efm 520 commercial

A guy I know says his EFM520 has a commercial pot. Would this have been a burner out of a 700 or 900 that was substituted to increase output? What kind of BTU's would that put out?

leward wrote:A guy I know says his EFM520 has a commercial pot. Would this have been a burner out of a 700 or 900 that was substituted to increase output? What kind of BTU's would that put out?

No the 700 900 & 1300 uses a whole different stoker assembly then the 350 or 520.
The first S-15 Pot used a 14" ash ring The S-20 stoker uses a 14.5" ash ring on top of pot
EFM made & still makes a S-22 pot ring that is 15.5" which gives a extra 5k of btu per hr .

The 700 900 ad 1300n Are much bigger pots and the rotate knocking off the ash as well as using bigger Auger's
and tubes .

Feed rates where higher 700 3lbs per hr per tooth max feed rate 10 teeth 30lbs per hr.
With Buckwheat size coal Rice would be 1/2 lb more per tooth . 700 900 1300
900 feed rate 3.5 lbs per tooth 10 teeth max 35lbs per hr
1300 Feed rate 4.5 lbs per hr per tooth max 45lbs per hr

The S-15 stoker pots had a feed rate of 2.5 lbs per hr per tooth 6 teeth max 15lbs per hr
The first S-20 pots 2.5 lbs per hr 8 teeth max 20lbs per hr
The newer S-20 pots 2.5lbs per hr 10 teeth max 25lbs per hr
All with rice coal using buckwheat size the feed rate is 2lbs per hr per tooth .

Look at the links below to see the difference between 350 520 and 700 900 1300

http://www.efmheating.com/manuals/DF520 ... lation.pdf

http://www.efmheating.com/manuals/Stoker%20Manual.pdf

Thanks Coal Berner. I was just curious how EFM did that. So if you wanted to do that today, on a new Boiler, you could still order the S22, and gain 5k in output.

You can order the S22 ring, but there are none in stock right now. They must be made at the foundary.