摘要 |
Cooling apparatus comprises a cooling chamber such as a freezing tunnel having a pipeline for introducing liquid nitrogen into it and an exhaust passage for cold nitrogen vapor. The exhaust passage extends through a rotary regenerative heat exchanger. Downstream of the heat exchanger is a fan operable to draw the exhaust gas through the heat exchanger. A second passage extends through the heat exchanger and is arranged for the flow therethrough of relatively warm air, whereby, in operation, the air is able to transfer heat to the exhaust gas in the heat exchanger.
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