Series Loop preheater

[flackvillefarms]

The coin valve I added is actually the highest point in the preheater system. Still tinkering with it to get it set right. I believe it is set about right now though. Boiled for about an hour or so at full steam didn't see any issues yet. It was pretty neat to hear the valve venting though when it was filling up.

[maple flats]

Good another success story. Good job!

[flackvillefarms]

Test boil was great. averaging in the 150's on the temp coming out of the preheater. Only boiled for about an hour. That was amazing compared to outside temp sap hitting direct into the float box of the flue pans like it did before. I have my levels up in my pans as well pretty conservative at 2" right now as I have much dryer wood this year and the preheater. Since I'm sure I can bump up those temps I will be adding a partition between my flue pan and syrup pan to partially separate the two within the hood but still allow steam to exit out through the hood from the front pan. I will also include drip rails on the partition to move any water to the main drip rail of the hood. I will also be adding a damper to the steam stack. I will probably do that during the first cleaning. I have two front pans so usually I swap them and on the third go I pull the flue pan and pressure wash it out as well, at that point I will have the hood off and will be able to drill and clean it up without contamination.


I also want to add a gasket to the rail of my flue pan where the hood sits. Not sure what to use or where to acquire from?

[Sugarmaker]

You did good! The damper will help the most to get your sap in the preheater to 180+ Don't worry too much about the gasket. The hood needs to have some air going in to get some draft anyway. Your damper doesn't need to be 100% closed, about 70 -80 % is usually about right. You will know when the steam strarts filling the room as it comes out of the cracks in the hood. Open the damper just a little and that's as good as you can do. Sap temp should jump up to 180 or maybe 200?

Regards,
Chris

[Eberzin]

Now I need to make at least a preheater. What kind and size of plastic tubing is it that you are using coming into your rig? I was using cpvc but may switch to something else.

[flackvillefarms]

I will give that a shot. I bought the aluminum to build one just haven't gotten to it yet. Had a snafu in the woods involving my vacuum system. Its all good now. The short version is plastic breaks due to vibration.

Eberzin the hose I'm using is a 3/4" food grade flexible hose I source from my local maple supply place ( Macks Maple supply in Potsdam, NY). I used the line instead of PVC or copper in case of a freeze. That way stuff has room to grow if I forget to drain something. I use it all around besides from the feed tank. Makes great transfer pump hose too. I do have an 8" long piece of 3/4"copper in the system coming from feed tank to give me a place to heat if I need to start thawing out stuff.

I don't remember if I mentioned it but my preheater is built with 3/4" copper and ended up having 6 loops.

[flackvillefarms]

For those following I built the steam stack damper, rain catcher for steam stack( may need revision), and divider plate that helps traps the steam to the flue pan while still venting the front pan. The divider has its own rain cutter "broke" into it that drains the water to the side troughs of the hood. I added a piece of 1"x1"x2' sheet angle between the flue pan and smoke stack to catch condensation and channel it to a bucket. I'll post some picture later if any would like, but it's off to my day job for now.

What does this all matter? At a full boil, while I was sweetening the pans. I had sap temps of +180 degrees coming from the preheater to the float box. Super happy with that. I also filled two and a half stock pots of water that came down the condensation drain tube. So I also had plenty of water to clean stuff up with. Which makes trips back to the house very minimal. Life is good. super happy with the results. I had 100 gallons of sap yesterday here so its starting to move.

[Sugarmaker]

Ok I applaud you for your work and documenting the results! Yes the hot water is a nice plus and you got the sap temp about as hot as possible. Nice!
Regards,
Chris

[mainebackswoodssyrup]

Revived an old thread rather than starting a new one. Is 1/2” pipe the standard for most preheaters? I am going to have one built and he is suggesting 1/2”. I was thinking 3/4” pipe in my head probably because that’s what I have seen before. His reasoning being that the 1/2” will heat better and quicker. I agree, just worried about the vapor lock. Go with the 1/2” and add a small valve to the pipe at the high point as suggested?