Electric evaporator?

[TheNamelessPoet]

http://mapletrader.com/community/showthread.php?26665-Vermont-Electric-Cooperative-Launches-New-Program&highlight=electric+evaporator

This was the thread I found, but a lot of the links are too old ad do not work.

@Dr. Tim Perkins (or anyone else that can answer),

Has there been any more in the electric field? I am looking at possibly making my own electric unit that runs off of 240 (I have a 40-amp plug/breaker for my car so access to it would be easy.

I am trying to figure out how much energy would be needed to boil from mounting UNDER my pan, and insulating the heck out of it. I know you can out it IN the syrup but I have heard that it may give it a burned taste.

Has anyone don a study (I didn't find one) of the wattage-to-evaporation rate? Does it scientifically make sense?

Also, I know that under vacuum, water boils at a lower temperature. So, can you combine a vacuum with boiling, would that make a difference, or is the fact that it is under pressure and there is no steam outlet negate trying to combine the 2?

Looking to understand the science behind it to see if I can create something amazing (if it has not been done already that I can see lol)

[TheNamelessPoet]

What about IR heaters?
https://www.wattco.com/product_category/tubular-heaters/
Like these under the pan.

OR something like IR? I know these are for air, but what about ones that are not for that.
https://www.wattco.com/wp-content/uploads/2017/04/Infrared_Radiant_Heaters_1904318285.pdf

[TapTapTap]

This post got me thinking about comparable fuel cost.
Someone should check my math here. I didn't include efficiency which probably hurts wood more than the other fuels. And, I used 40 gal of water evaporation peyt gallon of syrup which would vary by sugar content of the sap.

BTU = 8100 evaporate water (google)
8100 BTU = 2.35 KWH (Google)
Evaporate 40 gal water for 1gal maple syrup = 93.6 KWH
$0.18/KWH = $16.85 per gal syrup

By oak firewood:
BTU= 25,000,000/cord (google)
Water evaporated= 3086 gal
Syrup= 77 gal per cord
Say $350 per cord = $4.54 per gal syrup

By heating oil:
BTU= 138,500/gal (google)
Water evaporated= 17 gal
Syrup= 0.425 gal per gal oil
$4.53 per gal oil
$10.65 fuel per gal syrup

Ken

[TheNamelessPoet]

Thaks Ken!!!

Electric is 100% efficient as far as converting electricity from the wall to heat.
Firewood is very inefficient as in like 45-55% in a fireplace. In a wood stove it is better but I THINK still under 70%. I will be honest, I am not that knowledgeable with them (wood stoves) 350 does sound correct.
Oil is in the high 80's these days, MAYBE 90% on a home furnace with a high rating (which drops relatively quickly if not cleaned often.

I don't suppose you have any idea propane?

Natural gas you can get efficiency up into the mid 90's, propane is less efficient, but it is still I think at LEAST in the 85%+ range, but I could absolutely be wrong.

Again, we are taking it in a non-controlled environment, but its not like we have THAT much of an option lol.

Part of my issue is, making no matter what you use, more efficient. With wood you have a heat loss going up the stack, same with oil, (I believe), gas, and propane. in part it is because you can't insulate it as well as you can the arch of a wood fired evaporator (aside from heat loss out the stack.

With electric, you could in theory, put the heating element just under the pan, and almost encase the pan (besides the top and SOME of the side) with insulation which would help to keep up efficiency on heat loss, not going up through the pan, like oil/gas/wood.

There are other benefits besides that by using electricity, but they are also worth with everything except wood, so you have to take that into account.

I am convinced there is a way to use pressure to lower the boiling temp as well (besides a steamaway). I just haven't wrapped my head around it yet.

I appreciate the numbers a TON Ken Thank you!

[TheNamelessPoet]

OK, so here is what I found after a quick look.

All seasoned Oak, in perfect conditions can produce between 20-30 million BTU's? Is that correct. Now of COURSE you have to account for immense loses, but even at 50% efficiency loss, that is 10-15M BTU's.

So 10M per Cord - $350 per cord
So to get 10 Million BTU's
Oil would take 72.202... Gallons, lets just say 75 for easy numbers. (I just paid 4.29 last week for oil) That is a total of $310.47 (surprisingly less than wood, I'll be honest I was not expecting that)
Natural Gas Natural Gas would take 1 unit (therm) more than oil for the same roughly. Locally it looks like NG is 3.0867 per therm. That comes out to about $231.50 for 10m BTU's. That does not seem right so I have to find a better source for pricing from the state website.
Propane is 3.56 per Gallon at the local Tractor Supply. So to get 10M BTU's it would be 110ish gallons. That comes out to $394.9
Electric is the most efficient in terms of heat generated, however the cost in CT is so crazy, it is unlikely that it is worth it. (still wont stop me!) 2931ish KW needed @ .24 per KW... is $703.50.
I have not taken into account efficiency, mostly because it has been a long time and I dont really remember them aside from how bad wood was overall as far as efficiency in heating (not counting in wood stove in a house)
That puts it atm as:
Natural Gas $231.50 (I don't think that is right)
Oil $310.47
Wood $350 (does include the efficiency tax)
Propane $394.90
Electric $703.50 (that is pretty laughable, but CT is one of the top 3 states in terms of cost)

[Pdiamond]

Dominion and Grimm made an electric evaporator.

[TapTapTap]

Here's another part of this discussion - how much electrical power does it take?

Again, someone should check my math.

For 100 gph of evaporation:
100 x 2.35 KWH = 235 KWH = 235,000 Watt-hour
@120 V, amps = 235000/120 = 200 amps
Obviously some of these evaporators come in something like 480 V setups.

So on a large scale electric would seem impractical. Even a hobby size operation would be a slow process unless you hook up on a 240V circuit.

Ken

[TheNamelessPoet]

Here's another part of this discussion - how much electrical power does it take?

Again, someone should check my math.

For 100 gph of evaporation:
100 x 2.35 KWH = 235 KWH = 235,000 Watt-hour
@120 V, amps = 235000/120 = 200 amps
Obviously some of these evaporators come in something like 480 V setups.

So on a large scale electric would seem impractical. Even a hobby size operation would be a slow process unless you hook up on a 240V circuit.

Ken

PERFECT, this is the kind of info I was looking for!

The good news is I have a free 40 (or is it 50 maybe) amp 220 line in my house already I can use with the outlet and everything. BUT, your calculation still comes up at 100 amps which is too much for the outlet.

TBF though I am not looking for anywhere close to 100 GPH evaporation, heck i would be ESTATIC with 10!

[CTguy923]

i think you also need to take into account that wood can be had for free most of the time

[TapTapTap]

i think you also need to take into account that wood can be had for free most of the time

I burn wood. But it comes at a significant cost - handling effort, equipment investment, and for some, actual hard dollar expense. And, it is more difficult to control and regulate the heat, sometimes with disastrous results. Fortunately, it also makes the best tasting syrup. Wood-fired is the best advantage a small producer has over the big operations. I'm proud to be a wood-fired maple producer.
Ken

[Fyreaway]

I made and have used a small electric evaporator for almost 10 years. There's a discussion here - http://mapletrader.com/community/showthread.php?25802-e-Vaporator (Keep in mind, if you read, that the cost figures mentioned in the discussion are 8 years old!)

I designed the unit to be able to go tree to table but in truth I finish inside on an induction cooktop. The concern about burning sap on a heating element IN the pan is valid. I clean the element daily and move the sap to a finishing kettle when it starts to get some good color. I use a 240V water heater element so the efficiency is as close to 100% as you can get. The part that I have really embraced as I get older is the absolute absence of obtaining fuel. NYSEG will deliver all I need all day long and the only effort is writing the check.

I make 5-6 gallons a year so I can't speak to how this process would scale to larger operations but as North America moves toward renewable electricity I would bet that the process will develop quickly.

[MajorWoodchuck]

Firewood is also something you can collect up during the off season. Anyone who has a woods that makes maple sap should have wood available as a natural byproduct of trees dying of. I am able to get all the pine crating scraps I want from my company and use that for making syrup. My company pays to get rid of their crating scraps so they are happy when I take it. I end up hauling firewood from my woods back home to sell to buy more maple syrup equipment.

[sandman6921]

I am going to chime in here --I burn COAL -- may well be the only coal fired evaporater going. Why- it cost me less than $80 for 10mbtu's. No other fuel comes close and it is nearly zero effort to fire. I understand it will only work for someone who can fabricate the burner unit, and that has coal available. I use anthracite, which is smokeless. You couldn't do what i do with Bituminous which makes too much smoke, soot and smell.
Regardless, take a look at this fuel comparison table where you can enter the fuel/cost of your choice and see the outcome.
https://coalpail.com/fuel-comparison-calculator-home-heating