Plate Heat Exchangers - How big?

[Darcey]

Hello All,

Well the (replacement) brewery is coming along nicely. The HLT and copper are built. 50l MLT purchased with all the fittings waiting a build day. I have the FV fridges ready, kegerator and gas ready to go.

Previously I have used an IC however I found it a little ineffective and I found myself with a hydrotherm (wortotherm). The only real purchase left is something to chill my wort. I have been looking at plate exchangers but having never used one I wonder how many plates I need and if I will need to recirculate the wort or if I can run direct in to the FV after one pass on the exchanger? I can control the flow of coolant water and wort in and out so I can do it that way? Anyone with any experience to pass on?

I used to brew outside/kitchen but now I am doing it in the cellar I am having to run hose pipes up and down so quicker I can cool and get them packed away the happier SWMBO will be (and by proxy the happier I will be!).

Thanks,

D

 

[pittsy]

no idea but thought i'd bump for you.

 

[ollyb]

no idea but thought i'd bump for you.

It's not like the post had drifted down the page!

I got a quote for a heat exchanger from a UK company recently. I wanted it to cool 200 litres in 20 minutes, not recirculating, based in 100 degree input temp, and 20 deg output temp. To get this, the suggested exchanger needed 400 litres of water (ie double the flow rate of the wort) coming in at 12 degrees, heating up to 50 degrees.

This was specified as 53kw of cooling capacity, cost £173 ex VAT, and was about 466mm x 74mm x 56mm deep, 20 plates.

Hopefully, as that cools 10litres per minute using 20litres per minute of water, that should give you an idea of the cooling capacity you need. I'd advise not recirculating, as it leads to a lower temperature gradient, and less efficient cooling.

Happy shopping!

 

[Aleman]

Once you get past a certain number of plates you don't get any significant increase in cooling (Anyone want a 60 Plate 130KW PHE??? ) What starts to matter more is the 'contact time' and the only way to achieve this is to add bigger plates.

I fancy these 30 Plate PHE's Probably the 125KW, as the 175 and 330KW would be a bit of overkill, plus you are going from long and thin plates to long and wide plates, rather than just increasing theh length (and therefore the contact time)

 

[ollyb]

I might be wrong about how they work, but doesn't more plates mean the unit can take more wort at once, so to cool at the same flow rate, the wort is flowing over each plate at a lower speed, therefore more contact time.

Eg, for same plate area, if you had double the plates, you could cool the same amount of wort by moving it at half the speed.

 

[Aleman]

It doesn't seem to work that way . . .I did speak to Sondex about a gasketed PHE, and they said the same thing about thier PHE's, once you have max coolant and optimal wort flow number of plates is irrelevant plate size becomes more important.

 

[ollyb]

Fairy snuff!

 

[Darcey]

Thanks for the replies everyone. I have been looking at a 44kW one I think I'll just have to buy and have a play with the flow rates in and out. Thanks for the advice everyone.