TWI542380B - Vacuum wet sprinkler equipment - Google Patents

Description

Negative pressure wet sprinkler

The present invention relates to a negative pressure wet sprinkler that can obtain a predetermined monitoring pressure even on a low floor.

In recent years, negative pressure wet pre-operated sprinklers have been installed in several building parts. The negative pressure wet type pre-sprinkling sprinkler system has the following functions: the water supply head is prevented from being damaged by the secondary side piping of the pre-action valve being filled with water and the secondary side piping is normally negatively pressurized. When the situation is wrong, the water is accidentally released, and the water is quickly released in the event of a fire.

Fig. 5 and Fig. 6 are schematic explanatory views showing an example of the above-described conventional negative pressure wet type prepreg sprinkler apparatus.

5 and 6, the negative pressure wet pre-type sprinkler apparatus 101 includes a sprinkler head 102 that is provided on each floor according to an installation reference, and a water supply pipe 105 that includes a main fire water pipe. The primary side pipe 103 and the secondary side pipe 104 for guiding the fire water to the sprinkler head 102 of each floor; the negative pressure wet type pre-action valve 106 is provided between the primary side pipe 103 and the secondary side pipe 104; The water supply device 108 sucks the water in the water storage tank 107 and pressurizes it into the primary side pipe 103 of the water supply pipe 105. The fire sensor 109 detects a fire earlier than the sprinkler head 102 and outputs a fire signal; the control unit 110, which controls the opening and closing of the pressurized water supply device 108 and the negative pressure wet pre-action valve 106 based on the fire signal from the fire sensor 109; and the negative pressure state securing means 111 for maintaining the negative side of the secondary side pipe 104 at a negative Pressure state.

If further detailed, the sprinkler heads 102 are each independently operated by the author.

The water supply pipe 105 connects the primary pipe 103 connected to the pressurized water supply device 108, the secondary pipe 104 connected to each sprinkler 102, and the primary pipe 103 to the secondary pipe by the negative pressure wet pre-action valve 106. The side pipes 104 communicate with each other and guide the fire water from the above-described pressurized water supply device 108.

The fire sensor 109 is provided on the same floor as the sprinkler head 102, and detects a fire earlier than the sprinkler head 102 and outputs a fire signal.

The negative pressure state securing means 111 connects one end side of the suction branch pipe 112a to the main branch pipe 104a of the secondary side pipe 104 of each floor, and connects the other end side of the suction branch pipe 112a to the drain pipe 113. Then, one end of the drain pipe 113 is communicated with the vacuum pump 115 via the gas-water separation device 114 and the main suction pipe 112, and the other end of the drain pipe 113 is opened in the water of the water storage tank 107, and the gas-water separation device 114 is set. The vacuum switch 116 and the solenoid valve 117 are disposed on the suction branch pipe 112a in the uppermost portion of the suction branch pipe 112a, and the side of the branch pipe 104a is autonomously disposed. The interior is maintained in a negative pressure state.

Further, an end test device 118 is provided at the end of the secondary side pipe 104.

Further, the fire sensor 109 is connected to the disaster prevention signal receiving disk 120 by a signal line (not shown). Further, the disaster prevention signal receiving disk 120 is connected to the control unit 110 by a signal line (not shown). When the fire signal detected by the fire sensor 109 is received by the disaster prevention signal receiving disk 120 via a signal line (not shown), the signal is received by the disaster prevention signal receiving disk 120 in addition to the predetermined signal receiving process. A signal line (not shown) is sent to the control unit 110. The control unit 110 is connected to the negative pressure wet pre-action valve 106 by a signal line (not shown).

Furthermore, the symbols of the valves indicated in the figures in the drawings indicate that the valve is in a closed state in the case of full blackout, and that the valve is in an open state in the case of not being completely blackened.

In the negative pressure wet pre-type sprinkler system 101, in the normal state, the primary side pipe 103 is filled with water in a pressurized state, and the secondary side pipe 104 is filled with water in a negative pressure state.

The vacuum switch 116 is connected to the control unit 110 via a signal line (not shown), and the control unit 110 is connected to the electromagnetic valve 117 via a signal line (not shown). When the vacuum switch 116 detects a pressure rise, the detection signal is transmitted to the control unit 110. The control unit 110 opens the electromagnetic valve 117 based on the signal.

[Action during fire]

In the event of a fire, the fire sensor 109 directly above or near the fire generating portion detects a fire and generates a fire signal. This fire signal is sent to the control unit 110 via the disaster prevention signal receiving tray 120. The control unit 110 opens the negative pressure wet pre-action valve 106 and operates the pressurized water supply device 108. Thereby, the fire-fighting water is pressure-fed to the sprinkler head 102 via the primary side pipe 103, the negative pressure wet pre-action valve 106, and the secondary side pipe 104, and the secondary side pipe 104 is changed from the negative pressure state to the pressurized state. The sprinkler head 102 sprays fire water. Thereby, fire prevention can be minimized.

[Action when water is accidentally released]

When the sprinkler head 102 is broken, air flows into the opening of the sprinkler head 102, and the pressure in the secondary side pipe 104 rises. Then, when the vacuum switch 116 detects this, the detection signal is sent to the control unit 110. The control unit 110 opens the electromagnetic valve 117 based on the detection signal. Then, the inside of the secondary side pipe 104 connected to the faulty sprinkler head 102 is continuously sucked by the operation of the vacuum pump 115. Thereby, it is possible to prevent the water sprinkler 102 from discharging water.

Although the water separated from the air by the gas-water separator 114 is discharged to the water storage tank 107 via the drain pipe 113, since the inside of the drain pipe 113 is in a negative pressure state, as shown in FIG. 4, the water is sucked to correspond to the vacuum pump. The height of the suction force of 115, the water exceeding this height will be accumulated in the drain pipe 113. At this time, a head pressure corresponding to the height is generated in each portion of the drain pipe 113.

For example, when the suction pressure of the vacuum pump 115 is -0.08 [MPa], the water is sucked to a height of about 8 [m] from the water surface of the water storage tank. Furthermore, the WL system represents the water level. In this state, when the vacuum switch 116 is disposed at a position lower than the water level WL of the drain pipe 113 by 5 [m], a head pressure of 5 [m] is generated in the vicinity of the vacuum switch 116. Even if the monitoring pressure of the vacuum switch 116 disposed on the floor higher than the water level WL in the piping is -0.08 [MPa], the monitoring pressure is also applied to the vacuum switch 116 disposed on the lower floor of the water level in the drain pipe 113. Only -0.03 [MPa].

Further, in the water supply pipe 105 for a building, there is a beam of a building or a pipe of an air conditioner, and the like, in particular, the secondary pipe 104 must be bent in a U shape on the lower side in order to bypass this. In one case, air is accumulated in the curved portion, whereby the head pressure is generated, so that the monitoring pressure near the sprinkler head 102 at the end of the secondary side pipe 104 is further increased.

As a result, the sprinkler head 102 may be damaged or malfunctioned, or the piping or the like may be damaged, and the sprinkler head 102 may not be prevented from being mistakenly discharged. For the above reasons, when the vacuum switch 116 is placed on the floor lower than the water level of the water in the drain pipe 113, it is difficult to arrange the negative pressure wet pre-type sprinkler.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a negative pressure wet pre-spraying apparatus that eliminates the disadvantages of the prior art described above, even at low floors, with a given monitoring pressure.

In order to achieve the above object, the invention of claim 1 is a negative pressure wet sprinkler apparatus comprising: a sprinkler head; a water supply pipe comprising a main fire water pipe, that is, a primary side pipe, and guiding the fire water a secondary side pipe to the sprinkler head; a valve portion provided between the primary side pipe and the secondary side pipe; and a pressurized water supply device that sucks water in the water storage tank and pressurizes it into the primary side of the water supply pipe a fire detector that detects a fire and outputs a fire signal earlier than the sprinkler head; the control unit controls the opening and closing of the pressurized water supply device and the valve portion according to a fire signal from the fire sensor; and a means for ensuring a negative pressure state One end side of the suction branch pipe is connected to the rising portion of the secondary side pipe, and the other end side of the suction branch pipe is connected to the drain pipe so that one end of the drain pipe and the lower portion of the gas-water separation device The upper part of the gas-water separation device is connected to the vacuum pump via the main suction pipe, and the vacuum switch and the electromagnetic valve are sequentially arranged on the rising branch side of the secondary side pipe. The negative pressure wet sprinkler system maintains the state of the water in the secondary side pipe by the negative pressure state ensuring means, and is maintained in the state, which is provided in the suction The drain pipe of the lower side of the branch pipe is provided with a water level detector, and a drain pump for discharging water in the drain pipe and a means for stopping/stopping the drain pump according to a signal from the water level detector are disposed below the water level detector. .

Further, in the above configuration, the drain pipe is branched on the upper side of the drain pump, and a check valve is provided at the end of the branch drain pipe.

In order to achieve the above object, the invention of claim 3 is a negative pressure wet sprinkler apparatus characterized by comprising: a sprinkler head; a water supply pipe comprising a main fire water pipe, that is, a primary side pipe, and a fire protection The water is guided to the secondary side pipe of the sprinkler head; the valve portion is disposed between the primary side pipe and the secondary side pipe; and the pressurized water supply device sucks the water in the water storage tank and pressurizes it into the water supply pipe. a primary side pipe; a fire sensor that detects a fire and outputs a fire signal earlier than the sprinkler head; and a control unit that controls opening and closing of the pressurized water supply device and the valve portion according to a fire signal from the fire sensor; and a negative pressure state And a water level securing means for connecting one end side of the suction branch pipe to the rising portion of the secondary side pipe, and connecting the other end side of the suction branch pipe to the drain pipe, and standing from the secondary side pipe The vacuum switch and the electromagnetic valve are sequentially disposed on the suction branch pipe, and the configuration includes: providing moisture to separate water from air at a position lower than a position of the suction branch pipe. a water level detector for detecting an internal water level; the other end side of the drain pipe is connected to a lower side of the gas water separation device; a vacuum pump for sucking air is provided; and the gas water separation device is provided The upper portion is in communication with the vacuum pump via a suction pipe; a drain pump for discharging water is disposed at a lower portion of the gas-water separation device; and a means for operating/stopping the drain pump based on a signal from the water level detector.

Further, in the above configuration, the drain pipe connected to the lower portion of the gas-water separator is branched, and the check valve is provided at the end of the branch drain pipe.

In the present invention, since the water is not accumulated in the portion of the suction branch pipe at the bottom of the drain pipe, the monitoring pressure and the high floor of the negative pressure wet pre-spraying device disposed at the bottom layer can be On the other hand, it is possible to stably obtain the negative pressure wet type pre-sprinkling sprinkler system regardless of the floor, that is, the effect of preventing accidental water spray when the sprinkling head is malfunctioned or the piping is broken.

Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

In Fig. 1, the component symbol 1 is a negative pressure wet pre-action sprinkler. The negative pressure wet type pre-operating sprinkling apparatus 1 has a sprinkler head 2 which is provided in each layer according to a setting reference, a water supply pipe 5 which is provided by the primary side pipe 3 of the main fire water pipe, and guides the fire water to each The secondary side pipe 4 of the floor sprinkler head 2 is configured; the negative pressure wet type pre-action valve 6 is provided between the primary side pipe 3 and the secondary side pipe 4; and the pressurized water supply device 8 sucks the water storage tank 7 The inside water is pressurized and sent to the primary side pipe 3 of the water supply pipe 5; the fire sensor 9 detects a fire earlier than the sprinkler head 2 and outputs a fire signal; and the control unit 10 is based on the fire sensor 9 The opening and closing of the pressurized water supply device 8 and the negative pressure wet pre-action valve 6 are controlled by the fire signal, and the negative pressure state securing means 11 maintains the inside of the secondary side pipe 4 in a negative pressure state.

If further explained, the sprinkler heads 2 operate independently of each other.

The water supply pipe 5 is composed of a primary pipe 3 connected to the pressurized water supply device 8 and a secondary pipe 4 connected to each of the sprinklers 2, and the primary pipe 3 is provided by the negative pressure wet pre-action valve 6. The communication with the secondary side pipe 4 allows the fire water from the pressurized water supply device 8 to be guided.

The fire sensor 9 is a sensor that is disposed on the same floor as the sprinkler head 2 and detects a fire earlier than the sprinkler head 2 and outputs a fire signal.

The negative pressure state securing means 11 connects one end side of the suction branch pipe 12a to the main branch pipe 4a of the secondary side pipe 4 of each floor, and connects the other end side of the suction branch pipe 12a to the drain pipe 13, One end of the drain pipe 13 is communicated with the lower portion of the gas-water separation device 14, and the upper portion of the gas-water separation device 14 is communicated with the vacuum pump 15 via the main suction pipe 12, and a check valve 16 is provided at the end of the drain pipe 13 to prevent the water storage tank The water of 7 does not flow into the drain pipe 13 side, and the water level detector 17 is disposed on the lower side of the lowermost suction branch pipe 12a, and the water in the drain pipe 13 is discharged below the water level detector 17. The drain pump 18 extends the discharge pipe 13a of the drain pump 18 to the water in the water tank 7, and the check valve 16 is provided at the end 13b of the drain pipe 13 so that the water of the water storage tank 7 does not flow into the drain pipe 13 side, and the autonomous operation The side of the branch pipe 4a is formed by sequentially arranging the vacuum switch 20 and the electromagnetic valve 21 in the suction branch pipe 12a, and the inside of the secondary pipe 4 is maintained in a negative pressure state by the vacuum pump 15.

Further, an end test device 22 is provided at the end of the secondary side pipe 4.

Further, the fire sensor 9 is connected to the disaster prevention signal receiving disk 25 by a signal line (not shown). Further, the disaster prevention signal receiving disk 25 is connected to the control unit 10 by a signal line (not shown). When the fire signal detected by the fire sensor 9 is received by the disaster prevention signal receiving disk 25 via a signal line (not shown), the signal is received by the disaster prevention signal receiving disk 25 in addition to the predetermined signal receiving process. A signal line (not shown) is transmitted to the control unit 10. The control unit 10 is connected to the negative pressure wet pre-action valve 6 via a signal line (not shown).

Furthermore, the symbols of the valves indicated in the figures in the drawings indicate that the valve is in a closed state in the case of full blackout, and that the valve is in an open state in the case of not being completely blackened. The following are the same.

In the vacuum-type pre-operating sprinkler system 1, in the normal state, the primary side pipe 3 is filled with water in a pressurized state, and the secondary side pipe 4 is filled with water in a negative pressure state.

The vacuum switch 20 is connected to the control unit 10 via a signal line (not shown), and the control unit 10 is connected to the electromagnetic valve 21 via a signal line (not shown). When the vacuum switch 20 detects a pressure rise, the detection signal is transmitted to the control unit 10. The control unit 10 opens the electromagnetic valve 21 based on the signal. Further, the secondary pipe 4 is in communication with the vacuum pump 15 via the suction branch pipe 12a, the drain pipe 13, the gas-water separator 14 and the main suction pipe 12, and the secondary pipe 4 can be operated by the operation of the vacuum pump 15. The inside is maintained in a negative pressure state.

Further, in the present embodiment, as shown in Fig. 1, a drain detector 13 located below the suction branch pipe 12a (symbol P) of the lowermost layer is provided with a water level detector 17, which is disposed below the water level detector 17. The drain pump 18 that discharges the water in the drain pipe 13 can extend the discharge pipe 13a of the drain pump 18 to the water in the water tank 7, and the check valve 16 is provided at the end 13b of the drain pipe 13, so that the water storage tank 7 is provided. The water does not flow into the drain pipe 13 side, and the drain pump 18 is operated when there is water on the upper side of the water level detector 17, and the drain pump is made when the water level in the drain pipe 13 is lowered from the water level detector 17 to a predetermined position. 18 stops.

When suction is performed by the vacuum pump 15, and the secondary piping 4 becomes a negative pressure, excess water flows into the drain pipe 13 and the water level of the drain pipe 13 rises.

When the water level detector 17 detects that the water level in the drain pipe 13 has reached a predetermined water level or more, the drain pump 18 is operated to discharge the water in the drain pipe 13.

When the water level detector 17 detects that the water level in the drain pipe 13 has sufficiently decreased, the drain pump 18 is stopped. Further, the drain pump 18 is a pump having a structure in which water does not flow in the direction of the drain pipe 13.

Since the check valve 16 is provided at the end 13b of the drain pipe 13, even if the vacuum pump 15 is operated, the water of the water storage tank 7 is not sucked.

Due to the above operation, the water level of the drain pipe 13 is lower than that of the lowermost suction branch pipe 12a (symbol P), so that even at the lowest level, it is not affected by the head pressure, and the pressure can be reduced in the same manner as the high floor.

According to the present embodiment, since the water is not stored on the lowermost suction branch pipe 12a (symbol P) in the drain pipe 13, the negative pressure wet pre-sprinkling water can be placed on the bottommost layer. The monitoring pressure of the equipment is equivalent to that of the high floor, and the negative pressure wet pre-sprinkling sprinkler can be stably obtained regardless of the floor, that is, the effect of preventing accidental water spray when the sprinkling head is malfunctioning or the piping is broken.

Fig. 2 is a schematic view showing a second embodiment of the negative pressure wet type prepreg sprinkler apparatus of the present invention, and the same components as those of the first embodiment shown in Fig. 1 are denoted by the same reference numerals, and the same configuration is omitted. In the description of the section, only the features are explained.

In the second embodiment, as shown in Fig. 2, the gas-water separator disposed at the uppermost portion of the drain pipe 13 is abolished. Further, the uppermost portion of the drain pipe 13 is directly connected to the suction pipe branch pipe 12a of the topmost layer.

In the second embodiment, the gas-water separation tank 30 is disposed below the lowermost suction branch pipe 12a (symbol P), and the lower side of the gas-water separation tank 30 is passed through the duct 32 provided with the valve 31 ( The branch pipe 32) is in communication with the drain pipe 13, a water level detector 33 is disposed inside the gas-water separation tank 30, and a vacuum pump 35 for sucking air is disposed, so that the upper portion of the gas-water separation tank 30 is connected to the vacuum pump via the suction pipe 36. 35 is connected, and a drain pump 37 for discharging water is provided below the gas-water separation tank 30, so that the discharge pipe 13a of the drain pump 37 is extended to the water of the water tank 7, and the check valve 38 is provided at the end 13b of the drain pipe 13 The water in the water storage tank 7 is prevented from flowing into the drain pipe 13 side, and the drain pump 37 is operated/stopped based on the signal from the water level detector 33.

Thereby, a negative pressure state and a water level securing means which can ensure the negative pressure and ensure the water level to be fixed can be constructed. Further, the drain pump 37 is a pump having a structure in which water does not flow in the direction of the gas-water separation tank 30 and the drain pipe 13.

That is, when the water flows into the gas-water separation tank 30 and the water level detector 33 detects that the water has reached the predetermined upper position, the drain pump 37 is operated, and when the water level detector 33 detects that the water level in the gas-water separation tank 30 has fallen to a predetermined lower position. The operation of the drain pump 37 is stopped.

Thereby, since the negative pressure can be ensured even at the lowest layer P, and the water level can be secured, the monitoring pressure of the negative pressure wet pre-spraying equipment installed at the bottom layer can be made comparable to that of the high floor. The function of the negative pressure wet type pre-sprinkling sprinkler device can be stably obtained regardless of the floor, that is, the effect of preventing accidental water spray when the sprinkler head is malfunctioned or the pipe is broken.

Further, in the first embodiment, as shown in Fig. 1, the check valve 16 is provided at the end 13b of the drain pipe 13, and in the second embodiment, the drain pipe is configured as shown in Fig. 2. The check valve 38 is provided at the end 13b of the 13th. However, when the drainage capacity of the drain pump (18, 37) is large, the end 13b of the drain pipe 13 and the non-return may be omitted as shown in FIG. 3 or FIG. The valve 16 (38), as shown in Fig. 3, directly connects the drain pipe 13 to the suction port of the drain pump 18, or directly connects the drain pipe 13 to the duct 32 of the gas-water separation tank 30 as shown in Fig. 4 . Moreover, even in the case where water is discharged to the drain pipe 13 due to breakage of the sprinkler head or other unpredictable events, it is known that the amount of water discharged to the drain pipe 13 in advance on the fire extinguishing device is small. When the drainage capacity of the conventional drain pump can be sufficiently drained, it can be set as a direct connection as shown in Fig. 3 or Fig. 4.

1. . . Negative pressure wet pre-action sprinkler

2. . . Sprinkler head

3. . . Primary side piping

4. . . Secondary piping

4a. . . Stand up branch

5. . . Water supply piping

6. . . Negative pressure wet pre-action valve

7. . . Water storage tank

8. . . Pressurized water supply device

9. . . Fire sensor

10. . . Control department

11. . . Negative pressure state assurance means

12. . . Main suction pipe

12a. . . Suction branch pipe

13. . . Drain pipe

13a. . . Spit tube

13b. . . End

14. . . Gas water separation device

15. . . Vacuum pump

16. . . Check valve

17. . . Water level detector

18. . . Drain pump

19. . . End test valve

20. . . Vacuum switch

twenty one. . . The electromagnetic valve

twenty two. . . End test device

25. . . Disaster prevention signal receiving tray

30. . . Gas water separation tank

31. . . valve

32. . . Branch pipe

33. . . Water level detector

35. . . Vacuum pump

36. . . Suction tube

37. . . Drain pump

38. . . Check valve

101. . . Negative pressure wet pre-action sprinkler

102. . . Sprinkler head

103. . . Primary side piping

104. . . Secondary piping

104a. . . Stand up branch

105. . . Water supply piping

106. . . Negative pressure wet pre-action valve

107. . . Water storage tank

108. . . Pressurized water supply device

109. . . Fire sensor

110. . . Control department

111. . . Negative pressure state assurance means

112. . . Main suction pipe

112a. . . Suction branch pipe

113. . . Drain pipe

114. . . Gas water separation device

115. . . Vacuum pump

116. . . Vacuum switch

117. . . The electromagnetic valve

118. . . End test device

120. . . Disaster prevention signal receiving tray

WL. . . Water level

P. . . Lowest level

Fig. 1 is a schematic explanatory view showing a first embodiment of the negative pressure wet sprinkler apparatus of the present invention.

Fig. 2 is a schematic explanatory view showing a second embodiment of the negative pressure wet sprinkler apparatus of the present invention.

Fig. 3 is a schematic explanatory view showing another embodiment of the negative pressure wet sprinkler apparatus of the present invention.

Fig. 4 is a schematic explanatory view showing another embodiment of the negative pressure wet sprinkler apparatus of the present invention.

Fig. 5 is a schematic explanatory view of a conventional negative pressure wet type pre-sprinkling device.

Fig. 6 is a view for explaining the state of the vacuum pump operation in the conventional negative pressure wet type prepreg sprinkler apparatus.

1. . . Negative pressure wet pre-action sprinkler

2. . . Sprinkler head

3. . . Primary side piping

4. . . Secondary piping

4a. . . Main branch pipe

5. . . Water supply piping

6. . . Negative pressure wet pre-action valve

7. . . Water storage tank

8. . . Pressurized water supply device

9. . . Fire sensor

10. . . Control department

11. . . Negative pressure state assurance means

12. . . Main suction pipe

12a. . . Suction branch pipe

13. . . Drain pipe

13a. . . Spit tube

13b. . . End

14. . . Gas water separation device

15. . . Vacuum pump

16. . . Check valve

17. . . Water level detector

18. . . Drain pump

20. . . Vacuum switch

twenty one. . . The electromagnetic valve

twenty two. . . End test device

25. . . Disaster prevention signal receiving tray

P. . . Lowest level

Claims (3)

A negative pressure wet sprinkler device comprising: a sprinkler head; a water supply pipe comprising a primary side pipe as a main fire water pipe, and a secondary side pipe guiding the fire water to the sprinkler head; the valve part Provided between the primary side pipe and the secondary side pipe; the pressurized water supply device sucks the water in the water storage tank and pressurizes it to be sent to the primary side pipe of the water supply pipe; the fire sensor is more sprinkler head The fire is detected earlier and the fire signal is output; the control unit controls the opening and closing of the pressurized water supply device and the valve portion based on the fire signal from the fire sensor; and the negative pressure state ensuring means is configured to connect the suction branch pipe One end side is connected to the rising portion of the secondary side pipe, and the other end side of the suction branch pipe is communicated with the drain pipe, so that one end of the drain pipe communicates with the lower portion of the gas water separating device, so that the gas water separating device The upper portion communicates with the vacuum pump via the main suction pipe, and the vacuum switch and the electromagnetic valve are sequentially disposed on the suction branch pipe from the rising portion side of the secondary side pipe; and the negative pressure wet sprinkler system is borrowed The negative pressure state ensuring means causes the water in the secondary side pipe to be in a negative pressure state and maintains this state; such a negative pressure wet type sprinkling device is characterized in that the drain pipe is located at a lower position than the suction branch pipe Setting a water level detector; a drainage pump capable of discharging water in the drain pipe is disposed below the water level detector; and the drain pump is operated when the water level detector detects that the water level in the drain pipe has reached a predetermined water level. The water level detector detects the means by which the drain pump is stopped when the water level in the drain pipe has been lowered to a predetermined position. The negative pressure wet sprinkler apparatus of claim 1, wherein the drain pipe is branched on the upper side of the drain pump, and a check valve is disposed at an end of the branch drain pipe. A negative pressure wet sprinkler device characterized by comprising: a sprinkler head; a water supply pipe comprising a primary side pipe as a main fire water pipe and a secondary side pipe guiding the fire water to the sprinkler head; a portion provided between the primary side pipe and the secondary side pipe; the pressurized water supply device sucks the water in the water storage tank and pressurizes it to be sent to the primary side pipe of the water supply pipe; the fire sensor, The fire detector detects the fire and outputs a fire signal earlier than the sprinkler head; the control unit controls the opening and closing of the pressurized water supply device and the valve portion according to the fire signal from the fire sensor; and the negative pressure state and the water level ensuring means, including a configuration in which one end side of the suction branch pipe is connected to the rising portion of the secondary pipe, and the other end side of the suction branch pipe is connected to the drain pipe, and is twice a vacuum switch and a solenoid valve are sequentially disposed on the suction branch pipe on the rising portion side of the side pipe; and a gas-water separation device that separates water from air is disposed at a position lower than a position of the suction branch pipe; The water separating device is provided with a water level detector for detecting the water level inside thereof; the other end side of the drain pipe is connected with the lower side of the gas water separating device; a vacuum pump for sucking air is provided; and the upper portion of the gas water separating device is passed through the suction pipe a vacuum pump is provided; a drain pump for discharging water is disposed at a lower portion of the gas water separating device; and a means for running/stopping the drain pump according to a signal from the water level detector; and a drain pipe connected to a lower portion of the gas water separating device Branching, and a check valve is disposed at the end of the branch drain.