ELECTOSTATIC PRECIPITATOR GROUP NO 10, SEC-D 1. M.PRANEETH 2. MD ABU TALIB 3. K.SURYA 4. M.JAYASURYA

DEFINITIONS ELECTROSTATIC: IT IS DEFINED AS A TERM RELATING TO STATIONARY CHARGES OR FIELDS AS OPPOSED TO ELECTRIC CURRENTS PRECIPITATOR: AN APPARATUS FOR CAUSING PRECIPITATION,ESPECIALLY A DEVICE FOR REMOVING DUST FROM A GAS

An electrostatic precipitator (ESP) is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit CARONA CHARGING A corona discharge is an electrical discharge brought on by the ionization of a fluid such as air surrounding a conductor that is electrically charged. Spontaneous corona discharges occur naturally in high-voltage systems unless care is taken to limit the electric field strength.

Types of precipitators There are different types of precipitators * PLATE PRECIPITATOR * ROTATORY PRECIPITATOR * WET PRECIPITATOR * DRY PRECIPITATOR * FABRIC FILTER PRECIPITATOR

TYPES OF PRECIPITATORS DRY PRECIPITATOR WET PRECIPITATOR PLATE PRECIPITATOR FABRIC FILTER PRECIPITATOR

PROCESS Electrostatic precipitation is a leading means for the control of particulate emissions from large industrial and power generation sources. It is capable of high particulate removal efficiencies, including the control of the submicron particulate fraction. . The electrostatic precipitation process is different from other mechanical means of particulate control, such as filters and clones, in that it uses electrical forces to separate the particles from the gas stream. These electrical forces are applied by exposing the particles to a corona discharge, there by charging them electrically, and then placing them in a zone of high electric field strength. The resultant electrical force, proportional to the product of the particle charge and the field strength, moves the particles towards a grounded collect interface here they are held until periodically rapped into hoppers for disposal. Modern industrial precipitators use the single stage design accomplishes the corona discharge and electric field functions simultaneously in a single geometry consisting of high voltage discharge electrodes placed between grounded collecting plates. The discharge polarity in these precipitators is negative. The discharge electrodes themselves are either small-diameter wires or more rigid bodies with points or sharp edges. PARTS:

WORKING MODULE 1 ESP PRINCIPLE :- An electrostatic precipitator (ESP) is a device that removes dust particles from a flowing gas (such as air) using the force of an induced electrostatic attraction (i.e, like charges repel; unlike charges attract) Electrostatic precipitators are highly efficient filtration devices that allow the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream. 2 . COMPONENTS USED IN ELECTROSTATIC PRECIPITATOR :- Electrodes of 440V 50HZ 3φ AC supply , High voltage transformer , Rectifier ,insulators , Hooper 3. USES OF COMPONENTS :- Control cabinet is used to interconnect the 3φ ac supply and transformer through wires. Transformer is used to step up or step down the voltage as per the design of Electrostatic precipitator. Rectifiers are used to convert the given ac supply into dc supply. Hooper is used to store the dust particles and ash content coming out from the Electrostatic precipitator. 4. Electrodes : - Based on DC current flow terminal electrodes can be divided as below, Discharge Electrode :- Electrode wire which carries negatively charged high voltage (between 20 to 80KV) act as discharge or emitting electrode. Collector Electrode :- Electrode wire which carries positively charged high voltage act as Collecting electrodes. Collector electrodes Discharge electrode. 5. WORKING OF ELECTROSTATIC PRECIPITATOR :- Stage- 1 :- 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 the discharge Electrode. Due to the formation of corona discharge, free electrons are emitted with high velocity from discharge electrode. This fast moving free electrons strikes the 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 using gas molecule more free electrons are emitted near the discharge electrode. Stage – 2 :- As the electrons leave the strong electrical field area around the discharge electrode, they start slowing down. This free electron again strikes the gas molecule but this time they are captured by gas molecule and became negatively charged ion. As the gas molecule are negatively ionized they move towards the (+) electrode (i.e., collector electrode). This negative gas ion fills the space of Dust particle and becomes negatively charged particles. These particles are captured by collector electrode using collecting electrode.

ADVANTAGES * HIGH PURIFICATION EFFICIENCY CAN SHOP SET ABOVE 0.01 MICRON FINE DUST. * HERE THE DUST IS COLLECTED IN DRY FORM AND CAN BE REMOVED IN EITHER DRY OR WET FORM. * BEST AND CHEAPER WAY TO REDUCE AIR POLLUTION.SO,ESP IS * USED IN CEMENT FACTORIES. * USED IN CHEMICAL FACTORIES. * USED IN COAL MINES.

PROBLEMS * THE TYPICAL PARAMETERS THAT PLAYS AN IMPORTANT ROLE ARE: 1. VOLTAGE/CURRENT 2. GAS TEMPERATURE 3. GAS COMPOSITION AND MOISTURE 4. GAS FLOW RATE AND DISTRIBUTION 5. RESISTIVITY OF COLLECTED DUST ON ABSORBING PLATES 6. DUST ACCUMULATION ON ELECTRODE RODS

SOLUTIONS 1, GAS LOAD OR AIR LOAD READINGS SHOULD BE TAKEN CARE DURING EVERY TIME OF USAGE WHICH HELPS US TO KNOW THE CONDITION OF WORKING PRECIPITATOR. 2,THE OPERATOR SHOULD HAVE SOME BASIC KNOWLEDGE REGARDING THE VOLTAGE AND CURRENT SUPPLY OF THE ESP. 3,THE RESISTIVITY OF DUST PARTICLES MUST BE IN LIMITED RANGE OF THE PRECIPITATOR. 4, MOREOVER THE DUST CONCENTERATION ON EVERY ELECTRODES MUST BE KEPT FOR CHECKING FOR EVERY MONTH AND IS CLEANED WHENEVR NECESSARY TO MAINTAIN THE EFFICIENCY.

PRACTICAL MODEL OF ESP Apparatus required: 1.Plastic box 2.Carona wire 3.High voltage supply 4.Holder 5.Silver foils 6.Current wires 7.Ground source(for collection of negative charge)

REFERENCES IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version:  (2006–) "electrostatic precipitator". Ali Farnoud "Electrostatic Removal of Diesel Particulate Matter", ProQuest, 2008 ISBN 0549508163, p. 23 "Chronicle". GEA Bischoff. Retrieved 25 January 2014.  http://www.fireproofingcorp.com/electrostatic-precipitator-cleaning-and-maintenance.html Johnson, F. W. (1937). "Adsorbed Moisture Film on the Surface of Glazed Porcelain". Phil. Mag. 24: 797.  Davidson, J. H.; McKinney, P. J. (1998). Chemical vapor deposition in the corona discharge of electrostatic air cleaners. Aerosol Science and Technology. 29. pp. 102–110. doi:10.1080/02786829808965555.  Gaspard Pardon, Laila Ladhani, Niklas Sandstrom, Wouter van der Wijngaart, Aerosol sampling using an electrostatic precipitator integrated with a microfluidic interface, Sensors and actuators. B, Chemical, ISSN 0925-4005, Vol. 212, 344-352. DOI: 10.1016/j.snb.2015.02.008 "Your Furnace Filter: What A Furnace Filter Can Do For You". Canada Mortgage and Housing Corporation. Archived from the original on 2008-05-14. Retrieved 2008-09-01.  "Plug-in Filter Cleans the Air." Popular Science, July 1954, p. 70, bottom of page.  A Jaworek - ‎2015 

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