RIMS brewing

[CoxR]

Hi Guys, I know there is a dedicated RIMS thread however it does not seem to get much action. I am looking at building a RIMS system so I can push out 3 cubes at a time. I want to hear from anyone running a RIMS that I could pm for advice. I have read through the thread and done other research but it is always good to hear from others that have hands on experience. Better yet, is there anyone on the North or North/West side of Brisbane that has such a brew rig that would be keen to show it off.
Thanks

 

[Matplat]

Contact wilsonbrewingcompany he's just setting up a 500l microbrewery with the mother of all RIMS systems...

 

[Adr_0]

Yep... Slightly smaller than 500L though. My current rig is 23L but I had a similar setup on my 50L.

Much like HERMS, high flowrate is your friend. Consider your mash tun geometry, your draw-off/false bottom and liquid distribution at the top, so that you can maximise your flow to get the most out of your element.

 

[CoxR]

I currently brew on a QLD kev inspired internal RIMS 23L system. I have never had an issue I just want to knock out 60L of 1050 wort at a time. I like brewing but not doing it every weekend or two.
Adr_0, I have a keg king pump and was going to use a spare 50L keg for a mash tun for the initial setup (as I have it) I will purchase a new pot for a boil kettle 80/100L and another Pot for sparge water, 30L maybe. I don't know what you mean about mash tun geometry. The keg I have is 500mm high and 350mm diam (approx)

 

[Cocko]

I have run a triple batch RIMs rig, I have since replaced RIMS for HERMS purely out of boredom and had the opportunity to do it.

Happy for PM chat to answer any questions I can OR post here and I will try and keep up, not on as much as I used to be though....

 

[CoxR]

Thanks Cocko, the main reason I am looking at RIMS is I have purchased the controller kit that Lael put together that I still haven't used yet. I was going to use that as the brains for the mash and use another PID I currently use for the boil kettle or even just put together an analog to control the bk element. I have a 3600w Romar element for that purpose. A 5 star 3600w elment will be used for the RIMS tube or is that overkill?
Cocko I was looking at mounting my RIMS tube vertical is that a bad idea?
As for pot sizes I haven't really looked into it, Mash tun for the time being will be the keg I described above, Boil kettle and pot for sparge water have yet to be purchased.

 

[Kingy]

I use laels brauduino with my herms. It works great. I was thinking the other day that if I was to make my boil kettle electric. I could just unplug the hex (from brauduino)and plug in the BK when it was time to boil and the controller would look after it.
That's gunna be a while untill I upgrade the sheds power.
Is there a reason why the controller would work better on a rims setup as compared to a herms?

 

[seamad]

I run a 3600 Watt RIMS for a double batch system, as it just cycles on and off it can't really be too powerful. You want a low watt density element for your RIMS, which the 5star probably is anyway. Any questions fire away, not sure why you want them via PM, your questions might be helpful to other brewers.

As to that Cocko, I wouldn't bother with him... Splitter h34r:

 

[CoxR]

Kingy, I thought I read somewhere in the very lengthy thread that the controller was not suitable for HERMS. I have not looked at the controller and will put it together in the next few days.
I am however happy to look at the HERMS option, however I like the idea of a RIMS for some reason.
Seamad I am happy to discuss with all in this thread rather than pm, as you said more info for others is a good thing.
.

 

[Adr_0]

Mounting the tube vertically is ok, but it should probably be element down to make sure there aren't any air pockets and you get dry spot on the element.

If you mount horizontally, make sure it is dead horizontal and the temp probe for your controller is as close to the element as possible. I soldered mine into an end plate so that the end is between the tip and the outlet connection. If it's too far away you risk overheating your wort - as you do with HERMS.

With the mash tun geometry, if it's a keg, ok... To be honest with 10-13kg of grain in that diameter you might find flow is limited, so will have to slow down the pump to avoid sticking, which will then slow down your ramp rates.

Think about the following:
-really good false bottom (flat or serrated on a stand, not domed) that fits tightly and has a bucket load of holes
-a couple of baffle plates underneath
-variable speed control on your pump

Good distributor will help reduce channelling or stirring up the bed as well.

It's really worth thinking about these things now to make sure flow doesn't slow you down with your ramp rates. 3600W should be good.

 

[DJ_L3ThAL]

I've got RIMS, vertically mounted (element sticks up through the bottom inlet and temp probe in through the top outlet), 2.4kW Still Dragon ultra low density element, can do 2.5x size batches so far and I have a domed false bottom in my mash tun. Also run an original Kaixin pump (slightly smaller than the normal ones you get now).

My biggest issues are with flow rates, I have yet to master the art, but you need to allow for some settling time at the beginning of the mash for the bed to first settle. Then the lines, pump and RIMS tube to push through the doughy/floury start of the recirculation. If you go too quick you suck the bed compact, if you go to slow, you lose valuable time to maintain temperature. I'm trying on my next batch a slightly higher strike temp to allow 5-10minutes at the beginning of the mash for me to slowing crank up the recirc flow.

Reading adr_0's post above, I didn't realise domed bottoms were not the best at allowing non-channeled flow, in fact I thought they were the best. But there you go! If I continue to have troubles that is the next thing I will look at.

 

[JDW81]

I'm a RIMS brewer and about to upgrade to a 100L kettle for at least triple batches. Run my RIMS with a 60L Blichmann MLT and an autosparge with a combination of gravity and pump.

Happy to answer any questions you have either.

JD

 

[CoxR]

Thanks JD, I think I am settled on a 98/100L kettle

 

[seamad]

I have the same blichmann MT as JDW, works well. I'm not sure 3600W for your kettle is enough ( it might be ), my kettle (70L insulated double batch ) has 2 X 2400 W elements, although I turn them down a bit once boil is reached. The 3600W may get a boil going, might just take a bit longer to get there.

 

[Adr_0]

Gas on the kettle if you can't get more electrical power.

Domes don't really have a lot of space under them and if they are not the full diameter you will get channelling and compaction will come on fairly soon. Plus if you take off the top you lose a few litres.

The flow/velocity in the outlet should be broken up as much as possible. So if there's only a bit of volume and surface area with a dome, the velocity in the bed close to the dome is actually pretty high.

A flat false bottom on a stand gives the wort a chance to slow down, so there is less velocity and less dP where the grain sits on the false bottom.

 

[Mardoo]

What about a full-diameter domed false bottom in a concave-bottom keg with a bottom outlet? Do you reckon that would improve the scenario at all?

 

[DJ_L3ThAL]

Gas on the kettle if you can't get more electrical power.

Domes don't really have a lot of space under them and if they are not the full diameter you will get channelling and compaction will come on fairly soon. Plus if you take off the top you lose a few litres.

The flow/velocity in the outlet should be broken up as much as possible. So if there's only a bit of volume and surface area with a dome, the velocity in the bed close to the dome is actually pretty high.

A flat false bottom on a stand gives the wort a chance to slow down, so there is less velocity and less dP where the grain sits on the false bottom.

What about the 2/3's diameter sizing rule of thumb for false bottoms, to prevent an easy flow path along the walls? Granted mine is nearer to 1/2 the diameter, so I probably could do with a larger bottom, but may look into having a flat one on a stand fabricated to suit my needs.

What about a full-diameter domed false bottom in a concave-bottom keg with a bottom outlet? Do you reckon that would improve the scenario at all?

Could this potentially risk channeling along the walls? although if the curve was the same, it may equalise the distance to the outlet from the middle and from the walls, resulting in perfect velocities no matter where the flow was coming from. Tough to fabricate though I imagine.

 

[Cocko]

Looks like I have been beaten to the punch with all the same answers I was going to offer....

As to that Cocko, I wouldn't bother with him... Splitter h34r:

Better than a spitter h34r: h34r:

 

[CoxR]

Would a coned bottom work better for a mash tun? I could build one by using stainless pipe and rolling a flat piece of stainless, or buy a thin bottom pot and drill/slot the bottom and weld a cone to the bottom.
Also as for power I do have a dedicated single phase 32amp circuit for brewing needs, I should of built a controller rather than purchasing the kit but when I did pay for it I was just looking at doing a single vessel build.

 

[Adr_0]

Sorry for the delay, I'm on night shift at the moment and pretty busy but Sunday night with everything steady has given me an opportunity to sit down at the computer.

Regarding preferential flow, this is going to be present any time you have a wall and a packed bed. A 2/3 diameter dome can will reduce amount of preferential flow, as this flow down the sides now has to come across horizontally into the area under the dome. This comes from the school of thought - which is actually a very correct, well-educated school, i.e. Weihenstephan - where slow, gently, drawn-out flow through a bed results in the highest efficiency. It should be applied during mash out conditions, but should be completely ignored during step changes where high flow is your friend. You can hopefully appreciate where a 2/3 dome is a good choice (increased lautering efficiency at mash out conditions) but is a big facepalm/d'oh when you are trying to get high flowrates when stepping your mash.

So, with that all considered, assuming a flat bottom mash tun...
- A braided hose offers the worst of both worlds: cripplingly low flow and big sacrifice in lautering extraction (efficiency).
- A full diameter false bottom hard against a flat bottom is probably the next step up, but the zone of compaction will still be pretty focussed right over the draw-off nozzle, which will limit your flow but might slightly increase your lautering extraction.
- A 2/3 diameter dome is the next best, with a more even compaction zone but still has a compaction zone over a reduced overall area
- A very close to full diameter false bottom with a voile bag is next best, as it permits the highest possible flowrate with a very small (difficult to measure...) sacrifice in lautering extraction due to the preferential flow down the sides
- A sealed, full diameter false bottom with high surface area (lots of holes, not much blank space) and a good few inches of disengagement space off the bottom is pretty well as good as it gets, but is going to be hard/impossible to fit into a keg unless you have a split design and silicone tube around the edge when you assemble
- The motherflippin shit-hot best solution is a full diameter, sealed false bottom with a 1:1 diameter to height or greater, a few inches off the bottom, with a circular baffle plate of 1/3 diameter an inch off the bottom to further break down the velocity and give maximum bling, efficiency, flow and bragging rights

A bit of SS duct/pipe with cone welded onto the bottom matched to a full diameter false bottom and voile bag for backup would be awesome. A full diameter dome on top of this cone would be pretty close to the full diameter flat with a stand, but a 2/3 diameter with a cone bottom would probably be worse than a 2/3 diameter on a flat bottom as your preferential flow down the cone sides is still there.

With the keg, you might struggle to get a full diameter false bottom in unless it's split, and a 2/3 diameter false bottom would actually be pretty bad given the very high bed loading (kg mash vs false bottom diameter) so your flowrate would actually be pretty low. A 4800W, 5, 6 7kW element would be great, but it would be off most of the time due to the low flow - i.e. the wort coming in over the element is pretty hot already, so the controller keeps it off/low most of the time so this would be a waste of money. Having said that if you make a good mash tun choice (duct/pipe with cone, full diameter false bottom) a 4800W would be your best bet, with a 3600W being ok but might limit you a bit. Run at max flowrates during ramps, and back this off through each step and during mash out/sparge to get the best efficiency.

Baffle plate is optional but that further spreads the velocity out to ensure you get a confident distribution over the full width of your bed without slightly higher velocity and compaction coming up through the middle zone.