Fluidized bed system and method for cleaning at least one filter of a fluidized bed system

Abstract

The invention relates to a fluidized bed system (10) having features of claim 1, and to a method for cleaning at least one filter (12) of such a fluidized bed system (10).

Description

[0001] Fluidized bed plant and a method for cleaning at least one filter of a fluidized bed plant

[0002] The invention relates to a fluidized bed plant having features of claim 1 and a method for cleaning at least one filter of a fluidized bed plant having features of the independent claim.

[0003] A conventional fluidized bed system contains several retention filters. These retention filters serve to retain the powder to be granulated in a process chamber of the fluidized bed system. Without the retention filters, the (fluidized) powder would be drawn into the exhaust air ducts of the fluidized bed system due to the air flow.

[0004] Over time, the retention filters become clogged and blocked due to the powder granulation process. To prevent this, the filters can be sealed off and the filter surface can be cleaned from the inside out with a burst of compressed air.

[0005] After the production process, the filters can be cleaned with a cleaning fluid (wet). The filters can be removed after the production process for cleaning. This can still contain residues of the processed medication on the filters. If the medication is highly active, i.e. toxic to the operator of the system, removal is correspondingly complex and dangerous. For this reason, the retention filters can also be made of stainless steel. The stainless steel filters do not have to be removed and can be cleaned within the fluidized bed system with a cleaning fluid. Residual substances can collect inside the stainless steel filter, particularly at its lower end. For this reason, stainless steel filters require an additional opening mechanism that opens the filter at the lower end so that, for example, the cleaning fluid with the residual substance can escape or be drained off.

[0006] To seal off and clean the filters, they have an opening at their top and bottom ends, which can be opened or closed for the respective cleaning process. Two pneumatic cylinders are typically used to open and / or close the two openings.

[0007] This solution is costly, complex, and requires a certain amount of installation space. Due to the space required, this solution is not feasible in small process systems (e.g., laboratory equipment).

[0008] It is therefore an object of the present invention to provide a fluidized bed plant and a method for cleaning at least one filter of a fluidized bed plant, wherein the above disadvantages are eliminated.

[0009] The above object is achieved by a fluidized bed plant having the features of claim 1.

[0010] The fluidized bed system comprises at least one filter, in particular a retention filter. The filter is elongated. The filter can, in particular, have a conical and / or cylindrical shape. The filter has a first end with a first opening and a second end. The first end can be arranged above the second end with respect to the direction of gravity. The filter can be oriented along the direction of gravity.

[0011] The fluidized bed system comprises a pipe. The pipe has a first pipe end for supplying a gas, in particular compressed air, into the pipe. The first pipe end is in particular open. The pipe has a second pipe end. The second pipe end can be open or closed. The pipe protrudes through the first opening of the filter into the filter and extends within the filter, in particular along the entire filter. The pipe can run along the central longitudinal axis of the filter. The pipe and the filter can be arranged coaxially with one another.

[0012] The fluidized bed system comprises an inflatable membrane, in particular a pinch valve, for closing and / or opening the first opening of the filter. The inflatable membrane, in particular the pinch valve, can in particular be designed as a pneumatic pinch valve. By closing the inflatable membrane, in particular the tube can be pinched off and thus the first opening of the filter closed. This makes it possible to provide a fluidized bed system which (or its opening / closing mechanism) is more cost-effective and less complex. In particular, a pneumatic cylinder for opening or closing the first (upper) opening of the filter, which can be designed as a fabric filter, can be dispensed with. This requires less installation space. In particular, the installation height of the fluidized bed system can be optimized (or made smaller).It is conceivable that existing machines can be subsequently converted (or retrofitted) to the above fluidized bed plant.

[0013] According to the invention, the second end of the filter has a second opening. The tube has a closure element at its second tube end. The closure element is designed to close and / or open the second opening of the filter. The closure element can be designed as a lid closing the second opening of the filter. The tube has several outlet openings for discharging the gas, in particular compressed air, from the tube. This makes it possible to provide a fluidized bed system which (or its opening / closing mechanism) is more cost-effective and less complex. In particular, a pneumatic cylinder for opening or closing the first (upper) opening of the filter, which can be designed as a metal filter, in particular a stainless steel filter, can be dispensed with. This requires less installation space. This means that stainless steel filters can also be used in laboratory equipment.In particular, the overall height of the fluidized bed system can be optimized (or reduced). It is conceivable that existing machines can be subsequently converted (or retrofitted) to the above-mentioned fluidized bed system.

[0014] According to a further development of the fluidized bed system, the outlet openings can be arranged at an outlet section of the pipe. This outlet section can be arranged between a closure point of the inflatable membrane, in particular the pinch valve, and the second opening of the filter. The outlet section can also be arranged between the first opening and the second opening of the filter. It is also conceivable for the outlet section to be arranged between the inflatable membrane, in particular the pinch valve, and the second opening of the filter.

[0015] This allows the cleaning effect of the gas escaping from the outlet openings to be further optimized. In particular, the outlet openings distributed along the outlet section of the pipe minimize the distance between the respective outlet opening and the filter (or its shell surface to be cleaned), thus increasing the cleaning effect (since the shell surface to be cleaned is positioned as close as possible to the outlet opening). According to a further development of the fluidized bed system, the outlet openings can be evenly distributed within the outlet section of the pipe. In particular, the outlet openings can be distributed equidistantly within the outlet section.

[0016] This allows for a uniform cleaning effect and thus further optimises the cleaning process.

[0017] According to a further development of the fluidized bed plant, the filter can be designed as a metal filter, in particular a stainless steel filter, or as a fabric filter.

[0018] This allows different filters to be used and makes the fluidized bed system more flexible.

[0019] According to a further development of the fluidized bed system, the fluidized bed system can have at least one nozzle for supplying a cleaning fluid to the filter. It is also conceivable that, alternatively or additionally, the cleaning fluid can be supplied via the pipe, in particular its first pipe end, and guided into the filter via the outlet openings.

[0020] This allows the supply of the cleaning fluid and thus a corresponding wet cleaning process to be implemented using simple means.

[0021] According to a further development of the fluidized bed system, the tube can be designed to be movable between a closed position and an open position. In the closed position, the second opening of the filter can be closed by the closure element. In the open position, the second opening of the filter can be left open.

[0022] This allows the second opening of the filter to be closed or opened using simple means.

[0023] According to a further development of the fluidized bed system, the fluidized bed system can comprise a drive for moving the tube between the closed position and the open position. The drive can be designed as a pneumatic drive. The drive can, in particular, be designed as a pneumatic cylinder.

[0024] This allows the pipe to be moved using simple means.

[0025] According to a further development of the fluidized-bed system, the fluidized-bed system can comprise at least one gas reservoir for supplying a gas into the pipe. The fluidized-bed system can, in particular, comprise a compressed air tank for supplying compressed air into the pipe. It is also conceivable that the gas reservoir (or the compressed air tank) can be used to operate the inflatable membrane, in particular the pinch valve (in particular to close the inflatable membrane, in particular the pinch valve).

[0026] This allows the supply of gas, especially compressed air, and thus a corresponding dry cleaning process to be implemented using simple means.

[0027] The above object is achieved by a method for cleaning at least one filter of a fluidized bed system with the features of the independent claim. The fluidized bed system is a fluidized bed system according to the above statements. The method comprises a dry cleaning phase. The dry cleaning phase comprises the steps:

[0028] Closing the first opening of the filter using the inflatable membrane, in particular the pinch valve.

[0029] In particular, closing the second opening of the filter by means of the closure element. This can be achieved, in particular, by moving the tube into the closed position.

[0030] Feeding a gas, especially compressed air, into the pipe through the first pipe end.

[0031] Discharge the gas from the pipe, particularly through the outlet openings. Discharge of the gas from the pipe can be carried out abruptly, continuously, and / or at intervals.

[0032] This allows a dry cleaning phase to be implemented using simple means. Regarding the advantages achievable with this process, reference is made to the relevant information on the fluidized bed plant. The measures described in connection with the fluidized bed plant and / or those explained below can be used to further refine the process.

[0033] According to a further development of the method, the method may include a wet cleaning phase. The wet cleaning phase may include the following steps:

[0034] Closing the second opening of the filter using the closure element. This can be achieved, in particular, by moving the tube into the closed position.

[0035] Feeding a cleaning fluid into the filter. The inflatable membrane, in particular the pinch valve, can be open or closed, and thus the first opening of the filter can be open or closed. Opening the second opening. This can be achieved, in particular, by moving the tube into the open position. It is conceivable that the second opening could be opened after a predetermined contact time for the cleaning fluid.

[0036] This allows a wet cleaning phase to be implemented using simple means.

[0037] According to a further development of the process, the wet cleaning phase can include the following steps:

[0038] Closing the first opening of the filter using the inflatable membrane, in particular the pinch valve.

[0039] Feeding a gas, especially compressed air, into the pipe through the first pipe end.

[0040] Discharge the gas from the pipe through the outlet openings.

[0041] This can increase the cleaning effect and further optimize the wet cleaning phase.

[0042] Further features, details, and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. They show:

[0043] Fig. 1 is a sectional view of a fluidized bed plant with a first opening of a filter being open;

[0044] Fig. 2 is a sectional view of the fluidized bed plant according to Figure 1, wherein the first opening of the filter is closed and

[0045] Fig. 3 is a sectional view of the fluidized bed plant according to Figure 1 with a second opening of the filter being open.

[0046] In the following description and in the figures, corresponding components and elements bear the same reference symbols. For the sake of clarity, not all reference symbols are shown in all figures.

[0047] Figure 1 shows a sectional view of a fluidized bed system 10. The fluidized bed system 10 comprises at least one filter 12. The filter 12 can be designed as a retention filter. The filter 12 is elongated, has a first end 14 with a first opening 16 and a second end 18. In the present case, the second end 18 of the filter 12 has a second opening 20. In the present case, the filter 12 is cylindrical and tapers conically towards the second opening 20. In the present case, the filter 12 is arranged along the direction of gravity 15. The direction of gravity 15 is indicated in Figures 1 to 3 by an arrow. In the present case, the first opening 16 is arranged above the second opening 20.

[0048] The fluidized bed system 10 comprises a pipe 22. The pipe 22 has a first pipe end 24 for supplying a gas, in particular compressed air, into the pipe 22. The pipe 22 has a second pipe end 26. The pipe 22 projects through the first opening 16 of the filter 12 into the filter 12. The pipe 22 extends within the filter 12. In this case, the pipe 22 extends along the entire filter 12. In this case, the pipe 22 is arranged coaxially with the filter 12. In other words, the pipe 22 extends along the central longitudinal axis of the filter 12.

[0049] The tube 22 has a closure element 28 at its second tube end 26 for closing and / or opening the second opening 20 of the filter 12. The tube 22 has a plurality of outlet openings 30 for discharging the gas, in particular compressed air, from the tube 22.

[0050] The fluidized bed system 10 has an inflatable membrane for closing and / or opening the first opening 16 of the filter 12. In this case, the inflatable membrane is designed as a pinch valve 32. To close the first opening 16, the tube 22 is pinched at a closing point of the pinch valve 32. In this case, the pinch valve 32 is open, thus opening the first opening 16 of the filter 12.

[0051] The outlet openings 30 can be arranged at an outlet section 34 of the tube 22. The outlet section 34 can be arranged between a closing point of the pinch valve 32 and the second opening 20 of the filter 12. This can ensure that the gas is discharged from the tube 22 into the filter 12.

[0052] The outlet openings 30 can be evenly distributed within the outlet section 34 of the tube 22. In particular, the distances between the outlet openings 30 can be arranged equidistantly in the longitudinal direction and / or circumferential direction of the tube 22.

[0053] The filter 12 is embodied as a metal filter, in particular a stainless steel filter. In this case, the filter 12 can have the first opening 16 and the second opening 20. It is also conceivable for the filter 12 to be embodied as a fabric filter. In this case, the filter 12 can have only the first opening 16 and, in particular, no second opening 20.

[0054] During normal operation of the fluidized bed system 10, air is extracted from a process chamber 44 of the fluidized bed system 10 through the filter 12 by means of an extraction system 46. The flow path of the air extracted through the filter 12 is indicated by arrows in Figure 1. The filter 12 prevents particles, particularly powder, from entering the extraction system 46 from the process chamber 44.

[0055] Figure 2 shows a sectional view of the fluidized bed plant 10 according to Figure 1, wherein the first opening 16 of the filter 12 is closed.

[0056] For dry cleaning of the filter 12, the first opening 16 and the second opening 20 of the filter 12 can be closed, with the first opening 16 being closed by the pinch valve 32 and the second opening 20 being closed by the closing element 28. A gas, in this case compressed air, is then introduced into the tube 22 via the first tube end 24. The gas spreads within the tube 22 and exits through the outlet openings 30. The gas exiting the outlet openings 30 flows through the filter 12 (or its filter or outer surface) from the inside to the outside, so that particles, in this case powder, which have settled on the filter 12 (or its filter or outer surface) are blown back into the process chamber 44. The path of the gas through the tube 22 and out of the outlet openings 30 is indicated by arrows in Figure 2.

[0057] The fluidized bed system 10 may comprise at least one gas reservoir 42, in this case a compressed air tank, for supplying a gas, in this case compressed air, into the pipe 22. The gas reservoir 42 is only indicated schematically in Figures 1 to 3.

[0058] After a production process, wet cleaning of the filter 12 may be necessary. For wet cleaning of the filter 12, a cleaning fluid can be introduced into the filter 12 so that the interior of the filter 12 is flushed with the cleaning fluid. The cleaning fluid must then be drained from the filter 12.

[0059] For feeding the cleaning fluid into the filter 12, the fluidized bed system 10 can have at least one nozzle (not shown). It is also conceivable for the cleaning fluid to be fed into the filter 12 via the pipe 22 (through the first pipe end 24 and the outlet openings 30). For discharging the cleaning fluid from the filter 12, the second opening 20 can be opened so that the cleaning fluid can flow out of the filter 12, in particular due to gravity. It is conceivable for at least a portion of the cleaning fluid to be forced through the filter 12 with the aid of compressed air, with the remainder of the cleaning fluid being able to drain out of the filter 12 through the second opening 20.

[0060] Figure 3 shows a sectional view of the fluidized bed system 10 according to Figure 1, wherein the second opening 20 of the filter 12 is open. The tube 22 can be designed to be movable between a closed position 36 and an open position 38. In the closed position 36, the second opening 20 of the filter 12 is closed by the closure element 28 (see Figures 1 and 2). In the open position 38, the second opening 20 of the filter 12 is not closed by the closure element 28. In the open position 38, the second opening 20 of the filter 12 is, in particular, open (see Figure 3).

[0061] Thus, the second opening 20 of the filter 12 can be opened by transferring or moving the tube 22 into the open position 38. Accordingly, the second opening 20 of the filter 12 can be closed by transferring or moving the tube 22 into the closed position 36.

[0062] To move the tube 22 between the closed position 36 and the open position 38, the fluidized bed system 10 can include a drive 40. The drive 40 can be configured, in particular, to be pneumatic. The drive 40 can be configured, in particular, as a pneumatic cylinder. The drive 40 is only indicated schematically in Figures 1 to 3. The movement of the tube 22 between the closed position 36 and the open position 38 is indicated in Figure 3 by a double arrow.

[0063] In the following, a method for cleaning at least one filter 12 of a fluidized bed plant 10 according to the above embodiments, in particular the fluidized bed plant 10 shown in Figures 1 to 3, is described with reference to Figures 1 to 3.

[0064] The process includes a dry cleaning phase. The dry cleaning phase includes the following steps:

[0065] Closing the first opening 16 of the filter 12 using the pinch valve 32. For this purpose, the pinch valve 32 can be closed. The pinch valve 32 can squeeze the pipe, particularly at a closing point.

[0066] Closing the second opening 20 of the filter 12 using the closure element 28. This can be done by moving the tube 22 into the closed position 36 (see Figure 2). By closing the first opening 16 and the second opening 20 of the filter 12, the latter is "locked off."

[0067] Feeding a gas, in this case compressed air, into the pipe 22 through the first pipe end 24.

[0068] The gas is discharged from the tube 22 through the outlet openings 30. The gas flows through the filter 12 from the inside outward toward the process chamber 44 and blows the filter 12 clean, particularly of any clogged particles or powder. The gas can be supplied abruptly, continuously, and / or at intervals. The dry cleaning phase can be carried out continuously over a specific period of time. It is also conceivable that the dry cleaning phase can be repeated several times at specific intervals.

[0069] After the dry cleaning phase, the first opening 16 of the filter 12 can be reopened by opening the pinch valve 32. Normal operation (see above) of the fluidized bed system 10 can be resumed.

[0070] The method may include a wet cleaning phase. The wet cleaning phase may, for example, be carried out after a production process of the fluidized bed system 10. The wet cleaning phase comprises the following steps:

[0071] Closing the second opening 20 of the filter 12 by means of the closure element 28. This can be done by moving the tube 22 into the closed position 36.

[0072] Feeding a cleaning fluid into the filter 12. This can be done using a nozzle (not shown). The pinch valve 32 can be open or closed. Accordingly, the first opening 16 of the filter 12 can be open or closed. It is also conceivable that the cleaning fluid can be introduced into the filter 12 via the pipe 22 (through the first pipe end 24 and the outlet openings 30).

[0073] Opening the second opening 20 of the filter 12. This can be done by moving the tube 22 into the open position 38. The opening of the second opening 20 of the filter 12 can be performed, in particular, after a certain contact time of the cleaning fluid. This allows the cleaning fluid to act within the filter 12 and particularly effectively detach the particles, in particular powder, that have settled in the filter 12. The cleaning fluid can then flow out of the filter 12 through the opened second opening 20 of the filter 12, in particular due to gravity.

[0074] The wet cleaning phase may include the following steps:

[0075] Closing the first opening 16 of the filter 12 using the pinch valve 32. This allows the filter 12 to be "locked off" since both openings 16, 18 of the filter 12 are closed.

[0076] Feeding the gas, in this case compressed air, into the pipe 22 through the first pipe end 24.

[0077] The gas is discharged from the pipe 22 through the outlet openings 30. This allows the wet cleaning phase to be combined with the dry cleaning phase. The cleaning effect can thus be increased and the cleaning process further optimized. In particular, the cleaning fluid or residues of the cleaning fluid can be blown off using the gas escaping from the outlet openings 30, and the filter 12 can be dried in this way.

Claims

Patent claims 1. Fluidized bed plant (10) comprising: - at least one filter (12), wherein the filter (12) is elongated and has a first end (14) with a first opening (16) and a second end (18), - a tube (22) with a first tube end (24) for supplying a gas, in particular compressed air, into the tube (22) and a second tube end (26), wherein the tube (22) projects through the first opening (16) of the filter (12) into the filter (12) and extends within the filter (12), in particular along the entire filter (12), - an inflatable membrane, in particular a pinch valve (32), for closing and / or opening the first opening (16) of the filter (12), wherein the second end (18) of the filter (12) has a second opening (20), wherein the tube (22) has a closure element (28) at its second tube end (26) for closing and / or opening the second opening (20) of the filter (12), wherein the tube (22) has a plurality of outlet openings (30) for discharging the gas, in particular compressed air, from the tube (22).

2. Fluidized bed plant (10) according to claim 1, characterized in that the outlet openings (30) are arranged at an outlet section (34) of the tube (22) which is arranged between a closing point of the inflatable membrane, in particular of the pinch valve (32), and the second opening (20) of the filter (12).

3. Fluidized bed plant (10) according to claim 2, characterized in that the outlet openings (30) are evenly distributed within the outlet section (34) of the pipe (22).

4. Fluidized bed plant (10) according to one of the preceding claims, characterized in that the filter (12) is designed as a metal filter or as a fabric filter.

5. Fluidized bed system (10) according to one of the preceding claims, characterized in that the fluidized bed system (10) has at least one nozzle for supplying a cleaning liquid into the filter (12).

6. Fluidized bed plant (10) according to one of the preceding claims, characterized in that the tube (22) is designed to be movable between a closed position (36), in which the second opening (20) of the filter (12) is closed by means of the closure element (28), and an open position (38), in which the second opening (20) of the filter (12) is not closed, in particular open, by means of the closure element (28). 7- Fluidized bed plant (10) according to the preceding claim, characterized in that the fluidized bed plant (10) comprises a, in particular pneumatic, drive (40) for moving the tube (22) between the closed position (36) and the open position (38).

8. Fluidized bed plant (10) according to the preceding claim, characterized in that the fluidized bed plant (10) comprises at least one gas reservoir (42), in particular a compressed air tank, for supplying a gas, in particular compressed air, into the pipe (22).

9. A method for cleaning at least one filter (12) of a fluidized bed plant (10) according to one of the preceding claims, wherein the method comprises a dry cleaning phase, wherein the dry cleaning phase comprises the steps: - closing the first opening (16) of the filter (12) by means of the inflatable membrane, in particular the pinch valve (32); - In particular, closing the second opening (20) of the filter (12) by means of the closure element (28) by moving the tube (22) into the closed position (36); - feeding a gas, in particular compressed air, into the pipe (22) through the first pipe end (24); - discharging the gas from the tube (22), in particular through the outlet openings (30).

10. The method according to claim 9, wherein the method comprises a wet cleaning phase, wherein the wet cleaning phase comprises the steps of: - closing the second opening (20) of the filter (12) by means of the closure element (28), in particular by moving the tube (22) into the closed position (36); - feeding a cleaning liquid into the filter (12); - Opening the second opening (20) of the filter (12), in particular by moving the tube (22) into the open position (38).

11. The method according to claim 10, wherein the wet cleaning phase comprises the steps of: - closing the first opening (16) of the filter (12) by means of the inflatable membrane, in particular the pinch valve (32); - feeding the gas, in particular compressed air, into the pipe (22) through the first pipe end (24); - Discharge of the gas from the pipe (22) through the outlet openings (30).

Images