e-Vaporator

[Fyreaway]

For anyone wondering if an electric evaporator is a valid option, the answer is yes.

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This is my electric fired evaporator version 2.0. For a small hobby producer this just might be something to kick around. With an evap rate of over 3gph it makes keeping up with less than 20 taps quite doable.

The kettle is fired by a 4500 watt stainless steel water heater element running at 240v. It's about 18" square and 12" deep and will hold a smidge over 6 gallons of liquid gold. Power is fed through a PID controller and relay (hence the heat sink) giving complete control of every aspect of the boiling process.

Here's a short list of why this thing works for me;
* Never run out of fuel. (Don't have to haul 20# cylinders of electricity.)
* It's cheaper than propane. (That should get some discussion going!)
* Does not need constant attention. (I can get work done around the house and have a meal with the family.)
* Instant on and off. (If I have to leave I just shut off the power, throw a cover on and go.)
* Filter on the fly. (As the sap darkens up I draw off into a bucket with a syrup filter and then dump it back into the kettle.)
* It's a batch boiler so I get a bit darker, richer syrup. (Always a win in my household.)
* At finishing time the PID lets me slow things down to a more controllable level.
* After final filtering the syrup goes back into the kettle and can be held at any temp for bottling.
* Quite portable. (On nice days I set up outside and on the other days I work in the back room with a fan blowing the steam out.)
* It's weird and it's different and I made it myself!

This is the third year boiling with only electricity. Version 1.0 was half a plastic barrel and no electronic controls. It worked as proof of concept so I had the stainless kettle made and stepped up to what I have now. Questions...?

Thanks for letting me share. ~Eric

[Dennis H.]

If the heating element is in the sap/syrup how much junk does the heating element get built up on it?

Neat concept.

[Jeff S]

Eric ,

I would like to see more of the details of your evaporator for example is your heating element directly exposed to the sap you are boiling. Have you considered insulating the sides at all ? Would like to hear your thought about shape of you evaporator, noticed its more narrow at bottom as opposed to just a rectangular box.

As an experiment couple of years ago I made 1 gallon of syrup with an electric roaster with a Kill A Watt to monitor electricity use, the end result was that it cost just under $20 to boil off 40 gallons of sap, how does yours compare. Great job by the way.

Jeff

[Cedar Eater]

It looks easily maintainable. How much did it cost for the custom tank?

[Fyreaway]

If the heating element is in the sap/syrup how much junk does the heating element get built up on it?

The element gets junk built up to a point where daily cleaning is necessary. An hour long soak in warm vinegar and then a few minutes at a rolling boil gets it cleaned up like new. Almost no scrubbing needed.

[Fyreaway]

Eric ,

I would like to see more of the details of your evaporator for example is your heating element directly exposed to the sap you are boiling. Have you considered insulating the sides at all ? Would like to hear your thought about shape of you evaporator, noticed its more narrow at bottom as opposed to just a rectangular box.

Jeff,
I'll have some more pictures after a cleanup. Version 3.0 will be in an insulated cradle and the drain valve will be bigger. The shape of the box was intended to make a complete drain possible without lifting the pan at all. It works really well. There is less than a tablespoon of liquid left in the pot. Without any real scientific research I thought that the triangular shape would allow heat transfer to the surface and create a bit of circulation in the sap. As it is, the heavy bits fall out of suspension and rest on the bottom beneath the heating element so there's no burning of nasties.

[Fyreaway]

It looks easily maintainable. How much did it cost for the custom tank?

I think I gave the welding shop about $200 for the tank. They used stock that was left over from another project so I had very little input into the material. It's plenty hardy but I would probably go with thicker stock next time. As for maintenance, it fits in the slop sink and other than spraying water all over the back room it cleans up very easily. Sometimes it gets a quick wipe down and other times it gets a bit o' polish. A quick soak in hot vinegar cleans the heating element when there's sap waiting and no time for a tear down.

[Jeff S]

Eric,

If your unit will evaporate at 3+ gallons an hour, I could make a gallon of syrup for around $8 a gallon that's not bad for not having to mess with wood.
After all the fees and charges that go with it I figure I pay $.14 a kilowatt to boil approx. 40 gallons of sap.
40 gallon/3 gallons per hour =13.33 hours
13.33hours X 4.5 KW = 60KW
60KW @ $.14 = $8.40 per gallon

Cant wait to see more details
Jeff

[WESTVIRGINIAMAPLER]

An electric stove with a stainless pan on all 4 burners would work good too and way cheaper than propane.

[Fyreaway]

Jeff,
Glad to see I used the same numbers you did. My last electric bill was about $0.09/kWh so I think I'm even farther ahead. The cost of propane is pretty close but the efficiency of the electric heater is real close to 100% where propane is doing well at 60%. I still think that the best part is that NYSEG is very happy to bring my fuel right to my house and they hardly ever run out in the middle of a batch.