HK1075220A - Filter apparatus - Google Patents

Description

Filter device

Background

Technical Field

The present invention relates generally to fluid bed granulators, coaters, and dryers. In particular, the present invention relates to a filtration apparatus including a movable filter bundle that can be selectively raised and lowered to facilitate maintenance of one or more filtration units on the movable filter bundle.

Prior Art

Granulation is a critical stage in many industries, such as mineral processing, agricultural products, detergents, pharmaceuticals, food products and specialty chemicals. This is a size-enlarging process where fine powder feed particles are bonded to form a mass or particles, such as in the formation of tablets. In wet granulation, a type of granulation, the particles are bound together by a fluid (also called a binder) that forms fluid bridges between the particles to bind the particles together. The bonding fluid is typically a solvent, such as water or ethanol, or a solution of a polymeric binder in a solvent.

A fluid bed granulator is a tall cylindrical or rectangular vessel that contains a bed of granules. Air is forced through the distributor on the base to fluidize and agitate the powder. The binding fluid is added by spraying from above, below or within the powder bed. These adhesive droplets collide with the powder particles and form liquid bridges which bind the adhesive droplets and the powder particles together by capillary suction. By heating the fluidizing air, the product can be granulated and dried simultaneously, which is particularly useful in the specialty chemical and pharmaceutical industries.

The result of these processes is that fluid bed granulators, coaters and dryers generate a large amount of dust that fills the process air used. Therefore, the above-described devices require the use of a filtration system in order to prevent the release of dust into the environment.

One such filtration system is a bag filtration system as described in U.S. patent No.5,446,974 to Gubler, which is incorporated herein by reference. The Gubler patent discloses a filter assembly having a cylindrical fluidized bed chamber in which process air enters at one end, is filtered by one or more bag filters, and then exits at the opposite end. During operation, the bag filter is rigidly attached to the mounting plate within the filter plenum, and is disconnected and removed from the filter assembly for servicing.

The single bag filter disclosed in the Gubler patent includes a flexible filter bag that is clamped over an underlying rigid frame. During operation, the filter bag is formed in a collapsible shape around and through the side bars of the rigid frame. Periodic reverse air pulses are applied to the bag filter forcing the filter bags outwardly from the rigid frame and removing particulate matter accumulated on the filter bags, thereby periodically sweeping the filter bags. While this is clearly effective, the filter bags must eventually be removed for cleaning or replacement.

Of course, there are a variety of other filter devices, filters and bag filters that can also be effectively used to filter process air. For each of the filtration systems described above, the difficulty of cleaning or replacing the filters in the fluidized bed system can increase costs and limit the run time of the filtration system and its corresponding fluidized bed system.

Disclosure of Invention

The present invention relates generally to a filter apparatus for a fluidized bed processor. The filter apparatus generally includes a fluidized bed chamber, a filter mount transport mechanism within the fluidized bed chamber, and a filter mount to receive the filter. The filter mount transport mechanism typically has one or more filters that are connected to corresponding filter mounts on the support structure. The filter mount transport mechanism may also include an indexing bar that rotationally secures the filter mount transport mechanism in the operating position. For example, in one embodiment of the invention, in the first position, air is filtered through the filter during operation of the filter assembly, and in the second position, the individual filters on the filter mount transport mechanism can be easily inspected, serviced, and/or replaced.

According to one embodiment of the invention, the strainer assembly transport mechanism further comprises at least one filter unit to form a movable strainer bundle. A preferred filter unit comprises a rigid frame, the flexible filter media being arranged relative to said frame such that the flexible filter media extends at least partially through an opening in the frame and into the rigid frame when the filter unit is subject to process air flow, the filter unit further comprising means to secure part of the flexible filter media to the rigid filter frame. Embodiments of the present invention may also include a sweep mechanism located intermediate the outlet openings for removing particulate matter accumulated on the flexible filter media by causing the flexible filter media to briefly flex outwardly from the rigid frame such that the flexible filter media extends substantially out of the openings. A blow-off tube is one such cleaning mechanism.

According to another embodiment of the invention, the filter mount transport mechanism further comprises an indexing rod. In this embodiment, the filter device further comprises at least one guide rod receiver, such as a tube or a ring, connected to the fluidized bed chamber. The index rod receiver is configured to receive the index rod to rotatably secure the filter mount transport mechanism in a desired rotational position when in the first position. Preferably, the number of index rod receivers is equal to the number of filter units to ensure a desired alignment between the filter units and other elements of the filter assembly, such as the blow-out tubes.

A method of servicing a filter in a fluid bed system according to the present invention includes first providing a fluid bed chamber in a filtration apparatus, the fluid bed chamber having a movable filter bundle having at least one filter attached thereto at a first location therein. Optionally, a portion of the fluidized bed chamber is swung outwardly away from the fluidized bed system and the product container is removed, thereby forming an open space for filter servicing. The movable filter bundle is then moved to a second position within the fluidized bed chamber. The filter is inspected, serviced and/or replaced at the second location.

According to one aspect of this embodiment of the invention, the first position comprises a raised position within the fluidized bed chamber wherein the filter device is capable of acting on filtered process air, and the second position comprises a lowered position within the fluidized bed chamber wherein the at least one filter is readily accessible for servicing.

Servicing the filter can include refurbishing the reusable bag filter by removing the filter element from the movable filter bundle, removing the bag filter media from the substantially rigid frame, and applying a different bag filter media to the substantially rigid frame, and attaching the refurbished filter to the movable filter bundle. Alternatively, the method can include replacing the filter simply by removing the filter from the movable filter bundle and connecting a different filter to the movable filter bundle. Yet another embodiment includes replacing the bag filter media on the underlying rigid frame that is still connected to the filter mount transport mechanism.

These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.

Brief Description of Drawings

In order that the manner in which the above recited and other features of the invention are obtained will be more fully understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

FIG. 1 is a filter assembly according to one embodiment of the present invention;

FIG. 2 is a view of components of a filter assembly according to one embodiment of the invention;

FIG. 3 is another view of a filter assembly according to one embodiment of the invention;

FIG. 4 is a view of another component of a filter assembly according to one embodiment of the invention;

FIG. 5 is a view of yet another component of a filter assembly according to an embodiment of the present invention;

FIG. 6 is yet another view of another component of a filter assembly according to an embodiment of the present invention; and

fig. 7 is yet another view of another component of a filter assembly according to an embodiment of the present invention.

Disclosure of Invention

The present invention relates to an improved filter assembly for a fluidized bed system. The assembly generally includes a filter mount transport mechanism that is selectively movable to first and second positions, such as raised and lowered positions, within the fluidized bed chamber. In the first position, during operation of the filter assembly, air is filtered through the filter attached to the filter mount transport mechanism. In the second position, individual filters can be quickly inspected, serviced, and/or replaced. Thus, the filter assembly according to the present invention minimizes the fluid bed system down time required to service the filter apparatus.

Because the filter device according to the invention is easier and faster to maintain than conventional filter devices, it is easier to maintain. For example, conventional filtration devices often have difficulty accessing the filter, and often a significant portion of the fluidized bed system must be disassembled to access the filter for servicing, whereas the filter bundle of the filtration assembly of the present invention is readily accessible when in the second position.

Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein it is shown and described what are presently preferred embodiments of the invention. As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various, obvious aspects all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known aspects of fluid bed and filtration processes and machinery have not been described in particular detail in order to avoid unnecessarily obscuring the present invention.

It is to be understood that the same structures are provided with the same reference numerals in the figures, which are diagrammatic and schematic representations of embodiments of the invention and are not necessarily drawn to scale. Further, the drawings show only the structures necessary for understanding the description of the present invention. Additional structures known in the art are not included to maintain the clarity of the drawing.

Referring now to the drawings, wherein like structures are provided with like reference designations, FIG. 1 depicts one embodiment of a fluidized bed system 10. By way of example, and not by way of limitation, the fluidized bed system 10 can be conceptually divided into one or more zones or chambers. The illustrated embodiment shows 5 such regions: an outlet plenum 12, a filter housing chamber 14, an expansion chamber 16, a product container 18, and an inlet plenum 20. Sometimes, it will also be necessary to refer to the fluidized bed chamber 17, which includes the filter housing chamber 14 and the expansion chamber 16. These areas will be discussed in further detail hereinafter, while some areas are more relevant to the present invention than others and require more discussion.

The location of the inlet plenum 20 is where the process air enters the fluidized bed system 10 and is directed upward toward the filter housing chamber 14. The process air is used to maintain the particulate matter in the fluidized bed system in a fluidized state.

Product container 18 is a conical chamber in which at least a portion of the fluidized bed is located when fluidized bed system 10 is in operation. When the fluidized bed system 10 is not in operation, product particles settle from the fluidized state and are collected in the product container. According to one embodiment of the present invention, product container 18 is connected to a movable trailer 21 so that it can be quickly disconnected from fluidized bed system 10, allowing product particles that have accumulated in product container 18 to be removed and exposing the open space between inlet plenum 20 and fluidized bed chamber 17.

After leaving product container 18, the air flows upward through expansion chamber 16, into filter housing chamber 14, and out of outlet plenum 12. In one embodiment, a vacuum is created in the fluidized bed system 10 by a fan (not shown) located at the upper end of the fluidized bed chamber 17. Furthermore, the binding solution used in the granulation process is preferably placed inside the expansion chamber 16.

Within the filter housing chamber 14 is a filter mount transport mechanism 22, as shown schematically in more detail in fig. 2. The filter housing chamber 14 communicates with the expansion chamber 16 therebelow, said chamber 14 having an opening in its upper side where the filter mount transport mechanism 22 is sealingly connected.

Outlet plenum 12, filter housing chamber 14, expansion chamber 16, product container 18, and inlet plenum 20 can each be formed of a variety of materials that are not susceptible to corrosion and that do not react unfavorably with the materials used in granulation. By way of non-limiting example, stainless steel and plastic are often suitable, as are combinations of stainless steel, plastic, and other non-corrosive materials. Furthermore, those skilled in the art will recognize that the details set forth herein with respect to outlet plenum 12, filter housing chamber 14, expansion chamber 16, product container 18, and inlet plenum 20 are merely illustrative of one preferred embodiment and are not limiting of the present invention.

Fig. 1 shows the filter mount transport mechanism 22 (and movable filter bundle 23) in a first position 24. As used herein, the term "filter mount transport mechanism" describes a mobile device in which the filter may or may not be a part thereof. Also as used herein, the term "movable filter bundle" is used to refer to a filter mount transport mechanism 22 that includes one or more filters and is movable between two or more positions. Accordingly, as shown in FIG. 1, in the first position 24, the top surface of filter mount transport mechanism 22 is disposed at the intersection of filter housing chamber 14 and outlet plenum 12 such that filter mount transport mechanism 22 is substantially located within filter housing chamber 14.

The support assembly is adapted to support the filter mount transport mechanism 22 in either the first or second position. As shown in fig. 3, the support assembly may include a cable 28 associated with the filter mount transport mechanism 22. Alternatively, as a non-limiting example, the support assembly may include a belt, chain, rod, or other structure that allows the filter mount transport mechanism 22 to move between the first and second positions. In addition, movement of the filter mount transport mechanism 22 can be accomplished using a variety of devices in combination with the support means, including pulleys, motors, cranks, and the like.

As also shown in fig. 3, the expansion chamber 16 can be pivoted away from the fluidized bed system 10 on a hinge, leaving an open space. In addition, product container 18 is positioned above trailer 21, as shown in FIG. 1, and can be completely removed. The combination of the rotation of expansion chamber 16 away from fluidized bed system 10 and the removal of product container 18 forms a filter servicing open space 36.

Accordingly, filter mount transport mechanism 22 is selectively movable by the support assembly to first position 24 and second position 26 such that the top surface of filter mount transport mechanism 22 is either within filter housing chamber 14 (the first position) or within filter service open space 36 (the second position). However, before filter mount transport mechanism 22 can be moved to second position 26, an open space 36 for filter servicing is created by the rotation of expansion chamber 16 away from fluidized bed system 10 and the removal of product container 18. Thus, the filter assembly transport mechanism 22 is easily accessible to filter assembly operators for servicing the filters.

In the first position of the embodiment shown in fig. 1, the filter device is in an operating mode for filtering process air through the device, and in the second position of fig. 3, the filter device is in a maintenance mode for servicing and/or inspecting the filter unit 29.

Compatible filters include single-use and reusable filter elements. Single use filter units can be quickly and easily replaced, while reusable filter units can be quickly and easily maintained by removing the used filter unit and refurbishing it or replacing it with a new or previously refurbished filter unit.

U.S. Pat. No.5,446,974 to Gubler, previously incorporated by reference in the specification (hereinafter "Gubler patent"), describes a compatible reusable filter unit arrangement. The filter unit arrangement will be described hereinafter to provide an illustration of a compatible device. However, those skilled in the art will appreciate that a variety of filter unit designs can be used with the present invention, including removable filter units as well as permanently attached filter units.

Accordingly, the Gubler patent discloses a filter unit assembly generally comprising a rigid filter frame, a filter bag, a clamp, and a gasket. The rigid filter frame comprises a cylindrical device having a generally flat top, a flat bottom, and parallel filter frame rods between the top and bottom. The filter top has a plate covering a portion of the filter top and a screw that allows the filter frame to be attached to a mount of the filter assembly, such as filter mount 44 shown in fig. 4. The top also has one or more openings to allow air to flow through the filter. The filter bottom is a solid plate that provides support for the filter frame rods. The filter frame rods are at one end at the perimeter of the top plate and at the other end at the perimeter of the bottom plate such that the side rods form the side wall shape of the filter frame assembly. The filter frame is generally reusable and may be made from a variety of rigid materials, such as plastic, metal, hard rubber, and wood, so long as they are strong. In addition, the size and shape of the filter frame can be varied to suit the desired filtering application.

The filter bag has an open top allowing the filter bag to be pulled up onto the filter frame during installation until the bottom media of the filter bag abuts the filter floor. The filter bag has a plurality of pleats so that the filter bag can expand during sweeping and contract during normal operation. During operation of the filter assembly, as process air acts on the filter bags, the filter bags form around and through the rigid frame rods in a manner that provides increased filter surface area in a minimal space. During use, particulate matter gradually covers the surface of the filter bag, reducing its filtering effectiveness. Advantageously, when a pulse of reverse air flow is applied to the outlet side of the filter bag, the filter bag is caused to stretch outwardly away from the filter frame, whereby the coated particles are shed from the outer fibers. This can be achieved without stopping the filtration process. Finally, the filter bag of the Gubler patent can be removed from the filter frame and washed in a washing machine prior to reuse.

The clamp secures the filter bag in a top position of the filter assembly. The clamp clamps around the perimeter of the filter frame and filter bag so that the filter bag is secured in a fixed position on top of the filter assembly. A gasket is also used to ensure that the filter assembly forms a tight seal against the filter mount.

One reason Gubler filter bags are advantageous is that they can be replaced in minutes, whereas many other conventional filter bag systems take hours to replace. Thus, the combination of the presently disclosed movable filter bundle and the Gubler filter bag provides a more rapid filter maintenance system. However, other reusable and single-use conventional filter designs are compatible with the removable filter bundle of the present invention.

Referring now to FIG. 4, according to one embodiment of the present invention, filter mount transport mechanism 22 includes a support structure 40 as an integral component thereof, coupling each seal 42, filter mount 44, guide rod 46 and connection block 48 into a single adhesive unit. The particular configuration of support structure 40 is not critical so long as it provides sufficient strength to support the weight of the various components of filter mount transport mechanism 22 and prevent the passage of air from locations other than openings 49 in filter mounts 44. As with each component of the fluidized bed system 10, the support structure 40 can be formed of any suitable material that does not corrode when in contact with the process material. For example, suitable materials may include stainless steel, plastics, other non-corrosive materials, and combinations of these materials.

The specific design of the filter mount 44 will vary depending on the particular filter unit used, but will include, for example, a filter receiving member that includes a threaded bore for receiving threads on the filter unit. Alternatively, filter mounts 44 can be permanently attached to at least a portion of the respective filters such that only a portion of each filter, such as the filter media, is removed for filter servicing. Although fig. 3 shows 5 filter mounts, one skilled in the art will recognize that the number of mounts can be varied to accommodate the filtering requirements of the filter apparatus. For example, 1, 2, 3, 4, or 6 fasteners may also be used.

Index rod 46 and connection block 48 illustrate two embodiments of connecting the filter mount transport mechanism 22 and the elements of the fluid bed system 10. Index rod 46 acts as a stabilizing rod to mount filter mount transport mechanism 22 in a desired rotational position when in first position 24 by cooperating with index rod receiver 60 on fluid bed system 10, as shown in fig. 5. In the lowered position, index rod 46 no longer engages index rod receiver 60, and therefore does not restrict rotation of the movable filter bundle. Thus, the operator can easily rotate the movable filter bundle 23 to access a desired filter.

Fig. 5 is a top view of the fluidized bed system 10 of fig. 1. As shown, index rod receiver 60 includes a plurality of openings arranged in a circular pattern about a central axis. Preferably, the number of index rod receivers 60 is equal to the number of filter mounts 44 and filter units 29, so that regardless of which index rod receiver 60 mates with index rod 46, each filter mount 44 and filter unit 29 is disposed in a desired orientation with respect to fluidized bed system 10 and blow out tube 64, as shown in FIGS. 6 and 7.

Accordingly, index rod 46 is positioned a distance from the center of filter mount transport mechanism 22 that corresponds to the distance from the center of the group of index rod receivers 60 to the center of one index rod receiver 60. This enables index rod 46 to be connected if it is in line with each index rod receiver 60 as they are brought together.

Although index rod receiver 60 may include a plurality of tubes sized to fit index rod 46, index rod receiver 60 may also include a loop and a non-enclosing structure such as a U-shaped member. The exact shape of index rod receivers 60 is not critical so long as they rotationally secure index rods 46, and thus movable filter bundle 23, in the desired position. Thus, the present design is particularly advantageous because guide rod 46 does not have to have any particular degree of rotation, as it will necessarily be aligned when guide rod 46 is inserted into one of guide rod receivers 60 by lifting.

According to one embodiment of the invention, as shown in FIGS. 1-4, the connection block 48 includes a cable attachment aperture 50 for attaching the cable 28. The cable attachment holes 50 are located in the center of the filter mount transport mechanism 22 so as to act as a single support point for the entire filter mount transport mechanism 22, while the weight of the mechanism 22 is evenly distributed around the periphery of the attachment holes 50.

Of course, as noted above, the support assembly is not limited to the cable 28 but can include a variety of other assemblies that can be used to raise and lower the filter mount transport mechanism 22. Thus, structures other than the cable attachment holes 50 and attachment blocks 48 can be used to provide a suitable assembly for attaching the support assembly to the filter mount transport mechanism 22. Non-exclusive examples include clamps, hooks, and/or a plurality of support assembly attachment members located at various locations on filter mount transport mechanism 22.

Referring now also to FIG. 2, according to one embodiment of the invention, cables 24 are connected to the connection block at cable connection holes 50 and pass through cable ducts 30 located on the outlet plenum 12. The cable 28 passes through a pulley mount 32 to a corresponding pulley (not shown) located thereon. The cable 28 can be connected to a pulley having a motor, crank or other device acting thereon. Alternatively, the cable 28 can extend over the pulley mount 32 and the outlet plenum 12 for connection to a motor, crank, or other device outside of the outlet plenum 12.

Fig. 6 is a top view of the outlet plenum 12 and fig. 7 is a perspective view of the outlet plenum 12. The outlet plenum 12 includes a dome portion 62 and a cylindrical portion 63 attached thereto. A plurality of blow-out pipes 64 are connected to the cylindrical portion 63. The blow-out tubes 64 communicate with additional piping and a blowing system (not shown) that coordinates the sequential blowing of air to each blow-out tube 64 on a predetermined schedule. The blow-out tubes are preferably positioned such that each blow-out tube is aligned with one filter attached to filter mount transport mechanism 22 when index rod 46 is mated with one of index rod receivers 60.

The purpose of aligning the filter unit 29 and the blow-off pipe 64 is so that the fluidized bed system 10 has the ability to periodically sweep away process material that it is plugging. This is accomplished by applying a reverse pulse of air through the blow-off tube 64 to the outlet side of each filter unit 29 causing the filter bag to flex outwardly from the center of the device frame. The air pulse serves to remove the clogged particles accumulated on the filter unit 29 as described above. This is preferably done in another way so that only one filter receives a purge of reverse air at a given time. The timing of the air pulses is triggered by an automatic periodic timing device cooperating with the valve manifold.

The actuator 66 is attached to the upper edge of the filter housing chamber or directly to the dome portion 62. According to one embodiment of the present invention, actuator 66 cooperates with filter mount transport mechanism 22 and outlet plenum 12 to ensure that seal 42 forms a tight seal between filter mount transport mechanism 22 and outlet plenum 12.

Accordingly, a preferred method of operating the present invention is as follows.

First, the filter device as described above is provided with a fluidized bed chamber therein. A movable filter bundle having at least one filter attached thereto is disposed at a first location within the fluidized bed chamber. The first position within the fluidized bed chamber is a position where the filter means can act to filter the process air, while the second position is a position where at least one filter on the movable filter bundle 23 can be easily accessed for servicing. Although it is preferred that the first position is a raised position and the second position is a lowered position, those skilled in the art will appreciate that the first and second positions can have different relationships with each other, such as being parallel to each other or the second position being a raised position. However, for the sake of brevity, further reference is made herein to embodiments having only a first position elevated relative to a second position.

For maintenance, the process air entering the filter device is stopped and the expansion chamber 16 is pivoted on the hinge 34 into the open position, and the trailer 21 together with the product container 18 is removed. As a result, a filter servicing open space 36 is formed. Movable filter bundle 23 is then moved to a second position within filter servicing open space 36. In this manner, the movable filter bundle 23 is very accessible to an operator and the filters can be inspected, serviced and/or replaced.

According to one embodiment of the invention, the at least one filter is a filter unit that can be selectively attached to or removed from the movable filter assembly. Thus, after the movable filter assembly is lowered, the filter element is removed from the movable filter assembly and a new or refurbished filter element is attached. This process is repeated on each filter on the movable filter bundle 23.

In those embodiments where the support assembly incorporates a flexible cable 28, the movable filter bundle 23 is free to rotate in the lowered position. Thus, an operator of the fluidized bed system can rotate the movable filter bundle to sequentially remove and connect each used and new filter.

According to one embodiment of the invention, a filter includes a filter element having a rigid frame with a plurality of openings therein and a filter media covering the openings. An example of such a filter is described in the Gubler patent, which is previously incorporated by reference. The step of replacing such filters preferably includes removing the at least one filter from the movable filter bundle 23, removing the filter media from the generally rigid frame, applying a different filter media to the generally rigid frame, thereby refurbishing the filter and attaching the refurbished filter to the movable filter bundle 23. Alternatively, such filters can be serviced by removing and replacing the filter media while the underlying rigid frame remains attached to the filter mount transport mechanism.

After the replacement of all filters is completed, the support assembly is moved, thereby lifting the movable filter bundle 23 to the first position. In this position, index rod 46 engages any one of index rod receivers 60 on outlet plenum 12 to rotationally secure movable filter bundle 23 for operation.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (26)

1. A filter apparatus for filtering process air generated by a fluid bed granulator, coater or dryer comprising:

a fluidized bed chamber;

a filter mount transport mechanism including at least one filter mount for receiving a filter and having:

a first position wherein the filter mount is in place for filtering process air; and

a second position in which the filter holder is in place for filter servicing.

2. The apparatus of claim 1 wherein the filter mount transport mechanism further comprises a support structure and a seal that prevents process material from bypassing the filter mount transport mechanism.

3. The apparatus of claim 1, further comprising a support assembly coupled to the fluidized bed chamber and the filter mount transport mechanism for selectively raising and lowering the filter mount transport mechanism within the fluidized bed chamber.

4. The apparatus of claim 1, further comprising at least one filter for filtering process air used by the fluid bed granulation apparatus, coater, or dryer.

5. The apparatus of claim 4, wherein the at least one filter comprises:

a rigid frame having a housing frame, an outlet aperture, and a plurality of apertures;

a flexible filter media arranged relative to the frame such that the flexible filter media extends at least partially through the opening into the rigid frame as process air passes through the filter unit;

a clamp securing a portion of the flexible filter media to the rigid filter frame.

6. The device of claim 5, wherein the filter device further comprises a sweep mechanism proximate the outlet opening for removing particulate matter accumulated on the flexible filter media by causing the flexible filter media to briefly flex outwardly from the rigid frame such that the flexible filter media extends substantially out of the opening.

7. The apparatus of claim 5, wherein the filter media comprises a pleated flexible filter bag.

8. The apparatus of claim 1, wherein:

the filter assembly transport mechanism further comprises a guide rod; and is

The filter apparatus further includes at least one index rod receiver connected to the fluidized bed chamber for receiving the index rod to place the filter mount transport mechanism in a desired rotational position when in the first position.

9. The device of claim 8, further comprising at least one filter unit, and wherein the number of guide rod receivers is equal to the number of filter units.

10. The apparatus of claim 1, further comprising 3 filter mounts.

11. The device of claim 1, further comprising 5 filter mounts.

12. The apparatus of claim 4, wherein the filters are quickly removable from the support structure to minimize the time required to replace one filter with another.

13. The apparatus of claim 4, wherein the filter is connected to the filter mount by a screw.

14. The apparatus of claim 4, further comprising a seal between the filter and the support structure that prevents process material from bypassing the filter.

15. A filter apparatus for filtering process air generated by a fluid bed granulator, coater or dryer comprising:

a fluidized bed chamber;

a movable filter bundle within the fluidized bed chamber, the movable filter bundle having a raised position in which the movable filter bundle is in position for filtering process air and a lowered position in which the movable filter bundle is in position for filter servicing, the movable filter bundle comprising:

a support structure;

a filter mount;

connecting blocks;

a guide rod; and

at least one filter unit for filtering process air generated by a fluid bed granulator, coater or dryer, the filter unit having a fastening device connecting the filter unit to a filter fixture;

a support assembly connected to the connecting block for selectively raising and lowering the movable filter bundle within the fluidized bed chamber; and

at least one guide bar receiver connected to the fluidized bed chamber for receiving a guide bar cable to place the movable filter bundle in a desired rotational position when in the lifted position.

16. The apparatus of claim 15, wherein the number of guide rod receivers is equal to the number of filter units.

17. The apparatus of claim 15 further comprising a seal between said movable filter bundle and said fluidized bed chamber that prevents process material from bypassing the movable filter bundle.

18. The apparatus of claim 15, further comprising at least one blow-out tube, the number of blow-out tubes being equal to the number of filter units, the blow-out tubes being positioned such that each blow-out tube is aligned with each filter unit when in the lifted position.

19. A method of servicing a filter in a filtration device, comprising:

providing a fluid bed chamber within the filter apparatus, the fluid bed chamber having a movable filter bundle therein at a first location, the movable filter bundle having at least one filter attached thereto;

selectively moving the movable filter bundle to a second position; and

servicing the at least one filter while in the second position.

20. The method of claim 19, wherein:

the first position comprises a raised position within the fluidized bed chamber wherein the filter arrangement acts to filter the process air; and

the second position comprises a lowered position wherein the at least one filter is accessible for servicing.

21. The method of claim 20, wherein:

at least a portion of the movable filter bundle is in the open space for filter servicing when the movable filter bundle is in the lowered position.

22. The method of claim 19, wherein the filter comprises:

a substantially rigid frame having a plurality of openings; and

a filter medium covering the plurality of openings.

23. The method of claim 22, wherein servicing the filter comprises:

removing the at least one filter from the movable filter bundle;

removing the filter media from the substantially rigid frame;

applying a different filter media to the substantially rigid frame, thereby refurbishing the filter; and

attaching the refurbished filter to the movable filter bundle.

24. The method of claim 19, wherein servicing the filter comprises:

removing the at least one filter from the movable filter bundle; and

different filters are connected to the movable filter bundle.

25. The method of claim 22, wherein servicing the filter comprises:

removing the filter media from the substantially rigid frame without removing the at least one filter from the movable filter bundle; and

applying a different filter media to the substantially rigid frame to refurbish the filter.

26. The method of claim 19, wherein:

said filter mount transport mechanism being rotatably held in place in the raised position by an indexing rod thereon cooperating with an indexing rod receiver located on the filter unit; and

the filter mount transport mechanism is freely rotatable in the lowered position.