Hermit Coil Heat Exchange Build

[Fourstar]

Quick update!

Received my coil last Friday and Maple, Brendo, CM2 and myself gave it a run through on our monster brew day #3 yesterday. Seemed to hold up to the pressures of mashing 30 odd kg of grain and ramping 70-120L of mash liquor from mash temps to mash out and beyond.

Only issue we ran into really was with my new PID controller. With the temperature calibration being out (so much for self calibrating) we ramped outside of mash temp without realising it (trying to hold at 64-66deg and were ramping to 70-73). Today I managed to calibrate and auto tune the PID and reading against my digital thermometer and it is now within .5 deg between 30-95c ramp readings.

The setup is a simple hermit + kettle job with a few ghetto holes drilled in the lid to run pipes and kettle is silicone glued to the plastic base. Im planning on upgrading it to an even ghetto-er $9 k-mart kettle jobby which is slightly smaller in dimensions and would be a much more stable base than my current setup.

I'm planning on running it on my own system tomorrow with a double batch of smoked porter. I will keep you posted on how it all goes with 'normal' batch sizes.
You can see the picture of the hermit (in the background) in the brewday http://www.aussiehomebrewer.com/forum/inde...st&p=898624 thread.

All in all a great bit of kit nev. :beerbang:

Cheers.

 

[QldKev]

Follow up from here

Ramped up to mashout temp no problems! As the HERMIT output hit 77c, the water inside the HERMIT hit 86c. Didn't time the ramp as I had both the RIMS + HERMS running together, as expected it was a lot quicker than the RIMS by itself (which the project was for). With 2400w RIMS + 1800w HERMS = 4200w worth of heat exchangers, I can now get reasonable ramp times.

I did find the first half of the ramping both heat exchangers ran full time, but once again the return line from the HERMIT hit about 5c higher than the output from the internal RIMS, so it hit mashout temps first and stated cycling. But since the output of my RIMS feeds the HERMS this will always happen. I don't have plans to modify it to run them in parallel.

Overall I call the HERMIT a success!



Has anyone insulated the PVC pipe to help reduce heat loss?


QldKev

 

[Online Brewing Supplies]

Has anyone insulated the PVC pipe to help reduce heat loss?


QldKev

Yes I have insulated my hermit but havent got any solid figures to show its quicker or more efficient. Obviously it will be more efficient but is it a big factor, dont know.
I think insulating your tun and having a lid on the vessels would gain better results.
Nev

 

[QldKev]

Yes I have insulated my hermit but havent got any solid figures to show its quicker or more efficient. Obviously it will be more efficient but is it a big factor, dont know.
I think insulating your tun and having a lid on the vessels would gain better results.
Nev

Cool, it looks safe to add the insulation. The Mash tun is already insulated and has a lid, and I've already got a piece of the same insulation ready for the HERMS, but wanted to make sure someone else had done it.

QldKev

 

[Truman42]

Cool, it looks safe to add the insulation. The Mash tun is already insulated and has a lid, and I've already got a piece of the same insulation ready for the HERMS, but wanted to make sure someone else had done it.

QldKev

What are you using to insulate it Kev?

 

[QldKev]

What are you using to insulate it Kev?

$5 camping mat from Sam's warehouse. Seems to work pretty well, if you touch the mat while it is running it is surprisingly cool. I just glued on some velcro to make removal easy.




QldKev

 

[Fourstar]

$5 camping mat from Sam's warehouse. Seems to work pretty well, if you touch the mat while it is running it is surprisingly cool. I just glued on some velcro to make removal easy.
View attachment 53588
QldKev

Ive so got to pull my finger out and do something like this as the idea of making up a neoprene wetsuit for my mash tun is slipping father away based on cost.

Bite the bullet and goto sams/kmart me thinks. Plents of camping/gym mats that are perfect for the job.

Well the grainbill is prepped for my smoked porter double batch tomorrow. If im not half asleep, i'll attempt to take some vitals on the ramps.

Cheers.

 

[mxd]

Ive so got to pull my finger out and do something like this as the idea of making up a neoprene wetsuit for my mash tun is slipping father away based on cost.

Bite the bullet and goto sams/kmart me thinks. Plents of camping/gym mats that are perfect for the job.

Well the grainbill is prepped for my smoked porter double batch tomorrow. If im not half asleep, i'll attempt to take some vitals on the ramps.

Cheers.

how did it go on the big mash ?

I'm still waiting for mine to arrive, but my normal is 12-14kg grain + water (35ltrs ?) to fill 50 ltr keg to hold mash or ramp.

I normally add 30 ltrs of water to mlt then ramp (via HERMS) to mash+3 degrees, then mash in and drop PID back to mash temp.

My current setup ramps about about 1 degree every 1.5 minutes with valves fully open (I always leave valves fully open) and holds the temp perfectly.

 

[brendo]

how did it go on the big mash ?

I'm still waiting for mine to arrive, but my normal is 12-14kg grain + water (35ltrs ?) to fill 50 ltr keg to hold mash or ramp.

I normally add 30 ltrs of water to mlt then ramp (via HERMS) to mash+3 degrees, then mash in and drop PID back to mash temp.

My current setup ramps about about 1 degree every 1.5 minutes with valves fully open (I always leave valves fully open) and holds the temp perfectly.

If we take the uncalibrated PID out of the equation, it performed extremely well on the 160l mash tun. 25-30kg grain with a pretty loose mash to aid recirc.

Should handle a full 50l tun with complete ease.

 

[Fourstar]

after calibrating thermocouple and reading from the outlet correctly here are the vitals from my double batch porter im brewing just now. i just hit the dextrinization rest.

10KG mash @ 3L:kg

dough in @ 55deg for 10 mins
ramp to 63 - 9:55-10:05 - 1 min 15 sec/deg ramp time
ramp to 70 - 10:40-10:49 - 1 min 17 sec/deg ramp time

PRetty kick arse and my digital thermomenter is reading within 1 deg in other parts of the mash.. stoked.

thinking about it, where we were measuring the temp in the mash was somewhat a deadspace as the return wort was passing below and away from the thermocouple so that may have also contributed to a dicky reading pre-calibration.

I calibrated last night at my mash temp (63deg) and then compared ranges from ambient (20deg~) all the way through to 95 deg and there was only ever 1 deg~ difference with my digital thermometer. Nothing as wide as what we were reading on the day.

 

[brendo]

after calibrating thermocouple and reading from the outlet correctly here are the vitals from my double batch porter im brewing just now. i just hit the dextrinization rest.

10KG mash @ 3L:kg

dough in @ 55deg for 10 mins
ramp to 63 - 9:55-10:05 - 1 min 15 sec/deg ramp time
ramp to 70 - 10:40-10:49 - 1 min 17 sec/deg ramp time

PRetty kick arse and my digital thermomenter is reading within 1 deg in other parts of the mash.. stoked.

thinking about it, where we were measuring the temp in the mash was somewhat a deadspace as the return wort was passing below and away from the thermocouple so that may have also contributed to a dicky reading pre-calibration.

I calibrated last night at my mash temp (63deg) and then compared ranges from ambient (20deg~) all the way through to 95 deg and there was only ever 1 deg~ difference with my digital thermometer. Nothing as wide as what we were reading on the day.

Nice work Fourstar!!

 

[Tim F]

Just solder the cord wiring to the corresponding terminals (I've shrink-wrapped the bare parts after soldering) & pass the cord through the side of the box using a grommet.

I was told never to use solder for mains wiring - you should always use the screw in push connectors as solder can get hot enough to melt with 240V in some circumstances. Dunno if that's 100% correct but worth mentioning

 

[Aces High]

I changed mine around a bit to save having to melt and flatten the PVC. This also allowed me to split another bit of tube and wrap it around the middle section for added support and insulation. Then a third layer split and heat bent to act as a holder for it. The unit attaches to the side of my BIAB trolley, but can be taken off when needed.

 

[iralosavic]

I changed mine around a bit to save having to melt and flatten the PVC. This also allowed me to split another bit of tube and wrap it around the middle section for added support and insulation. Then a third layer split and heat bent to act as a holder for it. The unit attaches to the side of my BIAB trolley, but can be taken off when needed.

Nice one. Where do you have the recirculation return going to? On/above the grain or down the bottom?

 

[Aces High]

Im working on a recirculating BIAB system. I picked up these ex laboritory collander from a grays online auction. Unfortunatley they also have holes right up the sides so I had to still put the bag in as I couldn't get a proper grainbed. Im thinking of maybe a circular thin stainless insert to go around the sides so i can get rid of the bag altogether. Its all still a work in progress, so its currently pretty messy

 

[DuaneS]

for the couple of people looking for a stainless vessel, try an exhaust shop, truck exhausts, I fitted a new stack to truck on the weekend, its chromed steel, but was 100mm dia, I am not sure if you can get it in stainless, but might be worth a few phone calls.
Doubt it will be cheap though

 

[sama]

Whats the basic operation of such a unit? Im a single infusion man... Do you.. 1. Dough in with appropriate water from HLT..2.Recirculate through HX back to MLT. Does the HX contents need to be pre heated before the first recirc? Where do u measure the wort temp in the tun to control the HX temp? When it comes to mashout, i take it you let the HX get the wort to a higher temp? batch sparge as per normal with appropriate water from HLT and recirc for clarity?

 

[kelbygreen]

1. you dough in usually higher I think as you are not infusing the mash with any extra liquid and a thin mash will help the flow of things.
2. Not sure about heating the hex before hand but warming the water to the same temp your mash should be wouldnt hurt. I guess the best method would be to run the system when the strike water is in till it maintains the temp then put the grain in and start your mash as normal.
The temp is usually measured as it comes out of the hex
3. if you are going to the trouble of recirculating I would be looking into fly sparging as you just spent all that time setting up a grain bed and a "filter" to go and stir it all up right at the end.

 

[Fourstar]

3. if you are going to the trouble of recirculating I would be looking into fly sparging as you just spent all that time setting up a grain bed and a "filter" to go and stir it all up right at the end.

if you brew in keg shaped vessels and do double batches... yes, adapt fly sparging where possible. i wanted to cry after getting such clean and polished wort to then mud it up with somewhat murky second runnings. <_<

single batches? heck im just going to gently add my 'sparge' water to the batch slowly as i raise to mashout or full volume mash it like BIAB. with the efficiency increase i had on the weekend with my double batch (an extra 9% , from 68% to 77% into fermenter) im not concerned about no sparge brewing and efficiency problems.

 

[bradsbrew]

3. if you are going to the trouble of recirculating I would be looking into fly sparging as you just spent all that time setting up a grain bed and a "filter" to go and stir it all up right at the end.

if you brew in keg shaped vessels and do double batches... yes, adapt fly sparging where possible. i wanted to cry after getting such clean and polished wort to then mud it up with somewhat murky second runnings. <_<

I am going to give fly sparging a go. I have found that since going to HERMS I have added an extra hour onto my brewday and alot of this time is spent recirculating my 2 sparges to get it clear again.

Hit 90% (64L into cubes) today using the coil in the $8 abode kettle. Obviously the increase was due to multiple things I've changed. But I wouldn't mind losing a few% eff to get a bit of time back.
Looks like I'll need another pump to fly sparge though?

Cheers