sea water chiller/cooler DIY possible?

[happy scallop]

hi chaps,

Would anyone have any knowledge of making an inexpensive sea water chiller for an aquaculture application?

Somewhere I've read about converting a fridge to do the job, has anyone got any ideas of what I could use as a low cost DIY option. I'd be looking to chill about 150L of sea water from 6C-10C.

cheers

[The MG Pony]

You can but you need Stainles Steel or titanium Heat exchanger or plastic coated pipe if you use copper.

[Lowrider]

Stainless steel or titanium is the way to go. The transfer through plastic coated copper is pretty bad. which will result in higher operating cost!

[K.R.Iyer]

Happy Scallop,

In how much time you need to cool 150 Lit sea water? I could not make out your temperature requirement - initial and final temp of sea water.

have you seen a storage type water cooler? It uses a SS tank with evaporator tubing wrapped tightly on the outer side of the tank. Condensing unit size will depend on the pulldown time you are looking for and the delta T drop. This will b e a very low cost one. Good luck!

[marinechiller]

Happy Scallop,

I design systems specifically for marine aquaculture as well as maintain them. Titanium is really the only long term answer for a direct ***** to seawater heat transfer. However, I have seen (but have yet to try) using stainless to transfer heat to a low pressure fluid that can then be carried in pex (or almost any thin-walled plastic) for the transfer to the seawater you use.

Best step you can take is over-design your heat recovery system so that your chiller will be very small. In aquaculture, water flow out should always equal water flow in. Heat recovery is where you will make or break the bank!!!!!!

[marinechiller]

Might I add that for your temperatures you need custom sized evaporators. I have seen unbelievable numbers of compressors burned out in aquaculture applications due to insufficient evaporation, hence low suction pressure, hence insufficient compressor coolant.

As a rule of thumb, I always expect to need twice the number of evaporators as recommended by the supplier (ironic eh?).

[steve_k]

I used a beer chiller for a sea water aquarium, the tank was 6'x3'x1'6" picked it up second hand for £100 and it run for 2 years with no problems, very easy to install the pipework

Just an alternative

[The MG Pony]

I used a beer chiller for a sea water aquarium, the tank was 6'x3'x1'6" picked it up second hand for £100 and it run for 2 years with no problems, very easy to install the pipework

Just an alternative

Beer chillers use 316 ss, hence why it worked out Ok, found a small titanium Hx on ebay for 240 bucks cad!

[marinechiller]

After reading about beer chillers I recall a hatchery in Norway using mobile milk chillers to cool seawater.