Hermit Coil Heat Exchange Build

[Stubbie]

What flow do you get and what pump are you running?
With both elements running and ramping up temps, did you measure the water bath temp in the HERMS, did the plastic housing get very soft?

Running a bog standard March 809. In truth, I didn't take an accurate flow rate measurement but guesstimated 3 litres/min. Definitely no observed problems with softening of the PVC - not yet, anyway.

My ultimate aim is to be able to fill the MT with a dough in volume of water, prime the pump and set the Hx and pump on a timer. Do that the night before a brew and, all going well, wake up in the morning to find the MT at strike temp, ready for doughing in. One of my concerns was whether the Hx could handle ramping water from say 15deg to say 61C (for a nominal protein rest) ASAP without bringing the Hx water to the boil. Whilst I did not measure Hx water temp, it certainly did not reach boiling point. But yes, would be informative to install either a thermometer or probe. Would be interseting to see how far the double element Hermit can be pushed before the Hx water comes to boil. One other observation, the PID controller was signalling the elements to remain ON for most of the ramp, so initial observations suggest 3700W is not an overkill at all.

My current MT is a Rubbermaid 38L esky, so holding a temperature was never really a concern. Going double elements was all about maximising ramp performance.

Clearly, it's early days and as I run the Twin Engine Hermit through its paces I'll endeavour to take some more accurate readings and learn more about how it performs.

Stubbie

 

[Stubbie]

Nice professional looking assembly there too Stubbie, well done!

Thanks John.

Managed to find some 'odd-ball' sized 1/2 BPS male / 12mm Pipe compression fittings in stainless. Friggin exy, though

Stubbie

 

[sean_0]

Anyone know if the craftbrewer 1/2" compression fittings will fit the Hermit coil? link here

 

[Stubbie]

Nice professional looking assembly there too Stubbie, well done!

Forgot to mention, I simply followed some very straight forward instructions.
A big credit to Nev for developing and sharing such a simple build for a HERMS Hx. :beer:

Stubbie

 

[Stubbie]

Anyone know if the craftbrewer 1/2" compression fittings will fit the Hermit coil? link here

If they're 1/2 inch, they won't be compatible with the 12mm HERMIT pipe.

 

[sean_0]

If they're 1/2 inch, they won't be compatible with the 12mm HERMIT pipe.

Thought as much - so can you share your source?

thanks,
Sean

 

[QldKev]

You can adapt the 1/2" compression fittings as per here. I've done quite a few brew so far with them setup like this no problems at all. A proper 12mm fitting would be better thou.

QldKev

 

[sean_0]

You can adapt the 1/2" compression fittings as per here. I've done quite a few brew so far with them setup like this no problems at all. A proper 12mm fitting would be better thou.

QldKev

thanks!

 

[Online Brewing Supplies]

Anyone know if the craftbrewer 1/2" compression fittings will fit the Hermit coil? link here

I have some 12mm compression elbow fittings on order for this purpose, also some short shaft thermo wells.
All due in approx 3 weeks.
Nev

 

[Online Brewing Supplies]

Running a bog standard March 809. In truth, I didn't take an accurate flow rate measurement but guesstimated 3 litres/min. Definitely no observed problems with softening of the PVC - not yet, anyway.

My ultimate aim is to be able to fill the MT with a dough in volume of water, prime the pump and set the Hx and pump on a timer. Do that the night before a brew and, all going well, wake up in the morning to find the MT at strike temp, ready for doughing in. One of my concerns was whether the Hx could handle ramping water from say 15deg to say 61C (for a nominal protein rest) ASAP without bringing the Hx water to the boil. Whilst I did not measure Hx water temp, it certainly did not reach boiling point. But yes, would be informative to install either a thermometer or probe. Would be interseting to see how far the double element Hermit can be pushed before the Hx water comes to boil. One other observation, the PID controller was signalling the elements to remain ON for most of the ramp, so initial observations suggest 3700W is not an overkill at all.

My current MT is a Rubbermaid 38L esky, so holding a temperature was never really a concern. Going double elements was all about maximising ramp performance.

Clearly, it's early days and as I run the Twin Engine Hermit through its paces I'll endeavour to take some more accurate readings and learn more about how it performs.

Stubbie

In practice the HX liquid cannot boil unless the pump stops and the power is on , believe me I have done it :lol:
Bloody volcano !
Nev

 

[Parks]

In practice the HX liquid cannot boil unless the pump stops and the power is on , believe me I have done it :lol:
Bloody volcano !
Nev

I also had a similar experience where my flow slowed considerably (belgian wit with 50% raw wheat) plus a badly configured PID. Needless to say my PVC tube is far from its desired shape <_<

I am currently working with a guy trying to make some amazing bling out of 4" stainless tube and 4" tri-clover fittings. I will post up details and photos once it comes to fruition...

 

[Stubbie]

Thought as much - so can you share your source?

thanks,
Sean

Geordi. (www.geordi.com.au) Located in Cheltenham. Not a stock item, though, so they'll need to be ordered in.
I bought mine over the counter. If you speak to Jodi, she'll know what you're after (1/2 inch BSP male / 12mm Pipe Compression Fitting). But a warning, $27.50 each, which I concede is somewhat extravagant but I wanted a secure mounting for the t-piece outlet, in particular.

Stubbie

 

[Stubbie]

I also had a similar experience where my flow slowed considerably (belgian wit with 50% raw wheat) plus a badly configured PID. Needless to say my PVC tube is far from its desired shape <_<

I am currently working with a guy trying to make some amazing bling out of 4" stainless tube and 4" tri-clover fittings. I will post up details and photos once it comes to fruition...

I had a similar approach in mind but chose to build a PVC version first for two reasons:
1. Wanted to prove the nominal 3.6kW design before committing to stainless, and
2. My HERMIT coil is ever so marginally greater in OD than the ID of nominal 100mm stainless tube. That would have meant having to slightly modify (read, tighten) the HERMIT coil so as to slide into 100mm stainless tube. Very interested to see how yours pans out.

Stubbie

 

[Parks]

2. My HERMIT coil is ever so marginally greater in OD than the ID of nominal 100mm stainless tube.

Hmmm.... that is a valid point, not sure we've checked that as yet. I guess that PVC would be 100mm ID. I'll get him to check!

 

[Stubbie]

Cannot recall the exact measurements but although there was only a millimetre or so discrepency in coil OD / 100mm tube ID, the other point to remember is that the HERMIT coils are not perfectly concentric and circular (although perfectly within acceptable tolerances for the intended purpose of a 100mm PVC pipe). So ideally, would want a few millimetres of nominal clearance between the nominal HERMIT OD and the intended tube ID.

Have tossed a few ideas around on how to jerry up a jig for tightening the coil, but for the time being that little project has been shelved.

Nev, if ever there's scope for even a 2 mm reduction in coil diameter, that would make for possibly a useful design change. Just a suggestion.

My 2c.

Stubbie

 

[Online Brewing Supplies]

Cannot recall the exact measurements but although there was only a millimetre or so discrepency in coil OD / 100mm tube ID, the other point to remember is that the HERMIT coils are not perfectly concentric and circular (although perfectly within acceptable tolerances for the intended purpose of a 100mm PVC pipe). So ideally, would want a few millimetres of nominal clearance between the nominal HERMIT OD and the intended tube ID.

Have tossed a few ideas around on how to jerry up a jig for tightening the coil, but for the time being that little project has been shelved.

Nev, if ever there's scope for even a 2 mm reduction in coil diameter, that would make for possibly a useful design change. Just a suggestion.

My 2c.

Stubbie

From memory I couldn't get the coils done in 1/2" tube due to the small diameter so had to settle for the 12mm tube at a nominal 98mm OD.
1/2 " tube would have been great but not do able in stainless.
Nev

 

[Stubbie]

From memory I couldn't get the coils done in 1/2" tube due to the small diameter so had to settle for the 12mm tube at a nominal 98mm OD.
1/2 " tube would have been great but not do able in stainless.
Nev

Oh no, wasn't suggesting a change in terms of 12mm tube, but rather a very minor reduction to the 98mm OD. 100mm standard stainless tube with a 1.6mm wall thickness has, IIRC, an ID of 97 point something mm - just a smidgen too small to accept the HERMIT as is. My thinking is that such a mod, if at all possible, would make an already successful product also compatible with standard 100mm stainless tube (ie. allow it to slide into the 100mm stainless tube).
A short length of 100mm stainless tube with 100mm off-the-shelf disc welded at one end and 100mm tri-clover fittings at the top end would make the basis for quite a blingy HERMIT Hx vessel, not to mention resistant to a meltdown. Just a thought.

Stubbie.

 

[Online Brewing Supplies]

Oh no, wasn't suggesting a change in terms of 12mm tube, but rather a very minor reduction to the 98mm OD. 100mm standard stainless tube with a 1.6mm wall thickness has, IIRC, an ID of 97 point something mm - just a smidgen too small to accept the HERMIT as is. My thinking is that such a mod, if at all possible, would make an already successful product also compatible with standard 100mm stainless tube (ie. allow it to slide into the 100mm stainless tube).
A short length of 100mm stainless tube with 100mm off-the-shelf disc welded at one end and 100mm tri-clover fittings at the top end would make the basis for quite a blingy HERMIT Hx vessel, not to mention resistant to a meltdown. Just a thought.

Stubbie.

I agree to the upgrade blingness, it would make things more permanent (volcano resistant ).
I will see if I can bring the OD down a bit but I am 90% sure it will be a no from the coil maker I have whipped them before :lol:
If its viable it will be done.
Nev

 

[Smokomark]

1.7 litres capacity.
1.8-1.9 degrees per minute on a double batch with one of Nev's little brown pumps.

Works for me.

 

[Online Brewing Supplies]

Great piece of HX build, if you can reproduce it on a mass scale I am sure you will be in demand.
I guess thats a mates rate build ? I would like one :icon_cheers:
Nev