The upper pipe looks good. I didn't check the inside of the lower pipe, but I have been replacing each season now
. I haven't done it yet this year, but did replace it last year.
I haven't replace the augers. My EFM rep hasn't given me a price yet...
However, might as well try the new coal first before replacing the augers. I suspect it will be here soon.
I'm going to start working on the air tube between the blower and upper pipe. I'll let you know what I figure out.
Replacing each season?? That tells me the pipe is getting severely corroded by your wet coal. The rough surface of a rusty pipe will grind the coal. Fines + moisture = black sludge = plugged holes in the pipe
Hundreds of people burn Kimmel's rice with out the issues you have reported. My family has burned about 50 tons of their rice in EFM 520's...some of the coal had more fines than I like, but it still burned fine without any of the issues you have reported. I tried to think of what makes your setup different than everyone else, and the only things I came up with are that you started out with a bent auger and have run sopping wet coal through rusty feed pipes. If your EFM guy can't get back to you with a price, find a new EFM dealer. There are guys with augers in stock that would be happy to get an order.
1. Switch your bin pipe to aluminum or stainless.
2. Make sure the pipes are cut square and fit tightly against one another in the coupler.
3. You already had to replace the pot bushing, which usually has the same or great lifespan as the auger...so the pot auger is probably not in great shape either. I would replace it. Same with the bin auger if it was bent. No more than 2.5-3 flights of the bin auger should stick out beyond the pipe.
4. If you can get coal with less fines, do it. Find a way to drain off the excess water.
I know that list is a lot of $$, but you have already spent a lot of money on a boiler...might as well get it running the way it is supposed to.