copper pre heater around base stack?

[MapleME]

I was brainstorming some way to utilize all that great heat going up the base stack. Rather than use a 5 gallon pre heater box, has anyone experimented with using copper tubing (the small diameter stuff you would supply water to a refrigerator with) wrapped around the base stack between your sap tank and evap pan?

I got thinking about this as I use a massive amount of copper tubing coils to cool down my beer. Copper is just such a great conductor, it works so well to draw the heat off my beer before I go to my fermenter. I figure it would work just as good going the other way.

Hope everyone is enjoying the fall. Im off to pheasant hunt :)

MapleME

[lpakiz]

Yeah, I did it. Worked pretty good. I used 1/2 inch and had about 8 coils around my 6 inch stack. It was not easy to use it, because I had to lift the coil off the stack when I quit for the night. Otherwise it would run empty and scorch. I used a feed tank on top of a 55 gal barrel and adjusted the flow with a ball valve. Sap was too hot to hold my finger under, but I only have a 2X3 flat pan at about 5-6 GPH. I also wrapped a blanket of fiberglass building insulation around the coil. The insulation is just about shot after one year, but I may put a metal sleeve around the coil and insulate over that.
Larry

[MapleME]

larry- ahh, VERY cool. I thought I would use the really small stuff, and do as many wraps as I can get on the 3 foot section above my pan.

do you think you really need to pull it off after you shut down for the day? I boil for 2 or 3 long days on the weekends, so its an "all at once" kinda thing for me. I imagine the copper would be ok on the stack as it cools down, no???

MapleMe

[tessiersfarm]

I use 1/2" flexible copper 6 wraps around my stack and it preheats to around 160 to 180 degrees. I have a small ball valve that I adjust the flow with to keep up with the boil rate. You need to keep it flowing all the time though so it doesn't burn. If my pans are getting too full I run water through it, into a bucket, to keep it from burning. I use the hot water to wash with so it really isn't wasted.

[Haynes Forest Products]

As long as you keep liquid running thru it your fine but just burn the sap once and you will be selling the copper for scrap.

[VA maple guy]

I have about ten wraps of 3/8 copper tubing arround the 7" stack on my
leader 2x6. At the end of a boil all i do is run some fresh water through
the tubing to clean out the sugar. By doing this i don't have to pull the tubing
away from the stack. I also have covered it with 1" ceramic insulation
blanket, it will last just about for ever.

[royalmaple]

Do a search and find johnny cuervo's rig, he has a nice set up like you mention. And it is not wrapped all the way around but held in place with springs so you can quickly remove the copper from the stack if you have to.

I have seen some go through the stack with a piece of copper pipe as a preheater as well. back and fourth.

[brookledge]

Mapleme
Most evaporators are set up with 1" or bigger feed pipes so if you need sap in a hurry it will flow fast enough to keep the problems away.
There fore if you restrict the flow by using a smaller dia. tubing you will want to keep a pail or have a method of being able to dump some sap in quick if you need to. Otherwise for a small set up it should work fine for you. And like the others said as soon as the flow stops it will cause the sap inside the tubing to boil and then burn. If that burnt syrup then makes it into your pan it will affect the flavor.
Keith

[peacemaker]

u need to go atleast 1/2 in i used the smaller and when it was cranking it would blow out in a nice burn mist shake and ralttle the stack scare you the first time it does it i moved up to the 1/2 in and i was all good only thing i didnt like is like some have said it always has to flow i use to have a sap bucket i could run sap in if i needed
and the hot water was also nice at the end of the night to clean up with

[lpakiz]

I had thought about using a second piece of stovepipe to make a "sleeve" that would slide up out of the way for heating and then down between the coils and the hot stack when I didn't want heat. Thought was that the extra layer would stop some of the heat from making it to the coils.
Another thought was a series of U-shaped coils that would mount from the side. Easy to remove. I suspect this is what Matt is talking about---a couple posts up.

[MapleME]

Well, I did a quick design on paper today. I thought if I soldered in a "T" fitting with a valve, I could use this to pour water in to cool it down as stated in the post. This way I wont have to disconnect it from the sap tank, and I can just close one valve and open the other on the water tank.

of all things this came to mind from my paramedic days when we had to piggy back 3 or 4 IV drips all running at different rates. sometime you would need to give a bolus of one drug, turn everything else off and flush it all with saline. It ended up, much of the time, a big mess of tubing and 3 way valves eventually making its way to one point of entry in the patient. The patient, in this case, just happens to be the evap pan :)...I knew those old skills would come in handy again!

[lpakiz]

Yeah, that's a great idea!! Another small feed tank with water, a couple valves--voila!!
THANKS!!

[maple flats]

Look up Johnny Cuervo and view his pics. He has a very neat and effective preheater with the ability to vary the degree of heating in the preheater. He has posted on this is the past.

[WESTVIRGINIAMAPLER]

When I used to have a homemade setup, I ran a section of 1/2" copper pipe the entire length of the firebox and at the end of the day, I would flush it out with aprox a quart of water. The biggest concern I would have about wrapping it around the stack is there is a lot of condensation that would be running onto the stack and dripping down on the evaporator arch. I know the heat would be like an instant drying/evaporation, but I am wondering if it would damage it over time or cause premature wear.

With the homemade setup, it did sometimes boil inside the pipe and shoot out, but it never damaged the sap any and it was always clear, no scorching because of the constant flow and supply.