JPH07392U - Overflow prevention device for water and foam drug compounding device - Google Patents

Abstract

(57) [Summary] [Purpose] In a foam fire extinguisher, maintain a normal mixture ratio of foaming agent to water throughout the operation of the fire extinguisher. [Structure] An overflow prevention valve 3 downstream of the mixing pipe 2, a bypass 5 having an orifice 4 in the overflow prevention valve 3, the pressure of the downstream pipe 1a is detected, and the valve 3 is operated by the water pressure of the pipe 1. Configuration of device 6 for opening.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a water / foam medicine blending device in a foam extinguisher.

[0002]

[Prior art]

 The foam drug mixing device is a device in which a mixing pipe is provided in the middle of a fire extinguishing pipe, water is supplied to the mixing pipe, and the foam drug is injected into this adjusting pipe to mix the foam drug with water. The overflow prevention device of this device prevents an excessive flow rate of the solution from flowing into the mixing pipe at the initial stage of starting the fire extinguisher, suppresses the flow rate inside the mixing pipe to the rated maximum flow rate or less, and mixes the water and the foaming agent. It prevents the abnormalities.

In this overflow prevention device, an overflow prevention valve is provided at the rear part of the mixing pipe, and the closed valve is slightly opened at the initial stage of water supply when the fire extinguisher is started, and the flow rate is adjusted by adjusting the opening degree. Is to suppress.

A commonly used apparatus measures the flow rate by a flow rate control apparatus by the differential pressure before and after the orifice in the mixing pipe as shown in FIG. 2, and controls the opening degree of the overflow prevention valve in response to the signal. Device to do. Alternatively, as shown in Fig. 3, the required opening of the overflow prevention valve and the filling time of the piping after the stop valve are calculated in advance, and the timer is activated, and the overflow prevention valve is opened slightly at the initial stage of device startup. , There is a device for controlling in two stages of full opening after filling.

[0005]

[Problems to be solved by the device]

 In all of the conventional devices described above, the overflow prevention valve is used in a slightly opened state, so the flow velocity at that portion is extremely high (40 m / s to 50 m / s), which may damage the seat surface of the valve. There is.

Further, in any of the devices, the overflow prevention valve requires a valve that operates by a signal from the outside, and generally requires electricity as a signal and a power source for operation in many cases, resulting in equipment cost and construction cost. It becomes expensive. In addition, it is difficult to install in an explosion-proof area, and if it is installed, it becomes an explosion-proof specification and becomes more expensive.

Further, since a flow rate controller, a timer or the like is required, the device becomes complicated and the failure probability increases. Particularly in the device shown in FIG. 3, the flow rate control is inaccurate.

The present invention provides an overflow prevention device that solves the above drawbacks.

[0009]

[Means for Solving the Problems]

 This invention will be described with reference to FIG. 1 showing an embodiment. An overflow prevention valve 3 that is normally closed and an orifice 4 that connects the front and rear of this valve 3 are provided in the lower pipe 1 of the mixing pipe 2 that is provided in the middle of the fire extinguishing pipe 1 and mixes the foaming agent in water. When the water pressure in the bypass passage 5 and the downstream downstream pipe 1a of the valve 3 after the water is passed through the pipe 1 is detected and rises to a predetermined pressure, the valve 3 is opened by using the water supply pressure of the pipe 1. The device 6 is a device for overflow prevention of a water / foam drug compounding device.

In the second aspect of the invention, in the first aspect of the invention described above, instead of the bypass passage 5 having the orifice 4, an orifice is provided in the overflow prevention valve 3 (not shown).

[0011]

[Action]

 The fire extinguishing pipe 1 is always an empty pipe, and when the fire extinguisher is activated, water enters the adjusting pipe 2 through the pipe 1. On the other hand, the foam drug enters the mixing pipe 2 from the foam drug pipe 7. The foam extinguishing liquid mixed in the mixing pipe 2 passes through the bypass passages 5 provided before and after the overflow prevention valve 3 and flows into the downflow pipe 1a. At this time, an appropriate flow rate flows downstream due to the orifice 4 provided in the bypass passage 5. When the downstream pipe 1a of the valve 3 is filled with the foam extinguishing liquid and the water pressure in the downstream pipe 1 gradually rises to a predetermined pressure (about 20 to 30% of the specified pressure), the downstream pipe 1a is operated by the device 6. The water pressure of the pipe 1 is detected, the water pressure of the pipe 1 is used to drive the valve 3, the valve 3 is fully opened, and the device becomes the normal operation to send a predetermined flow rate of the foam extinguishing liquid to the nozzle.

Further, in the case where the overflow prevention valve 3 is provided with an orifice instead of the bypass filter 5 having the orifice 4, the same operation is performed.

[0013]

【Example】

 With regard to the apparatus of FIG. 1, in particular, when water pressure in the downstream pipe of the overflow prevention valve 3 is detected after passing water through the pipe 1 and the pressure rises to a predetermined pressure, this valve 3 is used by utilizing the water supply pressure of the pipe 1. An example of the device 6 for opening the door will be described.

All of a, b, and c are water conduits, 6a is a piston device that drives the overflow prevention valve 3 to open the valve, and 6b is a pilot valve that controls the water pressure of the water conduit a connected to the pipe 1a. It operates by detecting and operating the pressure water of the water conduit b connected to the pipe 1 to the piston device 6a via the water conduit c.

The device 6 is a device for detecting the water pressure in the downstream pipe 1a and driving the valve 3 with the water pressure in the pipe 1, and there are various other means, but all of them are within the scope of the present invention. included.

The orifice provided in the overflow prevention valve 3 has a structure in which a small hole is formed in the disc of the valve body, and its size can be accurately calculated from the pressure of water, the specified flow rate of the mixing pipe, and the permanent pressure loss.

[0017]

[Effect of device]

 If the orifice suppresses an excessive amount of water supply to the pipe at the initial stage of fire extinguishing, detects the water pressure of the pipe after the overflow prevention valve, and uses the water pressure of this pipe to open the overflow prevention valve, the fire extinguisher The normal concentration of foam fire extinguishing liquid is emitted from the nozzle during operation, ensuring perfect performance.

Since the device for driving the overflow prevention valve and the device for detecting the water pressure in the pipe as in the embodiment use the piston and the pilot valve, respectively, it is easy to install the device without using electricity at all. However, if it is a simple device, it will be easy to handle and no trouble will occur.

[Submission date] December 24, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004] Generally it is apparatus used is measured by flow controller flow rate by the pressure difference before after orifice compounding vessel as given in Figure 2, the opening of Carew valve Ri by its signal The device that controls. Alternatively, as listed in Figure 3, to actuate the timer to calculate the Takashieki time required opening and explosion-stop valve after piping advance excess flow valve, and excess flow valve apparatus startup initial BiHiraku , There is a device for controlling in two stages of full opening after filling.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Further, in the case where the overflow prevention valve 3 is provided with an orifice instead of the bypass passage 5 having the orifice 4, the same operation is performed.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

[0013]

[Embodiment] With regard to the apparatus shown in FIG. 1, in particular, when water pressure in the downstream pipe of the overflow prevention valve 3 is detected after water is passed through the pipe 1 and the pressure rises to a predetermined pressure, the water absorption pressure of the pipe 1 is used. , by way of example about the device 6 to open the valve 3.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing an embodiment of an overflow prevention device of the present invention.

FIG. 2 is a piping system diagram showing a conventional overflow prevention device.

FIG. 3 is a piping system diagram showing a conventional overflow prevention device.

Claims (2)

[Scope of utility model registration request] 1. A bypass having an overflow prevention valve that is normally closed and an orifice that connects the front and the rear of the valve, which is provided in the middle of a fire extinguishing pipe, below the pipe of a mixing pipe for mixing a foaming agent into water. Water consisting of a passage and a device for detecting the water pressure at the rear of the valve after passing water through the pipe and increasing the pressure to a predetermined pressure and using the water supply pressure of the pipe to open the valve. Overflow prevention device for foam drug compounding device. 2. A bypass passage having an orifice,
The overflow prevention device for a water / foam medicine blending device according to claim 1, wherein an orifice is opened in the overflow prevention valve.