building a wood fired intermitent absorption fridge

I would like to build my own fridge that uses ammonia as the refrigerant and would be heated by a small wood fire. I have looked a few refrigeration textbooks and the lead me to believe such a system is relatively simple compared to continuous absorption systems.


How do I calculate the amount of water/refrigerant needed as well as the btus needed to boil out the ammonia?

Where does one obtain the ammonia? According to the book I have I need distilled water and a mixing tank plus some rust inhibitor. Does this stuff come premixed?

I understand that because of the corrosive nature of ammonia the system must be made from steel. What psi should I pressure test the system to?

Am I crazy to even attempt this?


thanks

I'd go with your last statement.

How ever you can get easily premade amonia fridges you can modify to be steam driven, and use a wood boiler to make the steam!

wwwdotnh3techdotorgslashabsdothtml

sorry for this funny url syntax but the board says I can't yet post links

Here is a rather simplified example of what I would like to try. Does anyone here have experience with this type of refrigeration system? It seems like it may predate the current refrigeration knowledge.

The check valve seems easy enough but what about this restrictor? It sounds like something that only allows the ammonia to drip through.

thanks
Joseph

It's a good link, here its is in a more readable way
http://www.nh3tech.org/abs.html
This is done to avoid spammers posting annoying messages.

Quote:

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Originally Posted by josephcrawley

wwwdotnh3techdotorgslashabsdothtml

sorry for this funny url syntax but the board says I can't yet post links

Here is a rather simplified example of what I would like to try. Does anyone here have experience with this type of refrigeration system? It seems like it may predate the current refrigeration knowledge.

The check valve seems easy enough but what about this restrictor? It sounds like something that only allows the ammonia to drip through.

thanks
Joseph

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Think of a steel cap with a tiny hole drilled in it, there ya go!