JPH0574382B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a fire extinguishing equipment that mixes water and fire extinguishing foam and is used for extinguishing facilities such as chemical factories, oil refineries, oil tanks, and parking lots. This invention relates to a foam extinguishing agent mixing device.

[Prior Art] The outline of a conventional fire extinguishing equipment using fire extinguishing foam is as shown in FIG. In other words, when a fire breaks out in a certain area and it becomes necessary to extinguish the fire,
An automatic valve 3 provided at the base end of a branch pipe 2 to which a foaming device consisting of a foam discharge head 1 installed in the area is connected is opened by an interlock control signal from a fire detector or the like. Then, the pressurized water supply device consisting of the pump 4 is activated and starts supplying pressurized water from the water source 5 to the main pipe 6. A mixer 7 is provided in the middle of the main pipe 6, and a part of the pressurized water in the main pipe 6 expands the diaphragm 9 of the foam concentrate tank 8 to send the foam extinguishing agent to the mixer 7, and the pressurized water are mixed at the specified ratio. This pressurized mixture of fire extinguishing foam and water is supplied to the foam discharge head 1 through the opened automatic valve 3, and is foamed and discharged from the foam discharge head 1.

[Problems to be Solved by the Invention] By the way, in a mixing device consisting of a mixer as described above, there is a flow rate range that can obtain a mixture liquid with a mixing ratio suitable for obtaining appropriate foam from the foam discharge head [this is not practical]. The working flow rate range] is up to 4 times the minimum flow rate for the orifice type and about 6 times for the ventilate type, assuming the minimum flow rate is 1. Therefore, as the number of foam discharging heads used at one time increases, the flow rate also increases accordingly, making it impossible to obtain a liquid mixture with an appropriate mixing ratio using the conventional mixing device as described above, so it is difficult to obtain a mixture of liquid with a proper mixing ratio. There was a limit to the number of foam discharge heads that could be installed in the equipment.

[Means for Solving the Problems] The foam fire extinguishing agent mixing device according to the present invention connects a plurality of mixers with different practical flow rate ranges in parallel through automatic release valves, and the mixed liquid flowing to the foaming device The above-mentioned problem has been solved by providing a flow rate detector for detecting the flow rate of the flow rate and controlling each of the automatic opening valves by a detection signal from the flow rate detector.

[Operation] With the above configuration, the flow rate detector always detects the flow rate of the liquid mixture currently flowing. Based on this detection signal, it is detected whether the flow rate of the mixed liquid is within the practical use flow rate range of the mixer currently in operation, and if the flow rate is above the range, it can operate in a higher flow rate range. The automatic opening valve connected to the mixer is controlled to open so that a proper mixture can be obtained even at higher flow rates, and when the flow rate is below the range, the automatic opening valve connected to the mixer is controlled to open, and when the flow rate is below the range, the mixer that can operate in a lower flow range is opened. A connected automatic release valve is controlled to open so that a proper mixed liquid can be obtained even at a lower flow rate.

[Example] An example of the foam fire extinguishing agent mixing device according to the present invention will be explained based on the drawings. Fig. 1 is a schematic diagram showing the configuration of the foam fire extinguishing agent mixing device according to the present invention. Mixers, that is, a mixer 10 for a small flow range, a mixer 11 for a medium flow range, and a mixer 12 for a large flow range are connected in parallel via automatic release valves 13, 14, and 15, respectively. These automatic release valves 13,
14 and 15, a solenoid valve 16 as an opening means,
17 and 18 are provided respectively. At the outflow side connection part of each automatic release valve 13, 14, 15, there is a
A flow rate detector 21 is provided to detect the flow rate of the mixed liquid flowing through the foam discharge head 20 via the foam discharge head 9, and each automatic opening valve 13, 14, 15 is controlled based on a detection signal from the flow rate detector 21. Controller 22
is provided.

The operation of the foam extinguishing agent mixing device according to the present invention configured as described above will be explained below.

Here, the minimum flow rate of the entire equipment is 50/min, the maximum flow rate is 7200/min, and the small flow area mixer 1
The practical use flow rate range of 0 is 50 to 300/min, and that of mixer 11 for medium flow range is 300 to 1800/min.
1800~7200/ that of mixer 12 for large flow area
Let it be min. The relationship between the flow rate and pressure loss of each of these mixers 10, 11, and 12 is as shown in the characteristic curve diagram in FIG. The characteristics of the mixer 11 are shown by curve B, and the characteristics of the mixer 12 for large flow range are shown by curve C. As is clear from the characteristic diagram, each of the mixers 10, 11, and 12 has a pressure loss of 0.1 Kgf/cm ² at the minimum flow rate and a pressure loss of 1.0 Kgf/cm ² at the maximum flow rate.

Now, under normal conditions, each automatic release valve 1
3, 14, and 15 are closed. When a fire occurs, the controller 22 sends a release signal to the electromagnetic valve 16 of the automatic release valve 13 connected to the small flow range mixer 10, causing the automatic release valve 13 to open. Then, the fire extinguishing water pumped from the fire pump 23 flows from the water supply main pipe 24 to the small flow area bypass pipe 25, and the small flow area mixer 10 is activated. Here, it is mixed with foam extinguishing agent, passed through a flow rate detector 21, and passed through a branch pipe 19.
The fire extinguishing foam is discharged from the foam discharge head 20 connected to the fire extinguishing foam. During this operation, the flow rate detector 21 detects the flow rate of the mixed liquid and continues to send a detection signal to the controller 22. This flow rate is 50~300/
While within the range of min, other automatic release valves 14,1
5 remains closed, so that mixer 10 for small flow ranges is activated.

As the number of foam discharge heads 20 for discharging fire extinguishing foam increases as the fire spreads, the flow rate also increases, eventually reaching a flow rate exceeding 300/min. Then, the controller 22 receives the 300
In response to a detection signal exceeding /min, the solenoid valve 17
A release signal is sent to the solenoid valve 16 to open the automatic release valve 14, and a close signal is sent to the electromagnetic valve 16 to close the automatic release valve 13. As a result, the medium flow range mixer 11 is activated, and the small flow range mixer 10 is stopped. Then, the flow rate is 300 to 1800
/min range, medium flow range mixer 1
By operating step 1, a mixed liquid with an appropriate mixing ratio can be obtained. During this time, other automatic release valves 13,
15 remains closed, so only the medium flow range mixer 11 is activated.

When the flow rate increases further and finally exceeds 1800/min, the controller 22 detects the flow rate detector 21.
In response to a detection signal exceeding 1800/min from
An open signal is sent to the solenoid valve 18 to open the automatic release valve 15, and a close signal is sent to the solenoid valve 17 to close the automatic release valve 14. As a result, the mixer 12 for the large flow rate range is activated, and the mixer 11 for the medium flow rate area is stopped. Then, the flow rate is
While the flow rate is in the range of 1800 to 7200/min, a mixed liquid with an appropriate mixing ratio can be obtained by operating the mixer 12 for large flow rate range.

During this time, the other automatic opening valves 13 and 14 remain closed, so only the large flow range mixer 12 operates.

Next, when the fire is extinguished and the number of foam discharge heads 20 that discharge extinguishing foam decreases, the flow rate also decreases to 1800/min or less, and the controller 22 detects the flow rate detector. 21 to 1800
/min, the solenoid valve 17
A close signal is sent to the solenoid valve 18 to open the automatic open valve 14, and a close signal is sent to the solenoid valve 18 to close the automatic open valve 15. As a result, the medium flow range mixer 11 is activated, and the large flow range mixer 12 is stopped. In this way, the flow rate is 300
-1800/min, a mixed liquid with an appropriate mixing ratio can be obtained by operating the medium flow range mixer 11.

In the same way, the flow rate is further reduced to 300/
min, the controller 22 receives a detection signal from the flow rate detector 21 that is less than 300/min,
An open signal is sent to the solenoid valve 16 to open the automatic release valve 13, and a close signal is sent to the solenoid valve 17 to close the automatic release valve 14. This results in
The mixer 10 for the small flow range is activated, and the mixer 11 for the medium flow range is stopped. In this way, a liquid mixture with an appropriate mixing ratio can be obtained even at a flow rate of 300/min or less.

[Effects of the Invention] As described above, the foam extinguishing agent mixing device according to the present invention connects a plurality of mixers having different practical flow rate ranges in parallel through automatic release valves, and
A flow rate detector was provided to detect the flow rate of the liquid mixture flowing into the foaming device, and each of the automatic opening valves described above was controlled by the detection signal of this flow rate detector.
It is possible to continuously obtain a liquid mixture with an appropriate mixing ratio over an extremely wide range of flow rates, which was not possible with a conventional single mixer.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the foam extinguishing agent mixing device according to the present invention, and FIG. 2 is a characteristic curve diagram showing the relationship between flow rate and mixer pressure loss used to explain the device of FIG. 1. , FIG. 3 is a schematic diagram of a fire extinguishing equipment using a conventional foam fire extinguishing agent. 23... Pressurized water supply device, 20... Foaming device, 1
0, 11, 12...Mixer, 13, 14, 15...
...Automatic release valve, 21...Flow rate detector.

Claims (1)

[Claims] 1. In a foam extinguishing agent mixing device that is located between a pressurized water supply device and a foaming device and consists of a mixer that mixes foam extinguishing agent into flowing water, a plurality of mixers with different flow rate ranges for practical use are each connected to an automatic release valve. A foaming device characterized in that a flow detector is connected in parallel through the foaming device and detects the flow rate of the mixed liquid flowing into the foaming device, and each of the automatic opening valves is controlled by a detection signal from the flow rate detector. Fire extinguishing agent mixing equipment.