US1816497A - Regenerative gas-fired open-hearth furnace - Google Patents

Description

July 28, 1931. w. scnucmqv 1,816,497

REGENERATIVE GAS FIRED OPEN HEARTH FURNACE U 7 Filed Aug. 24, 1926 6 Sheets-Sheet 1' y 28, 19-31 w. SICHUCVANY 1,816,497 7 REGENERATIVE GAS FIRED OPEN HEARTH FURNACE Filed Aug. 24, 1926' e Sheets-Sheet 2 y 28,1931 J. W..SCHUCANY 1,816,491

REGEN'ERATIVE GAS FIRED OPEN amimi FURNACE I 7 Fi ed Aug. 24, 1926 G She ets-Sheet 4s i l E 94 M '84 I y 1931 w. SCHUCANY 1,816,497

REGENERATIVE GAS FIRED OPEN HEARTH FURNACE Filed Aug. 24, 1926 6 Sheets-Sheet 5 Has July 28, 1931. W.,SCHUCANY' 1 I 1,816,497

adnnnwxva GAS vmm ornn nmn'm mama fo -in s 24, 1926 s Sheets-Sheet s mama 8 r I for:

Patented July 28, 1931 V venetian scene-any, or nonaluuun, GERMANY BEGElNL RiETIVE GASEIEEB CPEhF-HEAFEH FURNACE Application filed August 24, 1826, SeriaLNo.

This invention relates to improvements in the working of regenerative gas-fired furnaces, more particularly of the open-hearth type, and its object is create for the furnace a perfectly positive or compulsory conibustion process.

With this ob'ect in View accordin" to the present invention,

(l) the gas and combustion alr streams 19: issuing from the burners receive an equal,

or av predete mined different, heating dependent upon any existing calorific value of the Working gas, by an adgustment of the h burner outlet flue cross-sections'and a con, sequent distribution of the Waste-gas quantities over the re enerative heatin chambers, a l x (2)'1n connectionlwlth the pos tive supply of the gas and air'quantities required 29 for a normal Working of the furnace, the

ratio of the burner outlet flue cross sections on the fresh gas side end is automatically adgusted corresponding to the existing calorific Value of the gas. This adjustment done in such a Way that to the gas and air streams similar energies of movement are imparted whereby with a simultaneouscorrespondin adjustment of the burner outlet flue axes an intersection of the gas andeir treains and thus the Whole combustion proc ess takes place on the bath surface only,

(3) the direction or inclination. of the burner outlet flue axes is'so changed in a continuous alternation that a 'to-and-fro produced by the intersecting gas and air streams over the Whole bath surface is obtained,

(4:) said change of the directionor inchnation of the burner outletfiue axes can be limitedto a certain area or pointof the bath surface,

(5) during the toand-fro travelqof the poin't of impact of the flame on the bath surface, the velocity and direction of the air and gas streams is controlled by varying the cross sections of the air and gas outlet depen. on. the distance from the-outlet as 'm the p of impact while maintaining revel of the point of impact of thefiamefi the amount of preheating required for the 131,246, and. in Germany September 1,1525.

lets constant,

theratio of the respective gas and air out- (6) the reversal of the burners from fresh-gas to waste-gas position, and vice versa, takesplace in relative dependence upon one anoth in such a Way that when reversing from fresh-gas to'wastegasposi I tion the burner then assuming Waste-gas p0 sition is at once again prepared for the reversal;

I Aecordingto the invention, furthermore, an improved arrangement for executing the; improvedcombustion process is provided, by which the following advantages are ata F j fi Automatic adjustment'of theburners tained to waste-gas and fresh-gas positiomtoyary the quantities .of'gas and air flowing [there-- through, Without the insertion of separate nozzles, in such a Way-that, on the one hand,

on the fresh-gasside the ratio of cross-sections of the burner outlet openings is, ac-

cording to the calorific value J(hereinafter' briefly called; value) of the working gas,

such that to the gas and air streams,lwith' any value of the gas, energies of movement are imparted which are 'approximately similar, so that both currents intersect one 1 another on the bath surface and thus the combustion process actriallytakes place on the bath surface only, While, on the Wastegas side the ratio ofcro'ss-sections ofthe" burner openings is regulated depending upon the calorific value of the fuelfgas e. g. when gases rich in fuel const tuents aroused small in comparison to the air outlet, Wherey as when poor fuel gas is used thecross sectional area of the gas outlet is proportionally a,

larger and approaches or may even attain,

the cross sectionalare'a of the air outlet The sum' of. the cross-sections of the .gas a to the largerguantitiee' etwastmgas low a passage resistance as possible, is larger than on the fresh-gas side.

(B) vSweeping, in a continuous succession, of each point of the bath surface by the flame produced by the intersecting streams streams issuing from the burners met on an extension of the axes of the two flues on the bath surface. This could however not be attained with fixed outlet flue crosssections. With regard to fresh-gas conditions, the out- 9, let' c'ross-section of the flue hashitherto been kept small in order to project the gas stream at high speed onto the bath surface,

but since on the other hand with regard to the considerably larger waste-gas volume V ithe total cross-section of the gas and air fiues ofthe, waste-gas burner must not he reducedbeyond a certain minimum, the air flue opening relatively 'to' that 'of the gas flue must be, chosen so large that the burner, 9,, for supplying as uniform quantities as possible through both, fiues per unit of crosssection, thatis, per square metre, does not even suffice for working with gas of highest value, for which theair quantity amountsto a multiple of the gas quantity. The air quantity .due to. its low energy of movement, resulting from. the too large outlet flue cross-section, does not reach the bath surfaceatallbut itis upwardly deflectedby q its buoyancy immediately after its escape 7 fromthe burner, While the currentof h gher energy of movement does reach the bath surface but 1s then also upwardly de-' fie cted. 'Gas and airparticles come thus in 5, contact with one another and are not ignited on the bath surface, but farther upwards directly beneath the top wall-of the furnace. The prior combustion process is thus not at of the flameby the separately arriving gas stream, andfurthermore the whole combus-' fixed outlet flue cross-sections, did-not even suit the simplest requirements fo'rthe fur nace working with a gas of -approximatel constant value. Said requirements-can after 7 all be compliedwith only by the provision of meansfor perfectly adapting the energies of movementof the-gas and air currents to 1 one an other, and -inlaccorjdance with changes Perfectly automatic working of the all ideal, because the top wallof the furnace V nighly'strained by heat Whereas the bath i itself'is'rather cooled at the point of impact,

in the value of the gas necessary Cluringthe working of the furnace and requiring a variation in the ratio of quantities of gas and air, and thus of the speeds- Furtherr more, with increasing value of the gas also its specific weight isdecreased whereby the outlet flues, must be further increased for attaining an intersection of the two streams on the bath surface. For attaining said absolutelynecessary control of the energies of movement of the gas and air streams, the following cgnditions must be accomplished:

(1) a positive supply of the gas quantity required for a normal working of the furnace according to the gas value, and of the air quantity required therefor,

(2) a control of the ratio of outlet cross- I sections of gas and air fiues corresponding to the actual quantities supplied and to the specific weight of the gas.

An equal, or a pred termine'd difference as the case may be, heatingof gas andair, and furthermore the adaptation ofthe energies of movement on the fresh-gas side, for at-' taining an intersection of the gas and air currents on the bath surface, can be attained preferred arrangement for executing the improved process of heating open-hearth furnacesz 1 7 Fig. 1 shows that part of the main conupon the flap positions; v

Fig, 2 shows the mechanism for adjusting the flaps corresponding to the value of the heating gas;

Fig. 3 shows thesuspension of the main 7 control spindle and the drivinggear for the latter and the, auxiliary, control spindle,

application of the invention to a furnace, the line A-A indicating the axis'of symmetry of the improved arrangement;

Fig. 5 shows a general diagram contai n the parts shown in Figs. 1,2 and 8;

Fig. 6 shows a diagram of the burner flaw positions for the gas and air flues indicat their adjustments in accordance with the value I Fig. 7 is a section on vthe line 7? of Fig. 3; Y I

ratio of cross-sections, of gas to airv channel trol spindle which serves for directly acting ioo Fig. 4 is a sectional diagram showing the 1 r I v r 8 1S a section on the line 8-8' of- Fig. Fig. 3; I Fig. 91's a longitudinal secticnfhrougha flap showingthe cooling'thereof;

10 isa side view of the correction mechanism in the fresh-gas and waste gas position as well as of the device for reversing from fresh-gas to waste-gas position;

Fig. llis a section'ton the line .1111 of Fig. 2; V

Fig. 12 is a section on the line 12 12 of Fig. 9.

For the purpose of providing-the ends of the gas and air .flues ofthe burner heals respectively with ad ustable outlets (for the fresh-gas supply), and adjustable inlets (for the Waste-gas withdrawal) top and bottom" surfaces of the two flues in front of the gas between the burner head and furnace interior are formed as water-cooled (indicated at 11, Fig. 9) turning-flaps 1, 2, 8, 4- (Figs. 1 and 5), the flaps 1 and 2 belonging to the air flue and the flaps 3 and l to the gas flue.

In order to make a prior'combustion by a premature contact between gas and air impossible, between the two middle flaps 2 and 3 a likewise cooled partition-wall 5 (Fig. 5) is provided and firmly connected with the outer casing of the two fiues, said wall extending directly to the gap between burner head and furnace interior. The turning of the flaps is effected about hollow. shafts 6, through which water is passed and which are rigidly mounted in the outerfcasine; of

the furnace, the several operating-rods 7,;8,

9, 10 for the flaps being arranged on the outer ends of said shafts.

The arrangement of the mechanism for V actuating the burner flaps as shown in Fig.

i is for sake of clearnessonly, the control spindles 14 and 18 (hereinafter explained) being arranged in practice external to-the let cross-sections of the gas and air flues. corresponding to the quantitiesof gas and air flowing therethrough corresponds to a -fixed ralue of the gas, or to the specific ht of the gas, in such a way thatwith v supply of the quantities of gas and an q'uired for said value the energies of movement of suit one another that an intersection of both said streams'xtake's place on the bath surface only. Furthermore, for attaining a travel of the point of impact of the flame over the bath surface, on the onehand, the direction ofthe burner outlet flue axes 1- spondingly displaced and, the er hand, the outlet openings of g and burners must he or widened corrc respective positions t is gas and air streams so! as corn 1 sponding tothe removal or to the approachment of said point of impact from or to the placeiof issue of the supply, that is, the supplying burners, for adapting the energies of movement of gas and air to the different lengths of (the paths taken by the gas and air streams; in which connection, it must be noted, however, that the ratio of outlet crosssections of the gas andairflues per se, suit ing the actual gas value, must always be kept constant..For a displacement of the burner axes during the travel of the point of impact of the flame on the bath surface, the

main control spindle 14, to which the operating- rods 7, 8, 9, 10 are linkechis moved up and down in a continuous alteration by turin'g to the right or to the left, for which purpose it is mounted with its upper screwthreaded cnd in asliding nut 29. The latter is, in cross-head like fashion, clamped in a fixed race, member 30, so that it cannot execu e any movement during thisperiod- The adjuscment of the actually required flue cross-sections: takes place as follows: The free ends of the operating-rods. are not dircctly connected with the main control spindle 14 but located in'adjusting nuts27, 28 by a slot-and-pin connection to suit the changes of length of the rods when turning. Said nuts 27, 28 are screwed upon externally screw-threadedsleeves.15,15 and v16, 16.

Said sleeves are placed over the main control spindle 1 1 and provided with an inner guiding groove which is in engagement with a key 124 on the main control spindle 14-, whereby the sleeves can beverticall'y shifted on the main control spindle but are compolled} to participate inthe'rotations of the latter. As hereinafter explained, {said sleeves are locked in positionon the main control spindle relatively to one another by means o-f-regulating bushes 17, 17 serving YThe directions of the screw-threads ofthe sliding nut 29 and of the two sleeves 15,15 (for the air flue) and 16,16 (for the gasflue) are such that the adjusting nuts 27 (for the air flue) and 28' (for the gas flue) are. during one rotary. direction of the main control spindle 14 a preached to, and during the other removed for the control in accordance with the actual value of the gas.

from, one another, said removal takingplace during the downward movement of said. approachment during the upward movement of the main control spindle.

Adaptation of the burner outlet openings to the qua'ntities of gas and air flowing therethrough and changing with the gas value V I i By the above-describedarrangement, the

displacement of the point of impact of the flame-and the adaptationcf the burner out- I,

let oncnins's thereto recited. Si cedurthe travel of the -ooint of impact of fianieon the bath surface the ratio of outlet cross-sections of the gas and air fines for the actual gas value'must be independent of change of the outlet openings and thus the act upon the operating-rods for an tment of the burnerflaps: to a fixed value. ushes 17 (air flue)" and 17" (gas flue) are provided, of which each engages by screw 1 threads over each pair of sleeves 15, and

f'tion with reference to the main control 1G, 16. Said regulating bushes are rotatably mounted upon an integral guiding col- 28of the main controlspindle 1 1-, where byalso the sleeves receive their fixed posispindle 14:. Obviously, each pair of sleeves are moved toward or away from one another by correspondingly turning the regulating' bushesl't', 17, whereby the flaps of the gas and airlines vary the cross-sections thereoi independently from the other action of the.

maincontrol spindle 14 upon the same. The regulating bushes are driven each by a toothed gearing 57, 107. and 57, 108 respec- "tively fromv the auxiliary control spindle 18 for theadjustment of the gas value, which spindle: is mounted" in brackets 24:, 25 (Fig. 2).

lV'ithreference to the control of the ralue' the followinglinust be noted; generally For controlling the whole range from 1100 calories per cubic nietreh (pure blast-furnace gas) to-lOOO'calories per cubic metre (coke gas), the ratio of the burner outlet cross- 35isections of the gas and air fiues must be variable from 1: 1.1 (pure blast-furnace to 11 1.0 (coke gas)l- The action upon the flap positions for changing the ratio of cross-sections ofthe air andgasfines is with the improved arrangement such that .al-'

crosssection remainsconstant (flap posi{ "tion F), Fig. 6) while the gas-flue cross-section is gradually narrowed from the position 0 to the'position (Z, Fig. 6. In'order to permit the regulation bushes for the gas and all fines being driven separately, the two driving toothed wheels 107for 17.) and108 (for 17) are loosely mounted on the auxiliary control'spindle 18 and can be coupled therewith by means of the two clutches 19 (for 107) and 20 (for 108) respectively,

which are positively connected a. double link 21, 21. in such a way that clutch 19'is in eng ment when clutch 20 is disengaged, and we verse. Both clutches as as their links do not exert a pressure-=thereon,

a" n constant, it must be possible *to sepa Forthis purpose, the regulating always held positively in disengaged posh tion by spring act1on.

The control during the adjustment ofa' ratio of cross-sections from 1 1.151t0' 1 1.0 is as follows: Driving of the auxiliary con.-

trol spindle 18 is effected from the shaft 3 1 V (Fig. 5) by thebevel gearing 38 (Figs-. 2 and 5). The clutch 19 is supposed tofbe still inengagement from the preceding play. The screw-threads of the regulating bush 17 are so chosen with reference to the rotary direction of the driving shaft 34 that the two sleeves 1'5, 15 are approached to-hone another whereby the outlet cross-sectionof the air flue 1S gradually widened. The lower endof the'sleeve 15-- is fitted with an abut ment 56. As soon as the ratio of cross-secto air outlet) by the displacement of the two sleeves withreference to one another, the

abutment 56 strikes uoon the ear lever 22' fulcrumed at 72, whereby clutch 20' is engaged and the sleeves 16, 16 are removed? from no another by the regulating bush 1'! and conse 'uentl the as outletcross tions has been changed to 1:1.5 (gas outlet section narrowed. (see diagram, Fig.

Immediately. after-the beginning of this" movement, the abutment" 56 (Fig'.- 2) of the sleeve 16 frees the lever 28 fulcnumed at 7'3, .whereupon clutch 19 isautomatically' disengaged.

with the main control-spindle:

Coupling of the aux liary control spindl'e The driving of the shafts 33, which actupon the main control spindles by means of the bevel gearings 35, and of the'shaft 8-1, which acts upon the auxiliary controlfl spindle 18 by means of the beveligearing 38, is accomplished by' separatvand" inde- Theuncoupling of the motor 123 from pendent control systems operating through a common drivmg motor-129 (Figs.v '4- and the shaft 34 and-its coupling with the" shafts 33, or vice versa, takes place by acorrespondlng displacement of a hollow" shaft 224 mounted 011' the extended motor shaft 223v and on one end; of which one of the two bevel wheels of a bevel gearing 225' for the driving 'shaft' i ltis arranged'whil'e on the otherend the clutch 226 for driving the toothed gearing 55' (hereinafter men- I tioned) is located. The reversal of direction of the motor 123 itself.

Theauxiliary control spindle 18 is coupled with the main control spindleonly during the adjustment to another gas value, by the toothed gearing 57, 108 or'57,107 respectively, which coupling. takesplaee' automaticala ly in such a wayithat during. the drive of the shaft 34 the ropes 66 are wound-up? on a pulley 68 mounted ona friction cone 69 keyed on the shaft'34e; whereby, with the;

aid of links 58 pivoted to pressure I l it'l (Fig. 2) the toothed wheels *57',

the shaft 34 can be effected by reversing the rotary] loosely mounted on the bushes 17, 17, are pressed with their toothed faces 60 against a likewise toothed projection 61'of the regulating bushes 17, 17 andthereby coupled with the latter. 'The friction between cone 69 and gearing pulley 68 can be regulated by a corresponding adjustment of the nuts 70 in such a way that, on the one hand, the

counter-pressure of thedisengaging spring 74 (F 1 and 5) is overcome during the rotation oi the driving shaft 34 by pulling the ropes 66 and a corresponding contact pressure between the toothed wheels 57 and the toothed projections 61 of the regulating bushes is produced by the links 58 while, on the other hand, the friction is not so strong that there exists a danger of a breaking of the ropes 66 and of the links, so that the pulley 68 begins to slip on the friction cone 69 at a'certain tension of the rope. For indicating the adjusted ratio of the flue cross-sections corresponding to the actual gas value, a runner 71 is arranged on the drivingshaft 34 along a scale 71' (Figs. 3,

4 and 5) having charactersor numerals thereon indicating the value of the gas corresponding to said ratio.

Thus, as soon as a change in the value of V the heating gas takes place, the shaft 34 is put in gear by a displacement of the hollow shaft 224 whereby the toothed gearing 55 is disengagedtherefrom. After indication: by the runner 71 on the scale 71 of the ratio of cross-sections of the gas and air flues then required, the hollow shaft 224 is again brought into its coupling position with the toothed gearing 5 5. V I

Reversal of the furnace working:

Hereinafter, the total working'jof the arrangement and particularly its reversal to Waste-gas or fresh-gas position respectively, is to be described (Figs. 3, 4 and 5). The motor 123 acts, unless with a change of the gas value it is, as mentioned, connected with the common driving shaft 34 of the two auxiliary control spindles 18 by the toothed gearing 55 alternately upon each of' the two driving shafts. 33 of the main control spindles 14, that is, that, controlling 'the fresh-gas side. In 'orderto change the rotary direction of the main control spindle 14 during the up and down movement of the same without requiring a change of the rotary directionof the driving motor 123, on each driving shaft 33 of the two main con trol spindles 14 apair of oppositely disposed beveled gears is mounted, that consists of two loose wheels 84 on the driving shaft 33, which can be coupled therewith by means of the clutches 40, 41 and which are both in gear with'the common driving wheel 85 keyed on the intermediary shaft 49, and respectively, between motor-driven toothed gearing and the double bevel-wheel pair. The, operation of the clutch actuating rod 43 is effected bya runner 48, or 101 respectively, screwed on thecontrol threads '86 of the driving shaft 33 and prevented from turning thereon, so thatit ismoved to and fro according to the rotary direction of'the driving shaft.

- The control takes place as follOwst- It may be assumed that clutch 41 is engaged and the runner 48is moving along the control threads 86 from the right to the left, which corresponds to the travel of.

the point of impact of the flame from the nearest to the farthest (distant) 'place of impact of the fuel and air on the bath, or I respectively to the descent of the main con-' trol spindle 14. After completion of the rotations of the driving-shaft33 required for the extent of said control threads the runner 48 strikes against the fixed abutment 44 of the clutch actuating-rod 431 and re- .95 48 strikes against'the abutment 45, whereby. V i

again the reversal to the opposite rotary direction of the driving-shaft 33 is effected.

This to-and-fro play is repeated until a reverse] of the burner to waste-gas is required.

Reversal to 'waste-gas:.F0r the adjust;

mentof the nozzle flaps 1, 2, 3 and 4 to waste-gas, the abutment 45. is manually turned out of the path ofthe run'ner48, the different parts then move as follows: Themain control spindle 14 ascends; The point of impact of the flame travels to thenearest place of impact to the burners, that is the outlet cross-sections, at the burner head are widened, and the runner 48 moves along the control threads 86 from the left to the right. The proceeding must then belikewisecom tinued, that is, the runner 48 must further move along the controlthreads 86 to the right beyond the abutment 45 which for this purpose isturned aside (Fig. 10), until'the opening of the nozzle flaps corresponds to the waste-gas position. L Then, however, the l control spindle,14 screwing into the sliding-nut 29 would ascend far beyond the position corresponding to. the nearest' point of impact,-that,is the position of the "nozzle flaps 1', 2, 3, 4 would have too steep a downward direction when the waste-gas opening is attained. To prevent this, means are provided for permitting,"at the reversal to waste-gas and at acertain pointof'the movement, a further rotation of the main control spindle 14 but preventinga further ascent of the same. For this-purpose, the

therace member 80. .(l 8) out be locked and unlocked there n.

v h sliding -29 .te msh s the 5 is? rsupiler iss" ear n t r t m co trol spindle 14:, its unlocking i 'ointhe fixed her-50 can takexpiacegonly With pro; n of another hearing for the I1 icon rol spindle. For this purpose, below the screw-threads for the sliding-nut 29 other screw-threads are provided on the i pper end of the main control spindle for .c" gagement with the thrust-hearing d sc 7 I8 8. Both said .screw-threads run in the ie direction, so that, when screwing-up Y I the n ain control spindle into the sliding-nut,

- the (thrust-bearing disc 88, which is prey ted frpni rotation byclamping-members ual pitch of bothfsaid screw threads,

is erence'to the driving-boss 36, against the u per surface of which it to beer at the innient of the intended fix d position of height gt the main control spindle after the reversal ofthe burner to waste-gas order to selile/thenas a {substitute -ior the supporting of the nain control spindle, 'preyiously ter d b the sliding-nut 29,

thenunloclzed from the race menu'- her 305 .pitcli ofthe threads of the. thirnstebearing disc must be somewhat higher; As a reversing point to waste-gas position, theiplaceo t the nearest point of i, pactisfc hosen. Themain control spindle isth en infitshighest position, and the runner d8 has arrived et the placeof the then disengagedabutment 45, so that the drivingfshatt BS' r presented in the same direcp The thrnsti-bearing.disc88 hasbeen screwed tow rd and eta short.distange fro n acorrespond projection of the drivingbossfifi'and itQhas become disengagethhy a pull on the rope 91 attached thereto the lfeftehand clampingcontrivance 92 of the .slidingrnntlQQQ The latter would then be iiurther clamped by the right-hand pcl ain ping-c ontrivance 93 only, which is howe ls'c disengaged by action of the runner 48ft ,nntlielev er iid to which the rope 95 is nttnche d. The two clainping contrivances .Ia're n oiu ted each on. caselilreprojection oi the race member 7') and their construction is .cleariy ,ob rious from land 7 'At the iinprnent when the thrustrhearing disc 88 bears gains he d ngss 36,

the clam ing lnernbers 89 must have freed L 0 7 theirotation of the driving-boss 36 and thus ofthe main control spindle 14-. The of the-thrust-bearing disc 88 is etfected iii f h a .waylthat the clamping pr s d o en on n ther isscrewed down. With woiild no change .ettl1e. positi.on' height ofthe thrust-hear ng d1sc 88 with the disc, soYtliat the same can participate by means-of blade springs -(F-ig.

The clamping members- 89 are located in a recess of the thrust-bear ng d sc 88. They must thus part clpate 1n the up and down movement .of the sanie, but are prevented froniturning; Said clamping members are opened for free ng the disc 88 by rotation oithe cams 98 mounted on the disengaging shafts .97. Said cams are provided with inner gu ding grooves by whlch they can move up and down along guiding keys pro vided on the d1sengag1ng shafts 97 for the distance of the, path of the thrust-bearing disc. The operation of the disengaglng shafts is effected by bevel-wheel pairs 99 (Fig 3) from levers 100 arranged in 1.351 6 .f o n the upper surface of the driving boss 36. For this distance, thus,the main control spindle 14 drops whilethe jaws ofthe slid- 7 ing nut 29 turn the levers 100 downwards,

whereby the cams 9,8 assume such a position" that the clamping members free the thrust-bearing discv 88.

boss 36. A further screwing of thesa ne on the main control spindle is nrevented .bv

l friction of the contact faces whlchis further the sliding nut 29 on the spindle id, is Sa d levers 7 H p The latter bears thenagainst the projection of the drivingincreased b 7 the preferable toothed wei 'ht of the nain control spindle then "from the thrust-bearing disc. The main control spindle maintains thus its actual position of height, while with continued rotationin the same direction a further screwing-asunder of the nozzle tape 1, 2, 3, 4 takes place by'an approachnient of the nozzle adjusting nuts on the pertinent suspended sleeves 15, .15", 15, 16 until the" required 7 waste-gas opening'is attained. The sliding nut i 29 has meanwhile been screwed down for a corresponding distance on the inain control spindle, while the runner 4L8 has further moved in the hitherto direction to the right on the control threads of the driving-shaft 33. Shortly before the attainment of its position on the co3'1trolthreads 86 corresponding to-the waste gasposition of the nozzle flaps -1, 2, 3, i therunner 4L8 embraces with' its ,lower arm the doublearlned lever 53, the other arm otwhich acts upon the clutch. rod of .the mainnnotor i to;

'7 clutch-es sol "tch 51 in such way that e ii i b i 191' is put to work; In this nection, must be noted that the motor are by spring pressure continuously held in disengaged position, unless they are acted 'upon'by the lever 53 for clutch 51 and 53 for clutch s The two gearing levers 58 are mounted on a common shaft 51 forming the fulcrum for the same. Then for a shortmoment, 'themechanism for both furnace sides is at worlz, the runner 101 of the right-hand side inovi to the right and freeing the lever 53, so that motor clutch is disengaged by its spring pressure. The runner 48 is then in a position corresponoing to the waste-gas opening, and it has struck in the meantime, intermediate theputting-in gear of the motor .clntch' 51 and the puttingout-of-gear of the motor clutch 52, with its upper arm against the fixcd abutment 109 and by therclutch actuating-rod l3 disengaged the clutch 40. and engaged the clutch 41, t us preparing the waste-gas side on the left of the furnace for the reversal (F gs. 8 and As shown in Fig 4c, the whole mechanism of both furnace sides is perfectly symmetrical (see axis of symmetry AA) and thus similarly operated oneach furnace side incorresponding alteration, the proceeding in backward direction, e. waste-gasto fresh-gas position, on the hand side being now described: v

' On the right-hand side, the analogous proceeding has been COIDPlQtGCl and the runner 101 has returned to its end position to the left for ,-waste-gas position "of the right hand side, the motor clutch 52 being again eftengaged by lever 53. The runner eTS of the left-hand side is thus again on its travel to the left and has freed the lever 53, whereby the motor clutch 51 is automatically disengaged. The main controlspindle 14 main tains still its highest position, the outlet cross-section is gradually narrowed more and more by the then occurring removal of the nozzle adjusting nuts 27, 28 from one another, and the sliding-nut 29 is :being screwed upwards on the vertically fixed main control spindle 14. The left-hand clamping contrivance 921s heldiin its disengaged position by the rope 91 attachedto the clamping members'89 until the thrustbearing disc 88 after engagement of the clamping members 89 has again been screwed up for a certain distance on the main con,- trol spindle 1 1 with the thenexisting rotary direction of the latter. AsJsoon as,.thus, the sliding-nut29 has attained its highest position, it is automatically locked by theLengagement of a suitable notch therein with the only loot-h of the right-hand clamping contrivance 93, which is continuously kept in working posit-ion; A Asthe clampingmems bers 86 have lirmly engaged the thrust-bearin the dir/ tio ing disc 88 after the levers 100 have been turned up, the tl'irust-bearing disc is screwed up whereupon also the left-hand clamping 'cont'riva'nce comes to action. v The main control spindle begins to screw downwithm. the guiding-nut 29 from 1ts hithertorra1sed po-v exactness is'to be considered, Within which the an'angement works during the whole ads justment to a fixed value: of the working gas and during the sweeping of the bath sur- P L J. 1 J. race. It may be assumed that the COTIGCJ ratioof cross-sections BXlStSfOl a hxedvalue with a burner adjustment to the nearest.

point of impact of the v flame. With a changeof the burner flap positions for displacing further the point of impact, the

initially correct ratio of cross-section tests varieswithin certain limits. theangles,

for which the flaps oscillate, must normally remain constant for allowing a sweeping; of the total bath surface in question at any gas value, said variation of the ratio of cross-sections is theflarger,the-smaller the outlet cross-section in: question at the nearest point ofim'pact, orithe higher is the value of the gas. Furtherregard must be paid to the diiference'in the specific weights of gas and air increasingmore and more with increasing gas value.

Correction apparatus;

Said inexactnesses are dispensed with by the present invention in such a Way that on the fresh-gas side the diilerenceof the resulting energies of movement of gas and air does not exceed 15%, while on the wasteof the. heating temperatures of gas and-air of less; than, 10 0'only; This is attained by, a correction" apparatus (Figs. 1 and 11) effecting on the fresh-gas side aswell as on i the waster-gas side a corresponding limitation of thewidening ofthe outletcross-section ofthe gas flue depending upon the gas value. V I

Hence it follows that acorrection apparatus must be used, auxiliary control spindle 18, the driving of the sleeve 76; beingfleflected. by means of the toothed gearing 57 181'. of said-sleeve76 a boltf77, 78 is screwed and fitted'each witha bounding arm'79 for the fresh-gas and, 1 80 for ,the waste-gas adjust v which is; operated by the In each end side the adjustment permits a difference r 5 ment. The direction of the threads in the sleeve 7 or on the bolts 77, 78 is such that with the adjust; out for ahigher g=-s value the bolts are s ed out of the sleeve 76 and adapted, b the bounding arms TS f-or 7 l Jtreshs supply and 80 for waste-gas w thdrawal. LO hi i the widening of the flue .L' l 1 1 .1? outlet cross-sec ion by the yiel-aingly on the bat-l Furthermore, it must be noted that by a cor arranged-eperating rods 9, 10 (Fig. 1) bearing upon the surfaces of the arms. As shown in Fig'll-for one operating rod 10, the operating rods 9, 10 are each two-parted, one par 10 being arranged on the turning flap (4) and embracing theothcr part 10' that is linked to the main control spindle 14-. A bolt 81 fixed on said latter part engages in borings of the other forked part 10 while a spring 82 encased at 81 allows a certain degree of movement between the two parts 10, 10. .The bounding arms 79 for freshgas supply and 80 for waste-gas withdrawal are arranged at an angle of 90 to oneanother. When reversing from fresh-gas to waste-gas position, and vice versa, each time the respective arms are turned into working position and held therein until the next reversion takes place. Fig. 10 shows that said reversal can be effected in a simple way, simultaneously withv the manual turningaside of the abutment 45, by means of the draw-bar 124:. To prevent collision between the operating rods 9, 10 and the bounding arms 79, the reversal .must take place when the runner 48 lies at the abutment 4% (farthest point of impact of the flame) The whole arrangement worzs thus perfectly automatic, and that for both main operations: for the adjustment to a fixed value of the working gas and for the continuous sweeping of the whole bath surface, that is for a positive combustion directly surface. The control of the blowersfor gas and air, of which the capaci-, ties must be varied corresponding to the "quantity of gas and air to be supplied according to actual gas value, can be made dependentupon the runner 71 for indicating a certain gas value. The reversal of the arrangement at the change of'direction of the furnace working takes place ina simple Way by manually putting the. abutment 4 5 into 1ts'd1sengaged or work ng positions.

ment of the main operating elements, of.

allows combinations which make the ap paratus more than hitherto adapted for the various requirements of the furnace Working. I

What I claim is:

1. The method of vv'orl ing furnaces having air and ga heating checker chambers, a bath receiving iearth and burners at opposite ends of the hearth, said method comp-rising preheating the streams of andair for combustion to equal r predetermined different temperature for each thermal value of the said preheating being doneaccordin to the principle that the greater the calor c value of the gas the smaller the amount of waste gas necessary for the preheating of the gas in relation to the amount of waste gas necessary for the preheating of air and vice versa, and adjusting the cross-section of the burner openings at the outlet end of the furnace so that the greater the calorific value of the gas the smaller the proportion, according to which the waste gases are distributed to the gas and air chambers.

2. The method of working industrial gas furnaces havingair and gas heating checker industrial gas chambers, bath receiving hearth and burners at opposite ends of the hearth, said method comprising preheating the streams of gas and air forv combustion to an equal. .or predetermined dlfferent temperature for each thermal value of the gas by an adjust ment ofthe burner outlet fiue cross-sections on the Waste gas side and a consequent distribution of the waste gas quantities over the regenerative heating chambers, said preheating taking place according to the principle'that the greater the calorific value of the gas and consequently the ratio of'the amount of combustion air to the amount of heating gas, the greater must be the ratio of opening on the waste gas side and vice versa, andautomaticallyad usting the 1'at1o of the burner outlet cross-sections on the freshas of the two streams takes place'on the bath surface, the burner outlet flue axes being simultaneously and correspondingly adjusted and the Whole combustion process taking place on the bath surface only.

.3. The method of working industrial gas furnaces having air and gas heating checker the air" burner opening to the gas burner chambers, a bath receiving hearth and bum ers at opposite ends of the hearth, said method comprising preheating the streams of gas and air for combustion to an equal or predetermined different temperature for each thermal value of the gas by an adjustment of the burner outlet flue cross-sections on the waste gas side and a consequent distribution of the Waste gas quantities over the regenerative heating chambers, the ratio of the burner outlet cross-sections on the fresh gas side being adjusted automatically in such a Way that in connection with the positive supply of the gas and air quantities the energies of movement of gas and air streams for each thermic Value of the gas have such a value that the intersection of the two streams takes place on the bath surface, the burner outlet flue axes being simultaneously and correspondingly adjusted, the whole combustion process thus taking place on the bath surface only and the inclination or direction of the burner outlet flue axes being changed in a continuous alteration, so that a to and fro travel of the point of the impact of the flame produced by the in tersecting gas and air streams over the whole bath surface is obtained.

4. The method of Working industrial gas furnaces having air and gas heating checker chambers, a bath receiving hearth and burners at opposite ends of the hearth, said method comprising preheating the streams of gas and air for combustion to an equal or predetermined different temperature for each thermal value of the gas by an adjustment of the burner outlet flue cross-sections on the waste gas side and a consequent distribution of the waste gas quantities over the regenerative heating chambers, the ratio of the burner outlet cross-sections on the fresh gas side being automatically adjusted so that with a positive supply of gas and air quantities the energies of movement of gas and air streams for each thermal value of the gas have such relative values that the intersection of the two streams takes place on the bath surface, the burner outlet flue axes being simultaneously and correspondingly adjusted, the whole combustion process thus taking place on the bath surface only, the inclination or direction of the burner outlet flue axes being changed in a continuous alternation, so that a to and fro travel of the point of impact of the flame produced by the interesecting gas and air streams over the whole bath surface is obtained and said change of the direction or inclination of the burner outlet flue axes being limited to a certain range or point of the bath surface.

5. The method of working industrial gas furnaces having air and gas heating checker chambers, a bath receiving hearth and burners at opposite ends of the hearth, said method comprising preheating the streams of gas and air for combustion to an equal or predetermined different temperature for streams takes place on the bath surface, the

burner outlet flue axes being simultaneously and correspondingly adjusted, the whole combustion processthus takingplace on the bath surface only,the inclination or direction of the burner outlet flue axes being changed in a continuous alternation so that a to and fro travel of the point of impact of the flame produced by the intersecting gas and air streams over the whole bath surface is obtained, said change of the direction or inclination of the burner outlet flue axes being limited to a certain range point of the bath surface, the streams of gas and air receiving such energies of movement during the to and frotravel of the point of -I f impact of the flame on the bath surface, which are required. for a larger or smaller distance of said point of'impact of the flame from the fresh gas burner, the burner,

outlet flue cross-sections being gradually narrowed or widened, and the-ratio of the burner outlet cross-sections remaining constant during said adjustments provided a change of the last-mentioned ratio is not necessitated by a change of the calorific value of the gas. a I

6. A regenerative furnace having air and gas heating'checker chambers, a bath receiving hearth, burners at opposite ends of the hearth and flaps in each burner outlet operable to regulate the cross-section thereof in accordance with the thermic value of the,

gas. a

7. A regenerative furnace having air and gas heating checker chambers, abath receiving hearth, burners at opposite ends of the hearth, flaps in each burner outlet operable to regulate the cross-section thereof in accordance with the thermic value of the gas, a main spindle controlling the positions of said flaps to effect the adjustment of the cross-section of said outlet and to effect further the shifting of the burner flue outlet axes owing to the necessary changes of the cross-sections during the to and fro travel of the flame and an auxiliary controllingv spindle adapted to act upon said flaps to adapt the ratio of the burner outlet cross-sections to the instant calorific value of the gas.

8. A regenerative furnace having air and gas heating checker chambers, a bath receiving hearthhuiners at opposite ends of the hea'rth,. flaps in each burner outlet operable to negulete the cross 's'ection, thereof in accordance with thethermie Value of the/gas, a main. spindle dcdrltgollingl the positions of said flaps to effect the. "adjustment of the cross-sectioh of saidoutlet mid to effect fur flier thes'l lifting of the burner fluieofitlet 'txes owing to the necessary changes of the ci'oss-sctions cluring the to and fro travel of the flame, an auxiliary Controlling spindle adapted to act upon said flaps to adapt the ratio of the bur'ner outlet cross-sections to the: instant vcalorific Value of the'gas and a gearing for e'ontrolling said spindles Wherebyth-e various adjustments and a. reversing of said burners from their fresh gas p'ositin'n'to, the wzistegas position areauto- Inatieal1yeffected.- t i Ig-tes'timfony whereof I have 'hereunto set WALT-HER SCHUCANY.-

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