Compressors figures

For ease of illustration we will consider the characteristics and behaviour of a centrifugal pump which is similar in behaviour to radial/axial flow fans and centrifugal/screw compressors. Figure 63 shows the mechanical connection of a flow valve to control the output of the pump or the discharge of the fluid through the throttle of the valve. Figure 6.39 illustrates the characteristics of the pump ... 

Above a minimum intake flowrate of about 50,000 m /hr and depending on the required discharge pressure, axial compressors (Figure 4-15) offer certain advantages. Their polytropic efficiencies. 

Nitrous gases originating from the combustion units in nitric acid plants carry small amounts of unreacted ammonia, NH3. The ammonia may react with the nitrous gas to form microscopic particles of ammonium nitrate that adhere to solid surfaces. Within a short time, there is a growing layer of ammonium nitrate salt covering the internal surface of the nitrous gas compressor (Figure 4-27). This layer can obstruct the flow passages because it tends to increase the power consumption, provoke excessive vibrations, and even present a safety hazard since ammonium nitrate explosions can occur. 

Figure 3-10 shows a similar performance map for an axial-flow compressor. Note the smaller operational flow range for the axial-flow compressor as compared to the centrifugal compressor. Figure 3-11 shows a typical compressor map presented from a slightly different viewpoint. On this map. 

Centrifugal compressors in general are used for higher-pressure ratios and lower-flow rates compared to lower-stage pressure ratios and higher-flow rates in axial compressors. Figure 6-3 is a map for centrifugal compressors that shows the effect of specific speed (A ) and specific diameter (Z) ) on their... 

A pressure switch located so as to sense falling pressure at the earliest moment should be used to activate the standby pump. The switch should be so connected to the system as to permit testing the startup circuit without shutting down the compressor. Figure 8-8 shows four piping arrangements. The figure at b would be the recommended method. 

Several other types of compressors are used in the process industries for a wide variety of special applications that may not fit the larger reciprocating or centrifugal compressor selections. One of the smaller compressors is a diaphragm compressor. Figures 12-116 and 12-117 and Table 12-10. 

If the back pressure on the outlet side of the compressor is below the fixed output pressure, the compressed gas will simply expand in an expansion tank or in the initial portion of the pipeline attached to the outlet side of the compressor. Figure 3-74 shows the pressure versus volume plot for a typical rotary compressor operating against a back pressure below the design pressure of the compressor. 

The cantilever design is more susceptible to process instability than centerline centrifugal compressors. Figure 36.1 illustrates a typical cantilever design. 

The bullgear centrifugal compressor (Figure 44.7) is a multi-stage unit that utilizes a large helical gear mounted on the compressor s driven shaft and two or more pinion gears, which drive the impellers. These impellers act... 

Because a pure product is required, a separator is needed. The unreacted FEED is usually too valuable to be disposed of and is therefore recycled to the reactor inlet via a pump or compressor, Figure 13.1. In addition, disposal of unreacted FEED, rather than recycling, could create an environmental problem. 

Gas turbines have enjoyed a resurgence in popularity in recent years, mainly due to substantial improvements in efficiency [2,3]. Many implementations are possible for gas turbines, but in its basic configuration, atmospheric air is drawn into a rotary compressor (Figure 9.10). The compressed air enters the combustor, where it mixes with fuel and combustion takes place. The hot gases subsequently enter a turbine where mechanical work is extracted. The gases then exit at atmospheric pressure. 

Electrochemical gas compressor — Figure. Schematic drawing illustrating the operation principles of electrochemical gas compressors... 

Basis Weight of concrete is 5 times weight of compressor. Figure 19.8 Compressor foundation. 

A steam turbine drives a compressor (Figure PI.2) whose load can change with time. Small variations in the shaft speed of the turbine are controlled through the use of a flyball speed governor. For this system ... 

The increase in molecules of SO2 by 50% enables a build-up of pressure without use of a compressor. Figure 4.2 gives the condensation temperatures of pure sulfur dioxide at different pressures. This indicates that, if a pressure of 7-8 kg/cm is maintained in the system, the liquefaction can be achieved at ambient temperature using water at 35-40 °C cooling is required at the rate of 1.12 million kcal/tonne of product. 

An oxygen-enriched product gas containing -90% O2 can be produced at near-ambient pressure by this process. Table 7 describes the performance of this process using 5A zeolite and an adsorption pressure (step b) of 3.0 atmosphere [9]. The waste gases (steps e and f) contain about 85.7% N2. The process requires three adsorbers to obtain continuous flow of feed air and product gas and continuous operation of the compressor. Figure 8a shows a schematic diagram of the process flow sheet. 

A design study for a gasoline fuel processor/fuel cell system was presented by King and O day [616]. It consisted of an autothermal reformer, sulfur removal, water-gas shift and two stage preferential oxidation. The system pressure was close to ambient to reduce parasitic power losses of the compressor (Figure 9.39). 

The energy necessary for the compression is provided by a motor drive. Due to the significantly greater degree of efficiency of rotary piston compressors, a smaller total drive power suffices in contrast to gas ejectors in combination with liquid ring compressors (Figure 3.38). 

---