Reverse HERMS

[Not For Horses]

How do you reckon this would go for heating green malt during the conversion phase for crystal malt?

The idea being that you want to take wet green malt from the floor at ~16 degrees and heat it to 72 with minimal water used in the 'mash' to retain all the sugars inside the kernel thus maintaining a high extract value for the finished product.

 

[QldKev]

How do you reckon this would go for heating green malt during the conversion phase for crystal malt?

The idea being that you want to take wet green malt from the floor at ~16 degrees and heat it to 72 with minimal water used in the 'mash' to retain all the sugars inside the kernel thus maintaining a high extract value for the finished product.

I think it would work great

 

[Beerisyummy]

Did you end up trying this QldK?

 

[QldKev]

Did you end up trying this QldK?

Nope not yet, Beer projects are on hold due to other hobbies currently consuming my time and money. The only issue I have thought about is with the coil in the mash it will be harder to give it a thorough stir.

 

[Beerisyummy]

No probs. I'm brewing later today with something similar. Time will tell.

I think you've used a similar pot within a kettle for the mash? I could be thinking of someone else. Anyway, the whirlpool and recirculation seem to do away with stirring for me. Efficiency is great with a sparge.

cheers.

 

[RelaxedBrewer]

This is a really interesting idea.

One problem that might be an issue is that the heating coil will be in contact with actual grain. This may cause scorching of the grain.

I am going to into this further as I am trying to work out the best temperature control and ramp/step heating setup for my large system. The length of coil for the heat transfer is really appealing.

edit. on further thought. Where would you measure the temperature of your mash from?

 

[stux]

HEIRMS - heat exchanger in recirculating mash system

CIMRS - (simmers) coil in mash recirculating system

 

[Beerisyummy]

The ICHE - RIM maybe? :unsure: Immersion Coil Heat Exchanger - Recirculating Infusion Mash. No scratching allowed!

For anyone interested, I did a run with my set up on Friday and the results were promising. It's a 1v rig (sort of) with a small boiler used to supply hot liquid to the immersion coil.
As long as you have your grain contained in something along the lines of a malt pipe, the coil can be used to heat the mash water as well as chilling during the whirlpool.

A couple of observations:
- The system was really simple to control with an STC1000. My PID was unavailable, so I just tossed the STC probe in the same as the coil which did not cause any overshoot, although I think luck helped with the settings.
- Ramp times were almost identical to the other HE methods I've tried thus far. After 3 test runs and 1x 40l batch I'm convinced it should work consistently.
- With 15m of liquid filled coil and only enough water to cover the element, there was very little lag time when powered up.
- Cleaning was extremely easy and all parts in contact with the wort can be visually inspected before and after use.
- A LBP was enough to run the boiler system and coil. The little bugger handled 110c for a half hour as well.
- I was able to get 35L of water boiling in the kettle (during the last test run) after playing around with the boiler fluid. Unfortunately, I only have one LB pump which stopped me from testing higher temps.
- 35L of water being boiled by a 15m long element ( the coil) does not look normal. The pot looked like it was full of "Schweppervescence".

Based on the above, I can't see why you couldn't supercharge a small boiler to feed several remote coils. I'd imagine a coil inside the actual mash wouldn't work very well, but any moving liquid works just fine.

All a bit of fun if you like tinkering.

 

[TheWiggman]

Got any pics beerisyummy?

 

[QldKev]

Sounds great for a first run of a completely new idea.
The comment about "Cleaning was extremely easy and all parts in contact with the wort can be visually inspected before and after use." I think is a great point.
You mentioned you don't think it would work if the coil was in the grain, but what if the mash itself was being recirculated via another pump? That would ensure the wort is continually mixing.

A standard immersion chiller, a LBP and a $8 kmart kettle for an easy way to control mash temps, and the coil doubles as the chiller.

 

[Beerisyummy]

Sounds great for a first run of a completely new idea.
The comment about "Cleaning was extremely easy and all parts in contact with the wort can be visually inspected before and after use." I think is a great point.
You mentioned you don't think it would work if the coil was in the grain, but what if the mash itself was being recirculated via another pump? That would ensure the wort is continually mixing.

A standard immersion chiller, a LBP and a $8 kmart kettle for an easy way to control mash temps, and the coil doubles as the chiller.

Access for cleaning was what got me started on this experiment. The 30 plate chiller that I'd been using as a heat exchanger really had me worried. I looked at an easy way to jacket the bottom of my kettle and eventually decided the coil was a better design.

It's just my gut feeling about the coil not working in the grain bed. I guess if you had a really fluid slurry of grain, or extremely good flow through a grain bed the recirculation might be enough. I just think the heat transfer will be too slow.
The idea definitely warrants further investigation.

There was about 10L of clear runnings whirlpooling around the coil before being pumped up through the grain bed to recirculate. This way the boiler fluid never exceeded the runnings temperature by more than 17c.
That means the hottest parts of the 15m coil were never very hot, which was totally different in my old set up. Instead of very hot runnings being recirculated back into a cool mash this way the whole thing is very gentle.

Some other ideas I had for coil placement were under a false bottom or in the layer of water/ wort above the grain bed. The recirculation might be enough to get effective heat transfer. I figure it's someone else's turn to do some tests on that one. I won't be brewing again for a few days.

Got any pics beerisyummy?

That I do! I even got one of the coil boiling the kettle.
Give me a while and I'll get them posted up.

 

[Beerisyummy]

Pics as promised.

First one shows the coil I made. There is a tee half way down to split the coil in two halves. The general idea was that cooling water can go down to the outer tee and spread the cooling goodness. When I use it for heating the heated water is directed down to the inner tee which should give less flow restriction to the lower coil, just in case the top is above the liquid during the mash.


This is the cradle I use to pump water up through the mash. The next pot nestles onto it and gravity seals it all up. I have thought about making a few subtle changes to this part put it works well enough.


This is the part that holds the mash. 5- 6kg is a good size grain bill as is, for more I use a longer rod and add the offcut from the cradle as an extension collar.


All this drops neatly into the 50L pot and coil. The insulated lid fits snuggly over the top but I was yet to widen the side opening in this shot.


Add water, slowly add the grist while stirring and you're ready to put on the screens. 3kg of wheat and 2 kg of PPils in this time.


Three modified Ikea spatter guards. First is the glass type (with the glass removed) as a seal and then the two mesh types. It works and the parts were easy to source cheaply.


Turn it all on and walk away. If you get a stuck sparge from a fine grist it simply pops the mash pot up out of the cradle. reversing the flow for a bit will normally fix this or you can just use a sensible grind setting.


After the boil I simply kept the whirlpool going while running cold water through the coil. 15mins later it all got covered up and left to settle before draining in to the FV.


This shot is the 35L of water fizzing from the coil. I was only game to push the LBP to 110c during this experiment so it was a gentle boil. The whole thing looked like a big tub of soda water in the flesh.


Enjoy guys.

 

[Adr_0]

Yeah I already used the "Reverse Herms" term - "Backwards Herms" is still free if you want it.

I don't think it is a terrible idea. I think the best point of your system, which I don't think was mentioned, is that during the initial stages of the mash, where it is all gluey with starch etc and most likely to jam up, we can still heat the mash and get it converting so it flows nicely by the time you get to lautering. So in the end maybe you could run a thicker mash and maybe get some bigger batches for container size. Or go nuts with sticky adjuncts.

Actually I was wondering how you do your initial dough in?

And everyone is saying differential temperature is needed - and it is - but don't underestimate flowrate. If you have flow on both sides of the tube - and it looks like you do - and have the pumps to do it, that will do massive things for your ramp speed.

As Not For Horses said, narrower ID tube is best. I actually think 3/8 is the ideal as you get about 40% more power than 1/2" for the same flowrate and differential. On that same theory 6mm should be good, but you might lose pressure/flow with any decent sort of length and go backwards... unless you have awesome pumps.

If you get stuck, maybe try the AdRIMS...
*trolling*

 

[Beerisyummy]

Dent or me?

I think the narrower ID tube will totally stuff the flow rate, although I'm willing to snag some tube and try. It really comes down to the available pumps IMO.

 

[Adr_0]

Dent or me?

I think the narrower ID tube will totally stuff the flow rate, although I'm willing to snag some tube and try. It really comes down to the available pumps IMO.

Doing the initial dough-in... QldKev actually.

Yes, my gut feel is 6mm is too narrow but I have had great joy with 3/8" tube in the past mostly due to the higher velocity. I'm ignoring the poor availability of 3/8" fittings....

This is particularly the case for using garden hose for immersion chilling, for e.g. and 3/8" makes a measurable difference on 1/2". Unfortunately while higher velocity = more power, higher velocity = higher pressure drop so your pump has to be able to manage a decent flowrate with more back pressure on it. It will balance out somewhere, but my gut feel is that for 6mm tube it will be too low in the flow and any benefit you get from increased velocity will be negated. Somebody can run the hydraulic calcs, not me...

 

[TheWiggman]

Looks the goods beerisyummy. It looks like you're just pumping water, how did you manage to get it up to 110°C? The water's boiling though, so hot it was.
Adro, where did you get that number from (40%)? Not sure what you mean by power. Pipe diam won't affect power, only efficiency of thermal transfer.
I crapped on about it in the HERMS thread, but thinner pipe does not necessarily equal better efficiency. For a given flow rate, assuming flow is fixed, the larger diameter pipe the better. For a given velocity, the opposite is true. Now because we're talking small centrifugal pumps, the narrower the pipe the lower the flow, and hence going a smaller pipe has a bit of a compounding effect. But to maximise transfer, more flow is better. Thus larger pipe is better for a GIVEN LENGTH in this scenario.

 

[TheWiggman]

This is particularly the case for using garden hose for immersion chilling, for e.g. and 3/8" makes a measurable difference on 1/2". Unfortunately while higher velocity = more power, higher velocity = higher pressure drop so your pump has to be able to manage a decent flowrate with more back pressure on it. It will balance out somewhere, but my gut feel is that for 6mm tube it will be too low in the flow and any benefit you get from increased velocity will be negated. Somebody can run the hydraulic calcs, not me...

Sort of right. The specifics of the theory is right, but we're talking centrifugal pumps. Larger diameter = less pressure loss due to viscosity. Fewer losses = less pressure or 'head' on the pump, which equals more flow.
Never forget this - low discharge pressure = more flow for centrifugal pumps.
I could do the maths but it's a ball tearer and any change in flow requires a lookup to a Moody chart and a recalculation of the whole thing. Also, you're referring to velocity incorrectly - you meant flow when talking power. More flow means more power spent. These little pumps don't care about back pressure, nor do most centrifugal pumps. They just draw less power and internally recirculate more.

 

[Adr_0]

Sort of right. The specifics of the theory is right, but we're talking centrifugal pumps. Larger diameter = less pressure loss due to viscosity. Fewer losses = less pressure or 'head' on the pump, which equals more flow.
Never forget this - low discharge pressure = more flow for centrifugal pumps.
I could do the maths but it's a ball tearer and any change in flow requires a lookup to a Moody chart and a recalculation of the whole thing. Also, you're referring to velocity incorrectly - you meant flow when talking power. More flow means more power spent. These little pumps don't care about back pressure, nor do most centrifugal pumps. They just draw less power and internally recirculate more.

When I say 'power' I mean heat removed (joules/cal) per second - sorry, should have clarified that.

The 40% I worked out about 10-11 years ago halfway through doing my degree. It was basically about 20% extra due to the velocity, and about the same again for the extra turbulence. Both of these essentially just move fresh fluid to the contact surface. It is well accepted in the industry, with the trade off being increased pressure drop.

Which is where we agree: centrif pumps do go back on their curve with more back pressure, so it has to be balanced and you need the pump curve for this. Generally the beefier pumps have decent flow and aren't that sensitive to back pressure.

 

[TheWiggman]

Righto. Make sure you differentiate between flow and velocity - for a fixed flow, larger diameter means lower velocity so this changes the situation. You can't just talk about velocities in this scenario because it's driven by a pump.
If you care, I have the formula out of a heat transfer text book which shows the relationship between diameter and temperatures to determine your heat transfer convection coefficient. Can't do it now due to phone.
Make sure you pour a glass of your best home brew prior to reading though - it's riveting stuff.

 

[Burt de Ernie]

Kev,

Dropping the coil into the mash was what Rinnai build one had going. I had approximately 7 meter of 3/4 copper coil in the mash tun. (Notice the 3/4 mustard colour pipe dropping in to the mash tun below). I found the ramp times were not too desirable even running the Rinnai at 85 degrees.




The current setup I have could easily be incorporated into your 2 option which would give you good ramp times and this can be done running 75 degrees.