Flash boiler

[GreenMonti]

That should work well, you are talking 1/2" copper pipe and fittings for your plumbing, or 1/2" outside diameter tubing.

1/2" copper pipe.

The heavier stuff, I think it is type L.

 

[sanch]

Is there any reason not to put a damper on one of these? I have been inspired by you guys to take on this endeavor myself. I have my copper, 1/4 " soft copper i picked up at home depot,over the weekend. I was wondering if the hot air/gas from the burner is entering the flue at a slightly faster rate than it is exiting, wont it get hotter in the flue and thus transfer more heat to the water? I have been staring at my shop wood stove and pondering this. Thermodynamics is not one of my strong points. thanks for any input

 

[FSR402]

Is there any reason not to put a damper on one of these? I have been inspired by you guys to take on this endeavor myself. I have my copper, 1/4 " soft copper i picked up at home depot,over the weekend. I was wondering if the hot air/gas from the burner is entering the flue at a slightly faster rate than it is exiting, wont it get hotter in the flue and thus transfer more heat to the water? I have been staring at my shop wood stove and pondering this. Thermodynamics is not one of my strong points. thanks for any input

My build uses an old soda keg and I use the lid in this way. It does help me that's for sure.

 

[GreenMonti]

Is there any reason not to put a damper on one of these? I have been inspired by you guys to take on this endeavor myself. I have my copper, 1/4 " soft copper i picked up at home depot,over the weekend. I was wondering if the hot air/gas from the burner is entering the flue at a slightly faster rate than it is exiting, wont it get hotter in the flue and thus transfer more heat to the water? I have been staring at my shop wood stove and pondering this. Thermodynamics is not one of my strong points. thanks for any input

I had this thought but wanted to try it out this way first. So I could see any differences.

Keep us posted on your build please.

My build uses an old soda keg and I use the lid in this way. It does help me that's for sure.

Do you notice any problems with the flame? Not to sure how to word it....................... Are you getting total combustion? Maybe that's better.

 

[sanch]

My build uses an old soda keg and I use the lid in this way. It does help me that's for sure.

yours is the first flash boiler i saw here a while back, the one that got me thinking about it. i was planing on a pressure pot, it just dosent seem as diverse or expeditious as a flash boiler . this is my favorite HB project yet, thanks for the inspiration!
how much difference does it make in your water temperature wide open vs closed baffle, with the flame and flow at a constant setting ?

 

[sanch]

I had this thought but wanted to try it out this way first. So I could see any differences.

Keep us posted on your build please.



Do you notice any problems with the flame? Not to sure how to word it....................... Are you getting total combustion? Maybe that's better.

the current version of my plan is to use a simple butterfly damper maybe a foot above the top of the coils.
maybe you could test the theory with a piece of sheet metal with some holes/slots in it ? If the difference is exponential i will build my rig too test it farther. my mechanic buddy has an o2 sensor that he uses for carb tuning, that i am sure i could borrow. to test and fine for total combustion . at the very least it would be a fun experiment ! and i will post any progress i have . thanks dudes!!!

 

[FSR402]

Do you notice any problems with the flame? Not to sure how to word it....................... Are you getting total combustion? Maybe that's better.

Yes I get a good burn. I have never put a therm to it to see how big of a difference it makes moving it around I just know that the water comes out hotter with it closed off some. Even without the lid set in there I still have a smaller opening on top then you do. With the lid on it's closed off to about half the opening of the keg.

 

[GreenMonti]

the current version of my plan is to use a simple butterfly damper maybe a foot above the top of the coils.
maybe you could test the theory with a piece of sheet metal with some holes/slots in it ? If the difference is exponential i will build my rig too test it farther. my mechanic buddy has an o2 sensor that he uses for carb tuning, that i am sure i could borrow. to test and fine for total combustion . at the very least it would be a fun experiment ! and i will post any progress i have . thanks dudes!!!

Do you plan on using the boiler to do steam? Or are you planning on doing it like FSR402 does, and pump your wort through it?

Just interested cause I am not going to run wort through mine. I think the 1/4" copper is too small of tubing. I think small pieces of husk or grain might get stuck. Once one piece gest stuck the its all over.

I had that thought today at work to take a piece of sheet metal and close off part of the opening once I got it running at a stable rate. Then slide the sheet metal on it a little bit to see if the temp goes up. I plan on running the boiler this weekend.

 

[GreenMonti]

Yes I get a good burn. I have never put a therm to it to see how big of a difference it makes moving it around I just know that the water comes out hotter with it closed off some. Even without the lid set in there I still have a smaller opening on top then you do. With the lid on it's closed off to about half the opening of the keg.

I was thinking of building another one like yours out of 1/2" pipe. A small one, just one stick so 10'. So when I am running into the kettle I can fire it up and get the wort next to boiling temp as it goes in. Like you do. I figure it is either that or do a HLT. I am not sure why, but I just don't want a HLT on this system build. I already have all the burners I need.

At the same time I don't need to build it at all. It would just speed up the boil.

 

[sanch]

Do you plan on using the boiler to do steam? Or are you planning on doing it like FSR402 does, and pump your wort through it?

Just interested cause I am not going to run wort through mine. I think the 1/4" copper is too small of tubing. I think small pieces of husk or grain might get stuck. Once one piece gest stuck the its all over.

I had that thought today at work to take a piece of sheet metal and close off part of the opening once I got it running at a stable rate. Then slide the sheet metal on it a little bit to see if the temp goes up. I plan on running the boiler this weekend.

I plan to do steam like you and klaude. and also heat mash/sparge water. i do have a hlt on my rig so i will run the incoming water through the flash boiler to the hlt, to cut down on pre mash time. the thought of pumping wort through it is tempting, between mt and bk, but like you said the tubing is a little to small, that is why i have not cut in to my tubing yet i was thinking of exchanging it for 3/8".

maybe a second coil in the same flue, a 1/2 inch slinkey around the center coils, maybe even link them together in series when the recirc coil is not in use?

 

[FSR402]

I was thinking of building another one like yours out of 1/2" pipe. A small one, just one stick so 10'. So when I am running into the kettle I can fire it up and get the wort next to boiling temp as it goes in. Like you do. I figure it is either that or do a HLT. I am not sure why, but I just don't want a HLT on this system build. I already have all the burners I need.

At the same time I don't need to build it at all. It would just speed up the boil.

I'm still thinking of building another one but shorter for pumping the wort thru. On a 35 gallon batch of barlywine I did it was a pain. It was the first week in May so the ground water was around 40-45*. I had hooked the FB up and was recirculating to mashout and then started to sparge while still pumping thru it into the kettle.
The problem was it was being used, and now I had 30+ gallons of sparge water to heat and sprage with. It took forever to heat that much water from 40* to 170* without the FB. Made for a long day. This is when I really seen the benefit if the FB.

 

[GreenMonti]

I plan to do steam like you and klaude. and also heat mash/sparge water. i do have a hlt on my rig so i will run the incoming water through the flash boiler to the hlt, to cut down on pre mash time. the thought of pumping wort through it is tempting, between mt and bk, but like you said the tubing is a little to small, that is why i have not cut in to my tubing yet i was thinking of exchanging it for 3/8".

maybe a second coil in the same flue, a 1/2 inch slinkey around the center coils, maybe even link them together in series when the recirc coil is not in use?

I can't really say on the tubing size. I would think the 3/8" would work fine for the boiler. I am just not sure I want sugar water running through my boiler. That's why I (if I do) will make another heat exchanger (boiler) for my runnings.

If you need help with the diffuser let me know. I made another one today at work and I plan on making another one either tomorrow or next week. Only reason is cause I had the screen material and the tubing. One of the three will be bent 90 degrees. The tube is already bent. It was a bend test and then I thought about welding on the screen.

I had the same thought as you. The space on the sides of the boiler is perfect for another coil to fill the gap. But while thinking of it I realized it would be fired dry a lot of the time. I don't want to link the two. So if I do it I will run another burner. I am also playing with an idea for my mlt. It wont be the best and it will have its own cons, but I think the simplicity of fly sparging will be nice.

 

[GreenMonti]

I'm still thinking of building another one but shorter for pumping the wort thru. On a 35 gallon batch of barlywine I did it was a pain. It was the first week in May so the ground water was around 40-45*. I had hooked the FB up and was recirculating to mashout and then started to sparge while still pumping thru it into the kettle.
The problem was it was being used, and now I had 30+ gallons of sparge water to heat and sprage with. It took forever to heat that much water from 40* to 170* without the FB. Made for a long day. This is when I really seen the benefit if the FB.

So what were your plans on the build?

As I mentioned, I was thinking of 1 stick of 1/2" copper pipe. As you know I will need to go from 170 ish to 210 ish. I wonder how big a flat spirial 10 feet of pipe would make? You know like those big lolypops.

 

[kladue]

I went with a steam/wort mixer setup in the pumped wort recirculation line to the MLT and sparge ring. All the water you use is going to the MLT anyway, so start with strike water to MLT, then start recirculation and inject steam for heating, and finish with sparge water. Wort is diverted before mixer to flow to boil kettle and sparge water flows to distribution ring in MLT, this prevents pressure buildup in the boiler as discharge of boiler is connected to the mixer and MLT with no valves after boiler inlet. With this setup there is no plumbing switching when changing modes, just 2 valves to set before mixer inlet, one to mixer to control flow rate, other to boil kettle to set wort flow to boil kettle. I just measure strike water and pump water through boiler until gone, then refill water container with sparge water amount and use that for steam heating and the remainder for sparge, this way you can control final volume easily as only required water in container is used.

 

[sanch]

"I see said the blind man" you stated this same concept in an earlier post to someone else, and i could not make sense of it. maybe my marbles have rolled around enough to comprehend? that way there is no need for a secondary recirculation coil.

this question may have been answered previously, but what kind of temp increases do you experience from input to output on the steam mixer?

 

[GreenMonti]

I went with a steam/wort mixer setup in the pumped wort recirculation line to the MLT and sparge ring. All the water you use is going to the MLT anyway, so start with strike water to MLT, then start recirculation and inject steam for heating, and finish with sparge water. Wort is diverted before mixer to flow to boil kettle and sparge water flows to distribution ring in MLT, this prevents pressure buildup in the boiler as discharge of boiler is connected to the mixer and MLT with no valves after boiler inlet. With this setup there is no plumbing switching when changing modes, just 2 valves to set before mixer inlet, one to mixer to control flow rate, other to boil kettle to set wort flow to boil kettle. I just measure strike water and pump water through boiler until gone, then refill water container with sparge water amount and use that for steam heating and the remainder for sparge, this way you can control final volume easily as only required water in container is used.

Kladue,

What do you think of the second unit to give the runnings a boost on thier way to the kettle?

 

[kladue]

The part about flow to top of MLT that appeals is after heating mode the sparge water flushes everything into the MLT and cleans the top half of the circulating system. The old system is capable of raising the temperature nearly 50 degrees across the mixer at maximum firing rate and 300 degree steam input. I have not had enough time on the new system yet to see what it can do, but the boiler and burner are quite a bit larger than the old system.
When I first tried the boiler I used 2 corny kegs in series with compressed air to move the water, then broke down and bought a sureflo 120V diaphragm pump to move water from container to boiler. The pump is noisy and had to build a bypass back to tank to prime and keep pump from cycling on and off, but it met the need for water movement. Water level was measured with a large cork attached to a piece of welding rod that was marked at 1 QT intervals, crude but useable.

 

[kladue]

The wort to the kettle probably will not need an additional boost, fire the kettle burner when you have 2" wort in the bottom and by time kettle is full you should be at or near a boil.

 

[GreenMonti]

The part about flow to top of MLT that appeals is after heating mode the sparge water flushes everything into the MLT and cleans the top half of the circulating system. The old system is capable of raising the temperature nearly 50 degrees across the mixer at maximum firing rate and 300 degree steam input. I have not had enough time on the new system yet to see what it can do, but the boiler and burner are quite a bit larger than the old system.
When I first tried the boiler I used 2 corny kegs in series with compressed air to move the water, then broke down and bought a sureflo 120V diaphragm pump to move water from container to boiler. The pump is noisy and had to build a bypass back to tank to prime and keep pump from cycling on and off, but it met the need for water movement. Water level was measured with a large cork attached to a piece of welding rod that was marked at 1 QT intervals, crude but useable.

I
You posted while I was typing. Sorry.

 

[kladue]

The second unit will probably not be needed as a wort preheater as the sparge cycle should take about 20-40 minutes to get decent extraction. The slow flow of wort into the boil kettle means that you can fire the kettle burner at a low setting as it fills and it will hit boiling as the transfer from the MLT ends. I have used this method quite a few times and it keeps things simple, you will have to watch boiler temperature and flow rates to hold level in MLT above grain bed while sparging. The auxillary coil as a water preheater would not be a bad idea, wringing more heat out of hot gasses leaving boiler stack will improve efficiency and output, not sure what effect it would have during steam production.

 

[GreenMonti]

The second unit will probably not be needed as a wort preheater as the sparge cycle should take about 20-40 minutes to get decent extraction. The slow flow of wort into the boil kettle means that you can fire the kettle burner at a low setting as it fills and it will hit boiling as the transfer from the MLT ends. I have used this method quite a few times and it keeps things simple, you will have to watch boiler temperature and flow rates to hold level in MLT above grain bed while sparging. The auxillary coil as a water preheater would not be a bad idea, wringing more heat out of hot gasses leaving boiler stack will improve efficiency and output, not sure what effect it would have during steam production.

If one wasn't carefull about the length of the perheater on the input side.......it might turn to steam to quick? Is that possible, can the water vaporise too soon?

 

[sanch]

The part about flow to top of MLT that appeals is after heating mode the sparge water flushes everything into the MLT and cleans the top half of the circulating system. The old system is capable of raising the temperature nearly 50 degrees across the mixer at maximum firing rate and 300 degree steam input. I have not had enough time on the new system yet to see what it can do, but the boiler and burner are quite a bit larger than the old system.
When I first tried the boiler I used 2 corny kegs in series with compressed air to move the water, then broke down and bought a sureflo 120V diaphragm pump to move water from container to boiler. The pump is noisy and had to build a bypass back to tank to prime and keep pump from cycling on and off, but it met the need for water movement. Water level was measured with a large cork attached to a piece of welding rod that was marked at 1 QT intervals, crude but useable.

what was the wort flow rate?

 

[kladue]

The flow rate was 48-50 GPH, the right hand flow meter in the picture, the left hand flow meter is the water flow into the boiler 3GPH. The top temperature reading is into the mixer, the middle is the steam temperature, the bottom is the mixture temperature.http://picasaweb.google.com/kevin.ladue/InstantWaterHeater#5018859455426932690

 

[sanch]

OK, I have a base made. This is made from some scrap pieces I had around the garage. It is all together and I just need some small supplies to get it finished up. At least to a test stage. I will test it by heating up water and work out what I can before I build my diffuser for the steam injection. If all goes well I will put the mixing pieces together and give a mash a run. I can't wait.

On a side note, my TIG welder is acting up...... DAM# IT!!!!. It is a dinosour anyway I guess. I am just not ready for it to go out.


Here is a couple more shots.
All together, I got it a little off. It lists toward the back some.

A closer shot of the base,

I see why your welds look so sweet your machine is old and wise! I have a cast iron 30" band saw that is 102 yrs new and every project it lays it blade on turns to gold!!

 

[FSR402]

So what were your plans on the build?

As I mentioned, I was thinking of 1 stick of 1/2" copper pipe. As you know I will need to go from 170 ish to 210 ish. I wonder how big a flat spirial 10 feet of pipe would make? You know like those big lolypops.

That's kind of what I was thinking. I only need it to raise the wort temp not boil or make steam.

 

[FSR402]

The wort to the kettle probably will not need an additional boost, fire the kettle burner when you have 2" wort in the bottom and by time kettle is full you should be at or near a boil.

I agree with this actually. I only do it when I'm doing a big batch and starting with a 47 gallon boil. With only 15 or less I don't worry about it.

 

[GreenMonti]

That's kind of what I was thinking. I only need it to raise the wort temp not boil or make steam.

I agree with this actually. I only do it when I'm doing a big batch and starting with a 47 gallon boil. With only 15 or less I don't worry about it.

The lolypop idea was just that. It seemed like a good way to use up all of the burner and have a nice and small package. As for the workings of it, I really can't say. I am not up to speed on the whole surface area to water/wort ratio.

When I brew now, I light the fire while I am sparging. It still seems to take while. But I do like the idea of one less piece of equipment. Don't get me wrong, I like do giggers and whirly gigs. If I can get the same or close to the same results and not have to build another heat exchanger and have one less burner........

 

[sanch]

I can't really say on the tubing size. I would think the 3/8" would work fine for the boiler. I am just not sure I want sugar water running through my boiler. That's why I (if I do) will make another heat exchanger (boiler) for my runnings.

If you need help with the diffuser let me know. I made another one today at work and I plan on making another one either tomorrow or next week. Only reason is cause I had the screen material and the tubing. One of the three will be bent 90 degrees. The tube is already bent. It was a bend test and then I thought about welding on the screen.

sorry i missed this before. i would definitely be interested in in some diffuser help!! i was thinking of asking how much, if you would make me one, because i know mine would not turn out near the same caliber yours did, and didn't want to be a bother. I have a lot of tri clover stuff and was planing to use a big tee, in the fashion that you mentioned, and have tri clover connections on all ports of the tee so it can be easily inspected and cleaned i have an extra tee i could spare and the fittings if you might be interested in a trade of some kind ? if not just give me a price.

 

[sanch]

also what is the outside diameter of the tubing, i have a few stainless comp fittings i am hoping will work?

 

[CodeRage]

That's kind of what I was thinking. I only need it to raise the wort temp not boil or make steam.

I've got a little less than 20 feet of coiled 1/2" ID copper for sale in the classifieds.
https://www.homebrewtalk.com/f16/heat-exchanger-coil-154809/

 

[GreenMonti]

sorry i missed this before. i would definitely be interested in in some diffuser help!! i was thinking of asking how much, if you would make me one, because i know mine would not turn out near the same caliber yours did, and didn't want to be a bother. I have a lot of tri clover stuff and was planing to use a big tee, in the fashion that you mentioned, and have tri clover connections on all ports of the tee so it can be easily inspected and cleaned i have an extra tee i could spare and the fittings if you might be interested in a trade of some kind ? if not just give me a price.

No, worries. I can get you a diffuser. It is 1/4" ss tubing and my calipers confirm this with a reading of .249-.250. As for cost, IDK. The stuff is just left overs that have been around for a while. So these 3 diffusers haven't cost me anything but time. I also welded them at work. I'll shoot you a PM in the next day or two, ok?

On the big T fitting. I think it will be ok as long as there is turbulance in there. From what I understand you want the diffuser in the flow to help break up the steam bubbles and get it infused. This also helps with noise.

 

[GreenMonti]

You like pics?? I know I do.

Well the boiler got an addition today. I added another coil for a preheat on the incoming water supply. It also acts as a damper cause it bolcks/uses a lot of the heat on the outer edges of the chimney. After trying to bend 1/2" pipe I went and got some of the 1/2" soft copper type L to do the job. When asking the 1/2" tube to bend around 4" diameter pipe, it will flatten out quite a bit. In my case I wanted the flatening. It would allow it to fit around the boiler and in the current chimney. Oh it fits so nice in there.

This mod has increased the efficency by a lot. I fear I am going to have some issues later on with the lower flow. I got the water going at .5 GPM and lit the fire. It was quite easy to achieve the 170 mark. I would say the burner was a tad under half fire. I then let it rip and saw 212 with the boiler stuck in the transition mode between steam and hot water. After that I set the flow at 2oz a minute. AKA 3 GPH. I had no problem getting it to steam up.

This time I chose to do a very rough injection into some water. Not knowing flow rates I filled up the test pot and then slowed things down for the steam. I got some very loud poping at the point where the steam was hitting the water. I drained some off for it to flow into the air and then refilled it. It was then just like air being blown into water. With some back pressure on the system it runs so smooth. The boiler looks like it is under much less stress. I can only assume the pipes are able to sustan a more wet enviroment this way.

The pot of water went up 67 degrees in just 10 mins. I started out at 135 degrees and it hit a wall at 203 degrees in the ten min time frame. The pot of water had 6-6.5 gallons in it. I then cranked up the fire to see if I could get it to boil, after another ten mins it had only risen to 206 degrees. I now see that you need one massive boiler to boil with. This thing rocks and a propane burner would be more efficent at a boil. Though I did not build it to boil with. I guess it is time for some pics.

A shot of the new coil. I bought 10 feet of tube. I only lost about 2" so far.

Another shot of the new coil

A top down of the new coil. You can see how much the 1/2" flattened out. I can assure you that flow throught this thing is no problem at all.

Here you can see it all in the chimney. It fits nice.

In the other pics you can see the input was moved lower on the unit. Here is a shot of the input and the whole boiler.

At .5 GPM and a tad under half fire will get you 171. I watched this for a few mins to see how stable it would be. It only moved a degree or two.

This is a bad shot of the rough injection I did. However I did get a 67 degree boost with no other circulation on the pot. I moved the temp prob around a bit to see how even it was and it was all within a couple degrees. In this pic you can see I have the valve open. I was draining it at this point to see waht would happen to the loud poping noise I was getting. As I mentioned, it was refilled after it had been exposed to air.

 

[kladue]

Ahh the age old problem of blowing steam into stationary water, awsome test run though, now you have me contemplating a 1/2" od coil around the outside of the 1/4" coils as a preheater in the new boiler.

 

[sanch]

GM you are the man!!! your fab skills are unparalleled. that was a good idea with the 1/2"coil outside the primary coils. I think I will have to copy your design!!

 

[GreenMonti]

Ahh the age old problem of blowing steam into stationary water, awsome test run though, now you have me contemplating a 1/2" od coil around the outside of the 1/4" coils as a preheater in the new boiler.

Glad I could stir the pot for you.

 

[GreenMonti]

GM you are the man!!! your fab skills are unparalleled. that was a good idea with the 1/2"coil outside the primary coils. I think I will have to copy your design!!
What made you think of it ?

Copy away. No worries.

All the talk we did about another coil/exchanger. I then conversed with Kladue over it a little. I then thought why not. I am very happy in the end. I really can't wait to get it hooked up to a MLT now.

 

[sanch]

Copy away. No worries.

All the talk we did about another coil/exchanger. I then conversed with Kladue over it a little. I then thought why not. I am very happy in the end. I really can't wait to get it hooked up to a MLT now.

I also can't wait keep us posted !!

 

[Mista_Sparkle]

If you want to boil the pot with the steam, you would need it to be under pressure so just venting it into the pot would not be sufficient as the maximum temp you will get at 1atm would be 212ºF. If you ran it at your water pressure, and simply drained off the condesed vapor, you would be able to heat your steam up to around 300ºF and you would have a complete phase change to work with so you would probably get a much more efficient heating. Granted, working with higher pressure steam would be quite dangerous, but since your fittings are all brazed instead of soldered, you would probably be OK, somebody who knows more of what copper pipe is capable of would be better off confirming this.

Edit: Halfway through my post I forgot what I was talking about... So, yes, you can get your steam up to a higher temp with this rig, but if you get it under pressure, you can raise the transition temperature so when it actually boils off inside the generator, you will have steam at a higher temperature that is free to dump a lot more energy into your pot or mash or wherever you please as the temperature increases closer to 212...

 

[kladue]

With higher pressure you get saturated steam at higher temperature, still basicly 970 BTU's Lb on condensation. With the superheating you get the sensible superheat BTU's out then the 970 BTU's Lb when it condenses. There is no need to increase pressure in the flash boiler to raise output, just adjust firing and flow rate to achieve additional superheat and energy delivery.

 

[Mista_Sparkle]

True you still get about 970 BTU/lb on condensation but as boiling is approached, the temperature differential will approach 0 when the steam will condense so you the boundary area between the steam and water will have to increase to infinity to continue with heat transfer and you will only get the heat from reducing the steam from superheat to a saturated vapor as opposed to a full transition through the vapor dome to a liquid. Granted as long as the steam is used to keep the water hot, using steam at 1 atm will work well enough, it would just not be an efficient way to boil