Questions and request for inspiration for DIY HERMS(ish) system

[aday8310]

I have been using an all in one 5 gallon electric brewing system, however on a whim I bought a some sanke kegs converted into a mash tun and boil kettle for a propane burner on craigslist for cheap. As I brew with a friend we want to upscale our 5 gallon batches to at least 10 gallons, so we each get a corny keg to take our separate ways.

I want to take this opportunity to set up a HERMS style system utilizing the all in one system as well as the sanke kegs, all powered by electricity.

I've come up with a system to avoid a few things I see other systems use:
1) relatively expensive / complex PID controller setup for high wattage 240 V elements
2) necessity to use BIAB or grain basket in mash tun with a heating element in the mash tun

This is it:

Quick rundown:
Left:
the Digiboil all in one will only be used for heating the HERMS coil, and then later transferring fresh sparge water
Temperature here will be controlled by the onboard controller that's already in this system
extra heating element is added (maybe a hot rod) to help heat up large volumes for 10 gal brews

Middle:
Mash Tun with no direct heating elements
temperature is regulated through flow through herms coil in the digiboil, regulated by a standard Inkbird temperature controller which will turn the pump on/off as necessary

Right:
Post mash, wort is transferred to the boil kettle with a larger 5500 W element.
Here I do not need temperature control, just enough power to get the Wort boiling

This leads me to a few questions:
1) is this design feasible / any immediate flaws I'm overlooking or perhaps an even more simple setup suggestion.
2) what is the simplest and safest way to add a 5500 W element to the boil kettle without a controller (not mechanically, I can do that part), is there a simple way to have an on / off setup with a knob to manually control output power without a feedback loop?
3) Any suggestions for temp probe for inkbird and how to attach to the mash tun?

thanks for your help in advance!

 

[day_trippr]

You need to rethink the temperature sensor location as the system will not work well at all with the probe simply stuck in the mash (even assuming it'd survive - which may be another concern). Most herms systems with just a single temperature probe sense the system temperature at the output of the mlt and adjust the heat rate accordingly...

Cheers!

 

[aday8310]

You need to rethink the temperature sensor location as the system will not work well at all with the probe simply stuck in the mash (even assuming it'd survive - which may be another concern). Most herms systems with just a single temperature probe sense the system temperature at the output of the mlt and adjust the heat rate accordingly...

Cheers!

Yes, sorry that was an oversight in illustration, I think I'll try to fit a tri-clamp to the bottom and have a temp probe installed in there.

 

[day_trippr]

Typically folks fit a tee to the vessel drain port and have the temperature sensor held by a compression fitting threaded into the non-straight-thru leg.
Very effective while minimizing flow rate impediment. One can find many compression fitting IDs available to hold different sensor bodies. Biggest issue may be the sensor stem length. Longer can be better up to a point...

Cheers!

 

[LarMoeCur]

You don't need a controller on the pump. Most electric brewers run the pump for the entire mash. So a simple on/off switch will suffice. Monitored with temp probe at the exit of the MLT. I run my HLT 2 degrees higher then my desired mash temp and recirculate for the entire mash. If your controlling the HLT with the digiboil then there is no reason to have a controller on the MLT.

You show the sparge come off the HERMS coil. I'm assuming it will actually be a separate fitting from the HLT.

For ten gallon batches you may have to top off the sparge tank during the sparge. The 6 or so gallons may not be enough. Make sure you stir the HLT during the mash. Temperature can be way different near the element if left to sit.

IMO there is really no way to add a 5500w element with out some type of controller. Your wort would be jumping out of the kettle if you ran it on full blast for the entire boil. I'd also be very worried about potentially scorching the wort. A simple SSVR controller can be built for about 40 bucks.

 

[aday8310]

You don't need a controller on the pump. Most electric brewers run the pump for the entire mash. So a simple on/off switch will suffice. Monitored with temp probe at the exit of the MLT. I run my HLT 2 degrees higher then my desired mash temp and recirculate for the entire mash. If your controlling the HLT with the digiboil then there is no reason to have a controller on the MLT.

You show the sparge come off the HERMS coil. I'm assuming it will actually be a separate fitting from the HLT.

For ten gallon batches you may have to top off the sparge tank during the sparge. The 6 or so gallons may not be enough. Make sure you stir the HLT during the mash. Temperature can be way different near the element if left to sit.

IMO there is really no way to add a 5500w element with out some type of controller. Your wort would be jumping out of the kettle if you ran it on full blast for the entire boil. I'd also be very worried about potentially scorching the wort. A simple SSVR controller can be built for about 40 bucks.

I'm thinking of getting this DIY Controller Kit (stilldragon.com) for the controller.

and yes there is a recirculation pump on the digiboil to keep constant temp throughout the HLT.

 

[LarMoeCur]

Aday, That's the exact controller I would by if I where trying to keep to a budget.