DEAR Liquid air separation unit.The advantages of total immersion operation are: from the point of view of oxygen channel flow, the liquid oxygen surface is outside the plate unit, and the gas-liquid two-phase mixture with low density is inside the oxygen channel, which actually constitutes a liquid oxygen self circulation loop. When the heat load is constant, the higher the liquid oxygen level, the greater the liquid oxygen circulation rate in the oxygen channel.DEAR Liquid air separation unit.If two expanders operate at the same time, the total expansion capacity is 3500m3 / h due to throttling in front of the expander, and the parameters before the expander are P1 = 0.50mpa, T1 = 113k; the parameters after the expander are P2 = 0.125mpa, T1 = 83k, then the unit cooling capacity is ah = h1-h2 = 7955 (kJ / KMOL) - 7200 (kJ / KMOL) = 755kj / KMOL.The cold end cannot cool the air to the original required temperature. That is to say, the temperature difference of positive and back flow gas in the cold end, middle and hot end of the accumulator (or switching heat exchanger) should be enlarged. When the inlet air temperature rises, the temperature difference between positive and return flow gas changes along the height direction of the accumulator (or switching heat exchanger) (or with the positive flow air temperature).
The liquid oxygen surface of condensing evaporator is required to be kept at a certain height (data provided by the design and manufacturing unit) to strengthen heat exchange and ensure operation safety. The heat transfer process of condensing evaporator is the process of condensing gas nitrogen to release latent heat and transfer heat to liquid oxygen to vaporize it into gas oxygen.DEAR Liquid air separation unit.The solubility of N2O in water is very small, and N2O cannot be separated and removed with the process air after passing through the air filter, compressor, cooler and water separator. Most of N2O will be brought into the molecular sieve purifier, and the adsorption capacity of molecular sieve for N2O is less than that for CO2.DEAR Liquid air separation unit.The overall heating procedure in cold state is shutdown - liquid discharge - standing - cold blowing - heating - system blowing. The end point of heating is until the outlet temperature of heating gas reaches normal temperature. The overall heating operation procedure in hot state is divided into two steps: heating and blowing. In order to completely remove the moisture and achieve the purpose of drying, the outlet temperature of heating gas should be higher than normal temperature. In order to remove solid impurities, the blowing out process is more important in the overall heating operation under hot state.
The dew point can be measured by a special dew point meter. For example, the dew point of air after drying is - 50 ℃. According to table 8, the saturated moisture content corresponding to - 50 ℃ is 0.038g/m3, which indicates that the air still contains these moisture. If the dew point is - 60 ℃, the saturated moisture content is 0.011g/m3. The lower the dew point, the higher the degree of drying.DEAR Liquid air separation unit.Under the condition of 3200m3 / h oxygen generator, the air volume is 19580m3 / h, the absolute pressure of compressed air is 0.59mpa, the temperature of air entering the air cooling tower is 50 ℃, and the temperature of air leaving the air cooling tower is 30 ℃. In this case, the amount of water released from the air through the cooling tower can reach 220kg / h.DEAR Liquid air separation unit.Maintain the water level of the air cooling tower; the water spray volume should not be too large; the water quality should meet the requirements, reduce the inlet water temperature and reduce the scale. In case of water inflow accident, the working condition of the air cooling tower should be dealt with first, the water supply of the water pump should be stopped, the water level of the air cooling tower should be lowered, and the normal working condition should be restored.
