preheater question??

[mrnorthshore]

Hi everyone, I have a 30"x10' evaporator and built a copper preheater for it. It was built with 3/4" copper pipe and I have about 35 ft of it and I was just wanting to find out if I need a damper of the seam stack,( or do nI need more feet) This spring I could not get it over hot bath water temp and most of the time it was just warm. Any help would be great. Thanks Paul

[lew]

Yes. Put a damper in stack. When boiling, adjust damper so that just a whisper of steam comes out of the seams between the hood and pan every once in awhile. THis will give you the maximum that your preheater can provide.

[ClarkFarmMapleSyrup]

We recently purchased a used Patrick Phaneuf 2x6 with an A&A Metal Shop hood and preheater. Havent boiled on it yet, but the 2x4 flue pan, below the preheater, is all in one hood, and instead of a damper they put a 6inch stack on top to restrict what can go out. The 2x2 front pan has its own hood as well with same size stack and it is elevated to see in the pan,
Maybe you could just downsize your stack size instead?.

[maple flats]

Not good, the ability to adjust is better. Adding a damper is simple, but you need to get inside. Get an aluminum or all SS damper or it will rust.

[nymapleguy607]

A damper will help you gain some, but 35' seems a little small for a 30x10. Depending on how fast your boiling you might not have enough reserve to feed the pans when they take a big surge of sap. I have about 8 30" runs of pipe in my preheater. Usually get over 200 degrees without any problems.

[mrnorthshore]

Thanks Guys, I think I will add a damper and give it a test run. Then if it still does not help enough I will add some more feet to it. Thanks

[wiam]

I think I have about 35' on my 2x6 and that works well. Be careful with the damper. It is possible to close it too much. I have seen a 5x16 burn up both pans in a few seconds because the damper was closed too much. It appeared that the pressure pushed the sap out of the rear pan and there was none there when the front pan needed more. At that point there was not much to do.

[mrnorthshore]

Thanks for the heads-up, I would never of thought about that. Thanks

[Dennis H.]

I have a preheater made by Jim over at Smokey Lake maple. My evap has a 42" flue pan on a 2x5' arch. This preheater has something like 25-30' of 1/2" copper pipe in there. All parrallel feeding the float box.
I mave an 8" steam stack on it. The front pan hood is seperate from the flue pan hood. I get sap going into the float box at about 200 degrees.

It is a balancing act with how much you close off the stack. Too little and you are wasting heat that could be used to heat the sap. Too much and I found I don't get anymore heat into the sap but then have to deal with more condensate coming out of the hood..

[Kngowods]

I am gonna be building a preheater for a 2 x 8 so a 5 1/2 flue pan can I use 50 ft of 1/2 copper pipe or is that to small and go with 3/4? Also Is it ok to use aluminum angle for the drip pan or does it have to be stainless to be considered food grade??

Thanks Adam

[Flat Lander Sugaring]

I am gonna be building a preheater for a 2 x 8 so a 5 1/2 flue pan can I use 50 ft of 1/2 copper pipe or is that to small and go with 3/4? Also Is it ok to use aluminum angle for the drip pan or does it have to be stainless to be considered food grade??

Thanks Adam
I would deffinately use 3/4 copper if I had to do it over again. For the amount you need, just start building it as wide and long as possible that will fit under the steam hood and drip pan catch all the condensate.
My steam hood is aluminum so I dont see why you couldnt use alum. angle for your project