Precautions for toxic and harmful gas detectors
Once the fixed installation of the toxic gas alarm is in place, its position is not easily changed. The following points should be considered when applying it specifically.
(1) Identify the possible leakage points of the device to be monitored, analyze their leakage pressure, direction, and other factors, and draw a distribution map of probe positions. According to the severity of the leakage, it is divided into three levels: I, II, and III.
(2) Based on specific factors such as airflow direction and wind direction in the location, determine the direction of toxic gas leakage when a large amount of leakage occurs.
(3) Based on the density of the leaked gas (greater than or less than air), combined with the trend of air flow, a three-dimensional flow trend chart of the leak is synthesized, and an initial point setting scheme is made at the downstream position of its flow.
(4) Study whether the leakage state at the leakage point is micro leakage or jet like. If it is a minor leak, the location of the point should be closer to the leak point. If it is a jet leakage, it should be slightly away from the leakage point. Based on these conditions, develop a final site plan. In this way, the quantity and variety that need to be purchased can be estimated.
(5) For places with significant toxic gas leaks, according to relevant regulations, a detection point should be set up every 10-20 meters apart. For unmanned small and discontinuous pump rooms, attention should be paid to the possibility of toxic gas leakage, and a detector should generally be installed at the lower air outlet.
(6) For places with hydrogen leaks, detectors should be installed on the plane above the leak point.
(7) For media with a gas density greater than air, the detector should be installed on the lower plane below the leakage point, and attention should be paid to the characteristics of the surrounding environment. Special attention should be paid to the setting of monitoring points for places prone to the accumulation of toxic gases.
(8) For open environments where toxic gases diffuse and escape, if there is a lack of good ventilation conditions, it is also easy to make the toxic gas content in the air of a certain area close to or reach the lower explosive limit concentration. These are monitoring points that cannot be ignored.
According to the analysis of the on-site accident, more than half of it was caused by incorrect installation and calibration. Therefore, it is necessary to introduce the precautions for correct installation and calibration to reduce malfunctions.
