Pictures of a burned pipe and worm due to improper feed/air

Grego1968 wrote:I'm using the DF520 and I had to shorten the feed pipe. My pipe is 3 feel from the boiler. I have it feeding from a small bin. My pipe is heating up and I am getting a gas smell. I undertand what is happening. The coal in the bin is heating up. I don't really have the room to extend the pipe. Any suggestions? I've increased the feed and air flow. My air flow is set about 5 is that to much? The flame appears good. I'm new at burning coal.....HELP. I do have the oil set up. So until I am more familar....I burn oil at night so I can monitor the coal burning during the day.

increasing the air isnt a solution......do you have the manual?.......my efm is forced air here are some settings i think they are the same, chime in if they are not

feed teeth points on air indicator

1 1 3/4
2 2 1/2
3 3 1/4
4 4
5 4 1/2
6 5 1/4
7 6
do not exceed 7 teeth

make sure the damper is working also......need to check draft with a manometer......theres a loaner going around the forum for use

You don't say how many teeth of feed you are using, but you want to keep the air slightly less than the feed. Is the short pipe installed with the drilled holes facing up?

It's possible you have too much air vs. feed, or the pipe is too short, not recommended, a blockage in the flue, or not enough draft. Are all the openings in the base sealed with putty? Are the holes in the burner plates open?

I am adding, that it's also possible you have some bad coal, which is burning up too fast.

I'm using about 6 or 7 teeth on the feed and about 4 1/2 air. Seems like if I go lower on the feed my worm pipe gets heated up. This seems to be working okay...of course I might use to much coal. As far as the vent holes. I extended the pipe using exhaust pipe and drilled two vent holes. Total length of pipe from boiler is about 3 1/2 feet. Is this safe? How big should my vent holes be? It is feeding well but I can not get that dark spot in the center. No hot coal is falling into the ash pit though. I think it's doing well.......any thoughts? Thanks.

I've asked a 30 year veteran user of the stoker to get me a picture of the dark spot. He can't. He drove farther and paid extra for quality coal in Mahanoy City and got coal that he thinks is mixed. He's getting alot of clinkers and it's not burning well at all.

You might have poor quality coal, which would explain why you are burning so much with so little air. But as far as wasting money, the coal might be burning up like "sawdust" as my friend described his coal.

The factory pipe has holes that safely vent into the gooseneck, not into the room. They are about 1/8 or 3/16". There is a picture of the pipe at the top of this thread. The holes face upward.

so it is possible that i installed the aluminum feed pipe wrong?

A 50% chance. The only way to know is to pull out the pipe and take a look.

You? or Grego?

me......i honestly don't remember.....i didn't have an install manual, just the operating manual....i did replace all the gaskets, and i had to replace the burner plate bolts......i wish i had taken pics of the pile of parts that i started with

That is a question i also have ??"how hot should the bin feed pipe be" when it is running full till should it be cool?warm?luke warm?? i am using 4 teeth 3 air anymore feed i get hot coal spilling over, but i dont get the dark circle in the fire. the feed pipe is only hot about 3 inches down from the outside the stoker. this is how it has been operating for 3 years now and no wear on the worm when i cleaned it this summer. i know there is alot of variables to consider but from reading the posts i think i read into things too much, but any input would be appreciated

The post isn't meant to alarm anybody, but just to make people aware that this can happen. It's very rare, but with the various qualities of coal, I would certainly keep an eye on it after getting a new batch of coal, if only to make minor adjustments to the feed and air.

It seems a heat sensor and alarm or auto-dump-a-cup-of-water might be a good upgrade. The AHS S-130 has a heat sensor on the coal intake. If it get's hot it shuts off and the fire goes out.