| 摘要 |
The method for cooling a hot web by passing it across a rotating thermally conductive chill roller having a circulating coolant therein. In accordance with this invention, one introduces as a coolant to the chill roller a liquid refrigerant at a temperature and pressure permitting the refrigerant to exist in liquid form, the temperature being also above the dew point of the ambient atmosphere. Likewise, the boiling point of the refrigerant at the desired temperature and pressure is low enough to cause heat to be absorbed by the chill roller substantially by vaporization of the liquid refrigerant. One then withdraws refrigerant vapor from the chill roller, and typically refrigerates it to reform the liquid phase for return to the chill roller. Typically, chlorofluorocarbon refrigerants are preferred.
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