Preheater Recomendations

[Kippster]

Hey all! I'm new to this forum and comparatively primitive in my sugaring outfit. I have a 2x6 flat bottom pan with continuous flow partitions. I would like to build a preheater for the pan so I can get a good boil from one end of the pan to the other. I had a preheater tank similar to those used on the half pint rigs, but found that the condensation was doing as much harm as good. Thought of the copper coil around the stack, but don't want to have to worry about scorching the incoming sap if the fire got a bit too toasty. I like the hood idea, but don't yet have the extra cash to be able to lay out for that. Would a loop of 1/2" copper pipe around the inside of the pan with a valve at the end be a workable option? I'm open to suggestions to make this rig chug along a wee bit faster. Thanks in advance for the suggestions.

Hopefully I wasnt too long winded with this, just wanted to cover all details I thought were relevant.

[berkshires]

If the pipe is inside the pan and over the sap level, you'll get condensation problems again just like you saw. If it's under the sap level, any gains you get from heating the sap in the pipe you're losing from cooling down the sap in your pan - it's just the same as tossing cold sap into the pan, only you do so via a pipe.

If you can run your preheater pipe above the sap level, and then catch the condensate as it drips, so it doesn't go back into the pan - then great... But that's exactly what the fancy preheaters do.

[maple flats]

It doesn't take loads of cash laying around to make a hood nor a pre-heater. I've had 3 pre-heaters over the years, first on my 2x6 and then 2 different ones on my 3x8's. (I needed 2 because the first 3x8 had a 6' long flue pan, and my newer 3x8 has a 3x5 flue pan. All 3 of my pre-heaters were made of copper and each had a drip tray to catch condensate and run it into the gutter system on the hood. Until my current pan set, I made all of the hoods out of aluminum. On the 2x6 and my first 3x8 the hoods were made out of aluminum flashing and they were OK, but on that first 3x8 I decided to make a nicer hood and I bought 3x8 aluminum sheet goods to make a nicer hood. I think on that one I paid about $150 for the aluminum sheet stock and enough 1x1x1 U channel to make the gutter. That hood only took 2 days after work to build, the first one on that 3x8 took about 3 hours and the one I made for my 2x6 took about 2 hours and cost less than $40. plus pop rivets. You can do it, even if you need to bend angles over a 2x4. For a pre-heater both of my first 2 were just copper tubing plus tees and elbows.
I was also going to make a hood for my current 3x8, because the manufacturer gave me a price of $1975 back in 2011. When I got to the factory they asked if I was still interested in a hood and they had one that was a year old demo with some miner dents. I looked at it and said "how much", they said $900, I said $800 and you have a deal. I then had my first factory built hood. Yes, it's nicer than my homemade hoods but both would have served the same purpose. I later made a preheater to go in that hood, and it's the first one that I used factory made manifolds as headers rather than sweat copper t's together, like these https://www.supplyhouse.com/Sioux-Chief-678-20644-1-Copper-Manifold-w-1-2-Sweat-Loops-6-Outlets. If I were to do that again I'd use 1.25 headers with 3/4" take offs, to slow the flow, I think I'd get hotter sap. Right now I get 170-180F until the auto draw open, then it gradually drops to 110-120F.
My point is, just try making a hood, it will be well worth the effort, then make a preheater. Even if they are not the ultimate, they will make the boil faster. Don't forget to have a pan under the pre-heater to catch and drain the sweat out.

[Kippster]

Thanks for the encouragement Dave. Might just be the kick in the rear end that I needed. I've been known, on numerous occasions, to build my own toys. I guess I simply didn't know where to start. Thanks for giving me a nudge in the right direction. The old timer I made syrup with had, about 2000 taps all on gravity tubing. For whatever reason, he didn't use a hood on his 4x16 evaporator. Must be why I had no direction on that. Thanks again!!!

[maple flats]

While there are simpler designs, here's mine:
http://mapletrader.com/community/showthread.php?27826-I-just-made-a-new-pre-heater
Good luck.
A pre-heater really needs a hood, a condensate tray to get the drips out of there and it helps big time to have a damper in the steam stack. For the hood, you must have a gutter around the inside or all condensation goes right back into the pan. The steam stack condensate must also be caught.