How do electrostatic precipitators, scrubbers and catalytic converters prevent pollution?
How do electrostatic precipitators, scrubbers and catalytic converters prevent pollution?
Catalytic converter
Pollutant gases are made of harmful molecules, but those molecules are made from relatively harmless atoms. So if we could find a way of splitting up the molecules after they leave a car's engine and before they get pumped out into the air, we could crack the problem of pollution. That's the job that a catalytic converter does
Electrostatic Precipitators The electrostatic precipitator works by removing particles and smoke from a gas stream using an electrostatic charge.Dust particles travel past wires that have a high direct current (DC) voltage applied, which ionises the surrounding gas. This corona discharge causes the particles to pick up a small electrostatic charge.An oppositely-charged plate attracts the particles, neutralises and retains them. A regular tapping (rapping) of the plates then physically removes the collected particles.Introducing a water spray can reduce the electrical resistance of the dust particles, allowing them to accept the charge more easily.Electrostatic precipitators are an efficient way of removing particles and do not cause a significant pressure drop across the unit.
Scrubbers
Scrubbers help to remove most of the sulfur oxides from the smoke stack exhaust of a power plant. The smoke from the burning coal first goes through a particulate filter to remove soot and ash. Then it enters a scrubber. In the scrubber, there is a water spray that produces a cloud of fine water droplets. The water is mixed with crushed limestone, which reacts with the sulfur and pulls it out of the exhaust.
Pollutant gases are made of harmful molecules, but those molecules are made from relatively harmless atoms. So if we could find a way of splitting up the molecules after they leave a car's engine and before they get pumped out into the air, we could crack the problem of pollution. That's the job that a catalytic converter does
Electrostatic Precipitators
The electrostatic precipitator works by removing particles and smoke from a gas stream using an electrostatic charge.Dust particles travel past wires that have a high direct current (DC) voltage applied, which ionises the surrounding gas. This corona discharge causes the particles to pick up a small electrostatic charge.An oppositely-charged plate attracts the particles, neutralises and retains them. A regular tapping (rapping) of the plates then physically removes the collected particles.Introducing a water spray can reduce the electrical resistance of the dust particles, allowing them to accept the charge more easily.Electrostatic precipitators are an efficient way of removing particles and do not cause a significant pressure drop across the unit.
Scrubbers
Scrubbers help to remove most of the sulfur oxides from the smoke stack exhaust of a power plant. The smoke from the burning coal first goes through a particulate filter to remove soot and ash. Then it enters a scrubber. In the scrubber, there is a water spray that produces a cloud of fine water droplets. The water is mixed with crushed limestone, which reacts with the sulfur and pulls it out of the exhaust.
