A mechanical stoker suitable for small boilers, such as the vertical,
water-tube, and locomotive types. Coal is conveyed direct from a bunker or
hopper by a feed worm, which forces the fuel up through the bottom of the
retort in which it is burned. Volatiles driven off must pass through the
ignited fuel, thus eliminating smoke. An underfeed stoker operates most
successfully on graded coals with an upper size limit of 1 to 2 in (2.5 to 5.1
cm). See also: stoker;
vibrating grate. Nelson
Source:
Dictionary of Mining, Mineral, and Related Terms
