As we all know, there are toxic and harmful combustible gases in coal mines, such as methane, H2S, CO, and low oxygen or rich oxygen that cause harm to the human body.
First of all, considering that there is methane, a flammable and explosive gas in coal mines, the installed gas detector must be explosion-proof, with a protection level of IP65 or above for waterproof and dustproof. The anti-interference ability must be strong.
1. Methane:
Methane is the most common gas in coal mines. It is a flammable and explosive gas. When methane is mixed with air, it is easy to cause an explosion when it encounters fire. The explosion limit of methane is 5% to 15% vol, and its lower explosion limit is 5% vol, which is 100% LEL. The explosion limit is 4.9% to 16% (no combustion below the lower limit, quiet combustion above the upper limit) and the most violent explosion concentration is about 9.5%. Therefore, the methane gas concentration of the detector is very important. The fixed combustible gas detector produced by our company has CE, ATEX explosion-proof certification, uses catalytic combustion gas sensor, IP65 waterproof and dustproof, sends an alarm signal when the gas concentration reaches 25%LEL or 50%LEL, and can be connected to other linkage devices, such as fans, solenoid valves. When the alarm signal is sent, the exhaust fan is turned on to start the solenoid valve. At the same time, the gas concentration is detected 24 hours a day, and it supports 4-20ma or RS485 Modbus protocol to transmit signals and data in real time, which is convenient for detection.
2. Carbon monoxide gas:
CO is mostly produced by incomplete coal combustion, or equipment emissions produce CO.
The CO gas concentration detector uses an electrochemical sensor. The detection range of the fixed CO gas detector is 0-1000ppm. At 50/150ppm, an alarm signal will be sent, and the alarm value is adjusted according to user needs. Support remote control to set device parameters and perform calibration.
3.H2S gas
H2S gas is also produced by incomplete combustion of coal. The detection range of H2S gas detector is 0-200ppm, and an alarm signal is sent at 10/20ppm.
4.O2:
Coal mines are in a relatively closed environment underground, and there is a risk of oxygen enrichment or hypoxia. Therefore, fixed oxygen detectors can detect the oxygen concentration in the air 24 hours a day. When the oxygen concentration is less than 19.5%vol and greater than 23.5%, an alarm signal will be sent to avoid the risk of suffocation of workers.
5. In addition, there may be some combustion products, such as CO2, NO2, etc., which may gather and produce the risk of hypoxia. Therefore, fixed CO2 detectors are also needed for detection. CO2 detectors mostly use infrared sensors.
6. The coal mine environment is high in temperature and relatively humid, so the gas detector needs to have strong anti-interference ability. There are also some environments that require handheld portable gas detectors to be carried with you, such as the composite four-in-one H2S CO O2 CH4 gas detector, which needs to be equipped with rechargeable batteries or replaceable batteries. It is best if there is a real-time data storage function.
Fixed gas detectors can be transmitted to the ground monitoring panel through wireless transmission functions, such as 4G, LORA, and outdoor workers can also see data changes at any time.
Our company produces fixed and portable toxic and harmful gas detectors, composite coal mine gas detection needs, welcome to consult