Construction and Working of Ammonia - Water system in Vapor Absorption System :

I) AMMONIUM WATER SYSTEM :

An Ammonium - water refrigeration system uses ammonia as refrigerant with water as absorbent.

WORKING OF THE SYSTEM :

* After expansion in the valve, the liquid refrigerant enters the evaporator. There, it absorbs heat from the place to be refrigerated. Its phase changes from liquid to vapor.

* Then, the vapor reaches absorber where it is readily absorbed in a low temperature absorbing medium. So, it mixes with the weak solution, thus the solution now becomes strong. Some heat being rejected during the process.

* This strong solution is pumped to the high pressure and passes through heat exchanger. Here, it takes some heat from the weak solution which is throttled and returning back to the absorber. This increases the efficiency of the system.

* Generator heats the strong solution, thereby forming Ammonia vapor. During heating, some water may also be vaporized. This water vapor is separated in the analyzer.

* Even after this, if any water vapor is present, that will be condensed in the rectifier, by passing cooling water.

* Now, only pure ammonia vapor enters the condenser and cooling water is passed through the condenser. Because of the condensation refrigerant vapor becomes liquid and this liquid goes to the receiver. Thus the cycle continues.

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Mechinopedia For Mechanical Engineers

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