Absorbtion chiller Question

[balerjoe]

I'm a newbie to the refrigeration world. I know there are lithium bromide absorbtion chillers. Some told me today there are Ammonia & water instead of the lithium bromide. Is this true? If so how do they work?

[rbartlett]

google is your fiend

cheers

richard

[Argus]

google is your fiend

cheers

richard

Google really can be a fiend, sometimes, Richard!



Let?s put some facts to the question.

There are two type of cooling systems that use the absorption principle. The common denominator to both is that they contain two working fluids in mixture. One is always the absorbent, the other the refrigerant.

When using Lithium Bromide, the LiBro is the absorbent and the refrigerant is (distilled) water. The whole system utilises the low boiling point of water at vacuum pressures. Generally they are very large machines, usually in the megawatt range. I commissioned a Carrier 16JB some years ago that weighed in at about 100 tons R (about 350kW) and it was considered a tidler. They are usually around 500 - 1000 Ton R.

The other form uses ammonia and water. Ammonia is the refrigerant and water is the absorbent. Electrolux patented the idea a few decades ago and you can see their descendants in all the small mini-bar coolers in hotels etc that work on this principle.

An Italian company called Robur marketed a water chiller that used the same principle as the Electrolux units and they are around 20 ? 30 kW in capacity and gas fired.

Web site here.

http://www.robur.com/pag_tecnologia.jsp?idl=2&id_sez=48

There may be others that I don't know of.


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Cooking Forum

[Brian_UK]

Robur, Electrolux, Arkler all started in the States; good machines and finally caught up with the 21st century.

[ansellmayor]

The Li.Br. absorption chillers use distilled water as the refrigerant and the Li.Br. is the carrier agent that moves the refrigerant around in the circuit. Heat is applied to the Li.Br. in the generator section to remove the refrigerant, and conversly, heat is removed at the condenser section to re-absorb the refrigerant and repeat the cycle. Trane and Carrier both have excellant diagrams on these kinds of units, because they can be rather complicated in simply explaining them. Steam or another heat source is used to drive the refrigerant around in the circuit. The chiller is in a deep vacuum, thus enabling the refrigerant(distilled water) to boil at approx. 2 to 3 degrees Cel. Ammonia systems use ammonia as the refrigerant and water as the carrier agent. Again, heat is used to drive the refrigerant around in the circuit.

[717_dealler]

Dear Mr.Brain_UK, I am a new member in the forum , I joint in to looking for a technical & practical information about ammonia absorption air conditioning machines, specially Robur trademarked .
As I know u had worked with such kind units .
I wonder if u could give me a hand to understand it more better.
First , how can that machines work at low temp. lower than freezing temp. of water which still solute in small portion even when ammonia vapor leaving the generator & condensing without block the pipeline of liq. Ammonia after the expansion device as happen in R-12, R-22 machines ?
Thanks a lot for your time
717_dealler

[Brian_UK]

Have you looked at the Robur site for information?

Not the same expansion devices used.
See also the moving graphics here....

http://www.robur.it/documenti_prodot...0225121839.swf

[717_dealler]

Dear Brian , I saw it before ,I know in air conditioning system as window type as example is not problem beause the temprture of refrigurant is not lower the freezing temp. due to the Hi. pressure of refrigurant .
I read in ashra hand book that a small part of water is run with ammonia , its a problem specially if the machine work for refrigeration in temp. lower than freezing temp.
by the way do u work on Robur machines ?

[717_dealler]

Dear Brian , I saw it before ,I know in air conditioning system as window type as example is not problem beause the temprture of refrigurant is not lower the freezing temp. due to the Hi. pressure of refrigurant .
I read in ashra hand book that a small part of water is run with ammonia , its a problem specially if the machine work for refrigeration in temp. lower than freezing temp.
by the way do u work on Robur machine ?

[paddy]

on all large scale Abo,s there are 2 pumps, 1 for the refrigerant and 1 for the solution, the heat source (generator) is used to separate the low concentrated solution into highly concentrated refrigerant and as a by-product steam, which is then passed through the condenser where it obviously condenses back into water and is then pumped into the evaporator. this should helpyou a bit

[717_dealler]

Hi Brain_UK ,paddy I made search to get more information to understand how absorption chillers ( Robur , trade mark) work , & what it parts ‘s function & likeness .
I insure it was hard and long way ,even some time finished with closed end , specially when u looking for some thing u heard about it ,but u never see it
I would like ask some question I hope u could give me answers for it & other members kindly can do too .
* why the information that dealing about ammonia refrigeration is not much available like other refrigerants ? , despite its older in this field .
* did any one in the forum has experience on ( Robur ) absorption chillers or any other trade mark chillers works by NH3-WATER absorption ( small cooling capacity chillers ) could I bother him with my questions in this field of refrigeration ?

Thanks for your help and your time