JP2014018780A - Filtration tank made of concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filtration tank made of concrete capable of easily attaching a screen to a desired position.SOLUTION: There is provided a filtration tank made of concrete which comprises: a floating filter medium layer consisting of a floating filter medium; a screen which is disposed on an upper side of the floating filter medium layer and prevents outflow of the floating filter medium; a raw water inflow port and a backwash effluent discharge port which are disposed on a lower side from the floating filter medium layer; and a filtrate water storage part provided on an upper side of the screen. Raw water is filtered by passing raw water flowed from the raw water inflow port in an upward flow through the floating filter medium layer and the resulting filtrate water is stored in the filtrate water storage part. The filtration tank made of concrete comprises: a reception part which is embedded on an inner peripheral surface of a lateral wall of the filtration tank made of concrete and forms an opening port extending substantially in the horizontal direction in at least a part of the inner periphery of the filtration tank made of concrete; and a plate-like screen fixing member having an insertion fitting part inserted into the opening port and a mounting part on which the screen is mounted. The screen is fixed to the mounting part of the screen fixing member insertion-fitted to the opening port.

Description

  The present invention relates to a concrete filter tank, and more particularly to a concrete filter tank in which a floating filter layer made of a floating filter medium and a screen for preventing the floating filter medium from flowing out are disposed in a concrete water tank.

  Conventionally, as a filtration system that filters raw water such as sewage to obtain filtered water, it is placed above the floating filter media layer made of a large number of foamed filter media made of foamed polymer, and prevents the floating filter media from flowing out. There is known a filtration system including a screen, a raw water inlet and a backwash drainage outlet disposed below the floating filter material layer, and a filtration tank having a filtrate storage part located above the screen (for example, , See Patent Document 1).

  In the conventional filtration system using the floating filter medium, the raw water flowing in from the raw water inlet is passed upward through the floating filter medium layer, so that impurities (for example, garbage, foreign matters, etc.) and floating suspensions are suspended. Filtered water from which turbid substances have been removed is obtained. In addition, in the conventional filtration system described above, when the floating filter layer is supplemented with contaminants and suspended suspended solids and filtration resistance increases as filtration continues, filtered water stored in the filtrate storage section is allowed to flow down naturally. Thus, the floating filter medium layer is backwashed (hereinafter sometimes referred to as “backwashing”) in a downward flow.

  Here, the filtration tank of such a filtration system is conventionally constructed by putting floating filter material into a concrete water tank and then fixing a screen on the side wall surface of the water tank above the input floating filter medium. It was. As shown in FIG. 3, the screen is fixed in advance by embedding a plurality of anchor bolts 3 (hereinafter sometimes simply referred to as “anchors”) in the side wall 2 of the concrete water tank 1. The receiving frame 4 for supporting the screen is attached to the plurality of anchors 3, and the screen is fixed to the receiving frame 4 with bolts or the like.

Japanese Patent No. 3853738

Anchors installed in advance during the production of concrete water tanks were constructed by methods such as fixing to the formwork before placing the concrete or after mounting on the hole after the concrete has hardened. With the method of fixing to the mold before, it was difficult to fit within the range of dimensional errors allowed by the fittings and machine parts to be attached. In addition, in the method of post-attaching on the hole after the concrete is hardened, the construction is difficult and requires skill.
It is also possible to form a filter tank using precast concrete, and to install the anchor at a desired position by drilling a hole in the inner surface of the filter tank with a drill and attaching the anchor later. Opening the anchor and attaching the anchor is cumbersome and time consuming. Moreover, depending on the arrangement of the reinforcing bars inside the concrete, it may be difficult to make a hole at a desired position.

  Then, this invention provides the concrete-made filtration tank which can attach a screen to a desired position easily.

  An object of the present invention is to advantageously solve the above-described problems, and the concrete filtration tank of the present invention is arranged on the floating filter medium layer made of a floating filter medium, and on the floating filter medium layer, the floating filter medium layer. A screen for preventing the filter medium from flowing out, a raw water inlet and a backwash drain outlet disposed below the floating filter medium layer, and a filtrate storage section provided on the upper side of the screen, the raw water flow A concrete filtration tank for filtering raw water by passing the raw water flowing in from an inlet through the floating filter material layer in an upward flow, and storing the obtained filtrate in the filtrate storage unit, A receiving member that is embedded in the inner peripheral surface side of the side wall of the filtration tank and that forms an opening extending in a substantially horizontal direction in at least a part of the inner periphery of the concrete filtration tank, and an insertion that is inserted into the opening. And the screen A plate-shaped screen fixing member having a mounting portion on which the screen is mounted, and the screen is fixed to the mounting portion of the screen fixing member inserted into the opening. It is characterized by. The receiving member is embedded in the side wall, an opening having a predetermined length extending in a substantially horizontal direction is formed in at least a part of the inner periphery of the filtration tank, and a plate-like screen fixing member is inserted into the opening. Then, unlike the case where a plurality of anchors are used, it is not difficult to attach the screen fixing member due to the positional deviation between the adjacent members. Therefore, the screen fixing member can be easily attached to a desired position.

  Here, the concrete filtration tank of the present invention has a plurality of receiving members spaced apart from each other in the same horizontal plane, and the screen fixing members are respectively inserted into openings formed by the receiving members, It is preferable to provide a coupling portion that couples the screen fixing members. If a plurality of receiving members arranged on the same horizontal plane are used, and a screen fixing member is inserted into each opening formed by each receiving member and joined by a connecting portion, the screen is fixed over a wide range. This is because the working member can be easily attached.

  Moreover, it is preferable that the concrete filtration tank of this invention has a rubber member between the said receiving member and the fitting insertion part of the said screen fixing member. By having the rubber member between the receiving member and the insertion portion of the screen fixing member, the screen fixing member can be stably attached to the receiving member, and the receiving member and the screen fixing when using the filtration tank. This is because water can be prevented from entering between the members.

  Furthermore, in the concrete filtration tank of the present invention, it is preferable that the receiving member has a rubber layer that covers the opening side surface. This is because the screen fixing member can be stably attached to the receiving member, and water can be prevented from entering between the receiving member and the screen fixing member when the filtration tank is used.

  In the concrete filtration tank of the present invention, it is preferable that the screen fixing member has a rubber layer that covers the fitting insertion portion. This is because the screen fixing member can be stably attached to the receiving member, and water can be prevented from entering between the receiving member and the screen fixing member when the filtration tank is used.

  ADVANTAGE OF THE INVENTION According to this invention, the concrete filtration tank which attached the screen to the desired position easily can be provided.

It is explanatory drawing which shows an example of the installation position of a filtration system. It is explanatory drawing explaining schematic structure of the filtration system provided with the typical concrete filter tank according to this invention. (A) is a top view of the conventional concrete filtration tank, (b) is sectional drawing along the III-III line of the conventional concrete filtration tank shown to Fig.3 (a). (A) is a plan view of a typical concrete filtration tank according to the present invention, (b) is an end view along line IV-IV of the concrete filter tank shown in FIG. 4 (a), (C) is a figure which expands and shows the opening part vicinity of the end elevation shown in FIG.4 (b). It is a figure which shows the member for screen fixing roughly. It is a figure which expands and shows the opening part vicinity of the end surface of the concrete filter tank which concerns on the modification of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, what attached | subjected the same code | symbol in each figure shall show the same component.

  Here, the filtration system including the filtration tank according to the present invention is not particularly limited and can be used for sewage treatment and the like. Specifically, the filtration system including the filtration tank according to the present invention, as shown in FIG. 1 as an example of the installation position of the filtration system 100, in the combined sewer that flows rainwater and sewage through the same pipeline, It is placed near the combined sewage pipe 111 and used when the overflow (nQ excess) that exceeds the planned interception amount nQ and cannot be treated at the sewage treatment plant is treated on-site. Can do. The “planned interception amount nQ” is the planned interception amount of the interception pipe designed according to the treatment capacity of the sewage treatment plant, where “n” is a numerical value that varies depending on the city. Further, “Q” is the maximum amount of sewage during fine weather hours.

  In the combined sewer system to which the filtration system 100 shown in FIG. 1 is applied, when the amount of rainwater and sewage flowing into the combined sewer pipe 111 exceeds the planned interception amount, the overflow water (raw water) is combined with the sewer pipe. It flows into the filtration system 100 beyond the overflow part (not shown) provided in 111, and is processed. Here, the overflow section is desirably provided on the downstream side of the existing rainwater spout 112. However, if it is difficult to install the rainwater spout 112 on the downstream side, the rainwater spout 112 may be provided on the upstream side of the rainwater spout 112. Then, the overflow water (filtered water) that has been filtered by the filtration system 100 and improved in water quality is discharged into the river 114 and the like.

  Here, as shown in FIG. 2, the filtration system 100 according to an example of the present invention includes a filtration tank 10 having a floating filter material layer 12, a raw water pump 21, a raw water supply path 41, and a water collection pipe 61. Yes. The filtration tank 10 and the raw water pump 21 are disposed in the ground or on the ground, and raw water is supplied to the filtration tank 10 from a raw water tank (not shown) disposed in the ground or on the ground. The raw water supply path 41 is provided with a raw water supply valve 42.

  The filtration tank 10 functions as a filtration tank that filters raw water to obtain filtered water. Here, the filtration tank 10 is made of concrete. As shown in FIG. 2, the filtration tank 10 includes a screen 11, a floating filter medium layer 12 composed of a plurality of floating filter media supported by the screen 11, and a lower side of the floating filter medium layer 12 in a concrete water tank. The raw water inlet 13 installed at the bottom, the plurality of backwash drainage outlets 14 installed below the floating filter material layer 12, the filtrate storage part 15 provided on the upper side of the screen 11, and the upper side of the screen 11 And the filtered water outlet 16 provided in the above.

  Here, the floating filter medium is a filter medium having a specific gravity smaller than that of the raw water (that is, floating in the raw water). In the filtration system 100, a known floating filter medium such as a particulate floating filter medium made of a foamed polymer described in Patent Document 1 and Japanese Patent Application Laid-Open No. 2010-221197 can be used as the floating filter medium.

The floating filter material layer 12 is placed in the filtration tank 10 by placing a number of floating filter media in the filtration tank 10 filled with water up to a predetermined height, and then installing a screen 11 on the upper side of the input floating filter medium. Can be provided.
As the screen 11, a screen that can prevent the floating filter material from flowing out, for example, a punching metal or the like can be used. The screen fixing structure for installing the screen 11 in the filtration tank 10 will be described in detail below.

  Here, in this filtration system 100, the inlet of the raw water pump 21 is connected to a raw water tank (not shown) into which overflow water as raw water flows. The discharge port of the raw water pump 21 is connected to the raw water supply path 41, and the raw water supply path 41 connects the discharge port of the raw water pump 21 and the raw water inlet 13 of the filtration tank 10. As the raw water pump 21, a known pump can be appropriately selected and used.

  Further, in the filtration system 100, a plurality of (six in FIG. 2) backwash drainage outlets 14 located at the lower part of the filtration tank 10 are connected to a water collection pipe 61 that discharges the backwash drainage from the filter tank 10. The water collection pipe 61 extends to a backwash drain (not shown) disposed underground or on the ground. That is, the water collection pipe 61 connects the backwash drainage outlet 14 and the backwash drainage tank. The water collection pipe 61 has a water collection pipe valve 62.

Therefore, in this filtration system 100, the raw water pump 21 is operated with the raw water supply valve 42 opened and the water collection piping valve 62 closed, so that the raw water is transferred from the raw water tank (not shown) to the lower part of the filtration tank 10. And the raw water is passed through the floating filter layer 12 in an upward flow to obtain filtered water. Then, after the filtrate water obtained flows through the filtrate water storage unit 15 in an upward flow, it is discharged to a river or the like via the filtrate water outlet 16.
Further, in the filtration system 100, or when the filtration resistance increases to a predetermined value or more, the raw water supply valve 42 is closed, the raw water pump 21 is stopped, the water collection piping valve 62 is opened, and the floating filter material layer 12 is opened. Backwash. Specifically, the water in the filtration tank 10 is drained to the backwash drainage tank (not shown) through the water collecting pipe 61 using the head difference, and the filtered water stored in the filtrate storage section 15 is stored. Is passed through the floating filter layer 12 in a downward flow, and a number of floating filter media constituting the floating filter layer 12 are developed downward. Then, the impurities and floating suspended substances captured in the floating filter medium layer 12 are discharged from the floating filter medium layer 12, and the floating filter medium layer 12 is back-washed.

  Here, the screen fixing structure for installing the screen 11 in the filtration tank 10 will be described in detail below.

  As shown in the plan view of the concrete filter tank 10 in FIG. 4A, the filter tank 10 has a rectangular shape in plan view, and has a hollow rectangular parallelepiped shape with one end opened. That is, the filtration tank 10 is defined by four side walls and a bottom surface.

Here, as shown in FIG. 4 (b), an end surface along the line IV-IV in FIG. 4 (a), a receiving member 17 is embedded on the inner peripheral surface side of the side wall of the filtration tank. An opening 17 ′ is formed on the inner peripheral surface by the receiving member 17. A plate-like screen fixing member 18 is fitted into the opening 17 ′.
In the filtration tank 10, the screen 11 is fixed to the screen fixing member 18 with a bolt or the like. In FIG. 4, illustration of a screen, a floating filter material layer, and the like is omitted for easy understanding of the structure.

The receiving member 17 is formed of a long member having a concave portion extending in the longitudinal direction, and the concave portion forms an opening 17 ′ when the receiving member 17 is embedded in the side wall of the filtration tank. Specifically, as shown in FIG. 4C by enlarging the main part of the end face shown in FIG. 4B, the receiving member 17 has a substantially cross-sectional shape orthogonal to the longitudinal direction (extending direction). It is U-shaped. And the length of the receiving member 17 is shorter than one side of the side wall of a filtration tank.
The receiving member 17 can be formed, for example, by bending a metal plate. Further, as the receiving member 17, ready-made grooved steel can be used.

  And the receiving member 17 is embed | buried under each inner peripheral surface side of the four side walls of the concrete filtration tank 10, and forms four opening part 17 'extended in a substantially horizontal direction in the inner periphery of the filtration tank 10. To do. That is, the four receiving members 17 are embedded in the inner peripheral surface side of the concrete filtration tank 10 so as to extend in the substantially horizontal direction, and are substantially horizontal in the inner periphery of the filtration tank 10. Four openings 17 'extending in the direction are formed. The shape of the receiving member is not particularly limited as long as the opening 17 ′ extending in the substantially horizontal direction can be formed on the inner periphery of the filtration tank 10.

  Here, the substantially horizontal direction means not only a strictly horizontal direction but also a direction including a direction slightly deviated from the horizontal direction due to a deviation inevitably caused when the receiving member is buried. Specifically, the substantially horizontal direction includes, for example, a direction parallel to a line segment that forms an angle of 10 ° or less with respect to a horizontal plane orthogonal to the vertical direction. That is, the opening extending in the substantially horizontal direction includes an opening extending at an angle of 10 ° at the maximum with respect to the horizontal direction. Note that the extending direction of the opening is a direction in which the center line of the width in the height direction of the opening on the side wall surface side of the opening extends. Therefore, if the width center line in the height direction of the opening on the side wall surface side extends in the substantially horizontal direction, the opening portion on the outer side of the filtration tank with respect to the opening on the side wall surface side is inclined with respect to the horizontal plane. May be present.

  In addition, in order to install a screen horizontally, as shown in FIG.4 (b), the some receiving member 17 is provided in the substantially same height position of the filtration tank 10 over the internal peripheral surface of the filtration tank 10. As shown in FIG. ing. Therefore, the plurality of openings 17 ′ formed on the inner periphery of the side wall 10 of the filtration tank by the receiving member 17 are spaced apart at substantially the same height (that is, in the same horizontal plane) of the filtration tank over the inner peripheral surface. Is formed. Here, “the opening is formed in the same horizontal plane” means that the plate-like screen fixing member 18 can be fitted into the opening and the screen can be attached. “Formed inside” includes a case where the heights of the receiving members 17 are slightly different in the vertical direction within a range in which the screen can be attached.

  Incidentally, the receiving member 17 can be embedded in the inner peripheral surface side of the side wall of the filtration tank 10 by attaching the receiving member 17 to a desired position of the mold before drying the concrete. For example, the receiving member 17 is fixed to the mold frame at a plurality of positions in the longitudinal direction, and the ready-mixed concrete is poured into the mold frame in which the receiving member 17 is installed, cured, and dried. Can be buried.

  One screen fixing member 18 is inserted into each of the openings 17 ′ formed on the inner peripheral surface of the side wall of the filtration tank 10.

  The screen fixing member 18 is, for example, a plate-shaped steel material or a resin material. The screen fixing member 18 includes a fitting insertion portion 18 a that is fitted into an opening 17 ′ formed by the receiving member 17, and a placement portion 18 b on which the screen 11 is placed. The placement portion 18b of the screen fixing member 18 is configured to protrude in the horizontal direction from the side wall surface opening of the opening 17 ′ when the insertion portion 18a is inserted into the opening 17 ′. . That is, even when the opening is formed to be inclined with respect to the horizontal plane in the depth direction, the placement portion 18b on which the screen 11 is placed is horizontal.

  Specifically, as shown in FIGS. 4A and 5, the fitting portion 18a of the screen fixing member 18 has a shape corresponding to the opening 17 ′, and the length in the longitudinal direction is open. The length is equal to the length in the extending direction of the portion 17 ′, and the width is equal to the depth of the opening 17 ′ (the dimension in the direction from the inside of the filtration tank to the outside of the filtration tank). Further, the placement portion 18b of the screen fixing member 18 has a length in the longitudinal direction longer than that of the fitting insertion portion 18a, and is substantially equal to the length of one side of the inner surface of the side wall of the filtration tank 10 having a square shape in plan view. The width is an arbitrary width that can stably support the screen.

  The screen fixing member 18 described above can be attached to the opening portion 17 ′ by inserting the insertion portion 18 a into the opening portion 17 ′ formed by the receiving member 17. Then, when the insertion portion 18a of the screen fixing member 18 is inserted into the opening 17 ′ of the filtration tank, the screen fixing member 18 horizontally places the placement portion 18b in the filtration tank 10 as shown in FIG. It is fixed in the filtration tank 10 in an exposed state. Note that a rubber member 19 may optionally be interposed between the insertion portion 18 a and the receiving member 17.

Here, as described above, the four receiving members 17 are provided at substantially the same height of the filtration tank over the inner peripheral surface of the filtration tank. A plurality of openings 17 ′ formed on the inner periphery of the side wall of the filter tank are also formed at substantially the same height of the filter tank over the inner peripheral surface of the filter tank. Accordingly, the four placement portions 18b exposed in the filtration tank 10 exist in the same horizontal plane. Further, the dimension in the longitudinal direction of the mounting portion 18b of the screen fixing member 18 is larger than the dimension in the longitudinal direction of the fitting insertion portion 18a of the screen fixing member 18, and the inner surface of the side surface of the filtration tank 10 having a square shape in plan view. Is approximately equal to the length of one side. Therefore, even if the four openings 17 ′ are separated from each other, the placement portion 18 b is located over the entire inner circumference of the filtration tank 10.
Accordingly, in the filtration tank 10, the placement portions 18 b of the screen fixing members 18 that are respectively inserted into the four openings 17 ′ interfere with each other. Therefore, in the filtration tank 10, as shown in FIG. 4A, a part of the placement portion 18 b of the screen fixing member 18 is overlapped in the height direction of the filtration tank, and the placement portion 18 b is overlapped with the filtration tank 10. It is located over the entire circumference of the inner circumference.
Then, as shown in FIG. 4A, the portions where the placement portions 18 b partially overlap are joined by the joining portion 20. Although it will not specifically limit as the coupling | bond part 20 if it can couple | bond the part with which the mounting parts 18b partially overlap, For example, a volt | bolt is mentioned. Furthermore, as the coupling part 20, for example, by welding a part of the mounting parts 18b that overlap each other, a welded part that joins the parts, or a part of the mounting parts 18b that overlaps each other is bonded. The adhesion part which couple | bonds the said part by this is mentioned.

  Normally, it is difficult to install a single screen fixing member that goes around the inner surface of the filtration tank side wall. In this way, a plurality of receiving members 17 spaced apart from each other are arranged in the same plane, By inserting the screen fixing member 18 into each of the members 17 and connecting the screen fixing members 18 with each other by a connecting portion, the screen fixing member that makes a round around the inner side of the filtration tank side wall can be easily installed.

  Here, as shown in FIGS. 4B and 4C, a rubber member 19 is arbitrarily provided between the screen fixing member 18 and the fitting insertion portion 18a. Thus, by providing the rubber member 19 between the screen fixing member 18 and the fitting insertion portion 18a, the screen fixing member 18 can be stably attached to the receiving member 17, and the water in the filtration tank can be fixed. However, intrusion between the receiving member 17 and the screen fixing member 18 can be prevented.

  The rubber member 19 may be, for example, a rubber layer formed by covering either the opening side surface of the receiving member 17 or the fitting insertion portion 18a of the screen fixing member 18 with rubber. According to another example, the rubber layer may cover both the opening side surface of the receiving member 17 and the fitting insertion portion 18a of the screen fixing member 18. The rubber member 19 may be a separate member from the receiving member 17 and the screen fixing member 18.

  The screen 11 is attached to the screen fixing structure configured as described above. Specifically, the screen 11 is mounted on the mounting portion 18b of the screen fixing member 18, and is fixed to the mounting portion 18b of the screen fixing member 18 using, for example, a bolt or by welding or adhesion. Has been. In addition, when providing the above-mentioned coupling | bond part, the screen 11 can also be made into the shape which notched the four corners in which a coupling | bond part is located.

  In the concrete filtration tank 10 according to the above example, the opening 17 ′ is formed on the four sides constituting the inner periphery of the concrete filtration tank. However, in order to attach the screen 11 to the inside of the filtration tank, the opening is What is necessary is just to be formed in at least one part of the inner periphery of the side wall of the filtration tank 10. FIG.

In the conventional concrete filtration tank shown in FIGS. 3A and 3B, an anchor is installed on the inner peripheral surface side of the side wall of the filtration tank, and a receiver for fixing the screen using this anchor. A board was installed. Anchors were installed by methods such as fixing to the formwork before placing concrete or after mounting on the hole after concrete has hardened, but fixing to the formwork before placing concrete. However, it was difficult to fit within the range of dimensional errors allowed for the fittings and machine parts to be attached. In addition, in the method of post-attaching on the hole after the concrete is hardened, the construction is difficult and requires skill.
In the concrete filtration tank according to the present invention, as described above, a receiving member is embedded on the inner peripheral surface side of the side wall, and an opening extending in a substantially horizontal direction is formed in at least a part of the inner periphery. And the screen fixing member is inserted in the said opening part, and the screen is fixed to the mounting part of the screen fixing member exposed in the filtration tank. Therefore, the screen fixing member can be installed in the filtration tank with high accuracy, and the screen fixed to the screen fixing member can also be attached with high accuracy. More specifically, since one screen fixing member is inserted into each of the openings formed by the receiving member having a predetermined length, and the screen is fixed to the screen fixing member, the screen fixing member There is no possibility that the opening of the receiving member into which the screen fixing member is inserted is shifted in the height direction within the opening. Therefore, the screen can be easily attached at a desired position.

  As mentioned above, although the concrete filter tank of this invention was demonstrated using an example, the concrete filter tank of this invention is not limited to the said example, A change is suitably added to the concrete filter tank of this invention. be able to.

For example, as shown in FIG. 6, a screen fixing member support member 30 for supporting the screen fixing member 18 may be further provided on the inner periphery of the side wall of the filtration tank 10. The screen fixing member support member 30 is not particularly limited, and the rubber layer 19 is pulled out after the rubber layer 19 is attached to the concrete water tank in which the receiving member 17 is embedded using a known method such as a bolt. It can be attached for the purpose of restraining and fixing the support member 18.
Moreover, you may abbreviate | omit the coupling | bond part 20 mentioned above.

  Further, for example, the horizontal sectional shape of the filtration tank 10 may be a circle or a polygon. Further, as the filtration tank, a vertical hole formed by excavating the ground, for example, a manhole, may be used, or a concrete water tank formed on the ground may be used.

  ADVANTAGE OF THE INVENTION According to this invention, the concrete filtration tank which attached the screen to the desired position easily can be provided.

DESCRIPTION OF SYMBOLS 10 Filtration tank 11 Screen 12 Floating filter material layer 13 Raw water inlet 14 Backwash drainage outlet 15 Filtrated water storage part 16 Filtration water outlet 17 Receiving member 17 'Opening part 18 Screen fixing member 18a Insertion part 18b Mounting part 19 Rubber Member 20 Joint 21 Raw water pump 22 Suction port 30 Member support member 61 for fixing screen Water collecting pipe 62 Water collecting pipe valve 100 Filtration system 111 Combined sewer 112 Rain spout 113 Intercepting pipe 114 River

Claims (5)

A floating filter layer made of a floating filter medium, a screen arranged on the upper side of the floating filter medium to prevent the floating filter medium from flowing out, a raw water inlet and a backwash drainage outlet arranged below the floating filter medium layer And a filtered water storage section provided on the upper side of the screen, and the raw water flowing from the raw water inlet is passed through the floating filter material layer in an upward flow to filter the raw water, and the obtained filtration A concrete filtration tank for storing water in the filtrate storage part,
A receiving member embedded in the inner peripheral surface side of the side wall of the concrete filtration tank and forming an opening extending in a substantially horizontal direction in at least a part of the inner periphery of the concrete filtration tank;
A plate-like screen fixing member having an insertion portion to be inserted into the opening and a placement portion on which the screen is placed;
A concrete filtration tank, wherein the screen is fixed to the mounting portion of the screen fixing member fitted into the opening. A plurality of receiving members spaced apart from each other in the same horizontal plane;
The screen fixing members are respectively inserted into the openings formed by the receiving members,
The concrete filtration tank according to claim 1, further comprising a coupling portion that couples the screen fixing members.   The concrete filtration tank according to claim 1, further comprising a rubber member between the receiving member and the insertion portion of the screen fixing member.   The concrete filter tank according to any one of claims 1 to 3, wherein the receiving member has a rubber layer that covers the opening side surface.   The concrete filter tank according to any one of claims 1 to 4, wherein the screen fixing member includes a rubber layer that covers the insertion portion.

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