The pneumatic jetpump is an equipment suitable for leanphase pneumatic. Performance of a steam jet refrigeration system is defined in terms of the coefficient of performance cop. Pressurized pneumatic ash conveying may also be employed. In the steam jet refrigeration system, the pressure inside the chill tank compartments will be reduced by a series of steam jet boosters, to a pressure corresponding to the saturation temperature of the chilled water required and steam jet boosters are sized accordingly to remove the calculated amount of water vapour evaporated for the required. In this paper, the steam jet ejector was designed and then the cfd analysis was carried out for the geometry and the inlet condition data verified by the performance evaluation of the jet ejector. If the reprint or republication includes ed material, the credit should also state. Conventional lean slurry disposal system bottom ash discharge rate based on jet pump capacityssc capacity the fly ash handling system shall be assumed to operate continuously and the fly ash collection rates shall be same as the rates considered for sizing pneumatic conveying system, for the purpose of sizing of the disposal system. A large quantity of ash, is produced in steam power plants using coal. Fly ash handling wherever products are burned it is necessary to have an energy efficient ash handling system, especially in a power station environment where large quantities of pulverized fuel ash pfa are created. Watercooled screws or chain conveyors can be adapted easily for different furnace configurations and for any type of solid fuel being combusted. Since ash deposition is unavoidable coal contains ash, most pulverised coal boilers are fitted with a number of sootblowers, which operate.
System comprises of water impounded refractory lined bottom ash hopper of adequate capacity with water seal trough and dip plates, allowing free expansion of the furnace without any air ingress. Find details of companies offering ash handling systems at best price. 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. Name the system that is mainly employed for the disposal of fly ash. Ash from the various collecting points is pneumatically conveyed to the ash storage silo and is unloaded at.
Effluent limitations guidelines and standards for the steam electric power generating point source category to the federal register in. Ash handling systems andritz ash handling systems include conveyors and other equipment necessary for removal of bottom ash and fly ash from the power boiler. Fly ash is captured and removed from the flue gases by economiser, airpreheater and electrostatic precipitator esp. If the draught is produced by steam jet or fan it is known as artificial draught. Expression of interest for technology tieup for ash handling system. One of the methods for handling fly ash is wet system in which the ash is mixed with water to form slurry which is pumped to slurry pit. A bottom ash sluice system with a bottom ash hopper and a hydraulic jet pump has been applied, where the bottom ash is quenched and collected in a water impounded bottom ash hopper to be periodically removed by a jet pump through a clinker crusher and sluiced to ash pond. 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. The fly ash gets collected at various points, with most of it in esp hoppers. The hydraulic system applies high pressure water jet to take bottom ash from hopper which was located under steam boiler or under stoker. Steam jet ejectors bulletin 5eh singlestage ejectors fig.
Anyone wishing to make further use of ed material, by itself and apart from this text, should seek necessary permission. There are a few common actionsmonitoring such as automanual am change over, final control element. This system utilizes jets of high pressure steam, blowing in the direction of travel through a. Performance optimization of steam jet ejector using cfd. Ash handling refers to the method of collection, conveying, interim storage and load out of various types of ash residue left over from solid fuel combustion. 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. The authors are indebted to the mcnabb company, of bridgeport, conn. Watercooled screws or chain conveyors can be adapted easily for different furnace configurations and for any type of. 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. Dry ash collection at coal fired power plants and potential for wte. One of the methods for handling fly ash is wet system in which the ash is mixed with water to form slurry which is. The entire water requirement of the ashhandling 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. The pneumatic jet pump is an equipment suitable for leanphase pneumatic. The complete system for entire ash handling plant and equipment are included.
Switzerland for once through boilers and coal pulverisers. The motive steam requirement for individual stages is a function of compression. The hydraulic bottom ash handling system, utilizing the hydroseal pump, dominated the ash handling industry until the introduction of the jet pump which provided improved performance at a lower cost with reduced maintenance. Development of a steam jet refrigeration cycle for the. Working of ash handling system in thermal power plant. Zero discharge ash handling system costs and their sensitivity to unit retirement and ash make rate and their sensitivity to unit. System jet pumping system or submerged scraper conveyor system and. The bottom ash is then distributed by water jet through sluice way to wet storage sump see figure 1. Optimum efficiency, performance and reliability from the most trusted name in hybrid vacuum systems. Troubleshooting in dry fly ash conveying systems irjet. The ash is then carried by a high velocity air or steam to the point of delivery.
Fly ash handling system thru pneumatic vacuum conveying using water exhauster 4 x 37 tph. Andritz ash handling systems include conveyors and other equipment necessary for removal of bottom ash and fly ash from the power boiler. Especially the chemical industry makes largely use of steam jet ejectors to generate the vacuum required in many distillation processes. Wet ash handling systems project engineering division. This system utilizes jets of high pressure steam, blowing in the direction of travel through a conveying pipe in which the ash from the boiler ash hoppers is fed. Since ash deposition is unavoidable coal contains ash, most pulverised coal boilers are fitted with a number of sootblowers, which operate routinely on a daily basis, usually 23 times a day. The unit is available in standard sizes up to 6 and custom fabricated for larger sizes. Maintenance of ash handling plants and pneumatic conveying. Particulars unit value 1 primary fluid suction pressure torr 25. Comparative study of different types of high pressure boilers 9. Ash handling system in thermal power plant ash handling. Ash collected in economiser, primary air heater and secondary air heater hoppers drops continuously through suitable vertical pipe connections to the flushing connections provided beneath each of the hoppers. Jun 02, 2018 ash handling high pressure system hydraulic learn and grow. Up to the hopper part it is same as that of dry fly ash handling system.
With options varying from fly ash to bottom ash conveyors, and pneumatic versus mechanical ash handling systems, our experts are ready to help. Bottom ash system thru jet pump 2 x 76 tph with wtype water impounded hopper and excen crusher. Hydrovactor vacuum producers and steam jet exhausters provided the required vacuuminduced flows. The fly ash collector and storage system was designed to receive ash removed from the steam generator exhaust gases. Such ash can be a considerable environmental nuisance as well as being awkward to handle due to its abrasiveness and hydroscopic. Sep 30, 2018 working of ash handling system in thermal power plant. Army, usa, technical manual tm 58116, electric power plant design. In this method a low pressure jet of water coming out of the quenching nozzle is. Ash handling system are generally divided into three types fly ash handling system, bottom ash handling system and ash slurry disposal system. Dry bottom ash decision analysis technology alternativestechnology alternatives 1 worst, 5 best scale 15 recirc system sfc pax vax criteria for determing technology selection wt sc total sc total sc total sc total water usageavailability 0 2 03050 5 0 outage time available 0 5 04020 3 0 total installed costtotal installed cost 0 1 0 5 0 3 0 3 0. Ash handling system in thermal power plant ash handling plant.
When the ash storage pond at tennessee valley authoritys tvas kingston fossil plant in harriman, tenn. Fly ash is the major constituent of the ash generated from pulverized and fluidized bed coalfired boilers. Washing, heating, sterilising and rinsing are possible applications, and the list can be extended at will. Dry fly ash handling system by utilisation of air slides, water mixed in the hydroejector and slurry conveyed up to common ash slurry sump.
The operating conditions and geometrical dimensions are described in the table and figure below respectively. During the operation the fly ash deposited on the collecting surface of the esp is. Modest ash deposition is routinely removed by regular sootblowing operations using high velocity water andor steam jets. A typical ash handling system may employ vacuum pneumatic ash collection with ash conveying from several ash pick up stations and. Ash handling high pressure system hydraulic learn and grow. Study of different types of steam nozzle and design a nozzle 8. Macawber beekays product profile includes jet pumping system for intermittent removal of bottom ash collected at furnace bottom of pf type boilers. Hot water is an indespensable medium in industrial processes. The bottom ash can be taken out from the hopper by instruments such as water jet nozzle and spray nozzle.
The air is forced into the system by a blower or steam jet. Ash handling systems may employ different forms of pneumatic ash conveying or mechanical ash conveyors. Ash handling plant an overview sciencedirect topics. The flue is drawn sucked through the system by a fan or steam jet. Coal and ash handling in thermal power plant mcqs with.
System comprises of water impounded refractory lined bottom ash hopper bah of adequate capacity with water seal trough and dip plates. And housing the major advantage of a jet pump is the. Wet ash system is can be utilized for bottom ash handling with water impounded hopper and jet pumps for intermittent removal. Zero discharge ash handling system costs and their. A steam power plant converts the chemical energy of the fossil fuels coal, oil, gas. Steam jet car wash system including steam car wash sji8000e, car wash, steam machine. Bottom ash handling system macawber beekay, ash handling. Coarse ash material such as bottom ash is most often crushed in clinker grinders crushers prior to being transported in the ash conveyor system.
Coal and ash handling in thermal power plant mcqs with answers. Slurry transfer system is thru 300 nb cast iron disposal piping. One important, but often overlooked factor of an efficient ash handling system, is its compatibility with your facility. Swapan basu, ajay kumar debnath, in power plant instrumentation and control handbook, 2015. After the hopper instead of going into the vessel, the ash gets mixed with a high pressure water and this mixture goes to a slurry tank for further pumping. Kerala newsprint project 3x60 tph steam generator units hindustan paper corporation ltd. The ejector model has been selected from a steam jet refrigeration system developed for a chemical processing plant. Ash handling system free download as powerpoint presentation. Such ash can be a considerable environmental nuisance as well as being awkward to handle due to its abrasiveness and hydroscopic characteristics. The nash enerjet hybrid vacuum system offers an innovative design that reduces steam consumption and can pay for itself in 2 years or less with energy savings.
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