Page 909 - Basic Electrical Engineering

certain negative pressure in the furnace. Maintaining a certain negative
pressure inside the furnace avoids any backfiring through any opening. An
electrostatic precipitator is used before the ID fan (not shown in the figure)

to collect the fine dust particles so that these are not thrown into the
atmosphere along with the flue gases and pollute the atmosphere. This is a

must requirement provided by the environmental protection law, and the
power stations have to abide by this requirement of installing dust collectors

from the flue gases.

Figure 13.1 Schematic diagram of a coal-fired thermal power plant

Steam is taken out continuously from the boiler to the turbine. At the other
side of the turbine, used steam is condensed to water and fed back to the

boiler through a feed water pump. Thus, there is continuous withdrawal of
steam and continuous return of condensed water to the boiler. However, there
is some loss of water in the form of steam due to leakage, etc. This has to be

made up by adding make-up water to the boiler water system. Boiler water
has to be treated to remove calcium, magnesium, and other salts otherwise