BCS 460 and RIMS programming

I have my system 90% done and have been testing certain functions. One part I dont understand is cycle during RIMS mash.

This is what I have.
BCS controls elements and pumps.
RIMS tube with a 2500w 240v ULD element
Probe on the end of RIMS tub for reading RIMS state temp

Programming:
Direct on to reach temp for mash water with pump going. Pause for dough in. Then turn pump on to start circulating for 1 minute to get flow and then element on with PID control with setpoint of the desired mash temp. (151)

My question is, when using PID control for with RIMS state, does it cycle the element on and off? If so how much? I've read through the documentation and trying to grasp this part. The rest of the settings on the BCS I get.

PID works by adjusting the "throttle" on the control variable to achieve a desired set point. In the case of a heating element this is achieved by adjusting how long the element is turned on for a given amount of time. Say for example your period or cycle time is 1 second, and if your PID is calling for 50% throttle then it will turn on for 1/2 second then off for 1/2 second over and over. If its calling for 100% throttle it will be on for the entire second. I am not sure what the default cycle time is for the BSC or if it can be adjusted.

Yes, thats the part I'm trying to figure out. It seems like I could just use PID settings in the control and let it ramp up the mash water @ 100% to the set temp and then pause for dough in and resume at set temp with timer for mash. I am just worried about the cycle when holding the mash as to scorching.

I guess I'll just run a few test runs with water.

garbageman said:

Yes, thats the part I'm trying to figure out. It seems like I could just use PID settings in the control and let it ramp up the mash water @ 100% to the set temp and then pause for dough in and resume at set temp with timer for mash. I am just worried about the cycle when holding the mash as to scorching.

I guess I'll just run a few test runs with water.

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If you throttle at 100% till you hit the setpoint you may overshoot if there is any lag in the system. If you use PID on the ramp and it is tuned properly it will start to throttle back as you approach the setpoint so you don't overshoot it. You will have to run tests to see if you get overshoot with your setup or not.

When holding the mash temp how long the element is on will depend on how much heat your system is loosing. If you use a cooler that only drops a few degrees over an hour then it should hardly be on. If you use a kettle with no lid then it will have to add a lot more heat to compensate for how much you are loosing to the ambient air. I don't think you will have to worry about scorching. People use RIMS tubes all the time with no problems. RAHAHB.

I am using a RIMS with a 5500w element, but the idea is the same. I fill my MLT with cold water, turn on the pump and let the BCS460 control the RIMS at my dough in temperature. The PID keeps the element on until the temperature is close to the set point and then cycles it on/off as required. When it gets to temperature the BCS switches state to hold temperature for 10 minutes to verify stability. The program then switches the RIMS and pump off while I dough in. Switching to the next step turns on the pump and the RIMS with the PID set to my mash temperature. At mash out the BCS changes to the next step which increases the PID set point to 170 deg. after which it times for 10 minutes to mash out. I then stop for valve changes and start my sparge. As long as the pump is circulating through the RIMS tube during the entire time that the PID is in control there is no scorching, even with 5500 watts. Keeping the flow rate high enough is important, so I make certain to watch for compaction of the grain bed.

ChuckO,
Great thanks! Even though my element was switching on and off, I still thought it may be too high for the wort.

Can you briefly explain how you sparge? I was considering doing full mash with all the water needed to boil and no sparge. Basically getting the efficiency I need from recirculating the mash.

garbageman said:

ChuckO,
Can you briefly explain how you sparge? I was considering doing full mash with all the water needed to boil and no sparge. Basically getting the efficiency I need from recirculating the mash.

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I use my RIMS as a tankless water heater during the sparge, supplying feed water directly from my house supply. It's very capable of delivering 1 qt/min at 170 deg, so I don't need an HLT for supply.

The output of the RIMS only goes to a hose that sits on top of the grain bed in the MLT. I switch the RIMS pump input from the MLT to fresh water to put hot sparge water on top of the grain bed slowly. I adjust the pump output here to lower the flow rate for sparging as the RIMS does all of the heating from my cold water supply. I run the MLT drain from the false bottom through a second pump and into the boil kettle. I let the RIMS add the heat necessary to bring the supply water to sparge temperature controlled by the PID. Since the RIMS is now only heating water it doesn't matter what the flow rate is, as there is no chance for scorching anything. I do have alternate exit conditions set to shut things down if the sparge water gets too hot.

Since my boil kettle is electric, I start another BCS process when the element has been covered to bring up the wort to a boil. While it is heating I finish the sparge and shut down the RIMS PID and first pump.

Hope this helps explain my process. One of these days I will do a complete writeup on my system, as I have put a lot into the BCS programming to try to fool proof my system and it is somewhat hard to describe in words only without diagrams.

ChuckO said:

I do have alternate exit conditions set to shut things down if the sparge water gets too hot.

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I am building a setup exactly as you describe, 5500W element in a RIMS tube for a tankless water heater as I don't have room for a third vessel. Can you describe the above statement in greater detail?

Also can you describe/post a picture of your RIMS tube. I am curious of the dimensions, diameter, length, how it's mounted, etc.

Any input would be helpful.

Thanks ChuckO. Going to spend my break test running the BCS programming I have.

crane said:

Also can you describe/post a picture of your RIMS tube. I am curious of the dimensions, diameter, length, how it's mounted, etc.

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My RIMS tube is SS pipe 1 1/2" diameter about 12" long with a tee on each end. I'll post a photo when I get a chance. It's mounted about 5 degrees off of horizontal to allow it to drain through the wort inlet. At present I have an exit condition for the BCS process that shuts off the PID if the temperature goes above 180 degrees. A future enhancement will be to break the locking circuit on my main contactor at that point, making certain to shut down even if the SSR for the RIMS element fails closed.

My system is loosely based on Sizz's system.

Ok that makes sense. When you mentioned exit condition I thought you meant some sort of automated bypass valve to divert the hot water or something, but you are just implementing a simple fail safe shutdown.

When fly sparging are you able to go straight through the RIMS tube and directly into the mash tun or do you have to recirculate part of it like Sizz had to?

crane said:

When fly sparging are you able to go straight through the RIMS tube and directly into the mash tun or do you have to recirculate part of it like Sizz had to?

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I am recirculating in the same manner. It does even out the heating well. I tried doing without, but came to the same conclusion that Sizz did. Otherwise it could be a 1 pump system.

The only drawback that I can see to this 2 vessel method is the inability to chemically treat the sparge water since it comes directly from the tap.

Care to share what your current programming looks like? Just about ready to dive into mine.

Beeskneesbrew said:

Care to share what your current programming looks like? Just about ready to dive into mine.

Click to expand...

I'll send you a PM this evening, after I get done brewing an Irish Red.

Chuck

Fantastic....Thanks!