Dedicated Herms Guide, Problems And Solution Thread

[MastersBrewery]

Yep, I'm thinking 5/8" and possibly 3/4". Even 5/8" is a hell of a lot faster than 1/2". We'd easily cut 2 hours out of the brew day. Not that it gets pulled out that often...

The larger hoses need a bigger pump march 815 or bigger, flowrate is going to be the clincher for ramp times.

 

[Mardoo]

Yep.

 

[Moad]

I've got a 815-C so hoping I'll get enough flow through my HEX. Got ~6L of copper coil in a 10L pot. I really struggled to get it to seal properly... if it doesn't work I think I will put a Herm-IT together for maintaining temps/recirc and then add something like this into the HLT for ramping

Then the whole rig is stainless as well.

Will hopefully be able to test it in the next few weeks and report back

edit: I think I am just going to go with the Herm-IT and the coil in the HLT for ramping. Everything will be nice and shiny on the new rig and I'll have this ghetto HEX. Just isn't right to do it to the big rig

 

[Mardoo]

I really struggled to get it to seal properly... if it doesn't work I think I will put a Herm-IT together for maintaining temps/recirc and then add something like this into the HLT for ramping

Were you using thread tape on the compression fitting? That's been my source of leaks in the past. The compression fitting side doesn't seem to seal properly if you use thread tape.

 

[mb-squared]

Moad, I curious why you don't just go 3V all the way? Why have two HEXs? Seems overly complicated to me but perhaps there is a good reason.

 

[MastersBrewery]

Moad, I curious why you don't just go 3V all the way? Why have two HEXs? Seems overly complicated to me but perhaps there is a good reason.

If you mean HX coil in the HLT only, I think the issue would be lack of power to ramp the bach size. The hermit or HLT coil would probably hold temps but for ramping it's going to need a boost. For me I'd use the hermit for continuous duty to avoid over shoots and the HLT coil as boost for ramping.

 

[mb-squared]

There are so many 3V nano breweries out there that don't bother with two separate HXs -- just one HX in the HLT seems to do the trick. Of course, they have 2 5500W elements in the HLT, but if memory serves that is what Moad has too? Seems like it should be enough power. I just can't imagine all the valves and/or hose changes that you'd need to circulate your mash through two separate HXs. Seems way too complicated for me.

 

[TheWiggman]

Interesting idea with the separate HEx. You might run into trouble control-wise though because the HEx will ramp faster than the HLT and the pumped fluid will be inadvertently heating the HLT. Where is the temp going to be measured and what controller will be controlling each element? A single controller can't control both simultaneously because they will both have different heating rates, meaning you'll get overshoot or undershoot on one of the vessels. 2 separate controllers will work but that means two temps to set and two immersed probes.

 

[MastersBrewery]

Yeah get where you guys are going. I was always going to use a cfc in line. So mash>pump>cfc>hermit>return. The cfc being fed from HLT when ramping only. At the end of boil fill HLT with ice water and you have your second stage chilling. When and if variable control motorised valves become cheap you could then have finite control of the boost heating.

 

[Moad]

I only have 3500 + 4500 in HLT and kettle, 2 x 5500w just wouldn't be manageable on single phase if I want to do back to back batches

The idea is to use the Herm-IT to maintain and then use the coil in the HLT to give it a boost. I can end the coil circulation 1 or 2 degrees below the target temp and let the herm-it finish the job off to avoid overshoot.

I can't see me getting enough circulation with one or the other to bring that much liquid up in a reasonable amount of time.

What size batches do people manage with just coil in the HLT, what are the downsides of this configuration?

edit: I also wanted to constantly recirculate, if I went just coil in HLT and wanted to constantly recirculate I would need much bigger elements to heat sparge + mash. With regards to control, I have the BCS. The HEX will be measured at the return into the MT and I would measure recirculation through the HLT in the grain bed. I could stop the recirc when the grain bed gets to target temp minus a few degrees and let the HEX finish the job.

 

[mb-squared]

Moad, if you look through the "testimonials" page on the electricbrewery site you'll see there are several people brewing 30+ gallon batches with a standard 3V setup (i.e. 1 HEX coil in the HLT). But they are running 50A circuits with 2 ~4800W elements in the HLT and 2 more in the BK. In that setup, only the HLT *or* the BK can be fired.

my setup is similar, but I only have 1 5500W element in the HLT and 1 in the BK. I constantly recirculate both the HLT water and the mash and have no problems ramping through a range of steps. I use a water pump to recirculate the water in the HLT and a wort pump to recirculate the mash. I measure temp at the output of the HLT -- hottest point in the system and that way overshooting mash temp is impossible. It's an extremely simple setup! (I also use a BCS to control everything).

I currently brew 50L batches but am moving to 100L batches here soon. In setting the bigger brewery up, I'll add two additional elements: one in the HLT and one in the BK. I'll also be using a much bigger wort pump.

 

[mb-squared]

Yeah get where you guys are going. I was always going to use a cfc in line. So mash>pump>cfc>hermit>return. The cfc being fed from HLT when ramping only. At the end of boil fill HLT with ice water and you have your second stage chilling. When and if variable control motorised valves become cheap you could then have finite control of the boost heating.

MB, if you are already using the water in the HLT to heat the mash wort, then the only reason to add a hermit to the mix is if your CFC is an inefficient HEX. And it may be; I don't know. But if you put 15m of copper in your HLT, it will be a very efficient HEX and, if your HLT temp is where you want it to be you won't need to add any additional heat to your wort. At least that is my experience. But I like to keep things simple b/c I'm kinda stupid.

 

[Moad]

Interesting, what is the point of a separate HEX then?

 

[mb-squared]

I have never understood the point of a separate HEX, but there must be a point because many people on this board use them. 4V systems seem to be an OZ-specific thing, though, b/c I don't see them mentioned on other forums.

 

[MastersBrewery]

It's about lag in heating volumes of water. I'll post something a little more substatial from the pc tomorrow if I get the chance.

 

[MastersBrewery]

In essence when ramping from one step to the next it is optimal to have the wort exiting the the hx at the next step temp immediately if not as soom as possible. Remember the enzime activity is taking place in the wort not the grain, however having a stable grain bed temp is desrable as it means those reactions are taking place across the entire volume. A traditional HLT is slower in achieving that initial ramp purely due to volume. My idea of using the HLT as a booster was 2 fold, as it was not being used to hold mash temp it could be ramped earlier and ready to apply heat to the next step. Note this is with a convoluted ss cfc so HLT temp would have no effect on the mash until the pump is turned on. In the mean time the hermit is maintaining temp. If batch size were 10G or less I wouldn't bother with the cfc/HLT combo. There are pros and cons both ways. The guys with seperate small hx's like the tighter control and faster responce. But as mb has said it does add more gear and you can get there with 3v.

Ed bloody phone!

 

[TheWiggman]

The main point of a separate HEx is an increase in ramp times more efficiently. You are applying heat more directly the the mash liquor instead of the mash liquor + ~20l sparge water simultaneously. I've done both and wouldn't go back, particularly as it's very workable with 23l volumes and standard 240V 10A outlets.

 

[Moad]

Can someone correct me if I am wrong and add some calculations/experience if possible.

My flow rate looks like it will be 7.5LPM through 15m of coil in the HLT based on some initial tests.

say I have 30 Litres in the HLT covering the coil and 8KW of elements.

to heat 30L of water 1 degree with 8KW takes .26 minutes. To include the mash that's 130L and would take 1.2 minutes.

Say 1 degree in 1.5 minutes heating capacity to be conservative - http://processheatingservices.com/water-heating-time-calculator/

For all 100L of mash to pass through the HEX coil will take 13 minutes (at 7.5LPM)

If I set my HLT to desired temperature it should theoretically get there after ~15-20 minutes regardless of the increase (I don't know how to work out if the elements will keep up so am assuming the limiting factor is flow).

Now this means that the wort is being raised way faster than 1 degree per minute, is this a problem? Is 7.5LPM going to compact the grain bed? I've seen 5 thrown around as the magic number on a lot of systems...

Sorry about all the questions

 

[TheWiggman]

A high rate of change of the wort won't be a concern. There are some fundamentals of your system though that you need to consider when talking about the way it will behave.

1. The wort will act as a coolant much like the HLT will act as a heater. So even though you can calculate the rate of heating of the HLT independently, it won't quite heat this fast because the energy will be getting passed to the wort
2. The wort being returned to the MT will be hotter than the mash liquor until the system is in equalibrium
3. The HLT will reach target temp before the mash, meaning the mash temp will always lag behind the HLT temp
4. The heating rate will slow as the temps get higher (as the temp will get further from ambient)

Because of points 2 and 3 you may be hitting your target temp in 15-20 mins, but the mash temp will be quite a bit lower.

Regarding compacted grain bed, can't confirm. Lots of variables but the best way to get around it is by having as much surface area on your filter medium as possible (be it a braided hose or false bottom).

 

[Moad]

Thanks Wiggman,

1. This is why I caculated with 130L to factor in Liquor + mash
2. absolutely, I am hoping it is returning back into the mash 1 or 2 degrees lower than HLT temp due to losses. It is 15m of coil...
3. Yep no dramas there
4. gotcha, it is points like this why I am conservative with estimates until I can test real world.

the 15-20 minutes was a conservative estimate of the time to recirculate the volume of the MT once, I am making the assumption that the HLT temp will be maintained with the 8KW of elements (even with the mash liquor absorbing the heat). This is assuming HLT is set to target temp (+2 for losses). If I am ramping HLT while recirculating Mash I estimate it will blow out to ~30 minutes per 10 degrees.

There is a lot of estimates and assumptions here but if I am in the ballpark I am happy