On Tue, Jan 29, 2002 at 12:58:31AM -0500, Lee Bonnifield wrote: > hello... hello... is this thing on? > > I'm new here. I heard there's interest in using solar powered ammonia > absorption cooling to condense clean water out of the atmosphere. I > hadn't thought of doing that before, but it sounds like a good idea. > Welcome, Lee! I'm still backlogged in mail, so I never replied to this, but glad to have you on the list! > I think I know some technical details I can share regarding ammonia > absorption cooling. Around 1975 I studied "The Ammonia Absorption > Refrigeration Machine: Advanced Theory and Practice" written by > Voorhees about 1920. This described in great detail the state of the > art for large industrial cooling machines. > > I've forgotten a lot, and I don't have a copy of the book (stuffed > with graphs which I manually digitized) but luckily when it was fresh > knowledge I wrote a PL/I computer program to go thru the same solution > steps Voorhees described. Twenty years later I translated it to run in > QBASIC, which I can still run. I may be able to answer questions about > the interactions of variables like these: > > EVAPORATOR TEMP > AIR TEMP > TEMPERATURE STRONG INTO GENERATOR > TEMP WEAK FROM GENERATOR > TEMP RISE IN GENERATOR > TEMP DIFFERENCE: CONDENSER - AIR > TEMP DIFFERENCE: ABSORBER - AIR > [...] This is fantastic stuff! Thanks for posting it! > > This is ALL THEORY, I have never built an ammonia absorption system, > and Voorhees is not alive to check that I correctly programmed his > equations. These calculations are for continuous operation but many of > the results could be applied with some thought to batch operation. > > I am very ignorant of modern practice -- please send me URLs or emails > describing current real ammonia absorption systems, and catch me up > with what has been said / asked here. You can find web-archives of previous list postings here: http://reality.sculptors.com/~hyprmail/clean-water/ Check also this post, which I made just a few days before you joined, which has a data table on some of the condensation/dew points at different temperatures: http://reality.sculptors.com/~hyprmail/clean-water/0087.html I'm also not too familiar with ammonia absorption details, just the overall theory. One cool device I saw at Real Goods is a Solar Ice Maker that runs on the ammonia absorption cycle. This is what originally gave me the idea of using ammonia for a condenser, since if they could get cold enough to make ice, they could certainly make it cold enough to condense water. The machine is custom-built, and pricey, but considering that it can supply a remote village with refrigeration for between $10,000-$14,000 it's actually quite affordable. http://www.realgoods.com/renew/shop/product.cfm?dp=3104&ts=1062532&kw=ice%20maker Seems like we could make only slight modifications to a system like this in order to produce a conenser unit. I'm also currently (slowly) working on a new proof-of-concept condenser which uses a solid-state thermoelectric heat-pump to cool water for pumping through the coils. I haven't fired it up, yet, but am almost ready to try it. > > Lee Bonnifield > -- Pat ___________________Think For Yourself____________________ Patrick G. Salsbury - http://reality.sculptors.com/~salsbury/ Autopilots for ground- and air-cars: http://reality.sculptors.com/lists.html --------------------------------------------------------- || loka samastha sukhino bhavanthu || "May all beings in all the worlds have peace and happiness."
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