JP2019155254A - Filtering method and filter fabric used in the filtering method - Google Patents

Abstract

To provide a filtering method which is advantageous in a cost and can keep filtering performance, and a filter fabric used in the filtering method.SOLUTION: A filtering method for filtering a suspension S by pouring the suspension S to a lamination body 10 which is provided with a plurality of filter fabrics 1 and is formed by overlapping the plurality of the filter fabrics 1 from an upper layer side in a lamination direction includes: a first filtering process for filtering by pouring the suspension S from one surface 11 which faces an upstream side in a filtering direction of an upper filter fabric 1a located in an uppermost layer of the lamination body 10 to a lower layer; a removing process for removing the upper filter fabric 1a from the lamination body 10 after the first filtering process; and an additional process for adding a new filter fabric 1 to the undermost layer of the lamination body 10 after the removing process. The filter fabric used in the filtering method is provided.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a filtration method for filtering a suspension containing a granular material such as concrete and a filter cloth used in the filtration method.

  Conventionally, a sheet-like filter medium is sometimes used to filter a suspension containing particulate matter such as concrete generated at a construction site or the like.

  Patent Document 1 includes a filtration medium comprising a non-woven fabric, a frame for supporting the filtration medium, a filtration tank for installing the filtration medium and the frame, and a submersible pump for conveying the suspension to the filtration tank. An apparatus is disclosed. In the filtration device of Patent Document 1, the submersible pump is installed in a storage tank in which the suspension is stored, and pumps the suspension from the storage tank. The pumped suspension is poured into the filter medium from the top of the filter tank. The suspension poured into the filter medium is separated into a solid content and moisture, the solid content is deposited on the filter media, and the water is accumulated in the filter tank.

  Patent Document 1 discloses that a coarse fiber structure is joined to the upstream side of a filter medium to form a composite laminate, and clogging is alleviated by using the filter medium as a composite laminate. It is said that the filtration rate can be maintained for a long time.

JP 2002-28416 A

  However, in the above conventional filtration device, although the filtration performance can be maintained by devising the structure of the filter medium, it is necessary to replace the entire filter medium immediately if the filter medium is clogged. Cost. As described above, in the conventional filtration device, attention is not paid to maintaining the filtration performance while reducing the cost for replacing the filter material, and there is room for improvement.

  This room for improvement is not limited to filtering cement and other particulate matter, but also when filtering other suspensions, such as soil accumulated in rivers and lakes, and sludge in drainage. Exists.

  Then, this invention makes it a subject to provide the filter cloth used for the filtration method and this filtration method which are advantageous in cost and can maintain filtration performance in view of this situation.

The filtration method according to the present invention is a filtration method comprising a plurality of filter cloths, and pouring the suspension from the upper layer side in the laminating direction into a laminate in which the plurality of filter cloths are superimposed, and filtering the suspension. ,
A first filtration step of pouring and filtering the suspension from one surface facing the upstream side in the filtration direction of the upper filter cloth located in the uppermost layer of the laminate to the lower layer;
After the first filtration step, a removal step of removing the upper filter cloth from the laminate,
And an additional step of adding a new filter cloth to the lowermost layer of the laminate after the removing step.

  According to such a configuration, after the suspension is poured and filtered from one surface of the upper filter cloth located in the uppermost layer among the plurality of laminated filter cloths to the lower layer, the upper filter used for the filtration is used. The cloth is removed and a new filter cloth is added to the bottom layer of the laminate from which the upper filter cloth has been removed. Thus, in the excessive method, since some of the filter cloths constituting the laminate are replaced with new filter cloths, the filtration performance can be maintained.

  In this case, after performing the first filtration step, after the inversion step of inverting the upper filter cloth, and after the inversion step, the suspension is poured from the other surface of the upper filter cloth toward the lower layer and filtered. A second filtration step, and the removal step and the additional step are performed after the second filtration step.

  According to such a configuration, the upper filter cloth can be inverted and the suspension can be poured and filtered from the other surface to the lower layer, so the suspension is filtered using both surfaces of the upper filter cloth. be able to. Here, when the upper filter cloth is inverted, even if the solid content deposited on one surface of the upper filter cloth is peeled off and dropped, the solid content is placed on the filter cloth positioned below the upper filter cloth. drop down. As described above, since the suspension can be filtered using both sides of one filter cloth and the solid content can be reliably received, it is advantageous in cost and it is easy to maintain the filtration performance.

  As an aspect of the present invention, the first filtration step may be performed a plurality of times of filtration.

  According to such a configuration, one surface of the upper filter cloth can be used for a plurality of times of filtration.

  As another aspect of the present invention, in the second filtration step, filtration may be performed a plurality of times.

  According to this configuration, the other surface of the upper filter cloth can be used for a plurality of times of filtration.

As another aspect of the present invention, the additional step is a step in which the filter cloth on the upper layer side of the new filter cloth moves to the upper layer one layer at a time when the new filter cloth is added,
The additional process may be performed a plurality of times, and each filter cloth may be moved from the lowermost layer to the uppermost layer with one surface thereof facing the upstream side.

  According to such a configuration, the filter cloth added to the lowermost layer of the laminate moves to the upper layer one layer at a time with one side facing up, and finally moves to the uppermost layer. Here, in filtration in such a laminate, the suspension is filtered in order from the filter cloth located on the upper layer side, so that the filter cloth located on the lower layer side has a filter cloth located on the upper layer side. A solid content smaller than the solid content deposited in (1) is deposited. Therefore, on one side of the filter cloth added to the lowermost layer, while moving to the upper layer one layer at a time, a solid layer is formed in which the lower layer side has a small solid content and a larger solid content has been deposited on the upper layer side. The Therefore, the filtration performance can be improved by the deposited layer as the filter cloth is on the upper layer side.

  The filter cloth according to the present invention is a filter cloth used in the above-described filtration method, and is attached to a sheet-like filtration unit that filters a suspension, and the filtration unit, and in a state in which the filtration unit is spread out, A fixing portion for fixing to a fixed object.

  According to such a configuration, the filter cloth can be installed on the fixed object simply by fixing the fixed part to the fixed object in a state where the filter part is expanded, and therefore the filter cloth can be easily installed.

  As described above, according to the present invention, it is possible to provide a filtration method that is advantageous in cost and that can maintain filtration performance, and a filter cloth used in the filtration method.

It is a front view of the filter cloth used for the filtration method concerning this embodiment. It is a rear view of the filter cloth used for the filtration method concerning the embodiment. It is a top view of the filter cloth used for the filtration method concerning the embodiment. It is a right view of the filter cloth used for the filtration method concerning the embodiment. In FIG. 5, (a) is an enlarged view of the front side of the corner, and (b) is an enlarged view of the back side of the corner. It is sectional drawing of the filter cloth which concerns on the same embodiment, Comprising: It is sectional drawing in the VI-VI line position in FIG.5 (b). In FIG. 7, (a) is an enlarged view of the front side of the straight portion, and (b) is an enlarged view of the back side of the straight portion. It is sectional drawing of the filter cloth which concerns on the same embodiment, Comprising: It is sectional drawing in the VIII-VIII line position in FIG.7 (b). It is a figure for demonstrating the use condition of the filtration method which concerns on the embodiment. It is a figure for demonstrating the inversion process of the filter cloth which concerns on the same embodiment. It is a figure for demonstrating the state before and behind reversing the upper filter cloth which concerns on the same embodiment, Comprising: (a) is a figure of the state in which solid content has accumulated on one surface of the upper filter cloth, (b) ) Is a diagram showing the state in which the upper filter cloth is inverted and the solid content falls from one surface. It is the photograph which expanded the surface state of the filter cloth of FIG. 11 100 times, (a) is the state of one side of the upper filter cloth before reversing, (b) is the solid which fell from the upper filter cloth The surface state of the second-layer filter cloth subjected to the minute, (c) is the state of one surface of the upper filter cloth after being inverted. It is a figure for demonstrating the addition process of the filter cloth which concerns on the same embodiment. It is the photograph and figure for demonstrating the deposition state of the solid content to each layer in a laminated body, Comprising: The left side is the photograph which expanded the surface state of the filter cloth 1000 times, and the right side is the part reflected in this photograph. It is a side sectional view showing a section typically. (A) is a filter cloth located in the first layer, (b) is a filter cloth located in the second layer, and (c) is a filter cloth located in the third layer. It is the photograph and figure for demonstrating the deposition state of the solid content to each layer in a laminated body, Comprising: The left side is the photograph which expanded the surface state of the filter cloth 1000 times, and the right side is the part reflected in this photograph. It is a side sectional view showing a section typically. (A) is a filter cloth located in the fourth layer, (b) is a filter cloth located in the fifth layer, and (c) is a filter cloth located in the sixth layer. It is a figure for demonstrating the deposition state of the solid content to the new filter cloth added to the lowest layer of a laminated body, Comprising: (a) is the state located in the lowest layer, (b) is the 5th layer. (C) is located in the fourth layer, (d) is located in the third layer, (e) is located in the second layer, and (f) is the most It is a figure of the state located in the upper layer. It is a graph of the result of having confirmed whether filtration performance improves by the number of sheets of a layered product, Comprising: It is a graph of the result of having filtered the suspension created by mixing mortar, a coloring agent, a water reducing agent, and water. It is a graph of the result of having confirmed whether filtration performance improves by the number of sheets of a layered product, and is a graph of the result of having filtered the suspension created by mixing mortar and water. It is explanatory drawing of the filter cloth which concerns on other embodiment of this invention, (a) is explanatory drawing of the filter cloth with which the fixing | fixed part was attached only to the corner | angular part, (b) is attached to only a linear part. It is explanatory drawing of the obtained filter cloth.

  Hereinafter, a filtration method according to an embodiment of the present invention will be described with reference to the drawings.

  For example, washed water obtained by washing the pump of a concrete pump truck and the inside of a pipe that has finished discharging concrete contains particulate matter such as concrete and is suspended. The filtration method according to the present embodiment is used to filter the suspension S as the washed water and separate it into a concrete component (solid content S1) and moisture S2 (see FIG. 9). The filtration method of this embodiment is implemented using the filter cloth 1 as shown in FIGS. 1-8, for example. Specifically, the filtration method of this embodiment includes a plurality of filter cloths 1 as shown in FIGS. 1 to 8, and uses a laminate 10 (see FIG. 10) in which the plurality of filter cloths 1 are overlapped. Implemented. Therefore, first, the configuration of the filter cloth 1 will be described.

  In addition, in this embodiment, although the top view (figure which looked at the filter cloth 1 of FIG. 1 from the upper side) of the filter cloth 1 is shown in FIG. 3, the bottom view of the filter cloth 1 (filter cloth of FIG. 1) 1 is a shape that is vertically symmetrical with the filter cloth 1 illustrated in FIG.

  Moreover, in this embodiment, although the right view (figure which looked at the filter cloth 1 of FIG. 1 from the right side) of the filter cloth 1 is shown in FIG. 4, the left side view of the filter cloth 1 (FIG. 1). (The figure which looked at the filter cloth 1 from the left side) has a symmetrical shape with the filter cloth 1 shown in FIG.

  As shown in FIG. 1, FIG. 2, and FIG. 9, the filter cloth 1 is attached to the sheet-like filtration unit 2 that filters the suspension S and the filtration unit 2, and the filtration unit 2 is expanded. The fixing part 3 for fixing to the predetermined fixed object T (refer FIG. 9) and the connection means 4 (refer FIG. 2) for connecting the fixing part 3 to the filtration part 2 are provided. The fixed object T will be described later.

  As shown in FIG. 2, the filtration unit 2 includes an annular edge 21 formed along the edge 20 that defines the outer peripheral shape of the filtration unit 2, and the edge in the surface direction of the filtration unit 2. 21 and a main body portion 22 located inward. The filtration part 2 of this embodiment is formed in the rectangular shape. Specifically, the filtration unit 2 is formed in a rectangular shape. Hereinafter, the direction in which the long side of the filtration unit 2 extends is defined as the horizontal direction, and the direction in which the short side extends is defined as the vertical direction. Moreover, let the direction where the filter cloth 1 is laminated | stacked be a lamination direction. In addition, the filtration part 2 should just be formed so that a long side may be 176 cm and a short side may be 130 cm, for example.

  The filtration part 2 is formed of a resin material. The filtration unit 2 is a woven fabric in which resin fibers are woven. The filtration unit 2 is a plain woven fabric. For this reason, as shown in FIG. 12C, the lateral fibers 25 extending in the lateral direction and the longitudinal fibers 24 extending in the longitudinal direction appear alternately on the surface of the filtration unit 2. As a material of the filtration part 2 of this embodiment, although resin materials, such as a polypropylene, polyethylene, polyester, nylon, can be employ | adopted, polyester or nylon is preferable from a viewpoint of filtration performance. Moreover, it is more preferable that the material of the filtration part 2 is polyester from the point of suppressing cost.

  As shown in FIG. 1, the end edge portion 21 includes a horizontal end edge portion 21a extending in the horizontal direction and a vertical end edge portion 21b extending in the vertical direction. The edge portion 21 of the present embodiment is formed by overlapping sheet members. That is, the end edge portion 21 has a multilayer structure. As shown in FIG. 8, the end edge portion 21 includes a first belt portion 211 that is continuous with the main body portion 22, a second belt portion 212 that is superimposed on the first belt portion 211, and the second belt portion 212. The third belt-like portion 213 is overlapped, and three sheet members are overlapped.

  The edge part 21 is formed by folding the edge 20 part of the filtration part 2 inward. In the present embodiment, the end edge portion 21 is formed by a plurality of ends 20 of the filtration portion 2 being folded back from one surface 11 to the other surface 12 of both surfaces. The edge part 21 of this embodiment is formed by the filtration part 2 being folded back in the same direction. Specifically, since the end edge 20 enters the center side of the turn-up by the filter part 2 being turned back in the same direction twice, the second belt-like part 212 and the third belt-like part in order from the edge 20 side of the filter part 2. A portion 213 and a first belt-like portion 211 are formed. In other words, the second band-shaped portion 212 is formed by folding the filtration portion 2 once, and the filtration portion 2 is further folded back so as to wind the second band-shaped portion 212 inward, so that it overlaps the second band-shaped portion 212. A third strip portion 213 and a first strip portion 211 are formed.

  The first belt-like portion 211, the second belt-like portion 212, and the third belt-like portion 213 are sewn by the sewing thread L and are restrained to each other. The 1st strip | belt-shaped part 211, the 2nd strip | belt-shaped part 212, and the 3rd strip | belt-shaped part 213 are sewn on the vicinity by the side of the main-body part 22 in the overlapping state.

  The main body 22 is a single sheet-like member. That is, the main body portion 22 has a single layer structure. Thus, the filtration part 2 has a multi-layer structure at the end edge part 21 and a single-layer structure at the main body part 22.

  As shown in FIG. 2, the fixing | fixed part 3 is formed in elongate. Moreover, the fixing | fixed part 3 is comprised by the flat string body being piled up. As shown in FIG.6 and FIG.8, the fixing | fixed part 3 of this embodiment has the folding | returning part 30 in the center part in a longitudinal direction, and has comprised the shape by which one string body was folded. A plurality of fixing parts 3 are attached to the filtering part 2. In the present embodiment, the fixing part 3 is attached to the corner part 200 and the straight part 201 of the filtration part 2. The fixed portion 3 attached to the straight portion 201 is attached to the central portion of the straight portion 201. Eight fixing portions 3 of the present embodiment are attached. FIG. 2 is a view of the filter cloth 1 as viewed from the other surface 12 side. The fixing part 3 is attached to the other surface 12 side in the filtering part 2.

  One end of the fixing portion 3 in the longitudinal direction is attached to the filtration portion 2 and the other end is free. The fixed part 3 is attached to the filtration part 2 with the folded part 30 as one end side, and a pair of folded string bodies can be separated from each other on the other end side. The pair of string bodies is tied to a predetermined portion of the fixed object T. In the present embodiment, the fixing part 3 is attached to the end edge part 21 of the filtration part 2.

  The connection unit 4 is a unit for connecting the fixing unit 3 to the filtration unit 2. As shown in FIGS. 5 to 8, the connecting means 4 of the present embodiment is a sewing thread and forms a seam portion 40. Specifically, the fixing portion 3 is sewn to the filtering portion 2 using a sewing thread.

  The seam portion 40 is formed so as to intersect the longitudinal direction of the fixed portion 3. The stitch portion 40 includes a pair of first stitch portions 41 that are separated in the longitudinal direction of the fixed portion 3 and a second stitch portion 42 that is formed so as to connect the pair of first stitch portions 41. . The pair of first stitch portions 41 extends in a direction substantially orthogonal to the longitudinal direction of the fixed portion 3. The second stitch portion 42 extends so as to connect one end of the first stitch portion 41 of the pair of first stitch portions 41 and the other end of the other first stitch portion 41. . That is, the seam portion 40 of the present embodiment is formed in a Z shape.

  Hereinafter, the attachment state of the filtration part 2 and the fixing | fixed part 3 is demonstrated.

  FIG. 5A is an enlarged view of the corner portion 200 of the filtration unit 2 as viewed from the one surface 11 side of the filtration unit 2, and FIG. 5B shows the corner portion 200 of the filtration unit 2 as the filtration unit 2. It is the enlarged view seen from the other surface 12 side. The fixed portion 3 is attached at a position where the horizontal end edge portion 21a and the vertical end edge portion 21b overlap each other. For example, as shown in FIG. 6, the end edge portion 21 of the filtration unit 2 is formed by folding back the end edge 20 portion extending in the vertical direction in a state where the end edge 20 portion extending in the horizontal direction is folded back. . That is, at the corner portion 200, the horizontal edge portion 21a is folded twice as a part of the vertical edge portion 21b. For this reason, the first belt-like portion 211, the second belt-like portion 212, and the third belt-like portion 213 of the vertical edge portion 21b overlap each other with a three-layer structure. The filtration part 2) has a multilayer structure in which nine layers are overlapped.

  The fixed portion 3 is connected to an overlapping portion 210 in which the horizontal edge portion 21a and the vertical edge portion 21b overlap. The fixing portion 3 is connected to the overlapping portion 210 with a sewing thread. By connecting the fixing part 3 to the overlapping part 210 having a multilayer structure, the strength of the connection part between the filtering part 2 and the fixing part 3 can be increased. Specifically, when the sewing thread passes through an 11-layer multi-layer body W composed of an overlapping portion 210 having a nine-layer structure and a pair of string bodies superimposed on the overlapping portion 210, the filtering portion 2 and the fixing portion 3 And are connected. Further, the pair of first stitch portions 41 of the stitch portions 40 extend in a direction substantially orthogonal to the longitudinal direction of the fixing portion 3, thereby increasing the strength in the longitudinal direction in which the fixing portion 3 is pulled, and the filtering portion. The connection strength between 2 and the fixed portion 3 is ensured.

  FIG. 7A is an enlarged view of the straight part 201 of the filtration unit 2 as viewed from the one surface 11 side of the filtration unit 2, and FIG. 7B shows the straight part 201 of the filtration unit 2 as the filtration unit 2. It is the enlarged view seen from the other surface 12 side. In the straight line portion 201, the fixed portion 3 is attached to the end edge portion 21. FIG. 7B shows a state in which the fixing portion 3 is attached to the horizontal end edge portion 21a, but the state in which the fixing portion 3 is attached to the vertical end edge portion 21b is the same as that in FIG. 7B. is there. As shown in FIG. 8, in the straight portion 201, the sewing thread passes through the five-layered multi-layer body W formed by a pair of string bodies superimposed on the lateral edge 21 a of the three-layer structure. And the fixed part 3 are connected.

  The description of the filter cloth 1 is as described above. Hereinafter, the usage method of the filtration method which concerns on this embodiment is demonstrated, referring drawings.

  As shown in FIG. 9, the filtration method of the present embodiment is a filtration method in which the suspension S is poured from the upper layer side in the laminating direction into the laminated body 10 in which a plurality of filter cloths 1 are superimposed, and the suspension S is filtered. It is. The filtration method includes a first filtration step of pouring and filtering the suspension S from one surface 11 facing the upstream side in the filtration direction of the upper filter cloth 1a located in the uppermost layer of the laminate 10 toward the lower layer, After the first filtration step, the inversion step of inverting the upper filter cloth 1a, and after the inversion step, the suspension S is poured from the other surface 12 of the upper filter cloth 1a toward the lower layer and filtered. 2 filtration step, after the second filtration step, a removal step of removing the upper filter cloth 1a from the laminate 10, and an additional step of adding a new filter cloth 1 to the lowermost layer of the laminate 10 after the removal step And comprising. In the present embodiment, in the first filtration step, filtration is performed a plurality of times. In the second filtration step, the filtration is performed a plurality of times. Hereinafter, each step will be specifically described.

  In this embodiment, the main body that uses (performs) the filtration method will be described as an operator. However, the main body that uses the filtration method may be a device such as a robot.

  An operator installs the laminated body 10 on the fixed object T in a state where the central portion of each filter cloth 1 is recessed in a concave shape. The predetermined fixed object T of the present embodiment is, for example, a cage member having an opening formed on the lower side so that moisture S2 filtered by the filter cloth 1 can pass through. The operator binds the fixing portion 3 attached to each filter cloth 1 of the laminated body 10 to the frame of the fixed object T and fixes the laminated body 10 to the fixed object T. On the lower side of the fixed object T, a water receiving part P for receiving moisture S2 obtained by filtration may be provided.

  In the first filtration step, the operator pours the suspension S from the upper side of the laminate 10 toward the lower layer from one surface 11 of the upper filter cloth 1a located at the uppermost layer of the laminate 10. The suspension S is washed water obtained by washing a concrete pump car, etc., and may be washed water in an unfiltered state, or washed water that has been subjected to primary filtration by another filtering means. The pouring means for pouring the suspension S into the laminated body 10 may be, for example, a transportation means installed on the upstream side of the laminated body 10 or the operator may pour the suspension S stored in a bucket or the like. Manual means can be used. The pouring means may be a means for dropping the suspension S leached from the other filtering means directly onto the laminate 10 from the filtering means, and the pouring means is not particularly limited. ^ Suspension S is separated into solid content S1 and moisture S2 in the first filtration step. The separated solid S1 is deposited on the filter cloth 1, and the water S2 that has permeated through the filter cloth 1 accumulates in the water receiving portion P.

  In the present embodiment, for example, a state where the entire amount of the suspension S that requires filtration is filtered at the filtration site is a state where the first filtration step is performed once. Or let the state which filtered the predetermined amount of suspension S defined based on conditions, such as a magnitude | size and performance of the filter cloth 1, be the state where the 1st filtration process was implemented once. In the first filtration step, the filtration is performed a plurality of times until the one surface 11 is substantially covered with the solid content S1. In the first filtration step, for example, the filtration is performed three times.

  As shown in FIG. 10, in the reversing step, the operator removes the upper filter cloth 1 a from the fixed object T and reverses the front and back. In FIG. 10, the laminated body 10 is expressed flat, but the upper filter cloth 1 a may be reversed with the laminated body 10 fixed to the fixed object T. The operator reverses the upper filter cloth 1a, and then binds and fixes the fixing portion 3 to the fixed object T.

  FIG.11 and FIG.12 has shown the state before and behind reversing the upper filter cloth 1a. As shown in the diagram of FIG. 11A and the photograph of FIG. 12A, solid content S1 is deposited with a predetermined thickness on one surface 11 of the upper filter cloth 1a before the reversing step. When the upper filter cloth 1a is reversed in the reversing step, as shown in the diagram of FIG. 11 (b) and the photograph of FIG. 12 (b), the block-shaped solid content S1 becomes a lump and forms the filter cloth 1 on the lower layer side. Fall. FIG.12 (b) is the surface of the filter cloth 1 located in the lower layer side of the upper filter cloth 1a after the inversion process. From FIG. 12B, it can be seen that the solid content S1 dropped from the upper filter cloth 1a becomes a block-like lump and is received by the filter cloth 1 located on the lower layer side. FIG. 12C is a photograph of one surface 11 of the upper filter cloth 1a immediately after reversal, and most of the solid content S1 deposited on the upper filter cloth 1a is reversed so that one surface 11 is reversed. It can be seen that it peels off and falls.

  In this way, the solid content S1 falling from the upper filter cloth 1a by the reversing step falls as a block-like lump, and thus the solid content S1 hardly enters the eyes of the filter cloth 1 located on the lower layer side, and continues. In the second filtration step, the clogging of the filter cloth 1 located on the lower layer side can be delayed, and the laminate 10 as a whole can be prolonged.

  In the second filtration step, the operator pours the suspension S from above the laminated body 10 toward the lower layer from the other surface 12 of the upper filter cloth 1a located in the uppermost layer of the laminated body 10. The state of the suspension S and the pouring means are the same as in the first filtration step. Moreover, a 2nd filtration process implements filtration several times until the other surface 12 is substantially covered with solid content S1. In the second filtration step, for example, the filtration is performed three times.

  In the second filtration step, the one surface 11 of the upper filter cloth 1a is backwashed by pouring the suspension S from the other surface 12 of the upper filter cloth 1a. Therefore, when the upper filter cloth 1a is reused after the upper filter cloth 1a is removed, it is possible to save the cleaning water related to the cleaning of the upper filter cloth 1a and reduce the work load related to the cleaning. be able to.

  In the removal step, the operator removes the upper filter cloth 1a from the fixed object T and removes the upper filter cloth 1a from the fixed object T. And an operator adds the new filter cloth 1 to the lowest layer of the laminated body 10 after this removal process. FIG. 13 is a view after the upper filter cloth 1a is removed, and shows a state in which a new filter cloth 1 is added to the laminate 10 in a state where five filter cloths 1 remain. The new filter cloth 1 is added to the lower layer side from the lower filter cloth 1b located in the lowest layer in the stacking direction. In FIG. 13, the laminated body 10 is expressed flat, but a new filter cloth 1 may be laid under the lower filter cloth 1b in a state where the laminated body 10 is fixed to the fixed object T.

  After the additional step, the first filtration step is performed in order, and when the additional step is finished again, the first filtration step is further performed. Thus, the filtration method of this embodiment can be continuously filtered while maintaining the filtration performance while partially replacing the laminate 10 by repeating the first filtration step to the additional step. .

  Here, FIGS. 14 (a) to 14 (c) and FIG. 15 show the accumulation state of the solid content S1 on each filter cloth 1 from the uppermost layer (first layer) to the lowermost layer (sixth layer) of the laminate 10. This will be described with reference to (a) to (c). In order to observe the accumulation state of the solid content S 1 on each filter cloth 1, water was added to the mixture of the mortar and the water reducing agent to prepare a suspension S, which was poured into the laminate 10. A water-reducing agent was mixed at 1% with respect to the mortar to prepare a mixture, and water was added thereto so that water / mixture = 49 by volume ratio to prepare a suspension S.

  Six filtration cloths 1 were overlapped, and filtration was performed by pouring the suspension S from one surface 11 of the upper filtration cloth 1a located in the uppermost layer toward the lower layer. After the solid content S1 deposited on each filter cloth 1 was dried, the accumulation state of each filter cloth 1 was observed. FIG. 14A shows the surface of the filter cloth 1 positioned in the uppermost layer (first layer), and FIG. 14B shows the surface of the filter cloth 1 in order from the second layer. FIG. 15C shows the surface of the lower filter cloth 1b located in the lowermost layer (sixth layer). 14 (a) to 14 (c) and FIGS. 15 (a) to 15 (c), the deposition amount of the solid content S1 decreases in order from the top layer, and the particle size of the solid content S1 becomes smaller. I understand that.

  In the filtration method of the present embodiment, the additional step is a step in which the filter cloth 1 on the upper layer side of the new filter cloth 1 moves to the upper layer one by one when the new filter cloth 1 is added. The process is performed a plurality of times, and each filter cloth 1 is moved from the lowermost layer to the uppermost layer with one surface 11 facing the upstream side. When the additional process is performed a plurality of times, for example, the surface state of one surface 11 of the lower filter cloth 1b when the lower filter cloth 1b located in the lowermost layer moves to the upper layer one by one will be described.

  The surface state of the lower filter cloth 1b in the state where the second filtration step is finished is shown in order in FIGS. 16 (a) to 16 (f) with reference to FIGS. 14 and 15. FIG. As shown in FIGS. 16 (f) and 16 (a), in the state where the second filtration step is completed, a small amount of solid content S 1 having a small particle size is deposited on the surface of the lower filter cloth 1 b. When a new filter cloth 1 is added to the lowermost layer of the laminated body 10, that is, the lower side of the lower filter cloth 1b, the lower filter cloth 1b is counted from the uppermost layer to the fifth layer. Will do. Although the lower filter cloth 1b is not located in the lowermost layer, for the sake of explanation, it will be referred to as the lower filter cloth 1b until it is located in the uppermost layer.

  In the state where the lower filter cloth 1b is located on the fifth layer, the first filtration step, the reversing step, and the second filtration step are performed again, so that the surface of the lower filter cloth 1b located on the fifth layer is As shown in FIG. 16 (b), in addition to the solid content S1 deposited when it was positioned at the lowermost layer, a solid content S1 having a particle size larger than the solid content S1 is deposited (the solid content in FIG. 15 (b)). Equivalent to minute S1). Therefore, a larger amount of solid content S1 is deposited on the lower filter cloth 1b moved to the fifth layer from the lowermost layer, and the particle size of the solid content S1 is lower than the lower layer. The particle diameter increases toward the upper side.

  If a removal process and an addition process are implemented, the lower filter cloth 1b will move to the 4th layer from the 5th layer. In the state where the lower filter cloth 1b is located on the fourth layer, the first filtration step, the inversion step, and the second filtration step are performed again, so that the surface of the lower filter cloth 1b located on the fourth layer is As shown in FIG. 16 (c), in addition to the solid content S1 deposited when it is located in the lowermost layer and the fifth layer, a solid content S1 having a particle size larger than the solid content S1 is deposited (FIG. 15 ( a) corresponding to the solid content S1). As described above, as the lower filter cloth 1b moves to the upper layer one layer at a time, the fact that the solid content S1 having a large particle diameter is sequentially deposited on the solid content S1 having a small particle diameter is repeated. In this state, the solid content S1 is laminated as shown in FIG.

  When the first filtration step is performed in a state where the lower filter cloth 1b moves to the uppermost layer and becomes the upper filter cloth 1a, the laminate 10 causes the filter cloth 1 in the state of (f) of FIG. As the upper filter cloth 1a, the filter cloth 1 in the state of FIG. 16 (e) in the second layer, the filter cloth 1 in the state of FIG. 16 (d) in the third layer, and the state of FIG. 16 (c) in the fourth layer. The filter cloth 1 in the state of FIG. 16B is laminated on the fifth filter cloth 1, and the filter cloth 1 in the state of FIG. 16A is laminated on the lowermost layer (sixth layer). .

  In such a laminated body 10, when the lower filter cloth 1b moves to the uppermost layer and becomes the upper filter cloth 1a, the deposited layer of the solid content S1 on the upper filter cloth 1a has a larger particle diameter from the bottom to the top. When the first filtration step is started, the large solid content S1 is captured on the upper side of the deposited layer and the small solid content S1 is captured on the lower side of the deposited layer. Therefore, each filter cloth 1 improves the ability to capture solid content S1 as it moves to the upper layer side.

  As mentioned above, the filtration method of the said embodiment is equipped with the 1st filtration process, the removal process, and the additional process. The upper filter cloth 1a used for the filtration is removed, and a new filter cloth 1 is added to the lowermost layer of the laminate 10 from which the upper filter cloth 1a has been removed. Thus, in the excessive method, since some of the filter cloths constituting the laminate are replaced with new filter cloths, the filtration performance can be maintained.

  Furthermore, in the filtration method which concerns on this embodiment, in order to perform an inversion process and a 2nd filtration process after a 1st filtration process, the upper filtration cloth located in the uppermost layer of the laminated | stacked several filtration cloth 1 After pouring and filtering the suspension S from one side 11 of the la toward the lower layer, the upper filter cloth 1a is inverted, and the suspension S is poured from the other side 12 toward the lower layer and filtered. Therefore, the suspension S can be filtered using both surfaces of the upper filter cloth 1a. Here, when the upper filter cloth 1a is inverted, even if the solid content S1 deposited on one surface 11 of the upper filter cloth 1a is peeled off and dropped, the solid content S1 is placed below the upper filter cloth 1a. It falls on the filter cloth 1 located. In this way, since the suspension S can be filtered using both sides of one filter cloth 1 and the solid content S1 can be received reliably, it is advantageous in terms of cost and maintains the filtration performance. It becomes easy.

  Moreover, according to the said embodiment, a said 1st filtration process implements filtration in multiple times. Therefore, one surface 11 of the upper filter cloth 1a can be used for multiple times of filtration.

  Moreover, according to the said embodiment, a said 2nd filtration process implements filtration in multiple times. Therefore, the other surface 12 of the upper filter cloth 1a can be used for multiple times of filtration.

  Moreover, according to the said embodiment, the said additional process is a process in which the filter cloth 1 of the upper layer side from the said new filter cloth 1 moves to an upper layer one layer at the time of the addition of this new filter cloth 1, The additional process is performed a plurality of times, and each filter cloth 1 is moved from the lowermost layer to the uppermost layer with one surface 11 facing the upstream side.

  According to such a configuration, the filter cloth 1 added to the lowermost layer of the laminate 10 moves to the upper layer one layer 11 at the top, and finally moves to the uppermost layer. Here, in filtration with such a laminated body 10, the suspension cloth S is sequentially filtered from the filter cloth 1 located on the upper layer side, so that the filter cloth 1 located on the lower layer side has the upper layer side. A solid content S1 smaller than the solid content S1 deposited on the filter cloth 1 is deposited. Therefore, on one surface 11 of the filter cloth 1 added to the lowermost layer, while moving to the upper layer one by one, the lower layer side has a small solid content S1 and a larger solid content S1 is deposited on the upper layer side. A deposited layer is formed. Therefore, the filtration performance can be improved by the deposited layer as the filter cloth 1 on the upper layer side.

  Moreover, the removal process of the said embodiment is a process of removing only the upper filter cloth 1a of the uppermost layer. That is, in the above embodiment, the filter cloth 1 is used a plurality of times while moving from the state positioned at the lowermost layer to the upper layer, and only the oldest upper filter cloth 1a is removed. Therefore, for example, as shown in Table 1, the variation in the filtration performance before and after the removal of the upper filter cloth 1a can be suppressed, and a constant filtration performance can be maintained.

  For example, as shown in Table 1, after adding a new filter cloth 1, the degree of contamination of each filter cloth 1 in the laminate 10 before the first filtration process is performed (“a. First filtration process in Table 1”). “Before implementation”) is set to 75, 60, 45, 30, 15, 0 in order from the top layer side. After the 2nd filtration process is implemented through the 1st filtration process, each filter cloth 1 is in the state where it was dirty from before the 1st filtration process was implemented. The degree of contamination of each filter cloth 1 in the laminated body 10 in this state (“b. After the second filtration step” in Table 1) is set to 90, 75, 60, 45, 30, 15 in order from the uppermost layer side. Subsequently, the degree of soiling of each filter cloth 1 in the laminate 10 in which the upper filter cloth 1a is removed and the new filter cloth 1 is added ("C. Replacement of the upper filter cloth 1a after performing the second filtration step" in Table 1). ), As a result of each filter cloth 1 moving to the upper layer one layer at a time, the degree of contamination becomes 75, 60, 45, 30, 15, 0 in order from the uppermost layer side, and the contamination is improved. And the state of the laminated body 10 after the removal of the upper filter cloth 1a and the addition of a new filter cloth 1 (the state of “c. Replacement of the upper filter cloth 1a after performing the second filtration step” in Table 1) is the first filtration. It is close to the state of the laminate 10 before the step is carried out (the state of “a. Before the first filtration step” in Table 1), and the filtration performance before and after the removal of the upper filter cloth 1a does not vary greatly. However, when all the filter cloths 1 are replaced after the second filtration step ("b. After the first filtration step" in Table 1), the degree of contamination of all the filter cloths 1 ("d. The replacement of all the filter cloths 1) after the filtration step is performed becomes 0, and the fluctuation in the filtration performance before and after the removal of the upper filter cloth 1a becomes large. As described above, the filtration method according to the present embodiment also has an effect of facilitating the management of the filtration performance of the laminate 10 and the management of the dirt state of each filter cloth 1 by maintaining the filtration performance constant. obtain.

  Moreover, according to the filter cloth 1 which concerns on this embodiment, with respect to the sheet-like filtration part 2 which filters suspension, it is for fixing to the predetermined fixed object T in the state which this filtration part 2 was extended. Since the fixed part 3 is attached, the filter cloth 1 can be installed on the fixed object T simply by fixing the fixed part 3 to the fixed object T in the state in which the filter part 2 is expanded. can do.

  Furthermore, in the filter cloth 1 which concerns on this embodiment, since the fixing | fixed part 3 is attached also to the linear part 201 in addition to the corner | angular part 200 of the filtration part 2, it is fixed to the fixed object T in the state which expanded the filtration part 2. It becomes easy to fix.

  Furthermore, in the filter cloth 1 which concerns on this embodiment, since the stitch part 40 which has connected the fixing | fixed part 3 to the filtration part 2 is formed in Z shape, the connection intensity | strength of the fixing | fixed part 3 and the filtration part 2 is high. Rise.

  In addition, the filtration method of this invention is not limited to the said embodiment, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

  In the said embodiment, although demonstrated as invention of the filtration method, it can also be grasped as invention of the filter cloth 1 used for this filtration method. Moreover, it can also be grasped as invention of the laminated body 10 provided with the some filter cloth 1 and this filter cloth 1 having been piled up. About the structure of the filter cloth 1 and the laminated body 10, since it is common with the structure of the filter cloth 1 and the laminated body 10 in the said embodiment, description is not repeated.

  In the said embodiment, although the laminated body 10 demonstrated the case where it comprised with the 6 sheets of filter cloth 1, it is not limited to this. The number of filter cloths 1 constituting the laminate 10 is not limited. The laminated body 10 should just be comprised by the 2 or more filter cloth 1, and the filter cloth 1 may be 6 sheets or more, or 6 sheets or less.

  Here, the confirmation test of the filtration performance was performed about whether the filtration performance changed by changing the number of the filter cloths 1 which comprise the laminated body 10. FIG. The test results are shown in FIGS. In the confirmation test, two types of suspensions S were prepared: a first suspension S in which mortar, a colorant, a water reducing agent and water were mixed, and a second suspension S in which mortar and water were mixed. Also, in the confirmation test, five types of laminates 10 composed of one filter cloth 1 and 2 to 6 filter cloths 1 are prepared, and a total of 6 types are used as filters to each filter. The suspension S and the second suspension S were poured and filtered. The absorbance of moisture S2 obtained by filtering the filter was measured with an absorptiometer (UVmini-1240, manufactured by Shimadzu Corporation), and the relationship between the number of filters and the absorbance was graphed. The lower the absorbance, the clearer the moisture S2, which means better filtration performance. FIG. 17 is a graph showing the result of pouring the first suspension S, and FIG. 18 is a graph showing the result of pouring the second suspension S.

  From FIG. 17, when the first suspension S is filtered, the absorbance rapidly increases between the laminate 10 composed of three filter cloths 1 and the laminate 10 composed of four filter cloths 1. Decreased. That is, when the first suspension S is filtered, the laminate 10 is preferably composed of four or more filter cloths 1. Further, from FIG. 18, when the second suspension S is filtered, the absorbance between the laminate 10 composed of two filter cloths 1 and the laminate 10 composed of three filter cloths 1 is absorbed. Decreased rapidly. That is, when the second suspension S is filtered, the laminate 10 is preferably constituted by three or more filter cloths 1. From the above, it can be seen that the laminate 10 is preferably composed of at least three filter cloths 1 and more preferably composed of four or more filter cloths 1.

  In the said embodiment, although the filtration part 2 turned back and demonstrated the case where the edge part 21 comprised the multilayered structure, the filtration part 2 does not need to be turned back. For example, the filtration unit 2 may have a multi-layered structure with the edge portion 21 by overlapping a plurality of independent band-shaped members. Further, the end edge portion 21 may have a single layer structure. In this case, the edge of the filtration part 2 may be processed so that fibers are not frayed by fusing.

  In the said embodiment, although the filtration part 2 demonstrated the case where it was formed in the rectangular shape, it is not limited to this. The filtration part 2 may be formed in square shape. Moreover, the filtration part 2 may be formed in polygonal shapes, such as circular shape, elliptical shape, and triangular shape.

  In the said embodiment, although the fixing | fixed part 3 demonstrated the case where it was comprised by the elongate and flat string body, it is not limited to this. The shape of the string body is not limited, and the string body may have a circular outer peripheral shape like a rope. Moreover, the fixing | fixed part 3 should just have a structure which can fix the filter cloth 1 to the fixing target T, for example, may be a clip.

  Although the said embodiment demonstrated the case where the filtration part 2 and the fixing | fixed part 3 were sewn using a sewing thread, it is not limited to this. For example, the fixing part 3 may be fixed to the filtration part 2 using an adhesive such as a hot melt resin adhesive.

  Moreover, the through-hole which penetrates in the thickness direction is formed in the filtration part 2, a string body is attached to the fixed part 3, and the fixed part 3 is filtered by attaching the string body to the filter part 2 through the through-hole. You may make it attach to the part 2. FIG. In this case, a ring-shaped member may be attached to the inner peripheral edge of the through hole of the filtration unit 2.

  In the said embodiment, although the fixing | fixed part 3 was attached to the corner | angular part 200 and the linear part 201 of the filtration part 2, and demonstrated the case where eight pieces were attached in total, it is not limited to this. The mounting position and the number of the fixing portions 3 can be freely set. For example, the fixing part 3 may be attached only to the corner part 200 or may be attached only to the straight part 201, and a total of six fixing parts 3 are attached to each corner part 200 and each long side of the straight part 201. May be.

  In addition, the filter cloth 1 (refer FIG. 19A) in which the fixing | fixed part 3 is connected only to the corner | angular part 200, and the filter cloth 1 (FIG. 19B) in which the fixing | fixed part 3 is connected only to the linear part 201. If the laminated body 10 is configured by stacking alternately with each other, the fixing positions of the fixing portions 3 of the filter cloths 1 with respect to the fixing object T can be dispersed. It can be easily attached to T.

  In the said embodiment, although the inversion process and the 2nd filtration process were performed after the 1st filtration process, it is not limited to this structure. For example, after the first filtration step, the removal step may be performed without performing the inversion step and the second filtration step.

DESCRIPTION OF SYMBOLS 1 ... Filter cloth, 1a ... Upper filter cloth, 1b Lower filter cloth, 11 ... One side, 12 ... The other side, 2 ... Filtration part, 21 ... End edge part, 21a ... Lateral edge part, 21b ... Vertical end Edge part 22 ... Body part 24 ... Longitudinal fiber 25 ... Horizontal fiber 200 ... Corner part 201 ... Straight line part 211 ... First belt part 212 ... Second belt part 213 ... Third belt part 3 DESCRIPTION OF SYMBOLS Fixed part, 4 ... Connection means, 40 ... Seam part, 41 ... 1st seam part, 42 ... 2nd seam part, 10 ... Laminated body, P ... Water receiving part, S ... Suspension, S1 ... Solid content, S2 ... moisture, T ... fixed object, W ... multilayer body

Claims (6)

A filtration method comprising a plurality of filter cloths, and filtering the suspension by pouring the suspension from the upper layer side in the laminating direction into a laminate in which the plurality of filter cloths are superimposed,
A first filtration step of pouring and filtering the suspension from one surface facing the upstream side in the filtration direction of the upper filter cloth located in the uppermost layer of the laminate to the lower layer;
After the first filtration step, a removal step of removing the upper filter cloth from the laminate,
And an additional step of adding a new filter cloth to the lowermost layer of the laminate after the removing step. An inversion step of inverting the upper filter cloth after performing the first filtration step;
After the inversion step, a second filtration step of pouring and filtering the suspension from the other surface of the upper filter cloth toward the lower layer, and
The filtration method of Claim 1 which performs the said removal process and the said additional process after a said 2nd filtration process.   The said 1st filtration process is a filtration method of Claim 1 or Claim 2 which implements filtration in multiple times.   The said 2nd filtration process is a filtration method of Claim 3 subordinate to Claim 2 or Claim 2 which implements filtration in multiple times.   The additional step is a step in which a filter cloth on the upper layer side of the new filter cloth moves to the upper layer one layer at a time when the new filter cloth is added. The filtration method according to any one of claims 1 to 4, wherein the first surface is moved from the lowermost layer to the uppermost layer with one surface thereof facing the upstream side.   It is the filter cloth used for the filtration method of any one of Claims 1-5, Comprising: The sheet-like filtration part which filters suspension, The state attached to the filtration part, and the said filtration part was expanded And a fixing part for fixing to a predetermined fixing object.