JP2006082031A - Y-strainer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To backwash a screen using a fluid in a pipe without introducing a cleaning fluid from outside in a Y-type strainer and backwashing the screen without interrupting the flow of fluid in the pipe line It can be so.
A first on-off valve 21 provided on the upstream side of a screen 20 of the strainer 10, and a portion on the upstream side of the first on-off valve 21 and a portion on the downstream side of the screen 20 are communicated with each other. A bypass line 23, a second opening / closing valve 24 provided in the bypass line 23, and a drain provided downstream of the first opening / closing valve 21 and communicated with the contaminant capturing side of the screen 20. Pipes 28 and 30 and third on-off valves 29 and 31 provided in the drain pipes 28 and 30 are provided.
[Selection] Figure 2

Description

  The present invention relates to a Y-type strainer that is provided in a pipeline such as a water pipe and collects impurities.

  As such a Y-strainer, the one shown in FIG. 6 is known. Here, 1 is a storage chamber for storing a cylindrical screen 2 formed of punching metal or the like. The interior of the storage chamber 1 is partitioned by a screen 2 into an inside and an outside of the screen 2. A fluid inlet 3 communicates with the inside of the screen 2 in the storage chamber 1. A fluid outlet 4 communicates with the outside of the screen 2 in the storage chamber. The fluid inlet 3 and the fluid outlet 4 are arranged in a straight line so that the strainer can be arranged in a straight line. The distal end of the storage chamber 1 is formed so as to protrude obliquely downward from the axis of the pipe line, whereby the strainer is configured to have a Y shape. The front end of the storage chamber 1 is closed freely by the lid 5 being fastened by a bolt 6.

  According to such a configuration, the fluid 7 such as clean water that has flowed in from the inlet 3 enters the inside of the screen 2 in the storage chamber 1 and passes through the screen 2, thereby being contained in the fluid 7. Things are removed. Then, the fluid 7 purified thereby flows out from the outlet 4 to the downstream side.

  When such a strainer is used for a predetermined time, trapped impurities are accumulated inside the cylindrical screen 2. If a large amount of this is accumulated, the screen 2 is clogged, so the lid 5 is opened, and the foreign matter accumulated inside the screen 2 is discharged to the outside. Alternatively, the screen 2 in a state in which impurities are captured is taken out of the storage chamber 1 and then washed.

  However, it is necessary to open the lid 5 in this way, and it is necessary to block the flow of fluid in the pipeline during the operation. For this reason, for example, when the pipe is a water supply pipe, water is cut off every time the screen 2 is cleaned and washed, which is extremely inconvenient.

  Another example of the Y-type strainer is disclosed in Patent Document 1. This is to clean the screen by providing a nozzle capable of introducing cleaning water from the outside into the strainer so that the screen can be backwashed without being taken out of the storage chamber. The cleaning effect is enhanced by rotating the cylindrical screen itself from the outside of the strainer. In such a case, the screen can be cleaned without blocking the flow of the fluid in the pipe.

  However, in the one disclosed in Patent Document 1, it is necessary to install a system capable of supplying cleaning water having a pressure higher than that in the pipe line from the outside to the inside of the strainer using a nozzle. In addition, when such a system is applied to a water supply, that is, a pipe for supplying drinking water, it is necessary to manage the quality of the washing water, and a large-scale facility must be constructed. In addition, even if an attempt is made to rotate the screen inside the strainer, since a large amount of foreign matter is accumulated around the screen and its surroundings, there is a high possibility that the rotation function itself is hindered due to the biting caused by the rotation.

As still another example of the Y-type strainer, Patent Document 2 describes using air, a fluid similar to the fluid flowing in the piping, or the like as the backwash fluid.
However, Patent Document 2 does not describe a specific method such as how to prepare a fluid similar to the fluid flowing in the pipe.
JP-A-6-304418 (Claims) JP 2000-1117017 A ([0048])

  The present invention enables a Y-strainer to backwash the screen using the fluid in the pipe without introducing cleaning fluid from the outside, and reverses the screen without interrupting the flow of fluid in the pipe. The purpose is to be able to wash.

  In order to achieve this object, the Y-type strainer of the present invention includes a first on-off valve provided on the upstream side of the screen of the strainer, a portion on the upstream side of the first on-off valve, and a downstream side of the screen. A bypass conduit communicating with the portion on the side, a second on-off valve provided in the bypass conduit, and provided on the downstream side of the first on-off valve and communicated with the contaminant capturing side of the screen And a third on-off valve provided in the drain pipe.

  With such a configuration, when the first on-off valve is opened and the second and third on-off valves are closed, the normal use state is obtained, and the pipe fluid passes through the strainer and then is on the downstream side. The contaminants contained in the fluid are trapped and removed by the screen when passing through the strainer. On the other hand, when the first on-off valve is closed and the second and third on-off valves are opened, part of the in-pipe fluid passes through the screen in the reverse direction to perform backwashing. The fluid that contains impurities by this backwashing is discharged from the drain pipe together with the impurities. The remainder of the in-pipe fluid is supplied downstream without being subjected to backwashing of the screen.

  Therefore, according to the present invention, the screen can be backwashed using the in-pipe fluid without introducing the cleaning fluid from the outside, and the screen is backwashed without blocking the flow of the fluid in the pipe line. be able to.

  1 to 3 show a Y-strainer according to an embodiment of the present invention. In this Y-shaped strainer 10, reference numeral 11 denotes an inflow pipe having an inflow port 12. An outflow pipe 13 has an outflow port 14. The inflow port 12 and the outflow port 14 are arranged in a straight line so that the strainer 10 can be arranged in the straight line 15. 16 and 16 are flange joints for connecting the pipe line 15 and the strainer 10.

  Reference numeral 17 denotes a storage chamber, which is formed in a cylindrical shape, and is formed so that its tip protrudes obliquely upward from the axis of the duct 15 so that the strainer 10 has a Y-shape. . The inflow pipe 11 is formed so as to communicate with the bottom of the storage chamber 17, and the outflow pipe 13 is formed so as to communicate with the lower side portion of the storage chamber 17. A flange 18 is formed at the tip of the storage chamber 17, and a lid 19 for closing the storage chamber is detachably attached using the flange 18.

  A cylindrical screen 20 is disposed inside the storage chamber 17. The screen 20 may be formed of a punching metal as described above, or may be formed of a metal net-like body, or has a mesh opening on the outside of the cylindrical punching metal than the punching metal. It may be of a double structure covered with a fine net-like body, or may be of other configuration. The lower end of the screen 20 is held in a sealed state around the inner periphery of the storage chamber 17 and the inflow pipe 11 by an O-ring or the like. The upper end of the screen 20 is held in a sealed state on the inner surface of the lid 19 by an O-ring or the like. Accordingly, the storage chamber 17 is configured such that the inside and the outside of the screen 20 are partitioned in a sealed state.

  On the upstream side of the screen 20, that is, the inflow pipe 11, an on-off valve 21 such as a butterfly valve capable of blocking the flow of the inflow pipe 11 is provided. Reference numeral 22 denotes the operation handle.

  Between the portion upstream of the on-off valve 21 in the inflow pipe 11 and the communication portion with the outflow pipe 13 in the side portion of the storage chamber 17, between the portion downstream of the screen 20. Is provided with a bypass line 23 for backwashing. The bypass conduit 23 is provided with an openable / closable gate valve 24.

  A connecting portion between the bypass pipe line 23 and the storage chamber 17 is configured as follows. That is, as shown in detail in FIG. 3, a slit-like elongated opening 25 extending in the length direction of the storage chamber 17 is formed in a portion different from the communicating portion with the outflow pipe 14 in the storage chamber 17. The opening 25 and the bypass pipe line 23 are communicated with each other by a passage expanding portion 26. The passage expanding portion 26 is not connected to the cylindrical storage chamber 17 in the radial direction, but is connected in a direction having an angle with respect to the radial direction. For this reason, the fluid 27 from the bypass conduit 23 is also configured to flow from the opening 25 into the storage chamber 17 in an angled state, not in the radial direction. Therefore, the fluid 27 flows into the screen 20 from the outside of the screen 20 while forming a vortex inside the storage chamber 17.

  A lower drain pipe 28 communicates with the bottom of the inflow pipe 11 between the on-off valve 21 and the storage chamber 17. The lower drain pipe 28 is provided with an open / close gate valve 29. An upper drain pipe 30 that communicates with the inside of the screen 20 is connected to the lid 19. The upper drain pipe 30 is provided with an openable ball valve 31. The lid 19 is provided with an air vent pipe 33 having a ball valve 32 so as to communicate with the inside of the screen 20 at a position above the upper drain pipe 30.

  In such a configuration, when the fluid 27 is allowed to flow normally, the on-off valve 21 is opened and the gate valves 24 and 29 and the ball valves 31 and 32 are closed. Then, the fluid 27 that has flowed into the inflow pipe 12 from the pipe line 15 enters the inside of the screen 20 through the on-off valve 21, passes through the screen 20, and then is sent from the outflow pipe 13 to the downstream side pipe line 15. It is done. And when passing through the screen 20, the foreign matter contained in the fluid 27 is captured by the screen 20, and the outflow to the downstream side is prevented.

  If impurities accumulate inside the screen 20, the screen 20 is backwashed as necessary. At that time, the on-off valve 21 is closed and the gate valve 24 of the bypass line 23 is opened. Further, at least one of the gate valve 29 of the lower drain pipe 28 and the ball valve 31 of the upper drain pipe 30 is opened. The valve 32 of the air vent pipe 33 is closed.

  Then, the fluid 27 flowing into the inflow pipe 12 from the pipe line 15 enters the bypass pipe line 23 on the upstream side of the closed on-off valve 21, passes through the gate valve 24 and the passage expanding portion 26, and passes through the opening 25. At least one of the gate valve 29 of the lower drain pipe 28 and the ball valve 31 of the upper drain pipe 30 enters the inside of the accommodating chamber 17 in an opened state. At this time, since the opening 25 is formed in the length direction of the storage chamber 17, the fluid 27 also flows in the length direction of the storage chamber 17, that is, in a range extending in the length direction of the screen 20. Further, the fluid 27 flows into the interior of the storage chamber 17 in a state having an angle with respect to the radial direction of the storage chamber in accordance with the formation angle of the passage expanding portion 26 with respect to the storage chamber 17 and becomes a vortex. For this reason, although the opening 25 is formed only in one place along the circumferential direction of the storage chamber 17, the fluid 27 is normally used in the position over the entire length and the entire circumference of the screen 20. It can be fed into the storage chamber 17 so as to pass in the opposite direction to the time.

  As a result, the entire inner peripheral surface of the screen 20, particularly where impurities are deposited, can be reliably washed with the fluid 27 in a state where the pressure in the pipe line 15 is maintained. Further, since the eddy current can cause the foreign matter adhering to the inner surface of the screen 20 to float inward in the radial direction of the screen 20, effective cleaning can be performed. When the contaminants are heavy, that is, having a large specific gravity, it is preferable to discharge the fluid 27 together with the fluid 27 through the lower drain pipe 28. When the contaminants are light, that is, when the specific gravity is small, the fluid 27 is preferably discharged to the outside through the upper drain pipe 30. Similar drain pipes can be provided at other locations.

  A part of the fluid 27 from the bypass line 23 can be sent to the downstream side from the outflow pipe 13 without being subjected to backwashing of the screen 20. In this way, the screen 20 can be cleaned without stopping the flow of the fluid 27 in the pipe line 15. In particular, when the pipe line 15 is a water supply pipe, the screen 20 can be washed with continuous water. For this purpose, as shown in FIG. 3, the passage 27 is expanded so that the fluid 27 from the passage enlargement 26 is ejected from the opening 25 toward the outflow portion from the screen 20, that is, toward the outflow pipe 13. The shape of the portion 26 and the opening 25 may be set.

  In the above description, the on / off valve 21 is provided only on the upstream side of the storage chamber 17. However, the on / off valve can be provided on the downstream side of the storage chamber 17. The cleaning effect can be enhanced by adjusting the opening of the downstream opening / closing valve to increase the difference between the pressure of the fluid 27 for backwashing and the pressure inside the screen 20.

  The backwashing timing of the screen 20 may be set when the pipe pressure downstream of the strainer 10 is lowered, but the screen 20 may be periodically cleaned after a predetermined period. It is preferable to provide a pressure gauge or a differential pressure gauge so that the pressure difference between the upstream side and the downstream side of the strainer 10 can be checked.

  When the flow rate inside the pipe line 15 is not so high and the contaminants do not float so much, only the back washing of the screen 20 is performed periodically without draining from the drain pipes 28 and 30. It is only necessary to remove the impurities accumulated in the vortex. In this case, backwashing accompanied by discharge from the drain pipes 28 and 30 may be performed at a time when some impurities have accumulated to some extent.

  When the cleaning of the screen 20 is completed, the gate valve 24 of the bypass line 23 is closed, the gate valve 29 of the lower drain pipe 28 and the ball valve 31 of the upper drain pipe 30 are closed, and the on-off valve 21 is opened. As a result, the flow for backwashing that passes through the inside of the bypass line 23 is stopped, and the original flow that passes through the strainer 10 is resumed. If necessary, the inside of the storage chamber 17 is vented by opening the ball valve 32 of the air vent pipe 33.

  4 and 5 show a Y-strainer according to another embodiment of the present invention. In the Y-strainer 10, the bypass pipe line 23 is connected to the outflow pipe 13 instead of the storage chamber 17. In the bypass pipe 23, the part 35 provided with the gate valve 24 and connected to the inflow pipe 11 and the part 36 connected to the outflow pipe 13 are joined by a joint ring 37. Further, the portion 36 of the bypass pipe 23 is connected to and communicated with the outflow pipe 13 at a position shifted from the central axis of the outflow pipe 13 as shown in the drawing, that is, at a position eccentric with respect to the outflow pipe 13.

  For this reason, the fluid 27 from the bypass pipe 23 flows in the tangential direction with respect to the outflow pipe 13, and for this reason, as in the case of the previous embodiment, the fluid 27 is supplied to the screen 20 as a vortex. become.

  As described above, the strainer 10 can be backwashed without stopping the flow of the fluid in the pipe, and the structure is simple because there are no movable parts in the apparatus configuration. Moreover, since the cleaning can be performed only with the fluid in the pipe without introducing the cleaning fluid from the outside, it is possible to easily prepare the cleaning water and provide it for cleaning even when the fluid in the pipe is clean water. it can.

It is sectional drawing of the Y-shaped strainer of embodiment of this invention. It is an external view of the Y-shaped strainer. FIG. 3 is a cross-sectional view of a main part in FIG. 2. It is a figure which shows the Y type strainer of other embodiment of this invention. It is a cross-sectional view of the main part in FIG. It is sectional drawing of the conventional Y-shaped strainer.

Explanation of symbols

10 Y-strainer 20 Screen 21 On-off valve 23 Bypass line 24 Gate valve 28 Lower drain pipe 29 Gate valve 30 Upper drain pipe

Claims (1)

  A first on-off valve provided on the upstream side of the screen of the strainer, a bypass line communicating the portion on the upstream side of the first on-off valve and the portion on the downstream side of the screen, and the bypass A second on-off valve provided in the pipe line, a drain pipe provided on the downstream side of the first on-off valve and communicated with the foreign matter capturing side of the screen, and a second on-off valve provided on the drain pipe And a Y-strainer having three open / close valves.

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