Combustioneer 77B

Combustioneer 77B

PostBy: carlherrnstein On: Sat Jun 15, 2013 2:16 pm

I recently bought a late 80s vintage Combustioneer 77B I wouldn't have gotten it but, I just couldn't pass it up at $350 and only a half a county over the lady also had another one she was just about begging me to take I just dont have the room for it. As best as I can tell its in pretty good working order. No cracks any where, oil in transmission it a nice amber color, the hopper has no rust damage. I did have to replace the power cord because it was cracking badly, I had to fit a convection blower to it as the original was missing I used a king air 12 inch floor fan minus the "foot" and front wire grill, I found the hold fire timer was not working and discovered the clock motor was not hooked up according to the diagram on the timer cover so I hooked that up properly an it works every hour now, I straitened out the hinge and freed it up(it had rusted stuck and someone had forced it) and painted the lid as well as the top air grill.

I have looked at the tuyere sections an they appear to be relatively new there a light brown or red color and do not look burned at all, the windbox sides of them look like they were newly cast.

My question is are they all supposed to be even?

There is one that is about 1/8" higher than the rest and looking at it from the windbox side there are hooks on the tuyere sections that hook onto a lip on the retort but, the one that is high is not hooked under that lip it sits on top of that lip.

Is this something that has to be tended too an if so how would I go about that?

I'm sorry if this is a idiotic question I have zero experience with stokers so I'm sure I'll have other questions as well.
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous

Re: Combustioneer 77B

PostBy: LsFarm On: Sun Jun 16, 2013 8:37 am

A photo or two would be VERY helpful for us to help answer your question.

The tuyeres should be as close to an airtight fit as possible, you want the combustion air to be forced out of the air slots in the tuyere, not leaking out at the base of the tuyere.

It probably is just a bit of filing or minor grinding with a Dremel or small grinder to clean up the 'hooks' you describe so that they properly hook into the air chamber under the tuyere.

Photos would definitely help !! :D

Greg L
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Combustioneer 77B

PostBy: Berlin On: Sat Aug 24, 2013 6:05 pm

it's a pain because the refractory hearth is poured around (tight to) the tuyeres and, when replacing them, you have to remove (chip away at) a good deal of it to get the replacements to fit properly. Yes, you should pull them (there is a clamp that holds them together - standard worm gear stainless clamp) and install them correctly or you can have rapid burn out from improper air flow. Pick a nice coarse grained fireclay mix refractory putty or plastic refractory and fill the void (hearth) around the tuyeres after you reinstall the tuyeres and the clamp. Be sure to use a piece of masking tape on the tuyres to tell you where to keep the new refractory level - just below the outer ring of holes on the tuyeres - don't plug the holes.

Those tuyeres will last decades IF : you periodically (once/year) clean the holes, keep the fuel-bed DEEP, and don't use too much air.

You'll have less smoke and better performance if you allow the fuel bed to build a bit and keep the ash high, don't take out anything but clinker - especially if you are burning a coking coal = such as ohio #8 etc.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal


Re: Combustioneer 77B

PostBy: carlherrnstein On: Sat Aug 24, 2013 7:13 pm

Thank you berlin for your insight I had been in contact with willburt and they claimed that it was not enough to cause a problem I however had doubts. The refractory around the tuyeres had been removed and replaced with something that was falling apart so I just broke out what was loose and put red devil furnace cement in the void. I could see the clamp is a bolt type clamp.

I'm glad you weighed in I don't want to ruin the tuyeres id hate to think how much a replacement set would cost. I'm wondering if a air chisel/hammer would be faster easier and safer that a hammer and chisel. I could see me whacking one of those curved firebricks while swinging a hammer in that small firebox.

As for filling the void around the tuyeres after they are in right, I have never heard of fireclay mix refractory putty. Is it furnace cement or something different? Willburt sent me instructions to do this job and they recommend castable refractory to fill in the void.
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous

Re: Combustioneer 77B

PostBy: carlherrnstein On: Fri Dec 13, 2013 12:26 pm

I got the tuyeres all evened up and furnace cemented back in place and have been heating absolutely wonderfully with this mini stoker furnace.
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous

Re: Combustioneer 77B

PostBy: Berlin On: Fri Dec 13, 2013 1:51 pm

good job! Aren't those stoves great!
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Combustioneer 77B

PostBy: carlherrnstein On: Tue Dec 17, 2013 9:33 am

They really are good heaters once you figure them out, and it seems I haven't quite don that yet.

I had been burning stoker coal left over from my dads basement mine, I have gotten tired of packing 120lbs up the basement steps so I bought some stoker coal on Saturday and its burning differently.

The fire has built up higher, doesn't clinker quite right, and smokes a little when the stoker shuts off.

The clinkers forms as chunks about the size of chicken eggs, then are pushed over to the edge of the hearth area where it isn't hot enough to melt together.

The inside of the combustion chamber has developed a thin film of soot and I have seen small pieces of soot that have fallen out of the baro damper. The soot inside of the combustion chamber is fine with me but, Id rather not have black crap falling on the floor and getting blown around the house.

I read the manual over and over last night and figured it needs more combustion air, so I opened up damper up 1/2 turn and didn't remove any clinker. This morning when I checked it there was less fire than I expected and I didn't poke to see if there was a clinker.

Am I on the right track or am I picking the scab too much?
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous

Re: Combustioneer 77B

PostBy: Berlin On: Tue Dec 17, 2013 6:47 pm

Well, that's why unless your adventurous, most people like to stick with the same source of stoker coal. ;) Once it's dialed in right for the coal, you'll be set.

- Make sure that only clinker is removed (unless it's in the 60's and it's been idling all day, in which case, keep the ash to the bottom of the stoker door and remove loose ash that's above it)

- If you're burning a strongly coking coal (like I am right now) you will get chunks of black coke, keep these in the firebox, they will burn up in cycles.

- don't remove the clinker too much. with coal around 9% ash, you should be able to burn the hopper down to the start of the sloped section before you remove the clinker - you might have to hit it with a poker after you pry it up to get it out the door.

-clinker tongs or some sort of long fireplace tongs are a real necessity to carefully remove clinker from firebox.

- I've never had any soot fall out of my baro damper, you may have had a wind-related draft reversal or puff ?, is this plumbed in the same flue as an oil furnace ? (the sudden burner ignition can/will eject a bit of soot from the baro if tied together). Also, I would put the baro as close to the flue as possible, not the appliance.

- There will always be a light layer of soot in the firebox after shutdown, this will mostly burn off every few cycles, I don't bother brushing mine. Some coals smoke more than others after shutdown, be sure the air is adjusted properly (you want the fire to build and not smoke at all under fire, but there is a sweet spot, too much or too little air will create more smoke when the stoker shuts off).

-set the baro at -.04 or -.03, I'm not a huge fan of will-burt's instructions, although for some situations they seem to work ok.

- air adjustments of 1/16th of a turn DO make a difference in performance. This is not always readily apparent if you haven't been firing a stoker for a while.

-the ash should really reach the bottom of the loading door. Make sure the feed is on the lowest setting, even that, IMHO is too high for any decent coal. I use a smaller pulley than the factory supplied one. longer cycles is what you want.

- If you have room, a "magic heat" type reclaimer does wonders for the relatively high stack temps of these stokers.
Berlin
 
Hot Air Coal Stoker Furnace: Will-Burt Combustioneer 77B
Coal Size/Type: Ohio BITUMINOUS pea stoker coal

Re: Combustioneer 77B

PostBy: carlherrnstein On: Tue Dec 24, 2013 5:53 pm

I think I got ahold of it now, with the past few warm day the stoker was mainly just being cycled by the hold fire timer and was not running hard enough to make a clinker. This morning I checked it and there was a nice big clinker in there. I was worried that this "new" coal had a higher AFT and would not clinker but, It will.

Berlin, I made a clinker tong from 1/4" SS round rod its about 24" long. Its modled after a clinker tong thats in dads basment, there was a winkler stoker and a ideal #7 steam boiler down there but, thats all gone now :(

As far as the soot coming out of the damper im not sure what that was about either it hasent happened sense but, I will keep a eye on it. I have two small children and they don't need any help making the house a mess :D

I dont have much room for a "magic heat" reclaimer, I'm kind of close to the wall as it is about 17.5" so I'v got a heat shield on the pipe and a stove board mounted on the wall behind the stove. I know its gross over kill but, it keeps the insurance company from throwing tantrum and dropping me.
Also my stack is a kind of short so a high exhaust temp (350F) helps more than it hurts. I think?
carlherrnstein
 
Hot Air Coal Stoker Stove: combustioneer model 77B
Coal Size/Type: pea stoker/Ohio bituminous