Coal is transported in thermal power station either by railways,roadways or rope ways. In thermal power plants coal is generally used as fuel and hence the ash is produced as the byproduct of combustion. It includes fly ash fine powdery particles that are carried up the smoke stack and captured by pollution control devices as well as coarser materials that fall to the bottom of the furnace. Ash handling system of a thermal power plant slideshare.
Therefore, the ash can be conveyed by means of a pneumatic conveying system to the final silo figure 7. Ash that falls to the bottom of the boilers combustion chamber commonly called a firebox is called bottom ash. Switchyard is the area, which feed the grid supply to the station transformer and fees the grid by the power generator by the unit. Explaining ash handling systems for biomass to energy boilers. It is nowadays used in cement, concrete and other cement based applications in india. The furnace bottom ash and economizer ash is conveyed to dewatering whereas the flyash is conveyed to storage soils. Switchyard is the area, which feed the grid supply to the station transformer and fees the grid by the power generator by the. In a typical fly ash handling system, the material that is generated as a result of combustion is captured by an electrostatic precipitator esp or a baghouse before the flue gases reach the stack. Thermal power generation, coal consumption and ash generation in india. The ash content of the coal used at the thermal power plants ranges from 3040%, with the average ash content around 38%. All efforts is being made to increase the coc and thus to reduce the blow down from.
Respirable dust may be generated that if inhaled, can cause respiratory system irritation. Two types of cooling systems are used in thermal power plants tpps, i once. Coal handling system coal handling plant in thermal. Coal ash is the waste that is left after coal is combusted burned. The final component of a highquality ash handling system is the ash storage silo.
For mixing of fly ash with water, a tapping is provided for high pressure water below the hopper. These benefits are why newer plants are considering adopting dry bottom ash handling. Dec 02, 2008 storage silos shall be provided to store precipitator fly ash with adequate air space. In a coal based thermal power plant, huge amount of ash is. Ash handling systems ducon supplies both wet and dry type ash systems for power plants. With options varying from fly ash to bottom ash conveyors, and pneumatic versus mechanical ash handling systems, our experts are ready to help evaluate which application is best for your plant. A mechanical ash handling system is often the best choice for fluidized bed ash where headroom is restricted under. Ntpc has installed dry ash handling system in many of its power stations for handling the. In this paper, changchun hightech thermal power plant unit 2 25mw ash delivery system is taken as object describing the configuration and project delivery process of pneumatic ash handling system, according to the control performance requirements of the ash handling system unit designed to using siemens s7200 type plc for the control core of. Complete system can be distributed in four sub system. Power plant fly ash material handling system upgrade in 2016 tp automation was contracted to upgrade the fly ash handling system at a local power plant. They range in size from 300 cubic feet to 17,500 cubic feet, and are designed to work seamlessly with ash handling systems like the ones we have discussed.
Handling of ash is a problem because ash coming out of the furnace is too hot, it is dusty and irritating to handle and is accompanied by some poisonous gases 4. Diagram of a typical coalfired thermal power station. With dry fly ash handling system, ash water requirement is decreasing. Plant client ash handling system each unit capacity year of initial operati on brief description of system 6. Detailed project report for 2x mw imported coal based. Ash handling system power plant engineering amit mak youtube. Fly ash has proven to offer a wide range of benefits when used as a lwa, to the extent that it has become a key material in the construction industry. Pdf fly ash from thermal power plants waste management and.
Pressurized pneumatic ash conveying may also be employed. In a coal based thermal power plant, huge amount of ash is generated which has to be disposed off continuously. Thus, dry handling of fly ash is economically feasible for industry. Multi pd pumps for fly ash handling from schenck process duration. Most coal ash comes from coalfired electric power plants. Ash produced in about 10 to 20% of the total coal burnt in the furnace. Ash handling plant an overview sciencedirect topics. Fly ash from power plants is very toxic because it contains heavy metals. Storage capacity of bottom ash hopper permits sufficient maintenance time for sscc as well as reduces the extraction load on sscc. Kaniha, solapur coal stations and anta gas station have already.
International journal of environmental research, 5, 1, 2011, 101108. Some power plants operate a dry disposal system with landfills. Very finely sized fly ash often accounts for the major portion of the material conveyed in an ash handling system. The search for actions that can minimize speed variations in. Ash collected in economiser, primary air heater and secondary air heater hoppers drops continuously through suitable vertical pipe connections to the. A simplified schematic of a hydraulic system is shown in fig. Fly ash thru vacuum system 3 x 45 tph thru water exhauster.
May 07, 2014 requirement of ash handling system in thermal power plants coal is generally used as fuel and hence the ash is produced as the byproduct of combustion. The energy efficiency of a conventional thermal power station is defined as saleable energy produced as a percent of the heating value of the fuel consumed. Analysis of fly ash heavy metal content and disposal in three. Ducon supplies both wet and dry type ash systems for power plants.
Depending on the end use of coal, the chp facility processes coal to the correct size, making it suitable for boiler. This silo shall be used to collect dry fly ash for the purpose of sale. Fly ash collected from super thermal power plant had the least waterholding capacity 40. Mechanical equipment is used for ash disposal, mainly. Retrofit of all ash handling and storage systems for 2 x mwatt boilers including bottom ash, fly ash, pyrites, back pass and air heater ash positions. Since low ash, high grade coal is reserved for metallurgical industries.
This ash either bottom or fly ash needs to be cooled andor processed to a form that can be transported from the power plant. The presented system included a tapered section in order to achieve the bubble regime. The current paper discusses the problems associated with fly ash and its handling and mitigation measures. Wet ash system is can be utilized for bottom ash handling with water impounded hopper and jet pumps for intermittent removal. Protecting our waters from toxic power plant discharges. Plant ash extraction, conveyance and storage system this system consists of a bottom ash handling process and a flyash handling process. How works fly ash handling system in thermal power plant.
It shall have facilities for dry ash unloading into covered road tankers and conditioned fly ash in open road tankers. Fly ash generated while burning of coal in thermal power plants. Mechanical ash handling system bevcon wayors bulk made simple. Ash is not discharged as such to pollute the land, air and water, but slurry of ash is made in ash handling plant and this slurry is dumped in the wasteland, kept for the purpose. Pneumatic conveying systems to transport fly ash in dry mode are extensively used in coal fired thermal power plants in india in large capacities due to the high. Coal and ash handling systems in thermal power projects. A typical ash handling system may employ vacuum pneumatic ash collection with ash conveying from several ash pick up stations and resulting in delivery to an ash storage silo for interim holding prior to load out for disposal or reuse.
Thermal power plant pressure dense phase pneumatic ash plc. Vacuum system includes conveying of fly ash from various fly ash hoppers up to the intermediate buffer surge hopper ish located near esp. Within sscc, a temperature of less than 60degc is always maintained by continuous water makeup and overflow system. Ash is not discharged as such to pollute the land, air and water, but slurry of ash is made in ash handling plant and this slurry is dumped in the waste land, kept for the purpose. A simple cycle gas turbine achieves energy conversion efficiencies from 20 to 35%. The initial process in coal based thermal power plant is coal handling. Ash conveying systems densephase pneumatic conveying. This is due to the different chemical makeup of the coal based on the geology of the area the coal is found and the burning process of the coal in the power plant. The entire water requirement of the ash handling system may be met with circulating water where the plant does not have a cooling tower facilitythat is, for a oncethrough system in coastal stations using lake or river water, or seawater. Generally indian coal contains about 30 to 45% ash.
The schenck process method of fly ash handling is clean, efficient and fully enclosed, with exceptional reliability and requiring minimum maintenance. Bottom ash is extracted from the trough continuously using high quality chains, sprockets and bars. Ash handling options for coalfired power plants power. Fly ash, the fine particulate waste material produced by pulverized coalbased thermal power station, is an environmental pollutant, it has a potential to be a resource material. Lay out of coal handling plant btps wt 1 wt 2 wt 3 b br house b b con. In a typical electric power plant application, a series of small diameter mechanical fly ash collectors or cyclones of the reverseflow axial inlet type are grouped together sidebyside in a single shell and hopper chamber. Jun 25, 2011 fly ash from thermal power plants waste management and overview article pdf available in current science 10025. Coal and ash handling in thermal power plant mcqs with answers ch ramakrishna 062216. The effect of fly ash on the environment can vary based on the thermal power plant where it is produced, as well as the proportion of fly ash to bottom ash in the waste product. Requirement of ash handling system in thermal power plant s coal is generally used as fuel and hence the ash is produced as the byproduct of combustion. Coal and ash handling system in ppt arabicinstitute. In the thermal plants huge amount of the ash is produced,for coal combustion. Detailed project report 2x mw coal based tpp at paguthan, bharuch district, gujarat india table of content page 1 of 140 table of contents.
Ash generated in power plant is about 30 40% of total coal consumption and hence the system is required to handle ash for its proper utilization or disposal. Material may cause serious irritation of unprotected eyes. Pdf troubleshooting in dry fly ash conveying systems. Coal handling plant coal unloading system conveyor system crushing system feeding system.
The function of coal handling plant in thermal power plant is to receive, process, store, feed the coal bunkers consistently over entire life of the power plant. Combusting biomass in a boiler generates ash with high temperatures. Andritz offers complete solutions for biomass boiler ash handling. Fly ash or flue ash, also known as pulverised fuel ash in the united kingdom, is a coal combustion product that is composed of the particulates fine particles of burned fuel that are driven out of coalfired boilers together with the flue gases. If you want just send us the word file and the update will be done in your name. Bulk utilization in horticulture a longterm risk management option. Ash collected in economiser, primary air heater and secondary air heater hoppers drops continuously through suitable vertical pipe. Fly ash is considered a major global pollutant due.
A power point presentation on ash handling system made by me and my friends. Properties of fly ash from a thermal power plant in vietnam. Bottom ash comprises of waterimpounded hopper, crusher, jet pump and piping upto sump. Ash handling system what are the types of ash in thermal power plant. In an industrial context, it has traditionally referred to coal combustion and. Uong bi thermal power plant is one of the biggest power stations in vietnam. Power plant fly ash material handling system upgrade. A trial operation showed that mixed fly and bottom ash from a coal fued power plant can be reused as raw material for cement production 6. Pdf energy requirements for the developing countries in particular are met. Pdf treatment of fly ash from power plants using thermal plasma. Pneumatic conveying systems are used to handle dry fly ash. For example, theres a story about a new 800 mw coalfired plant, located in germany, that is using a dry bottom ash handling technique known as drycon instead of traditional water.
Oct 15, 2017 types of ash handling system in power plant engineering 1. Bottom ash is part of the noncombustible residue of combustion in a power plant, boiler, furnace or incinerator. The current utilization of fly ash is only about 55%, mainly in the areas of cement as well as concrete manufacturing and building products and to some extent in earth fills. Before their treatment, the fly ash was analyzed by many technics. Pdf operation and maintenance of coal handling system in. Ash handling system of coalfired power plant is a advanced, economic, environmental science and. Coal fly ash is an industrial byproduct produced from the burning of pulverized coal, during electricity generation in the thermal power plants. In this study fly ash was treated with a thermal plasma. In the thermal plants huge amount of the ash is produced,for coal combustion fly ash is the continuous by product. Results revealed that the fly ash obtained from a thermal power plant working on stokerfired combustor produced the highest waterholding capacity, followed by the one working on pulverized fuel combustor. Eia report for mw coal based thermal power plant at naraj marthapur. Stock of each type of ash available at ntpc stations as on 30.
Coarse ash material such as bottom ash is most often crushed in clinker grinders crushers prior to being transported in the ash conveyor system. Pneumatic conveying systems to transport fly ash in dry mode are extensively used in coal fired thermal power plants in india in large capacities due to the high ash content of indian coal and the increasing requirements of conveying fly ash in dry form. Coal and ash handling in thermal power plant mcqs with. Need for mechanized ash handling systems mechanized ash handling systems developed as the size of coal fired boilers increased beyond the sizes permitting manual handling of large quantity of ash. Hot products used for ash handling system automation in thermal power plant cs cone crusher mtw milling machine vsi crusher pfw. Pdf fly ash from thermal power plants waste management.
Characteristics of fly ash from thermal power plants and. This plant generates about mw of power, and produces a huge amount of fly ash a waste solid as a byproduct. Coal handling plant can handle coal from its receipt to storage, reclamation, preparation until the final point of use in thermal power plant. Ash storage silos can be constructed for both fly ash and bottom ash applications. Bottom ash directly falls down in water filled bottom due to gravity. One important, but often overlooked factor of an efficient ash handling system, is its compatibility with your facility. Water is required in thermal power stations for cooling purposes in condensers and plant auxiliaries, disposal of ash to ash dyke, various other consumptive uses like service water, potable water etc. Coal based thermal power plants generate huge amount of fly ash that is a major problem of disposal of fly ash in india. Ash handling pneumatic conveying handling system from. Find details of companies offering ash handling systems at best price. Complete systems or specific equipment andritz has the solution. Swapan basu, ajay kumar debnath, in power plant instrumentation and control handbook, 2015. Management of ash disposal guru nanak dev engineering. Coal and ash handling in thermal power plant mcqs with answers ahsan 071919 good information and some more info like size of coal and equipment descriptions or dictionary of these terms to be included.
Aug 09, 2016 introduction to thermal power plant general layout of thermal power plant site selection criterion of thermal power plant coal preparation coal storage ash handling electrostatic precipitator. When the ash storage pond at tennessee valley authoritys tvas kingston fossil plant in harriman, tenn. Water used for bottom ash handling is recirculated from the dewatering bins. Fly ash laden flue gas enters this single chamber and is distributed over and shunted through. Vacuum system is generally adopted when the extraction distance is less, numbers of esp hoppers are more and plant layout demands twostage conveying. The bottom ash quantity is around 20% of the total ash generation and there are mainly two types of bottom ash disposal systems.
The selection of firing method adopted for a particular power plant depends upon the following factors. Bottom ash handling system macawber beekay, ash handling. Site 2 power plant has asias first 100% dry ash extraction system with transit ash storage silos and final storage in the form of ash mounds. Bottom ash is most often conveyed in a hydraulic system in which the ash is entrained in a highflow, circulating water system and delivered to an ash pond or to dewatering storage bins. In typical thermal project of 2000mw capacity, the daily ash production will be about 2200 tonnes of bottom ash and about 1 tonnes of fly ash. What is the processor of ash handling system in thermal power plant boiler. The thermal power plants ash generation has increased from about 40 million tonnes during. In plant handling it is referred to transferring coal from dead or live storage to the boiler. Requirement of ash handling system in thermal power plants coal is generally. Wet ash loading systems fly ash handling for coalfired power plants the fly ash is separated from the flue gas by esps or fabric filters. An example of this method is presented in 1, regarding operation and maintenance of coal handling system in a thermal power plant.
The thermal power plants have to use high ash, low grade coal. Bottom ash the ash which is directly collected from bottom of boiler. Ntpc plants it is found that about 20% of the total ash is bottom ash and the balance 80% is fly ash. Ash handling systems may employ different forms of pneumatic ash conveying or mechanical ash conveyors. A large quantity of ash, is produced in steam power plants using coal. Introduction thermal power is still an important power in many countries. Once the ash mound has reached the prescribed height, it is sprayed with polymer layer and vegetation is grown on top of it.