The core principle of icing on the outer wall of the air separation incubator is that the cooling capacity of the box leaks out, and the water vapor in the ambient air condenses and freezes when it is cold. Now, the icing causes and one-to-one corresponding on-site treatment measures are described as follows:
1. sealing failure of the box: the sealing gasket at the manhole and pipeline threading plate is aging, the bolts are loose, the box weld is cracked, the wet air penetrates into the box, and the cold energy is transmitted to the outer wall to cause ice formation. Disposal measures: tighten loose bolts, replace aging gaskets, repair cracked welds, and completely plug the air leakage gap.
2. deterioration of insulation layer: pearlite is hardened by moisture, insufficiently filled or has holes, forming a cold bridge, reducing the thermal insulation performance, and the cooling capacity penetrates the insulation layer to cool the shell. Disposal measures: replace the damped pearlescent sand, fill up the vacant parts of the insulation, eliminate the cold bridge, and ensure the compactness of the insulation layer.
3. leakage of low-temperature medium: the low-temperature pipes and valves in the box are damaged, and the low-temperature medium such as liquid oxygen and liquid nitrogen is leaked, with local rapid and large temperature drop, thick ice layer and centralized points. Disposal measures: mark the frozen area, stop the machine for leak detection and maintenance, prohibit repair under pressure, and start the machine after the fault is eliminated and de icing.
4. abnormal nitrogen gas seal: the gas seal pressure is insufficient, the pipeline is blocked, the micro positive pressure in the box cannot be maintained, and the wet air is poured back into the box. Disposal measures: dredge the gas seal pipeline, calibrate the nitrogen gas seal pressure, maintain the micro positive pressure in the box, and isolate the external moisture.
5. impact of environmental conditions: high humidity, low temperature and large temperature difference between day and night, high moisture content in the air will aggravate condensation and icing on the outer wall. Disposal measures: conduct intensive patrol inspection in bad weather and appropriately increase the gas seal pressure; For slight frosting, blow with hot air. It is strictly prohibited to hit the box with hard objects.
