Rotating machinery

Generally, pump casings are fabricated in a material matching that used for the piping system. Pump internals are usually fabricated in corrosion-resistant materials with additional resistance to erosion, the choice of materials being dependent upon the process conditions. 

Pumps handling seawater or brine above 40 °C contaminated with oil and HjS should be fabricated in one of the super duplex stainless steels or a more corrosion-resistant material. When a wet gas stream is corrosive, the first stage of wet gas compressors should be fabricated in a corrosion-resistant material such as 13% Cr steel. 

Exhaust stacks for gas turbines should be fabricated in corrosion-resistant carbon steel. Also, stacks should be protected externally by an aluminum metal spray with an aluminum silicone sealer. Care should be taken to ensure that the design eliminates thermal fatigue. 

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Hydrate formation is possible only at temperatures less than 35°C when the pressure is less than 100 bar. Hydrates are a nuisance they are capable of plugging (partially or totally) equipment in transport systems such as pipelines, filters, and valves they can accumulate in heat exchangers and reduce heat transfer as well as increase pressure drop. Finally, if deposited in rotating machinery, they can lead to rotor imbalance generating vibration and causing failure of the machine. 

BE-7398 Advanced and preventative diagnostics of fluid handling rotating machinery Dr. F. C. Visser BW/IP International B.V. PUMP DIVISION... 

Density is a particularly important characteristic of alloys used in rotating machinery, because centrifugal stresses increase with density. Densities of the various metals in Table 1 range from 6.1 to 19.3 g/cm. Those of iron, nickel, and cobalt-base superaHoys fall in the range 7-8.5 g/cm. Those alloys which contain the heavier elements, ie, molybdenum, tantalum, or tungsten, have correspondingly high densities. 

EMEC 1988b. Monitoring and Diagnosis of Vibration in Rotating Machinery. Eoss Prevention Data Sheet No.17-4. Eactory Mutual Engineering Corporation, Norwood, MA. 

Roiaiing elecirical machines. Classificaiion ol degrees of protection provided by enclosures for rotating machinery 4691/1985 BS 4999-105/1988 ... 

Recommended practice for. testing insulation resistance of rotating machinery. 

The significance of this term can be realized by the fact that the voltage stress of a surge, having a maximum amplitude of 4.5 p.u.. with a front time / of 5 ps. will roughly be the same or even less severe compared to a surge with an amplitude of only 2 p.u. and a front time of 0.2 ps (see Insulation Sub-committee. Rotating Machinery Committee, 1981). 

I I Insulation Sub-committee. Rotating Machinery Committee. Impulse voltage strength o) AC rotating machines, IEEE Transactions on Power Apparatus and SsKtenis, PAS-100. No. 8, August (1981). 

These benefits directly translate into lower costs and improved operating efficiency for rotating machinery. Lubrication is unnecessary. The bearing is operable in hostile environments and, in many cases, can operate in the process fluid at high pressures and temperatures. Experience shows that total consumption of frictional power is drastically reduced. 

Application of Active Magnetic Bearings to Industrial Rotating Machinery, printed material of Bearing Manufacturer S2M, Vernon, France. 

Rotating machinery usually performs efficiently if it works under design point conditions. However, off-design conditions require a predictive model of the machine s performance. In a FCC power train system, mass flow deviation is quite common for adjusting production capacity to meet the requirements of petrochemical product markets. 

Gas turbines are used as prime movers for pumps, electric generators, and large rotating machinery. Their main economic advantage is driving... 

The natural structural frequencies of most large systems are also in the low-frequency range, and care must be exercised to avoid resonant couplings between the structure and the foundation. The excitation in rotating machinery comes from rotating unbalanced masses. These unbalances result from four factors ... 

Air blast, explosion, or earthquake. Nearby unbalanced macliinery. Blows, impact. Present in all rotating machinery. 

Forced (resonant) vibration. In forced vibration the usual driving frequency in rotating machinery is the shaft speed or multiples of this speed. 

Figure 5-20. Characteristic of forced vibration or resonance in rotating machinery. (Ehrich, F.F., Identification and Avoidance of Instabiiities and Seif-Excited Vibrations in Rotating Machinery, Adopted from ASME Paper 72-DE-21, Generai Eiectric Co., Aircraft Engine Group, Group Engineering Division, May 11, 1972.)...

As with other types of rotating machinery, an axial compressor can be described by a cylindrical coordinate system. The Z axis is taken as running the length of the compressor shaft, the radius r is measured outward from the shaft, and the angle of rotation 6 is the angle turned by the blades in Figure 7-2. This coordinate system will be used throughout this discussion of axial-flow compressors. 

Arcoumanis, C., Martinez-Botas, R.F., Nouri, J.M., and Su, C.C., 1997. Performance and Exit Flow Characteristics of Mixed Flow Turbines, International Journal of Rotating Machinery, 3(4) 277-293. 

Because of the minimal contact between the stationary ring and the rotor, these seals, when properly designed, are ideal for high-speed rotating machinery. 

Boyce, M.P., Morgan, E., and White, G., Simulation of Rotor Dynamics of High-Speed Rotating Machinery, Proceedings of the First International Conference in Centrifugal Compressor Technology, Madras, India, 1978, pp. 6-32. 

Bently Nevada Corp., Balancing Rotating Machinery, Report 1970, Minden, Nevada. 

Thearle, E.L., Dynamic Balancing of Rotating Machinery in the Field, Trans. ASME Vol. 56, pp. 745-753, 1934. 

Active equipment Denotes physical motion or activity in the performance of the equipment s function, as with rotating machinery. 

Ubiquitous in rotating machinery, flywheels have been used as a component of manufacturing equipment since their application in potters wheels before 2000 B.c.E. 

Safety around mechanical vacuum pumps is possibly no different than that for other process mechanical rotating machinery. However, there is a decided danger of an... 

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