Increasing burn efficiency

[Rastis]

I started off with a Sunrise Metal Fab 2x3 flat pan and arch. Over the summer I purchased a Leader 2x6 dropped flue pan set and lengthen the arch to accommodate the pans. Firebox on the arch is 2x2 and flue is 6". Firing with natural draft I was boiling about 22 GPH. I added forced draft below the fire and increased the evaporation rate to about 32 GPH. Flue temp averages around 500 degrees. One of the things I noticed both before and after adding force draft is there was quite a bit of medium brown smoke coming from the stack. This tells me that it is not burning as efficiently as possible. How do I increase burn efficiency to eliminate the smoking? I would think that this would increase temps in the arch and increase the evaporation rate.

Thanks.

[JDP]

Wait on an expert but I think AOF is needed. Stack temps should be higher? Green wood? Too much wood so AUF is not full value?

As I said.... Wait on the expert. Someone will be along soon.
Have a good season!

[Swampmapleman]

How dry is your wood? Are u still opening your natural draft door? Or is that where you are forcing air through? Also where in belchertown are u cooking?

Matt

[mellondome]

Your not getting enough air in there.... air over fire will help if the smoke is due to unburnt gasses. But if your stack temps are that low, I would look at the wood you are burning. How wet is it? How small are you splitting it ? How often are you feeding the fire? On a 2x you should be feeding the box every 5 to 10 min with wrist size wood. If it is bigger than your soda can, split it again. Unburnt gases will usually show as grey/black smoke.

[Rastis]

I'm forcing in air through the draft opening with an inline duct fan that matches the size of the draft opening. Wood is a combination of 2-3 year old pine and black locust and feeding it every 10 minutes. I'll try doing smaller pieces tonight to see if it makes a difference.

Matt, I'm on Rockrimmon, just up from Fairview Sportsman Club.

[wiam]

Need a squirrel cage. The duct fan is not enough air

[eustis22]

you might think of adding a higher percentage of hardwood in your mix. pine burns fast and hot but doesn't leave much in the way of coals which I have found to be a big diff in internal temps.

pallets are a quick source, though a bit labor intensive

[Rastis]

I have a friend that owns a tree service and log truck, so I get regular deliveries of free wood. I'll have him bring more hardwood over pine.

The duct fan appears to put out enough pressure and volume. So much that I've had to damper the input, otherwise it will begin to blow out smoke from under the syrup pan. Actually this makes me think maybe the 6" stack is too restrictive.

[Swampmapleman]

Sounds like you need an 8 inch stack. What's the base stack width? 18 inches is the minimum. How much stack height do u have? Also wood should the diameter of yur wrist. And it doesn't matter what kinda of wood. Anything will work.

[mellondome]

If you blow smoke out pan sides, then you have enough air under your fire. Concentrate on the wood. That will be the key. With that much air you should be able to make your base stack glow.

How are you measuring stack temp? Internal probe or magnet surface guage?

[Tweegs]

I have a 10" stack on my 2X6.

That's how Leader had it set up.
Came with the arch/pans.