Best way to increase GPH

[ckkrotz]

We have an oil tank evaporator, which currently has 3 steam table pans. It is lined with insulation and firebricks, but does not have a blower of any kind. We really need to get better GPH (we were getting about 5 last year). We weren't really preheating last year, and we plan on doing that somehow this year, but other than that, what would be the best next step... installing a blower of some sort, or would a new pan be the better place to invest our time/money?

and if we were to install a blower, we have no electricity, so would a car blower off a battery work, or is there a better fan that doesn't use electricity?

[Treetapper]

How tall is your smoke stack? Increasing the diameter or length can help with draft and GPH. I used to use a damper in the stack that can be fine tuned to increase your boil.
A deep cycle battery on a car heater blower would help but try to max it out with your stack and draft door under your fire first. Preheated sap is a must to increase your boil / GPH as well.

[ckkrotz]

I believe the smoke stack is about 10 feet tall. Last year was the first year using this set up and we were struggling to keep the back pan boiling. I think this was largely due to cold sap, but also partly not enough air to the fire. We often had to keep the door cracked to really get it roaring. I guess my only concern with adding a blower with the current pans is if the boil will be too hard and splash out of our 6 inch pans. I guess time will tell. Our preheating plan as of now is on the stove in the camper... not too efficient, but hey, at least it'll keep it warm in there for the kids :)

[RileySugarbush]

Make sure your arch has combustion air coming in up through the grate and not over the top of the fire.

A good next step is a blower if you can do it.

Also check into converting one or two of your pans to drop tube. There are several threads on the trader that describe how to do it. It will at least double the rate of that pan and maybe triple it.

6621

[psparr]

Also do you have a ramp to push the flame up to your pans?
Do you have any pics you can share?

[ckkrotz]

I have thought about converting a pan to drop tube, but can't decide if it's worth it for 1 or 2 years until we get a real pan. If I remember correctly, we have sand in the back of the firebox to create a ramp. (It's not in yet in the picture) We are thinking we might be able to cut in a vent behind the firebox to put a blower on. 66326633

[RileySugarbush]

understood. The blower is the next best bet.

[b116757]

your stack should at least be double the lenth tall as the horitontal travel of the evaporator measured from the pan level not the ground sounds like raising your stack may help you if its only 10' tall and I would also install a damper in the stack you can keep a great deal of heat under the pans instead of going up the stack with a $10 butterfly damper.

[Treetapper]

It looks like you could use more space under the fire grate. If you had at least 10" of space under the grate and plenty of air flow coming in under the fire grate you should notice a measurable difference as well. Where does the the combustion air enter now?

[Treetapper]

If you have some left over fire brick put 1 in each corner under the grate to get it up off the ash floor and get fresh air under the grate. Cut them in half to save some space underneath. Also keep your ash cleaned out to aid air flow. Hope it helps.

[ckkrotz]

You're right that there isn't much space under the grate, so maybe we should raise it some. There is not really any good place for combustion air to enter right now. We were having to run it with the door cracked most of the time to really get it cranking last year. This was put together in about 2 Saturdays right before the season started last year, so there is much room for improvement. I do think the smoke stack is tall enough, as it is (I think) 4 pieces of chimney pipe, which are something like 30-36 inches long each. Thanks for all the suggestions. We are thinking we will be tapping around 50 taps this year, and we only get to boil on Saturdays (I know, not the best, but it's the best we can do right now), so we really need to maximize our boil rate!

[Treetapper]

If you can cut a separate door into the front, bottom of the fire box it will let air under the bottom of the fire and will help you to clean out ash "on the fly" If you are opening your wood door for air, you are letting in cold air that is mixing with the fire but may be somewhat cooling your pans. Also allowing the heat to go up the stack quicker. Air under the fire, natural or forced, is where you want to start for good combustion. Wasn't sure by your posted picture if your wood door and ash door are 1 large door or if they are separate.

[valleyman]

I agree with treetapper about getting more air under your fire. I have a block evap and the grate sits 8" up from the base. I have an opening below the grate and I small table fan blowing some xtra air thru. Last year I hooked up an electric leaf blower to some 3"duct work and tried that for forced air and it practically blew flames out of the 10' stack! Even on the low speed setting. With no snow cover last year, I thought I would ignite the woods. Too much of a good thing!

I saw your photo and I thought for an easy fix for now maybe you can flip your grate upside down to increase the area beneath your fire. Just a thought.

6636

[maple marc]

CK, I admire your efforts. My first several years were on a home-build steam pan rig. I remember...ladle, ladle, ladle, ladle......It was a water pressure tank with enough of the top cut out to suspend 4 pans. We started the first year with only 3 pans. That fourth pan will make a difference. I think we were getting between 6.5 and 8 gph. You need plenty of stack. That thing held a lot of wood. We shoved in pieces 4' long, which really worked to put the fire under each pan.

Eventually I really got tired of ladling and the long days. Got a real boiler (Leader WSE 2x4) and raised my rate to 17 GPH. I would go right to the 2x6 if I had to do it over. Just about the same price.

Marc

[70 Buick]

I agree if you can make a drop flue give it a try, doesn't cost much & really improves your GPH
I made this one last year for about 30.00 boils like a SOB
It sounds like a purring V-8 engine LOL


http://shootthebull.freeforums.org/download/file.php?id=263&t=1


Watch this video & notice how the back pan is boiling, you can see where the tubes are it jump up 3 inches

http://www.youtube.com/watch?feature=player_embedded&v=PJA7LHhsCWw#!