PDA

View Full Version : Preheat without a hood



JohnM
05-11-2004, 08:24 PM
Has anyone tried running a coil in to the stack or arch as a hot water heater then another coil into a hot water tank to preheat incoming sap :?: 8)

Thanks!

brookledge
05-12-2004, 06:33 PM
i've never tried it. It seems like its more trouble than its worth. I would think if you had water in a coil to circulate into a hot water tank you would have problems with it freezing when you are not boiling. also if the coil in the stack was to run dry it might heat up and melt solder connections. the other problem is that the coil in the stack could vaporize and explode. What you are asking kind of sounds like a pressure washer with a oil burner. except the pressure washer shuts off the heat when you get to hot. I just dont think your idea will work for the fact that the coil will get to hot with no way to turn off the heat in your stack. Temps in the base stack can reach over 1,000 degrees. The manufactuers have tried all kinds of ways over the years and have settled on using steam as the heat source. Even with steam you can vapor lock your pre heater.

WF MASON
05-12-2004, 08:04 PM
A gentleman several years ago told me he ran a 1/2'' stainless pipe from the back of his arch inside of his arch along the bricks (fire side) up across under the syrup pan , back down the other side and out . Piping it up into the rear pan. He said it worked great. Sometimes the homemade stuff works good.

JohnM
05-12-2004, 08:40 PM
Just thinking about ways to recover some of the heat that goes out the top.

I will be using a flat pan next season and would like a way to preheat incoming sap to help keep an even rate of boil.

Thanks!

WESTVIRGINIAMAPLER
05-12-2004, 09:03 PM
John,

Here goes with what I did last year with the 3x7 pan you will be getting. I set my 150 gallon galvanized feed tank behind the pan and above it for good head pressure. I then mounted a brass faucet with a type of water hose fitting and connected a 10' section of 1/2" copper tubing to it. I then ran the tubing under the back of the pan which was easy since I had it setting on 1" mineral rock insulation. I then brought the tubing thru the arch up to the back of the firebox. I then brought the tubing out of the side of the arch and bent it over the top of the pan where it would feed right into the arch. :D

At the end of each boil, I would unhook the pipe at the tank and pour abot a quart of tap water thru it to make sure I got out all the sugar water. It makes you boil off an extra few ounces of water, but better than scorching sap inside the pipe. :D

It worked good and I controlled the flow with the valve on the tank. The sap was coming into the pan boiling hot and sometimes jumping out of the pipe. This didn't hurt anything and nothing could be damaged as the pipe was pointed into the pan. :D

It was cheap to do and simple to operate and I hope I didn't confuse anyone! :lol: :lol: :lol:

michaelh05478
05-13-2004, 09:54 AM
Theres a canadian company that uses there stack for pre heating.... I believe its part of the preheater hood.......They say it works great....

WESTVIRGINIAMAPLER
05-13-2004, 10:41 AM
Another idea I will throw out there for some of you that like to experiment. I have a 2x8 Leader and the way Leader makes their arches if you push the pans all the way towards the front of the evaporator and put a piece of gasket between the two pans, you still have around an inch space at the back of the flue pan where you can see down into the arch. You could run a piece of copper pipe(1/2" or 3/4") down inside on wall and across the bottom of the arch and bring it up the other side wall and from there to the float box.

You would need to make some connections on it where you could pull it out whenever you quit feeding the evaporator or when you are done boiling at the end of the day. It wouldn't be hard at all to design it where you could pull it out at the end of the day and it should work great.

I haven't tried it, but I don't see any reason at all why it wouldn't work great and would be cheap and very easy to make! :D :D

wanabe
05-14-2004, 09:40 AM
John,


This is what I did last year to preheat my sap for a 2x4. This may be a little confusing to read but is pretty simple to build. I built a small box out of steel for a base and put a grill burner in the bottom. Then I put a 14x24 ss pan on top of it with a devider in the middle making two 14x12 sections. You put a valve in each section then run them to a tee then place another valve(use this to control your sap flow to the evaporator) past the tee. You can run the pipe into the evaporator pan after the tee. Now what I would do is turn one valve off on the pan and one on and set your flow on the contol valve. I did not have a flow of sap to the preheater I would just scoop from a barrel to the preheater with a gallon scoop. When one side of the preheater got low I would shut that valve off and open the other which would be full of hot sap then refill the empty side and let it get hot. This worked very well somtimes had to regulate heat on burner because sap was boiling in the preheater. I was getting 210+ sap to the pan and was getting around 16 gph on a 2x4. Also when you get done boiling you can use this whole set up for a finisher. The only draw back is Propane can get a bit pricey but its worth it.


Sorry think I was babbling a bit!!! :oops:


Jeff