Specifications

Enquiry Specification for Wagon Tippler with Side Arm Charger and Associated works
NRO/CON/WT/533
EPI – New Delhi Volume-2B, Rev.0 Page 14 of 63
The number of pressure regulating units shall depend upon the position /
elevation of spray bars. Generally independent pressure regulating units shall
be provided when the elevation of spray bars exceeds 3 m. Further the number
of nozzles operating from one PRU should not exceed 6 ~ 8.
(3) Flow activation stations (FAS)
The flow activation station shall consist of solenoid valves in air & water line,
pressure switch in the airline, selector switch, and indication lamps. Isolation
ball valves shall be provided in the air & water line. All the equipment shall be
installed in a metallic enclosure with inspection door with rubber sealing
arrangement. Flexible hoses shall be provided with each FAS for connection to
air and water pipeline.
The "ON - OFF" control of the fogging system shall be through the flow
activation stations with facility for both manual and auto mode. A three position
selector switch shall be provided to select the mode of operation. The switch
when energized shall open the electric solenoid valves, which shall permit
compressed air and water to enter into the pressure regulating units and spray
bars.
In addition, a pressure switch shall be installed in the airline to ensure that air
and water solenoid valves are energized only when sufficient air pressure is
available in the line. This shall ensure that the system cannot operate without
sufficient air pressure to the nozzles and reduces the chance of un-atomized
water to pour into the dust source. Flow activation shall have indication for: -
- System ON
- System OFF due to lower air pressure
(4) Auto operation
The flow activation stations shall have provision for both manual and automatic
operation. For manual operation, the system shall become operational with
selector switch in manual mode and in auto mode, the fogging operation starts
on receiving a signal either from a speed switch cum belt load monitor or limit
switches installed at a strategic location in the material conveying line or
potential free Tender from the drive motor of equipment as per requirements.
Each dust suppression system location shall be provided with requisite number
of spray bar assemblies with DFDS atomizing nozzles. Pressure regulating units
shall be provided at each location to regulate the pressure of compressed air
and water.
The dust suppression system shall be divided into independent circuits taking
into account the flow diagram, operational requirements, distances between
dust suppression locations etc. Flow activation stations with instruments for
auto operation are provided for each circuit for ON/OFF control of the dust
suppression system.
(5) Centrifugal Pump :
Horizontal back pull out pump shall be provided. Pump casing shall be vertically
split type. Impeller rpm shall generally not exceed 1450. However, for pumps
with low capacity & high head may be provided with 2900 rpm. Pump shall be