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Manufactured Ice

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  P- 277

2025-12-27

509

 In the making of manufactured ice, the water to be frozen is poured into cans set in a large tank containing brine (Fig. 1). Coils of pipe are placed in the tank, and in these coils ammonia which has been liquefied by pressure is allowed to vaporize. The pressure is reduced by pumping the ammonia vapor back into the compressor. By the vaporization of the liquid and the rapid expansion of the vapor, the temperature of the brine is lowered to about - 10° С. The freezing of the water in the cans goes on rapidly, the crystals of ice extending from all sides. The heat produced in compressing and liquefying the ammonia is allowed to dissipate before the liquid ammonia is returned to the coils. The cooling of the compressed ammonia is brought about by causing cold water to drip over the pipes leading from the compression cylinder, before they connect with the expansion cylinder. This cools the ammonia before it enters the expansion cylinder and thus secures a lower temperature in the brine tank.

FIG.1