JP2008190219A - Backflow preventing structure of boost water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backflow preventing structure of a boost water supply device improving the installation property of the boost water supply device. <P>SOLUTION: The backflow preventing structure is provided with a backflow preventing device comprising a primary side check valve 21 for primary side backflow prevention with a larger pressure reducing effect than a check valve 6 on the discharge side of a booster pump part 3, on the suction side of a booster pump part 3 to doubly regulate backflow from the water supply side to the distributing main side by diverting the check valve 6 to secondary side backflow regulation, and a discharge mechanism 25 for discharging water from the secondary side of the primary side check valve when primary side pressure and secondary side pressure with the primary side check valve 21 held between are in an equal pressure state. With this constitution, since components of a pump unit 1 serve as both the exclusive secondary side check valve part and an intermediate chamber required in a conventional backflow preventing device, the backflow preventing device 20 can be miniaturized, and the degree of installation freedom of the boost water supply device can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a backflow prevention structure for an increased pressure water supply apparatus that is connected to, for example, a water supply main and supplies water to each door.

  Water supply systems that supply tap water used in condominiums and apartments are regulated by the water supply mains supply pressure, so if the amount used increases, the water supply will not catch up and the water supply capacity will be insufficient There is a case. Therefore, in a water supply system of an apartment or an apartment, such a situation is avoided by adopting a pressure increasing water supply device.

  Normally, a booster water supply device is installed when the pressure or flow rate of the water supply main is insufficient by installing a pump unit having a pressure booster pump in the middle of the pipe from the water main to the home. The pressure pump unit is operated and pressurized to compensate for the water supply.

  By the way, there is a possibility that the tap water on the water supply side will flow backward to the water distribution main because the pressure-increasing water supply device is connected directly to the water distribution main and supplies water. Therefore, in the pressure boosting water supply device, as a backflow prevention structure, a backflow prevention device is provided on the suction side of the pressure boosting pump unit to prevent backflow of tap water to the water distribution main.

In the backflow prevention device, as shown in Patent Document 1, a primary check valve portion communicating with the tap water distribution main pipe side is assembled on one side of an intermediate chamber having a drain port portion, and a pressure increasing pump portion is placed on the opposite side. The pressure reducing device is equipped with a secondary check valve that communicates with the suction part, and a diaphragm-type open / close valve that discharges water to the outside when the primary check valve is abnormal in the intermediate chamber. Used. And, even if one of the check valves malfunctions due to the double check valve structure or water leakage discharge structure (for example, when a foreign object is caught between the valve body and the valve seat), the reverse flow toward the water supply mains I try to prevent it.
JP 2003-278191 A

  By the way, it is desired that the pressure-increasing water supply device be made as small as possible so that it can be installed even in installation places where space is limited.

  However, the outer shape of the backflow prevention device is considerably large due to the structure for discharging the intermediate chamber, the double check valve portion and the water leakage to the outside of the device, and occupies a considerable area. For this reason, the backflow prevention device is a factor that hinders the installation of the pressure increasing water supply device. In particular, the backflow prevention device is difficult to be installed in a pump unit that does not have enough internal space because it requires a large area. Usually, a separate structure from the pump unit is used. The device which raises the installation nature of a water supply device is demanded.

  Then, the objective of this invention is providing the backflow prevention structure of the pressure increase water supply apparatus with which the installation property of a pressure increase water supply apparatus is improved.

  In order to achieve the above object, the invention according to claim 1 uses a check valve on the discharge side of the booster pump unit as a backflow prevention device as a backflow prevention device for regulating the reverse flow on the secondary side. In this way, a primary check valve for preventing primary back flow that has a greater pressure reduction effect than the check valve is provided to restrict the back flow from the water supply side to the water distribution main pipe side, and this primary check valve is sandwiched between When the pressure on the primary side and the pressure on the secondary side are equivalent to each other, each part of the pump unit is configured using a structure having discharge means for discharging water from the secondary side of the primary check valve. However, it also serves as a dedicated secondary-side check valve and intermediate chamber, which are necessary for conventional backflow prevention devices.

  The invention according to claim 2 has a simple mechanical structure, and the discharge means includes a primary side and a secondary side sandwiching the primary check valve so that water leakage is discharged when the secondary check valve is abnormal. A bypass passage communicating with the side, a drain opening provided in the bypass passage, a drain opening provided in the drain opening, and applying a primary pressure and a secondary pressure on both sides of the diaphragm, A structure having a diaphragm type differential pressure on / off valve that opens the drain port when the differential pressure with the secondary side pressure disappears was adopted.

  The invention according to claim 3 is configured to incorporate the primary check valve and the drainage means, which are each device of the backflow prevention device, into the pump unit by utilizing the advantage that the backflow prevention device is compact.

  In the invention according to claim 4, the pressure-intensifying pump section is composed of a plurality of pumps connected in parallel so that maintenance of the pump unit can be performed without water interruption.

  According to the first aspect of the invention, each part of the pump unit serves as a dedicated secondary-side check valve and intermediate chamber, which are necessary in the conventional backflow prevention device, and the water distribution main pipe from the water supply side. Backflow to the side can be prevented, and water leakage can be discharged to the outside. For this reason, the backflow prevention device need only be a primary side check valve and a discharge means for draining water leakage to the outside, and can be made compact.

  Therefore, the degree of freedom in installing the pressure-increasing water supply device increases, and the installation property of the device can be improved.

  According to the invention which concerns on Claim 2, it is a simple and reliable mechanical type valve structure, and can discharge | emit the water leak at the time of primary side check valve abnormality.

  According to the third aspect of the present invention, since the entire backflow prevention device can be accommodated in the pump unit using the compacted backflow prevention device, the degree of freedom in installing the pressure increasing water supply device is increased, and the increase It becomes easy to install the pressure water supply device.

  According to the invention which concerns on Claim 4, even if it maintains one pressure-intensifying pump, since water supply can be continued if another pressure-intensifying pump is operated, the maintenance of a pump unit can be performed without water interruption.

  The present invention will be described below based on the first embodiment shown in FIG.

  FIG. 1 is a schematic configuration diagram of a pressure-increasing water supply apparatus, in which 1 indicates a pump unit. The pump unit 1 is configured, for example, by arranging a pressure increasing pump unit 3 in a cabinet 2. The booster pump unit 3 includes, for example, an electric booster pump 8 in which an on-off valve 5 and a check valve 6 for preventing backflow are assembled on the discharge side, and an on-off valve 7 on the suction side, and a booster pump 8 Bypass passage 12 with a check valve 11 for bypassing between the header pipe 9 forming the discharge pipe and the header pipe 10 forming the suction pipe (between the primary and secondary with the pressure-intensifying pump 8 interposed) (tap water distribution main pipe) And a passage when water is supplied only with the pressure of Of these, the end of the header pipe 9 on the discharge side protrudes out of the cabinet 2 to form a discharge port 13, and the end of the header pipe 10 on the suction side protrudes out of the cabinet 2 to connect the suction port 14. Forming.

  For example, a water supply pipe 16 extending from the water supply side of an apartment or an apartment door (not shown) is connected to the discharge port 13. A water distribution pipe 17 extending from a tap water distribution main (not shown) is connected to the suction port 14. Thus, when the pressure increasing pump 8 is operated when the water supply capacity is insufficient, the tap water from the tap water distribution main is increased so that the water supply capacity can be compensated. Reference numeral 18 denotes an on-off valve provided at the downstream end of the water distribution pipe 17.

  A backflow prevention device 20 is interposed between the suction side of the pump unit 1, for example, the suction port 14 and the on-off valve 18, and a backflow prevention structure that restricts backflow from the water supply side to the water distribution main side is constructed. ing.

  That is, the backflow prevention device 20 has a check valve 21 (one) provided between the suction port 14 and the on-off valve 18, and a primary pressure and a secondary pressure sandwiching the check valve 21. A structure in which a discharge mechanism 25 (corresponding to the discharge means of the present application) that discharges water from the secondary side pipe of the check valve 21 when an equivalent pressure state is obtained is used.

  Specifically, the check valve 21 allows the flow of water from the water distribution main side to the pump unit 1, but restricts the flow of water from the opposite pump unit 1 to the water distribution main side. 21 (corresponding to a primary side check valve for preventing primary side backflow of the present application) is used. The check valve 21 uses a valve structure having a greater pressure reducing effect than the check valve 6 disposed on the discharge side of the pressure increasing pump 8 and the check valve 11 disposed on the bypass passage 12. For example, the urging force of a spring member 21a for urging the valve body constituting the check valve 21 (which urges the valve body 21b in the closing direction) is applied by a spring member (not shown) of the check valve 6 (11). The valve hole 21c which is large or opened / closed by the valve body 21b is made smaller than the valve hole of the check valve 6 (11). By simply installing the check valve 21, the pump unit 1 is disposed on the secondary side of the booster pump 8 and the reverse flow regulation (primary side) from the water supply side to the water distribution main side caused by the check valve 21. The reverse flow control from the water supply side to the water distribution main side (secondary side) provided by the check valve 6 is given, and when the flow of tap water stops, the backflow of tap water from the difference in pressure reduction effect Measures appropriate to regulations are taken. That is, when the circulation of tap water is lost, the secondary check valves 6 and 11 are closed after the primary check valve 21 is closed. A pressure gradient is generated in which the pressure on the side of the water distribution pipe becomes higher.

  The discharge mechanism 25 is provided with a drain port 26 (corresponding to the drain port portion of the present application) on the secondary side of the check valve 21, for example, on the secondary side, and the drain port 26 is opened by a differential pressure type on-off valve. The structure to be used is used. For example, a diaphragm type differential pressure on / off valve 28 is used as a differential pressure type on / off valve. In this differential pressure on-off valve 28, for example, a valve body 30 for opening and closing the drain port 26 is disposed at the drain port 26, and a valve opening direction extending in the middle of a valve rod 31 capable of reciprocating displacement extending from the valve body 30 is provided. A body for driving the valve body 30 by the displacement of the diaphragm 35 by attaching the spring member 32 for biasing to the diaphragm 35 and attaching the end of the valve rod 31 to the diaphragm portion, specifically, the diaphragm 35 for partitioning the diaphragm chamber 34. A structure having a portion 36 and a pressure introducing portion 37 for introducing the pressure on the primary side and the secondary side sandwiching the check valve 21 into each space partitioned by the diaphragm 35 is used. Specifically, the pressure introducing portion 37 includes a communication pipe portion 39a that communicates between the end side chamber space 35a partitioned by the diaphragm 35 and the primary piping portion of the check valve 21, and the remaining diaphragm 33 on the opposite side. A structure using the chamber space 35b partitioned by the second and the secondary side of the check valve 21, more specifically, a communication pipe part 39b communicating the pipe part on the secondary side from the drain port 26 is used. Thus, when the differential pressure between the primary side and the secondary side across the check valve 21 disappears (when the secondary side has the same pressure as the primary side), the valve body 30 is moved to the open side, and the drain 26 Is open. Such a double restriction structure and a differential pressure type drainage structure provide the pump unit 1 with the same function as a conventional decompression type backflow prevention device.

  That is, for example, when there is no demand for tap water and the tap water does not flow from the tap water distribution main to the water supply side (when pumping by the booster pump 8 or pumping through the bypass 12 is not performed) ) After the check valve 21 on the primary side is closed, the check valve 6 (21) closes the check valve 6 (check valve 11) on the secondary side, and the tap water is moved to the tap water distribution main. Prevent backflow. In the differential pressure on / off valve 28, the pressure state in the pipe caused by the pressure reducing effect of the check valve 11, that is, the pressure in the chamber space 35b (secondary pressure) is smaller than the pressure in the chamber space 35a (primary pressure). The drain port 26 is closed using the pressure difference (differential pressure).

  At this time, for example, foreign matter (for example, sand) is sandwiched between the valve body 21a and the valve seat 21b of the check valve 21 on the primary side, and water leakage occurs through the gap between the valve body 21a and the valve seat 21b. (When an abnormality occurs).

  Then, the pressure on the secondary side of the check valve 21 increases due to water leakage of the check valve 21. When the pressure on the secondary side becomes equal to the pressure on the primary side of the check valve 21, specifically, the same pressure, in the diaphragm portion, the pressure difference between the chamber space 35 a and the chamber space 35 b, that is, the differential pressure Disappears. Then, the valve body 30 of the on-off valve 27 is driven to the open side by the urging force of the spring member 33 to open the discharge port 26. Thereby, the water leakage is discharged to the outside from the discharge port 26, and the backflow depending on the check valve 6 on the secondary side is prevented. Of course, the discharge from the discharge port 26 is monitored by a sensor (not shown) at any time. When the discharge starts, the operator is notified of the abnormality.

  When the secondary check valve 6 (or the check valve 11) malfunctions, there is no problem because the backflow prevention function of the primary check valve 21 is firmly maintained.

  In this way, in the backflow prevention device 20, the check valve 6 arranged on the discharge side of the pump unit 1, that is, the discharge side of the booster pump 8 also serves as the secondary check valve portion of the conventional decompression backflow prevention device. Since the periphery including the pressure boosting pump 8 also serves as an intermediate chamber of the conventional decompression type backflow prevention device, the backflow from the water supply side to the water distribution main side can be performed only by the primary check valve 21 and the discharge mechanism 25. It can be prevented by a heavy structure, or the discharge of water leakage when the check valve 21 is abnormal (primary side) can be performed.

  That is, the backflow prevention device 20 is compact because it only adds the primary check valve 21 and the discharge mechanism 25 that drains the leaked water to the outside.

  By making the backflow prevention device 20 compact, the device 20 can occupy less area, and accordingly, the degree of freedom of installation of the pressure-increasing water supply device is increased, and the pressure-increasing water supply device can be easily installed (installability). Improvement).

  FIG. 2 shows a second embodiment of the present invention.

  In the present embodiment, the backflow prevention device 20 can be accommodated in the cabinet 2 constituting the pump unit 1 by utilizing the fact that the backflow prevention device 20 becomes compact. That is, in the cabinet 2 of the pump unit 1, since the booster pump 8 is disposed in a limited space, there is little space available. For this reason, a device having a considerably large outer shape such as a conventional decompression type backflow prevention device cannot be incorporated in the cabinet 2 together with the pressure increasing pump 8. However, when the backflow prevention device 20 becomes compact as described above, it is possible to incorporate the backflow prevention device 20 into the cabinet 2 together with the pressure increasing pump 8 that has been considered difficult.

  FIG. 3 shows a third embodiment of the present invention.

  In this embodiment, an electronically controlled differential pressure on / off valve 40 is used as the differential pressure on / off valve. The differential pressure on / off valve 40 is provided with, for example, a normally closed electromagnetic on / off valve 41 at the discharge port 26, pressure sensors 42 a and 42 b for detecting the pressure on the primary side and the secondary side of the check valve 21, and a control unit 43. When the pressure on the secondary side of the check valve 21 is equal to, for example, the same as the pressure on the primary side, the solenoid on-off valve 41 is opened. It is made to operate. Even if it does in this way, there exists an effect similar to 1st Embodiment.

  FIG. 4 shows a fourth embodiment of the present invention.

  In this embodiment, even if one unit is maintained, the booster pump unit 3 is composed of a plurality of (for example, three) booster pumps 8 connected in parallel so that water supply can be continued if the other unit is operated. Is. In this way, maintenance of the pump unit 1 can be performed without water interruption.

  2 to 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The present invention is not limited to the first to fourth embodiments described above, and various modifications may be made without departing from the spirit of the present invention.

Schematic which shows the backflow prevention structure which concerns on the 1st Embodiment of this invention with a pressure increase water supply apparatus. Schematic which shows the backflow prevention structure which concerns on the 2nd Embodiment of this invention. Schematic which shows the backflow prevention structure which concerns on the 3rd Embodiment of this invention. Schematic which shows the backflow prevention structure which concerns on the 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Pump unit, 2 ... Cabinet, 3 ... Booster pump part, 6 ... Check valve, 8 ... Booster pump, 20 ... Backflow prevention device, 21 ... Check valve (primary check valve), 25 ... Discharge Mechanism (discharge means), 26 ... drainage port (drainage port part), 28 ... diaphragm type differential pressure on-off valve.

Claims (4)

Regulates the backflow from the water supply side to the water distribution main side to a pump unit that has a check valve on the discharge side and has a pressure-intensifying pump that can pressurize water from the water distribution main and pump it to the water supply side. A backflow prevention structure for a pressure increasing water supply device configured by providing a backflow prevention device,
The backflow prevention device is provided on the suction side of the booster pump unit, and the check valve on the discharge side of the booster pump unit is diverted to the secondary side backflow regulation, so that the backflow from the water supply side to the water distribution main side A primary-side check valve for preventing primary-side backflow that has a greater pressure reducing effect than the check valve,
A discharge means for discharging water from the secondary side of the primary check valve when the pressure on the primary side and the pressure on the secondary side across the primary check valve are equal to each other. A structure for preventing backflow of a pressurized water supply apparatus, characterized by being configured as follows. The discharging means is
A drain port provided on the secondary side of the primary check valve;
A diaphragm type that is provided in the drain port portion, applies a primary side pressure and a secondary side pressure to the both sides of the diaphragm, and opens the drain port portion when the differential pressure between the primary side pressure and the secondary side pressure disappears. The backflow prevention structure of the pressure-increasing water supply device according to claim 1, comprising: a differential pressure on-off valve.   The backflow prevention structure of the pressure increase water supply apparatus according to claim 1, wherein the primary check valve and the drainage means are incorporated in the pump unit.   The backflow prevention structure of the booster water supply apparatus according to claim 1, wherein the booster pump unit includes a plurality of booster pumps connected in parallel.

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