Cylindrical body for filtration unit, and filtration unit

Abstract

This cylindrical body 10 for a filtration unit is used in a filtration unit 1 that comprises the cylindrical body 10, which is made of paper, and a base 50, with a filtration membrane 30 being placed between the cylindrical body 10 and the base 50, and that filters a to-be-filtered substance O accommodated in the cylindrical body 10. In the cylindrical body 10, an annular part 20 protruding radially inward is formed in the vicinity of a lower end part 11A of the cylindrical body 10.

Description

Cylindrical body for filtration unit, and filtration unit

[0001] The present disclosure relates to a cylindrical body for a filtration unit and a filtration unit.

[0002] In a conventional filtration unit that filters a filter medium housed in a cylindrical body, the cylindrical body has been made of paper to facilitate easy replacement and disposal in order to reduce the labor and time required for cleaning, sterilization, etc. For example, Patent Document 1 discloses a microorganism collection device that includes a housing integrally molded from resin and having a filter housing section and a funnel mounting section, a membrane filter housed in the filter housing section, and a paper funnel (cylindrical body) whose bottom peripheral edge is liquid-tightly attached to the funnel mounting section via a resin sealing means. This housing presses the peripheral edge of the membrane filter from above with a substantially ring-shaped resin packing to prevent it from floating up.

[0003] Japanese Patent Application Laid-Open No. 2001-309776

[0004] However, in the configuration disclosed in Patent Document 1, a paper funnel or membrane filter is attached to a housing containing a membrane filter by using a non-paper resin sealing means or resin packing. If a paper funnel or membrane filter is attached directly to the housing, if sufficient sealing cannot be ensured around the attachment point, there is a possibility that the material to be filtered will leak (liquid leakage) or that the material to be filtered will remain between the paper funnel and the housing during filtration (liquid residue).

[0005] The present disclosure is a technology developed based on the above circumstances, and relates to providing a cylindrical body for a filtration unit, and a filtration unit, which are made of paper but have improved sealing properties to prevent liquid leakage and residual liquid.

[0006] The present disclosure relates to a cylindrical body for a filtration unit, which includes a paper cylindrical body and a base, a filtration membrane placed between the cylindrical body and the base, and is used in a filtration unit that filters a material to be filtered housed in the cylindrical body, and in which a ring-shaped portion that protrudes radially inward is formed near the lower end of the cylindrical body.

[0007] The present disclosure also provides a filtration unit in which the cylindrical body for a filtration unit is attached to a base, so that an end of a filtration membrane is sandwiched between the annular portion and the base.

[0008] According to the present disclosure, it is possible to provide a cylindrical body for a filtration unit, which is made of paper but has improved sealing properties to prevent liquid leakage and residual liquid, and a filtration unit.

[0009] FIG. 1 is an exploded perspective view of a filtration unit according to an embodiment; FIG. 2 is a front view of a filtration unit; FIG. 3 is a cross-sectional view of a lower part of the filtration unit; FIG. 4 is an enlarged cross-sectional view of a part of a lower part of the filtration unit; FIG. 5 is a view of a cylindrical body from below; FIG. 6 is a view of an overlapping part of the cylindrical body from below;

[0010] <Embodiments> An embodiment of the present disclosure will be described in detail. The following description is intended to concretize the technical idea of ​​the present disclosure, and unless otherwise specified, the present disclosure is not limited to the following. Note that the drawings will be described assuming that the arrow direction X is the radial direction of the cylindrical body, and the arrow direction Y is the axial direction (up-down direction) that intersects with the radial direction of the cylindrical body. In Figure 5 and subsequent figures, the direction Y toward the front of the paper surface is the axial direction.

[0011] 1 and 2, the filtration unit 1 includes a paper cylindrical body 10, a filtration membrane 30, and a base 50. The filtration membrane 30 is placed between the cylindrical body 10 and the base 50, and filters the body to be filtered O housed in the cylindrical body 10. The cylindrical body 10 is a cylindrical body for the filtration unit used in this filtration unit 1, and is sometimes called a funnel (reservoir). The base 50 is sometimes called a base.

[0012] The object to be filtered O is not particularly limited and may contain, for example, a liquid and a solid. Examples of the liquid include various solvents, foods and beverages, pharmaceuticals, cosmetics, and liquids that are raw materials for these. Examples of the solid include fine particles and microorganisms. The filtration unit 1 of this embodiment captures and filters bacteria (microorganisms) contained in the object to be filtered O with the filtration membrane 30. Hereinafter, the object to be filtered O that has passed through the filtration membrane 30 (the liquid after filtration) may be simply referred to as liquid.

[0013] The material of the cylindrical body 10 is not particularly limited as long as it is made of paper, and for example, one made by agglutinating fibers can be used. Examples of fibers include plant fibers and other fibers, and as plant fibers, one or more types of pulp such as softwood kraft pulp, hardwood kraft pulp, groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, and deinked pulp can be used. A resin may be applied to a cylindrical body made from such fibers.

[0014] The configuration of the filtration membrane 30 is not particularly limited as long as it can capture solids from the filtered body O. For example, a membrane filter can be used. This membrane filter can be either a hydrophilic or hydrophobic membrane filter. Examples of hydrophilic membrane filters include hydrophilic plastic materials such as hydrophilic PTFE (polytetrafluoroethylene), hydrophilic PVDF (polyvinylidene difluoride), hydrophilic PS (polysulfone), hydrophilic PC (polycarbonate), hydrophilic PA (polyamide), hydrophilic PE (polyethylene), and hydrophilic PP (polypropylene), as well as materials such as acetyl cellulose or nitrocellulose. Examples of hydrophobic membrane filters include PVDF, PTFE, PE, etc., or hydrophilic filtration membranes with relatively high hydrophobicity, such as PC, PP, PA, and PS. The pore size of the filtration membrane 30 can be changed appropriately depending on the solid to be filtered and captured from the filtered body O, but it may be a pore size that can capture bacteria contained in the filtered body O, for example, and specifically, it may be a pore size of several μm or less, 1 μm or less, or 0.45 μm or less.

[0015] As shown in FIG. 2 , the base 50 is placed on a discharge member 60 through which the liquid that has passed through the filtration membrane 30 is discharged. The material of the base 50 is not particularly limited, and any known material can be used as long as it can maintain a seal with the cylindrical body 10 and the filtration membrane 30. The base 50 can be made of one or more of the following materials: plastics such as polyethylene, polypropylene, polystyrene, and polysulfone; or a mixture of paper powder and polyolefin resin (e.g., "MAPKA" (registered trademark) manufactured by Environmental Management Research Institute, Inc.). The discharge member 60 is connected to a vacuum pump (not shown), and the interior can be reduced in pressure by driving this vacuum pump. Therefore, the filtration unit 1 is configured to reduce the pressure below the filtration membrane 30 (inside the discharge member 60) to filter the filtered body O under reduced pressure. The discharge member 60 may be a container that receives the liquid that has passed through the filtration membrane 30, or a manifold that discharges the liquid to the outside.

[0016] As shown in Fig. 3, the cylindrical body 10 includes a main body portion 11 that is a cylinder extending in the axial direction and has a tapered shape with a length (diameter) in the radial direction decreasing toward the bottom, and an annular portion 20 that is disposed near a lower end portion 11A (lower end portion of the cylindrical body 10) of the main body portion 11 and that protrudes from the inner circumferential surface of the main body portion 11 toward the inside in the radial direction X (inside the cylindrical body 10). The lower end portion 11A includes a cylindrical extension portion 15 that extends downward beyond the annular portion 20. The shape of the main body portion 11 is not particularly limited, and may be a cylindrical shape that does not tapered, or may be a cylindrical shape other than a circular shape.

[0017] As shown in Fig. 2, the cylindrical body 10 is formed by molding a rectangular piece of paper into a cylindrical shape. Specifically, the cylindrical body 10 has circumferential ends 12A, 12B that overlap radially (inside and outside in the radial direction: see Fig. 6) to form an overlapping portion 12, thereby forming a cylindrical shape. The outer peripheral surface (outside surface in the radial direction) of the cylindrical body 10 is flush throughout and forms a smoothly curved surface. The outer peripheral surface near the lower end 11A of the main body 11 (outer surface 15A of the extension portion 15 shown in Fig. 4) is also flush.

[0018] As shown in FIG. 6 , near the lower end 11A of the main body 11, the outer peripheral surface 12C of the overlapping portion 12 and the adjacent surfaces 12A1 and 12B1 are flush and form a smoothly curved surface. The method for flushing the outer peripheral surfaces, such as the outer peripheral surface 12C, is not particularly limited. For example, the outer peripheral surfaces 12B1 and 12C of the radially outermost end 12B of the circumferential ends 12A and 12B of the cylindrical body 10 may be smoothed by sanding. The molding process for the cylindrical body 10 is not particularly limited; for example, the shape of the cylindrical body 10 may be formed by pulp molding. In this case, the cylindrical body 10 does not have a portion corresponding to the overlapping portion 12, but its outer peripheral surface is flush.

[0019] As shown in FIG. 5 , the annular portion 20 has a circular shape surrounded by a radially inner end portion 20A, forming an opening S that opens in the axial direction. The annular portion 20 also includes a plurality of notched slits 22 extending radially outward from the end portion 20A, and a plurality of holes 24 arranged along the circumferential direction (the direction around the axis) and opening in the axial direction. While the position and size of the holes 24 are not particularly limited, they are preferably positioned and sized so that a portion of the filtration membrane 30 can contact all or part of the holes 24 when the annular portion 20 presses the filtration membrane 30. This allows the portion of the filtration membrane 30 that overlaps the holes 24 to absorb the filtered material O. Of the multiple (four) slits 22, two holes 24 are arranged between two circumferentially adjacent slits 22. While the number of holes 24 and the number of slits 22 are not particularly limited, it is preferable that each be three or more, and more preferably four or more.

[0020] The tip 22A on the radially outer side of the slit portion 22 is located radially inward of the main body portion 11 and does not contact the main body portion 11. The tip 22A is located at a position in the radial direction equal to the center of the hole portion 24 or at a position radially outward from the center of the hole portion 24. When an arc passing through the center of the hole portion 24 and concentric with the main body portion 11 is denoted as L, the tip 22A is located at a position in the radial direction equal to the arc L or at a position radially outward from the arc L. The tip 22A may have a shape that protrudes slightly radially outward from the arc L. Note that, in another embodiment, the tip 22A may be located at a position radially inward from the center of the hole portion 24. On the other hand, in the present embodiment, the hole portion 24 is located radially inward from the main body portion 11 and does not contact the main body portion 11. In this embodiment, the shape of the hole 24 is circular in plan view, but is not limited to this and may be polygonal such as triangular or rectangular, elliptical, or irregular.

[0021] As shown in Fig. 3, the base 50 is disk-shaped and includes a mounting portion 51 on which the filtration membrane 30 is placed, a recessed concave portion 54 disposed radially outward of a peripheral end portion 51A of the mounting portion 51, an extension portion 55 located below the radially outer end of the recessed portion 54, and a cylindrical discharge portion 53 disposed in the radial center of the mounting portion 51 and discharging liquid that has passed through the filtration membrane 30 downward (to the discharge member 60). The mounting portion 51 includes an uneven portion 52 that forms a flow path for flowing the liquid that has passed through the filtration membrane 30 to the discharge portion 53. As shown in Fig. 4, an upper surface (mounting surface) 51A1 of the peripheral end portion 51A is curved downward as it extends radially outward.

[0022] As shown in FIG. 4 , the recess 54 includes a rising portion 54A that extends radially outward from the peripheral end 51A of the mounting portion 51, a bottom portion 54B that forms the bottom of the recess 54 and extends radially outward from the lower end of the rising portion 54A, and a rising portion 54C that rises upward from the radially outer end of the bottom portion 54B. The upper surface 54A1 of the rising portion 54A is continuous with the upper surface 51A1 of the peripheral end 51A and forms a curved surface that curves downward as it extends radially outward. The upper surface (concave bottom surface) 54B1 of the bottom portion 54B is continuous with the upper surface 54A1 of the rising portion 54A and extends radially outward from the lower end of the upper surface 54A1. The inner surface 54C1 of the rising portion 54C rises upward from the radially outer end of the concave bottom surface 54B1. The extension 55 extends downward from the radially outer end of the bottom 54B. The lower portion of the radially outer end of the base 50 is made up of the lower part of the recess 54 and the extension 55, and forms a step shape as a whole.

[0023] In the filtration unit 1, the cylindrical body 10 is attached to the base 50 by fitting the extending portion 15 of the cylindrical body 10 into the recess 54 from above. At this time, the filtration membrane 30 is placed on the mounting portion 51 so that the peripheral end 30A of the filtration membrane 30 overlaps the upper surface 51A1 of the peripheral end 51A of the mounting portion 51. When the cylindrical body 10 is attached to the base 50 (attached state), the peripheral end 30A of the filtration membrane 30 is sandwiched between the radially inner end 20A of the annular portion 20 and the upper surface 51A1 of the peripheral end 51A of the mounting portion 51. In this attached state, the end 20A of the annular portion 20 elastically deforms, bending (inclining) slightly upward as it moves radially inward, and its restoring force presses (biases) the peripheral end 30A of the filtration membrane 30 against and abuts the upper surface 51A1 of the peripheral end 51A of the mounting portion 51. This contact causes the peripheral edge 30A of the filtration membrane 30 to deform in a manner conforming to the upper surface 51A1.

[0024] At the lower end 11A of the cylindrical body 10, the lower end surface 15B of the extension 15 is flat so as to be able to abut against the concave bottom surface 54B1 of the bottom portion 54B of the pedestal 50. The method for making the lower end surface 15B flat is not particularly limited, and the lower end surface 15B may be smoothed, for example, by sanding it with a file. In the mounted state described above, the lower end surface 15B abuts against and abuts against the concave bottom surface 54B1. Similarly, the outer surface 15A of the extension 15 is also abutted against the inner surface 54C1 of the rising portion 54C.

[0025] 7 , in the above-described attached state, when a filtration membrane 30 having a diameter larger than the opening S and capable of covering a portion of the hole 24 (at least up to the center of the hole 24) is used, the tip 22A of the slit 22 is slightly exposed radially outward from the peripheral end 30A of the filtration membrane 30. Note that the filtration membrane 30 may cover the entire slit 22 and hole 24.

[0026] Next, the effects of this embodiment will be described. In this embodiment, the filtration unit cylinder 10 includes a paper cylinder 10 and a base 50, a filtration membrane 30 is placed between the cylinder 10 and the base 50, and is used in a filtration unit 1 that filters an object to be filtered O housed in the cylinder 10. The filtration unit cylinder 10 has an annular portion 20 that protrudes radially inward near a lower end 11A of the cylinder 10.

[0027] With this configuration, the cylindrical body 10 is made of paper, making it possible to provide a cylindrical body 10 for a filtration unit that can be easily replaced or disposed of. Furthermore, when the cylindrical body 10 is brought close to the base 50 and pressed against it, the annular portion 20, for example, elastically deforms, and its restoring force can press the filtration membrane 30 against the base 50. This improves the sealing performance at the contact points between the filtration membrane 30 and the annular portion 20 and between the annular portion 20 and the base 50, thereby preventing liquid leakage. Furthermore, this pressing down can prevent the filtration membrane 30 from wrinkling or folding.

[0028] The annular portion 20 has a slit portion 22 extending radially outward from a radially inner end portion 20A. With this configuration, the annular portion 20 is easily bent and deformed when it presses against the filtration membrane 30. This deformation allows the annular portion 20 to adhere closely to the filtration membrane 30, further improving the sealing performance.

[0029] The annular portion 20 has a plurality of holes 24 arranged along the circumferential direction thereof. With this configuration, it is possible to prevent the filtered body O from remaining (liquid residue) between the cylindrical body 10 and the base 50 during filtration processing.

[0030] The lower end 11A of the cylindrical body 10 has a flat surface that can be placed in face-to-face contact with the base 50. With this configuration, when the cylindrical body 10 is attached to the base 50, the sealing performance between the cylindrical body 10 and the base 50 is improved, and liquid leakage can be suppressed.

[0031] The outer peripheral surface of the cylindrical body 10 near the lower end 11A is flush. The cylindrical body 10 is formed into a cylindrical shape by radially overlapping its circumferential ends to form an overlapping portion 12, and near the lower end 11A of the cylindrical body 10, the outer peripheral surface of the overlapping portion 12 and the surface in its vicinity are flush. This configuration makes it easy to attach the cylindrical body 10 to the base 50, and when the cylindrical body 10 is attached to the base 50, the sealing performance between the cylindrical body 10 and the base 50 is improved, making it possible to suppress liquid leakage.

[0032] Furthermore, in this embodiment, the filtration unit 1 is shown in which the filtration unit cylindrical body 10 is attached to the base 50, so that the end of the filtration membrane 30 is sandwiched between the annular portion 20 and the base 50. The lower end 11A of the cylindrical body 10 has an extension portion 15 that extends downward below the annular portion 20, and the base 50 has a recess 54 disposed radially outward thereof, and the extension portion 15 fits into the recess 54, so that the cylindrical body 10 is attached to the base 50.

[0033] With this configuration, in the installed state, the filtration unit 1 can improve the sealing between the cylindrical body 10 and the filtration membrane 30, between the filtration membrane 30 and the base 50, and further between the cylindrical body 10 and the base 50, thereby suppressing liquid leakage.

[0034] The filtration unit 1 is configured to filter the object to be filtered O by reducing the pressure below the filtration membrane 30. Furthermore, the filtration unit 1 is configured so that the filtration membrane 30 captures bacteria contained in the object to be filtered O. With this configuration, the filtration unit 1 can be made practical for capturing bacteria.

[0035] <Other Embodiments> The present disclosure is not limited to the embodiments described above and in the drawings. For example, the following embodiments are also included within the technical scope of the present disclosure. Furthermore, various modifications other than those described below can be made without departing from the spirit of the present disclosure.

[0036] In addition to the above-described embodiment, the configuration of the base can be modified as appropriate. The base may be configured so that the liquid that has passed through the filtration membrane flows toward the discharge portion. For example, the upper surface of the mounting portion may be an inclined surface that slopes downward toward the discharge portion.

[0037] The uses of the above-mentioned cylindrical body and filtration unit are not particularly limited. The cylindrical body and filtration unit may be used to capture solids such as fine particles and microorganisms. The cylindrical body and filtration unit may also be used for testing and research, industrial production, etc. in various fields such as food and beverage, pharmaceuticals, and cosmetics.

[0038] 1... Filtration unit, 10... Cylindrical body (cylindrical body for filtration unit), 11... Main body portion, 11A... Lower end portion of cylindrical body, 12... Overlapping portion, 15... Extension portion, 20... Annular portion, 22... Slit portion, 24... Hole portion, 30... Filtration membrane, 30A... Peripheral end portion, 50... Base, 54... Recess, Filtered body... O

Claims

1. A filtration unit cylinder comprising a paper cylinder and a base, with a filtration membrane placed between the cylinder and the base, used in a filtration unit that filters a material to be filtered housed in the cylinder, wherein a ring-shaped portion that protrudes radially inward is formed near the lower end of the cylinder.

2. The cylindrical body for a filtration unit according to claim 1, wherein the annular portion has a plurality of holes arranged along the circumferential direction thereof.

3. A cylindrical body for a filtration unit according to claim 2, wherein said annular portion has a slit portion extending from said radially inner end to said radially outer end.

4. A cylindrical body for a filtration unit according to claim 1, wherein the lower end of said cylindrical body is flat so as to be able to rest against said base.

5. A cylindrical body for a filtration unit according to claim 1, wherein the outer peripheral surface of the cylindrical body near the lower end is flush.

6. A cylindrical body for a filtration unit as described in claim 5, wherein the cylindrical body has a cylindrical shape with its circumferential ends overlapping in the radial direction to form an overlapping portion, and near the lower end of the cylindrical body, the outer peripheral surface of the overlapping portion and the surface in its vicinity are flush.

7. A filtration unit in which the cylindrical body for a filtration unit according to any one of claims 1 to 6 is attached to the base, so that the end of the filtration membrane is sandwiched between the annular portion and the base.

8. A filtration unit as described in claim 7, wherein the lower end of the cylindrical body has an extension portion extending downwardly beyond the annular portion, the base has a recessed portion disposed radially outwardly thereof, and the cylindrical body is attached to the base by fitting the extension portion into the recessed portion.

9. The filtration unit according to claim 7, wherein the filtration unit is configured to filter the material to be filtered by reducing the pressure below the filtration membrane.

10. The filtration unit according to claim 7, wherein the filtration membrane is configured to capture bacteria contained in the body to be filtered.

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