Dedicated Herms Guide, Problems And Solution Thread

[nala]

Interesting Adr thanks for that!
Are there better pumps for this application given flow rate is such an important variable

Pump is almost erelevent if you don't have the perculation/flow through the grain bed,you can only pump at the rate of the flow.
My experience tells me that stuck mashes are mainly caused by pumping too fast and creating a compressed grain bed,no matter what size pump you have you will be controlled by wort flow through the grain bed.

 

[billygoat]

If you are getting a compacted grain bed due to pump suction maybe an underback could be useful.
I've seen them used in some micros.

 

[Moad]

What about an agitated mash?

 

[Adr_0]

Maybe, but it would re-compress pretty quickly.

I think that a tall, narrow mash tun is asking for trouble, full stop. So you want a wide, flat (rectangular esky?) mash tun. If that's not an option multiple draw-off points is one option, as well as picking an operating point further back, i.e. more coil = less flow. You could take off 2-3 points and flow more sideways/diagonally through the mash. Obviously an occasional stir would help.

The reality is, as Tex n Oz said, you can't escape the energy requirement. If you want speed as well, then the power has to come from somewhere - either high turnover in the mash tun, or a high differential temperature which means your wort hovers a few degrees above setpoint for a while.

 

[Adr_0]

The reality is, as Tex n Oz said, you can't escape the energy requirement. If you want speed as well, then the power has to come from somewhere - either high turnover in the mash tun, or a high differential temperature which means your wort hovers a few degrees above setpoint for a while.

And that doesn't necessarily mean a bigger element, as once your coil outlet temp hits the setpoint the element starts to back off and it doesn't help your mash unless you have the flowrate to back it up:

Blue 4800W, orange 7200W, red 10000W

For a 90L mash, 6000W is the theoretical requirement for 1°C/min (90L x 65W/kg.°C) and I believe the next convenient size up is 7200W but that's still a lot of current.

If that's not possible, maybe gas boost with a 3600-4800W? 3-ring should give you 6-8kW. You would need to knock it off but it might be an option.

But every effort should be made to get that circulation up around 15-19lpm. It's a big batch, 120L, so if you are only getting 6-8lpm in a 90L mash it's going to take 10-15min just to do one circulation and your element is not going to be doing much.

Here is the same 2m coil in a 5L HEX, 7200W with flowrates of 10, 13 and 19lpm:


You can see which one has the best ramp time and gets the most value out of the element.

 

[Moad]

Gas isn't an option for me, the space I am building under the house doesn't have great ventilation. Basically a fan blowing air from one side of the room across and out a window.

7200w shouldn't be an issue circuit wise, I'm not pulling much elsewhere on the main board and can get an electrician to put in a 30a circuit I'd say.

Would a herm-it coil and cyclinder with a 7200w element and a pump to achieve 15+ L/minute get me above .5? I need to go back over your graphs on the PC, mobile is a bit hard to see.

 

[idzy]

Problem with too wide is preferential channeling. Reliability for me is important and stuck mashes suck.

 

[Moad]

Is anyone using a 40 gallon stout MT with a hex that can chime in. It seems like the best thing for me to do is go for the biggest flow rate and dial it back if needed.

The coil length being shorter means the hex will get hotter but the net effect is the same. I need the biggest flow rate I can get without creating a vacuum.

Stout actually have a wort grant as they call it which could be used to avoid the vaccuum effect.

So...what pump useable in brewing has a flow rate I'm looking for? Search time...

Edit: looks like the march 815 has 20l p minute flow rate, excluding reductions from the coil.

 

[Adr_0]

The graph on page 76 has the March 815 beer pump curve as well if you want it. 18lpm with a 4m coil pushing up 0.5m in height.

Did you have any other vessels in mind if you don't get a 40gal stout tank?

 

[Moad]

Thanks Adr, I;m on the laptop now so will go back and have a better look at those graphs.

I am open to ideas, I like the bottom draining stout tanks as they have the bits and pieces installed already.

I'm not scared of some DIY but am a little time poor so don't mind paying a little extra to have the work done for me.

Edit:

I think I am going to go with the big w 7.6L pot with 5m x .5" of copper with a 6kW element for my HEX using a chugger pump to recirc. I can use the HEX as a HLT for a little sparging on my 1v if I use the pot rather than knock of a smaller chamber.

Do you just use compression fittings to go from the copper to bsp thread? I'll go through the side of the pot so will need to keep it sealed.

 

[Moad]

Sorry for double post... Looking at this coil http://www.ebay.com.au/itm/copper-pancake-coil-1-2-x-5M-roll-air-conditioning-pipe-tube-/171670481239?hash=item27f85ba957

Is that .5 inch OD? Then I use 1/2" ID compression fittings to get it to 1/2" BSP?

 

[Tex N Oz]

Sorry for double post... Looking at this coil http://www.ebay.com.au/itm/copper-pancake-coil-1-2-x-5M-roll-air-conditioning-pipe-tube-/171670481239?hash=item27f85ba957

Is that .5 inch OD? Then I use 1/2" ID compression fittings to get it to 1/2" BSP?

Refrigeration piping is always measured OD and plumbing is measured ID so it will fit perfectly inside a 1/2" fitting.

 

[Moad]

Thanks Tex, Reece actually has the pipe cheaper. Confirmed it is 1/2" OD with them, they also have 1/2" compression > 1/2" BSP but not sure if they are stainless. Will go and check it out.

Hope I can get it into the 7.6L pot.


Edit: They weren't stainless at Reece and the annealed copper only comes in 18m coil BUT the guy cut me off 6-7m.

Picked up the compression from spvalves.com.au

 

[Adr_0]

Have you seen Husky's build?

I had the link but lost it...

Anyway, he has welded a connection halfway up the vessel. This is actually used for a return, but I don't see why you couldn't use a similar concept for a draw-off, and use a basket (or solder some mesh).

The purpose of this would be to draw off perpendicular from the bed and mostly used during temperature ramps. You would still draw off the bottom as well, but the actual flow with gravity should be reduced, allowing you to stay up at a high flow without compressing the bed too much.

 

[Moad]

Good idea and got me thinking, no reason the return couldn't be halfway to mix the grain bed around or would it simply move it to the other side of the pot?

 

[Adr_0]

I think you also want your draw-off halfway up,or 1/3 for eg.

 

[Moad]

makes sense I'll check out Husky's build.

I posted this in my build thread but this might get some more views, chasing info on vessels now.

Looking at 150 BK, 120 MT and 100 HLT. I like the stout tanks and people seem happy with them but they will cost a bomb to get in...

 

[Moad]

Here is my HEX so far, I'm thinking I will cut one coils off the top to pull it in a bit tighter to give some more space between coil and pot and take it a little lower in the pot.

I need to find a short 6000w element or mount 3 x 2400w's.

The coil I got was super easy to bend, I bent it around a petrol tin with no sand or anything in it. No kinks or flat spots until I tried to bend 90 degrees to get to the fittings and realised I need elbows there.

 

[Tex N Oz]

Here is my HEX so far, I'm thinking I will cut one coils off the top to pull it in a bit tighter to give some more space between coil and pot and take it a little lower in the pot.

I need to find a short 6000w element or mount 3 x 2400w's.

The coil I got was super easy to bend, I bent it around a petrol tin with no sand or anything in it. No kinks or flat spots until I tried to bend 90 degrees to get to the fittings and realised I need elbows there.

would it be possible to shorten the coil to half the height of the kettle and make a few more coils, each one a smaller diameter than the last, until you have 3 or 4 parallel coils? You could then get two larger pieces of copper pipe and use them as headers to attach all the coils to for a supply and return port. This would greatly reduce the volume of water in your kettle and increase the speed of heating.

 

[Moad]

I could cut it in half and use a T compression fitting. I think the flow rate is going to be the issue here as I will be running 6kw hopefully.