RIMS Tube with Step Mashing Capability

[FredTheNuke]

Initial power up testing and de-bugging is complete. A few more power wires, install on the rig and it should be a solid brew day for break in on Saturday! Assuming I can get the PID settings worked out...

The heaters are 1500 watts each. One will run when I'm holding the temp during mashing and the full 3000 watts will be used to change the mash temp. Pump will run the entire mash cycle to ensure an even grain bed temperature and excellent bed filtration (I've had good success with this method). RIMS outlet temp is measured just before the wort returns to the MLT. RIMS is controlled by grain bed temp of course (via 8 inch thermowell).

 

[Dgonza9]

Interesting project. I'm curious to see how well it works in practice. Are you planning to have one of the PIDs off to maintain temps and use both in manual mode to ramp temps?

I assume you are thinking about large temp changes here, like protein rests and the like. But my experience in ramping mashes following protein rests is not good. A lot of protein gunk and a definite danger of scorching in my experience. I don't think I'd do it again without stopping to clean out the RIMS tube and element before ramping. I've personally moved to using a 220V element at 120V to maintain mash temps and minimize scorching issues.

While I ramp 10 or 20 degrees for mashouts, I think there's a danger there. Additionally, I used to have a RIMS tube like yours, but moved to a tri-clamp once I saw how crusted up the elements can get, even with circulation and even soaking in oxy.

Though it's not as elegant, I think infusing boiling water from HLT may be the best way. But that's just my limited experience. A lot people never have scorching issues at all.

Cheers.

 

[FredTheNuke]

Good info! The number one purpose of the tube is to maintain my Fred's Pilsner at 152F during mashing - that is very intermittent and light duty and I know will work wonderfully. The other uses are untested and will probably result in what you mentioned.

To explain the controller:

The 2 top blue lights are Heater 1 Energized and Heater 2 Energized - these mean 120 vac is actually being sent to the heaters. The switches in order left to right are: Control Power (the 3 devices will turn on), Pump 1 on/off, Pump 2 on/off, Enable Heater 1 and Enable Heater 2. The enable heater switches break the PID output so that I can decide which if any actually turn on even if the PID is calling for them to be on.

The bottom left PID is the RIMS controller. It's output is both heaters (the enable switches let me decide how many actually turn on - 0, 1 or 2). It's input is the MLT thermowell sensor which is 8 inches into the grain bed.

The top left STC 1000 is monitoring the RIMS output temp just before the wort goes back into the MLT so I can see how much heat is going into the mash vs the mash temp.

The top right STC 1000 will monitor the BK. no actions just to get rid of the analog temp gauge.

The bottom right PID is primarily an emergency backup to the RIMS PID. It is monitoring the HLT temp and because it is a PID could one day allow me to automate the propane so the HLT will maintain and change temps automatically (don't really need this but meh)...

 

[FredTheNuke]

Well the brew day went good - two 15 gallon batches back to back are complete. One 40 amp SSR died within 2 minutes so one of the 1500 watt heaters was down all day (did not really need it anyway for 152F mash Lager).

Here are the performance specs of this sized RIMS tube:

35 lbs of grain with 13.5 gallons of strike water at 164F. Strike water added then mash stirred to break up any dough balls. The typical lag (that I typically see) was there.

GRAIN TEMP RIMS OUTLET TEMP TIME HEATER
135 143 2 minutes ON
146 145 10 minutes ON
150 147 17 minutes ON
151.5 149 22 minutes ON
152.5 146 27 minutes OFF
151.5 144 33 minutes ON
152.5 150 43 minutes OFF

I stopped paying attention to it at that point. Obviously I need to calibrate my RIMS outlet STC 1000 (the PID has a pt100 so is more than likely more accurate - but I will check each). The more important note is the delta in temperature - which is relatively LOW and in no danger of scorching the wort so my typical pump flowrate for mash recirc should be good to go. I'll test step mashing once I get a new SSR in.

 

[MercMan]

Great project - what model PIDs did you use and what size pipe did you use?