Dry sprinkler system and method for manufacturing the same

Abstract

We provide a fire extinguishing system that does not discharge water even if a sprinkler head malfunctions. [Solution] The system comprises a secondary pipe 102 connected to a closed-type sprinkler head 103 and a negative pressure pump 204 connected to the secondary pipe 102. The negative pressure pump 204 has a first operating mode that maintains the secondary pipe 102 at a first vacuum level under normal conditions, and a second operating mode that maintains the secondary pipe 102 at a second vacuum level that is higher than the first vacuum level.

Description

Technical Field

[0001] This invention relates to dry sprinkler equipment and a method for manufacturing the same.

Background Art

[0002] Conventionally, dry sprinkler equipment is disclosed in, for example, Japanese Patent Application Laid-Open No. 2019-25237 (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional dry sprinkler equipment, there has been a problem that although there should be no water in the secondary piping (piping adjacent to the sprinkler head), water may be present in the secondary piping.

Means for Solving the Problems

[0005] The inventor of the present invention has earnestly studied the reason why water exists in the secondary piping of dry sprinkler equipment. As dry sprinkler equipment, there are those in which the air pressure in the secondary piping is atmospheric pressure, those in which it is pressurized, and those in which it is under negative pressure. In any case, there should be no water in the secondary piping in terms of design. However, in reality, there are examples where a non-negligible amount of water exists in the secondary piping. A valve exists at the connection between the secondary piping and the primary piping. If water leaks from this valve, water flows from the primary piping to the secondary piping and water exists in the secondary piping. However, even when there is no water leakage in this valve, water may exist in the secondary piping.

[0006] In this specification, "negative pressure" and "vacuum" refer to pressures lower than atmospheric pressure.

[0007] The inventors of the present invention have found that during trial runs conducted after the completion of a sprinkler system, water fills the secondary piping and remains in the secondary piping.

[0008] To solve this problem, we succeeded in removing the water from the secondary piping by reducing the pressure in the secondary piping, which caused the water inside to boil at room temperature.

[0009] A dry sprinkler system, based on this understanding, comprises piping connected to closed-type sprinkler heads and a vacuum device connected to the piping. The vacuum device has a first operating mode that maintains the piping at a first vacuum level under normal conditions, and a second operating mode that maintains the piping at a second vacuum level that is higher than the first vacuum level. "Normal conditions" refers to a normal state, meaning a state in which no fire has occurred.

[0010] In a dry sprinkler system configured in this way, the piping is set to the first operating mode during normal operation, and when water remains in the piping after the trial run, it is set to the second operating mode with high vacuum, which allows the water remaining in the piping after the trial run to be boiled at room temperature and removed.

[0011] A different type of dry sprinkler system includes piping connected to closed-type sprinkler heads and a connector that is connected to the piping and used for high-vacuuming after commissioning.

[0012] In a dry sprinkler system configured in this way, a connection is provided for high-vacuum evacuation after trial operation. By performing high-vacuum evacuation after trial operation, it becomes possible to evaporate any remaining water in the piping at room temperature.

[0013] Preferably, the piping is at atmospheric pressure under normal conditions or is pressurized.

[0014] A method for manufacturing a dry sprinkler system includes the steps of: attaching a closed-type sprinkler head to a pipe and performing a trial run in which water is filled into the pipe; and creating a vacuum in the pipe after the trial run and boiling the water inside the pipe at room temperature.

[0015] In a manufacturing method for a dry sprinkler system that incorporates such a process, the piping is evacuated after the trial run and the water inside the piping is boiled at room temperature, thereby removing any remaining water inside the piping after the trial run.

[0016] Preferably, the step of boiling the water in the pipe at room temperature is performed by maintaining a pressure inside the pipe that is 0.08 MPa or more lower than atmospheric pressure. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of a dry-type vacuum sprinkler system according to Embodiment 1. [Figure 2] This is a schematic diagram of a dry-type pressurized sprinkler system according to Embodiment 2. [Figure 3] This is a schematic diagram of a dry sprinkler system according to Embodiment 3. [Modes for carrying out the invention]

[0018] (Embodiment 1) (Sprinkler system configuration) Figure 1 is a schematic diagram of a sprinkler system according to Embodiment 1. As shown in Figure 1, the dry sprinkler system 1 is installed in building 10. Building 10 has a first section 11 which is the lower floor and a second section 12 which is the upper floor.

[0019] The water discharge system 100 includes a primary pipe 101, a secondary pipe 102 connected to the primary pipe 101, a sprinkler head 103 installed in the secondary pipe 102, a valve 105 installed at the boundary between the primary pipe 101 and the secondary pipe 102, and a water pump 106 for supplying water to the primary pipe 101.

[0020] The primary pipe 101 is filled with water. This water is pressurized by a water pump 106. Water is supplied to the water pump 106 from a fire extinguishing water tank (not shown). Water may be supplied to the water pump 106 from an elevated water tank on the top floor of the building 10.

[0021] The primary pipe 101 rises vertically from the water pump 106 to the top of the building 10 and branches at each floor. In this embodiment, a two-story building 10 is described, but the number of floors of the building 10 is not limited to two.

[0022] The water in the primary pipe 101 is stopped by a valve 105, and when the valve 105 opens, the water in the primary pipe 101 is sent to the secondary pipe 102. The opening and closing of the valve 105 are controlled by a computer 302.

[0023] The secondary pipe 102 is connected to the valve 105. The secondary pipe 102 is arranged in the second section 12. In this embodiment, an example where the valve 105 is arranged in the second section 12 is shown, but the valve 105 may be arranged in the first section 11.

[0024] The secondary pipe 102 is arranged on the ceiling of the second section 12. A plurality of sprinkler heads 103 are provided on the secondary pipe 102. The number of sprinkler heads 103 is determined by the size of the second section 12.

[0025] In this embodiment, an example where the sprinkler heads 103 are provided in the second section 12 is shown, but the secondary pipe 102 and the sprinkler heads 103 may be arranged in the first section 11.

[0026] The sprinkler head 103 is a closed-type sprinkler head with multiple holes for discharging water. The sprinkler head 103 has a heat-sensitive mechanism (fusible metal piece). Under normal conditions, the water-discharging holes and the primary piping 101 are shielded within the sprinkler head 103. When the heat-sensitive mechanism melts due to flames during a fire, the shield is released. The valve 105 opens, and water is discharged from the holes in the sprinkler head 103 via the primary piping 101 and secondary piping 102.

[0027] The negative pressure system 200 includes a negative pressure pipe 201 connected to the secondary piping 102, and a negative pressure pump 204 that creates a negative pressure inside the negative pressure pipe 201.

[0028] The negative pressure pump 204 is installed in the first section 11 to generate negative pressure. In this embodiment, the water pump 106 and the negative pressure pump 204 are installed in the same first section 11, but they may be installed in different sections. The negative pressure pump 204 can draw in air and water. If the negative pressure pump 204 draws in only air and not water, it is necessary to install a gas-water separator in the negative pressure piping 201 to prevent water from flowing into the negative pressure pump 204.

[0029] The negative pressure pump 204 has a first operating mode in which it maintains a steady state and creates a first vacuum level in the negative pressure piping 201, and a second operating mode in which it maintains a higher vacuum level than the first vacuum level. In addition to the negative pressure pump 204, an additional vacuum pump for high vacuum may be provided, so that only the negative pressure pump is driven in the steady state to achieve the first operating mode, and the additional vacuum pump is driven to achieve the second operating mode with a high vacuum.

[0030] The negative pressure piping 201, connected to the negative pressure pump 204, rises vertically from the negative pressure pump 204 to the top floor of building 10, and branches out on each floor. On each floor, the negative pressure piping 201 branches out, and negative pressure piping 201 is laid out in each room.

[0031] The detection system 300 includes a fire detector 301 and a computer 302. When a fire occurs in the second compartment 12, the fire detector 301 detects the heat or smoke. The computer 302 and the valve 105 are connected by a signal line 311. The computer 302 and the water pump 106 are connected by a signal line 312. The computer 302 and the vacuum pump 204 are connected by a signal line 313.

[0032] This sprinkler system may be a so-called pre-action type, where the computer 302 receives a signal from the fire detector 301 after the fire detector 301 detects a fire, and the computer 302 opens the valve 105 via the signal line 311. Even without fire detection, if air flows through the sprinkler head 103, the system may detect a change in air pressure in the secondary piping 102 and open the valve 105. In this case, it is not a pre-action type.

[0033] (Trial run of dry sprinkler system) After the dry sprinkler system 1 is manufactured, a trial run of the dry sprinkler system 1 is conducted. The trial run is broadly divided into a pressure test, in which water is filled into the secondary piping 102, and a water discharge test, in which water is actually discharged. First, the pressure test will be explained. In the pressure test, the valve 105 is opened in a non-fire state. This allows water from the water pump 106 to fill the secondary piping 102 via the primary piping 101. Then, the inside of the secondary piping 102 is pressurized using a pressurizing means (not shown) up to 1.5 times the maximum operating pressure of the water pump 106 (for example, 1.4 MPa) (2.1 MPa). The pressure test is completed after confirming that the secondary piping 102 is filled with water in this state. Next, the water discharge test will be explained. In the water discharge test, a test is conducted to see if a predetermined amount of water can be discharged from a test end valve (not shown) attached to the end of the secondary piping 102. In this test, it is confirmed whether water flows from the end test valve and whether a predetermined flow rate of water flows from the end test valve. One way to confirm the flow rate is to measure the water pressure at the end test valve. This completes the trial run. After the trial run is complete, open the end test valve and drain the water from the secondary piping 102.

[0034] (Processing of secondary piping 102 after trial operation) The negative pressure pump 204 is set to a second operating mode to create a high vacuum in the negative pressure piping 201. This also creates a high vacuum in the secondary piping 102. As a result, water in the secondary piping 102 evaporates even at room temperature.

[0035] The dry sprinkler system includes a secondary pipe 102 connected to a closed-type sprinkler head 103, and a negative pressure pump 204 connected to the secondary pipe 102 as a vacuum device.

[0036] The negative pressure pump 204 has a first operating mode that maintains the secondary piping 102 at a first vacuum level under normal conditions, and a second operating mode that maintains the secondary piping 102 at a second vacuum level that is higher than the first vacuum level. The vacuum system may consist of multiple negative pressure pumps, in which case the vacuum system has a first negative pressure pump that achieves the first vacuum level and a second negative pressure pump that achieves the second vacuum level. The first and second vacuum levels are at atmospheric pressure below atmospheric pressure, and the second vacuum level is at a lower pressure than the first vacuum level.

[0037] (Embodiment 2) Figure 2 is a schematic diagram of a dry-type pressurized sprinkler system according to Embodiment 2. In Figure 2, the secondary piping 1102 is under normal pressure, which is different from the dry-type sprinkler system according to Embodiment 1. A pressurizing system 1200 is provided for pressurizing the secondary piping 1102.

[0038] The pressurization system 1200 includes a compressor 1204 and piping 1201 connected to the compressor 1204. Piping 1201 is connected to secondary piping 1102 by a connection point 1202.

[0039] A branch pipe 1205 is provided as a connection point for creating negative pressure in the secondary piping 1102. A negative pressure pump 204 is connected to the branch pipe 1205. The branch pipe 1205 is connected to the secondary piping 1102 by a connection point 1206. The length of the branch pipe 1205 is not particularly limited. The branch pipe 1205 may also be a valve provided in the secondary piping 1102. The negative pressure pump 204 does not need to be provided at all times. It is sufficient for the negative pressure pump 204 to be present when creating negative pressure in the secondary piping 1102 after trial operation.

[0040] (Trial run of dry sprinkler system) After the dry sprinkler system 1 is manufactured, a trial run of the dry sprinkler system 1 is performed. During the test run, valve 105 is opened while there is no fire. This allows the test run to be conducted in the same manner as in Embodiment 1. After the test run is completed, the water in the secondary piping 1102 is drained from the end test valve.

[0041] (Processing of secondary piping 1102 after trial operation) The negative pressure pump 204 is set to operating mode to create a vacuum inside the branch pipe 1205. This also creates a high vacuum inside the secondary piping 1102. As a result, the water inside the secondary piping 1102 evaporates even at room temperature.

[0042] The dry sprinkler system 1 includes a secondary pipe 1102 connected to a closed-type sprinkler head 103, and a branch pipe 1205 connected to the secondary pipe 1102 and used for high-vacuuming after commissioning.

[0043] (Embodiment 3) Figure 3 is a schematic diagram of a dry sprinkler system according to Embodiment 3. It differs from the dry sprinkler systems according to Embodiments 1 and 2 in that, as shown in Figure 2, the pressure inside the secondary piping 1102 is atmospheric pressure under normal conditions.

[0044] A branch pipe 1205 is provided to create negative pressure in the secondary piping 1102. A negative pressure pump 204 is connected to the branch pipe 1205. The branch pipe 1205 is connected to the secondary piping 1102 by a connection point 1206. The length of the branch pipe 1205 is not particularly limited. The branch pipe 1205 may also be a valve provided in the secondary piping 1102. The negative pressure pump 204 does not need to be provided at all times. It is sufficient for the negative pressure pump 204 to be present when creating negative pressure in the secondary piping 1102 after trial operation.

[0045] (Trial run of dry sprinkler system) After the dry sprinkler system 1 is manufactured, a trial run of the dry sprinkler system 1 is performed. During the trial run, valve 105 is opened in a non-fire state. This allows the trial run to be performed in the same manner as in Embodiment 1. After the trial run is completed, the water in the secondary piping 1102 is drained from the end test valve.

[0046] (Processing of secondary piping 1102 after trial operation) The negative pressure pump 204 is set to operating mode to create a vacuum inside the branch pipe 1205. This also creates a high vacuum inside the secondary piping 1102. As a result, the water inside the secondary piping 1102 evaporates even at room temperature.

[0047] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described above, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of Symbols]

[0048] 1 Dry sprinkler system, 10 Building, 11 First section, 12 Second section, 100 Vacuum sprinkler system: 101 primary piping, 102, 1102 secondary piping, 103 sprinkler heads, 105, 209, 219 valves, 106 water pump, 200 vacuum system: 201 vacuum piping, 202, 212, 1202, 1206 connection points, 203 intake, 204 vacuum pump, 205 connecting pipe, 300 detection system: 301 fire detector, 302 computer, 311, 312, 313, 1313 signal lines, 1200 pressurization system: 1201, 1205 piping, 1204 compressor.

Claims

1. Piping connected to a closed-type sprinkler head, The system includes a vacuum device connected to the aforementioned piping, The vacuum device has a first operating mode for maintaining the piping at a first vacuum level under normal conditions, and a second operating mode for maintaining the piping at a second vacuum level that is higher than the first vacuum level, in a dry sprinkler system.

2. Piping connected to a closed-type sprinkler head, A dry sprinkler system comprising a connection part connected to the aforementioned piping and used for high-vacuum evacuation after commissioning.

3. The dry sprinkler system according to claim 2, wherein the piping is normally at atmospheric pressure or pressurized.

4. The manufacturing method for a dry sprinkler system is: A process of attaching a closed-type sprinkler head to the piping and performing a test run by filling the piping with water, A method for manufacturing a dry sprinkler system, comprising the steps of creating a vacuum in the piping after the trial run and boiling the water in the piping at room temperature.

5. The method for manufacturing a dry sprinkler system according to claim 4, wherein the step of boiling the water in the pipe at room temperature is to bring the pressure inside the pipe to a level at least 0.08 MPa lower than atmospheric pressure.

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