2.28.4
Wrenches and Gaskets
Wrenches shall be provided as required for opening boiler manholes,
handholes, and cleanouts. One set of extra gaskets shall be provided for
all boiler manholes and handholes, for pump barrels, and other similar
items of equipment. All gaskets shall be packaged and properly identified.
2.29
COAL HANDLING EQUIPMENT
2.29.1
Screw Conveyor
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NOTE: Where motor starters for mechanical equipment
are provided in motor control centers, delete the
reference to motor starters.
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Screw conveyor for the lateral distribution of coal shall consist of steel
screw conveyor with capacity of not less than [_____] cubic meters/second
cubic feet per hour when handling coal of the specified maximum lump size.
Maximum capacity of the conveyor shall be based on the screws carrying not
more than 30 percent of their cross section (except feeder conveyors), and
the maximum speed of conveyor shall be 60 rpm. Conveyor and housing shall
be assembled in sections. The sectional flights shall be mounted on steel
pipe and connected by coupling shafts. A feeder conveyor may be installed
to assume the proper distribution of the load. Both the feeder screw and
the extended screw shall have their flights mounted on the same pipe. The
conveyor shall be provided with sectional supporting hanger bearings of the
babbitted type. Conveyor length between bearings shall not exceed 3.7 m 12
feet. Trough ends shall be fabricated cast-iron type with feet and fitted
with babbitted bearings. The drive shall be at the discharge end of the
conveyor and shall consist of an electric gear motor and chain drive. The
chain drive from the motor to the reducer shall be enclosed in an oil-tight
casing. Thrust in either direction shall be absorbed by the thrust
bearings. The motor may be mounted on top of the trough. The trough
conveyor housing shall be not less than 4.8 mm 3/16 inch steel with a 1.897
mm 14 gauge steel cover and shall be dust-proof. Discharge spout and coal
gate shall be furnished as indicated. An approved type of supporting
saddle shall be provided. Supports shall be spaced at not more than 3 m 10
foot intervals. Motor enclosure shall be [totally enclosed, nonventilated]
[totally enclosed, fan-cooled type suitable for installation in a Class II,
Division 1, Group F hazardous location in conformance with NFPA 70].
[Motor starter shall be [manual] [[magnetic] [across-the-line] [reduced
voltage start]] type with [weather-resistant] [dust-tight]
[explosion-proof] enclosure.] Dust controlling covers and inlet and
discharge enclosures shall be provided for each conveyor.
2.29.2
Belt Conveyor
Belt conveyor shall be of the trough type, as shown. Maximum incline of
the belt conveyor shall not exceed 15 degrees. The conveyor support frame
shall have sufficient rigidity to maintain belt alignment, at least 75 mm 3
inches clearance to prevent damage to the edge of the belt on its return
run, and adjustments for aligning shafts. Decking to protect the return
belt from coal sifting and to provide lateral stiffness shall be placed on
top of the stringers. Idlers shall be accurately made to provide a rigid
framework that will maintain permanent alignment of well balanced,
smooth-running, easy turning idler rolls. All idlers and return rolls
shall be CEMA Belt Book, Series C5. Pressure lubrication shall be provided
SECTION 15559A
Page 80
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