How Do Coal-Fired Plants Work?
Generation of electricity in a coal-fired steam station is similar to a nuclear station. The difference is the source of heat. The burning of coal replaces fissioning, or splitting , of uranium atoms as the source of heat. The heat turns water to steam in steam generators. The steam is then used to drive turbine generators.
1. Firebox
Before the coal is burned, it is pulverized to the fineness of talcum powder. It is then mixed with hot air and blown into the firebox of the boiler. Burning in suspension, the coal-air mixture provides the most complete combustion and maximum heat possible.
2. Boiler
Highly purified water, pumped through pipes inside the boiler, is turned into steam by the heat. At temperatures of up to 1,000 degrees Fahrenheit and under pressures up to 3,500 pounds per square inch, the steam is piped to the turbine.
3. Turbine|Generator
The enormous pressure of the steam pushing against a series of giant turbine blades turns the turbine shaft. The turbine shaft is connected to the shaft of the generator, where magnets spin within wire coils to produce electricity.
4. Condenser
After doing its work in the turbine, the steam is drawn into a condenser, a large chamber in the basement of the power plant. The condenser is an important part of a steam-electric unit, whether nuclear or coal-fired. This device condenses the steam leaving the turbines back into water so that it can be used over and over again in the plant. This essential cooling process requires large quantities of water; thus, most steam-electric stations are located on lakes or rivers.
5. Condenser Cooling Water
Millions of gallons of cool lake water are pumped through a network of tubes that runs through the condenser. The water in the tubes cools the steam and converts it back into water. After the steam is condensed, it is pumped to the boiler again to repeat the cycle.
