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BrewBeemer

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I read about the High Gravity system that use a low density 4,500 watt electric heating element in their 15.5 gallon HLT and a 3,500 for their brew pot. From what I understand they run their system at 220 volts for brewing up to 15 gallon batches.

Questions I have:

Would the heating element cause scorching the wort being run at 220 volts vs 120 volts?

Is there enough heat from 3,500 watts on the brew pot to allow a rolling boil without scorching? This with a converted keg operating in a 60 degree F environment.

What I am thinking is why not weld in a 1 1/2" by 15" long stainless tube into the lower section of a keg with a cap on end plus a step down fitting to 1" pipe thread for the 4,500 watt screw in heater and run it on 220 volts. Have a short sight gauge connected to this tube that extends outside the keg filled with anti-freeze allowing for the sight level plus expansion of the anti-freeze when heated. This way you can have a high electrial heating with 220 volts plus a large surface area from the 1 1/2" by 13" long stainless tubing allowing for heat transfer without scorching.
I have propane plus natral gas in the patio but rather have a electrically heated and PID controlled system.

Am I thinking on the right track here?
Only at a paper design stage here.
 

slnies

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Take a look at a thread called RIMS set ups. One of the posts is from Kladue. In it he shows some nice calculations for heating elements. As for the wort scorching, as I understand it, it is all about surface temperature on the element. In the boil kettle it doesn't matter so much because the thermal dynamics say the fluid will have a natural flow across the element. In a mash tun, the fluid is thicker, and not as viscous, so you would need something to stir it or the keep the fluid moving across the element. You could also use RIMS, HERMS, or steam infusion in the mash for temp control. As for the elements go... Think extra low density. Fifty watts per Square inch, this keeps surface temps on the element manageable.
 
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BrewBeemer

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I ran across heating elements as low as 30 watts per sq inch.
After reading the "RIMS set up" threads with one reply stating 50 watts
per sq inch "should" not cause scorching, this did not sound like a 100% scorch free system. Nothing would be worse that spending time and money on a brewing system with built in problems lowering the quality of the bier.

As for the dry type of heating element granted the wattage is too low, that system still is not a consideration even if it had 6,000 watts of available heating. Thanks for the reply anyway as i'm still open to any suggestions.

I even considered going to a 3 1/2" diameter thin wall stainless tubing 14 1/2" long inside the keg allowing 169 sq/in surface area including the end cap. With a 4.5 KW heating element on 220 volts results in 26.62 watts per sq/in. The question I have will 3 1/2" x 14 1/2" thin wall stainless tubing transfer 4.5KW of generated heat without causing the 50/50 anti-freeze water mix inside the tubing to go into a boil?
Still in the paper designing stage with untouched kegs so no mistakes applied to kegs.
 

kladue

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This is just a guess, the element in a chamber with antifreeze will probably boil the antifreeze because of insuficient heat transfer without forced circulation. It would help if one could use a pump to induce flow over the direct contact element to move the heat and reduce element surface temperature to a point low enough to prevent scorching.
 

wilserbrewer

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Not all that knowledgeable here but I do have experience using a standard 120 volt 2000watt element (both heat stick and kettle mounted). I have never detected any scorching! I even have used the stick to adjust mash temps (constantly stirring) w/out scorching the "high gravity" first runnings.

My field experince, and what I gather from what I've read is that fears of scorching are overstated. Of course ymmv.

Mike
 

shafferpilot

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anti-freeze isn't the best material for your plan. I'd use an oil with a high smoking point. Like synthetic hydraulic oil, or maybe even peanut oil.
 

Sea

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Sounds like a lot of work to avoid a something that may not even be a problem, meanwhile constructing something that will require a field test to assess functionality. I don't think anyone here can do better than guess at what the heat transfer will be like, but I tend to agree with Kladue, that it won't be great.

As for whether a 4500 w element will maintain a rolling boil, depends on how much wort, and I'd be much more concerned with how long it took to bring it too a boil:


4500 watts = 15,363 Btus

3500 watts = 11,949 Btus
 

AiredAle

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The boil rate is independent of how much wort you are boiling. Once the wort reaches the boiling point, you need 970 BTU to vaporize a pound of water.

A 4500 watt element will heat ten gallons of wort about 3 degrees F a minute assuming no heat loss to the surroundings and assuming the wort has the same specific heat as water.

Making the same assumptions as above, it takes an electric heating element running at about 3600 watts to boil off wort at a rate of 1.5 gallons per hour, which is a typical boil rate for most of us. One gallon per hour boiloff requires 2400 watts of power.

Echoing others above, lots of folks have success using elements in direct contact with wort, and some in contact with the mash. I would use your obvious ingenuity to build an electric RIMS or HERMS system to heat mash.
 
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BrewBeemer

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All good replies I must thank you all.
I want to have over 10 gallons at the end of the boil so the total volume before boil must be around 13 gallons, just a guess figure to heat up.
On using oil vs anti-freeze that sounds like a great idea as there would be no pressure cap to increase the boiling point of the anti-freeze.
Now Amsoil synthetic ATF has a flash point (vapor) of 428 degrees Fahrenheit, way above what I would have to worry about. I will add a gear case sight gauge for filling, heat expansion and sight.
As far as extra work for myself you all know labors free besides it's the building of the project that counts. A little more welding than just welding half of a one inch coupling into a keg besides I have the welding equipment and not paying to have it welded plus have one odd manufactured keg that I can experiment on.
On the High Gravity Home Brewing and Wine Making Supplies forum they show a build your own electric brewing system with a 15.5 gallon HLT kettle heated by 4,500 watts at 220 volts and the 15.5 gallon boil kettle heated with 3,500 watts at 220 volts. They claim 30% boil off hence only a 60 minute boil time.
 

AiredAle

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The flash point of the vapor is not as important as the smoke point of the oil you use if you go this way. Corn oil and peanut oil have smoke points of 450 F, and are somewhat cheaper than synthetic oils.

You need to think through the heat transfers and temperatures your element, heat transfer fluid and stainless tube need to be at to transfer enough heat from the element to the wort to boil it. You may need your transfer medium to be at 400 F (for example) to boil the wort if you have low transfer efficiency. You also need to find out what temperature the element is designed to run at. I don't know but I suspect a water heater element is designed to run at some temp not too far from 212 F.
 

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can we come up with a good way to make that pipe out of copper, but still get it to seal to the keg? Perhaps the heating element could be vertically mounted so it doesn't need to seal through the keg? Copper sure transfers heat faster than SS. Or does someone know of a specific brass brazing rod that will bond to copper and SS?
 
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BrewBeemer

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Jim; this is the forum where I got more jazzed about heating with electric as I do want to heat with electricity vs propane. Should I have failures I will go to nautral gas, oh god help me if this happens.

http://www.highgravitybrew.com/ProductCart/pc/viewPrd.asp?idcategory=269&idproduct=2351

Tell me what ya think. For their $1,000 asking price I can spend some time and labor converting 15.5 gallon kegs that I already have.

I like the idea of a controller that can be added, again a build it yourself item.
With the difference in heat transfer of stainless vs copper is why I was thinking of a larger diameter thin walled stainless tube at 3 1/2" in
diameter for plenty of surface area.
I'm the type of person that asks why not instead of doing what i'm told, heck maybe egg on face but i'll build it and find out. I do not follow the masses and may have warped thinking.
Yes I already thought about a copper tube with end cap and threaded fitting screwed into the keg internally into a stainless coupling. On the outside a oil sight gauge and heater screwed into the coupling. Many many different ideas.

Nice calculator scoates, added to my file.
What is the efficiency of a electric heating element in general, for example a 4.5KW element? And a 3.5KW element?
 

kladue

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If you want to install a copper pipe in a stainless keg you need to use 55% silver solder and stay-silv white flux. You will be better off going with direct immersion elements rather than trying to create an indirect heating element with a high wattage element in a oil bath without circulation. I have had a fair amount experience with hot oil heat trace systems and have never seen a gravity circulated heater with the kind of wattage that you are contemplating. Before you go to all the trouble to work up a system, try an element in a steel bucket first and find out if it will work before trying a closed system.
 

slnies

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BrewBeemer said:
Jim; this is the forum where I got more jazzed about heating with electric as I do want to heat with electricity vs propane. Should I have failures I will go to nautral gas, oh god help me if this happens.

http://www.highgravitybrew.com/ProductCart/pc/viewPrd.asp?idcategory=269&idproduct=2351

Tell me what ya think. For their $1,000 asking price I can spend some time and labor converting 15.5 gallon kegs that I already have.

I like the idea of a controller that can be added, again a build it yourself item.
With the difference in heat transfer of stainless vs copper is why I was thinking of a larger diameter thin walled stainless tube at 3 1/2" in
diameter for plenty of surface area.
I'm the type of person that asks why not instead of doing what i'm told, heck maybe egg on face but i'll build it and find out. I do not follow the masses and may have warped thinking.
Yes I already thought about a copper tube with end cap and threaded fitting screwed into the keg internally into a stainless coupling. On the outside a oil sight gauge and heater screwed into the coupling. Many many different ideas.

Nice calculator scoates, added to my file.
What is the efficiency of a electric heating element in general, for example a 4.5KW element? And a 3.5KW element?
What exactly are you looking for? Eff. of heat transfer to the wort? Eff. of the element?
 

scoates

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The "Efficiency" number in that tool is just a fudge factor that reduces the number. I generally treat it as a "% heat I'm losing due to poor insulation."

Truth is I leave it around 95% all of the time, but the idea is that if you have actual numbers for how long your setup takes to boil a given volume with given power, then you can calculate upgrades/wattage changes.

S
 

tbulger

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:off:

i hAve a question about electric brewing. Would it be possible to have a propane fired hlt to get it up to temp fast. As well as a electric heater hooked up to a temp controller to retain temp for a herms system isntead of trying tor regulate propane.
 
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BrewBeemer

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I was questioning the Eff of heating elements in general, will a rated 4.5KW element produce 4.5KW of heat? I figure there would be heating losses thru the oil and the stainless tube, how much a good question where only a test would provide.
My many odd and maybe stupid questions, must show how much of a newbie I am. Lots to learn.

tbulger; that adds another good idea to the build, thanks as that would speed up the process. I would use natural gas.
 

scoates

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Perhaps I'm just wrong, but I understand that a 4500W element (at the exact proper voltage) will produce 4500W of actual heat. If it was inefficient in any way, wouldn't the inefficiency be a heat loss anyway?

Now, my elements are rated for [email protected] I generally see between 218 and 222v according to my meter, so I'm actually getting somewhere around 2750W (19.2Ω element). Ohm's law + the first law of thermodynamics says that power has to go SOMEWHERE... right? (-:

S
 

shafferpilot

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scoates said:
Perhaps I'm just wrong, but I understand that a 4500W element (at the exact proper voltage) will produce 4500W of actual heat. If it was inefficient in any way, wouldn't the inefficiency be a heat loss anyway?

Now, my elements are rated for [email protected] I generally see between 218 and 222v according to my meter, so I'm actually getting somewhere around 2750W (19.2Ω element). Ohm's law + the first law of thermodynamics says that power has to go SOMEWHERE... right? (-:

S
It's so refreshing to hear a comment like this. Yes, all the energy goes to heat.
 

slnies

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scoates said:
Perhaps I'm just wrong, but I understand that a 4500W element (at the exact proper voltage) will produce 4500W of actual heat. If it was inefficient in any way, wouldn't the inefficiency be a heat loss anyway?

Now, my elements are rated for [email protected] I generally see between 218 and 222v according to my meter, so I'm actually getting somewhere around 2750W (19.2Ω element). Ohm's law + the first law of thermodynamics says that power has to go SOMEWHERE... right? (-:

S
no. Ineff. in an element is the flow of electricity that does not get turned into heat. It is the electricity that flows to complete the circuit. In essence it goes to ground. Your math is correct though and for all intensive purposes the ineff. is minimal. Transformers are considered the perfect machine because they perform work but have no moving parts. There inefficiency is reflected in heat loss because they are made out of imperfect material. The same is true of heating elements. They operate on resistance, resistance represents a load and in an element perfect would be 100% energy transfer, meaning that 100% of a watts energy would transfer. This however does not happen because, elements are imperfect. Elements are rated in Watts because that is what they use when they are hooked up to electricity. This how ever does not represent the actual amount of heat that goes into the liquid in BTU's. It is close, but not perfect. Don't get me wrong here. I am not saying that elements are bad, just be realistic. They are designed on inefficiency to produce heat, that is their genius. This means that according to the Law of conservation mass ( 1st law of thermal dynamics) that the energy is going somewhere, just not to heat.
 

scoates

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It's on my 80L kettle, but I only boil ~26L with it (I have a 2nd port for a 2nd element that's currently plugged). I get a rolling boil with the full "3000" (2750) watts, but not too vigorous.

For heat times, see the calculator I linked earlier in this thread. My results are pretty close to what I get from it.

S
 
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BrewBeemer

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With your slow boil at 3000 watts and the High Gravity Company add claiming a "vigorous boil" and having a short "60 minute boil time due to evaporation rate of 30%" I have questions for them. I have a question about their converted 15 gallon stainless boil keg with a 3500 watt heater allowing for what they claim a "vigorous boil". This with 5 gallons not 10? Can it boil a 10 gallon batch not alone with added extra gallons that get evaporated? This morning I sent a email to High Gravity asking how big of a batch they boiled and how long in minutes to bring to boil a 10 gallon batch. Starting out that is with more than 10 gallons allowing for evaporation and a finished boil with 10 gallons. Will post their reply.
 

scoates

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I boil off about 6L/h on my setup (start with 26-28L). It's a lot.
My kettle is very wide for doing small batches like this. I'll go 10gal eventually.

I find it hard to believe that they're boiling 10gal, much less 15gal with 3500W.

S
 

slnies

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BrewBeemer said:
With your slow boil at 3000 watts and the High Gravity Company add claiming a "vigorous boil" and having a short "60 minute boil time due to evaporation rate of 30%" I have questions for them. I have a question about their converted 15 gallon stainless boil keg with a 3500 watt heater allowing for what they claim a "vigorous boil". This with 5 gallons not 10? Can it boil a 10 gallon batch not alone with added extra gallons that get evaporated? This morning I sent a email to High Gravity asking how big of a batch they boiled and how long in minutes to bring to boil a 10 gallon batch. Starting out that is with more than 10 gallons allowing for evaporation and a finished boil with 10 gallons. Will post their reply.
It take a lot of watts to bring 10 gallons to a boil, two 4500w elements for a decent short time I would believe, but that takes juice. In fact I have read many threads here on HBT and it would seem the best electric boil set ups use two. That is my take on it. S.
 
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BrewBeemer

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scoates and slnies;

This is the reply from High Gravity word for word tyoday.

"When we are doing a 5 gallon batch we collect 7 gallons of wort, and end up with about 5. When we do a 10 gallon batch we collect about 13 to end up with 10. We energize the heating element as soon as it is fully covered with wort to get a head start while we continue to sparg. Once we are done it usually takes 10 minutes before a rolling boil is reached".

Thanks very much,
Dave Knott

Note: they didn't say "10 minutes before a rolling boil is reached" with 7 gallons (5 gallon batch) or 13 gallons (10 gallon batch) did they?

This above reply I also question about how this "vigorous boil" reply by High Gravity can happen with only 3500 watts, maybe a sales pitch or selling point by them? I am with you scoats and slnies about this with the low wattage and the reported results you have had. How long did it take you guys from wort transfer to a full boil in volume and the degrees temperature rise difference? Makes me thing why not go to two 3000, 3500, 4500, heck 6000 watt elements or a mix match with 6000 and a 3500 watt to reach a boil then run on the smaller wattage element?
Why not add a voltage chopper like a motor variable drive or light dimmer, rather large like a commercial unit allowing for variable voltage to the smaller single element to control the rolling boil without having a SSR switching on and off all the time? On off going from boil to below boil temp sounds like a bad idea, for controlling a HLT or MLT I can see this type of control. Thinking with a open mind with many options that can be applied here. I love electricity as I was an electrician until this back injury confined me to the house. Watts Is Power, not the city of Watts in L.A. California.
 
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BrewBeemer

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scoates said:
I boil off about 6L/h on my setup (start with 26-28L). It's a lot.
My kettle is very wide for doing small batches like this. I'll go 10gal eventually.

I find it hard to believe that they're boiling 10gal, much less 15gal with 3500W.
S

Well today I got another question answered by High Gravity at (http://www.highgravitybrew.com).

Dave replied, "In our experience it takes about 10-15 minutes from the time we have completed sparging until we have a nice rolling boil with a 10 galon batch (13 to begin with)".
 
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BrewBeemer

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shafferpilot; this is what came up on the Millerwelds forum that I frequent a lot when I have welding questions.
http://i83.photobucket.com/albums/j287/sbsae86/DSC00068.jpg
Stainless cap welded with stainless rod on 16 ga copper tube. This will also work with copper filler rod with copper cap as well copper tube to stainless fitting that screws into a stainless coupling welded into the keg.
Another question answered for my build project.
 

shafferpilot

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Interesting. I never thought that SS and copper could ever be "welded" together. The differences in melting temps are so huge. I'm guessing that the stainless never truly melts. Give it a shot with scrap pieces and definitely let us know how it works out. I'm thinking that the high silver content solder mentioned in your thread on the welding forum might be the next best option. I'm gonna go see if there is a flux coated brass brazing rod that'll do the job. I'll check back in on this in a few days.
 

shafferpilot

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I am finding information on soldering of copper or brass to stainless. The catch is in the flux. Here's an exerpt from brewingtechniques.com:

The silver solder commonly sold for home plumbing with copper pipe will work on stainless, but a different flux is needed. Look for a flux containing hydrochloric acid or one that says it is for fluxing nickel alloys or stainless

There's a ton of info on that page, so I'll let you check it all out:

http://brewingtechniques.com/library/backissues/issue2.6/palmer.html
 
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BrewBeemer

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For testing I was thinking about soft soldering copper tubes to stainless fittings that tread into couplings in the boil keg.
Heat with two 4,500 watt elements until near boiling temp then maintain a rolling boil with one element.
 

slnies

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BrewBeemer said:
Well today I got another question answered by High Gravity at (http://www.highgravitybrew.com).

Dave replied, "In our experience it takes about 10-15 minutes from the time we have completed sparging until we have a nice rolling boil with a 10 galon batch (13 to begin with)".
Say BrewBeemer, how long does their sparge take? Their answer to you in one of the past posts states that they turn the element on as soon as it is covered by wort. This being the case the wort is actually taking the time of the sparge as well before the boil is achieved. Does this sound a little more believable since a sparge will add between 20 and 45 minutes to the time?
 

shafferpilot

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slnies said:
Say BrewBeemer, how long does their sparge take? Their answer to you in one of the past posts states that they turn the element on as soon as it is covered by wort. This being the case the wort is actually taking the time of the sparge as well before the boil is achieved. Does this sound a little more believable since a sparge will add between 20 and 45 minutes to the time?
Now that explains it, doesn't it. nice catch
 

keiths

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I use one 4500 watt ultra low density element in each of my keggles and do 10 gal. batches. I havent timed the boil but it starts fast & very vigorous rolling boil.I have never noticed any signs of scorching either.
BOIL

MLT
 
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BrewBeemer

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Thanks for the reply keiths this adds more information for my keg building project.
I bet a lot faster heating to a boil could be achieved with a insulated keg vs bare even with a lower wattage. Many different ideas to ponder about.
 

keiths

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I have all of my kegs insulated. I wraped the Mash tank twice with the foil type bubble wrap. And it holds temps real nice.


 
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