JP4471702B2 - Inflatable filter - Google Patents

Description

  The present invention relates to a filter in various industrial filtration devices for removing a suspension in a liquid by filtration, and more particularly to an expansion / contraction type filter using a bag-shaped filter cloth that can be expanded / contracted.

  As a filter (filter module) used in filtration equipment used for filtering or concentrating suspensions of sludge generated during the treatment of various industrial waste liquids and water and sewage systems, or for recovering valuable materials from various industrial waste liquids The outer peripheral surface of a hollow cylindrical body made of a hard synthetic resin having a large number of liquid passage holes on the peripheral surface is covered with a filter cloth via a spacer such as a net, or a porous material made of a hard material such as ceramic. What was comprised in the filter body of the hollow cylindrical body is known. Further, as disclosed in Patent Document 1, a filter cloth made of a flexible sheet formed in a cylindrical shape or a bag shape (collectively referred to as a bag shape in the present application) is used as a filtrate collecting member. The filter cloth is contracted to the surface position of the flow path material when filtering or resting, and is flattened, and when the filter cloth is washed from the flow path material side, the filter cloth is expanded to form a cylindrical shape. An expansion-contraction filter that can be formed into a bag-like structure is also known.

  Such a conventional expansion / contraction type filter is normally operated by blowing air when the filter cake is peeled off. However, accumulation of filter cake tends to occur at the upper part of the inner surface of the filter device equipped with the filter. As a result, the accumulation grows downward and the filtration surface is reduced, resulting in a decrease in performance. Depending on the situation, it is necessary to stop the operation and remove the accumulated lump of filter cake.

Moreover, in order to prevent this situation, it is possible to improve to some extent by increasing the amount of blown air, but basic improvement has been difficult. In order to prevent the occurrence of such a problem, Patent Document 2 discloses that the airtight treatment at the filter cloth attachment portion is made strict and the accumulation of the filter cake is prevented by preventing the progress of filtration at the attachment portion. However, there remains a problem that the removal and removal of the filter cake in the vicinity of the attachment portion is insufficient. In the expansion and contraction type filter, if the separation and removal of the filter cake at the end of the filter cloth attachment is insufficient, the accumulation of the filter cake proceeds in the vertical direction from that part, and the above-mentioned inconvenience occurs. It was. In addition, since an additional cost has been incurred when attaching the filter cloth due to the above airtight treatment, it is necessary to improve this portion in order to reduce the cost.
Japanese Patent No. 276659 No. 7-28896

  Accordingly, an object of the present invention is to provide an expansion / contraction type filter capable of preventing the accumulation and progress of filter cake at the filter cloth mounting portion and allowing the filter device to which the filter is attached to operate stably. There is to do. In other words, the accumulation of filter cake from the filter (filter cloth) attachment part during filtration causes a drop in filtration capacity, so that it is possible to prevent this and to stably demonstrate the specified equipment capacity for long-term use. And

  In addition, smooth removal and removal of the filter cake is achieved, and at the same time, the amount of blowing fluid for removing the filter cake is minimized, reducing the consumption of fluid used for blowing the fluid and reducing running costs. It is also an issue to plan.

  Furthermore, by preventing the accumulation of filter cake, it is possible to simplify the installation of the filter cloth for the conventional airtight treatment, and to reuse the used parts and to use inexpensive parts. It is also an issue to reduce this.

  In order to solve the above-mentioned problems, an expansion / contraction type filter according to the present invention includes an inflatable / deflable bag-shaped filter cloth that is contracted during filtration and inflated by blowing a fluid into the inside when removing filter cake, and the filter. It is arranged in the cloth, guides the filtrate in the direction of discharging the filtrate and guides the filter cake removing fluid into the filter cloth, and holds one end of the filter cloth, from inside the bag-shaped filter cloth And a holding member provided with an inflow path for the filter cake removing fluid into the bag-like filter cloth, and the outflow filter on the filter cloth holding part side of the holding member. A fluid reservoir having a cross-sectional area larger than the cross-sectional area of the flow path and inflow path is provided.

  In this expansion / contraction type filter, a throttling portion having a cross-sectional area that gradually decreases in comparison with the cross-sectional area of the reservoir portion at a portion following the reservoir portion in the inflow direction of the fluid (fluid removal fluid) of the holding member. It is preferable that a portion is provided. Moreover, it is preferable that an opening is provided in a part of the portion extending from the reservoir to the throttle. In the reservoir, the flow rate of fluid (for example, air) flowing in at a high flow rate is reduced to weaken the jet flow when directly flowing into the filter cloth, and the jet flow from the opening provided in the throttle and the fluid flow into the filter cloth To distribute. By the jet flow from the opening, it is possible to complete the separation of the filter cake, particularly at the throttle portion, and to prevent the accumulation and growth of the filter cake.

Moreover, it is preferable that the terminal part of the said throttle part is formed in the flow path shape with a flat cross section. It is preferable to adopt a structure in which one end of the channel material is inserted and held in the flat central portion in the thickness direction of the flat channel at the terminal end of the throttle portion. Furthermore, it is preferable that protrusions having a spherical top surface are provided on both outer surfaces of the wall forming the flat flow path at the terminal end of the throttle portion. Since the end of the throttle part is formed in a channel shape with a flat cross section, especially when the channel material is formed in a flat shape, it contracts to a flat shape during filtration along the channel material It becomes easy to allow the filter cake removing fluid to flow into the filter cloth, and the filter cake can be effectively removed. Further, one end of the flow channel material is inserted and held in the central portion of the flat flow channel at the terminal end of the throttle portion, so that the fluid flows evenly to both sides of the flat flow channel material, and as a result It becomes possible to allow the fluid to flow uniformly into the filter cloth being shrunk. Furthermore, by providing openings in the throttle part and providing protrusions on both sides of the flat part, the filter cloth that is strongly flattened by the filtration pressure during filtration and is difficult to expand can be In addition, the fluid can easily flow into the filter cloth corresponding to the above, and the filter cloth can be easily expanded from the protrusions, thereby enabling more rapid expansion. And, by this action and the fluid blowing at the aperture of the throttle part, it becomes possible to completely remove the filter cake at the end of the filter (for example, the upper end). At the same time, the smooth expansion from the end portion (for example, the upper end portion) of the filter cloth enables peeling of the filter cake to be achieved with a small amount of fluid over the entire surface of the filter cloth.

  Achieving the desired peeling and removal of filter cake eliminates the need for a strict airtight structure as the attachment structure of the filter end (for example, the upper end), enables simple attachment using a commercially available hose attachment band, etc., and reduces cost. It becomes possible.

  In the expansion / contraction filter according to the present invention, it is preferable that the flow path material is made of a flexible material. By providing flexibility to the flow path material together with the filter cloth, the entire filter can be flexible enough to be folded and folded. Generally, the filter is attached in a dense state in the can. Further, due to clogging of the filter surface over time, it is necessary to remove the filter from the can body and regenerate the filter surface in order to replace or clean the filter cloth of the filter. In such removal work, by providing flexibility as described above and allowing the filter to be worked to be folded or folded, the can opening of the smallest size when removed from the can body (For example, manholes) will be sufficient, and the work will be easier. Furthermore, the handling inside the can body is very easy work, and the necessary space inside the can body can be minimized. The specific material of the flexible material constituting the flow path material is not particularly limited as long as it has flexibility, but in particular, a flexible rubber material such as a soft rubber material or a flexible plastic sheet may be used. High material is preferred. Moreover, what consists of plate-shaped members can be used as this flow-path material. Furthermore, it is preferable to provide the channel material with grooves extending in the filtrate discharge direction, and it is particularly preferable to provide such channels on both sides of the channel material. The shape of the groove is not particularly limited as long as it has an appropriate width and depth so that the filtrate can be discharged and the filter cake removing fluid can be smoothly flowed in.

  According to the expansion / contraction type filter according to the present invention, the reservoir portion of the fluid having a larger cross-sectional area than the flow passage cross-sectional area of the filtrate outflow passage / fluid removal passage is provided on the filter cloth holding portion side of the holding member. By providing, the flow rate of the fluid that has flowed in can be appropriately reduced, and in particular, the fluid flow for separating and removing the filter cake that tends to accumulate in this portion and the fluid flow into the filter cloth can be properly distributed. It is possible to peel and remove the filter cake under uniform and desirable conditions over the entire surface. In particular, by providing a throttle and an opening, it is possible to prevent accumulation and progression of the filter cake in this part, and the filter cake can be almost completely peeled and removed, thus simplifying the mounting structure at this part. Can be achieved, and the cost can be reduced. As a result, it is possible to stably maintain desirable performance over a long period of time while having an inexpensive structure.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIGS. 1-5 has shown the expansion / contraction type | mold filter which concerns on one embodiment of this invention, and a filtration apparatus using the same. FIG. 1 shows a schematic configuration of the entire filtering device 1, and the can body 2 is partitioned into an upper chamber 4 and a lower chamber 5 by a partition plate 3. A plurality of expansion / contraction type filters 6 are disposed in the lower chamber 5, and each filter 6 is suspended and suspended from the partition plate 3 with its upper end fixed to the partition plate 3. Manholes 7a and 7b are installed in the upper chamber can body 2a and the lower chamber can body 2b, respectively, and are used for filter cloth replacement work, filter installation work, and replacement work as described below in addition to various maintenance work. Can be done. During the filtration operation, the processing liquid introduced into the lower chamber 5 through the processing liquid introduction pipe 8 is filtered by the filter 6, and the processing liquid from which the suspended matter and the like are removed is removed from the upper chamber 4 to the filtrate pipe. 9 is discharged to a predetermined destination. When the filter cake trapped on the filter cloth surface of the expansion / contraction filter 6 is peeled and removed, air is instantaneously introduced into the upper chamber 4 from the air introduction pipe 10, and the filter cloth inner surface of each filter 6. The filter cake is ejected from the side to the outer surface side, and the filter cake is peeled and removed.

  As shown in FIG. 2, the expansion / contraction filter 6 is an inflatable / deflable bag-like filter cloth 11 made of a flexible material, and is disposed in the filter cloth 11 and filtered by the filter cloth 11. A flow path member 12 that collects the filtrate and discharges it into the upper chamber 4 is provided. In the present embodiment, the flow path member 12 is also made of a flexible material (for example, a rubber material having flexibility), and the filter 6 can be folded or folded as a whole, and even a long filter 6 is easy. It is possible to perform replacement, maintenance work, transportation, etc. Moreover, in this embodiment, the flow path material 12 is comprised by the plate-shaped member, and the some groove | channel 13 extended in the filtrate discharge | emission direction is provided in the both surfaces. The groove 13 functions as a guide groove when collecting and discharging the filtrate to the upper chamber 4 side, and when the filter cake is peeled and removed, the groove 13 enters the contracted filter cloth 11 from the upper chamber 4 side. It also functions as a guide groove for an inflowing fluid (air in this embodiment, but liquid, particularly water (backwash water) is also possible). At the time of filtration operation, the filter cloth 11 is pressed against the surface of the flow path material 12 by the filtration pressure as shown by the solid line in FIG. 2 to have a flat shape as a whole. As shown by a two-dot chain line, the filter cloth 11 is expanded into a cylindrical shape as shown by a two-dot chain line, thereby constituting an expansion / contraction type filter.

  Each filter 6 is configured as shown in FIGS. As shown in FIG. 3, the filter 6 holds one end side of the filter cloth 11, and the fluid for removing the filter cake from the bag-like filter cloth 11 into the outflow path of the filtrate into the bag-like filter cloth 11. The holding member 15 is provided with an inflow passage 14, and an outflow passage / inflow passage 14 portion of the holding member 15 is inserted into the partition plate 3 and fixed to the partition plate 3 by a nut 16. A reservoir of fluid having a cross-sectional area larger than the flow path cross-sectional area of the outflow passage / inflow passage 14 is located on the filter cloth holding portion side of the holding member 15, that is, on the side opposite to the outflow passage / inflow passage 14 portion. A portion 17 is provided. In this embodiment, the reservoir portion 17 is formed in a hollow portion having a circular cross section. As shown in FIG. 4, the holding member 15 is provided with a constriction 18 that gradually decreases in cross-sectional area as compared with the cross-sectional area of the reservoir 17 at a portion following the reservoir 17 in the fluid inflow direction. In addition, the end portion 19 of the throttle portion 18 is formed in a flow channel shape having a flat cross section. Therefore, the cross-sectional shape of the throttle portion 18 is continuously changed so as to gradually change from the circular cross-section shape in the reservoir portion 17 to the shape of the flat flow path 20 in the terminal portion 19.

  As shown in FIG. 5, at the end portion 19 of the throttle portion 18, the opposing walls extend in parallel by a predetermined length so that the flat flow paths 20 form a flat shape having a predetermined length by the walls facing each other. It is installed. One end (upper end in the present embodiment) of the flow path material 12 is inserted into the flat central portion in the thickness direction of the flat flow path 20 in the end portion 19 and is held via a fixture 21 (illustrated in FIG. 3). It is held by the member 15.

  An opening 22 is provided in a part of the portion of the holding member 15 extending from the reservoir 17 to the throttle 18. In the present embodiment, the apertures 22 are provided in the walls on both sides at substantially the center in the longitudinal direction of the throttle portion 18. Further, projections 23 are provided on both outer surfaces of the wall forming the flat flow path 20 at the terminal end 19 of the throttle portion 18. In this embodiment, the protrusion 23 is formed by the head of the fixture 21 of the flow path member 12, but may be formed separately from the fixture 21.

  The cylindrical filter cloth 11 is covered from the reservoir part 17 of the holding member 15 configured as described above to the terminal part 19 of the throttle part 18, and one end of the filter cloth 11 is held by, for example, a hose clamp 24 which is a commercially available metal fitting. It is fixed to the outer periphery of the member 15. FIG. 3 shows a state during filtration, and the lower side of the filter cloth 11 is contracted into a flat shape as shown in FIG.

  In the filter 6 configured as described above, filtration is performed via the filter cloth 11 during filtration. When filtration is continued, filter cake accumulates on the surface of the filter cloth 11. If the filter cake accumulates, the filtration resistance increases and the efficiency of filtration decreases, so that the operation of removing the filter cake and performing filtration is performed. If the removal of the filter cake is not carried out smoothly, the filter cake accumulates and the filtration ability is lowered, so that the ability cannot be exhibited. In this embodiment, the filter cake is peeled and removed by introducing compressed air from the air introduction pipe 10 into the upper chamber 4, and from there through the outflow passage / inflow passage 14 of the holding member 15 to the reservoir portion 17. Here, the flow velocity of the air is once reduced, and then a part of the introduced air is blown out from the inner surface of the filter cloth 11 to the outer surface through the opening portion 22 in the throttle portion 18, and the filter cake accumulated in this portion. The other most of the introduced air is sent to the lower side along the inner surface of the filter cloth 11 while expanding the filter cloth 11 into a cylindrical shape. At this time, the air that has traveled straight to the lower side of the filter cloth 11 travels along the flow path member 12, particularly along the grooves 13 provided on both surfaces of the flow path member 12, toward the lower side. At this time, while the filter cloth 11 is expanded, a part of the air is released from the filter cloth 11 and proceeds while peeling the filter cake. This operation is performed instantaneously. If the expansion of the filter cloth 11 does not proceed smoothly and smoothly from the upper part of the filter cloth 11, if a part of the lower side first peels off the filter cake, air is released from the peeled part of the filter cake. Will occur and the upper part of the filter cake will remain incomplete. If the peeling is incomplete, the filter cloth surface is not sufficiently regenerated, and the filtration resistance at that portion is increased, so that the filtration capacity is reduced.

  In the present invention, the flow rate of the compressed air introduced through the outflow passage / inflow passage 14 of the holding member 15 is once reduced in the reservoir portion 17, and then introduced into the straight direction, and the upper portion of the filter cloth 11 (holding member). Since the distribution of the filter cake accumulated on the outer periphery of the filter cloth 15 with the air for peeling is easily performed appropriately, the filter cloth is expanded on the upper side of the filter cloth 11 and the filter cake is peeled off favorably. The purpose of the air reservoir 17 is to reduce the inflow air flow velocity and to distribute a part of the air to the upper filtration surface. As the size (cross-sectional area) of the reservoir portion 17, for example, the inflow air flow velocity is 1 What is necessary is just to select an aperture so that it may fall to / 5 to 1/10 or more.

  Moreover, in order to make the filter cake peeling on the upper side of the filter cloth 11 more complete, in this embodiment, the opening portion 22 and the projection 23 are provided. A part of the air distributed in the reservoir portion 17 is blown out from the inner surface of the filter cloth 11 to the outer surface through the opening portion 22, and the filter cake accumulated in this portion is peeled off and removed. The aperture portion 22 of the throttle portion 18 preferably has an area equivalent to the diameter of the inflow passage 14 in the aperture area of the aperture portion 22 provided on both surfaces. Further, during filtration, the filter cloth 11 is pressed by the filtration pressure, and is in close contact with the throttle end 19 of the flat holding member 15. In this state, in order to prevent the inflow of air into the filter cloth 11, 23 has a function of preventing the filter cloth 11 from being completely adhered, facilitating the inflow of air from the opening portion 22 of the throttle portion 18 and making the expansion effective. In this embodiment, a total of four protrusions 23 are provided on both sides of one side in this embodiment, and the protrusions 23 have the same shape and height on both sides in order to equalize the flow of air on both sides. Further, if the protrusion shape is an acute angle, the filter cloth may be damaged, so that the protrusion top surface is a spherical surface.

  Furthermore, in the present embodiment, the end of the flow path member 12 is disposed in the flat shape center portion of the flat flow path 20 in the thickness direction, and the introduced air is evenly distributed along both sides of the flow path member 12. With the introduction of air, the filter cloth 11 that has been shrunk flatly is evenly expanded on both sides simultaneously. Thereby, the whole is easily expanded uniformly to the lower part of the filter cloth 11, and at the same time, air is released over the entire surface through the filter cloth 11, so that the filter cake is peeled and removed well over the entire filter surface.

  By obtaining such a good filter cake peeling effect, the cylindrical filter cloth 11 can be directly attached with a commercially available metal fitting such as a hose clamp 24 in the attachment of the filter cloth 11, and the conventional airtight treatment can be performed. It becomes unnecessary, and a significant cost reduction can be achieved.

  The expansion / contraction type filter according to the present invention can be applied to any filtration device using an expansion / contraction type filter used for filtration, concentration, recovery, etc. in the treatment of various industrial waste liquids and water and sewage systems. It is suitable for a filtration device that requires stable filtration performance over a wide range.

It is a schematic longitudinal cross-sectional view of the filtration apparatus using the expansion-contraction type filter which concerns on one embodiment of this invention. It is an expansion cross-sectional view of the expansion-contraction type filter of FIG. FIG. 2 is an enlarged vertical sectional view of the expansion / contraction filter of FIG. 1. FIG. 4 is an enlarged longitudinal sectional view of a holding member in the expansion / contraction filter of FIG. 3. FIG. 4 is an enlarged cross-sectional view of a throttle end portion and a flow path material end of the holding member in the expansion / contraction filter of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Filtration apparatus 2 Can body 2a Upper chamber can body 2b Lower chamber can body 3 Partition plate 4 Upper chamber 5 Lower chamber 6 Expansion / contraction type filter 7a, 7b Manhole 8 Liquid to be processed 9 Filtrate tube 10 Air introduction tube DESCRIPTION OF SYMBOLS 11 Filter cloth 12 Channel material 13 Groove 14 Outflow path / inflow path 15 Holding member 16 Nut 17 Reservation part 18 Restriction part 19 End part of restriction part 20 Flat flow path 21 Mounting tool 22 Opening part 23 Protrusion 24 Hose clamp

Claims (9)

  An inflatable and bag-like filter cloth that is shrunk during filtration and fluid is blown into the interior when removing the filter cake, and disposed in the filter cloth, guiding the filtrate in the direction of discharging the filtrate and removing the filter cake. A flow path material that guides the working fluid into the filter cloth, and a fluid for removing the filter cake that holds one end of the filter cloth and flows out the filtrate from the bag-shaped filter cloth into the bag-shaped filter cloth In the expansion / contraction type filter having a holding member having an inflow passage of the fluid, a reservoir portion of a fluid having a cross-sectional area larger than the flow passage cross-sectional area of the outflow passage and the inflow passage on the filter cloth holding portion side of the holding member An expansion-contraction type filter characterized by comprising:   The expansion / contraction filter according to claim 1, wherein a constriction portion having a cross-sectional area that gradually decreases in comparison with a cross-sectional area of the reservoir portion is provided at a portion following the reservoir portion in the fluid inflow direction of the holding member. .   The expansion / contraction type filter according to claim 2, wherein an opening is provided in a part of a portion extending from the pool part to the throttle part.   The expansion / contraction type filter according to claim 2 or 3, wherein a terminal portion of the throttle portion is formed in a channel shape having a flat cross section.   The expansion / contraction filter according to claim 4, wherein one end of the flow path material is inserted and held in a flat central portion in the thickness direction of a flat flow path at the end portion of the throttle portion. 6. The inflatable filter according to claim 4 or 5, wherein protrusions having a spherical top surface are provided on both outer surfaces of a wall forming a flat flow path at the terminal end of the throttle portion of the holding member. .   The expansion / contraction type filter according to claim 1, wherein the flow path member is made of a flexible material.   The expansion / contraction filter according to any one of claims 1 to 7, wherein the flow path member is a plate-like member.   The expansion / contraction type filter according to claim 8, wherein grooves extending in a filtrate discharging direction are provided on both surfaces of the flow path member.

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