Air separation equipmentThe start-up includes three stages: cooling, hydrops and purification. For a certain equipment, the start-up time is roughly certain. For low voltageAir separation equipment,Air compressorThere is no room for adjustment of the pressure, generally depending on two setsExpanderWork at the same time to increase the refrigerating capacity in the start-up stage and shorten the start-up time. Even so, according to the maximum refrigeration capacity and the cooling required by cooling and Hydrops of the device, the start-up time of the device needs to be more than 36 hours.
Large air separation plantGenerally, liquid oxygen storage tanks are also equipped as emergency standby oxygen. If necessary, can liquid oxygen be filled into the tower to shorten the start-up time of the air separation plant? Theoretically, it is completely possible. For example, if 1 m is reversely charged to the main cold inside3Liquid oxygen, equivalent to providing 0.47 × 10 from the outside6The cooling capacity of kJ is about 5000 m3The refrigerating capacity of the expanded air in 2 H. Some factories have done tests, filling 20 m into the tower when starting3Liquid oxygen, for 6500 m3/H air separation plant can shorten the start-up time by 16.5 h; for 10000 m3/H air separation plant can shorten the start-up time by more than 8 hours.
Of course, when filling the tower with liquid oxygen, firstly, pay attention to the timing, and be sure to wait until the cooling of the unit starts to produce liquid in the main cooling, and then pour it inside, in order to avoid damaging the equipment due to thermal stress caused by excessive temperature difference; the second is to pay attention to the filling pressure. Because only higher than the tower bottom pressure can into liquid oxygen, but not more than liquid oxygen tank relief valve set pressure, to avoid relief valve action.
