RIMS Safety and Grain Compaction

[chrish15]

Currently, I'm in the process of building a compact three tier brewing system with a single pump and a RIMS for mashing.

To sparge I use gravity. Thanks Earth. The top kettle doubles as an HLT and Boil Kettle. I use the bottom kettle as a grant/HLT.

During my over analysis of building a RIMS setup I decided to start a thread to learn how to brew safer (I'm not saying your system isn't safe!) with a RIMS tube, limit grain bed compaction and improve efficiency.

If you have used any of the following options we'd (the royal we'd) love to hear about successes/failures/opinions. With that being said, yes I've heard of rice hulls! I work for a homebrew shop, so they are off the list.

The four main things I've researched so far are:

1. Liquid Flow Switch
http://www.gemssensors.com/Products/Flow/Flow-Switches/Piston/Alloy/FS-10798-Series-Flow-Switch

These are adjustable from .5gpm to 40gpm and are placed after the RIMS outlet to shut off the heating element if flow falls below set level.

2. Liquid Flow Meter (aka Rotameter)
http://blue-white.com/blue-white-products/?filter_choose-by-product-type=76

Blichmann uses these in their tower of power setup. They are made of polysulphone bodies and poly or stainless fittings (handle heat up to 212). Can be used to set flow from mash tun during re-circulation AND sparge. Oh and will also double as a sight glass

(though obviously not as sexy). I believe they make these that can sound alarms if flow rate drops. Blichmann has one but that is either custom or I haven't found it yet.

3. Liquid Filled Vacuum Gauge
http://brewhardware.com/measurement-devices/thermometers-71/163-psivac

Click the link above for info, it's straight from Bobby M. Enuff said.

4. Installing a Vacuum Break

This is the best example I could find of how I would install one. Essentially, you place a tube starting below the false bottom ending above the mash level to relieve suction from the pump. I'm most skeptical of this because I haven't seen many out there. Finding this photo was so tough, I almost went with this...

Summary
I'd like to hear what people say before coming to a conclusion on what I'll end up using. So far I'm committed to the liquid flow meter (rotameter) because it will also be useful for setting sparge flow rate. I'd like to use a Liquid Flow Switch because I tend to get distracted while brewing and would like the added comfort of knowing my element is off IF I ever have a stuck recirc or pump failure. Would really like feedback on the vacuum break because I'm having a hard time finding info on it.

I'm sure there's plenty I missed, which is why we're here... so any help/info is much appreciated.

Ok, GO! :rockin:

 

[Indian_villager]

I was thinking along the same lines. Using one of these http://www.ebay.com/itm/Generic-Mag...095?pt=LH_DefaultDomain_0&hash=item51b8ddb35f.

I was thinking about routing the signal line to the ssr through the flow switch to essentially create an "and" gate for power to the element.

 

[chrish15]

That could work. I'd check dimensions on the inside to find out if it will restrict flow. Looks like one side is smaller than the other.

As for wiring, I found a diagram that seems to make sense.

Is that what you're thinking?

 

[processhead]

I can possibly see the value of some of these devices on a RIMS for brewing the first batches and fine tuning your process.

I also predict that after a half dozen or fewer batches, you will be able to regulate your flow rates just fine without the aid of the flow switch or rotometer.

My RIMS has been in operation for 6 or 7 years now, and it is about as basic as it gets. A heater, pump and manual ball valve.

I can recall a total of 2 stuck mashes over the years, both during the first year of use.

 

[atoughram]

I can possibly see the value of some of these devices on a RIMS for brewing the first batches and fine tuning your process.

I also predict that after a half dozen or fewer batches, you will be able to regulate your flow rates just fine without the aid of the flow switch or rotometer.

My RIMS has been in operation for 6 or 7 years now, and it is about as basic as it gets. A heater, pump and manual ball valve.

I can recall a total of 2 stuck mashes over the years, both during the first year of use.

X2 - After the first initial stuck mashes, I only stick them when I change something in the process. I can hear the pump cavitating, when it happens but I wouldnt mind having a rotameter.

 

[dyqik]

I use "listening to the pump" as my safety device. If it starts to whine, the mash bed has stuck. You do have some time to respond before the RIMS tube overheats too much.

The only way I can make it make this sound is to close the valve on the mash tun - I've not had a problem in 3 brews from a bitter at 1.75 qt/lb, a Tart of Darkness clone (12.5% oatmeal) at 1.5 qt/lb and a Pliny clone at 1.25 qt/lb. I have a domed mesh false bottom in my cooler, and I'm using the US Solar pump. With all of these brews, I ran the pump unthrottled for the mash out step, with no stuck bed at all. That said, I've been using the LHBS mill or pre-crushed grain from Morebeer for these batches, and getting a lower efficiency than I'm used to, which suggests a coarser crush. We'll see how it goes next batch with my own mill.

Out of interest, why on earth would you working for a home brew shop put rice hulls off the list?

 

[chrish15]

Out of interest, why on earth would you working for a home brew shop put rice hulls off the list?

I was hoping to illustrate that I already understand their usefulness in recirculating systems and to avoid that being a topic of discussion in this particular thread. That being said, if anyone reading this is new to rims/herms, use rice hulls...

dyqik, I'm gathering from you and other folks that knowing your system is good enough to get by without having a stuck sparge or a potentially dangerous situation.

I guess I'm more curious how the basic process could be made a little more automated, say if I step away for 5 minutes and can't use listening to the pump as a fail-safe.

 

[dyqik]

I was hoping to illustrate that I already understand their usefulness in recirculating systems and to avoid that being a topic of discussion in this particular thread. That being said, if anyone reading this is new to rims/herms, use rice hulls...

dyqik, I'm gathering from you and other folks that knowing your system is good enough to get by without having a stuck sparge or a potentially dangerous situation.

I guess I'm more curious how the basic process could be made a little more automated, say if I step away for 5 minutes and can't use listening to the pump as a fail-safe.

Well, I've only run 3 batches, but all at different thicknesses, and I've entirely failed to get a stuck sparge on my particular system despite running in the worst case scenario with a completely wide open pump. Once set up and stabilized, the recirculation is very stable, and isn't going to suddenly stick for no reason.

I've also simulated a stuck sparge by closing the mash tun outlet valve when running with water (with the water at 170F), and nothing particularly bad happened. The water in the 1500W LWD RIMS tube did start to boil, but the PID loop stopped it very quickly before I stepped in and opened the valve again. The return flow to the mash tun also stopped very quickly, just returning what was already in the return pipe. Now, with wort, you'd probably have to stop recirculating and clean the element, but it's not dangerous as such. With an ULWD element, you don't have to worry about running the element dry either. I'm really not sure what you mean by a dangerous situation.

Basically, test your system with water first, then with a cheap grain bill. Then decide what features you want to add. A good false bottom is probably the best safety feature.

 

[processhead]

One feature I would suggest incorporating into a RIMS design, is to electrically interlock the heater to the pump switch.

This prevents the heater from coming on if the pump is not running.

It doesn't guarantee liquid is flowing through the heater, but your flow switch does that. It is a really simple way to avoid dry-firing the the RIMS element because you forgot to turn the pump on.

 

[chrish15]

If I interlock the flow switch to the pump, won't it interfere with the pump during processes other than mashing since there won't be flow through the switch?

I'm far from an electrician so excuse me if that's a dumb question.

Oh and D, this is all I'm worried about -

 

[mattd2]

If I interlock the flow switch to the pump, won't it interfere with the pump during processes other than mashing since there won't be flow through the switch?

I'm far from an electrician so excuse me if that's a dumb question.

Oh and D, this is all I'm worried about -

The diagram shows a double pole switch used to control the pump. One side would switch the mains power to the pump- the other is in the low voltage DC control circuit of the SSR, basically it means that for the element to turn on the flow switch must be closed, the pump must be turned on and the PID must want the element on. I guess you could say that it is overkill because as long as there is flow it should not matter if the pump is on or not (or the flow switch is already telling you the pump is on)

 

[Poobah58]

Flow switches aren't necessary if you are present. A vacuum gauge on the pump inlet is a must IMO. Make sure you have plenty of support under your false bottom just in case. Just keep an eye on the gauge and check the top of the mash every once in a while.

 

[processhead]

The diagram shows a double pole switch used to control the pump. One side would switch the mains power to the pump- the other is in the low voltage DC control circuit of the SSR, basically it means that for the element to turn on the flow switch must be closed, the pump must be turned on and the PID must want the element on. I guess you could say that it is overkill because as long as there is flow it should not matter if the pump is on or not (or the flow switch is already telling you the pump is on)

Agree, in this circuit, the pump interlock would be overkill.

I posted it to show the basic concept of how I use it in my RIMS system, which does not use a flow switch.

 

[dyqik]

The concern I'd have for my system is what the minimum flow rate required to activate that flow switch is - I run a fly sparge through my RIMS tube so that I can get away with a cooler HLT and not worry about the heat loss during a long fly sparge (by retuning the PID when I start the sparge, I can happily run very low flow rates). Obviously this isn't a concern if you aren't worried about sparge water temperature, or you batch sparge.