POU HLT?

[MartyBrewerer]

Sanity check, please.

My big point of failure (distraction, excessive brew time, etc.) during my last batch (10 gal Leffe Blonde clone (Beersmith Innocent Blond)) is hot water management. I've been trying to mix gallon-by-gallon, which process is a pita. Having the right temperature water from a spigot would be a huge improvement.

I've got a >4KWatt burner on my stove, a 3 gal stock pot, an arduino and a few FREE dual solenoid controlled valves (from retired clothes washers) that tested impervious to boiling water. Seems to me that with some temp sensing I could make me a Point-Of-Use gravity fed hot water heater for almost free.

What worries me is that while I see some discussion of commercial POU for brewing (problems are $$ and that their set points don't usually go near 170F) I've NEVER seen POU like I'm envisioning in the arduino/brewing sphere. Up until this point EVERYthing I've imagined has been thoroughly detailed online, usually many times over. Great ideas, inane ideas, complex, simple, redundant, useless--They've all been done and documented. I don't see this and I'm not vain enough to think it's my brilliance that makes me the first to conceive of this. What am I missing?

Here's what I'm imagining:
1. Reservoir of boiling water on stove, replenished by siphon tube from cold water reservoir fed from sink faucet.
2. 1/2" siphon tubes from reservoirs feeding the dual valve (lower by 1.5', ~= 0.75 psi head), and the mixed output discharges thru a short hose into a waiting pitcher.
3. Temperature sensor in the hot water supply to pause mixing until the hot supply is at least at set temp.
4. Temperature sensor dangling with end of discharge hose to measure the mix temp.
5. Arduino w/2 temp sensor inputs, two solenoid drivers, a temperature setpoint selector switch (H = strike, L = sparge) and an AC supply.

Initially the set temperatures would be hard programmed in and the mixing action would happen whenever the system had power (i.e. flip the outlet strip switch to turn on and off). All sorts of improvements and conveniences would follow of course. No PID to start with, just a simple algorithm to mix hot & cold.

Could work? Never work? Thoughts? _________Marty

 

[Inspire]

So your main problem is your pot is too small (3 gallon), and you want a method to get a lot of boiling water (at least 10 gallon) in 1 go?
- You want to heat small pot of water and pour it into another bigger container (Your Hot Liquor Tank)?
- You want to heat small pot of water, then at target temp open valve and gravity will feed water into HLT?

If I am correct, you can always get a keggle. Get a keg and turn it into a kettle, and boil it on your stove. That makes your life easier.

If you want to use your method, yes it looks good. You'll need to insulate your HLT a lot, because its going to need to wait for your stove to boil the water.
- If you find you can't boil water fast enough into HLT, then you can always find a way to get the HLT water back into stove and cycle through that.

1 Question: Also how do you start the siphon tube?

 

[MartyBrewerer]

Hi Inspire, thanks for replying.

Well not 8 gallons of boiling water, but 8 gallons of (whatever temp, maybe 175F). I'd have hot (boiling) and cold (tap, ~60 F) water going to the dual valve. A temperature controller would turn each on as appropriate to hit target temp.

Siphon starting--I think I'd fill the tubes with cold water and install them into the pots with minimum air bubbles.

My physicist neighbor says that if I have 4 KW of heat actually into the water, I could heat 60F water up to 180F at a rate of 4 minutes per gallon. If I started with 3 gallons of boiling water then I could go substantially faster until my 3 gallon reservoir cooled down. That raises the question--How fast might one use water, not strike but sparge water when batch sparging?

 

[BrunDog]

I am not really clear on the rationale for doing this, but FYI I use a RIMs tube in my rig which has a supply relay which switches between 120V and 240V, effectively allowing me to heat water quickly when: strike water heating, sparging on the fly (5500W at ~ 70% duty brings H2O from ~75 to ~160 at 1 qt/min). My strike water heats from 70 to 160 in about 15 mins( that’s around 4.5 gallons).

 

[MartyBrewerer]

Rationale? Well, for one thing, as some famous person said, "Sure, I could just buy beer...". That's one of two major factors, and part of that is that it can involve an arduino.

The other factor is that I need something, *ANY*thing, to reduce the p.i.t.a. water mixing chaos at minimum price in my fairly junior setup.

5500W at 70% is almost 4000W (averaged). 1 qt per min. That's encouraging, it's like math works or something. Of course, I have a stovetop and a pot, and I am positive I won't be getting 100% of the heat into the water so we'll see what throughput I get.

I guess another excu^h^h^h^hreason for doing PointOfUse is that I get water at temp as soon as it starts to be at temp; I don't have to wait for the entirety of a HLT to come to temp.

I think it'll boil down to (haha) how Rube Goldberg the water supply system needs to be. I'm currently trying to keep the hot reservoir fed by a siphon from the cold reservoir, so that'll be a Very low altitude difference. (The cold reservoir will be fed from a trickle from the sink and overflow will just leave down the sink. If that all ends up impractical (unfunctional or too awkward) I'll try rethinking. Then again, thinking is what got me started in the first place.

Btw thanks, Brundog.

 

[BrunDog]

Sorry I am not of more help... but I do like the general idea of heating as you need it! In all truth, I really don’t know why everyone doesn’t employ on demand heating!

 

[MartyBrewerer]

Update, discouraging. I did some flow testing. 5/8" tubing at an altitude difference of 8" has pretty good flow rate. At 3' difference in altitude I fill a qt in maybe 10 seconds, very sufficient. Same, but with the valve in line, and the flow is almost non-existent. A qt would take several minutes.

So maybe the solution is to let hot water free flow at some rate, using a manual valve. The arduino would mix to temperature by adding cold to the stream. The arduino would always be active. Before starting, without being immersed in water in the 1 gallon mixing pitcher the sensor would be under temp and stay closed. When I start the hot water flow it'd have to catch up but probably easily.

Darn. I wanted to use that dual valve so badly--Free, bullet-proof, boiling safe (if not boiling drinking water safe). Oh well.

 

[BrunDog]

Certain valves are piloted to reduce their current use. Piloting uses input pressure to help open the valve. Like a relay switching a relay. Dunno for sure if that’s your situation but worth checking. In any event, that valve won’t work in your application (if I understand it correctly, which I don’t. But low pressure I am sure).

 

[MartyBrewerer]

Brundog, I think you're right; looking around, graphics of washing machine types of valves with the pressure assist match closely what is in the valve. Sadness prevails. Leffe assuages. But still...

Very disinclined to figure out how to pressurize my hot water; just seems like a wrong direction to go in.

So....how about a *manual* hot water valve along with automatic cold flow to match temp? Actually, that seems like a better design, a non-obvious but substantial advantage. In both designs I need to command the system to gimme a gallon of X temp water, so it might as well be a manual gate valve as a button. And flow testing impressed me with the good flow rate available from a mild altitude change, so with a good valve my flow rate ought to be as high as I want it.

So the new brilliant design:

-Pot of boiling water (maintaining level of the water is left for later consideration);
-Siphon tube (copper) from the bottom of that up and over and down to a gate valve dumping into a gallon pitcher;
-Tap water hose leading to a solenoid controlled valve, dumping into the same pitcher;
-Temperature sensor danging in the pitcher;
-Arduino reading the temperature sensor and controlling the valve to inject cold water to reduce pitcher water temperature until it's at the right temp.​

An empty pitcher, or no pitcher, would be cool, and so the cold water would stay off. Upon me opening the hot water valve, hot water hitting the temp sensor would inform it (the arduino) to solenoid to turn on the cold water until the temp is right.

Letchya know. First we have to survive the wind storm that's just starting (MD).