LOW-TEMPERATURE DEVICE FOR SEPARATING AND PURIFYING GAS BASED ON SMALL-SIZED LOW-TEMPERATURE REFRIGERATING MACHINE

摘要

A low-temperature device for separating and purifying gas based on a small-sized low-temperature refrigerating machine comprises a primary heat exchanger, a secondary heat exchanger, a quaternary heat exchanger, at least one small-sized low-temperature refrigerating machine, and at least one liquid collecting tank. The small-sized low-temperature refrigerating machine comprises a first cold head and a second cold head; the secondary heat exchanger is arranged on the first cold head to form a primary cold head heat exchanger; the quaternary heat exchanger is arranged on the second cold head to form a secondary cold head heat exchanger; a mixed gas outlet is connected with an inlet of the primary cold head heat exchanger; an outlet of the primary cold head heat exchanger is connected with an inlet of the liquid collecting tank; and a gas outlet of the liquid collecting tank is connected with an inlet of the secondary cold head heat exchanger. By adopting the primary and secondary cold heads of the small-sized low-temperature refrigerating machine as cold sources, the gases with different condensing temperatures are liquefied and solidified respectively, accordingly high-purity gas at a lower condensing temperature is obtained, and two or more gases can be separated and purified at a lower cost.