2.11.6.3
Discharge Doors or Gates
Provide each hopper with refractory lined, dusttight, water cooled,
vertical lift doors, of an opening size not less than 560 by 560 mm 22 by
22 inches. Each door shall be [air-cylinder operated] [chain wheel
operated]. [Provide intermediate positioning capability with air cylinder
operators.] Provide each door with guide rollers and support arms to ensure
smooth operation without binding. When doors are vertical, minimum number
of guide rollers shall be 4; for a sloping surface, minimum number of guide
rollers shall be 6.
2.11.6.4
Hopper Lift Door Enclosure
Provide not less than 6 mm 1/4 inch thick steel, dusttight, enclosure, for
each vertical lift door. Match enclosure to housing of clinker crusher and
make enclosure large enough to enclose the outlet and the vertical lift
door. Provide hinged inspection and cleanout door on enclosure front.
2.11.6.5
Hinged Hopper Access Door
Provide on one side wall of each hopper. Door shall be cast iron, air
tight swingaway locking type with refractory lining. Install door so that
it is conveniently accessible and easy to use.
2.11.7
Clinker Crusher
Provide mounted below each hopper discharge outlet, under vertical lift
door enclosure, capable of reducing clinkers from bottom ash to a maximum
size of 50 mm 2 inches at a rate not less than conveyor system capacity.
2.11.7.1
Construction
Single roller crusher unit with extra heavy housing, outboard bearings
sealed against grit infiltration, motor and drive. Housing shall be 15 mm
1/2 inch thick. Crusher rollers shall have replaceable cam segments
(teeth) with a minimum Brinell hardness of 450. Each cam tooth shall be
designed to permit resurfacing with hard material. Stationary heavy cast
iron or manganese steel abrasion resistant wear plates, of a Brinell
hardness not less than 350, shall be mounted about the crusher rollers.
Cam shaft rotational speed shall not exceed 20 rpm.
2.11.7.2
Fluid Gear Drive
Crushers shall be driven by a fluid gear drive including a totally
enclosed, fan cooled, [_____] volt, three phase, 60 Hz electric motor not
less than 3.75 kW 5 hp, as specified in paragraph entitled "Motors and
Drives," fluid coupling and reduction gear, integrally mounted in dust and
oil tight enclosures. Fluid drive shall protect unit from excessive shock.
Drive shall automatically reverse when stalled; crusher shall reverse and
move forward three times and, after third time, shut down and alarm when
still stalled.
2.11.8
System Valving
2.11.8.1
Side Intake Valves for Fly Ash Collection
Provide at each hopper, including dust collection hoppers and rear pass
hoppers, and other collection points. Side intake valve shall be
SECTION 15501N
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