RIMS problems

[indianaroller]

I am brewing with a single tier RIMS. My mash is controlled with a heating element and a PID and the pump recirculates constantly. My mash tun is a keg with a Northern Brewer false bottom.

Lately, I have been getting a lot of stuck mashes. This problem has been getting worse over the past 6 batches or so. My last batch got stuck within minutes of starting the recirulation. This is very weird because I never get mashes.

Today I filled my mash tun with hot water and turned the pump on. I watched the water flow out of the return pipe that sits on the top inside of the mash tun.

After monitoring a steady flow for several minutes I decided to switch the heater on. Within a minute the flow of water started to pulsate. The pulsating action of the water continued for about half a minute from when the heater was turned off.

Since I could not hear any difference in the pump noise I'm guessing the heat from my heater is causing the pulsating flow and for my mashes to get stuck.

Does anyone know what I should do? I am using a brand new heat stick beause last batch the heater chamber ran dry and the heater burnt up. I have tried plugging in my brewery to differnent circuits.

 

[Walker]

I can't say anything about the pulsing, but wanted to ask if you are limiting the flow out of the pump with a ball valve when you are circulating or whether you are letting the pump just go as fast as it can.

The only time I have had a stuck mash with my HERMS was because I had the pump fully open and it compacted the grain bed. If I restrict the output of the pump with a ball valve, I don't have any issues.

 

[Bobby_M]

Where have you installed the temp probe for the PID?

I also hope you're running the pump output restricted. You can't create that much suction under the FB without compacting the grain bed. Conditioning your malt before you mill it will make a huge improvement also.

 

[Ohio-Ed]

Where is your RIM's heater in relation to the pump? Before the pump or after?
How are you controlling flow?

My setup is:

MT > Pump > Ball Valve > Rim's Heater > MT

I have a temp probe in the MT and in the output of the Rim's Tube. The temp control is based on the Rim's output.

When I start recirculating my mash, I do so very slowly, then gradually increase the volume.

Is it possible that the pulsing may be that your Rim's heater is boiling the contents???

 

[indianaroller]

Heater is after the pump and I do have a ball valve on the outlet of my pump.

 

[Catt22]

I'm gonna guess that there is an air pocket trapped in the heating chamber. I'm thinking that the pulsing is an indication of this. The element is possibly only partiially submerged and there is some localized boiling of the wort. The expanding steam is causing pressure changes in the line The pressure changes then cause the pulsing phenomenon. The solution may be to mount the heating chamber vertically with the inlet on the bottom and outlet at the top. This would make it nearly impossible to get air trapped inside. I dont have an electric RIMS, so I'm just logically thinking what may be the problem. It would be worth looking into IMO.

IMO, a full FB will work better than the pie plate type. Much more surface area with the full FB.

Also, the pulsing action may be contributing to the sticking problem. Pulsing is essentially a rapid series of surges and this would be similar to suddenly opening the flow control valve. It's the sudden suck down that will gradually compact the grain bed. You want to keep the grain suspended in the mash as much as possible. Too much suction or opening the flow valve suddenly can cause sticking problems.

 

[indianaroller]

I'm gonna guess that there is an air pocket trapped in the heating chamber. I'm thinking that the pulsing is an indication of this. The element is possibly only partiially submerged and there is some localized boiling of the wort. The expanding steam is causing pressure changes in the line The pressure changes then cause the pulsing phenomenon. The solution may be to mount the heating chamber vertically with the inlet on the bottom and outlet at the top. This would make it nearly impossible to get air trapped inside. I dont have an electric RIMS, so I'm just logically thinking what may be the problem. It would be worth looking into IMO.

IMO, a full FB will work better than the pie plate type. Much more surface area with the full FB.

Also, the pulsing action may be contributing to the sticking problem. Pulsing is essentially a rapid series of surges and this would be similar to suddenly opening the flow control valve. It's the sudden suck down that will gradually compact the grain bed. You want to keep the grain suspended in the mash as much as possible. Too much suction or opening the flow valve suddenly can cause sticking problems.

That is how I have my heater setup though.

 

[Catt22]

OK, but it still sounds like there is an air or vapor pocket forming or trapped in the heating chamber somehow. I would assume you are pushing the wort through the heating chamber. ie, the chamber is on the outlet side of the pump. If it were on the suction side, the reduced pressure could possibly cause some of the wort to boil. The vapor pockets could interfere with the pump and it might result in losing prime which would seem similar to a stuck mash. If the grain bed were partially compacted at the same time it could exacerbate the problem. I'm guessing obviously, so it may well have nothing to do with this.

never mind the par asking if the pump was in front or in back of the heater. I see you already answered that question.

 

[Catt22]

Is the pump making any rattling noises when all this is going on? Does is sound any different from normal operation?

 

[Ohio-Ed]

Any pictures of your setup?

What is the size/volume of your Rims tube? What temp do you have your PID set to?

My tube is fairly large... 2" threaded pipe. The reason for the question, is that this can contribute to how sensitive you setup is to boiling in the tube. Mine has enough volume that when I shut the flow off completely, the temp stays well below boiling, but it does spike. The PID will only respond so quickly to a sudden change and with a small tube, I can see where the wort would quickly boil.

 

[indianaroller]

Is the pump making any rattling noises when all this is going on? Does is sound any different from normal operation?

The pump sounds fine.

 

[indianaroller]

any pictures of your setup?

What is the size/volume of your rims tube? What temp do you have your pid set to?

My tube is fairly large... 2" threaded pipe. The reason for the question, is that this can contribute to how sensitive you setup is to boiling in the tube. Mine has enough volume that when i shut the flow off completely, the temp stays well below boiling, but it does spike. The pid will only respond so quickly to a sudden change and with a small tube, i can see where the wort would quickly boil.

1"

 

[indianaroller]

OK, but it still sounds like there is an air or vapor pocket forming or trapped in the heating chamber somehow. I would assume you are pushing the wort through the heating chamber. ie, the chamber is on the outlet side of the pump. If it were on the suction side, the reduced pressure could possibly cause some of the wort to boil. The vapor pockets could interfere with the pump and it might result in losing prime which would seem similar to a stuck mash. If the grain bed were partially compacted at the same time it could exacerbate the problem. I'm guessing obviously, so it may well have nothing to do with this.

never mind the par asking if the pump was in front or in back of the heater. I see you already answered that question.

Yes, I think you maybe right about the air pocket. I just don't know how I would fix that or why all of a sudden this started happening.

The only reason I can think of why this started is because I shortened the RIMS tube when I converted from a 2 tier to a single. Could making the tube longer fix my problem?

 

[Ohio-Ed]

Yes, I think you maybe right about the air pocket. I just don't know how I would fix that or why all of a sudden this started happening.

The only reason I can think of why this started is because I shortened the RIMS tube when I converted from a 2 tier to a single. Could making the tube longer fix my problem?

Shortening the tube would decrease the volume and make it more susceptible to flash boiling.

Personally I think we need more details on your setup / configuration... for instance, what is the relation ship of your rims output to the MT return? (is it possible a siphon is being created and emptying the rims tube?). Without more info, I think we are just shooting in the dark.

 

[CodeRage]

Sounds to me like you are getting steam into the pump head. Supposing that is true, here are the issues.

1. Your temp probe feedback is located too far away from the rims tube, It should be at the end of the rims tube output, in the rims tube by the exit is better yet. It should not be getting hot enough to flash boil.

2. If probe location is okay then your PID needs to be re-tuned.

3. The RIMS tube should be mounted so that it is above the pump. ideally the output should be the highest point on the RIMS tube.

 

[indianaroller]

Sounds to me like you are getting steam into the pump head. Supposing that is true, here are the issues.

1. Your temp probe feedback is located too far away from the rims tube, It should be at the end of the rims tube output, in the rims tube by the exit is better yet. It should not be getting hot enough to flash boil.

2. If probe location is okay then your PID needs to be re-tuned.

3. The RIMS tube should be mounted so that it is above the pump. ideally the output should be the highest point on the RIMS tube.

It's not steam in the pump head because the RIMS tube is down of the pump. Everything else you mentioned is in check.

Maybe I will just make the jump to a direct fire mash setup.

 

[CodeRage]

Maybe I will just make the jump to a direct fire mash setup.

Thats a little drastic.
Sounds like you may be under the assumption that steam can't go against a higher head pressure. I was having a RIMS problem and steam was blowing out both the intake and outlet of my plumbing with the pump on and a 2 foot of head pressure. If you're flow rates are low it is very possible.

If the problem started and went away with the element turning off and on then I would be inclined to believe it is an electrical problem. The fact the problem occurs with the element turning on and stays for some time after the element is removed before going away is indicative of a priming problem. It only takes a very small bubble to cause the priming issues you are seeing.

When this does happen, if you open the throttle all the way does the problem seem to go away faster?

I have 4500W before the pump so I guess I may have the worse case scenario but, after relocating the temp probe and re-tuning the PID I haven't had any issues at all.

Another thing that could cause this is the minimum on time for the PID unit. Depending on the flow rate, you will reach a temperature where the rims tube will heat up very rapidly, Happens to me in the 140s during mashing. If the on duration is set too long the element will stay on long enough to cause a quick flash of vapor. To fix this I had to set the minimum on time to 0 seconds on an Auber PID. This set's the output to a minimum of .5s.

 

[Ohio-Ed]

I am brewing with a single tier RIMS. My mash is controlled with a heating element and a PID and the pump recirculates constantly. My mash tun is a keg with a Northern Brewer false bottom.

Lately, I have been getting a lot of stuck mashes. This problem has been getting worse over the past 6 batches or so. My last batch got stuck within minutes of starting the recirulation. This is very weird because I never get mashes.

Today I filled my mash tun with hot water and turned the pump on. I watched the water flow out of the return pipe that sits on the top inside of the mash tun.

After monitoring a steady flow for several minutes I decided to switch the heater on. Within a minute the flow of water started to pulsate. The pulsating action of the water continued for about half a minute from when the heater was turned off.

Since I could not hear any difference in the pump noise I'm guessing the heat from my heater is causing the pulsating flow and for my mashes to get stuck.

Does anyone know what I should do? I am using a brand new heat stick beause last batch the heater chamber ran dry and the heater burnt up. I have tried plugging in my brewery to differnent circuits.

Describe your "New Heatstick"...
Why did your chamber run dry?
What did you do to correct the problem?
How does "plugging your brewery into different circuits" come into play?
You said in another post that your RIMs element is in a 1" diameter tube and you said you had recently shortened it.
CodeRage suggested you tune your PID, to which you replied "everything else is in check"... Did you run Autotune?
I still think you have an issue with super heating the wort in the RIMs chamber, which can probably be resolved with tuning and maybe some re-configuration. You haven't done a very good job describing your system other than to say "A single tier RIMS", so it makes it pretty tough to try to help you.

Many folks here are using RIM's successfully...

 

[indianaroller]

Describe your "New Heatstick"...
Why did your chamber run dry?
What did you do to correct the problem?
How does "plugging your brewery into different circuits" come into play?
You said in another post that your RIMs element is in a 1" diameter tube and you said you had recently shortened it.
CodeRage suggested you tune your PID, to which you replied "everything else is in check"... Did you run Autotune?
I still think you have an issue with super heating the wort in the RIMs chamber, which can probably be resolved with tuning and maybe some re-configuration. You haven't done a very good job describing your system other than to say "A single tier RIMS", so it makes it pretty tough to try to help you.

Many folks here are using RIM's successfully...

Describe your "New Heatstick"...
4500 watt, low density, 240v water heating element.

Why did your chamber run dry?
Because of a stuck mash due to this same problem.

What did you do to correct the problem?
Nothing yet.

How does "plugging your brewery into different circuits" come into play?
I did this to see if there was too much draw on one circuit and if it was messing with my pump. It is not.

You said in another post that your RIMs element is in a 1" diameter tube and you said you had recently shortened it.
My brewery used to be 2 tier with the HLT on the second tier. When I changed to a single tire I shortened the tube from 24" to 14" for cosmetic reasons only.

CodeRage suggested you tune your PID, to which you replied "everything else is in check"... Did you run Autotune?
I ran Autotune again and set the time on to "0" as he said. Still having the same problems.

I still think you have an issue with super heating the wort in the RIMs chamber, which can probably be resolved with tuning and maybe some re-configuration.
I'm positive that it's steam in the RIMS tube also.

You haven't done a very good job describing your system other than to say "A single tier RIMS", so it makes it pretty tough to try to help you.
What else would like to know? I can take more pictures if you like.

 

[CodeRage]

Pictures would be awesome.

 

[Ohio-Ed]

Describe your "New Heatstick"...
4500 watt, low density, 240v water heating element.

Why did your chamber run dry?
Because of a stuck mash due to this same problem.

What did you do to correct the problem?
Nothing yet.

How does "plugging your brewery into different circuits" come into play?
I did this to see if there was too much draw on one circuit and if it was messing with my pump. It is not.

You said in another post that your RIMs element is in a 1" diameter tube and you said you had recently shortened it.
My brewery used to be 2 tier with the HLT on the second tier. When I changed to a single tire I shortened the tube from 24" to 14" for cosmetic reasons only.

CodeRage suggested you tune your PID, to which you replied "everything else is in check"... Did you run Autotune?
I ran Autotune again and set the time on to "0" as he said. Still having the same problems.

I still think you have an issue with super heating the wort in the RIMs chamber, which can probably be resolved with tuning and maybe some re-configuration.
I'm positive that it's steam in the RIMS tube also.

You haven't done a very good job describing your system other than to say "A single tier RIMS", so it makes it pretty tough to try to help you.
What else would like to know? I can take more pictures if you like.

I haven't seen ANY pictures...? If you have some, they would be helpful (you know the whole, a picture being worth 1000 words thing).

4500 watts in a 1"x14" tube is probably WAY to much power. Every time it kicks on, it is likely boiling the wort which is where your "pulsing" is coming from. I have a 1500 watt element in my 2" diameter RIMS heater and it does fine maintaining mash temps for 10 gallon batches. You can try cutting the voltage to your element to 120v which should leave you with 1125 watts.

Are you using the RIMS heater for more than maintaining mash temps? Just curious why you are using a 4500 watt element.

 

[indianaroller]

I haven't seen ANY pictures...? If you have some, they would be helpful (you know the whole, a picture being worth 1000 words thing).

4500 watts in a 1"x14" tube is probably WAY to much power. Every time it kicks on, it is likely boiling the wort which is where your "pulsing" is coming from. I have a 1500 watt element in my 2" diameter RIMS heater and it does fine maintaining mash temps for 10 gallon batches. You can try cutting the voltage to your element to 120v which should leave you with 1125 watts.

Are you using the RIMS heater for more than maintaining mash temps? Just curious why you are using a 4500 watt element.

Sorry I meant to say that it is a 240v element that is ran to 120v which leaves me with 1125 watts. Pics are in post #5. I can see them. I will try again.

 

[indianaroller]

Mash tun return manifold.

 

[paledragon]

your pump is oriented wrong. put the inlet facing downward and the outlet upward. that's how i've got mine and have never had a problem.

p.d.

 

[Ohio-Ed]

Cool... now I see some pictures.

Some thoughts...

As PD said, rotating the pump head may help with priming, but I don't think it will make much difference once you get it going.

Is your pickup tube in the MT 3/8"? If so, that will put a pretty significant restriction on your flow.

I would swap your RIMS tube end for end, putting the element on the bottom. As you have it, if it drains to the outlet, the element will be exposed.

I would also lower the RIMS, looks like your output is close to the same level as your mash could be... I would lower is so there should ALWAYS be fluid. If it boiled where it is, it wouldn't take a lot to empty the return line exposing the element.

Also, how long is your temp probe? Is it reaching past the tee in the outlet?

 

[paledragon]

i'd also put some cable ties on those hose barbs. an accidental tug on the pump tubing, and you've got a 150* disaster on your hands.

p.d.