this section, 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 reduction gear.
Drive
from output shaft of the reduction gear to the conveyor head shaft
shall be by means of finished steel roller chain conforming to
ASME B29.1M running over cut tooth sprockets conforming to ASME
B29.1M complete with steel plate chain guard.
Roller chain
attachments shall conform to ASME B29.1M.
2.11.3.2
Screw Conveyors
Provide each screw conveyor dusttight and furnished complete, with trough,
screw, inlet and discharge spouts, discharge gates, bearings, bearing
hangers, dust cover, electric motor, reduction gear, [service platform,]
and supports.
2.11.3.3
Inlet and Discharge Spouts
Arrange as indicated. Spouts shall be flanged and square with opening
dimensions equal to the inside diameter of the trough.
2.11.3.4
Screw Trough
Provide dusttight screw trough with trough covers. Support trough by 6 mm
1/4 inch thick steel plate feet at not less than 3 meters 10 foot
intervals. Individual trough sections shall not be greater than 3 meters
10 feet long with steel angle end flanged connections.
2.11.3.5
Bearings and Hangers
Provide thrust bearings and trough end dust seals for both drive and tail
bearings. Thrust bearings shall be bronze in antifriction pillow blocks.
Screw hanger bearings shall be babitted-type, with cast iron hangers having
removable bearing caps held in place by a U-bolt. Design hangers to fit
inside the conveyor trough and equip bearings for grease lubrication with
grease fittings penetrating the dust cover to allow bearings to be greased
without removing dust cover. Hangers shall not be located at trough
joints, feed, or discharge openings. Locate hangers at not less than [3.66
meter12 foot intervals for screw diameters larger than 250 mm 10 inches]
[and] [3 meters10 foot intervals for screw diameters 250 mm 10 inches in
diameter and smaller].
2.11.3.6
Conveyor Screws and Couplings
Construct conveyor screws of helocoid-type flights and connect with cold
rolled steel couplings. Assemble conveyor screws so that at the hangers
there is 180 degrees rotation between the flight ends of each adjacent
screw section. Screw flight shall end over last discharge spout so bare
pipe extends across this area to prevent material carry-over.
2.11.3.7
Electric Motor
Totally enclosed, fan cooled, high torque, [_____] volt, three phase, 60
Hz, not less than [_____] kW hp as specified under paragraph entitled
"Motors and Drives" in this section. Install motor at discharge end of the
conveyor. Motor shall be supported by a unit bracket attached to the screw
conveyor trough end plate and shall be connected to reduction gear through
a V-belt drive. Reduction gear shall be shaft mounted, double reduction
SECTION 15502N
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