JP6380025B2 - Long fiber filtration device - Google Patents

Description

  The present invention relates to a long fiber filtration device.

  In the long fiber filtration device, basically, a plurality of filter media formed by forming a turbidity trapping material on the circumferential side of the core string is loaded inside the tower, and the plurality of filter media are downstream of the tower when raw water is passed through. In a suspended state that can be bent and deformed along the direction of water flow so that a part of the turbidity trapping material forms a consolidated state and is released from the consolidated state when a wash water is supplied to form a rough state. It has a suspended structure, is effective for removing turbidity in raw water, and is sometimes called a turbidity removal device (Patent Document 1). For example, various shapes of molding cords described in JP-A-2002-061041 (Patent Document 2) can be used as the turbidity trapping material, and the molding cord is fixed to the core cord with an adhesive. I can do it.

  By the way, in the long-term operation, since the above-described compaction state and the rough state are repeatedly performed, the deterioration of stress in water of the adhesive used for fixing to the core string is promoted. There is a drawback that partial peeling occurs in the fixed state of the core string and the molding cord, and the molding cord does not function as a turbidity trapping material.

Japanese Patent No. 4649799 Japanese Patent Laid-Open No. 2002-061041

  This invention is made | formed in view of the said situation, The objective is to provide the long fiber filtration apparatus improved so that the stable turbidity removal function could be exhibited over a long period of time.

  That is, the gist of the present invention is a long fiber filtration device in which raw water is passed in a downward flow format and cleaning water is supplied in an upward flow format, and a raw water flow piping is provided at the top of the tower (1). A cleaning drain discharge pipe is provided, a treated water discharge pipe and a cleaning water supply pipe are provided at the bottom of the tower (1), and a turbidity trapping material is provided around the core string (41) inside the tower (1). A plurality of filter media (4) are formed, and the plurality of filter media (4) are pressed downstream of the tower (1) when the raw water is passed, and a part of the turbid trapping material forms a consolidated state. In addition, when supplying the washing water, the suspended state is suspended in a suspended state that can be bent and deformed along the flowing water direction so that a rough state can be formed by releasing the compacted state. The braided molding cord (42) is formed on the circumferential side of the braided cord, and the braided molding cord (42) is a strand constituting the braid. The loop (42a) is formed by strands in one of the clockwise and counterclockwise directions, and the braided body (42b) of the core is formed by the strands and strands in the other direction. The braided body cord (42b) of the braided molding cord (42) is fixed to the core cord (41) by sewing processing (42c) having a width of 2 to 20 mm every interval of 50 to 600 mm. In the featured long fiber filtration device.

  According to the long fiber filtration device according to the present invention, the fixed state of the core cord and the mould cord as the turbidity trapping material is hardly deteriorated, and a stable turbidity removal function can be exhibited over a long period of time. .

Schematic explanatory diagram of an example of a long fiber filtration device that can be suitably used in the present invention Schematic explanatory diagram of an example of a filter medium that can be suitably used in the present invention Drawing substitute photograph of the appearance of an example of a filter medium that can be suitably used in the present invention

  Hereinafter, the present invention will be described in detail.

  First, the long fiber filtration apparatus shown in FIG. 1 will be described. The partial diagram (a) is an explanatory diagram of the raw water treatment operation, and the partial diagram (b) is an explanatory diagram of the cleaning operation. This long fiber filtration device is basically the same as the turbidity removal device described in the above-mentioned prior art (Japanese Patent No. 4649799).

  The long fiber filtration device used in the present invention is a long fiber filtration device in which raw water is passed in a downward flow format and cleaning water is supplied in an upward flow format. Therefore, the top of the tower (1) is provided with a valve and a raw water passage pipe connected to the raw water tank and a washing drain discharge pipe with a valve, and the bottom of the tower (1) is provided with a valve. A treated water discharge pipe, a cleaning water supply pipe, and an air supply pipe are provided. In the apparatus shown in FIG. 1, the pipes used in the raw water treatment operation and the washing operation are common, and the water flow direction is changed by the valve operation.

  That is, in the raw water treatment operation, only the valves (61) and (62) are opened, and the raw water containing turbidity is passed from the valve (61) through the pipe (51) into the tower (1). Watered. At this time, the filter medium (4) exhibits a compacted state as will be described later, and the suspended matter entrained in the raw water is captured by the filter medium (4). The treated water containing no turbidity is discharged from the valve (62) via the pipe (52).

  On the other hand, in the case of the washing operation, the valves (61) and (62) that were open during the raw water treatment operation are closed, and the washing water passes through the pipe (52) from the valve (64) into the tower (1). To be supplied. On the other hand, air is supplied into the tower (1) from the valve (63) via the pipe (53). As will be described later, the filter medium (4) is released from the compacted state, and turbidity is removed from the filter medium (4). The bubbling action of the air causes the filter medium (4) to vibrate, and the separation of turbidity adhering to the filter medium (4) is promoted. Wash water containing turbidity is discharged from the valve (65) via the pipe (51).

  An upper support (2) and a lower support (3) are arranged inside the tower, and a plurality of filter media (4) are placed between the upper support (2) and the lower support (3). The upper suspension string (7) and the lower suspension string (8) at the end are fixed in a suspended state.

  The structure of the upper support (2) and the lower support (3) is not particularly limited as long as the structure does not hinder the flow of water and the filter medium (4) can be fixed by the hanging strings (7) and (8). For example, a lattice structure, an eye plate structure, a stitch structure, or the like can be appropriately employed.

  The filter medium (4) is formed by forming a turbidity trapping material having a specific structure on the peripheral side of the core string as will be described later. The filter medium (4), the core string, the upper suspension string (7), and the lower suspension string (8) are configured to be bent and deformed along the flowing water direction. Such a configuration is achieved by selecting the type, form, thickness, etc. of the material. Each of the above elements is usually made of a synthetic resin material such as polyester, nylon, or polyvinylidene chloride. In addition, when the core string (41) of the filter medium (4) is long and protrudes from both ends of the turbidity trapping material (specifically, both ends of the braided body (42b) described later), It can be used as a hanging string (7) and a lower hanging string (8).

  In the long fiber filtration device, the plurality of filter media (4) are pressed at the downstream side of the tower (1) when the raw water is passed by fixing both ends of the core string in the tower (1) and It is necessary to suspend in a suspended state that can be bent and deformed along the direction of flowing water so that a part can form a consolidated state and when the washing water is supplied, the consolidated state can be canceled to form a rough state. Such a state includes the distance (LA) between the upper support (2) and the lower support (3), the length (LB) of the filter medium (4), and the length (Lb1) of the upper suspension string (7). This can be achieved when the length (Lb2) of the lower suspension string (8) satisfies the following expressions (1) to (3).

[Equation 1]
LA <(Lb1 + LB + Lb2) Formula (1)
LB <LA Formula (2)
(LB + Lb2) <LA <(LB + Lb1) Formula (3)

  That is, in the long fiber filtration apparatus, as shown in the formula (1), the total length (Lb1 + LB + Lb2) of the filter medium (4), the upper support (2) and the lower support (3) is the upper support (2). Longer than the distance (LA) between the lower support (3) and the lower support (3). Accordingly, any of the above elements exists in a relaxed state in the tower (1).

  Moreover, as shown in Formula (2), the distance (LA) between the upper support (2) and the lower support (3) is longer than the length (LB) of the filter medium (4). Therefore, a region where the filter medium (4) does not exist is formed along the flowing water direction between the upper support (2) and the lower support (3). In other words, the movable range of the filter medium (4) is formed along the flowing water direction. In addition, although the clearance gap exists between filter media (4) in the schematic explanatory drawing of FIG. 1, there is actually no clearance gap between filter media (4), and several filter media (4) will be in a consolidated state. Therefore, the whole of the plurality of filter media (4) moves only along the flowing water direction (vertical direction).

  Furthermore, as shown in Formula (3), the total length (LB + Lb1) of the filter medium (4) and the upper suspension string (7) is the total length (LB + Lb2) of the filter medium (4) and the lower suspension string (8). ) Longer. Therefore, at the time of raw water treatment operation in which raw water is passed in the downward flow format, as shown in FIG. 1 (a), the filter medium (4) comes into contact with the lower support (3) and lower suspension string (8 ) And in the vicinity of the bottom of the tower, and in the cleaning operation in which cleaning water is supplied in an upward flow manner, the filter medium (4) is brought into contact with the upper support (2) as shown in FIG. 1 (b). Without being extended with the lower suspension string (8) in the tower.

  As a result, in the long fiber filtration device, trapping and discharging of turbidity by the filter medium are efficiently performed by releasing the compacted state of the filter medium during the raw water treatment operation and releasing the compacted state of the filter medium during the washing operation.

  In the long fiber filtration device used in the present invention, each of the above elements preferably satisfies the following formulas (1 ') to (3'). The numerical value of the magnitude relationship of each element in the formulas (1 ') to (3') is a value determined in consideration of the economics of the apparatus.

[Equation 2]
1.01 × LA <(Lb1 + LB + Lb2) <2.00 × LA Formula (1 ′)
1.01 × LB <LA <1.50 × LB Formula (2 ′)
1.01 * (LB + Lb2) <LA <1.01 * (LB + Lb1) Formula (3 ')

  The dimensions of the above-mentioned elements of the long fiber filtration device are as follows. That is, the distance (LA) between the upper support (2) and the lower support (3) is 100 to 400 cm, the length (LB) of the filter medium (4) is 70 to 300 cm, and the upper suspension string (7) The length (Lb1) is 10 to 250 cm, the length (Lb2) of the lower suspension string (8) is 5 to 20 cm, and the diameter of the tower (1) is 20 to 360 cm.

  Next, the filter medium (4) shown in FIG. 2 will be described. The filter medium (4) is formed by forming a braided molding cord (42) as a turbidity trapping material on the peripheral side of the core string (41). The length of the braided molding cord (42) in a state in which the compacted state at the time of supplying cleaning water is released is not particularly limited, but is usually 1 to 5 m or more. Such a length is obtained by measuring the length of the braided molding cord (42), in fact, the length of the braided body (42b), which will be described later, for the filter medium (4) before being loaded inside the tower (1). It can be confirmed.

  By the way, when the conventional long fiber filtration device that fixes the molding cord to the core string with an adhesive is enlarged, the above-mentioned compaction state and the rough state are performed at a long distance, so the adhesive in water Stress deterioration is further promoted, and partial peeling easily occurs in the fixed state between the core cord of the molding cord and the molding cord during long-term operation. On the other hand, since the long fiber filtration device of the present invention does not use an adhesive for fixing the molding cord to the core string, there is no problem as described above. Therefore, it can be said that the long fiber filtration device of the present invention is particularly effective in the case of a large-sized device in which the length of the braided molding cord (42) is 1 m or more, preferably 1.5 m or more.

  The braided molding cord (42) is basically one of the molding cords described in the above-mentioned prior art (Japanese Patent Laid-Open No. 2002-061041). It is introduced as a spiral-shaped braided molding cord described in Japanese Patent No. 50298. And it is pointed out that there is a limit in terms of productivity because it is manufactured by adopting a braiding method.

  However, in the case of long fiber filtration, a spiral strip braided molding cord described in Japanese Utility Model Publication No. 63-50298 is suitable as a basic structure. That is, the braided molding cord (42) used in the present invention is configured in the same manner as the above braided molding cord, and either one of the clockwise and the counterclockwise rotations of the strands (strings) constituting the braid. A loop (42a) is formed by the strands in the direction, and a braided body (42b) of the core portion is formed by the strands in this direction and the strands in the other direction.

  However, the spiral braided molding cord described in Japanese Utility Model Publication No. 63-50298 is “Uses a fiber material with relatively low elongation, such as natural fiber and chemical fiber, for the strand in the direction of forming the loop. And at least one of the strands in the other direction is made of a material such as natural rubber, synthetic rubber, elastic chemical fiber, etc. that elastically expands and contracts, and a spiral braided molding cord is formed by its elastic recovery force. However, in the present invention, the material of the strands in the direction in which the loop is formed does not have to be different from the material of the strands in the other direction. Rather, the helical formation utilizing the elastic recovery force is disadvantageous for use as a turbidity trapping material in the present invention.

  In FIG. 2, for the sake of understanding the loop (42 a), and for explaining the braided body (42 b) of the core part and the sewing process (42 c) to be described later, the strand is made up of one monofilament thread for convenience. Although represented, the actual braided molding cord has an appearance as shown in FIG. Such a braided molding cord can be produced using multifilament yarn as a strand. The yarn diameter can be arbitrarily selected from a very thin one to a very thick one. Further, it may be crimped.

  The greatest feature of the present invention is that the braided cord body (42b) of the braided molding cord (42) is fixed to the core cord (41) by sewing processing (42c) having a width of 2 to 20 mm every 50 to 600 mm. There is in point.

  Although the illustration of the sewing process (42c) is omitted, it is usually performed from both ends of the braided body (42b). When the interval of the sewing process (42c) is less than the above range, the formation of the sewing process (42c) is too dense, and the bending deformability (flexibility) of the braided body (42b) is impaired. When exceeding, it cannot be said that fixation of the braided body (42b) to the core string (41) is sufficient. On the other hand, when the width of the sewing process (42c) is less than the above range, it cannot be said that the braid body (42b) is sufficiently fixed to the core string (41), and when the width exceeds the above range, the braid body The bending deformability (flexibility) of (42b) is impaired. In either case, the function of the braided molding cord (42) as a turbidity trapping material is reduced. The sewing process (42c) is usually performed by sewing, but the sewing is performed in a direction perpendicular to the core string (41). The thread used for the sewing process (42c) is made of the aforementioned synthetic resin material.

  Next, an operation method of the long fiber filtration device shown in FIG. 1 will be described. The operation method of this long fiber filtration apparatus consists of repeatedly performing a raw water treatment operation and a washing operation.

  In the raw water treatment operation (FIG. 1 (a)), as described above, only the valves (61) and (62) are opened, and raw water containing turbidity passes through the pipe (51) from the valve (61). The water is passed through the tower (1). The suspended matter entrained in the raw water is captured by the filter medium (4). The treated water containing no turbidity is discharged from the valve (62) via the pipe (52).

  In the raw water treatment operation, for example, the raw water treatment operation is stopped when the performance of the long fiber filtration device is reduced by means such as pressure measurement of a raw water flow pump (not shown) and water quality analysis of the treated water. The stop of the raw water treatment operation may be automatically performed every certain time.

  In the cleaning operation (FIG. 1B), as described above, the valves (61) and (62) that were open during the raw water treatment operation are closed, and the cleaning water is supplied from the valve (64) to the pipe (52 ) To be fed into the tower (1). On the other hand, air is supplied into the tower (1) from the valve (63) via the pipe (53). The supply of air may be started simultaneously with the supply of cleaning water, or may be started later than the supply of cleaning water. Wash water containing turbidity is discharged from the valve (65) via the pipe (51). At this time, the filter medium (4) does not come into contact with the upper support (2), but extends upward in the tower together with the lower suspension string (8). However, it is not necessary to perform a long-time washing operation until the suspended turbidity concentrated on the upper part of the filter medium (4) is removed because a large amount of washing water is used.

  In the above-described washing operation, raw water or turbidity removal treated water can be used as washing water. As turbidity removal treated water, water treated with a filter or membrane (reverse osmosis membrane, ultrafiltration membrane, microfiltration membrane, etc.) or water treated with the turbidity removal device used in the present invention is used. Is done.

1: Tower 2: Upper support 3: Lower support 4: Filter medium 7: Upper suspension string 8: Lower suspension string 51-53: Piping 61-67: Valve

Claims (1)

  A long fiber filtration device in which raw water is passed in a downward flow format and cleaning water is supplied in an upward flow format, and a raw water flow piping and a cleaning drainage piping are provided at the top of the tower (1). The bottom of the tower (1) is provided with a treated water discharge pipe and a washing water supply pipe, and a plurality of filter media are formed in the tower (1) by forming a turbidity trapping material on the peripheral side of the core string (41). (4) is loaded, and the plurality of filter media (4) are pressed downstream of the tower (1) when the raw water is passed, so that a part of the turbidity trapping material forms a consolidated state and when the washing water is supplied, The suspended matter is suspended in a suspended state that can be bent and deformed along the direction of flowing water so that the rough state can be formed by releasing the state, and the turbidity trapping material is a braid formed on the peripheral side of the core string (41) The braided mall cord (42) is clockwise, left of the strands (strands) constituting the braid. A loop (42a) is formed by the strands in one direction of either of the wires, and the braided molding cord (42) is formed by forming the braided body (42b) of the core portion with the strands of this direction and the strands in the other direction. The braided body (42b) is fixed to the core string (41) by a sewing process (42c) having a width of 2 to 20 mm every interval of 50 to 600 mm.