Simple Amonia refrigerator

Hi Guys (and Gals) - I'm not from your industry and your forum is interisting although I dont understand much. My son wants to build a kerosine/amonia fridge for a science project - does not have to be complex but it must work. I got the following picture on the web but there's a few things I dont understand.
1. Water Seperator - the picture does not show what it looks like or how it works.
2. Is the evaporator basically 4 pipes that's interconnected but twisted together?
3. The boiler looks complex? how does the strong amonia get to (d) container with the weak amonia?

Would be much appreciated if someone will take the time to help.

amonia is not the only gas in the pipes it is a poisonous gas and if you breathe it in it can attack your lungs

If it is just for a science progect I'm sure there is a simple test tube arrangemnt to demonstrate the principle with amonia. I saw it on a movie once - you guys know the movie where the guy invents or discovers the process.

http://en.wikipedia.org/wiki/File:Absorption_fridge.jpg

Might help visualize. The boiler/aqua separator/generator incorporates a trapped liquid propulsion arrangement like a coffee percolator....That is only circulation in unit not driven entirely by differences in partial pressures of mixtures. Water separator works by impingement, though some have a form of demister pad. The geomtry of each component is critical as eventually its graveity that delivers wek aqua back to the absorber, from the annular space around the boiler's discharg e tube; particularly as the warm water returns from the inlet side of the condenser.

There's a lot of "tube in tube" construction here which is pretty involved...And open flames and either hydrogen or ammonia do not make freindly combinations.

Hi,

a much easier and safer option would be to use a peltier device. This is an electrical component which can be readily bought. The priciples is dissimilar metals, the current flow through the one junction produces heat while as the opposite end it get cold.

Major components you will need are a 12V gel cell a simple thermostat to control the temperature and a heatsink and fan to cool the hot side of the peltier device.

Google "peltier projects" and similar, there are lots of articles. Many people use these to cool a single can of cooldrink.

If you reverse the current flow then the unit can be used to heat.

Cheers
Andrew

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Originally Posted by joeBotha

Hi Guys (and Gals) - I'm not from your industry and your forum is interisting although I dont understand much. My son wants to build a kerosine/amonia fridge for a science project - does not have to be complex but it must work. I got the following picture on the web but there's a few things I dont understand.
1. Water Seperator - the picture does not show what it looks like or how it works.
2. Is the evaporator basically 4 pipes that's interconnected but twisted together?
3. The boiler looks complex? how does the strong amonia get to (d) container with the weak amonia?

Would be much appreciated if someone will take the time to help.

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Hi, joeBotha :)

stay beside and try to help to your son ... here is one link ...

http://www.coolmaxbar.com/service/20...007062910.html

another one here ...

http://lionheart.net/fridge/descript.htm

... be careful please ... safety first, always ...

this type of fridge was very common before 40+ years ... no rotation parts .. maybe some leaks ... if stop working just tumble the fridge upside down and switch the heater again or ignite a gas ... and much more friendly then today's fridges ... but business is business ... and for that reason a big producers of *****s - (all *****s are poisons - so named green *****s also, but make a big income to producers) are against ammonia which is a natural compound ...

I will try to find some more info to help ... I will send it to you via email ... found it in your vCard...

Best regards, Josip :)

I would not even suggest that you son tries to build one, the mysteries of absorption systems is a fine line between death and distruction.
Suggest he buys an old caravan type model, rips out the unit and set on a stand, heat source could be kerosene LPG or electric.
Or as some one suggested a peltier bridge system, commonly known as thermoelectric cooling.