NATIONAL ALUMINIUM COMPANY LIMITED - Rites

fogging type with a minimum pressure of 2.5 kg/sq.cm(g) at spray nozzle inlet. It should be
possible to operate any number of zones simultaneously. The operation of wagon tippler
dust suppression system shall be automatic so that the foggi fogging ng water spray shall get
activated only when the tippling is in operation.
16.5.4 Each spray head shall have a provision for installing a pressure gauge whenever required.
Further, pressure gauges shall be provided at least at two locations.
16.5.5 Sump Pumps
Sump pumps shall be vertical centrifugal type with separate discharge pipe and shall be
capable of developing required head at rated capacity for continuous operation. Sump
pumps shall be suitable for handling coal slurry & sludge. Head capacit capacity y curve of the pump
shall be rising type up to the shut off condition. Sump pumps alongwith level switches &
piping upto nearest Owner's drain (max upto 50.0 mtrs. from outside the building) shall be
provided at all locations wherever natural drainage is nnot
ot possible. Further sump pumps
alongwith drain pits shall be provided at other locations also, if required, during detailed
engineering stage. The capacity of each pump shall not be less than 50 cub. M/hr.
Continuous motor rating (name plate rating) at 50 deg. C. for sump pump shall have at least
10% margin above the maximum load demand of the equipment in the entire operating
range (including run out condition of pumps in case of parallel operation). The maximum
load demand shall include the drive losses in the transmission system. Size of the sump pit
shall not be less than 2.0 meters x 2.0 meters x 2.5 meters. One no. of settling pit, of
adequate size, before the sump pit shall also be provided so that water without heavy coal
particles goes into sump pu pump mp pit. High and low level switches shall be provided in the sump
pump pit.
16.5.6 Service Water (SW) System
Service water connections are to be provided in conveyor galleries and tunnels at 50 meter
intervals. Adequate number of these connections shall be provided in all transfer houses
with minimum one no. at each floor. Each connection shall be provided with one (1) no. 32
NB globe valve and quick coupling. One (1) No. Hose pipe with nozzle shall be provided in
each building. Service water distributio distribution n system shall be designed considering the water
scheme and water requirement indicated in tender drawings.
16.6 CONSTRUCTION REQUIREMENT
16.6.1 Water Supply Pumps
16.6.1.1 Water supply pumps shall be provided as required.
16.6.1.2 The pumps shall be complete with drive motors, baseplate and other accessories. The
constructional features of the pump shall be as follows:
Technical Specification:Sec-4,System System Parameters, Operation & Control Philosophy
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