flat-faced flanges. Turbine shall be complete with insulation and
lagging. Insulation shall be as specified in Section 15080N
MECHANICAL INSULATION. Turbine governor shall be of direct oil
relay type with 10 percent adjustable speed range. Lubrication
shall be of the manufacturer's standard non-pressure type.
[c.
Mechanical Drive: Mechanical drive shall include variable speed
oil tight case, and running in a bath of oil. Bearings shall be
of the anti-friction type, with hardened inner and outer races and
fitted with forced lubrication fittings.]
[d.
Hydraulic Drive: Hydraulic drive when required shall include a
complete hydraulic system with adequately sized reservoir, dual
pumps, oil piping to and from drive, control and isolating valves,
oil cooler, when required, with self-operated cooling water
control valve, oil temperature indicator, and other accessories
for a complete, operating system. Hydraulic drive system motor,
shall be [_____] volt, [_____] phase, 1200 rpm, 60 Hz totally
enclosed, fan cooled, not less than [_____] kW hp as specified
under paragraph entitled "Motors and Drives" in this section.]
e.
Miscellaneous Equipment: For a stoker drive system, provide a
complete operating unit with necessary shafting, couplings,
bearings, drives with guards, linkages, rods, and other equipment,
as required or necessary for any interconnecting of the stoker
units and drives. This equipment shall be provided even though it
is not specifically mentioned herein. The front and rear shafts
of the grate are to be fitted with a forced system of lubrication
with fittings located on the outside of the setting. The devices
for changing the speed ratio of the grate drives shall be
connected to the fuel feed regulation system, so both fuel feed
and grate speed can be synchronized and controlled automatically
by the combustion control system. A manual adjustment shall be
provided to regulate grate speed ratio to fuel feed in order to
compensate for variations in ash content of the fuel. A suitable
safety release device shall be provided to prevent damage to the
drives or grates, due to foreign material or other obstruction
interfering with the grate operation. Gears, chains, belts,
couplings, and other moving parts shall be properly enclosed or
guarded.
2.4.2.6
Overfire Air System
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NOTE: Designer should include bracketed sentence
when cinder return (fly ash reinjection) will not be
incorporated in the project.
**************************************************************************
Provide a high pressure overfire air system for each stoker, including fan,
[motor drive,] ductwork, dampers and nozzles. The fan shall have a
capacity of not less than 15 percent of the total air required at maximum
steaming capacity when operating at the predicted amount of excess air in
the furnace. Static pressure of the fan shall be sufficient to ensure full
penetration of the furnace by the air jets, but not less than 6225 Pa 25
inches of water. Overfire air distribution nozzles shall be fabricated
from heat resistant alloy. Locate air jets properly and in sufficient
numbers to create proper furnace turbulence for complete combustion at all
SECTION 15502N
Page 69
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