Filter mounting structure and decompression device

Abstract

To provide a filter mounting structure and a decompression device capable of using a properly selected generic filter.SOLUTION: A filter mounting structure 24 as a part of a decompression device 10, comprises a filter support part 96 and a filter pressing part 98. The filter support part 96 has: a filter mounting plate part 102 having filter mounting holes 100 each formed in a shape and a size corresponding to a shape and a size of a filter main body 90; and a hooking part 104 hooked on a hooking surface 46 facing outside of a housing space S in an inner periphery 28c of a container opening part 28. A filter flange part 92 and the filter pressing part 98 are disposed between the filter mounting plate part 102 and a suction pipe connected to a pipe body 60 of a connection part 16, and the hooking part 104 is interposed between the inner periphery 28c of the container opening part 28 and the connection part 16, in a state in which the filter main body 90 is inserted into the filter mounting hole 100.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pressure reducing device that reduces the pressure of a storage space that stores an object to be treated, and a filter mounting structure used in the pressure reducing device. [Background technology]

[0002] The reduced pressure drying apparatus described in Patent Document 1 is a type of conventional reduced pressure apparatus, and is equipped with a container, a vacuum pipe for sucking gas from inside the container, and a filter for preventing the material to be treated inside the container from being sucked into the vacuum pipe.

[0003] The filter has a bottomed, tubular filter section with flanges and a bottomed, tubular support frame with flanges, the filter section is placed over the outside of the support frame, and the flanges of the support frame and the filter section are overlapped with each other. The filter is inserted into an opening formed in the connecting end (container opening) of the container, and each flange of the filter is sandwiched between the connecting end (container opening) and the lid (connecting section).

[0004] In the vacuum drying apparatus described in Patent Document 1, the flanges of the filter are designed to fit the shape and size of the connection end (container opening) and the lid (connection), so it was necessary to prepare a dedicated filter. Under these circumstances, there was a need for a filter mounting structure that would allow for the appropriate selection and use of a general-purpose filter. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-148349 Summary of the Invention

[0006] An object of the present invention is to provide a filter mounting structure and a pressure reducing device that allow for the appropriate selection and use of a general-purpose filter.

[0007] In order to achieve the above object, a feature of the filter mounting structure according to the present invention is a filter mounting structure for mounting a filter having a filter body that allows the gas to pass through and captures solids contained in the material to be processed and a filter flange portion provided on an outer periphery of a gas outlet of the filter body to a pressure reducing device that includes a container having a storage space that stores the material to be processed and a container opening for opening the storage space to the outside, a suction pipe that sucks gas from the storage space through an opening formed by the container opening to reduce the pressure of the storage space, and a connecting portion that airtightly connects an upstream end of the suction pipe in the gas flow direction to the container opening, the filter mounting structure including a filter support portion that supports the filter in the storage space and a connecting portion that secures the flow of the gas and a filter pressing portion that presses and fixes the filter flange portion to the filter support portion while holding the filter flange portion in place, the filter support portion having a plate-like filter mounting plate portion with a filter mounting hole formed in a shape and size corresponding to the shape and size of the filter body, and a hook portion that is provided on the outer periphery of the filter mounting plate portion and is hooked onto a hook surface facing outward from the storage space on the inner periphery of the container opening, so that when the filter body is inserted into the filter mounting hole from outside the storage space, the filter flange portion and the filter pressing portion are positioned between the filter mounting plate portion and the suction tube, and the hook portion is sandwiched between the inner periphery of the container opening and the connection portion.

[0008] In this filter mounting structure, the filter mounting hole in the filter support part is formed to a shape and size that corresponds to the shape and size of the filter body, so a variety of filters of different shapes and sizes can be mounted on the filter mounting plate part. This allows for high design freedom and the ability to appropriately select and use versatile, inexpensive filters, thereby reducing manufacturing costs.

[0009] In addition, the filter flange and filter holder are located between the filter mounting plate and the suction tube, and the filter can be supported with a simple structure in which the hook is sandwiched between the inner periphery of the container opening and the connection part, thereby reducing manufacturing costs.Furthermore, the position of the filter on the filter mounting plate can be easily changed by simply changing the position of the filter mounting hole on the filter mounting plate.

[0010] Another feature of the filter mounting structure of the present invention is that the filter mounting plate portion has a plurality of filter mounting holes formed in shapes and sizes corresponding to the shapes and sizes of the filter bodies of each of the plurality of filters, and a confluence space is formed at the upstream end or upstream side of the upstream end of the gas flow in the suction pipe, for merging the gas that has passed through the plurality of filters and guiding it to the suction pipe.

[0011] This filter mounting structure allows multiple filters to be attached to the filter mounting plate, which increases the overall filter area and improves gas suction efficiency. Therefore, a high vacuum can be easily achieved even in a decompression device that generates gas (such as sublimated vapor) in the storage space, such as a freeze-drying device.

[0012] Another feature of the filter mounting structure according to the present invention is that the connection portion has a merging space forming portion that forms the merging space.

[0013] In this filter attachment structure, the connection portion has a joining space forming portion, so it is easier to ensure a wide joining space compared to when the end of the suction tube has a joining space forming portion.

[0014] Another feature of the filter mounting structure according to the present invention is that the filter pressing portion has a merging space forming portion that forms the merging space.

[0015] In this filter mounting structure, the filter pressing portion has the joining space forming portion, so it is easier to ensure a wide joining space compared to when the end of the suction tube has the joining space forming portion.

[0016] Another feature of the filter mounting structure according to the present invention is that the filter pressing portion is formed integrally with the connecting portion.

[0017] In this filter mounting structure, the filter pressing portion is formed integrally with the connecting portion, so the number of parts can be reduced, manufacturing costs can be reduced, and assembly workability can be improved.

[0018] Another feature of the filter mounting structure according to the present invention is that a plurality of air holes are formed in an even distribution over the entire area of ​​the filter pressing portion that faces the filter mounting plate portion.

[0019] In this filter mounting structure, the filter flange can be reliably pressed down by the filter pressing portion regardless of the position, size, or number of filters mounted on the filter mounting plate.

[0020] Another feature of the filter mounting structure of the present invention is that the hooking portion has a cylindrical peripheral wall portion with one opening blocked by the filter mounting plate portion and the other opening open, and a hooking flange portion provided on the outer periphery of the opening end of the peripheral wall portion and hooked onto a hooking surface facing outward from the storage space on the inner periphery of the container opening, and the filter flange portion and the filter holding portion are arranged inside the peripheral wall portion, and the filter holding portion is held down by the connection portion.

[0021] In this filter mounting structure, by changing at least one of the length of the peripheral wall portion in the axial direction and the length of the filter pressing portion, the length of the space in which the filter flange portion is arranged can be appropriately determined according to the thickness of the filter flange portion.

[0022] Another feature of the filter mounting structure of the present invention is that it includes a spacer that is placed between the filter holding portion and the connecting portion while ensuring the flow of the gas, and the filter holding portion is indirectly held by the connecting portion as the spacer is held by the connecting portion.

[0023] In this filter mounting structure, by changing the length of the spacer in the axial direction of the container opening, the length of the space in which the filter flange portion is disposed can be appropriately determined according to the thickness of the filter flange portion.

[0024] Another feature of the filter mounting structure of the present invention is that when the cylindrical inner surface of the container opening is defined as a first surface, the inner surface of the container excluding the first surface is defined as a second surface, and an imaginary surface is imagined that includes the boundary line between the first surface and the second surface, the surface of the filter mounting plate portion facing inward toward the storage space is positioned in a position that overlaps with the imaginary surface.

[0025] In this filter mounting structure, no recess is formed between the surface of the filter mounting plate facing inward into the storage space and the inner surface of the container, thereby preventing the creation of areas in the storage space where foreign matter is likely to accumulate, and ultimately preventing the entry of foreign matter (contamination).

[0026] In order to achieve the above object, the decompression device according to the present invention is characterized by comprising: a container having a storage space for storing a material to be treated and a container opening for opening the storage space to the outside; a suction pipe for sucking gas from the storage space through an opening formed by the container opening to reduce the pressure of the storage space; a connection part for airtightly connecting an upstream end of the suction pipe in the gas flow direction to the container opening; a filter having a filter body for passing the gas and capturing solids contained in the material to be treated and a filter flange part provided on the outer periphery of a gas outlet of the filter body; a filter support part for supporting the filter in the storage space; and a filter pressing portion that presses and fixes the filter support portion, the filter support portion having a plate-shaped filter mounting plate portion with a filter mounting hole formed in a shape and size corresponding to the shape and size of the filter main body, and a hook portion that is provided on the outer periphery of the filter mounting plate portion and is hooked onto a hook surface facing outward from the storage space on the inner periphery of the container opening, so that when the filter main body is inserted into the filter mounting hole from outside the storage space, the filter flange portion and the filter pressing portion are positioned between the filter mounting plate portion and the suction tube, and the hook portion is sandwiched between the inner periphery of the container opening and the connection portion.

[0027] In this pressure reducing device, the filter mounting hole in the filter support part is formed to a shape and size that corresponds to the shape and size of the filter body, so a variety of filters of different shapes and sizes can be mounted on the filter mounting plate part. This allows for a high degree of design freedom, and allows for the appropriate selection and use of versatile, inexpensive filters, thereby reducing manufacturing costs.

[0028] In addition, the filter flange and filter holder are located between the filter mounting plate and the suction tube, and the filter can be supported with a simple structure in which the hook is sandwiched between the inner periphery of the container opening and the connection part, thereby reducing manufacturing costs.Furthermore, the position of the filter on the filter mounting plate can be easily changed by simply changing the position of the filter mounting hole on the filter mounting plate. [Brief explanation of the drawings]

[0029] [Figure 1] 1A and 1B are diagrams showing the configuration of a pressure reducing device according to an embodiment, in which (A) is a front view showing a state in which a filter is positioned at the top, and (B) is a partially enlarged front view showing the configuration of a main part. [Figure 2] 1A and 1B are diagrams showing a filter mounting structure according to a first embodiment, in which (A) is a cross-sectional view and (B) is an enlarged view of a portion IIB in (A). [Figure 3] 1 is an exploded perspective view showing a filter mounting structure according to a first embodiment. [Figure 4] 1A is a cross-sectional view showing a filter mounting structure according to a second embodiment, and FIG. 1B is a cross-sectional view showing a filter mounting structure according to a third embodiment. [Figure 5] 10A and 10B are diagrams showing a filter mounting structure according to a fourth embodiment, in which (A) is a cross-sectional view and (B) is a plan view showing the configuration of a filter pressing portion. [Figure 6] 10(A) is a cross-sectional view showing a filter mounting structure according to a fifth embodiment, and FIG. 10(B) is an exploded cross-sectional view showing a first modified example of the filter pressing portion shown in FIG. [Figure 7] 7A and 7B are diagrams showing modified examples of the filter pressing portion shown in FIG. 6A, where (A) is an exploded cross-sectional view showing a second modified example, and (B) is an exploded cross-sectional view showing a third modified example. [Figure 8] FIG. 10 is an exploded cross-sectional view showing a filter mounting structure according to a sixth embodiment. [Figure 9] 10A and 10B are diagrams showing a filter mounting structure according to a seventh embodiment, in which (A) is an exploded cross-sectional view and (B) is a partially enlarged cross-sectional view. [Figure 10]13A and 13B are diagrams showing a filter mounting structure according to an eighth embodiment, in which (A) is an exploded cross-sectional view and (B) is a partially enlarged cross-sectional view.

[0030] Hereinafter, a filter mounting structure and a pressure reducing device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, for convenience of explanation, the upper side of the paper will be referred to as "upper" and the lower side of the paper will be referred to as "lower."

[0031] (Decompression device according to an embodiment) Fig. 1 shows the configuration of a pressure reducing device 10 according to an embodiment, with Fig. 1(A) being a front view showing a state in which a filter 22 is positioned at the top, and Fig. 1(B) being a partially enlarged front view showing the configuration of a main part. Fig. 2 shows a filter mounting structure 24 according to a first embodiment, with Fig. 2(A) being a cross-sectional view, and Fig. 2(B) being an enlarged view of part IIB in Fig. 2(A). Fig. 3 is an exploded perspective view showing the filter mounting structure 24 according to the first embodiment.

[0032] The decompression device 10 shown in Fig. 1(A) is configured as a freeze-drying device that dries a frozen object to be processed under reduced pressure, and includes a container 12 having a storage space S for storing the object to be processed, a suction tube 14, a connection part 16 for connecting the suction tube 14 to the container 12, a rotation drive part 18, and a control part 20. Furthermore, as shown in Fig. 2(A), the decompression device 10 includes two filters 22, 22 and a filter mounting structure 24.

[0033] As shown in Figure 1 (B), the container 12 has a container body 26 that forms the storage space S, a first container opening (container opening) 28 that opens the storage space S to the outside, a second container opening 30 for discharging the treated material in the storage space S to the outside, and a jacket 32.

[0034] The container body 26 has a cylindrical first peripheral wall portion 34a extending in the vertical direction, a second peripheral wall portion 34b tapered upward from the upper end of the first peripheral wall portion 34a, and a third peripheral wall portion 34c tapered downward from the lower end of the first peripheral wall portion 34a. An attachment hole 36a for attaching the first container opening 28 is formed in the upper end of the second peripheral wall portion 34b, and an attachment hole 36b for attaching the second container opening 30 is formed in the lower end of the third peripheral wall portion 34c.

[0035] As shown in FIG. 2(A), the first container opening 28 is a portion that constitutes an opening 38 that connects the inner space and the outer space of the storage space S. In this embodiment, the first container opening 28 is formed in a cylindrical shape having an inner circumferential surface 40 and an outer circumferential surface 42 that are centered on the central axis L of the container 12. The inner circumferential surface 40 of the first container opening 28 has a first surface 40a that is the cylindrical inner surface and a second surface 40b that is the inner surface excluding the first surface 40a. The inner diameter of the second surface 40b gradually increases downward, and the second surface 40b forms part of the inner surface of the container body 26.

[0036] The lower end 28a of the first container opening 28 is joined to the inner periphery of a mounting hole 36a formed in the second peripheral wall portion 34b, and the upper end 28b of the first container opening 28 protrudes upward from the outer surface of the container body 26.

[0037] 2(B), a step 44 is formed on the inner periphery 28c of the first container opening 28 so that the inner diameter increases upward. As shown in FIG. 3, the surface of the step 44 facing outward from the storage space S, i.e., the surface of the inner periphery 28c facing outward from the storage space S (hereinafter referred to as the "hooking surface") 46, is formed as a flat surface perpendicular to the central axis L of the container 12.

[0038] 1(B) is a cylindrical portion that constitutes an opening 48 for discharging the material to be treated from the storage space S to the outside, and the upper end of the second container opening 30 is joined to the inner periphery of an attachment hole 36b formed in the third peripheral wall portion 34c. A lid 50 is detachably attached to the lower end of the second container opening 30.

[0039] The jacket 32 ​​shown in FIG. 2(A) is a means for cooling or heating the object to be treated in the storage space S, and has a jacket body 52 formed along the outer surface of the container body 26. A heat medium flow path 54 through which a heat medium flows is formed between the container body 26 and the jacket body 52. ​​When a heat medium is supplied to the heat medium flow path 54, the entire container body 26 is cooled or heated according to the temperature of the heat medium, and the object to be treated in the storage space S is cooled or heated. The type of heat medium is not particularly limited, but in this embodiment, silicone oil is used.

[0040] As shown in Figure 1 (B), when the portions of the jacket body 52 that face the first circumferential wall portion 34a, the second circumferential wall portion 34b, and the third circumferential wall portion 34c of the container body 26 are defined as the first circumferential wall facing portion 56a, the second circumferential wall facing portion 56b, and the third circumferential wall facing portion 56c, the upper end of the second circumferential wall facing portion 56b is joined to the outer periphery of the first container opening 28, and the lower end of the third circumferential wall facing portion 56c is joined to the outer periphery of the second container opening 30.

[0041] 2(A), at the top of the container 12, the gap between the container body 26 and the jacket body 52 is sealed by the first container opening 28. Although not shown, at the bottom of the container 12, the gap between the container body 26 and the jacket body 52 is sealed by the second container opening 30. In other words, at the top of the container 12, the first container opening 28 is supported with sufficient strength by the container body 26 and the jacket body 52, and at the bottom of the container 12, the second container opening 30 is supported with sufficient strength by the container body 26 and the jacket body 52.

[0042] 1(A) is a member for sucking gas from the storage space S through the first container opening 28 to reduce the pressure in the storage space S, and is formed by connecting multiple tubes 14a to 14d in a U-shape. Tube 14b, located in the middle of the U-shape, is flexible or bendable, which allows the user to easily connect suction tube 14 to container 12.

[0043] The connecting part 16 shown in Fig. 1(A) is a member that airtightly connects the upstream end 58 of the suction tube 14 in the gas flow direction to the first container opening 28. As shown in Fig. 3, the connecting part 16 of this embodiment has a straight pipe body 60 and a disk-shaped lid part 62. A receiving port 60a is formed at the upper end of the pipe body 60, and a circular through-hole 62a is formed in the center of the lid part 62. The lower end of the pipe body 60 is fitted into the through-hole 62a and joined to the lid part 62.

[0044] As shown in Fig. 2(A), the lid portion 62 of the connection part 16 is placed on the upper surface of the first container opening 28 and is fixed to the first container opening 28 using a clamp 64 (Fig. 1(B)). The end portion 58 of the suction tube 14 shown in Fig. 1(A) is inserted into and joined to a socket 60a of a pipe body 60 that constitutes the connection part 16. Note that the fixing means for fixing the lid portion 62 to the first container opening 28 is not limited to the clamp 64, and other fixing means such as a bolt and nut may also be used.

[0045] 1(A) is a device for rotating the container 12, the suction tube 14, etc., and has cylindrical first and second rotating shafts 66a and 66b fixed to opposite side surfaces of the container 12, and first and second bearings 68a and 68b that rotatably support the first and second rotating shafts 66a and 66b. The rotation centers of the first and second rotating shafts 66a and 66b are arranged so as to be perpendicular to the central axis L (FIG. 2(A)) of the container 12.

[0046] The rotary drive unit 18 also has a drive motor 70 for applying a rotational force to the first rotary shaft 66a. The control unit 20 is electrically connected to the drive motor 70, and the drive motor 70 rotates or stops in response to a control signal provided by the control unit 20.

[0047] A heat medium supply pipe 72a for supplying silicone oil as a heat medium to the heat medium flow path 54 ( FIG. 2(A) ) of the jacket 32 ​​and a heat medium discharge pipe 72b for discharging the silicone oil as a heat medium from the heat medium flow path 54 of the jacket 32 ​​are arranged inside the first rotating shaft 66a. The upstream end of the heat medium supply pipe 72a is connected to the discharge port of a pump 74, and the suction port of the pump 74 is connected to the outlet of a heat medium source 78 via a connecting pipe 76. The downstream end of the heat medium discharge pipe 72b is connected to the inlet of the heat medium source 78. A control unit 20 is electrically connected to the pump 74 and the heat medium source 78, and the pump 74 is driven or stopped in response to a control signal provided by the control unit 20. The heat medium source 78 also adjusts the temperature of the silicone oil in response to a control signal provided by the control unit 20.

[0048] The downstream end of the suction pipe 14 is connected to the wall of the second rotating shaft 66b, and the end of the second rotating shaft 66b supported by the second bearing 68b is connected to the inlet of a vapor recovery device 85 via an exhaust pipe 82, and the outlet of the vapor recovery device 85 is connected to the suction port of a vacuum pump 84. In other words, the storage space S of the container 12 and the suction port of the vacuum pump 84 are connected by a sealed gas flow path 86. The vapor recovery device 85 in this embodiment is a cold trap, and vapor (moisture) flowing through the gas flow path 86 is recovered as ice. The vacuum pump 84 and the vapor recovery device 85 are electrically connected to a control unit 20, and the vacuum pump 84 and the vapor recovery device 85 are driven or stopped in response to control signals provided by the control unit 20.

[0049] 3, the filter 22 has a filter body 90 that allows gas to pass through and captures solid matter contained in the material to be treated, and a filter flange portion 92. The filter body 90 has a frame body 90a and a bag-shaped filter cloth 90b that covers the frame body 90a, and the entire filter body 90 is formed in a bottomed cylindrical shape with an internal space. The open end of the filter body 90 serves as an outlet 94 for gas that has flowed into the filter body 90 through the filter cloth 90b (hereinafter referred to as the "gas outlet"), and a brim-shaped filter flange portion 92 is formed on the outer periphery of the gas outlet 94.

[0050] When the filter 22 is viewed from the direction in which the gas outlet 94 is oriented (from above), the diameter of the circumscribing circle circumscribing the filter flange 92 is set to be larger than the diameter of the circumscribing circle circumscribing the filter body 90. In this embodiment, the filter flange 92 is formed in an annular shape, and the filter body 90 is formed in a cylindrical shape with a bottom, so the outer diameter of the filter flange 92 is set to be larger than the outer diameter of the filter body 90. In other words, the filter flange 92 is formed to protrude outward from the filter body 90.

[0051] 1(A) is a device that controls each electrical device for operating the pressure reducing device 10, and is configured by a microcomputer (not shown) that includes a CPU, ROM, RAM, a timer, etc. The ROM stores operation programs for each electrical device.

[0052] (Filter mounting structure according to the first embodiment) The filter mounting structure 24 shown in Figures 2(A) and (B) is a structure for mounting a filter 22 to a pressure reducing device that includes a container 12, a suction tube 14, and a connection portion 16, and has a filter support portion 96 that supports the filter 22 in the storage space S, and a filter pressing portion 98 that presses down the filter 22 supported by the filter support portion 96 from above.

[0053] As shown in Figure 3, the filter support portion 96 has a plate-shaped filter mounting plate portion 102 with two filter mounting holes 100, and a hook portion 104 provided on the outer periphery of the filter mounting plate portion 102 and hooked onto the hook surface 46 of the first container opening 28.

[0054] The filter mounting plate 102 is sized to be insertable into the opening 38 of the first container opening 28, and is formed in a shape corresponding to the cross-sectional shape of the opening 38, i.e., circular. Each filter mounting hole 100 is sized to correspond to the size of the filter body 90 in the filter 22, and is formed in a shape corresponding to the cross-sectional shape of the filter body 90, i.e., circular.

[0055] As shown in Figure 3, the hooking portion 104 has a cylindrical peripheral wall portion 106 with one (lower) opening blocked by the filter mounting plate portion 102 and the other (upper) opening open, and a hooking flange portion 108 provided on the outer periphery of the opening end 106a of the peripheral wall portion 106 and hooked onto the hooking surface 46.

[0056] As shown in FIG. 2(B), the filter body 90 of the filter 22 is inserted into the filter mounting hole 100 of the filter mounting plate 102 from the outside (upper side) of the accommodation space S via a gasket 110, and the filter flange 92 is hooked onto the inner periphery of the filter mounting hole 100 via the gasket 110. Therefore, the gap between the filter 22 and the filter mounting plate 102 is sealed by the gasket 110. In this state, the filter flange 92 and the filter pressing portion 98 are disposed between the filter mounting plate 102 and the suction tube 14 (FIG. 1(A)). In addition, the hook flange 108 of the hook portion 104 is sandwiched between the inner periphery 28c of the first container opening 28 and the connecting portion 16. Note that instead of the gasket 110, a configuration may be adopted in which an O-ring groove is provided on at least one of the lower surface of the filter flange 92 and the upper surface of the filter mounting plate 102, and an O-ring is attached to the groove.

[0057] As shown in Figure 2(B), the filter pressing portion 98 is a member that presses and fixes the filter flange portion 92 against the filter mounting plate portion 102 of the filter support portion 96 while ensuring the flow of gas toward the suction tube 14 (Figure 1(A)) through the filter 22. Note that in Figure 2(A), the flow of gas is indicated by dashed arrows.

[0058] 3, the filter pressing portion 98 has a size that allows it to be placed inside the peripheral wall portion 106 of the filter support portion 96 and a shape that corresponds to the shape of the filter mounting plate 102, i.e., a circular, plate-like filter pressing main body 112, and a brim-like filter pressing flange portion 114 formed on the outer periphery of the upper end of the filter pressing main body 112. The filter pressing main body 112 is formed with a uniform thickness as a whole, and has two through holes 116 formed therein that correspond to the gas outlets 94 of the filter 22. As shown in FIG. 2(B), the thickness of the filter pressing main body 112 is determined so that when the filter pressing portion 98 is pressed by the lid portion 62 of the connection portion 16, the pressing force is transmitted to the filter flange portion 92.

[0059] As shown in Figure 2(A), in this embodiment, a junction space Q is formed upstream of the upstream end 58 of the gas flow in the suction tube 14 (Figure 1(A)), i.e., inside the tubular body 60 that forms the connecting part 16, for merging the gas that has passed through the two filters 22 and guiding it to the gas flow path 86 of the suction tube 14. In other words, the connecting part 16 has a junction space forming part 118 that forms the junction space Q.

[0060] In other words, the internal space of the pipe 60 that constitutes the connection portion 16 is positioned so as to overlap with the gas outlets 94 of the two filters 22 in the axial direction of the pipe 60, and as a result, the internal space of the pipe 60 becomes the confluence space Q.

[0061] As shown in Fig. 3, when attaching the filter 22 to the pressure reducing device 10, the user first hooks the hooking flange portion 108 of the filter support part 96 onto the hooking surface 46 of the first container opening 28 via the gasket 120. Then, as shown in Fig. 2(B), the filter mounting plate portion 102 of the filter support part 96 is positioned inward from the opening end of the first container opening 28 toward the accommodation space S. Note that instead of the gasket 120, a configuration may be adopted in which a groove for an O-ring is provided on at least one of the lower surface of the hooking flange portion 108 and the hooking surface 46, and the O-ring is attached to the groove.

[0062] Next, the user inserts the filter body 90 of the filter 22 into each filter mounting hole 100 of the filter support part 96 via the gasket 110, and places the filter pressing part 98 on the upper surface of the filter flange part 92. Then, as shown in Figure 2(B), the gasket 120, the hook flange part 108, and the filter pressing flange part 114 are overlapped in this order on the hooking surface 46.

[0063] Thereafter, the user places the lid portion 62 of the connection portion 16 on the upper surface of the filter holding flange portion 114 via the gasket 122, and secures the lid portion 62 to the first container opening 28 using a clamp 64 (FIG. 1(A)). As a result, as shown in FIG. 2(B), the lid portion 62 presses the filter holding portion 98, and the pressure presses the filter flange portion 92. Note that instead of the gasket 122, a configuration may be adopted in which a groove for an O-ring is provided on at least one of the lower surface of the lid portion 62 and the upper surface of the filter holding flange portion 114, and an O-ring is attached to the groove.

[0064] (Operation of pressure reducing device) When freeze-drying an object to be processed using the decompression device 10 shown in FIG. 1A, a user first places the frozen object into the storage space S of the container 12 through the second container opening 30. Next, the user turns on the drive switch of the decompression device 10. The control unit 20 then activates the vapor recovery device 85, drives the vacuum pump 84 to decompress the storage space S, and drives the drive motor to continuously rotate the container 12. Furthermore, the control unit 20 drives the pump 74 to supply silicone oil to the jacket 32 ​​and controls the heat medium source 78 to appropriately adjust the temperature of the silicone oil. These operations cause the solid (ice) contained in the object to sublimate (sublimate) into a gas (water vapor), thereby drying the object. The control unit 20 may drive the drive motor intermittently or alternately rotate forward and backward depending on the state of the object to be processed.

[0065] (Effects of the embodiment) The pressure reducing device 10 and filter mounting structure 24 of this embodiment can achieve the following effects due to the above configuration. That is, because the filter mounting hole 100 of the filter support portion 96 shown in Fig. 3 is formed in a shape and size corresponding to the shape and size of the filter body 90, various filters 22 of different shapes and sizes can be mounted on the filter mounting plate portion 102. This allows for a high degree of design freedom, and allows for the appropriate selection and use of a versatile, inexpensive filter 22, thereby reducing manufacturing costs.

[0066] As shown in Figure 2(B), the filter flange 92 and the filter pressing part 98 are disposed between the filter mounting plate 102 and the suction tube 14 (Figure 1(A)), and the filter 22 can be supported and maintained with a simple structure in which the hook part 104 is sandwiched between the inner periphery 28c of the first container opening 28 and the connecting part 16, thereby reducing manufacturing costs. Furthermore, the position of the filter 22 on the filter mounting plate 102 can be easily changed by simply changing the position of the filter mounting hole 100 on the filter mounting plate 102.

[0067] 2(A), two (or more) filters 22 can be attached to the filter attachment plate 102 of the filter support part 96, which makes it possible to increase the overall area of ​​the filters 22 and improve the gas suction efficiency. Therefore, even if gas (such as sublimated vapor) is generated in the storage space S, a high vacuum can be easily achieved.

[0068] As shown in Figure 2(B), the filter flange portion 92 and the filter holding portion 98 are arranged inside the peripheral wall portion 106 that constitutes the filter support portion 96, and the filter holding portion 98 is held down by the connection portion 16.Therefore, by changing at least one of the length of the peripheral wall portion 106 in the axial direction of the peripheral wall portion 106 and the length of the filter holding portion 98, the length of the space in which the filter flange portion 92 is arranged can be appropriately determined according to the thickness of the filter flange portion 92.

[0069] Because the connecting part 16 has the merging space forming part 118, it is easier to ensure a wide merging space Q compared to when the end part 58 of the suction tube 14 has a merging space forming part. That is, as shown in Figures 8, 9, and 10, the design of the merging space forming part provided in the connecting part 16 can be easily changed to ensure a wide merging space Q.

[0070] (Variation) The present invention is not limited to the pressure reducing device 10 of the above embodiment, and various modifications are possible without departing from the scope of the present invention. That is, in the above embodiment, the filter body 90 is formed in a cylindrical shape with a bottom and the filter flange portion 92 is formed in an annular shape, but the shape, structure, size, and material of these may be modified as appropriate as long as the filter flange portion 92 is formed to protrude outward from the filter body 90. For example, the filter body 90 may be formed solely from a filter cloth with excellent shape retention.

[0071] In the above embodiment, the connection part 16 has the pipe body 60, but the pipe body 60 may be omitted. In this case, the upstream end 58 of the suction tube 14 in the gas flow direction may be connected to the lid part 62 of the connection part 16. Furthermore, a merging space Q may be formed at the end 58. In other words, the upstream end 58 of the suction tube 14 in the gas flow direction may have a merging space forming part (not shown) that forms the merging space Q.

[0072] In the above embodiment, the pressure reducing device of the present invention is configured as a freeze-drying device that dries frozen objects to be processed under reduced pressure, but the pressure reducing device of the present invention may also be configured as a reduced-pressure drying device that dries unfrozen objects to be processed under reduced pressure, or as a reduced-pressure device whose sole purpose is to reduce pressure.

[0073] (Filter mounting structure according to the second embodiment) FIG. 4A is a cross-sectional view showing a filter mounting structure 124 according to the second embodiment.

[0074] The filter mounting structure 24 according to the first embodiment is configured to be able to support two filters 22, but the number of filters 22 that can be supported may be one, or three or more. The filter mounting structure 124 shown in Fig. 4(A) is configured to be able to support one filter 22, and one filter mounting hole 100 is formed in the filter mounting plate portion 102 of the filter support portion 96, and one through-hole 116 is formed in the filter holding body 112 of the filter holding portion 98.

[0075] In this configuration as well, by appropriately selecting the shape and size of the filter mounting hole 100, various filters 22 of different shapes and sizes can be mounted on the filter mounting plate portion 102.

[0076] (Filter mounting structure according to the third embodiment) FIG. 4B is a cross-sectional view showing a filter mounting structure 126 according to the third embodiment.

[0077] In the filter mounting structure 24 of the first embodiment, a filter holding portion 98 having a filter holding flange portion 114 is used, but a filter holding portion 98 that does not have a filter holding flange portion 114 may also be used, as in the filter mounting structure 126 shown in Figure 4 (B).

[0078] In this configuration, the hooking surface 46 can be brought closer to the upper surface of the first container opening 28 by an amount equal to the thickness of the filter holding flange portion 114, making it easy to secure the hooking surface 46 even if the vertical length of the first container opening 28 is short.

[0079] (Filter mounting structure according to the fourth embodiment) 5A and 5B are diagrams showing a filter mounting structure 128 according to a fourth embodiment, in which FIG. 5A is a cross-sectional view and FIG. 5B is a plan view showing the configuration of a filter pressing portion 130.

[0080] In the filter mounting structure 24 according to the first embodiment, the through holes 116 of the filter holding portion 98 are formed to correspond one-to-one to the gas outlets of the filter 22, but as in the filter mounting structure 128 shown in Figure 5(A), multiple air vents 132 may be formed and evenly distributed over the entire area of ​​the filter holding portion 130 that faces the filter mounting plate portion 102.

[0081] In this configuration, regardless of the position, size, or number of filters 22 attached to the filter mounting plate portion 102, the filter flange portions 92 of all filters 22 can be pressed and fixed to the filter mounting plate portion 102 while ensuring gas flow.

[0082] (Filter mounting structure according to the fifth embodiment) FIG. 6A is a cross-sectional view showing a filter mounting structure 134 according to a fifth embodiment.

[0083] In the filter mounting structure 24 according to the first embodiment, the connecting portion 16 has a merging space forming portion 118 that forms the merging space Q, but as in the filter mounting structure 134 shown in Fig. 6(A), both the connecting portion 16 and the filter pressing portion 136 may have the merging space forming portions 118, 138, or only the filter pressing portion 136 may have the merging space forming portion 138 (not shown). The filter pressing portion 136 shown in Fig. 6(A) has a plate-shaped filter pressing main body 142 in which a plurality of through holes 140 are formed, and a tubular merging space forming portion 138 that protrudes upward from the outer periphery of the filter pressing main body 142.

[0084] In this configuration, the joining space Q can be secured in a wide area inside the first container opening 28, so it is easier to secure a wide joining space Q compared to when the end 58 of the suction tube 14 has a joining space forming portion.

[0085] FIG. 6(B) is an exploded cross-sectional view showing a first modified example of the filter pressing portion 136 shown in FIG. 6(A).

[0086] In the filter pressing portion 136 shown in Fig. 6(A), the filter pressing main body 142 and the merging space forming portion 138 are integrally formed, but as in a first modified example shown in Fig. 6(B), the filter pressing main body 142 and the merging space forming portion 138 may be formed independently of each other. In this configuration, the merging space forming portion 138 is pressed by the connecting portion 16, and thereby the filter pressing main body 142 is indirectly pressed by the connecting portion 16. In other words, the merging space forming portion 138 functions as a "spacer" that is disposed between the filter pressing main body (filter pressing portion) 142 and the connecting portion 16 while ensuring the flow of gas.

[0087] In this configuration, by changing the length of the confluence space forming portion (spacer) 138 in the axial direction of the first container opening 28, the length of the space in which the filter flange portion 92 is arranged can be appropriately determined according to the thickness of the filter flange portion 92.

[0088] FIG. 7(A) is an exploded cross-sectional view showing a second modified example of the filter pressing portion 136, and FIG. 7(B) is an exploded cross-sectional view showing a third modified example of the filter pressing portion 136.

[0089] In the first modified example shown in Fig. 6(B), a filter holding flange 144 is formed in the merging space forming portion 138, but as in the second modified example shown in Fig. 7(A), the filter holding flange 144 may be omitted. In this configuration, the hooking surface 46 can be brought closer to the upper surface of the first container opening 28 by the thickness of the filter holding flange 144, so that the hooking surface 46 can be easily secured even when the vertical length of the first container opening 28 is short.

[0090] 7(B), multiple (two in the third modification) merging space forming portions 138 functioning as "spacers" may be stacked and used. In this configuration, by changing the number of merging space forming portions 138, multiple filters 22 having filter flange portions 92 with different thicknesses can be accommodated.

[0091] (Filter mounting structure according to the sixth embodiment) FIG. 8 is an exploded cross-sectional view showing a filter mounting structure 146 according to the sixth embodiment.

[0092] In the filter mounting structure 128 according to the fourth embodiment shown in Figure 5 (A), multiple air vents 132 are evenly distributed over the entire area of ​​the filter pressing portion 130 facing the filter mounting plate portion 102, but since some of the air vents 132 are blocked by the lid portion 62 that constitutes the connection portion 16, there is room for improvement in the gas suction efficiency.

[0093] 8, the portion of the cover portion 62 excluding the outer periphery thereof is formed to bulge upward, thereby forming a junction space forming portion 148. In other words, the connection portion 16 has the junction space forming portion 148 that forms the junction space Q that communicates with all of the air vents 132. Therefore, all of the air vents 132 can be used without waste, and the efficiency of gas suction can be improved.

[0094] (Filter mounting structure according to the seventh embodiment) 9A and 9B are diagrams showing a filter mounting structure 150 according to a seventh embodiment, in which (A) is an exploded cross-sectional view and (B) is a partially enlarged cross-sectional view.

[0095] In the filter mounting structure 146 of the sixth embodiment shown in Figure 8, the filter holding portion 130 is provided inside the first container opening 28, but as in the filter mounting structure 150 shown in Figures 9(A) and (B), the filter holding portion 152 may be provided in the internal space of the connection portion 16.

[0096] In the filter mounting structure 150 shown in Fig. 9(A), a housing portion 154 for housing and positioning the filter pressing portion 152 is formed on the inner surface of the merging space forming portion 148 provided in the connecting portion 16. Then, as shown in Fig. 9(B), the filter pressing portion 152 is housed inside the housing portion 154.

[0097] With this configuration, the filter support portion 96 placed inside the first container opening 28 can be made smaller, thereby improving workability when installing the filter support portion 96 on the inner peripheral portion 28c of the first container opening 28.

[0098] 9(B), in the filter mounting structure 150, the inner circumferential surface 40 of the first container opening 28 has a first surface 40a which is a cylindrical inner surface and a second surface 40b which is the inner surface excluding the first surface 40a, and the second surface 40b forms part of the inner surface of the container body 26. When an imaginary plane X including the boundary line between the first surface 40a and the second surface 40b is imagined, the surface 102a of the filter mounting plate portion 102 which faces inward of the storage space S is positioned so as to overlap with the imaginary plane X.

[0099] In this configuration, no recess is formed between the surface 102a of the filter mounting plate portion 102 facing inward into the storage space S and the second surface 40b, i.e., the inner surface of the container 12, thereby preventing the formation of areas in the storage space S where foreign matter is likely to accumulate, and thus preventing the entry of foreign matter (contamination).

[0100] 9(A), the filter pressing portion 152 and the connecting portion 16 are formed independently of each other, but the filter pressing portion 152 may be formed integrally with the connecting portion 16. In this case, the number of parts can be reduced, which reduces manufacturing costs and improves assembly workability.

[0101] (Filter mounting structure according to eighth embodiment) FIG. 10 shows a filter mounting structure 156 according to an eighth embodiment, where (A) is an exploded cross-sectional view and (B) is a partially enlarged cross-sectional view.

[0102] In each of the above embodiments, the hooking surface 46 on which the hooking portion 104 of the filter support portion 96 is hooked is provided below the upper surface of the first container opening 28. However, as in a filter mounting structure 156 shown in FIG. 10(A), the hooking surface 46 may be provided on the upper surface of the first container opening 28. The entire filter support portion 96 may be formed in a flat plate shape. In this case, the outer periphery of the plate-shaped filter support portion 96 becomes the hooking portion 104 that is hooked on the hooking surface 46, and the portion excluding the outer periphery becomes the filter mounting plate portion 102. Therefore, the filter flange portion 92 of the filter 22 supported by the filter support portion 96 protrudes upward from the upper surface of the first container opening 28.

[0103] In a filter mounting structure 156 shown in Fig. 10(A), a housing portion 158 for housing and positioning the filter pressing portion 152, the filter flange portion 92, the gaskets 110, 120, 122, and the hook portion 104 is formed on the inner surface of the merging space forming portion 148 provided in the connecting portion 16. Then, as shown in Fig. 10(B), each of the above-mentioned parts is housed inside the housing portion 158.

[0104] In this configuration, the workability when assembling the filter mounting structure can be improved because there is less of the portion disposed inside the first container opening 28. Furthermore, even if the vertical length of the first container opening 28 is short, it is easy to ensure the hook surface 46. [Explanation of symbols]

[0105] L...central axis, Q...merging space, S...storage space, X...imaginary surface, 10...pressure reducing device, 12...container, 14...suction tube, 14a-14d...tubes, 16...connecting portion, 18...rotation drive portion, 20...control portion, 22...filter, 24...filter mounting structure, 26...container body, 28...first container opening (container opening), 28a...lower end portion, 28b...upper end portion, 28c...inner periphery, 30...second container opening, 32...jacket, 34a...first peripheral wall portion, 34b...second peripheral wall portion, 34c...third peripheral wall portion, 36a, 36b...mounting hole, 38...opening , 40...inner peripheral surface, 40a...first surface, 40b...second surface, 42...outer peripheral surface, 44...step portion, 46...hooking surface, 48...opening, 50...lid body, 52...jacket body, 54...heat medium flow path, 56a...first peripheral wall opposing portion, 56b...second peripheral wall opposing portion, 56c...third peripheral wall opposing portion, 58...end portion, 60a...receiving port, 60...tube body, 62...lid portion, 62a...through hole, 64...clamp, 66a...first rotating shaft, 66b...second rotating shaft, 68a...first bearing portion, 68b...second bearing portion, 70...drive motor, 72a...heat medium supply pipe, 72b...heat medium discharge pipe, 74...pump, 76...connecting pipe, 78...heat medium source, 82...exhaust pipe, 84...vacuum pump, 85...vapor recovery device, 86...gas flow path, 90...filter body, 90a...frame body, 90b...filter cloth, 92...filter flange portion, 94...gas outlet, 96...filter support portion, 98...filter pressing portion, 100...filter mounting hole, 102...filter mounting plate portion, 102a...surface facing inward of storage space S, 104...hook portion, 106...peripheral wall portion, 106a...opening end, 108...hook flange portion, 110...gas gasket, 112...filter holder main body, 114...filter holder flange portion, 116...through hole, 118...merging space forming portion, 120, 122...gasket, 124, 126, 128, 134, 146, 150, 156...filter mounting structure, 130, 136...filter holder portion, 132...vent hole, 138...merging space forming portion, 140...through hole, 142...filter holder main body, 144...filter holder flange portion, 148...merging space forming portion, 152...filter holder portion, 154, 158...accommodation portion.

Claims

1. a filter mounting structure for mounting a filter having a filter body that allows the gas to pass through and captures solids contained in the material to be treated and a filter flange portion provided on an outer periphery of a gas outlet of the filter body to a pressure reducing device including: a container having a storage space that stores the material to be treated and a container opening for opening the storage space to the outside; a suction pipe that sucks gas from the storage space through an opening formed by the container opening to reduce the pressure of the storage space; and a connecting portion that airtightly connects an upstream end of the suction pipe in the gas flow direction to the container opening, a filter support portion that supports the filter in the accommodation space; a filter pressing portion that presses and fixes the filter flange portion to the filter support portion while ensuring the flow of the gas, the filter support portion includes a plate-like filter mounting plate portion having a filter mounting hole formed in a shape and size corresponding to the shape and size of the filter body, and a hook portion provided on the outer periphery of the filter mounting plate portion and hooked onto a hook surface on the inner periphery of the container opening portion facing outward from the accommodation space, A filter mounting structure in which, when the filter body is inserted into the filter mounting hole from outside the storage space, the filter flange portion and the filter pressing portion are positioned between the filter mounting plate portion and the suction tube, and the hook portion is sandwiched between the inner periphery of the container opening and the connection portion.

2. the filter mounting plate portion has a plurality of filter mounting holes formed in shapes and sizes corresponding to the shapes and sizes of the filter bodies of the plurality of filters, 2. The filter mounting structure according to claim 1, wherein a confluence space is formed at the upstream end or upstream side of the gas flow in the suction pipe, for confluence of the gas that has passed through the multiple filters and leading it to the suction pipe.

3. The filter mounting structure according to claim 2 , wherein the connecting portion has a merging space forming portion that forms the merging space.

4. The filter mounting structure according to claim 2 , wherein the filter pressing portion has a merging space forming portion that forms the merging space.

5. 5. The filter mounting structure according to claim 1, wherein the filter pressing portion is formed integrally with the connecting portion.

6. 5. The filter mounting structure according to claim 1, wherein a plurality of ventilation holes are formed in the filter pressing portion and are evenly distributed over the entire area of ​​the filter pressing portion facing the filter mounting plate portion.

7. The hooking portion has a cylindrical peripheral wall portion having one opening closed by the filter mounting plate portion and the other opening open, and a hooking flange portion provided on the outer periphery of the opening end of the peripheral wall portion and hooked onto a hooking surface on the inner periphery of the container opening portion facing outward from the storage space, 5. The filter mounting structure according to claim 1, wherein the filter flange and the filter pressing portion are disposed inside the peripheral wall portion, and the filter pressing portion is pressed by the connecting portion.

8. a spacer disposed between the filter pressing portion and the connecting portion while ensuring the flow of the gas; The filter mounting structure according to claim 7, wherein the spacer is pressed by the connecting portion, thereby indirectly pressing the filter pressing portion by the connecting portion.

9. 5. A filter mounting structure as described in any one of claims 1 to 4, wherein when a cylindrical inner surface of the container opening is defined as a first surface, the inner surface of the container excluding the first surface is defined as a second surface, and an imaginary surface including the boundary line between the first surface and the second surface is imagined, the surface of the filter mounting plate portion facing inward of the storage space is positioned in a position overlapping with the imaginary surface.

10. a container having a storage space for storing the object to be treated and a container opening for opening the storage space to the outside; a suction pipe for sucking gas from the storage space through the opening formed by the container opening to reduce the pressure of the storage space; a connecting portion that airtightly connects an upstream end of the suction pipe in the gas flow direction to the container opening; a filter having a cylindrical filter body that allows the gas to pass through and captures solid matter contained in the object to be treated, and a filter flange portion provided on an outer periphery of a gas outlet of the filter body; a filter support portion that supports the filter in the accommodation space; a filter pressing portion that presses and fixes the filter flange portion to the filter support portion while ensuring the flow of the gas, the filter support portion includes a plate-like filter mounting plate portion having a filter mounting hole formed in a shape and size corresponding to the shape and size of the filter body, and a hook portion provided on the outer periphery of the filter mounting plate portion and hooked onto a hook surface on the inner periphery of the container opening portion facing outward from the accommodation space, When the filter body is inserted into the filter mounting hole from outside the storage space, the filter flange portion and the filter pressing portion are positioned between the filter mounting plate portion and the suction pipe, and the hook portion is sandwiched between the inner periphery of the container opening and the connection portion.

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