Blower questions for my homemade arch

[blaircountysugarin85]

Hey everyone, last year I built a homemade evaporator with a 2x3 divided pan. This year I want to add a centrifugal blower to the ash door to get the boiling rate up a little. The grates are made of angle with holes in them for draft. Now my thinking is and really with all the bower set ups, if I attatch a blower to the ash door openings wouldnt that draft be too much force to allow the wood to settle and therefore the ash go out the stack. I have an ash compartment below the ash door and am wondering if it will not longer collect ash with a blower. I am also concerned as I do not want all the ash blowing out the stack and making a mess and getting into my sap and everything else as I boil outside. As far as centrifugal blower size I am looking at some on ebay and what cfm would you say is appropriate, I dont want to get something too strong either. Thanks everyone! 495449554956

[jluckay]

i have mine on the ash door also. i have a removable cleanout pan inside. the air from the fan in deflected upwards off the front of the cleanout pan & works just fine. as far as blowing ash out the flu i have never noticed anything out of the ordinary & my flu is piped outside my sugarhouse anyway. not sure as what size my fan is. i know it was from grainger. i welded it directlly to the ash door with a slidable pice of sheetmetal in between as a adjustable damper of sorts. ill c if i can upload aome pictures of it in ther next day or two. good luck!!!

[Indiana-Jones]

Hi, I have been learning about blowers myself. Here is the best place that I have found for small blowers. https://www.surpluscenter.com/sort.asp?catname=electric&keyword=EBSA

I agree that you won't need a whole lot of CFM's to light up your wood with air under the fire. One of the 60CFM units would work, but let one the other guys here with more experience chime in.

Nice looking rig.

[buckeye gold]

I added a blower to my half pint last year and was really happy with the results.I cut a hole in the fire box and plumbed pipe into the mid area (across fire) of the firebox. I think I'll spit it into two nozzles this year as sometimes wood blocked air flow on one side. I used a blower out of an old vacuum and really don't know the CFM, but it works fine. I had no problem with ash going up my flue pipe. I'm guessing my efficiency went up 20-30% with the blower. I would definately recommend it even for small evaporators.

[English River Maple]

I agree with the blower suggestion. We used to have a Mason 2x3 with a homemade preheater and just a small fan clipped on the ash door blowing air in under the grates. We would simply switch the fan off when we opened the door to fire. We increased our evaporation rate from 7 to 9+ gph. Boiled like crazy, had a lot of fun!!

[RileySugarbush]

With a blower adding air up through the grates you will get much more complete combustion and therefore much less ash. If you really crank it up, you might get some flying out the stack, but it shouldn't be bad. If you want to throttle back the blower, I find the best way is to have an adjustable baffle on the blower inlet. It is much easier on the motor and works great.

Also, from looking at your photos, I suggest you tilt your sap warmer and have it hang over the back of your pan so condensate doesn't drip back into your sap, forcing you to evaporate it again.

[blaircountysugarin85]

Thanks alot guys I will take that into consideration and yes typically I pull the preheater back as there is about a 6 inch gap between the base stack and the pan so it just leans up agains the base stack for the most part. I ordered a centrifugal blower off of ebay a few days ago and I am planning on hooking up rheostat or variable speed control knob to adjust the speed. Also when looking at alot of you commercial and factory build evaporators i notice that they mount the blower behind the firebox and not in front on the ash door. What is the reasoning behind this and/or does it make a difference? Thanks

[RileySugarbush]

Thanks alot guys I will take that into consideration and yes typically I pull the preheater back as there is about a 6 inch gap between the base stack and the pan so it just leans up agains the base stack for the most part. I ordered a centrifugal blower off of ebay a few days ago and I am planning on hooking up rheostat or variable speed control knob to adjust the speed. Also when looking at alot of you commercial and factory build evaporators i notice that they mount the blower behind the firebox and not in front on the ash door. What is the reasoning behind this and/or does it make a difference? Thanks

It won't make a difference in performance. It is just blowing air in the volume under the grates. much more convenient and quiet out of the way back there though.

[blaircountysugarin85]

ok that's what I had figured thanks

[wiam]

Thanks alot guys I will take that into consideration and yes typically I pull the preheater back as there is about a 6 inch gap between the base stack and the pan so it just leans up agains the base stack for the most part. I ordered a centrifugal blower off of ebay a few days ago and I am planning on hooking up rheostat or variable speed control knob to adjust the speed. Also when looking at alot of you commercial and factory build evaporators i notice that they mount the blower behind the firebox and not in front on the ash door. What is the reasoning behind this and/or does it make a difference? Thanks



I have fired rigs with blower in front and underneath. The nice part about underneath is your not bumping it with wood or tripping over it.

[ACollette]

I have a similar homemade arch. I have a 350 cfm blower plumbed through my ash door. I retrofitted my ash door from a hinged door to sliding doors which split at the mid point. I welded an adaptor to recieve my air duct. When I first started using it, I found out that the blower was way too big. I was blowing my fire almost out, and I was wasting precious heat up my stack. I built a regulator to limit the intake on my blower so that it reduced the cfm. There is no doubt the evaporation rate was dramatically increased by the blower. My pan is a 2 X 3 and at peak efficiency I was showing about an 11 gph evaporation rate. I do have quite a bit of ash going out my stack. I have looked at ways to reduce this. Changes that I will try this season are installing a damper on my stack to act as a baffle and possibly screening the cap of my stack.

[wiam]

Changes that I will try this season are installing a damper on my stack to act as a baffle and possibly screening the cap of my stack.

I would not put a damper in the stack. I tried 1/4" screen on top and it plugged solid in less than 12 hrs boil time.

[rookie]

i just used a 60 cfm bath fan from home depot it was cheap, like 20 bucks then used an adjustable switch designed to be used on a table lamp, every thing all plugged together easy peasy! doubled my boil rate. Full blast was blowing fire out the door to the point where i was worried the shack would go up piped it in from the back of the arch using iron pipe and used a fernco ( rubber pipe clamp adapter) to adapt the fan to the pipe

[valleyman]

Indiana
Thanks for the Surplus Web site for small blowers. I've been using a a small desk fan and it blows a low level amount of air under the fire and it made a noticeable difference. I'm from the school bigger is better, more is better so I hooked up an electric leaf blower up and that nearly incinerated the trees 30' up. Pushed way to much up and out the stack! Went back to the little fan for my small block evaporator. But I melt the little plastic fans every year. I think i'm going to a metal one from the link you posted.
Thanks

[rookie]

I would not put a damper in the stack. I tried 1/4" screen on top and it plugged solid in less than 12 hrs boil time.

wiam, why not put a damper in?

[wiam]

I do not think you would want to slow the draft.

[getting started]

I wouldn't put your blower in the front , i think that you would be much happier with it under you arch. I have a 2 x 6 and i run a 540 cfm blower on it, thats what leader recomended and you may want to buy a quality blower like a Dayton ,around 125$ for my 540 cfm at the local heating supply store

[TC matt]

if you google "stanley blower fan" you'll see a nice yellow, multi-speed fan. I bought this on a recommendation from someone last year on this site last year. Best $39 ever spent on maple equipment! i blow it into my ash door and it does a great job - makes a huge difference. the bottom of my firebox is an iron grate with fire brick placed on top of the grate and i build the fire right on top fo the bricks. I leave about 1/4 to 1/2 inch inbetween the bricks to allow the forced under the fire.