JP2014180617A - Compression membrane for filter press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compression membrane for a filter press machine which has high sealing property with respect to a filter plate and has high strength and high durability.SOLUTION: A compression membrane 20 includes a seal part having lip portions 27 and 29 which is formed around a pressure receiving surface on the side configured to receive a pressure of a compressed fluid. The lip portions 27 and 29 are secured to a pressure plate 10. The lip portions 27 and 29, or the pressure receiving surface on the side configured to receive the pressure of the compressed fluid is made of elastomer with low hardness. The lip portions 27 and 29 or the pressure receiving surface is therefore apt to deform so as to improve sealing property with respect to the pressure plate 10.

Description

  The present invention relates to a squeezed membrane (diaphragm) used in a filter press that squeezes sludge, slurry, and the like to separate it into solid and liquid.

  Some filter press apparatuses use a squeezable membrane (diaphragm). The pressing membrane swells in the direction of pressing the filter cloth in response to the pressure of the pressing fluid (such as air or water), and presses the filter cloth. In response to this pressing, the liquid content in the undiluted undiluted solution in the filter cloth squeezes out through the filter cloth, and the solid content (cake) remains in the filter cloth. Such a compressed membrane is usually used by being fixed around the filter plate. Specifically, an annular recess is formed around the filter plate, and a protruding lip portion that is fitted into the recess is formed around the compressed membrane. The lip portion is fitted into the concave portion and fixed with a screw or the like, and the compressed membrane is attached to the filter plate.

  The squeezed membrane is generally made of a rubber such as natural rubber or synthetic rubber that is soft and easy to swell in consideration of expansion and contraction. However, in consideration of strength, heat resistance, and durability, it is preferable to produce with an elastomer or the like (PP-EDPM etc.) harder than rubber, and a plastic squeezed membrane has also been commercialized. There is a demand for improving the sealing performance when attached to a filter plate in a compression membrane made of such a hard material such as plastic. This is because when the lip portion and the filter plate are fitted into the recess, the lip portion has low elasticity, so that they may not be in liquid-tight contact with each other, and the squeezing fluid may leak.

  This invention is made | formed in view of said problem, Comprising: It aims at providing the squeeze film for filter press machines with high sealing performance with a filter plate, and high strength and high durability.

The first squeezing membrane for a filter press according to the present invention is a squeezing membrane that is equipped in a filter press and presses a filter cloth under the pressure of a squeezing fluid, wherein two or more different materials are laminated. To do.
The second squeezing membrane for a filter press according to the present invention is a squeezing membrane that is equipped in a filter press and presses a filter cloth under pressure of a squeezing fluid, and the pressure receiving surface on the side receiving the pressure of the squeezing fluid has a hardness. It consists of a low elastomer, The pressing surface on the side which presses the said filter cloth consists of a highly rigid elastomer, It is characterized by the above-mentioned.

  A pressing membrane for a filter press according to a specific aspect of the present invention is a pressing membrane that is provided in a filter press and presses a filter cloth under pressure of a pressing fluid, and is a pressure receiving surface on a side that receives the pressure of the pressing fluid. A seal portion having a lip portion is formed around the periphery, and the surface of the seal portion is made of an elastomer having a low hardness, and the other portion is made of an elastomer having a high hardness.

A seal portion having a lip portion for preventing the compressed fluid from leaking outside is formed around the peripheral portion of the compressed membrane or around the central hole. In some cases, the seal portion is an attachment portion where the squeezed membrane is attached to the pressure plate. According to the present invention, the lip portion or the pressure receiving surface on the side that receives the pressure of the compressed fluid is made of an elastomer having low hardness, so that the portion is easily deformed, and the sealing performance with the pressure plate or the like is improved. it can.
In addition, since the pressing surface of the pressing membrane (the surface on the side where the filter cloth is pressed) is made of a material having high hardness, it is possible to obtain high strength and durability almost the same as those of a conventional plastic pressing membrane. .

  The “low hardness” referred to in the present invention is, for example, Shore A hardness 70-80, preferably Shore A hardness 73-77. On the other hand, “high hardness” is, for example, Shore A hardness 90 to 100, preferably Shore A hardness 95 to 99. As the elastomer, for example, PP (polypropylene) -EPDM (ethylene propylene diene rubber) can be used.

  As is clear from the above description, according to the present invention, the lip portion, which is the attachment portion of the compressed membrane to the filter plate, is made of a material having low hardness, so that the groove into which the lip portion is fitted or a through-hole to be contacted It becomes easy to deform | transform with respect to the side surface, and the sealing performance with a filter plate improves. Moreover, since the surface which presses a filter cloth is a material with high hardness, it can also provide sufficient intensity | strength and durability.

It is a sectional side view explaining the structure of the pressing board provided with the pressing film which concerns on embodiment of this invention. It is a disassembled perspective view explaining the structure of the pressurization board of a pressing board. It is a figure explaining the structure of a pressing film, FIG. 3 (A) is a top view, FIG.3 (B) is a sectional side view. It is a figure explaining an example of the manufacturing process of a pressing film. It is a figure explaining the effect | action of the pressing film at the time of pressing, FIG. 5 (A) is a side sectional view at the normal time, and FIG. 5 (B) is a side sectional view at the time of pressing. It is a figure explaining an example of the filter press machine which uses a pressing board.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, a filter plate for a filter press according to an embodiment of the present invention will be described with reference to FIG.
The filter plate 1 includes a pressure plate 10 and a receiving plate 40. As will be described later, in the filter press, the pressure plates 10 and the receiving plates 40 are alternately arranged. A pressing film 20 (diaphragm) is attached to both sides of the pressure plate 10, and no pressing film is attached to the receiving plate 40.

The pressure plate will be described with reference to FIGS.
As shown in FIG. 2, the pressure plate 10 has a square planar shape, has a predetermined thickness, and is made of a resin such as polypropylene, for example. On both surfaces of the pressure plate 10, concave portions 11 having a shallow bottom are formed. An opening 13 that penetrates in the thickness direction is formed at the center of the recess 11. Into this opening 13, the undiluted undiluted solution flows through a filter cloth. In addition, on the side surface (in this example, the upper side surface) of the pressurizing plate 10, an introduction path 15 for introducing a squeezing fluid that communicates with both concave portions 11 from the same surface is opened. Further, an annular groove 17 into which a lip of a compressed film, which will be described later, is fitted is formed outside the concave portions 11 on both sides.

  As shown in FIG. 3, the compressed film 20 is a sheet-like member whose planar shape is substantially the same as the planar shape of the pressure plate 10, and is made of an elastomer in the present invention. The material and manufacturing method of the pressing film 20 will be described later. As shown in FIGS. 2 and 3, the compressed film 20 includes an outer peripheral portion 21 and an inner expansion / contraction portion 23. As shown in FIG. 3B, the expansion / contraction portion 23 is a shallow concave portion that is recessed in the direction of one surface (inward direction, the side facing the pressure plate). A lattice-shaped shallow groove 24 is formed in the expansion / contraction portion 23. The groove 24 serves as a passage through which the filtrate after pressing flows down. An opening 25 penetrating in the thickness direction is formed in the center of the expansion / contraction part 23. The opening 25 communicates with the opening 13 of the pressure plate 10.

  An annular lip portion 27 is formed on the inner surface (surface facing the plate) of the outer peripheral portion 21 of the compressed film 20. As described above, the outer peripheral lip portion 27 is fitted into the groove 17 formed around the pressure plate 10. Further, a short circumferential lip-shaped lip portion 29 protruding inward from the periphery of the opening 25 is formed on the inner surface of the compressed film 20. This circumferential bank-like lip portion 29 is fitted into the opening 13 of the pressure plate 10.

  As shown in FIG. 3B, a through passage 31 that penetrates in a direction orthogonal to the length direction of the lip portion 27 is opened on one side (the lower side in this example) of the outer peripheral lip portion 27. The through passage 31 is a discharge passage through which the filtrate after pressing is discharged.

  The squeezed membrane 20 is disposed facing the pressure plate 10, the outer peripheral lip portion 27 is fitted into the annular groove 17, and the circumferential bank-like lip portion 29 is inserted into the opening 13 of the pressure plate 10. Then, it is fixed to the pressure plate 10 with screws or the like at the four corners.

Next, an example of the material and manufacturing method of this pressing film 20 will be described.
The pressing membrane 20 has a two-layer structure, and has a low-hardness elastomer on the inner side (side receiving the pressure of the pressing fluid, the side facing the pressing plate 10) and the outer side (the side pressing the filter cloth, opposite to the pressing plate 10). Made of high hardness elastomer. That is, the outer peripheral lip portion 27 and the surface of the circumferential bank-like lip portion 29 around the central opening 25 provided on the inner surface of the squeezed film 20 are made of an elastomer having low hardness. The “low hardness” can be, for example, Shore A hardness 70-80, preferably Shore A hardness 73-77. On the other hand, “high hardness” can be, for example, Shore A hardness 90 to 100, preferably Shore A hardness 95 to 99.

  As the elastomer, for example, PP (polypropylene) -EPDM (ethylene propylene diene rubber) can be used. In the case of PP-EPDM, the hardness can be adjusted by changing the blending ratio of PP and EPDM. For example, in order to obtain a relatively low Shore A hardness of 75, the blending ratio of PP may be reduced. In order to obtain a relatively high Shore A hardness of 97, the PP blending ratio may be increased.

  By doing in this way, the contact part of the pressing film 20 and the pressurization board 10 (a seal part, between the outer periphery lip part 27 and the annular groove 17, and between the circumferential bank-like lip part 29 and the side surface of the opening 13) , The surfaces of the lip portions 27 and 29 made of a low hardness material are in contact with the side surfaces of the grooves 17 and the openings 13. Accordingly, the surfaces of the lip portions 27 and 29 are easily deformed according to the side surfaces of the groove 17 and the opening 13 due to elasticity, and the adhesion to the same surface can be improved. Thereby, the undiluted undiluted solution is prevented from leaking between the squeezed membrane 20 and the pressure plate 10. And since the outer surface (surface on the side that presses the filter cloth) of the squeezing membrane 20 is made of a material having high hardness, it obtains the same high strength and durability as those of a conventional plastic squeezing membrane. You can also.

With reference to FIG. 4, an example of the manufacturing process of a pressing film is demonstrated.
First, as shown in FIG. 4A, an elastomer having a low hardness (material: PP-EPDM, Shore A hardness: 75, thickness: 3.0 mm) and an elastomer having a high hardness (material: PP-EPDM, Shore) (A hardness: 97, thickness: 6.5 mm) Extruded sheets 201 and 202 are prepared.
Next, as shown in FIG. 4 (B), the extruded sheets 201 and 202 are stacked and press-molded with a mold including upper and lower molds 301 and 302. At this time, an extruded sheet 201 made of an elastomer having a low hardness is made to be the inner surface of the compressed film. Examples of molding conditions are: temperature: 200 ° C., pressurization time: 7 minutes, pressure: 36 kgf / cm ² .

  By this press molding, as shown in FIG. 4 (C), a pressed membrane is produced in which the surface or the whole of the lip portions 27 and 29 is made of a material having low hardness. When only the lip portion and the surrounding seal portion are made of a material having low hardness, the extruded sheet 201 having low hardness may be disposed only in the portion.

Next, the receiving plate 40 will be described with reference to FIG.
The receiving plate 40 is a plate-like member having substantially the same planar shape as the pressure plate 10. On both surfaces of the receiving plate 40, a shallow concave portion 41 is formed. A lattice-shaped groove 42 is formed in the recess 41. The groove 42 serves as a passage through which the filtrate after pressing flows down. In the center of the recess 41, an opening 43 penetrating in the thickness direction is opened. Into this opening 43, the undiluted undiluted solution flows through a filter cloth. Further, a through passage 45 is formed from both the concave portions 41 so as to communicate with one side surface (the lower surface in this example) of the receiving plate 40. The through passage 45 is a discharge passage through which the filtrate after pressing is discharged.

With reference to FIG. 5, the process of pressing the to-be-squeezed undiluted | stock solution with this filter board 1 is demonstrated.
As shown in FIG. 5A, the pressure plate 10 and the receiving plate 40 of the filter plate 1 are alternately arranged with the filter cloth 50 interposed between the concave portions 11 and 41 facing each other. A space between the opposing recesses 11 and 41 is a filter chamber C. The filter cloth 50 is also passed through the communicating openings 13 and 43. In this state, as shown in FIG. 5A, each pressing film 20 of the pressure plate 10 is in a state of being recessed in the recess 11.

  As shown in FIG. 5 (B), when the undiluted concentrate is introduced into the filter cloth 50, the undiluted undiluted solution passes between the openings 13 and 43 and between the concave portions (filter chamber C) of the pressure plate 10 and the receiving plate 40. Also flows. Then, a squeezing fluid (such as air or water) is introduced into the squeezing fluid introduction passage 15 of the pressurizing plate 10. The introduced fluid flows into the both concave portions 11 of the pressure plate 10 through the introduction path 15. Then, the expansion part 23 of the pressing film 20 accommodated in the recessed state in the recessed part 11 is pushed outward (on the opposite side to the pressure plate 10) with the fluid. Thereby, the undiluted undiluted solution in the filter chamber C is squeezed between the expanded portion 23 of the swelled compressed membrane 20 and the concave portion 41 of the receiving plate 40, and is filtered by the filter cloth 50. The filtrate that has passed through the filter cloth 50 travels along the groove 24 formed in the expanding portion 23 of the compressed membrane 20 and the groove 42 formed in the concave portion 41 of the receiving plate 40, and the discharge paths 31 and 45 of each plate. Discharged from.

With reference to FIG. 6, an example of the filter press machine 100 using the pressing board 1 of this example is demonstrated.
As described with reference to FIG. 1 and the like, the pressing plates 1 are alternately arranged with the pressing plates 10 and the receiving plates 40 across the filter cloth, and are attached to the fastening device 101. To the central through hole of the pressing plate 1, a compressed stock solution supply pipe 103 having an on-off valve 104 is connected in the middle. Further, a squeezing fluid introduction pipe 105 having an on-off valve 106 is connected to the squeezing fluid introduction path 15 (see FIG. 2) of each pressurizing plate 10. The discharge passages 31 and 45 of the pressure plate 10 and the receiving plate 40 are connected to a filtrate discharge pipe 107 provided with an on-off valve 108.

  When the pressurizing plate 10 and the receiving plate 40 that are alternately arranged are tightened from both sides by the tightening device 101 and the on-off valve 104 is opened to introduce the stock solution from the stock solution introduction pipe 103, the stock solution becomes the opening 13 of each plate 10 and 40. , 43 and flows into each filter chamber. Next, when the on-off valve 106 of the fluid introduction pipe 105 is opened to introduce the squeezing fluid into the recess 41 of the pressurizing plate 10, the squeezing membrane 20 expands as described above, and the stock solution in the filter chamber is filtered. The filtrate is discharged through the discharge pipes 31 and 45 of the plates 10 and 40. On the other hand, the solid content (cake) in the stock solution remains in the filter cloth 50.

DESCRIPTION OF SYMBOLS 1 Filter plate 10 Pressure plate 11 Recess 13 Opening 15 Fluid introduction path 17 Groove 20 Squeezed membrane 21 Outer peripheral part 23 Expansion / contraction part 24 Groove 25 Opening 27 Outer peripheral lip part 29 Circumferential bank-shaped lip part 31 Filtrate discharge path 40 Receiving Plate 41 Recess 42 Groove 43 Open 45 Filtrate discharge path 50 Filter cloth 201, 202 Extruded sheet 301, 302 Vertical mold

Claims (3)

A pressing membrane that is equipped in a filter press and presses the filter cloth under the pressure of the pressing fluid,
A squeezed membrane for a filter press, characterized by laminating two or more different materials. A pressing membrane that is equipped in a filter press and presses the filter cloth under the pressure of the pressing fluid,
The pressure receiving surface on the side receiving the pressure of the compressed fluid is made of an elastomer having low hardness,
A pressing membrane for a filter press, wherein a pressing surface on the side of pressing the filter cloth is made of an elastomer having high hardness. A pressing membrane that is equipped in a filter press and presses the filter cloth under the pressure of the pressing fluid,
A seal portion having a lip portion is formed around the pressure receiving surface on the side receiving the pressure of the compressed fluid,
The surface of the seal part is made of an elastomer with low hardness,
A pressed membrane for a filter press, wherein the other part is made of an elastomer having high hardness.

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