Limestone is produced by the breakdown of calcium, typically found in shells and coral. It has many applications due to its abundance, from an ingredient in concrete and stone block materials to adjusting the pH in water treatment plants. It has also been used to absorb standing water around outhouses, as it can absorb up to one-fourth its weight in water and still remain dry. It also has a relatively new use in the production of fossil fuels by working to eliminate harmful byproducts from coal-burning power plants.
Instructions
1. Transport the fuel source --- in this case, coal --- from its bunker in the coal storage facility into the milling area. Coal dust is created through the milling process and sprayed into the boiler for incineration.
2. Use a fan system to generate a forced air draft to begin the combustion process. The steam will activate the turbines and produce energy. Condensation develops on the walls of the main condenser, which is part of the power plant's cooling system. The heat from condensation mixes with cooling water, typically from a river source, and is vented into the cooling tower.
3. Strain the flue gas, which is the vented steam in the cooling tower, through a pre-washer. The pre-washer is a two-step vacuum system that separates the fluoride and chloride pollutants in flue gas from fly ash, which is composed primarily of silicon dioxide and calcium oxide. During the washing process, the flue gas is cooled to 50 degrees Celsius.
4. Spray lime, in its suspended form, onto the fly ash. The silicon dioxide will react with the lime and become gypsum, which will be pumped into a holding area for later re-use.
5. Heat the remaining flue gas to 70 degrees Celsius so that it can be successfully vented out of the cooling tower and into the atmosphere in its non-pollutant form.
Tags: cooling tower, degrees Celsius, silicon dioxide