Immersion, Plate or Counter Flow?

[kelper]

I'm not sure i'd go to 50l in reality. Just be a pain to store. at 40l batches I can do two cornies and a few bottles. That's the sweet spot for me I think.

Make yer mind up! You said 70L in post #1

 

[Hudson1984]

oh noooo that's just the size of the brewster - it's a 70l setup.

I'd be doing 40l or at the very most 50 as the fermzilla is max 55ltr

sorry, my bad, poor typing it seems.

 

[kelper]

A 70L unit won't actually hold 70L anyway, not without boiling over. No worries.

 

[Buffers brewery]

I have a second home made immersion chiller which I'm planning to use on my next brew day which I'll put in line before the chiller in the wort, and will be in a bucket of water, so when the wort hits the mid 30's where the cooling rate seems to stall to a crawl, I'll chuck a bag or two if ice in the bucket to chill the water before it gets into the main chiller.

That's what I do, especially in the summer.

 

[RGeats]

I've been looking into this recently as my immersion chiller quickly gets the wort down to the mid to high 30 degrees pretty quickly, but seems to take an age to get it down to the high or mid 20's and seems to stall there. I have a second home made immersion chiller which I'm planning to use on my next brew day which I'll put in line before the chiller in the wort, and will be in a bucket of water, so when the wort hits the mid 30's where the cooling rate seems to stall to a crawl, I'll chuck a bag or two if ice in the bucket to chill the water before it gets into the main chiller.

Maybe a plate or CFC might work better, but more expense right now so a second home made emersion chiller in a bucket of iced water might be a cheap option for now if it works.

I've done this too. I used freezer packs, I set up a spare FV a few hours before wanting to chill, filled with water and ice packs. That way is allows the water to get to a really cold temperature before needed. I start the cooling with both immersion chillers in series, but with the first just on the floor. Then I'll put it in the chilled water when the chilling slows down.

 

[JockyBrewer]

To improve an immersion chiller you should use small bore tubing and lots of it. for best heat transfer, the flow needs to be turbulent. A slowish flow through a larger bore can result in laminar flow.

Will you get laminar flow in anything smaller than 10mm tubing?

The fastest immersion chillers out there use two or three runs in parallel to reduce pressure and maximise coolant flow and surface area.

 

[kelper]

Flow changes from laminar to turbulent dependent on the cross-sectional area and the speed/flowrate. So laminar flow can happen in any pipe or tube if flowrate is below a threshold.

The Reynolds number (R) helps predict flow patterns in different fluid flow situations. R depends on density, viscosity, pipe diameter and flow. When R is below 2,100 flow is laminar. When R is above 4,000 it will be turbulent. There's an online calculator HERE

10 mm tube with 1mm thickness has an ID of 8mm. For turbulent flow, we need R to be 4,000 or more. A flow rate of 1.52 litres per minute would do it.

So hook the chiller up to your water supply and use a large jug to measure the flow in litres per minute! Please verify the tube ID. If the pipe coil is very long, it might restrict the flow, especially if water pressure is low.

Yes, I am a big nerd!

 

[The-Engineer-That-Brews]

Counterflow.

 

[Seaside brew]

My immersion chiller is homemade and was made before I had of boil kettle and a fair few of the coils aren't covered by wort when in use, do you think there could be an issue with sanitisation because there not in the boiling liquid? I just assumed the steam would do the job. It chills fine btw just got me thinking reading kelper's post about making sure the chiller is fully covered

 

[Buffers brewery]

I started with a homemade immersion chiller then had a sortie into HERMS and fitted a heat exchange coil to my pot. Now have a separate HERMS heat exchanger so use the fitted coil as an immersion chiller. The other immersion chiller is used as a booster in the summer in a bucket of ice/water.

 

[kelper]

@Seaside brew
Steam will take longer unless the 'pot' is covered. Can you plug the holes and invert it?

 

[The Baron]

Fly in the ointment time, save money and do no chill your wasting water that could be used to make beer with chillers

 

[Seaside brew]

I think I’m going to alter it now!! I used a paint can to Mould the coils round the outside coil and a bit of 4” soil pipe for the inner coil, so I need to find something with a large diameter to rejig it and have it all covered. It’s always going to be at the back of my mind otherwise!

 

[Buffers brewery]

I think I’m going to alter it now!! I used a paint can to Mould the coils round the outside coil and a bit of 4” soil pipe for the inner coil, so I need to find something with a large diameter to rejig it and have it all covered. It’s always going to be at the back of my mind otherwise!

 

[Seaside brew]

Very nicely done that. Clever idea

 

[private4587]

Having cleaned a lot of industrial plate coolers, which can be dismantled, I would not want to use a welded plate cooler. The plates get a varnish on and lose efficiency. They need scrubbing to get really clean. We can use CIP (clean in place) equipment for intermediate cleaning but they still benefit from regular dismantling. To improve an immersion chiller you should use small bore tubing and lots of it. for best heat transfer, the flow needs to be turbulent. A slowish flow through a larger bore can result in laminar flow.

One poster said above (post #6) that he didn't want to put something into his wort after the boil. Most people put the immersion chiller into the boiling wort for the last few minutes and this sterilises the chiller. (no cooling water flowing)

And, with an immersion chiller, you can see if it's clean.

For the same reasons, I would not use a counterflow coil.

have to agree with you Kelper, when i was working spent many an hour stripping, cleaning and rebuilding Alfa Laval plate coolers. Even in their much larger state a right pain in the wosits to get to seal 1st time

 

[AdeDunn]

I switched from a copper immersion chiller to a decent sized plate chiller when I returned to brewing last year. Immersion chillers are easier to keep clean for sure (wort doesn't run through them at any point, so no risk of clogs), where a plate chiller you have to make very sure that wort is filtered before it goes through (using a hop spider or the like is pretty much mandatory). Also, you lose some wort and have to account for this in your volumes, when you use a plate chiller, to spills whilst disconnecting and also just to the chiller itself that you can't easily get back out.

That said, I would NOT go back to an immersion chiller. My plate chiller cools to pitching temps in a fraction of the time (and that's using the recirculation method, where you cool the whole batch in the boiler, recirculating through the chiller, before transfer to the FV), using a tiny fraction of the water that I used to use with my plate chiller, especially in warm weather. Immersion chillers, in my experience, use an insane quantity of water, and for this reason alone I would use either a plate chiller or, if you can source a decent one, a counterflow chiller.

Cleaning, flush it through with the same solution I clean my boiler with (warm), then attach hose to wort side but back flush so it's going opposite way to what the wort was going in. Then put away. Sanitisation, same as with an immersion pretty much, start pumping wort through it 10-15 minutes before the end of the boil (without turning the cold water on) but do not touch the body of the chiller whilst doing this, it gets ruddy hot. lol Oh yeah, you kinda do need some form of pump that can cope with hot wort......

 

[hoppyscotty]

In my brewzilla instruction it mentions you could use the emersion chiller by pumping the wort through the coil with the coil sat in a bucket of cold water, so I guess approximating a counterflow chiller but without the counterflow. Anyone tried this?

 

[Wynne]

@AdeDunn, I agree on the importance of a hop filter. I found my Chinese stainless steel basket tends to clog up (mesh too fine for hops) so switched to a helix which works well. I try to minimise wort losses by running freshly a litre or two of boiled water through the hop bed, pump and chiller to flush the retained wort into fermenter.

 

[JockyBrewer]

In my brewzilla instruction it mentions you could use the emersion chiller by pumping the wort through the coil with the coil sat in a bucket of cold water, so I guess approximating a counterflow chiller but without the counterflow. Anyone tried this?

I haven't, but unless you're agitating the chiller you'll find that the water immediately around the coils (within a few mm) warms rapidly and then the cooling effect drops away to nothing.