Design & Development of A System For Automation Gas Distribution Test For ESP

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 4, Issue 2, February 2014)

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Design & Development of A System For Automation Gas

Distribution Test For ESP

S

. Madhava Reddy1, G. Dayanand2

1_{Associate Professor,}2_{P.G. Student, Department of Mechanical(Mechatronics) Engineering, MGIT, Hyderabad-75, India}

Abstract—In this paper, designing an automated system

for measuring the gas distribution throughout the cross-section of the ESP, then the experimentation with wind velocity sensors (vane probe anemometer type) and also design of overhead travelling mechanism for horizontal and vertical motions to carry the sensors and to capture the wind velocity data, using wired/wireless network system for capturing the data from the sensors to a database pc and also the development of application software’s for creating a database for each trial. An Electrostatic precipitator is a large, industrial emission control unit. It is designed to trap and remove dust particles from the exhaust gas stream of an industrial process. Precipitators are used in industries like Power, Electric, Cement, Chemicals, Metals, Paper. In many industrial plants, particulate matter created in the industrial process is carried as dust in the hot exhaust gases. These dust-laden gases pass through an Electrostatic precipitator that collects most of the dust. Cleaned gas then passes out of the precipitator and through a stack to the atmosphere. A unidirectional high voltage is applied between the electrodes, connecting its negative polarity to collecting electrodes, which are also earthed. The charged particles are then attracted to and deposited on plates. When enough dust has accumulated, the collectors are shaken to dislodge the dust below. The dust is then removed by a conveyor system for disposal or recycling. Properly adjusting the gas distribution based on the analysis of the collected data using this invention, the emissions can be reduced by optimizing the ESP efficiency and lifetime of certain components can be increased.

I. INTRODUCTION

Particulate matter (particles) is one of the industrial air pollution problems that must be controlled. It's not a problem isolated to a few industries, but pervasive across a wide variety of industries. That's why the U.S. Environmental Protection Agency (EPA) has regulated particulate emissions and why industry has responded with various control devices. Of the major particulate collection devices used today, electrostatic precipitators (ESPs) are one of the more frequently used. They can handle large gas volumes with a wide range of inlet temperatures, pressures, dust volumes, and acid gas conditions. They can collect a wide range of particle sizes, and they can collect particles in dry and wet states. For many industries, the collection efficiency can go as high as 99%.

Modern society primarily depends on coal fired thermal power stations for the generation of sustainable electricity. However the combustion of coal results in production of a large quantity of the ash, which essentially constitutes bottom and fly ash. The fly ash particles, which are in the form of suspension in the flue gas, from combustion units, contribute to an increased suspended particulate matter (SPM) in the surrounding environment. Therefore, in order to safeguard the environment, reduction in emission levels of SPM becomes essential. In order to achieve this, various devices such as electrostatic precipitators (ESP), bag filters and cyclone separators are employed.

Electrostatic precipitator is a technique that employs the application of an electric field to separate out the suspended particles from the flue gas. In addition, to minimize the emission of sulphur dioxide from the chimneys of coal fired power plants. The electrical resistivity of the fly ash generally increases as the ratio of sulphur-t-ash content in the coal decreases, which results in very low collection efficiency of ESP.

1.1.1 General Description

The Electrostatic Precipitator may be divided into two major groups, viz., electrical parts and mechanical parts. The various parts of precipitator are illustrated in the EP General Arrangement drawing for a typical precipitator. The Assembly of precipitator is divided into sub-groups, which are numbered in the drawing. The electrical parts comprise of high voltage rectifier, main and auxiliary controls, switches, heaters and inter-locks. The mechanical parts constitute the EP proper, which consists of the casing and functional parts forming internals of the precipitator.

1.1.2 Particle charging

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Fig: 1 Transfer of particle charging moving to collection plates

1.1.3 Particle separation

The dust that collects on the profiled collection electrodes is periodically cleaned by a tap-off mechanism and is thus removed from the gas stream (Fig.2 and fig.3). The formation of so-called collection pockets on the collection electrodes prevents there-entrainment of particles that have already been separated from the gas stream. Electrostatic precipitators are therefore extremely well suited for separating fine dust from gas flows.

Fig: 2 Collection plates

Fig: 3 Cross sectional view of collection plates

1.2 Casing

Casing is made up of wall panels, hoppers, roof panels and supporting members. The casing rests on sliding supports, which are fixed, to the supporting structures. These supports allow for thermal expansion of the casing. The roof beams support the weights of internals and rectifiers, disconnecting switches, insulator housing etc., mounted on it. These weights are transferred through the columns of wall panels to the supporting structures.

The HOPPERS are delivered to the site in pre-fabricated panels of suitable size. The bottom portions of hoppers are equipped with electrical heating elements to facilitate free flow dust into the ash disposal system. In order to prevent untreated gas from sneaking below the collecting electrode each hopper is provided with sets of deflection plates suspended in the hoppers.

1.3 Gas distribution systems

1.3.1 Description

For optimum performance of the precipitator, it is essential that flue gas entering the precipitator is evenly distributed over its entire cross-sectional area. For this purpose, two sets of gas distribution plate with perforations are located at the inlet of the casing. One set of gas distribution baffles is proved at the outlet of ESP. Final adjustment of the gas distribution prior to commissioning of the precipitator will be carried out by installation of deflection plates or throttling perforations with screen sheets by AQCS/EDC. The screen is provided in the outlet funnel of ESP to ensure proper distribution of the flue gas in the last field.

1.3.2 Emitting Electrode System

The most essential part of the precipitator is the discharge (emitting) electrodes system. The discharge electrode system consists of a rigid box like frame, which is suspended from four insulators from roof of the precipitator as shown in fig.4.

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The insulators are housed in double walledinsulator housings. In order to keep the insulators above the dew point of the gas, eachinsulator compartment is equipped with electrical heating element of rating approximately 1 KW. The operation of the heating elements is controlled by Thermostat. The emitting electrodes are hard drawn / annealed spiral stainless steel wires of diameter 2.7. These are delivered at site in the form of coils, having hooks at the ends. At site these coils are stretched out between top and bottom holders in each tier of the discharge electrode framework by stretching tool.

Fig:5 Collection electrodes

1.3.3 Collecting Electrode System

The collecting plates are made of steel sheets and shaped in special profile by roll forming. These profiles of the collecting plate lend mechanical rigidity to it and also limit re-entrainment of collected dust during rapping. The collecting plates of 400-mm width are Fig.5 provided with hooks at the top edges with which they are hung.

In the case of 750 mm wide collecting plates, slots are provided at the top edges. The collecting electrodes of 750-mm width are hung from the hooks of collecting suspension frames, which are supported, from the roof beams.

1.3.4 Rappers for discharge Electrodes

During electrostatic precipitation, a fraction of the dust will be collected on the dischargeelectrodes. This suppresses the corona, which is the source of ionization. It is therefore necessary to rap clean the discharge electrodes occasionally. This is done with a rapping system employing tumbling hammers, which are mounted on a horizontal shaft in a staggered fashion.These hammers hit the specially designed shock beams to which the intermediate part of discharge frame is attached. In this manner the vibrations generated by the hammers are transmitted to the discharge electrodes. For two levels emitting system one level of rapping mechanism is connected to a geared motor mounted on the side panels of the casing through the shaft insulator.

For three level emitting system: Two levels of rapping mechanism are connected to a geared motor mounted on the roof panel through the shaft insulator and pin wheel arrangement.

1.4 Working principle of ELECTROSTATIC

PRECIPITATOR

The Electrostatic precipitator essentially consists of two sets of electrodes called‘ Collecting Electrodes ‘ and ‘ Emitting Electrodes’ and (also called discharge electrodes). The collecting electrode is made up of steel sheet pressed to a special profile and the emitting electrode is a thin wire draw in to a helical form. A unidirectional high voltage is applied between these electrodes, connecting its negative polarity to the emitting electrodes and the positive polarity to collecting electrodes, which are also earthed. The dust laden flue gas from boiler passes between rows of collecting and discharge electrodes shown in fig.6. The high voltage induces ionization of gas molecules adjacent to the negatively charged emitting electrodes. The positive charges of the ions created travel towards the discharge electrodes and the negative charges towards the collecting electrodes. On their way to the collecting electrodes, the negative charges get deposited on the dust particles. Thus the dust particles are electrically charged. In the presence of high electric field between the electrodes the charged dust particles experience force which causes the particles to move towards the collecting electrodes and finally get deposited on them. Minor portions of the dust particles, which have acquired positive charges, get deposited on the emitting electrodes also. Periodically these are dislodged from the electrodes by a process called ‘rapping‘. The particles then fall into the hoppers at the bottom.

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II. GAS FLOW RATE AND DISTRIBUTION

Gas flow rate determines most of the key design and operating parameters such as specific collection area (ft2/1000 acfm), gas velocity (ft/sec) and treatment time within the ESP, and specific corona power (watts/1000 acfm). The operator should calculate the flue gas flow rate if the ESP is not operating efficiently. For example, significant variations in oxygen may indicate large swings in the gas flow rate that may decrease ESP performance and indicate the need to routinely determine ESP gas volume. Low SCA values, high velocities, short gas treatment times (5 seconds or less), and much higher oxygen levels at nearly full load conditions are indicators that excess flue gas flow rate may be causing decreased ESP performance. Presently, most sources do not continuously measure gas velocities or flow rates. Gas velocities are generally only measured during emission compliance testing or when there is a perceived problem. Manual Pitot tube traverses are normally used to measure gas velocity. Because of new technologies and regulations, some of the larger sources are beginning to install continuous flow measurement systems as shown if fig.7 . Multi-point pitot devices, ultrasonic devices, and temperature-based flow devices can be used to continuously measure gas velocity. These devices must be calibrated to the individual stack where they are installed. Most existing facilities currently use indirect indicators to estimate gas flow rate; these include fan operating parameters, production rates or oxygen/carbon dioxide gas concentration levels.

Another important parameter is gas flow distribution through the ESP. Ideally the gas flow should be uniformly distributed throughout the ESP (top to bottom, side to side). Actually, however, gas flow through the ESP is not evenly distributed, and ESP manufacturers settle for what they consider an acceptable variation. Standards recommended the Industrial Gas Cleaning Institute have been set for gas flow distribution. Based on a velocity sampling routine, 85% of the points should be within 15% of the average velocity and 99% should be within 1.4 times the average velocity. Generally, uneven gas flow through the ESP results in reduced performance because the reduction in collection efficiency in areas of high gas flow is not compensated for by the improved performance in areas of lower flow. Also, improper gas distribution can also affect gas sneak age through the ESP. As stated earlier, good gas distribution can be accomplished by using perforated plates in the inlet plenum and turning vanes in the ductwork.

Gas flow distribution tests are conducted when the process is inoperative, and the ESP and ductwork are relatively cool. This often limits the amount of gas volume that can be drawn through the ESP to less than 50% of the normal operating flow; however, the relative velocities at each point are assumed to remain the same throughout the normal operating range of the ESP. A large number of points are sampled by this technique. The actual number depends upon the ESP design, but 200 to 500 individual readings per ESP are not unusual. By using a good sampling protocol, any severe variations should become readily apparent.

Fig: 7 Details of SO3 flue gas conditioning system.

III. DESIGN AND OPERATING PARAMETERS OF ELECTROSTATICPRECIPITATOR (ESP)

3.1 Background Information

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The discharge electrodes are kept in between collecting electrodes and the electrodes are arranged alternatively. A typical cross sectional arrangement of ESP is shown in Figure 2.3.3. At the inlet of the chamber, gas distributor screens are provided which consist of perforated steel plate. The screens help in uniform gas distribution across the section of the chamber. The collecting plates at its power portion contain shock bars over which rapping hammers hits periodically, to dislodge the dust from it. Rapping is provided for discharge of emitting electrode to dislodge ash from the wire.

3.1.2 Design Parameters

In ESP the flue gas stream is passed between two electrodes, across which a high potential difference is maintained. Out of the two electrodes, one is the discharging electrode and the other a collecting electrode. Because of high potential difference and the discharge system, a powerful ionizing system is formed. Gas ionization is the dissociation of gas molecules into free ions and potentials as high as 40 to 60 KV are used. Consequently, ionization creates an active glow zone (blue electric discharge) called the corona or corona glow.

As the particulate in the carrier gas pass through this field, they get charged and migrate to the oppositely charged collecting electrode. The particles, once deposited on the collecting electrode, lose their charge and are removed mechanically by rapping or vibration to a hopper placed below.

The four steps in ESP process are as follows: 1. Place charge on the particle to be collected 2. Migrate the particle to the collector 3. Neutralize the charge at the collector 4. Remove the collected particle.

The function of ESP depends upon the properties of gas and fly ash particles, which are governed by the characteristics of coal burned, the boiler design and operation practices. The composition, temperature and pressure of the flue gas govern the basic corona characteristics of the ESP. The size, concentration and electrical resistivity of the fly ash particles affect both the corona and collecting aspects.

3.1.3 Gas flow quantity

The quantity of combustion gas produced in the boiler depends on the composition and amount of coal burned, the excess air used for combustion and air in-leakage. The volume flow rate through the ESP is also a function of temperature and pressure.

3.1.4 Coal quality

The performance of ESP is dependent on the properties of coal burned in the furnace. Upon burning, coal release ash and other residues of combustion like inert oxides and silicates.

3.1.5 Flue gas quality

The sulphur trioxide produced in the combustion process is important in ESP because of its effect in reducing the resistivity of fly ash. Dew point of the flue gas is substantially elevated by the presence of SO3 and it affects the ESP performance.

3.1.6 Fly ash characteristics

The chemical composition of fly ash, particle size and resistivity are the three main components that are critical for ESP performance. The resistivity of fly ash is dependent upon the composition and size of fly ash as well as temperature, water-vapour and SO3 content of the flue gas. Although most of the sulphur in coal is converted to SO2 after burning, about 1% of the total sulphur is converted to SO3. Therefore the amount of SO3 produced increases with the content of sulphur in coal and the relationship is variable. Fly ash from low sulphur coal has high resistivity and is difficult to precipitate. Fly ash from high sulphur coal has low resistivity and is relatively easy to precipitate.

3.1.7 Particle resistivity

Particle resistivity is a measure of the resistance of the dust particle to the passage of current. For practical operation the resistivity should be 107 and 1011 ohm-cm. At higher resistivity’s, fly ash particles are too difficult to charge and lead to decrease in efficiency. At times, particles with higher resistivity may be conditioned with moisture to bring them to the desired range. If the resistivity is too low, particles accept a charge easily but dissipate it so quickly that the particles are not collected at the electrode and are re-entrained in the gas stream. Particle resistivity depends upon the composition and continuity of dust, gas temperature and voltage gradient that exists across the dust layer.

3.2 Design Criteria

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3.2.1 Specific collection area (SCA)

The collection surface of an ESP required for a given gas flow and efficiency is usually computed from the modified Deutsch-Anderson Equation. The practical values of SCA usually range between 140 and 250 m2/m3/s, the higher values for higher collection efficiency.

3.2.2 Gas velocity

The importance of gas velocity is in relation to rapping and re-entrainmentlosses of fly ash from the collecting electrode. Above some critical velocity, these losses tend to increase rapidly. The critical velocity depends upon the composition, temperature and pressure of gas flow, plate configuration, ESP size. The gas velocity is calculated from the gas flow and cross section of ESP. The maximum gas velocity is 1.1 m/s and the optimum limit is 0.8 m/s for high efficiency ESP.

3.3.3 Aspect ratio

The importance of aspect ratio is due to its effect on rapping loss. Aspect ratio is defined as the ratio of the total active length of the fields to the height of the field. Collected fly ash is released upon rapping and is carried along the gas flow path. If the total field length is too short compared to height, some of the carried particles will not reach the hopper and goes out. The minimum aspect ratio should be between 1.8 to 2.4, the highest figure for highest efficiency.

3.3.4

Disadvantages of earlier gas distribution method

Fundamental problems Mechanical problems Operational problems

1.High resistivity particles

2. Re-entrainment of

collected particles Poor

gas flow

3. Gas velocity too High

1. Poor electrode alignment 2. Vibrating or swingingcorona Wires

3. Distorted collecting plates

4. Excessive dust depositson

collecting electrodesand corona electrodes 5. Air leakage into hoppers,

shells or gas ducts 6. Formation of dustmountain in ESP inlet andoutlet ducts

1. Poor electrode alignment 2. Vibrating or swinging corona wires

3.Distorted collecting plates 4. Excessive dust deposits on collecting electrodes and corona electrodes 5. Air leakage into hoppers, shells or gas ducts 6. Formation of dust

mountain in ESP inlet and outlet ducts

IV. RESULTS AND DISCUSSION

4.1 Overview Of Hardware Analysis

Fig: 8 System Architecture Block Diagram

Block diagram explanation

In this section we will be discussing about complete block diagram and its functional description of project. And also brief description about each block of the block diagram.

Microcontroller

A microcontroller is a general purpose device, but that is meant to read data, perform limited calculations on that data and control its environment based on those calculations. The prime use of a microcontroller is to control the operation of a machine using a fixed program that is stored in ROM and that does not change over the lifetime of the system. The microcontroller design uses a much more limited set of single and double byte instructions that are used to move data and code from internal memory to the ALU. The microcontroller is concerned with getting data from and to its own pins; the architecture and instruction set are optimized to handle data in bit and byte size.

The AT89C51 is a low-power, high-performance CMOS 8-bit microcontroller with 4k bytes of Flash Programmable and erasable read only memory (EROM) as shown in fig.9. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is functionally compatible with the industry-standard 80C51 microcontroller instruction set and pin out. By combining versatile 8-bit CPU with Flash on a monolithic chip, the Atmel’s AT89c51 is a powerful microcomputer, which provides a high flexible and cost- effective solution to many embedded control applications shown in fig.10.

The Major Features

 Compatible with MCS-51 products

 4k Bytes of in-system Reprogrammable flash memory

 Fully static operation: 0HZ to 24MHZ

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 Six interrupt sources

 Programmable serial channel

 Low power idle power-down modes

Fig: 9 Pin configuration of AT89c51 Microcontroller

Fig: 10 AT89C51 Block Diagram

4.2 Advanced Automated Gas Distribution Design & Development

4.2.1Present Design:

The present invention relates to a method for carrying out measurement of gas distribution in an ESP and also relates to a gas distribution measurement system for measurement of gas velocities in an ESP. The gas distribution system comprises probe carrier that moves in the ESP, air velocity probe that record the air velocity readings and a display controller.

Methodology

1. A method for measuring gas distribution in an electrostatic precipitator with at least one collecting electrode, comprising:

a) Installing inside the electrostatic precipitator on a surface of the collecting electrode, at least one remotely controlled probe carrier comprising at least one air velocity probe adapted to collect and record air velocity readings; and b) Moving by remote control the probe carrier along the surface of the collecting electrode to cover an entire cross section of the electrostatic precipitator to capture and record a plurality of air velocity readings while moving the probe carrier along the surface of said collecting electrode.

2. Wherein the electrostatic precipitator has at least two collecting electrodes each with at least one remotely controlled probe carrier installed thereon.

3. The moving of the probe carrier, obstacles are sensed through an attached sensor.

4. The probe carrier on the surface of the collecting electrode is stopped for a defined time period to measure air velocity.

5. A gas distribution measurement system for measuring gas distribution in a electrostatic precipitator having a plurality of collecting electrodes, the system comprising: at least one probe carrier comprising at least one air velocity probe adapted to collect and record the air velocity readings; and a display controller comprising means for storing, calculating and reporting collected air velocity readings, and means for controlling movement of the probe carrier-remotely.

6. A probe carrier for measuring gas distribution in an electrostatic precipitator comprising: at least one air velocity probe adapted to collect and record air velocity readings; a control device adapted to receive air probe velocity readings; and a motion and clamping mechanism adapted-to-allow.

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8. The gas distribution measurement system the probe carrier includes a plurality of guides to lateral shifting during

4.2.2 Brief description of the ESP drawing

The invention will now be described in more detail with reference to the appended drawings in which Fig. 11 shows a cross sectional view of an ESP as seen from perspective side.

Fig: 11 Advanced automated design for the system

Components List In The Design

1. Two bobbins 2. A shaft/rod 3. Steel casing 4. Two roller shafts 5. Four wheels

6. Sprocket chain mechanism with two gears 7. Two helical gears

8. Thread holding steel bar 9. U-shaped thread 10.Probe carrier 11.fan blower

Fig: 12 simplistic sight in plan of the probe carrier of the gas distribution measurement system.

Fig: 13 Wire frame design of gas distribution measurement system of the ESP

4.2.3 Working

The probe carrier has a control device mounted on it. The control device has a microcontroller with inbuilt memory, a signal conditioner and a motor controller. The microcontroller receives air velocity readings signals in range of 4-20 mA or 0-5 V via the signal conditioner, which are connected to the air velocity measurement probe. The microcontroller also receives signals form attached obstacle sensors on probe carrier for detecting obstacles on the path of the probe carrier and controlling accordingly the air velocity probe arm folding and extending. A servomotor/DC motor is used for air velocity probe arm folding and extending. The microcontroller controls the movement as well as speed of probe carrier via a motor controller, which also includes a motion encoder that is used to detect the position of the probe carrier. The microcontroller also communicates with a display controller for providing data and executing operational commands through the control unit. The control device is connected with a display controller through a signal cable and with a power supply through a DC power cable shown in Fig.15

The power supply is from a source inside/outside of the ESP and is connected to integrated display controller and control unit box and subsequently connected to the probe carrier through a common power-signal cable or through separate cables. In another embodiment, the control device is stationary and kept inside the ESP. It is connected with probe carrier with suitable common power-signal cable or through separate cables. With the display controller, it is connected either through a suitable wire or wirelessly. The power supply is from a source inside/outside of the ESP and is connected to the control unit box and subsequently connected to the probe carrier through the cable as described. Power supply is given onboard through a battery and a transmitter is present for wireless communication. The control station has a receiver for wireless communication along with power supply unit and display controller. There is no physical connection between the control station and probe carrier.

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The display controller also has power supply and interface board. The display controller is user programmable to define the ESP size, field number, reading position etc. It will have manual as well as automatic mode option to provide enough flexibility to the operator. Display controller has flexibility to adapt to different ESP sizes and configurations. Display controller can also control multiple probe carriers simultaneously. When readings are taken by air velocity probe , the control device will send the data to the display controller using certain communication protocol and after finishing the measurement inside the ESP, display controller can connected to the computer through a suitable communication interface that may be via USB/RS232 and all the readings from memory will be imported to the computer .The data acquisition software in computer will correlate, calculate and display the data in presentable form (with color coding, graphs, etc.) and finally prepare the report. For measurement of sneak age in ESP, the velocity probe can be mounted on probe carrier in parallel to the direction with the collecting electrode through a suitable probe holder (not shown) which is an extended arm almost 700 mm long. When probe carrier 9 is at near the end of collecting electrode, the air velocity probe will extend beyond its end in the range of 500 mm towards roof orhoppers. It will enable to take measurement of air sneak age in the gaps between electrode end and ESP roof orhoppers. The gas distribution measurement system described above is lightweight and portable, can be carried through the ESP manhole by an operator. The gas distribution system is protected from dust and splashing water. The gas distribution measurement system is easy and quick to assemble and to dismantle.

When the probe carrier is back, side locking pin will be released and the probe carrier will be mounted on the alternate collecting electrode and the procedure will be again repeated taking the alternate collecting electrode till all the collecting electrodes are covered shown in fig.16. Having two air velocity probes projecting on both sides of a collecting electrode facilitate covering the measurement area on both side of collecting electrode. It results in half number of required movements of probe carrier that greatly reduce the time period for measurements. Movement of probe carrier then can be planned on alternate collecting electrodes as measurement for one side of any collecting electrode is done in previous movement. Mounting will be done by operator and can be done automatically with help of moving picking machine.

For measuring sneakage in ESP, the probe carrier with the velocity probe attached in parallel direction to the collecting electrode through probe holder/extended arm, directly moves to any end (toward the roof or the hopper) of the collecting electrode at fast speed and stops automatically near its end by sensing the end through a sensor. Now the air velocity probe which is extending 500 mm in the gap between roof or hopper and collecting electrode end takes reading of air velocity in this gap. Using the application software in display controller or computer data like operator details, date and time, site name, the ESP size designation, job reference no., customer name, purchase order no., test number, pass name and ESP information like collecting electrode height, electrode spacing, selection of measurement grid, numbers of electrode, measurement option like alternate grid point or all grid points, numbers of probe carrier to be used, obstruction activation and deactivation, obstruction elevation from collecting electrode bottom point, obstruction gap, sneakage measurement can be fed or opted initially.

Fig:15 In PCB board the connection details connected with microcontroller and linked with LCD

Fig: 16 Stepper motor working with the help of hardware components

4.2.4 Features And Advantages FEATURES

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2. The robot crawler climbs up the side edge of each plate taking readings of the gas flow between the plates

3. The inspector only has to enter the ESP housing to attach the robot to the bottom of the next plate

4. A pair of sensors measure gas flow rates in two channels at once

5. The final report is generated from the readings in a matter of minutes

Advantages

 The previously described versions of present invention have many advantages, including that it speeds up and simplifies the measurement of gas distribution in ESP.



The method of present invention not only ensures the safety of operator by

V. CONCLUSION

By designing a new methodology with newly developed automated measurement system it ensures the safety of operator by eliminating the need for operator to climb high in ESP and reducing his residual time in dusty ESP but also improve significantly accuracy and quality of collected data by eliminating the man-induced errors. With the higher speed of data collection in the method of present invention, a higher number of measurements can be taken in less time thus increasing the quantity of measurements significantly. By properly adjusting the gas distribution based on the analysis of the collected data using this invention, the emissions can be reduced by optimizing the ESP efficiency and lifetime of certain components can be increased.

Present invention is also advantageous for that fleet of ESP where gas distribution measurement is not possible due to too small space/gap for human access inside the ESP. Hence there is a saving of cycle time of testing and also save man power cost.

REFERENCES

[1] Bibbo, P. P. 1982. Electrostatic precipitators. In L. Theodore and A. Buonicore (Eds.), Air PollutionControl Equipment-Selection, Design, Operation and Maintenance (pp.3-44). Englewood Cliffs, NJ: Prentice Hall.

[2] Cross, F. L., and H. E. Hesketh. (Eds.) 1975. Handbook for the Operation and Maintenance of Air Pollution Control Equipment. Westport, CT: Technomic Publishing.

[3] Englebrecht, H. L. 1980. Mechanical and electrical aspects of electrostatic precipitator O&M. In R. A. Young and F. L. Cross (Eds.)

[4] Operation and Maintenance for Air Particulate Control Equipment (pp. 283-354). Ann Arbor, MI: Ann Arbor Science.

[5] Katz, J. 1979. The Art of Electrostatic Precipitators. Munhall, PA: Precipitator Technology.

[6] Richards, J. R. 1995. Control of Particulate Emissions, Student Manual. (APTI Course 413). U.S. Environmental Protection Agency. [7] Szabo, M. F., and R. W. Gerstle. 1977. Electrostatic Precipitator

Malfunctions in the Electric Utility Industry. EPA 600/2-77-006. [8] Szabo,M. F., Y.M. Shah, and S. P. Schliesser. 1981. Inspection

Manual for Evaluation of Electrostatic Precipitator Performances. EPA 340/1-79-007.

[9] U.S. Environmental Protection Agency. 1985. Operation and Maintenance Manual for Electrostatic Precipitators. EPA 625/1-85/017.