Thoughts/Suggestions Re: my steam/electric hybrid plans?

[Beucepholis]

Hey, Y'all. Long time Lurker, first time poster.

I'm hoping some of you more experienced gents might have a moment to help me out with my design.

I'm trying to marry a flash boiler to an auto-sparge type manifold. This creates a potential problem, since stopping the flow of water at the auto-sparge device will cause water to sit in the coil and absorb more heat. When the auto-sparge finally opens, I'd end up hitting the mash with water over 170f and start leaching tannins.

I think I've addressed this by combining a "point of use" hot water / steam system with a PRV... but I'm not 100% sure it would work as I envision it. The idea is to release hot water into a blowoff tube once the auto sparge closes and 15PSI is subsequently reached (almost immediately as standard hose pressure is over 15psi), keeping the water flowing through the flash boiler (and into my wash tub) at the correct temperature while the system waits for the auto-sparge to call for water. Thoughts?

I've posted a drawing of my planned rig. The overall elevation drawing is incomplete... the system I'm asking about is represented in the detail/flowchart.

(A big call out to Yuri_Rage and Kladue for endless inspiration for this stuff. Keep posting!)

View attachment Drawing2.7.pdf

 

[DarkNoonBrewer]

Are you married to the flash boiler idea? What batch size are you looking for? At .3gpm, you can get to 174 degrees from 55. Thats 18 gallons of water over the course of an hour with a 5500 Watt heating element. If you're concerned about running costs, that scenario costs $0.55 @ $0.10 per kW. That boiler idea sounds really complicated way to heat water. Are you planning to use steam to boil as well?

Can you share the links to your inspiration?

 

[Beucepholis]

Yes, I like complicated.

I'm pretty married to the flash boiler. The system is built around steam mashing, so I need a steam source of one kind or another. The alternative to a flash boiler is a pressurized heated keg, which is much more disastrous if it goes awry.

I find that I spend lots of time and energy calculating decoctions and heating water. The worst is when I need to perform a mashout followed quickly by a sparge. Two different temps in short succession. Adding an electric HLT costs more than the flash boiler, takes more time, and is less versatile. Plus I'm a complicated guy who took on home brewing to serve my need to overcomplicate things.

https://www.homebrewtalk.com/showthread.php?t=242040&page=2

That's a link to Sanch's steam kit. Most of the heavy hitters in the steam crowd have posted and linked from it.

 

[Beucepholis]

DarkNoon, I think I failed to answer some of your questions:
1) I am currently doing 5 gallon batches but building to accommodate 10g.
2) No, I will not be using steam to boil. I will be using a 5500W element for that. Yes, I could use my kettle to heat and maintain my sparge water... but then I could not lauter into my kettle. (I'd either need to transport my sparge water to a passive vessel for sparging, where it would start to cool; or invest in a second element and appropriate vessel, and likely run a second 240v line with breaker; OR i'd need to lauter into a third vessel, and wait for my sparging to complete before beginning to bring the wort to a boil.)

 

[froot]

With a flash boiler you literally have the power at your finger tips, it's just going to come down to knowing and being able to apply the required flow rates to the flash boiler. Note and this is the important bit none of the flash boiler designs I've seen here; and I too went through all the appropriate threads; are designed to deal with back pressure. Steam under pressure is down right dangerous. The flash boiler should be openly vented on the outlet at all times. Raising a mash to mash out, maintaining, and then sparging can be done, you may have 5 minutes where your mash is not being attended by steam; that won't kill your beer, maybe 2 deg drop, if that is a concern, insulate the tun.

 

[Beucepholis]

Thanks Froot! I appreciate you chiming in.

Can you help me understand the danger/risk of allowing a flash boiler to operate under 15psi of back pressure?

 

[froot]

The flash boiler isn't rated for pressure, also control of the flash boiler gets more complex. Things happen faster once pressure rises, 15 psi don't sound like much (a PET bottle of coke shaken is probably higher) PRV's do fail, if that happened and anyone or anything was near it, there'd be little left, if you happened to survive, you'd be in a burns unit for a long long time. I wouldn't do it even with 3 redundant PRV's. But note just your piping will create back pressure which is fine Greenmonti I think quoted 6 Psi.

On the outlets I would use 'L' type 3 way valves with a blow off to waste, obviously things even look like going sideways and you kill the burner, the water flow will quite quickly settle things down.

My advice read all you can before heading down this path, PM the guys that have built them and get their advice kladue is one of the original guys to build one and has even gone to the extent of automating it (note he is some sort of engineer and worked with steam turbines for years).

good luck and brew safe

froot

 

[Beucepholis]

Even standard hose pressure is greater than 15 psi I believe. I just need the hot water to flow elsewhere when the valve in the auto sparge stops calling for water. Figured a very low rated PRV would vent automatically when the main valve closes.