DE10146778A1 - Production of compact solid particles, e.g. granules, in continuously operating fluidized layer, involves using fluidized layer, feeding raw material to part of layer, and feeding material produced into fluidized layer - Google Patents

Abstract

Production of compact solid particles involves using a fluidized layer having a region with a higher flow speed of the air stream impinged by the material to be treated; feeding raw material into the region, and then into the fluidized layer; and feeding a part of the material of the fluidized layer back into the region, so that a particle circulation occurs between the fluidized layer and the region. Production of compact solid particles, e.g. granules, in a continuously operating fluidized layer involves using a fluidized layer (9) having a region (16) with a higher flow speed of the air stream impinged by the material to be treated; feeding raw material (2) into the region; feeding the material from the region into the fluidized layer; and feeding a part of the material of the fluidized layer back into the region, so that a particle circulation occurs between the fluidized layer and the region. An Independent claim is also included for a fluidized layer system for producing compact solid particles. Preferred Features: Material deposited in a deposition chamber (IV) is fed to the region. Granulation seeds (3) are fed to the region. The material is introduced into the region from below and in the flow direction of the air.

Description

The invention relates to a method and the associated Fluid bed system for the production of compact solid particles according to the features mentioned in the preamble of claims 1 and 5.

Fluid bed systems for the treatment of different Materials are well known. For example, according to the DD 119 304 known, liquids by means of nozzles on a To spray fluidized bed. The fluidized bed system is there from an apertured vertebral floor, the one from below Drying and fluidizing air is supplied.

There are different versions of both Design of the fluidized bed system and the feed of the Injection material known. The fluidized bed system can both round and rectangular as a swirl gutter or as Fluid bed apparatus be formed. The spraying of the in the Fluidized bed of existing material with appropriate materials can be from the top of the fluidized bed (top spray) or from below into the fluidized bed (bottom spray) or from the side respectively. The spray liquid can be used as a solution, suspension, Emulsion, melt or as any other pumpable and atomizable Liquid system available.

A fluidized bed apparatus is known from DE 197 00 029 A1, in which the regulation of the material properties of the final product by means of internals arranged above the inflow floor. By the installation of specially designed weirs takes place Influencing the material cycle in the fluidized bed and thus influencing the material properties of the materials to be manufactured. This is an agglomeration of the individual material particles desired.

EP 0 163 836 B1 describes a process for the production of Granules known in which the germs pass through the fluidized bed internal products are generated. By integrating Dust separators in the fluidized bed apparatus become dusts and fine particles in the fluidized area of the fluidized bed recycled. These materials form corresponding ones in the fluidized bed Agglomerates.

In the systems described, there are mainly deliberate ones Agglomerates. The agglomerates have a rough surface structure and the roundness of the individual particles is not full pronounced. In the manufacture of solid product forms, it is in many use cases necessary, precisely defined To produce particle structures. For many applications it turns out Granules as advantageous, which by granulation in the Fluid bed can be produced. With these granules is particularly on a compact structure with very good roundness and smooth particle surface.

In order to create these special material characteristics, the use is of risers in batch apparatus for coating for example tablets according to US 3,089,824, US 3,241,520 and US 3,253,944. One is known from US 3,241,520 Series connection of many individual devices known, at which is the exit material of the previous stage Entry material to the next stage is. The coating process described is broken down into individual devices here. The facility is very complex and has a complicated geometry.

The applicant has already made an older application for Coating of particles in a continuous Process control proposed according to DE application 101 30 334. there the coating material is continuously in at least two different areas applied to the fluidized bed.

The object of the invention is a method and Fluid bed system for the production of compact solid particles to be designed in such a way that a through Build-up granulation or coating (coating) produced end product with defined particle structures while avoiding Agglomeration effects arise.

According to the method according to the invention, the task with the features of claim 1 and the associated Device according to the features of claim 5 solved. Advantageous embodiments of the method and the device are shown in specified in the subclaims.

By applying the material to be treated in one Area with a higher flow velocity and in Connection with a particle circulation between this area and the fluidized bed becomes an agglomeration of the material avoided. Through the particle circulation and through the structure an expanding area due to the higher Flow velocities arise under defined particle structures Avoiding agglomeration effects.

By arranging built-in parts in the process space of the Fluid bed system above the nozzles of the spray system becomes one Uniformization of the granulation achieved. This is supported on the one hand by arranging the built-in parts at a distance above the fluidized bed and on the other hand through the larger one Opening ratio of the gas passage openings of the Fluidized bed bottom below the built-in parts compared to the rest Gas passage openings of the fluidized bed. In the upwards Directed air flows in the built-in parts become too Granulating or to be coated particles largely in the Airflow dispersed, so that they as single particles with Liquid can be sprayed. The liquid evaporates the granules grow or form one closed covering made of coating material around the particles. It arises with an end product while avoiding agglomeration effects a defined particle structure. By arranging several, Installation parts arranged along the length of the fluidized bed the grain size of the material to be produced is influenced.

By adjusting the distance between the lower edge of the built-in parts of the fluidized bed, the opening ratio of the Gas passage openings arranged under the built-in parts Fluidized bed bottom and the height and diameter or Width of the built-in parts depending on those to be manufactured Solid particles become the material formation in the fluidized bed and influenced in the built-in parts so that unwanted Agglomeration effects are largely avoided and the Products to be manufactured exactly according to the requirements have a defined particle structure.

The invention is illustrated by means of exemplary embodiments explained. In the accompanying drawings:

Fig. 1 is a schematic sectional view of the fluidized bed system of the invention in rectangular design,

Fig. 2 is a schematic sectional view of the fluidized bed system according to the invention, round type,

Fig. 3 shows a variant of FIG. 1,

Fig. 4 shows a cross section according to Fig. 1 with approximately executed mounting parts,

Fig. 5 shows a cross section according to Fig. 1 with rectangular executed mounting parts,

Fig. 6 shows a further variant of FIG. 1.

The products are produced in granular form by fluidized bed granulation (build-up granulation, layering) in a substantially horizontally oriented fluidized bed 9 . The fluidized bed system for the production of compact solid particles consists of a fluidized bed 8 provided with gas passage openings, to which a spray system 13 with corresponding nozzles is assigned via a supply air chamber 7 . In process space II of the fluidized bed system, built-in parts 10 for delimiting the spraying area are arranged above the area of the nozzles of the spray system 13 , the respective lower edge of which is spaced from the surface of the fluidized bed base 8 and the respective upper edge of which ends at a distance above the surface of the fluidized bed 9 , or extends into relaxation room III of the fluidized bed system. The distance between the lower edge of the mounting parts 10 of the fluidised bed 8, the aperture ratio of the gas passage openings of the arranged below the mounting parts 10 fluidized bed bottom 8 and the height and the diameter or the width of the mounting parts 10 can be variably adjusted as a function of the produced solid particles. According to the technical circumstances, it is possible to arrange the built-in parts 10 at a predetermined angle with respect to the vertical.

The fluidized bed 8 located below the built-in parts 10 is provided with gas passage openings, the opening ratio of which is greater than in the rest of the area of the fluidized bed 8 . The built-in parts 10 have a round, rectangular, square or polygonal cross section in accordance with the conditions prevailing in the fluidized bed 9 .

In the continuous coating of powdery to fine-grained solid particles, separating plates 24 are arranged on the ceiling of the fluidized bed system, which protrude in the relaxation space III of the fluidized bed system in the area between two built-in parts 10 and end above the built-in parts 10 .

The mode of operation of the fluidized bed system according to the invention is as follows:
To produce compact solid particles in granulate form by means of fluidized bed granulation, a liquid raw material 2 is introduced into the fluidized bed 9 via the nozzles of the spray system 13 . The particles contained in process chamber II are whirled up by an upward air stream 1 . This flow not only serves to form the fluidized bed 9 itself, but at the same time it forms the drying or cooling agent, depending on whether the drying of a liquid which is present as a solution, suspension or emulsion, or a crystallization or the like is to be brought about which the liquid raw material is in the form of a melt or the like. The supplied air flow passes through a supply air housing I into the fluidized bed system. The supply air housing I is divided into several supply air chambers 7 in order to be able to set a directed flow or different air volumes. The delimitation of the supply air housing I from the process space II is formed by the fluidized bed 8 , which serves to even out the air flow over the cross section of the apparatus and to prevent the fluidized bed mass from falling into the supply air housing I. In the case of a build-up granulation by thermal drying in the fluidized bed 9 , the liquid raw material 2 is sprayed onto the particles contained in the fluidized bed 9 . The liquid evaporates on the surface thereof and the solid of the injected raw material 2 adheres to the particles, which leads to an almost shell-like grain growth.

The evaporated liquid is discharged with the now cooled fluidizing agent from the process room II via the expansion room III and the separating room IV from the fluidized bed system as exhaust air 5 . Since the intensive mixing and particle movement in the area of the fluidized bed 9 leads to the formation of abrasion and thus the formation of fine dust, dedusting of the exhaust air stream is necessary, which can take place both externally outside the actual fluidized bed system and in a separation space IV integrated within the fluidized bed system. Combinations of both variants are also conceivable, in which a pre-separation takes place in the fluidized bed system and a fine material separation takes place downstream of the fluidized bed system.

In Fig. 1, an internal filter 11 is indicated, which is cleaned by a cleaning mechanism 12 , for example by compressed air 4 if necessary or time-controlled. The dust separated in the process falls back into the fluidized bed 9 , where it is used as granulation nuclei, to which the liquid raw material 2 is sprayed. Alternatively or in parallel, granulation nuclei 3 can be supplied from the outside. These can be obtained by grinding a partial stream of the finished product 6 or by oversize separation.

Furthermore, the contribution is simultaneous or alternative of foreign material from other processes is conceivable if For example, a starting grain can be coated with another component should. This process is called coating, coating or Encapsulation refers to and represents a special case of structural granulation represents.

If germs are introduced into the fluidized bed system from the outside, a pressure seal between the interior of the fluidized bed system and the environment is necessary in most applications. This takes place, for example, through a cellular wheel sluice 14 or through a double flap system. In other cases, the entry can also be made openly. The finished product 6 can be discharged in various ways. In the exemplary embodiment, the material is discharged via a speed-adjustable rotary valve 15 which, depending on the speed and chamber volume, draws a defined volume flow from the fluidized bed 9 and thereby guarantees the completion of the pressure. Further variants can represent the most varied weir internals at the end of the fluidized bed 9 . For example, it is very easy to keep the fluidized bed height constant using an overflow weir.

Within the fluidized bed system, the arrangement and design of internals in the form of internals 10 set optimal process conditions for the granulation. The built-in parts 10 influence the homogenization of the granulation. A nozzle is arranged under each installation part 10 , through which granulation or coating liquid is injected. The built-in parts 10 are at a distance from the fluidized bed 9 , so that the solid particles of the fluidized bed 9 are sucked in as a result of the higher flow velocity in the built-in parts 10 , guided upwards and sprayed by the spray liquid in the spraying area 16 . The particles to be granulated or coated are largely dispersed in the air flow in the upward air flows in the built-in parts 10 , so that they can be sprayed with liquid as individual particles. The liquid evaporates, the granules grow, or a closed coating of coating material forms around the particles.

The fluidized bed 8 has a higher opening ratio in the area under the built-in parts 10 than in the rest of the area. This results in higher flow velocities in the built-in parts 10 . This flow rate depends on the particle size and density.

In technically interesting fluidized bed systems of this type, usually several nozzles are installed side by side across the width of the fluidized bed 8 . The built-in parts 10 can then be designed as internals with a rectangular cross section and capture all nozzles which are arranged next to one another. Such an arrangement is shown in FIG .

After passing through the built-in parts 10 , the solid particles fall outside the built-in parts 10 in the area of the particle circulation 17 onto the fluidized bed 9 and are again caught by the upward gas flow of the built-in parts 10 . The process is repeated several times over the length of the fluidized bed 9 until the particles are sufficiently large or the coating layer is sufficiently thick.

The positively guided material flow serves to achieve evenly structured granules. Agglomeration between the particles is avoided, especially as long as they are fine-grained. In the case of coating, high quality standards are achieved. Closed coating surfaces or the application of a solid matrix to the particles are possible. In the case of coating, external dust filters are generally used. The little dust can be easily removed from the system and used for other purposes without reducing the product quality of the end product if it is returned to the fluidized bed 9 .

In Fig. 2 a fluidized bed system is shown in a round design. In this embodiment, the built-in part 10 is located centrally in the middle of the fluidized bed 8 . Given a corresponding size of the fluidized bed system, a plurality of built-in parts 10 are arranged uniformly distributed around the centrally arranged built-in part 10 on an outer circular ring. The center can also be left free, so that the built-in parts 10 are evenly distributed over the fluidized bed 8 .

In Fig. 3, a rectangular fluidized bed system for the continuous granulation of liquid containing solids, which is introduced via a spray system 13 , is shown. An installation part 10 is arranged at a certain distance above the fluidized bed 8 above each nozzle of the spray system 13 operating in bottom spray. The dust 19 returned from the cyclone separators 21 is introduced into the spraying area 16 under the built-in part 10 and serves as a seed material for the granulation to be carried out. The material supplied from the cyclone separators 21 is sucked in together with part of the material from the fluidized bed 9 by the gas flow in the built-in part 10 and dispersed in the gas flow and sprayed with liquid raw material 2 by the spray system 13 . The dust-containing exhaust air 18 again reaches the cyclone separators 21 and is dedusted there. The grown particles are discharged from the built-in part 10 with the air stream 1 and reach the fluidized bed 9 outside the built-in parts 10 again via the particle circulation 17 . When a corresponding particle size is reached, the material is discharged via the granulate discharge 20 . If the material particles have not yet reached the required size, they are again drawn in by the ruling in the fixture 10 gas flow and further pelletized in fitting 10th The material discharged via the granulate discharge 20 is classified in a zigzag sifter 22 known per se and operated with sifting air 23 . The finished product is discharged via the rotary valve 15 , while the dust-containing exhaust air 18 is fed to a cyclone separator 21 .

In FIG. 6, a fluidized bed system with a rectangular geometry is shown for the continuous coating of powdery to fine-grained solid particles. An integrated separator system for dust is avoided because the coating quality deteriorates. Dust is discharged from the fluidized bed system with the exhaust air 5 and separated outside. The special feature of this variant are the separating plates 24 between the coating areas. As a result, the exhaust air 18 is guided in a targeted manner and exits the system as exhaust air 5 . The separating plates 24 avoid gas movement and thus particle movement in the longitudinal direction of the fluidized bed 9 . The separating plates 24 extend down to the area of the upper edge of the built-in parts 10 and are formed over the entire width of the fluidized bed 9 .

In summary, the following can be stated:
The invention relates to a method and the associated fluidized bed system for the production of compact solid particles according to the features mentioned in the preamble of claims 1 and 5.

The object of the invention is a method and Fluid bed system for the production of compact solid particles to be designed in such a way that a through Build-up granulation or coating (coating) produced end product with defined particle structures while avoiding Agglomeration effects arise.

• - die Wirbelschicht wenigstens einen Bereich 16 mit einer höheren Strömungsgeschwindigkeit des mit dem zu behandelnden Material beaufschlagten Luftstroms 1 aufweist,
• - der Rohstoff 2 in den mit höherer Strömungsgeschwindigkeit betriebenen Bereich 16 zugeführt wird,
• - das Material aus dem Bereich 16 der Wirbelschicht (9) zugeführt wird,
• - dass ein Teil des Materials der Wirbelschicht 9 in den Bereich 16 wieder zugeführt wird, so dass zwischen der Wirbelschicht 9 und dem Bereich 16 eine Partikelzirkulation entsteht,

beziehungsweise dadurch, dass zur Vergleichmäßigung der Granulation und zur Erzeugung einer definierten Partikelstruktur der herzustellenden Feststoffpartikel im Prozessraum II der Wirbelschichtanlage über den Bereich der Düsen des Sprühsystems 13 Einbauten in Form von Einbauteilen 10 angeordnet sind, deren jeweilige untere Kante von der Oberfläche des Wirbelschichtbodens 8 beabstandet ist und deren jeweilige obere Kante in einem Abstand über der Oberfläche der Wirbelschicht 9 endet und das Öffnungsverhältnis der Gasdurchtrittsöffnungen des Wirbelschichtbodens 8 unterhalb der Einbauteile 10 größer ist als im übrigen Bereich des Wirbelschichtbodens 8. Aufstellung der verwendeten Bezugszeichen 1 Luftstrom
2 Rohstoff
3 Granulationskeime
4 Druckluft
5 Abluft
6 Fertigprodukt
7 Zuluftkammer
8 Wirbelschichtboden
9 Wirbelschicht
10 Einbauteil
11 Filter
12 Abreinigungsmechanismus
13 Sprühsystem
14 Zellenradschleuse
15 Zellenradschleuse
16 Bedüsungsbereich
17 Partikelzirkulation
18 Abluft
19 Staubrückführung
20 Granulataustrag
21 Zyklonabscheider
22 Zick-Zack-Sichter
23 Sichtluft
24 Trennblech
I Zuluftgehäuse
II Prozessraum
III Entspannungsraum
IV Abscheideraum
According to the invention this is achieved in that

• the fluidized bed has at least one region 16 with a higher flow velocity of the air flow 1 to which the material to be treated is applied,
• the raw material 2 is fed into the area 16 operated at a higher flow rate,
• - The material from the area 16 of the fluidized bed ( 9 ) is fed,
• that part of the material of the fluidized bed 9 is fed back into the region 16 , so that a particle circulation arises between the fluidized bed 9 and the region 16 ,

or in that, in order to equalize the granulation and to produce a defined particle structure of the solid particles to be produced in process space II of the fluidized bed system, internals in the form of built-in parts 10 are arranged above the area of the nozzles of the spray system 13 , the respective lower edge of which is spaced from the surface of the fluidized bed base 8 and whose respective upper edge ends at a distance above the surface of the fluidized bed 9 and the opening ratio of the gas passage openings of the fluidized bed 8 below the built-in parts 10 is greater than in the remaining area of the fluidized bed 8 . List of the reference numerals used 1 air flow
2 raw material
3 granulation seeds
4 compressed air
5 exhaust air
6 finished product
7 supply air chamber
8 fluidized bed
9 fluidized bed
10 built-in part
11 filters
12 cleaning mechanism
13 spray system
14 rotary valve
15 cellular wheel sluice
16 Spray area
17 particle circulation
18 exhaust air
19 dust recirculation
20 granulate discharge
21 cyclone separators
22 zigzag sifters
23 visible air
24 divider
I supply air housing
II process room
III relaxation room
IV separation room

Claims (11)

1.Procedure for the production of compact solid particles, in particular built-up granules in a continuously operated fluidized bed, in which the starting materials are pure liquids, solutions, melts, solids or gases and the fluidized bed from below is a fluidizing agent stream to maintain the fluidized bed and to dry or cool the Fluidized bed material are supplied and the discharge of the end product takes place with or without a classifying discharge, characterized in that
the fluidized bed has at least one region ( 16 ) with a higher flow velocity of the air flow ( 1 ) to which the material to be treated is applied,
the raw material ( 2 ) is fed into the area ( 16 ) operated at a higher flow rate,
the material from the region ( 16 ) of the fluidized bed ( 9 ) is fed,
that part of the material of the fluidized bed ( 9 ) is fed back into the area ( 16 ), so that a particle circulation arises between the fluidized bed ( 9 ) and the area ( 16 ). 2. The method according to claim 1, characterized in that the material ( 19 ) deposited in a deposition space (IV) is fed to the region ( 16 ). 3. The method according to claim 1 or 2, characterized in that the area ( 16 ) granulation nuclei ( 3 ) are supplied. 4. The method according to one or more of the preceding claims, characterized in that the material is fed into the region ( 16 ) from below and in the direction of flow of the air ( 1 ). 5. Fluidized bed system for the production of compact solid particles, in particular built-up granules with the following design:
a fluidized bed system consisting of supply air housing, process room, relaxation room and separation room,
a supply air housing consisting of one or more chambers, on the bottom of which are arranged feeds for the entry of a fluidizing medium for maintaining the fluidized bed and for drying or cooling the fluidized bed material,
a fluidized bed which is arranged above the supply air housing and which is provided with gas passage openings for uniformizing the fluidization medium,
a solid material feed opening into the fluidized bed above the fluidized bed,
a spray system opening from below into the fluidized bed, which consists of one or more spray nozzles for supplying a raw material,
an arrangement of internals in the process space of the fluidized bed system to influence the material properties of the products to be manufactured,
a material discharge for the end product arranged after the process room,
characterized in that, in order to homogenize the granulation and to produce a defined particle structure of the solid particles to be produced in the process space (II) of the fluidized bed system, internals in the form of built-in parts ( 10 ) are arranged above the area of the nozzles of the spray system ( 13 ), the respective lower edge of which the surface of the fluidized bed ( 8 ) is spaced and their respective upper edge ends at a distance above the surface of the fluidized bed ( 9 ) and the opening ratio of the gas passage openings of the fluidized bed ( 8 ) below the built-in parts ( 10 ) is greater than in the remaining area of the fluidized bed ( 8 ). 6. Fluidized bed system according to claim 5, characterized in that the upper edge of the built-in parts ( 10 ) protrudes into the relaxation space (III) of the fluidized bed system. 7. Fluid bed system according to claim 5 and 6, characterized in that the built-in parts ( 10 ) have a round, rectangular, square or polygonal cross section. 8. Fluidized bed system according to claim 5 to 7, characterized in that with a rectangular cross section of the built-in parts ( 10 ) a plurality of nozzles of the spray system ( 13 ) arranged over the width of the fluidized bed ( 9 ) are arranged below the respective built-in part ( 10 ). 9. The fluidized bed processor according to claim 5 to 8, characterized in that the distance of the lower edge of the mounting parts (10) from the fluidised bed (8), the aperture ratio of the gas passage openings of the arranged below the mounting parts (10) fluidized bed bottom (8) and the height and the The diameter or the width of the built-in parts ( 10 ) can be variably adjusted depending on the solid particles to be produced. 10. Fluidized bed system according to claim 5 to 9, characterized in that in the continuous coating of powdery to fine-grained solid particles on the ceiling of the fluidized bed system separating plates ( 24 ) are arranged, which extend over the entire width of the fluidized bed system and in the relaxation room (III) Fluidized bed system protrude in the area between two built-in parts ( 10 ) and end above the built-in parts ( 10 ). 11. Fluidized bed system according to claim 5 to 10, characterized in that the dust return lines ( 19 ) of the cyclone separator ( 21 ) connected downstream of the fluidized bed system open into a spraying area ( 16 ) lying below the built-in parts ( 10 ).