The presentation throws light on the AFBC boilers about the problems faced in the AFBC boilers, the fluidised bed problems and fuel partical sizing with the more overlooked air ingress losses.
This document discusses various operational aspects and emergencies that can occur in an atmospheric fluidized bed combustion (AFBC) boiler. It outlines important parameters to monitor such as bed height, air pressures, temperatures, and fuel sizes. It then describes several emergency conditions that can happen including low or high drum levels, high furnace pressure, high or low bed/furnace temperatures, tube failures, and flame failures. For each condition, it discusses potential causes, effects on the boiler, and recommended actions to address the problem.
The slides describe the factors that affect the performance of AFBC boilers and how to improve the performance of AFBC boilers. These type of boilers are mainly used in the below 100 MW power boilers.
Thermax Limited is an Indian company established in 1966 that provides sustainable energy and environmental solutions. It offers integrated solutions for heating, cooling, power, water, and air pollution control. The document focuses on Thermax's internally circulating fluidized bed circulating boiler (IR-CFBC) technology. The IR-CFBC uses a unique two-stage particle separation system and U-beam impact separators to efficiently separate solids from flue gas. This compact design results in lower maintenance costs compared to conventional circulating fluidized bed boilers. The IR-CFBC also has advantages like high combustion efficiency, low emissions, and improved performance during variable and low loads.
The presentation is for the engineers of HIRA POWER PLANT,. The complete calculations for calculation of boiler efficiency are described in the presentation
The presentation details about the Boiler Operation specifically while lightup of boiler and loading of boiler. the course participants discuss in details about the operations carried in their respective power stations
The Presentation discusses the Air-Heater Performance Indices and the Boiler Performance calculation. One can Calculate the air ingress in the air-heater and the boiler and losses incurred thereby. The presentation also describes in details about the boiler efficiency and its calculation.
MS Lines, Turbine Casings and rotors and other steam lines including Steam Stop Valves, MSV, CV, ESV heating, Turbine Rolling, Flange and Stud heating, Turbovisory and speeding the turbine to 3000 RPM.
This document discusses various operational aspects and emergencies that can occur in an atmospheric fluidized bed combustion (AFBC) boiler. It outlines important parameters to monitor such as bed height, air pressures, temperatures, and fuel sizes. It then describes several emergency conditions that can happen including low or high drum levels, high furnace pressure, high or low bed/furnace temperatures, tube failures, and flame failures. For each condition, it discusses potential causes, effects on the boiler, and recommended actions to address the problem.
The slides describe the factors that affect the performance of AFBC boilers and how to improve the performance of AFBC boilers. These type of boilers are mainly used in the below 100 MW power boilers.
Thermax Limited is an Indian company established in 1966 that provides sustainable energy and environmental solutions. It offers integrated solutions for heating, cooling, power, water, and air pollution control. The document focuses on Thermax's internally circulating fluidized bed circulating boiler (IR-CFBC) technology. The IR-CFBC uses a unique two-stage particle separation system and U-beam impact separators to efficiently separate solids from flue gas. This compact design results in lower maintenance costs compared to conventional circulating fluidized bed boilers. The IR-CFBC also has advantages like high combustion efficiency, low emissions, and improved performance during variable and low loads.
The presentation is for the engineers of HIRA POWER PLANT,. The complete calculations for calculation of boiler efficiency are described in the presentation
The presentation details about the Boiler Operation specifically while lightup of boiler and loading of boiler. the course participants discuss in details about the operations carried in their respective power stations
The Presentation discusses the Air-Heater Performance Indices and the Boiler Performance calculation. One can Calculate the air ingress in the air-heater and the boiler and losses incurred thereby. The presentation also describes in details about the boiler efficiency and its calculation.
MS Lines, Turbine Casings and rotors and other steam lines including Steam Stop Valves, MSV, CV, ESV heating, Turbine Rolling, Flange and Stud heating, Turbovisory and speeding the turbine to 3000 RPM.
The document discusses the turbine protection system of a thermal power plant. It describes 13 different turbine trip conditions such as low lube oil pressure, high drum level, low main steam temperature, high exhaust steam temperature, fire protection operation, axial shift limits, low vacuum, high hydrogen cooler temperatures, high exciter air temperatures, liquid in bushings, master fuel trip, generator faults, and emergency trip from control room. It provides details on the logic, sensors, and mechanisms for each protection system to safely trip the turbine during abnormal operating conditions.
The presentation deals with the most complex and fundamental process in a CFBC boiler. i.e., Combustion. Provides an insight into the various features in a CFBC boilers which are incorporated to enhance cpmbustion.
The document discusses traditional pulverized fuel firing systems and circulating fluidized bed combustion (CFBC) boilers. It provides details on the principles and types of CFBC boilers, as well as their advantages over traditional systems, including greater fuel flexibility, lower emissions, and easier desulfurization. CFBC boilers allow for in-furnace reduction of NOx and SOx through low-temperature combustion and the addition of limestone, providing an inherently more environmentally friendly combustion system compared to pulverized fuel firing.
Fireball Formation and Combustion of Coal in a BoilerZalak Shah
The document discusses coal combustion in boilers and fireball formation. It describes the combustion process and reactions, factors that influence combustion efficiency like excess air and temperature. Pulverized coal is used to increase surface area and combustion efficiency. A fireball forms when pulverized coal and air are mixed and ignited in the boiler furnace. Controls and optimization techniques help maintain combustion efficiency and reduce harmful emissions like NOx.
1. The document discusses various boiler emergency situations during operation with an emphasis on safety aspects like boiler protection systems and controls. It provides descriptions of potential causes, effects, and recommended actions for issues like low or high drum level, high furnace draft, flame failure, boiler feed pump failure, high boiler pressure, furnace explosion, tube failures, coal feeder or burner trips, and more. The goal is to safely manage emergencies and prevent damage to the boiler.
Fireball configuration in coal fired boilers can be wall-fired, tangentially fired (corner-fired), or roof-fired depending on the location of the burners. Tangentially fired furnaces have burners located in the corners which allows for self-stabilizing flames and staged combustion. Wall-fired furnaces have burners located on the furnace walls and allow for stable flames from individual swirl burners. Recent improvements to firing systems using jet burners have demonstrated better temperature control and flexibility in fuel use without spray attemperation.
The document discusses points related to sub critical and super critical boiler design, including boiler design parameters, chemical treatment systems, operation, feedwater systems, boiler control, and startup curves. It provides explanations of sub critical and super critical boiler technologies, comparing drum type sub critical boilers to drumless super critical boilers. Key differences in operation and response to load changes are highlighted.
This document provides guidance on diagnosing poor condenser vacuum in thermal power plants. It explains that a slight increase in condenser pressure can result in significant energy losses. It describes the key components and function of a surface condenser, and explains how lower condenser pressure allows more steam turbine exhaust energy to be converted. Diagnosing the root cause of higher pressure involves comparing to expected design pressures and evaluating potential issues like low cooling water flow, tube fouling, incondensable gases in the condenser shell, or excessive heat duty. Definitions of relevant temperature terms are also provided.
The document provides information on protection and interlocks in modern power plants. It discusses various boiler safety protections that detect abnormal conditions like high or low drum level, high steam pressure or temperature. It also describes interlocks that isolate faulty equipment to prevent damage and switch on backup equipment. Specific causes, effects and actions are outlined for issues like drum level high/low, flame failure, boiler feed pump failure, and loss of fans. The protections and interlocks are designed to trip the boiler or isolate equipment in emergencies to maintain continuous and reliable plant operation.
This document discusses three case studies related to circulating fluidized bed combustion (CFBC) boilers:
1) A case study of a CFBC boiler co-firing rice husk and coal that developed cracks in the cyclone outlet cone.
2) The importance of loop seal air nozzle arrangement in transferring ash particles between the cyclone and furnace and preventing gas bypass.
3) A case study of frequent failures of panel superheater tubes in a CFBC boiler due to insufficient anchoring of refractory bricks and erosion of tubes from the bottom. Modifications to the anchoring arrangement and use of a phosphate-bonded refractory were recommended.
This document provides information about boilers, including:
1. It defines what constitutes a boiler according to Indian law and defines related terms like boiler components and steam pipes.
2. It describes the basic systems that make up a boiler system, including the water treatment, fuel supply, air supply, and flue gas systems.
3. It lists different types of fuels that can be used in boilers and describes the main types of boilers, including fire tube, water tube, packaged, stoker fired, pulverized fuel, waste heat, and fluidized bed boilers.
Improve plant heat rate with feedwater heater controlHossam Zein
This document discusses improving thermal efficiency in power plants by optimizing feedwater heater performance and control. It contains the following key points:
1. Small deviations in heat rate can have large impacts on annual fuel costs, so precise control of feedwater heater levels is important for efficiency. Poor level control leads to heat losses.
2. Feedwater heaters use extraction steam to preheat feedwater and improve boiler efficiency. Accurate level control ensures optimal heat transfer. Instrument errors can degrade performance.
3. Two case studies show how unreliable level controls increased annual fuel costs by $243,000 in one plant and led to excessive heater bypasses in another. Updating controls provided paybacks of 1
The document provides information on the commissioning process for a boiler. It involves several key steps: air leakage and hydro testing, ensuring boiler auxiliaries are ready, gas distribution testing, light up of the boiler, alkali boil-out and passivation to clean the boiler, steam blowing of piping, safety valve testing, and finally coal firing. The commissioning aims to make the boiler and its systems available for safe, smooth, and reliable operation after erection is completed.
The document discusses different types of boilers, including fire tube and water tube boilers. It also describes the basic model of ignition and flame propagation in boilers. Key points covered include the conditions needed to form a stable flame during coal combustion, and the processes of nucleate/convective boiling and film boiling that occur as heat is transferred to water in boiler walls. Departure from nucleate boiling is explained, along with how it can be avoided by increasing pressure, fluid flow rate, or using a lower temperature bulk fluid.
Heat rate is the pulse rate of a power plant to know the health of the plant.
Net heat rate is the single parameter that encompasses total performance indices of a power plant.
The document discusses boiler circulation systems and boiling phenomena. It covers:
1) Sub-critical and super-critical boiler systems and different circulation methods like natural, forced, and assisted circulation.
2) Features of boiling like nucleate boiling, critical heat flux, film boiling, and departure from nucleate boiling (DNB).
3) Special features of once-through supercritical boilers including their start-up system using a boiler circulation pump (BCP) to maintain minimum flow during low load conditions.
This document provides an overview of boiler fundamentals and best practices. It discusses steam production and uses, steam purity and quality, types of boilers including fire tube, water tube and waste heat boilers. It also covers basic boiler principles, calculations, and internal water treatment programs. Effective internal water treatment is needed to control deposition, corrosion and carryover in boilers. Common treatment programs use polymers and phosphates to precipitate hardness and control sludge through crystal modification and dispersion.
Cement industry : grinding process of ball millPankaj Verma
this is the presrntation which i made when i was in traning in ultratech cement hirmi , i got project on studying the process and operations of grinding process of ball mill in the cement industry , after the clincker formation.
The document discusses fluidized bed combustion boilers. It describes the introduction and history of FBC boilers, their mechanism and characteristics, types including atmospheric fluidized bed combustion, circulating fluidized bed combustion, and pressurized fluidized bed combustion. It provides details on the components of FBC boilers like fuel and air distribution systems, heat transfer surfaces, and ash handling. It compares the advantages of FBC boilers to conventional boilers such as higher efficiency, fuel flexibility, lower emissions, and easier ash removal. The only disadvantage mentioned is the higher power requirement for the forced draft fan.
The document discusses the turbine protection system of a thermal power plant. It describes 13 different turbine trip conditions such as low lube oil pressure, high drum level, low main steam temperature, high exhaust steam temperature, fire protection operation, axial shift limits, low vacuum, high hydrogen cooler temperatures, high exciter air temperatures, liquid in bushings, master fuel trip, generator faults, and emergency trip from control room. It provides details on the logic, sensors, and mechanisms for each protection system to safely trip the turbine during abnormal operating conditions.
The presentation deals with the most complex and fundamental process in a CFBC boiler. i.e., Combustion. Provides an insight into the various features in a CFBC boilers which are incorporated to enhance cpmbustion.
The document discusses traditional pulverized fuel firing systems and circulating fluidized bed combustion (CFBC) boilers. It provides details on the principles and types of CFBC boilers, as well as their advantages over traditional systems, including greater fuel flexibility, lower emissions, and easier desulfurization. CFBC boilers allow for in-furnace reduction of NOx and SOx through low-temperature combustion and the addition of limestone, providing an inherently more environmentally friendly combustion system compared to pulverized fuel firing.
Fireball Formation and Combustion of Coal in a BoilerZalak Shah
The document discusses coal combustion in boilers and fireball formation. It describes the combustion process and reactions, factors that influence combustion efficiency like excess air and temperature. Pulverized coal is used to increase surface area and combustion efficiency. A fireball forms when pulverized coal and air are mixed and ignited in the boiler furnace. Controls and optimization techniques help maintain combustion efficiency and reduce harmful emissions like NOx.
1. The document discusses various boiler emergency situations during operation with an emphasis on safety aspects like boiler protection systems and controls. It provides descriptions of potential causes, effects, and recommended actions for issues like low or high drum level, high furnace draft, flame failure, boiler feed pump failure, high boiler pressure, furnace explosion, tube failures, coal feeder or burner trips, and more. The goal is to safely manage emergencies and prevent damage to the boiler.
Fireball configuration in coal fired boilers can be wall-fired, tangentially fired (corner-fired), or roof-fired depending on the location of the burners. Tangentially fired furnaces have burners located in the corners which allows for self-stabilizing flames and staged combustion. Wall-fired furnaces have burners located on the furnace walls and allow for stable flames from individual swirl burners. Recent improvements to firing systems using jet burners have demonstrated better temperature control and flexibility in fuel use without spray attemperation.
The document discusses points related to sub critical and super critical boiler design, including boiler design parameters, chemical treatment systems, operation, feedwater systems, boiler control, and startup curves. It provides explanations of sub critical and super critical boiler technologies, comparing drum type sub critical boilers to drumless super critical boilers. Key differences in operation and response to load changes are highlighted.
This document provides guidance on diagnosing poor condenser vacuum in thermal power plants. It explains that a slight increase in condenser pressure can result in significant energy losses. It describes the key components and function of a surface condenser, and explains how lower condenser pressure allows more steam turbine exhaust energy to be converted. Diagnosing the root cause of higher pressure involves comparing to expected design pressures and evaluating potential issues like low cooling water flow, tube fouling, incondensable gases in the condenser shell, or excessive heat duty. Definitions of relevant temperature terms are also provided.
The document provides information on protection and interlocks in modern power plants. It discusses various boiler safety protections that detect abnormal conditions like high or low drum level, high steam pressure or temperature. It also describes interlocks that isolate faulty equipment to prevent damage and switch on backup equipment. Specific causes, effects and actions are outlined for issues like drum level high/low, flame failure, boiler feed pump failure, and loss of fans. The protections and interlocks are designed to trip the boiler or isolate equipment in emergencies to maintain continuous and reliable plant operation.
This document discusses three case studies related to circulating fluidized bed combustion (CFBC) boilers:
1) A case study of a CFBC boiler co-firing rice husk and coal that developed cracks in the cyclone outlet cone.
2) The importance of loop seal air nozzle arrangement in transferring ash particles between the cyclone and furnace and preventing gas bypass.
3) A case study of frequent failures of panel superheater tubes in a CFBC boiler due to insufficient anchoring of refractory bricks and erosion of tubes from the bottom. Modifications to the anchoring arrangement and use of a phosphate-bonded refractory were recommended.
This document provides information about boilers, including:
1. It defines what constitutes a boiler according to Indian law and defines related terms like boiler components and steam pipes.
2. It describes the basic systems that make up a boiler system, including the water treatment, fuel supply, air supply, and flue gas systems.
3. It lists different types of fuels that can be used in boilers and describes the main types of boilers, including fire tube, water tube, packaged, stoker fired, pulverized fuel, waste heat, and fluidized bed boilers.
Improve plant heat rate with feedwater heater controlHossam Zein
This document discusses improving thermal efficiency in power plants by optimizing feedwater heater performance and control. It contains the following key points:
1. Small deviations in heat rate can have large impacts on annual fuel costs, so precise control of feedwater heater levels is important for efficiency. Poor level control leads to heat losses.
2. Feedwater heaters use extraction steam to preheat feedwater and improve boiler efficiency. Accurate level control ensures optimal heat transfer. Instrument errors can degrade performance.
3. Two case studies show how unreliable level controls increased annual fuel costs by $243,000 in one plant and led to excessive heater bypasses in another. Updating controls provided paybacks of 1
The document provides information on the commissioning process for a boiler. It involves several key steps: air leakage and hydro testing, ensuring boiler auxiliaries are ready, gas distribution testing, light up of the boiler, alkali boil-out and passivation to clean the boiler, steam blowing of piping, safety valve testing, and finally coal firing. The commissioning aims to make the boiler and its systems available for safe, smooth, and reliable operation after erection is completed.
The document discusses different types of boilers, including fire tube and water tube boilers. It also describes the basic model of ignition and flame propagation in boilers. Key points covered include the conditions needed to form a stable flame during coal combustion, and the processes of nucleate/convective boiling and film boiling that occur as heat is transferred to water in boiler walls. Departure from nucleate boiling is explained, along with how it can be avoided by increasing pressure, fluid flow rate, or using a lower temperature bulk fluid.
Heat rate is the pulse rate of a power plant to know the health of the plant.
Net heat rate is the single parameter that encompasses total performance indices of a power plant.
The document discusses boiler circulation systems and boiling phenomena. It covers:
1) Sub-critical and super-critical boiler systems and different circulation methods like natural, forced, and assisted circulation.
2) Features of boiling like nucleate boiling, critical heat flux, film boiling, and departure from nucleate boiling (DNB).
3) Special features of once-through supercritical boilers including their start-up system using a boiler circulation pump (BCP) to maintain minimum flow during low load conditions.
This document provides an overview of boiler fundamentals and best practices. It discusses steam production and uses, steam purity and quality, types of boilers including fire tube, water tube and waste heat boilers. It also covers basic boiler principles, calculations, and internal water treatment programs. Effective internal water treatment is needed to control deposition, corrosion and carryover in boilers. Common treatment programs use polymers and phosphates to precipitate hardness and control sludge through crystal modification and dispersion.
Cement industry : grinding process of ball millPankaj Verma
this is the presrntation which i made when i was in traning in ultratech cement hirmi , i got project on studying the process and operations of grinding process of ball mill in the cement industry , after the clincker formation.
The document discusses fluidized bed combustion boilers. It describes the introduction and history of FBC boilers, their mechanism and characteristics, types including atmospheric fluidized bed combustion, circulating fluidized bed combustion, and pressurized fluidized bed combustion. It provides details on the components of FBC boilers like fuel and air distribution systems, heat transfer surfaces, and ash handling. It compares the advantages of FBC boilers to conventional boilers such as higher efficiency, fuel flexibility, lower emissions, and easier ash removal. The only disadvantage mentioned is the higher power requirement for the forced draft fan.
Clay is a key ingredient in making structural clay products like bricks. It consists mainly of kaolinite along with other minerals. Good brick earth contains 20-30% alumina, 50-60% silica, and small amounts of lime, iron oxide, and magnesia. Harmful ingredients to avoid include alkalis, limestone, iron pyrites, pebbles, and organic matter. Bricks are manufactured by preparing the earth, moulding, drying, and burning in kilns. Common brick bonds used in construction include stretcher bond, header bond, English bond, and Flemish bond.
This document discusses the process of manufacturing bricks. It begins by describing the composition of bricks, noting that good bricks should contain 20-30% alumina, 50-60% silica, and small amounts of lime, iron oxide, and magnesia. The document then outlines the key steps in brick manufacturing: preparation of clay, moulding, drying, and burning. For moulding, it describes hand and machine methods, and for burning it explains the three stages of dehydration, oxidation, and vitrification. The document provides details on each stage of the manufacturing process.
This document discusses the process of manufacturing bricks. It begins by describing the composition of bricks, noting that good bricks should contain 20-30% alumina, 50-60% silica, and small amounts of lime, iron oxide, and magnesia. The document then outlines the key steps in brick manufacturing: preparation of clay, moulding, drying, and burning. Moulding can be done by hand or machine, drying takes 3-10 days, and burning involves dehydration, oxidation and vitrification to harden the bricks. Proper composition and manufacturing process are necessary to produce durable bricks of consistent quality.
This document discusses various agricultural and industrial wastes that can be used as construction materials. It provides details on sugarcane bagasse, rice husk, straw bale, coir fiber, fly ash, blast furnace slag, red mud, marble powder waste, newspaper wood, nappy roofing, recycled plastic bottles and blood bricks. For each material, it describes how it is produced as a waste, its composition, and advantages of using it in construction such as cost-effectiveness, sustainability and improved mechanical properties of construction elements.
Brick - " GOOD for construction but BAD for environment "Mohit Metlaw
Building material, BRICKS as per is codes. it basically covers all the aspects of brick right from manufacturing to finishing and stats to improvement can or needed to be done.
This is all u need to go through to understand the concept of bricks. 2k17
Pelletization of iron ores and the type of wear liners used in thier eqipmentsGulshan Kumar Singh
Now a days about 60% of iron ore converted to fines during mining, handling and transporting so pellet is a process of utilizing iron ore fines up to size of 0.15 microns. i investigate its process,equipment used in process, wear and other problems in them and its future scope
This document discusses fluidized bed combustion boilers. It begins with an introduction that fluidized bed combustion has emerged as a viable alternative to traditional grate firing systems for low quality coal in India. It provides a brief history of the development of fluidized bed combustion. It then describes the three main types of fluidized bed combustion boilers and the basic mechanism of how fluidized bed combustion works. The document proceeds to describe the key components of a circulating fluidized bed combustion system and provides maintenance tips for inspecting and maintaining a CFB boiler.
1. The document describes the key components and processes involved in a cement production plant, including limestone quarrying, crushing, raw material storage and blending, preheating, clinkering in a kiln, cooling of clinker, and cement milling and storage.
2. The major stages involve quarrying limestone, crushing it, blending with additives, preheating the raw materials mixture in a preheater, calcining in a rotary kiln to produce clinker, cooling the clinker, grinding it into cement with gypsum in a cement mill, and storing the finished cement product.
3. Key components described include the limestone quarry, raw material storage and blending silos, pre
The document discusses fluidized bed combustion (FBC) boilers. It describes the key advantages of FBC boilers like their ability to efficiently burn low quality coal and reduce emissions. It explains the basic mechanisms of fluidization and combustion. There are three main types of FBC boilers - atmospheric fluidized bed combustion, circulating fluidized bed combustion, and pressurized fluidized bed combustion. The document provides details on the design and operating principles of atmospheric fluidized bed combustion boilers.
This document discusses various agricultural and industrial wastes that can be used as construction materials. It describes sugarcane bagasse, rice husk, straw bale, and coir fiber - agricultural wastes that have applications in construction. It also discusses industrial wastes like fly ash from thermal power plants and blast furnace slag from steel plants that can replace materials like cement and sand in concrete production. The use of these agricultural and industrial waste materials in construction provides environmental benefits and more cost-effective building solutions.
- The coating on refractory bricks in the burning zone was washed away due to high variation in clinker chemistry when switching between cement types, exposing the bricks to damage. The formation of a distorted flame also eroded coatings and bricks.
- Refractory bricks experienced severe thermal and chemical stresses due to variation in clinker chemistry and the use of petcoke, which increases liquid viscosity and damages bricks. Cracks in bricks showed they were under mechanical stress from shell distortion.
- Installation errors like non-perpendicular brick rings led to gaps that formed hot spots, shortening refractory life. Proper installation is needed to avoid subjecting bricks to unnecessary mechanical stresses.
Loesche Mills for Cement and Granulated Blast Furnace SlagLOESCHE
Grinding of cement clinker and granulated blast furnace slag in roller grinding mills (vertical airswept grinding mills) is a technology introduced by Loesche. The first use of a Loesche mill, with a grinding track diameter of only 1.1 meters, was used as log ago as 1935. However, the breakthrough in grinding this type of material on the vertical roller mill did not take place until the beginning of the 1990s.
Information soil bricks/Best Brick Production MethodsBricks Machines
Manufacture of bricks is generally a good business. a successful brick manufacturing business has three main items:1. the correct type of clay soil should be available in quantities required .2. a good production factory consisting of good quality robust machinery and an energy efficient drying and firing process. 3- a good market for the products. besides the above sound technical and managerial ability to manage the production process is essential. after sales support for the machinery is another asset .*QUALITY IS A TRADITION AT HAMGAM SANAT*.
Lime is an important cementing material used in construction. It is classified as quicklime, hydrated lime, and hydraulic lime based on its composition and properties. Quicklime has a high calcium oxide content and must be slaked before use. Hydrated lime is pre-slaked at the manufacturing stage. Hydraulic lime contains clay, which gives it adhesive properties even under water. Lime is manufactured by burning limestone in kilns or temporary clamps. The properties and tests of lime determine its suitability for building applications.
Lime is an important cementing material used in construction. It is classified as quicklime, hydrated lime, and hydraulic lime based on its composition and properties. Quicklime has a high calcium oxide content and must be slaked before use. Hydrated lime is pre-slaked at the manufacturing stage. Hydraulic lime contains clay, which gives it the ability to set under water. Lime is manufactured by burning limestone in kilns or temporary clamps. The properties and tests of lime determine its suitability for use in buildings.
The document discusses the sintering process used at the Rourkela Steel Plant in India. It describes how iron ore fines, limestone, dolomite and other raw materials are blended and formed into nodules. These nodules are then processed through a sintering machine, where combustion of coke forms sintered agglomerates. The sinter is cooled, crushed, and screened before use as a raw material input for blast furnaces. Key aspects of the sinter plant like the mixer, nodulizer, sinter machine, cooler and screens are explained. Parameters that affect sintering quality like raw material chemistry and size, moisture content, and suction pressure are also summarized.
The presentation is based on the discussions of starting operations of a coal based thermal power plant. This presentation is based on the in-house training to the operation engineers of the thermal power plant. It describes the activity chart for the starting of boiler, Turbine and synchronising of Generator, picking up the load etc.
This is a presentation series part 3 on Frequently Asked Questions on Steam Turbines in large steam power plants. All questions are answered properly and any doubt may be mailed to the writer.
Green building concepts and good building practicesManohar Tatwawadi
The power sector must adopt the green building concepts and go for good building practices. In fact all industries need to go for the same. The same practices can also be adopted in all commercial as well as residential buildings.
Auxiliary Consumption and Saving due to Increase in Boiler EfficiencyManohar Tatwawadi
Discussions on Auxiliary consumption in a 4 X 210 MW TPS, the common systems and individual unitwise Auxiliary consumption has been briefed in the presentation. Also savings in various aspects due to increase in Boiler Efficiency are also discussed in the presentation.
COMPRESSED AIR SYSTEM . ENERGY CONSERVATION OPPORTUNITIESManohar Tatwawadi
The presentation gives an idea as to how the compressed air system is designed and the performance of the compressed air system. The losses, conservation of energy, the cost of leakages etc are discussed in the presentation
This document contains frequently asked questions and answers about steam turbines. It discusses issues like speed variation, vibration, deposits, erosion, washing, compounding, and monitoring. Questions cover topics such as reducing speed variation through governor adjustments, the effects of deposits on efficiency, solid particle erosion, monitoring internal efficiency, and reducing vibration damage through blade design modifications. Causes and remedies of issues like governor lubrication problems, safety trip valve trips, and foreign particle damage are also addressed.
- A stage in an impulse turbine consists of moving blades behind a nozzle, while in a reaction turbine each row of blades is a stage.
- Diaphragms hold the nozzles and seals between turbine stages. Tip leakage is a problem in reaction turbines where steam escapes across moving blade tips.
- Thrust bearings maintain the rotor's axial position, while radial bearings support the rotor at each end of the steam cylinder and must be accurately aligned.
- Deposits in a turbine can be detected through pressure monitoring, efficiency monitoring, and exhaust steam temperature monitoring. Deposits are removed through washing with condensate or wet steam for water soluble deposits and mechanically after dismantling for water insoluble
The presentation gives a basic idea of cooling towers in big industries including the Power Plants. The performance of cooling towers and the commonenly used terms with reference to the cooling towers are also discussed at length. Care to be taken while in freezing temperatures in the European countries is also discussed.
The presentation is based on the discussions about the safety in Power Plants and substations. The presentation is a part of the seminar on Electrical safety and reliability. The reporting of accidents was also discussed at length in the seminar
Cost accounting, cost control and cost reduction in TPSManohar Tatwawadi
The subject matter discuss in details about the cost accounting being practiced in a thermal power station for calculating the actual cost of generation of electricity. The cost centres and the cost affecting factors alongwith steps to reduce the cost of generation are described in the presentation. The PPMS system adopted can be further be well designed by any power plant engineer.
Environmental and pollution control in Thermal Power StationsManohar Tatwawadi
The presentation gives the basic idea as to the environment, pollutions and laws, the governing bodies and the limits of the emmissions. Also specifically about the solid waste, liquid waste and the gas emmissions from the Thermal Power Plants.
Energy Audit & Energy Conservation Opportunities in Electrical Equipments ...Manohar Tatwawadi
The discussion is for the Energy Conservation drive in the thermal power plants in the Auxilliary Consumption of the Electrical Auxilliaries in the Plant and thereby identify the steps to be taken for the reduction in Auxilliary Consumption
The presentation details the process of combustion in a 500 MW Coal based Thermal Power Plant where the main fuel is Pulverised coal. It details about the combustion of coal partical in the furnace and also the combustion equations related to the process, the excess air that is supplied.
The presentation gives an idea about the primary requirements for the establishment of a coal based THERMAL POWER STATION. The estimates are quite fair.
The discussion on "Handling of Turbines During Emergencies" has been detailed in the ppt. Some case studies are also discussed in the session where the course participants express their difficulties while coming across the emergencies in handling the turbines at their locations.
Effect of Coal Quality and Performance of Coal pulverisers / MillsManohar Tatwawadi
The presentation discusses about the change in performance parameters of a pulveriser due to change in coal quality and the measurement of performance and troubleshooting of coal firing system as a whole.
The Presentation describes the basics about the Efficiency and performance of a steam based power plant. It also describes how the heat rate of the power plant is important from the point of view of fuel savings.
ENERGY AUDIT METHODOLOGY FOR TURBINE CYCLE IN A POWER PLANTManohar Tatwawadi
This document outlines the methodology for conducting an energy audit of a turbine cycle. It discusses collecting operational data on the steam turbine and associated equipment. Key measurements of steam and water parameters throughout the cycle are described. The document explains evaluating the turbine's heat rate and efficiency using enthalpy calculations. Factors that could impact the heat rate such as equipment performance, operating conditions and maintenance issues are identified. Methods to analyze the performance of feedwater heaters and determine deviations are also provided.
This document describes the thermal power cycle of a steam turbine power plant. It includes diagrams of the boiler, turbines, condenser and other components. It discusses the efficiencies of the boiler (86.5%), high pressure turbine (81.11%), intermediate pressure turbine (89.83%) and low pressure turbine (85%). It states that the overall steam cycle efficiency is 40%, with 60% of heat being removed by the condenser. Losses at each stage are also outlined.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
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2. WHAT IS FLUIDISED BED?
When air or gas is passed through an inert bed of
solid particles such as sand supported on a
perforated plate, the air, initially, will seek a path
of least resistance and pass upward through the
sand.
With further increase in the velocity, the air starts
bubbling through the bed and the particles attain
a state of high turbulence. Under such conditions,
the bed assumes the appearance of a fluid and
exhibits the properties associated with a fluid and
hence the name 'Fluidised Bed'.
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3. MECHANISM OF FLUIDISED BED
COMBUSTION
If the sand, in a fluidised state, is heated to
the ignition temperature of the fuel and the
fuel is injected continuously into the bed, the
fuel will burn rapidly and the bed attains a
uniform temperature due to effective mixing.
This, in short, is fluidised bed combustion.
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4. MECHANISM OF FLUIDISED BED
COMBUSTION….
While it is essential that temperature of bed
should be at least equal to ignition
temperature of fuel and it should never be
allowed to approach ash fusion temperature
(1050°C to 1150°C) to avoid melting of ash.
This is achieved by extracting heat from the
bed by through evaporator tubes immersed in
the bed.
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5. MECHANISM OF FLUIDISED BED
COMBUSTION….
If gas velocity is too low, fluidisation will not
occur, and if the gas velocity becomes too
high, the particles will be entrained in the gas
stream and lost. Hence, to sustain stable
operation of the bed, it must be ensured that
gas velocity is maintained between minimum
fluidisation velocity and particle entrainment
velocity.
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6. THE BED
We are supposed to operate in regime of Bubbling Bed. But invariably we may land in
regime of Turbulent Bed, where even coarser particles are seen getting out of the bed.
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7. THE BED MATERIAL
In a fluidized bed combustion system, the fuel
/ bed material is a source of the particles.
In the case of coal, the burning particles & and
the burnt particles are the main contributors
which decide the fluidization behaviour in the
bed.
The bed material which is used for start up of
a bed may be particles which have been
sieved from the ash obtained from Fluid bed
combustor or it is generally sieved river sand /
sieved crushed refractory bricks...
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8. SAND AS BED MATERIAL
• When sand is used as bed material, particles
less than 1.5 mm should be used. These
particles are generally round in shape. When
the sand particle happens to be on the higher
size, we can notice that the sand is sharp in
nature. Such sand particles are found to be
erosive when the bed is not properly fluidized.
It is not necessary to remove the finer portion
of sand. The sand size range of 0-1.5 mm gets
the best combustion of fuels in many
installations. Sand is practically a crystallized
material and does not have pores.
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9. Bed Material
CRUSHED REFRACTORY
The refractory bricks are made from recycled bricks & fresh
refractory clay. The old refractory bricks dismantled from ore
melting furnaces and many other refractory furnaces are
crushed to minus 3mm as part of raw material preparation in
refractory manufacturing industry. The refractory grog
prepared in this way is screened in 20 & 8 mesh and the
material that is lying in between is used as bed material for
FBC.
This bed material is found to be less erosive. As the density of
this material is lesser as compared to sand. The size range is
2.35 to 0.85 mm (corresponding to mesh numbers 20 & 8).
Higher size has been permitted here as the particle density is
lower due to presence of pores.
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10. FUEL SIZING…COAL
• Even if the sand / refractory bed material
conforms to required size range, over a period
of FBC operation, the entire particles are going
to be replaced with the ash particles
generated from fuel.
• Thus the fuel sizing is very critical for trouble
free FBC operation.
• Ignorance to maintain screen system at coal
handling plant can lead to accumulation of
oversize particles.
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11. FUEL SIZING……. COAL
• Once the over size particles are accumulated,
the bed goes for spouting.
• Even the heavier particles get thrown out of
the bed.
• The loss on ignition would go up if the furnace
residence time is less.
• If the coal is reactive with high volatile matter,
the unburnt in ash may not go high.
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12. FUEL SIZING……COAL
• In the case of under bed firing, the erosion of
bed coils is accelerated due to violent
turbulence at fuel feed points.
• Smaller particles have more surface area to
conduct the heat to bed heat transfer
surfaces.
• Hence the generation would come down as
the FUEL particle size increases.
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13. FUEL SIZE … BIOMASS
• In the case of agro fuels such as rice husk, de-
oiled bran (DOB), ground nut shell the ash
from fuel does not contribute to bed particle
size.
• Whatever the bed material used gradually
disintegrates and the fines go out of bed.
• Regular addition of bed material is required in
order to maintain the bed height.
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14. DE-OILED BRAN FIRED…
• DOB fired boilers experience peculiar problem
of heavier particle generation due to melting
of ash. DOB ash melts and agglomerates to
over the sand / bed material. More sand will
be required to offset the bed particles
becoming heavier.
• In general agro fuels are having lesser density
as compared to bed material and they try to
leave the bed earlier. Using finer material
helps to achieve a good bed expansion and
binds the fuel particles better.08-Aug-19 14total output power solutions
15. HUSK FIRED…..
• Stone ingress in husk fired boilers is well
known among old installations. More drains
had been added in some cases to bring out
the stones. The stone removal by mechanical
screen system is not effective. Only way to get
the best from these combustors is to resort to
frequent draining and recharging screened
bed material. Fine sand is the right option for
husk fired boilers as the disintegration of the
refractory type bed material could increase
the operational cost.08-Aug-19 15total output power solutions
16. DOLACHAR AND COAL FIRED
• Dolachar & coal are fired together in boilers used in
sponge iron industries. The Dolochar contains iron
particles which are heavier. As one can expect the
bed can have segregation of particles to bottom of
bed. In many cases, this is ignored. Once a bed lands
in to segregation of particles, there is no way out in
the case of flat distributor plate designs. Only open
bottom design can pull out the oversize particles
which settle at bottom. Alternately sloped distributor
plate / DP with many drains can help to control the
particle separation. Particles separation when takes
place preferential erosion of bed coils is seen.
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17. DOLACHAR FIRED……
• In these combustors, the generation of bed
ash is also more. We may not find a
requirement to add bed material.
• Except for a fresh start up we may not use iron
free bed material. Bed coils in these boilers
call for early replacement and the availability
of the boiler is greatly disturbed due to
unscheduled shut downs.
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18. DOLACHAR + COAL FIRED
• In under bed feed system, the erosion of bed
coils is localized whereas in overbed the
erosion is not so, provided we keep removing
heavier lot.
• If heavier lot is allowed to accumulate, the
bed coil erosion is of different kind. The coil is
seen eroded in between studs to as in
photograph. There is a gross erosion of bed
coil.
• All these troubles are related to iron
accumulation.08-Aug-19 18total output power solutions
20. DOLACHAR + COAL FIRED
• They solution could be a continuous bed ash
iron removal system. The bed ash must be
cooled and discharged to an automated
magnetic separator system & over size screen
system. The screened bed material should be
recharged to bed through a bed material silo
and feeder system.
• It is advised to resort to continuous bed ash
removal and recharge system.
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21. FLUIDIZATION PROBLEMS FACED
• 90 TPH coal fired AFBC boiler with over bed
feed arrangement.
• Restarting the boiler after a shut down from
cold condition after 5 days shut period.
• The bed material was not changed. Whatever
remained before the shut had been used as
such.
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22. FLUIDIZATION PROBLEMS FACED
• Naturally the bed material size will be right
from fly ash dust to coarser ash.
• If the boiler is provided with over bed start up
burners, the height of the bed material has to
be kept to 600-700 mm in order to cover up
the bed coil.
• The bed plate is designed for a pressure drop
of 300 mm at MCR.
• Therefore Air Nozzles pressure drop required
= 600+300 = 900 mm minimum.08-Aug-19 22total output power solutions
23. AFBC BOLER Fluidisation
• The burner is put on for 3 hrs to raise the
boiler pressure slowly and to promote
circulation in bed coils & other evaporative
circuits.
• In over bed burner start up system, the bed
never gets heated up beyond 150 deg C.
• The airbox pressure was raised to 800 mmWC
and the coal feed was done.
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24. AFBC BOLER Fluidisation
• There were temperature differences between bed
thermocouples even after 12hrs after start up.
• In this situation whatever fluidization which was
observed was clearly a regime of fluidization with
two sets of particle groups.
• To correct the situation simply drain the bed material
from several drain points simultaneously to bring out
the coarser fraction of material at the bottom.
• Use finer bed material. (minus 1.5 mm sand )
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25. BED SLUMPING
• Slumping of the bed is done to meet the
steam demand. It is not correct to keep same
compartment under slumped condition. In the
slumped bed heat transfer to bed coil becomes
less. The circulation of water ceases. This may
result in high pH corrosion / caustic gouging /
settling of iron oxides / corrosion products in
such bed coils, depending on boiler water
chemistry. See figure for appearance of tube
inside on a caustic gouging failure.
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27. AIR INGRACE IN THE BOILER
• Many boiler users are ignorant about the air
ingress in their boilers. In these slides / article,
the detrimental effects of air ingress are
brought out.
• Reality is that some of our fellow boiler users
are carrying losses with air ingress.
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28. WHAT IS AIR INGRESS?
• In balanced draft furnace, the FD fan / SA fan
/ PA fan pump the air in to the furnace. The
flue gas produced is drawn through the boiler
by the ID fan. Hence the furnace and
downstream the furnace the boiler is under
negative pressure. Thus if some leakage spots
are there, the ambient air is drawn through
such openings.
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29. WHY IS THIS AIR INGRESS?
• By virtue of boiler configuration, openings are to be
made in the boiler enclosures / Waterwall enclosure.
If a seal is improperly designed or improperly erected
the seal may fail and develop leakages.
• The seals may not have been erected properly. It is
possible some of the seals are not taking care of
thermal expansion or the service conditions and thus
leakage may develop.
• One step further the repairer has not put back the
seals as per design since he may not have the blue
print of the original design.
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30. EFFECTS OF AIR INGRESS
• 1. High unburnt carbon in fly ash
It is a general practice to trim the air flow based on
O2 indication from flue gas. When the air leakage is
present the O2 indicated by the on-line O2 meter
would mislead the operator. The furnace runs in to
sub-stochiometeric condition. This ultimately leads
to increase in unburnts.
• 2. Increased fuel consumption.
The air ingress downstream the flue path leads to
increased heat loss in the chimney. To compensate
for the heat loss one has to feed more fuel.
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31. EFFECTS OF AIR INGRESS
3. Overloaded ID fan
When we experience that the ID fan is falling short of
capacity, we tend to invest in new ID fan / we start
with fan vendors for increasing the fan capacity. In
many cases the second ID fan is opted with higher
capacity with the assumption that the existing ID fan
is short of capacity. In some cases even the second ID
fan may also prove useless as the leakage persists
and the furnace still goes with positive pressure. The
boiler operating expenses increase due to additional
power consumption.
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32. EFFECTS OF AIR INGRESS
4. Back fire in furnace
The back fire is continuously experienced. The ID
damper is at full open position. The operator has
no option except to continue with the problem.
The unsafe situation persists. The Insulation of
the boiler is spoilt on this account. Soot is seen
around the furnace access doors.
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33. EFFECTS OF AIR INGRESS
5. Secondary combustion in superheater zones
The furnace begins to starve when the air ingress is
more from roof seal box / Convection SH seal box.
The leakage air allows secondary combustion of
volatiles. The SH temperature becomes
uncontrollable. Particularly at the time of load
variation, the fuel feeder rpm is regulated by the
operator and he finds the SH steam temperature
rises faster than the pressure. This is seen in boilers
fired with biomass fuels.
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34. EFFECTS OF AIR INGRESS
6. Secondary combustion in Boiler bank hoppers
The Unburnt fuels burn at the boiler bank ash
hoppers, since the furnace is at
substochiometeric conditions when there is
air ingress is present downstream. The
unburnt fuel travels downstream instead of
completely burning in the furnace. The ash
hoppers get distorted due to secondary
combustion
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35. EFFECTS OF AIR INGRESS
7. Ash blockages in boiler bank Baffles
When the ash is not fully burnt in the furnace, the
flow ability of ash comes down. The ash particles
now contain fuel particles which may be fibrous /
irregular in nature. Thus the fuel and ash settle at
every possible location, where the surfaces are less
inclined or flat. The ash does not flow freely and thus
ash accumulates at baffles. Whatever the draft is set
the ash does not flow due to nature of the
accumulations.
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36. EFFECTS OF AIR INGRESS
8. Ash blockages in Hoppers
Carryover of fuel particles to ash hoppers
would lead to combustion in ash hoppers.
Lumps form due to static combustion. We try
to poke the ash drain pipes but situations
repeat often. The combustion is not complete
at the furnace and hence the troubles.
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37. 9. Shifting of Combustion Zone
The furnace is designed to be hotter as the
combustion is to take place here. The furnace
dimensions are so chosen, to achieve the
necessary residence time for the fuel particle
to burn fully. Starvation occurs when the air
can bypass the furnace and enter the flue gas
downstream.
Under such conditions the combustion zone
shifts to SH section
EFFECT of AIR INGRESS
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38. Excess Superheater Spray
Shifting of Combustion Zone and heat transfer
at SH section leads to excess Steam
temperature.
If excess capacity is available in the spray
control valve, we tend to spray more. More
spray may lead to solids added to SH section.
The solids left behind in SH lead to deposit
related failures.
More the spray the turbine blade deposition is
experienced.
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39. EFFECT of AIR INGRESS
10. Clinkers formation in furnace
The furnace temperatures are controlled by
incorporating necessary heat transfer surface
and by admitting required excess air to cool
down the gas below the ash melting
temperatures. The excess air can not be given
in the furnace when the ID draws the leakage
air downstream. Refractory furnaces get
coated with ash deposits. Honey combing of
ash accumulations is seen in some agro waste
fired boilers. Refractory roof tops eventually
collapse due to increased weight.
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40. AIR INGRESS… Effects
11. High furnace temperatures and refractory
walls cave in
The excess air when not given in the furnace,
the furnace temperature exceeds the design
gas temperatures. When the fuel does not
have much of ash, the furnace temperatures
go up. The refractory walls expand unusually
leading to furnace walls caving in.
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41. Furnace doors failures
12. Furnace doors in balanced draft furnaces
are refractory lined to thickness of not more
than 250 mm. The doors get cooled by the
outside ambient air present around the door.
When the furnace is under +ve pressure the
ambient air is not present near the vicinity of
the doors. Then the doors bulge. The manhole
frame and manhole distort due to heat. We
think the doors fail due to material defect.
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42. Furnace refractory failures
13. The refractory totally collapse often since
they loose strength at higher temperatures.
The High temperatures are experienced when
the excess air is less and the furnace
temperatures go up. The refractory design
would be unstable at higher service
temperatures unless the design is modified for
the new service conditions.
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43. Furnace seal plates run hot
14. Many furnaces, particularly in small
boilers, are provided with casing plates to
prevent air ingress. When the furnace
temperatures are controllable due to
insufficient excess air, the casings run hot.
When the furnace goes positive, the gas
reaches the air gap between the casing plate
and the refractory. The flame / smoke is seen.
Particularly in gas fired boilers the gas burns
inside the casing.
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44. Fly ash nuisance around the boiler
15. The fly ash poses a great nuisance not only
harming the eyes but also lungs. The boiler
house becomes shabby. The industrial
standards go down in front of your customers.
The costs for cleaning the boilers go up.
During maintenance, hours are to be allocated
only for cleaning. The boiler downtime
increases due to this.
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45. PROBABLE AIR INGRACE POINTS
• In the balance draft furnace there are several areas
for ingress. The possible locations include
1. Roof top where SH coils penetrate in
2. Membrane walls where the convection banks
penetrate
3. Roof tubes termination in steam drum
4. Boiler bank tubes termination in side, front, rear
of steam drum
5. Boiler bank tubes termination in side, front, rear
of water drum
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46. Air Ingress Points
6. Between boiler bank hopper and water drum
7. Hopper manholes
8. Hopper isolation gates & flanges
9. Worn out rotary ash feeders
10. Failed fabric expansion joints
11. Corroded metallic expansion joints
12. Incomplete fastened flange joints
13. Improper roped flanged joints
14. Refractory wall cracks
15. Eroded / corroded APH tubes
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47. Air Ingress Points
16. Economiser casing joints
17. Access doors
18. Roof panel to side walls side joints
19. Water drum to bank casing plates
20. Nose panel to Water drum termination
21. Soot blower openings
22. Gas pressure tappings
23. Leaky view holes
24. Boiler bank casing plate joints
And many more……………………..
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48. LOCATING THE AIR INGRESS
• There can be many more possible locations
from where the air leaks in. An easy way in
solid fuel fired boiler is of course the ash
would leak out in locations where the air goes
in. You can always see the fresh ash spillages
around leakage points.
• To locate the leakage points the smoke test is
done.
• Another way is to carryout a flame test with ID
fan running.
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49. CORRECTING THE AIR INGRESS
• Having identified the leak points measures are to be
taken to arrest the leakage. Some leakages are simply
rectified.
• But at some locations, the design may be faulty, for
which one has to call up the designer / consultant for
help.
• The seals may call for better contemporary design.
• The design may need for a review from the boiler
thermal expansion point of view.
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