Building a supercharger for my 2X6.

[Justin Turco]

I spoke with a guy this morning who said his front pan only boils in the center with a blower. (My blower came off the plenum on the back of my woodstove. Not sure of the CFM. I'll go with a rheostat in case it's too big.) Anybody got any experience with blowers and what kind of problems come up and or what kind of improvement I should be looking for.

Without a blower: I have always thought and time has seemed to indicate that a couple well placed bricks in back of the firebox will keep the heat up front long enough to give us a good boil across the whole fron pan. We also believe that a couple bricks placed just inside of the ash cleanout can direct air and flames straight up on to the bottom of the syrup pan. of course, configured like this my fluepan boils real good up front and dies out toward the back. With the supercharger I am hoping to see a good hard boil front to rear. What is the ideal stack temp??

Has anybody experimented with baffles in the "V" shaped air tube that feeds the air into the ash box? ie: make it so that air comes in only at the sides of the ash box or in the center or else evenly across the width of the ash box. Here is one for you: is the fire box a high pressure or low pressure situation? If I was standing in front of the arch looking in and could see the air flow, would it rotate clockwise or counter clockwise as it moved to the rear of the arch and up the stack. Maybe that would mean putting air on one side or the other of the ashpit would make a diference. Maybe smooth airflow isn't the best thing but just a good amount of turbulence and volume.

Sorry for overthinking this thing.. But I really hate to be disapointed after the time it takes to fab. the tube and then cut a hole into the back of my arch.

Thanks for your thoughts.

[mountainvan]

Boiling only in the center sounds like cold air is being pulled in under the sides of the pan. Rail gasket will take care of that. Blow the air across the whole firebox, you're basically making a forge. Most airtight arches come with special grates to get the air evenly distributed in the firebox. My stack temp is usually 800 at the base stack.

[Sugarmaker]

Justin,
I had some similar thoughts when I wanted to include a blower on my evaporator. Never having run a blower I just called Leader and at that time they had a gentleman that gave me a lot of advice. He was not trying to sell me a blower. He told me I needed about a 550 cfm blower for the 3 x 10. I asked about the v shaped plenum he said it was mostly for show and to just run a duct from the blower into the back of the ash pit. I made a duct same size as the blower discharge , about 5 inches square and fastened it to the ash pit. I did add a damper in the square tube to control the draft if you need to. This system works great for me I have a two speed switch and run on high till it gets boiling good then dial back to low speed. My guess is that stack temp is near 1000 deg F at times? I have a good rolling boil in all areas of all pans.

Chris

[Hop Kiln Road]

Justin -

On my first attempt I used an old bathroom vent fan and it wasn't big enough. Got a bigger fan and attached it directly to the back of the ashbox. Wired it with a rheostat. It creates a hell of a boil with little wood in the firebox. You will also quickly find any air leaks in the arch! I ended up putting insulation against the inside of the ash door as between the hotter combustion and heat column very little ash drops. As long as the fan is big enough and you can control the speed you won't have to worry about the shape or delivery of the air. You'll love it!

Bruce

[WESTVIRGINIAMAPLER]

You may not be pushing enough CFM's to push air thru the grates all the way across vs just the center. If you have enough air, you will boil all across the pans. 200 to 250 cfm should be good for a 2x6 with stanard grates.

[RileySugarbush]

I have 210 CFM in my 2x6. Seems like plenty.

[Justin Turco]

I appreciate your responses. I think I'll make a square tube the same size as the blower. I'll do a rheostat and a maybe a damper of some sort. Good info! Thanks!! I am going to try to find a stack thermometer. They won't stick to stainless will they?



Bow, NH is zoned for chickens???! Cool!
Cocka Doodle Doo!!!

[WESTVIRGINIAMAPLER]

Condar makes a nice stack thermometer that I have for my evaporator and it has a magnet and sticks right to my stainless stack. I paid $ 25 for mine and Jon(tapper) has one he bought at a True value for around $ 15. It is rated from 200 to 1700 degrees and mine usually stays between 1400 and 1600 degrees.

[Sugarmaker]

I have to get one of those stack thermos this year! I need another thing to watch.:)

Chris

[Hop Kiln Road]

Just remember the rheostat needs to have a motor control if you're using an unknown fan, don't use a dimmer switch.

Bruce

[WESTVIRGINIAMAPLER]

Bruce,

What exactly do you mean by that?? I use a 5 amp fan speed control and it has always worked good??

[Hop Kiln Road]

Brandon -

Some electric motors are built (cheap) to operate at one speed, like a bathroom exhaust fan. The motors designed to operate at variable speeds have a device to protect the motor from shorting out if the current is too low to turn the motor and just heats up the coils. Some rheostats have this protection build in, a dimmer switch doesn't. Sounds like your switch is designed as a motor control and not a light dimmer switch and your motor is probably a variable speed to begin with. I get concerned with some of the experimentation I read, particularly when it involves electrical current in wet environments !!

Bruce

[Justin Turco]

Well, I got the blower installed. I think it may move 800 cfm. (Thats way too much I guess.) When I turned it on you'd of thought we were running on rocket fuel. (It really was pretty cool.) Also, as you would expect, the ashes really went flying from around the doors. I tried bleeding off some of the pressure with a hole in the plenum. Didn't really work. Still a lot of ash from around the firebox doors. Without an inferno arch I think this blower is not going to work for me. Anybody have any luck putting a sealing gasket on these old cast iron doors?

On another note: anybody have any ideas where we could get a roll of the 1" thick pan gasket material that everbody sells for 50.00 for 25 feet. We spend a lot of money on doo-dads for sugaring, But I think that is just too much for what it is. I like to put a new one on every year. But not at that price. If we could find a supplier I would think it could be had for 1/2 that if bought in a larger quantity.

Thanks.

[Sugarmaker]

Justin,
800 cfm is a bunch. can you use a damper in the duct to shut it down a little? It might work better with less ash coming out the front? I have firbrick across the from on the grates to keep some of the heat away from the doors this amy als help keeping ash from blowing out too?

Good luck. They do boil with a blower!

Chris

[mapleack]

We've been experimenting with homemade forced air for years. First it was a blower into the front of the ash pit, then from the back, then from the back with a 12" wide duct with holes drilled in the top. The newest incarnation, in use since last season has been the best. We came through the back of the ash pit with a 12" rectangular duct, then attached a homemade manifold the width of the fire box. We then added four 3" round ducts to this manifold, which extended to the front of the fire box and are held up with a flat iron frame at the front. There are four or so rows of 1/4" holes drilled the length of each 3" duct. The two ducts closest to the center got a few less holes. This design seems to work quite well, and still lets ashes pass by.

[WESTVIRGINIAMAPLER]

Some ceramic blanket cut in strips works to the same purpose for the arch rails.

[ibby458]

With unknown cfm blowers, I've found it easier to control the air with the suction sides partially plugged off than to try to choke off the discharge. My current blower has intake on only one side, and I have a disc of sheet metal on the other that I can swivel in and out of the air flow. It'll go from full open to full closed, and the suction holds it where you put it.

[Justin Turco]

Ok...thats what we did... We put a piece of metal over one of the intakes for the blower. That backed it down the air volume enough to be able to use it. I am liking it!! We've got noticeably more steam coming out roof now. Not sure what the gph evaporation is doing yet. But all too often I think we WERE at about 25 per hour. Maybe it's running like it should. 30 or so. (My wood is kind of damp this year.)

Had a great day. Lot of visitors and made maybe 8 gallons of nice syrup today.

On another note: I had some etching on my syrup pan from my overzelous oakite use earlier in the week, but today the pan seemed to work fine. Just not as shiny anymore.