The heating furnace of the molecular sieve purifier is used to heat the nitrogen used for molecular sieve regeneration. Nitrogen is a low-pressure gas, and the design working pressure of the heating furnace is also low-pressure. In actual operation, several accidents have occurred in the heating furnace. Analyzing the reasons, they are all caused by the influx of high-pressure air.
There are two reasons why high-pressure air flows into the heating furnace: firstly, the valve is not tightly closed during switching. If the nitrogen inlet valve of the working adsorption cylinder is not tightly closed, high-pressure air will flow into the heating furnace; If the high-pressure air inlet and outlet valves of the regenerating adsorption cylinder are not tightly closed, high-pressure air will enter the adsorption cylinder and then cascade into the heating furnace. The second issue is poor valve maintenance and poor maintenance quality. If the sealing surfaces of the nitrogen inlet valve and high-pressure air inlet and outlet valves of the adsorption cylinder are not well sealed or there are impurities on the sealing surfaces, which makes the valve not tightly closed, it is also possible to cause high-pressure air to flow into the heating furnace. There are safety hazards. The measures include:
1) A safety valve should be installed on the heating furnace;
2) When switching, the nitrogen inlet valve and high-pressure air inlet and outlet valves of the adsorption cylinder must be tightly closed;
3) During installation and maintenance, air pipelines and valves should be blown clean. To check the sealing condition of the valve, grind the damaged sealing surface to ensure its sealing performance;
4) When testing the pressure of the adsorption cylinder, the valve on the nitrogen outlet pipeline of the heating furnace should be opened.
