Gas Compressor Essay Example for Free

Gas Compressor EssayA gas compressor is a mechanized device that cast ups the pressure of a gas by reducing its volume. Compressors atomic number 18 similar to pumps both increase the pressure on a fluid and both piece of tail transport the fluid through a pipe. As gases ar compressible, the compressor in addition reduces the volume of a gas. Liquids are relatively incompressible, so the main treat of a pump is to pressurize and transport liquids.Types of CompressorsCentrifugal compressors Centrifugal compressors use a rotating disk or impeller in a shaped housing to force the gas to the rim of the impeller, increasing the velocity of the gas. A diffuser (divergent duct) section converts the velocity energy to pressure energy. They are primarily used for continuous, stationary answer in industries such as oil refineries, chemical and petrochemical plants and natural gas processing plants.123 Their application female genital organ be from 100 horse power (75 kW) to thou sands of horsepower. With multiple staging, they washstand achieve extremely eminent turnout pressures greater than 10,000 psi (69 MPa). Many large snow-making operations (like ski resorts) use this type of compressor. They are also used in internal combustion engines as superchargers and turbochargers. Centrifugal compressors are used in comminuted gas turbine engines or as the final compression stage of medium sized gas fortuity or mixed-flow compressorsDiagonal or mixed-flow compressors are similar to centrifugal compressors, but have a radial and axial velocity component at the exit from the rotor. The diffuser is often used to turn gash flow to the axial direction. The diagonal compressor has a lower diameter diffuser than the equivalent centrifugal compressor.Axial-flow compressorsAxial-flow compressors are dynamic rotating compressors that use arrays of fan-like airfoils to progressively compress the working fluid. They are used where there is a extremity for a high flo w rate or a compact design. The arrays of airfoils are set in rows, usually as pairs one rotating and one stationary. The rotating airfoils, also known as blades or rotors, accelerate the fluid. The stationary airfoils, also known as stators or vanes, decelerate and redirect the flow direction of the fluid, preparing it for the rotor blades of the neighboring stage.1 Axial compressors are almost always multi-staged, with the cross-sectional area of the gas passage diminishing on the compressor to maintain an optimum axial Mach number.Beyond about 5 stages or a 41 design pressure ratio, variable geometry is normally used to improve operation. Axial compressors can have high efficiencies around 90% polytropic at their design conditions. However, they are relatively expensive, requiring a large number of components, laughable tolerances and high quality materials. Axial-flow compressors can be found in medium to large gas turbine engines, in natural gas pumping stations, and within certain chemical plants.Reciprocating compressors Reciprocating compressors use pistons driven by a crankshaft. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines.145 Small reciprocating compressors from 5 to 30 horsepower (hp) are commonly seen in automotive applications and are typically for intermittent duty. Larger reciprocating compressors well all over 1,000 hp (750 kW) are commonly found in large industrial and petroleum applications.Discharge pressures can range from low pressure to very high pressure (18000 psi or 180 MPa). In certain applications, such as air compression, multi-stage double-acting compressors are said to be the most efficient compressors available, and are typically larger, and more costly than comparable rotary units. 6 Another type of reciprocating compressor is the swash plate compressor, which uses pistons which are moved by a swash plate mounted on a shaft.