DE19528584A1 - Fluidised bed appts. to treat granular material e.g for coating tablets - with concentric rings of feeder plates in base to give uniform treatment conditions - Google Patents

Abstract

Fluidised bed appts. to produce and/or treat a granular material has a revolving chamber (42). The base (24) of the chamber has concentric rings (26,28) of overlapping feed plates (32,34). A gaseous medium (78) can be fed into an inlet chamber (22) below the plates.

Description

The invention relates to a fluid bed apparatus for manufacturing and / or further processing of granular material, with a Circulation chamber, the bottom of which is arranged in a ring shape, over has overlapping guide plates, and with one under the guide plate arranged inlet chamber into which a gaseous Medium can be fed.  

Such a fluid bed apparatus is known from EP-A-0 370 167 known.

In the known fluid bed apparatus, for example Coating tablets is used, which flows into the Entry chamber introduced gaseous medium, for example hot air, between the overlapping baffles guided horizontally and directed circumferentially into the circulation chamber a. A good received in the circulation chamber is replaced by the introduced medium circulated and at the same time in a circle movement in the circulation chamber. After the medium Flowed through well, it is removed from the apparatus, for example, it is through a central central dip tube led downwards out of the apparatus. The flow Conditions are chosen so that the goods to be treated are in one annular air overlap layer overlapping Baffles hover. Nozzles in the floor make it possible to to spray a liquid coating medium onto the material that is dried by the gaseous medium.

Each individual guide plate is approximately in plan view of the floor circular sector, and in the overlap area of two conductors plates are formed radially extending openings over the the medium from the inlet chamber into the circulation chamber crosses.

In the case of large fluid bed apparatuses, that is to say those with a large one The diameter, for example more than 2 m, is the radially inner one Edge in the form of a circular arc much shorter than the radial one outer edge of a guide plate.  

If you now consider two of each other in the circumferential direction following openings between the guide plates, so are radial inner area after a relatively short running distance of the goods two openings available, but only in the radially outer area after a relatively long distance that is even a multiple the radially inner running distance can be.

The good tends to hit the ground due to gravity drop in the circulation chamber. That through the guide plates, for example horizontally blown medium is supposed to create an air cushion, the impact of the circulated goods on the guide plates of the soil prevented.

If you follow the circular circulation path of the goods on a radial inner side, it passes through between two openings relatively short distance before there is a new thrust through that entering the circulation chamber between the guide plates Medium. This can accelerate the goods relatively strongly be, and it is prevented that there are two on top of each other following openings sinks to the floor. Now follow that Good at a radially outer point, so to get an even one Maintaining circulation is essential from the start greater circumferential speed of the goods is necessary. Here but the distance between two inlet openings on the radially outer The area is much larger than the radially inner one Only enter the estate after a much longer run renewed thrust imposed, which anyway because of the greater peripheral speed should be greater than in the radial inner area. This has already been attempted wear that the height of the gap between two overlapping Guide plates in the radially outer area is larger than in the radial inner area, so that in the radially outer area more medium can pass through.  

There are limits to this measure as far as too strong divergence too strong gradations or at an angle standing baffle surfaces would arise.

In the case of very large fluid bed apparatuses, it is disadvantageous that a uniform treatment of the goods is no longer guaranteed is, and that there is also a risk that the good in the radial Open the outer circumferential area on the floor of the circulation chamber can.

It is therefore an object of the present invention to remedy this to create and continue moving a fluidized bed equipment form that even with large-diameter fluid bed apparatus an even treatment of the goods is possible.

According to the invention the object is achieved in that the floor has several concentrically arranged rings on guide plates.

This measure now has the advantage that by providing concentrically arranged wreaths the guide plates that the build each wreath, not over the entire radial Dimension of the circulation chamber must extend, but only over that respective radial dimension of a wreath. This makes it possible the floor with a large-diameter fluidized bed apparatus Correspondingly in segments from several rings on guide plates build up smaller radial dimension.

Through intensive investigations it was found that it was for a certain range of the grain size of the to be treated There are certain ideal dimensions of guide plates, d. H. a certain Ideal degree of radial extension of a guide plate and a certain one Ideally, a large distance between two successive Openings through which the medium enters the circulation chamber  can. It is therefore possible with large fluidized bed equipment to build a whole grid of concentric rings whose individual baffles both what the radial dimension as well as what the circumferential dimension is in the ideal range.

It also opens up the possibility of the guide plates each individual wreath to the ideal conditions in the Annular sector of this wreath set it and on top of each other vote.

Overall, can be achieved by the indi Visual and active control option with a fluid bed apparatus with large diameter throughout ideal flow and thus treatment conditions can be created.

In addition, there is another advantage in that that with a very large apparatus, individual wreaths were shut down be the radial inner or the radial outer, thus in principle the possibility is opened, a very large fluidized bed equipment, even as smaller ones Operate apparatus.

The task is thus completely solved.

In a further embodiment of the invention, the individual Wreaths separated from one another by a ring wall.

This measure has the advantage that clear through the ring wall delimited wreath areas are created, the ring wall can also serve to make the individual baffles concentric to fix wreaths arranged in one plane to it.  

In a further embodiment of the invention, a upper edge of the ring wall approximately aligned with the guide plates.

This measure has the advantage that the ring wall does not flow technical or mechanical resistance to the represents rotating amount of material above the ground.

In a further embodiment of the invention, the ring wall formed so that there is a covering device for covering at least one wreath is deductible.

This measure now has the advantage that the ring wall at the same time serves if the fluidized bed apparatus as a smaller apparatus to be used, the corresponding cover start.

In a further embodiment of the invention, the plurality Wreaths from a common entrance chamber from below acted upon the gaseous medium.

This measure has the advantage that despite the construction of the floor from different wreaths an inflow from one single entry chamber is possible. This is because the individual wreaths, although they are of a different Number of individual baffles are built, thus also one different number of openings for the medium have, but seen with respect to each individual opening are constructed in the same way. So it is not necessary complicated and structurally complex individual feeds to the to create individual wreaths.

In a further embodiment of the invention is in the common inlet chamber arranged a distributor.  

The measure of the distributor has the advantage that the entry flow as such can be targeted or one-sided, for example through a side connector, the distributor but then ensures an even distribution of the medium, before this then approaches the underside of the guide plates. An even flow against the bottom of the bottom of the Circulation chamber also contributes to the even entry of the Medium into the circulation chamber and ultimately equal to one moderate treatment of the goods in the circulation chamber.

In a further embodiment of the invention, the Distributor from a perforated intermediate floor.

This measure makes this structurally simple Distribute the medium in the entry chamber before it enters the Circulation chamber overrun reached.

In a further embodiment of the invention, this is radial Measure each of the concentric wreaths approximately the same.

This measure now has the advantage that approximately the same training Components can be used to build the wreaths.

In a further embodiment of the invention, each wreath associated with a number of circumferentially distributed nozzles.

This is another contribution to being active and self-employed Control of each wreath area, i.e. H. should respond to the good liquid medium is sprayed on, for example for coating, so each wreath can have its own, ideal for its conditions wear arranged and controlled nozzle group assigned. Thereby it is then also possible that such a nozzle group, if such a wreath is also actively switched off can be.  

In a further embodiment of the invention, a flow bed equipment used with a central immersion tube is provided, in which the medium rising in the circulation chamber can enter at the top and be discharged downwards, whereby two ring-shaped rings on guide plates around the central dip tube are arranged around.

For practical use and with regard to the constructive Such a design has proven to be extremely inexpensive proven to be an ideal treatment of the material in the circulation chamber to achieve.

It is understood that the above and the following standing features to be explained not only in each specified combination, but also in other combinations or can be used alone, without the scope of to leave the present invention.

The invention is selected below based on a Embodiment in connection with the accompanying Drawings described and explained in more detail.

Show it:

Fig. 1 is a horizontal sectional view of a fluidized-bed apparatus in a first setup state, in plan view of the bottom of a circulation chamber,

Fig. 2 is a somewhat enlarged partial section along the line II-II in Fig. 1,

Fig. 3 is a section along the line III-III in Fig. 1,

Fig. 4 is a side view of the fluidized-bed apparatus of Fig. 3 during an emptying process,

Fig. 5 is a Fig. 1 corresponding top view of a Umrüstzustandes the fluidized-bed apparatus of Fig. 1, and

Fig. 6 is a representation of Fig. 3 corresponding Dar position of the converted apparatus.

The fluidized bed apparatus shown in FIGS . 1 to 4 is provided with the reference number 10 in its entirety.

The fluidized bed apparatus 10 has an approximately cylindrical double-walled container 12 , the lower base part 14 of which is connected to a support 15 .

An inlet 16 extends through the support 15 , between which an outlet 18 is arranged.

The outlet 18 is designed as a central immersion tube 20 , which is arranged upright in the center of the container 12 .

The inlet 16 is connected to an inlet chamber 22 of the container 12 , the upper end of which is formed by a bottom 24 of the circulation chamber 42 arranged above it.

As can be seen in particular from FIG. 1, the bottom 24 is composed of a first inner ring 26 on overlapping guide plates 32 and a second outer ring 28 on likewise overlapping guide plates 34 .

The two wreaths are separated from one another by an annular wall 30 .

In the enlarged sectional view of Fig. 2, the overlapping annular arrangement of three successive guide plates 34 ', 34 ''and 34 ''' of the second outer ring 28 is shown.

The same basic construction is present for the guide plates 32 of the first inner ring 26 .

From the illustration of Fig. 2 it can be seen that an approximately horizontally extending gap is formed by the overlapping guide plates 34 '' and 34 ''', via which a medium 78 introduced into the inlet chamber 22 via the inlet 16 (see arrow in FIG. 2) can also pass from the inlet chamber 22 into the circulation chamber 42 . The medium 78 is thus introduced approximately horizontally and circumferentially into the circulation chamber 42 .

Some of the guide plates, in Fig. 2 the guide plate 34 '', carry nozzles 36 through which a liquid medium can be sprayed onto the material received in the circulation chamber 42 , for example when coating tablets with a coating layer.

For this purpose, the nozzle 36 is connected via a line 38 to a liquid source.

The angle of attack of the guide plates 32 and 34 can be changed, the facial expressions required for this purpose are not shown here for the sake of clarity.

The annular wall 30 not only serves to separate the first inner ring 26 and the second outer ring 28 but also serves to fasten the guide plates 32 and 34 . The approximately ring-shaped circulation chamber 42 is closed at the upper end by a dome-shaped cover 44 which has a plurality of viewing windows 45 .

The lid 44 is pivotally attached to the container 12 via a hinge 46 so that the lid 44 , as shown in FIG. 4, can be lifted off. A seal 47 ensures a gas-tight seal between cover 44 and container 12 .

As can also be seen from FIG. 4, the container 12 is connected to the base part 14 via a hinge 48 , so that the container 12 can be tilted for emptying.

For emptying, there are lateral emptying flaps 50 , 51 which can be opened or closed via piston / cylinder units 52 and 53 .

The material 58 treated in the circulation chamber 42 can thereby be emptied laterally into a container 59 .

As can be seen in particular from FIG. 3, a distributor 54 , which is designed as a perforated intermediate floor 55 , is arranged in the inlet chamber 22 approximately at a central height.

From Fig. 1 it can be seen that the radial dimension RM of the first inner ring 26 and the second outer ring 28 is the same.

Furthermore, it can be seen from the top view of FIG. 1 that both the guide plates 32 of the first inner ring 26 and the guide plates 34 of the second outer ring have the same radial dimension and approximately the same contour.

In particular, the circular arc dimension 56 of the outer circumferential edge of a guide plate of the first inner ring 26 is the same as the circular arc dimension 56 of a radially outer edge of a guide plate 34 of the second outer ring 28 .

That is, the running distance through which the material 58 , which is ring-shaped in the circulating chamber 42, runs between two outlet openings between two overlapping guide plates of the inner ring at its outer radial area is the same as at the radially outer area of the second outer ring 28 .

That is, in other words, the same conditions are present over the radial extent of the first inner ring 26 as seen over the radial extent of the second outer ring 28.

The fluidized bed apparatus shown in FIGS . 1 to 4 works as follows:
After filling to be coated material 58 into the plenum chamber 42, for example to be coated tablets, in closed-end discharge flaps 50 and 51 and closed cover 44, a gaseous medium 78, for example, hot dry air is carried out through the inlet 16 of the inlet chamber 22nd After flowing through the intermediate base 55 , the hot air arrives at the underside of the base 24 in an evenly distributed manner and, due to the geometry of the first inner ring 26 and the second outer ring 28, is uniformly distributed into the circulation chamber 42 .

The conditions are chosen so that a kind of air cushion forms under the material 58 , the material 58 itself is circulated such that it rotates in an air sliding layer in the circulating chamber 42 around the central dip tube 20 . By actuating the nozzles 36 and 37 , a liquid coating medium can be sprayed onto the material 58 at the same time, which is dried by the hot air. After flowing through the material 58 , the medium 78 enters the dip tube 20 at the upper end via an opening 21 and is removed from the bottom of the apparatus 10 .

In the illustrated embodiment, the dip tube 20 is curved inwards at the upper end; it can also be expanded like a trumpet to facilitate gas entry. In addition, it can be provided that a filter cloth is stretched over the opening 21 in order to hold back entrained particulate material 58 .

After the end of the treatment process, the goods 58 are emptied laterally, as previously described in connection with FIG. 4.

In Fig. 5 and 6, 10 can be seen in another setup status of the fluidized bed apparatus.

For this purpose, an upper section 70 of the immersion tube 20 was removed and a covering device 60 was put on.

The cover device 60 is designed as a hood-shaped reduction collar 62 .

The covering device 60 has a lower cylindrical section 64 , the diameter of which corresponds exactly to the diameter of the ring wall 30 .

The height of the cylindrical section 64 corresponds to the height of the radially opposite wall of the container 12 .

The cylindrical section 64 protrudes upwards in a truncated cone section 66 which has an opening 68 at the upper end. The height and the size, and thus the position of the opening 68 , corresponds to the position of the opening 21 of the immersion tube 20 as it was previously (see FIG. 3).

An annular base 72 extends between the lower remaining section 71 of the immersion tube 20 and the lower end region of the cylindrical section 64 of the covering device 60 , which thus closes the first inner ring 26 in a gas-tight manner.

Fasteners 74 and 76 serve to connect the reduction collar 62 and the lower section 71 of the dip tube 20 to one another.

By this measure, the original circulation chamber 42 has now been converted into a lower-volume circulation chamber 42 ', as can be seen in FIG. 6.

A much smaller batch can now be treated, but with the same layer height SH in the volume-reduced circulation chamber 42 ', as can be seen from FIG. 6.

If, as shown in FIG. 6, the gaseous medium 78 is introduced into the inlet chamber 22 via the inlet 16 , this medium can only pass through the guide plates 34 of the second outer ring 28 , since the first inner ring 26 is covered. Since in the ring area of the second outer ring 28 the same gas entry conditions are present on the bottom side and the same product or bed height SH can be used in the volume-reduced circulation chamber 42 ', the same ideal treatment conditions are present in the reduced circulation chamber 42 ' as in the in setup state with the large volume treatment chamber 42. Fig. 3 illustrated.

Also in the example shown in Fig. 6 setup state with the volume-reduced circulation chamber 42 'can the medium 78 after it has good 58 flows through transfer across the central opening 68 in the cover 60 and down, as before, via the section 71 of the dip tube 20 are removed from the apparatus 10 .

The retrofitting process described above led to an “inner” covering of the first inner ring 26 .

Accordingly, it is alternatively also possible to cover the second outer ring 28 , specifically by a section corresponding to the cylindrical section 64 of the covering device 60 , which section is then not angled inwards but outwards towards the wall of the container 12 . In this case, the central dip tube 20 can then remain.

Claims (10)

1. Fluidized bed apparatus for the manufacture and / or further treatment of granular material, with a circulation chamber ( 42 ), the bottom ( 24 ) of which has crown-shaped, overlapping guide plates ( 32 , 34 ), and an inlet chamber arranged under the guide plates ( 32 , 34 ) ( 22 ) into which a gaseous medium ( 78 ) can be introduced, characterized in that the base ( 24 ) has a plurality of concentrically arranged rings ( 26 , 28 ) on guide plates ( 32 , 34 ). 2. Fluidized bed apparatus according to claim 1, characterized in that the individual rings ( 26 , 28 ) are separated from one another via an annular wall ( 30 ). 3. Fluidized bed apparatus according to claim 2, characterized in that an upper edge of the ring wall ( 30 ) is approximately flush with the guide plates ( 32 , 34 ). 4. Fluidized bed apparatus according to claim 2 or 3, characterized in that the ring wall ( 30 ) is designed so that there is a covering device ( 60 ) for covering at least one ring ( 26 ) can be removed. 5. Fluidized bed apparatus according to one of claims 1 to 4, characterized in that the plurality of rings ( 26 , 28 ) from a common inlet chamber ( 22 ) from below with the gaseous medium ( 78 ) can be acted upon. 6. Fluidized bed apparatus according to claim 5, characterized in that a distributor ( 54 ) is arranged in the common inlet chamber ( 22 ). 7 fluid bed apparatus according to claim 6, characterized in that the distributor ( 54 ) consists of a perforated intermediate floor ( 55 ). 8. fluidized bed apparatus according to one of claims 1 to 7, characterized in that the radial dimension (RM) of each of the concentric wreaths ( 26 , 28 ) is approximately the same. 9. Fluidized bed apparatus according to one of claims 1 to 8, characterized in that each ring ( 26 , 28 ) is assigned a series of circumferentially distributed nozzles ( 36 , 37 ). 10. Fluidized bed apparatus according to one of claims 1 to 9, with a central immersion tube ( 20 ), into which the medium ( 78 ) rising in the circulation chamber ( 42 ) enters at the top and can be removed downwards, characterized in that two annular rings ( 26 , 28 ) are arranged on guide plates ( 32 , 34 ) around the central dip tube ( 20 ).