2.3
PROTECTION FROM MOVING PARTS
Moving parts of the equipment, such as drive chains and sprockets, shall be
fully enclosed in removable guards. Equipment above the level of the
sewage-carrying channel shall be fully enclosed in a cast-iron or 1.720 mm
(14 gauge) 14 gauge sheet steel or wrought-iron housing. Housing shall be
provided with a sufficient number of doors or removable panels to insure
ready access to any part of equipment for repairing, replacing, or
cleaning. Joints between the housing and the concrete foundation shall be
made leakproof.
2.4
MATERIALS
Materials shall conform to the following:
2.4.1
ASTM A 48/A 48M Class 30, minimum.
2.4.2
ABMA 9 and ABMA 11.
2.4.3
Aluminum Alloy
ASTM B 108.
2.4.4
Miscellaneous Metal
Bolts, nuts, anchors, washers, and other types of supports necessary for
the installation of equipment shall be of steel or wrought iron, galvanized
according to the requirements of ASTM A 153/A 153M. Anchor bolts and nuts
for the comminutor, motor, or power unit shall be Type 316 stainless steel,
ASTM F 593.
2.5
ELECTRIC MOTOR AND CONTROLLER
Electric motor shall conform to NEMA MG 1.
Motor controller shall conform
to NEMA ICS 2.
2.6
COMMINUTOR
The comminutor shall be of the [rotating] [or] [oscillating] type for use
in a sewage treatment plant. It shall consist of an electric motor-driven
mechanical shredder or cutter with [gear motor] [hydraulic drive] capable
of continuous and automatic operation and shall reduce sewage solids to
particle sizes between 6.4
and 9.5 mm 1/4 and 3/8 inch. The cutting and
screening mechanism shall cut or shred all sewage solids including sticks,
rags, and stringy material, without removing them from the sewage flow,
without clogging the screen, and without binding, jamming, or stalling the
moving parts.
2.6.1
Rotating Drum Type
The rotating drum type comminutor shall include a slotted drum that
functions as a screen and support for the rotating cutters, a casing
supporting the stationary cutters, and a drive assembly. Evenly spaced
cutting teeth shall pass through a stationary comb section cutting against
it as the cutters rotate. The unit shall have a smooth, continuously
SECTION 11331
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