Cedar Eater
04-01-2016, 01:43 AM
One of the problems with both of my electric evaporators is that they have flat bottoms instead of the V bottom that Fyreaway's eVaporator has. The liquid level can go slightly below the top of the elements, because the upwelling of liquid caused by the heating carries the heat away as long as the flow is strong enough, but I can't let the level get too low or the element will get too hot and burn the sugars. So for the electrified kitchen sink, the minimum volume is 8 quarts and for the electrified steam table pan, the minimum volume is 6 quarts.
With the low sugar content of the sap this year and the initial slow start to the season. I was doing small batches of 10 to 30 gallons of sap that were only producing 1 to 4 pints of syrup. This meant that I was boiling up to 7 quarts of water away in my kitchen for each batch. I had several ways to boil that off outdoors, but they either required propane or temporarily disconnecting my electrical evaporators and using my electric smoker instead.
So I put a 5500W 240V spa heating element in a half-size steam table pan, but instead of putting it in the middle to get the nice well behaved fountain that I get from the 4000W element in my full sized steam table pan (see first photo below), I put it as close to the side as I could (second photo) so that I could tilt the pan as the liquid level decreased and make a V bottom. The half size pan fit conveniently into an old 1' square plastic milk crate. Stainless steel is great for not transmitting heat out to the pan rim, so the plastic crate didn't suffer from the first test of it.
1408214081
Without a way to reduce the current as necessary, I didn't want to wire the pan up to 240 Volts. I also wanted the portability advantage of plugging into other circuits so that I could use my 240 Volt 50 Amp feeder for the other evaporators, so I spliced high temperature wire to a 12 AWG 110V extension cord that I cut the female end from, and I plugged it into an outdoor receptacle. That only puts 1375 Watts into the pan, which will slowly evaporate 9 quarts of water, but it barely brings six quarts of water to a weak boil. But 8 quarts of hot sap that has already been concentrated down in the electrified kitchen sink reduced down to 2 quarts at 216 degF outdoors in 50 degF weather in about 2 hours as I slowly increased the tilt on the milk crate until I had it up to 45 degrees without spilling over the side. By that time it was boiling so vigorously that I needed to either reduce the current or move the 2 quarts into a pan in the kitchen. That 2 quarts reduced down fairly quickly to about 1-1/4 quarts of syrup on the kitchen stove.
This was just a first test boil. Insulating the pan will make it more efficient and I may wire a 15A infinite switch into a 1 foot square box to allow me to reduce the sap further in this pan, but I'm actually pretty happy with the way it works now. The closer the sap is to syrup, the faster it will boil down, but it wasn't terrible as it was. It would have taken longer to boil it down entirely on the kitchen stove. I will probably just replace the splices with an on/off switch.
The materials cost was around $50.
With the low sugar content of the sap this year and the initial slow start to the season. I was doing small batches of 10 to 30 gallons of sap that were only producing 1 to 4 pints of syrup. This meant that I was boiling up to 7 quarts of water away in my kitchen for each batch. I had several ways to boil that off outdoors, but they either required propane or temporarily disconnecting my electrical evaporators and using my electric smoker instead.
So I put a 5500W 240V spa heating element in a half-size steam table pan, but instead of putting it in the middle to get the nice well behaved fountain that I get from the 4000W element in my full sized steam table pan (see first photo below), I put it as close to the side as I could (second photo) so that I could tilt the pan as the liquid level decreased and make a V bottom. The half size pan fit conveniently into an old 1' square plastic milk crate. Stainless steel is great for not transmitting heat out to the pan rim, so the plastic crate didn't suffer from the first test of it.
1408214081
Without a way to reduce the current as necessary, I didn't want to wire the pan up to 240 Volts. I also wanted the portability advantage of plugging into other circuits so that I could use my 240 Volt 50 Amp feeder for the other evaporators, so I spliced high temperature wire to a 12 AWG 110V extension cord that I cut the female end from, and I plugged it into an outdoor receptacle. That only puts 1375 Watts into the pan, which will slowly evaporate 9 quarts of water, but it barely brings six quarts of water to a weak boil. But 8 quarts of hot sap that has already been concentrated down in the electrified kitchen sink reduced down to 2 quarts at 216 degF outdoors in 50 degF weather in about 2 hours as I slowly increased the tilt on the milk crate until I had it up to 45 degrees without spilling over the side. By that time it was boiling so vigorously that I needed to either reduce the current or move the 2 quarts into a pan in the kitchen. That 2 quarts reduced down fairly quickly to about 1-1/4 quarts of syrup on the kitchen stove.
This was just a first test boil. Insulating the pan will make it more efficient and I may wire a 15A infinite switch into a 1 foot square box to allow me to reduce the sap further in this pan, but I'm actually pretty happy with the way it works now. The closer the sap is to syrup, the faster it will boil down, but it wasn't terrible as it was. It would have taken longer to boil it down entirely on the kitchen stove. I will probably just replace the splices with an on/off switch.
The materials cost was around $50.