JP2001276253A - Mixing apparatus for foam fire extinguishing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing apparatus for a foam fire extinguishing system which apparatus can prevent water and an aqueous foam solution from going into its foam concentrate bag even if a stop valve does not shut immediately when the mixing apparatus is stopped. SOLUTION: A tank 3 is located below a main pipeline l having a proportioner 2. The tank 3 and the main pipeline 1 are connected through a foam concentrate supplying pipe 8. The foam concentrate supplying pipe 8 consists of a vertical part 8a and a horizontal part 8b. The horizontal part 8b is located below the tank bottom 3b, connects the vertical part 8a and the tank bottom 3a and has the stop valve 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing apparatus for a foam fire extinguishing system, and more particularly to a diaphragm pressurized proportional mixing apparatus.

[0002]

2. Description of the Related Art A conventional mixing apparatus for a foam fire extinguishing system includes a proportioner provided in a main pipe; a tank containing a stock solution bag; and a water supply pipe connecting the tank and the upstream side of the proportioner in the main pipe. And a stock solution supply pipe connecting the stock solution bag and the proportioner.

In this conventional example, the tank is disposed below the main pipe, and the rear end of the stock solution supply pipe is connected to the head of the tank. Therefore, when fire extinguishing water flows through the main pipe, the static pressure is reduced in the throat of the proportioner, causing a pressure difference from the inside of the stock solution supply pipe. The foam stock solution in the stock solution bag is drawn into the main pipe, and To form an aqueous foam solution.

[0004]

However, when the mixing device is stopped and the water supply to the main pipe is stopped, the pressure difference in the proportioner does not occur. Attempts to return to the stock solution bag due to the head difference due to the difference in specific gravity of the foam stock solution. For this reason, the fire extinguishing water or the aqueous foam solution in the main pipe is drawn and flows into the stock solution bag, and the foam stock solution is diluted. If this thin foam liquid is supplied into the main pipe, a foam aqueous solution having a designed mixing ratio cannot be obtained.

[0005] Therefore, in order to prevent water or aqueous foam solution from being drawn into the stock solution bag, a blocking valve such as an electric valve is provided in the stock solution supply pipe. However, in this motor-operated valve, the water or the aqueous bubble solution flows back into the stock solution bag unless the valve is closed before or immediately after the supply of water to the main pipe is stopped. In addition,
It is conceivable to provide a check valve on the stock solution supply pipe to prevent backflow.However, in the case of a proportional mixing device, the mixing ratio is greatly affected by the pressure difference between the throat of the proportioner and the stock solution supply pipe. Providing a check valve in the stock solution supply pipe that affects the differential pressure is avoided.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to prevent water or an aqueous solution of foam from flowing into a stock bag without immediately closing a stop valve when water supply to a main pipe is stopped.

[0007]

According to the present invention, there is provided a mixing section provided in a main pipe; a tank containing a stock solution bag; and a water supply pipe connecting the tank and the mixing section of the main pipe upstream.
A foam extinguishing system comprising: a stock solution supply pipe connecting the stock solution bag and the mixing section; wherein the tank is arranged below a main pipe, and at least a part of the stock solution supply pipe is provided in the tank. Characterized in that it is located below the bottom of the.

The present invention provides a mixing section provided in a main pipe; a tank containing a stock solution bag; a water supply pipe connecting the tank and the main pipe upstream of a mixing section; And a stock solution supply pipe connecting the tank with the tank, wherein the tank is arranged below the main pipe, and at least a part of the stock solution supply pipe is located below the bottom of the tank. And a blocking valve is provided on the upstream side or the part of the stock solution supply pipe.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, the specific gravity of a foam concentrate such as a protein foam concentrate, a water-formed foam concentrate or a synthetic surfactant foam concentrate is greater than fire-extinguishing water, and the foam concentrate is located below the fire-extinguishing water. It uses the property of accumulating.

That is, the tank is disposed below the main pipe,
At least a part of the stock solution supply pipe is located below the bottom of the tank, and a blocking valve is provided on the upstream side or the part of the stock solution supply pipe immediately after stopping supply of water to the main pipe. Prevent fire water or aqueous foam solution from flowing into the stock bag. Therefore, it is not necessary to close the check valve immediately after stopping the water supply. Further, after the water supply is stopped, the blocking valve is closed before the water diffuses into the foam concentrate and mixes.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view showing a state when the mixing apparatus is started, and FIG. 2 is a state when the mixing apparatus is stopped. FIG. The mixing apparatus M of the foam fire extinguishing equipment includes a mixing section such as a venturi throat provided in the main pipe 1 and a tank 3 provided below the main pipe 1.

The tank 3 contains a stock solution bag 5 made of rubber.
Is provided. The upper part 5a of the stock solution bag 5 is fixed to the head part 3a of the tank 3, and the lower part 5b is the bottom part 3 of the tank 3.
b. In the stock solution bag 5, a foam stock solution, for example,
It is filled with a water film foaming stock solution 6 having a specific gravity of 1.1.

The bottom 3 b of the tank 3 is connected to the mixing section 2 via a stock solution supply pipe 8. This supply pipe 8 communicates with the inside of the stock solution bag 5 at the lower portion 5b of the stock solution bag 5,
The supply pipe 8 inside the stock solution bag 5 is provided with an outlet for the stock foam solution 6. The supply pipe 8 communicates with the inside of the stock solution bag 5 at the lower portion 5b of the stock solution bag 5, and the supply pipe 8 inside the stock solution bag 5 is provided with an outlet for the foam stock solution 6. The supply pipe 8 includes a vertical portion 8a and a horizontal portion 8b outside the tank 3.

The leading end of the vertical portion 8a is connected to the mixing section 2, and the trailing end extends below the bottom 3b of the tank 3. The horizontal portion 8b is connected to the vertical portion 8a, and the tank 3
Is located below the bottom 3b. The horizontal portion 8b is provided with a manual type stop valve 10.
Does not include a check valve.

The body of the tank 3 is connected to the main pipe 1 via a water supply pipe 12, and the connection position is the mixing section 2.
On the upstream side of

Next, the operation of this embodiment will be described. Start-up of the mixing device M: When a pump (not shown) is started and the blocking valve 10 is opened by manual operation, the fire extinguishing water W is pumped into the main pipe 1. At this time, a pressure difference is generated between the venturi throat of the mixing section 2 and the stock solution supply pipe 8. At the same time, the pressure of the main pipe 1 acts on the stock solution bag 5 in the tank 3 via the water supply pipe 12, and the fire extinguishing water W of the main pipe 1 is pushed out through the water supply pipe 12 while pushing out the foam stock solution 6 in the stock solution bag 5. Into the tank 3. Then, the foam concentrate 6 in the concentrate bag 5 flows into the main pipe 1 from the concentrate supply pipe 8 via the mixing section 2 and mixes with the fire extinguishing water W, so that a foam aqueous solution W2 is generated (see FIG. 1). . The foam aqueous solution W2 is supplied to a foam head (not shown) connected to the main pipe 1 and foams. Note that the fire extinguishing water W injected into the tank 3 has a lower specific gravity than the foam concentrate, and thus accumulates from the top of the tank 3.

Stopping the mixing device M: When the supply of water to the main pipe 1 is stopped, the pressure difference in the mixing section 2 disappears, so that the undiluted liquid foam 6 in the undiluted liquid supply pipe 8 becomes undiluted with the undiluted bag due to the difference in head due to the difference in specific gravity. Try to return to 5. Therefore, the fire extinguishing water W flows into the vertical portion 8a of the stock solution supply pipe 8 from the tip side, that is, from the mixing unit 2 side. Therefore, the fire extinguishing water W does not flow down any more (see FIG. 2).

Here, the position of the head difference H, that is, the balance position L is determined by the foam concentrate 6 when the foam concentrate 6 remaining in the tank 3 after being sent out and remains under the tank 3 in the concentrate bag 5.
This is the upper surface position of the layer. The foam concentrate layer is a portion where the concentrate bag 5 is almost in close contact with the entire inner wall of the tank 3. Therefore, this balance position L is equal to
Is the lowest, that is, the position of the bottom 3b of the tank 3 is the lowest, and does not take a position lower than this. If the stock solution bag 5 does not exist, the foam stock solution 6 in the tank 3 is sent out during the operation of the mixing device M, and then the foam stock solution 6 is pushed out from the stock solution supply pipe 8 by the fire extinguishing water W in the tank 3. However, since there is the stock solution bag 5, the foam stock solution in the stock solution supply pipe 8 is not pushed out. This lowest balance position L is the lowest position of the stock solution bag 5, that is, the position L 'of the bottom 3b of the tank 3. In the first embodiment, there is a portion 8z of the stock solution supply pipe 8 located below this position L '. Then, at least a part of the stock solution supply pipe 8 (that is, the part 8z) is located at the position L ′ of the bottom 3b of the tank 3.
Since it is located lower than the above, the fire extinguishing water W from the mixing unit 2 does not enter the stock solution bag 5 via the portion 8z and does not flow into the portion 8z for the above reason. Therefore, even if the stop valve 10 is not closed immediately after the stop of the water supply, the fire extinguishing water W does not flow into the undiluted solution bag 5, and there is no need to quickly close the stop valve 10. The blocking valve 10 may be closed before the fire extinguishing water W is diffused and mixed into the foam concentrate 6 in the portion 8z by a diffusion phenomenon.

A second embodiment of the present invention will be described with reference to FIG. 3. The difference between this embodiment and the first embodiment is as follows. That is, (1) a first undiluted liquid supply pipe 18 having a leading end connected to the mixing section 2 and a trailing end extending downward from a position L ′ of the bottom 3b of the tank 3;
A vertical portion 18a, a first horizontal portion 18b connected to the rear end of the vertical portion 18a and positioned below the position L 'of the bottom 3b of the tank 3, and a second vertical portion connected to the rear end of the horizontal portion 18b. And a second horizontal portion 18d connecting the second vertical portion 18c to the tank head and the head 5a of the stock solution bag 5. (2) The blocking valve 20 is disposed on the second vertical portion 18c. In addition, a portion 8z of the stock solution supply pipe 18 located below the position L 'at the bottom of the tank 3 exists. (3) When the mixing device M is stopped, the fire extinguishing water W passes through the portion 18z of the stock solution supply pipe 18 as in the first embodiment.
And does not flow into the portion 18z.

The embodiment of the present invention is not limited to the above. For example, the stock solution supply pipe may be an inclined pipe or a flake pipe, and at least a part of the stock solution supply pipe is located below the bottom of the tank. Thus, the effects of the present invention can be obtained. In addition, the blocking valve may be disposed at a more stable position of the head difference, that is, at a more stable position of the fire extinguishing water and the foam concentrate.
In the above embodiment, since the boundary between the fire extinguishing water W and the foam concentrate in the portions 8z and 18z is somewhat agitated, the blocking valves 10, 20 are located at positions sufficiently separated from the boundary,
If the parts 8z and 18z are provided on the upstream side, the fire extinguishing water W will not mix on the upstream side of the check valves 10 and 20.

[0021]

According to the present invention, as described above, even if the supply of water to the main pipe is stopped and the pressure difference in the mixing section disappears, the fire extinguishing water flows to the position of the head difference of the stock solution supply pipe. It is in a stable state and does not flow down any further.
Therefore, fire extinguishing water and aqueous foam solution are not mixed into the foam raw solution.

Further, even if the stop valve is not closed immediately after the supply of water to the main pipe is stopped, the fire extinguishing water or the foam aqueous solution does not mix with the foam stock solution, thereby facilitating the valve closing operation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, and is a diagram showing a state when a mixing apparatus is started.

FIG. 2 is a longitudinal sectional view showing a state when the mixing device is stopped.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present embodiment, and FIG.
FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main piping 2 Mixing part 3 Tank 5 Stock solution bag 6 Foam stock solution 8 Stock solution supply pipe 10 Check valve

Claims (6)

[Claims] A mixing section provided in a main pipe; a tank containing a stock solution bag; a water supply pipe connecting the tank and an upstream side of the mixing section of the main pipe; a stock solution bag and the mixing section; And a stock solution supply pipe connecting the tank; wherein the tank is disposed below a main pipe, and at least a part of the stock solution supply pipe is located below a bottom of the tank. A mixing device for foam fire extinguishing equipment. 2. A mixing section provided in a main pipe; a tank containing a stock solution bag; a water supply pipe connecting the tank and an upstream side of the mixing section of the main pipe; and a stock solution bag and the mixing section. And a stock solution supply pipe connecting the tank; wherein the tank is disposed below a main pipe, and at least a part of the stock solution supply pipe is located below a bottom of the tank. A mixing device for foam fire extinguishing equipment, characterized in that a blocking valve is provided upstream of or at a part of the stock solution supply pipe. 3. The undiluted solution supply pipe according to claim 1 or 2, wherein the undiluted solution supply pipe comprises a horizontal portion connected to the bottom of the undiluted solution bag and a vertical portion connected to the mixing portion. Mixing equipment for foam fire extinguishing equipment. 4. A stock solution supply pipe, a second horizontal portion connected to the head of the stock solution bag, a second vertical portion connected to the horizontal portion, and a bottom portion of the tank connected to the second vertical portion. A first horizontal portion located below the first horizontal portion, and a first vertical portion connected to the first horizontal portion and having a tip connected to the mixing portion. The mixing device of the foam fire extinguishing equipment as described in the above. 5. The mixing device for a foam fire extinguishing system according to claim 3, wherein a blocking valve is provided in the horizontal portion. 6. A mixing device for a foam fire extinguishing system according to claim 4, wherein a blocking valve is provided in the second vertical portion.