Rotating compressor

Gas turbine systems operate in a manner similar to steam turbine systems except that combustion gases are used to turn the turbine blades instead of steam. In addition to the electric generator, the turbine also drives a rotating compressor to pressurize the air, which is then mixed with either gas or liquid fuel in a combustion chamber. The greater the compression, the higher the temperature and the higher the efficiency that can be achieved in a gas turbine. Exhaust gases are emitted to the atmosphere from the turbine. 

Most rotating equipment includes electric motors or steam dryers that generate noise at a constant frequency. Air cooler fans are a source of noise that can be reduced by lowering the fan speed and increasing the number of blades. Pump motor noise can be reduced by including a shroud or fan cover that is accurately lined. Centrifugal compressor noise reduction can be achieved by blade design and the use of compressor pulsation noise reduction, silencers, and vibration isolation. 

Screw-Type This type of rotary compressor, as shown in Fig. 10-80, is capable of hancmng capacities up to about 4.248 X lO" m m (25,000 fF/min) at pressure ratios of 4 1 and higher. Relatively small-diameter rotors allow rotative speeds of several thousand rev/min. Unhke the straight-lobe rotary machine, it has male and female rotors whose rotation causes the axial progression of successive sealed cavities. These machines are staged with intercoolers when such an... 

Applications Two principal applications are rotating equipment oil coolers and compressor inter- and after-coolers. Although seemingly different applications, both rely on the shellside finning to enhance the heat transfer of low heat-transfer characteristic fluids. 

Rotary compressors are also PDC types, but where refrigerant flow rotates during compression. Unhke the reciprocating type, rotaiy compressors have a built-in volume ratio which is defined as volume in cavity when the suc tion port is closed (V = m vj over the volume in the cavity when the discharge port is uncovered (V = m vj). Built-in volume ratio determines for a given refrigerant and conditions the pressure ratio which is ... 

Compressors A compressor is a device that pressurizes the air in a gas turbine. It transfers energy by dynamic means from a rotating member to the continuously flowing air. The two types of compressors used in gas turbines are axial and centrifugal. Figures 29-25 and 29-26 depict typical industrial gas turbines. 

Radial-Inflow Turbine The radial-inflow turbine, or inward-flow radial turbine, has been in use for many years. Basically a centrifugal compressor with reversed-flow and opposite rotation, the inward-flow radial turbine is used for smaller loads and over a smaller operational range than the axial turbine. Radial-inflow turbines are only now beginning to be used because little was know about them heretofore. Axial turbines have enjoyed tremendous interest due to their low frontal area, making them suited to the aircraft industiy. However, the axial machine is much longer than the radial machine, making it unsuited for certain vehicular and helicopter applications. Radial turbines are used in turbochargers and in some types of expanders. 

Vlanv process machines operate at speeds diFFerent From the one oF their drivers. Typical oF cases where the machine rotates. dower than the driver are reciprocating compressors typical examples oF machines rotating/ js / er than the drivers are centriFiigal compressors driven bv electric motors. In either case, ear. are used to match the two speeds, (iears can also be designed to accommodate shaFts that... 

The Guidelines for Process Equipment Reliability Data with Data Tables covers a variety of components used in the chemical process industry, including electrical equipment, analyzers, instrumentation and controls, detectors, heat exchangers, piping systems, rotating equipment (pump, compressor, and fan), valves, and fire protection systems. 

Damage to the labyrinth requires replacement of the expander heat barrier or compressor shaft seal. A replacement design (Figure 5-6) uses a replaceable stainless-steel labyrinth mounted on the shaft. Because the seal is not tapered, axial movement of the shaft has little or no measurable effect on seal gas flowrates. Each labyrinth has an integral oil slinger incorporated into the design. Also, each rotating... 

The active magnetic bearing s versatility allows it to be used in almost any rotating machine. Examples include compressors, blowers, pumps, turbines, centrifuges, x-ray tubes, vacuum pumps, spindles for... 

The surge protection described above is for a simple, single section, constant geometry compressor with constant inlet conditions and constant speed of rotation. Many compressor installations involve more complex configurations and applications. 

Compressors driven by steam mrbines, gas turbines, hot gas expanders, or variable speed electric motors usually employ variable rotation speed for capacity control. Generally, the surge limit slope varies witli rotation... 

Axial-Flow Compressors. An axial-flow eompressor eompresses its working fluid by first aeeelerating the fluid and then diffusing it to obtain a pressure inerease. The fluid is aeeelerated by a row of rotating airfoils or blades (the rotor) and diffused by a row of stationary blades (the stator). The... 

The radial-inflow turbine, or inward-flow radial turbine, has been in use for many years. Basically a centrifugal compressor with reversed flow and opposite rotation, the inward-flow radial turbine is used for smaller loads and over a smaller operational range than the axial turbine. 

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