Excessive nitrogen oxides (NO2) form when peak combustion temperature exceeds 1950°C. To lower the combustion temperature, many engines have EGR system. It recirculates about 10% of the inert gas back into the intake manifold The cooler exhaust gas absorbs heat from the much hotter combustion process. It reduces peak combustion temperature and lowers the formation
Exhaust Gas Recirculation (EGR) System – Pedagogy Zone Read More »
Air pollution and its control I.C engines convert heat energy into mechanical energy by burning the fuel in its combustion chamber called cylinder. Mostly, petrol and diesel oil are used as fuels for I.C engines. These fuels contain hydrogen and carbon in various combinations. During combustion, oxygen combines with hydrogen and carbon to form Water
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Detonation in S.I Engines: If the temperature of an air fuel mixture is raised high enough, the mixture will self ignite without the need of a spark plug Knocking or detonation in S.I engines. This phenomenon is called as self ignition or Auto ignition. The temperature above which self ignition occurs called the self ignition
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The coal preparation includes sizing, removal of rock originating from mine roof, removal of ash forming and sulphur bearing minerals, drying to remove excessive surface moisture and blending of different coals to achieve desired physical and chemical properties. The fig. shows the flow diagram of coal preparation plants. The coal cleaning equipment is relied on
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Definition of metrology is a “Science of measurement”. The most important parameter in metrology is the length. Metrology is divided into Industrial Metrology and Medical Metrology under consideration of its application and may be divided into metrology of length and Metrology of time under consideration of its quantity. Definition of Metrology is mainly concerned with
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As we have discussed already, the torque of an engine crankshaft varies considerably throughout the working cycle, due to variations in the crank positions, the pressure in the cylinder and the inertia force on the piston and connecting rod. If the value of the crankshaft torque, the turning moment T is plotted against the crank
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Vapour compression refrigeration system uses a liquefiable vapour as the refrigerant. In this system, the refrigerant used alternatively undergoes a change of phase from vapour to liquid and liquid to vapour during the cycle. In this, the isentropic expansion of Carnot cycle is replaced by a throttling process, expansion in a valve or capillary tube.
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In this chapter, we shall discuss the static and dynamic force analysis of planar mechanisms in detail. In our studies of “Kinematics of Machinery“, we limited ourselves to consideration of the geometry of the motions and of the relationships between displacement and time. But the force required to produce those motions were not considered. In
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The subject ‘Theory of Machines’, also known as ‘Mechanics of Machines’, comprises: (i) the study of the relative motion between the parts of a machine, and (ii) the study of the forces which act on those parts. It is understood that most mechanical engineering activities revolve around a mechanical system whose function depends on the
Theory of Machines and Branches – Dynamics of Machinery Read More »
In an I.C engine, moving parts rub against each other causing frictional force. Due to the frictional force, heat is generated and the engine parts wear easily. Power is also lost due to friction. To reduce the power loss and also wear and tear of the moving parts, a foreign substance called lubricant is introduced
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