Pre Heater

[lfdiaff]

I have a question about in flue copper coils as a pre heater. My question is will the sap burn in the preheated or is it fine. I think im gonna build a float setup to constantly keep the pan at a certain level. The sap running through the heater will flow through but kinda slow. Im thinking about 4gph. Just wondering if it will be alright.

[maple connection]

I am not sure were you are putting these copper coils as your preheater? In the steam of the pan around the stack?
Kevin

[lfdiaff]

I was planning on putting the coil either in or around the stack.I have read where people have done this. Will it warm enough put around the outside of the stack.

[jmayerl]

Lots of people have done this with mixed results. Make sure that your tube is always dripping because if it stops and vapor locks the sap will burn inside.....not good. And it would have to be around the outside not inside the stack. My people have it so that it almost touches the stack with about .5" clearance.

[Zamkev]

Any chance anyone has a picture of copper piping around the stack? I'm also considering this and could use any advice. How many coils? How far away to keep the storage tank from pre-heater/evaporator? Is lead soldering aok?

Thanks.

[TimJ]

If you search for 'coil' and 'preheater' you will probably find pics. I have seen them on here at various times. Be careful with that kind of setup...

one minute of searching came up with these

http://mapletrader.com/community/showthread.php?12514-Copper-wrap-on-stack-as-preheater/page2
http://www.flickr.com/photos/57535094@N00/sets/72157601539320490/

[Zamkev]

Thanks Tim. As a newbie, I'm still learning how the site works.

Kevin

[SevenCreeksSap]

use lead free solder. it comes in smaller rolls and is more expensive, naturally but you dont want to poison yourself or anyone else

[Ren]

I am thinking that if you run it around the stack on the outside you should be fine, but I would not run it on the inside at only 4 gph. If you run it on the inside, i would add a tee with a valve before the float box so that you can flow a little more gph in to a bucket or it will likely boil in the pipe. I have 5' of 1/2" copper zig zagged in the rear of my arch and at an average of about 10gph it would boil in the pipe. That was a 2x4 divided flat pan. With My new pans I do not have this problem though.

[KenWP]

I found a one way valve to place at the top of the copper coil so that it never vapor locks again.It has to go towards the pan now and sucks new sap into the coil.