HU185004B - Process for separating dry substant content of solutions and/or suspensions and in forme of granulate, and for granulating powders and mixtures of powders in a layer fluidized with gas, and apparatus for the process - Google Patents

Abstract

The solids content of solutions and/or suspensions is recovered as granules in a gas fluidized bed which contains particles, the composition of which is identical with that of the solid material in the solution and/or suspension to be processed, in which bed the solution and/or suspension is sprayed on the surface and/or interior of the hot gas fluidized layer, and from which bed particulate material is continuously withdrawn at a mass flow rate corresponding to the solids content of the liquid phase sprayed in, and also, in which bed a grinding effect is created by forcing continuously particles formed in the bed through at least one slit of controllable clearance, located in the fluidized layer itself, in order to produce in a single step, in a single apparatus particulate material of predetermined particle size distribution. The apparatus disclosed has in the fluidized layer a slit-forming device consisting of free rolling rollers and a grinding surface, said rollers being periodically rotated with respect to the grinding surface. <IMAGE>

Description

The present invention relates to a process for recovering the solids content of solutions and / or suspensions in a gas-fluidized layer, wherein the solution and / or suspension to be processed is a surface of a layer of the dissolved and / or suspended material / or is sprayed into its interior and the mass flow particulate material corresponding to the dry matter content of the spray liquid is continuously discharged from the fluidized bed. The invention also relates to methods for granulating powders and powder blends in a gas fluidized bed by spraying a binder-containing liquid onto a layer of the powder or powder blend to be fluidized with a warm gas, particularly hot air, and drying the resulting wet agglomerates. The invention also relates to a device for carrying out the above processes comprising a fluidization cell, at least one liquid atomiser and, if necessary, a solid material dispenser and a particle removal unit.

Solutions or solutions The dry matter content of suspensions is usually multi-process technologies. In the simplest case, a technology consisting of three operations - crystallization - separation (eg filtration) - drying - is required to separate a well-crystallizable component from solution. If the particle size distribution of the solids thus produced does not, or only partially, meet the requirements for use, the technology will be further expanded. It becomes necessary to fractionate the crystals, to recycle the particles below the size limit to the crystallization process (eg, re-crystallization, or re-dosing as a nucleus). crushing crystal particles above the size limit. It is often the case that the size of crystalline particles below the size limit is large or that the material or material is less than the size of the crystal. because of the technological characteristics, only microcrystalline g material is formed. In order to obtain the desired particle size, it is often necessary to use a forming step, granulation. In the case of dilute solutions, the concentrate prior to crystallization is further subjected to a further step. may include the introduction of f operations. t

Solutions or solutions spray-drying is suitable for recovering the total solids content of the sprayable suspensions. Spray-dried solids have a very small grain size (typically 10-400 µm) and, in many cases, an additional step, granulation application is required to obtain the appropriate grain size. At the same time, spray drying is economical primarily for processing high concentration solutions, so the solution is usually concentrated prior to spray drying. So, when appropriate, spray drying is just another,

Including 2q additional operations (eg evaporation, granulation) -! is the technology to solve the problem. In addition to the exemplary technologies, there are, of course, other technologies used to extract the solids content of solutions, but the overwhelming majority of these are characterized by their multiple operations. The same applies to technologies developed for the extraction of solids content of suspensions (eg filtration - drying - comminution or granulation; spray drying - granulation, etc.). 1

3Q In recent years, the fluidization process has become increasingly common; more often used solutions or solutions. suspensions dry-! material in granular form. This process, unlike multi-step technologies, enables continuous operation to produce granules from solutions or solids in one step (one device). suspensions.

Particle formation from solutions (or suspensions) in a gas fluidized bed (hereinafter referred to as ₄ Q direct particle formation) is carried out as follows. In a fluidized bed fluidized bed, particulate material is maintained in a fluidized state by the flow of hot gas. The material quality of the particulate material is the same as that of the component in solution (or suspension). The solution (or suspension) to be processed is sprayed onto the surface (or an interior space) of the fluidized layer thus formed - The sprayed liquid droplets are applied to the surface of the continuously moving X particles. As a result of the hot gas, the solvent (or suspending agent) evaporates from the surface of the liquid-moistened particles and is removed from the unit with the exhaust gas. The solids content of the solution (or suspension) remains on the surface of the particles in the fluidized bed. The mass flow particulate material corresponding to the solids content of the spray liquid is continuously discharged from the fluidized bed.

Comparing direct granulation economics with spray drying, it has been found that if the liquid (water) evaporation is less than 60 kg / h, the cost of evaporating 1 kg of liquid (water) by direct granulation is less than by spray drying. At the same time, the investment cost of the fluidisation device is approximately one-third of the investment cost of the spray dryer. half. Examining equipment with the same production capacity, it was found that fluid

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.1 the space requirements of the equipment and, consequently, the size of the associated investments (building, scaffolding, etc.) are significantly smaller (CHRISTMANN, G .: Chem Anlagen Verfahren 1, 42-43, 1973; KASPAR,

J. ROSCH, M .: Chem. Ing. Tech. 45, 736-739, 1973.). ₅ For economic comparison, it is agreed that the two processes do not produce the same quality product in terms of particle size. The spray-dried material still needs to be granulated in order to obtain a product having nearly the same particle size as direct granulation. However, the costs of granulation were not taken into account in the economic comparison.

An essential prerequisite for the industrial applicability of direct particle formation is the production of stationary mode of operation, including the production of a stationary particle size distribution of the product -jg. The size of the particles in the fluidized bed is gradually increased by the solids deposited from the solution (or suspension). This mode of grain growth is surface layering. At the same time, agglomeration of liquid-wetted particles also occurs, resulting in a rapid increase in particle size. The principle of methods known in the literature for the determination of stationary particle size distributions is based on the recognition that the introduction of an appropriate amount of small particles (base particles) and the growth of said size increase processes. should be compensated.

In practice, the most common method is pellet metering. In the simplest case, some of the granules exiting the apparatus are recycled back to the fluidized bed immediately after 30 (US Patent No. 2,363,334) or after comminution (VOLKOV, V.F. et al., Khim.Prom.42,450-453, 1966). It is preferable to fractionate the granules leaving the plant and recycle particles smaller than a certain size limit (SAHOVA,

N.A. et al. Khim. Prom. 44, 446-448, 1966; 49, 299-301, 1973; 49, 690-594, 1973; KASPAR, J. ROSCH, M .: Chem. Ing. Tech. 45, 736-739, 1973.). Of similar practical importance is the process whereby particles larger than a certain size range are returned to the fluidized bed after shredding (British Patent No. 1,381,480). A known and common solution is the combination of the previous two methods, whereby particles smaller than the lower limit of the product 45 are returned directly to the fluidized layer after shredding (and sorting) (GD 2,263,968 and 3,475,132 IS). U.S. Pat.

Another, less widespread, method of developing stationary particle size distribution is based on the fragmentation process resulting from fluctuations in the surface temperature of the particles in the fluidized bed (TODAS,

Ο. M .: Christ. Tech. 7, 729-753, 1972.). The essence of the phenomenon is as follows. The particle in the "drier" zone of the fluidized bed enters the atomization zone, where it comes into contact with a liquid spray at a temperature substantially lower than the particle temperature. The grain surface suddenly cools. Fragmentation occurs due to different temperature and thermal expansion θθ conditions on the surface and inside of the particle. In some cases, this method has also succeeded in establishing a stable stationary process. (KOZLOVSZK1J, V.V. et al., Khim. Prom. 46, 122-123, 1970; NAL1M0V, S.P. et al.

Zh. Prikl. Khim. 43, 581-586,1970.). ₆₅

Both of the methods described above for the determination of stationary particle size distribution have several disadvantages. In the case of pellet metering, various additional equipment is required. For example, continuous fractionator, continuous solid feeder, continuous and adjustable shredder, pneumatic solid conveyor (or other solid conveyor), etc. Nevertheless, the stationary particle size distribution can only be controlled within a relatively narrow size range. thus, changing demands on particle size are difficult and in many cases cannot be met. The productivity-reducing effects of solids recirculation should not be overlooked either. The rate of fragmentation processes resulting from surface temperature fluctuations is usually high enough to produce a stationary particle size distribution only at high bed temperatures (180-250 ° C). This factor greatly limits the range of materials that can be processed, since it is not possible to obtain components that melt or decompose at lower temperatures under steady state conditions. Relatively high bed temperatures are also unfavorable for energy use and productivity. Requirements for the particle size distribution of a granular product are generally defined by providing a lower and upper size limit between which the amount of granules (the so-called product fraction) should be maximum. The numerical value of the amount of the "product fraction" is usually around 80-90%. The particle size distribution of the granular material produced by fluidization granulation has some regularities regardless of the quality of the base material and the binder. Experience has shown that the particle size distribution of a granular product can be described as a function of logarithmically normal distribution (Ormós, Z., Csukás, B., Pataki, K .: Hung. J. Ind. Chem. 3, 193 (1975); Rankell, AS, Scott, MW, Liebermann, HA, Schow, FS _r Battista, JV: Pharm Sci 53, 320 (1964); Han, Ch D., Wilenitz, I.: Ind. Eng. Chem. Fundam 9, 401 ( 1970); etc.). It follows that, in many cases, a product in a relatively narrow size range cannot be directly produced by fluidization granulation. With the optimization of the technological parameters, auxiliary procedures, e.g. mechanical mixing (Hungarian Patent No. 168,675, 1971) seeks to provide favorable conditions for fluidization granulation. In spite of all this, the granular product will in any case contain a significant amount below or below the lower limit. granules larger than the upper limit. Of course, by adding additional operations (fractionation of the particles, partial grinding of the particles above the size limit, or further granulation of the particles below the size limit), the total amount of material can be converted into granules within a given size range. However, this requires the use of complex and costly technology.

It is an object of the present invention to provide a method and apparatus for gas fluidisation with a desired particle size distribution and / or particle size distribution meeting different quality requirements. finely divided granular material (granules) can be prepared from solutions or suspensions, as well as from powders and powder mixtures, in a batch mode or in a continuous mode under steady state conditions without

-3185 004 falling material for subsequent operations - e.g. fractionation, shredding, etc. - should be subjected.

The object of the present invention is to obtain the solids content of solutions and / or suspensions in the form of granules having an appropriate particle size distribution. for granulating powders and powder blends with the desired particle size distribution also by designing and applying a process according to the present invention, wherein the fluid is formed in the fluidized bed. the floating material particles introduced therein and growing therein are subjected to a mechanical stress pre-selected in the fluidized bed itself and continuously forced through at least one of the slots. The coercion of material particles floating in the fluidized bed is accomplished by creating and maintaining a relative displacement of the latter (s) between the material (s) and the material particles.

The present invention is based on the recognition that the formation and distribution of stationary particle size the base particles required to control them as required can be formed in the fluidized bed itself by subjecting the granules therein to mechanical stress.

The essence of the process according to the invention is therefore that the solution or solution in the fluidized bed is solubilized. The particle size increase processes (surface stratification, agglomeration) resulting from the spraying of the suspension or the solution containing the binder are determined by the formation of the stationary particle size distribution g. for the purpose of regulating itself; in a fluidized layer so that it has a variable degree of comminution in the fluidized * layer? we create a special mechanical stress with which · The maximum size and / or size of the particles produced; the particle size distribution of the resulting particulate material can be controlled within a relatively wide range.

In preferred embodiments of the process of the invention, the floating material particles formed in the fluidized bed are forced through a continuously changing spatial slot (s) in the fluidized bed, preferably spatially, e.g. rotational movement in a particular portion of the fluidized bed, preferably in the lower zone of the bed. The particles entering this zone of the fluidized bed are forced to pass through the continuously moving slit (s). As a result, particles larger than the slit (s) and / or particles of the slit (s). optionally, some of the particles smaller than the size of the gap (s) are necessarily finely divided.

The object device suitable for carrying out the method according to the invention has at least one gap forming member disposed in the region of the fluidized layer in the interior of the fluidization cell, preferably having at least one shaft with a variable aperture and . The chopping surface and / or the surface of the roller (s) is preferably roughened, e.g. The nominal value of the gap aperture A2 between the shredding surface A2 and the roller surface can be adjusted to the desired particle size distribution by means of a slot adjusting device. In order to avoid overload, fractures, it has been found to be advantageous for the slit-forming member, in particular its slit-adjusting device, to be displaced temporarily from the shredding surface in accordance with a threshold force as the gap opening increases. The efficiency of shredding larger particles can be further enhanced and, possibly, the occurrence of fluidization disorders may be prevented by the occasional use of a backward-curved blender.

The method and apparatus of the present invention advantages can be summarized in the following _five:

By this method, solutions or solutions are obtained. The solids content of the suspensions, unlike multi-step technologies, can be obtained in a single step, in the form of granules (granular material) having a direct physical properties (particle size distribution, moisture content) in a fluidized bed fluidizer.

One of the main advantages of the process is that the stationary physical properties (particle size, moisture content) of the solid formed are already formed in the fluidized bed and controlled as required. The particulate material removed from the fluidisation device does not need to be subjected to subsequent operations (eg fractionation, comminution, solids transport and addition, etc.). 2Q Therefore, it will be much easier to operate the equipment, but especially to operate the equipment. At the same time, the specific productivity of the equipment increases because there is no need to recycle or dispose of part of the outgoing solid. to create a high bed temperature 25. The investment and operating costs of the equipment are significantly reduced due to the above factors (taking into account the cost factors of the shredder and the drive motor).

The product has a (relatively wide) particle size of approx. In 3Q 0.2-5.0mm range, it can be reliably controlled with very simple tools (by changing the roller size, number or gap opening (s)). At the same time, increasing the speed of the chopping device by reducing the particle size, even during operation. The main weight of the exit particulate material (about 90% by weight) varies depending on the parameters of the comminution, but in very narrow dimensions (eg 0.2-0.8 mm, 0.6-1.6 mm, 1-2), 5 mm, etc.), which is further processed, disassembled or disassembled. it is also advantageous for use.

Even when granulating powders and powder mixtures, a granular product with a narrow grain fraction can be produced which does not require further processing, a maximum particle size greater than that desired in the 45 products can be set, and the particle size distribution can be controlled during operation. It is 20 to 25% more compact, has a smoother surface, has better fluidity and strength properties than granules produced by conventional fluidization granulation. The applicability of the process is not limited by the physical characteristics of the materials to be processed (eg low melting point or decomposition temperature).

The process is applicable to a variety of chemical and allied industries for the production of intermediate and end products. 55 for example, in the pharmaceutical industry for the extraction and for the preparation of a gtanulate containing the active ingredient and excipient for tableting; in the herbicidal formulation, the active ingredient is granular or preparing a granular end product comprising the active ingredient and a carrier; and in other areas of the organic chemical industry, eg. recovering various enzymes in granular form from fermentation broths; in the fertilizer industry, one or more. for the production of multi-component granular fertilizers; 65 for recovering various inorganic salts in the inorganic chemical industry; in many areas of the silicate industry, e.g. the news

-4185 004 Materials and materials for broadcasting ceramics recovering mixtures of feedstock from suspension, etc.; and various food preparations (e.g. instant cocoa granules). The list is, of course, not exhaustive. 5

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to some exemplary embodiments of the apparatus, based on the accompanying drawings, and on practical examples illustrating the process. In the attached drawing, ₁ θ

Figure 1 illustrates a solution or solution for carrying out the process according to the invention. an exemplary flowchart of the equipment and server units for suspensions,

Figure 2 _1g fluidi- ionization cell and associated résképzőszerv of an exemplary schematic sectional view of the

Figure 3 is a sectional view of another exemplary embodiment of a slot forming member,

Fig. 4 is a sectional view taken along line IV-IV in Fig. 3;

Figure 5 is a cross-sectional view of the apparatus of Figure 3 with a square cross-sectional view taken along line IV-IV of Figure 3,

Fig. 6 is a sectional view taken along the plane VI-VT of Fig. 2, with a further plate mixer 25 of the apparatus of Fig. 2;

Figure 7 also supplemented lapkeverővei ^3!, .L.

Figure 9 is a sectional view taken along line IV-IV of the exemplary apparatus of Figure 9;

Fig. 8 is a schematic sectional view of a fluidization cell according to the invention suitable for granulating powders and powder mixtures, and the associated slit-forming organ,

Fig. 9 is a sectional diagram of another exemplary embodiment of a slot forming member. 35

Solutions or solutions or to the dry matter content of the suspensions. obtaining the desired particle size distribution granules (granular material) under stationary conditions, for example, as shown in Figure 1, by the process of the invention. In the rolling fluidization cell 1, a fluidized layer 3 of the particulate material is disposed above the bed support and air distribution plate 2. The chemical composition of the granules in the layer is the same as the dissolved or solubilized solution in the liquid to be processed. chemical composition of the suspended material. In the lower zone of the fluidized layer 3 is located a slit forming device 4 formed of rollers 43 and driven by a variable speed electric motor 5. The air for the fluidization movement and the removal of the solvent (or suspending agent) is sucked in by a fan 50 through an air filter 6 and fed through a heat exchanger 9 into the fluidization device. The air flow rate is controlled by 8 sliders. The hot air flows through the washer 2 to form the fluidized layer 3. The air exiting the fluidized bed 3 enters the conical air space 10 of the fluidization device, where its linear flow velocity is reduced and then exits the fluidization device through an outlet 11. Dusting of the air is done by 12 cyclones. The separated powder is continuously fed back into the fluidization wage 60 with a 13-cell dispenser. Air re-dusting can be done with a continuous 14 wet dust remover, as required by environmental regulations. The liquid required for post-dusting is the solution or solution to be treated. a portion of the slurry delivered by pump 18 to valve 14 through wet valve 65. The concentration of the liquid used for dust removal is increased by evaporation of the solids separated and dissolved from the air and the solvent (or suspending agent). The fluid exiting the wet dust remover 14 is returned by a pump 19 to a fluid reservoir with a stirrer. Purified air can be discharged from the wet dust extractor 14 to the outside via a fan 15 (controlled by a slider 16). The solution was dripped. the suspension is conveyed from the fluid reservoir 21 via a valve 23 to a pump nozzle 24. The liquid spray exiting the nebulizer 24 reaches the surface of the particles on the surface of the fluidized layer 3. Under the influence of warm air, the solvent or solvent is removed. the suspending agent evaporates and the dry matter content of the spray liquid is based on the particles. The particle size increase processes (surface layering, agglomeration) in the fluidized bed can be compensated for by the slit forming member 4 so that the product particle size distribution meets the quality requirements. The product is withdrawn with a variable speed electric motor 26 driven by a screw feeder 25 into a solid storage container 27.

An exemplary fluidization apparatus for carrying out the process of the present invention comprises a vertically located cylindrical fluidization cell (1). A circular cross-sectional layer and air distribution washer 2 are connected to the lower part of the cell 1. The crankshaft 41 driving the slit-forming member 4 is positioned vertically in the center line of the cylindrical fluidization cell 1. The crankshaft 41 is lower or upper driven. The gear should go that way! configured so that the rotation of the crankshaft 41 is variable. The slit forming means 4 is intended to comminute, in particular, larger particles in the lower zone of the fluidized bed 3 and is therefore preferably located directly above the bed support and air distribution pad 2. The slot forming member 4 comprises one or more rollers 43, as appropriate for the task. However, it is preferable to have at least two rollers 43 use the rollers 43 in pairs. The rollers 43 of the pair of rollers are disposed symmetrically at the ends of properly formed drive arms 42. This arrangement provides symmetrical loading of the 41 crankshafts. It is noted that more than one odd number of rollers 43 can be formed into a gap forming member 4 which symmetrically loads the crankshaft 41. The rollers 43 at the ends of the drive arms 42 are exemplary! In the embodiment of the embodiment, the fluidization cell 1 is freely mounted with a slit aperture S on the inner surface of the cylindrical shell of the fluidization cell, preferably with a notched groove 46. The adjustability of the slit opening S is provided by slit adjusting means 45, which are preferably such that the slit opening S can be resiliently varied about the set value depending on the size and strength of the particles formed in the fluidized layer 3, thereby preventing any deformation or deformation of the roller member 43. break.

During operation of the exemplary apparatus described above, the rollers 43 rotate in a circumferential distance S from the crushing surface 46 as a result of rotation of the crankshaft 41. The shear is subjected to mechanical stress due to the shear and compression forces exerted between the preferably notched surface of the rollers 43 and the also notched shredding surface 46, while the rollers 43 have their axes 44

They can turn freely around -5185 004. The degree of comminution, through which the desired stationary grain size distribution, is determined by the number and size of the rollers 43, the size of the slot aperture S and the crankshaft 41 can be adjusted or adjusted. It can be changed. The slit opening S also determines the maximum particle size in the product. Administration or administration of the liquid (solution or suspension) it is evenly distributed on the surface (or interior) of the fluidized bed by means of a nebulizer 24, and the product can be removed by means of a mechanical dispenser and a 25-screw dispenser. The dispenser 25 is connected to the side wall of the cylindrical fluidization cell 1, preferably in the middle or lower zone of the fluidized layer 3.

The types of equipment suitable for carrying out the process according to the invention may vary depending on the location of the shredding surface 46. 2 and 6, the shredding surface 46 is located on the inner peripheral surface of the cylindrical fluidization cell 1. 3, 4 and 5, the crushing surface 46 is a specially shaped, coarse (notched) surface in the plane of the carrier and air distributor washer, but may also be the carrier and air distributor 2 itself (e.g. porous, metal surface with a rough surface). The larger particles formed in the fluidized layer 3 are mainly located in the lower zone of the layer 3, in the immediate vicinity of the washer 2, so that the shredding surface 46 located in the plane of the layer holding and air venting layer 2 provides effective comminution of large particles. The comminuting surface in the plane of the bed support and air distributor 2 underlays allows for a square or a square cross section of the fluidizing device. the use of rectifying fluidizers (Figure 5).

The drive levers 42 of the fluidization cell 1 of the apparatus illustrated in Figures 3, 4 and 5 for practicing the process of the present invention, preferably but not necessarily connected to the crankshaft 41 disposed vertically in the centerline, provide a further possibility of acting on the particles in for adjusting mechanical stress. The axes 44 of the rollers 43 are connected to the ends of the levers 42, but the levers 42, which are also horizontally disposed themselves, can serve as their own axes. Thus, the distance of the rollers 43 from the crankshaft 41, together with the travel speed (circumferential speed) of the rollers 43, can be varied at constant crankshaft revolutions, and several rollers 43 of the same or different size can be simultaneously operated. a pair of rollers can also be fitted. The size of the crushing surface 46 in the plane of the bed support and air distributor washer 2 and the gap S between the rollers 43 can be adjusted to the desired value by means of a rigid or flexible (e.g. telescopic) connection. The particle size distribution can be controlled by varying the slot aperture S, the crankshaft speed 41, the size of the crushing surface 46 (the size and number of rollers). The liquid can be introduced and evenly distributed by means of the atomizer 24 and the product can be removed by means of a mechanical (e.g. screw) dispenser 25.

3, 4 and 5, the slit forming member 4 is located in the lower zone of the fluidized bed 3 and thus serves to comminute larger particles therein. The lower layer 3 fluidized ^zónája-: Ban comminution efficiency of the particles in W növelhet- 'Si Juk by being placed in a mixing element above the support layer and directly levegőéiosztó plate 2 | g and is connected to the crankshaft 41, which facilitates the transfer of large particles of less intense fluidization motion at the bottom of the layer 3 between the rollers 43 and the comminuting surface 46. Such solutions are illustrated in Figures 6 and 7. In the figures, the designation (numbering) of the known structural elements of θ is identical to the designation of the same structural elements of the equipment illustrated in Figures 3, 4 and 5.

In Figure 6, the shredding surface 46 is located on the inner wall surface of the cylindrical fluidization cell 1. Buckled 47 sheets ₁ g mixer - located just above the layer support and air distribution pad and attached with a detachable joint. ' resides on the crankshaft 41 for variable speed rotary movement - larger particles at the bottom of layer 3 are centered vertically on fluidization cell 1

2q to the wall surface (the shredding surface 46). This ensures that the bottom of the layer 3 is ophthalmic! The discs are placed in front of the comminution rollers 43, but at the same time prevent the formation of fluidization disorders 9 (stator, channelization) in the lower zone of the fluidized layer.

In Figure 7, the shredding surface 46 is located at the level of the bed support and air distributor washer. The role of the backward-curved j 13 mixer in this case, too, is to place the ί grains in the path of the rollers 43 on the comminuting surface 46.

3Q relay, respectively. prevents fluidization disorders.

Granulation of powders or powder blends to a narrow-grain product can be accomplished by the process of the invention, for example in batch mode as shown in FIG. In the cylindrical fluidization cell 1, the fluidized layer 3 of the powder to be granulated is located above the bed support and air distribution pad 2. In the lower zone of the fluidized layer 3 is located a slit forming member 4 formed of rollers 43, driven by a variable speed electric motor through the crankshaft 41. The size of the gap opening S, which is the distance between the roller 43 and the crushing surface 46, is adjusted to the desired value by means of the gap adjustment mechanism 45 located on the guide arms 42. The powder to be granulated is kept fluidized with warm gas, preferably air. The slit-forming member 4 is actuated at the correct speed, and the nebulizer-containing fluid (so-called granulating fluid) is sprayed onto the surface of the fluidized bed by means of the atomizer 24. At this point, 50 agglomerations of dust particles begin to form. granulation formation. The volume flow rate of the hot gas for fluidizing movement and drying of the agglomerates is increased in accordance with the rate of increase in particle size. Granules larger than the slit aperture S, respectively. a part of the granules which limit the size of the slot aperture S are continuously milled to the desired extent while the rollers are rotated about their own vertical axis 44. The mechanical stress of the crusher is due to the shear and compression forces exerted on the granules between the coarse, preferably notched 50 ridge 50 and the also notched crushing surface 46. The degree of comminution, thereby the desired particle size distribution by the number and size of the rollers, the size of the gap opening S and the crankshaft 41 can be adjusted or adjusted. It can be changed.

185 004 \

In addition to the partial grinding, the rollers exert a compacting effect on the particles. As a result, the resulting granules will have a lower porosity and higher bulk density than conventional fluidization granulation. As the granulation progresses, the amount of particles below the lower limit is gradually reduced to a minimum. if necessary, it is completely consumed, while the granules above the upper size limit are rolled to the desired extent by the rollers. This results in a granule with a relatively narrow particle size, dust free, and favorable physical properties.

The exemplary apparatus shown in FIG. it is intended to illustrate a slot 4 formed by rollers 43 and backscatter plate blades 47 disposed on horizontal axes 44. Such a configuration of the slot forming member 4 provides an additional possibility to change (control) the mechanical stress on the particles in the fluidized layer 3. The drive levers 42 connected to the crankshaft 41 themselves serve as the axis of the rollers 43. Thus, the distance of the rollers 43 from the crankshaft 41, together with the travel speed (circumferential speed) of the rollers 43, can be varied at constant crankshaft revolutions. a pair of rollers can also be fitted. The size of the chopping surface 46 in the plane of the bed support and air distributor washer 2 and the gap S between the rollers 43 can be adjusted to the desired value by means of a rigid or flexible (e.g. telescopic) connection. The particle size can be controlled by varying the slit aperture S, the crankshaft revolution, and the size and number of rollers. In the arrangement shown in Fig. 7, the backward-curved blender 47 deflects particles larger than the upper limit of the upper size range likely to occur in the lower zone of the fluidized layer 3 into the path of the rollers 43 to the shredding surface 46. prevents fluidization disorders. In the fluidization cell 1, which may be cylindrical or flattened (e.g., square in cross-section), the fluidized layer 3 is located above the washer 2 into which the powder or powder mixture to be granulated is mechanically fed, e.g. Feed with a 28-screw dispenser. The granulating fluid is atomized by means of an atomiser 24 onto the surface of the hot gas fluidized bed. The granulated product is withdrawn by a mechanical feeder, preferably a 25 screw feeder.

Some exemplary embodiments of the process of the invention are described below:

Example 1

Granular sodium chloride is prepared from 250 g / l aqueous solution as follows. The fluidization apparatus (0.3 m internal diameter of the cylindrical cell) is charged with 15 kg of particulate sodium chloride (about 0.6-0.8 mm in particle size) and fluidized with a volume of 100 Nm ³ / h at 120 ° C. The speed of the slot forming member having the given dimensions and slot S is set to 18 rpm. The slit forming member is configured and positioned as shown in Figures 3 and 4. Thereafter, spraying of the sodium chloride solution is started at a rate of 5 L / h and the solids are removed from the fluidized bed at a flow rate of 1.25 kg / h. continuous recirculation of solids (typically less than 0.3 mm) separated from the air. From the start of the spraying to the stationary state, which is approx. the average residence time of the solid (12 hours) is gradually increased to 180 Nm ³ / h for the fluidization movement and the evaporation air at constant air temperature (120 ° C).

The moisture content of the particulate sodium chloride discharged in the steady state is below 0.2 s% and the particle size distribution, as determined by sieving, is as follows:

0.2-0.4 mm 9.0 s%

0.4-0.6mm 23.1s%

0.6-0.8mm 28.1s%

0.8-1mm 32.1s%

1.0-1.6 mm 7.7 s%

After prolonged stationary operation, the rpm was increased to 30 rpm. The formation of the new stationary state is similar to the previous one. It took 10 hours. During this time, the air flow rate was reduced from 180 Nm ³ / h to 140 Nm ³ / h. The moisture content of the granular material discharged in a stationary state remained below 0.2 s% and the particle size decreased:

0.1-0.2 mm 2.9 s% 0.2-0.4 mm 32.0 s% 0.4-0.6 mm 34.2 s% 0.6-0.8 mm 20.2s% 0.8-1 mm 8.1% 1 -1.6 mm 2.6 s% Example 2

Granular urea is prepared from an aqueous solution of 450 g / l as follows. The fluidization apparatus ⁴⁰ (inside diameter of the cylindrical cell is 0.3 m) is charged with 9 kg of granular urea (about 0.6-0.8 mm in particle size) and 80 µm. ^{It is} fluidized with air at 100 ° C at a flow rate of ³ / h. ⁵ the number of revolutions résképzőszerv slot opening sizes in the respective adjusted value of 12 rev / min. The slot forming and positioning is identical to that shown in Figure 2. Thereafter, the urea solution is sprayed at a rate of 3 L / h, the solid is removed from the fluidized bed at a flow rate of 1.35 kg / h, and the solids separated from the air are continuously recirculated. From the start of spraying to the stationary state - which takes approx. Duration corresponding to the average residence time of the solids (6, 7 hours) - the volume flow rate of the fluid providing the fluidization movement and evaporation of the solvent is gradually 160 Nm ³ / h

value at constant air temperature (100 ° C). The moisture content of the granular urea discharged in the stationary state is 0.5% by weight, and its distribution is as follows: 0.4-0.6 mm 13s% 0.6-0.8 mm 1.7 s% 0.8-1 mm 16,6s% 1 -1.6 mm 78.9% 1.6-2.5 mm 13s%

185,004

After prolonged stationary operation, the rpm was increased to 30 rpm. The development of the new stationary state is approx. It took 6 hours. During this time, the air flow rate was reduced from 160 Nm ³ / h to 120 Nm ³ / h. The moisture content of the granular urea discharged in the stationary state remained below 1 s% and the particle size decreased:

0.2-0.4mm 0.4-0.6mm 0.6-0.8mm 0.8-1mm 1-1.6mm

2.1 s%

23.3 s% 29.5 s% 38.7 s% 6.4 s%

Example 3

Granulated beet sugar is prepared from a 700 g / l aqueous solution as follows. 12 kg of granular (about 0.6-0.8 mm) beet sugar was charged into the fluidization apparatus (inside diameter 0.3 m) and kept fluidized with 100 g air at a flow rate of 130Nm ³ / h. The slit-forming member or the aperture having the aperture of a given size is provided. adjust the speed of the insert mixer to 47 rpm. The slit-forming device and the backward-curved insert mixer design, respectively. positioning is the same as that shown in Figures 2 and 6. Subsequently, the beet sugar solution is sprayed at a rate of 3.5 l / h, and the solids are removed from the fluidized bed at a flow rate of 2.45 kg / h. continuous recirculation of the solids separated from the air. From the start of spraying to the stationary state - which takes approx. time corresponding to the average residence time of the solid (4.9 hours) - gradually increasing the volume of air to provide fluidization movement and evaporation of the solvent to 200 Nm ³ / h at constant air temperature (100 ° C). The moisture content of the granulated beet sugar discharged in the stationary state is less than 0.2 s% and the particle size distribution is as follows:

Tetramisol HCl. . . . 12s% 0.2-0.4 mm 0.8 s% Starch .... .. 10s% 0.4-0.6 mm 7.4 s% Lactose....... .. 33 s% 0.6-0.8 mm 16.7 s% Sucrose ...... ..45 s% 0.8-1 mm 35.5s% 45 1.0-1.6 mm 39.6 s% The batch mode h of FIG

After prolonged stationary operation, the slot speed was reduced to 30 rpm. The development of the new stationary state is approx. It took 5 hours. Meanwhile, the air flow was gradually raised to 300 Nm ³ / h to 200 Nm ³ jh value. The moisture content of the particulate material discharged in the steady state was reduced to less than 0.1 s% and the particle size increased:

0.4-0.6 mm 0.6-0.8 mm 0.8-1 mm 1 -1.6 mm 1.6-2.5 mm

0.8 s% 3.0 s%

18.5 s%

58.5s% 19.2s%

Example 4

The preparation of particulate iron (III) oxide from an 830 g / l aqueous suspension containing 4 g / l of the organic component in dissolved state is carried out as follows. The fluidization apparatus (0.3 m internal diameter of the cylindrical cell) is charged with 25 kg of particulate iron (III) oxide (approximately 0.4-0.6 mm particle size) and air at a flow rate of 200 Nm ³ / h at 130 ° C. kept fluidized. A slit-forming member having a gap opening of a given size, or adjust the blade speed to 20 rpm. The gap-forming organ or the backward-curved plate mixer is configured and positioned as shown in Figures 3 and 7. Thereafter, the slurry is sprayed at a rate of 10 L / h and the solids are removed from the fluidized bed at a flow rate of 8.34 kg / h. continuous recirculation of the solids separated from the air. From the start of spraying to the stationary state - which takes approx. It takes 3 hours to gradually increase the mass flow rate of air to provide fluidization movement and evaporation of the suspending agent to 300 Nm ³ / h. The moisture content of the particulate material discharged in a stationary state is below 0.5 s% and the particle size distribution is as follows:

Below 0.2 mm 0.2-0.4 mm 0.4-0.6 mm 0.6-0.8 mm 0.8-1 mm

10.9s%

26.5s%

38.9 s%

20.6s% 3.1s%

Example 5

The veterinary medicinal product was granulated in powder form (less than 10 ⁴ m in particle size) and the composition of the granulated final product was as follows:

7 kg of powder mixture was charged into a conditioning device (0.3 m internal diameter of the cylindrical cell). The composition of the powder mixture was as follows:

Tetramisol HCl .... 16.8 s%

Starch ...... 14.0%

Lactose ......... 46.2%

Sucrose ........ 23.0%

The powder mixture was maintained fluidized with air at a flow rate of 40 Nm ³ / h at 60 ° C. The crankshaft rotation speed of the slot forming member having the given dimensions and aperture was set to 70 rpm. The spraying of the granulating liquid was then started at 5.98 · 10 ^-3 m ³ / h. flow rate. The granulating liquid (binder solution) was an aqueous solution of sucrose at 600 kg / m ³ . As a result of the spraying of the binder solution, the agglomeration of the granules started to increase and the particle size increased. Therefore, the fluidized state

185 004 nι milling with slit charger ank. he cried his ale. In order to maintain the fall of the icing roller, it was necessary to introduce more and more airflow. The air volumes were gradually increased to 160 Nm ³ / h until the granulation was completed, with constant air temperature. The granulation time was 0.78 h, during which time 4.67 · 1 CT of ³ m ^{3 of} granulating liquid (containing 2.8 kg of sucrose) was injected to form the final composition of the product. The granulate was then dried for 0.2 h to achieve the desired moisture content (1% by weight). The particle size distribution of the granulated products was determined by sieve analysis.

For the sake of comparison, granulation was performed under the same conditions

(a) in a conventional manner without the use of a mechanical stirrer and slit-forming device, ₁ θ

(b) mechanical stirring, using a back-blade blade (0.29 m in diameter) at 45 rpm,

(c) using a gap-forming device and a mechanical stirrer, the design of which is identical to that shown in Figure 7 at 45 rpm,

d) using a gap forming device having the design shown in Figure 8 and 45 rpm,

e) using a gap forming device having the design shown in FIG. 8 and a rotation speed of 70 rpm. 25

The particle size distribution and / or distribution of the granulated product. the% product fractions are given in Table 1 and compared.

Example 6

Granulation of a powder mixture of sodium chloride and eight different spices (4 · 1CT less than ⁴ m) in a batch fluidized bed granulator (0.3 m internal diameter of the cylindrical cell). The device was charged with 11 kg of powder mixture. The composition of the powder mixture was as follows:

sodium chloride ........ 70% by weight of spices total ...... 30% by weight of spices: a5je teI. spreadsheet

Particle size (Mm) quantity (Wt%) the b c d e Below 0.25 17.3 1.6 3 1.7 4.5 0.25-0.4 15.9 38.5 15 27.9 39.8 0.4-0.63 27.4 26.4 46.9 48 42.4 0.63 to 1 22.5 17.5 24.4 16.5 10.5 1 to 1.6 6.4 13.7 10.7 5.9 2.8 Above 1.6 10.5 2.3 - - - "Product fraction" 0.25 to 0.63 43.3 54.9 61.9 75.9 82.2 "Product fraction" 0.25-1 65.8 72.4 86.3 92.4 92.7

os e; e • e.

through: k i u ta, it

It can be seen from Table 1 that when using a slit-forming device, a product with a narrow grain fraction can be produced, but the amount of particles above a given size, in this case above 1 µm, can be minimized. Other physical properties of the granulate are also favorably influenced by the use of a slot forming means.

As a result of the roller compaction effect of the rollers, the porosity of the granules is on average approx. halves, and its bulk density is approx. It is increased by 20% compared to the granules produced in the conventional moiety (see (a) and (b)). The mechanical strength and the fluidity of the granulate are also significantly improved.

The powder mixture was maintained fluidized with air at a flow rate of 110 Nm ³ / h at 60 ° C. The crankshaft rotation speed of the slot forming member having the given dimensions and aperture was set to 45 rpm. Spraying of the granulating liquid (binder solution) was then started with a flow rate of 3 · 1 CF ³ m ³ / h. The granulating liquid was an aqueous solution of gelatin at 50 kg / m ³ thermostated at 60 ° C. In accordance with the rate of particle size increase due to the spraying of the binder solution, the flow rate of the fluid providing the fluidization movement was gradually increased to 230 Nn / h at constant air temperature until the granulation was completed. The granulation duration was 1.1 h, the amount of liquid sprayed was 3.3 · 1 CT ³ m ³ and the amount of gelatin injected with the liquid was 0.165 kg. The resulting granules did not require further drying and had a moisture content below the prescribed 2% by weight. The dry matter composition of the product granulate was as follows:

sodium chloride ........ 69.0 s% total spices ...... 29.5 s% gelatin ............. 1.5 s%

The particle size distribution of the granulated products was determined by sieve analysis.

For the sake of comparison, granulation was performed under the same conditions

(a) conventionally without mechanical mixing and without the use of a gap-forming device,

(b) mechanical stirring, using a back-blade blade (0.29 m in diameter) at 45 rpm,

(c) using a gap-forming device and a mechanical stirrer having the same design as that shown in Figure 7 at a speed of 45 rpm,

d) using a gap forming device having the design shown in FIG. 8 and 45 rpm. The particle size distribution and / or distribution of the granulated product. the percentage of 'product fractions' is given in Annex II. and are compared.

Claims (15)

Patent claims A process for obtaining continuously or semi-continuously the solids content of solutions and / or suspensions in the form of granules having a desired particle size distribution, wherein the solution and / or suspension to be processed is fluidized with warm gas consisting of its own granules, particularly hot air. is sprayed onto the surface and / or interior of the layer of the fluidized state, and the mass flow particulate material corresponding to the dry matter content of the fluidized fluid is continuously or semi-continuously discharged from the fluidized layer. introducing and growing the floating material particles under continuous mechanical compression of the at least one slit having an adjustable opening in the fluidized bed itself. (Priority: 05.03.1979) A fluidizing process for producing a predetermined fine grain fraction granulate from powders or powder blends, in a batch or continuous mode, by spraying a binder-containing liquid into a layer of the powder or powder blend maintained in a fluidized state with warm gas, preferably hot air, formed or produced there. subjecting the growing granules (granules) to a continuous mechanical force exerted on at least one of the slots in the fluidized bed itself, having a controlled opening, at least one slot having a controlled opening, (Partially: 29.05.1980). 3. A method according to claim 1 or 2, characterized in that the forced particles of material floating in the fluidized bed are forced through the gap (s) by creating and maintaining a relative displacement between the latter and the material particles. (Priority: 05.03.1979) 4. The process of claim 3, wherein the process is formed in a fluidized bed 185 004 ₂ floating material particles in a fluidized bed are forced through a continuously variable spatial gap (s) XW · (Priority 05.03.1979). ". 5. The method of implementing claim 4, Characterized in that the spatial position of the slot (s) in the fluidized bed is periodically varied. (Priority: March 5, 1979) 6. A method according to any one of claims 1 to 6, characterized in that the material particles 10 are forced through a gap (s) in the fluidized bed having a variable degree of aperture with respect to the nominal size of the pre-selected orifice. (Priority: March 5, 1979) 7. Apparatus according to claims 1-6. A method according to any one of claims 1 to 14, comprising a fluidization cell, at least one liquid atomiser, at least one solids dispenser and a particle removal unit, characterized in that at least one gap forming member (4) is arranged inside the fluidizing cell (1) in the region of the fluidized layer (3). it is. (Priority: March 5, 1979) An embodiment of the apparatus according to claim 7, characterized in that the slit forming means (4) has at least one axis (44) of a rotary surface (46) and an adjustable slit opening (S) which can be varied relative to the latter. consists of a roller (43). (Priority: March 3, 1979) An embodiment of the apparatus according to claim 8, characterized in that the slit-forming means (4) preferably At least two rollers (43) embedded at each end of a transverse drive shaft (42) on a lower driven, preferably vertical driven crankshaft (41), to change the slot opening (S) of the rollers (43) with a shredding surface (46). at least one slot 35 adjusting device (45). (Priority: March 3, 1979) The apparatus of claim 9, characterized in that at least in the region of the fluidized layer (3) has a fluidizing cell (1) having a cylindrical jacket with an axis parallel to the main axis (41), the crushing surface (46) being the cell (1). is formed on its inner cylindrical surface, and the rollers (43) are formed with a slit opening (S) with the shredding surface (46), at the ends of the driving arms (42) with respective slit adjusting means (45) parallel to the components of the shredding surface (46). Around 45 are freely mounted bearings. (Priority: March 5, 1979) 11. An embodiment of the apparatus of claim 9, wherein the shredding surface (46) is a fluidized bed support arranged in the lower portion of the fluidization cell (1). 50 and is formed on an air distributor washer (2), and the rollers (43) form a gap opening (S) with this crushing surface (46) at the ends of the driving arms (42) connected to the crankshaft (41) by means of a gap adjusting device (45). preferably bearings are freely mounted around horizontal ten55 bushes (44). (Priority: March 3, 1979) An embodiment of the apparatus according to any one of claims 8-11, characterized in that rollers (43) with a displacement shaft (44) are displaced by a force of a certain threshold relative to the chopping surface (46) for temporary expansion of the gap opening (S). (Priority: March 5, 1979) 13. The apparatus of claim 12, wherein for a given slit aperture (S) 65, the surfaces of the shredding surface (46) and the rollers (43) -10185 004 has a slit adjusting device (s) (45), preferably having a spring-loaded telescopic member, which permits flexible changes in the slot opening (S). (Priority: 03/05/1979) 14. A 8-13. An embodiment of the payroll according to any one of claims 1 to 3, characterized in that the chopping surface (46) and / or the surface (s) of the roller (s) (43) are roughened, preferably notched. (Priority: 03/05/1979) 15. A 9-14. An embodiment of the apparatus according to any one of claims 1 to 3, characterized in that it also preferably has a plate mixer (13) mounted on the crankshaft (41) in the region of the fluidized layer (3). (Priority: 05.03.1979)