| 摘要 |
A drum contact freezer system which reduces or eliminates a stagnant layer of refrigerant on an interior surface of the drum freezers is provided. A boiling refrigerant is sprayed into the interior of the drum freezers to scrub an interior surface thereof having the stagnant layer. This scrubbing reduces or eliminates the stagnant layer and thus provides an enhanced rate of heat transfer. The boiling refrigerant is preferably in a temperature range of approximately -100 DEG F. to -40 DEG F. at or near atmospheric pressure. Additionally, the boiling refrigerant may be circulated within the drum freezers by providing troughs on the interior surface thereof to help lift the boiling refrigerant and prolong contact between the boiling refrigerant and the interior surface of the drum freezers to provide a further enhanced rate of heat transfer. The material to be frozen may be provided on an outer surface of the drum freezers using a drop nose feed conveyor, soft sponge rollers, or a sprayer assembly depending upon the type of material to be frozen. |
