Refrigeration advice.

[Omniata]

Might need a saparate pump and 3ph motor at this rate, ideally needs to have 2mm wall and ends threaded on ~15mm copper pipe to attach into 50mm diameter 3mm wall steel stainless pipe.

Pump on each end will do to push: pull the fluid but I think there'll need to be ~16m of copper pipe for the cooling coil, 100mm spacings between loops and 500mm diameter loops!!

I think the propylene glycol:water mix should operate quite well at an 80:20 mix, but a lab test will have to be run first.
The problem with a 50:50 salt ice bath is maintaining it, it rapidly cools on mixing and will have to be monitored and drained continuously.

A better solution might be to make a stainless bath for a chest freezer and fill it full of 100% propylene glycol and submerse the cooling coil into it though a slot cut in the side, place a vent on the top and an agitator and it's self contained and regulating.
You'll need one that can go as low as -30°C to make it cost effective though, but once running should be ok. Several could be linked in banks then to work together in a "cooling plant"...

 

[rtbcomp]

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Piman keep us posted on how you get on with this I would like to visit to see this in operation if/when you go live .......

That has nothing to do with the fact that a silo full of beer is involved!

 

[eil]

Should start with your cooling load requirements.Then match up a suitable condensing unit to handle the load, like Ive said previously it being done daily with 2500 litres a small bulk tank in milking parlours, milking machine, pre cool through an Alfa Laval plate heat exchanger and dumped into the ice bank tank and controlled at 4*c.
Wheres all the tractor boys on this site they will know.

 

[Omniata]

That has nothing to do with the fact that a silo full of beer is involved!

I don't drink beer Only my own vino or spirits when I can handle them, affects me too badly these days due to almost zero body fat

Should start with your cooling load requirements.Then match up a suitable condensing unit to handle the load, like Ive said previously it being done daily with 2500 litres a small bulk tank in milking parlours, milking machine, pre cool through an Alfa Laval plate heat exchanger and dumped into the ice bank tank and controlled at 4*c.
Wheres all the tractor boys on this site they will know.

I can see this turning into quite a fun project, Eil those milk cooling equipment designs may well be the answer in this instance with a bit of modification to cool the coolant rather than the beer

 

[eil]

Just think of the Beer being the Milk............ against the grain i know

 

[Omniata]

It's just with Piman saying it's in a "jacketed" vessel it might be awkward pumping it out and back it...

If you pump the coolant through the heat exchanger and agitate the beer that might be a better option...

 

[snowcat]

wouldn't you just build a matrix into the tank, the same as eil suggests? this is the way iv heated (steam for hot) liquid for cold, a seperate tank with an evaporator cools the liquid (water in the exchanger) then its pumped around the system , as someone who's dabbled a bit with A/C ammonia would be the choice of the industrial set up.......or have I missed what the OP wanted to do.....

 

[eil]

Right so the jacket is the insulation and he wants to drop in a coil evaporator of whatever size bore/length for the refrigerant to flow through to which he intends to connect up to this unknown condensing unit fill with water/ glycol and build up an icebank then pump that through the beer as the secondary refrigerant?...... will have to wait to get the full pic when he comes back methinks.

 

[Omniata]

No, from what I've got he wants to pass the coolant through the jacket and cool it in the ice bath before it returns...
Putting the coil directly into the ice bath to cool the glycol:water before it returns to the jacket...

But I suggested a pressure increase/drop from the pipes from the jacket into a relatively narrow bore coil inside the bath to apply pressure effects to the cooling to increase it further...

wouldn't you just build a matrix into the tank, the same as eil suggests? this is the way iv heated (steam for hot) liquid for cold, a seperate tank with an evaporator cools the liquid (water in the exchanger) then its pumped around the system , as someone who's dabbled a bit with A/C ammonia would be the choice of the industrial set up.......or have I missed what the OP wanted to do.....

That may work but then a matrix consists of multiple narrow pipes so the pressure drop might be removed altogether, and you'll need a flow of coolant through the matrix to remove any localised heating effects...
This might not be a bad thing though as it will make less mess if it ruptures...

Being a food enviornment I doubt anhydrous, or concentrated, ammonia will be an available option

 

[eil]

Right he`s got a fermenting vat of 2500 litre capacity which is at 22C, he has another 1000 litre tank of water, he wants to reduce the temp of the water by creating an ice bank then pump the cold water through the beer or vice versa, so he needs to build up at least 3xD of evap pipe with ice in readiness to use as his secondary refrigerant, any less and the heat load of 2500 L would surely overload his condensing unit. so he would need the water/glycol to be at least 0C, and for that to reach zero deg he would have to evaporate his refrigerant (freon) gas at -5C.

 

[snowcat]

ammonia is used in all big food systems.....its what all the frezers at supermarkets are filled with.....its far better than running a system thats full of PAG oils...

personally I would build a fridge unit to cool a water matrix running directly in the tank, this is the way bulk tanks work on milking parlors, you work on a indirect system, evap, condenser compressor setup, cools the water this in turn is pumped through the matrix, you would never gas a system like this as it would end up being huge.....

 

[eil]

Yes a dx system is more efficient, and ammonia is one if not the best refrigerant, but ammonia plant needs constant supervision, he has already got a condensing unit but for what refrigerant though?

 

[snowcat]

414? or something......if you've got half the plant it would be a fairly easy job...

 

[Omniata]

Will be interesting to see how this develops, it all depends on if they can put anything into the brewing vessel though. Contamination is a massive problem with brewing and guaranteeing that it is clean, almost to sterility, every time would be difficult wouldn't it, in terms of a matrix??

 

[snowcat]

they should be able to clean a matrix, with the correct cleaners, bulk tanks in milking parlours are washed and disinfected daily, in the days of old when my father ran a dairy heard everything was steam sterilised horible job, chemical flush systems are much better......

 

[Omniata]

Bit off topic but I use a combination metabisulphite and citric acid for sterilising, with brewclense for cleaning...
For cleaning my glassware I prefer nochromix and for really grubby stuff chromic acid

What sort of things would you use on tanks like the one Piman has with a matrix involved???
The metabisulphite and citric acid combination is pretty much out of the question I would have thought due to the amount of SO2 produced. Even though it is really effective...

 

[snowcat]

good question, I'm sure Friends in the trade could answer or MikeyD maybe, had a goggle search found the brands but no SDS to say what was in em, big corrosive sign printed on the outside tho.....

 

[piman]

Hello all,

thank you for your inputs.

We already have one small bulk milk tank of 1300 litre capacity. We use the chilled water in the water jacket as a coolant for our existing fermenters and the main part of the tank is filled with water (where the milk normally goes) as a coolant for our heat exchanger which is used to cool the beer as it is pumped to the fermenter.

As we have ordered another fermenter, we do not have sufficient cooling capacity so the IBC idea came up as we have several knocking about. The milk cooler jacket has 10mm approx tube running horizontally around the cooler at about 100mm pitch so there is quite a length of pipework as the evaporator. The jacket volume is about 300litre at a guess.

Eil,
I have downloaded the Coolpak link, but not yet used it. We don't actually have the 1 1\2 H.P. unit yet, I just saw one for sale. Why do you say that is not where to start? The other slight problem we have is that we are on single phase supply and getting three phase is prohibitively expensive.

So far it is early days yet and we would prefer it if we can find a complete unit at a good price as cash is tight.

Alec

 

[eil]

Right getting more of the picture now, the reason for my statement that the condensing unit is not where to start is because you did not know what work it had to do. First of all you would do a heat/cool load calc then match up a evaporator then condensing unit etc. but I can see where you are coming from by copying what you have already which was doing the job at what used to be the load, now if the load is say doubled then you need to double the cooling! think Ive got the jist of it. and copying what you have already will mean you don't have to wade through all them sums as they have been done already for you. That 10mm pipe will be 1/2" should imagine different copper for refrig.

 

[piman]

Hello all,

as far as load goes the existing bulk tank can cope with two fermenters at the same time and it's compressor is a 1 h.p unit I would imagine that a 1 1\2 H.P would more than cope with the load of an additional fermenter. This is running a water rather than glycol\water (or whatever additive would be suitable for a food environment). I can see the benefit of having the coolant at a lower temperature but so far it hasn't been needed. Remember that the coolant has a long time to do the job, as we don't want rapid cooling (shocks the yeast)

Alec