Mech_int By Avinash Sir
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Pressure Ratio Ratio of absolute discharge press. / absolute inlet pressure
Compressor capacity It is the quantity of actual free air delivered by the compressor
Free air delivered(FAD) It is the volume of air actually delivered under the conditions of temperature and pressure existing at the compressor intake.
Swept volume It is the volume swept by the recip. compressor piston during suction or delivery stroke
Pneumatics, the use of pressurized gases to do work. See compressed air energy storage. Vehicular transportation using a compressed air vehicle Energy storage Scuba diving, to inflate buoyancy devices. Cooling using a vortex tube. Gas dusters for cleaning electronic components that cannot be cleaned with water. Railway braking systems Road vehicle braking systems Diesel engine cranking Paintball ammunition propulsion Airsoft ammunition propulsion Air tools Cleaning the insides of electronics
SINGLE STAGE
One suction and one delivery
MULTI STAGE
One actual suction and multiple sub suctions and sub-deliveries
SINGLE ACTING
One piston delivers from only one side
DOUBLE ACTING
Piston delivers from both sides
ď ˝ Construction
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Volumetric efficiency
Depends on clearance(IP) Piston ring leakage Speed of compressor(IP) Fresh air coming in contact with hot wall expands and decreases Vol. Eff.
Isothermal efficiency
Mechanical eff. = IP / SP
Vol. eff. Increases Power IP decreases Uniform torque and flywheel size reduced Max. temp reduced so less lubrication Reduced leakage loss due to reduced pressure difference across piston and valves Reduced wt. of cylinders.
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Screw compressors Positive displacement compressors Driver and driven rotor (sometimes only one rotor) Air is sucked form one side and compressed in the variable space between the rotors both axially and radially Advantages: High volumetric eff. Uniform and continuous flow Perfect balancing due to pure rotary motion
Same as screw compressor Both rotors have mating geometric profiles Air is compresses in the variable space in the mating of the blowers
Spring fitted vanes to vary the space between the vanes The rotor is fitted eccentrically to obtain the variable area Reversibly and irreversibly compressed Low speeds are suitable