inscribed with a unique tag number assigned using the specified scheme.
Submit drawings of mounting locations for devices to be mounted.
2.12.1
System Operation
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NOTE: Failure Analysis. Provide a complete control
system failure analysis demonstrating and explaining
the effects of various system component failure on
the system. The failure analysis shall specifically
identify the control system features which will be
provided to minimize the effect of component
failures and protect the equipment, especially the
fabric filter bags.
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Operation and control of the Flue Gas Cleaning System shall be accomplished
by a full-time operator from the steam plant control room. The control
system shall be designed to allow operation of FGD system in either of two
modes; remote manual or semi-automatic. In the remote manual mode the
various dampers, control valves, pumps and associated equipment will be
opened or closed, started or stopped from individual switches or push
buttons located on the main control panel. In the semi-automatic mode the
FGD system components for each boiler will automatically placed in or taken
out of service in the proper sequence when the start or stop push button is
activated. In both modes sufficient interlocks shall be provided to assure
that proper sequencing is followed and to allow equipment to be
automatically tripped when required. The control system shall be designed
to ensure that in the event of a power failure of FGD system equipment
failure, the necessary corrective action to prevent damage to the equipment
will automatically be initiated. Contractor shall provide a complete
system failure analysis. Process variable indicators and alarms required
for proper monitoring of system performance shall be located on the main
control panel. Furnish necessary instrumentation to provide positive
indication of operational status of equipment; such as, flow or pressure
switches to verify operation of pumps and limit switches to indicate
position of dampers and valves. Local controls shall be provided for
valves, dampers, and motors. A complete system graphic display shall be
provided.
2.12.1.1
Lime Slurry Preparation
Provide a control panel adjacent to the truck unloading fill pipe
connection. Provide a NEMA 4 enclosure for panel. Panel shall include bin
vent filter fan indicating light, low bin level indicator light, high bin
level indicator light and audible alarm with alarm silencer button. When
truck unloading tube is connected to the fill pipes, a limit switch mounted
on the fill pipe shall be actuated. Limit switch actuation shall activate
bin vent filter exhaust fan. Disconnection of truck pipe shall return
limit switch to normal and operate bag cleaning mechanism for a preset
period of time. Reaching high bin level during truck unloading shall sound
alarm. Level switches for high and low feed bin level shall be provided,
as specified in paragraph entitled "Instrumentation and Controls." Provide
local and remote monitoring of feed bin levels. Provide signal from low
and high bin level indicators as required for input to control of pneumatic
lime conveying system from bulk lime storage silo. Silo, conveying system,
and controls for bulk lime storage will be provided by the Contractor.
Provide space for additional level monitors on FGD system panelboard for
use with bulk storage silo. Primary control of the lime slurry preparation
SECTION 15864N
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