Using A Plate Chiller As A Pre Chiller

Australia & New Zealand Homebrewing Forum

Help Support Australia & New Zealand Homebrewing Forum:

proudscum

Well-Known Member
Joined
17/9/10
Messages
471
Reaction score
2
Has anyone had experience with using a plate chiller packed in ice as a pre chiller for cooling water post boil?
I am now thinking of using my plate chiller for this purpose after reading quite a few American forums on the cleaning process involved when passing wort through one...its a bit of a case of it seemed like a really good idea a few months ago but didnt do enough research.

I had great success with whirlpooling by hand today using two coils.So the idea is now to whirlpool via the Hoprocket and march pump and use the plate as a prechiller for my immersion chiller.To me its less cleaning and easier sanitising .

your thoughts.

Cheers SCum
 

chadjaja

Well-Known Member
Joined
4/10/08
Messages
430
Reaction score
2
passes thru chiller and cools......can't see a problem using it. Only water going thru it so no problems with cleaning either just a more expensive option but if you have one already.

I promised myself i'd have my small copper pre chiller by this summer going too...... :rolleyes: :rolleyes:
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,652
Reaction score
4,088
Location
Newcastle
Sticking a plate chiller in a bucket will be of very little use, you would need to have the circuit pumped for both liquids. Plate chillers rely on flows in opposite directions to work.
You would be better off with a small copper coil in a bucket of ice and water, what drives cooling is the difference between the temperature of the wort and the tap water, at the start the difference is large and you get rapid cooling. As the wort gets cooler the difference gets smaller and the rate of cooling drops off. You could very effectively start with just tap water then drop the in line precooler into the bucket of ice/water when the difference is down to 20oC or so, that way you use up much less ice (energy).
Most people use too high a flow rate to be truly efficient , the water in the cooler needs time to take up heat, the water coming out of the cooler should be very near the temperature of the wort.
With a bit of thought and patience you can use a lot less water and ice and still get very effective cooling and save on both energy and water ($).
Mark
 

yardy

BI3V
Joined
25/2/06
Messages
3,065
Reaction score
9
Most people use too high a flow rate to be truly efficient , the water in the cooler needs time to take up heat, the water coming out of the cooler should be very near the temperature of the wort.
Mark,

are you talking about the flow rate of the cooling water ?

I've got a CFC and I reduce the flow of wort to the minimum, are you saying that running the wort flow at standard rates and the cooling water at a reduced rate will be more efficient ?

Yard
 

TidalPete

BREWING BY THE BEACH
Joined
2/8/04
Messages
5,182
Reaction score
481
Location
Sunshine Coast, Queensland
Mark,

are you talking about the flow rate of the cooling water

I've got a CFC and I reduce the flow of wort to the minimum, are you saying that running the wort flow at standard rates and the cooling water at a reduced rate will be more efficient ?

Yard
The way I read Mark's post he's saying it's more efficient in a pre-chiller although I'd say it's likewise just chilling. He's also saying that this method saves water. I run bore water through a sand spear (higher pressure & a few deg cooler than town water) through my chiller & cut the flow down to the minimum to ensure rapid heat transfer & that works well until the temp's just under the 30 deg mark. Cutting right back on the wort flow on the OUTLET side of the pump gets me down to 24 deg in the middle of summer faster than just leaving it sit as mentioned above. Planning on making up a post-chiller soon to get those lager worts down to a more acceptable level before sticking the fermenter in the fridge & pitching next morning.
Waiting with interest for Mark's reply. :)

TP
 

AndrewQLD

RED ON WHITE IPA
Joined
12/3/04
Messages
4,149
Reaction score
306
I found I can cool wort faster using my plate chiller if I return the wort back into the boiler with the flow set fairly fast, effectively recirculating cooler wort as you go and the temp drop is pretty quick, I then reduce the flow rate for transfer to fermenter to get the wort as close to tap temp as possible.

It seems to take a lot less time to chill saving water as well.

I have tried the method you suggested proudscum and it was not effective at all, as MHB said you need the counter flow affect of cool water flowing through the chiller.

Andrew
 

TidalPete

BREWING BY THE BEACH
Joined
2/8/04
Messages
5,182
Reaction score
481
Location
Sunshine Coast, Queensland
I found I can cool wort faster using my plate chiller if I return the wort back into the boiler with the flow set fairly fast, effectively recirculating cooler wort as you go and the temp drop is pretty quick, I then reduce the flow rate for transfer to fermenter to get the wort as close to tap temp as possible.

It seems to take a lot less time to chill saving water as well.

Andrew
Thanks for reminding me Andrew. :icon_cheers:
I recirculate fast via the pump as well then back into the kettle through my whirlpool tool (for want of a better term).

TP
 

MHB

Well-Known Member
Joined
1/10/05
Messages
6,652
Reaction score
4,088
Location
Newcastle
I was referring specifically to an immersion chiller, tho all the equations are related and mostly start with Newtons law of cooling; there is a reasonably good overview in an old BYO Mr Wizard, unfortunately all in imperial numbers.
When we look at an immersion chiller there are three main components to the equation that we can control, the flow rate of the coolant, the difference between the coolant and the wort lastly the material between the two i.e. what the chiller is made of and how much surface area there is (really going to be a choice between copper and stainless not going to make as much difference as people thing, we keep hearing how crap a conductor stainless is and it is for a metal but tends to be thinner and easier to keep clean and doesnt add Cu to your wort swings and roundabouts).
So once we have an immersion chiller we can control the flow rate of the coolant and by adding a pre-chiller the difference between the wort and the coolant.
Increasing the flow rate of the coolant increases the differential uses more coolant.
Increasing the differential increases the rate of heat transfer uses more energy.

Thats where it starts to get interesting!
If the flow rate is such that the water leaving the cooler is at (well nearly) the temperature of the wort it has taken up as much heat as it can thats the effective minimum flow rate.
The last variable being the differential, at the start if your cooling water was at 20oC and the wort was at 100oC D=80oC, when the wort cool to say 30oC D falls to 10oC, by driving that back up (cooling the coolant) we can get faster heat transfer.

I last played with the equations 15 odd years ago while doing a dip Chem, just had a quick look at whats on Wikipedia and I would have to spend a lot of hours refreshing before I could make use of the equations.
If someone wants to spend the time and construct a spreadsheet it would be quite easy to see the colorations, I do remember drawing up the graphs for how fast a cup of coffee cools (in theory).
Mark
 

dr K

Well-Known Member
Joined
22/9/05
Messages
1,270
Reaction score
58
MHB as usual makes sense.
Just a small point, I had always worked the theory that a slow coolant flow was faster, as Mark states..the idea being that the slower flow gives better heat transfer, I even use the same output temp = wort temp model!!
BUT..reading the Jan-Feb 2012 Zymurgy I see an experiment on home wort chillers (as well as all the physics for those who care).
It graphs the time taken to chill 18 litres of 13P wort from 93C to 27C using 21C water flowing through an immersion chiller into still wort (no agitation).
At 4 litres per minute 24 minutes (thus 96 litres)
At 10 litres per minute 17 minutes (170 litres)
If you whirlpool or even just agiate to break the boundary layer you can halve these times.
So whats going on here.
Simple really, whilst the water needs time to take up the temp once it has done so it no longer cools, so a faster flow in fact practice gives faster cooling, a faster flow is also much less water efficient and unless you have a needed use for the water, a waste.
There's an old joke in Canberra about water restrictions and brewing, if you attach your coolant outlet to a lawn sprinkler (when we are in restricted times) its illegal, if you let it down the drain its not !!
I have a pre-chiller built, I just have not used it, its 15 meter fitted hose, still coiled !!

K
 

proudscum

Well-Known Member
Joined
17/9/10
Messages
471
Reaction score
2
Sticking a plate chiller in a bucket will be of very little use, you would need to have the circuit pumped for both liquids. Plate chillers rely on flows in opposite directions to work.
You would be better off with a small copper coil in a bucket of ice and water, what drives cooling is the difference between the temperature of the wort and the tap water, at the start the difference is large and you get rapid cooling. As the wort gets cooler the difference gets smaller and the rate of cooling drops off. You could very effectively start with just tap water then drop the in line precooler into the bucket of ice/water when the difference is down to 20oC or so, that way you use up much less ice (energy).
Most people use too high a flow rate to be truly efficient , the water in the cooler needs time to take up heat, the water coming out of the cooler should be very near the temperature of the wort.
With a bit of thought and patience you can use a lot less water and ice and still get very effective cooling and save on both energy and water ($).
Mark
That works for me pumping the iced water through the plate as i have a good sized pump for emptying the bath water for grey water use.Was amazed with the temp drop by whirlpooling by hand.
 

Latest posts

Top