Power Plant Engineering

Fig. 4.28. A Pulverised Coal Burner System.
The various types of burners are as follows :
1. Long Flame Burner (U-Flame Burner). In this burner air and coal mixture travels a consid-
erable distance thus providing sufficient time for complete combustion [Fig. 4.29(a)].
2. Short Flame Burner (Turbulent Burner). It is shown in Fig. 4.29(b). The burner is fitted in
the furnace will and the flame enters the furnace horizontally.
3. Tangential Burner. A tangential burner is shown in Fig. 4.29(c). In this system one burner is
fitted attach corner of the furnace. The inclination of the burner is so made that the flame produced are
tangential to an imaginary circle at the centre.
4. Cyclone Burner. It is shown in Fig. 4.29(d). This burner uses crushed coal intend of pulver-
ised coal. Its advantages are as follows :
Coal and Primary
Air 
Secondary
Air
Coal and Primary
Air 
Secondary
Air
(a)
(b)

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STEAM POWER PLANT
165
Coal and
Primary Air A
Sec. Air
Furnace
Molten
Slag
Sec.
Air
Coal and
Primary
air
Section at A.A
(c)
(d)
(e)
A
Fig. 4.29. Various Types of Burners.
Economizer
Air
Preheater
To stack
Boiler
Tubes
Boiler Drum
Convection
Super Heater
Water Wall
Pulverised Coal
Burner
Fig. 4.30. Pulverised Coal-fired Boiler.
(i) It saves the cost of pulverisation because of a crusher needs less power than a pulveriser.
(ii) Problem of fly ash is reduced. Ash produced is in the molten form and due to inclination of
furnace it flows to an appropriate disposal system.
Fig. 4.30 shows a pulverised coal-fired boiler.

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166
POWER PLANT ENGINEERING
Raw Coal
Bunker
Conveyor
Breaker
Cyclone
Furnace
Valve
Crusher
Rotary
Seal
Feeder
Primary
Air
Slag
Tank
Coal Pipe
Conveyor