NOTE: Delete fluidizing system if not necessary.
**************************************************************************
Provide a fluidizing system on silo floor to ensure a constant and uniform
feed of ash through the silo discharge outlet. System shall consist of a
series of diffuser modules, a conical diffuser hood, designed to support
the total weight of ash when silo is full, and compressed air piping. Each
diffuser module shall be mounted on the silo floor using sloped concrete
pads. System shall operate from the plant air system. Provide pressure
reducing valves, safety valves, and controls for a complete system.
2.12.11
Control Panel and Controls
Provide a semi-automatic control system for the ash handling system [as
indicated]. Provide a centrally controlled operation, with auxiliary local
operation, and a monitoring control system with graphic display for the ash
conveying system. Provide local control stop-start pushbuttons and
indication stations for chain drag conveyor, screw conveyors, bucket
elevator, and rotary ash conditioner. Ash handling system manufacturer
shall provide measuring devices, status switches, solenoid valves, and
auxiliary parts necessary to safely control and operate the system.
Provide related electrical work required to operate the ash handling
system. [Provide detailed control logic diagrams from ash handling system
manufacturer to manufacturer of the digital process control and data
acquisition system.]
2.12.11.1
Control Panel
Provide a [separate control panel] [subpanel mounted in the main plant
control panel] of NEMA 12 construction, centrally located in the main plant
control room. Panel front shall include a system graphic display as
indicated. Display shall be approximately to scale and painted with an
industrial acrylic enamel. Outline items with 3 mm 1/8 inch wide black
lines. Lettering shall be on engraved plastic screwed to front of panel,
with white letters on a black background. Provide controls for operation
on [_____] volt, [_____] phase, 60 Hz ac. Panel shall be complete with an
annunciator and interlocks, relays, switches, running and safety lights,
and auxiliary parts necessary to safely control and operate the system.
Items located in the door shall be dusttight and oil tight with
push-to-test transformer type indicating lights. Control relays shall be
10 amp, 600 volt class with convertible contacts. Provide and mark
terminals for connections with the exception of the neutral. Panel shall
contain [_____] percent spare terminals. Wiring shall be No. 14 AWG type
THHN stranded. Neutral wire shall be white and remaining wiring of 120
volts or less shall be color coded and labeled. Provide a plastic wire
duct of sufficient size to provide [_____] percent cross sectional spare.
Wiring shall be in accordance with requirements of NFPA 70.
a.
Panel Devices: Control panel shall include the following
indicating lights (color in parenthesis):
(1)
Power - ON
(red)
(2) System Run (3 required)
Chain drag conveyor to elevator
(green)
Screw conveyors to drag conveyor
(green)
Bucket elevator to silo
(green)
(3)
Ash Silo - HI LEVEL
(red)
SECTION 15501N
Page 117
Previous Page
