2. The original air filter adopts the most advanced pneumatic self-cleaning air filter in China and imported filter element, and its service life can reach 1-2 years. Modular design, small floor space, convenient installation and maintenance, non-stop maintenance. Imported PLC controller and imported solenoid valve are used for automatic pulse back-blowing dust removal, which can realize automatic unmanned operation. PLC is equipped with complete sets of equipment and placed next to the machine. The filtration efficiency is 99.99% and the filtration accuracy is 65438±0um.
3. The filtered air enters the centrifugal air compressor and is compressed by the compressor. Both the feed air compressor and the booster air compressor adopt centrifugal compressors, which are driven by steam turbines or motors. The function of feed air compressor is to provide pressurized feed gas for the device, and the function of pressurized air compressor is to provide gas source for capacity expansion and hyperbaric oxygen gasification for the device. The feed air compressor can adopt built-in cooler (Mann turbine) or external cooler (Siemens, etc.). ), equipped with impeller cleaning mechanism, can easily clean the impeller. The adjustment modes are inlet guide vane adjustment and variable speed adjustment, which can meet the requirements of stable operation of air separation under variable load operation.
And then enters an air cooling tower for cooling. Cooling water is water cooled by water cooling tower and ammonia evaporator. The air passes through the air cooling tower from bottom to top, and is purified while cooling.
The air pre-cooling system adopts a new high-efficiency air pre-cooling system and a cooling tower with water. The air cooling system makes full use of the unsaturated hygroscopicity of polluted nitrogen through the water cooling tower to reduce the temperature of cooling water, thus reducing the refrigeration capacity of ammonia cooling device and saving investment and operating expenses. The air cooling tower and the water cooling tower adopt specially designed random packing, which has high heat and mass transfer efficiency, great operational flexibility and small resistance drop.
6. The air cooled by the air cooling tower enters the molecular sieve purifier for switching use, and carbon dioxide, hydrocarbons and moisture in the air are adsorbed. The molecular sieve purifier is used by two switches, one working and the other regenerating. The switching period of the purifier is about 480 minutes, and it is automatically switched at regular intervals.
7. The molecular sieve adsorption system adopts long-period double-bed purification technology, and the switching system adopts shock-free switching control technology. The single cylinder adsorption time of molecular sieve adsorption system is 4 hours, and the switching period is 8 hours. Regenerated gas heater adopts energy-saving steam heater. The purified air is divided into two streams. A stream of air enters the low-pressure plate heat exchanger, cooled by the returning dirty nitrogen, and directly enters the lower tower.
8. The other part of the air goes to the booster air compressor, which is divided into three parts: the first part is instrument air and factory air, which are compressed and cooled by the first-stage booster air compressor and sent to the instrument air pipe network; The second part of the air is pressurized by the second-stage booster air compressor, then enters the expander booster fan for pressurization, then enters the high-pressure plate heat exchanger after being cooled to normal temperature by the cooler, and then is pumped out from the middle and lower part of the plate heat exchanger to enter the expander for expansion. The expanded air is sent to the lower tower. The third part of the air continues to be pressurized in the third section of the pressurized air compressor, and after cooling, it enters the high-pressure plate heat exchanger to exchange heat with high-pressure liquid oxygen. High-pressure air enters the lower tower after throttling.
9. After the air is preliminarily rectified in the lower tower, liquid air, pure liquid nitrogen and dirty liquid nitrogen are obtained, which are supercooled in the cooler and throttled into the upper tower. After further rectification in the upper tower, liquid oxygen is obtained at the bottom of the upper tower, compressed by the liquid oxygen pump, then enters the high-pressure plate heat exchanger, reheated, and then comes out of the cold box and enters the oxygen pipe network. In addition, liquid oxygen is pumped from the bottom of the upper tower and sent to the liquid oxygen storage tank for standby.
10. Pressurized nitrogen is obtained from the top of the lower tower, reheated by the low-pressure plate heat exchanger and discharged from the cold box.
1 1. The low-pressure nitrogen pumped from the upper tower is sent to the low-pressure nitrogen pipe network. Another liquid nitrogen is pumped to the liquid nitrogen storage system.
12. After passing through the cooler, high-pressure plate heat exchanger and low-pressure plate heat exchanger, the polluted nitrogen discharged from the upper part of the upper tower is divided into two parts: one part enters the steam heater of the molecular sieve system as regeneration gas of the molecular sieve, and the other part goes to the water cooling tower.
13. Draw a certain amount of argon fraction from the middle of the upper tower and send it to the crude argon tower. The crude argon tower is structurally divided into two sections, and the reflux liquid at the bottom of the second section is pressurized by the liquid argon pump and sent to the top of the first section as reflux liquid; The argon fraction is rectified by a crude argon tower to obtain crude argon, which is sent to the middle of a pure argon tower, and after rectification by the pure argon tower, refined argon with argon content of 99.999% is obtained at the bottom of the tower.