Knowledge material

In this machine slip-rings and brushes are eliminated and excitation is provided not by conventional direct current exciter but by a small alternator. The a.c. exciter has the unusual arrangement of 3phase output windings on the rotor and magnetic...

An electric propulsion system for a ship is often simply described as a diesel electric or turbo electric system. It is characterised only by the type of prime mover, with no reference to the...

Sudden load current surges (eg. Due to motor starting) on a generator causes a corresponding change in its output voltage. This is due to an internal voltage drop in the generator winding and effect is called...

Different types of surveys Normal survey : These are the conventional survey processes in which the tail- shaft is completely withdrawn at intervals as detailed in Table:1 and thoroughly examined to the satisfaction of the Recognised...

Industrial Sources The three major primary sources of NOx, in combustion processes: Thermal Nox - Formed when nitrogen and oxygen in the combustion air supply combine at high flame temperatures. Thermal NOx is generally formed...

Refrigeration Cycle Compression The function of a compressor is to raise the pressure of a refrigerant vapour, by compressing the vapour. With the function of the compressor, a refrigerant carries heat from low temperature region to...

The part of iron and carbon alloy system line diagram representation of unalloyed iron and an interstitial compound, iron carbide (Fe3C), containing 6.67 percent carbon by weight is called iron-iron carbide equilibrium diagram. It...

Brinell hardness test Rockwell hardness test Vickers hardness test Pendulum test Charpy testI-zode test Fatigue test Bending test Non destructive Test VisualMicroscopyRadiographyDPTUltrasonicMagnetic particle Radiography Test DPT FatigueQuenchedGrindingOverloadImpactPorosityPin holesLack of fusion Steps used in the DPT  experiment: 1. Clean the surface with...

Twice in 5 years Open the boiler vent valve when pressure inside is just above the atm pressure to ensure that there is no vacuum in the boiler Allow the boiler to cool and...

Steering gear compartment must be separated from machinery spaces and readily accessible. Every vessel should be provided with main steering gear and auxiliary steering gear. The failure of one steering gear must not render the another one...