How to use damper for preheater?

[PACMAN]

I have read that there should be a damper in the steam pipe for the preheater.How would you use the damper?

[Bucket Head]

You can partially close the damper to hold a little more steam in the hood to heat the preheater better. The more the damper is closed, the hotter your sap will get. However its never completly closed. You have to play around with one and see where the happy medium is- the highest incoming sap temperature you can get but still be allowing the steam to escape without it being restricted. With that said, a damper is not a requirement in order to have a preheater. Steam will still surround the preheater and heat the sap without one. I get 190 degree incoming sap with my preheater with the damper wide open, and 190 degree sap is still way better than 45, or 39, or 33 degree sap- whatever the outside ambient air temperature is!

Steve

[PACMAN]

So if I start with the damper half closed,that should be a starting point?I can play around with it while I am boiling. I read the Leader cataloge and it said they recommend a damper.They also said the pre-heater would work better with a stainless hood. theWhat is the hottest the sap should be comming from the preheater into the control box?

[RileySugarbush]

You can close it until steam starts leaking out of the hood. Then open it until that stops. That will maximize the preheating and still keep you out of the fog. I have a 7" steam stack on my 2 x 3 flue pan and run it w/o a damper and get very hot sap. Probably 160 to 180 F.

[wiam]

There is no "too hot" for sap out of the preheater. I have seen a rig burn up both pans from the damper closed all the way. Literally fire in the pans and ruined both pans. 5x14 Be careful.

[Bucket Head]

Yes, a damper would be reccomended, but its not a 'must have' for a preheater to still preheat. It just won't get as hot as it could with one. A stainless hood would hold the heat a little better than an aluminum one, because aluminum disapates (spelling?) heat better. However, I doubt you'd see a difference between the two. Mine is aluminum and it works flawlessly. Its less expensive than stainless and its easier to move because its a little lighter.

As for Leaders suggestions, their trying to sell stuff and make money. Their going to reccomend a lot of things and push stainless items over the aluminum ones. We, as frugal sugarmakers, will share what works and what works well for us, and will share how to do it inexpensively.

Steve

[lew]

As others have said, close the damper until steam comes out of the cracks , then open it up until the steam stops leaking out the cracks. On windy days you might need to leave the damper open a bit more. As far as how hot. You need to have a vent on the preheater or you can get it too hot and start the sap boiling in the tubes. without a vent it can vapor lock and not let any sap through to your pan.

[Dennis H.]

I used a preheater for the 1st time last night and worked great.
I haven't had the time to put the damper in yet so I am using a flat cookie sheet to cover the steam stack.
I ran it with out any resitriction and had sap going into the float box at 180 covered the steam stack 2/3 and sap went up to 196!!
Good enough for me.

Like someone said earlier, way better that 35 degrees.

[wiam]

Sweet