# Rims Input Needed



## rwmingis (11/10/08)

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 (11/10/08)

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 (12/10/08)

razz said:


> 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.
> ...



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


----------



## fraser_john (12/10/08)

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 (12/10/08)

Brewing Bob said:


> 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 (12/10/08)

fraser_john said:


> 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 (12/10/08)

razz said:


> 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 (12/10/08)

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 (13/10/08)

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 (15/10/08)

newguy said:


> 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)




newguy said:


> 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...



newguy said:


> 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 (15/10/08)

Brewing Bob said:


> 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 (15/10/08)

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 (15/10/08)

newguy said:


> 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.



newguy said:


> 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 (15/10/08)

Yorg said:


> 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: 




Yorg said:


> 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 (15/10/08)

subscribing


----------



## newguy (16/10/08)

Brewing Bob said:


> 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 (18/10/08)

Brewing Bob said:


> 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 (19/10/08)

Yorg said:


> 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.
> 
> 
> 
> ...



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 (4/11/08)

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 (4/11/08)

Brewing Bob said:


> 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.
> 
> 
> 
> ...


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


----------



## FarsideOfCrazy (4/11/08)

Hi Brewing Bob, What I'm most interested in is what are you going to use to control the temp?

You mentioned a digital temp controller, but is it going to be a variable controller or just an on/off type. Ive been doing a bit of reading about electrical setups and I've deciced that that is the way I want to go with my HB setup but haven't made my mind up on what is the best sort of controllers to use. I've seen SSR (solid state relays) on ebay and temp controllers but this is just a on off type controller. But I would have thought that some sort of potentiometer type unit might be better. 

edit. I'm not just looking at a RIMS controller but elements/controllers for HLT and brew kettle.


----------



## newguy (5/11/08)

FarsideOfCrazy said:


> Hi Brewing Bob, What I'm most interested in is what are you going to use to control the temp?
> 
> You mentioned a digital temp controller, but is it going to be a variable controller or just an on/off type. Ive been doing a bit of reading about electrical setups and I've deciced that that is the way I want to go with my HB setup but haven't made my mind up on what is the best sort of controllers to use. I've seen SSR (solid state relays) on ebay and temp controllers but this is just a on off type controller. But I would have thought that some sort of potentiometer type unit might be better.
> 
> edit. I'm not just looking at a RIMS controller but elements/controllers for HLT and brew kettle.



On/off control is the only possible type. A potentiometer arrangement would create a tremendous amount of waste heat in the control unit and that's why they're not used. That's why PWM (pulse width modulation) is employed (pulsing the element on/off). By turning the element full on or full off, the energy from the supply is almost 100% consumed by the heating element when on, not by the control circuitry. This means less waste heat in the control unit, which translates to a more efficient use of energy.


----------



## Justin (5/11/08)

On/Off control works fine, personally I measure temp just before the return manifold on the output of the heating chamber/exchanger. If your flow is reasonable I have found that grain bed temp is right there with output temp, if the probe was elsewhere in the system then i doubt they would be that close. Actual use has shown them to end up very, very close in temp.

On the pump priming issue, so many people have trouble with it but it really can be very simple. My recommendation and the technique that i use is to design your plumbing so that you can fill your lines before grain ever hits the system, and that you can fill any line in your brewery at any time. I use my HLT as the source for filling the lines. Here is a plan of how my plumbing works (I'v used the simple picture, it now has a HERMS for fun but the procedure is the same). 





This is how my brew goes. I heat my water in my HLT, once I'm at or near temp I open valve 1 and valve 4 (valve 2 and 3 are closed, so nothing flows). Then I open valve 2 wide open. This blows air out of the pumps inlet and starts to fill the mash tun through the bottom via gravity. Close valve 2. Open valve 3-gravity from the HLT now fills that hose. Now I turn the pump on and pump the hot strike water over to the mash tun from the HLT and run it at full tilt, this clears any remaining bubbles. Close valve 4 (and valve 2 if you want but it's not needed).

Once my mash tun has the required volume of strike water, if it needs a bit more heat I'll pump it though the heat exchanger until it gets to the required temp or I'll use a hand held element, either way I just let the pump run. Then I close valve 3 and mash in (pump can still run, valve 2 can still be open, nothing will flow). Once I'm mashed in and finished stirring I will give it a minute to settle and then slowly start to crack open valve 3. Valve three is where I regulate the pump flow speed.

Notice how I can control the speed with valve 3 standing upright, looking into the tun while watching the actual outflow speed rather than bending down and adjusting a valve directly on the pump - blind to what is actually coming out of the pump (this is something to consider). Having the valve controlling speed at the bottom of the system directly on the pump is a little clumsy in my books. I can watch the outflow and change the pump speed and keep adjusting it until I'm happy with the flow.

I also dont have to disconnect any input lines throughout the brew so I dont lose prime. If for some reason I do loose prime I can just fill the hoses from the HLT again. Simply close the valve on the vessel, disconnect the hose from the vessel, open HLT valve and let the water fill the lines again, close HLT valve then reconnect the hose and you are ready to go again. Pain free. Trying to clear air from the pump lines using wort from the mash tun just doesn't work because the flow isn't there and you are being careful not to compact the bed, use the HLT and you can crack it wide open. Just make sure you disconnect the end of the hose so there isn't an airlock preventing flow. This is where most people come unstuck i think.

In this picture when I transfer to the kettle I'll close valve 2 and move the hose going to valve 3 over to the kettle. Then I'll control pump speed transferring to the kettle using the kettle valve. 

Hope it gives you a few ideas. As always, I'm happy to answer question if you need it. Good luck and hope it works out.

More pics here:
http://hbd.org/discus/messages/366/33903.html?1187742085


----------



## matho (5/11/08)

hi guy's

i found this website yesterday it could be usefull has alot of cool stuff
link

cheer's matho


----------



## rwmingis (5/11/08)

FarsideOfCrazy said:


> Hi Brewing Bob, What I'm most interested in is what are you going to use to control the temp?
> 
> You mentioned a digital temp controller, but is it going to be a variable controller or just an on/off type. Ive been doing a bit of reading about electrical setups and I've deciced that that is the way I want to go with my HB setup but haven't made my mind up on what is the best sort of controllers to use. I've seen SSR (solid state relays) on ebay and temp controllers but this is just a on off type controller. But I would have thought that some sort of potentiometer type unit might be better.
> 
> edit. I'm not just looking at a RIMS controller but elements/controllers for HLT and brew kettle.



Hi Farside of Crazy,

Newguy is right, a potentiometer used to control power to the element would be huge, waste lots of energy, and generally get really hot. I know of two ways of controlling the power to the heating elements in an efficient manner.

Option 1: Manual control using an SSR (Solid state relay).

This is the option that I imagine you are looking for, and it's VERY easy. This uses a solid state relay that is controlled by a potentiometer. The relay does the power control (it basically does the work done in option 2, but all in the background), all the potentiometer does is tell the relay how much power to let through, so no power is really lost through the potentiometer. Note, this potentiometer in many cases is live, so you'd need to make sure that it's protected from water and fingers. Also, make sure you address the heat issue, many SSR's require a heat sink, depending on how much power you are supplying. I know of some however that are rated for 40 amps. If you are using only 5 amps (1200W) then you "may" not need a heat sink. A bit of trial and error will tell. See "SSR-125 Solid State Relay" at http://www.oceancontrols.com.au/relays/ssr/conch_ssr.htm

Option 2: Automatic digital control of an SSR

This is the method I am using. Basically, you use a Zero crossing SSR, it doesn't turn on or off until the AC sine wave crosses the 0V level which reduces EMF noise. See SSR-100 Solid State Relay SS-240DA 40A @240VAC at http://www.oceancontrols.com.au/relays/ssr/conch_ssr.htm. Then using a microcontroller, you send it a PWM signal that has a duty cycle between 0 and 100% in 1% increments at a PWM frequency of 1 second. To explain a little better, AC mains works at 50 Hz. Knowing this and knowing that an AC sine wave has a positive and negative half that look exactly the same, you really have a pulsing wave at 100 Hz (if you don't care about positive or negative). If you use your microcontroller to turn the SSR on for 0.25 seconds and off for 0.75 seconds during each 1.0 second period, you have a duty cycle of 25%, and effectively you are running the element at 25% power. (ie it's on for 25 cycles and off for 75 cycles) It's very easy this way, if you know how to use a microcontroller. If you're patient, i'll happily share my code with you when I make mine. 

Thanks to "leathalCorpse" to explaining option 2 to me in the first place

Cheers  

Rob


----------



## FarsideOfCrazy (5/11/08)

Thanks for that Bob. Yeah it makes sense that a potentiometer would use too much power, just like a dimmer does for lights.

So how would one of these relays go hooked up to one of these?

http://karlslittlegarden.com/TEMPERATURE.html 

or 

http://cgi.ebay.com.au/PID-TEMPERATURE-CON...1QQcmdZViewItem

Or have I got it wrong and you can't use something like this :huh: ?


----------



## newguy (6/11/08)

Either of those controllers would work. In fact, that type of controller is what a lot of brewers use for their RIMS/HERMS. Should you ever want to add a pump and "upgrade", you'll already have a controller that will handle it.


----------



## rwmingis (6/11/08)

newguy said:


> Either of those controllers would work. In fact, that type of controller is what a lot of brewers use for their RIMS/HERMS. Should you ever want to add a pump and "upgrade", you'll already have a controller that will handle it.



Hi FSOC,

These are designed to run the SSR's (exclusively I think). The one you were looking at gives 8V at 40ma, which is well within the control voltage range for a 4-32V SSR. However, I don't know if these modules have PWM output on a 1 second period scale as I discussed in my previous post. You'd have to investigate.

Cheers,

Rob


----------



## LethalCorpse (6/11/08)

Wouldn't matter what the control period is. They're PID controllers, so they're designed for PWM. There will be an issue if they're set up for 60Hz at low resolution though - a zero crossing SSR on 50Hz power would give spurious results.


----------



## ausdb (6/11/08)

The first one, is only a relay output ie binary on/off
http://karlslittlegarden.com/TEMPERATURE.html
If you want proportional output you will need one with SSR output


----------



## LethalCorpse (6/11/08)

Nah, it's got to be an SSR output. I know it says relay output, but they mean solid state relay - they have to, if it's got PID control. You can't do PID control with a mechanical relay, and they claim PID control.


----------



## ausdb (6/11/08)

I have seen those controllers available as both SSR output and just plain relay output. I would not assume anything unless I had it in writing or an actual spec sheet on the device


----------



## Yorg (7/11/08)

I have about 4 PID controllers, of both varieties, SSR and regular (internal) relay.
Check out Auber Instruments in the US, where I got mine from.
I would use the SSR variety for controlling an element - which I do on my steam generator - works fine.
The relay variety may not drive 10A @ 240V, limiting your element wattage, and in any case would have a short life from all the on and off.


----------



## Thirsty Boy (7/11/08)

LethalCorpse said:


> Nah, it's got to be an SSR output. I know it says relay output, but they mean solid state relay - they have to, if it's got PID control. You can't do PID control with a mechanical relay, and they claim PID control.



ahhh, sorry. Yes you can and I do.

My Rims runs from a PID unit's very much mechanical "relay" outputs via a 12V control circuit routed through a separate 10A mechanical relay.

The reason for the mechanical relay instead of an SSR... well I understand Mech relays and I dont understand SSRs, it was under $10 from dick smith and I didn't have to worry about heat sinks etc.

Yeah sure - it'll wear out eventually, and when it does I will swap to the SSR circuit of the PID unit - till then I am happily obtaining PID control from my mechanical relay set-up.

TB


----------



## LethalCorpse (7/11/08)

fair enough, I'll buy that, I just don't understand how. Is it just using a very long control period? The reason I was so sure in that last post that you can't do it with mech relays is not just the stress on the relay, but the timing issues of it taking a few ms to switch a relay. I guess if you're only switching on and off once every few seconds it makes sense.


BTW, if you understand mech relays you understand SSRs. As far as the user is concerned they're exactly the same thing. You just need to make sure it's got the right specs for the load, same as a mech relay. You usually won't need a heatsink, unless the load is close to the rating and you expect to be running close to 100%


----------



## rwmingis (7/11/08)

LethalCorpse said:


> fair enough, I'll buy that, I just don't understand how. Is it just using a very long control period? The reason I was so sure in that last post that you can't do it with mech relays is not just the stress on the relay, but the timing issues of it taking a few ms to switch a relay. I guess if you're only switching on and off once every few seconds it makes sense.
> 
> 
> BTW, if you understand mech relays you understand SSRs. As far as the user is concerned they're exactly the same thing. You just need to make sure it's got the right specs for the load, same as a mech relay. You usually won't need a heatsink, unless the load is close to the rating and you expect to be running close to 100%



I'm with you LC, but there is one safety difference with SSR's and that is that the circuit beyond the SSR is still hot even when it's turned off. They always conduct a minute amount of current even when off on the order of microamps I think. However, most circuits have a load which would drain the output of the relay and keep it near 0V. If the circuit was open though, the output of the SSR would be 240V even when off!


----------



## LethalCorpse (7/11/08)

Well, yeah, that's true, but ultimately it doesn't mean much. As you say, it only allows microamps when "off" - the impedance is so high that the open circuit voltage is 240VAC, but if you put yourself in the circuit you couldn't electrocute yourself. Maybe if you opened up your chest and put it directly on either side of your heart, but even then you need a few milliamps (the open heart surgery in the shed might do some damage though). Either way, the SSR is only to control the power output, you consider it to be live whenever the controller has power. If you want it to actually be off you use the main switch on the back. And if you actually want to open it up and touch the contacts you switch it off, unplug it from the wall, burn some incense, throw salt over your shoulder, check it again, check it a third time then think about it carefully for a bit.


----------



## Thirsty Boy (7/11/08)

Long control period it is - I run the PID on a 2 second control period when I am mashing and a 10-15 second control period when I use it as a fermentation controller.

I have figured that at the rated number of actions for the relays lifetime and the frequency with which I brew, it will last for slightly longer than 10 years.

I am somewhat happier about the notion if using an SSR now though. Thanks for that.

TB


----------



## LethalCorpse (7/11/08)

No problem. You'll probably find it performs a lot better when it's got a much shorter control period - the longer your control period gets, the more you approach the behaviour of an on-off controller. For the PID loop to work effectively it has to be able to give variable power to the element, and faster control periods more closely approximates this. 

What's your controller TB? In most cases you should be able to just swap out your mechanical relay with an SSR, but if you give me a model I should be able to confirm. SSRs draw very little current, much less than a mechanical relay so it might need a little tweaking to make sure it can turn off correctly. Shouldn't be necessary though, and if it is it'll just be a resistor across the inputs or something. And if you get a 40A SSR you won't need a heatsink for a 10-15A element.


----------



## FarsideOfCrazy (7/11/08)

Ok, so now I know about the same as I did before :huh: .

So lets do a hypothetical.

LC if you were looking go electric what would you buy ,(actual items), in the way of some sort of controller/controllers to run a 3600w element and on a different circuit a 2400w element. These element would be used for a brew kettle and HLT.

I was thinking that a 3600w element would be big enough to do a double batch with the assistance of a hand held 2400w element if needed.

I'm lucky that I already have a 15a circuit in the garage for running my floor sanding machines so running bigger than 2400w elements is a prob unless I want to go to 4800w.

The other thing I'm looking at is just buying a 40 litre urn for $280 to be used as a HLT.


----------



## Thirsty Boy (8/11/08)

Thanks LC - the controller has dedicated SSR output, can just be wired straight in. But I am more than happy with the Mechanical relays ATM.

They dont and as far as I am concerned don't need to adjust the power out-put of the element (or approximate doing so anyway). They do their job simply by adjusting the amount of time they leave the element switched on for. The PID function enables the system to anticipate cooling before it happens and to creep up on set temps when its heating up. The controllers have the ability to be set to run as on/off units, and when I tried them as such, don't come close to the accuracy and temp stability I get when they run in PID mode.

Its not as "good" as it would be with an SSR - but its still pretty damn good and much better than on/off. Like I said, I will swap when the units internal mech relays go south, but till then I will stick with them as they are... unless I get bored.

FarsideOfCrazy - I think you are going too complex. The things that LC and I have been talking about are really fine control for re-circulating mash stuff. If you are talking a RIMS unit, thats the sort of controllers you are looking at - if you are talking elements for a kettle and a HLT, the situation is much less complex.

Kettle - 4800W or two 2400W is more than enough for a double batch. You can get the control you might like by simply going with two 2400W units - both on to heat up, both on for a double batch, turn one off if you are boiling a single batch. No need for a controller at all though you could add one later if you dont like what you are getting without it.

HLT - all you need is a simple set-point on/off controller like the mash mate or a simple thermostat. I have a 40L urn for my HLT because I didn't want to be bothered making one.

Cheers

TB


----------



## FarsideOfCrazy (10/11/08)

Thanks for that TB. I can see what you mean about just using the elements without a controller. It shouldn't be too hard to rig something up if needed down the track if it's not working right. 

Like the old saying, KISS, Keep It Simple Stupid.


----------



## Thirsty Boy (10/11/08)

Actually, I was just reading the "advice on going electric" thread and it sounds like even 2 x 2400W would be going too far. People seem to be having success with a 2400W + 1800W - both running to get up to a boil or for double batches. One or the other (probably the 2400W) for single batch boiling.

If you haven't, check out that thread for more of the same stuff you have been getting here - but from a slightly different angle

TB


----------



## justsomeguy (10/11/08)

Thirsty Boy said:


> Actually, I was just reading the "advice on going electric" thread and it sounds like even 2 x 2400W would be going too far. People seem to be having success with a 2400W + 1800W - both running to get up to a boil or for double batches. One or the other (probably the 2400W) for single batch boiling.



Yep, 2 2400 watt elements might be a little too much. I run a 1800 and 2400 element in my kettle and a 1800 watt in my HLT. Single batches are fine with either the 1800 or 2400 watt element only during the boil. Depends on ambient temperature as to which one is used. I've found that I'm using both the 1800 and 2400 watt elements on double batches in my kettle (50 litre keggle).

About the only advantage with 2 2400 watt elements would be getting to a boil is little faster. I put my HLT on a timer so that when I get up in the morning I have water pretty close to strike temp though this will change once I get my microprocessor controller finished.

gary.


----------



## rwmingis (19/11/08)

Well I'm getting there, hardware design is almost done. I'll upload a progress report soon. Thanks for all of your input so far. :icon_cheers: 

Before I do that, I want to consider a filter on the inlet of the pump, mainly to keep clogs from occuring. The one I am considering is below:







It's only rated for 70C however, I think it would be okay to exceed that by 5 or so degrees with no ill effects. I do intend on programming in a cleaning cycle for the unit which I was hoping would run around 90C, which may be a bit much. Worst comes to worse, it's only 30 bucks. For reference it's about 75mm in diameter.

My question for you all is what do you all think about the filter itself getting clogged. From my experience, I have had only small amounts of grain getting past the grain bed during normal mashing, but I've never done a consistent recirculation mash. If there's heaps that make it through during a RIMS mash, it could be a problem.

I'd be able to empty the filter it by elevating the unit above the mash tun and removing the basket. Doubt it would spill wort all over the place, but I would have to reprime the pump afterwards.

Any comments?

Cheers,

Rob


----------



## browndog (19/11/08)

I will say right here I know bugger all about control of electric elements, but from what I have read, made me purchase burst fire controllers from Sutronics to run my two 3000W kettle elements. I understand they are a very good way to vary the power to your elements.

BTW, If you look at Mr Wizards column in the latest BYO, you will see a question by me about electric kettles caramalising wort.

cheers

Browndog


----------



## newguy (20/11/08)

Brewing Bob,

I've never actually thought of using a filter - it would help to prevent grain husks from getting to your heating element. I wonder why I've never actually seen a RIMS with a filter before......makes a lot of sense. Great idea. :beer: 

Practically, since it's only rated to 70C, is it possible for you to plumb the filter into the system in such a way that you can easily bypass it? I'm thinking of QDs. I don't use use QDs, so excuse any naming errors in the following description.

QD "male" --> filter inlet, filter outlet --> QD "female"

Bypassing the filter would be simple since the QD "upstream" female would mate with the QD "downstream" male. Once the wort gets to ~70C, remove the filter. Practically, there are very few grain husks circulating after the sacch rest is complete so the filter really doesn't need to be there.


----------



## rwmingis (20/11/08)

newguy said:


> Brewing Bob,
> 
> I've never actually thought of using a filter - it would help to prevent grain husks from getting to your heating element. I wonder why I've never actually seen a RIMS with a filter before......makes a lot of sense. Great idea. :beer:
> 
> ...



Since i'm hard piping, I suppose I could just have it on tri-clover clamps and replace the filter with a straight pipe when the temperature get's too hot. Good point. Otherwise could use a diverter valve and a check valve, but space is somewhat of a premium. I haven't as yet been able to find tri-clover to BSP fittings yet, defeats the purpose of a sanitary connection i reckon.

So, yes, clogs are an issue, is husks touching the the element an issue as well?

Rob


----------



## LethalCorpse (20/11/08)

Brewing Bob said:


> Since i'm hard piping, I suppose I could just have it on tri-clover clamps and replace the filter with a straight pipe when the temperature get's too hot. Good point. Otherwise could use a diverter valve and a check valve, but space is somewhat of a premium. I haven't as yet been able to find tri-clover to BSP fittings yet, defeats the purpose of a sanitary connection i reckon.
> 
> So, yes, clogs are an issue, is husks touching the the element an issue as well?
> 
> Rob


there's no point bothering with tri-clovers unless you've got a tig welder, are using stainless end-to-end, and want to spend about four times as much on your system.

I don't think a filter will add value. The piping will be free enough that what few husks make it through the filter bed will come out the other side unmolested. To prevent them scorching on your element, just recirc for a few minutes to form a grain bed before you start heating. It'll rn clear after that.


----------



## newguy (20/11/08)

As LethalCorpse said, scorching isn't an issue if you don't turn on the element for maybe 5 minutes after your start recirculating. However, if you happen to forget.....

I mention scorching because a friend has a RIMS and his beers started to turn smokey all of a sudden. When he finally pulled apart his heating chamber, it was almost plugged solid with what resembled charcoal. All it takes is a few husks to lodge and the vicious circle starts.

I also have to ask why hard piping? It's a PITA to clean. You can see when reinforced vinyl gets dirty and it's easy and cheap to replace.


----------



## LethalCorpse (20/11/08)

I thought vinyl was dodgy in contact with hot food product?


He's not going to forget to recirc before heating though. His controller is going to do it for him


----------



## newguy (20/11/08)

I'm sure that the hoses I have are rated for up to something like 80 or 85C. They're food grade, as they're used for potable household water. Maybe they're not vinyl - could be something else.


----------



## rwmingis (20/11/08)

newguy said:


> As LethalCorpse said, scorching isn't an issue if you don't turn on the element for maybe 5 minutes after your start recirculating. However, if you happen to forget.....
> 
> I mention scorching because a friend has a RIMS and his beers started to turn smokey all of a sudden. When he finally pulled apart his heating chamber, it was almost plugged solid with what resembled charcoal. All it takes is a few husks to lodge and the vicious circle starts.
> 
> I also have to ask why hard piping? It's a PITA to clean. You can see when reinforced vinyl gets dirty and it's easy and cheap to replace.



I'm hard piping it as I want it to be a bit more permanent. I reckon a failure is less like than it would be with flexible. If there's a failure, what a mess that would make of the kitchen and my marriage! If i do use any flexible tubing, it will likely be silicone rather than vinyl. I already have the spiral wound anti-collapsing silicone tubing on the suction end of the pump coming from the mash tun (but that's suction). Theres also the bling factor as well which is absent with flexible hosing in my opinion.

I reckon I might be able to keep scorching at bay by limiting the power to the element as a function of the flow rate. If it's zooming through the heating chamber, I can add heaps of power to the element. If it's piddling about, not much power at all.

As for cleaning, i plan on running hot caustic through the system as part of the cleaning cycle. This should clean the element and the piping of sugars etc.


----------



## rwmingis (8/3/09)

Hi Everyone,

We'll i've found some time and progressed the design a bit. I've attached a P&ID to show the layout, see below: (you may need to click on the bar at the top of the image to see a readable version)






My goal is based on KISS but with a few bells and whistles. 

To describe the system as it stands now:

1. I'll be using the quick disconnect couplings like you see online at beer belly. With those connectors I'll use that plutone spiral wire reinforced tubing so that it doesn't collapse.

2. I've put a inline strainer on the pump inlet. This will prevent clogs further down the system. I will be able remove the basket and empty with hopefully no drips as filter basket is at a high point in the system, and the sources of head are isolatable via manual ball valve out tun outlet and check valve line up the side of the tun.

3. I've got DN20 polycarbonate tubing to view the pump inlet, mainly to see if there's air and view wort quality. (Thanks Yorg!)

4. Pump is march pump 809-PL-HS (230V). I have a modified pump curve for 50 Hz if any one wants it. The March pump website has one for 60Hz but there's a fair difference in head and flowrate due to the difference in speed.

5. Outlet of pump has a sample port for ph Measurement, SG measurement, and air bleed. Still struggling to find a suitable right angle valve that's still small. does anyone have any ideas?

6. Diaphragm flow control valve for precise flow regulation.

7. I have a flow meter comprised of an orifice plate and two differential pressure sensors. I use two (0 to .3 psi and 0 to 5 psi) to get a good level of resolution among all flow rates. By knowing the flowrate through the system (and therefore the heating chamber) i can limit the amount of power to the element to prevent scorching. Ie if flow is zero, the diff pressure meter reads zero, and no heat will go to chamber, otherwise it could boil. If the flow is rocketing through the chamber, I can put the heat on full blast. The amount of limiting will likely be some proportion to the flow rate and be determined during commissioning.

8. The valve to the kettle is normally closed except during sparging. By using the static head in the return line, i have approx 600mm head at the valve to give flow through. This removes the need for a selector valve between recirculation and filling the kettle. An added bonus is that during both mashing and sparging (filling the kettle) the flow rate remains the same in the system, as what doesn't go into the kettle, goes back into the mash tun. The check valve prevents flow from going backward through system when cleaning out strainer basket.

Thats about it so far, any issues or comments would be appreciated. Hopefully no showstoppers are left in the design.

I've made a 3d model and will post that up for comments when ready.

Thanks to all for the input.

Cheers

BB.

Edit: Fixed error in P&ID


----------



## rwmingis (8/1/10)

Hi all, just an update here on my progress with the RIMS unit.

I finally finalised the design and found a couple days over the Christmas break to begin fabricating the unit. The final layout is completely different (thanks to all of your input) is in the next few images. Yorg, note the clear plastic tube you provided me in front of the control box. Thanks again!  














The operation will be as follows:

1. Wort will enter via the far left camlock fitting at the filter which is set at 50 microns. It's a bit small and need to figure out how to get a coarser mesh. It clogged once, but only when i gave the mash a vigorous stir which I don't think I'll need to do once I get this thing going.

2. A check valve follows the filter to keep wort from back flowing when i empty the filter basked if it does clog. The check valves also prevent cross flow between the MT and HLT.

3. Wort then travels through the inlet manifold to the March pump (809HS + 815 impeller upgrade) via a clear plastic tube. The clear tube allows me to see the condition of the wort entering the pump, ie check for air bubbles and monitor colour. There is a bleed/sample valve after the pump (not shown, but on the far side of the tee) to aid in priming the pump and taking wort samples during the mash.

4. There is a diaphragm valve after the pump to control flow. Unfortunately it's a manual one due to costs of a motorised one.

5. The wort then heads into the heating chamber. It's designed so that the wort enters at a tangent and exits at the opposite tangent so that it creates a spiral flow. This increases the flow velocity over the heating element by about 20 times to minimise any possibility of scorching.

6. A flow sensor is installed after the heat exchanger to monitor wort flow rate in order to check for stuck mashes, and help determine how much power to give the heating chamber. If the flow is high, I'll add a lot of heat, if the flow is low, I will add a little heat to control scorching.

7. After the flow sensor, the wort then heads back to the mash tun via the return line, or if the sparge valve is open, some of the flow can be diverted to the kettle during sparging. The flow rate in the system will likely be the same since what doesn't go into the kettle will return to the mash tun. This might cause my efficiency to go down (recirculating during sparging) so if that's the case, then I can reduce the entire system flow rate to the sparge flow rate via the throttle on the pump outlet and completely divert all flow to the kettle.

8. During sparging, there is a second inlet from the HLT (the second camlock fitting from the left). This is controlled via a solenoid valve which is then controlled via the wort level. I'll set the level sensor to keep the wort about 20mm above the surface of the grainbed. Because the HLT water surface level is higher than the MT wort surface level, and because the grainbed introduces head losses, the pump will draw a little more from the HLT than it will from the MT thereby topping up the MT with sparge water.

Thats about it for the time being. Once I finish fabrication, I'll provide an update with the control design.

Hope this is of some help to somebody out there.

Cheers,

Rob


----------



## rwmingis (10/1/10)

Well I've begun fabricating the heating chamber, see below: 






Jeez it's hard work doing this without a proper shop; have been pre-heating the unit by spanning it over two stove burners while brazing and had the drill press on the kitchen counter and drilling with dull bits using olive oil as lubricant. Finally got the hard bit done, just need to braze the inlets and outlets to the chamber and I'll be done with this component.

I do have one question though, how do you clean all the (for lack of a better word) 'slag' off of the silver soldered joints and also where the copper has turned black and crusty from all the heat? Is this something that can be pickled, and if so what brand of solution and where can I get it?

Don't have access to a sand blaster any more, might have to get out the salt and pepper shaker instead to be consistent with the rest of the project!  

Rob


----------



## newguy (10/1/10)

You mean on the inside, right? Any chance you can hook up a sacrificial pump and recirculate a bit of sandy water for while? On the outside I'd just use some sandpaper. 220 grit will be fine.


----------



## rwmingis (10/1/10)

newguy said:


> You mean on the inside, right? Any chance you can hook up a sacrificial pump and recirculate a bit of sandy water for while? On the outside I'd just use some sandpaper. 220 grit will be fine.



Yes, I'm mainly concerned with the inside, I was just hoping I could do the outside at the same time.

I've heard of pickling after soldering/brazing but never seen the pickling solution. I have used lemon juice on something small which does work, however, this would take an awful lot of lemon juice.

Pumping sand through it would work great, but unfortunately, I don't have a sacrificial pump. Sounds like I'll be using the 220 grit on the outside at least.


----------



## bigfridge (10/1/10)

Brewing Bob said:


> Yes, I'm mainly concerned with the inside, I was just hoping I could do the outside at the same time.
> 
> I've heard of pickling after soldering/brazing but never seen the pickling solution. I have used lemon juice on something small which does work, however, this would take an awful lot of lemon juice.
> 
> Pumping sand through it would work great, but unfortunately, I don't have a sacrificial pump. Sounds like I'll be using the 220 grit on the outside at least.




Use cheap Vinegar as Copper + weak acid = clean.


----------



## rwmingis (14/1/10)

Just updating the P&ID to show the latest design... See attached. It'll never be done, but it's good enough.

BB. 

View attachment P_ID_Rev_F.pdf


----------



## rwmingis (28/1/10)

Just a quick update. Progress is going along well, I have almost completed the heating chamber which is the hardest part of the fabrication portion of the project... I think. I just have to add a drain plug/temp probe fitting on the bottom side of the heating chamber and give whole thing a _thorough_ scrub up.

Was hoping someone could give me a bit of input with regards to the type of fitting that I can use for this plug. I need to have a drain (say half inch ID) so that I can drain the heating chamber of water and any husks when done. Am thinking of putting it at one end of the heating chamber and obviously on the bottom. Since I already have a fitting here, I thought it would also nicely double up as a temperature probe connection as well, see below for what I am thinking of doing.







I could use a standard coupling fitting, like the one show below (which is how i connect the output of the heating chamber to the rest of the system) but it's a bit bulky. It is however, the exact configuration I am looking for as I can just braise the temperature probe where the tube would normally go, and voila.






Does anyone know of a suitable brass fitting and where I could get one?


----------



## Spoonta (29/1/10)

try trade link mate


----------



## rwmingis (16/1/11)

Well, I think it's time to post an update. 2-1/2 years into it, I've _finally_ started building the thing, to say I've been procrastinating may be a slight understatement. The Christmas break looked like it was going to be a good time to get back into it, 17 days off and all, but I only ended up getting 2 days to myself to tinker during the whole time. It proved just enough to get things going though! 

I finalised the design after realising that recirculating during the sparge is not a good idea efficiency-wise. With the old design, in order to keep the level control working, it had to be recirculating, even during the sparge. The new design incorporates a 3-way T-port ball valve that separates the main loop into two loops: the sparge loop and the level control loop. When sparge time comes, i simply throw the 3-way valve to split the loops. The sparge loop will be "Input from Mash Tun" (first connection from left in image below) --> Filter --> Check valve --> 3-way valve --> Flow control valve --> Kettle (second connection from left). The level control loop will be HLT (third connection from left) --> Solenoid valve --> Check valve --> Pump --> Flow control valve --> Heating chamber --> Flow Meter --> "Mash Tun return" (4th connection from left).

After a final revision to the P&ID schematic (attached at the bottom of this post) i finished the drawing and bought a base board. I had been looking for some sort of HDPE or PVC plank forever (this was a large part of the delay) but it's a total rip-off to buy here in Australia. Something like 2-3 hundred bucks to get get something that's the equivalent of a few plastic cutting boards glued together. Didn't feel like shipping from overseas either. So I just bought some 19mm pine panels and glued them together to get 38mm. The extra thickness will provide somewhere to run all the power and control cabling by creating channels on the underside using a router. Neat and tidy.

Here's the final design below:









And the pictures of it starting to come together below:









Still a lot to go, but the 3-way diverter valve (recirc / sparge selector) and the sparge flow control valve come tomorrow, so i'll be making a bit more progress in the near future. Exciting.

Once I get it all together, I'll need to start working on the controls. I've done a bit of embedded programming on microcontrollers (PIC's) in the past, and when the programs get complicated (ie user interface and menus) it gets _very_ time consuming. So I've decided to simplify it by having all the low level control such as communicating with temperature sensors, burst fire control for the element, flow sensor measurement, level control, etc done on the PIC, and then via USB link, have all the high level control such as the user interface, mash control overall, datalogging, and PID done on the laptop in VB since it's much easier. Better to show in a diagram rather than words, but that will come one day soon. There will be manual and automatic control for the system most likely selected by an "Oh sh!t switch".  

Anyway, all for now. Just gotta keep it up.

Cheers,

Rob 

View attachment P_ID_Rev_H.pdf


----------



## raven19 (17/1/11)

Noice! Keep those updates coming fella! Looking good, very sharp and compact too.


----------



## rwmingis (18/1/11)

raven19 said:


> Noice! Keep those updates coming fella! Looking good, very sharp and compact too.



Thanks Mr. Raven, that was my main goal (aside from making good beer) which was to make it compact since I live in a shoebox; it's gotta be low enough to slide under the futon.


----------



## rwmingis (19/1/11)

Finally tested the whirlpool in the heating chamber, it works! Here's the .

I'm hoping that the whirlpool will keep the flow fast enough over the elements (removed for video) so that they don't scorch the wort. The flow in the 1/2 inch copper line is about 700mm / second and the edge of the whirl pool would be moving somewhere near that speed. If it was along the element, then it's something like 25 mm/s, almost 30 times slower. The way i see it, if the flow is along the element, the same bit of wort is touching the element the whole time in the chamber which get's it a lot hotter than the wort around the edges. It's a lot more efficient this way.

Ignore the dodgy brazing job at the inlet, jeeeez it's REALLY hard to silver solder something with so much mass as the end fitting. Had to put it over the gas burner and then put the map gas torch on it for about 5 minutes. Painful.

Better get back to it.


----------



## rwmingis (23/1/11)

Today I ran the system for the first time. I've got the piping all done up from the clear plastic suction inlet all the way up to the discharge of the heating chamber and thought it a good time to run it's first test. 

First thing I learned was how important it is to have some kind of valve just above the discharge of the pump so that you can prime it properly. If you supplying the pump with a tank, ie mashtun, with a water level higher than the pump, then you can just open the small valve on the pump discharge until water starts coming out, or if you don't have a low water level, you can use the valve outlet to suck water through the pump until it's flooded.

The pumping system worked nearly perfectly the first time. I even introduced air into the suction, it sputtered, and immediately re-primed once i submerged the suction hose again. The only problem was the gasket between the flange on the heating element and the heating chamber... it leaks a fair bit, a drip every second. I think the problem is that I would really need to crank down on the heating element as it's screwed in, but since it's such a big thread 2 or 2.5 inch, I don't have a wrench anywhere big enough to do this. I could only get it as tight as channel locks permit. I think the real problem is that the supplied gasket is some kind of hard white, probably hi temperature, material, which really needs to be compressed to work properly.

I do have some 3mm EPDM rubber sheet that I used for vibration isolation on the pump mounts. I could easily cut a gasket to suit, and I'm pretty sure this will do the trick, the only problem is will EPDM have a high enough temperature rating? Seeing that the chamber is full of water, I doubt that the metal near the heating element would get much hotter than 100C. Wikipedia states that the maximum air temperature for EPDM is 100-120C, but I was hoping someone out there could provide some practical experience. Any input appreciated.  

Cheers,

Rob


----------



## razz (23/1/11)

Brewing Bob said:


> Today I ran the system for the first time. I've got the piping all done up from the clear plastic suction inlet all the way up to the discharge of the heating chamber and thought it a good time to run it's first test.
> 
> First thing I learned was how important it is to have some kind of valve just above the discharge of the pump so that you can prime it properly. If you supplying the pump with a tank, ie mashtun, with a water level higher than the pump, then you can just open the small valve on the pump discharge until water starts coming out, or if you don't have a low water level, you can use the valve outlet to suck water through the pump until it's flooded.
> 
> ...


One question on the leak from the RIMS gasket Rob, what temp was the water? If it was ambient temp then I would think that at mash temps the leak will take up with the heat. I have an outlet on my hlt that does this (drips) and stops with some thermal expansion.


----------



## rwmingis (23/1/11)

razz said:


> One question on the leak from the RIMS gasket Rob, what temp was the water? If it was ambient temp then I would think that at mash temps the leak will take up with the heat. I have an outlet on my hlt that does this (drips) and stops with some thermal expansion.



Good point, it was at room temperature. I haven't hooked up the element because I want to get an RCD first and I'm not too keen on drips near 240v. 

I reckon nice gooey sugary wort would stop the leak over time too!


----------



## rwmingis (3/9/11)

Hi Everyone,

Back on this again, slowly but steadily. I have most of the mechanical bits done. Only have to plumb the inlets and outlets to the system to the fittings on the front. Since hard piping this will be quite difficult to do (to make everything line up) I'd like to plumb it using hose. As such, I need to get me some right angle 1/2 inch BSP to 1/2 inch hose tails, like this one:






Does anyone know where I can find these? I have looked all over (the world actually) but not too much luck. I've asked one of our favourite HB shops in Queensland, but no luck there either (the photo shows the one I'm looking for which came from my MT false bottom from there). Any leads would be appreciated.

I'm also looking for a bit of aluminium flat or plate that's 100W x 130L x 3 thk to use as a mount for my inlet strainer. Bunnings doesn't really sell anything this size. THey almost have it in angle section, but I'd have to buy at least a metre of it which is too much. Does anyone know a place to get such a beast or have an offcut willing to share in exchange for a few beers? 

I should have some photos of the assembled unit to share in the next few weeks.

Cheers!

Rob


----------



## raven19 (3/9/11)

Beerbelly have those fittings on their false bottoms:
Linky

Might be worth emailing them.


----------



## DWC (3/9/11)

Brewing Bob said:


> Hi Everyone,
> 
> Back on this again, slowly but steadily. I have most of the mechanical bits done. Only have to plumb the inlets and outlets to the system to the fittings on the front. Since hard piping this will be quite difficult to do (to make everything line up) I'd like to plumb it using hose. As such, I need to get me some right angle 1/2 inch BSP to 1/2 inch hose tails, like this one:
> 
> ...


Nova distributors in Newcastle have them, about $5 from memory.
Cheers

Dave


----------



## rwmingis (4/9/11)

Thanks guys, I'll give those suppliers a go. 

Wally, I was going to use that arrangement, but the two hosetail tips would touch for each end of the hose due to the short length of run. If I can't find the single piece ones, I'll have to use your arrangement and trim the tips. That might work fine actually...

Rob


----------



## Tim F (17/9/11)

Would these ones from CB do it?

http://www.craftbrewer.com.au/shop/details.asp?PID=1158


----------



## rwmingis (22/9/11)

Tim F said:


> Would these ones from CB do it?
> 
> http://www.craftbrewer.com.au/shop/details.asp?PID=1158



YES they would! That's the one I had. I'll get me a second one. I didn't realise that they were only 3/8 inch, but will suit the sparge line since it's just a trickle. 

Wally, you're concept was a winner, that's what I'm doing for the other ones. Thanks!

Rob


----------



## hsb (22/9/11)

I think I've got a spare one of those lying around - I'm up in Kingsford, work in Randwick... Not certain on the barb size but it's definitely too small for 1/2" silicone tubing, so maybe no use to you??
You're welcome to grab it - or I could probably stick in the post at work. It's just a leftover from something or other, a false bottom maybe. It is just the one though.


----------



## rwmingis (24/9/11)

hsb said:


> I think I've got a spare one of those lying around - I'm up in Kingsford, work in Randwick... Not certain on the barb size but it's definitely too small for 1/2" silicone tubing, so maybe no use to you??
> You're welcome to grab it - or I could probably stick in the post at work. It's just a leftover from something or other, a false bottom maybe. It is just the one though.



Sounds great, thanks! I'll PM you just now.

Rob


----------



## rwmingis (8/11/11)

IT WORKS!

Well I've finally finished the hardware side of this thing, I didn't realise how much work this project would be be! It feels so good to have this bit done now, it was really hard work and time consuming too. I think what made it so difficult was trying to fit everything with so much accuracy over short spaces (ie lining things up with threaded fittings, etc.). I think next time I'll just used stainless tubing and be done with it, probably would have saved money too with all the trial and error! Anyway, thanks for all the help from those that gave input, it has made this thing a better product by far. 

I've done a dry (wet) run and it seems to work well. I designed it for 4 L/min as that's what I've heard on the forums as the max flow you typically see without getting a compacted grain bed. First tests give me 6L per minute, so pretty chuffed (upgrading to a 815 march pump impeller from an 809 helped). Those screwed fittings are quite hard to make leak proof I tell ya. Under mains pressure, it gets a few drips from a few joints, but under pump pressure there's no leaks, so I think it's good enough. I just need to do all the electrics and program it up. Shouldn't be too hard as it can be done from the couch and not my make shift shop spread over 5 rooms!  I'll share my electrical and controls design for a bit of constructive criticism soon if you guys are willing to give it. 

I've included a few pic's below:

The finished Base





Plan view on top of final assembly





Looks just like the model  





Front view





Left view





Right view





Cable ducts on the bottom (router comes in quite handy on this project)





Handholds in the sides of the base are a must, this thing weights a tonne!


----------



## raven19 (9/11/11)

Now to brew with it!

Very nice. Any drips of wort will make that timber nice and sticky.


----------



## hsb (9/11/11)

Looks great Rob, just don't go trying to take it on any planes! Looks like a 'device'!!
How does it fit together with your other gear, is that similarly compact?

Being so compact, looks like a 'BobMeister' has been born!

Like the sight tube to see that there's flow, and the built-in filter.

As raven said - Now to brew with it!


----------



## rwmingis (17/10/12)

Hi everybody,

Wow, I really got side tracked, it's been over a year since my last post and working on this thing. I moved away for a year, then moved back and bought a home, so not much has been happening on the brewing front. Getting 'round to it though. 

So yes, my RIMS is built now, and it works great. I wrote the PID routine last night and tested it out today; I seem to have gotten it right the first go - beginners luck. Attached is the graph of the data below:







The red line is the heating chamber discharge temperature, the brown the mash tun temperature, black the set point temperature, purple the power to the element in % (2400W element) and blue is the pump flow in L/min measured on the right axis (4-5 L/min typically) It goes right to the set point and stays there which is what I want. 

These numbers reflect a maximum heating element power of 100% but I imagine I need to limit this to some value. At full power it's 72 W/m which doesn't sound bad, but I don't know what sounds good either. I've done a google search and only found one fellow that limits his to 30 W/m which sounds low. For mine this would mean limiting my power to the heating element to 42% max. Given that at mashing temperatures i'm loosing 25% of the total power out of the uninsulated heating chamber, I don't have much left over to go that low.

Does anyone know a reasonable watt density to start with from experience?

Cheers!

BB


----------



## squirt in the turns (17/10/12)

Bob, that graph, like this whole set up, is a thing of beauty. Nice one! I just went with an off-the-shelf Sestos PID for my recent HERMS control panel. Looking at all the amazing work that's being done with the Brauduino and other embedded systems, I'm already thinking about the next version...


----------



## rwmingis (18/10/12)

Hi Squirt,

Thanks for the kind words.

The embedded controllers are great fun they can do nearly anything all in one package. I know little of the Arduino ones, I just happend to start on PIC by chance so I'm using the SBC44UC http://www.modtronix.com/product_info.php?products_id=286 which does a lot of of stuff, in this case:

- Read multiple DS18B20 temperature sensors
- Reads a flow sensor
- Controls the heating element using burst fire control
- Opens and closes HLT solenoid
- Controls the pump
- Reads several level sensors in the mash tun
- Reads and control the HLT temperature. 
- Talks to the PC

It's a busy little thing, and done mostly using interrupts. You program it in C too which is pretty good. It has the built in USB's too and routines to chat straight to the PC using a serial port style routine which makes it much easier.


----------

