Pre-Heat with Steam?

[justlookingon]

As I watched the steam column leaving my pan today (Mason 2x3), I wondered if a guy could build a hood with piping to pre-heat the sap with the steam?? Has anyone played with this? Could you use 1/2" copper pipe with lead-free solder instead of stainless? Is this a waste of time with the answer being "get a larger evaporator?" Thanks!

[RileySugarbush]

That is exactly how most bigger evaporative pre heat. It is much better than trying to pull heat off the stack:

It can't burn

It works very well and is consistent

It provides a nice supply of sustained water for the sugarhouse


There are lots of example photos here for you to check out.

[brookledge]

There are a lot of preheaters in use. as for copper it is an excellent conducter of heat so it is used. There are probably more out there made from copper than there are from stainless. Anyways the majority of them are called parralel flow preheaters that have many pipes parralel to each other. That gives you the necessary heat surface and higher volume flow than you would get by having a single continueous pipe. Then all you need is a drip pan underneath to collect the condensate and plumb it out to the side.
Most evaporators that usepreheaters do so in the flue pan. That way the syrup pan can be left open or you can suspend a hood over the syrup pan so you can easily see the syrup all the time
Keith

[500592]

I have seen some and they look like they work good

[Maplebrook]

My parallel flow preheater is 5 runs of 1/2" copper, 30' in total, enclosed in a hood. Will preheat to 180 degrees easy.

[Dill]

I have a circular preheater but the exact same idea. I get between 165 and 185 depending on how hard I'm pushing the wood to her. Put a thermometer on it. Not only does it give you something to look at, but it really lets me know how I'm doing at any point in the boil.

[Jeff E]

Yea, it is a great idea and worth working it into your system.
I have done this from my first year with a 2x4 flat pan, setting steel bars across the pan and puting several pots of sap on the bars, in the steam. This was what got dumped in the pan when I needed to add sap.
I would have pots sitting next to the smoke stack, every flat piece of steel on the evaporator, on the bars over the pan....quite a site.

Now I have a piggyback type steam pan the gets my sap to 205 deg before it hits the evaporator. I see about a 60+% increase in evaporator efficiency with it.

Every bit of steam going up in the air is wasted energy...

[Dill]

Actually I pretty much did that on the 2x4, I had a steam tray pan on the back corner of the flue pan. With a tap to trickle sap into the flu pan. It really bumped my rate.

[WESTVIRGINIAMAPLER]

Here is a link to my hood and preheater. It is really simple to build and it works really good. I have plans for building a preheater if you want to send me an pm with your email, I will try to find them and email them to you.

http://s203.photobucket.com/albums/aa160/wvmapler/Preheater/