Economisers An economizer is an heat exchanger which is used to raise the temperature of feed water with the help of waste heat energy of gases before it is supplied to the boiler. Note that the temperature of gases is about 350°C 550°C at exit of last heater/ superheater having large amount of heat energy … Read more

Methods of Superheat Temperature Control For proper and efficient operation of power plant it is essential to control the temperature of steam according to load on the power plant. The reduction of about 20°C temperature of superheated steam causes the increase in 1% heat rate (H.R.) [H.R.-Work output x 3600 Efficiency (kJ / kWh) my] … Read more

Reheaters Figure A Reheaters are used in between the stages of turbine to reheat the steam so as improve overall efficiency of plant and to avoid low dryness fraction of steam in later stages of turbine. Therefore, the basic concept and design is similar to superheater except that these operate comparatively at lower pressures and … Read more

Basic Arrangement of FBC System Advantages and Disadvantages The basic arrangement of FBC system is represented in Figure. It consists of a shell with a distributor plate at its bottom with holes in it. The shell carries the boiler evaporator tubes which remain immersed in the fluidized bed as shown in figure. Coal of 6 to … Read more

Principle of Operation of Fluidized Bed Combustion System Figure A shows the simple fluidized bed which has a finely divided particles of fuel half filled in the column. At its bottom a distributor plate is fitted through which the air is passed in upward direction with some low velocity. The pressure drop across the combustion … Read more

Fluidized Bed Combustion (FBC) Systems Due to the escalation in oil and gas prices continuously the world over, the power engineers were trying to develop new combustion systems with coal as fuel since it is available in abundance in India. In the earlier designs of furnaces using Pulverized coal were required to be operated upon … Read more

Pulverizing Mills  Pulverizing mills called pulverizers are used to convert the crushed coal into fine dust particles. It helps in promoting the rapid combustion of fuel and air.  Various pulverizing mills used are : Ball and race mill Bowl mill Ball mill Impact or hammer mill The pulverizers are driven by electrical motors. Working of … Read more

Dust Collection System In coal fired boilers the flue gases have certain particles of solid matter in suspension this is called smoke or dust. In case of pulverized coal furnaces the fly ash remains in suspension with flue gases. If the particles in suspension are of size from 1 to 100 microns it is called … Read more

Various Ash Handling Systems Various ash handling systems used are : Hydraulic ash handling system. Pneumatic ash handling system. Mechanical system. 1. Hydraulic Ash Handling System : The schematic diagram of hydraulic ash handling system is shown in Figure A. Figure A This site is med for larger power plant. In this system ash from … Read more