Tuning my Leader 2x4 WSE

[maple marc]

New member here, second season on my Leader 2x4 WSE. I have to admit last year I felt like a chimp flying the space shuttle. I got some good tips from the helpful people at Leader, but I had never even seen an evaporator operate. I had previously boiled 3 years on a homemade rig. I was interested to read here that a large evaporator is easier to operator than a small one--I guess it's sort of like backing trailers!

I would like to compare notes with others who have this evaporator or a similar model--or get some ideas from you vets using other gear. I'm getting a 14-15 gph rate, using good wood and firing every 8 minutes--love that egg timer. Would like to improve on this if possible. Sap depth is about 1.75", to the top of the "tunnels." Last year when we started, I had no stack thermometer on my 10" pipe, and by following the advice to keep the draft door open, the stack was glowing red before we realized it. Sap was spitting all over the place. Adding a stack thermometer really helped, and we are trying to keep the temperature in the 800-900 degree range. Boil is more moderate now, but a bit lower gph. Evidently we had too much draft--this evaporator does not appear to need a 10" stack, at least in a converted corn crib. We keep the draft door as far closed as it will go, and block the remainder with fire bricks. This is the only way we can keep it from overheating. Would we benefit from a damper? Last year we used up a lot of hardwood--more than a cord to make 14 gallons of syrup.

My biggest problem last year was surging syrup pan temperatures during draw off. I would open the valve, draw off a bit, and the temperature would surge up by 3 or 4 degrees, giving us heavy syrup. Evidently some mixing was going on. Any ideas on how to prevent this? I take off one to two quarts at a time, which seems to work out. I run it immediately through a cone filter so I do not have to refilter this finished syrup before bottling. With the price of propane today, I want to finish on the evaporator using wood!

Thanks for any ideas.
Marc

[Mike]

Marc, Try drawing off a little sooner.....One of the big operators up here told us the syrup is still cooking when you draw off.....He draws off 1-2 degrees sooner......

[WESTVIRGINIAMAPLER]

You will use more wood on a smaller evaporator. It would take the same amount of wood for a 2x4 as a 2x6 and on a 2x6, you have 2' more of flue pan and thus a lot more evaporation with the same amount of wood.

As far as larger evaporators being easier to use, that's the first time I have ever hear that.

I run stack themps of 1400 to 1600 on my Leader 2x8.

[maple marc]

Brandon, 1400 to 1600 degrees is so much hotter than what I am running now. At what point do you start seeing the cherry red color on the stack that we were seeing last year before we toned things down? Do you ever see that? And is your sap popping and spitting all over the place? How much does your gph vary with stack temperature? At what point do you start to burn up the rig?

When I attended a seminar last year, a Leader rep told us to maintain a stack temperature at eye level of 700-800. What am I missing?

Many thanks for your ideas,
Marc

[HHM-07]

marc

I have an older 2x4 leader with a trop flue rear pan and 2 section front pan , i run about 3 inches in the rear and one section of the front the other section i run .50 to .75 i have a valve between the 2 front sections . the 3 inches is to give me plenty of volume to move my syrup along when i draw off, i don't ever draw more than 1 quart i draw off at a slow rate so i maintain my .75 in my syrup section this works best for me and allows me to have syrup every 20 mins or so. Isee no point in trying melt the rig down i go at a moderate pace and try to have good quality. last year i made 16 gals 5 fancy the rest light and med amber. i go at a pace that i can control it and also enjoy it, i'm retired i'm not going anywhere. Good luck & enjoy it !!!

[RileySugarbush]

There are tradeoffs between maximizing evaporation rate and using your fuel efficiently. If you want to really crank it, then burn as much fuel as fast as you can. The whole rig will be jumping, because the high volume of very hot gases are flowing under the pans. The downside is they are still hot as the enter the stack and that is lost heat up and out of the system. In a longer rig, it would be useful in boiling more sap, increasing efficiency.

Imagine though if you doubled the length of the flue pan, pulling more of the heat out of the flue gases. That is free evaporation because the heat was just going to be going up the stack anyway. At some point, you could maximize fuel efficiency by stretching the flue pan way out, but the stack end would not be boiling hard, if at all. I think it in all of us to not let that happen. It just drives us crazy if the whole pan isn't ripping, so we pour on the fuel, and the stack temp goes up and we waste heat.

Bottom line:

For max fuel efficiency, in gallons per cord of wood, keep the stack temp kind of low, even 400 to 600F, but it may not be boiling hard on the back end.

For max evaporation rate, pour on the fuel and run that stack as hot as you dare.

All of that assumes that the rig is set up right, with sufficient draft and proper spacing and insulation in the flues.

[WESTVIRGINIAMAPLER]

I don't really care about how much wood I burn but I expect it will be less this year than in the past. I have access to free wood and all it takes is mainly my time. I live 30 minutes away from the sugarhouse and work full time, so I want to run it as hard as it will go as I don't have a lot of extra time. As far as stack, it is stainless and never shows any color changing other than the heat making it a little different color. I am running a 760 cfm blower wide open and the wood I burn is mainly locust that has been seasoned for several years and has been drying for 8 months with no moisture and air circulation. Locust is the highest btu wood on the chart. I also burn some red oak and hickory too, but not that much. It is the closest thing to gasoline in wood other than maybe burning pallets.

[Saltlick]

Marc, I have an older 2x4, and have played with the operation for a few years now. And I'm still playing but this is what has worked best for me so far. I don't try an finish in the evaporator. I get the syrup up to approximately 217 degrees and drawoff into a pot with a prefilter setting in a stainer. This prefilter takes out most of the crap. I finish on a small propane stove, (which doesn't take long) and then, pour the finished syrup into a tank with another prefilter in a strainer on top of a sock filter. I never have any trouble with a filter plugging up, by doing it this way. I'm only drawing off about every 4- 5 hours and an able to drawoff a gallon or more at a time. Seems to me that when the syrup gets to the 216-217 level , I have to really cut back on my boiling rate, for control, thats why I decided to drawoff at that point. I should also point out that I try an keep my syrup pan at a 1-2 inch level by using a scoop to put more sap into the syrup pan. Good Luck,
Bruce

[Sugarmaker]

Good thread!
Several very different boiling styles represented here. I see low end easy boil I see moderate rolling boiling and then cranking sap spitting all out let her rip!
You pick your style and get comfortable with it. At some point the rig will only do so much. If you want to boil faster you can only supercharge these so far then you would need to add a R.O to get the boil time down.

We boil pretty hard but try to keep the stack from MELTING DOWN! I do need to pick up a stack thermometer! its a good indicator. I want all compartments boiling hard. That gets me about 80-90 gph max.

Chris