Yellow Flame to Tri-Burner Conversion. What Do You Think?

StokerDon wrote:

McGiever wrote:Having a larger breech reduced to fit a smaller flue pipe could contribute heavily to the lack of adjustability you describe.

Hummm,,,

Hopefuly the 8" chimney will improve the situation.

SD, you running on the 8" now?

And for the BoilerMate, are you using 24 volt or 120 volt for control?

McGiever,

I am temporarily hooked into the 6" chimney. I don't have a baro on it either. Pulling between .02 and .03 draft. I hope to put the 8" chimney up in the next week or so. That reminds me, I still need to get an 8" baro. The stoker mostly idles now.

I hooked the Boiler Mate up for 120 volt operation as per Smitty. Below is the detailed thread about how to do it.

Fixing the Dreaded Boilermate Buzz: Control Board Repair

-Don

I think I have learned the settings on this little stoker setup over the passed week. I filled the hopper at about 1100 this morning with about 90 pounds of rice coal. Now we will see how long it takes to eat 90 pounds.

One issue I have with the Tri-Burner is that it doesn't have a very wide range between idle and full blast. It won't run on my 15 minute repete cycle timer and if I turn down the rehostat much below 2:00, the fire goes out also. I guess that a coal-trol would help that issue. Good thing the Meet & Greet is next Saturday, I can talk to some people about it.

-Don

I just filled the hopper for the second time, 3.5 days between fillings. I put in about 80 pounds.
It has gotten chilly here for a night or two so I turned the thermostat up to see how this little stoker would handle it. The answer was, not very good. If I crank the Tri-Burner feed rate up 4 or 5 turns to get maximum burning coal on the grate, the blower / heatexchanger just drag the boiler temp down. It never caught back up again after 2 hours. I will keep playing with it, just incase I missed something.
Maybe StovepipeMike was right about "That large amount of heat transfer surface inside". He was concered about the draft though, my draft has been good but not the heat output.

-Don

The Tri B is rated 90K btu/hr.

What is the rating of the Yellow Flame Burner?

Tri-burner is probably rated based on input, and hard to say what they assumed for a btu/lb value. Generally it seems like the older equipment had more conservative ratings. The original stoker probably runs at a higher feed rate, and the location/pattern of the fire within the boiler might (just guessing) impact the performance.

StokerDon wrote:If I crank the Tri-Burner feed rate up 4 or 5 turns to get maximum burning coal on the grate, the blower / heatexchanger just drag the boiler temp down. It never caught back up again after 2 hours.

I think the difference in usable output between the Tri-Burner and YF stokers is larger than you have estimated, and it probably should be expected that the unit will have trouble carrying any significant heating load. Rated on an input basis, I think even a Keystoker 3-plate stoker would come out around 200k btu/hr, and AFAIK the YF burn plate area is bigger than the Keystoker. Compared to 70, 85 or whatever your Tri-Burner turned out to be, it's not close.

In that context, I think Rob's earlier advice to insulate the boiler looks pretty good. Much of the output from the little stoker is being dissipated by the boiler acting as a radiator, leaving even less to carry the attached load. Even with insulation, though, I think this would provide another example of the problems that can arise when the usable boiler output is insufficient to carry the attached load.

Mike

Someone please explain how insulating a boiler will make for more complete burning of coal.

McGiever wrote:Someone please explain how insulating a boiler will make for more complete burning of coal.

It won't. It just allows you to burn less coal if the boiler room is presently warmer than desired.

You guys are right, it is possible that the YF 3 grate puts out more BTU than I have esimated. I don't know if there is a way to figure that out. The YF basicly has a burn area of13"x8.5"= 110.5sq in. The grate holes are bigger in diameter than the Tri-Burner and the Keystoker. Another thing I have noticed but not measured is the coal bed looks to be a good bit thinner in the Tri-Burner.

I was going to do the boiler insulation last weekend. I went to my local to pick up my new 8" chimney parts and thought I would just get some foam board while I was there, they don't carry it! I talked to my other local, they don't carry it either! Looks like I will need to make a trip to HD to get that.

If it ends up that the Tri-Burner can't carry the heat load of the house in mild weather, it's not a total failure. The little Tri-Burner does fine for heating DHW, that part I have already proven. With out a doubt, The Tri-Burner gives a more complet burn and uses less coal when run on a very low setting than tha Yellow Flame. The Yellow Flame seems better suited for high output.

-Don

If you haven't given up on the Tri B and want to "tinker"...try making and fastening a "speed bump" across the edge of the grate at the downhill side, in order to have the coal backup just a little bit.
Should give you a little thicker bed of coal on the grate for a more intense fire.

May be worth a shot if it makes it thicker and you can make all the air and feed tweaks required.

I'm Gonna tinker with it for another 2 weeks at least McGiever.

Re-filled with about 80 pounds late this afternoon. I emptied the ash pan yesterday after I got back from the Meet & Greet. The ash pan was full with a little mound over the top, it felt pretty light for a full pan!

-Don

Have you tried drilling out the grate holes to make them the same size as the YF's?

OK, I finally found some 1" foam board insulation! My local actualy had some hidden away. We went out to the warehouse to look at some 1/2" stuff and we found this instead!

1" foil faced, R=7.2
So, on it went!
One of the problems I had with installing the insulation is, my boiler has these realy big tits. Some of them stick out a good 1/2" or so!
So basicly I line up the foamboard, then smack it down over the tits. The tits themselfs hold the foamboard in place pretty well.
Some how, she just ain't as pretty with her tits all covered up with insulation.
Oh well,

-Don

blrman07 wrote:Have you tried drilling out the grate holes to make them the same size as the YF's?

Larry,

That's an idea I had not thought of. Bigger holes and a bigger combustion blower coupled with a thicker coal bed would give it a few more BTU's.

Then again, I could just furnace cement the holes in the YF so that the area is a little bigger than the Tri-Burner. Then do the Keystoker blower mod. I could just have a set of sommer and winter grates instead of summer and winter stokers.

Something to think about.

-Don