Evaporators for milk cooling

[neslorelyks]

I am trying to determine what type of evaporator would be best for a small (40L max) bulk liquid (milk) cooler.

There will be a maximum of 17L poured into the refrigerator at one time, to be cooled with an approximate thermal load of 70W. The milk will have to be maintained at approximately 40F for three days.

I have searched high and low and have come to the conclusion that a direct expansion evaporator (stainless) would be most effective.
1. Can anyone comment on this speculation?
2. If this will be an effective solution, where would I find a supplier for such a small evaporator?
3. Are there many other solutions that would be more effective?

Thanks for your time and I look forward to the comments.

[Sridhar1312]

Plate heat exchanger is best for cooling milk as it can be cleaned in place after the process.
for your quantity container with jacket wher chilled brine is circulated to cool the milk in the container. after getting cooled you can store the milk in the refrigerator or cold room maintaining 40 degree F

[lowcool]

dont know about most effective but its a basic straight forward approach,you will need a regulator but i cant rember the name off the top of my head but their are blokes here who work on vats.then trot off to your nearest reputable stainless/sheet metal company,preferably one that has dealt with refrigeration gear.wrap your cylinder in copper and get em to fix in place,fit an outer sleeve with caps,urethane fill with foam.depending on the design of your pot you may need an agitator

[monkey spanners]

I think your best solution would be to have a water jacket around your milk vat. In this jacket make a copper coil on which ice can be formed.

When you need cooling, you will need to agitate the milk with some sort of motorised paddle, and to move the water around either with a small water pump or make a spray rail at the bottom of the water jacket through which air is blown.

This is not as efficient as a dx system but there are no issues with it having to be full of milk before you turn it on, and the ice water will keep the milk cool.

Many commercial milk cooling tanks work this way.

[kbouwman]

For this small volume would it work to pour it into 1 gallon jugs or keep it in 5 gallon pails and then put them in a residential refrigerater from your local appliance store?

[monkey spanners]

For this small volume would it work to pour it into 1 gallon jugs or keep it in 5 gallon pails and then put them in a residential refrigerater from your local appliance store?

Hi kbouwman,

A domestic or even a commercial fridge would keep it cool but it wouldn't cool the milk from animal body temperature to the storage temperature quickly enough to stop bacteria from growing too much in the milk, especially as they plan to keep it for three days. 36F would be a better temperature too for a 72 hour storage time.

Jon