JPH05142109A - Multi-component gas detection device - Google Patents

Abstract

PURPOSE:To enable a multi-component gas to be subjected to suction detection by a common pump by providing a plurality of intake lines which communicate with a chamber to be measured, a gas sensor which is inserted between the lines,. a flow control valve, an exhaust line, a pump for intake, and a feedback line for communicating between the intake side of the pump and the exhaust side. CONSTITUTION:A throttle valve 8 is inserted into a feedback line 7 reaching from a discharge side to an intake side without inserting a flow control valve at the intake side of a pump 5. By adjusting the throttle valve 8, for example 3 litter/min gas is fed back to the intake side from the discharge side of the pump 5 through the feedback line 7, thus enabling a total amount of intake to be equal to 5 litter/min. In this manner, a draft resistance of a line can be reduced since no flow control valve is used, thus enabling a pump load to be reduced and a life of the pump 5 to be extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-component gas detector, and more particularly to a multi-component gas detector for sucking and detecting a multi-component gas by a common pump.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional gas detector, 1 is a chamber to be measured such as a gas cylinder storage or a clean room, 2 is an electrochemical gas sensor, 3 is a detection gas indicator,
Reference numeral 4 is a flow control valve, 5 is a vibration pump such as a diaphragm pump, and the gas sucked from the measured chamber 1 by the pump 5 is detected by the gas sensor 2 and displayed on the display 3. Generally, the output of this kind of gas sensor tends to be influenced by the flow rate of the gas passing therethrough, so that the flow rate is controlled by the flow control valve 4 to a constant value, for example, 1 liter / liter.
It is limited to min.

However, several gases such as phosphine, silane, arsine, diborane, etc.
When hydrogen chloride etc. is generated, as shown in FIG.
The individual gas sensors 2a to 2e and the flow rate control valves 4a to 4e are set to 5
Each of the intake lines is used by being inserted, and the gas from each of these lines is sucked by one common pump 5.

[0004]

However, in the conventional apparatus as shown in FIG. 3, the flow rates of the gas sensors 2a to 2e flowing through the respective intake lines are individually controlled by the flow rate control valves 4a to 4e and adjusted to constant values. Because you need to
The ventilation resistance of each intake line changes each time the adjustment is performed, and the total load also fluctuates in a large range. Therefore, for example, a suction capacity of 6 liters / min, which is slightly larger than the total intake air amount of 5 liters / min, is usually used. A pump having a large capacity such as 8 liters / min is used as the pump 5 that may be present, and a flow control valve 6 is inserted on the suction side of the pump 5, and the flow control valve 6 is squeezed to reduce the total suction amount from the pump 5. Is set to 5 liters / min. For this reason, the ventilation resistance of the line increases, and the pump is used with a large load corresponding to the amount throttled by the flow control valve 6, resulting in a short pump life, waste of power consumption, and difficult maintenance. was there.

The present invention is designed to eliminate the above drawbacks.

[0006]

A multi-component gas detecting device of the present invention includes a plurality of intake lines communicating with a chamber to be measured, gas sensors and flow control valves inserted in the respective lines, and the above-mentioned lines. An exhaust line commonly connected to the exhaust side, an intake pump inserted in the exhaust line, and a feedback line for connecting the intake side and the exhaust side of the pump.

[0007]

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

In the present invention, as shown in FIG. 1, a feedback line 7 extending from the discharge side of the pump 5 to the suction side is provided without interposing the flow control valve 6 on the suction side of the pump 5. 7, a throttle valve 8 is inserted, and the throttle valve 8 is adjusted so that gas is fed back from the discharge side of the pump 5 to the suction side through the feedback line 7 by 3 liter / min, and the total suction amount is 5 liter / min. Set to min.

[0009]

Since the multi-component gas detector of the present invention is constructed as described above, the ventilation resistance of the line is reduced because the flow control valve 6 is not used, and the pump load can be reduced accordingly. When the vibration pump is used, the life of the pump becomes longer, and the pulsation in the flow passage is reduced, which not only reduces the influence of vibration on the gas sensor but also reduces the error of the indication of the flow meter. ..

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a multi-component gas detection device of the present invention.

FIG. 2 is an explanatory diagram of a conventional gas detection device.

FIG. 3 is an explanatory diagram of a conventional multi-component gas detection device.

[Explanation of symbols]

 1 chamber to be measured 2 gas sensor 3 detection gas indicator 4 flow control valve 5 pump 6 flow control valve 7 feedback line 8 throttle valve

Claims (1)

[Claims] 1. A plurality of intake lines communicating with the chamber to be measured, gas sensors and flow control valves inserted in the respective lines, an exhaust line commonly connected to the exhaust side of each line, and the exhaust line. Intake pump inserted in the line,
A multi-component gas detection device comprising a feedback line that connects the suction side and the exhaust side of the pump.