e-Vaporator

[Cedar Eater]

If an electric preheater is more efficient than a propane-fired preheater, then people who don't go electric for the boil can at least benefit from some sort of immersion type 120 VAC preheater, which would be much cheaper to build than an e-Vaporator and wouldn't require routing a 240 VAC circuit. That's where I see the benefit of adding an electric preheater. It makes the gas burners more efficient. My intent is to stay a small scale hobby producer of maple and birch syrup, with 20 - 30 taps max for maple and 10 or less for birch. So I like the flexibility of being able to use other methods when the primary boiler can't keep up with the sap influx. On-demand point-of-use heaters seem like a useful idea if the temp can be set high enough. Coffee makers and room humidifiers heat water to boiling temp, so they seem like natural candidates for a kluge. I'll look into that after I get my In-Sink-Evaporator running.

The solar preheater could be made with a used Dish or Direct TV antenna with small pieces of mirror or aluminum "furnace" tape glued to the curved surface to focus the sunlight on a glass or metal cup. A Sun-follower to move the antenna isn't that hard to make. Someone else is more than welcome to work up a design for that. I do too much of my boiling at night to think about daytime boiling.

[Locust Farms]

His surface area is closer to 2 sqft, but I'm curious how you came up with that estimate for 5 sqft. The reason I ask is because mine will also be close to 2 sqft.

Hi CE, Trying to get handle on the surface area his 4.5 kw heat source will support for a fast boil when adding a surface breeze which evap faster but requires more btu to maintain boil.

I have extensively used a window fan to apply air to the surface of my 2.5x5.5 flat pan evaporator (wood fired) increases evap rate considerable, also has to be fired hotter with added combust air.

Dwight

[Locust Farms]

Eric,

Another question. How fast do you get a boil in your unit. using full power?

I ask because I installed a 4.5 kw unit in the finish end of my flat pan. It instantly boiled so agressively in 3in of sap, had to shut off.

Dwight

[saphound]

Just based on my limited experience..pre-heating sap makes a huge difference unless maybe you could trickle in sap at about the rate your boiling off water. I didn't have a way to do that so I preheated pots (about 1.5 gal) of sap to boiling on my stove and then poured it in my main boiler outside and it never hiccuped. Otherwise, adding cold sap, I would lose my boil for a good 10-15 mins. That's another hour every 4 pots of sap I didn't have to wait. A slow trickle of cold sap might work..but I haven't tried it.

[Cedar Eater]

Hi CE, Trying to get handle on the surface area his 4.5 kw heat source will support for a fast boil when adding a surface breeze which evap faster but requires more btu to maintain boil.

I have extensively used a window fan to apply air to the surface of my 2.5x5.5 flat pan evaporator (wood fired) increases evap rate considerable, also has to be fired hotter with added combust air.

Dwight

I'm thinking a fan over any evaporator might be a good idea. If Fyreaway can get 3-4 gph from his e-Vaporator, maybe I'll be able to get that from mine.

[67HEAVEN]

I'm thinking a fan over any evaporator might be a good idea. If Fyreaway can get 3-4 gph from his e-Vaporator, maybe I'll be able to get that from mine.

I boiled over propane in the Southern Ontario outdoors and a west wind was always howling across my pan. In my case, a fan would be superfluous.

[Cedar Eater]

I boiled over propane in the Southern Ontario outdoors and a west wind was always howling across my pan. In my case, a fan would be superfluous.

Sounds like you could have used a wind preheater.

[Fyreaway]

...a fan would be superfluous.

67HEAVEN wins the 'word of the day' contest. Well played, sir.

[Fyreaway]

I'm thinking a fan over any evaporator might be a good idea.

Here's how I move the air without excessively cooling the pot.

IMG_0034.jpg

[Fyreaway]

...then people who don't go electric for the boil can at least benefit from some sort of immersion type 120 VAC preheater

CE,
You're exactly right, that would be a perfect place for a scaled down electric unit. A 1500 watt heater in a hotel pan would heat a fair amount of sap to a helpful rise in temp. Also, as you say, there wouldn't be the need for a dedicated high voltage circuit. The key would be the actual evap rate of the primary boiler. The preheater will only work so fast and if you're boiling faster than that there wouldn't be the benefit.