JPS59230138A - Alarm for harmful gas - Google Patents

Abstract

PURPOSE:To reduce the operation time for stop valves and to detect quickly the monitoring regions where a harmful gas is generated by connecting the respective gas passages connected respectively to the plural monitoring regions to one flow passage for detection interposed with a harmful gas detector. CONSTITUTION:Gas passages 2 are respectively connected to monitoring regions 1, 1, 1 such as a production room, etc. in a semiconductor plant, chemical plant, etc. and all of the passages 2 are connected to one flow passage 4 for detection interposed with a harmful gas detector 3. Stop valves 5 can be selectively operated to be closed by a selective operating mechanism 6 interlocked to the detector 3, thereby constituting a gas alarm detecting the regions 1- where the harmful gas is generated. The alarm is therefore constituted inexpensively simply by providing one detector and moreover the time for operating the stop valves is reduced and the monitoring regions where the harmful gas is generated are quickly detected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a harmful gas alarm device for detecting the generation of harmful gases due to unresponsive accidents in monitoring areas such as a large number of manufacturing rooms in semiconductor factories, chemical factories, etc.

Conventional alarms include those in which harmful gas detectors are installed in each ventilation path connected to the monitoring area, or those in which a harmful gas detector is installed in each ventilation path connected to the monitoring area. It is connected to a single exploration channel with a gas detector interposed therebetween, and an on-off valve is provided in each of the ventilation channels, and these on-off valves are selectively opened in sequence for a predetermined period of time, such as every 5 minutes, for example. There was something.

However, in the former case, as the area to be monitored increases, the number of detectors that must be provided also increases, resulting in a disadvantage in terms of cost. On the other hand, in the latter case, after opening the on-off valve and sampling, it takes time to sample the next time, especially as the number of monitoring areas increases, the non-sampling time becomes longer, and harmful gas may be released in the process. Even if the gas is generated, it cannot be detected, resulting in a delay in detecting the generation of harmful gas, resulting in a lack of safety.

SUMMARY OF THE INVENTION In view of these circumstances, it is an object of the present invention to enable the detection of harmful gas generation to be performed inexpensively and quickly using a single detector.

To achieve this objective, the harmful gas alarm of the present invention connects each of the ventilation channels connected to a plurality of monitoring areas to a single inspection flow channel with a harmful gas detector interposed therebetween. 1) A type 1 opening valve is provided in each of the ventilation passages, and a selection operation mechanism is provided for selectively closing the opening/closing valve 1111 when the detector detects a harmful gas.

According to this characteristic configuration, although only one detector is provided, gases from all monitoring areas simultaneously flow into the detector in a mixed form during normal times, and noxious gases can be detected in any one part of the monitoring area. If a gas is generated, the detector detects it, and then the on-off valve is selectively closed, and the N6 monitoring area where noxious gas is generated can be detected.

In the past, it was possible to detect the location of harmful gases in multiple monitoring areas, but it could be constructed at low cost by installing only one detector, and it was possible to detect the occurrence of harmful gases in any of the monitoring areas. If this is the case, it can be detected immediately, and the monitoring area where harmful gases are generated can be detected by selectively closing the on-off valve after the detection, so the on-off valve can be selectively closed for a set period of time. Compared to conventional systems that require opening and closing operations, the operating time for the on-off valve is extremely short, and the monitoring area where harmful gases are generated can be quickly detected, improving safety.

Practical embodiments of the present invention will be described below with reference to the drawings.

Monitoring areas such as manufacturing rooms in semiconductor factories, chemical factories, etc. [
A ventilation path (2) is connected to each of the 11+11 fils, and all of these ventilation paths (2)... are connected to one exploration flow path (4) with a harmful gas detector (3) interposed therebetween. and connected to the ventilation path (2)... respectively electromagnetic first to third normally open on-off valves (5a), (5b).
, (5c), and the detector (3
) by the selection operation mechanism (6) linked to the on-off valve (5).
... is configured to selectively close the monitoring area f1. A harmful gas alarm device that detects I... is configured.

The ventilation path (2)... is provided with a suction pump (71), a flow meter (8), and a flow rate adjustment valve (9), and the required amount of gas is sucked from each monitoring area (1)... The sensor (3) is configured to be adjustable so as to be supplied to the detector (3).

The selection operation mechanism (6) includes a control circuit 00) which inputs a signal from the detector (3) and a control circuit 001 thereof.
The on-off valves (5a) and (5b
) and (5c), and a drive circuit 5!6Q1) that closes the valve (5a).

(5b) and (5c) are selectively closed to detect monitoring areas (1) where harmful gases are generated.

Specifically, the control circuit Oa is an on-off valve (5a).

For example, (5b) and (5c) are closed as follows.

That is, when the detector (3) detects the generation of harmful gas, (1) First, the second and third on-off valves (5b) and (5c) are closed.

0 Next, the second on-off valve (5b) is opened, and the first on-off valve (5a) is closed.

θ Finally, the third on-off valve (5C) is opened and the second on-off valve (5b) is closed.

With the above operations, it is possible to detect in which monitoring area (1) harmful gas is being generated. Of course, even if harmful gas is occurring in two monitoring areas at the same time, the situation can be detected. can.

FIG. 2 shows an embodiment in which there are a large number of monitoring areas (1), in which the monitoring areas M, 111... are divided into groups (Gl..., and the intermediate flow paths for each group fG)... (2)・
...The ventilation path (21-) is connected to the exploration flow path (4) through each, and an electromagnetic normally open on-off valve α3 is provided in each intermediate flow path (c). Using the operating mechanism (6), in the same procedure as in the above embodiment, first, the group (G) that generates harmful gas is detected, and then the group (Gl) in which harmful gas is generated is detected. The first to third on-off valves (5a) in the same manner as described above,
(5b) and (5c) are opened and closed to finally detect the monitoring area (1) which is the source of harmful gas.

In addition, when the number of ventilation passages (2) is large, the selection operation mechanism (6) may be constructed from a microcomputer.

Further, the suction pump (7) may be provided on the discharge side of the exploration channel (4).

[Brief explanation of the drawing]

The drawings show an embodiment of the harmful gas alarm of the present invention, with FIG. 1 being a flow sheet and FIG. 2 being a flow sheet showing another embodiment. (1)...monitoring area, (2)...ventilation path, (3)...
...detector, (4) ... flow path for exploration, (5) ... normally open type on-off valve, (6) ... selection operation mechanism.

Claims (1)

[Claims] Each of the ventilation passages connected to the plurality of monitoring areas is connected to one exploration flow passage with a harmful gas detector interposed therebetween, and each of the ventilation passages is provided with a normally open on-off valve, A harmful gas alarm comprising a selection operation mechanism that selectively closes the on-off valve when the detector detects a harmful gas.