In this case, as an example only, the valve 30, is a solid member, separating the two chambers into t-wo individual andindependent compartinents. 'I'lle pre heated gases, the heating system can be positioned anywherein the exhaust assembly. flow through the anterior chamber to undergo, catalysis in a low oxygen environment. The gases emer i g g into space 31 are NOx reduced and are here sujected to the addition of air 32 (rich in oxygen and can be pre heated to a high temperature). 'Me conditions are now high in oxygen and are ideal for the oxidation. of the carbon, hydrocarbon and carbon Monoxide components. The gases are in this design.f,-.).reed to move upwards through the plate arrangements to emerge into the second chamber space 32 and move out of the catalyser via outlet 3 to emerge, converted in four species. In. the forward charinber the gaseous distdbiition is even and related to gas law mechai-Lies.

A flu-ther explanation is needed to clarify the concepts involved m FOUR M7AY CATALYSIS. The FOUR refers to the number of species of exhaust gas constituents that the design catalysis. In the above design see Fig 9,, CARBON PARTICL7L.AlTES, NOx, HYDROCARBON CONSTITUENTS (of wMeh there cali be many) and CO are being converted to acceptable end constituents. Total catalysis is possible and on converting the sulphur compounds, in addition to the above four species in the exhaust, results in FIVE MI.A.'5,'C-,kT-ALYSIS. Seefi, gilrcz,, 1 a.

Me four way catalyser lvvc)i.k-s by converting Lhe exhaust gases t?sio dilTerent conditions. The fu.st chamber of this design acts iin lo%.v oxygen environment to convert the NOx component of the exhailst fumes. The NOx is a complex of n1IT(-,. gen oxides that requires a low oxygen. en,,,rironrnent to achieve the complicated three species interacti.on, catalytic reduction process, required to reduce the nitrogell. oxides to 1 nitrogen. 11e oxygen. is removed from the N(.)x molecules to oxidise the other exhaust gas species.

In diesel exhai-ist there is a great deal (comparably) of oxygen so tat the reduction process of NOx is inhibited. N1 Ox reduction is very difficult in oxygen nch en-,.ronments because the reducing species preferentially take up the free oxygen. To overcome this problem the patent as already described earlier in this specificationrequires the preheating of the catalyser to a high temperature. At high temperatures the available oxygen interacts more efficiently with thl- various species and m the case of the Four Way. catalyser the pre-heating of the fbiward. chamber (d-ds can be done in many ways including electrical. As an example only a licatig element and compressing inechanism can be worked off the battery or the accumulator since the generator is already tapping

11 1-1 Crierg. o--iiie):icreases the rate of reaction amongst the various exhaust gas y from the eng species. 1.1e hy,-irocaxbons take up the free oxygen to oxidise to carbon di.,)xl.de and water, the carbon rrionoxide takes up free oxygen to oxidise to carbon dioxide, and the hot carbonaccous parficulates take up the free oxygen to oxidise to carbon,. iioxidei'carbon monoxide. The conditions in the forward chamber are thus oxygen. depleted. These conditions favor the reduction of the NOx species. Oxygen is removed by the competing species to liberate Nitrogen.

The low NOx exhaust gases move on to the second chamber where they are subjected to additional pre-heated air richiri oxygen.

19 Most of the carbonaccous palticulates are oxidised in this hot oxygen nch envisonn-ient. At the sainel time the hydrocarbons and the c,,ffbon monoxide are beine oxidised in the oxygen in excess environment. All species are oxidised provided dissociation conditions we inet at the prevailing conditions. Nitrogen requires a. temperature of about 10000c to react with free oxygen at NTP. The press are hdn the converter assembly is low.. F,,16 represents another possible way for the four way cat,,dytic converter to be assembled.

The pre-heating of the exhaust gases can be achieved in many ways and the site of the J 1 pre-heating of exhaust gases is determined by prevailing conditions.

Molecules respond to temperature by altering their speed of movement. As the temperature increases the molecules in the chamber move about more quickly and undergo more interactions, that can result in conversion. The "collisions" are a chance processes that is improved when molecules are brought into reactive proximity.

If the heabna element is positioned close to the manifold section and the thermostatically controlled heating system maintains a temperature at about the dissociation temperature of the hydrocarbon species than all the free oxygen Yrffi be used up in the exhaust or fa-st chamber of the assembly. The free oxygenwill react with the hydrocarbon and carbon species. Carbon monoxide -will buni in an oxygen environment to give carbon dioxide. 'Me criviroruncrit under these conditions is severely depleted of free oxygen and the remaining hydrocarbon species, carbonaccous parficulates and other components will interact in the third order symphone state required fk-)r'.NOx reduction. At these temperatilres, the'..MOx species covert to Nitrogen.Dioxide and the chemistry of NOx exhaust com; erslon at these temperatures is virtually the reduction. chemistry of Nffi, As the exhaust gas moves do-%,,,m the e-.,,:haiist system, if the heating arrangement is sit-iiated some distance from the catalyser, the reduction of NOx proceeds so that as the exhaust gas emerges into the second chamber the exhaust gas is free- of NOx. In this chamber the exhaust gas is subjected to oxygen rich air. At these temperatures CO will. readily oxidise to give C0-, plus heat. The reaction is exothermic. Here the remaining hydroeaxboiis and carbon particulates are oxidised toC02. The exhaust gas emerges out of theexhaust system free of N-Ox, carbon particulates, hydrocarbon and carbon mono-.1Ude.

Given the above conditions, it remains to be detennined, in detail the precise conversion rates that can be achieved without,the use of -die expansive catalyst elements that are currently rcrnployed.

le leading edge cont- 1.

A large number of possib igurafions is possible. The prevailing conditions and the Viscosit, of themoving mass across the plates deten- nines t - he Mal impedance to k,-)Phmum design for the plate. 'Ihe smooth flow design allows for mini the flowing mass. In the case of the catalytic converter design related. to the flowing exhaust gases benefits from the reduction of back pressure because the smooth flow of the exhaust gases reduces the amount of energy required to push the exhaust gas-Is out of the exhaust pipe. In the smooth flow design all parameters are directed at reducing turbulence to promote lamina flow whereas in the turbulent flow design all parameters are designed to maximise turbulence and eliminate larnina flow.

The best arrangement is the provision of the pyramidal section at the leading edge of the plate. The acute angled pyramid presents the leading edge configuration with the least resistance to the impinging gases. As the gas:impacbs on surface of the pyramid it is deflected to be channeled into the hole betvreeri the pyramidal section. The flowing L-ases continue into the hole to quickly establish main flow (seen to establish within about half the diameter of the hole) characteristics. 'Fhe main. body of the mo-6ng gas travels at the fastest pace down the center of the short tubule whilst the masses closer to the wall of the tubule move at. a progressively within about. half the diameter of the hole) characteristics. The main body of the moving gas travels at the fastest pace down the center of the short tubule whilst the masses closer to the wall of the tubule move at a progressively slower pace. Little movement occurs at the surface of the hole. The main body of the mass emerges out of the hole travelling in a straight line to impact on the follo in pyramidal section of the next plate and repeat the process.

wing, 31 In order to mii-iii-nisee the drag induced by turbulence the trailing edge is designed into a trailing pyramidal member. TIUs feature elirninates dead space and allows the moving gases to flow over the styuctili-e without causing turbulence. The moving gases continue 11 11oi;%,irlg to the next hole in -the following plate, to repeat the process.

Fig 17 represents the cross section of a small area of -the odd and even plate _5 arrangement and illustrates the arrangement of the corle sections. The leading cone (can also be pyramidal, or raised) section. 33, forms the leacling edge of the part of the plate stnicture that interacts vOth the moving mass. At the base of the cone is to be found the main body of the plate 34 which extends in. all directions to give the main structural component of the plat-, mass. In between the cone leading sections are holes 6, traversing the body of the plate 34, to provide a passage through the plates to the next pait of the chamber. The trailing edge cone 35 contains the moving mass in a smooth flowing attitude in space 36, providing the minimum possible dead space at point 37., and directs the flowing mass into hole opening. In this region 40, the colliding mass suffers the greatest number of collisions from the adjacent coiie deflections. The colliding gases iindergo changes and establish maiii flow conditions 38, in holes 6, to move on to the next plate and impact on the surface of the next cone. Gasses movffig via tabules manifest laminay flow conditions in which gases adjacent to the walls of the tubule move at the slowest speed whilst the gases towards the center of the tubule move at the fastest speed 38, see figure 24. The moving mass impacts oil the surface of -ale following cone sections and e. g. 33, are deflected, to repeat the process on the fo)wing 11C plate cone. Area 40 is the mainflow intermixing volume.

Fig 18 represents an. altemative possible design. of the t.Tailing edge of the plate design. which reduces the dead space at. the trailing edge configuration..1-lere vortexes occur to re-circulate a proportion of the gaseous mass. The longer the gas spends in the chamber the better the prospect of complete com, ersion of the exhaust gas species. This is particularly true of the diesel carbonaceous particulates. The exhaust gases in the case of the hydrocarbon fael engines flows through the chamber in a similar way to the gases in Fig 17.

Fig 19 represent.; the side of the arrangement of leading edge cone sections. In this arrangement the cones 33 aice arranged at 45 degrees to provide a regLdai configrilration of leading e(ge surfaces 41. for die moving mass [o impact on die catalyst covered surface. In the smootli flow design the cones aic interconnected by raised sections 421, designed to a sharp point spanning the space between two adjacent pyramids. The niass 11 11 of these sections expands gradually from the floor of die disc. to niciic. ,nldi the body. of the cione and confinue at. the same incline into the body of the plate. The holes traverse thebody of the plate 5 to direct the mass directly onto the apex of the n. ext plate cone, see Fig 17. In this design the acute angle of the pyramidal leading edge sections and the acute angled interconnectingor members 42, are designed to mirilMise the impedance to the flowing gases. Gases entering the plate mass tubulle 6 establish main flow conditions and the tubule length is important in stabilising the mc, m'g gases. In &,c case of the catalytic converters the entire leading siirface of each plate is coated with catalytic elements. The thicImess, and hardness of the catalytic coating determines the longevity of the coat.

Gases at speed behave according to the lows relating to molecular kinetics and given that a moving gas although extremely responsive to a chalige, ffi direction, will move in a straight lie, until acted on. Gases therefore inove in sbraight lilies and impact kth surfaces they come upon. By prodding an acute surface for the interaction theic results a deflection of the moving gas that manifests a lesser change in the moirientuill of flie gas thail is seen in situations wliere flie gas impacts on a surface. at right: angles to its direction. of flow. 'By minimising the loss of momentum the back pressure of the catalytic converter can be minimised. 'Fhe plate design smooth or turbulent flow, provides a means by which ll the gas impactingon the plate surfaces comes in (Erect contact with. the catilyst covered surface. 'I.Iiek)retically,. )lily two plates are required to ensure that all the gas moving through the assembly interacts wth the catalyst.

Fig 20 represents the Plan View of the design shown in Fi 19. In this hew the holes 6 ZZI- - 9 traversing the substance of the plate are situated at the bottom of the cone sections prOjecting out of the page, to end in points 33. The interconnecting members 42 are represented only as sharp lines traversing the area between the cone to merge with the 33 body of the cone. Such a configuration induces the minimum of impedance to the flowing gases. The fact that in tl-ds view, offly,' the porit 33, of the cones 28 figure 19 and the sharp edges of the iritercon-ii(., ctirii. inembers 42 are indicated, illustrales the acute angle design of these leading members. All leading members start with point. surfaces to expand gadually and merge Lli three dimensle-ms. to pi.o\.llde the mininium possible impedance to die moving inass of gas impi 1 2 on the leading surfaces of plate design..In this way smooth flowing conditions result to minimise the loss of kinetic energy (.heiice.low ba.c pressure') of the rno,,nng.mol-ecular species and solid particles. Smooth flow coriditions result.

The design of the substrate for the converter determines the shape and size of the converter housing.

In Fig 21 a flat rectangular housing results for the flat plate rectangular substrate. The above substrate facilitate desiens which are substantially smaller than the conventional catalysers. The plan View demonstrates the Bilet body 1 and the outlet 3 of the rectangular box design also seen fl:oni the fonvard view and the side view.

The three dimensional view is seen in Fig 22. The cut a,,,.,av three dimensional view, the arrangement of plates within the catalyser housing is seen. The inlet 2 contains the gases in the upper part of the housing 1 to move through the plates and emerge into the exhaust system via the catalyser outlet ^3. k'-Tases from the engnie, inove into the space above the plates to disperse across the enre plate surface because the prevailing pressures force the gases to all parts of the chamber. 'lli.e.high pressure above the plates forces the gases through. the holes in the first plate to IMpacton the surface of the plate. 'Ihe gases come into direct contact with the catalysi elements c]-rig dissipating the momentum as they strike- die catalyst surface and. are displaced. according to the laws of Idnetics. The gases repeat the procedure throughout the con,.,,erter and emerge irito space- 31 to move in direction 26 The gases emerge from the chamber at 3.

The horizontal arrangement of plates m a rectangular arrangement maximises the available surface area and often is more convenierit thari the circular plate designs. The 34 space between the plates 8, does not have a major effect on the back pressure of the design so thatgaps of about lmin between the plates is a practical possibility.

The final aii-aikgein(cnt of the converter is detemlined by many factors and in situations wlicre Five Way catalysis is demanded, in a quest for total catalysis, a schernatic design, Fig 23. is illustrated. The cylindrical design, as an example only is designied in a standard configuratik-.m. The inlet 2 opensinto the body of the converter 1, which can be lined with a thernially insulatng mateml 4, catalysis the gases to force them out of the outlet 3. Section SI is connectedto the rear, of the fourway convertersection, of the exhaust -system. Gases from the engine enter the first converter chamber 11. Three way catalysis takes place in the first chamber. The gases move on to the second chamber 12, where oxygen rich pr-- heated air 10, is. pumped into the second chamber, to undergo conversion of four exhailstspecies. The gases move on to third chamber S1, where the sulphur component is removed. to result in the removal of five exhaust species, "Clean" exhaust gas 44, emerges out of the system at 3.

The unIque advantage of the above designs are the specific design featuxe of gases impacting directly onto the surface of the catalyst covered substrate. Me interaction,A,rith the catalysing elements is maximised. The mechanical forces exerted between the inoving molecules and the catalyst covered surfaces has a slightly abrasive effect. 'nie abrasiveness of the moving mass of gas is a specific feature of the design. The abrasive forces have the effect of rerilovig very slowly and progressively a very- d-lin layer of -ale catalysing elements depositedon the substrate stirface. The removal. of thin. layers of the catalysing elements result,,; in the exposureof fresh catalytic element that achieves the best conversion. ratios.

Catalysts suffer from the poisoning effects of impurities found. in faels of all Idnds. These poisoning -effects destroy the abilit-y of the catalysing -elements to act as catalysts and the converter efficiency falls. In older catalysers the conversion efficiency can be as low as 50%. New catalysers acIlieve conversion efficiency well in excess of 90%. The constant gTadual abrasion of the surface of the substrates therefore removes the tj-LiIi lavers of poisoned catalysing elements and exposes fresh catalyst, to give fresh catalyst i i criteria that effectively and performance. 'n-ie above design therefore acIiieves desl-91 factually provide a catalytic converter that has fresh catalyser performance tlirough ut g 0 ICS life.

Loikgevity of the above design is a fanclion of die catalysiRg element c(. )itiRgs. The hardness of the catalysg element: coating, co-,effikg the substiates andthe tffickness of such coatings is the design variable that can conf.Tol. the working span of the catalytic converter. The harder the coatin.E. the greater the resistance to abrasion. The thicker the coating the longer the ibrasll"e eftects, can be accommodated and thelonger the life span of the catalytic converter. Optimised factors determine the act. iil coating technology applied to our designs.

A large number of combinations of coating mixtures is also possible. In practice optimised factors determine the actual choiCe of the coating.

The presencC of sulphur i orgarde hydrocarbon fuels causes a great deal of difficulty to the catalyser designers on environmental grounds. The eenvironinental damage caused by the oxidation products of sulphur (S) are very considerable particularly in towns m71-deh have a large proportion of buildings made froin the natuial stone which is high m calelwri carbonate. Limestone as an example only reacts very readily mdth the products of sulphur. The carbonic aci d also reacts readily with the carbonates and can cause excessive daniage to historic build:igs mid indeed to any structure whose stiuctural m aterial reacts with the acids created in the exhausts of vehicles.

Most living matter is damaged by high. concentrations of acids and major dam. age to the forests of the industrialised world, is caused by acid rain, that results when. acIds produced from the combustion of hydrocarbon fuels, precipitate on trees. The acids are made from the sulphur present in all living matter and of course remain in the mass of the oil, that results from the natural degradation process of living matter. The sulphur present in the oil distillates that are used for fli. el bums in the oxidation process during combustion to form a acidic. gas called sulphur dioxide. Sulphur burns readily in an oxygen rich environiii-ent to release S02gas into the -exhaust system. The S02 then 36 react., in a voluine reduciig reaction to forin the P-as S03 and althou. is 11 - h SOA produced favorablv at higher pressures m practice almost all the S02 is converted to SI at 1 - atmospheric pressure. 7lic addition of fiesh air W an), catalyser flivors the foiinaori of S03.

In the converter ideal condifions exist for the conversion of the -. stilplrtii. to SO--,. In fact an. industfialised processes.for the maniifacftirc,.)f.siilp.huiic acid specl.fically uses the conditions of a platinum catalyst at ffigh temperature an.d pressure to convert the S02 into S03. 'lli.e flirther step in this chemical reaction. IS flor the Sffi to react Mth water to produce a powerfill acid called sulphuric acid. Any acid falling on cha.11-, type rock or on vegetation eXacts heavy damage. Chalk- reacts vigorously with sulphuric acid to release CO and water. 7he substance ofthee material is therefore degraded:

S -i'- 0, --bum- S02 2S02 - 02 ------- 121-SO3 Heat In the 5 WAY converter:

S02 --- 02 -450 c, Pt Catal-yst- SO-, S03 '+' 14P0 --vigorously- EkS04 Becatise die above design of catalyser isse, effective a forciikg the inoving gases to 11 1 - impact on. the plate surfaces it is proposed to use theimpaction. to force the exhaust caM,ing the acids to impact on. a number of possible materials that vifill readily interact chemically with the acid to convert. the acid into a harmless non reactive materials.

3 7 It is for iii,,,s;taiicp- that S03 -,as reacts directly -,,vitli rnany metallic oxides forming sulphates:

S03 + MO ------- M1IS0,1 Indeed the readily react,-.,ith basic oxides as well:

)3 ( + XO ------- XUS04 The reactions if they go to completion will readily react in their acid forms with very many basic materials grid as an example only if tie sulphuric acid interacts with CaCOi but vigorous chemical reaction results to give C02 water and. a sulphate. In any case the acid is completely neutralised and no acid remains to cause damage tQ the environment. Fig 23 therefore represents a 5 W'AY CATALYSER that will convert the oxides of nitrogen M the first chamber 11, which depends on the available oxygen at high temperature being reduced in the tl-drd order reaction wherever the initial process is allowed to occur.

The nitrogen oxide free exhaust gas then enters the second chamber 12, which has prelicated air pumped into the chamber. This produce the second set of ideal conditions that form the 3 WAY CATALYSES, for the oxidation of CO to C02, the hydrocarbons to C02 and the carboriaceous pai ticulates C, to C02- By this stage of conversion any Sulphur has in this oxygen. rich. atmosphere at increased pressure and temperature and M contact,w;. lth the Platinum and a plentiful supply of m olecular water resultant from the oxidation of released hydro-Cn.is entirely converted to the sulphuric acid or S03. The acid is here in tl-ds third. stage S1 of the converter design forced to impact Ath the metal oxides or the carbonates or any of the other reactive materials that are available to the industry to completely neutralise the acid before the exhaust gas emerges out of the exhaust system. Although the conversion conditions are complex and. intermingled. the four basic concept, of providing different ideal conditions, for the conversion of the various species is as aii example only clearly illustrated above.

38 Exactly the same principals apply to any other acid in the exhaust that happens to be produced and the carbonic acid, Mlious or 1Utric acid, be neutralised in the siiiiilai way.

The desig-n fea lures of this Curd stage S 1, in the 5way converter, will be the thickile's's of the plate and a removable section that can replace plates at reglilar servicing pel.ods in the same way that an oil filter is replace.

This concept is equally useffil. to the fixed factory floor en gin.es, and the power stations and any other fossil fli.el combusting situation.

Fig,' 23 therefore represents a catalyser that has three separate environmental conditions, each ideal for a given set of chemical reactions. T1iis catalyser is divided into the first chamber 11 where the Nitrogen oxides are reduced to nitrogen gas and the oxides of carbon andwater. In the second chamber 12, pre-heated air. if required hot, is pumped into the chai-riber via a suitable delivery systern 10, to increase the aniount of available oxygen because all the reactions in this part of the catalyser favour conversion in a high oxygen environment. Buffer plates 45, can be placed in any desired situation writhin the converter. 'Me third part of the converter S 1, has tliick- plates or plates, iriade fl.om irietal oXides, basic oxide or other suitable reactant coinpounds to inactivatethe acid components in the edlau.,st. The gases inix in the plate inter-space 46. 'I'llis fifih conversion, removes the acid component to give a 5.sr,,,a, conver-ter design.

lurther applications for the above concepts is emerging.

In Fig 24 the arrows passing through a hole in the plate vary in thickness, the thicker the arrov., the greater the volumetric throughput via the plate holes. Maximum volumetric throughput 477 occurs via the center of the holes 6. As the gas flow nears the sides of the tubules the flow rate- decreases 48 and virtually does not move at all when. in contact with the sides of the holes at 49. This fact of lamina flow has the effect of creatbig different layers of movement through the holes. The difference in the rate or speed of 39 flo,,v,inp- liquids or gases creates tearing forces that split layers of material v,,ithi the hole.

As the floArh-19 in aterial impacts on the,,, olid surface of the trailing plate eextrem e turbulence is caused. 'nlc violent movement of the material tears apart die flo-wing matter. The practical effect of these differing layers of inoveirient is that separation of liquid layers occurs which. in effect tears apart the liquid and has the effect of mixing the liquid, gas. suspensions, inixtures, varying densities elc.

The useof the plate homogeniser provides the means whereby the homogenised mixture is compressed into a. compression chamber containing a plate design. at. the outlet end. The effect of the holesin. this outlet plate is to distnbute the homogenised flie.[,'air mixture into the combustion chamber and thus avoid the hot spots caused by fli,el injection technolo_R-,,. currently used.

Further developments of the holed plate concept appear to provide very good distribution of gases in compressed chamber situations. Injet engines, the heated gas flows out of the exhaust end in a laniina flow state. This fact means that the gases flowing near the walls of the engine eexhaust travel at a slower speed than gases -.merging out of the centre of the exhaust pipe.

In an attempt to reduce the loss of efficiency due to thIS lamination, it is proposed to fix a plate at the end of the combustion chamber so that mainflow conditions are enierc= 11 9 at the exhaust end of the engine. around the entire exhaust section. In this way it is proposed to have main flow conditions across the entire section. of the exhaust. A. flirther modification in this design is to have directi.onal channelled holes drilled through the plate so that the area of thrust is increased.

The effect of positioning plates at the end of the engine chamber is to provide unified gas pressure- distribution throughout the combustion chamber. All parts of fi-ie combustion chamber are at equal pressure and. this fact improves the homogenised fuel/air distribution within the chamber. From this equalised pressure within the chamber all parts of the gas flow will be at the same pressure so that equal thrustwill be provided at the periphery of the exhaust end of the chamber, providing maximuin mid equal thrust across the entire section of the engine -,-d-iaust.

The proVislon of the cone sections of the plate design allo%A, a combination of plates to be arranged so that as in the smooth flow, design a movable plate can be mounted on a suitable hydraulically controlled system so that the distance between tlic.plates can be The advantage of this valiable plate design is that. the pressure -, t i. t e varied. wl h. 11 combustion chamber can be vaned whilst the engine is worldng. Minimum inter chamber pressure Is achieved when the plates are furthest apart and maximum pressure vrithin. the combustion chamber is achieved when the plates are in close proximity. Extreme pressures can be achieved by allowing the cone sections of one plate to encroach into the J holes of another plate.

The useftilness of this design is that combustion engines can increase pressure of combusted gases without re-heat facilities. Extreme pressures can be achieved by tMs arrangement, resulting in faster flowing gases eemergiiig at 58.

Directionally designed chamiels in the trailing plate can force the exhaust gases emerging from the eng-ine in any direction desired. If suitable catalysing elements Carl be utilised 11 the plates can be coated to provide further catalyses for jet engcinc.

As an example offly, the principal will be demonsti-ated using Fig 215. 77he example demonstrates the exhai.Lst endof the jet engine,here showing the trailing plate 50, fixed to the housing of the exhaust. Theleading plate 51, Es fixed to the movable hydraulically 2:) controlled system 52, which has a pumping arrangement 53, for distnibuting the C) ZD preheated air 54, into space 56. Demonstrated in this diagram is, the flat sill-face of the front face of the leading plat-, 5 1. The flat surface allows a better gas flow distribution, across the face of the leading plate. The pressure in thds section of the exhaust system is equal throughout the volume of the combustion chamber 571 and outlet 58. Fig 26 ftirther demonstrates the close arrangement of the complementary, leading and trailing plat-Is. 'Mis arrangement constricts the passage of hot gases by virtue of the fact that the cone section of the trailing edge is encroaching into the complementary hole section of the leading plate. The reduction of space so obtaied, causes a very high back pressure iri chamber -57 The pressure build up, M chamber 57, can by this ineans be totally Fli. 27 demonstrates the plate at cruising speed. Here the pla:tes are moved further apart so thatthe second combustion chw nber 56 has a larger volume than in Fig 25. 'I'lle preheated air, pumped under pressure -53, is delivered to a. suitable place 56, via 55, in the forward plate 5 1, provides oxygen. In excess, to oxidise the incompletely combusted fuel. In the second combustion chamber 56,.Fice oxygen from the injected air flirther oxidises any hydrocarbon constituents, the unbumed carbon particles and the carbon monoxide that remains from the combustion of fuel. THREEWAY catalyses is thus achieved in chamber 56. Further oxidation of the carbon containing species is achieved in chamber 56, continuing in the holes 6 of the trailing plate and the atmosphere outside the jet exhaust 58.

In practice, any number of possibilities for the system design is feasible and Fig 2 7 demonstrates as an example only, a further possible arrangement of the hydraulically controlled leading plate mowiting. The advantage of having the forward plate free to move is that the pressures are less on either side of the plate than the pressures on the fixed plate 50.

As an example only, a heat exchanger unit 54 is demonstrated ill Fig 25. Here, a proportion of the exhaust gas, is directed into the heat exchanger unit. The hotgrases from the second combustion charnber are channelled to pre-heat the air that is being pumped by the compressor 53, and delivered to the second combustion. chamber 56.

The plate design provides a means therefore whereby the compression of the combustion chamber can be controlled. The plate design also provides a means whereby the whole of the engine exhaust ffinctions at flill mainflow pressure. The- size of the exhaust can be varied to suit requirements and the plates can be madee to any desired cross sectional area, shape, size and thickness. The plate design furtherallows the establislunent of a second combustion chamber that allows tree way catalyses to be acl-deved.

42 In all cases materials suitable to the function,,,vill need to be used but the structufal inteopity of these plates owi be made hard enough for the proposed function.

The usefulness of the plate deskon. owi be extended to -the hoiriogeluisation of liquids or the dispersion of solid phase/liquid suspended inixtures and -the like.

Fig 2 and Fig 3, demonstrates the basic unit in a. homogenising no rno,. ing part system that canbe extended to provide homogenising or mixing systems for many media e.g. paints, and other industrial applications.

In the case of viscous fluid mixtures such as paint, the plate is used in a single disk constraction arrangement that is allowed to move within the chamber or container. The movement of the plate through the medium contained in the e.g. tin, is achieved by gravity or low density displacement. Most liquid containers have a flat bottorn, parallel perpendicular sides and a flat top section which holds the lid or the depressible arrangement in pressurised delivery systems.

The proposed mixing or hornogenisiig arrangement, in for example o7fly, the pressurised delivery- paint systenis contained in. spray cans or -the like would contain a plate arrangement with holes perforatirg the plate and airaiged in a variety of ways. The holes can be any size, shape or form suitable for the job it has to perfomi. This plate can be made from metal, synthetic materials, plasticsor otherhydrocarbon materials suitable for the job. To these materials can be added a number of suitable composites, aggregates e.g. sand, metals or other dense matenals, as already specified in the St,yTocTete concept, that would increase the densit of the plate. The weight of such a plate would be greater than an equal volume of the liquid being homogenised.

As an example on13,, in the pressurised can dispensers, the plate would sink to the bottom of any such container. When the liquid media contained in the can was to be honiogenised the container would be turned upside down allowing the perforated plate to traverse the can length and sink to the bottom of the iiaverted can. As the plate moves 43 through the media the liquid passing through the many holes in the platel would be rnixed m a number of wwys:

1 By being broken up in passage through the holes. See Fig 4.

2 By vortexing as it emerges out of the distal side of the holes the nieditlin is traversing.

11 - See Fig 1, (7).

3 By the lamina flow conditions that are established in all moving media as they move th-r,-.)iigh.holes,"dth. a continuous boundary (see previous Fig 24).

The reverse arrangement can also be eMploy-d. In this. case the plates can be manufactured to be of a lower density than the liquid they are contained. in. As an example only when a variety of plastics or synthetic or natwal materials are manufactured in the Styrocr-lte way. additives can be of exfoliated synthetic materials or natural or manufactured clays. When such additives are mixed with, as an example only, plastics or other suitable materials they coat all the exfoliated particles to produce a composite that has a number of useful properties. (refer to Styrocreete patent applicafions).

These low density compo sites can be cast or moulded into a laige number of shapes or sizes and m the case of the above design plates that are of lower density.than the inedia they are placed into. When the plate is required to homogenise the contents of the can., the can. is inverted so that the plate is at the bottom of the can.. Because it's density is lower than that of the liquid, the plate is displaced by the heavierliquid and is forced to ascend through thcliquid. Mixing of the liquid occurs by the above pfincipals.

Inverting the can as the plate sinks or floats induces considerable mixing of the liquid contained in any such a can or container. Excellent homogeneity is achieved by such an arrangement.

In Fig 24 the arrows passing through a hole in the plate vary ill thickness. the d-licker the arrow the greater the volumetac throughput via the plate holes. This fact of lannina flow has the effect of creating different layers of movement through the holes. The difference in die rate or speed of flowing liquids orgases creates tearing forces that split layers of iiiaten.al,.,,itliiii the hole. The. practical cffect of these differin layers of movement is 9 ' that separation of liquid layers occurs wItich in effect tears apart the liquid and has the effect of.1 1 g the liq id, gas, suspensions, m' tires. van g densities etc.

rn xing 1 ui 1 1X yin 1 The homogenisingsystem, provided by means of the turbulent flow design hole offset configpiation, provides for an exceptional means of hornrogenising media. or gas mixilires etc.

In the hydrocarbon fli.el engine the homogenising mechanism is one of fuel and air impacting on the solid surface of the trailing plate. The impaction has the efrect of splattering large drops of fael to break them up into srnaller ones. Each impaction repeats th-e breakdown of the size of the fael drops until eventually the fliel drops axe very small and everlly distributed with the air mass. All fuel gas interphasels can in this way be extensively homogenised.

To homogenise the liquid phase even further, the invention describes a means whereby tile plates axe heated by various means so that the fuel and air impacting on the solid surface of die Caffing disc become heated. The heat energy transferred from the plate to th.eliquid/air impacting on the surfacerof the homocreniser.facilitate speedier chemical. reaction. between the two media, once they are ignited in the combustion chamber. 1. 1e effect is one of providing complete combusilion of the fuel more readily than cold fuel.

t) In all cases the temperature of the plate is somewhat less than the spontaneous combustion of the homogenised mixftire.

In wholly gaseous mixtures such as gas and air mixtures the homogenising effect is even mor-e effective since the gas, le. methane as an exaniple only, has no surface tension to speak of and the two gases interinix. readily. BY homogenisirlg the gas air mixture prior to combustiem a morel complete even combustion process incurs. The gas IS niore readily oxirffised and n-jore efficiently combusted to utilise inore of the trapped energy. Complete cid 1 xl ation's acMe,,,ed.

The metliod of air deh...,ery mto a gas flow stream, is described 1, n)ltli the view. of further oXidisirig the rion coiribusted remnants of oxidation ofjel fuel. Iii a gas ar healertype of applicati.on, the air canying oyygen to the burner can also be pre-heated by a heat exchange system as schernatically described in. figs 25, 26 and 27. '[lie air can either be drawn via the pressure drop of theflue design or be actively drawn la the heat exchanger, by assisted mechanical. means. In all cases, the intention is to provide a means of pre-heatirig the participating mixtures so that the oxidative processes can more readily occur. The impact of the gas mixtures onto the following flat surfaces causes turbulence that mixes the partici ating agents so that contact between the participating molecules ip can occur more readily.

Many better more, efficient designs of bumers can be. achieved by honlogeffising fael oxygen mixtures, prior to combustion.

The oxidised fuel releases if s crierg:, y into the surrounding environment so that the heat energy saturates the surrounding area. The energised molecules impact on all surfaces in the environment transferr rig their heat energ- y to the impaction sites. Convected lie t transfers it's heat energay to everything it comes into coiltact,,,ith. In all cases, the niore contact there isbetween the heat energy and the surta.ces in the environment the greater the heat energy transfer that occurs. The texture of surfaces has a part to play in the surface area of contact, as does the ability of the material to transfer the heat energy lrom the impactingmolecules, to the body of the plate and the associated assembly.

Z:) 1 The gas preheater assembly in Fig 25 could benefit by the provision of the flat disc design which would force the mo,.ng air to flow in a turbulent flow mode across the heat exchanger unit 54. In this way, the air molecules impacting on a flat surface of the plate or disc, would come into direct contact with the metal surfaces of the -exchanger design b,--:ig heated externally by th- jet exhaust, passing across the heat exchanger. The 16 nupaction of the air molecules with the surface of the heated metal parts of the exchanger,,,vould transfer more heat energy than a system whereby the gas is allowed to flow in a lamina flow staLe. In this case most of the gas moves via the central portion of the duct, See Fig 24, so that the heat energ -arisfer froin the metal parts to the gas is y ti mostly by radiation and convection.

By forcing the ga's to impact directly onto the hot metal. surface-,, the heat energy trans.fer occurs by conduction and is very efficien.t.

The heat transfer system as described, can of course be reversed and the oxidised ga-ses emerging of the tubule of the leading disc can be forced to impact on the flat surface of the system containing fluids or gases or mixtures or any other material that is to be heated. In the home, as an example only, heaters, can force the gas to impact on heating surfaces which can thence transfer the heat to other media. In the heater for domestic hot water supplies, the heated molecules can be forced to ernerge out of the plate hole ajid impact on surfaces of water contairwig heat exchangers. In thi-is way all the hot gas molecules from the combustion process impact directly and violently on the stirfacle of the water containing heat -exchangers.

In industry, heaf tiansfer can be more efficiently passed from the exited iriolecules by bein forced to impact on the surface, of the heat exchange designs then by flo-wing, in 9 lamiria flow conditions. In the lamina flow designs the hottest gases always flow doWrl the centre of any flov,, through. spaces.

Coolers can of course benefit from the flat disc turbulent flow design by forcing gases or liquids or other media to impact on the surface of the hot plates. [leat. exchange occurs both way, le. heat is taken up by whatever is being deprived. of it. Many applications come to mind. If radiators need to work more efficiently than it is much more efficient to force the gases to impact on the offiet hole arrangement than alloving the gas to flow through spaces in a smooth flow way. Heaters, air conditioners, coolers, ventilating coolig systems for machinery, computers, w spaces, cars, machines etc. etc. can all benefit from the turbulent flow heat exchanging mechardsm described. The use of the 1 7 disc design as heat exchangers opens up the possibility of providig heat exchangers of a novel desigli. In particular, the disc design can be manufactured so that it has Several regions on the sarne plate. separated by spacers, which are inade of a good heat conductor material to provide the optimised separation between the offset plates. In Fg 29 the outer and inner perforated disc design is demonstrated to show that tv.,7o or illore counter current can circulate duough the same plate. 7hese re ions are isolated and can 11 91 be any of the specifled liquids, gases mixtures etc. F'ig 29 demonstrates the plan iew of the outer heat exchanger casing 1, the holes in. the specifically assembled outer section C1 2:) -59, the separation. ring 60 and the inner section 61 with ofR, et holes as already described. Fig 30 shows the side view of the same disc as in. Fig 29 and demonstrates the seParation ring. 60 and. plate 5. Fig. 31 demonstrates the plurality of plates assembled 59, to form the heat exchanger. This figure d o.es not show the outer easing 1.

* Fic- 32 demonstrates a cross section of a schematic heat exchanger such as a domestic We -1 water heater. boiler or other such appliance that can be used to exchange the heat energy from the oxidation of methane gas, or hydrocarbon fliel, be it gas, or liquid, or sohc hydrocarbon, or whatever energy source is used, in home, office or industry. In a home appliance, item 1, in Figure 32 is the outer easing of the heat exchanger. Itein 60, is the separation rings and 61 the scaled gas oxidation chamber which is heated by the flowing gaseous product of the oxidised fael 62. 7he fuel is distributed by the burner 63 and oxidised in space 64. 'lle products of the oxidised waste products escape Via the cutlet 65. The liquid (in this case water, as an example only) enters the appliance space 66, traverses the chamber 67. flowing through the offset disc design 5, and 8, comig into direct contact with the heated plates. to remove heat from the plates. As the water continues to flow through the container 67, it interact with the heated discs to becomes heated arid emerges out of the appliance at 68, to be piped to a given site. 'llie heated gases at the burner oxidise the fuel and flow upwards according to the laws of physics. The vi orous iriteraction of the hot gas against the conducting surface of the 9 ":) perforated plates or discs imparts- heat energy to the material of the disc. The heat moves dol,,m heat gradients and flow,, to tliel cooler section., of the plates to transfer heat.

Cnew in ill:, ), to th(c hq id corni into contact the plates m die outer section of the appliance. The flow of fluids and gases can be, by -xisffiig gradients, power assisted, by I- beirig p-Limped, by means of suitable pumping arrangements or other suitable arrangements.

As a modification to the principal, the discs can be manufactured to be hollow and idor gas, flows iinidireeflonall.y, within. the space of the sequeritidy connected so that flUl Z disc body. The holes in tlas case, become p' es r,;liich go duough the hollow body. of lp the disc container and form a closed interconected space through the coolant material flows m a given direction. 1 In the reverse role, the system could be used. as a cooling system for maintaining ambient temperatures in.li,,,,lng spaces, industrial or commei-dd applications, or as coolers for industrial machinery or commercial uses such as vehicles etc.

Any number of design feabires can be incorporated t,,-) pr,-.),v-.ide systems in many shapes, siZOs and forms and earl be applied to niany uses.

As an example only, the Fusion Industry has a serious cooling problem in their FUSION CHAMBER design- 'nie TOKAMAK machine, requires coolers to be extremely efficient and. the disc design is ideal because of it's exceptional heat exchange efficiency.

W Fig 33 demonstrates scheinatically, the proposed TOK-AMAK heat -exchanger, whereby , Q 1-, the cooffii-, gas is circulated into the heat exchanger inner chambe 71. to ci culate, vi Cr / ir 1 la the offiset plate design and impart heat to the solid disc design. The material of the disc 1 D being made from a. good coji.tliict,,-)r of heat, conducts the heat to theheat sink region and thereafter to the disc body 69. Coolkg gases or hqidds circulate 1171a the offset discs to impart heat to the circulating material and thereafter, to a cooling system YTI-deh earl be separated from the heat exchanger or be incorporates as part of the heat exchanger.

Exceptionallyefficient heat exchangers can be designed using the offset disc design.

Claims

CLAIMS:

I. A catalytic converter compr[sing a casing housingan Inlet and an outlet tor the flow of exhaust gases thereth-rough, and a plurality of catalyst coated plates provided v-Irl the ca"sing, substantially transverse to the flow of the exhaust gas, the said plates having a series of apertures therein for the flow of gas therethiough, wherein the said plat-Is Lire so arranged that the apertures in one plate axe offset from the apertuxes in an adjacent plate.
I. - er accora- ig to cl i 1 wherei i the plates are substantially 1 A catalytic convert aim 1, 11 disc shaped.
3. A catal,,tic converter accordiig to any precedh-ig claim, wliereii the surface of the plates which is closest to the inlet is provided willi a plurality of protrusions.
4. A catalytic converter according to clMn 3,.,vlierein the protrusions are cone of pyramid shaped.
5. A cataly-tic converter according to either of clairns I or 2, wherein the plateshave a surface which. is free of protrusions or projections.
6. A catalytic converter according to any preceding claim, comprising a first and. a second chamber, both chambers having a plurality of plates with apertures, the plates being arranged. so that the apertures on one plate are offset from the adjacent plate, the first chamber being at the inlet side of the converter and the second chamber being at the outlet side of the converter, the, fu-st chamber ha i an atmosphere with a relatively low VM9 oxygen content and the second chamber having an atmosphere -Vidth a relatively high oxygen Content.
A catalytic converter according to claim 6, wherein the first and second chambers are pre-heated to above 4001C.
8. A catalyrtie converter according to either of claims 6 or 7 s,Th--rei pre-licated air is inject,-d:ito the second chamber.
9. A catalytic converter according to any of claims 6 to 8. conipnsing a third chamber situated between the outlet and the second cliainber,,,,,, herelrl the plates M the third chamber are thicker than the plates in the JErst and second chambers.
l,'). A catalytic converter according to claim 9 wherein. the third chamber is confligwed to convert sulphur dioxide to non acidic components.
11. A catalytic converteraccordingto either claims 9orlO,whereMth.-plat-sinth-, third chamber are remos-able.
12. A catalytic converter according to wr,, preceding claim, wherein the converter comprises a chamber and the convelter is configured to be capable of converting, three chemical species.
13. A catalytic converter accorfi. ig to claim 12. wherein the three chemical species are NOx, CO and HC.
14. A catalytic converter according to any of claims 6 to 8 wherein the converter is configured to convert NOx- CO, HC and oxidise carbon particles.
15. A cataly-he converter according to claim 9, wherein the first and second chambers are configured to convert NOx, CO, I-IC and oxidise carbon parheles.
16. A catalytic converter according to any preceding claim, comprising from 10 te, 15 plates.
17. A catalytic converter according to any preceding claim, comprising plates with a diam eter in the range frorn 9eni to 21 em.
18. A catalytic converter according to any preceding claim,,,,7hercln the apertilres have a diam eter in the range fi-oni I rnm to 1-mil.
19. A cafaly-tic converter according to any preceding clairn, viliereiri the nearest edges of adjacent apertures are separated by a dislanec, flom 0.5mm to 1.51rlill,
20. A oatalytc converter according to any preceding claim, NN-heTein the plates have a thickness of greater than. or equal to 2rnm.
2L A cataly-he converter according to claini 20, wherein the plates have a thickness from 4mm to 6mm.
22, A catalytic converter according to any, prece 1"Th inside walls eding claim, ierein the of the casing are coated with a catalyst.
23. A cataNtic converter accordif ig to any preceding cla.1111, wherei-i the thdckness of 4 the Plates is greater than the radius of their apertures.
24. A caLdydc converter according to any preceding claim, v1herein a raised lip section is provided at the ends of the apertures.
25. A catalytic converter according to any preceding claim, wherein the apertures of different sIzes are provided.
26 9 n - in A catalybc converter accordin to any preceding claim, wherei the plates comprise particles of a first material. suspended in asecond material and said first material has a lower density than saidsecond material.
27, A catalytic converter according to clalln.26, wherein the second. material is a ceramic.
53 A catalytic converter accordiner to either of clairns 26 or 27 wherein the first material is chosen fron-i expanded polystyrene, exfoliated clay or glass.
29. A ca Lalyfic converter according to any of claims 1 to 2 5 1,vlierc:i the plates comprise a material,iInch has a. pluialiP), of air vacuoles.
30. A catalyrtic converter according to any, of claims 26 to 29, wherein the diameter of the particles or air vacijoles 1S less than Imm, more preterably less than 0.5mm.
31. A catalylic converter according to any of claims 26 to 30, wherein the homogeneous mixture comprises from 70% to 90% by volume of particles.
32. A plate for a catalytic converter, the plate being prodd-.d ivith a plurality, of apertures for the- flow of gas therethrough, the plate comprising particles ofa first material suspended in a second niaterig where-in said first material has a lower density than that of said second material.
33. A mixing component comprising a plurality of parallel plates, the said plates having a series of apertures thereffi for the flow of a fluid or gas medium therethrougA wherein side plates are arranged so that the apertures of one plate are offset from the apertures in the ai acent plate sothat the gas flow of the inedium through the apertures in one plate impacts against the adjacent plate.
A spray can comprising a mixing component according to claim 33.
35. An iridiistnal niixing.system comprising a mixing component according to claim 33.
36. A heat transfer de-de.v comprising a plurality of parallel plates, the said plates hadjig a series of apertures therein for the flow of a fluid or gas snediumtherethrough, wherein side plates axe an.ariged so that the apertures of one plate are offset from the apertures in 511 the a(jacciit plate so that the gas flow of the medium through the apertures in on.e plate impacts against the adjacent plate.
37. A heat transfer de.dee acecrdiikg to clairn 36 corifigured as a rarhalor.
38. A li(.at transfer device according to claim 36, confi.gared as a cooler.