please help me figure out whats wrong with my rig!

[nitsujlobos]

So i need help figuring out why i cant get a good boil going on my barrel evaporator. I purchased it as a work in progress and it had a oil burner mounted on the front. So i cut off the burner cause i wanted to use wood and i welded a stove door onto it. When i got it the entire barrel was empty so i lined the sides with fire brick. I also built a wall about 18in. in from the front of the barrel. So my firebox is 13x18in. So i finally got it all done and went to fire it up yesterday and burned for a couple of hours and could only get a slight boil going in the middle of the pan. And that was with a fan blowing directly into the fire with the door open. I'm going to build an air duct setup today so can blow in air from the rear and have it come up right through the firebox so i can keep the door closed. I will post some pictures later on today. What else do i need to do to get this thing going right? Please help, the sap is going to be flowing soon!

[KenWP]

What kind of wood are you useing. If its damp nothing will ever get hot.

[Haynes Forest Products]

On your test run was the wood smoking alot? Do you have a draft door? If you open the doors and blow air into the arch are you blowing the flames away from the bottom of the pans. Blowing in a blanket of cold air to keep the fire hot but also blowing the heat away is counter productive. What size flue pipe do you have?

[Turtlecreek]

Did you ramp the back of the arch so the flames play on the back of the pan before exiting out the flue? Could use a flue damper maybe. how deep are you running you pans? How far below the pan is you fire and does you fire have a grate below it so it gets good flow? Pictures would probobly help answer a bunch of questions.

[Jeff E]

I agree with where Haynes is going. On my rigs I loose the good boil when I open the doors to add wood. To much cool air under the pans.

#1 you need good wood. DRY. A lot of BTU's get used up cooking out moisture from wood before it can burn if you have green wood.

#2 Keep the fire door closed, let the air in below and adjust to get a no smoke fire. My rigs would burn clean, meaning no visible smoke, about 10 minutes after starting up the fire.

[Haynes Forest Products]

NitBo: What size flue pipe do you have? Others have mentioned you need to keep the heat in the arch. There is a fine line between the fire you have in the arch and the gases leaving the flue stack.

[Mac_Muz]

And how tall is the smoke stack, also what diameter is it. We need pics.

I don't have the best wood, as it is years dead standing, no bark, not particularly dry, but I understand what a exhaust system should be, and so can get a 21x34x6 pan boiling alll over , even add hunks of sugar ice and not slow the boil.

If you like see a thread I made for sap seeker to see (pics heavy)

[TapME]

Mac you are on to something there stove pipe length.
Haynes, your suggestion about dry wood sound good.
I would suggest that you look at MacMuz pics and see if you can match his. From what I have seen it Boils great.

[nitsujlobos]

ok so i have good dry wood, i dont think thats an issue. i rigged up the forced air fan and it seems to be much improved but not a roaring boil like i want. i got about 1/2 the pan boiling but not the front. i'm using 6 inch pipe. it goes up about 2ft, straight out through the wall then up 6 feet. I'm thinking maybe try a flue damper. I took some pictures going to try to load them on now

[nitsujlobos]

not sure if this is going to work but is should be a link to the photos

http://viewmorepics.myspace.com/index.cfm?fuseaction=viewImage&friendID=16738716&albumID=351846&imageID=50869418

[Sugarmaker]

Try removing the two bricks that are some what blocking the fire from going directly to the flue. They are running across the evaporator. Then fill the rest of the raised portion with sand to the level of the bottom of the flue. Might help?

Chris

[Haynes Forest Products]

OK thats it Im mad Dunkin Donuts doesnt sell beer in Denver. I think filling in the back area so the flame doesnt go down away from the pan and then out.

[birdmancf]

I think it's all about your flue and not having a damper. It's just like a problem someone had earlier with an old box heater converted to t sap stove. You have to have a damper in it to slow the speed that the hot gases exit, that is why now just the back half is boiling. Open the damper wide to get the wood cranking, close it down part way to keep the heat longer and get the sap going. You'll play with the amount to find the "sweet spot" (pun intended). You should be able to do fine on that rig.

[TapME]

ok so i have good dry wood, i dont think thats an issue. i rigged up the forced air fan and it seems to be much improved but not a roaring boil like i want. i got about 1/2 the pan boiling but not the front. i'm using 6 inch pipe. it goes up about 2ft, straight out through the wall then up 6 feet. I'm thinking maybe try a flue damper. I took some pictures going to try to load them on now

you have 2 90 degree elbows in your pipe. The 90's will slow the exit of the flue gases and may be part of the problem. A straight stack is like a chimney and yours has a few obstacles. something to think about. Raising the fire bed and the ability to get air under the fire could be an option. Pics would be a real plus.

[Haynes Forest Products]

He has pictures of it along with a DUNKIN DONUTS THAT SERVES BEER.

[nitsujlobos]

so im going to install a damper and rearrange the fire brick pattern in the rear and see if that helps. not sure on the pan guage but it is thin. also dont worry that is not a dunkin donuts that serves beer its fenway park in the backround

[Brian Ryther]

Surface aera. It appears that your walls are 1/2 as wide as the pan surface. I might remove the top cource of brick or cut them in half. It looks like your are insulating 6+ inches of the bottom of the sides of the pan.

[Pete S]

IF,.........I'm following your posts correctly, the last post shows what you're currently working with.

IF,...........that's the case, from the burn pattern that's there,............you're just not burning hot enough. The bricks should be all white and chalky looking.

We have a small evaporator, much "like" yours,.................and you need to build and maintain a fire in it as if you were trying to destroy it with fire!

Dry wood, and air, and at least a 5-6' stack should get you where you want to go!

Keep us posted!

Pete

[Mac_Muz]

Well I am not sure what is wrong. If that were mine the first thing I would forget is the fan blower, what ever that is.

Then I would remove the 2 bricks at the rear of the fire box, and take one as a test and sort of block off the smoke stack exit.

The next thing I would do is add another section of pipe.

A normal damper is optional, one that turns.

i think it would be a good idea to look at the internal damper I made in my stove. All I did was take scrap from the cutting out of the top, and bend it like a 1/2 bucket with tabs to tack weld it to the back of the barrel, adding a 1/2 circle from the cut out for the pipe.

How deep is this pan , meaning how many inches of sap is in it full? My pan is 6 inches tall, but only 5 inches of sap when full. I can make the whole pan come to a mad boil. 6x 21x 34.

see the thread to sap seeker.

In other words I sawed out the circle for the smoke stack, and took that disk and cut it in 1/2 to use as a bottom in the 1/2 bucket.

Yes there is a 90 degree down turn for the flame path, and yes then there is another 90 degree turn up and out.

I use a lot more wood than I need to, but because I am trying to get rid of a lot of nasty dead trees as fast as I can.

Get the cool air in low and get plenty of it with out that blower.

I am none to sure about the bricks really, but it appears as these are blocking heat to the pan too.

I can't really take a picture of my rig at full boil, because you can't see anything with the steam.

No pics are at a full blown boil, for that reason.

I can't see the intake grill or what ever is there...

And what kind of fan is it anyway?

[swierczt]

What about the size of the firewood? I run a barrel-type rig too, and I know if I don't keep the firewood small (no bigger than the size of your wrist) I'll kill the boil in a hurry. I've learned that trying to burn yule logs won't make the times between firings any shorter, just later nights in the sugarhouse.

[nitsujlobos]

so i installed a damper and moved around my fire brick a little bit and made it so there is only about 2 inches or less between my wall and the bottom of the pan. got a very big improvement. finally got the whole pan boiling pretty good in about an hour and had a great bed of coals. so i think im at the point where it should work good once a get it screaming hot and just keep feeding it. still could use some fine tweaking but i think ill wait till i got some sap so im not wasting my wood on just plain water.

[Haynes Forest Products]

Throw some Lobsters in that there cooker.

[Sugarmaker]

Ahhhh! another satisfied person watching water boil. It doesn't get any better than this:)

Regards,
Chris

[maple flats]

When you get the good bed of coals keep adding wood every 5-6 minutes by using a timer. Fill it only to within about 7 or 8" below the pan. Criss cross the wood some to get max air flow. You should now have a good full boil.

[Mac_Muz]

While in bed half asleep I wondered about raising the 2 back bricks, by maybe adding on more to create a dual flame path.

I can't tell how much room there is there, but if a brick more can be placed close to the pan, at the rear of the fire box, it might roll the flame back to the front of the stove and force the flame to split, making the flame run abound that last brick to the left and right.

The effect might cause the flame to run an oval shape just under the pan.

That 1/2 bucket damper I made forces the flame high under the pan, and it is up there hard, before the flame has to fight with itself and turn down hill sharply.

Also I think the bricks behind the fire box wall step down and the flame is drawn down to the exit hole, in effect taking heat away from the pan bottom.

[RileySugarbush]

If you are burning on grates, you don't want a bed of coals. With adequate draft, especially if you have a blower, the wood should burn to almost no ash. If you have lots of coals they choke off the draft.