- Bottom ash handling system.
- Coarse ash (economizer ash) handling system.
- Air pre-heater ash handling system.
- Fly ash handling system.
- Ash slurry disposal system.
- Inertial separators.
- Fabric filters.
- Wet scrubbers.
- Electrostatic precipitators.
- Unit collectors.
Q. What is : (I) fire tube boiler? (II) water tube boiler? Also write their maximum pressure, capacity and one example for each type.
Fire tube boiler : It is a boiler for generating steam by passing hot gases and other combustible products through tubes (fire tubes) immersed in water to a chimney or uptake. The maximum pressure which can be obtained is about 17.5 kg/ cm² and with a capacity of 9000 kg of steam per hour. Examples are Cochran, Lancashire and Locomotive boilers.
Water tube boiler : It is a form of boiler in which steam is generated by circulating water through tubes exposed to the source of heat. A pressure of 125 kg/ cm can be obtained with high temperature of 315ºC to 575°C. Most modern water tube designs are within the capacity range 4500 to 120,000 kg of steam per hour. Examples are Babcock and Wilcox,stirling, Yarrow boiler etc.
Q. State the function of following components of a thermal power station : (I) Economizer (II) Air preheater (III) Alternator (IV) Condenser.
- Economizer :This is usually used to utilized the waste heat of the chimney to preheat the boiler feed water thus increasing the boiler efficiency.
- Air-preheater : This is usually used to utilized the waste heat of the chimney to preheat the furnace air thus increasing the boiler efficiency.
- Alternator : Generator or alternator is the electrical end of a turbo-generator set. It converts the mechanical energy of turbine into electricity.
- Condenser : The condenser condenses the steam from the exhaust of the turbine into liquid to allow it to be pumped. It provides lowest economic heat rejection temperature for steam. It is used to introduce make-up water.