Electrostatic precipitator principal construction working

1. Prepared by:-
Gaurav

2. Electrostatic precipitator (ESP)- PRINCIPLE :-
An electrostatic precipitator (ESP) is a device that
removes dust particles from a flowing gas (such as air) using
force of an induced electrostatic attraction (i.e. like charges
repel; unlike charges attract)
Electrostatic precipitators are highly efficient filtration devices
that allow flow of gases through device, and can easily
remove fine particulate matter such as dust and smoke from
air stream.

4. environment protection has become a crucial problem and
the authorities are requested to set increasingly more
stringent limits , one of which is the emissions from the
industrial plants of solid particulate and other gaseous
pollutants.
ELECTROSTATIC PRECIPITATOR

5. HOW IT WORKS!!

8. SCHEMATIC OF WIRE-PLATE ESP
Schematic of wire-plate electrostatic
precipitator

10. Components used in electrostatic precipitator
 Electrodes
 440V 50HZ 3φ AC supply
 High voltage transformer
 Rectifier
 insulators
 Hooper

11. 20 – 80 KV DC
Basic diagram of an electrostatic precipitator
AC supply
Control cabinet High voltage
transformer
Rectifier Dust gas
Clean gas
Hooper
Discharge
electrode
Collector
electrode

12. Control cabinet
Control cabinet is used to interconnect the 3φ ac supply and
transformer through cables
Transformer
Transformer is used to step up or step down voltage as
per design of Electrostatic precipitator.
Rectifier
Rectifier is used to convert ac supply into dc supply.
Hooper
Hooper is used to store dust particles and ash content
coming out from the Electrostatic precipitator.

13. Electrodes : -
Based on DC current flow terminals
electrodes can be divided as below:-
Discharge electrode :-
Electrodes wire which carries
negatively charged high voltage
(between 20 to 80KV) act as
discharge or emitting electrodes.
Collector electrode :-
Electrode plate / wire which
carries positively charged high
voltage act as Collecting electrodes.
Collector
electrodes
Discharge
electrode

14. Processes of electrostatic precipitator are in three main
stages:
particle charging,
transport
collection.
Main process of ESP

15. MECHANISM OF ESP
Mechanism of electrostatic precipitator

16. WORKING OF ELECTROSTATIC
PRECIPITATOR
Several things happen very rapidly (in a matter of a
millisecond) in the small area around the discharge
electrode.
Electric field is emerged due to dc terminal
arrangement. The applied (-) voltage in discharge electrode
is increased until it produces a corona discharge, which
can be seen as a luminous blue glow around discharge
Electrode.
Due to the formation of corona discharge, free electrons
are emitted with high velocity from discharge electrode.
Stage - 1

17.  This fast moving free electrons strikes gas molecule
thus emission of free electron from gas molecules takes
place.
 The positive ion molecule move towards discharge
electrode by electrostatic attraction
 As a result with gas molecule more free electrons are
emitted near the discharge electrode.

19. Stage - 2
As electrons leave strong electrical
field area around discharge
electrode, they start slowing down.
This free electron again strikes gas
molecule but this time they are
captured by gas molecule and
become negatively charged ion.
As gas molecule are negatively
ionized they move towards (+)
electrode (i.e. collector electrode).
This negative gas ion fills space of
Dust particle and becoming
negatively charged particle.
This particle are captured by collector
electrode using electrostatic
attraction.