Barrel evaporator questions

[Turtlecreek]

I have a leader half pint and the arch is a homemade barrel arch it is all in good shape.

I have some simple questions, since this is my first real evaporator.

I have taken all of the brick out of the barrel and am going to re brick it. I have bought 1/2 inch ceramic blanket to put in the barrel then I plan on using full brick in the fire box, and 1/2 bricks on the top of the arch under the back of the pan. The question is how long should i make the fire box before I lay up a wall to force the heat under the back of the pan.

How much space should I leave between the bottom of the pan and the bricks leading to the flue pipe?

The arch has a blower on it too that is in the front of the barrel and uses a 2 inch pipe.

I know I'm forgetting something, if anyone has anything to add that would be great.

[3rdgen.maple]

I not sure but I would guess with a half pint the whole thing is the firebox. I don't think there is enough room to make a ramp without a major sacrifice in the length of wood you are gonna need to fire it.

[C.Wilcox]

Turtlecreek,

If you haven't already looked at these, check out the links below. They should take you to very detailed threads on building barrel style evaporators and they might give you some ideas.

http://mapletrader.com/community/showthread.php?t=3922&highlight=barrel+evaporator

http://mapletrader.com/community/showthread.php?t=3922&highlight=barrel+evaporator

[RileySugarbush]

Just leave enough length for your firewood. If you cut yours to 16" then 19 or 20" firebox length is as small as I would go. You might want to reduce the thickness of the firebrick on the front of the arch to preserve some length. Ceramic blanket and splits will be plenty of insulation, good for the side walls too. For maximum evaporation rate you want the wall as far forward as possible. Some have added a little forward projecting steel shelf to make the wall act as if it was further forward and even added notches to the back edge to force the flow of flue gasses to the back corners.

Here is a shot of a friends half pint with the wall installed:

http://www.mapletrader.com/community/attachment.php?attachmentid=1013&stc=1&d=1258725589

[BarrelBoiler]

when we first used our barrel evaporator we just added wood to the totaly open barrel i tink the wood was about 12-14 inches long and we kept the fire close to the door and draft. After about an hour the coals and ash built up and formed a hump that forced the heat and flame up toward the bottom of the pan. it took a while but finally the light went on:o and we bricked a wall up about 12 inches from the door and filled the back to get the heat to the pan

do you have a grate? you said it had a blower. if you have a grate you will probably need to match the fire box depth to it

have fun

[Turtlecreek]

I have a grate to put in it, it is a old drain grate that has been used before. I assume that the blower is supposed to be pointed in to the fire instead of below it in the ashes, right?

I never thought of it but I assume I have to brick up the front aroud the door to prevent some heat going out that wAy too?

The barrel has two pieces of angle iron welded inside I'd it to put a steel plate on in the rear, so when I lay up the wall I can put the plate on the on the angles and brick over it with half bricks.

I bought the whole thing this summer from Dan W here on the trader and it was set ip pretty nice, I am just trying to get as much out of this little thing as I can.

[Gary R]

Typically the grate is raised off the firebox floor. Some type of manifold is placed under the grate. The air blows up through the grates. This means cutting a hole in the arch or using an ash door if it is seperate from the wood firing door. You can use 3" 26ga. pipe for the manifold. It's used for exhaust on gas water heaters. It may only last a couple years because of the heat. But, it is cheap. The air will blow the ashes out of the way. You may have to turn off the blower when you open the wood firing door.

You may want to consider insulating the front and door of the arch. It will keep the heat in and won't be so hot when your standing in front of the arch checking things.