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training in instrumentation department at rama newsprint and paper ltd .

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  1. 1. SR.NO. CONTENTS SLIDE NO. 01 Company profile 5 TO 8 02 Deinking Plant Flow 9 &10 Chart 03 Paper machine Flow 11 Chart 04 Instrumentation 12 TO 55 05 UITILITY 56 TO 77 TOTAL NO. OF SLIDE – 1 TO 77
  2. 2. We would like to express our sincere thanks to management of RNPLand deep sense of acknowledgment toMr. R.K CHAKRABORTY,.G.M. (ELEC. & INST.) for permitting us toundergo industrial training in esteem companyRAMA NEWSPRINT AND PAPER LIMITED.We express our heartiest gratitude and are greatly indebted to ourtraining guidesMr.N.K TRIPATHI AND Mr. ASHOK PATEL (Sr. manager ofinstrumentation)discipline for their valuable guidance for fulfilling the objective of thistraining. They stood by us right from the beginning to the end oftraining encouraging us in all manners.They have guided us right from the beginning till end and helped usunderstand the role of instrumentation in a big process plant. They werealways there to clarify out doubts.The vocational training has helped us to get acquainted with practicalside of instrumentation and control.
  3. 3.  Rama News & Paper mill is India’s largest private sector company & it is established in 1996 by Mr. Vasu Singhania. The company meets 22% of India’s newsprint production capacity.. It is fully integrated paper mill. It’s totally integrated for manufacture of paper and pulp with modern wide width high speed paper machine besides in house conversion facilities to address customers specific requirement. At RNPL the technology is based on recycling of used paper and a process that is devoid of using chlorine and other such chemicals abnd thereby making it a 100% ecology and environoment friendly paper plant(ETP) ensures preservation of environment. A highly advance, ultramodern, state-of-the-art laboratory maintains stringnent quality control and also conducts research and development for continuous product improvisation
  4. 4.  A 23 MW capacity powerplant ensure continuous operation of the mill without any interruption due to powercut.The in house engineering facilities help speedy implementation of improvisation in the operation to maintain our quality standards. It has installed DCS/ QCS for efficient and accurate control. The company has a private take in well on the river which pumps the water through a 17 Km long pipe line to the mill. The company manufactures about 1,32,000 tonnes per annum of Newsprint or 1,80,000 tonnes per annum of Printing and writing paper or a mix of both. The company has turnover of about Rs. 288 crore for the accounting year 2007-2008.
  5. 5. Deinking Plant Slat Conveyer HC Pulper Fiberizer Buffer Tank Drum Screen Dump Tower H.D. Cleaner Pri. Coarse ScreenL.C. Cleaner L.C. Cleaner Multi Sorter Multi Sorter 2nd Stage 1st Stage Feed ChestL.C. Cleaner Ter-coarse 3rd Stage screen feed chest Tex-Coarse Screen Eco gaus#1 Pre Floatation Primary Diabola Foam Tank Floatation#1 secondary
  6. 6. Primary Fine Screen Feed Chest Primary Fine ScreenSecondary Disc Filter #1Fine ScreenFeed Chest M/C Pump #1SecondaryFine Screen Dewatering Press Screw PressTertiary Fine Steam Mixture Plug ScrewScreen Feed Chest Krima DischargeMini Sorter Peroxide Tower Discharge & Dilution Screw L. C. Pump Intermediate Chest Post Floatation Primary Eco Gaus #2 Disc Filter #2 Foam Tank #2 M/C Pump #3 Post Floatation AHL Mixer Secondary Hydrosulphite Bleaching Tower H.D. Tower To Paper m/c
  7. 7. Paper Machine Flow Process Deinking pulp ChemicalsStock Preparation Broke (reuse paper)Centrifugal Cleaner Reject (Heavy particle) Primary Cleaner Reject (size wise) Head Box Wire Part Press Part DryersSize Press (PM-2) Dryers Calender Paper Reel Rewinder Finishing House
  8. 8.  LEVEL MEASUREMENT Level measurement is one of the oldest measurements. Liquid level refers to the position or height of a liquid surface above a datum line. Level measurements are made to ascertain the quantity of the liquid held within a container. The measurement of industrial process level parameters is of great importance in the industrial field. Level affects both the pressure and rate of flow in and out of the container and as such its measurement and/or control is an important function in a variety of processes. Hence, the quality may be affected in case of error in the process fluid level. Here, different methods of level measurement have been discussed with their merits and demerits.
  9. 9.  The sight glass (also called a gauge glass) is one of the widely used instruments. It is used for continuous indication of liquid level within a tank. It consists of a graduated tube of toughened glass which is connected to the interior of the tank at the bottom in which the water level is required. Liquid level in the glass tube matches the level of liquid in the tank. As the level of liquid in the tank rises and falls, the level in the sight glass also rises and falls accordingly. Thus, by measuring the level in the sight glass, the level of the liquid in the tank is measured. Ranges:- The standard practice is not to go in for a glass tube of more than 900 mm length. In case the height of the tank is more than 900 mm, two or more sight glass level gauges are provided at different levels.
  10. 10. Measurement of flow rate and quantity is the oldest of all measurements of process variables in the field of instrumentation. Measurements of fluid velocity, flow rate and flow quantity with varying degree of accuracy are a fundamental necessity in almost all the flow situations of engineering importance. It is made for determining the proportions and the amount of materials entering or leaving a continuous manufacturing process. Studying ocean or air currents, monitoring gas input into a vacuum chamber, metering materials in a pilot plant, or detecting and measuring blood movement in avein, the scientist or engineer is faced with choosing a method to measure flow. For experimental procedures, it may be necessary to measure the rates of flow either into or out of the engines; pumps, compressors and turbines; steam generators and all heat transfer apparatus. Without flow measurements, plant material balancing, quality control and even the operation of any continuous process would be almost impossible. For the purpose of cost accounting, suchmeasurement is often required to be made for steam, water and gas services to domestic consumers, and in the gasoline pumping stations. Flow measurements are made both for fluids and solids. Flow measurements are made both for fluids and solids. Here, different methods of flow measurement have been discussed with their merits and demerits.
  11. 11.  Pressure measurement is undoubtedly one of the most common of all the measurements made on systems. In company with temperature and flow, pressure measurements are extensively used in industry, laboratories and many other fields for a wide variety of reasons. Pressure measurements are concerned not only with determination of force per unit area but are also involved in many liquid level, density, flow and temperature measurements. Measurement of pressure is also needed to maintain safe operating conditions, to help control a process and to provide test data. Nearly all industrial processes use liquids, gases or both. Controlling these processes requires the measurement and control of liquid and gas pressures. Thus, pressure measurement is one of the most important of all process measurements.
  12. 12. Open Vessels:- Pressure transmitters, when used for liquid level, measure hydrostatic pressure head. This pressure is equal to the liquid height above the tap multiplied by the specific gravity of the liquid. It is independent of volume or vessel shape.For open vessels, a pressure transmitter mounted on near thebottom of the tank will measure the pressure corresponding to the height of the liquid above it. Pressure is sensed by the process flange and transmitted to the high pressure side of the sensing element. The low pressure side of the sensing element is vented to atmosphere. If it is desired to have a zero reference at point above the location of the range must be performed.
  13. 13. Closed Vessels:- For closed vessels, pressure inside the vessel (above the liquid) will affect the pressure measured at the bottom; pressure sensed at the bottom is equal to the height of the liquid, multiplied by the specific gravity of the liquid, plus the vessel pressure. To measure true level, vessel pressure must be subtracted from the measurement. This accomplished by making a pressure tap at the top of the vessel connected to the lowpressure side of the transmitter. Vessel pressure is equalized at the high and low sides of the transmitter. The resulting differential pressure is proportional to the liquid height multiplied by the specific gravity. Differential capacitance between the sensing diaphragm and the capacitor plates is electronically converted to a two –wire, 4-20 or 10-50 mA dc output signals directly proportional to pressure. This approach is based on the following concept: P = K (C1-C2)/ (C1+C2) Where: P = process pressure K = constant. C1 = capacitance between the sensing diaphragm and the high pressure side. C2 = capacitance between the sensing diaphragm and the low pressure side.
  14. 14.  Temperature is probably the most fundamental parameter, and is a widely measured and frequently controlled industrial variable. It is required in the routine control of an industrial plant. Measurement of temperature potential is involved in thermodynamics, heat transfer and many chemical operations. The conditions, under which temperature has to be measured, differ so widely that no fixed rule can be followed. All that is essential is that one should select the most appropriate method of temperature measurement for a particular use. Basically all the properties of matter such as size, color, electrical and magnetic characteristics, and the physical states (i.e. solid, liquid and gas) change with changing temperatures. The occurrence of physical and chemical changes is governed by the temperature at which a system is maintained. During the selection of the method to measure temperature, one must consider the points such as, sources of error or limitations, precautions to be observed, the exact location of the sensing probe, etc. The steps to be taken to check the accuracy of instruments before, during, and after the test are also of extreme importance. Here, different methods of temperature measurement have been discussed with their merits and demerits.
  15. 15.  Platinum RTDs are capable of measuring from -450 °F to 1200 °F. Thermocouple ranges are 32 to 1400 °F for Type J. -328 to 2,300 °F for Type K. -328 to 660 °F for Type T. 32 to 2300 °F for Type N. 32 to 2640 °F for Type R 1472 to 3092 °F for Type B.
  16. 16.  The working principle of a thermocouple, which depends on the thermo- electric effect, was first observed by Seebeck in 1821 and is known as Seebeck effect. If two dissimilar metals are joined together so as to form a closed circuit, there will be two junctions where they meet each other. If one of these junctions is heated, then, a current flows in the circuit which can be detected by a galvanometer. The amount of the current produced depends on the difference in temperature between the two junctions and on the characteristics of the two metals. The emf produced per degree of temperature change must be sufficient to facilitate detection and measurement. The emf of a simple thermocouple circuit is generally given by the following equation: E = At+Bt2/2+Ct3/3 Where, t = temperature in 0C E = emf produced A, B, C = constants dependent on the thermocouple material
  17. 17.  Composed of a positive leg which is iron and a negative leg which is approximately 45 % nickel-55% copper. (Note - Constantan is Copper-Nickel.) When protected by compacted mineral insulation and appropriate outer sheath, Type J is useable from 0 to 816°C, (32 to 1500°F). It is not susceptible to aging in the 371 to 538°C, (700 to 1000°F) temperature range. A drift rate of 1 to 2°C, (2 to 4°F) occurs with Type E and K in the 371 to 538°C, (700 to 1000°F) temperature range. This low cost, stable calibration is primarily used with 96% pure MgO insulation and a stainless steel sheath. Thermocouple Grade- 32°F to 1382°F, 0 to 750°C Extension Grade- 32°F to 392°F, 0 to 200°C
  18. 18.  Composed of a positive leg, which is approximately 90% nickel, 10 chromium and a negative leg, which is approximately 95% nickel, 2% aluminum, 2% manganese and 1% silicon. Due to its reliability and accuracy, Type K is used extensively at temperatures up to 1260°C (2300°F). Its good practice to protect this type of thermocouple with a suitable metal or ceramic protecting tube, especially in reducing atmospheres. In oxidizing atmospheres, such as electric furnaces, tube protection is not always necessary when other conditions are suitable; however, it is recommended for cleanliness and general mechanical protection. Type K will generally outlast Type J because the JP (iron) wire rapidly oxidizes, especially at higher temperatures.
  19. 19.  Composed of a positive leg, which is approximately 90% nickel, 10 chromium and a negative leg, which is approximately 95% nickel, 2% aluminum, 2% manganese and 1% silicon. When protected by compacted mineral insulation and appropriate outer sheath, Type T is usable from 0 to 350°C, (32 to 662°F). Type T is very stable and is used in a wide variety of cryogenic and low temperature applications. For applications below 0°C, (32°F) special selection of alloys are usually required.
  20. 20.  Type N (Nicrosil�Nisil) (nickel-chromium- silicon/nickel-silicon) thermocouples are suitable for use between -270 °C and 1300 °C owing to its stability and oxidation resistance. Sensitivity is about 39 �V/°C at 900 °C, slightly lower compared to type K. When protected by compacted mineral insulation and appropriate outer sheath, Type N is useable from 0 to 1260°C, (32 to 2300°F). Type N was developed to overcome several problems inherent in Type K thermocouples. Aging in the 316 to 593°C, (600 to 1100°F) temperatures is considerably less. Type N has also been found to be more stable than Type K in nuclear environments.
  21. 21.  Composed of a positive leg which is approximately 70% Platinum, 30% Rhodium and a negative leg which is approximately 94% Platinum, 6% Rhodium. When protected by compacted mineral insulation and appropriate outer sheath, Type R is usable from 0 to 1482°C, ( 32 to 2700°F).Type R has a higher EMF output than type S. Also easily contaminated, and damaged by reducing atmospheres. Type R should by protected in a similar fashion as Type S.
  22. 22.  Composed of a positive leg which is approximately 14% chromium, 1.4% Silicon and 84.6% Nickel, a negative leg which is approximately 4.4% Silicon, 95.6% Nickel. When protected by compacted mineral insulation and appropriate outer sheath, Type B is usable from 871 to 1704°C, (1600 to 3100°F). Also easily contaminated, and damaged by reducing atmospheres. The same protective measures as shown above apply to type B Thermocouples.
  23. 23.  Composed of a positive leg, which is approximately 90% nickel, 10 chromium and a negative leg, which is approximately 95% nickel, 2% aluminum, 2% manganese and 1% silicon. When protected by compacted mineral insulation and appropriate outer sheath, Type E is usable from 0 to 900°C, (32 to 1652°F). This Thermocouple has the highest EMF output per degree of all recognized thermocouples. If the temperature is between 316 to 593°C, (600 to 1100°F), we recommend using type J or N because of aging which can cause drift of 1 to 2°C, (2 to 4°F) in a few hours time. For applications below 0°C, (32°F), special selection of alloys are usually required.
  24. 24.  Composed of a positive leg which is approximately 70% Platinum, 30% Rhodium and a negative leg which is approximately 94% Platinum, 6% Rhodium. When protected by compacted mineral insulation and appropriate outer sheath, Type S is usable from 0 to 1482°C, (32 to 2700°F). Easily contaminated. Reducing atmospheres are particularly damaging. Type S should be protected with gas tight ceramic tubes, a secondary tube of porcelain and silicon carbide or metal outer tubes, as conditions require.
  25. 25.  Resistance Temperature Detector (RTD) Every type of metal has a unique composition and has a different resistance to the flow of electrical current. This is termed the resistively constant for that metal. For most metals the change in electrical resistance is directly proportional to its change in temperature and is linear over a range of temperatures. This constant factor called the temperature coefficient of electrical resistance (short formed TCR) is the basis of resistance temperature detectors. The RTD can actually be regarded as a high precision wire wound resistor whose resistance varies with temperature. By measuring the resistance of the metal, its temperature can be determined. Several different pure metals (such as platinum, nickel and copper) can be used in the manufacture of an RTD. A typical RTD probe contains a coil of very fine metal wire, allowing for a large resistance change without a great space requirement. Usually, platinum RTDs are used as process temperature monitors because of their accuracy and linearity. To detect the small variations of resistance of the RTD, a temperature transmitter in the form of a Wheatstone bridge is generally used. The circuit compares the RTD value with three known and highly accurate resistors.
  26. 26. A Wheatstone bridge consisting of an RTD, three resistors, a voltmeter and a voltage source is illustrated in Figure 1. In this circuit, when the current flow in the meter is zero (the voltage at point A equals the voltage at point B) the bridge is said to be in null balance. This would be the zero or set point on the RTD temperature output. As the RTD temperature increases, the voltage read by the voltmeter increases. If a voltage transducer replaces the voltmeter, a 4-20 mA signal, which is proportional to the temperature range being monitored, can be generated. As in the case of a thermocouple, a problem arises when the RTD is installed some distance away from the transmitter. Since the connecting wires are long, resistance of the wires changes as ambient temperature fluctuates. The variations in wire resistance would introduce an error in the transmitter. To eliminate this problem, a three-wire RTD is used.
  27. 27.  The Bourdon tube is the most frequently used mechanical type pressure gauge because of its simplicity and rugged construction. The action of the Bourdon gauge is based on the deflection of a hollow tube caused by the applied pressure difference. It covers ranges from 0-15 psig to 0-100,000 psig, as well as vacua from 0 to 30 inches of mercury.
  28. 28.  The pressure responsive element of a Bourdon gauge consists essentially of a metal tube, called Bourdon tube, oval in cross-section and bent to form a circular segment of approximately 200 to 300 degrees. One end of the tube is closed but free to allow displacement under deforming action of the pressure difference across the tube walls. The other end of the tube is fixed and is open for the application of the pressure which is to be measured. The tube is soldered or welded to a socket at the base, through which pressure connection is made. The figure shows the schematic arrangement of a complete Bourdon tube gauge. As the fluid under pressure enters the Bourdon tube, it tries to change the section of the tube from oval to circular, and this tends to straighten out the tube with a consequent increase in its radius of curvature i.e. free end moves away from the centre. The free end of the tube is connected to a spring loaded linkage which amplifies the displacement and transmits it to the angular rotation of a pointer over a calibrated scale to give a mechanical indication of pressure.
  29. 29.  The tip of the Bourdon tube is connected to a segmental lever through an adjustable length link. The lever length also may be adjustable. The segmental lever end on the segment side is provided with a rack which meshes to a suitable pinion mounted on a spindle. The segmental lever is suitably pivoted and the spindle holds the pointer, as shown in figure. A hairspring is sometimes used to fasten the spindle to the frame of the instrument to provide the necessary tension for proper meshing of the gear teeth, thereby freeing the system from backlash (lost motion). Any error due to friction in the spindle bearing is known as ‘lost motion’. Bourdon tubes are made of a number of materials, depending upon the fluid and the pressure for which they are used, such as phosphor bronze, alloy steel, stainless steel, ‘Monel’ metal, and beryllium copper. The material chosen to fabricate a Bourdon tube will relate to the instrument sensitivity, accuracy and precision. For adequate reliability, the materials for Bourdon tubes must have good elastic or spring characteristics. Bourdon tubes are generally made in three shapes:  C-type  Helical type  Spiral type
  31. 31.  The different types of orifice plates are : • Concentric. • Segmental. • Eccentric. • Quadrant Edge.
  32. 32.  The concentric orifice plate is used for ideal liquid as well as gases and steam service. This orifice plate beta ratio fall between of 0.15 to 0.75 for liquids and 0.20 to 0.70 for gases, and steam. Best results occur between value of 0.4 and 0.6. beta ratio means ratio of the orifice bore to the internal pipe diameters. (45º beveled edges are often used to minimize friction resistance to flowing fluid )
  33. 33.  The eccentric orifice plate has a hole eccentric. Use full for measuring containing solids, oil containing water and wet steam. Eccentric plates can use either flange or vena contracta taps, but the tap must be at 180º or 90º to the eccentric opening. Eccentric orifices have the bore offset from center to minimize problems in services of solids- containing materials.
  34. 34.  The segmental orifice place has the hole in the form segment of a circle. This is used for colloidal and slurry flow measurement. For best accuracy, the tap location should be 180º from the center of tangency. Segmental orifices provide another version of plates useful for solids containing materials.
  35. 35.  It common use in Europe and are particularly useful for pipe sizes less than 2 inchs. Quadrant edge orifices produce a relatively constant coefficient of discharge for services with low Reynolds numbers in the range from 100,000 down to 5,000.
  36. 36.  The orifice plate Flow Detector is the simplest of the flow-path restrictions used in flow detection, as well as the most economical. Orifice plates are flat plates 1/16 to 1/4 inch thick. They are normally mounted between a pair of flanges and are installed in a straight run of smooth pipe to avoid disturbance of flow patterns from fittings and valves. Three kinds of orifice plates are used: concentric, eccentric, and segmental (as shown in Figure F1).
  37. 37.  An orifice plate installed in a line creates a pressure differential as the fluid flows through it. This differential pressure is measured via impulse lines by a differential pressure transmitter which converts it into an analogue or digital signal which can be processed to provide a display of the instantaneous rate of flow. The relationship between the rate of flow and the differential pressure produced is very well understood and is fully covered by comprehensive national standards. The relevant standards are BS 1042 and the equivalent
  38. 38.  What do meters measure? A meter is a measuring instrument. An ammeter measures current, a voltmeter measures the potential difference (voltage) between two points, and an ohmmeter measures resistance. A multimeter combines these functions, and possibly some additional ones as well, into a single instrument. A multimeter is an instrument used to check for AC or DC voltages, resistance or continuity of electrical components and small amounts of current in circuits. This instrument will let you check to see if there is voltage present on a circuit, etc. Heres how to use an analog multimeter.
  39. 39.  Jacks or openings in the case to insert test leads. Most multimeters have several jacks. The one pictured has just two. One is usually labeled "COM" or (-) ,for common and negative. This is where the black test lead is connected. It will be used for nearly every measurement taken. The other jack(s) is labeled "V" (+) and the Omega symbol (an upside down horseshoe) for Volts and Ohms, respectively, and positive. The + and - symbols represent the polarity of probes when set for and testing DC volts. If the test leads were installed as suggested, the red lead would be positive as compared to the black test lead. This is nice to know when the circuit under test isnt labeled + or -, as is usually the case. Many meters have additional jacks that are required for current or
  40. 40. INTRODUCTION Control of the processes in the plant is an essential part of the plant operation. There must be enough water in the boilers to act as a heat sink for the reactor but there must not be water flowing out the top of the boilers towards the turbine. The level of the boiler must be kept within a certain range. The heat transport pressure is another critical parameter that must be controlled. If it is too high the system will burst, if it is too low the water will boil. Either condition impairs the ability of the heat transport system to cool the fuel. In this section we will look at the very basics of control. We will examine the fundamental control building blocks of proportional, integral and differential and their application to some simple systems.
  41. 41.  Consider a typical process control system. For a particular example let us look at an open tank, which supplies a process, say, a pump, at its output. The tank will require a supply to maintain its level (and therefore the pump.s positive suction head) at a fixed predetermined point. This predetermined level is referred to as the setpoint (SP) and it is also the controlled quantity of the system. Clearly whilst the inflow and outflow are in mass balance, the level will remain constant. Any difference in the relative flows will cause the level to vary. How can we effectively control this system to a constant level? We must first identify our variables. Obviously there could be a number of variables in any system, the two in which we are most interested are: The controlled variable - in our example this will be level. The manipulated variable . the inflow or outflow from the system. If we look more closely at our sample system (Figure 1), assuming the level is at the setpoint, the inflow to the system and outflow are balanced. Obviously no control action is required whilst this status quo exists. Control action is only necessary when a difference or error exists between the setpoint and the measured level. Depending on whether this error is a positive or negative quantity, the appropriate control correction
  42. 42.  In order for an electronic control signal to operate a pneumatic instrument (such as an electronic controller operating valve), the electronic signal must be changed into pneumatic signal. This is accomplished by using I/P converter or current to pneumatic transducer. I/P converters accept 4 to 20 mA and provide a pneumatic output of 3 to 15 psi. However, an essential characteristic of a transducer is that it is able to produce an output signal that is proportional to the input.
  43. 43.  Figure shows I/P converter in which a coil is positioned in the field of a fixed permanent magnet. The coil magnet mechanism converts the signal to motion by the interaction of the two magnet fields. One field surrounds the permanent magnet and the other field surrounds the force coil. The magnetic field in the coil is produced due to the current flowing through the coil. The lines of flux of the magnetic coil are concentrated in the magnet. An increase in the input current forces the coil to move because of the intensified magnetic field surrounding the coil. A decrease in the current causes the coil to move in the opposite direction. The coil movement changes the baffle-nozzle relationship. A change in the nozzle back pressure is sensed by a diaphragm in the relay. The movement of diaphragm positions a valve. This valve position determines the signal output value from the relay. A balance force on the beam is provided by the feed back bellows. A spring pivot provides a pivot point for the beam. As the coil moves up, the baffle moves toward the nozzle.
  44. 44. % mA PRESSURE PSI KG/CM² 0 4.00 0.2 kg 325 8.00 0.4kg 650 12.00 0.6kg 975 16.00 0.8kg 12100 20.00 1.0kg 15 INPUT – I/P – ( 4 TO 20)mA
  45. 45.  DM PLANT (Demineral Water Plant) DEAERATOR COAL PLANT BOILER TG
  47. 47. Cations Anions Calcium (Ca2+) Chloride (Cl-)Magnesium (Mg2+) Bicarbonate (HCO3-) Sodium (Na+) Nitrate (NO3-) Potassium (K+) Carbonate (CO32-) Iron (Fe2+) Sulfate (SO42-)
  48. 48.  A deaerator is a device that is widely used for the removal of oxygen and other dissolved gases from the feedwater to steam-generating boilers. In particular, dissolved oxygen in boiler feedwaters will cause serious corrosion damage in steam systems by attaching to the walls of metal piping and other metallic equipment and forming oxides (rust). Dissolved carbon dioxide combines with water to form carbonic acid that causes further corrosion. Most deaerators are designed to remove oxygen down to levels of 7 ppb by weight (0.005 cm³/L) or less as well as essentially eliminating carbon dioxide
  49. 49.  Why gases need to be removed from boiler feedwater Oxygen is the main cause of corrosion in hotwell tanks, feedlines, feedpumps and boilers. If carbon dioxide is also present then the pH will be low, the water will tend to be acidic, and the rate of corrosion will be increased. Typically the corrosion is of the pitting type where, although the metal loss may not be great, deep penetration and perforation can occur in a short period. Elimination of the dissolved oxygen may be achieved by chemical or physical methods, but more usually by a combination of both. The essential requirements to reduce corrosion are to maintain the feedwater at a pH of not less than 8.5 to 9, the lowest level at which carbon dioxide is absent, and to remove all traces of oxygen. The return of condensate from the plant will have a significant impact on boiler feedwater treatment - condensate is hot and already chemically treated, consequently as more condensate is returned, less feedwater treatment is required.
  50. 50.  Water exposed to air can become saturated with oxygen, and the concentration will vary with temperature: the higher the temperature, the lower the oxygen content. The first step in feedwater treatment is to heat the water to drive off the oxygen. Typically a boiler feedtank should be operated at 85°C to 90°C. This leaves an oxygen content of around 2 mg / litre (ppm). Operation at higher temperatures than this at atmospheric pressure can be difficult due to the close proximity of saturation temperature and the probability of cavitation in the feedpump, unless the feedtank is installed at a very high level above the boiler feedpump. The addition of an oxygen scavenging chemical (sodium sulphite, hydrazine or tannin) will remove the remaining oxygen and prevent corrosion. This is the normal treatment for industrial boiler plant in the UK. However, plants exist which,
  51. 51. Coal Circuit Coal Storage Hopper Magnetic Separator Impact Crusher-1,2Vibration Screen-1,2 Bunker-1,2Coal Feeder-1 to 12Coal Feeder Line with PA-1 to 24 Furnace
  52. 52. In RNPL there are two types of coal Indian Imported Indian coal Indian coal comes from the mines of Nagpur, Chandrapur . It gives low calorific value compared to the second one. It absorbs low moisture so we can use it in monsoon also. It has approximately 5000 GCV per ton. It’s market price is nearly about 2700 Rs. Per ton. Imported coal Imported coal comes from mines of China, Australia and Indonesia. But this coal is used rapidly, because it gets the moisture from the atmosphere and burns. In addition to that this type of coal absorbed moisture more than the first one. So this types of coal not much prefer in monsoon. It’s approximately 6400 GCV per ton. It’s market price is about 3200 Rs. Per ton. In RNPL they use 400 tones daily.According to the requirement they use ratio of both coals like 50:50, 70:30 etc of Indian and imported.
  54. 54. BOILER FURNECE COAL STEAM STEAM CAPACITY TEMPH. BUNKARSl. Description CAPACITY Pressure TEMP.No. Item/Section (Kg/Cm2) (oC) 1 Multi-fuel Boiler(AP-2) 84 470oC 90 450 T 2 Multi-fuel Boiler(CE-4) 84 470oC 107 550 600 T 3 Oil fired Boiler(OK-8) 60
  55. 55. DRUM LEVEL (LOW) DRUM LEVEL (HIGH)40 % ------------- ALARM 70 % ------------- ALARM30 % ----------------- TRIP 80 % -------------- TRIP PA DEMPER FD DEMPER SA DEMPER OVER FEEDING ROTARY FEEDER SCREW FEEDER
  56. 56. Ash Circuit Furnace Flue Gas + Ash ESP Ash + Comp. Air SILO Ash + Water Creek
  57. 57. Air Circuit Atm. Air Force Draft Air Pre heaterPrimary Air Tank Coal Fluidising air + PA Furnace
  58. 58. Gas Circuit Furnace Bed Super HeaterSuper Heater (Primary & Secondary) Bank Tubes Economizer Air Pre Heater ESP-1,2,3Chimney (Through I.D. Fan)
  59. 59. Feed water CircuitCondensate Storage TankDeaerator Feed pump Boiler Feed pump EconomizerMain Drum (water + steam) Boiler Banks Mud Drum (water) Lower Header Water Tubes Upper Header
  60. 60. Steam Circuit To Process To DeaeratorBoiler Main Drum 4 kg/cm2 PrimarySuper heater De - Super heater 11 kg/cm2 SecondarySuper Heater De – Super To Siemens Heater 35 kg/cm2 Turbine Secondary Bed Super Fine Screen Heater To AEGMain Steam 84 kg/cm2 Turbine Line
  61. 61. Cooling Water Circuit River (Tapi) Pump No. 1, 2, 3 W T P Pump 1, 2, 3, 4 Water Storage Tank Make up WaterCooling Water Storage Chemical Dosing Pump -1, 2, 3 Condenser Cooling Tower
  62. 62. KW 23000 PF 0.8FREQUENCY 50 RPM 1500 VOLTS 11000 AMPS 1509 VOLTS 175 AMPS 489 COOLING CACW