Flash boiler project #2

ScubaSteve said:

You could do that, but my concern is that simply laying a coil on the grate isn't as much focused, intense heat as placing it into a chimney with red hot coals or a burner with direct heat. The burner on a propane grill is probably much lower BTU's than a turkey fryer burner, too...

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True, I guess it depends on what's more important - efficiency of propane or speed. If you're looking to multi-task and cook food at the same time, you can throttle back the water speed and while it will take longer than the chimney column, it's may end up faster than the stove or full pot on the burner and still cook using propane you were using for the food anyways, saving you some $.

if you want super fast super efficient - then yes, I see your point. All depends on what you want out of it.


Since we're comparing this to cooling products, I see potential in a reverse plate chiller. You blast major heat on the many many plates while pushing liquid through, and voila - it sits nice and flat and might be ultra efficient if you encase it in some sort of box maybe?

It would be interesting to at least test if anyone has a plate chiller that is deemed not safe for wort but can still be used as a test device to see how fast water can heat up in it.

jezter6 said:

True, I guess it depends on what's more important - efficiency of propane or speed. If you're looking to multi-task and cook food at the same time, you can throttle back the water speed and while it will take longer than the chimney column, it's may end up faster than the stove or full pot on the burner and still cook using propane you were using for the food anyways, saving you some $.

if you want super fast super efficient - then yes, I see your point. All depends on what you want out of it.


Since we're comparing this to cooling products, I see potential in a reverse plate chiller. You blast major heat on the many many plates while pushing liquid through, and voila - it sits nice and flat and might be ultra efficient if you encase it in some sort of box maybe?

It would be interesting to at least test if anyone has a plate chiller that is deemed not safe for wort but can still be used as a test device to see how fast water can heat up in it.

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With the testing of my FB I have found that it's a fine line from 180 to boiling. With the copper tubbing it does not bother me but will a plate chiller handle that?
I'm sure the inside will but will the outside handle the flame heat?

FSR402 said:

With the testing of my FB I have found that it's a fine line from 180 to boiling. With the copper tubbing it does not bother me but will a plate chiller handle that?
I'm sure the inside will but will the outside handle the flame heat?

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I've only seen plate chillers at the store, never really looked hard at them. Theory could be pretty sound though, which is why I said someone who has a spare/semi-broken one to test one --- I would never advocate screwing with a nice working plate chiller.

If it wouldn't handle the direct flame, what about a "chiller in a box" kind of concept. Something like an iron box that the plate chiller sits inside. The box takes the direct flame but transfers indirect heat and traps it inside a box where the plate chiller would be?

Just go with a cold plate sitting on your grill for an easy way to do this, otherwise I like the idea of charcoal, or even make one of these things to put over your firepit to use free firewood to heat with.

conpewter said:

Just go with a cold plate sitting on your grill for an easy way to do this, otherwise I like the idea of charcoal, or even make one of these things to put over your firepit to use free firewood to heat with.

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Which brings to mind the charcoal in the chimney idea -- what about a good heap of charcoal on the plate chiller? Sort of like a good ol' dutch oven on the campfire.

ScubaSteve said:

All very true. In another post, you made the point that inline heating is quicker, i.e. a 0.5 gpm flow rate would heat 5 gals in 10 mins. vs. the 45 mins we see with bulk heating. That seems to make sense to me.

One concern I have is the thermal mass of the water...a small amount of heated water trickling into an unheated keggle is gonna drop in temp quickly. Maybe if you dumped a gallon of hot tap water in first to preheat, you could counteract this.

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I look at this flash heating thing whether it's gas fired or electric heating element based as an HLT replacement actually unless you're going to use it as a HERMS exchanger.

If you're using it to heat strike water, I'd use an output temp based on known MLT heat losses from the vessel and grist size/temp just like you would if you were bulk heating in an HLT.

Even though I'm nowhere near ready to build it, I'm still leaning toward electric due to its ease of regulating via PID for more exacting temp output. Again, I could be talking out of my a$$ since I'm not ready to build yet and haven't invested enough time into researching it.

jezter6 said:

I've only seen plate chillers at the store, never really looked hard at them. Theory could be pretty sound though, which is why I said someone who has a spare/semi-broken one to test one --- I would never advocate screwing with a nice working plate chiller.

If it wouldn't handle the direct flame, what about a "chiller in a box" kind of concept. Something like an iron box that the plate chiller sits inside. The box takes the direct flame but transfers indirect heat and traps it inside a box where the plate chiller would be?

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https://www.homebrewtalk.com/f11/plate-chiller-herms-58747/

I think if you were only going to pump clean water thru the coldplate it would work great but pumping wort thru would be bad.

Once I have this thing done and built into the rig I'm going to have to get a pump and use ut also for a HERMS and to help speed up the wort boil.

Yeah, I don't know....I think the cold plate is probably ok at cold temps, but who can say what's inside? There's probably some gaskets/seals that might melt.

Does anyone know the cheapest place to find ss tubing? McMaster seems to be around $55 for 50' of 1/4". Or, would 3/8" be better?

I like the idea of running wort thru as a step mash, but you'd really have to keep the burner down.

Are you dead set on SS, ScubaSteve? The reason I ask is because 50' of 3/8 copper is only 32.90$ plus shipping @ CopperTubingSales.com :: ICS Indsutries ::

With the setup I have the boiler output feeds the mixer then on to the sparge ring in the mash tun. This way it sends strike water to mash tun without circ pump, fire circ pump and mix steam into wort for step heating, switch pump to fill boil kettle and run sparge water through mixer again to clean and fly sparge without changing connections.

kladue said:

With the setup I have the boiler output feeds the mixer then on to the sparge ring in the mash tun. This way it sends strike water to mash tun without circ pump, fire circ pump and mix steam into wort for step heating, switch pump to fill boil kettle and run sparge water through mixer again to clean and fly sparge without changing connections.

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I guess i don't understand your use of the term "mixer"....?

talleymonster said:

Are you dead set on SS, ScubaSteve? The reason I ask is because 50' of 3/8 copper is only 32.90$ plus shipping @ CopperTubingSales.com :: ICS Indsutries ::

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Oh Snap! That's a good deal! I wasn't set on SS, but I got tired of putting crimps in the copper because it was so soft. I figured I might be able to get ss and do tighter coils.

SO....I was thinking about simplifying Kladue's design and just doing two interlaced coils...and instead of a 4 way splitter at top/bottom, I'd just use tees. If I had 50', I could cut the coil into two equal pieces. I figure 3/8' copper ought to provide a nice ratio of gpm and heat transfer....

Question....at the tees, what size would be good? Should I stay with 3/8", or should I go up to 1/2" since I'd effectively have 2 lines (the coils) in 3/8"?

Here is a picture of the new wort/steam mixer Picasa Web Albums - Kevin - New system st... steam/hot water enters through check valve on right side, wort through center of tee, steam and wort mix in tube and exit through left hand tee. Only have operating information on old system as new system is waiting for software completion to begin operation. Here is a shot of the old system control panel in a max boiler output test Picasa Web Albums - Kevin - Flowmeters wort into mixer 130 deg F, Steam into mixer 292 deg F., mixed wort out temp 166 deg F. at 50 GPH (.8 GPM) wort flow. The mixer has a 2" long 1/4" od SS screen wire diffuser to keep steam bubbles small when they hit liquid so it is fairly quiet in operation, a sizzling sound as steam bubbles collapse is normal at high steam temp/flow.

Wow. That's awesome. Out of my price range, definitely something I would never have thought of myself.....but awesome.

I think it's cool that you CAN step mash wort...but I want to focus on heating the hell out of some water in a quick fashion. I'd like to have my HLT filled with about 8 gallons of 190F water in 15 mins. If I can achieve that in a small package, I think I might have broken the "HLT Barrier" in brewing with my rig. I brew tomorrow....I'll test the properties of the jury-rigged prototype, take pics (beer porn :rockin then next paycheck I'll consider getting new copper, fittings, etc. (if this one sucks) and chop my corny.

I'm convinced 6" is probably gonna be too small for a chimney.

All the mixer parts could be made with brass or copper parts from hardware store, the mixer screen could be brass screen, or one could drill a bunch of small holes in the tube to spread steam out . The idea of injecting steam into liquid was a copy of industrial unit for starch cooking in the paper industry, just scaled down to homebrew system size. If one recirculates the wort in the mash tun, the steam injection system offers a way to get much more heat into the wort without carmalization on hot surfaces, and the ability to control temperatures for repeatability. With a 6 gallon batch the old system will raise temp from 130 to 152 deg F. in 10-12 minutes with mixed wort temp of 152 to mash tun. As to the size of the chimney here is a shot of the new boiler with 6" tube, 4-20' coils of 1/4" SS tube, and a 4" hurricane burner underneath.http://picasaweb.google.com/kevin.ladue/NewBoilerAndMixer#5244098716185213058

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

kladue said:

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

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Yeah. You got yourself a point.

kladue said:

All the mixer parts could be made with brass or copper parts from hardware store, the mixer screen could be brass screen, or one could drill a bunch of small holes in the tube to spread steam out . The idea of injecting steam into liquid was a copy of industrial unit for starch cooking in the paper industry, just scaled down to homebrew system size. If one recirculates the wort in the mash tun, the steam injection system offers a way to get much more heat into the wort without carmalization on hot surfaces, and the ability to control temperatures for repeatability. With a 6 gallon batch the old system will raise temp from 130 to 152 deg F. in 10-12 minutes with mixed wort temp of 152 to mash tun. As to the size of the chimney here is a shot of the new boiler with 6" tube, 4-20' coils of 1/4" SS tube, and a 4" hurricane burner underneath.Picasa Web Albums - Kevin - New Boiler an...

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How long is your chimney? Seriously though. Looks like you curved some ss sheet and welded it. I'd like to be able to keep the height right about that of a sanke. I think they're 24" or so....

kladue said:

If one has a flash boiler why would you need a HLT any more?, just heat the water as needed.

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You can but how would you know how much you are heating? I don't have gallon marks in my MLT. Plus it's a little touchy as to what the temp is coming out at. So I want o use my HLT as a holding tank that I can also use to adjust the water temp if needed.
If you are just going right from the FB to the tun and you under shoot the temp, what are you going to do about it?

Good point...for that matter you could just use a sight glass in the BK to measure initially, then get a nice sparge/mashout with just the FB going into the MLT. It looks to me like kladue is really trying to do step mashes with his. If I see it right, it looks like the steam mixer really is just a few added tees and compression fittings, with a site glass for coolness. It could easily be added after the fact.

I plan on just filling my HLT with mine, as hot as I can get it. By the time everything equalizes in the HLT and then the MLT, I'm sure I'll be hitting strike temps easily.

Both old and new system have a cold water tank that holds all water needed for brewing session, pump moves water through flow meter then to boiler into mash tun. Old system has a ghetto level indicator (cork float with marked ss welding rod), new system is electronic level transmitter. If you undershoot temp, fire circulation pump, cut water flow to 2 gph and make steam to heat water, all water used comes from tank so you can not exceed water quantity for batch, the more you use in mash the less you use in sparge at end.

kladue said:

Both old and new system have a cold water tank that holds all water needed for brewing session, pump moves water through flow meter then to boiler into mash tun. Old system has a ghetto level indicator (cork float with marked ss welding rod), new system is electronic level transmitter. If you undershoot temp, fire circulation pump, cut water flow to 2 gph and make steam to heat water, all water used comes from tank so you can not exceed water quantity for batch, the more you use in mash the less you use in sparge at end.

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The problem I have with that is this..
1. I don't have a pump and it may be a year before I get one.
2. The way you are adjusting the temp you are basicly doing a infusion of steam to heat it up more thus you are changing your grain to water rate. Not something I want to do. If I'm using a rate of 1.25/1 then that's what I'm going to have.

Now once I do get a pump I'll look more into the recurc idea.

I started out using 2 corney kegs in series and comperssed air to move water through boiler, filled corney's with batch water, measured water in tun at start, then ran boiler until water ran out during sparge. Here is a shot of the old mixer made from 3- 1/2" swagelok tees, steam in on right, wort in middle, mix out left side, black cable is sensor for love control used for temperature indication.Picasa Web Albums - Kevin - Instant water...

During the step mash steam production there is less than 1 quart of water used per step, not a big impact on mash water ratio. This system grew out of need to get away from lifting 5+ gallons of 180 degree water to top of stand for gravity system.

kladue said:

During the step mash steam production there is less than 1 quart of water used per step, not a big impact on mash water ratio. This system grew out of need to get away from lifting 5+ gallons of 180 degree water to top of stand for gravity system.

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That's why I have a 3 tier rig that's all piped for water. All I do is open a valve and the water fills the HLT and the sight glass tells me when to turn it off.

You have some really cool stuff man.

kladue said:

Both old and new system have a cold water tank that holds all water needed for brewing session, pump moves water through flow meter then to boiler into mash tun. Old system has a ghetto level indicator (cork float with marked ss welding rod), new system is electronic level transmitter. If you undershoot temp, fire circulation pump, cut water flow to 2 gph and make steam to heat water, all water used comes from tank so you can not exceed water quantity for batch, the more you use in mash the less you use in sparge at end.

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So basically instead of a HLT, you've got a CLT. What if you hooked a flowmeter to your supply hose? You could measure your input to the boiler, which would more or less be equal to the amount you'd pour into the MLT for strike water.

So, kladue, what was wrong with the old FB that made you decide to basically double the amount of coil and increase the height as seen in your new FB? It seems you're focusing on steam, so was that just a better way to make it? I just want 7-10 gallons of near boiling water in 10-15 mins. What kind of tubing diameters and lengths do you think would be best for such a task? I'd like to stay away from the super high pressures and dangers of steam, but if it gets near producing steam, so be it.

The old boiler will bring .25 gpm from 50 Deg F to boil temp, new system has tested out to .5 gpm @ 165, the SS tube was used because of known performance with old boiler. Operating scenario is .5 gpm@165 for strike water, .05 gpm for superheated steam for step mashing, and .2 gpm @175 for sparge water. This system is designed to run without outlet flow control and significant back pressure for safety reasons. I have purposely dry fired the ss coils to orange heat and hit them with cold water to test for failure in tubing and fittings before sharing design and pictures as I figured it would eventually happen to some one. The ss tube is much more malleable than the hard drawn copper and will make nice coils and short radius bends without flattening. Have about 400 feet of 1/4" hard drawn copper tube left over from previous project, but not the time to build 4 new copper coils for new boiler. Probably will make 4-20' coils of soft copper and replace ss coils after phase 2 system is running.

I went back last night with an actual tubing bender and redid my coils. It still isn't pretty, but the coils are all over the tube and there's no open space. That thing was totally worth $12. I still have blisters on my hands from trying to bend by hand...

ScubaSteve said:

I went back last night with an actual tubing bender and redid my coils. It still isn't pretty, but the coils are all over the tube and there's no open space. That thing was totally worth $12. I still have blisters on my hands from trying to bend by hand...

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Got pics?

I uncoiled mine Thursday night and last night I recoiled half of it around a 3" pvc pipe then tried to stick into a 4" pipe so I could coil it around the outside of that. It did not work so well. After getting only a few feet inside the bigger pipe I gave up and then had a hell of a time getting it back out. Kinked the tube bad. So I cut it into two pices and took the 2nd half and coiled it around the 4" pipe.
Put the one inside the other and now need to join them with a compression fitting. Hope it seals up good.

Got mine back together. I have one section 25' coiled at 3 inches, one 25 foot section coiled at 4" then I took an 18 foot section I had left over from the first try and hooked that to the 3" coil that was inside the 4" coil.
I then ran the 18 foot part around the whole mess the long way crossing over on the upper and lower ends and hooked that into that 4" section.

So now the water will go in the bottom, coil it's way up then com down one side, across to the other and back up. It will do this 4 times before entering the larger 4" coil and coiling back down to the bottom and out.

68 feet of copper tube.

Did not get a chance to test it yet, heading over to a friend's place for dinner and beers.

Well, here's my pics of my jury-rigged version: hawkie333/HOMEBREWING/FLASH BOILER - Photobucket - Video and Image Hosting

I did this on a 35F day...so it was the ultimate test. It took me roughly 40 mins to get 9 gallons of 140F water. If I slowed the input down to really heat the water up, it erupted in steam, which was counterproductive in filling the HLT. I might put this project on the shelf for a while, because I'm going to see how a bucket heater on a timer combined with about 10 mins of propane heating works for me. Be sure to post pics of when you guys fire up your boilers. It sounds like you're using way more tubing and taller chimneys, so I'd be interested in the results.

Looking at your pics I think your biggest problem is that you have the coldest water hitting the hottest part of the tube. The cold water is sucking all the heat right out of that tube and as it moves away from the flame it's not getting any or much hotter.

I just tried to do a test of the new coils and I have a leak. So I have to pull it back apart and fix it. Guess I should have checked that before putting it back together.

I'm dead set on making one of these.

Do you guys think it would work as well with 1/4" copper? I'm thinking of using 50' of 1/4" copper tubing.
I just think it would be easier to coil the 1/4" and then fan it out in opposing directions than it would be to do it with 3/8" or 1/2".

I like the idea of having an inline valve to help regulate the flow.

Yep, this is on my list of projects. Just thinking and drawing it out right now to tinker with.

I just picked up 50' of 3/8 off of Craigslist for 25 bucks.

I'll be making one of these for sure.

I got to use it for the first time yesterday and it worked great.
The water went into the HLT within 10* of what I wanted and then I used the burner under the HLT to adjust the temp.
When I was filling the sparge water I hit the temp going in right on so there was no waiting :rockin:
I would say that this knocked at least an hour off the brew but I don't know for sure because I did back to back 10 gallon brews so it was a long day either way.

So how long would you say it took to fill your HLT? All in all, it looks like you're on to something....

Your burner on top is bolted down, right?

ScubaSteve said:

So how long would you say it took to fill your HLT? All in all, it looks like you're on to something....

Your burner on top is bolted down, right?

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It took less then 5 minutes to get 26qt into the HLT at 160-175*.

Yes the top burner is bolted down.