How to correctly select the environment for combustible gas detectors?
Once the combustible gas detection probe is installed in a fixed position, its position is not easily changed. Based on years of accumulated work experience, the following points should be considered for specific applications.
(1) Identify the potential 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) Determine the direction of combustible gas leakage when a large amount of leakage occurs based on specific factors such as airflow direction and wind direction in the location.
(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 map of the leak is synthesized, and an initial point plan is made at the downstream position of its flow.
(4) Study whether the leakage state of the leakage point is micro leakage or jet like. If it is a slight 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, a final site setting plan has been formulated. In this way, the quantity and variety to be purchased can be estimated.
(5) For places with significant combustible gas leakage, a detection point should be set up every 10-20 meters according to relevant regulations. For small and discontinuous pump rooms that are not on duty, attention should be paid to the possibility of combustible gas leakage. Generally, a detector should be installed at the lower air outlet.
(6) For places with hydrogen leakage, the detector should be installed on the plane above the leakage point.
(7) For media with a gas density greater than air, the detector should be installed on a plane below the leakage point, and attention should be paid to the characteristics of the surrounding environment. For places prone to the accumulation of combustible gases, special attention should be paid to the setting of safety monitoring points.
(8) For open combustible gas diffusion and escape environments, if there is a lack of good ventilation conditions, it is easy to make the combustible gas content in the air of a certain location close to or reach the lower explosive 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 precautions for correct installation and calibration to reduce malfunctions.
