Question

Given below is the diagram of electrostatic precipitator. Identify A, B, C and D and select the correct option.

A. A- Negatively charged wire, B- Negatively charged dust particles, C- Discharge corona, D- Collection plate B. A- Negatively charged wire, B- Discharge corona, C- Collection plate, D-Negatively charged dust particles C. A- Positively charged wire, B-Positively charged dust particles, C- Discharge corona, D- Collection plate D. A- Positively charged wire, B- Discharged corona, C- Collection plate, D-Positively charged dust particles

Answer 1

Hint: Electrostatic precipitator is used for the purification of gas. The principle behind Electrostatic precipitator is neutralization as it neutralizes the charge on the carbon particles.

Complete answer:
 An electrostatic precipitator is a cleaner which works on static electricity until the smokestacks go out to eliminate the soot and ash from exhaust fumes. With the help of electrical energy to charge particles like positively or negatively it eliminates particles from a gas stream. Then the charged particles are shifted to collector plates in opposite charge. The particles can be eliminated as dry material from the collector plates. The crucial components of electrostatic precipitators are collection electrodes, discharge electrodes, high voltage power supply, precipitator controls etc. These are designed as either single or two stage configurations. In these devices the electrically charged wastes are attracted to oppositely charged electrode wires of the collecting surfaces due to development of corona effect around the electrode due to high voltage properties. The main principles of electrostatic precipitator are it uses electrostatic forces and it consists of discharge wires and collecting plates. High voltage is applied to discharge wires to form an electric field between the discharge wires and the collecting plates.
When dust particles in smoke flow between the discharge wires and the collecting plate, dust particles in the gas are charged by the ions. Electric field causes a coulomb force which leads the charged particles to collect on the collecting plates and thus gas is purified.

Hence, the correct answer is option (B).

Note: These electrostatic precipitators are employed in thermal power plants and industries involved in power generation, petroleum oil refineries, cement plates, paper mills etc. It is a device that removes particulate pollutants very effectively.