Application of gas detector in sewage treatment plant
This site2017-04-08 17:27:03
The underground pipe gallery unique to the sewage treatment plant occupies a very wide area and has a complicated terrain and poor ventilation. Therefore, no toxic gas and methane leak or oxygen concentration is too low. In particular, there are many underground pipe corridors in sewage treatment plants. Once someone is in danger in the pipeline corridor, but no one finds it in time, it will be regarded as death. The mud area is a high-risk area. Generally, when the dewatering pump room and drying room equipment are operating normally, the hydrogen sulfide concentration is higher than 50 ppm. Therefore, the gas detectors and gas alarm control systems used in sewage treatment plants should have the following characteristics:
※ The equipment and system have fast response speed and high safety level
※ The equipment works stably, with long service life and small maintenance.
※ The layout is dense and the coverage is wide
※ There are three types of gases to be tested. Gases to be tested:
In different processes of sewage treatment, a large amount of flammable gas and toxic gas will be produced in different plant areas. The main gases to be tested are: ※ hydrogen sulfide ※ sulfur dioxide ※ carbon monoxide ※ methane ※ ammonia gas ※ oxygen.
four. Arrangement of the detector
Sewage treatment plant, the location of the detector should consider the following locations that are prone to leakage: ※ Grille room ※ Inlet pump room ※ Radon sedimentation room ※ Sand washing room ※ Mud collecting well ※ Concentration tank ※ Dewatering machine room ※ Drying room ※ Pipe gallery.
When determining the location of a detector, it should be noted that some detectors are sensitive to location and airflow. According to whether the density of the leaked gas is greater than air, and combined with the air flow trend, the detector arrangement is comprehensively completed. According to the prevailing wind direction of the place, the possible circulation phenomenon and upward trend of the air flow, and the customary passage of the natural flow of air in the underground pipe gallery, etc., and determine the direction of gas leakage when a large amount of leakage occurs, the detector should usually be installed below wind direction.
According to whether the density of the leaked gas is greater than air, and combined with the air flow trend, the detector arrangement is comprehensively completed. For places where the type of leaked gas and air are suspected, the detector should be placed near the operating surface; for places lighter than air, the detector head should be placed above the protected equipment or area. At the same time, where conditions permit, the detector should be placed higher than structural steel, pipelines, and equipment that will change the way air flows.
Investigate whether the leak state at the leak point is micro leak or spray. If it is a slight leak, the set point should be closer to the leak point; if it is a spray leak, it should be slightly away from the leak point. For locations where area coverage is required, the detectors should be arranged relative to the floor and operating surface based on the heating and ventilation system and potential gas release characteristics. The maximum distance between the detectors is 13 ~ 15m. For areas with large outdoor areas, it is possible to combine the key leak points separately and evenly.
When uniformly arranged, the distance between each monitoring point should be 10-20m, and the density of its installation can be appropriately increased or decreased according to the degree of safety requirements of the production process. For places where the indoor ventilation is not smooth, where the gas is easy to accumulate, and where underground gas trenches, heat trenches, and sewage trenches with sealed cover plates are often or where gas is easily accumulated under abnormal production conditions, the The detector is fixed in a dead spot where there may be leaked gas.