Boiler for boiling

[MadViking]

I've tried searching the forums and haven't found the right answer to this question, but has anyone tried using a boiler (either electric or flash) to generate steam in a closed loop, pressurized system to boil the wort?

I work at a refinery in a unit that has three 600# steam boilers. These boilers work by thermocycling water through piping in a waste heat duct. Basically, cooler water flows from the bottom of a steam drum down through the piping in the waste heat duct picking up heat and turning the water to steam and then the steam goes back into the top of the steam drum. A pressure controller allows the steam to escape the steam drum.

What I'm thinking of is trying this in reverse. Using a keg as a boiler, generating steam that flows through copper tubing in a boiler kettle. This steam would lose its heat to the wort, collapse into condensate and return to the boiler. The low pressure area where the steam collapsed to condensate would allow steam to flow into that area, thus creating motion of steam from the boiler to the brew kettle.

We all know that steam carries a tremendous amount of heat and with enough motion can transfer that heat quickly. I'm just curious if anyone has tried this or something similiar and if so, what kind of times did you get for boiling?

And really, it's not a matter of if it's more effecient or effective, it's just that I like to play and say that I did it.

Oh, and with any piece of equipment that has that much potential, all the correct safety fittings, relief valves and monitoring devices will be installed first.

 

[WrongCoastBrewery]

I work in a similiar enviroment. To be honest, thats a bit overkill. You would need a lot of piping, a few pumps to get the water back to the kettle, and a heat exchanger to handle it all. Steam that is at atmospheric pressure has little to no real heat retention. Plus, you would need to make the heating system be able to handle a relatively higher pressure than what you might be thinking. You might find this to be tougher to do and more time consuming. You would probably need to superheat the steam, which means higher pressures. Why heat a kettle to boil water to heat wort when you just need to boil the wort. With the system you are thinking about, your efficiency (and I mean Steam Cycle efficiency) would be in the crapper. Even if you were to build the system, you other concerns would be heat losses to ambient prior to the wort heat exchanger. Then what about when you want to steep things? It sounds cool, but not realistically viable.

Here is some hard data to show you what you would need in terms of system specs: Estimating heat losses of 50F, you would need a saturated steam temperature of say, 262 degrees. Your steam pressure would need to be somewhere in the 25-30 PSI and you would need to be able to produce a constant 933.7 BTU/hr to make the latent heat of vaporization to get your system to boil wort. Granted, the BTUs isnt the problem. It would be the pressure you would need to get the steam temperature to boil wort.

 

[MadViking]

It actually wouldn't be hard to put together. Build a pressurized boiler to produce the steam (which I was going to do in the first place to heat the mash), drop a set of copper coils in the brew kettle, connect the boiler outlet (steam out) to the coil inlet and the coil outlet to the boiler inlet (condensate in), heat up the boiler and away I go. There is no need for pumps because the steam will flow via thermocycling; that is the steam collapses to condensate, the resulting collapse of steam creates a low pressure area that more steam from the boiler will fill thus creating low pressure in the boiler which is fill by the condensate. This is how our boilers operate, no pumps. The whole shebang would be controlled by controlling the heat source, which in my case will be an electric heating element, which is controlled by a thermocouple in the wort. It wouldn't be that different than having a steam jacketed brew kettle, it's just that the jacket is really a coil in the kettle.

 

[WrongCoastBrewery]

The question is why would you? Steam is a vapor and therefore you cant "pump" it. However, when the steam flows from the HP source to the heatsink, which is at LP, there is flow. This is just basic thermodynamics and fluid flow. However, how do you propose the get the condensate back to the "boiler"? Unless you use a pump, the expansion of the water and the pressure build up from the boiler will send water back through the system and it will equilibriate at the boiler temperature. Only way to get around that is to put the wort heat exchanger at a high enough heigth the the pressure created would overcome the boiler pressure. Plus you would need something to collect the condensate like a well. Yet again, I come back to why? A burner and a good CFC will more than adequately do the job. Steam jacketed kettles are usually large and require a big heat source. They usually are either gas or electrical, which requires a bigger electrical source. All they really are is nothing more than boiling water inside a kettle which requires to be filled every now and then. Even in electrical plants they still have to fill their systems every now and then from expansion tanks. Larger steam kettles actually have a steam source and the condensate is pumped back to the heat source. The more heat that is required, the more pressure in the boiler. Therefore, a pump is needed to overcome that pressure to send condensate back to the boiler.

You say that you are going to also create a boiler to do the mash? Yet again, why? How will you use boiling water and saturated steam to maintain temperaures at 150-160F?

I disagree this would be easier and more efficient than the tried and true methods of fellow homebrewers. While it sounds cool, its WAY overkill and I would go out on a limb and say you will end up spending hundreds of dollars to do this. Even if you have equipment and materials handy, it still would be more of a hassle to run besides the afore mentioned burner and CFC.

I guess maybe I fail to see your design unless you are just going to let the condensate drain away and not re-use it in a closed system. In that case, thats another loss of efficiency.

 

[GreenMonti]

I've tried searching the forums and haven't found the right answer to this question, but has anyone tried using a boiler (either electric or flash) to generate steam in a closed loop, pressurized system to boil the wort?

Yes, I have. I was successful too. I used a flash boiler to accomplish the task. Despite the other view, I was able to get about 65% eff, out of my DIY steam setup. That beats the pants off of direct firing a kettle. I can't match electric yet, but I hope too. (Yea right,lol) I have boiled with copper coils, a condenser unit, and jacket-ting a keg bottom.

One nice thing about steam IMO is the temp of it. You won't ever scorch your brew. Providing you keep the steam temp under 300. I was able to boil with only about 10 PSI. That keeps it in the realm of not needing a pressure cert. My project has been on the "shelf" for a while but, IIRC I was using 2-3 GPH flow through the FB. I used a cold intake and let the condensate go to waste. I have built and run a recirc setup prior to the setup I'm speaking of. My build, uses a keg as the kettle. I'm closing in the bottom skirt area in, for the steam jacket. I did a test of this and it worked well for my needs. My FB is a copy of Kladues FB. I used copper instead of the SS that he used.

I'll also use the steam for mash temps. I plan to directly infuse the steam into the mash. Also another idea of Kladue. My setup when done, will be a single heat source brewery. I will heat my water on demand, make steam for the mash, and then boil with the steam.

 

[WrongCoastBrewery]

Yes, I have. I was successful too. I used a flash boiler to accomplish the task. Despite the other view, I was able to get about 65% eff, out of my DIY steam setup. That beats the pants off of direct firing a kettle. I can't match electric yet, but I hope too. (Yea right,lol) I have boiled with copper coils, a condenser unit, and jacket-ting a keg bottom.

One nice thing about steam IMO is the temp of it. You won't ever scorch your brew. Providing you keep the steam temp under 300. I was able to boil with only about 10 PSI. That keeps it in the realm of not needing a pressure cert. My project has been on the "shelf" for a while but, IIRC I was using 2-3 GPH flow through the FB. I used a cold intake and let the condensate go to waste. I have built and run a recirc setup prior to the setup I'm speaking of. My build, uses a keg as the kettle. I'm closing in the bottom skirt area in, for the steam jacket. I did a test of this and it worked well for my needs. My FB is a copy of Kladues FB. I used copper instead of the SS that he used.

I'll also use the steam for mash temps. I plan to directly infuse the steam into the mash. Also another idea of Kladue. My setup when done, will be a single heat source brewery. I will heat my water on demand, make steam for the mash, and then boil with the steam.

When I was talking efficiency, I was talking steam cycle efficiency. However, I am curious about this since I work in closed loop HP steam systems to generate electrical power and propulsion. Could either one of you show me the system via diagram or pictures?

 

[GreenMonti]

When I was talking efficiency, I was talking steam cycle efficiency. However, I am curious about this since I work in closed loop HP steam systems to generate electrical power and propulsion. Could either one of you show me the system via diagram or pictures?

I don't have many pics anymore. I would have to take some. I can show you what I have left though.

This is the heart of the boiler. Its going though a mod here to get more out of it. The water enters the outer coil on the bottom, then goes into the other set of coils at the top. The now pre-heated water goes to the bottom and splits off into the 4 coils. That's where it turns into steam.

This is an early pic of it. You can see though that the coils are inside of the chimney pipe. I'm using a simple burner on the bottom of it.

This is the keg I welded the skirt shut on. It was a down and dirty job, just too see if it would work.

This is where the steam entered the jacket. You can just see the top of my steam temp gauge.

This is the boil I got from it. There is 8 gallons in there IIRC. The corney keg is feeding the boiler to produce the steam. You can hear my burner hissing in the back ground.

 

[GreenMonti]

This is another short video. I was just shooting the even heating on the bottom of the kettle.

 

[WrongCoastBrewery]

Interesting. I must admit I wouldnt do it this way since it seems overkill to me. I guess I am old fashioned that way. Plus, having to do this on a very much larger scale at work leads me to not want to do that at home.

 

[GreenMonti]

Interesting. I must admit I wouldnt do it this way since it seems overkill to me. I guess I am old fashioned that way. Plus, having to do this on a very much larger scale at work leads me to not want to do that at home.

I can understand that. I myself like to build things. Things I can't afford. Overkill.........you bet. With a fair size cool factor IMO. A lot of the things built on here are overkill. The fully automated setups, ect.

I have had thoughts of my first setup. How simple it was. I enjoyed the beer it made too. Very much so. It must be the American dream. To own the biggest, nicest, brightest, credit card bill. LOL

 

[WrongCoastBrewery]

I can understand that. I myself like to build things. Things I can't afford. Overkill.........you bet. With a fair size cool factor IMO. A lot of the things built on here are overkill. The fully automated setups, ect.

I have had thoughts of my first setup. How simple it was. I enjoyed the beer it made too. Very much so. It must be the American dream. To own the biggest, nicest, brightest, credit card bill. LOL

LOL. Yeah, I myself like to make sure I always have the coolest brewing toys. Already planning my build of lauter and mash tuns. Here is overkill for ya.....I am already eyeballing a welder just to weld brewery stuff. Hell, I could just solder everything, but why?

 

[GreenMonti]

LOL. Yeah, I myself like to make sure I always have the coolest brewing toys. Already planning my build of lauter and mash tuns. Here is overkill for ya.....I am already eyeballing a welder just to weld brewery stuff. Hell, I could just solder everything, but why?

Ha,Ha. Now you sound like a home brewer. OhioEd is in the same boat as you. He just picked up his welder.

 

[MadViking]

This is the idea that I was going with for a boiler setup to boil the wort;

Essentially, I would use a thermocouple in the wort to control the heating element in the boiler. If the wort needed more temperture, it would keep heating the water in the boiler, creating pressure and generating even more heat in the process. There would be a high pressure switch that would cut power to the heating element if the pressure got too high. Also, there would be a pressure relief valve.

As the steam moves to the the coils in the wort, the cooler wort would cause the steam to collapse into condensate which in turn creates a low pressure area where the steam was (for those who don't know, steam takes about 1600 times more space than water). Two things happen now at the same time; 1) the steam now pushes into the area of low pressure and 2) the cooler and heavier condensate drains back into the boiler. When this happens, motion is started that allows the steam to flow from the boiler into the coils in the wort and then back as condensate. It's this motion that allows the wort to heat up. Sure, the water level will reach an equilibrium, but there will still be motion because of the temperature differential between the boiler water and the condensate created in the coil.

This is the design of the boilers that I deal with at work just in reverse.

This can also be used to heat the mash the same way, it's just that the pressure in the boiler would be regulated lower because the mash needs less heat than the boil.

The diagram is very simplified, but gives you an idea of what was going through my head. Again, it's not that I have/need to build something like this, I just want to because I believe it's in the nature of the homebrewer to experiment and try new things. Plus, I like to build things.

Cheers
Mad Viking

 

[MadViking]