Tender Document for Repowering Project of Ghorasal 3rd Unit - BPDB

interconnecting piping & valves, spray water manifold and spray nozzles.
The various components of the system are shown in schematic diagram
enclosed. Wash water tank shall be used to draw and mix wash water and
detergent to the required dilution, compressed air taken from existing
instrument air header shall be used to pressurise this fluid and to forward to
the spray water manifold. The spray nozzles shall make a high velocity jet
spray to clean the compressor blades while the rotor shall be kept in
spinning operation.
i) Wash water tank shall be a cylindrical pressure vessel with dished
ends on both sides. This tank shall be provided with necessary
appurtenances and accessories such as
a) Compressed air inlet.
b) Water inlet with isolation valve and inlet strainer.
c) Breather vent with isolation valve.
d) Drain line with isolation valve.
e) Detergent inlet nozzle with isolation valve.
f) Pressurised water outlet with isolation valve.
g) Level gauge glass with isolation valves.
h) Hand holes with covers.
i) Pressure relief valves.
j) Pressure gauge connection.
ii)
iii)
iv)
Detergent hopper to hold the detergent for every wash cycle.
Interconnecting piping between wash water tank and compressor
spray system. This line shall be provided with strainer, drain valve,
pressure gauge, and orifice plate.
Water wash manifolds.
This manifold shall be located within the compressor inlet and it
shall distribute the wash water into the compressor inlet air stream.
The manifold shall be equipped with a drain valve.
v) Set of spray nozzles shall effectively spray water, detergent water
for efficient cleaning.
To introduce the above-mentioned wet washing system for
compressor cleaning of gas turbine generating unit. The following
works shall be reformed:
a) Installation of the wash water system.
b) Providing spray nozzle on compressor inlet manifolds.
c) Taking a tapping from instrument compressed air header to
supply compressed air for washing system.
d) Routing the wash water to the Gas Turbine Compressor.
e) Providing various drain lines with isolation valves at drain
points from the compressor and turbine to drain the wash
water during washing cycle.
f) Providing bearing seal air piping to protect bearing during
washing cycle.
g) Drainage system to drain out the water.
Re-Powering Ghorasal 210 MW 3 rd Unit (Vol-2A of 2) 46