Smoke out of Hopper- EFM

Hey guys! So this week I got my first delivery of oiled rice coal. I've heard getting the coal oiled you cut back on fines and dust, which I definitely want! But tonight I went down to fill the hopper ( a 50 gal drum with the worm going right into it) and as the stoker was running smoke was coming up through the coal in the hopper. The worm was not hot but warm like usual. Smoke only appears when the stoker is running, smells like oil, not sulfer and my entire system was cleaned (by my dad who has been doing it in my house since it was my great aunt's- over 30 years). It did not smoke a week ago, and I'm assuming the new coal is now starting to burn that's oiled. Is this normal? There has not been much change in weather, and I can't measure my draft but with my new chimney insert and a full clean a few months ago, I don't think it's clogged. Thanks!

It could be the oil on the coal is a little much, hard to say, but you should always check/set your baro damper (if you have one) and check your draft with a draft gauge. On some units, if you have too much draft, it will burn back in places you don't want it to, like the hopper and cause moisture or smoke and CO. I know the EFM's are a bit different than a standalone stoker unit iwth the hopper on the back of the stove.

I assume you have a good CO detector also.

Welcome to the forum.

I have no experience with oiled coal but when damp coal is in the barrel there is never any problem. Also, the feed pipe should not be warm. Are you using a bin auger, or just the short feed auger?

If you are using just the short feed auger I would suggest installing the 4 foot bin auger. This usually keeps any gasses from come out of the fire pot. Keeping the draft within spec is a must. CO detectors are a must too.

-Don

was hopper near empty?

I'm using a short feed auger, no smoke piling up in the chimney and I can see right up with a mirror. I'm thankful I just installed new co detectors and slept downstairs last night with no problems. Still smoking as of this morning but not enough smoke to even remotely fill the room, it's almost like a mist type of smoke and like I said it stops as soon as the stoker kicks on. I'm getting fines like always so I don't think there's a clog there and my worm always gets a little warm when running for a while to heat the house. Also not empty but I'm letting it run low to see actually wwhat's going on down there. When I initially stuck my hand down into the coal to see if it was hot the coal was substantially damp with oil/h20. My friend who installed the stainless steel sleeve for the worm assured me the fire won't go back into the hopper, but I just want to get to the bottom of this smoke!

Have you checked the little holes drilled in the stoker end of the auger pipe to make sure they are clear. Seems wet and oiled coal fines might clog those up and cause this.

The only way smoke can be coming out of your barrel is if combustion gas is going down the feed pipe to it. You should not be feeding from just the short auger. The pipe should not get warm. If you put the 4 foot bin auger on it the problem will likely go away.

One simple thing to try is turn the air setting down a bit. That will lesson the tendency for combustion air to go down the feed pipe.

-Don

Check draft, back off air a bit, plan on getting a real auger pipe instead of just the short piece.

Based on the info supplied by the OP I think I'd view extending the auger as more of a last resort than as a go-to option. As described, the smoke problem only started when the unit started to burn the oiled coal. If the basic problem was that the auger is too short, there would have been combustion gas odors before, even if there were less/no smoke. I think nepacoal's suggestion is good, and follows the manual's caution regarding problems that can be caused by excessively oiled coal. My suggestions would be:

- get some dry unoiled coal into the bin and see if the problem goes away;
- if it does, blend dry coal with the oiled coal for now, and consider sourcing dry coal in the future. Dust issues can be controlled through methods other than oil.
- if you get a combustion gas aroma, clear the air holes in the pot auger pipe (and the pot itself if needed)
- in addition to checking the draft, make sure the feed barrel has a tight-fitting lid, and that the boiler room gets adequate make-up air.

I agree with Don that the auger pipe shouldn't be particularly warm. I'd suggest checking that the fire isn't burning too deep in the pot, and that you have no more than about a 2" ash ring after a long run.

If none of that works, you might need to consider extending the auger.

Mike

Running the short auger is always a compromise. Sure, some people make it work - but EFM will tell you it is a bad idea, and I have heard & seen enough problems with it to agree. The oiled coal may just be making an existing issue easier to see.

EFM says it is permissible to shorten/eliminate the bin auger, as long as the feed drum is sealed. The only thing prohibited in the manual is shortening the pot auger. Maybe we need one of those forum polls, because in my experience many people use the pot auger/drum set-up without any problems, and the people who use bin augers do so in support of an overall coal handling plan. In the process the "short auger" folks save $ and ease space constraints, so the "compromises" go both ways. If the OP had said he had combustion gas odors all along, and had done everything else in the manual to eliminate them, I'd agree 100% with extending the auger. Here, I don't think anyone can provide assurances that a full bin auger would even stop the smoke if in fact the smoke is resulting from clogging of the pot auger pipe air holes by the oiled coal.

Mike

The clogged air holes is a good point, that would cause problems regardless of anything else mentioned.

It does not take much "extra" auger to make the system less sensitive to draft and combustion air settings. I guess if someone knows they will never need to run more than 4 teeth of feed, or burn buck, just the pot auger is fine. Those are the compromises I was thinking about.

Rob, thanks for clarifying. I'm curious about the clogging, as well as (IIRC) Don's point about the warm pipe and possible burning low in the pot.

Mike

Pacowy wrote: ↑

Mon. Jan. 29, 2018 9:26 am

EFM says it is permissible to shorten/eliminate the bin auger, as long as the feed drum is sealed. The only thing prohibited in the manual is shortening the pot auger. Maybe we need one of those forum polls, because in my experience many people use the pot auger/drum set-up without any problems, and the people who use bin augers do so in support of an overall coal handling plan. In the process the "short auger" folks save $ and ease space constraints, so the "compromises" go both ways. If the OP had said he had combustion gas odors all along, and had done everything else in the manual to eliminate them, I'd agree 100% with extending the auger. Here, I don't think anyone can provide assurances that a full bin auger would even stop the smoke if in fact the smoke is resulting from clogging of the pot auger pipe air holes by the oiled coal.

Mike

I don't know Mike. I have manuals for EFM's and none of them say it's permissible to run only the pot auger. None of them say it's permissible to shorten the bin auger either. I think I'll throw the BS flag on this one. As far as having experience using only the pot auger, it has never worked out well for anybody I know to go short.

Scott, I'm going to call BS on your post because what I said was basically verbatim from the 520 manual posted on EFM's website:

"3. The bin feed worm can be shortened and a storage drum used to store coal over the pick-up end...In no case should the first section of worm from the burner be shortened. It is also necessary to place a lid with a seal on top of the storage drum to prevent the possibility of carbon monoxide from escaping into the boiler room." See "Installation and Operating Manual for the EFM Stoker Boiler Unit • Model DF520" (http://cdn.efmheating.com/DF520-Installation.pdf) at page 3.

Maybe the people you know would have better experiences with short augers if you told them what the manual says about how to make them work. My guess would be that somewhere around half are set up and run successfully that way.

Mike