7.6L HERMs pot - How much copper tube can you fit?

[Vanoontour]

Hey All,

Just got a 7.6L pot from Big W and want to know how much 1/2" copper tube you guys have managed to fit in there for your HERMs set ups? Is 7-8m being a bit too optimistic?

Cheers

 

[Glot]

Diameter of the pot times 3 will give you the approx. length per turn. Then take the height and work out how many 1/2 inches will go into it.

 

[boybrewer]

I have the exact same pot from Big W and managed to squeeze in 6 mtrs . I rolled the copper tube around a Milo tin , I think it was the 1kg size . You could try a 1lt paint can . I have the inlet and outlet on the side wall and have 11 turns of copper in it . The only problem I had was with the outlet , I had it too high so I cut the lip on the top of the pot which also severed the wire ring inside the rim and now it is out of round . Works great tho .

 

[Yob]

What ramp times do you get beer belly?

 

[Vanoontour]

I have the exact same pot from Big W and managed to squeeze in 6 mtrs . I rolled the copper tube around a Milo tin , I think it was the 1kg size . You could try a 1lt paint can . I have the inlet and outlet on the side wall and have 11 turns of copper in it . The only problem I had was with the outlet , I had it too high so I cut the lip on the top of the pot which also severed the wire ring inside the rim and now it is out of round . Works great tho .

Excellent mate, thanks. Any chance of a pic?

 

[QldKev]

I used to think you needed heaps of length in the HERMS, with the more the merrier. Now I believe a fairly short run will work.

Have a look at Nev's HERMS coil. It's stainless which is not as good a conductor as copper, but better from cleaning and also Bling. At just 2.5m to 3m (length from memory) and works great, it exchanges heat as fast as my kettle heating element can produce.
Also in the spirits world they build condensers such as a liebig. (not discussing spirits, just the condenser) I've seen one that is a 1/2" copper pipe inside a 3/4" copper pipe, which is only 1m long. They pump water between the 1/2" and 3/4" jacket in a counter flow direction, and this 1m length cools the spirit from steam into a cool liquid. I've never seen it in life happen at higher power, but they claim to be able to run up to 4500w worth of heating and the condenser keeps up as long as you have enough cold water flowing through it. And that's just 1m worth of pipe.

To me having the minimum amount of copper to conduct the heat is best. A nice small HERMS unit, not much beer out of the main mash tun, less back pressure on the pump when running, and to me a very important factor is the smallest water volume I can achieve to do the job. The less water the less time for it to heat, ie less undershooting, and the less thermal mass to overshoot.


If I ever built one again I think I would go a tighter coil such as pic below, the coil on the right. (pic stolen from the Internet) Then I could shove a kegking element up it's guts and keep the volume really small.

 

[nifty]

I've got about 7 metres of 1/2" copper pipe in a 7 and a bit litre pot. I have the inlet and outlet coming out through the lid, it's not pretty but it works well.

Just to add to what QldKev said about the length of copper pipe, I only 1/2 to 3/4 fill the pot. I don't have a fancy pid, just a Dixell temp controller and I found that with a full pot of water there was a massive temp swing. With less water and a decent flow rate, the temp swing is only about 1 to 1.5 degrees.

cheers

nifty

 

[Yob]

Nifty, do you mean overshoot when you say temp swing? That's quite a lot.

 

[nifty]

Nifty, do you mean overshoot when you say temp swing? That's quite a lot.

Yep, that's the word I was after, overshoot.

If I set the controller to 64.5deg, it will go to about 66deg. I've found that to be ok for the beers I make.

cheers

nifty

 

[Vanoontour]

I managed to get 6.5m in the pot. Cheers for the help guys.

Dan

 

[Yob]

Yep, that's the word I was after, overshoot.

If I set the controller to 64.5deg, it will go to about 66deg. I've found that to be ok for the beers I make.

Gosh...

I 2/3 fill a 20lt BigW pot (with an OTS element) and only get 0.4'c - 0.6'c overshoot, if Im ramping up to say 72 I'll set STC to 71.6, it then settles on 72 and I adjust the controller to 72..

I think the STC is OK for the HLT but even with the minimum setting at 0.3 it's still a 0.6 swing so Im starting to think about PID for the HEX only.

Dont forget the piccies vanoontour

:icon_cheers:

 

[Vanoontour]

Gosh...

I 2/3 fill a 20lt BigW pot (with an OTS element) and only get 0.4'c - 0.6'c overshoot, if Im ramping up to say 72 I'll set STC to 71.6, it then settles on 72 and I adjust the controller to 72..

I think the STC is OK for the HLT but even with the minimum setting at 0.3 it's still a 0.6 swing so Im starting to think about PID for the HEX only.

Dont forget the piccies vanoontour

:icon_cheers:

Hey Yob, check here for the pics mate: http://aussiehomebrewer.com/topic/70532-3-tier-gravity-build/page-2#entry1107061

 

[boybrewer]

Gosh...

I 2/3 fill a 20lt BigW pot (with an OTS element) and only get 0.4'c - 0.6'c overshoot, if Im ramping up to say 72 I'll set STC to 71.6, it then settles on 72 and I adjust the controller to 72..

I think the STC is OK for the HLT but even with the minimum setting at 0.3 it's still a 0.6 swing so Im starting to think about PID for the HEX only.

Dont forget the piccies vanoontour

:icon_cheers:

I get around 1* C per minute . It takes about 10 min to go from mash temp to mash out . Eg 66* - 76* C 10 -12 min . My STC now runs the kegorater . I run a PID for my mash and HERMS . Set and forget well almost . I still like to check the mash temp from time to time .

 

[boybrewer]

Here are acouple of photos . I have a cheap 2400kw immersion heater in it . Which is controlled by the PID .