New Child Containment Device

[MrNate]

..Or possibly a brew kettle, I haven't decided yet. I'm estimating it at around 40-45 gallons.


http://i230.photobucket.com/albums/ee226/nutkeis/Brewing/IMG_0756.jpg

[impaktdevices]

She's beautiful!

(and so is your daughter) :D

[dparsons]

Probably 40 (a standard size). Just don't let her climb in when its full.

[MrNate]

Ah, thank you! Anyone have a rough idea of how many BTUs it would take to boil 30 gallons in this beast? I need to size a burner.

[acdavis]

I'm a HVAC engineer, I used the following equations to size your burner. If anyone wants to check my math, I won't take any offense. I did use a very low tap water temperature, mainly because 33 degrees is the coldest that could come out of your tap. Perhaps this is being overly safe. Most tap water is around 40-60 degrees F. You could rework the tap water part of the equation with the actual water temp coming out of your tap, just measure it with a thermometer.

Q(BUTH)=500*Volume(GALLONS)*(Temp of boil-Temp of Tap Water)
Q(BTUH)=500*30(Gallons)*(212-33)
Q(BTUH)=2685000 BTUH

Have fun,

Adam

[MrNate]

Yikes.. 2.7 million BTUs/hr? Am I reading that right?

Just out of curiosity, what does the 500 constant represent?

[impaktdevices]

A BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

There are about 8 lbs of water in a gallon. So 30 gallons of water should weigh about 240 lbs.

240 BTUs would raise the water 1 degree F. To raise it ~180 (bring to ~212) would require a 43,200 BTU unit to boil it in one hour at full blast..

I'd say aim high. A 100,000 BTU burner would knock that down to half an hour.

EDIT:

I just remembered that you're also dealing with heat loss due to ambient temp, evaporation, etc. I would estimate a 50,000 BTU burner would take about 90 minutes to boil thirty gallons of water. But that's just my ass talking.

[impaktdevices]

More:
According to this link (http://www.lalagniappe.com/mall/lobbycookerfaq.htm), assuming 50% efficiency it will take 8000 BTU to boil a gallon of water in one hour. Based on that, you'd need a 240,000 BTU burner to do it in an hour.

Yikes.

[MrNate]

Ah, that's sounding a little more believable! I should be able to use one of those 300k BTU NG burners that Northern Brewer used to carry. I've heard of people who use one or two cajun cookers for a 1bbl boil and it takes "a really long time" so your math seems about right.

Also, you guys aren't taking into account that the sweet wort is already hot, so your delta t is going to be something like 75 degrees max.

The 25 gallons of sparge liquor on the other hand...

[Dangerous Beans]

I think ACDavis is talking about the total heat contained in the boiling wort, the amount of energy you will need to add in the worst case scenario.
I would double check his calculations, but I can't be bothered doing the imperial-to-metric-to-imperial conversions. Plus BTUH is a completely new measure of energy to me.

[zoom6zoom]

Just find a surplus jet engine from the .gov, it'll make a great burner. You'll have that thing boiling in seconds.

[Dangerous Beans]

Ok, I'll have a crack at this. All units, constants and conversions courtesy of google.
30 gal is 113.6L. At 20c water is 0.998g/ml, or near enough to 1kg/l.
So we have 113.6kg of water.
We want to get it from 20c to 100c, so delta-T is 80. Specific heat of 4.19kJ/kg.
So 113.6 x 4.19 x 80 = 3,807.87kJ total energy.
To bring to the boil within 30min (1800s) we need to add 3,807.87 / 1800 = 21.15kJ/s, or 21.15kW.
So assuming a 50% efficiency you want a 42.3kW burner minimum. According to wikipedia, 42.3kW = 39.9 BTU/second, or 14,366.03BTU/h.
So I would buy a 50kW to 60kW burner, on the basis that it's better to have too much than not enough. If I were you, I would double check my kJ to BTU.
And if I were emperor of the world I would force Americans to convert to metric :P

[MrNate]

So assuming a 50% efficiency you want a 42.3kW burner minimum. According to wikipedia, 42.3kW = 39.9 BTU/second, or 14,366.03BTU/h.
So I would buy a 50kW to 60kW burner, on the basis that it's better to have too much than not enough. If I were you, I would double check my kJ to BTU.

That sounded way too low to me, so I googled it... I love their new conversion calculator feature. Misplaced decimal, maybe?

42.3 kilowatts = 144 333.591 BTU / hr

Seems like between everyone we're getting into the right ballpark. 250 BTUs minimum for a similarly sized HLT and 150 for the kettle. I'm thinking I could maybe get away with 200 for both if I insulated the HLT. Does that seem like I'm cutting it too close? Thanks for the help, guys...


And if I were emperor of the world I would force Americans to convert to metric :P

Actually, I'm with you on that one.

[ClaudiusB]

Ah, thank you! Anyone have a rough idea of how many BTUs it would take to boil 30 gallons in this beast? I need to size a burner.

One thing is to boil off 30 gallons, or to reach boiling temp and then boil off 5-10%. like we brewers do.

30 gallons
If we use delta T 80° F
10% boil off

To get to the boiling temp only, you need 20016 Bthu's/h ,DT 80°F or 36028.8 Btu's/h , DT 80°C without losses.

Btu's/h= (30 gl x 8.34lb/gl= 250.2) x 1 (water) x DT80°F= 20016 Btu/h
kW= 20016/3412=5.87 kW

Delta T 80°C (144°F)as per Dangerous Beans
Btu's/h= (30 gl x 8.34lb/gl= 250.2) x 1 (water) x DT 144°F= 36028.8 Btu/h
kW= 36028.8/ 3412= 10.56 kW

To boil away 10% off your wort you need an additional 24269.4 Btu's
BTU's= 970 Btu/lb/°F(latent heat of vaporization)x (3 gl x 8.34lbs/gl= 24589.5

Total Btu's DT 80°F= 20016 + 24589.5 = 44605.5 or 13 kW, no losses, 100% efficiency
Total Btu's DT 80°C (144°F)= 36028.8 + 24589.5 = 60618.3 or 17.76 kW, no losses, 100% efficiency

Losses from the surface of water per hour = ~850W/ft², 60% rel. humidity,
Surface losses from uninsulated tank walls = 0.6 W x ft² x DT°F

As you can see a 300,000 Btu burner is a waist of energy.

My edit: DT 80°C
Posted by acdavis
Q(BUTH)=500*Volume(GALLONS)*(Temp of boil-Temp of Tap Water)
Q(BTUH)=500*30(Gallons)*(212-33)
Q(BTUH)=2685000 BTUH = 787 kW a little bit too much;)

If we boil off all 30 gallons we need 287,479.8 Btu's or 84.26 kW, 100% efficiency


Cheers,
ClaudiusB

[chapesh]

i like to begin adding heat while sparging. when i get about 2" of wort in the boil kettle i start the burner. this seems to take a little time off. and by the way all that math hurts my head!

[ClaudiusB]

--------------------------------------------------------------------------------

i like to begin adding heat while sparging. when i get about 2" of wort in the boil kettle i start the burner. this seems to take a little time off.
It is of great help, the only thing you won't be able to do is get a good mash efficiency reading based on pre-boil volume and OG.
Is it important?

As long you take a frst run reading you are in good shape too.

and by the way all that math hurts my head!Sorry
Tell MrNate to stop asking:D or push the erase button.

Cheers,
ClaudiusB

[MrNate]

It should hurt - you're exercising your brain.

I just like to try understanding this stuff. I'm not very good at it, but I like to try. Good thing Claudius is patient!

[MrNate]

As you can see a 300,000 Btu burner is a waist of energy.


Ok, so I looked over this again, and I'm thinking to myself that it doesn't seem right. After all, I use a 55k BTU burner for my current 5g batches. So is 36k really sufficient?

But then I said to myself, wait a minute - he's calculating total BTUs required at 100% efficiency - zero loss. So the real question is, how quickly can I put those BTUs PLUS whatever BTUs get lost to the ambient into the wort?

Or more to the point, how quickly will the common burner sizes (55k, 200k, 300k, etc.) get me to 212, and which of these can be eliminated because they cannot overcome the efficiency loss (or take too long to overcome it)?

[ClaudiusB]

Hallo MrNate,

To prevent further reader headaches sent me all the pot data.
I am only a home brewer so expect mistakes too.:D
Are you planning on using a wind shield for the burner?

My edit:
After all, I use a 55k BTU burner for my current 5g batches.
Here is a good number: 12,000 BTUh is enough= 3.52 kW
Most starting German home brewers use a 1800 Watt electrical brew pot, 20 liter (5Gl) but are straggeling.

Cheers,
ClaudiusB

[MrNate]

No, no wind shield because this will be going in the basement.

I use a 55k burner now because it's what comes in the turkey fryer kit. It's a very common propane burner.

Those numbers seem incredibly small to me... I know Germans are efficient, but that's crazy! Of course, I brew outdoors right now in ~20f ambient. That might be scrubbing off a lot of heat. Do they mostly brew indoors over in Deutschland?

[ClaudiusB]

Those numbers seem incredibly small to me...
Come by my brewery and you can see math in action.:D
but that's crazy
No, 1+1=2?
We better quit or we find our selves in another forum.



Cheers,
ClaudiusB

[chapesh]

trust me i understand the need to know. i was just trying to lighten it up a little. and the truth is you're going to spend money for this burner so you want the one that is going to fit your system. and i don't normally take a first running reading, is it that big a deal?

[dparsons]

No, no wind shield because this will be going in the basement.

I use a 55k burner now because it's what comes in the turkey fryer kit. It's a very common propane burner.

Those numbers seem incredibly small to me... I know Germans are efficient, but that's crazy! Of course, I brew outdoors right now in ~20f ambient. That might be scrubbing off a lot of heat. Do they mostly brew indoors over in Deutschland?

The electric heater will get more heat to the pot than a burner under the pot. Less heating of gasses that go elsewhere.

[MrNate]

The electric heater will get more heat to the pot than a burner under the pot. Less heating of gasses that go elsewhere.


I meant that it seems small because I use a 2000w element in my HLT that takes an incredibly long time to bring 6.5gallons up to temperature.

[barleyburps]

i use a 28 gallon brew pot that sits on 2 dual electric burners each rated at 825 watts per burner (that's 4 burners) and I'm able to achieve a full wort boil of 15-20 gallons in about 50 minutes typically.

[ClaudiusB]

MrNate
I use a 2000w element in my HLT that takes an incredibly long time to bring 6.5gallons up to temperature.

Going from 50°F - 212°F should take 1.5 hours.

barleyburps
I'm able to achieve a full wort boil of 15-20 gallons in about 50 minutes typically.
15 gallons and a 60°F temp rise sounds OK.

Cheers,
ClaudiusB

[MrNate]

Going from 50°F - 212°F should take 1.5 hours.
Cheers,
ClaudiusB


So my problem is just impatience, then. Honestly, if German brewers are willing to wait over 1.5 hours to get to a boil, more power to them. It seems like a waste of time to me.

[ClaudiusB]

Honestly, if German brewers are willing to wait over 1.5 hours to get to a boil, more power to them. It seems like a waste of time to me.

In our excample I used 162°F rise.

Here you can see what German home brewers use and do(2000 watts only):confused:
Here you can see a perfect starter set as used by German home brewers.
2000 watt pot with temp control, all stainless, 29 L (7.66 gl) for $80.00 (http://i238.photobucket.com/albums/ff156/ClaudiusB/2kW%20brew%20pots/Rommelsbacher-ka2000e_350.jpg)

Modified, all the brewing done in the same and only one pot.
Includes a pump too. (http://www.hobbybrauer.de/modules.php?name=eBoard&file=viewthread&fid=12&tid=4639&p)

Brew pot in action video commercial version, automated. (http://s238.photobucket.com/albums/ff156/ClaudiusB/2kW%20brew%20pots/?action=view&current=Braumeister.flv)

My edit: Sh*** photobucket cuts off the video after 5 minutes.
For a complete and better video send me a PM.
Cheers,
ClaudiusB

[BikeNBrew]

No, no wind shield because this will be going in the basement.

Isn't that a lot of combustion in an enclosed space for a relatively long time? Am I the only one thinking Carbon Monoxide poisoning? Hate to lose a homebrewer to that...If you are considering this then I hope you have some ventilation plans.

[MrNate]

In our excample I used 162°F rise.

Here you can see what German home brewers use and do(2000 watts only):confused:
Here you can see a perfect starter set as used by German home brewers.
2000 watt pot with temp control, all stainless, 29 L (7.66 gl) for $80.00 (http://i238.photobucket.com/albums/ff156/ClaudiusB/2kW%20brew%20pots/Rommelsbacher-ka2000e_350.jpg)


So the 1.5 hrs includes mash step-up as well. That is brilliant. I thought I remembered someone coming up with a system like this, but I wasn't sure. Is the commercial version available in the states or do I have to build my own? Though I guess in my case the 60lbs of grain ( dry weight) for a 1bbl batch would require some sort of mechanical lifting. This has given me something to think about.

Also, a quick question about the bulkhead fitting shown on hobbybrauer - My German is terrible... Gott sei dank fur Google Translate. Does it say that is a 1/2" stopper that has been drilled/machined out? It looks nice. I think I'll be asking for a Mini Lathe this Christmas. :D


[edited for clarity]

[ClaudiusB]

Originally Posted by MrNate
Does it say that is a 1/2" stopper that has been drilled/machined out? It looks nice. I think I'll be asking for a Mini Lathe this Christmas.
Correct.
do I have to build my own?
Yes, perfect project to stay out of trouble.
Though I guess in my case the 60lbs of grain ( dry weight) for a 1bbl batch would require some sort of mechanical lifting.
My solution for a heavy load (http://s238.photobucket.com/albums/ff156/ClaudiusB/Winch/)

Cheers,
ClaudiusB

[Powhatan]

I was searching for posts on heat shields - this was the closest one I found. I brew using a 30 gallon Blichmann boilmaker and it take about an hour to get 20+ gallons to a boil on a bayou classic burner.

I just bought a few 55 gallon drums ($8 ea) that I'm converting into heat shields to try and bring down the heat up time. Has anyone else tried this, and, if so, any tips?