Rims/herms Hybrid Heating Chamber

[rwmingis]

Wrong! You need a flux capacitor!

"One. point. twentyone. jiggawatts!"

 

[rwmingis]

Sorry for the mass response, but I'm lazy and it's late.

My advice in regards to your heat exchanger is to not over-engineer your system. I think people get caught up in the shiny stuff and forget that you make good beer with a plastic bucket.

It's obviously RIMs envy, I've seen it before. Seriously though, I agree, but, for me building this stuff is just as much of the hobby as making the beer. Just cost's sh!tloads more...

Nice rendering of your setup - what did you use for that?

Just plain old Autocad. I've got another thread running for the actual RIM's system, but it needs an update. Will post some of the plans etc on it, when I'm done. It's here

I suggest using a straight rims...

But once again - for the cost and trouble... you could get a nice custom low density element made up and do direct RIMS without all the intermediate stuff.

This is what i'm starting with, I got the impression that HERMs is the best, it's just a bit clunky for me, so thought eventually would like to upgrade to this hybrid element. I've got a LD element at the moment I think, it's the 2631 element here and is 77.5 kW/m^2. Is that low density? What kind of power can you put through these elements without scorching? I'll be monitoring the flowrate and a processor will determine how much juice it can put through the element given a flowrate without scorching. Of course, I need to do some experimenting to program it...

For a homemade jobbie Tin would be ideal... If you acid cleaned all the surfaces and fluxed it should wet on really well to.

Tin sounds like a good idea actually, it'd be lighter than lead, that's for sure, and it conducts heat 120 times better than water too. Hmmmm, you might be on to something. Can you buy the stuff, haven't seen it before?

What's wrong with air and a small gas flame? And a well insulated chamber.

Nothing, I just don't feel safe with letting the processor control a flame on it's own, and I'd also need a gas bottle and extra hose. Buuuuuut, along those lines, is there such a thing as heat tape where i could just wrap it around a section of coiled pipe? Might be worth a look.

 

[LethalCorpse]

This is what i'm starting with, I got the impression that HERMs is the best,

Why? HERMS is a lot more popular, I suspect because it's easier to setup. I think that with a RIMS system, though, you've got scope for much more precise control. It becomes a single control loop with much shorter τ. With a HERMS you've got to control the temperature of the secondary vessel (using the same sort of PID or similar controller on an element) and then control the temperature of the mash by adjusting the flow rate through the coil. Alternatively, you set the temperature of the secondary vessel at the temperature you want your mash, and get the flow rate as high as you can to minimise the time (it will be very slow). Too much dicking about for mine, very fiddly to control. With a RIMS, you just have a fixed flow rate and the control loop is quite simple. I doubt very much that with a reasonable flow rate you'd ever get scorching - most people don't have a problem with buckets of doom, and that's usually a small element running at 100% with only natural convection to prevent scorching. If you do find you get scorching, just determine the maximum duty cycle for your element at your given flow rate and set that as a limit in your control loop.

With your concept, all you're doing is reducing the rate at which heat can be absorbed by the wort, and hence increasing the time constant and reducing the accuracy of your control loop.

 

[seravitae]

As a thermal transfer solid, how about using copper shavings. they will oxidise on the outside but will still maintain the thermal conductivity properties of the bulk unoxidised material.

Im sure you can pick up copper shavings from somewhere, if not you could be a badass and make a funnel and grind up some waste copper from a metal recycler with a bench grinder.

..In before "but it'll have gaps between the shavings!", it'll have good enough thermal response for you to not care about.

 

[LethalCorpse]

..In before "but it'll have gaps between the shavings!", it'll have good enough thermal response for you to not care about.

No, it won't.

 

[newguy]

My advice would be just to go with a RIMS and be very anal about cleaning the heating chamber after every brew. A friend bought a RIMS system many years ago and he made a lot of really great beer with it at first, but then he started getting bad batches. They all had a smoky taste which he initially thought was a wild yeast infection issue (phenols) but he eventually traced to his heating chamber. It was almost totally clogged with scorched husks. He would flush his system after every brew but he had never taken apart the chamber because it was difficult to access. After he found the problem, he took it apart for cleaning every time he brewed and never had an issue after that.

I like the layout of your system, particularly the heating chamber with the inlet down low on one side and the outlet high on the opposite side - that's smart. There will be plenty of turbulence inside the chamber which will maximise heat transfer. My only modification would be to put the outlet at the highest point in the chamber or slightly incline the chamber so that the outlet as drawn will be at the highest point. This will minimise the air in the chamber and eliminate hot side aeration.

I'd recommend that you not create a pseudo-HERMS solid metal heat transfer medium system. Beyond the weight and cost issues, you're essentially creating a RIMS with a very very low power density heating element. May as well just go with a straight RIMS. Another thing to consider is the safety side - at the end of your mash you're going to have a - what, 5 kg? - mass of metal @ 75C on your system. It will take forever to cool down and until it does, it's a skin burn hazard. Accidents happen, people get distracted, sometimes brewers imbibe whilst brewing - it's a recipe for a trip to the burn unit.

Just create a RIMS and make very sure that the heating chamber is both easily accessible and easily disassembled for cleaning and you'll be brewing the best beer of your life in no time. :icon_cheers:

 

[ausdb]

Im sure you can pick up copper shavings from somewhere, if not you could be a badass and make a funnel and grind up some waste copper from a metal recycler with a bench grinder.

Have fun getting copper shavings off a bench grinder with standard wheels, you could try and pick it out of the grinding wheels with a sharp object but you wont get many shavings.

 

[rwmingis]

Why? HERMS is a lot more popular.....

LC, You're right, I don't really like HERMs as I do not like having to control the heat addition by how fast the flow is going through the coil. Too difficult when considering the variable losses through the grainbed. Both options have merits though, that's why I want the hybrid.

I suppose I'm just a little unsure about a hot element directly in the wort as I have no experience with it. The goal is just to get the heat from heating element to the fluid. Ideally, some kind of heating element like a wire heating element be bonded to a length of copper pipe which can then be coiled into a coil would be the best idea, but not sure how to implement. I've heard of heat tape, but this is generally low power. Might need something with a bit more ummph. Watch this space...

My advice would be just to go with a RIMS and be very anal about cleaning the heating chamber after every brew. A friend... ...started getting bad batches. They all had a smoky taste which he initially thought was a wild yeast infection issue (phenols) but he eventually traced to his heating chamber. It was almost totally clogged with scorched husks.

I like the layout of your system, particularly the heating chamber with the inlet down low on one side and the outlet high on the opposite side - that's smart. There will be plenty of turbulence inside the chamber which will maximise heat transfer. My only modification would be to put the outlet at the highest point in the chamber or slightly incline the chamber so that the outlet as drawn will be at the highest point. This will minimise the air in the chamber and eliminate hot side aeration.

Thanks for the advice. I don't think i'll have husk scorching as I'll have a filter installed before entering the system which means there won't be any husks in the system. The filter will be as seen in the layout picture, and I've tried it out in a dry fit test run as seen below on the outlet of the mash tun:

I was worried that it would clog up big time as it's only 50 micron, however, it only clogged up once and that was while I was really stirring the mash, lots of little husks got into the basket. I just removed it, emptied it, and voila, clean running again. In the design, I will make the filter basket easy to remove.

As for the hydraulic design, I did the inlet at a tangent to the cylinder to get circulation in the chamber. Did the numbers, with circulation the fluid will flow across the element at about 25 times faster than just the gross flow over the element this way. I angled it back a bit to get the stagnant water near the base of the element, however, I've heard that this section of the element is not really heated anyway (shown that the first inch or so of the element is not black from where they did the testing in the factory).

I didn't even think about air bubbles in the chamber, very good point, I will update the design to have the exit at the top. Thanks for that!

This is great information!

Cheers,

Rob

 

[ausdb]

LC, You're right, I don't really like HERMs as I do not like having to control the heat addition by how fast the flow is going through the coil. Too difficult when considering the variable losses through the grainbed. Both options have merits though, that's why I want the hybrid.

Why is this not an issue with a RIMS? your circulation rate through your heat exchanger which is basically what both systems are will be just as important with a RIMS as a HERMS.

I like your element below, it looks like a three phase one connected in a Star connection. If you are only running 240V single phase to it then you could play around with series/parallel connections to lower its watt/density.

 

[Doogiechap]

If you are still 'inclined' to go down a solid/ semi solid media (my money is on the oil). The other option would be to get a blacksmith to fill the cavity with bronze. Absolutely no idea about cost but it is feasible.
Cheers
Doug

 

[rwmingis]

Why is this not an issue with a RIMS? your circulation rate through your heat exchanger which is basically what both systems are will be just as important with a RIMS as a HERMS.

With a HERMs, I understand that you have a pail of ?boiling? water which has a coil in it. The faster you pump wort through the coil, the less heat you add to the wort. The slower, the more heat you add to the wort. It all depends on the amount of time the wort is in the chamber.

With a RIMs you vary the power to the element (via burst fire control) which varies the amount of heat going to the wort. If the wort is going slow, you don't want to add too much heat to it or it might scorch. If it's really moving through the chamber, then I can add a lot more power and therefore heat to the wort be cause the faster wort flow takes the heat a way faster. In my case, the amount of power i send to the element will be a function of the flowrate that the sensor tells me.

I like your element below, it looks like a three phase one connected in a Star connection. If you are only running 240V single phase to it then you could play around with series/parallel connections to lower its watt/density.

I like it to. If i put one of the elements in series, I loose a lot of power. My decision will probably be, do I connect the middle one or not. They will be in parallel I think.

 

[LethalCorpse]

With RIMS, the flow rate is important - it has to be high enough to prevent scorching, particularly if you're doing a step and the element is running flat out - but you don't need to be able to infinitely vary the flow rate with precision. It's a whole lot easier to vary the power applied to an element than it is to vary a flow rate by controlling valve apertures or a pump's power waveform.

I wouldn't bother with a filter before the RIMS. If your RIMS chamber is relatively free flowing, just recirculate for a few minutes without the element on until it runs clear. The grain bed will form the filter, and no husks will come through after that. Alternatively, if they get stuck in there regardless of whether the element is on to scorch and stick to them, you can put in a bypass valve. Recirculate through the bypass valve until you get clear wort, then shut the valve and run it through the RIMS.

 

[newguy]

With a HERMS (at least mine anyway), the water in the heat exchanger gets to be a max of 2 - 2.5C above the mash temp when ramping. I don't throttle back the flow through the system at all; I just let it run flat out. The electronic controller takes care of "throttling" the heating element to achieve steps or hold the current temperature. PID control is essential here.

Because the flow rate through the system is high, that wort "carries away" the heat from the HE pretty much instantaneously. If you had boiling water or near boiling water in the HE, the wort passing through it will have its enzymes denatured (destroyed). You don't want that. With a HERMS, the temperature of the water in the HE mirrors that of the mash, other than the small 2 - 2.5C difference whilst doing a ramp.

 

[rwmingis]

I wouldn't bother with a filter before the RIMS. If your RIMS chamber is relatively free flowing, just recirculate for a few minutes without the element on until it runs clear. The grain bed will form the filter, and no husks will come through after that. Alternatively, if they get stuck in there regardless of whether the element is on to scorch and stick to them, you can put in a bypass valve. Recirculate through the bypass valve until you get clear wort, then shut the valve and run it through the RIMS.

I have a paddlewheel flow sensor, and I use the filter to keep husks out of that. There is also a small orifice jet at the entrance to the flow sensor thats about 5-6mm in diameter. Without the filter, then I run the risk of clogs here too.

I put the flow sensor in the system to tell the processor how much heat can be added to the element. When I set the flow rate at the start, I set a flag value too. If the flow rate strays too far from that flag value, then I know i've either got a stuck mash or a hose has come loose and processor will sound the alarms and I can put my beer down, get off the couch and fix it. I suppose the flow rate would vary a bit due to starches changing to sugars but I'm straying off topic now...

 

[Thirsty Boy]

You may have issues with your filter - when you first start to re-circulate, often there is quite a bit of solid matter.. this settles out quickly as the grain bed sets... but it might be enough to gunk up your filter before hand - if you really need to keep the filter, then Lethal's idea with the bypass valve to go around it till the wort clears - make a lot of sense.

Trust me - with the area you have on your element, you wont have scorching issues with direct wort contact.. look at what I am using

Element on the bottom right. 2000W (ish) , controlled by a PID.. but it's through a mechanical relay, so we are talking about flicking it on and off rather than controlling the power density. When its on -- its the full 2000W. I get a light layer of protein build up on the element each brew - and if I didn't give it a bit of a scrub after every brew, that would eventually build up, insulate the element from transferring its heat to the wort - and then the protein layer would scorch. I strongly suspect that when people get "wort scorching" thats whats happening. This protein is pretty susceptible to PBW and I have cleaned the element spotlessly clean with a CIP circulation... so you could get away without disassembling every time. Mine is made to pull down fast and easy, so I do - but I could CIP instead.

You'll note the diameter and length of my RIMS unit. Made this way to both accommodate the short and wide element.. but also so that I could get a LD element made up to "fill" it if needed, and also so that in a pinch.. it would take a tightly wound copper coil for a RIMS/HERMS hybrid exactly as you are proposing - I was planning on using either water (with a blow off line in case of boiling) or mineral oil as the heat transfer medium if I decided I needed to... I haven't needed either the LD element or the hybrid... but I might get the element made up anyway when the cheap one burns out - it will eventually, so I might as well get a good one to replace it now that I know I like RIMS better than HERMS.

TB

 

[rwmingis]

TB, thanks for the assurance, I have a bit more confidence now in the RIMs chamber option now. I actually remember seeing your posts when you were building this chamber. It looks great, and handy that you can just disassemble it so easily. Mine won't be so easy, but will make the power lead removable so i can unscrew the element easier for cleaning.

Cheers,

Rob