MECHTALK

 LAMONT BOILER  Lamont boiler is the first forced convection boiler which is introduced in the year 1925. • A LaMont boiler is a type of forced circulation water-tube boiler in which the boiler water is circulated through an external pump through long closely spaced tubes of small diameter. The mechanical pump is employed in order to have an adequate and positive circulation in steam and hot water boilers. A water circulating pump is used in the boiler to circulate water inside the boiler. This pump is driven by the steam turbine which uses steam of boiler. It is used in power plant industries to generate electricity. Principle: This boiler works on basic principle of forced convection. If the water is circulate by a pump inside the tube, the heat transfer rate from gas to the water is increases. It is the basic principle of it. Construction: This boiler is the first force circulation boiler. This boiler consist various part which are as follow.  Economizer: Economizer use to pr

  High Pressure Boilers : There are two types of High pressure boilers are as follows. 1.     Benson Boiler 2.  Lamont Boiler FIGURE 1: BENSON BOILER Construction  1. Air Preheater : It preheats the air before entering into the furnace. The preheated air increases the burning efficiency of the fuel. 2. Economiser: It heats the water to a certain temperature. 3. Radiant Superheater : It is super heater which heats the water with radiation produced by the burnt fuel. It raises the temperature to supercritical temperature. 4. Convection Evaporator : It evaporates the superheated water and converts them into steam. It does so by the convection mode of heat transfer to the water from the hot flue gases. 5. Convection Superheater : It superheats the steam to the desired temperature (nearly 650 degree Celsius). 6. Furnace: It is the place where the fuel is burnt. 7. Feed Pump : It is used to supply the water inside the boiler at supercritical pressure of 225 bars.   Wor

  STEAM NOZZLES AND TURBINES   Flow of steam through nozzles, shapes of nozzles, effect of friction, critical pressure ratio, supersaturated-flow.   Impulse and reaction principles, compounding, velocity diagrams for simple and multistage turbines, speed regulations-governors and nozzle governors. Numerical Problems.   STEAM NOZZLES AND TURBINES Some Technical Terms :   1. Wet steam : The steam which contains some water particles in superposition. 2. Dry steam / dry saturated steam : When whole mass of steam is converted into steam then it is called as dry steam. 3. Super heated steam : When the dry steam is further heated at constant pressure, the temperature increases the above saturation temperature. The steam has obtained is called super heated steam. 4 . Degree of super heat : The difference between the temperature of saturated steam and saturated temperature is called degree of superheat. 5. Nozzle :It is a duct of varying cross sectional area in which