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

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

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Steam Boilers, Engines, Nozzles and Turbines
Coke is produced by

Enriching carbon in the coal
Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
Heating wood in a limited supply of air at temperatures below 300°C
Pulverizing coal in inert atmosphere

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