Need suggestions - preheater placement

[bussell]

Hey Guys,

This is going to be my first year with a decent sugaring rig. I have a wood fired 2x4 oil tank arch and a 2x4 partitioned flat pan. There is about a 7" space between the stovepipe and the back of my pan. Most of this space is metal so its not directly over the flame, but I figured it would be a good place for some sort of preheater. I'd like to have a preheater that is more or less automatic in its injection of heated sap. Rather than having to pour or ladle it in manually.

The problem is, if I'm going to utilize this space, and I rely on gravity, I thinking I am either have to have a really tall preheater, or use something to lift it up so that it is above the flat pan height in order to get the heated sap to drip down.

Is this so? Can you guys think of another solution?

If I were to use a tall vessel of some kind for a preheater, what should I use?

If I have to use something to raise the preheater's height, what should I use? Another pan? Copper tubing?

Thanks again for the advice.

[KenWP]

If you could make a square box like container that fit in that space the same width of the evaporator it could be what ever height you wanted it to be. It would get heat from the flat part of the arch and from being tight against the stack. Then you have a valve near the bottom to dribble sap into the pan. You could also rig up a float system to auto fill also. I am sure your going to get about 50 ideas before the nights finished.

[bussell]

Thanks, Ken. I want all the ideas I can get.

[gator330]

bussell,

Check out the other thread about pre heaters that is talking about the copper coil aroond the stack. Very common pre-heater. Will work great just be shure to get soft copper.

[BarrelBoiler]

my son and i have discussed this a lot for the rig we want to build
my suggestion is a pan something like the warmming pan on a half pint sitting on a frame of angle iron that is covered with attached sheet metal ( anything noncombustable) to gather the heat, like an open top oven, with space at the bottom to allow for air flow. the pan would sit on angle tabs so the hot air could flow around it. a narrow steam table pan would work with something to lift the lip to let the air flow add a small valve and your there

dont know how high the sides of your pans are so this could add some height
hmmm i just realized that using a steam table pan would allow experimentation as to just being in hot air or having hot air flowing around works better

[Gary R]

Bussel,

My first year, I had a preheater similar to what you described. I had a 4 ft. pan on a 5' oil tank arch. I made a square pan that I placed right behind my sap/syrup pan. It was upside down and all the flue gases went into that pan. I made a hole out the back of it for my smoke stack. I then put a preheater pan on top of that. I used a needle valve to regulate flow out of the preheater. I would dump a few gallons in at a time as needed. I later set up a head tank that would flow into the preheater. It worked good. My sap temp would vary depending on how much sap I dumped into the preheater. The best thing about this set up is there's nothing that can go wrong.

[3rdgen.maple]

Siphon the sap from the preheater into other pan. You would have to run the preheater depth at the same depth as you want your other pan. Run an overhead tank into that and regulate the flow with a valve. Might not get extremely hot but something is better than nothing.

[Haynes Forest Products]

What are your abilities as far as welding ,bending sheet metal. If the arch has the stack out the top of the back could you remove the stack build a square extension out of heavey sheet metal that is open on the top for a SS steam table pan? Even Home Depot square furnace duct will work with oil comes in prefab stick together sections.Then run the flue pipe out the back and up. With oil you dont need the natural draft that wood does. Make the hight above the flue pan and regulate the sap with a valve or float box as if the preheater was a bulk head tank. Then as mentioned a small coil before the pan will bring the temp up even more.

[umpwood1]

I am also working on a preheater. I am going to test mine next week. I am coming out of the sap tank, wrapping 1/2 od soft copper around the stack to a ball valve. Just before the ball valve, I will have a tee and a safety ball valve. At the top of the wrap I an putting a tee with a piece pf copper straight up to just above the max water level of the sap tank. On top of the stand pipe I am putting a tea pot whistle, incase of over boil. :confused:
We'll see what happens.
Umpwood in PA

[Haynes Forest Products]

You dont want to be standing under the vent tube. It takes a few seconds to figure out that it hurts:o

[vtsnowedin]

The problem that comes up in these designs is what to do when shutting down and you no longer have sap in the preheater but still plenty of heat in the stack. If your hitched tightly to the stack or haven't thought about your valve set up you can scorch the inside of the preheat pan and per "Flavor" all your sap before it even gets into the pan.
A seven inch pan 24 inches wide and twelve inches tall will hold five gallons of sap and still be small enough to lift off if you need to get it away from the heat. Handles would be a good thing. With a 2x4 that would give the sap about twenty minutes residence time in the preheater depending on how good a boil rate you achieve. If you pipe in the sap from an elevated tank you can put the inlet tube in so it lets the cold sap in down near the bottom. You could use a short piece of copper on the end of the plastic line and just clip it to the inside of the preheater pan. Then a short length of straight tubing could come out near the top of the pre heater to let the heated sap drizzle into the back of your main pan. The valve in will control both in and out that way. At the end of the run just unclip the inlet pipe and set it over into the main pan then lift off the pre heater and pour it into the main pan. If you add a drain to the bottom of the preheater you could draw it off into a five gallon pail then refill it with water to have the stack heat give you hot water to clean up with. There are a lot of ways to clip metal sheet or copper pipe around the stack to hold the heat against the side of the preheater pan but if they take time and tools to hook up and disconnect that can cause scorching problems that a little pre planning can avoid.
Just my .02. Have fun with it.
:cool: Now if you made a L shaped or U shaped pan it could be touching more of the stack.........

[bussell]

Hey Guys,

I ended up finding a cool stainless pan on ebay (it was an unused x-ray developing tank) - it fits my space requirements perfectly and it holds 5 gallons. I just had to have a hole plugged in the bottom and a nipple inserted on the front. Check out my pictures.