RIMS tubes

KC

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Who makes commercial RIMS tubes with element included? I know what I want and should probably built it except that I don't need another project right now; I do need to make a Christmas list.

I'm about to kick my Mash&Boil through the wall with all the E4 faults and constant scorching that gets harder to clean each batch. Brew days aren't supposed to be 12 hours long.
 
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I use a rims tube from Brewers Hardware. Very high quality, tri-clamp design, but the element would be up to you. Voltage, current capacities and physical sizes are all over the place. I personally have a 208 volt, 5500 watt all stainless steel element that I run at 120V. The advantage is I can get the maximum power out of a 20 amp circuit. The wattage is around 1850 at 120 volt. I get about 2 degrees F per minute rise on a 5 gallon batch.

I didn't get the kit from them, I built my own so I could keep the RIMS tube shorter, I shortened it by using a 1.5" "T" and a 1.5" x 12" tube. I got 1/2" barb adapters for the in/out. The adapter for the heating element is about the best out there. The whole thing comes apart and is very easy to clean.

It wasn't much of a project, I had it together in one night after work. It really works well. Total cost was about $200, well worth it.

https://www.brewershardware.com/RIMS-Tube/

Heating element

https://www.highgravitybrew.com/store/pc/Heating-Element-5500-Watt-SS-14-inch-208V-423p9768.htm
 
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The wattage is around 1850 at 120 volt
I think that's a 4 ohm coil, I think anywhere from 4-8 ohms would work. I like the lower heat density over 14". That is a nice element adapter.

If I had the time, I'd do a rectifier circuit and PCM MOSFET to dial in heater control separately from flow. I already have a brewpi. Control isn't an issue as long as there's a thermowell that accepts the brewpi probes.
 
think that's a 4 ohm coil, I think anywhere from 4-8 ohms would work.
You use Ohm's Law to figure out what element would work. So for example if you found a 208 heater element you need to know the resistance:
5500/208V = 26.4 amps.

Once you know the current at rated voltage you can figure out it's rated resistance in ohms:
208V/26.4 amps = 7.89 ohms

Now you can calculate the current flow for a different voltage:

120V/7.9 ohms = 15.2 amps

15.2 amps x 120 volts = 1824 watts.

The maximum wattage allowed by NEC is 80% of the rated breaker current, so a 20 amp breaker is not to exceed 1920 watts continuous load. That leaves just enough for a controller (20 watts) and a March pump (50-60 watts). Perfect!

A 240V, 5500 watt element will give you about 1400 watts, so you pick up about 400 watts when you switch to a 208V element.

A 4 ohm element at 120 volts would be about a 30 amp load at @ 3600 watts. Way too high. If you want that kind of power, then switch to 240 volts to reduce current and wiring costs.

DO NOT run a 208 element at 240. That is simply stupid and dangerous. Lower voltages, no problem
 
Once you know the current at rated voltage you can figure out it's rated resistance in ohms:
208V/26.4 amps = 7.89 ohms
This is not correct for AC circuits. V-A is not the same as Watts. RMS figures are more accurate.

These heater coils are fixed resistors but they do have inductance. The phase shift alters the exact power load, but for a quick check:

<deleted to avoid confusion>
 
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This is not correct for AC circuits. V-A is not the same as Watts. RMS figures are more accurate.

These heater coils are fixed resistors but they do have inductance. The phase shift alters the exact power load, but for a quick check:

Pavg = Vrms^2 / R

at 120VAC:

Vrms = 85V
P = 85^2 / 4ohms = 1800W
P = 85^2 / 8ohms = 900W

And on that 208V element:

Vrms = 147V
5500W = 147^2 / R; R = 3.93 ohms ~ 4
You can measure it to check
I think you misunderstand. 120Vac is the RMS value. These elements are, for all practical purposes, a purely resistive device. At 50/60 hertz, the induction would be in the milli-henry range, not even worth adding into the formula. You are right that V/A is not the correct formula for a reactive load. These are not reactive devices, that's why the V/A formula works.

The voltage of a 120vac is 169 volt peak, or @ 340 volts peak to peak, pretty high. But all ratings, whether current or voltage, are always RMS unless otherwise stated. So if you use your formula, you will exceed current ratings by a huge factor. I have measured the elements with a ohm meter and the calculations are spot on and I have measured the current as well and it was also spot on. It's important to get this right or a guy can have some pretty nasty surprises in store.

So for a 20 amp/120 volt circuit you should never drop below 8 ohms or so.
 
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Yes, sorry, you're right - somehow you triggered my brain into analog world where any voltage not labeled as RMS is peak to peak. Deleted the above misleading calcs. My original rectifier idea itself wasn't even right.

So anyway I like the parts available at Brewer's Hardware. 16" tube isn't too long. Do you have a thermowell? Concerned that a 14" element will interfere with one at either port on the opposite end.
 
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Yes, sorry, you're right - somehow you triggered my brain into analog world where any voltage not labeled as RMS is peak to peak. Deleted the above misleading calcs.

My original idea to half wave rectify 120VAC to 85VDC, so for 1800W is 4 ohms, that's where that came from. But then I didn't want a project and started this thread instead. What I didn't do was toss out the burner assumptions when I dropped that approach. So 4-8 isn't relevant anymore.

Anyway back to the thread. I like the parts available at Brewer's Hardware. 16" tube isn't too long. Do you have a thermowell? Concerned that a 14" element will interfere with one at either port on the opposite end.
I don't use a thermolwell, I have a 6" Omega RTD probe that is inside the mash tun (when I did it a lot of people said it wouldn't work, but I think it the best place for it). But the other place to place the thermal probe would be on the inlet of the rims tube and I doubt the heater with give you any trouble with it. You can use a another "T" to add a RTD probe. The hard work and the most fun is in the designing of the system.

The best part of my system, IMHO, was when I was designing it. When you brought up the RMS voltage issue and the inductance side of AC I knew you had put a lot of thought into your system, good for you. There just something about brewing a beer on a system you designed and built that gives a joy that never gets old.
 
When you brought up the RMS voltage issue and the inductance side of AC I knew you had put a lot of thought into your system
That's just it - I didn't put much thought at all, just applying snippets of theory from non-residential space on a brew system that doesn't do what I need it to. This is why I don't need more projects right now.

I do know I want a sensor at the RIMS outlet to verify the recirc isn't denaturing, and another in the grain to monitor the actual mash temp
 
I do know I want a sensor at the RIMS outlet to verify the recirc isn't denaturing, and another in the grain to monitor the actual mash temp
That's one thing I have not actually checked, the outlet temperature. I run my March pump with the valve fully on and circulate as hard as the pump and false bottom will allow, this keeps the wort moving through the RIMS tube at a high rate preventing too sharp of a temperature rise. Occasionally I'll get a stuck mash from using oats, wheat or even rice, so when I think I will have a chance of a slower recirculation, I add 4-8 ounces of rice hulls.

An important to aspect of the system is a good false bottom, it makes life a lot easier when it works well.
 
one caution, I ran one for about 4 years and I wouldn't use it again without a flow or pressure sensor turning the power off when not filled and also you never use it to mash out or raise above a couple of degrees or more you will boil wort inside the tube and burst a hose, ask me how I know ;) , just use it to maintain the mash temperature
 
Brew Hardware had a good recommendation to run flow control on the RIMS inlet, not the outlet, and not to use a mash ball or anything that might clog and prevent pressure relief in a boil situation.

I run my March pump with the valve fully on and circulate as hard as the pump and false bottom will allow
I already know this is an issue with the grains I use and the crush I run. It can drain very slow and I sometimes have the recirc pump at a trickle.
 
one caution, I ran one for about 4 years and I wouldn't use it again without a flow or pressure sensor turning the power off when not filled and also you never use it to mash out or raise above a couple of degrees or more you will boil wort inside the tube and burst a hose, ask me how I know ;) , just use it to maintain the mash temperature
I had a time when I shut off the pump but I forgot the heater was on, needless to say the RIMS got very hot. To help with the situation, I slaved the heater to the pump, in other words, the heater is not allowed to turn on without the pump on. It's still left to the user to makes the flow is reasonably good, for me it's not a big deal because I'm checking it frequently. If you could use that flow meter and get a go/no-go indication out of it, you could slave the heater to the flow indicator and would have no need for the pump side of the slave circuit. This would be the best solution.

I already know this is an issue with the grains I use and the crush I run. It can drain very slow and I sometimes have the recirc pump at a trickle.
You going have to get the flow moving pretty good. Without a good flow, the RIMS systems don't work very well. My system recirculates close to a gallon a minute when its's running hard, that's when it works the best. The outlet side is just a 1/2" hose return to the top of the grain bed. It's long enough to lay on the bed and create a whirlpool flow. The outlet is not restricted in anyway.

I use a Sabco (Brew Magic) mash tun, which I highly recommend. The problem with that system is the price. It's hard to justify $600 for just a mash tun. But if you could mimic or find a false bottom that works as well, you could get by with a cheaper setup.
 
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I'll keep using the Mash & Boil as a tun for its inner basket and bottom temp readout. The M&B basket isn't the problem. The grain I've been using contains a lot of rootlets and endosperm that clog up the mesh bag I use in the basket. I'm going to try a different local malter.
 

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