The power of 210,000 BTUs

[Todd]

I don't want to switch this up here but is part of the inefficiency due to the heat transfer of the pot? I think what I'm asking is, would there be a big difference if there was a skirt on the pot and the burner was encased to contain the heat? I know my fryer heats the ground quite a bit and there is a lot of heat coming up beside my keggle.

Any thoughts? Would it be safe?

I forget who but someone on here had a burner like this in an old stainless pot to prevent wind and such.

Does anyone other than me find this incredibly energy wasteful ? These high output propane burners are nice because they are fast, but I think they are incredibly inefficient.

BTW: I have a banjo burner ! I have mixed feelings about it.



10 gallons x 8.33 lbs/gallon x (170-50) = 10,000 btus. If you are running the burner at 100,000 btus for 40 minutes, that 66,000 btus. Efficiency is only 15% !

Propane and natural gas might be cheaper on a per btu basis, but electric heating is nearly 100% efficient. The speed factor of these big burners is nice, but with something like mash water, one could easily plan ahead and have it heated electrically.

I was debating this weekend whether I would heat the water on my new brewstand electrically or with propane/natgas. I hate the thought of having a bunch of 220V power running around my brewstand, but the efficiency and propane cost per brew is causing me to reconsider.

In the above example, 10,000 BTUs is less than 3KWHr with electric heating. At 7cents per KWHr, the cost is 21 cents to heat that water. Propane is $10 per 20 pound tank. 66,000 BTU is about 3 pounds, so it costs $1.50 to heat the water.

 

[brewman !]

I don't want to switch this up here but is part of the inefficiency due to the heat transfer of the pot?

Yes, its all the inefficiency of the heat transfer to the pot. On the other hand, natural gas hot water heaters are very efficient. Lots of surface area to conduct the heat.

The burning of the gas is good as long as the flame is blue. An orange flame means not enough air.

I think what I'm asking is, would there be a big difference if there was a skirt on the pot and the burner was encased to contain the heat? I know my fryer heats the ground quite a bit and there is a lot of heat coming up beside my keggle.

A skirt underneath and around the bottom and around the sides of the pot will all help. And I know that pots used for moutaineering can have heat exchanger ruffles on them. All this would help. But how much does one want to do to save a few dollars of propane ?

I wonder how one of these heaters would work ?
http://www2.northerntool.com/product-1/200332705.htm

28,000 BTU doesn't sound like much, but its still 8.20 KW ! If the bottom of the pot was totally black, one of these might be a really efficient heater. Plus you could insulate the outside of the pot to keep it warm. If the 28K BTU radiant heater was 50% efficient, it would warm the water faster than the flame would.

 

[EdWort]

Fast is a measure of efficiency.
220v brewstand isn't very portable.
Blue flames are purty.

Amen Brotha! A buck fiddy for fast! I'm all about that! :fro:

 

[Desert_Sky]

one thing Im begining to notice is that this burner doesnt like any amount of wind

 

[brewman !]

Don't ever boil the pot over or the flame goes out. And I find the draft adjustment at the intake to be sensitive. I've had the flame snap back and burn at the needle valve several times.

I think there are much better burners out there, specifically these:
http://morebeer.com/product.html?product_id=17249

I'm going to test one of these and if its good, I'll be selling my banjo burner.

 

[knipknup]

It is 50F and windy today but I want to save some time. I'm going for it!

For me, my time is worth way more than a few bucks saved in energy efficiency. Oh, and global warming is as real as y2k was...

Oh damn, why didn't I see that one from bb&mb earlier...?

 

[brewman !]

Oh, and global warming is as real as y2k was...

Excuse me... I have to go buy more energy stocks.

 

[Ol' Grog]

10 gallons x 8.33 lbs/gallon x (170-50) = 10,000 btus. If you are running the burner at 100,000 btus for 40 minutes, that 66,000 btus. Efficiency is only 15% !



I'm not sure I'm following your logic on this. What's the 170-50?
Since 1 BTU is equal to 252 calories.
1 BTU will raise 252 grams of water 1 degree centigrade OR 1 gram of water 252 degrees.

That rate is linear until the boiling point of the water (wort) is reached. Then it takes 2.13 BTU (539.6 calories) to get that 1 gram of water to boil (heat of vaporization for water).
This assumes that the heat transfer is 100% and there is no heat lost to the enclosure (pot) or surrounding atmosphere.

Water is 8.3 lbs. per gallon
and 1 lbs. is 453 grams.
Therefore 5 gallons of water is 37,600 grams.

Assuming perfect heat transfer from the burner to the water -
it will take a minimum of 80,770 BTU to get the 5 gallons of water from 100 degrees Centigrade to boiling.

 

[brewman !]

I'm not sure I'm following your logic on this. What's the 170-50?

He said:

It gets 10 gallons to mash temps in about 30-40 minutes for me from 50 degree water.

So I assumed that mash temp was 170F, as in the water used for sparging the mash.

it will take a minimum of 80,770 BTU to get the 5 gallons of water from 100 degrees Centigrade to boiling.

That is only true if you boiled away 100% of your water. The heat of vaporization assumes you are converting all the water to vapor. What really happens when you "boil" the wort is you boil about a gallon of it and the rest just gets heated to 100C.

.

 

[Willsellout]

Don't ever boil the pot over or the flame goes out. And I find the draft adjustment at the intake to be sensitive. I've had the flame snap back and burn at the needle valve several times.

I think there are much better burners out there, specifically these:
http://morebeer.com/product.html?product_id=17249

I'm going to test one of these and if its good, I'll be selling my banjo burner.

My question is how do you hook it up? Are there premade stands to install this thing in or do you fabricate it?


Dan

 

[brewman !]

My question is how do you hook it up? Are there premade stands to install this thing in or do you fabricate it?

First of all, let me emphasize that I don't know if it would work. I'm just suggesting it.

I doubt there is anything premade for those. I might be wrong.

We had one of those on the farm. I think it took high pressure propane right off the bottle. I'd guess there is a 1/4" NPT fitting that goes to the POL (bottle fitting).

If it was me, I'd remove the wire guard, which is probably only there so you don't burn your hand. Then I'd weld a 1/4" nipple to the stand, horizontally and I'd connect the burner to one side and a hose to the tank on the other side.

There are lower btu models available as well. I chose to link that one because I didn't want the 210,000 btu crowd to fall over laughing.

I think the efficiency of radiant heat on the bottom of a black pot surface would be pretty good. 14,000 btu at 70% transfer would be a pretty fast heat source.

McMasterCarr (www.mcmaster.com) see item 1719K2 and others on page 588.

The glass ceramic stoves use radiant heat to heat pots.
http://en.wikipedia.org/wiki/Glass-ceramic

.

 

[brewman !]

Fast is a measure of efficiency.

Just in case anyone is confused by this, fast is a measure of speed. The big propane burners are fast and they are inefficient. I'm not judging anyone for using them, I'm just stating what they are. In this case fast is NOT efficient.

 

[Orfy]

I agree with you on that one Brewman.

210,000 is the measure of amount of energy it can consume not the heat it puts out
I'd like to see the actually calculation of heat out put based on it's ability to raise the temperature of water compared to my 29,000 btu heater.

I can boil 5 gallon of wort from sparge temp to boiling in around 25 - 40 minutes. I Don't think a burner wit 7 times the BTU rating could do it 7 times faster. I'd be surprised if it could do it 3 times faster.

BUT YES!!!!! I want one.

 

[brewman !]

210,00 is the measure of amount of energy it can consume not the heat it puts out

Provided the fuel gets enough air, its making 210,000 BTUs. The question is, how much of that heat gets to the water ? Using the numbers supplied, not very much.

I've done a lot of food canning with our banjo burner. I've had is since 1998 IIRC. Its not too bad efficiency wise if you keep it turned down. But if you really turn it up it burns through the propane quickly and there is a lot of heat lost.

I'm just saying what I see.

 

[knipknup]

All this science talk is getting me hot...

I almost bought a different bayou classic burner that is at coscto because it comes with a 48Qt pot. My current one is only 30Qts. However, I had already ordered the banjo and the other one doesn't say what the btus are anywhere on the box. $65 for the banjo and $59 for the other at costco. I may still go get it, haven't decided.

 

[Ol' Grog]

I'll be firing mine up this weekend. Really curious now after reading all this. I don't imagine I'd crank 'er up all the way because of what brewman is saying, I know from experience that a lot of heat would be lost because of transfer losses. But, I hate to say this, it's nice knowing I CAN CRANK this puppy up if I should ever need to!!!! I'd rather have too much of a good thing than not enough.

 

[BierMuncher]

I read where the cooking surface is 17" X 17".

Can a half barrel keg fit on this? I thought the half barrel was 17" in diameter.

Is that too close a fit for a keggle?

 

[olllllo]

It's tight but do-able. I don't have kids and the dog stays away, so I'm not concerned about it.

 

[BierMuncher]

It's tight but do-able. I don't have kids and the dog stays away, so I'm not concerned about it.

Thanks olllllo.

I took a look at your gallery. Your "keggle" pic...is that the banjo burner underneath?

You're right, tight but it appears there is an inch or so extra room.

 

[olllllo]

Thanks olllllo.

I took a look at your gallery. Your "keggle" pic...is that the banjo burner underneath?

You're right, tight but it appears there is an inch or so extra room.

Indeed it is.

 

[Ol' Grog]

I surely wouldn't want to bump it during a full boil and because of the weight of that thing fully loaded. It's not as sturdy as I'd like, but it's about the widest one out there off the shelf.

 

[Beer Weevel]

I could care less about efficiency, Brewing is Brewing and I would do it no matter what it costs me. A lot of guy's have $30,000.00 boats sitting in their driveways and only use them 6 months out of the year. I have about four grand in brewing and I use it all year. I don't think $13.00 worth(per 5 gal.) of propane will keep me from brewing.