Air separation system's heat exchange system and product delivery system

Air separation unit heat exchange system

Strictly speaking, the heat exchange system is designed with multi stream mixed media in the same heat exchanger, so that the heat transfer of each medium is automatically balanced and the energy consumption is the lowest. However, for the internal compression process, all heat exchangers will be high-pressure heat exchangers, which will increase the accumulation of investment. Therefore, it is more economical to use the method of separating high and low pressure for the organization of internal compression heat exchangers above 20000, and all high-pressure heat exchangers below 20000.

Air separation unit product delivery

For low-pressure oxygen and nitrogen products, the product regulating valve and vent flow path are set to vent into the silencer (the nitrogen internals are carbon steel and the oxygen internals are stainless steel). The waste nitrogen shall be vented to the water cooling tower (it plays the role of waste nitrogen venting, dispensing regeneration gas and adjusting the pressure of the upper tower. It is required that the diameter of the water cooling tower can meet the discharge requirements. In particular, when nitrogen is also introduced, the pressure of the upper tower cannot be suppressed. The resistance of the water cooling tower is 6kpa (8m high packing), the pipeline and valve are 4kPa, and the pressure difference to the atmosphere is 2KPa, a total of 12kpa).

For the venting of high-pressure oxygen products, two-stage throttling is adopted. First, the high-pressure product gas is throttled to 10barg, passes through the eccentric reducer, and a Monel noise reduction plate is set in the middle. Then, the pipeline diameter is expanded through the eccentric reducer, and the flow rate of oxygen medium is controlled below 10m/s, and then flows into the silencing tower for throttling and venting. The silencing element is stainless steel; For high-pressure nitrogen products, the nitrogen products are throttled to 10bar, passed through the stainless steel noise reduction plate, and then led to the silencing tower for throttling and venting. The silencing element is carbon steel; The oxygen valve shall not be operated by people (the regulating valve shall not be equipped with a hand wheel, and the manual valve shall be placed in the explosion-proof wall).

The silencing tower can also be integrated with the venting of the compressor system. The noise reduction of the air compressor booster (calculated according to the air compressor capacity) is led into the silencing tower and the pressure relief air of the purification system. The booster returns and discharges.