Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
  • B01F27/95—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with stirrers having planetary motion, i.e. rotating about their own axis and about a sun axis
  • B01F27/951—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis with stirrers having planetary motion, i.e. rotating about their own axis and about a sun axis with at least one stirrer mounted on the sun axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/80—Mixers with rotary stirring devices in fixed receptacles; Kneaders with stirrers rotating about a substantially vertical axis
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
  • B01F33/80—Mixing plants; Combinations of mixers

Definitions

• the invention relates to a method and an apparatus for mixing fluids, especially by dispersion and emulgation, according to the generic portions of claims 1, 9 and 16, respectively.
• the production of desired final products is generally based on a quantity ratio according to a formula.
• thermodynamic and flow processes may make a different procedure advisable or even necessary.
• the invention relates to a two-stage dispersing method wherein a partial stream is deviated from the main stream of a reagent I coming from a container and a second partial stream (secondary stream) of a mixture with a reagent II is supplied to said first partial stream, which mixture is produced in a premixing chamber, the mixture of the two partial streams then being fed to the residual main stream via a rotating dispersing apparatus.
• This method is extremely economic and highly efficient. Partial streams of small quantities may be adjusted easily as required and with very little inertness, most easily by means of a dosing pump.
• the partial stream technique has the advantage that the concentration of the reagent to be added only has to have the quantity ratio which relates to the partial stream. This will also apply to the - otherwise often difficult - phase-emulsion emulgation in the hot/cold process.
• dispersing apparatuses known per se with a coaxially engaging rotor/stator system may be used, in which system shearing forces between closely neighboured concentric toothed baskets, of which at least one is rotated, will homogenize the material to be mixed as it passes through, said material being discharged via periodically aligned channels.
• Cyclic pressure differences in such a dispersing apparatus will support quick and uniform distribution of the reagents in that the reagent I is always fed into the premixing chamber during high-pressure periods, dispersing uniformly with the reagent II in the premixing chamber under turbulance and pulsation in each following period of lower pressure. From the point of view of process engineering, mixing will thus be optimally achieved, irrespective of the quantity ratios to be adjusted for the final product. Because of the extremely short retention time of e.g. only 5 ms, minimum heat exchange takes place in the premixing chamber so that a reagent II that is fed hot will cool down only slightly during intensive mixing with reagent I.
• the main stream and the partial streams receive different energy densities, which will essentially contribute to optimum dispersion and emulgation with the smallest particle or droplet sizes possible.
• the mixture of partial streams may be provided in the premixing chamber with an energy density which is considerably higher - e.g. by at least one order of magnitude - than the energy density of the main stream. Where high specific energies are not applied, e.g. when a desired chemical reaction is to be effected, at least good uniformity supporting this process will be achieved. For example, a particle fineness below 0.5 ⁇ m may easily be obtained.
• a reduction of viscosity generally occurs owing to the increase of energy during inflow into the premixing chamber, which reduction will substantially improve the mixing with low-viscosity substances.
• the energy density and retention time in the partial stream i.e. the volume- and time-related energy input, may be controlled so that a critical energy density resulting in an emulsion reversion will not occur, which is very important e.g. for the production of mayonnaises, dressings, etc.
• the mixture (R l+ll) may be adjusted as to temperature and quantity ratio without substantial shear load.
• This zone may be followed by a zone of maximum shear defined by the rotor/stator system, especially at a long tooth edge of the rotor, whereby the adjusted partial stream method surpasses the conventional technique by far.
• a phase mixture may be produced from the reagents in the premixing chamber under different velocities and different static pressures, with a phase I being fed directly into said chamber and a phase II getting into the premixing chamber via inlet channels by means of pulsation due to of cyclic pressure differences.
• the invention for homogenization of substances, e.g. paste-like compounds, and/or for production of emulsions with droplet sizes in the ⁇ m range, using a dispersing apparatus arranged in or on a container with at least one rotor/stator system, in particular near the bottom of the container, and with feeding devices for a carrier stream if necessary, the invention, according to independent claim 9, provides for two-stage generation and mixing of defined partial streams by producing in a first process step an initial product from a reagent or wax solution and by adding this product to the carrier stream in a second process step.
• the term wax comprises all substances that are solid at ambient temperature and liquid or flowable at an increased temperature, such as fats, paraffins, esters, etc.
• a hot reagent stream (secondary stream) is united in a first process step by which a partial stream is branched off from a main cold carrier stream in a dosed quantity and - with addition of the energy necessary for the droplet size - is dispersed , whereupon the mixture is remixed with the remaining part of the carrier main stream in a second process step to obtain the final product.
• the desired concentration of reagent II in reagent I may be obtained after one cycle already. For example, a processing duration of just 15 min for 2000 kg of cream can be easily reached. Agglomeration as with Oswald ripening will not occur because the emulsion quantity necessary for absorption of the added wax is small, and noticeable cooling down is thus avoided.
• the wax can be worked into the carrier at high energy density without striation. Particle fineness is substantially assisted by the admission of energy to the rotor/stator system wherein the increase of surface energy is reached or even many times exceeded. During the subsequent shock-like cooling down at the big volume of the main stream of the cold carrier, the wax particles will harden so that secondary agglomeration is avoided. Thus a homogeneous particle-size distribution will be reached and consequently a substantially improved product behaviour.
• peripheral velocities above 20 m/s may occur in the rotor/stator system so that the medium present in the premixing chamber will be pressed vigorously outward through the dispersing apparatus owing to high centrifugal acceleration whereby the energy is increased.
• the premixing chamber may be assigned to the lower and radially outer parts of the rotor, and the initial product may first be diverted outwards before it is accelerated at the upper side of the stator and fed to the mainstream flowing radially more inside.
• the pressure in the main chamber is expediently set by means of its dimensions and by the choice of the ratio between inlet and outlet cross-sections.
• powdery substances are required for the final product, they will be added to the main stream from above so that they are quickly vortexed and absorbed by the main stream at high speed.
• the invention further relates to a device serving for homogenization of substances, e.g. paste-like compounds, and/or for production of emulsions with droplet sizes in the ⁇ m range, and being provided with a dispersing apparatus on or in a container having at least one rotor/stator system near the container bottom, with a product inlet at the upper side and at least one feeding device arranged in said upper zone if necessary.
• a supply line for especially a hot reagent leads into a premixing chamber below the rotor, which chamber has or may have a flow connection, via an outlet channel with a main chamber at the bottom of the rotor/stator assembly, and therefore requires very little space.
• the device according to the invention is also extremely favourable in respect of power consumption. It represents a considerable further improvement over conventional devices, e.g. according to DE 296 08 712 U1 , which have V-shaped or wedge-like stator and/or rotor projections that have a decisive influence on the flow behaviour due to different surface portions and sharp edges.
• DE 296 08 713 U1 which causes disproportionate changes of the shearing-gap volume by readjustment of the axial distance between stator and rotor
• the invention also achieves a substantially accelerated dispersion by incorporation of the premixing chamber.
• the premixing chamber is preferably arranged in the outer area of the rotor between its bottom and the confining wall of the casing, particularly in such a way that it reaches from the center of the rotor bottom up to an outlet of the premixing chamber. Requiring a minimum of space, said premixing chamber is thus optimally accommodated at the rotor/stator system.
• the outer stator ring may include stator teeth that project downwards from the main chamber, overlapping the rotor circumference with a minimum of clearance without contacting it, and that extend to a bottom flange located centrally opposite the rotor bottom. This design contributes to producing an increased static pressure in the premixing chamber which is thus limited to a small volume wherein an intensive initial dispersion - e.g. of a hot reagent fed - takes place without disturbing cooling-down effects.
• a supply line leads into a preferably inclined inlet channel which is integrated into the bottom flange as a radial channel parallel to the bottom, in particular opposite the outer bottom of the rotor.
• the construction may be designed so that the rotor has its maximum diameter and circumference, respectively, at its flat or concave top, with an outer surface reentering toward the rotor bottom from a peripheral edge or curve.
• a very intensive radial feeding of the medium will be achieved if a deflecting body consisting of a flat cone reaching up to the area of the premixing chamber and having at least one cone-shaped or concave outer surface with a steeper cone sector angle, is formed at the bottom of the rotor, the transition between neighbouring deflection surfaces being preferably designed as a sharp edge in order to obtain additional vortexing. Consequently at least two conical and/or curved surfaces bordering obtuse- angled on each other may peripherally enclose a stepped surface of the rotor hub and have angles that become steeper to the outside. Said deflection surfaces will guide the partial stream particularly effectively into the main chamber. Therefore the vigorous centrifugal flow at the outer stator ring has already an axis-parallel component which will most effectively enhance the introduction of the partial stream into the main chamber.
• a preferred embodiment has a stator with a hood which confines, outside the outer stator ring, a deflection chamber provided near the bottom flange with outlet orifices distributed over the circumference, the feeding element being arranged adjacent the rotor directly above the inlet formed centrally in the hood.
• This extremely compact assembly may be flanged directly to a container bottom. It ensures a high degree of homogenization by recirculation in a narrow space.
• Dispersing apparatuses are typically manufactured with very small tolerances for precise assembly.
• a drive designed as hollow shaft motor is very useful, with support by a bottom flange and a bearing flange arranged at right angle.
• the rotor shaft is preferably axially supported within a slide ring packing by stops and disc springs so that a linear extension of the hollow shaft and thus of the driving shaft will only be possible in the direction away from the bottom flange.
• heat influences caused by the underlying motor will be reliably compensated for in a surprisingly simple way.
• the driving shaft may reach temperatures of e.g. up to 120 °C in continuous operation, practically no thermal expansion will thus occur at the dispersing apparatus arranged above; rather, linear extensions of the hollow shaft of the motor, which are inevitable during heating up, will occur only in the direction leading away from the dispersing apparatus. Therefore an optimum shearing effect will always exist at the rotor/stator system owing to the invariably narrow gap.
• the pressure distribution in the dispersing apparatus is controlled at the outlet side, preferably by choosing the flow path, the flow distance and the looping angle, respectively, in the outlet channel behind the outlet socket; or by means of surface dimensioning and arrangement of the outlet orifices, which permits easy adaptation to special operating conditions.
• An attachment to be flanged to the container bottom may have an inlet pipe surrounding the feeding element, which provides for particularly vigorous suction of the medium.
• a line branches off which may be controlled by e.g. a valve and which returns to or into the upper part of the container, if desired with such a tangential angle that a product rotation generated by the agitator or feeding element will be slowed down. Air pockets will be avoided if the line is returned below the minimum product level in the container.
• the return line can be heated or cooled as required and be installed at least partly outside the container which holds e.g. 16 I [liters] in a laboratory plant and e.g. 10,000 1 [liters] in an industrial plant. With high dispersion powers, e.g.
• the invention provides for a separately attachable predispersion stage, especially for retrofitting existing homogenization or dispersion plants in an economic way.
• a separate dispersing apparatus is continously charged only with that portion R I" of the main stream to which the reagent R II has been dosed in the premixing chamber in the quantity corresponding to the total stream R I.
• a superconcentration of R II will develop in the outlet stream mixture of the dispersing apparatus, then to be treated in a considerably smaller high-pressure homogenizer and be remixed with the remaining reagent stream R P.
• Fig. 1 is a schematized axial cross-sectional view of a process container with flanged-on dispersing apparatus
• Fig. 2 is a flow diagram
• Fig. 3 is a partial cross-sectional view of a rotor/stator system with a premixing chamber
• Fig. 4 shows an enlarged detail corresponding to zone IV in Fig. 3
• Fig. 5 is an axial cross-sectional view of a homogenizer with a schematically indicated drive
• Fig. 6 is an axial cross-sectional view of a similar homogenizer with an attachment
• Figs. 7a, 7b, 7c show axial cross-sectional views of different parts of an attachment according to Fig. 6, partly in exploded view (Fig. 7a), Figs. 8a, 8b, 9a, 9b show each a plan view, partly sectional, of stator rings,
• Figs. 10a, 10b are side views of a driving shaft as well as of a stirring shaft to be coupled to it and Figs. 11a, 11b, 11c show each a plan view and a side view, respectively, of a rotor and of projections.
• Fig. 1 shows a schematized survey of a mixing plant comprising a container F with an incorporated agitator S and a counterrotating straight arm paddle agitator W which has an inlet pipe 19 at its lower end.
• Said pipe 19 faces a bottom flange 14 (Fig. 5) by means of which a socket 16 of a dispersing apparatus 10 is attached to the casing 12 of a container F for which Figs. 5 and 6 show different examples.
• a feed line 30 having a connection 32 leads with an inlet 38 (Fig. 3) to the bottom flange 14.
• the dispersing apparatus 10 is connected via a return or recirculation line Z to the upper part of the container F.
• a pressure system projects that is provided with a shut-off device and with spray heads for periodical cleaning.
• the dispersing apparatus may also be used without recirculation line in accordance with the embodiment of Fig. 5.
• a carrier (reagent I) is kept ready according to the formulation.
• a receiver (not shown either) supplies an additive (reagent II), e.g. hot wax.
• the receiver is connected to the feed line 30 of a premixing chamber 60 of the disperser 10.
• the agitator S - if available - is started in the container F, whereupon the dispersing apparatus 10 is put into operation.
• the reagent I flows through the disperser 10 and via the recirculation line Z (or directly) back into the container F.
• the dosing device at the receiver is switched on so that the reagent II will flow as partial stream R II into the premixing chamber 60 of the dispersing apparatus 10 where it will mix with the partial stream R P of the reagent I in an extremely short time.
• the components (R I + R II) are intimately dispersed in the premixing chamber 60, resulting in fine to finest dispersion depending on the process conditions chosen. Because of the static pressure differences and of the geometry of the premixing chamber 60, the partial stream R l+ll formed will combine and mix with the remaining main stream R I" of the reagent I of the dispersing apparatus 10.
• This product III often already the final product consisting of the reagent I enriched with the reagent II, is returned as a final stream E into container F. Its circulation through the dispersing apparatus 10 will be continued until product III has reached the formula concentration of reagent II in reagent I. In most cases, the addition of an emulsifier is not necessary at all or only in a small dosis.
• FIGs. 3 and 4 show details of the mixing zone and of the premixing chamber 60, elucidated by the examples of Figs. 5 and 6 in combination with the following explanation of the basic layout.
• a rotor shaft 24 passes through an inlet pipe 19. At its lower end, said shaft is provided with a recess 27 by which it is connected via a coupling extension 25 to a shaft 22 (Figs. 10a, 10b) of a driving motor 20 attached to a supporting flange 18.
• the contours of motor 20 - which is rather heavy when high-powered - are only indicated by dashed lines, as is a lateral terminal box (on the right) for electric connections (not shown).
• the motor shaft 22 has a cone bearing 23 as second bearing for stabilization of rotor shaft 24 which latter is supported via disc springs 13 by the bottom flange 14 through a fixed bearing and by the supporting flange 18 through a loose bearing.
• the supporting flange 18 holds the socket 16 and is additionally supported by the bottom flange 14 through distance pins 28.
• the motor 20 is sealed against the container by means of a slide ring packing 26.
• the rotor shaft 24 holds a hub 51 of a rotor 50, and its free end is connected above in a non-rotatable way to an agitator shaft 43 which holds an agitating element 44 shaped as a propeller.
• the lower side of the rotor 50 faces the bottom flange 14 directly in which an inlet channel 38 is arranged, especially in an inclined manner, into which channel a feed line 30 leads that is preferably integrated into flange 14 parallel to its bottom, e.g. in a radial direction.
• said feed line may be an external pipe which inclines toward the mouth of the inlet channel 38.
• the connection 32 with a shutoff element 34 e.g. a rotary slide valve or another valve, serves for supply of hot wax from a storage reservoir (not shown).
• An operating lever 36 may optionally be arranged in a way other than shown.
• the bottom flange 14 is rigidly or integrally connected to a stator 40 that reaches over the rotor 50 from above and has a suction orifice 45 below which there is a main chamber 15 confined at the bottom by the top face 53 of rotor 50.
• Both stator 40 and rotor 50 include gears or cogwheels which have axis-parallel teeth and which are fitted into each other with minimum radial clearance.
• the stator 40 has an inner stator ring 41 with inner stator teeth 46 and an outer stator ring 42 with outer stator teeth 48.
• the rotor 50 has inner projections or teeth 63 as well as outer projections or teeth 65 between which there are radial outlets 66 (Fig. 11a).
• Corresponding radial outlets 47 are provided on the inner stator ring 41 (Fig. 8a), as are radial outlets 49 on the outer stator ring 42 (Fig. 8b).
• the projections 63, 65 of the rotor 50 protrude vertically from its upper side 53 (Fig. 11b) and have inclined lateral and top surfaces, the upper ends of the teeth 63 and 65, respectively, comprising inclined surfaces 67. All teeth or projections 63, 65 may have vane-type faces 64 which are inclined in a circumferential direction (Figs. 11a, 11c).
• the rotor 50 (Fig. 11b). Its hub 51 has a central bore 52 and a plane face 54 bordered by a stepped surface 55 parallel to the top surface 53. At a radius defined by the position of the mouth of inlet channel 38, there is a transition from the stepped surface 55 to a flat cone 56. Following a sharp edge 57, a concave outer surface 58 extends under a steeper angle to the periphery 59 near or at the top surface 53. In this area, the outer stator teeth 48 with minimum clearance over the rotor 50 which has its greatest diameter here and is provided at its circumference with a number of preferably concave outlet channels 68 (Figs. 3 and 4).
• the premixing chamber 60 is of central importance for admixing and dispersing. It is arranged between the inner perimeter of the outer stator teeth 48, the outer surface 58 of the rotor 50 and the adjacent upper side of the bottom flange 14. In this small volume which includes in a periphery position the volume of the corresponding outlet channel 68, the hot reagent II coming from the feed line 30 after deflection at the flat cone 56, which acts as reflecting surface, is vortexed into a mixture with the medium I already available in the main chamber 15.
• Said mixture flows as partial stream R l+ll through the assigned outlet channel 68 to the outer stator teeth 48 and through the outer radial passages 49 into a deflection chamber 61 and continues as dispersed fluid along the casing 12 through radial outlets 62 of the stator 40 into a container (not shown).
• the agitating element 44 will steadily feed the main stream R I from the container F to the inner main chamber 15 until the dispersion has reached the desired degree of homogenization.
• the final stream F of the final product III is drained via an outlet (not shown).
• the stator 40 is not a hood but features a top plate provided with a central suction orifice 45 and rigidly connected to a cylindrical casing 70 which is closed at the bottom by the also rigidly attached bottom flange 14.
• the preferably inclined inlet 38 is connected to the connection 32 in a space-saving way by a feed line 30 again which is designed as a radial channel in the flange 14 running parallel to the bottom.
• the casing 70 has a socket 69 (Figs. 6, 7b) with a connection 72 for a return line (not shown here) to the upper side of container F.
• the stator plate 40 is crowned by an attachment 17 fixed by means of a fastening flange 71 for enclosing the agitating element 44 in an inlet pipe 19 (Fig. 7a) that is welded to the flange 71 and is rigidly connected to an upper flange 29 onto which a flange ring 39 - shown in exploded view in Fig. 7a - is attachable, which ring may be screwed to the casing 12 and a connected flange socket, respectively.
• the casing 70 has a reduced wax feed connection 32 which as part of the bottom flange 14 is welded thereto directly below casing 70.
• the connection 32 is inserted directly into the wall of the casing 70 whereby additional saving of space is achieved.
• this process takes place in the predispersing chamber whose volume mainly depends on the rotor diameter which, in turn, determines the power consumption of the rotor to the power of five. It has proved to be a great advantage of the new adjusted partial stream process that for the change from a 3.0 kW laboratory plant to a 45 kW dispersing apparatus, the rotor has only to be enlarged in a ratio of 1 :1.72 which corresponds to a ratio of 1 :2.95 of the volume increase in the predispersing chamber. This can be considered to be infinitesimal as against the transformation factor of 300. During practical tests, the formulations developed in the laboratory plant could be identically adopted for the production plant, with the produced product matching the laboratory result perfectly.
• the production time required for this process step is considerably decreased. For example, with 200 kg for a batch cycle, the average time sank from 2.5 h to 40 min from the beginning of container filling to the end of pumping off. The result is a considerable saving of energy, apart from the great increase of the daily production.
• fatty acid is dosed into the prechamber 60 as the reagent II.
• the dissolved CaOH complex of the partial stream R P of the reagent I (lime milk) is sufficient to neutralize the weak fatty acid.
• the saturation concentration is reached again by the CaOH in suspension. The previously annoying formation of agglomeration of lime and fatty acid is successfully avoided by the partial stream method.
• Application example B Addition of flocculants in water treatment
• the quantity ratio between reagent I and reagent II can be exactly adjusted so that the cooling of the recirculation line Z corresponds to the reaction heat amount.
• the essence of the method and of the apparatus according to the invention is a two- stage dispersion with the following main requirements to the dispersing apparatus 10:
• the unit is provided with an external recirculation line (Z) which may be heated and/or cooled as required.
• a branch-off means for the partial stream of the plant is necessary.
• a high-pressure homogenizer may be additionally inserted into the recirculation line Z from the second dispersing apparatus to the container F for ultrafine dispersion.
• the final product i.e. the reagent III
• Said homogenizer has only to be dimensioned for the partial stream R l+ll, which will advantageously save a lot of costs and energy.
• This variant is particularly suitable for feeding "difficult products", such as vitamin E.
• a high-pressure homogenizer may also be interconnected in a single two-stage dispersing apparatus 10 provided a suitable partial stream connection is available.
• the hot phase is then added via connection 30, 32 which leads directly into the premixing chamber 60.
• the dispersing apparatus 10 rotates with a speed of approximately 3000 min "1 for about 15 min, the motor current has to be kept constant at e.g. 40 A. Though variable viscosities may cause speed changes, constant energy supply is achieved.
• the dispersing apparatus 10 is alternately switched off and on during final reagitating periods of 5 min each.
• Heating of the hot phase will require 35.00 kWh
• a base preparation is used which is the same for all colours of the same type and which determines the total quantity of water required.
• the actual hair dye is prepared by addition of the desired shade-determining substances to a reduced quantity of the hair dye base.
• a dispersing apparatus 10 and a double-motion agitating system W only so much water is added according to the hot/cold method for obtaining the base preparation as is required in the conventional process for the hair dye with the proportionally smallest quantity of water (in general this is the colour black).
• Part of the hair dye base is then pumped into a smaller plant of e.g. 250 I [liters] which is equipped with a dispersing apparatus 10 including a premixing chamber 60.
• the substances determining the shade are added via connection P4 to the partial stream R II.
• the water quantity is chosen such that in the final product III, the water ratio will meet the formulation of the chosen shade, allowing for the possibly smaller quantity of water previously added to the basic product.
• the hot/cold partial stream method may advantageously be applied in cases where reagent II, though not solid at ambient temperature, has a deliberately low viscosity when hot so that mixing with reagent I will be performed at a high energy level, e.g. with highly concentrated tensides or vitamin E products.
• reagent II though not solid at ambient temperature
• the cold/cold batches commonly used in industry may also be processed in a very economic way.
• a preferred process conduct for homogenization of substances e.g. paste-like compounds, and/or for production of emulsions with droplet sizes in the ⁇ m range uses a dispersing apparatus 10 arranged at a container F with a rotor/stator system 40, 50 near the bottom and with feeding devices S; 44 if necessary.
• an e.g. hot initial product generated from a reagent or wax solution is dispersed in a first step in the form of a secondary stream R II with a dosed partial stream of an e.g. cold carrier R I' and is remixed in a second step with a carrier main stream R I" being fed from above.
• a premixing chamber 60 is assigned to the lower side of the rotor wherein the secondary stream R II is vortexed with the partial stream R P fed from above or outside.
• the fast- running rotor 50 generates an upside-down cone whose reduced pressure will assist self-dosing of the secondary stream R II.
• a partial stream feeding device 30, 38 enters the prechamber 60 below the rotor 50, preferably near its periphery.
• the prechamber 60 is confined in an outer stator ring 42 and leads into a main chamber 59 at the lower side of the rotor/stator system 40, 50 via an outlet channel 68.
• Outer stator teeth 48 project down to a bottom flange 14 faced by the lower side of the rotor 50 which may be provided with a flat cone 56, a sharp edge 57 and a steeper outer surface 58.
• An agitating element 44 may be arranged directly above an inlet 45 formed centrally in the hood near rotor 50 or in an inlet pipe 19 above the rotor/stator system 40, 50 where an outlet socket 69 branches off.
• a recirculation line Z which can be shut off may be installed at least in part outside the container F and/or may be heated or cooled.
• shut-off element 65 outer projections / teeth

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• 2000
  • 2000-07-10 EP EP00114789.1A patent/EP1121974B1/de not_active Expired - Lifetime
  • 2000-11-24 WO PCT/EP2000/011700 patent/WO2001056687A1/en not_active Application Discontinuation
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