Flash boiler project #2

If you want to copy the boilers that have been built with 1/4" tube here are a couple pointers, coil the tube around 2" pvc pipe in tight coils, stretch the coils to 1" space between coils, mesh all four coils together and use a dowel to keep coils together as you spread them out to create a four leaf clover pattern in chimmney tube. Once the tubes are secured in the inlet and outlet fittings you can remove the dowell and the coils should stay in position. If you want to copy the cross fitting in swagelok like I have used and have trouble finding the components pm me and I will help out.

Thought I would give a bump to this thread.
I am trying to understand the the coiling instructions kladue gave above. The meshing of 4 coils together using a dowel to achieve a clover leaf pattern I have a hard time picturing.

Cheers
Steve

Here's what i did, rolled 4 individual coils around 2" pvc pipe, spread coils 4 tube diameters apart, meshed all 4 coils to make tube, put dowell down center and pulled each of the coils away from center to get cloverleaf pattern. Here is a top down shot of the old boiler if it helps Picasa Web Albums - Kevin - Instant water... A suggestion is to leave dowell in center until coils are joined together, then pull dowell and fine tune individual coils. The wrapping of the coils is the easy part, when you mesh 4 coils it can be a struggle to get them meshed evenly.

I was looking at that top view of your boiler...impressive probably beyond my build skills kladue. I was wondering how the plate chiller panned out that was mentioned earlier in this thread earlier? I was thinking that if you could place a chill plate on a stove element with the input prefiltered water it might cut down of heat up times.

Cheers
Steve

BeerCanuck said:

I was looking at that top view of your boiler...impressive probably beyond my build skills kladue. I was wondering how the plate chiller panned out that was mentioned earlier in this thread earlier? I was thinking that if you could place a chill plate on a stove element with the input prefiltered water it might cut down of heat up times.

Cheers
Steve

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I'm not sure how well that would work. I have found that the water can really zap the heat out of the tube fast. So I'm thinking that it wont have enough contact time. Give it a shot and tell us how it works.

any new info on the system?

Not from me.
I have been useing this for every brew from 10 gallon batches to 35 gallon batches. It works great.
I have even used it after my pump. I have pumped from the MLT thru the FB and back into the MLT to do a "mash out" and then have also pumped from the MLT thru the FB and into the kettle to get the wort closer to a boil as I was fly sparging.

When I get time and some extra cash I'm going to make another one but about half the size just for the mashout part. It works the way it is but I always do back to back brews so if I'm running the mash thru it I can't use it for the water. So I need two of them. Plus the shorter size should make my pump not work so hard.

i was wondering when you'd decide to set up a second flash. i think it would help you immensely for heating sparge water also. since it would allow you to heat a second batch while sparging with the first on your really big brews.



are you gonna host a gathering in sept? check the michigan preds thread in gatherings.

Why did I build a keggle HLT? This is much better. To piggy back on the plate chiller idea, <cough> I have prechiller that is an Impala Heater core (yes this is for a car) that <cough> might work. The heater core costs $28 at auto nation and looks like copper. Only issue I see is tubing and closeness to the flame. I have some extra 9/16 silicon tuning laying around from a misshipment that I could experiment with.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?VISuperSize&item=310164594199

The heater core idea is good, the problem is the lead solder holding things together, you might look for an oil or transmission cooler with aluminum or copper tubing and no solder joints.

I would not trust using an automotive radiator. It was never meant to be food safe so you have no idea what would be in it. The solder, any oils that were used and so on.

my company builds those radiators...all aluminium but the flux used to fuse the parts together is a definite health hazard. use as a prechiller, ie not in direct contact with your wort, should however pose no problems.

eriktlupus said:

my company builds those radiators...all aluminium but the flux used to fuse the parts together is a definite health hazard. use as a prechiller, ie not in direct contact with your wort, should however pose no problems.

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Well the good news is that I still have a prechiller full of lead and not a HTL full of it.

Got to wrap my head around this thread some more to figure out how to build this. So my options are 3 in coil going up and 4in coil going down vs an engineered clover leaf pattern.

Ok went shopping.

60' 1/4 ID copper. ($45)
6" x 2' stove HVAC pipe ($4)
6" chimney rain cap ($7)
8" to 6" reducer (for base) ($7)
6" male x male adapter ($2)

Have to check what size pvc I have in the basement for wrapping. But before that I have another question.

Currently i have 50" wort chiller of 1/8" ID. Not sure if I should sacrifice the wort chiller for the boiler and make a new wort chiller with the 1/4" copper or just use the 1/4" copper in the bolier.

If use the 1/8", should I stick with the 6" diameter pipe or go smaller?

The smaller the ID the better the heat transfer is going to be. If you plan to use this with the mash like I do you will want the larger tube, less likely to plug up if some grain gets in there.

I would just use the new tube. If you used the IC then you would still need to re make that.

The 6" pipe should work fine. The stove cap may or may not work I tried one on my first build and it melted really fast. But that was only a 10-12 inch tall pipe.

The main thing you need to do is to maximize the contact time with the flame.

FSR402 said:

The smaller the ID the better the heat transfer is going to be. If you plan to use this with the mash like I do you will want the larger tube, less likely to plug up if some grain gets in there.

The main thing you need to do is to maximize the contact time with the flame.

Click to expand...

I am only makig this to heat the HLT. My rig is set up for cooler based batch fly sparging. The chiller worted well for 5 gallon batches, but for 10 gallons its not doing to well. So a am leaning to re purposing the chiller and making a new one.

Just repurposed my 3/8" x 50' wort chiller to a 3" coil. Compressed its about 12.5" and relaxed its 14".

On a side note I returned the copper, down graded to refridgeration grade, swithced stores, and upgraded the diameter. 1/2" x 50' for $38 at lowes.

Also return the rain cap for an elbow. The rain cap looked pretty sweet, but not worth $7 if it melts.

I converted my 3" coil into spiral by extending each individaul coil outward. Before inserting the spiral into stove pipe, things looked really good for over lapping. However after inserting the spiral into the store pipe there became a definate pattern such the 2" in the the center of the stove pipe had no copper.

Thus I took out the spiral, recoiled back to 3" coil as best I could, and did the exercise again but this time bending the coil inward instead of outward. The results before hand looked better than previously. However the same pattern emerged again, this with about 1" diameter of dead space.

Note sure if a 4" coil in 6" stove pipe would be better or worse. Also thinking about throwing the stainless steal stem from my converted keg in the center and capping it. Another idea is take some 1/2" copper pipe and make 4 pipe channel in the center and run the water through that first. Note sure of my soldering skills and or the connectivity from 1/8 copper the 1/2" however.

any thoughts?

This is why I did it the way I did. The water comes in the bottom and spirals up to the top (3 inch dia) then it loops from top to bottom like 4 times then spirals back down and out the bottom (4 inch dia)
This gives me 5 times that I'm getting direct contact with the flame (maybe more).

I just had an idea now that may make this better.

If you were to take two burners set side by side and build a box above them to help catch the heat (not closed completely) and then ran the copper tube in a zig zag type of way and have like 2 or 3 layers so that it's covering most if not all of the burners. This would give a lot of contact time with less copper. More burners and more horizontal space though.

Went to hardware store to buy stuff. Could not figure out how to do 1/4 tubing to 1/2 pipe. Started looking at adapters and elbows and the cost started adding up. Punted the 4 1/2" copper pipes n the center.

Bought 20ft 1/4 OD tubbing for like $9, 1/4" to 1/4" for $3, and 1/4 to garden hose for $4.

Original ideal was to run 10" lengths of copper back and forth vertical in the little 1" center whole of the boiler. I used a 3/4" pvc pipe as my turn guide. Looked nice but maybe a little big. Tried it in the pipe, no way, not even close.

Have brief fealing of wasting 20ft of copper, took the copper and started coiling it around the 3/4 pvc. Was not sure it would kink or not. But it did not (for the most part(if the copper was not already bent from failed attempt above, there would be not kinks)). Made a 10" coil and then reversed direction and made an outer coil around the inner coil. The outer cable lasted about 6 inches.

Now the fun and my maybe dangerous part, putting the coil through the center whole. After a few attempts I was able to get the coil in 9" out of the 10". Wired up the compression fittings (I hate them!) and I think I have a flash boiler.

Tested it a few times to get rid of leaks. One thing I noticed is that the amount of water coming out is not allot and there did not seem to be too much pressure either (aka no 10ft streams) when maxing out the garden hose. So I might have a kink or two in coil restricting something. My concern is not the lack of water, but rather it works too well and I just get steam instead and cant regulate it. Tomorrow I need to make a hole for the garden hose 1/4" out let and maybe test it.

I am think about buying a flat paving stone and put it on top of the coils the in the stove pipe. Maybe drilling a few small holes in as well. On the bottom I will probably have to drill in some screws to support the coils then.

you will need to hold the coils up off the burner somehow. I don't get a huge flow from mine either. you don't want that, to fast and you wont be able to heat it.
I think if it can run at full flow and you just control the flame that would be he best.

Make sure you don't cap the tube off to much or you will just choke out the flame.

It would probably be better to use a screen wire baffle instead of the solid block, you need the flow to keep enough draft to make burner work correctly.

Tested it out today. Can raise water 100 degree F (60 to 160) at a rate of 4:15 per gallon. Pretty hard to adjust.

Tried using steam to heat water in the MLT and did it not hold much merit.

My burner is a bayou banjo burner, so I have allot of small even blue flames. I lowered and expanded my copper tubing to the bottom of the 8" to 6" reducer. The blue flame tips are still a few inches below the copper tubing. I don't have much control on the burner, its does what it does. The burner is 11" and the bottom of the boiler is 8". Not the best use of propane.

I am going to returning the end cap for the boiler and install a damper instead. This should increase the internal boiler temperature a few degrees.

so you basically got a 100* increase at a rate of just over 1 minute per quart.
I see nothing wrong with that. Take a gallon of 60* water and time it to see how long it takes to heat it to 160*. I'm sure longer then 4 minutes.
But where these flash boilers make the biggest difference is when you are dealing with larger amounts of water. Because you're not heating the large batch, just a small amount at a time.

Hope the boiler works out better, I have built 2 with 1/8"(1/4")Od Stainless Steel tubing and have been able to hit 105 deg F rise at .5 gpm in the new boiler. http://picasaweb.google.com/kevin.ladue/BoilerTest#5258312805039313506. The steam into water is going to be noisy without a screen diffuser to limit the steam bubble size, open tube generaly makes a popping/rumbling racket depending on flow.

The experimenting with stream was surprisingly loud.

I am questioning my burner now, or rather stand now. I have this this cooker stand vs this classic stand:

Never noticed the difference before until youtubing some videos tonight. Might be a good ebay purchase gone bad.

I am suspending the stand under a wire shelf via stainless zip ties, so the stand is not really supporting any weight.

so is your tubing not touching the flame?
If not then you need to lower it so that it is.

Hi kladue
I'm new here and very interested in building a 1/4'' copper version of the flash boiler using 4 20' coils.

I was wondering what guage of copper tube to use?
http://coppertubingsales.com/copper_tubing_prices.php

Should I be using Type K tubing because of the thicker tube wall (withstand greater steam pressure) or the thin refridgeration tubing for greater heat transfer?

I am also considering coiling some extra tubing around the outside of the housing and so that it sits between that and a heat shield to soak up any excess heat before the water enters the boiler proper. What do you think about that? Good idea or bad? How much heat leakage are you getting out of the sides? My calculations say I could fit approx 140' of 1/4'' tube around the housing in this way. I am thinking only using 40' in the lower (hotest) part (25 windings at 6'' dia = bottom 9'' of the 52.5'' high housing) as 140' seems pretty excessive.

Finally, what temperature sensors are you using? Do you know of a cheap source?

Thanks

Take a look at Greenmontis flash boiler build, he has copied the 1/4" tubing around 2" pipe coiling and has come up with 2 ways of tubing connection to 1/2" copper. The boiler is built to deliver hot water and steam to the wort circulation system and discharge into MLT sparge system. It should not develop significant pressure during operation, temperature is controlled by inlet water flow rate and burner gas flow, not valving in outlet which could lead to high pressures which water feed would not be able to overcome. If you need additional assitance give me a PM and I will gladly help you work through the various design and control aspects of the flash boiler.

Thanks Kladue. The fact that you mentioned my build means a lot comming form you.

Here is the link to my build. It is a close copy of Kladue's build. I just put heat to it today.
https://www.homebrewtalk.com/f51/flash-boiler-153116/

so your basicly making a water heater with out a tank

climberguy said:

so your basicly making a water heater with out a tank

Click to expand...

Yes it's like an on demand water heater. But unlike a store bought one I can make the water as hot as I want it. Even make steam if I want to.

I currently use a high temperature crab cooker cooker that produces a serious 200,000 btu/hr heat output through a 20 nozzle brass jet cast iron burner. The burner is located 15 inches below the cooking surface to take advantage of where the heat is greatest and all gasses have been combusted,(meaning no black soot on the bottom of the kettle). I originally got this set up because I was tired of waiting for wort to come to a boil using my turkey fryer, and I wanted something that I could eventually use for 10 gallon batches. The burner works great but in doing 5-6 gallon batches I use about 1/2 of the USEABLE propane in the bottle.

I have been looking far and wide for a way to increase the efficency of using this sucker to boil with when I found the DIY link to flash boilers. To me these are gas fired calandrias. I'm looking to put a coil of 3/8"copper pipe coiled under the cooking surface and circulate the wort through this pipe via a march pump. Instead of interupting the burner's flame I plan to just go around it hoping not to get a steam problem.

Has anyone ever done this or could the flash boiler guys chime in on this. I have thought that maybe using 1/2" copper pipe to help with this but I have an old chiller made of 3/8" pipe I need to make use of now that it's obsolete. Since the flash boilers used 3/8" I know this could work. Here is a picture of my burner assembly. The steel is 1/4" so it should provide some protection incase of a failure. I'm not an engineer and thought someone here could be one. Thanks in advace

Got here tonight by looking for a way to convert the burner from a natural gas water heater. Read the whole thread and am interested if any of the posters have continued to use their flash burners, and if so, if there are any improvements to suggest. Hoping to bring this thread back from the dead!

I abandoned my flash burner idea and still use the jet burner as is but I have switched the burner to natural gas. Most commercial rigs are jacketed and use steam to heat... not super heat the bear like I was thinking to do. This is one reason this wasn't pursued by me.

I have my steam injector more or less assembled and ready for the flash boiler build.