JPH10281316A - Emergency shutoff valve device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an emergency shutoff valve to fully close, by accurately discriminating whether a distributing water pipe is really damaged or not at disaster time of earthquake or the like, in accordance with whether a pressure has become in a negative or atmospheric pressure. SOLUTION: An emergency shutoff valve device 10 is constituted by an emergency shutoff valve unit 11 and a control circuit 17, the emergency shutoff valve unit 11 comprises a main emergency shutoff valve 13 and a sub emergency shutoff valve 15. By a signal of a seismometer 18, the main emergency shutoff valve 13 is first closed, thereafter with the lapse of a fixed time, when a signal of a pressure gage 16 is a negative pressure, damage of a distributing water pipe 2 is eliminated, when the signal is approximate to the atmospheric pressure, damage of the pipe is judged, the sub emergency shutoff valve 15 is also closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency shutoff valve device for preventing outflow of stored water when a distribution pipe of a distribution reservoir provided for stable supply of tap water is damaged due to an earthquake or the like.

[0002]

2. Description of the Related Art In a water supply system supplied by each municipality,
In order to provide stable water supply even when the amount of water used in each household fluctuates, distribution reservoirs are installed on small hills and mountains, and the headwater is used to compensate for fluctuations in water supply. This reservoir stores 8 to 12 hours of the average amount of water used per day. In the event of a disaster such as an earthquake, the reservoir also serves as an emergency water supply. I do.

[0003] The distribution pipe at the outlet of the reservoir, which sends out water from the reservoir, has an emergency cutoff for water supply in order to prevent the reservoir water from flowing out if the distribution pipe downstream of the outlet is damaged by an earthquake or the like. A valve is provided.

This emergency shut-off valve is generally a butterfly valve. A weight is attached to an operation lever of the valve, and the valve is normally kept fully open by a brake or a lock means attached to a valve shaft. In some cases, the brake or locking means is released by a detection signal and the valve is closed by the weight of the weight. The closing speed is controlled by a hydraulic shock absorber to prevent the occurrence of water hammer during the valve closing operation by the weight of the weight, and the valve shaft is manually or electrically operated when the valve is reset to the fully open state. It is designed to be fully opened by rotating and held by brake or locking means.

[0005]

By the way, as a method of closing the above-mentioned emergency shut-off valve by a detection signal of an earthquake or the like in the event of a disaster such as an earthquake, when the seismic intensity meter of the earthquake detects a seismic intensity exceeding a set seismic intensity, it is closed by the detection signal. Alternatively, a method of detecting an overflow velocity in a water distribution pipe with a differential pressure switch or the like and closing the same by using such a method is generally used.

[0006] However, even if the seismic intensity detected by the seismometer exceeds the set seismic intensity, the water distribution pipe downstream from the reservoir is not necessarily damaged. There are special cases where large amounts of water are consumed and this does not always lead to damage. Whether the set value is correct or the valve works effectively is, in fact, evident when an earthquake has occurred and the pipe has been damaged and cannot be confirmed.

On the other hand, if the emergency shut-off valve is closed for any reason even if there is no breakage in the middle of the water distribution pipe, the water is immediately cut off, so that the emergency shut-off valve must be constantly monitored. However, since the reservoir is generally located at a high place away from the city, opening the valve manually or electrically requires a great deal of labor and maintenance.

[0008] In addition, it is necessary to conduct an operation test at normal times to check whether the emergency shut-off valve operates normally in the event of a disaster. However, if the valve closing operation is performed rapidly, a water hammer (impact pressure) or a pipe line will be required. There is a possibility that a secondary disaster of pipe breakage may occur due to water column separation caused by negative pressure generated in the upstream part due to the pulling of water in the downstream. Further, the conventional emergency shutoff valve has a disadvantage that it is very expensive due to its complicated structure.

The present invention takes into account the various problems of the conventional emergency shut-off valve and accurately determines whether the water distribution pipe has been actually damaged during a disaster such as an earthquake, depending on whether the pressure has become atmospheric pressure or negative pressure. It is an object of the present invention to provide an emergency shutoff valve device that can determine and completely close an emergency shutoff valve.

[0010]

According to the present invention, as a means for solving the above problems, a main emergency shut-off valve for urgently shutting off the outflow of water due to breakage of a water distribution pipe is provided to the main water distribution pipe and the flow of the main water distribution pipe is controlled. Sub-emergency shut-off valves are installed in the bypass pipes to bypass the main emergency shut-off valve, respectively. A seismometer installed to detect earthquakes in the surrounding area and a pressure sensor installed to detect pressure in the main water pipe A control circuit that controls the opening and closing operation of both emergency shutoff valves with a signal, the control circuit closes the main emergency shutoff valve when the detection signal of the seismometer is detected, and then the detection signal of the pressure sensor after a certain period of time has elapsed The emergency shut-off valve device is configured to close the sub-emergency shut-off valve at atmospheric pressure.

[0011] According to the emergency shut-off valve device having such a configuration, the emergency shut-off valve device is fully closed only when the water distribution pipe is actually damaged at the time of a disaster such as an earthquake to prevent the outflow of water from the reservoir. it can.

When a disaster such as an earthquake occurs, the main emergency shutoff valve is temporarily closed by the earthquake detection signal, but the secondary emergency shutoff valve is kept open. This is to prevent a secondary disaster caused by water hammer or water column separation caused by emergency closing of the main emergency shut-off valve by opening the sub-emergency shut-off valve.

After a certain period of time, it is determined from the detection signal whether the pressure sensor is still at a negative pressure or at the atmospheric pressure at that time. And closes the secondary emergency shutoff valve.

If the pressure sensor remains at a negative pressure, there is no breakage in the middle of the water distribution pipe and the water is pulled by the downstream water. Therefore, it is determined that the pressure is a negative pressure. Control is performed to restart the main emergency shutoff valve.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall conceptual diagram of a system for supplying water from a reservoir via the emergency shutoff valve device of the embodiment. As shown in the figure, the reservoir 1 is installed at a high place such as a mountain or a hill, and water supplied from the reservoir 1 is sent to each consumer household A in the city by a water pipe 2. Water is stored in the reservoir 1 by being supplied with water from a water purification plant (not shown) provided separately. In addition, each consumer household A directly from a water supply pump provided on
The water supply system for supplying water to the water supply system and the water supply system of this embodiment are completely separate.

The emergency shutoff valve device 10 of this embodiment is provided at the outlet of the reservoir 1 and has a main emergency shutoff valve 13 provided on a main water pipe 12 having the same diameter as the water pipe 2. Emergency shut-off valve unit 11 in which sub-emergency shut-off valve 15 provided in bypass pipe 14 having both ends connected to main water pipe 12 so as to bypass the shut-off valve, and opening and closing of both emergency shut-off valves 13 and 15 And a control circuit 17 for controlling. FIG. 2 is an external perspective view of the emergency shut-off valve unit 11,
FIG. 3 shows a plan view, a side view, and a front view. Note that 12
Reference numerals a and 12b denote an inlet and an outlet, and 16 a pressure gauge. The measured value is indicated on an indicator, and the state of the set pressure value is detected and sent out as a switch signal. In the illustrated example, the pressure gauge can measure up to a minimum negative pressure of 50 mmHg. When the negative pressure is reached, a switch signal is output. When the atmospheric pressure (gauge pressure is 0) is reached, the switch signal is turned off and the negative pressure is increased. Atmospheric pressure can be detected. Note that two pressure switches may be provided to separately detect the negative pressure and the atmospheric pressure.

The primary and secondary emergency shut-off valves 13 and 15 are basically the same type of shut-off valve, but a butterfly valve is used as the primary emergency shut-off valve 13 and a ball valve is used as the secondary emergency shut-off valve 15. The size of each of them is different from that of the main water distribution pipe 12 and the diameter of the bypass pipe 14.
In the illustrated example, the main emergency shutoff valve 13 has an inner diameter of 150 mm.
The φ, the secondary emergency shutoff valve 15 has an inner diameter of 25 mmφ, and if the diameter is reduced as described above, it cannot be manufactured unless it is a ball valve type.

FIG. 4 shows a specific example of the emergency shutoff valve. (A)
The figure is a front view and the figure (b) is a side view. A butterfly valve 21 is provided in the valve body 20, and a gear mechanism for transmitting a rotational force is connected to a rotary shaft 22 extending above the valve through a path shown by a dotted line in FIG. , 1
Power from 5M is transmitted. As described above, a butterfly valve having a small diameter is replaced with a ball valve. Reference numeral 23 denotes a shut-off valve case. As will be described later, when a battery is not provided in the control circuit 17, a battery 24 for an emergency power supply is built therein. Reference numeral 25 denotes an opening meter, and reference numeral 26 denotes a clutch shaft. As shown in the enlarged view of the arrow, when the clutch shaft 26 is pulled out, a rotational force can be manually input from a manual shaft 27, and when the clutch shaft 26 is pushed in, the valve can be automatically opened and closed. It has become.

As shown in FIG. 1, a pressure detection signal from a pressure gauge 16 and an earthquake detection signal from a seismometer 18 are input to a control circuit 17, and based on the detection signals, the main and auxiliary emergency shutoff valves 13 are provided. , 15 are controlled to open and close the motors 13M and 15M. Although not shown, a battery is built in the control circuit 17 as an emergency power supply. If the original power supply is cut off, the control circuit 17 and the motors 13M and 15M are operated by the emergency battery power supply.
The main and auxiliary emergency shutoff valves 13 and 15 are provided with automatic closing devices for valves by means of brakes such as electromagnetic brakes and weights.
Alternatively, no hydraulic shock absorber for controlling the closing speed of the valve is provided.

According to the emergency shut-off valve unit configured as described above, the emergency shut-off valve operates as follows in the event of a disaster such as an earthquake. This will be described below with reference to the flowchart of FIG. When the control is started, the automatic or manual control mode is selected first in step S _1, the process proceeds to the next step unless manually. This is because the shut-off valve is designed to be manually operated in an emergency.

At steps S ₂ and S ₃ , the main and sub shut-off valves are opened. In this state, the control circuit 17 normally monitors the seismometer signal at normal times. If the seismometer 18 detects a set earthquake having a seismic intensity 5 or more, the control circuit 17 proceeds to step S
_{In step 5} , a signal for closing the main shutoff valve 13 is output, and the main shutoff valve 1 is output.
3 is closed. However, the secondary shutoff valve 15 remains open.

Therefore, even if the main shut-off valve 13 is rapidly shut off, the water supply is slightly flowing through the bypass circuit, so that a water hammer (such as occurs in a conventional system including only the main shut-off valve) is used. Impact pressure) does not occur.
This is because if the detection signal from the seismometer 18 is equal to or higher than the set value, there is a possibility that the water distribution pipe route may be broken somewhere, so the main shutoff valve 13 is closed and most of the water supply is stopped. This is to prevent the occurrence of water hammer when the cutoff is performed rapidly.

The main shut-off valve 13 receives a signal due to such an earthquake.
When the closed, checks the pressure switch S ₇ when actuating the timer from the moment of the detection signal caused by the earthquake S ₆ elapses a predetermined time has become a negative pressure. This means that if the water pipe is broken, the pressure in the water pipe will not decrease and will eventually reach the atmospheric pressure (gauge pressure = 0). This is because the pressure is reduced because of the inability to perform the operation, resulting in a negative pressure.

[0024] Accordingly, it is determined that the pressure not the water pipe if the negative pressure is broken, to open the main shut-off valve 13 returns to the beginning of the step S _2. If, when the pressure approaches the atmospheric pressure does not become negative pressure, it closes the auxiliary shut-off valve 15 as damage to any of the water pipe at S ₈ occurs, water distribution reservoir to ensure not to flow out .

In the above-described embodiment, an example has been described in which the emergency shutoff valve unit is used to prevent water from flowing out of the water distribution pipe connected to the reservoir due to a disaster such as an earthquake. For example, to prevent water from flowing out due to an earthquake or other disaster from a water pipe connected to a water storage tank installed on the roof of a high-rise building or high-rise apartment building, the scale is different, but in principle it is exactly the same Applicable to

The main emergency shutoff valve 13 and the secondary emergency shutoff valve 1
In the case of No. 5, the ratio of the inner diameter to the inner diameter is preferably about 1/10 to 1/5.

[0027]

As described above in detail, the emergency shutoff valve device of the present invention has a main emergency shutoff valve in the main water distribution pipe and a sub emergency shutoff valve in the bypass pipe. A control circuit that controls the opening and closing of the shut-off valve is provided, and after the main emergency shut-off valve is closed by the detection signal of the seismometer, the secondary emergency shut-off valve is also closed if the detection signal of the pressure sensor is atmospheric pressure after a certain time In the event of a disaster such as an earthquake, most of the water supply is temporarily stopped by closing only the main emergency shut-off valve, but the secondary emergency shut-off valve is kept open to avoid water hammer and water column separation. The sub-emergency shut-off valve is closed by detecting whether the water pipe is damaged and accurately detecting whether the water pipe has been damaged. Can be opened and closed.

Further, both emergency shut-off valves need only be opened and closed by driving a motor. By integrating the two emergency shut-off valves into a single unit, advantages such as simple construction and economical production can be obtained. There is an advantage that the operation test can be easily performed any number of times without greatly affecting downstream water supply.

[Brief description of the drawings]

FIG. 1 is an overall system schematic diagram of an emergency shutoff valve device according to an embodiment.

FIG. 2 is an external perspective view of an emergency shutoff valve unit.

FIG. 3 is a plan view, a side view, and a front view of the above.

FIG. 4 is a configuration diagram of an emergency shutoff valve.

FIG. 5 is a flowchart illustrating an operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reservoir 2 Distribution pipe 10 Emergency shutoff valve device 11 Emergency shutoff valve unit 12 Main distribution pipe 13 Main emergency shutoff valve 14 Bypass pipe 15 Secondary emergency shutoff valve 16 Pressure gauge 17 Control circuit 18 Seismograph

Claims (4)

[Claims] 1. A main emergency shut-off valve for urgently shutting off the outflow of water due to breakage of a water distribution pipe, and a sub-emergency shut-off valve for a bypass pipe for bypassing the flow of the main water distribution pipe to the main emergency shut-off valve. Equipped with a control circuit that controls the opening and closing operations of both emergency shut-off valves with a detection signal from a seismometer installed to detect an earthquake in the surrounding area and a pressure sensor installed to detect the pressure of the main water pipe. When the detection signal of the seismometer is detected by the control circuit, the main emergency shut-off valve is closed, and after a predetermined time or more, if the detection signal of the pressure sensor is atmospheric pressure, the sub-emergency shut-off valve is also closed. Shut-off valve device. 2. The control circuit closes the main emergency shut-off valve in response to a detection signal from the seismometer, and then restarts the main emergency shut-off valve if the detection signal from the pressure sensor after a certain period of time has passed is negative. The emergency shutoff valve device according to claim 1, wherein: 3. The emergency shut-off valve device according to claim 1, wherein the control circuit includes a battery as a power supply in an emergency. 4. The main and sub emergency shut-off valves are opened and closed by a motor, and a main emergency shut-off valve provided on a main water distribution pipe and a sub-emergency shut-off valve provided on a bypass pipe are integrally unitized. The emergency shutoff valve device according to claim 1, wherein the emergency shutoff valve device is provided.