Aggresive atmosphere

[G Cook]

We look after a small room which is used to store tripe. The evaporator coil in the room will not last due to the ammonia fumes which are given off by the tripes. It seems to be very corrosive towards the copper in the coil.
The last coil we replaced was coated using a spray on type coating but has lasted around 18 months and is now out of action!!
We thought a stainless steel coil would be the solution but this is not proving to be easy as it is just a small evaporator. Also considered trying a different make of evaporator, but this seems an expensive way to find out!

Does anyone have any ideas of a way round the problem?

[mad fridgie]

You could use an air to air heat exchanger (aluminium)

Your evap is standard, out side to room and has its own seperate compartment (not the room air)
This cold air is passed through one side of the heat exchanger, the air for the room passes through the other side of the heat exchanger and back to the room.

[chilliwilly]

Please forgive my ignorance about tripe, but couldn't you just cover the tripe to enclose the fumes? I didn't know that any food actually gave off noxious fumes that would cause corrosion, especially when its cold.

[monkey spanners]

Think Frimetal do a stainless evap, remeber seeing one in a maggot room at fishing shop.

http://www.frimetal.es/productsCoolers.htm

Looks like pendle sell them,

http://www.pendle-refrig.com/ppage.asp?p_id=12

Jon :)

[stuartwking]

Try beehive coils, they should be able to make one to suite.
www.beehivecoils.co.uk

[RANGER1]

Luv'e,Gutner,Cabero all make stainless steel air coolers at reasonable price.

Have seen similar situation in cool room for cow hides & the ammonia eats silver solder out of
joints as well.
Pipe everything in room in stainless as well with proper welded joints TIG welding, no silver solder
& all will be good long term.

[G Cook]

Thanks for the info guys, very helpful! There is a bit of a time constraint as the room is needed, I get the impression this stuff will not be pleasant at 20 degrees!! We have ordered another standard evap to fit in the mean time to buy us some time. The suppliers we spoke to were talking 7 to 10 weeks for anything not on the shelf. This will let us get a long term solution.
Yeah the fumes appear to be fairly aggressive, the room has had several evaps in the past, galvanised metal within the room is also being eatin, yet aluminum is unaffected. Unfortunately the tripes are delt with in the room so keeping them covered is not really an option.
We tried beehive but unfortunatly they don't do stainless. I like the sound of the stainless pipes in the Frimetal monkey. I take it that stainless would be the answer? One supplier suggested getting a coil dipped by Blygold, has anyone any experience with this product, or do you still suggest stainless?

Thanks

[cadwaladr]

galvanised dole plates rubber/automotive hose made by manuli sold by dean + wood thats what i used on a maggot fridge enclosed it put a fan+motor to move the air over it 10 years ago still going strong.