DPL has an installed capacity of 641 megawatts across 7 units of varying capacities built between 1960 and 2008. Boiler mountings are safety and control devices like pressure gauges and fusible plugs, while accessories like feed water heaters, boiler feed pumps, and steam separators help improve boiler efficiency and operation. Key boiler mountings discussed are pressure gauges, fusible plugs, and feed check valves. Accessories covered are feed water heaters, boiler feed pumps, and steam separators.
2. ABOUT THE DURGAPUR PROJECTS LIMITED
DPL today is a renovated and upgraded power utility. A total of seven units of different
capacities have an aggregate 701-mega watt of installed capacity out of which 2X30 mega
watt units have been decommissioned reducing the aggregate installed capacity to 641
mega watt. After fulfilling total requirement of its command area customers, DPL surplus
power goes to the West Bengal State Electricity Distribution Company Ltd (WBSEDCL).
3. ABOUT THE DURGAPUR PROJECTS LIMITED
Description Unit I Unit II Unit III Unit IV Unit V Unit VI Unit VII Total
Capacity(MW) 30 30 77 77 77 110 300 641
Date of
Synchronisation
10.6.1960 10.4.1960 23.4.1964 19.6.1964 4.5.1966 3.7.1985 29.12.2007
Date of
Commercial
Operation
10.8.1960 10.6.1960 23.6.1964 29.6.1964 4.7.1966 1.1.1987 30.4.2008
Present Status Decommissioned Decommissioned
In
operation
In
operation
In
operation
In
operation
In operation
4. Fitting and devices which are necessary for the safety and control are knows
as boiler mountings
6. • A pressure gauge is an instrument by means of which the
pressure exerted inside a vessel can be measured.
• There are two types of pressure gauges, one is Bourdon tube
pressure gauge and the other is diaphragm type gauge.
MAEC. MECHANICAL
PRESSURE GAUGE
10. FUSIBLE PLUG
Function: To extinguish fire in the event of water level in the boiler shell
falling belowa certain specified limit.It protects fire tubes from burning when the level
of the water in the water shell falls abnormally low and the fire tube or crown plate
which is normally submerged in the water, gets exposed to steam space which may
not be able to keep it coo
11. FEED CHECK VALVE
I ) To allow the feed water to pass into the boiler.
ii) To prevent the back flow of water from the boiler in the event of the
failure of the feed pump.
12. Fitting or devices which are provided to increase the efficiency of the boiler
and help in the smooth working of the plant are knows as boiler accessories.
• Feed water heater
• Boiler feed pump
• Steam separator
14. Air Preheater
• Used to recover heat from the exhaust flue
gases
• Installed in between the economizer and
chimney.
• Temperature of the required air for
combustion is passed through the air
preheater where its temperature is raised.
• Then hot air passed to the furnace.
ADVANTAGES
• Gives higher furnace temperature which
results more heat transfer thus increase
evaporative capacity
• Approximately boiler efficiency increases
about 2% for each 30-35oC rise in air
temperature.
16. FEED WATER HEATER
Function : Feed water heater is a plant in which the feed water is heated before it
enters into a boiler, the heat being taken from the exhaust steam of steam engine
Cylinders or of steam turbines.
17. BOILER FEED PUMP
Function: The pump is used to deliver feed water into a boiler
against boiler steam pressure.
18. STEAM SEPARATOR
Function : The steam separator is fitted before the steam engine or steam
turbine to separate water particles from steam.