Steam Boilers, Engines, Nozzles and Turbines
The object of producing draught in a boiler is

All of the listed here
To exhaust the gases of combustion from the combustion chamber
To discharge the gases of combustion to the atmosphere through the chimney
To provide an adequate supply of air for the fuel combustion

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Steam Boilers, Engines, Nozzles and Turbines
Equivalent evaporation of water is the evaporation for a feed water supply at 100°C

Conversion into steam at atmospheric condition
And its corresponding conversion into dry saturated steam at 100°C and 1.033 kg/cm²
Conversion into steam at the same pressure at which feed water is supplied
And its corresponding conversion into dry steam at desired boiler pressure

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