JP2005193161A - System for backwashing strainer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for backwashing a strainer in which the foreign matter stuck to a filter can be removed completely by backwashing in spite of its simple constitution and consequently the washing work is made more efficient. <P>SOLUTION: When the strainer 100a is backwashed, a stop valve 113a is opened and stop valves 105a, 110 are closed. Supplied original water is filtered by the strainer 100a to become the treated water and the treated water is made to pass through a discharge route 109b and supplied to a discharge route 109a as washing water. The washing water supplied into a filtration case 101 from a water inlet/outlet 107 is made to pass through a cylindrical filter 103a from the outside to the inside and enter the inside of the cylindrical filter 103a while exfoliating/removing the foreign matter stuck to/accumulated on the inside surface of the cylindrical filter 103a. Then the washing water is made to pass through a discharge route 114a and discharged to the outside while removing the foreign matter from the cylindrical filter 103a, flinging up the foreign matter accumulated on a bottom plate filter 103b by the scouring effect of a current of the washing water and guiding the flung foreign matter to dirty water sucking ports of elbows 200, 202. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a strainer backwash system for removing foreign substances from raw water.

  The strainer is used for the purpose of removing foreign substances from water used in factories and plants. This strainer has a function of filtering the foreign matter mixed in the raw water by allowing the raw water to pass through a filtration unit having a filter such as a metal mesh.

  By the way, in such a strainer, if raw water is continuously filtered, foreign substances in the raw water adhere to the filter and the filter is clogged. When such clogging occurs in the filter, the load of the water pump increases, so it is necessary to periodically clean the inside of the strainer manually, which is a heavy burden on work efficiency.

  For this reason, conventionally, a cleaning strainer having a backwashing mechanism for removing foreign matter adhering to the filter has also been adopted. In a washing strainer equipped with such a backwashing mechanism, the washing water is passed through the filter in the direction opposite to the inflow direction of the raw water during normal filtration. It has the structure to remove.

  However, in a bottomed cylindrical filter, a strainer that injects raw water into the cylindrical filter and discharges treated water to the outside is a backwashing method that has been proposed in the past. When the clogging is eliminated, the foreign matter that has caused the clogging settles on the bottom plate filter.

The size of the hole provided in the bottom plate filter for discharging foreign matter is the same as or slightly larger than the hole in the cylindrical filter, and foreign matter larger than the hole diameter cannot pass through the bottom plate filter and is not discharged from the strainer. There was a problem of depositing and remaining on the filter.
For this reason, when the raw water is filtered again, the foreign matter accumulated on the bottom plate filter is used with stirring, so that the cylindrical filter is clogged in a short period of time, and backwashing is performed. There was a problem of inefficiency that had to be repeated.

Moreover, if the hole diameter of the bottom plate filter is made larger than before in order to facilitate the discharge of foreign matter, the sewage drainage pipe may become clogged, making it impossible to play a sufficient role as a strainer. It was.
Therefore, regarding the removal of the foreign matters remaining in the strainer, there is a problem in operation in a state where the worker relies on the cleaning of the strainer.

  The present invention has been made in view of the above-mentioned problems, and enables simple removal of foreign matters in the strainer by backwashing with a simple configuration, thereby greatly improving the efficiency of the cleaning operation. A strainer backwash system is provided.

  Another object of the present invention is to implement a strainer backwash system at a low cost by adding a simple structure without significantly modifying the main structure of an existing strainer.

  In order to solve the above problems, the strainer backwash system of the present invention includes a filtration member that is housed in a filtration case and divides the filtration case into a primary side and a secondary side, and raw water is supplied to the primary side of the filtration member. A raw water supply unit for supplying and catching foreign matter and draining from the secondary side, and a cleaning for supplying cleaning water from the secondary side to the primary side of the filtration member to remove the foreign matter from the filtration member A water supply unit, and a sewage discharge unit configured to communicate with the primary side of the filtration member and to discharge foreign substances removed from the cleaning water and the filtration member through a filtration member having a coarser mesh than the filtration member. In the strainer, a bypass path is provided to communicate the sewage discharge portion and the primary side of the filtration member (first invention).

  According to a second invention, in the first invention, the filtration member is a bottomed cylindrical shape, and the bypass passage is attached to a bottom portion of the filtration member and passes through the filtration member vertically. And a sewage suction port which is connected to the upper portion of the short pipe pipe and hangs down and opens at a lower surface so as to oppose the upper surface of the filter member with a predetermined distance.

  According to the present invention, the foreign matter in the strainer can be completely removed by backwashing with a simple configuration, which can greatly improve the efficiency of the strainer cleaning operation.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a partial cross-sectional view of a strainer in the present embodiment. As shown in FIG. 1, the strainer 100 includes a filtration case 101 having a drain hole at the bottom, a lid 102 provided at the top of the filtration case 101, and a bottomed cylindrical filtration housed in the filtration case 101. The filter part 103 which has a member is provided.

  The filtration unit 103 divides the space in the filtration case 101 into an inner raw water side (primary side) and an outer treated water side (secondary side), and captures foreign matters at normal times and a bottom plate. Filter 103b. The bottom plate filter 103b serves as a bottom plate of the cylindrical filter 103a and serves as a mounting base for the sewage suction port 112 (described later). The mesh diameter is the same as or slightly larger than the mesh diameter of the cylindrical filter 103a.

  Further, for example, an elbow-shaped raw water supply unit 104 protrudes from the lid 102, and the raw water supply unit 104 is connected to a raw water supply path 106 via an opening / closing valve 105. As a result, the raw water is introduced from the supply path 106 into the cylindrical filter 103 a in the filtration case 101 via the valve 105.

  Further, a water outlet 107 is formed on the outer periphery of the filtration case 101 so as to protrude sideways. The water inlet / outlet port 107 has a function of discharging treated water after filtration by the cylindrical filter 103a from the filtration case 101 in normal times, and a washing water supply unit that supplies washing water into the filtration case 101 in backwashing. It also serves as a function. The water inlet / outlet port 107 is connected to a discharge path 109 for discharging the treated water after filtration from the filter case 101 via an opening / closing valve 108.

  Furthermore, the filtration case 101 has a sewage discharge part 111 in the lower part thereof, and the sewage discharge part 111 is a sewage suction port as a bypass passage which is a characteristic part of the present invention provided in the bottom plate filter 103b during backwashing. The sewage flowing through the section 112 is connected to a discharge path 114 for discharging through the open / close valve 113.

  The opening / closing valves 105, 108, 113 are connected to a valve opening / closing instruction device (not shown), and are opened / closed as necessary during normal raw water treatment and backwashing, as will be described later.

FIG. 2 is an enlarged perspective view of the inside of the dotted circle in FIG. 1 and shows an assembled state of the sewage suction port.
As shown in FIG. 2, the sewage suction port portion 112 includes a plurality of elbows 200 serving as a sewage suction port (a filter may be provided) whose one end faces the top surface of the bottom plate filter 103b. The cheese 201 having the elbow 200 connected to both ends, the cheese 203 having the cheese 201 connected to one end, the cheese 203 having the elbow 202 connected to the extreme end, the convex end of the cheese 203 connected to one end, and the other end having the bottom plate filter 103b And a single pipe pipe 205 fixed by welding or the like so as to be sandwiched between a pair of nuts 204 above and below the opening of the through hole.

  FIG. 3 shows the configuration of the backwashing system in the present embodiment, (a) an explanatory diagram of the open / close state of the open / close valve during normal raw water treatment, (b) an explanatory diagram of the open / close state of the open / close valve during backwashing, c) Partial sectional view of the strainer showing the flow of water during normal raw water treatment, (d) Partial sectional view of the strainer showing the flow of water during backwashing.

  When the strainer is used in a factory, a plant, or the like, at least two or more of the plurality of strainers 100 are connected in parallel. In this embodiment, an example in which two strainers are installed is shown.

  As shown in FIG. 3 (a), the downstream portions of the drainage passages 109a and 109b of the two strainers 100a and 100b of the a flow path and the b flow path were treated with a plurality of strainers via the valves 110. A collective discharge path 115 for discharging the treated water collectively is provided.

  As shown in FIGS. 3 (a) and 3 (c), when raw water is filtered, first, the on-off valves 113a and 113b are closed, and then the on-off valves 105a, 105b, 108a, 108b, and 110 are opened to open the raw water. Raw water is supplied to the supply path 106.

  Then, the raw water that has passed through the raw water supply path 106 and is supplied from the raw water supply unit 104 into the filtration case 101 is supplied to the inside of the cylindrical filter 103a, passes through the cylindrical filter 103a from the inside to the outside, and Water is fed from the water inlet / outlet 107 to the treated water discharge passage 109 while capturing and removing foreign matter in the raw water inside the cylindrical filter 103a.

  Then, the treated water that has passed through the discharge passage 109 and collected in the collective discharge passage 110 is supplied to the next apparatus.

  Thus, when filtration is continued for a long time, a foreign material adheres and accumulates on the inner surface of the cylindrical filter 103a, and the cylindrical filter 103a is clogged. For this reason, it is necessary to perform the backwashing operation of the cylindrical filter 103a at a predetermined frequency. Next, the back washing method will be described.

  As shown in FIGS. 3B and 3D, when the strainer 100a is back-washed, the open / close valve 113a on the flow path side is first opened, and then the open / close valves 105a and 110 are closed to supply the raw water supply unit 106. To supply raw water.

  The raw water supplied to the raw water supply unit 106 flows all through the b flow path through the raw water supply path 106b because the open / close valve 105a of the a flow path is closed, and is filtered by the strainer 100b to be discharged as treated water. Although it tries to flow to the collective discharge path 115 through the path 109b, since the on-off valve 110 is closed, all is supplied to the discharge path 109a as washing water from the flow direction opposite to that during normal processing.

  Accordingly, the wash water that has passed through the discharge passage 109a and supplied from the water inlet / outlet 107 into the filter case 101 passes through the cylindrical filter 103a from the outside to the inside, and adheres and accumulates on the inner surface of the cylindrical filter 103a. It enters the inside of the cylindrical filter 103a while removing and removing foreign substances. The cleaning water from which foreign matter has been removed from the cylindrical filter 103a is contaminated water containing foreign matter. The foreign matter accumulated on the bottom plate filter 103b is rolled up by the scouring effect by the water flow, and the foreign matter is led to the sewage suction ports of the elbows 200 and 202. The foreign matter is contained and discharged through the single pipe 205 and the discharge path 114a.

  In other words, when at least two or more strainers are connected in parallel, when the strainer is backwashed, first, the strainer is connected to the backwash target strainer in order to discharge the sewage after the strainer backwashing. The on-off valve 113 is opened, and then the on-off valve 105 connected to the backwash target strainer is closed so that raw water is not supplied to the backwash target strainer. And, since the treated water filtered by the strainer not subject to backwashing is used as washing water, the flow path for feeding water to the collective discharge path 115 is closed and the treated water is supplied to the water inlet / outlet 107 of the strainer subject to backwashing. The on-off valve 110 is closed.

  With the backwashing system according to the present invention, all foreign matters in the filtration unit 103 are removed, and the manual strainer cleaning work that has been conventionally required is reduced.

  In the present embodiment, as shown in FIG. 2, the elbows 200 and 202 are arranged at the same height from the bottom plate filter 103b, but may be arranged at different heights. . In other words, it is most effective to install the sewage suction port in a position facing the bottom plate filter at a position where the washing water has the highest scouring effect.

  Further, in this embodiment, the treated water drainage part and the washing water injection part are combined, but provided separately, the direction of the injection port of the washing water injection part is the same as the tangential direction in the circumferential direction of the filtration case, and the filtration case It is possible to install the cleaning water injected into the filter case so as to reach a wide range through the inner surface of the filtration case, or to arrange a water flow by providing a screw in the cleaning water injection path.

It is a partial cross section figure of the strainer in this embodiment. It is the perspective view which expanded the inside of the dotted-line round frame of FIG. 1, and shows the assembly state of a sewage suction inlet. It is explanatory drawing of the opening-and-closing state of the opening-and-closing valve at the time of the usual raw water treatment, showing the composition of the filtration system in this embodiment. It is explanatory drawing of the opening-and-closing state of the opening-and-closing valve at the time of backwashing showing the composition of the filtration system in this embodiment. It is a partial sectional view of a strainer which showed composition of a filtration system in this embodiment, and showed a flow of water at the time of usual raw water processing. It is the partial sectional view of the strainer which showed the composition of the filtration system in this embodiment, and showed the flow of water at the time of backwashing.

Explanation of symbols

100 strainer (= 100a, 100b)
101 Filtration case 103 Filtration unit 103a Cylindrical filter 103b Bottom plate filter 104 Raw water supply unit 105 Open / close valve (= 105a, 105b)
106 Raw water supply channel (= 106a, 106b)
107 Water outlet 108 Open / close valve (= 108a, 108b)
109 discharge path (= 109a, 109b)
110 On-off valve 111 Sewage discharge part 112 Sewage suction part (bypass)
113 Open / close valve (= 113a, 113b)
114 discharge path (= 114a, 114b)
115 Collective discharge path

Claims (2)

A filtration member housed in a filtration case and dividing the inside of the filtration case into a primary side and a secondary side;
A raw water supply unit for supplying raw water to the primary side of the filtration member to capture foreign matter and drain it from the secondary side;
A cleaning water supply unit for supplying cleaning water from the secondary side of the filtration member toward the primary side to remove the foreign matter from the filtration member;
In a strainer provided with a sewage discharge unit for discharging foreign matter removed from the cleaning water and the filtration member through the filtration member having a coarser mesh than the filtration member and communicating with the primary side of the filtration member,
A strainer backwashing system comprising a bypass passage that communicates the sewage discharge section and the primary side of the filtration member. The filtering member has a bottomed cylindrical shape, and the bypass passage is attached to the bottom of the filtering member and vertically passes through the filtering member, and is connected to the upper portion of the short pipe and hangs down. The strainer backwashing system according to claim 1, further comprising: a sewage suction port having a lower surface opened to oppose the upper surface of the filtration member with a predetermined distance.

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