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kladue said:
I have taken a look at an orifice chart for high pressure and after a couple calculations I figured out the BTU output and LP flow rates for various pressures. It looks like the flowmeters sent are a bit too small so I will look into aquiring correct size units for testing.

5 PSI LP......53614 BTU's...21.45 CFH...10.12 LPM
10 PSI LP....75822 BTU's...30.33 CFH...14.31 LPM
15 PSI LP....92863 BTU's...37.15 CFH...17.53 LPM
20 PSI LP..107229 BTU's...42.89 CFH...20.24 LPM
25 PSI LP..119886 BTU's...47.95 CFH...22.63 LPM
Flow was based on 2500 BTU/CF LP gas
PSI/BTU's were derived from #56 sized orifice chart
I hope this helps with input heat calculations for boiler
Click to expand...

I setup for a test run for gas usage. This is the best I can do.

1 Full turn on the reg = 2.5 Psi
1.5 Turns on the reg = 7 Psi
2 Full turn on the reg = 11.5 Psi
3 Full turns on the reg = 22 Psi
With the water tank up to temp (200*) I am able to boil plenty hard running the reg open 1 full turn. I can't see the need to run the fire any more hot when running the steam for the mash, so I decided to run it for 1 hour at the 1 turn or 2.5 Psi. After the hour my scale says I used 1 lb of propane. I don't have access to a very good weight scale. I used my bathroom scale. It is a digital and it reads in .5 lb increments. I feel the the use of 1 lb an hour is close enough cause I did weigh it every 5 mins during the run. Right on the half hour mark I lost .5 lb.

Just for kicks here is how I had it setup and how I got the Psi readings.
P1010018.jpg

P1010017.jpg
 
kladue said:
After looking at the test run results and doing some calculations it appears that the heat transfered with the steam system is nearly 10 times the expected output of the 4 KW electric element. While this heating system approach is not for everyone it appears to be a viable way for a DIY'er to build a system with a single heat source that will give results that are beyond the reach of the current electric systems. With a bit of engineering and design work this could be integrated into a brew system to handle strike water heating, step mashing, sparge water heating, and finally boiling. Scalability of this boiler and calandria design would make it a viable heating system for the 55 gallon drum systems that need more heat than direct fire burners can easily provide. With the ability to heat water to strike at 2.5+ GPM with current design, and deliver 156.9K BTU's/hr to the water for boiling it almost is overkill on 1/2 barrel systems.
Click to expand...

EDIT:
Read this wrong. This is impossible, I think. 10x the output of a 4kW element? That is 40,000 watts? That would effectively boil 12 gallons, from 50F in 7 minutes. Where is this math coming from? 10x the output of a 4kW element is 136,000 BTUs, Monti is posting that he is netting about 25% of that.

Monti posted a few times about 40 minutes to reach the boil, that only requires 16,000 BTUs from 50F, in 40 minutes that means you effectively have a 24,000 BTU heater there, in 14 gallons it is like a 27,000 BTU heater.

How can this be used on a 1/2 barrel system, how many gallons is that?
 
willynilly said:
EDIT:
Read this wrong. This is impossible, I think. 10x the output of a 4kW element? That is 40,000 watts? That would effectively boil 12 gallons, from 50F in 7 minutes. Where is this math coming from? 10x the output of a 4kW element is 136,000 BTUs, Monti is posting that he is netting about 25% of that.

Monti posted a few times about 40 minutes to reach the boil, that only requires 16,000 BTUs from 50F, in 40 minutes that means you effectively have a 24,000 BTU heater there, in 14 gallons it is like a 27,000 BTU heater.

How can this be used on a 1/2 barrel system, how many gallons is that?
Click to expand...

A half barrel system is a standard sanke. 15.5 gallons.
 
kladue said:
If you are turning 3.1 Lbs/minute of water to steam in boiler and then back to water in kettle the heat transfer would be around 52Kw.
Click to expand...

You are right, but I have yet to see any numbers that support that claim.

With a 170,000 BTU burner, you would have to be getting about 106% eff. from that burner to do so. This makes the assumption that the water you are making into steam is already at 210F... which in Monti's case it is not. If your boiler inlet water is 170F, you need to add 124 BTUs per minute to reach boiling, this in addition to the 3007 BTUs/min to create the steam, for a total of 3131 BTUs/min. or 187,860 BTU/hr

You would also be heating 14 gallons in the kettle from 50 to a boil in 6 minutes.

So it is not coming close to that number of actual transfer, because 170,000 BTUs cannot create that amount of steam, it is mathematically impossible.

The burner may be producing nearly 170,000 BTUs, but that is irrelevant, what is relevant is what is making it to the kettle, and Monti's testing so far indicates about 28,000 BTUs making it to the kettle, that is 8.2kW. Unless I am missing something, which is possible...

14 gallons
117 pounds water
Temp rise of 160F
Time to do so 40 minutes
BTUs needed to reach the boil: 18,720
18720/40(time to reach boil): 468BTUs per minute
468 BTUs/min x 60 minutes: 28,000 BTU/hr or 8.2kw
 
What is not known is how much the nominal burner rating is being exceeded as the steam rate indicates a firing rate in excess of the manufacturers nominal 170,000 Btu's rating. I wish I were able to use the hardware on my new brew system as the gas flow is controlled with a massflow controller and actual Btu's into burner can be measured along with actual water flow and temperatures. For now all we can measure is the water flow and steam temperature for a means of heat output from the boiler, actual burner firing rate can only be estimated from inlet pressure and orifice size. With only liquid condensate leaving the kettle it would be assumed the phase change has released the 970 Btu's/Lb into the water of the kettle, otherwise you would live steam blowing out the condensate connection.
 
I know what you are saying... with the steam creation...

But you cannot claim 52kW of heating power when it takes you longer to boil 14 gallons than it takes me with 9kW. If you have 52kW of power, then you are boiling in 6 minutes, not 40, those numbers will never lie. You can assume that you are getting 52kW of heat energy to the kettle, but the actual numbers do not support this assumption in the kettle. If this system is 52kW of energy, then my electric heater is even more powerful than that, I can assume. But that is a silly assumption as the heat is not present in the kettle.

Everything else aside, the end result is what matters, and there is certainly not 52kW of heat energy getting to that kettle. There is MUCH less, right? If you actually have 52kW of heating power, why is it so slow to heat? He is netting 8.2kW and on the front end you are claiming 52kW of energy at your disposal... this is 15.7% efficiency from the system, which is worse than simply placing a burner under a kettle.

Also, lets assume that the burner is derated to a degree. You are still losing A LOT of BTUs from that boiler (exhaust from the top and radiating heat from the walls of the chamber) To get a NET of 187,000 BTUs you would need to start with comfortably over 200,000 BTUs gross.

If we want to stick with the idea that there is 200,000 BTUs being created by the burner, that means that in the 40 minutes it takes Monti to reach a boil you are burning 6 pounds of propane?

The thing is, it is REALLY easy to determine the output of the burner, but I don't think Monti has done it yet.... just crank it up for a specified period of time and weight the cylinder. He already knows that his NET heat is 8.2kW, if he nails down the GROSS heat potential then he can get a real eff. #.
 
Lets try this calculation out,
14 Gallons * 8.34/Lbs Gallon =116.76 Lbs
50 degrees raised to 212 degrees = 162 Degree delta
162 degree delta * 116.76 Lbs = 18,915 Btu's
116.76 Lbs *970 Btu's = 113,257
Total Btu's to reach boil 132,172
Heat input to the kettle rate 3007 Btu's/Minute
Theoretical time to boil 132,172Btu's/3007 Btu's = 44 Minutes

That seems to be close to what was actually observed in operation and is consistent with steam generated and liquid condensate leaving kettle which indicates phase change is complete inside kettle. What is not covered is heat losses from kettle during heating or actual burner firing rate.
 
kladue said:
Lets try this calculation out,
14 Gallons * 8.34/Lbs Gallon =116.76 Lbs
50 degrees raised to 212 degrees = 162 Degree delta
162 degree delta * 116.76 Lbs = 18,915 Btu's
116.76 Lbs *970 Btu's = 113,257
Total Btu's to reach boil 132,172
Heat input to the kettle rate 3007 Btu's/Minute
Theoretical time to boil 132,172Btu's/3007 Btu's = 44 Minutes

That seems to be close to what was actually observed in operation and is consistent with steam generated and liquid condensate leaving kettle which indicates phase change is complete inside kettle. What is not covered is heat losses from kettle during heating or actual burner firing rate.
Click to expand...

So, you are telling me that with a 9kW element, at 30K BTUs, using your logic, that it will take me 4 hours to reach a boil? That is how long it would take me to input what you just calculated

This is your problem...

You are doing the math incorrectly. It doesnt take 970 BTUs per pound to BOIL 117 pounds of water... it takes 970BTUs to create a pound of vapor... or as we say, boil off a pound. So your calculation assumes that you are creating 117 pounds of steam, which is a gross miscalculation. You are only creating about 12 pounds of steam per HOUR in a typical boil.

I can boil this same amount, slightly faster, with only 9kW. So if you have 52kW, why am I heating faster?

It only takes 18,954 BTUs to reach this boil that you created... not a whopping 132,000. You think you have a lot of heating power, because you are grossly overestimating the BTUs needed to reach a boil.

I can prove this mathematically and through practical use of my kettle. I have 9kw, 9,000W or 30K BTUs

14 gallons from 50F to 212F (boil) takes 39 minutes.
This is an input of ONLY 20,000 BTUs
It takes 18,954 to boil this volume, the rest is lost to radiant heat losses etc.

It then takes me 4kW to maintain about 1.5g/hr boil off
1.5 gallons is 12.5 pounds
12.5 pounds of vapor in an hour requires
970 BTUs x 12.5 pounds = 12,125 BTUs
MY INPUT is 13,648 BTUs, the difference is lost to radiant heat loss etc.

These are not assumptions, these are hard numbers from real world boiling. BTU output of an electric heater is easy to control, which makes it much easier to get data, there are no assumptions here.

I create 33,648 BTUs to reach this boil from 50F to 212 AND to boil off 1.5 gallons, TOTAL. That is a total of 9.8kWh of energy only, at a cost of $1.18 You are claiming that it requires 132,000 BTUs JUST to reach the boil, at a cost of $5.46, which is incorrect.

Your assumptions and calculations are off, this is what is giving the illusion of 52kW of heating power in the kettle.
 
Yeah, the 113257 BTUs you have listed would be the amount of energy need to convert the entire 116 lbs of saturated water to saturated steam. The conversion process is what we consider boiling typically as its when you get the pretty bubbles and stuff.
 
I guess the definition of a boil is confused here, the electric element boil is like the dropping of a piece of red hot iron into cold water, the water boils around the iron because of the high heat flux, but the rest of the water is not heated to boiling. The lower temperature steam heat source we are using diffuses more heat into the water before the localized heat source generates the steam bubbles that signal boiling. It might be enlightening to work out the surface temperatures of the 4500 watt elements and the relative heat transfer rate into water, this might explain the steam bubble formation on the surface of the elements at full power before the total energy balance is reached. In the end does it matter?, the hop acids isomerize, evaporation is removing the required amount of water, and beer is made.
 
We are all making beer, but the 52kW claim is wholly false, as it only takes 19,000 BTUs to reach a boil in 14 gallons. The only question is how long does it take you to get that 19,000 BTUs into the kettle. It takes Moni 40 minutes, it takes me 39. I dont know how else to say it, but it is true. I just want the correct information out there.

Your calculation assumes that all 117 pounds of water are being converted to vapor, your kettle would be dry. This is the largest hole in your theory.

Your claim about flash boiling around the element with electric would be plausible, but it only takes me 39 minutes to get 19,000 BTUs into the kettle, (30K BTU/hr) which is all that is required to hit boiling temps. FWIW, I do not get bubbles forming on the surface of my elements prior to boiling, after the boil is reached I cannot see clearly enough to tell.

Heating with a heating element is NOT like tossing a red hot piece of iron into cold water, my heating elements only produce 170BTUs per sq. in surface area in an hour.

Then it takes only another 12,100 BTUs to boil off 1.5 gallons or so, the question is, how long does it take you to get that 12,100 BTUs in there? It takes me 60 minutes at 4kW
 
Boiling, a type of phase transition, is the rapid vaporization of a liquid, which typically occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding environmental pressure.

What you see when you boil water is the water undergoing a phase transition from saturated water to saturated steam, The amount of energy required to convert 1 lbm of water at its boiling point at 1atm(14.7psia) is 970 BTU/lbm. So, say you want 10% boil off, The amount of energy that takes neglecting heat transfer to the surroundings, is 97 BTU/lbm so you take your total mass man multiply it by your 97BTU/lbm, that isthe amount of energy you need.

I have pages and pages of charts on properties of water, but I haven't been able to find a good online equivalent

The water is all the same temperature. The only thing that is different is where it is vaporizing. If the water was below its boiling point, when it vaporizes, it would almost instantly collapse back to a liquid and transfer all of its energy back into the colder water.

Probably the best way to go about it would be to ask how many BTUs does it take to reach the boiling point.

there is no magic property that exists in the vicinity of the heating element that makes it boil, all it is is a phase change from the liquid to the vapor state. So it doesnt really matter how large your element or heat transfer thingie is, once you are at the boiling point, and additional heat transfer will lead to a phase change in the fluid. The reason you get scorching and things like that is because the solids or sugars in the pot essentially get in the way of the heat transfer into the water and therefore can have very large temperature drops across them.
 
willynilly said:
With a 170,000 BTU burner, you would have to be getting about 106% eff. from that burner to do so. This makes the assumption that the water you are making into steam is already at 210F... which in Monti's case it is not. If your boiler inlet water is 170F, you need to add 124 BTUs per minute to reach boiling, this in addition to the 3007 BTUs/min to create the steam, for a total of 3131 BTUs/min. or 187,860 BTU/hr
Click to expand...

While I can't say much about the efficency, I can tell you that the input water is probly at a higher temp then the 210* you posted. In the test run documented in the boiling with a FB thread. I was just using a water tank to capture the condensate. When that tank got up to the 200* mark, that's when I saw the 6* min increases in the 14 gallons of water. I haven't posted on it yet but I have a heat recovery coil that has the boiler input/feed water running through a CFC in reverse. The steam condensate runs into the water tank while the boiler feed runs against it in the CFC, giving me the boiler feed input water at the hottest point of the condensate line. I hope that makes sense.

The MK-I if far less efficient then the copper coils, and I have boiled very hard with it running the heat recovery coil and only needed the 2.5 PSI on the burner. Plenty hard. Not quite wort spreader material but close. I still need to run the copper coils with the recovery coil to see what it does with it on line. I would almost bet i get to turn down the fire a little more. Getting me closer to the .5 lbs an hour of propane to match the electric element BTU output.

So, in short. Yes, the input feed water is at or above 210*.
 
Okiebrewer said:
Beautiful Build... subscribe... but if I read any more math I think I might have a stroke :cross:
Click to expand...

Ha, ha. You and me both. I am glad you like the build. Hopefully soon the MK-2 will be around.

That is if any laser guy in the northern hemisphere is willing to do the work. Laser must be long, or slang for lazy. I have talked and dealt with a few now, and they all suck.

I wonder why the USA is in such distress??? UHMMM. That's another thread though.

Stay tuned, I am sure one day we will get it done.:D
 
GreenMonti said:
Ha, ha. You and me both. I am glad you like the build. Hopefully soon the MK-2 will be around.

That is if any laser guy in the northern hemisphere is willing to do the work. Laser must be long, or slang for lazy. I have talked and dealt with a few now, and they all suck.

I wonder why the USA is in such distress??? UHMMM. That's another thread though.

Stay tuned, I am sure one day we will get it done.:D
Click to expand...

Send it to be made in Oz they are a crazy bunch, as well NZ also, OMG bier drinking party animals.
 
I have been doing some thinking and I have an idea about what might be going on. I don't really have a clue but, it's a theory. I believe condensate is getting in the way and robbing precious energy. So to see if I am right the MK-I went under the knife. I moved the steam input down and on the side. I plan on running it this weekend. I hope there will be an increase in performance. This will be a test too. Since I don't want to weld in another fitting into my test keegle, I will need to fill it up just about to the top. So the test will be with something like 15 gallons of water.:D

Since I am a fan of pics, here is a couple to show the new input.

P1010143-2.jpg

P1010142-2.jpg
 
You are one sick individual... sick... :cross: Your fabrication skills are a testament to "All That Is Man!!!!" I hope everything works out for you and you get this figured out soon.

Every time I see adds to this thread I have to pop in and check it out, lol.

You frickin' rock man :rockin:
 
WortMonger said:
You are one sick individual... sick... :cross: Your fabrication skills are a testament to "All That Is Man!!!!" I hope everything works out for you and you get this figured out soon.

Every time I see adds to this thread I have to pop in and check it out, lol.

You frickin' rock man :rockin:
Click to expand...

"A sick mind is a happy mind that's thinking all the time" (RIP from dad).
 
WortMonger said:
You are one sick individual... sick... :cross: Your fabrication skills are a testament to "All That Is Man!!!!" I hope everything works out for you and you get this figured out soon.

Every time I see adds to this thread I have to pop in and check it out, lol.

You frickin' rock man :rockin:
Click to expand...

BrewBeemer said:
"A sick mind is a happy mind that's thinking all the time" (RIP from dad).
Click to expand...


I guess that settles it then. I have always wondered if I was. Now that's two who confirm it.


:tank:
 
GM, your fabrication skills are unrivaled on HBT... and you arent a jerk, that sayes a lot.
 
still trying to wrap my brain around the function of this kind of system, but i love the fab work you are doing. keep the pics coming!
 
Slightly OT but I'm curious what equipment you use to give your pieces the brushed/shiny look? I have a few items I want to spiff up but not polish.
 
Slightly OT but I'm curious what equipment you use to give your pieces the brushed/shiny look? I have a few items I want to spiff up but not polish.
Click to expand...
Bar Keeper's Friend (BKF) will clean SS pretty well. To get SS to look like Monti's items, you will need to sand it in some manner. Power tools work great (angle grinder, polishing pads and compound), but if you don't want to do that you could get a sheet of 800 or 1000 grit sandpaper from an automotive parts store and sand by hand.
 
pickles said:
Slightly OT but I'm curious what equipment you use to give your pieces the brushed/shiny look? I have a few items I want to spiff up but not polish.
Click to expand...

As others have mentioned. I am a very big fan of scotch brite pads. The main body is made of two short pieces of SS tubing that I welded together. It had a nasty outside finish on it. Being they were rems, they had nicks and dings in them. Once I welded them together I used sand paper and spun it on my wood lathe. Everything else has just been hit with scotch brite. I also like to use the unitized wheels from 3M.(Grey) They move material faster then you would think and they don't leave heavy scratches behind. A quick rub with a scotch brite pad and you can blend it all in.
 
As GM stated "blend" as it's far better than a shiny finish that amplifies ever nick, scar and dent, call it a purpose added finish. I went as far a glass bead blasting a keg, it looked good until it was hit or rubbed against any hard object then it has a shiny streak that really stood out as an eyesore. A Scotchbrite finish can reapplied to hide a flawed added mark. Then the other option is buy brand new which is way over the top in cost to have Sabco advertisement model looking kegs.
 
Ok, There was an increase in performance. The MK-I brought 15 gallons of water from a cold start to a boil in 45-46 mins. Without any mods to it. Running a cold water feed into the boiler also. I was running my burner at a rate of 2 lbs of propane per hour. So I got right about 60-62% system efficency. I can't seem to break this barrier. Every setup I have tried latley I keep getting these numbers. I don't believe I am in a bad spot with these numbers. I mean, I am heating water....so that water......can heat up more water. Sure seems backwards. But 60% efficiency out of a gas burner is pretty good.


So, I believe I am done testing and I am going to start planning my build and get busy. Well, since I have everything out. I am going to run the last condenser I built one more time just for fun. I am going to put it in the same 15 gallons of water. It will have a little bit of a head start, but it rocks for its size and the intensity of its boil. The head start should give me a more realistic run anyway. We don't boil our beer from cold starts.
 
passedpawn said:
where do you get scotch brite pads? Can I just get them at Target in the kitchen section? I want to give this a try.
Click to expand...


Yes, I have used the green ones before. I like the red (maroon) colored ones. IMO you get more life and better results from them. I got mine from the auto paint store. I have also been known to grab a couple from work every once in a while. The pic of my new keggle in the begging of the thread is purely a scotch brite rub by hand.

Edit:You deleted your post as I was typing. No bother to me. You didn't have to delete it. Totally fine.
 
Here is a video of the MK-I running yesterday.

This is right after I started making steam. You can see the little bubbles coming up and out of the calandria. I was trying to show the up flow. It seems to move a fair amount of liquid.
 

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