Counterflow cooler HERMS system

Seveneer · Post by **Seveneer** » Thu Oct 19, 2006 9:54 pm

Hi Tribs,

the heat exchanger has a loose fitted cover. It looks like it's sealed because I did seal it (there's glue residue left on the lip) but then I needed to replace the first coil I fitted as it was kinked so I took the lid off. I was going to re-seal it and use an expansion tank but then I thougt that would be overkill and left it open.

The tube is reinforced PVC and is rated to (I think) 65C. This obviously causes an issue with delaminating so I've ordered some silicone tubing which I hope will turn up soon.

/Phil.

tribs · Post by **tribs** » Thu Oct 19, 2006 10:23 pm

Thanks Phil

1) That explains it. Do you find that the water in the exchanger ever boils like crazy? Do you ever need to top it up during the mash?

2) I've often wondered about the use of PVC in this situation. I have heard that PVC can be leached of toxic chemicals. However I think most homebrewers probably use PVC tubing for their run-off. I believe that some reinforced PVC is rated to be used at up to 100C for short periods, but I've no idea where to get it. Silicone seems like a good solution. From what I've seen though its pretty expensive and difficult to find in some sizes. Where have you sourced yours from?

Post by **Andy** » Thu Oct 19, 2006 10:26 pm

I would doubt that the PID controller would let the H.E water get anywhere near boiling point.

Frothy · Post by **Frothy** » Thu Oct 19, 2006 10:57 pm

PID arrived from Hong Kong & came with a thermocouple

I was also wondering if seveneers HE was sealed.

Matt

Vossy1 · Post by **Vossy1** » Fri Oct 20, 2006 5:35 am

PID arrived from Hong Kong & came with a thermocouple

Result Matt

Full speed ahead

Mine still haven't arrived

Seveneer · Post by **Seveneer** » Fri Oct 20, 2006 7:11 am

Tribs,

there is a problem with the system in that if the mash get's stuck or "someone" forgets to open the flow valve then the water does boil. This is because the PID is measuring the recirculated wort temperature. Of course, if you stop recirculating the temperature of the wort never rises so the PID drives the temperature of the heat exchaner up with no effect on wort temp. Hence it boils. I might use another sensor in the heat exchanger to stop this but it's not been a problem so far.

I have ordered my silicone hose from Morebeer.

Frothy, I've seen a heat exchanger on the web that is sealed and has a pressure gauge too. I've sent the guy an email asking why he did it this way but have not had a reply. My feeling is that it's an unnecessary danger. The thing could explode!

Glad your PID arrived. have you connected it up yet?

/Phil.

eskimobob · Post by **eskimobob** » Fri Oct 20, 2006 8:56 am

Seveneer wrote:Frothy, I've seen a heat exchanger on the web that is sealed and has a pressure gauge too. I've sent the guy an email asking why he did it this way but have not had a reply. My feeling is that it's an unnecessary danger. The thing could explode!

Phil, I'd hazzard a guess that he has done that so that he can get over 100C (since under pressure) in the heat exchanger in order to heat the wort more quickly. Not sure if heating quickly is desirable in these systems so I could be talking rubbish...

steve_flack · Post by **steve_flack** » Fri Oct 20, 2006 9:51 am

Seveneer wrote:The thing could explode!

Maybe that's why you haven't heard from him?

Seveneer · Post by **Seveneer** » Fri Oct 20, 2006 9:57 am

eskimobob wrote:Phil, I'd hazzard a guess that he has done that so that he can get over 100C (since under pressure) in the heat exchanger in order to heat the wort more quickly. Not sure if heating quickly is desirable in these systems so I could be talking rubbish...

That's exactly my thinking. I think it'd do more harm than good raising the wort to those kind of temperatures.

When I was building mine I thought this through quite thoroughly. I just couldn't see any situation when you'd want to heat the heat exchanger above boiling point. Maybe there's something quite obvious about it but I can't see it.

Perhaps if you didn't use a coil but only a single length of copper to carry the wort and had a high flow rate you could get away with it but it's much easier to use a coil. High flow rates are a no-no anyway due to the potential to compact the grain bed.

/Phil.

Post by **Andy** » Fri Oct 20, 2006 2:33 pm

Frothy wrote:PID arrived from Hong Kong & came with a thermocouple
I was also wondering if seveneers HE was sealed.

Matt

Frothers - did you have to buy the thermocouple separately or was it included in the original auction ?

And what are you doing re: an SSR, didn't you ask the PID seller to flog you one ?

Vossy1 · Post by **Vossy1** » Fri Oct 20, 2006 5:26 pm

Hi 7, Did you consider using a/the heat exchanger to heat your sparge water, ie, cold water feed direct.

Obviously, this would require a larger heat exchanger.

I'm just curious

Seveneer · Post by **Seveneer** » Fri Oct 20, 2006 5:42 pm

Hi Vossy,

Not done this myself and I don't think my HE would be up to it. I didn't consider this at all when I built mine as I was blinded by shininess

Is this something you're considering? I would think you'd get away with it if you had maybe 20 feet of copper in the coil. Though, this would make the HE quite big which conflicts with the theory of having it as small as possible to allow it to react quickly to changing temperatures. I guess you could have two heat exchangers, one for the mash and one for the sparge but it'ss be cheaper to buy a HLT.

Dunno really...

/Phil.

Post by **Andy** » Fri Oct 20, 2006 5:51 pm

You could use the HE to give already heated sparge liqour a final "kick" up to sparge temperature but that would seem kind of pointless. I suppose it would assist in cleaning the HE copper of mash-wort residue though....

Seveneer · Post by **Seveneer** » Fri Oct 20, 2006 6:52 pm

I have done that when I was working out the best process for my equipment. There was no real reason why I needed to though and I don't do it now.

Vossy1 · Post by **Vossy1** » Fri Oct 20, 2006 6:52 pm

I was blinded by shininess

A fitting reason, indeed

Is this something you're considering?

Not really, just thinking aloud, considering options, whilst waiting for the ruddy PID.

I might try it just out of curiosity. I've must have close on 20 ft in there.

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