Sap Preheater Pic for Eberzin

[Johnny Yooper]

Here's a pic of my sap preheater

[Sugarmaker]

Does it work well?
Regards,
Chris

[Johnny Yooper]

Does it work well?
Regards,
Chris

Yes: 40°F sap in, 160°F sap out. I'm thinking about splicing in more length to get beyond 160°F; I like to experiment each season to up the game (efficiency) so that's probably one of the things I'll try this year.

[Cjadamec]

Try wrapping the preheater in insulation or some sheet metal. It will gain you a fair bit more heat without need more tubing.

[Johnny Yooper]

[QUOTE=Cjadamec;364215]Try wrapping the preheater in insulation or some sheet metal. It will gain you a fair bit more heat without need more tubing.[/QUOTE

I wrap the preheater with aluminum flashing; I just rough assembled the parts together yesterday to snap a pic for Eberzin, I probably won't start boiling here for another 5+ weeks. What is the outcoming sap temperature on your preheater?

[Cjadamec]

As long as I have the pump throttled the sap coming out is too hot to touch. When things are going full force it's warm enough not to kill the boil. Never really took the time to measure output temp. Figured as long as the pans stay boiling when there is a stream of water being pumped in that was hot enough.

I have about 35 feet of 3/8 copper tubing wrapped around the stack. I used a leftover piece of ceramic wool and covered that in aluminum tape. I make sure to flush it with clean water at the end of the boil and take the plastic valves off so it can drain and dry out.

[Eberzin]

Thanks for the pics

[David Wayne]

I know this is an old thread, but I tried this sort of thing today. I used 10' of 5/16 copper around the stove pipe to feed directly from my ro bucket. Temp rise was minimal, so I put a ceramic blanket on it. Sap temp went up too hot to hold my hand under witch was great until I noticed the stove pipe was cherry red.
Because of the layout of my setup the stove pipe runs horizontal 4' to the wall exit, so I am thinking of going with 3/8 or 1/2 inch tubing and maybe 25' to give more time for heat transfer. also thinking of running it back and forth across the top rather than around so I can just lift it off when the ro is not running.
Any chance this will work? Or am I wasting my time?

Thanks David

[Cjadamec]

You could always just get more 5/16 tubing and just add to the 10 you have already. 10 feet of tubing isn't that long of a run.

You could also try a price of sheet metal over the coil you have rather than insulation. That will trap heat on the coil but still allow the stove pipe to radiate heat.

You can try laying the coil ontop of the pipe if you are able to make those bends without putting a kink in the tubing. Thin copper tubing is difficult to bend into a tight radius without kinking it.

My rig also tends to get a little glowy at times but it's not due to the preheater on the stack.

[David Wayne]

That is scary hot. I will go more tubing for sure just not sure of size yet. Biggest issue is keeping it tight to the pipe but I will experiment with possibly cutting the ceramic into strips to leave some space for heat to radiate out, and some wire to hold the tubing tight to the pipe. I guess too many hours watching sap boil makes
the mind start thinking of different things to try.

David

[dadtkm]

Hi David , being able to remove when not in use is a good thing. My first pre heater was tubing wrapped around the stack and every time I started to run sap through it started with nasty green stuff that I had to catch so that it didn't get into the pan. Here's what I use. When the pan starts to boil I put the pre heater in place and remove it when I'm finished.2094720948

[Johnny Yooper]

2020 update on my copper coil preheater shown in the top of this thread - since that picture, I doubled the length of the copper coil, and continue to wrap it with aluminum flashing to minimize heat loss around the coil, did some experimenting with and without the blower running for air under fire....incoming sap temperature was ambient, so in the 40's; without running the AUF, sap exit temperature around 160 to 170F, but with the AUF and the rig really rocking the sap temperature increased to 194F, so I'm raising sap temperature by 150F just by using heat going up the stack, pretty satisfied with the results.

[Kchamp]

I have been thinking of doing this, what size cooper line did you use? any more pics?

[Johnny Yooper]

I have been thinking of doing this, what size cooper line did you use? any more pics?

I believe it's 1/2 inch trade size flexible copper tubing, but I'll verify when I get to the shack to take some pics, should have them on here in a day or two.