How to use the combustible gas detector

The combustible gas alarm is composed of a detector and an alarm control host. It is widely used in the petrochemical industry where there are flammable gases in petroleum, gas, chemical, oil depots, etc., to detect the leakage of indoor and outdoor dangerous places, and to ensure production and personal safety. Important instrument. When there is a combustible gas in the tested place, the detector converts the gas signal into a voltage signal or a current signal and transmits it to the alarm meter, and the instrument displays the percentage concentration value of the lower limit of the explosion of the combustible gas. When the concentration of flammable gas exceeds the alarm set value, an audible and visual alarm signal is generated, and the on-duty personnel take timely safety measures to avoid the occurrence of a blasting accident.
1. Precautions during application Once the fixed-point installation of the combustible gas alarm is in place, its position is not easy to change. Based on the accumulated work experience over the years, the following points should be considered for specific applications.
(1) Find out the possible leak points of the devices to be monitored, analyze their leakage pressure, direction and other factors, and draw the probe position distribution map, according to the severity of the leakage into three levels I, II, III.
(2) According to the specific factors such as the airflow direction and wind direction of the site, determine the leakage direction of the combustible gas when a large amount of leakage occurs.
(3) According to the density of the leaking gas (greater or smaller than the air), combined with the trend of air flow, integrated into a three-dimensional flow trend diagram of the leak, and an initial set point scheme is made at the downstream position of the flow.
(4) Study whether the leakage state of the leak point is a micro leak or a spray. If it is a micro leak, set the position of the point close to the leak point. If it is a jet leak, it should be slightly away from the leak. Based on these conditions, a final set-up plan is drawn up. In this way, the quantity and variety that need to be purchased can be estimated.
(5) For places where there is a large flammable gas leak, according to the relevant regulations, a detection point should be set for each distance of 10-20m. For small, non-continuously operated pump rooms that are unattended, attention should be paid to the possibility of flammable gas leakage. Generally, a detector should be installed at the downwind.
(6) For places with hydrogen leaks, the detector should be installed on the plane above the leak point.
(7) For media with a gas density greater than air, the detector should be mounted on a lower surface below the leak point, and pay attention to the surrounding environment. Special attention should be paid to the setting of safety monitoring points for places where flammable gas is easily accumulated.
(8) For the open flammable gas diffusion and escape environment, if there is no good ventilation condition, it is easy to make the flammable gas content in the air of a certain part close to or reach the lower explosion limit concentration. These are safety monitoring points that cannot be ignored. .
According to the analysis of on-site accidents, more than half of them were caused by incorrect installation and calibration. Therefore, it is necessary to introduce the correct precautions for installation and calibration to reduce malfunctions.
2. Precautions for the installation of flammable gas alarms (1) There must be no strong electromagnetic fields (such as high-power motors and transformers) that affect the operation of the instrument around the flammable gas alarm.
(2) The alarm device is a safety instrument with sound and light display function. It should be installed in a place that is easy for the staff to see and hear, so as to eliminate hidden dangers in time.
(3) The installation height of the alarm should generally be 160-170cm, so that maintenance personnel can carry out routine maintenance.
(4) The alarm probe is mainly a detecting component that contacts the combustion gas sensor. The platinum wire coil is coated with alumina and a binder to form a spherical shape, and the outer surface thereof is provided with a rare metal such as platinum or palladium. Therefore, be careful when installing to avoid breaking the probe.
(5) The density of the gas to be measured is different, and the installation position of the indoor probe should also be different. When the measured gas density is less than the air density, the probe should be installed 30cm away from the roof, and the direction is downward; otherwise, the probe should be installed 30cm away from the ground, and the direction is upward.