drop flue Q's

[stoneslabs]

Hey all,

I'm sitting here at my summer job, thinking up ways of increasing boil rate on my rig. currently I run 27" X 48" continuous flow flat sap pan with a 27" X 30" continuous flow flat syrup pan. with a hood and pre-heater and with good wood and natural draft only, I am averaging 18GPH, with +/- 160 taps on 3/8" natural slope high vacuum.

what I would like to do is build a new drop flue sap pan, without modifying the wall height on my arch, which would net me 4" flues.

my question is, with six 4" deep flues and 2" in between each, is the gain worth the effort and cost to me?

BTW I will also be upgrading the arch to run AUF and possibly AOF as well.

opinions and experience are most welcomed, Thanks!

[n8hutch]

My opinion would be that if your going to go through the work of making a flue pan, make the flues a min of 8", get all you can. It sounds like you are going to modify the arch anyway so why not just keep going. You could even cheat & just add 6" above your current arch rails, add your AOF in that area and you shouldn't have to touch what you have below.

I've always found that only going half way leaves me half satisfied in the end. Good luck.

[RileySugarbush]

You could also modify your sap pan by adding copper drop tubes. It's pretty easy and you can pack them in. I've added them to steam table pans with great results. WarnersPoint has 144 in his if I recall. search on here for some ideas.

[MapleMark753]

Just my thoughts, but you said you are going to add forced air, so why not do that first and see what it nets you in added gph? If its not good enough you could then add the flue pan (which you'll be planning for anyway). The forced air could put you near to right where you wanna be for your tap count.
I do agree with the thought that maximizing the flue depth for your set up is a pretty good idea. Will you then have enough sap to run the rig long enough to make it worth while?
good luck with your plans
take care Mark

[stoneslabs]

My opinion would be that if your going to go through the work of making a flue pan, make the flues a min of 8", get all you can. It sounds like you are going to modify the arch anyway so why not just keep going. You could even cheat & just add 6" above your current arch rails, add your AOF in that area and you shouldn't have to touch what you have below.

I've always found that only going half way leaves me half satisfied in the end. Good luck.

I thought of that but due to the level of my head tank it wont work.


MapleMark, I only tapped 160 of the 200 or so available taps this year because it was a gusher this spring and I couldn't keep up on heavy run days. I was boiling 17hrs for 6 days and watched the 300 gal sap tank overflow 6 to 8 hrs each day :cry: if need be, there are another 100 or so trees within fairly easy reach to keep it wet if need be. I really would like to have a set-up that boils +/- 30 GPH that would cut my time in half...

[maple flats]

Find a way to get an RO, either purchase or build one. Anything near or above 100 GPH will make a huge improvement. If you can somehow come up with an RO in that range, you can tap all of those and still only boil 5-6 hrs. or less. Even a 50 GPH will cut your time greatly.
A 50 GPH that can take 2% sap to 8%, will give you 1/4 as much to boil, a 75 GPH will give you an output matched to your current boil rate, but now you will be reducing the sap by 75 GPH (56 gph permeate removal and 18 gph evaporation = 74 gph. In that time you will draw off 1 2/3 gal of syrup too.

If that can't fit the budget, make the flues 7 or 8" tall and alter the arch to fit. Make the flues 5/8-3/4" wide for sap and 1.5" wide for fireside. Your evap. is a 27" by 6.5' you should be able to get 35-40 GPH, most 2x6's get that if you give it enough air.

[BreezyHill]

I run a 2'x6' with forced draft. and steam hood over the back pan that preheats the incoming sap to the rear raised flue pan.

We have used this rig for several years on the farm until my dad pasted 12-2010 and then we started back up in 2012 due to my middle son insisting and the other two wanting to get back into maple also. That season we had the original 70 cfm fored air fan under the fire and I son added a piggy back of another 140 cfm fan and increased boiling rate from18-20 to 27 for an average. The youngest son could kick that rate to 30-31 and I can not figure how he did it. BUt this past season he still holds the boiling rate record. He does put more in the arch for wood and is always putting wood in.
Last season I added a much larger blower that was picked up at auction from an exhaust fan to remove from garages truck exhaust. 8" suction pipe. This was used half covered so that it would not blow the fire out of the fire box.
This unit jumped boil rate to 37-40 with good would.

I totally agree with Flats. We have an RO. It was first put into service in 1982. The old technology with the current xle membranes will allow me to hookup 4 additional membranes to match the orginal pressure pump to a total of 6 4"x 40" vessels and get the highest sugar level possible in 1 pass.

In the current design of 2 440s I batch to 10-15% sugar and fill the head tank with about 2 hours of concentrate and fire the rig up. I then use the RO to pull of enough sap to have a 40 gallon batch of concentrate every hour. This is very easily achieved by some simple calculations using a refractrometer from ebay for under $15 and opening and closing supply and concentrate valves I added to the RO.

Currently I have a bunch of time on my hands as my family was hit by a drunk driver this past Saturday night. Funny thing is I found out from the troppers last night I was not expected to live. So I cheated the Reaper for a while. I am on bed rest but the coach is more comfortable. I am sorry that I have not been good about getting on the pc since the accident but I only had my cell at Albany Med and the nurse took it away one day. Seems she thought a fractured spine should slow down a farmer.

I still plan to have the new RO setup running by next season but it will be welded in Dec rather than Aug as my oldest son has a separated shoulder and I am banned from trucks for a while right now. So we cant go buy a tig welder before he returns to Morrisville in Mid August.
.
With this large of a fan I will not be adding AOF for a while since I am getting excellent fuel conversion and went all season without cleaning out any ash.

Yes the cost and effort will pay off due to your increasing the surface area that flame will contact sap in the boiling chamber. The more you increase this area the better. I think my flues are 6". If you need I can see if I can get somebody to go to the sugar house to do a quick measurement. It just may take a day.

I would look at doing a combination of drop and raised flue to get more surface area since you are building your own pan. This will maximize your surface area and allow the use of the same arch without changes in bricking or minor changes.

Drop flues require careful fueling of the arch and the ramp design of the arch changes less. Raised flue needs the flame pushed up into the flues for most efficient use of the flame.

Sorry if I bounce around I have a major concussion.

Good Luck!
Ben

[stoneslabs]

nice! pushing 40 with a 2 x 6'... thanks for posting Breezy, and might I say good luck in healing up. unfortunately, these things happen waaaaayyy too often and always to good honest folks!! I seriously hope things go well for you.

I also agree that an RO would make much sense, problem being that the shack is acres away from power. I hadn't mentioned that in the OP...

so getting back to the pan itself, i could get away with 6" deep flues without running into head pressure problems ( sap comes in by gravity due to no power at shack ) 3/4" wide flues for the back sap pan, how much space between? 1"? 1.5"?

thanks for the input guy's!

[lpakiz]

Ben and family,
Sorry to hear of your misfortune, and glad you are doing as well as you are!
Best wishes for a speedy recovery!

[bmbmkr]

"If that can't fit the budget, make the flues 7 or 8" tall and alter the arch to fit. Make the flues 5/8-3/4" wide for sap and 1.5" wide for fireside. Your evap. is a 27" by 6.5' you should be able to get 35-40 GPH, most 2x6's get that if you give it enough air." MAPLE FLATS

My home made arch is 20x60, (AUF) I started with steam table pans, but am now building a 20x20 syrup pan and 20x40 flue pan. I have access to the brake and shear, and my wife is a welder! I have 20ga 304 SS, and want to make a hybrid pan, I have laid out several designs with raised and drop flues. I see most manufactured raised flues are narrower, like the 5./8-3/4 wide mentioned in Maple flats post. Right now with 12" sides, I have a design for 5" deep drops and 3" high raised flues. 36" long inside the 40" pan. Does anyone have any input, recommendations or suggestions. There is only one other sugarmaker in my county, and they hobby on a flat batch pan. I've never laid eyes on a real pan, just what I have seen and read here.

[BreezyHill]

Thanks to all for the well wishes!

I would suggest staying with the industry standard space between flues to facilitate purchase of flue brushes for cleaning off the carbon that can buildup.

Send me an email at bhffeed@msn.com if you want pics of our flue pan. I have not been successful in sending pics in a pm.

Ben

[wiam]

My suggestion would be to look at some pans in person.