retro fit arch, oil -> wood

[Brian Ryther]

If these links work they show my current progress on converting my 6x15 arch from oil to wood. Any feed back , other than why oil to wood, would be helpfull. If anyone has an arch of similar size that is wood fired I would like feed back regarding arch demensions and bricking sudgestions. Flue pan is of the raised type.
Thanks Brian
http://i186.photobucket.com/albums/x3/brianryther/th_evap007.jpg (http://i186.photobucket.com/albums/x3/brianryther/evap007.jpg)
http://i186.photobucket.com/albums/x3/brianryther/th_evap005.jpg (http://i186.photobucket.com/albums/x3/brianryther/evap005.jpg)
http://i186.photobucket.com/albums/x3/brianryther/th_evap004.jpg (http://i186.photobucket.com/albums/x3/brianryther/evap004.jpg)

[Sugarmaker]

Brian,
WOW big project. Its a big evaporator! I am not used to the framed hump in the fire box under the flue pan but assume you got this design from other raised flue arches. This rigs should boil severl hundred gallons per hour!

How many taps?

Looks like it will be a wood eater, but man the syrup should flow out of the draw off once its rolling. Plus you will loose some weight firing that unit.
I dont really mind firing with wood having used both, Will stay with the wood till I get out of the syrup mood or hit the lotto.
Pictures were good. What are the pan sizes? Like 10 foot flue and 6 foot syrup pan? Are they stainless? Have you considered re tinning the sides of the arch, or are they in good shape?

Send/ post some pictures as you progress. I spent about 2 years restoring our 3 x 10 King arch from a pile of castings.

For the fire brick I used full size fire brick, laid on edge and mortared them in with refractory cement. 6 years and it still looks very good in there.

Regards,
Chris

[Brian Ryther]

Chris,
I saw the photos of your restoration. Mine is not as involved but pretty close. I found the arch front @ Bascoms with two very warped doors and the draft door missing. I will have to re make those. When you bricked did you line the arch with arch board first? Did you install a floor under the brick in the fire box, or is the brick on the floor? The pans are SS, the flue is 6x9 and the front is 6x6. As far as the hump goes I am going with what I bielive will not create a restriction in the draft. I will be adding a blower but not completly relying on for all fresh air. It will draw it's fresh air from the area between the new arch floor and the old arch floor.
Thanks
Brian

[Sugarmaker]

Brian,
Sounds just about as involved as mine. I had never rebuilt a arch so some of the items I did may way other ideas I got from neighbors with similar rigs.
Well I did not put arch board in next to the side walls but would recommend it! Any thing to keep the heat under the fire will allow you to produce more syrup.
My brick only goes from the grate ledge up to the rail. I dont think you need brick below the grate level, since it should just be cooler draft air.
I have the evaporator bottom frame setting on cement. Again I dont think you need fire brick the bottom of the ash area.

OK I need a little help in understanding your draft system? Usually on a forced draft you would want all your air to come in from the blower I believe.
Also not sure about the area you refer to as between the old and new arch floor? Sorry I may just not understand your explanation.
My forced draft enters about mid way up the ash pit in the back of the ash pit. I closed off the front draft door tight.

Also look at the Leader grat system for forced air grates. They put fire brick across in front of the arch doors to reduce the forge effect on the doors. What are you going to use for grates?

Maybe you could find good used doors???

Lot of guys on here have much more evaporator knowledge than I do. Keep going. Pans sound like good units!

[Parker]

I know on my evap. if there is an opening (like the draft door is a littel open) when the blower is on lots of sparks-ash and heat blow out the opening,,I have to keep my arch closed tight when the blower is on,,,,if you have to find some new doors anyways you might want to consider making some forced air doors-meaning making hollow doors that air is forced into(thru a hollow bottom mabey) then goes straight in towards the fire thru a series of nozzels),,the more air you can jam into the firebox the better,,,,if you are going to run regular cast doors I would insulate them with 1"ceramic blanket then a 1/4" piece of boiler plate,,,has worked well on mine for the last 3 years,,although my boilerplate burned thru this spring and will have to be replaced,,,
I plan on building an airtight front for mine befor spring and incorperating the forced air doors,at least 1 more blower,a locking handel for the doors (mine blew open if not locked shut with a section of pipe) much more interior insulation,,and useing bricks for grates, these were suggestions from 802 maple and I think they will make a big diffrance in my GPH rate and wood to syrup ratio
as far as bricking goes my arch has no floor under the grates,,just sits on the concrete floor of the sugarhouse,,I put 1"ceramic blanket aginst my arch tin then bricked using firebricks and refractory cement,,under the fluepan there is enough room for 1 brick standing on edge from the arch bottom to the arch rail,,,,I laid brick in flat lining the floor of the arch under the flue pan then filled the arch with sand the the level of the rails (raised flue) that is how it was set up where I bought it-removed it from,,,,basically the hump you maid in yours is done with sand in mine,,,one foot befor the stack ,the sand ends and just the brick show on the floor under the stack,,,,,,hope this is not too confuseing,,,

[Brian Ryther]

Parker
On my last arch I had combined forced combustion air and draft doors. I never had a problem with sparks coming out the draft doors. I am wondering if because you have the sand tight to the bottom rail that you have created a restriction for natural draft? Thanks for the feed back.
Brian

[Parker]

that could well be the problem

[802maple]

The sand shouldn't restrict the draft as a intens-O- fire is right up to the rail with insulation. Most bottoms of raised flue pans are atleast 3/4 of a inch higher than that.

[Brian Ryther]

802
Would you then sugest that I bring the bottom of the arch to the bottom of the pan rail under the flue pan? I am currently 5". I planed on this allowing a brick on edge under the rail, and half bricks across the flat of the arch giving me aprox. 2"-3" of clearance. The raised flue is about 1" higher than the edge of the pan.
Thanks
Brian

[802maple]

You need to close that up to within an inch of the bottom of your flues to keep the heat up inside them. With 5 inches of clearance the heat will just fly right out of your evaporator and won't be very efficient. At about 10 to 12 inches from the back of your fluepan you can then drop down to allow the heat down out and up your stack. A good rule of thumb for that measurement is width of your base stack.

[danno]

Well, this could very well have been my problem last year. After making my arch air tight, raising the stack, adding forced air and a preheater, I could still not get 50 gph's out of my 30x8.

I've got two rows of brick across my arch about 1/3 and 2/3 down my flue pan pushing the heat/flame into my flues. But between those rows, my sand is probably 6" below my flues.

What can I put in to take up that space - more sand? I'm afraid the weight would take out the arch. What's the vermiticule (sp) all about? Is that a better option?

[brookledge]

Danno
I have a raised flue and I filled my area with vermiculite to take up space before laying fire brick on top of the vermiculite. It is very light and I would not recommend anyone using sand especially if your arch has galvanized steel sides. The sand will hold moisture and if you ever get rain down your stack and the sand gets wet it will lead to your arch rotting out.
http://en.wikipedia.org/wiki/Vermiculite
You can get it at most mason supply stores
Keith

[Fred Henderson]

Any building supply store also sells it.

[Russell Lampron]

I put Pearlite in mine and covered it with fire brick so that it is even with the rails. Pearlite is the white stuff in potting soil and it is very light. If you don't cover it a good draft will pull it out of the evaporator. It is cheap and doesn't hold moisture like sand.

Russ

[802maple]

You can use either and what I have done in the past is put a thin layer of dry mortar over it and then spray it water with a misting bottle just to dampen it. That will hold either insulation in fine. Once I get out of the fire box area I hardly ever use fire bricks, I just put 1/2 inch wire mesh over the insulation and spread mortar about a inch thick. I have pre bricked arch's and shipped them as far as Wisconsin with no problems this way, and they hold up to the heat well. This a quite a bit less expensive.

[Parker]

HHMMMMM- might have to give Marvin the pan off makeover......

[danno]

So, it appears that I don't need the two rows of brick that run across the arch if I'm gonna run insulation right up to the bottom of the rails.

Why have all the archs I've ever seen seem to be 8" or so deep under the flue pan. Seem like you could just make the arch 2 or 3 inches deep, and fill it with morter or block and save allot of sheet metal.

Dan

[Fred Henderson]

Because archs are made for both raised and drop flue pans.

[802maple]

Fred hit it right on the nose. It is cheaper to build one size fits all instead of retooling for every arch.

[brookledge]

Also you still need the 8" or so to allow the gasses to go back down at the back of the arch to go up into the stack
Keith