Making a "new" evaporator?

[Pete S]

I've been lurking and posting for only a short time, and was looking for some additional advice.

Yesterday, the Boss and I were talking about how nice it would be to be able to boil down 60 gallons of sap in 8 hours instead of the 15+ hours we now endure.

I've currently got a home made rig, that's REAL basic, utilizing a large commerical aluminum cake pan and a Nesco pan for pre-heat (my photo was too big). I have a fasination with the 250 gal oil barrel rigs, as I'd like to build my own.

BUT, does a bigger "flat" pan, and possibly more heat assure me to reach an appreciable increase in my boil rate?

Because we all know, the faster one can boil, the more taps and buckets we need.

Are there "better" pans that would "drop on" to a 250 gal oil barrel rig when we decide to make the next move,.........if we simply started with a flat pan?

Thanks!
Pete

[Dennis H.]

I know there is more knowledgable people out there to help you out more than me but I will explain my case.
When designing my rig, check out the posting "Building a Drum Evaporater", I had to take into account how much sap I thought I was going to have at any giving time. I am starting out small, 16 trees, and knew that I wouldn't have a ton of sap at one time. So I had to size my evap pan to that and how often I was planning on boiling.
My plan right now is to boil once or twice durning the week in the evening and then on the weekend. That way I would get enough sap to be able to do a good boil.
My pan is going to be a flat pan with no dividers, for now. I was going to do batch boils
So with all that info and all the help I got here I determined that a pan that would fit on a 55gal drum would do just fine, for me that is. My pan will be 20"x34".
I could of went bigger but with a larger pan and with the amount of sap I think I will have I would run the risk of scrotching the syrup. I have been told that the shallower you can run the pan , about 1" or so, the faster you will evap but the more of a chance something could go wrong, fast.

I hope this helps a little, I know I have lerned a lot in the little amount of time I have been here. This is a great bunch of people to ask when in of help.

Dennis

[Cardigan99]

Hi Pete. I'm not sure there are regular pans out there that will 'drop on' to an oil tank rig. The one I have measures 27 inches across. I had a stainless flat pan made up for it at a tin shop i used to work at. It cost me around $250, but we were getting a good 15 GPH out of it without a hood. That said, I know there are some slimmer tanks must be closer to 24 inches wide and I'm sure you can get a 'professional' pan to fit that with some minor modifications to the tank.

[Dennis H.]

I knew there was reason I told you the size of the pan I was going to use, I hate when the train of thought derails.

A gal of sap takes up about 231 cu/in. For my pan 20"x34" a 1 in layer of sap is about 3 gals. 2 in would be about 6 gals. Someone correct me if I am wrong here.
Anyway, with my 16 trees I think I will get 1/2gal per tree per day, I am trying to be on the low side here, and since I was planning on boiling every 2 to 3 day I figure I will have 16 to 24 gals to boil at a time. So with that info I know that I don't want to let the pan get less than 1"(3gal) I think my pan is sized about right for my amount of sap. At the end of the day boiling I will take that semi-syrup and set aside till I have enough semi-syrup to boil a whole batch to syrup or I will use a propane burner to finish the syrup depends on how much semi-syrup I have.

Clear as mud right?? I hope this helps in showing that the size of the pan depends on how much sap you will be boiling and how much time you have to boil.

[Pete S]

Well here's my thought(s),....................Currently, it takes us about 16+ hours to boil through about 60 gallons of sap. I haven't really commited any math to a boil rate, but that's a long time.

Our current pan will hold about 3" deep of sap............in the center cuz it's got a purty good belly.

We are very attentive to our boil down, but after the sun starts to drop, and I've been out there (outside, no shack........see cupola venting post) I feel like I've been watching paint dry all day!

We just keep awn adding, and adding..................boiling and boiling.........!

Anyway, IF I would KNOW that I could at least cut my time in half, by building a bigger better rig............that would make me real interested in getting started SOON on the design/build.

We get busy during that time of year, and I typically boil one day a week,.........namely Saturday.

I'm not becoming disinchanted with this process, just am looking to move'er awn up!

Thanks for the responses!
Pete

[Grade "A"]

It is all about surface area and lots of heat, so the more steel that is in contact with the flue gases and your sap the more you can boil in a hour. That is why a flue pan boils so much because it has alot more surface area than a flat pan. My math tells me you are boiling about 3.75 gph. What size is your pan now? I would think you could get around 10 gph out of a flat bottom pan the size of a 275 gal. oil tank. I am sure that somebody here in maple land would have more/better info for you than me. I learn something new here everyday. Good luck!

[JFH51]

I have a 20 X 30 flat pan setup that I maintain a 6.5 to 7.00 gph on. I have a 9 x 12 x12 preheat tank that gives me 190 deg into the evaporator pan. I boil indoors and do have forced air into the fire box. I typically boil for 10 hours and then draw it off and finish in a small propane heated unit. I find that this method gives me nice light colored product and I can finish up in a comfortable amount of time.
John

[325abn]

Here is a shot of my Small Brothers Lightning raised flue pan. I am not sure where you could find one of these pans but I bet there is one out there somewhere. I picked this rig up last year from a divorce situation. As you can see it is sitting on a oil fired oil tank arch. After VERY much tweeking I was able to coaks about 29- 31 gal/hr out of this rig using a 2gal/hr nozzle.

[WESTVIRGINIAMAPLER]

325,

Definitely is a great evap rate out of that pan with that size nozzle!!! What size is it, 2x4??

[325abn]

Closer to 18" X 4'. I also have a hood that goes on the rig and the sap is preheated with copper tube aroung the smoke stack.