Water Jacket For Mash Tun With Herms

[chappo1970]

Been planning phase 2 of the brewery which revolves around 2 important elements, well to me anyway. The first is a HERMS system to the mash tun and the second is a recirculating water jacket around the mash tun using the HERMS. Being the eternal tinkertot I have put an idea to paper.

Please note I would rather not discuss the HERMS here as there is already another great thread which I will post to in regards to that part of the build however if it's important to the overall scheme of things then go for it.

Now I can't claim this as my own idea as it has been discussed with another AHB member who is a genius with this stuff and it was his original idea and concept. I won't name ya mate but certainly chime in if ya feel the need.

The water jacket:
The idea is basically I will upgrade the 55lt esky to an 80lt pot. Now I already have a very robust 125lt pot I picked up from the markets which I want to use as the outer liner with the 80lt pot forming the inner liner. Now I have measured both up and they fit nicely within each other with about 30mm gap all the way around and about 120mm head space. Heaps of room to plumb in the pick up and return for the Mash Tun HERMS (inner 80lt pot). The pick up and return for the recirculation system for the water jacket will be placed in such a way as whirlpool both the HERMS kettle and the water jacket therefore creating even heating through both, maybe? Uneven water displacement thereofre volumes maybe my undoing but not to sure ATM. The idea is to use the HERMS for both heating requirements and hopefully creating a stable temperature throughout mashing as what ever the HERMS is at the water jacket in theory should be as well.

Anyway here's a sketch I have knocked up for the idea.




All comments, critiques and thoughts gladly accepted as always.

Cheers

Chappo

 

[jonocarroll]

Just curious - I don't use HERMS myself just yet, but what advantage does the recirc-jacket provide over insulation? Wouldn't this provide a heat source for the mash, rather than just help to maintain the temperature? My understanding of HERMS was that you recirculated to move between step temps, and held at those temps in between - thus the kettle should be at a higher temperature than the mash. That may be wrong.

Seems like you could save a lot of effort (not to mention a whole pump) if you insulated the mashtun and used the HERMS to raise the temp.

$0.02 is all that's worth.

 

[raven19]

Looks like you have put a lot of thought into this already.

There will be lag times between heating the water in the skin compared to the mash obviously, but with time you will get that down pact and control it well, once you have used this new setup & rig a few times.

I like the whirlpooling effect you will also get with the orientation of the coiling.

Dont be concerned with the water displacement, as you have plenty of headspace.

Other thoughts - a 3 way valve for draining the water jacket once finished (probably locate it next to the heater element)

Location of pump below to keep it primed (probably also covered already).

Final note of course.... More brew p0rn piccies expected by us all during construction & operation!

Super :icon_offtopic: Extra note - Does it get a name, I am thinking Sherman get's Nadia in American Pie 3, how about Nadia as the jackets name!? - This is assuming its named Sherman after American Pie of course!

 

[Adamt]

From what I gather, you're using the jacket as extra heat transfer surface? The surface of the inner pot would be quite a lot lower than the working area of the heat exchanger in the HERMS - i.e. you will increase your heat transfer but not by much (over just the HERMS). You will also have to take into account losses through the exterior of the jacket (negligible if you insulate it) and losses through the piping between the extra jacket/HERMS reservoir, AND you will need a second pump! Good idea but probably not worth it.

 

[Vossy1]

I've used a HERMS system in the U.K for the last 2 years. My heat exchanger has a 3ltr volume and a 2.4kw electric element.
I use a March 809HS pump set at 2ltr/min for recirc. I have used the same HE with both a non insulated 50ltr mash tun, and a 80ltr insulated (foam) MT, and both have held temp perfectly, at whatever pre set temp.
My advice C (for what it's worth) keep things as simple as possible.

 

[sav]

Hi bud I was talking to my mate the other day about a similar design,(hes a sparky) And the differance in heat loss would be much greater with the jacket than keeping recurculation within the herms ,my brew I just completed didnt loose 1degree over 70 min mash Its just insulated I am going herms type one day but the benifit is for step mash and recurculation,eg save time and you can save on a pump,All I am saying is to much going on worrying about differant temps everywhere.
Keep it simple brother.

sav peace out

 

[Millet Man]

For my simple home system I use a 19 lt stock pot for a mash tun and sit it inside a 30 lt electric urn (my hlt/kettle) to maintain temp, does the job beautifully but is not so good for raising temp - for that I use infusions and an immersion element. I also transfer my mash to a separate lauter tun because of the nature of the malt I use, it works best for me.

Water jacket idea does work well for insulation, and it also provides sparge water.

However, if you use a herms and insulate your mash tun then you really don't need the water jacket as the herms will maintain the temperature and allow you to raise it. Seems like a bit of overkill to have both.

Cheers, Andrew.

 

[schooey]

However, if you use a herms and insulate your mash tun then you really don't need the water jacket as the herms will maintain the temperature and allow you to raise it. Seems like a bit of overkill to have both.

I agree. I'm a happy HERMS user and I reckon by using a HERMS, at most all you need is insulation on your tun, Chappo. I dreamt up all sorts of weird and wonderful ideas when I kicked off, but I got some good advice from some of the old stagers here; KISS, no need to complicate a simple thing.

Have my HERMS in the HLT and I only need to have my HLT water ~3 degrees warmer than what I want the water to exit the HERMS coil and once at temp, mash doesn't vary half a degree from target temp.

 

[jimmyjack]

Chappo no need to insulate tun if you have a properly designed heat exchanger.. I have a seperate 2.5 HE and am able to ramp temperature during steps very quickly.


Cheers,

JJ

 

[browndog]

I've thought long and hard about this Chappo and come to this conclusion. The reason I want a Herms is to attain perfect mash temps and maintain them if necessary. By doing it the water jacket way, it will work and probably work well, however the drawback is that you will have to recirculate the water in the jacket for the duration of the mash or you will loose a huge amount of heat when you stop recirculating. I want to recirculate till I hit my desired temp then shut off the pump and let it be so I'm going for an insulated mash tun and heat exchanger. By the look of your design, you have the best of both worlds there. In my design the jacket inlet was at the bottom of the tun with the outlet at the top allowing gravity to drain it back into the HE.

cheers

Browndog