JPS62197075A - Fire extinguishing equipment for duct - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to fire extinguishing equipment for ventilation, transportation, etc., and in particular to a fire extinguishing system for ducts that can extinguish fires that occur in ducts without stopping the airflow in the ducts. It is related to equipment.

Conventional technology When a fire occurs due to spontaneous ignition of dust accumulated in a duct such as a ventilation duct or a transport duct, conventional methods
The air temperature inside the duct is stopped by stopping fans for supply, exhaust, or suction, and fire extinguishing gas such as CO2 or halon or foam is injected into the duct where the airflow has stopped to extinguish the fire.

Problems that the invention aims to solveIn recent years, there has been an increase in the number of places such as semiconductor factory clean rooms where forced ventilation is used to maintain a constant environment at all times. If the ventilation ducts used, such as exhaust ducts, stop their air flow, the indoor environmental conditions will change and cause serious problems.

Therefore, even if a fire occurs within the duct, it is necessary to extinguish the fire without stopping the airflow flowing through the duct.

Therefore, if foam or fire extinguishing gas is supplied into the duct without stopping the airflow, the foam or gas will be swept away or diffused by the airflow, so the duct may be filled with foam or the necessary gas In order to set the temperature to 4 degrees 2, for example, 40 to 50% for CO□ and 4 to 5% for halon, it is necessary to supply a large amount of foam or fire extinguishing gas.

In view of the above circumstances, it is an object of the present invention to provide a fire extinguishing equipment for a duct which can extinguish the fire with a small amount of extinguishing gas without stopping the airflow flowing through the duct when a fire occurs in the duct.

Means for Solving the Problems The present invention is a fire extinguishing equipment for a duct, characterized in that a gas discharge nozzle is provided upstream of the ignition point of the duct, and the nozzle is inclined toward the windward side.

When extinguishing gas is discharged diagonally from the duct discharge nozzle toward the windward side of the duct for a short period of time while an airflow is flowing in the duct, the velocity of the airflow is momentarily reduced by the radiation pressure of the gas. , the gas released into that area forms a highly concentrated extinguishing gas layer.

When the gas emission ends, the air velocity is restored and the extinguishing gas layer is swept downwind to pass the ignition point and extinguish the fire.

Embodiment One embodiment of the present invention will be explained with reference to the accompanying drawings. In FIG. 1, 1 is an exhaust duct, and the windward side Ia is a manufacturing equipment installed in a clean room (not shown), such as a CV
It is connected to a D furnace, a thermostat, a work bench, etc., and the leeward side 1b communicates with the outside air through an exhaust fan 2, a purification device (not shown), etc.

A plurality of gas discharge nozzles 3 are provided on the duct wall 1c.

The plurality of gas discharge nozzles 3 are arranged on the same circumference of the duct wall IC, and their central axes 3a intersect with each other on the center line C of the duct.

The central axis 3a of the nozzle 3 is inclined toward the windward side from a right angle to the center line C of the duct 1, and the angle θ (referred to as the radiation angle) is, for example, 5 degrees to 20 degrees.

The gas discharge nozzle 3 is connected to a fire extinguishing gas cylinder 4 via a solenoid valve 5.

6 is a smoke-type, heat-type, or flame-type fire detector, which is connected to the control panel 7.
It is connected to the.

When the control panel 7 receives a fire signal output from the fire detector 6, it opens and closes the solenoid valve 5 a plurality of times at predetermined time intervals.

The control panel 7 is composed of a circuit shown in FIG.

In FIG. 2, reference numeral 11 denotes an input terminal into which a fire signal from the fire detector 6 or a signal from a manual switch (not shown) is input. 12 is the first vehicle stabilizing multivibrator,
A fire signal or a manual signal produces an output for a few seconds, for example 5 seconds. Reference numeral 13 denotes a timer, which starts operating upon input of a fire signal or a manual signal, and produces an output after a predetermined time, for example, 15 seconds.

Reference numeral 14 denotes a second jlL stable multivibrator connected in series with the timer 13, which generates an output for several seconds, for example, 5 seconds, based on the timer output of the timer 13.

Reference numeral 15 denotes a control relay which is opened when the first and second monostable multivibrators 12 and 14 are generating outputs, and operates the solenoid valve 5 by its meter contact (not shown).

Next, to explain the operation of this embodiment, a fire occurs in the duct 1 in which the exhaust air flow (airflow) is flowing in the direction of arrow A1 by the exhaust fan 2, and the fire detector 6 is activated. When it activates and outputs a fire signal to the control panel 7, the control panel 7 responds to ? Operate the II magnetic valve 5 to open it.

When the solenoid valve 5 opens, the extinguishing gas in the extinguishing gas cylinder 4,
For example, CO□ is discharged obliquely from the gas discharge nozzle 3 toward the windward side within the duct 1.

This released gas tries to flow against the airflow flowing in the A1 direction, so the airflow velocity inside the duct 1 is momentarily reduced, the released gas stays in that part, and the inside of the duct A fire extinguishing gas layer 16 with a high concentration higher than that required for extinguishing the fire is formed.

The extinguishing gas from the gas discharge nozzle 3 is emitted for a short period of time at a radiation pressure such that the airflow speed ranges from approximately 172 to 0 relative to the set speed of the airflow, but this short-time emission is performed intermittently. is desirable.

If you do this, the high concentration gas FJ16 will flow through the duct 1.
Since the water flows at intervals, the fire can be extinguished more reliably.

Furthermore, if the radiation time of the fire extinguishing gas is prolonged, it is undesirable as it will obstruct the air flow for a long time.Furthermore, the radiation angle θ of the nozzle 3 should be increased, or the radiation angle θ should be completely directed to the windward side, or the gas radiation should be increased. If the pressure is too high, the pressure of the radiated gas will cause the airflow to flow backwards in the duct, which is undesirable.

Next, when the gas discharge nozzle 3 finishes discharging gas, the highly concentrated extinguishing gas layer 16 is swept downwind by the revived air current, and as it passes the fire point 19, the gas layer 16 is suffocated, cooled, and Extinguishes fire due to catalytic effect.

In addition, when providing a plurality of gas discharge nozzles 3, the plurality of nozzles may be provided while being slightly shifted back and forth.

Effects of the Invention In this invention, a gas discharge nozzle is provided upstream of the ignition point in the duct, and the nozzle is tilted toward the windward side, so that the gas discharged from the gas discharge nozzle into the duct is
The airflow velocity is momentarily reduced and a highly concentrated extinguishing gas layer is formed in that area, and this extinguishing gas layer is swept downstream by the revived airflow and passes the ignition point.

Therefore, the fire can be extinguished with a small amount of gas without stopping the heat inside the duct.

In addition, the speed of the airflow flowing inside the duct is set to low/S, and the radiation angle θ of the gas discharge nozzle (the direction perpendicular to the airflow is 0 degrees, the leeward side is +, and the windward side is -) is CO3 is released for 5 seconds at each angle. CO7 is released in an amount that makes a 100 m long duct 20% concentration in no wind), CO2 concentration (%) at measurement point 20 on the leeward side. When measured, the following results were obtained.

In this way, the CO7 concentration 5 necessary for extinguishing a fire can be determined by the radiation angle θ.
This experiment has shown that 0% may or may not be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a circuit diagram of the control panel shown in FIG. 1. 1...Exhaust duct 2...Gas release nozzle 19...Ignition point Agent Patent attorney Yu Saito (2 others)

Claims (1)

[Scope of Claims] 1) A fire extinguishing equipment for a duct, characterized in that a gas discharge nozzle is provided upstream of the ignition point of the duct, and the nozzle is inclined toward the windward side. 2) The fire extinguishing equipment for a duct according to claim 1, wherein the gas discharge nozzle is provided on the duct wall. 3) Claim 1, characterized in that a plurality of gas discharge nozzles are provided on the same circumference of the duct wall.
Fire extinguishing equipment for ducts as described in section. 4) The fire extinguishing equipment for a duct according to claim 3, wherein the central axes of the plurality of gas discharge nozzles intersect with each other on the center line of the duct.