New evaporator under way!

[tonka]

So I've started building my new evaporator. It is a 4'x17'. Instead of building the traditional drop/raised flue pan I wanted to do something different and more efficiant. The idea I got is taking the concept of a steam engine boiler and incorporating it into an evaporator (I see that I'm not the only one who has attempted this idea so I won't say it's 100% my idea). My tube pan will have 90 2" pipe 10' long which will calculate to about 450 sq ft of heated surface. I will be having aof and auf. When designing this rig I studied steam engine boilers/fireboxes and will be having a firebrick arch that will extend from the bottom of the tube pan 1/3 of the fire box horizontally towards the door that will act as a ramp for better combustion of the gasses.
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[wiam]

When I had this style pan it seamed to work best with about 1” gap under the bottom of the pan to the insulation. Mine was a Mason. Leader produced a few of these many years ago but they could not hold the solder joints between copper pipes and English tin pans. ( different expansions)

[tonka]

Not sure if I fallow you on having 1" gap between bottom of pan and insulation. I will be using stainless steel pipe for the tubes and they will be getting tig/mig welded into place.

[Mark]

Is it fire tube or is the sap in the tubes? What about cleaning under the tubes?

Here is an old Maple Digest that has a tube flue pan in it that you may find interesting.
http://www.maplesyrupdigest.org/?p=249

[tonka]

Fire in the tubes.

[tonka]

Thanks Mark for the link, interesting arrival. They made quite the design.

[whity]

Our Mason system is similar. We have a 2x8 with 16 2" tubes in the flue pan. about half inch apart. It boils over the extension we had built. As for 1" between the bottom of your drop tube pan and arch bottom is a good suggestion. We are running 1" as well.

[Woodsrover]

Cool idea!

[wiam]

Not sure if I fallow you on having 1" gap between bottom of pan and insulation. I will be using stainless steel pipe for the tubes and they will be getting tig/mig welded into place.
Fire went through tubes. Fire went under bottom of pan also. 1” gap under pan. I have seen no other pan boil as violently.

[Zucker Lager]

Most of the fire tube boilers I'm familiar with are fired through a large flue from front to back then they return that hot gas through smaller tubes to the front again where it vents to the chimney. I wonder if you could do that with your project and have the firebox flow go under the pan first then return to the front of the pan through the tubes? Drawback would be a chimney in the front of your arch. The total flow of hot gas would be longer maybe squeeze more BTU's out? just a thought Jay

[tonka]

Zucker lager, I talked to a local welder who also is a steam engin (tractor) expert, he restore them and he even made 3 engines 1/3 scale size, so in other words he knows his stuff. During the designing stage I stopped and talked with him to get any advise and to see what he thought, he brought that same thing up on how there is a steam jet that blows steam up the stack to create draft do to the lack of proper stack hight. One big thing why I'm against doing it is the risk of fire with the embers getting blown out because the air is being pulled instead of being forced in. All the diagrams I have seen online and talking with the local welder I did not see or hear anything to fit your description Zucker, it's a good idea though. The way I have my set up designed and how I have it built to this point I won't be able to have a 1" gap under the pan unless I do some cutting and rewelding just to make it with a 1" gap under the pan. Maybe after next season after I see how the rig functions I might have to make some modifications that you all have suggested, so thank you guys for all your input!

[tonka]

How dose my aof and auf look. I have 1/2 nozzles on the floor, there is about 9 nozzles psf, the air manifold is 6" from the bottom of the pan, 2 rows of 1/4" pipe spaced 3" apart. The air manifold is 1 1/2" x 7" c channel. Tried to fallow what was suggested in the artical about cumbustin in the fire box.
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[tonka]

How dose my aof and auf look. I have 1/2 nozzles on the floor, there is about 9 nozzles psf, the air manifold is 6" from the bottom of the pan, 2 rows of 1/4" pipe spaced 3" apart. The air manifold is 1 1/2" x 7" c channel. Tried to fallow what was suggested in the artical about cumbustin in the fire box.
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[tonka]

A little update: haven't had much time to work on the arch, all I have left is to make and install door and a collar for the smoke stack. I did get my forced air regulated done with. 17043 17044 I built my air regulator with positions the get moved in to close/shot off the air flow and pulled out for more air flow, I achieve moving the pistion by turning a crank or battery powers impact on the outside of the arch (the threaded rod) to push and pull the position. The horizontal short pipe will be the air inlet and the 2 longer horizontal pipe are for the air outlet, top one is for aof and the bottom one is for auf. I will be purchasing a bounce house blower to use for the forced air.

[tonka]

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So I have my arch pretty much done, only thing left is to insulate and brick the arch.
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Been working on some stainless. Have all 3 syrup pans almost done, only thing left is to put the dividers in. Float box done and a trough on the one side is almost done, waiting on the coupling to weld in for the drain.

[tonka]

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So I've got the majority of the work done on the cooker. All I have left is to plumb the bounce house blower to my air manifold, insulate and brick the arch and make a few sections of steam stack and I'm ready to do a test boil.

[Ontario Ian]

nice job! looks like you have a couple hours into this. keep us posted, i'm interested to see how your tube pan will perform

[Ontario Ian]

tube pan picture, there are some studs welded in (across bottom of pan and top right and left corner) what are these for? Hold blanket and brick?

[tonka]

Thank you Ontario Ian! Yes those studs are for holding the mineral wool in place. I will be buying my insulation from Menards, one bundle of mineral wool I think is like $20, the bats are 3" thick too.