water-tight terminal boxes, supported on corrosion-resistant metal framing
and shall have rust-resistant steel reflectors with an approved coating.
Heaters and connections shall be wired using NEMA 4 enclosures, in
accordance with NEMA ICS 1, suitable for cleaning by hosing down with water.
2.23.11
Coal Spouts, Chutes, Inlet Boxes, and Outlet Hoppers
Coal spouts, chutes, inlet boxes, and outlet hoppers shall be constructed
of ASTM A 36/A 36M steel members not lighter than 3.416 mm (10 gauge) 10
gauge, adequately reinforced and braced with angle frames, and with all
joints dust tight. Slopes shall be as steep as possible, but not less than
55 degrees off horizontal. Liners shall be stainless steel or ultra-high
molecular weight polyethylene (UHMWP). If UHMWP liners are used, each side
of chute at each floor level shall be provided with a warning sign "DANGER
- DO NOT WELD - FLAMMABLE PLASTIC LINER." Impact liners shall also be
used. Access openings and inspection openings with cover plates shall be
provided as indicated and required. [Silo frames shall be constructed of
heavy channel frames the full size of the silo opening and shall be
provided with concealed steam pipe and coil around opening.] [Outlet
hoppers shall be provided with rack-and-pinion type gates and shall be
lined with austenitic stainless steel [_____] mm inches thick, conforming
to ASTM A 167, Type 304L]. Rack-and-pinion gates shall be of the type
specified for track hoppers.
2.23.12
Car Spotter
Car spotter shall be electric-motor driven having a capstan mounted
vertically on a rigid housing that completely encloses the gears. The
gears shall include helical gears and worm gear; the helical gears shall be
fabricated of high grade steel accurately finished and splash-lubricated,
and the worm gear shall be fabricated of bronze. All of the mechanism
shall be mounted on a steel base rigidly welded to maintain alignment. The
unit shall be coupled to, and driven by, a separate, [_____] W hp, totally
enclosed, nonventilated, hoist-type motor with a full-load speed of 1720
rpm. The coupling shall be roller-chain flexible type enclosed in a
revolving casing and protected by a heavy steel guard. The unit shall have
a starting pull of 23 kN 5000 pounds, a running pull of 11 kN 2500 pounds,
and an average rope speed not in excess of 230 mm/sec 45 fpm. The unit
shall be complete with [_____] m feet of [32 mm 1-1/4 inch diameter manila
rope with a breaking strength of 60 kN 13,500 pounds, minimum,] [19 mm 3/4
inch diameter marline-covered standard steel wire rope with a breaking
strength of 170 kN 37,600 pounds, minimum,] and a steel car pulling hook
with an allowable rope pull of 45 kN 10,000 pounds, so fabricated as to be
readily attachable to, and removable from, the car frames.
2.23.13
Coal Bunkers
Suspension coal bunkers of size and capacity indicated shall be constructed
of ASTM A 36/A 36M steel plate, reinforced and braced as required, and
installed dust-tight. Bunkers shall be provided of a design optimized for
coal flow, not susceptible to rat-holing or hangups. Cylindrical or silo
type bunkers to reduce stagnation shall be provided for each boiler, each
with conical discharge hoppers and slopes not less than 70 degrees. The
outlet cone shall be manufactured of, or lined with, ASTM A 167, Type 304L
stainless steel. Bunkers shall be provided with rack and pinion type coal
shutoff valves, self-cleaning, and dust tight. Valve materials exposed to
flowing coal shall be of corrosion resistant steel. An emergency diverter
shall be provided for emptying the bunker.
SECTION 15555A
Page 74
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