Rims Input Needed

[rwmingis]

Hi all,

I'm building a RIMS system at the moment. For me it's just a fun gadget to build, but I think it will be quite helpful in keeping my mash temperature the same throughout, help with small mash temperature steps, and also increase wort clarity.

I'm just looking for a bit of constructive criticism for the system before I begin ordering parts. My main worries are issues with grain clogging, scorching, etc.

To briefly describe the system:

1. All plumbing is half inch to match the size of the March pump.
2. Wort enters from the outlet on the base of the mash tun via a non-collapsing hose to the inlet of the pump.
3. It then goes through a diaphragm valve for flow control.
4. After the valve, it goes through an orifice (not shown, but adjacent to valve, will be a nominal 7mm dia.). I measure the differential pressure across this orifice to get the flow rate.
5. Wort then goes through the heating chamber which is either DN40 or DN50 copper pipe. It's about 550mm long so that it can accommodate the long low watt density elements to prevent scorching.
6. At this point I measure the outlet temperature of the heating chamber to ensure it's not too hot to avoid enzyme denaturing. I'm sure the enzymes are pretty hardy, but need to make provision for it in case i get conversion problems.
7. Lastly the wort heads to 2 selector ball valves where i can select between recirculation to the tun (for mashing) or filling the kettle during the sparge, or a combination of both for heating during the sparge.

If you know the flow rate through the system, you can limit the power going to the heating element (0-100%) so that you don't scorch the wort. If you slow the flow down with the same heat input, it gives the wort more time in the heating chamber to heat up. I'll probably use the two DS1820 temperature sensors (one in the mash tun, and one at the exit of the heating chamber) along with a honeywell diff. pressure sensor to feed a PIC chip to control power to the heating element using PID control.

See photos below (the white piping is conduit for the mains wiring)

So my questions are:

a.) Rather than throttle the flow with a diaphragm valve, what do you think of using motor control on the pump instead. Will this cause the pump motor to overheat?

b.) Have any of you had any issues with the suction head of the pump not being great enough to suck wort through the grain bed. Does it change during the mash as the starch converts?

c.) Does anyone have any experience with what the minimum fitting ID i should use when it comes to grain clogging the system. The orifice ID which is at a nominal 6-7mm at the moment has to be set exactly as it affect the pressure vs flowrate function. (at the moment 7 L/m should give me a 1 psi drop over the orifice) My thinking is that if it get's through the false bottom that the grain bits would be smaller than 3 mm or so.

d.) Any ideas where the best place in the mash tun is to place the temperature sensor?

e.) Lastly, any control tips? I think that one might be that if i have manual flow control, have it beep at me if the flowrate gets too high as the starch converts, or too low if there is a stuck mash.

I know it's a lot of questions, but any input at all would be greatly appreciated.

Cheers,

Rob

 

[razz]

G'day Rob.
a. Don't attempt to change motor speed of a March pump, they don't like it. Just vary the flow at the outlet via a valve.
b. Such a great little pump, no issues.
c. All my plumbing is 1/2 inch copper, don't see the need for anything smaller. I think most users of RIM's use a temp controller at the RIM's to turn the power on and off for a set temp.
d. Mine sits smack in the middle of the grain bed using a HERMS, but in a RIMS probably at the outlet of the RIMS or inlet at the mash tun.
e. Stuck mash can be avoided in many ways, grain milling, rice hulls in the mash and varying the flow out of the pump just to name three.
Can't give you much more than that, did you search for RIMS setups ? Also try http://www.brewzilla.nl/?brewhalla
Many RIMS on there.

 

[rwmingis]

G'day Rob.
a. Don't attempt to change motor speed of a March pump, they don't like it. Just vary the flow at the outlet via a valve.
b. Such a great little pump, no issues.
c. All my plumbing is 1/2 inch copper, don't see the need for anything smaller. I think most users of RIM's use a temp controller at the RIM's to turn the power on and off for a set temp.
d. Mine sits smack in the middle of the grain bed using a HERMS, but in a RIMS probably at the outlet of the RIMS or inlet at the mash tun.
e. Stuck mash can be avoided in many ways, grain milling, rice hulls in the mash and varying the flow out of the pump just to name three.
Can't give you much more than that, did you search for RIMS setups ? Also try http://www.brewzilla.nl/?brewhalla
Many RIMS on there.

Good stuff. So do you ever get clogs from grain in the system?

 

[fraser_john]

Make sure your filter bed setup is correct. Sometimes grain gets sucked around the edge of mine and I have had to cancel a brew whilst I clean the whole thing out! This was a problem when doing wheat beers and the suction got too much. I resolved this by adding 1kg of rice hulls when doing 44 liter batches. Slowing down the flow also helps prevent compaction of grain bed.

My system uses two heater elements in series, greatly reducing the chance of scorching, but I still get a 1.5c ramp rate when heating.

Check my website for details.

 

[razz]

Good stuff. So do you ever get clogs from grain in the system?

Morning Rob. No, no blockages from grain. I've had a few stuck sparges, since then I've used rice hulls and lately switched from a copper manifold to a ss 12" false bottom in the mashtun.

 

[rwmingis]

Make sure your filter bed setup is correct. Sometimes grain gets sucked around the edge of mine and I have had to cancel a brew whilst I clean the whole thing out! This was a problem when doing wheat beers and the suction got too much. I resolved this by adding 1kg of rice hulls when doing 44 liter batches. Slowing down the flow also helps prevent compaction of grain bed.

My system uses two heater elements in series, greatly reducing the chance of scorching, but I still get a 1.5c ramp rate when heating.

Check my website for details.

Great website John!

I too use rice hulls in about every brew, at about 5-10% depending on how much wheat I have in the mix. What flow rate do you use when you recirculate? Ultimately i'd like to figure out flowrate vs element watt density vs heating power applied to figure out how much juice I can give it before scorching. (I have to admit, i'm verging on poindextering here, my apologies). Eventually I think i'll have two flowrates, one for ramping up temperature between steps and a slower one for temperature maintenance, so i'll need to figure out the max flow rate until it starts compacting the grain bed.

So you're website says 800 watts per element, but I work out 1125W, how does one figure it out, my electronics is a bit rusty. Have you figured out your watt density yet for your elements. It would be good to have a figure to work towards. On my system I was thinking of using a 2.0-2.4 kW element and varying the power using a zero crossing SSR and a PWM signal to control it. By varying the number of "on" half cycles in a second (2 half cycles per full cycle x 50 Hz = 100 half cycles in 1 second) you can get power control from 0 to 100% in 1% increments which should be more than plenty.

Rob

 

[rwmingis]

Morning Rob. No, no blockages from grain. I've had a few stuck sparges, since then I've used rice hulls and lately switched from a copper manifold to a ss 12" false bottom in the mashtun.

Go the twelve incher! Never had a stuck sparge with mine either...

 

[newguy]

Sounds like you've thought through the system very well. I'm leery about the restrictor orifice - my gut feeling is that it will be the source of many, many clogs. Plumb in a bypass on a valve just in case - easier to throw the valve to get flow again rather than take the whole thing apart while it is filled with really hot wort.

Regarding wort scorching - that happens mainly due to some hulls getting by the false bottom and lodging in the heating chamber, which creates a vicious positive feedback cycle that encourages more scorching. You get the most hulls in the system for the first 3-5 minutes, so either don't turn on the element during that time, or severely restrict the power.

Control unit - get a PID unit from ebay. Omega make some good units but there are others available.

Pump power/suction - just place the pump below the mash tun and there will be no issues with suction. Also put a bleed valve just following the pump for priming. March pumps will loudly object (scream actually) if you try to run them dry.

 

[fraser_john]

Yep, 1125W for each element (2250W total) is right, the website was for when I was using different elements, but I just have failed to update the whole site properly! Need to do that!

P=VI P 4500 Watts
V 240 Volt
I 18.75 Amp

V=IR V 240 Volt
I 18.75 Amp
R 12.8 Ohm

2R in Series R 25.6 Ohm

I=V/R V 240 Volt
R 25.6 Ohm
I 9.375 Amp

P=VI V 240 Volt
I 9.375 Amp
P 2250 Watts


Like someone else said, just buy a PID unit from ebay to handle your temperature management, its the far easiest and most elegant solution! Probably one of the cheapest as well!

I just throttle the outlet of the pump for flow control. I adjust it so that is flowing well, but not compacting the grain bed at all, each brew is different and actually changes based on what temperature the grain bed is at, protein rest I flow it quite slow, but sach rest I can up the flow rate a bit.

 

[rwmingis]

Sounds like you've thought through the system very well. I'm leery about the restrictor orifice - my gut feeling is that it will be the source of many, many clogs. Plumb in a bypass on a valve just in case - easier to throw the valve to get flow again rather than take the whole thing apart while it is filled with really hot wort.

You are probably right, I might consider making an orifice that is tapered instead with a larger ID (and smaller pressure drop)

Control unit - get a PID unit from ebay. Omega make some good units but there are others available.

Probably will do my own PID as i have two sets of sensors and will be doing my own control logic such as alert user if clogged, etc...

Pump power/suction - just place the pump below the mash tun and there will be no issues with suction. Also put a bleed valve just following the pump for priming. March pumps will loudly object (scream actually) if you try to run them dry.

You must tell me of this bleed valve you speak of. I've heard of valves that only let air escape, but have only seen them on the industrial scale. Any ideas where to look for small scale ones?

:icon_cheers:

 

[newguy]

Probably will do my own PID as i have two sets of sensors and will be doing my own control logic such as alert user if clogged, etc...

Buying one is something to consider. I built my own, but to be honest it would have been far cheaper & easier to buy one.

You must tell me of this bleed valve you speak of. I've heard of valves that only let air escape, but have only seen them on the industrial scale. Any ideas where to look for small scale ones?

What I meant is to put in a T between the pump's output and the other T you have planned that routes between recirculation and pumping to the kettle. Just place a valve on the T so that you can easily open the valve, prime the pump, then close the valve and turn on the pump. I originally plumbed my system without one (my layout was close to what you have planned), and priming the pump was nearly impossible.

Hope this helps. :icon_cheers:

 

[Yorg]

Have quick scanned replies, so apologise if some of this is already covered but from my learnings doing similar things with pumps and plumbing:
Big pain with this pump is priming. My solutions relating to this were:
Have some polycarbonate tubing on on the inlet side to actually observe the flow, and how clean it is - this will aid when you are vorlaufing. I used the new style plumbing fittings for the new plasctic house piping - 3/4 inch brass fittings for the tube(I have heaps and can send you some at cost.)
Orientate your pump inlet/outlet and RIMS tube vertically to fill from bottom and push air out. Unless all air is out this pump often still runs but at a crawl. It doesn't really suck - it works via a flooded inlet principle. So the other thing is to take a good look at how you tap off your tuns, because they supply the inlet - and I stll have trouble flooding/priming the inlet - those with no problems at all I've found aree mostly those that tap off the bottom of their tuns - but that's another story.
Use a three way valve as the diverter valve. The less plumbing the better - which leads to:
Cleaning. The thing very underestimated and very important. Try and design for easy dis-assembly, as flushing is not perfect, and the occasional physical clean is a good thing to have the option of. (The stuff I've found in my ball valves!!!)
I also have a 12" - false bottom that is - never had a stuck sparge, but I always ramp up the flow rate, not turn on with valve fully open.
I am aware of the theory of placing the temp probe at the outlet, but I disagree. Doing that implies you have a theoretically 100% perfect insulator as a mash tun, since it will never be higher temp than your rims outlet and must be lower in practical terms. That means you don't have a system suited to ramping through rests. Monitor the mash for mash temp. Monitor the outlet to ensure you don't cook the enzymes - even though they will momentarily be above your mash temp when maintaining temp, and considerably above when ramping.

quick thoughts and now back to work.

 

[rwmingis]

Buying one is something to consider. I built my own, but to be honest it would have been far cheaper & easier to buy one.

Easier, most definately. Cheaper, i dunno, the PIC chips cost about 10 bucks and the displays about 15. Can't beat it with a stick.

What I meant is to put in a T between the pump's output and the other T you have planned that routes between recirculation and pumping to the kettle. Just place a valve on the T so that you can easily open the valve, prime the pump, then close the valve and turn on the pump. I originally plumbed my system without one (my layout was close to what you have planned), and priming the pump was nearly impossible.

Good point, will try to work something out. I also like the idea of orientating the pump so that the outlet on top of the pump to make priming easier too, maybe a combination of both.

 

[rwmingis]

Have some polycarbonate tubing on on the inlet side to actually observe the flow, and how clean it is - this will aid when you are vorlaufing. I used the new style plumbing fittings for the new plasctic house piping - 3/4 inch brass fittings for the tube(I have heaps and can send you some at cost.)
Orientate your pump inlet/outlet and RIMS tube vertically to fill from bottom and push air out. Unless all air is out this pump often still runs but at a crawl. It doesn't really suck - it works via a flooded inlet principle. So the other thing is to take a good look at how you tap off your tuns, because they supply the inlet - and I stll have trouble flooding/priming the inlet - those with no problems at all I've found aree mostly those that tap off the bottom of their tuns - but that's another story.

I like the idea of the polycarbonate tubing. I assume that this is clear hard plastic tubing? Where do you get it? Will definately re-orient the inlets and outlets so that they are vertical, it does make the plumbing a bit more bulky though, this thing does need to slide under the bed so as to not breach the contract. :unsure:

Use a three way valve as the diverter valve. The less plumbing the better.

I originally had a 3 way diverter ball valve in the design but took it out as i couldn't find a domestic supplier that didn't require a trade reference. Would love to find one, any ideas where?

 

[LethalCorpse]

subscribing

 

[newguy]

Easier, most definately. Cheaper, i dunno, the PIC chips cost about 10 bucks and the displays about 15. Can't beat it with a stick.

I know what the PICs cost, and you're right, they're cheap. However, to get a PCB made costs a lot. You have to get an enclosure too. There are other things that pop up. Take your time to actually develop it into account, and it quickly gets very expensive. For instance, it took me probably about 4-5 weeks of full time work to develop mine. I happened to have most all of the parts in stock already, so it wasn't that big of a deal and I happen to do that sort of coding/development work anyway, so it wasn't all that bad for me. If you're in the same boat, great - it's a really good learning experience. If not, it's way cheaper to buy one, all things considered.

Someone else already mentioned this, but avoid hard piping when you build it. Use reinforced vinyl tubing whenever possible so that it's easy to tear down, inspect, and clean. Hard piping is a real PITA to clean, and it hides grime.

 

[Yorg]

I like the idea of the polycarbonate tubing. I assume that this is clear hard plastic tubing? Where do you get it? Will definately re-orient the inlets and outlets so that they are vertical, it does make the plumbing a bit more bulky though, this thing does need to slide under the bed so as to not breach the contract. :unsure:

Like I said - I have plenty of 19 mm ( which fits 3/4 fittings )- Actually I am happy to give you some + postage. You will need about 2" more than you want showing (hidden by fittings). If you find out postage and tell me length, I will send you some.

I originally had a 3 way diverter ball valve in the design but took it out as i couldn't find a domestic supplier that didn't require a trade reference. Would love to find one, any ideas where?

Geordi has them, but expensive about $120.
VFS has brass but still about $80.
I am sure you can search cheaper.
I saw brass ones at bunnings once.

 

[rwmingis]

Like I said - I have plenty of 19 mm ( which fits 3/4 fittings )- Actually I am happy to give you some + postage. You will need about 2" more than you want showing (hidden by fittings). If you find out postage and tell me length, I will send you some.



Geordi has them, but expensive about $120.
VFS has brass but still about $80.
I am sure you can search cheaper.
I saw brass ones at bunnings once.

Hi Yorg,

Thanks for that, yes, I would be interested in a bit of the clear plastic pipe, i thought you were just talking about the fittings. I will PM you soon.

I was also able to find a stainless steel 3 way BV at TS fittings too, but haven't checked on the price yet.

Much obliged. :icon_cheers:

Rob

 

[rwmingis]

Right, I have my heating element! It's a 2400W triple element (3 x 800W = 2400W). If i run it at full power it has a watt density of about 72 W/m^2 whereas many of the ones about are about 120 W/m^2. I reckon this will help limit wort scorching, however, if worst comes to worst, I put two of the elements in series and one parallel with that set (giving me 1200W). This is in addition to a digital power controller, so I should be able to control scorching.

Now my problem is where do I find fittings and large diameter copper pipe. I want to make the heating chamber out of DN65 pipe. I've chosen this size as it gives about 7mm clearance between the elements and the inside of the pipe. As I have the flow coming in perpendicular to the chamber and offset from the chamber's centre line, it should have a slow vortex type flow through the chamber, concentrating the flow over the elements. Plumbing shops do sell the stuff, but in 6m lengths and it that would be cost prohibitive. Does anyone know where i could buy a 300mm offcut? I'm happy to pay well for it, just don't wanna buy heaps of the stuff.

I have found a 2" BSP threaded to DN65 capillary fitting for about 30 bucks. Probably won't find anything better than that...

I haven't even considered how i'm going to get down from DN65 to DN15... Ho hummmm <_<

Any ideas?

Thanks for all your help so far, Cheers!

Rob

 

[ausdb]

Right, I have my heating element! It's a 2400W triple element (3 x 800W = 2400W). If i run it at full power it has a watt density of about 72 W/m^2 whereas many of the ones about are about 120 W/m^2. I reckon this will help limit wort scorching, however, if worst comes to worst, I put two of the elements in series and one parallel with that set (giving me 1200W). This is in addition to a digital power controller, so I should be able to control scorching.

Now my problem is where do I find fittings and large diameter copper pipe. I want to make the heating chamber out of DN65 pipe. I've chosen this size as it gives about 7mm clearance between the elements and the inside of the pipe. As I have the flow coming in perpendicular to the chamber and offset from the chamber's centre line, it should have a slow vortex type flow through the chamber, concentrating the flow over the elements. Plumbing shops do sell the stuff, but in 6m lengths and it that would be cost prohibitive. Does anyone know where i could buy a 300mm offcut? I'm happy to pay well for it, just don't wanna buy heaps of the stuff.

I have found a 2" BSP threaded to DN65 capillary fitting for about 30 bucks. Probably won't find anything better than that...

I haven't even considered how i'm going to get down from DN65 to DN15... Ho hummmm <_<

Any ideas?

Thanks for all your help so far, Cheers!

Rob

That element looks great and gives you plenty of options for series parallel connection. Best place for your pipe is to befriend a plumber that does commercial plumbing installations in big buildings or shopping centres they will probably have an offcut or a refrigeration company that does large refrigeration systems you may get an offcut of 2,1/2" tube from them . You will probably not get the 2" BSP adapter any cheaper but making the connections to 1/2" (DN15) is pretty easy in reality copper is pretty malleable so you could squeeze down the DN65 to suit the smaller tube or just drill a hole slightly undersize through the side of the larger pipe then form the copper with a tapered piece of metal to allow the smaller ipe to slip in. Braze the lot up with 15% (brown tip) phos copper silver solder which is self fluxing on copper-copper joints