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Where can literature, experience, technical info be found regarding the repair of small absorption fridges (mostly Electrolux made)?
The most common advice they give is turn it upside down for some hours and then turn it again and switch it on.
But on a very small Dutch forum I co-moderate, there's a person asking how you need to recharge these.
I don't have a clue what's in it and in what proportions.
What's the procedure to refill it?
Lithium bromide should never be refilled. It is hazardous, and very much toxic. It is a strong reagent. It can penetrate the body via the skin and lungs.
It causes various damages to kidneys, and to nerve system, like psychosis and mental deterioration.
It can only be handled with respiratory apparatus and complete heavy rubber clothing.
These are factory sealed when made and can not be recharged, a new unit is required if the ammonia has leaked. as for turning upside down for a few hours, it only takes seconds. turn over then shake, the gas locking effect will clear almost instantly. if it does not then it is scrap.
Two items of sound advice there Peter, it's a matter not to be taken lightly at all.
We come across these alot, personally myself I dont like them. They use a dangerous substance, which is not sutiable for what applications they are used in.
Using this method is good, but most of the time its only a temporary fix.
A very sweeping statement there Takeshi, I trust that you can back that up with some facts and figures.Quote:
Originally Posted by Takeshi
I just dont like the thought of them being used in small camper vans, hospitals etc where if there was a leak, especially in a camper van, could possibly kill you. I know normal refrigerants are bad - but the stuff used in these irritates your throat badly and possibly stop you from breathing, where-as HFC's/CFC's I think personally myself are much safer, unless released in huges qauntities.
I don't know if the Electrolux units are ammonia or LiBr? In any case, any chemical is dangerous if handled incorrectly. In the USA, every RV (recreational vehicle, I believe you call them caravans in Europe) has an ammonia absorption unit. These units last for many years and are trouble free if operated correctly. The one in my travel trailer is a 1995 model and the only problem has been a control board.
If you operate them out of level, you can get some crystalization and the unit will stop working. SOMETIMES you can get them running again, again by turning them on the top and a couple of side for a few hours.
As a point of interest, the LiBr units are not well suited as most refrigerators have a freezer section as well. In the LiBr unit, the water is the refrigerant and the LiBr is the transport agent. Water freezes at 32 dF (0 dC). In ammonia absorption units, the water is the transport agent and the ammonia is the refrigerant. Ammonia absorption systems operate well below freezing when applied as double and triple effect systems. We have a triple effect ammonia absorption sytem on heat recovery on the west coast of the United States.
To state that the sytems are unsafe is a lack of understanding of the application. First look at the thresh hole limits where you first smell ammonia, then where it is an irritant, then again where it will cause eye or respitory damage and finally death. These limits are very wide.
A RV refrigerator will ususally fail with a small pin hole leak and is not noticed until the unit stops working or the door has been closed for several days and then opened. Then you only get a whiff. You wll smell more ammonia if you use ammonia to scrub the kitchen floor. I have never heard of a massive rupture of a unit.
Ken
I had a RV owner come to me with his fridge not cooling. I was expecting to be an absorbtion unit, but it had a small 24 volt AC compressor unit with a inverter so it could run on 12 volt DC and mains,so there are alternatives.
By the way how do you scrap an absorbtion fridge:confused:
there are 2 ways to scrap an ammonia absorber.Quote:
Originally Posted by Mickvee
1, Take it to your local council refuse depot and supply them with a valid domestic postcode then they will dispose of it.
2, Dump it in a field when nobody is watching.
i suggest that number 1 is the more legal of the two and do it in a car not a signwritten van as you will get charged for being trade.
Ammonia and absorption fridges are not necessarily synonims
txiceman is right the electrolux units are ammonia, and if the stat is okay(not open circiut) then its down to either the electric heater element or the gas jets , which ever is used to heat the unit. generally turning it upside down as daft as it sounds does work but if the unit fails you dont mess with it you just replace the unit
Quote:
Originally Posted by Peter_1
Hi
Peter plz contact me for info on dom/absorpion
louw2@aapt.net.au
Yer this i agree with take this advice as this is good advice :)Quote:
Originally Posted by slingblade
Electrolux RV Refrigerators [in Australia] are Ammonia Absorption type Units. They are charged with Aqua Ammonia, Sodium Chromate [corrosion inhibitor]& hydrogen. The system works on Dalton's law of partial pressures and the hydrogen charge pressure is approximately 400 psi [2800 kPa]. The units can be recharged, however finding out the information so far as I have found has been closed shop.
I hope this sheds some light on your question.
These absorption units can be repaired and the charge consists of ammonia, water, hydrogen and sodium chromate. The pressure is about 2000 kpa, depending on the type of unit.
In South Africa there were more than five manufacturers (myself included) about 20 years ago. Now there is only one. There are still quite a few people here repairing these units.
Hello Refrigeration Engineer Family
As I stated in a post [04/07/2008], these units can be repaired/rebuilt, however, you need the right fittings & equipment to do the job. Plus Aqua Ammonia, Sodium Chromate & Hydrogen, together with the correct formula to give you the right charge.This last information is kept closely guarded, or available at a rediculuous price.
Before I go, I have never heard of a domestic absorption unit using Lithium Bromide.
I hope this helps.
Hi,
I have bough a caravan it came with a Bosch absorption fridge, I have managed to get it working by turning it upside down, but it worked for a week and stopped. I turned it upside down again it worked for 2 days. So now I have to turn in it over every couple of days to get it working. Is it possible that the ammonia is crystallizing and this is causing the fridge not to work? If it is it so how can I fix this problem? Or maybe it is a different problem? I would really appreciate your help.
i would really appreciate if you could help me out, as i am looking to build an absorption refrigerator based on the electrolux design by refabricating it. plz give me some technical data related to its fabrication and charging if possible.Quote:
Originally Posted by Fridgeteach
Worked for Electrolux through the 70's and 80's,changed countless units as we also built the gaslux ones sold by the old gas board and repaired them.Had two leak when working on them over 15 years,not life threatening but not pleasant,saved me using vick nasal spray.
Always need to be plumb level with a nice clean flame if on LPG.
Old units are prone to corrosion of the steel tubing and can fracture when removing units. Protective gloves,glasses etc should be worn when carrying out repairs,outside preferably and cover the unit when removing with a fire blanket etc to prevent any leakage.
LPG gas.
Forgot but I still have a few units stored away somewhere.
HI! were any of you folks around in the early 70s when all the Arklra, Day and Night, and whirlpool gas air conditinors were being installed? PG&E were pushing the sales of them.
I was exposed to ammonia many times.that and to asbestos, and cigarettes. and all the other stuff of the trade. now I have emphysema, and COPD. but with meds I got it all under control.
so guys take care of your longs. there is a lot of good information on this post. gas absorption are nasty. not to be field serviced. if you smell ammonia or see a yellow spot anywhere on the unit, get rid of it, I don't care how, just get rid of it.
Hello, meanu is right, the electrolux cycle contains usually ammonia, water and hydrogen, chrome6 as inhibitor. I had to investigate some of these interesting machines. They vary in mixture, Ammonia/Water 18/82% to 25/75% and the are filled up with hydrogen 17 to 22 bars. I modeled some of the machines in software, it's quite
interesting. So if u want to rebuild one sidkale, be prepared to use Chrome6 (poisonous) as inhibitor or good
steel alloys for production.
sfn,
we have still working a couple of kerosene powered absorbsion fridges ,,electrolux,,,when they used to decide to go slow we put a pot of boiling water inside and close the door,,,,wait an hour or so and start it up again,,,works most times and is easier than turning it upside down and over.
Lawrie
RE read the thread and it reminded me of the turbulent days of lpg caravan fridges in the 70's,folks used to travel with the gas flame lit (before the 12volt option was added),the draft bent the flame away from the bolier tube igniting anything near by and on several occasions cars were towing caravans that were on fire before they realised! plus they filled up with petrol too.
We still use the ammonia absorption in RVs (caravans) in the U.S. We run on propane when on the road and they have improved them to the point that the flame is shielded so you seldom have problems.
Ken
Do you fill up in the gas station with it lit? they don't work well when being shaken about whilst tavelling,the 12 volt option was introduced so you start them up on gas or mains voltage then switch over to 12 volt for travelling which simply maintained the temperature already acheived.Quote:
Originally Posted by TXiceman
Is it legal in the US to travel with it lit,what happens when a vehicle with a flame is inolved in an accident,was a firefighter for 30 years so can only hope it's not legal. Accidents involved in tunnels etc would all be the worse if thats the case.
It is best to shut it down before you fuel with gasoline. But the reality is that gasoline vapors are heavier than air and sink to the ground. The frig on out trailer is some 3 feet off the ground. There are more serious things to worry about....like the door/dome light switch which arcs when you open the door. The bigger problem is the starter motor which is very low to the ground.
The rocking motion when traveling does not harm the unit.
95% of the units on the road in the U.S is propane/120 Volt. A few have the 12 volt option.
It is legal to travel with them on. There is a big split in the RV community about using them on propane while traveling. The propane tanks are fitted with excess flow valves which shut down the propane flow in the event of a line rupture or break.
I have dealt with propane and ammonia as a refrigerant for over 40 years now and with all of the naysayers their is not one documented RV or fuel station fire attributed to an RV frig operating on propane. The truth is you are much more likely to have a fire due to an electrical issue.
Most tunnels and ferries require that propane bottles be closed at the bottle.
If propane was such a dangerous fuel, how can you operate a vehicle fueled by CNG?
I prefer to arrived at the end of a day on the road with the ice cream frozen and the beer cold.
Ken
Hi Lawrence1
I read your response to the question of an absorption fridge not working/cooling.Your suggestion was to use boiling water inside the compartment, it actually makes a bit of sense to me, because one reason for that is formation a precipitate from the solution especially when the fridge is not balanced well, could you shed more light how hot water can help in this regard. I am always dealing with these absorption fridges' problems
Regards
Voltair(Humphrey)
" If propane was such a dangerous fuel, how can you operate a vehicle fueled by CNG? " never understood that one here,market forces demnded it I presume was always a concern to firfighters etc.
I'll have a Beer though if you have one going,hope it's this http://www.bateman.co.uk/home and not that see through stuff :) ,not too cold mind you.
Cheers
BG
I like my beers dark and stout. The horse piss sold in the US is not worth buying. I like Stouts, porters, IPA, bitters and dark ales. Full body and a good amount of hopps.
Ken
Those ammonia driven absorption fridges are always a bit iffy. The older ones need to be levelled within three degrees when the vehicle is stationary. Later models can allegedly tolerate six degrees of tilt. The #1 problem is that ammonia attacks copper so all the pipework is made from steel. Steel as everyone knows, rusts and the failure point is usually where the burner is. New fridges of this type and size retail at £400 in the UK but depreciate at an appalling rate. It might be more economic to reverse-engineer the thing with a Danfoss BD35 twelve volt compressor and other parts. If a coolbox "ice bank" was used the compressor would only need to run for a few hours per day. On the other hand "conc" (concentrated aqueous) ammonia is not expensive (the "ammonia" in punctured fridges loses its NH3 and becomes like water) In theory it should be possible to recharge these fridges and weld them up, after all there is an old Birmingham proverb "What men can do, other men can do!" Apart from inverting them one can also sweep the chimney but that is about all that Joe Average can do.
Does anyone know of a 15" wide compressor driven refrigerator that is a direct replacement for the Electrolux?