Filter purification device and powder / granular material processing device

Abstract

This filter purification device provides high purification performance even for filters composed of highly rigid filter media, such as metal or ceramic filter media. [Solution] The filter purification device 5 comprises a gas ejection unit 6 inserted inside the filter F, a gas supply unit 7 that supplies compressed air P1 to the gas ejection unit 6, and a moving mechanism 8 that moves the gas ejection unit 6 in the vertical direction. The outer peripheral surface (opposing peripheral surface) of the nozzle portion 6a of the gas ejection unit 6 faces the inner peripheral surface of the filter material Fa with a gap between them, and a gas outlet is provided on the opposing peripheral surface of the nozzle portion 6a. When purifying the filter F, compressed air P1 is supplied to the gas supply unit 7, and while compressed air is ejected from the gas outlet of the nozzle portion 6a of the gas ejection unit 6, the moving mechanism 8 moves the gas ejection unit 6 in the vertical direction inside the filter F.

Description

Technical Field

[0001] The present invention relates to an apparatus for purifying a filter for solid-gas separation, and a granular material processing apparatus provided with this filter purification apparatus.

Background Art

[0002] For example, a fluidized bed apparatus, which is an example of a granular material processing apparatus, is an apparatus that performs processes such as granulation, coating, and drying while suspending and fluidizing granular materials accommodated in a processing chamber of a processing vessel by a processing gas introduced from the bottom of the processing vessel. In this type of fluidized bed apparatus, a filter is disposed above the processing chamber in order to separate granular particles from the exhaust gas of the processing gas mixed with granular particles (fine powder, etc.). As the filter, in addition to a filter composed of a cloth filter medium called a bag filter, a cartridge-type filter composed of a cylindrical filter medium made of resin, metal, or ceramic and a holding member for holding the filter medium is used (Patent Documents 1 to 3).

[0003] Due to use, the granular particles separated from solid and gas may adhere to the inside or the outer peripheral surface (collection surface) of the filter medium, which may cause a decrease in filtration performance (clogging). Therefore, it is necessary to timely remove the granular particles adhering to the filter medium to restore the filtration performance. As a means for restoring the filtration performance, in Patent Documents 1 to 3, compressed air such as pulse air is supplied into the filter, passed through the inside of the filter medium, and ejected from the side of the outer peripheral surface, thereby blowing off and removing the granular particles adhering to the filter medium (backwashing).

[0004] Specifically, Patent Document 1 describes a method of backwashing in which a pulse jet nozzle is placed above the exhaust port of a cartridge-type filter, and pulsed air is ejected from the pulse jet nozzle into the interior of the filter. Patent Document 2 describes a method of backwashing in which a gas ejection pipe is placed in the center of a cartridge-type filter, and compressed air is ejected from multiple gas ejection ports provided in the gas ejection pipe. Patent Document 3 describes a method of backwashing in which a porous pipe is placed in the center of a bag filter, and compressed air is ejected from perforations provided in the porous pipe. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-313089 [Patent Document 2] Japanese Patent Publication No. 2011-36829 [Patent Document 3] Japanese Utility Model Publication No. 62-13516 [Overview of the project] [Problems that the invention aims to solve]

[0006] While filters made of metal or ceramic media offer excellent filtration performance, they also have drawbacks. Because the media are highly rigid and do not deform under the pressure of backwash gas, granular particles adhering to the media are not adequately removed, resulting in a failure to restore filtration performance, or requiring a large supply or extended supply time of backwash gas to restore performance. This tendency is particularly pronounced when processing highly adhesive and cohesive granular particles.

[0007] Furthermore, in configurations such as Patent Document 1, where compressed gas is ejected from the top of the filter towards the inside of the filter, the pressure of the compressed gas weakens at the bottom of the filter, often preventing uniform purification of the entire filter. Also, in configurations such as Patent Documents 2 and 3, where a gas ejection tube is inserted inside the filter, the pressure of the compressed gas ejected from the gas outlet at the bottom of the gas ejection tube weakens, sometimes preventing uniform purification of the entire filter. These tendencies become more pronounced with filters that have a large axial length.

[0008] The objective of the present invention is to provide a filter purification device that exhibits high purification performance even for filters composed of highly rigid filter media, such as metal or ceramic filter media. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a filter purification device for purifying a solid-gas separation filter having a cylindrical filter medium, comprising: a gas ejection unit inserted into the filter; a gas supply unit that supplies compressed gas to the gas ejection unit; and a moving mechanism that moves the gas ejection unit in the axial direction of the filter, wherein the gas ejection unit has a facing circumferential surface that faces the inner circumferential surface of the filter medium with a predetermined gap between them, and a gas ejection port provided on the facing circumferential surface, and when purifying the filter, the compressed gas supplied from the gas supply unit is ejected from the gas ejection port of the gas ejection unit toward the inner circumferential surface of the filter medium, and the gas ejection unit is moved in the axial direction inside the filter by the moving mechanism, thereby providing a filter purification device.

[0010] In the above configuration, it is preferable that the gas nozzle has an annular slit shape that is continuous in the circumferential direction of the opposing circumferential surface.

[0011] Furthermore, the gap (δ) between the opposing circumferential surface and the inner circumferential surface of the filter material is preferably δ = 0.00125D to 0.1D with respect to the diameter D of the inner circumferential surface of the filter material, and the width (h) in the axial direction of the opposing circumferential surface is preferably h = 0.01L to 0.1L with respect to the axial length (L) of the filter material. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a filter purification device that exhibits high purification performance even for filters composed of highly rigid filter media. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view showing one example of the configuration of a fluidized bed apparatus equipped with a filter purification device according to the embodiment. [Figure 2] This is a cross-sectional view of a filter purification device. [Figure 3] Figure (a) is an enlarged cross-sectional view showing the gas ejection section and its surrounding area, and Figure (b) is a view from above of the section cut along line bb in Figure (a). [Figure 4] This diagram schematically shows the flow of treated gas during filter purification. [Figure 5] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 6] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 7] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 8] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 9] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 10] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device. [Figure 11] This diagram schematically illustrates an example of the operation of the mobile mechanism of a filter purification device.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] FIG. 1 shows an example of the configuration of a fluidized bed apparatus as a powder and granular material processing apparatus.

[0016] The processing container 1 of the fluidized bed apparatus includes a processing chamber 2 for granulating, coating, or drying powder and granular materials, for example, drying powder and granular materials, and an exhaust chamber 3 provided above the processing chamber 2. The processing chamber 2 and the exhaust chamber 3 are partitioned by a partition wall 4.

[0017] At the bottom of the processing chamber 2, a gas dispersion plate 2a formed of a perforated plate (or wire mesh) such as punching metal is disposed. The processing gas G such as hot air supplied from a supply duct (not shown) to the supply chamber is introduced into the processing chamber 2 through the gas dispersion plate 2a. Incidentally, when performing granulation or coating treatment, a spray nozzle for spraying a spray liquid (film agent liquid, binder liquid, etc.) is installed in the processing chamber 2.

[0018] In the upper space of the processing chamber 2, one or more filters, for example, a plurality of cartridge-type filters F are arranged. Each filter F is detachably attached to the partition wall 4 with mounting screws or the like. The processing chamber 2 and the exhaust chamber 3 communicate with each other through the filter F, and the processing gas G that has passed through the filter F from the processing chamber 2 and entered the exhaust chamber 3 is exhausted from the exhaust outlet 3a of the exhaust chamber 3 to an exhaust duct (not shown). When the processing gas G passes through the filter F, solid particles (fine powder of powder and granular particles, etc.) mixed in the processing gas G are captured by the filter F (solid-gas separation). Further, above the exhaust chamber 3, a filter purification device 5 for jetting compressed gas, for example, compressed air, into the filter F to purify the filter F (backwashing) is installed.

[0019] In this embodiment, the filter F is a cartridge-type metal filter composed of a cylindrical filter material Fa made of metal (such as a metal mesh, a woven or nonwoven metal fiber fabric, or a porous metal material such as sintered metal) and a metal or resin retaining member that holds it. The filter F has an exhaust port Fb at one end in its axial direction X (the upper end in this embodiment), and the other end in its axial direction X (the lower end in this embodiment) is closed by a retaining member (end cap). The inside of the filter F communicates with the exhaust chamber 3 via the exhaust port Fb. Furthermore, multiple sets of the filter purification device 5 and the filter F are arranged at predetermined intervals along the circumferential direction of the processing container 1, for example, four sets at 90-degree intervals.

[0020] Figure 2 shows the filter purification device 5. The filter purification device 5 includes a gas ejection unit 6 inserted inside the filter F, a gas supply unit 7 that supplies compressed gas, such as compressed air P1, to the gas ejection unit 6, and a moving mechanism 8 that moves the gas ejection unit 6 in the axial direction X (up and down in this embodiment) of the filter F.

[0021] In this embodiment, the gas supply unit 7 includes a gas supply pipe 7a having a gas supply port 7a1 at its upper end. The moving mechanism 8 is configured as a linear actuator, for example, a gas pressure cylinder, particularly an air cylinder, and includes an outer cylinder 8a having intake and exhaust ports 8a1 and 8a2 at its upper and lower ends, respectively, an annular piston 8b disposed inside the outer cylinder 8a, and a hollow operating rod 8c attached to the lower end of the piston 8b. The operating rod 8c extends below the lower end of the gas supply pipe 7a, and a gas ejection unit 6 is connected to the lower end of the operating rod 8c. The piston 8b and the operating rod 8c are externally fitted to the outer circumference of the gas supply pipe 7a and are movable vertically relative to the gas supply pipe 7a and the outer cylinder 8a. When moving vertically, the piston 8b slides against the inner surface of the outer cylinder 8a and the outer surface of the gas supply pipe 7a, and the operating rod 8c slides against the outer surface of the gas supply pipe 7a and the inner surface of the slide bush 8d attached to the lower end of the outer cylinder 8a. The vertical movement of the piston 8b and the operating rod 8c is achieved by switching the supply and exhaust of compressed air P2 to the intake and exhaust ports 8a1 and 8a2 of the outer cylinder 8a.

[0022] As shown in an enlarged view in Figure 3, the gas ejection section 6 has a larger diameter disc-shaped nozzle section 6a than other parts. The outer circumferential surface 6a1 of the nozzle section 6a faces the inner circumferential surface Fa1 of the filter material Fa of the filter F with a small gap δ between them. Hereinafter, the outer circumferential surface 6a1 of the nozzle section 6a will be referred to as the "opposing circumferential surface 6a1". A gas ejection port 6a2 is provided on this opposing circumferential surface 6a1. The gas ejection port 6a2 has a continuous annular slit shape along the circumferential direction of the opposing circumferential surface 6a1. Alternatively, the gas ejection port 6a2 can have the form of a number of ejection holes that open at predetermined intervals along the circumferential direction of the opposing circumferential surface 6a1.

[0023] In this embodiment, the gas ejection section 6 is composed of a tubular first member 6b connected to the outer circumference of the lower end of the operating rod 8c by screw connection or the like, and a tubular second member 6c connected to the outer circumference of the first member 6b by screw connection or the like. The connection between the first member 6b and the operating rod 8c, and the connection between the first member 6b and the second member 6c are each airtightly sealed by a sealing member such as an O-ring. The lower end of the first member 6b is closed by a disc portion 6b1 with a larger diameter than the rest of the section, and the lower end of the second member 6c is a circular flange portion 6c1 with a larger diameter than the rest of the section. The upper surface of the disc portion 6b1 of the first member 6b and the lower surface of the circular flange portion 6c1 of the second member 6c face each other in the vertical direction separated by a small gap S0, forming the nozzle portion 6a. The portion where the gap S0 opens on the opposing circumferential surface 6a1 of the nozzle portion 6a becomes an annular slit-shaped gas ejection port 6a2. Furthermore, a flow passage S is formed inside the nozzle portion 6a, connecting the inside of the operating rod 8c with the gas outlet 6a2. This flow passage S consists of a space S1 and a plurality of communication holes S2 provided at the lower end of the first member 6b, a space S3 that communicates with the space S1 via the communication holes S2, and the aforementioned gap S0 that communicates with the space S3.

[0024] The gap δ between the opposing circumferential surface 6a1 of the nozzle portion 6a and the inner circumferential surface Fa1 of the filter material Fa is set to a value within the range of δ = 0.00125D to 0.1D, with respect to the diameter D of the inner circumferential surface Fa1 of the filter material Fa. Also, the width h in the axial direction X of the opposing circumferential surface 6a1 of the nozzle portion 6a is set to a value within the range of h = 0.01L to 0.1L, with respect to the length L in the axial direction X of the filter material Fa (see Figure 4). The width in the axial direction X of the gas outlet 6a2 is approximately 0.5 to 2 mm.

[0025] The compressed air P1 supplied from the gas supply port 7a1 to the gas supply pipe 7a passes through the inside of the gas supply pipe 7a and enters the inside of the operating rod 8c. From the inside of the operating rod 8c, it passes through the above-mentioned flow passage S inside the nozzle section 6a and is ejected from the gas outlet 6a2 on the opposing circumferential surface 6a1 toward the inner circumferential surface Fa1 of the filter material Fa. The compressed air supplied to the gas supply pipe 7a may be an intermittent flow (pulsed air) or a pulsating flow, but in this embodiment, a continuous flow (steady flow) of compressed air P1 at a constant pressure is supplied to the gas supply pipe 7a.

[0026] The movement mechanism 8 is operated by controlling the supply and exhaust of compressed air P2 to the intake and exhaust ports 8a1 and 8a2 of the outer cylinder 8a. Specifically, when compressed air P2 is supplied to the inside of the outer cylinder 8a from the intake and exhaust port 8a1 at the upper end, and compressed air P2 is exhausted from the inside of the outer cylinder 8a from the intake and exhaust port 8a2 at the lower end, the piston 8b and the operating rod 8c descend. As a result, the gas ejection part 6 moves downward along the axial direction X of the filter F. On the other hand, when compressed air P2 is supplied to the inside of the outer cylinder 8a from the intake and exhaust port 8a2 at the lower end, and compressed air P2 is exhausted from the inside of the outer cylinder 8a from the intake and exhaust port 8a1 at the upper end, the piston 8b and the operating rod 8c rise. As a result, the gas ejection part 6 moves upward along the axial direction X of the filter F. The vertical movement range of the gas ejection section 6 is set so that the opposing circumferential surface 6a1 of the nozzle section 6a moves over the entire length L in the axial direction X of the filter material Fa.

[0027] When purifying the filter F, compressed air P1 is supplied to the gas supply pipe 7a, and the gas ejection unit 6 is moved vertically inside the filter F by the moving mechanism 8 while the compressed air P1 is ejected from the gas outlet 6a2 of the nozzle 6a of the gas ejection unit 6. The compressed air ejected from the gas outlet 6a2 of the nozzle 6a collides with the inner circumferential surface Fa1 of the filter material Fa, which is opposite the nozzle 6aa via a gap δ, passes through the inside of the filter material Fa, and is forcefully ejected from the outer circumferential surface Fa2 of the filter material Fa. As a result, powder and granular material adhering to the inside of the annular area and the outer circumferential surface Fa2 of the filter material Fa, which is opposite the nozzle 6aa, is brushed off the filter material Fa and returned to the processing chamber 2. Furthermore, the operation of the moving mechanism 8 causes the nozzle portion 6a to move vertically over the entire length L of the filter material Fa, thereby purifying the entire filter material Fa in the manner described above. Such purification operations for the filter F can be performed during processing of the powder or granular material, such as drying, granulation, or coating, within the processing container 1.

[0028] In this embodiment, the filter purification device 5 purifies the filter material Fa by ejecting compressed air from a gas outlet 6a2 on the opposing circumferential surface 6a1 of the gas ejection unit 6 (nozzle unit 6a), which faces the inner circumferential surface Fa1 of the filter material Fa via a gap δ. This effectively removes powder and granular material adhering to the inside and outer circumferential surface Fa2 of the filter material Fa. Furthermore, the compressed air ejected from the annular slit-shaped gas outlet 6a2 uniformly purifies the annular area of ​​the filter material Fa facing the opposing circumferential surface 6a1 of the nozzle unit 6a. Moreover, since the gas ejection unit 6 is moved vertically within the filter F by the moving mechanism 8 while purification is performed, the entire surface of the filter material Fa can be uniformly purified. This high purification performance is similarly demonstrated even for filters F with a large filter material length L.

[0029] Furthermore, by making the compressed air P1 (compressed air supplied from the gas supply unit 7 to the gas ejection unit 6) ejected from the gas ejection unit 6 a continuous flow at a constant pressure, pressure fluctuations within the processing container 1a can be suppressed compared to the case where compressed air is ejected in an intermittent or pulsating flow, thereby maintaining the normal operation of the powder and granular material processing within the processing container 1a.

[0030] Figure 4 schematically shows the flow of treated gas G during the purification of filter F by the filter purification device 5. Inside filter F, the pressure of compressed air P1 ejected from the nozzle portion 6a of the gas ejection section 6 and the annular slit-shaped gas ejection port 6a2 into the gap δ between the opposing circumferential surface 6a1 of the nozzle portion 6a and the inner circumferential surface Fa1 of the filter material Fa divides the inside of filter F into upper and lower regions R1 and R2, with the nozzle portion 6a (opposing circumferential surface 6a1) as the boundary. The region R1 above the nozzle portion 6a is closed off at the bottom by the nozzle portion 6a, but since there is an exhaust port Fb at the top, the treated gas G in the processing chamber 2 passes through this region R1 and flows out into the exhaust chamber 3 (ventilated region R1). On the other hand, the region R2 below the nozzle portion 6a is closed off both above and below, so the treated gas G in the processing chamber 2 cannot pass through this region R2 (non-ventilated region R2). Therefore, the effective filtration area of ​​the filter media Fa of filter F is approximately equal to the area of ​​the filter media Fa in the aeration region R1, that is, the area obtained by multiplying the outer diameter D0 of the filter media Fa by the length L1 in the axial direction X of the aeration region R1. Also, the area of ​​the filter media Fa in the non-aeration region R2, that is, the area obtained by multiplying the outer diameter D0 of the filter media Fa by the length L2 in the axial direction X of the non-aeration region R1, is the unfiltered area. The filtration area and unfiltered area of ​​the filter media Fa change in a trade-off relationship as the gas ejection part 6 (nozzle part 6a) moves vertically. When the nozzle part 6a is at the lower end position of the filter media Fa, the filtration area is at its maximum and the unfiltered area is at its minimum. When the nozzle part 6a is at the upper end position of the filter media Fa, the filtration area is at its minimum (effectively zero) and the unfiltered area is at its maximum.

[0031] As described above, as the gas ejection section 6 (nozzle section 6a) moves vertically, the filtration area and unfiltration area of ​​the filter media Fa of the filter F change, which can cause fluctuations in the flow rate of the treated gas G passing through the filter F and thus pressure fluctuations within the treatment chamber 2. Figures 5 to 11 schematically show an example of operating the movement mechanism 8 of the filter purification device 5 so that the sum of the filtration areas (or sum of the unfiltration areas) of the filter media Fa of all sets of filter F is constant when multiple sets (four sets in this embodiment) of the filter purification device 5 and filter F are arranged. In Figures 5 to 11, the sets of the filter purification device 5 and filter F are referred to as "filter sets," and the filter sets visible from left to right in these figures are indicated by the symbols F1, F2, F3, and F4.

[0032] Figure 5 shows the state before the purification of filter F begins. In filter assembly F1, the nozzle portion 6a (gas ejection portion 6) is raised to its maximum position and is at the upper end of the filter media Fa. Therefore, the filtration area of ​​the filter media Fa in filter F in filter assembly F1 is minimized (effectively zero). On the other hand, in filter assemblies F1 to F4, the nozzle portion 6a is lowered to its maximum position and is at the lower end of the filter media Fa. Therefore, the filtration area of ​​the filter media Fa in each filter F in filter assemblies F2 to F4 is maximized. At this time, the filtration area A1 of the filter media Fa in each filter F is A1 ≈ D0 × L, where D0 is the diameter of the outer surface Fa2 of the filter media Fa and L is the length of the filter media Fa. Therefore, the treated gas G in the treatment container 1 is separated into solid and gas by the filters F of the three filter assemblies F2 to F4 with a filtration area of ​​(3 × A1).

[0033] When the purification of filter F begins, as shown in Figure 6, the nozzle portion 6a of filter assembly F1 descends, and in sync with this, the nozzle portion 6a of filter assembly F2 rises. In filter assembly F1, the increase in the air permeability area R1 (increase in filtration area) due to the descending of the nozzle portion 6a is offset by the decrease in the air permeability area R1 (decrease in filtration area) due to the rising of the nozzle portion 6a in filter assembly F2. Therefore, the sum of the filtration areas in filters F of the four filter assembly sets F1 to F4 is maintained at (3 × A1).

[0034] As shown in Figure 7, when the nozzle portion 6a of filter assembly F1 is lowered to its maximum extent and the nozzle portion 6a of filter assembly F2 is raised to its maximum extent, the nozzle portion 6a of filter assembly F1 stops at its lowest position. Then, as shown in Figure 8, the nozzle portion 6a of filter assembly F2 is lowered, and in sync with this, the nozzle portion 6a of filter assembly F3 is raised. In filter assembly F2, the increase in the air permeability area R1 due to the lowering of the nozzle portion 6a is offset by the decrease in the air permeability area R1 due to the raising of the nozzle portion 6a in filter assembly F3. Therefore, the sum of the filtration areas in the filters F of the four filter assembly sets F1 to F4 is maintained at (3 × A1).

[0035] As shown in Figure 9, when the nozzle portion 6a of filter assembly F2 is lowered to its maximum extent and the nozzle portion 6a of filter assembly F3 is raised to its maximum extent, the nozzle portion 6a of filter assembly F2 stops at its lowest position. Then, as shown in Figure 10, the nozzle portion 6a of filter assembly F3 is lowered, and in sync with this, the nozzle portion 6a of filter assembly F4 is raised. In filter assembly F3, the increase in the air permeability area R1 due to the lowering of the nozzle portion 6a is offset by the decrease in the air permeability area R1 due to the raising of the nozzle portion 6a in filter assembly F4. Therefore, the sum of the filtration areas in the filters F of the four filter assembly sets F1 to F4 is maintained at (3 × A1).

[0036] As shown in Figure 11, when the nozzle 6a of filter assembly F3 is lowered to its maximum extent and the nozzle 6a of filter assembly F4 is raised to its maximum extent, the nozzle 6a of filter assembly F3 stops at its lowest position. Then, when the nozzle 6a is lowered and raised between filter assembly F4 and filter assembly F1 as described above, the state returns to that shown in Figure 5. Subsequently, the operations shown in Figures 5 to 11 are repeated as needed. In all states, the sum of the filtration areas in the filters F of the four filter assembly sets F1 to F4 is maintained at (3 × A1).

[0037] In addition to the fluidized bed apparatus described above, the present invention can be widely applied to powder and granular material processing equipment equipped with a filter for solid-gas separation, such as agitation and granulation apparatus. [Explanation of Symbols]

[0038] 1. Processing container 2 Processing Room 3. Exhaust chamber 4 Partition wall 5. Filter purification device 6. Gas ejection section 6a Nozzle section 6a1 Opposing peripheral surface (outer peripheral surface) 6a2 Gas nozzle 7. Gas supply unit 7a Gas supply pipe 8 Moving mechanism 8a Outer cylinder 8b Piston 8c Actuator Rod F filter Fa filter media Fa1 Inner surface Fa2 outer surface δ gap D Diameter of the inner surface of the filter media h width of the opposing surface L - Length of filter media R1 Ventilation area R2 Non-ventilated area F1~F4 filter set

Claims

1. A device for purifying a solid-gas separation filter having a cylindrical filter medium, The filter comprises a gas ejection unit inserted inside the filter, a gas supply unit that supplies compressed gas to the gas ejection unit, and a moving mechanism that moves the gas ejection unit in the axial direction of the filter. The gas ejection section has an opposing circumferential surface that faces the inner circumferential surface of the filter material of the filter via a predetermined gap, and a gas ejection port provided on the opposing circumferential surface. A filter purification device that, when purifying the filter, ejects compressed gas supplied from the gas supply unit toward the inner surface of the filter material from the gas outlet of the gas ejection unit, and moves the gas ejection unit in the axial direction inside the filter by the moving mechanism.

2. The filter purification device according to claim 1, wherein the gas outlet has an annular slit shape that is continuous in the circumferential direction of the opposing circumferential surface.

3. The filter purification device according to claim 1, wherein the gap (δ) between the opposing circumferential surface and the inner circumferential surface of the filter material is δ = 0.00125D to 0.1D with respect to the diameter D of the inner circumferential surface of the filter material.

4. The filter purification device according to claim 1, wherein the axial width (h) of the opposing circumferential surface is h = 0.01L to 0.1L with respect to the axial length (L) of the filter material.

5. The filter purification device according to claim 1, wherein the gas supply unit supplies the compressed gas to the gas ejection unit in a continuous flow at a constant pressure.

6. The filter purification device according to claim 1, wherein the filter material is a metal filter material.

7. A powder and granular material processing apparatus comprising a processing container for powder and granular material and a filter purification device according to any one of claims 1 to 6, The processing container has a processing chamber into which the powder or granular material to be processed is contained and into which a processing gas for processing the powder or granular material is introduced, and an exhaust chamber into which the processing gas introduced into the processing chamber is exhausted, and the processing chamber and the exhaust chamber are separated by a partition wall. The filter is positioned in the processing chamber with one end in the axial direction attached to the partition wall, and the processing chamber and the exhaust chamber are in communication via the filter, in a powder and granular material processing apparatus.

8. Multiple sets of the filter purification device and the filter are arranged at predetermined intervals along the circumferential direction of the processing container. In each of the aforementioned sets of filters, the side of one end in the axial direction from the opposing circumferential surface of the gas ejection portion is a ventilated region through which the treated gas passes, and the side of the other end in the axial direction from the opposing circumferential surface of the gas ejection portion is a non-ventilated region through which the treated gas does not pass. The powder and granular material processing apparatus according to claim 7, wherein the moving mechanism of the filter purification apparatus moves the gas ejection unit such that the sum of the filtration areas or the sum of the unfiltration areas in all sets of filters is constant, with the area of ​​the filter material in the aeration region being the filtration area and the area of ​​the filter material in the non-aeration region being the unfiltered area.

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