Flash boiler

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What I hope GreenMonti can do is couple the boiler output to an immersion chiller in a pot of water and bring it to boil that way. This would be similar to the heating method used in some of the boil kettles I have seen in various breweries.
 
Its not quite as fantastic as what you guys have made. I was thinking of making a coil fashioned as such about 12 inches across and wind it in on itself.

http://thevinylvillage.files.wordpress.com/2008/12/lollipop.jpg

and attach it to the bottom of my HLT/keggle above the burner and run my incoming water through it to preheat the water.

Also I could run the water in the HLT through it to quickly raise the temp if needed. Would that help any, or would it be a waste of time?

Make any sense????

Didn't think so.
 
kladue said:
What I hope GreenMonti can do is couple the boiler output to an immersion chiller in a pot of water and bring it to boil that way. This would be similar to the heating method used in some of the boil kettles I have seen in various breweries.
Click to expand...



So how would I build the coil to try and get a boil? I am all for trying to get a boil to happen. Should I use 1/4" or a larger diameter? How many feet would be sensable?
 
If you have an immersion chiller it would serve as the heating coil, if not then 10+ feet of 3/8"-1/2" tube should be a start. Roll the coil like a tube and steam would start at the top and condensate would leave the bottom and go out of the kettle.
 
Making a flat coil and installing it under the kettle will help heat the water in the HLT, copper is a much better heat conductor than the SS kettle bottom. Only problem might be when recirculating the flow you will have high enough flow rate to not boil water in coil, it would be noisy from the popping sounds of steam bubbles forming and collapsing in the tubing. The only thing the coil might do is block the heat flow to the keg bottom and slow the heating rate if there is not enough coil surface area.
 
Changing this to a pressurized system would not be a wise idea. It raises the potential energy of the system by many times, and if you have a failure, it could be catastrophic.

Also, simply placing another burner under your boil kettle will be much more efficient than running an uninsulated steam line to your boil kettle and using a homemade heat exchanger.
 
Something to tinker with I suppose.

Not Pressurized.

Just take the inlet hose to your HLT coil it, place it over your burner, then continue on to your HLT, no pressure to contain.

Not looking to make steam. I suppose you could dial the flow back to create steam, more like a poor mans tankless water heater.
 
The steam coil experiment is to verify the practicality of using a single heat source in a homebrewing scale operation. Efficiency would not be the same as a direct fired kettle, but this method would lend itself to a vented combustion heat source for indoor brewing activities where electrical system limitations preclude all electric system designs.
Here is a picture of a boiler and BK vented combustion system http://picasaweb.google.com/kevin.ladue/WetTestProgressPhotoS#5225298796424700082
 
Cut a hole in the bottom of your HLT/keggle, weld a corny keg inside and seal the top off.

Run your coil up inside of it. Place the whole contraption on top of your burner.

You've got a a steam coil inside of your HLT.

Wrap your HEX for your HLT around the now intruding vessel.

How's that sound?

Or you don't even have to seal it off. Just plumb from the top.
 
any idea how hot your output steam is?

Keep in mind that to keep a pot boiling, you have to be condensing at least as much water as your boiling off and that is never going to happen unless your steam temperature is stupidly high*

*yeah there a couple other factors at work here, but the vapor temp will drop very quickly as the mass flow rate is very low
 
That is interesting, SS steam kettles seem to work quite well with 5 PSI steam at 222 degrees, the copper heat exchange coil should make for an even tighter approach temperature ~215-218 degrees for boiling. I have seen breweries use anywhere between 10 - 100 PSI saturated steam in thier steam jackets and calendria for boiling. The flash boiler can hit those temperature ranges at atmospheric pressure, delivering ~ 240 Lbs steam an hour. I would hope that boiling 9 Lbs an hour from the BK would be in reach of the boilers steam generating capability, only aspect not calculated is heat transfer from copper heating coil.
 
OK it is now running and I had some issues. I grabed my immersion chiller and it fit right on the boiler with a simple fitting change. The coil was at the bottom and the temp probe in the middle. After just 5 min I saw a temp increase from 60* to 142*. I would suspect this was just the convection of heated water flowing past the probe. Then, while looking at things, I saw the solder go liquid right in front of me. Oh no. I shut it down and saved a big Oops.

After some more mod work I have it running again. I cut some off the chiller and made the output better for the system design. It has been running 25 mins and I have gone from 50* to 191*. The output has changed from a lot of liquid to much more steam.

I will post up more in a bit. I hope it boils.
 
kladue said:
That is interesting, SS steam kettles seem to work quite well with 5 PSI steam at 222 degrees, the copper heat exchange coil should make for an even tighter approach temperature ~215-218 degrees for boiling. I have seen breweries use anywhere between 10 - 100 PSI saturated steam in thier steam jackets and calendria for boiling. The flash boiler can hit those temperature ranges at atmospheric pressure, delivering ~ 240 Lbs steam an hour. I would hope that boiling 9 Lbs an hour from the BK would be in reach of the boilers steam generating capability, only aspect not calculated is heat transfer from copper heating coil.
Click to expand...

With just a couple pounds of pressure, the sat temperature of the steam is higher than the temp required to boil the water so the steam can condense back to a liquid which releases tons more energy than keeping it in the same phase. If you condense all the steam, you are getting almost all of the energy out that went in.

Without that extra little bit of pressure though, you are going to have a very hard time recovering all the energy that went into making the steam though as you approach boiling as the water will not have any reason to condense as it will still be in the vapor dome. Once your below the saturation temperature though, you can recover all of your energy.

If you could attach some sort of relief valve, such as one from a pressure cooker to the end of your heating/cooling coil perhaps, as a vent for condensed water, you would probably have a much easier time getting to a boil.

wait, wait, 240lbs of steam an hour from this thing?!?!
 
GreenMonti said:
OK it is now running and I had some issues. I grabed my immersion chiller and it fit right on the boiler with a simple fitting change. The coil was at the bottom and the temp probe in the middle. After just 5 min I saw a temp increase from 60* to 142*. I would suspect this was just the convection of heated water flowing past the probe. Then, while looking at things, I saw the solder go liquid right in front of me. Oh no. I shut it down and saved a big Oops.

After some more mod work I have it running again. I cut some off the chiller and made the output better for the system design. It has been running 25 mins and I have gone from 50* to 191*. The output has changed from a lot of liquid to much more steam.

I will post up more in a bit. I hope it boils.
Click to expand...

as a thought, do you have a tube on the output of the coil? you could submerge it in a long piece of pvc or something sort of like a giant blowoff so you can get a couple feet of head pressure on the outlet if your pump will allow it. 4' of head pressure will bump your steam temp to ok, only 216, so not much more... if would also give you a steam pressure of about 16.1psia

thats kind of dissapointing actually
 
Yep, 4 Lbs a minute is a conservative estimate based on the ability to boil .5GPM water at less than 100% firing rate.

The steam temperature to soften the solder would have been ~430 degrees, only the lower part of the boiler is generating steam, the upper half is superheating it, sometimes too much. I have hit 500 degrees in a SS coil boiler of identical design, not by intent but during PID loop tuning.
 
Ok, I thought I read somewhere that it ended up being like 2 gallons an hour... not sure where I got that.

or is it 4lbs/min of boiling water or 4lbs/min of steam?

233000BTU or so would be needed to convert .5 gal/hr to steam not accounting for losses to atmosphere or cold water
 
My apologies, I am way too optomistic, a conservative number would be .25 GPM, the .5 would be above the current burner rating to turn all the water into steam. The heat required for .5 GPM would be 284,427 BTU's, half that for .25 GPM which would generate 126 Lb steam an hour should be sustainable.
 
Ok I am done. I hit a wall and could not get past.

The outside temp is 47*. I was using an alum pot to do the boil test in. I think my chiller is 3/8". I had about 6.5-7 gallons in the pot. I first started the test off at 4oz a min. I can't say where things ended up after that. So, 4oz a min and a very low flame. After the last go I was trying to be carefull not to undo the solder again. So I ended up at the same numbers I put up eairlier. From 50* to 191* in 25 mins. I could not get past 196*. I tried several different settings. I can't say for sure what the input steam temp was at any time since the setup wasn't setup that way. No matter what I did the output steam temp stayed 210*.

I can get the mesurement of the total run and the coil length to you if you would like. None of it was insulated. Not even the pot.

This is the setup when I first went for it. The hose you see attached only goes about 10'. It was just there to keep the splashing off the boiler. This is the setup I lost the solder on. It came undone on both side of the 90.
P1010102.jpg

P1010103.jpg


The chiller was then cut down (probly by half) and the pot was moded. No back pressure on this setup.
P1010104.jpg


A shot of how it was blowing on the output.
P1010106.jpg


Since I can't say for sure how high the flame was, here is a pic of it. It was not up very high. The tips of the flame is about 1 1/4" above the top of the burner.
P1010105.jpg



As I mentioned before, at .5 GPM the boiler will sit and shutter like it is boiling inside. I get a mix of steam and water on the output without being placed in anything. No back pressure.
 
That was a good test, it appears that it will take some time to finish adding the necessary heat to transition the water in the pot to boiling. About 14% of the heat is used to raise the water to 212, the other 86% is needed to boil the water. It appears that it is going to take at least 52 lbs of steam to boil off one Lb of water, probably more as heat loss through pot walls will be a factor. The short answer to this problem will be it takes time and a lot of surface area to pass the heat needed to boil quickly, superheating will help as the higher temperature difference increases heat transfer. This method appears to be more suited for water heating as not as much steam is needed to just raise the water to strike temperature (14% of total). The temperature plateau you experienced was the point where the other 86% of the energy had to be absorbed to start the boiling process. If you were patient it would have reached that point eventually. For boiling it appears that the brute force burner under the pot is the fastest method.
 
210 may very well be the saturation at your altitude. What is happening is that your steam is cooling and condensing inside your coil and you will have a mixture of both liquid water and steam. When you have a mixture of water and vapor, you can not get it any hotter or colder until its all gas or all liquid. Ideally, you will have 100% water at the saturation temperature as this would be the point where your pot could only get colder. If you are staying reasonable below this temperature maybe 20º or more, you should have more than enough available heat to remain at that temperature. If however, you want a higher temperature, the only way to do this would be to increase the steam pressure, which is inherently dangerous. The higher the pressure, the higher the saturation temperature which will ensure a total phase change from gas to liquid recovering all 790BTU/lb of energy that went into converting the water to steam.

The bubbling that you heard when you cranked up the flame on the boiler was the water boiling then re condensing as it was exposed to the slightly cooler water around it.

As Kladue mentioned earlier, there are steam kettles that will boil just fine at 5 psig but they are jacketed and have a very large surface area. at 5psig, your saturation temperature is around 227 which will boil water, but you need enough surface area for heat transfer which is why the jacket works well. you could boil water with just steam but in order for it to boil, the exit temperature has to be more than 212º which is almost not possible at atmospheric pressure. Granted, it could be done if the steam is moving at a very high rate and was at an extreme temperature, but that's very unreasonable.

If you want it to boil water, your going to have to increase the pressure otherwise you would probably be better off using the steam to heat the water to 200º or whatever it will reach and supplement with a 500w or 1kw heat stick to kick it over to boiling as 25lbm water per hour steam that inst condensing is about 500 watts assuming a starting temperature of 400º, only 1690 BTU/hr

edit: what kladue said^

edit edit: would it be difficult to attach a pressure cooker type valve to the end? if you do this though, it would be releasing boiling water so you want to keep it from spraying all over
 
The .5 GPM flow is more than the boiler can turn entirely into steam and the boiler is making a lot of racket, about half that should be able to completely convert to dry steam. The design of the flash boiler makes it possible to add heat to the vapor phase of the steam in the upper reaches of the coils, the boiling phase is in the lower level of the boiler. This makes it possible to reduce the water flow into the boiler to a point where the actual boiling is in the lower 2-4" of the coils and the upper reaches are heating the steam well above the saturation temperature for that pressure. The upper superheat temperature limit is a function of the materials used for the boiler and the burner firing rate, 500 degree steam is not hard to achieve in this design, practical , not really, better to flow more pounds of steam at a lower superheat than superheat to high temps. The original use for the flash boilers I have built was to heat water and directly inject the steam into flowing liquid for wort heating, not boiling.
 
So based on what I am reading, The reason I could not get any higher then 196 is due to the fact that the output was open and the system had zero back pressure, right? So my saturation temp is very low.


Never the less, in a mash enviroment this thing will boost temp to what ever I want in no time. Mash has half the volume and a bit more density then just plan water.

If I wanted to run steam through a coil in the kettle I could raise the temp while firing the kettle and get a boil in just minuets. At least that is how it would appear. If I wanted a perment immersion chiller in the kettle, I could make it so I could run the steam through it to get the kettle up to temp.

I do wonder about the 5-6 ish feet of uninsulated copper being exposed to 47 degree air, sucking some life out of the steam?

In the idea of what I just tested, if this was a somewhat closed loop. Meaning I captured all the output to an open top tank. All that tank water would raise in temp and require less energy to acuire the same steam temps. I am wondering if a coil in the mash tun is a better way to go? No dilution and less energy to reheat the same water being used. An open top resivor would not allow any pressure to build in the system.
 
Without water quantity control the coil in the mash tun would be the method of choice, with water quantity control direct injection offers tighter control. The water source can be entire water needed, or divided into strike water first, then refilled for balance of water needed. The boil test was a good test, water warmed quite quickly as steam condensed, as water and steam temperatures got closer to each other the condensation dropped and heat transfer dropped off quickly. If you plan to use a coil in the mash tun then heat from the coil will have to be redistributed by stirring or recirculation of the wort just like when you direct fire a mash tun.
 
kladue said:
Without water quantity control the coil in the mash tun would be the method of choice, with water quantity control direct injection offers tighter control. The water source can be entire water needed, or divided into strike water first, then refilled for balance of water needed. The boil test was a good test, water warmed quite quickly as steam condensed, as water and steam temperatures got closer to each other the condensation dropped and heat transfer dropped off quickly. If you plan to use a coil in the mash tun then heat from the coil will have to be redistributed by stirring or recirculation of the wort just like when you direct fire a mash tun.
Click to expand...

The water warmed very fast IMO.

Can you break it down in laymans terms? How does one get the condensation rate to stay high? Do I add pressure? Could I add pressure, say 5lbs? If so, could I just use a rocker off of a pressure cooker?

Based on the setup I did, How do I improve on it? Am I thinking correctly on the loop idea?
 
Ok, I reread the posts. Based on what I have seen and just reread. I think I got it now.
 
GreenMonti, you're dealing with a unique property of water (water is actually an amazing chemical) in that it takes as much energy to raise water from 1 degree C to 100 degrees C as it does to raise it from 100 degrees c to 101. Basically, the phase transitions of water require a huge amount of energy.

I've been thinking on how to integrate the steam mixer into the system and I'm worried about wort flowing back through the mixer screen and into the flash boiler. Provided that I don't disconnect the water input, this won't happen right?

I'm thinking I can dough in via the flash boiler and step mash also. All I'll need is a mash tun outlet valve, a boiler inlet valve and a boiler outlet valve in the entire system (ignoring the faucet and gas lines). Is this correct?
 
I am running again right now and I am very close to a boil. I will let you all know if I get to boil.
 
Ok, I am done for the evening. I would like to continue but I have to wake at 3 AM.

I was able to get my steam output to 216-220 degrees. That is after the coil. The magic flow was 1 pint or 16oz a min. The boiler was at max fire.

I think I need more surface area to achieve a rocking boil. I had to lid up on the pot to get it to heavily simmer. You might call it a boil.

The next test will have my other idea in place about capturing the output in a container and re-pumping it through the boiler. This should reduce the drastic up take of heat on the incoming water. It will also help the water bill.:D

Oh yea, I quickly insulated the steam line with a couple shop rags and a canvas painters tarp. The outside temp was 48 degrees. The test was done in the same thin wall alumn pot, uninsulated. I will get total gallons a little later.

Here is a quick video of the simmer/boil. You can see it got dark on me.
 
Farside said:
GreenMonti, you're dealing with a unique property of water (water is actually an amazing chemical) in that it takes as much energy to raise water from 1 degree C to 100 degrees C as it does to raise it from 100 degrees c to 101. Basically, the phase transitions of water require a huge amount of energy.

I've been thinking on how to integrate the steam mixer into the system and I'm worried about wort flowing back through the mixer screen and into the flash boiler. Provided that I don't disconnect the water input, this won't happen right?

I'm thinking I can dough in via the flash boiler and step mash also. All I'll need is a mash tun outlet valve, a boiler inlet valve and a boiler outlet valve in the entire system (ignoring the faucet and gas lines). Is this correct?
Click to expand...


I can't say for sure as I have not had the boiler on line yet. (In a mash or a recirc line) I have had the same thoughts of back flow through the diffuser. While the system is producing I can't see this as being a problem. But there will be times when the steam isn't needed. My thoughts to combat this, was to run the steam input from the top of a T fitting. I plan on running it up for a few inches and then back down to the boiler. Maybe Kladue can comment on this.

I am not sure I follow your last statement. The boiler will provide me with the strike water(what ever temp I want), the steam to do my steps in the mash, and the sparge water for the fly sparge. My drain will go to a pump so the pump can put it back on top of the grain bed where the steam will be injected right before the sparge arm. I will then use the same drain to go to the kettle and up the water flow throught the boiler to give me hot water not steam through the same sparge arm. This will clean/rinse the sparge arm while giving me the sparge water. I will not have a HLT.

After a few more tests I may not have a direct fired kettle.:D
 
I have incorporated a check valve on the boiler outlet to prevent reverse flow on the new system. On the old system I killed the burner and let the boiler refill for about 30 seconds with water to prevent back flow as steam condensed. When you refire for sparge the hot water cleans any residue out of the upper reaches of the boiler. It appears that the steam will bring the pot to a boil but the limited surface area of the coil makes that a slow process, more practical to use a burner and dump more heat into pot to boil.
Valving for the system should be water into boiler, mash tun outlet pumped wort to boil kettle valve, and pumped wort to mixer/sparge ring valve, no manual valve on boiler outlet to prevent pressurization of boiler.
 
Kladue,

What check valve do you recomend? I imagine they're expensive due to the temp.
 
Let me check my spare parts stock at home next weekend and I should have a swagelok check valve spare for you to use. I might get some tuning time on the new system after some plumbing repairs from freezing weather in december.
 
kladue said:
Let me check my spare parts stock at home next weekend and I should have a swagelok check valve spare for you to use. I might get some tuning time on the new system after some plumbing repairs from freezing weather in december.
Click to expand...


That would be SWEET. I checked the other package and it is in OR right now. They say I have it tomorrow.:ban: Thanks again.


That's a bummer about the plumbing. I hope it isn't too awfull bad for you. Let us know if you get to do some tuning on your rig.
 
If you want a challenge try directing SWMBO through shutting off the water service at the street and capping a 1/2" PEX water supply line over the phone from over 1,000 miles away. Then explaining which fittings to buy and which tools to use to assemble and install a cap on the end of the damaged line. Fortunately the water did not hit any of the electrical or control system components, just ran on the floor to the drain and out the door as the inside walls are still not finished yet.
 
kladue said:
If you want a challenge try directing SWMBO through shutting off the water service at the street and capping a 1/2" PEX water supply line over the phone from over 1,000 miles away. Then explaining which fittings to buy and which tools to use to assemble and install a cap on the end of the damaged line. Fortunately the water did not hit any of the electrical or control system components, just ran on the floor to the drain and out the door as the inside walls are still not finished yet.
Click to expand...



LOL. It's not funny but it is. :tank:
 
I ran the boiler again today. I was testing the ability to boil again. I first ran it with a newly wound coil for the heat exchanger. I rewound it at a 4" diameter. All still worked out just fine and I was able to boil.

I then rigged up a simple rig to run the condensate back through the boiler to make it more energy effi. While it worked ok, it needs some work. I was able to boil with this setup, and it did so at about 1/2 fire opposed to full fire. Better fuel consumption for sure. But it didn't run smoothly. It shimmyed and bounced around a lot. It has been suggested that the preheat coil I added is the cause of this. The already hot water comming into the boiler is boiling before it enters the lower section of the boiler, which is where we want the boil to happen. Oops. Kladue was nice enough to point this out to me.

As it stands I am able to bring 6 gallons of water from 47* to a boil in 30 mins on a 45* day. In a brewing situation I should be able to boil in 15-20 min. Not too bad. I am torn on wether or not to use the boiler as a heat source for the boil. The mash side of things is sealed in stone, It will be used. No question.
 

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