Patent ID: 11945026
Assignee: NANJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS
Field: Materials, metallurgy (Chemistry)
Classification: CPC B | IPC B

Claim 4:
5. The multi-path internal microporous efficient refrigeration method for the frozen sand mold according to claim 1, wherein when the low-temperature refrigeration system operates, a liquid nitrogen tank is first opened to exhaust air inside a pipeline, a temperature of a space inside the pipeline decreases after a period of time, and liquid nitrogen is delivered into the pipeline in a liquid form; next, a nitrogen tank is opened, a nitrogen flow meter is adjusted, nitrogen is enabled to enter a gas-liquid mixing chamber and mixed with the liquid nitrogen, the nitrogen exchanges heat with the liquid nitrogen by low-temperature characteristics of the liquid nitrogen, and low-temperature nitrogen is ultimately formed and delivered to a condenser tube inside the multi-path internal microporous efficient refrigeration device through a thermal insulation pipeline to cool the frozen sand mold.