Question

Why are chimneys provided over furnaces in factories?

Answer 1

Hint: Chimneys are fitted over the furnace in factories because the hot fumes are less dense than the air particles. They rise within the chimney. The vapor, fumes, etc., around the furnace haste, into their place, and they are engulfed out. Thus, the chimney helps to separate the undesired fumes, smoke, etc. The burning of combustible fuel in factories produces smoke containing a few harmful gases and fine dirt particles. The chimneys take the dangerous smoke and gases apart from us.

Complete step-by-step solution:
A chimney is a structural ventilation made of clay or metal that separates hot poisonous exhaust gases or smoke generated by a boiler, stove, furnace from human existence areas. Chimneys are vertical, or as near as feasible to vertical, to ensure that the gases pass smoothly, drawing air into the oxidation is named the stack or chimney effect. The area inside a chimney is termed flue. Chimneys are near large industrial factories, fossil fuel combustion facilities, or sections of buildings and ships.
The altitude of a chimney affects its ability to carry flue gases to the external environment through the stack effect. Additionally, the diffusion of pollutants at higher elevations can decrease their impact on the surroundings. The dispersion of pollutants over a larger area can overcome their concentrations and promote compliance with governing limits. When coal, wood, oil, or any other fuel is combusted in a stove, oven, hot water boiler, fireplace, or industrial furnace, the hot combustion output gases formed are termed flue gases. Those gases are consumed in the ambient outside air by chimneys or industrial exhaust gas stacks.
The combustible gases inside the chimneys are much warmer than the ambient external air and, therefore, light-dense than the ambient air. That makes the bottom of the vertical column of hot flue fumes lower pressure than the pressure at the ground of an identical column of outside air. That more significant pressure outside the furnace is the driving force that passes the required combustion air into the combustion region and moves the flue gas upward and outside the chimney. That flow of combustion air and exhaust gas is called the stack or chimney effect. The higher the stack, the more draft is produced. If a stack is overly great about the heat being thrown out of the stack, the flue gases may chill before reaching the chimney's height. This situation can result in poor drafting, and in the state of wood-burning devices, the cooling of the vapours before emission can cause creosote to compress near the top of the chimney. The creosote can regulate the exit of flue gases.

Note: Factories have large chimneys as they have a unique device called an electrostatic precipitator situated inside the chimneys. Electrostatic precipitators function as emission control systems that catch dust particles, soot particles from the fumes ready to be discharged out of the chimneys.