provide for simple adjustments between feeders for equal fuel
delivery and also for single feeder biasing.
b.
Line Shaft Feeder: The feeders driven by a line shaft shall be
driven through a variable speed drive having a ratio of not less
than three to one. Feeder drive shall be so arranged that each
feeder is independently driven from a lineshaft so that any feeder
can be engaged or disengaged without disturbing the operation of
the remaining feeders. Fuel delivery shall be governed by the
combustion control system.
c.
For either 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.
Provide safety release to prevent damage to the units
due to foreign materials in the coal or other causes of overload.
d.
Distributor: The distributor shall be driven by a variable speed
electric drive which is manually adjusted to achieve optimum
distribution.
2.4.2.5
Stoker Grate Drive
Drive the grate the stoker by [hydraulic package] [electrical motor] [a
steam turbine] through a variable speed device with a speed ratio of at
least six to one, with the speed changing device, controlled automatically
by the combustion control system. Provide a manual adjustment to regulate
grate speed ratio to fuel feed in order to compensate for variations in the
ash content. Provide a suitable safety release device to prevent damage to
the drive or grates due to foreign material or other obstruction
interfering with the grate operation.
**************************************************************************
NOTE: Make heat balance to determine whether it is
more economical to use turbine drives rather than
**************************************************************************
a.
Electric Motor: Motor shall be [_____] volt, [_____] phase,
[_____] rpm, 60 Hz, totally enclosed, fan cooled, not less than
[_____] kW hp as specified under paragraph entitled "Motors and
Drives" in this section.
b.
Steam Turbines: Drive shall be by steam turbine conforming to
NEMA SM 23 as modified below. Turbine shall be noncondensing
capable of producing braking power [_____] kW horsepower at
[_____] rpm at a steam rate of not more than [_____] kg pounds per
brake power hour. Inlet steam condition, upstream of built-in
governor, shall be [_____] kPa (gage) psig and [_____] degrees C F.
Exhaust steam conditions at exhaust nozzle shall be [_____] kPa
(gage) psig. Turbine rotation shall be [clockwise]
[counterclockwise] and shall be [direct connected] [geared] to the
driven piece of equipment which shall operate at [_____] rpm.
Piping connections 50 mm 2 inches and smaller shall be screwed.
Connections 65 mm 2 1/2 inches and larger shall be flanged. Inlet
flanges shall be raised face suitable for the inlet pressure
specified. Exhaust flanges shall be Class 125 or Class 150
SECTION 15502N
Page 68
Previous Page
