Vapour absorption system_lect_5

Refrigeration

and

Air-Conditioning

Lecture-5

Mechanical Engg. Department

Geeta Engineering College

Naultha Panipat

Simple vapour absorption system

Simple vapour absorption system• In this system an absorber, a pump, a generator and a pressure

reducing valve replace the compressor.

• The low pressure ammonia vapour leaving the evaporator

enters the absorber where it is absorbed by the cold water in

the absorber.

• The water has the ability to absorb the large quantity of

ammmonia vapour.

• Heat is removed in the absorber to increase the absorption

capacity of water.

• The strong solution in the absorber is pumped to the genarator.

• The strong solution is heated in the generator during the

heating the ammonia vapours are driven off the solution and

the weak solution flows back to the absorber.

Practical vapour absorption system

Practical vapour absorption system

• The simple vapour absorption system discussed previously is

not very economical.

• To improve the effectiveness it is fitted with the accessories an

analyser, a rectifier and two heat exchangers

Ammonia Hydrogen (Electrolux)

Refrigeration system

Electrolux Refrigeration system• This type of refrigerator is also called three fluid absorption

system

• The main purpose of this system is to eliminate the pump so

that in the absence of moving part the machine becomes

noiseless.

• The three fluids used are ammonia, water and hydrogen.

• The ammonia act as the refrigerant.

• The hydrogen being the lightest gas is used to increase the rate

of evaporation of the liquid ammonia passing through the

evaporator.

• Water acts as the solvent.

Lithium Bromide Absorption system

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