Raised flue or drop flue

[dano2840]

i know this has probably been dicussed alot but im not sure which is better drop flue or raised flue. i personally like the drop because its simpler you dont need to put any thing in the arch to raise the heat to the flues and there is 1 float for the whole rig. both pans boil at the same level. But is raised flue better? Just wondering as the rig that im going to purchase is raised flue and i was thinking of finding a drop flue pan for it but wondering if it matters?

[Haynes Forest Products]

I had a 2x6 drop flue and Then went to 3x10 raised flue and I like the raised. What I did like about the drop was you could drain and hose clean the pan..........but it was a pain to disconect the drain and lift out of the arch for total cleaning. You will get a small amount of mixing of the sap with the drain pipe from one section to the next.What I like about the raised flue is you can slide the pan out from under the hood and clean. With the drop flue you could raise the pan slightly and would get pan to fully drain that isnt true with my raised flue.The arch you make for a raised flue is smaller and cheaper to build.

[dano2840]

i wonder which is better at being more efficiant though?

[maple flats]

I think most ratings for like size evaporators I have seen give the raised flue higher rates of evaporation but not by much.

[dano2840]

ok good to know thanks
hey has any one bought a leader MAX flue pan? from what it sounds like they want you to use a tight fitting steam hood, i dont really like hoods, so i wonder if i could use the MAX and not get smoked out of my sugar house? well steamed out......

[brookledge]

Danno
As for efficiency I was told that once you get to the wider evaporators like 5 or 6 foot the drop flue will have more flues than a raised flue thus giving you nore heating surface and give you higher boiling rates.
As for me I have boiled on a 2X6 and a 3X8 drop flue for about 20 years and then went to a 3X12 raised flue. The reason I switched was the price the raised flue was alot cheaper than the drop.
I would also say as long as each flue pan have a drain valve then it is a matter of preference. I have boiled with both and really don't have a preference.
Keith

[Banjo]

Although I don't have much (any) first hand experience, I've talked to a lot of people.

I always had a preference to a raised flu, mainly because you could drain the flu pan. I thought that often times you could get an extra flu or two on a raised flu too.

The clincher for me came last spring when talking with someone with a new drop flu evaporator who had a few close calls with scorched pans. Dawned on me that the extra float in a raised flu setup should give you an improved "control system" for the sap/syrup depth.

FWIW, cheers, Andrew

[brookledge]

Banjo
Every drop flue I have had, had a drain in the flue pan.
Keith

[gmcooper]

I am on my 3rd drop flue and am happy and would get another one when we go bigger again. I like the single float. From some that I have compared the drop flues were narrower and had a extra flue over the raised flues. May not be the case with all of them though.
Probably a "Ford vs Chevy" thing really.
All of our drop flues have drains.
Mark

[WESTVIRGINIAMAPLER]

TheMapleKing got a set of 3x8 max pans for his evaporator last year and it gave him about a 40 to 45 percent increase and he has a stanard arch with a woodsaver package on it which consisted of a blower and forced air grates, but the arch was not completely airtight and he told me he didn't push them very hard last year due to getting used to them. He was running 140 to 145 gph on his 3x8 and he loved the pans. This year he has went to a Leader inferno arch and a steamaway, so he is hoping to be somewhere around 240 to 250 gph.

I talked to another guy that was field testing the pans for Leader 2 or 3 years ago and he was in VT before they sold the pans to the public and he had a 3x12 with a steamaway and he was running 300+ gph and loved the pans too.

I don't know how much more percentage wise they cost above a stanard pan, but if you didn't plan on adding an RO, I think they would be worth the extra money if you are boiling close to 50% more sap with the same amount of wood and cutting your boiling time drastically. I haven't heard any issues with them making more dark syrup over stanard pans and that was apparently an issue in the past when some of the manufactures were selling pans with 11.5 inch flues but we will know the answer to this in time and with the price of all bulk the same across the board, it isn't an issue any longer as long as the prices stay the same for each grade where in the past it made a big difference in the syrup you sold.

[dano2840]

maybe i will check out what the wallet damage will be on it next year, idont even know what kind of a rig im getting yet so we will see