Vapour Absorption Refrigeration Systems:
John Leslie in 1810 kept H2SO4 and water in two separate jars connected together. H2SO4 has very high affinity for water. It absorbs water vapour and this becomes the principle of removing the evaporated water vapour requiring no compressor or pump. H2SO4 is an absorbent in this system that has to be recycled by heating to get rid of the absorbed water vapour, for continuous operation. Windhausen in 1878 used this principle for absorption refrigeration system, which worked on H2SO4.
Ferdinand Carre invented aqua-
ammonia absorption system in 1860. Water is a strong absorbent of NH3. If NH3 is kept in a vessel that is exposed to another vessel containing water, the strong absorption potential of water will cause evaporation of NH3 requiring no compressor to drive the vapours. A liquid pump is used to increase the pressure of strong solution. The strong solution is then heated in a generator and passed through a rectification column to separate the water from ammonia.
ammonia absorption system in 1860. Water is a strong absorbent of NH3. If NH3 is kept in a vessel that is exposed to another vessel containing water, the strong absorption potential of water will cause evaporation of NH3 requiring no compressor to drive the vapours. A liquid pump is used to increase the pressure of strong solution. The strong solution is then heated in a generator and passed through a rectification column to separate the water from ammonia.
The ammonia vapour is then condensed and recycled. The pump power is negligible hence; the system runs virtually on low- grade energy used for heating the strong solution to separate the water from ammonia. These systems were initially run on steam. Later on oil and natural gas based systems were introduced.
In 1922, Balzar von Platen and Carl Munters, two students at
Royal Institute of Technology, Stockholm invented a three fluid system that did not require a pump. A heating based bubble pump was used for circulation of strong and weak solutions and hydrogen was used as a non-condensable gas to reduce the partial pressure of NH3 in the evaporator. Geppert in 1899 gave this original idea but he was not successful since he was using air as non-condensable gas. The Platen-Munters refrigeration systems are still widely used in certain niche applications such as hotel rooms etc.
Royal Institute of Technology, Stockholm invented a three fluid system that did not require a pump. A heating based bubble pump was used for circulation of strong and weak solutions and hydrogen was used as a non-condensable gas to reduce the partial pressure of NH3 in the evaporator. Geppert in 1899 gave this original idea but he was not successful since he was using air as non-condensable gas. The Platen-Munters refrigeration systems are still widely used in certain niche applications such as hotel rooms etc.
Another variation of vapour absorption system is the one based on Lithium Bromide (LiBr)-water. This system is used for chilled water air-conditioning system. This is a descendent of Windhausen’s machine with LiBr replacing H2SO4.
In this system LiBr is the
absorbent and water is the refrigerant. This system works at vacuum pressures. The
condenser and the generator are housed in one cylindrical vessel and the evaporator and the
absorber are housed in second vessel. This also runs on low-grade energy requiring a boiler
or process steam.
Posts
2 comments:
Offering efficient solutions to the consumers with trust worthy policies, we don’t compromise on quality iqf freezer manufacturers in chennai
Great.! It was very useful information about Vapour Absorption Refrigeration Systems and please also update about IQF freezer manufacturers
Post a Comment