conveying run.
2.9.9.7
Grating
Hopper grating shall have openings 90 by 90 mm 3 1/2 by 3 1/2 inches.
Construct grating of 65 by 10 mm 2 1/2 by 3/8 inch steel bars and 20 mm 3/4
inch diameter steel rods. Weld grating and make in sections for ease of
removal. Provide intermediate beams to support grating.
2.9.9.8
Flight Feeder Drive
Flight feeder shall be driven by an electric motor direct connected by
means of flexible coupling to a reduction gear unit having alloy steel
helical or herringbone gears and antifriction bearings enclosed in oiltight
housing. Provide an adjustable base for motor and gear. Drive from output
speed shaft of the reduction gear to the conveyor head shaft shall be by
means of standard finished steel roller chain running over cut tooth
sprockets, both conforming to ASME B29.1M and complete with steel plate
chain guard. Roller chain attachments shall also conform to
ASME B29.1M. Properly tension drive chain.
2.9.9.9
Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60 Hz
not less than [_____] kW hp as specified in paragraph entitled "Motors and
Drives."
]2.9.10
Bucket Elevator
Dusttight [centrifugal discharge] [continuous bucket] type having
approximately [_____] meters feet [_____] mm inch sprocket centers,
vertical chain and bucket, operating at a speed not to exceed [_____] m/s
fpm, and having a capacity of not less than [_____] Mg tons per hour of
[_____] size coal. Provide bucket elevator complete with continuous double
chains and attached buckets, upper and lower sprockets, gears, shafts,
bearings, casing, top hood, discharge spout, bottom boot, access doors,
electric motor drive, reduction gear, service platform, and accessories.
2.9.10.1
Head and Foot Shafts
Cold rolled steel not less than [_____ and _____] mm [_____ and _____]
inches in diameter, respectively. Mount shafts in antifriction roller
bearings with forced lubricating type fittings. Mount head shaft in fixed
pillow blocks. Foot shaft shall have screw-type takeups with not less than
a [_____] mm inch adjustment. Shafts shall fit tight in sprocket hubs.
2.9.10.2
Terminal Sprockets
Cast iron with chilled rims. Head sprockets shall be not less than [_____]
mm inches in diameter and foot sprockets not less than [_____] mm inches in
diameter.
2.9.10.3
Buckets and Chain
Construct buckets of [malleable iron] [not less than [_____] mm inch steel
plate] not less than [_____] mm inches long, [_____] mm inches wide, and
[_____] mm inches deep. Buckets shall be mounted by not less than four
bolt attachments to double strand of steel bushed chain each having an
ultimate strength of not less than [_____] kg pounds and pitch of [_____] mm
SECTION 15501N
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