SUB:FLUID POWER ENGINEERING

ENROLLMENT NONAME KISHAN TAKOLIYA SHREYASH THACKER DIGANAT THAKKAR VISHAL THAKOR NIRAV VAGHELA

 Rotory Compressor  Positive Displacement rotory compressor 1. Roots blowers 2. Vane type blowers 3. Screw compressor 4. Scroll compressor  Roto-dynamic rotory compressor 1. Radial flow compressor 2. Axial flow compressor

 In this compressor air is compressed by trraping it in a reducing passage formed by asset of engaging surfaces.  The gas pull from suction side and push to delivery side by help of engaging surfaces.

 In this typw of compressor,the compression of gas is carried out by a rototing elements imparting velocity to the flowing gas and developed desired pressure and compression is achieved by dynamic action of rotor  In rotodynamic compressors,the gas is not trapped in specific volume but it flows through compressor

 Rotary air compressors are also positive displacement compressors. The most common rotary air compressor is the single stage helical or spiral lobe oil flooded screw air compressor, consisting of two rotors within a casing where the rotors compress the air internally. There are no valves. These units are basically oil cooled with the oil sealing the internal clearances. Since the cooling takes place right inside the compressor, the working parts never experience extreme operating temperatures making them continious duty compressors.

 It is positive displacement machine,hence it produces high pressure of gas.  It is high speed rotory compressor,large volume of gas can be handaled by it.  No need of lubrication oil since no metal to metal contact.  The simplicity of screw compressor is its assets.

 The root blower is as shown in fig,consist of two lobes.  For higher pressure ratio,three or four lobes may be used.  Here the pressure of air deliverd is slightly above the atmosphere  The machine consists of a fixed casing which contains two shafts fitted with two lobe rotors.

 There is no any reciprocating parts,only two rotating parts.  Since rotors are symmetrical about their centre of rotation and hence it is dynamically balanced  No clearance and it is positive displacement type machine  It delivers gas contiously

 It is positive displacement type compressor.  It provides higher efficiency and flow rates over a wide range of pressure  Rotary vane compressor consist of rotor with a number of vanes inserted in the radial slots cut in rotor.

 The rotor is mounted eccentric in a casing.  The vanes slides radially in and out of the rotor.  As the rotor rotates at higher speed, centrifugal force throws the vanes outward keeping the end of vane in contact with the stator ring.

 As the rotor turns, compression is achieved as the volume goes from a maximum at intake port to minimum at the exhaust port.  An oil is injected into the air intake and along the stator walls to cool the air and lubricate bearing and vanes and to provide a seal between the vane and stator wall to reduce internal leakage.

 Simple design  Compact in size  Light in weight  Easy to install  Low cost  Low maintenance cost  Longer life  Few moving parts  Low rotational speed  Expensive foundation not required ADVANTAGES:

 Lower efficiency  Difficulty with higher pressure above 200 psi  Oil injected designs have oil carryover DISADVANTAGES: