Electrostatic Smoke

PrecipitatorKhusro Kamaluddin

B.Tech Ist Year (ME-1) Quantum School of Technology, Roorkee

Introduction● The global scenario indicates that air pollution

has become an alarming issue. ● One of the major constituents of pollutants is

suspended particulate matter(SPM).● It’s very dangerous and causes many serious

diseases like lung cancer and cardiopulmonary problems.

● The main source for such particles is the emission from motor vehicles, industrial/factory etc.

The methods used for controlling the level of SPM

● Internal(cyclone) Collectors● Fabric Filters/collectors/baghouses● Wet Scrubber● Electrostatic Precipitators(ESP)

ESP is the most efficient ,maintainable & cost effective among the above listed methods.In 1907 Dr. Frederick G. Cottrell patented the first commercial ESP model(after it’s invention by Hohlfeld in 1824).

What is an Electrostatic Smoke Precipitator(ESP)?

● An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a fluid (like air).

● It uses the force of an induced electrostatic charge(works on the principle of electrophoresis).

● Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.

● In contrast to wet scrubbers in which energy is directly applied to the flowing fluid medium whereas an ESP applies energy only to the particulate matter being collected and therefore is very efficient in its consumption of energy (in the form of electricity).

What is the Principle of ESP ?

● The basic principle of ESP is Electrophoresis.● Electrophoresis is the motion of dispersed

particles relative to a fluid under the influence of a spatially uniform electric field.

Working Principle of ESP

Collecting Sheet

Any conducting metallic sheet which can bear charge on outer surface.

RapperParticulate which accumulates on collecting electrode surfaces and on discharge electrodes must periodically be dislodged by rapping the collecting plates and discharge electrodes.Rapping removes particulate to the hoppers for disposal and maintains both the discharge and collecting electrodes in an "operationally" clean condition for proper operation.

Hopper

It collects/stores the precipitated SPM in Large amount.

Types of ESP

There can be may types of ESP on the basis of● Cleaning method/fluid● Type of air(Depending on Source)● Working

Dry Type ESP

Dry type Electrostatic precipitator can be a fixed-electrode type or a moving-electrodetype.In the fixed-electrode type, a collecting plate rapping device is used to remove the dustcollected on the collecting plate when the dust has accumulated to a certain thickness.

In our moving-electrode type, the collecting plates are divided into short strip elements thatare joined by chains, and the collecting plates are moved slowly. The dust collected on thecollecting plate elements is completely scraped off by rotating brushes provided in thehoppers.

Wet Type ESPIn wet systems, water is passed over the collecting electrode surface of an ESP to form a water film, and the water film collects the aerosol , which iswashed away along with the water film, or an aerosol consisting of liquid droplets in a mist,etc. SPM is collected and washed down off the collecting electrode surface.

Conclusion Electrostatic Smoke Precipitator is a very fine technique for removing

Suspended Particulate matter from the Factory outlets etc.

SPM pollution is estimated to cause 22,000-52,000 deaths per year in the United States(from 2000) and 200,000 deaths per year in Europe. It is much higher in India.

It is not that the authority is not aware. The problem is that people concerned are not serious about it even after knowing the adverse effects.

The need of the hour is to constitute strict rules to prevent pollution of air due to factory outlet so that to keep the environment safe.

Further the Rule should be strictly implemented

Thank You