Casing multistage

Ring Section Casing (multistage) 1. Pressure containment (2.2.7 2.2.8)... 

Membranes mostly made of acetylcellulose or more preferably polyamide. Large pressure differences mean complicated desalination plant construction (in some cases multistage). Pretreatment of water necessary as for distillation plants... 

The coalescence times for oil and water drops at the crude oil/water interface using the three crudes Tia Juana Medium, Put River and Zakum are shown in Table 1. Multistage coalescence was observed for oil and water drops with Zakum at pH 11, in all the other cases multistage coalescence was not observed. The Zakum oil/water interface at pH 11 also exhibited the lowest (hardly measurable) interfacial viscosity of all the systems studied. 

In many cases, multistage vacuum pumps consume less energy than single-stage pumps while doing the same job. Power requirements may be reduced as much as 50%. Rotary blowers are often called mechanical booster pumps because they are commonly used as a first stage in a multistage system. 

Since its conception, the dynamic filter has been widely reported and further developed. Most European designs are comprised of a multistage disk arrangement (Fig. 28) with both the rotating and stationary elements covered with filter cloth, thus utilising the space inside the pressure vessel. Such filters have been found (29) to be from 5 to 25 times more productive in mass of dry cake per unit area and time than filter presses for the same moisture content of the final slurry. In some cases, the moisture content with the dynamic filter was actually lower than with a filter press. The maximum productivity was achieved with peripheral disk speeds from 2.8 to 4.5 m/s. 

Polypropylene polymers are typically modified with ethylene to obtain desirable properties for specific applications. Specifically, ethylene—propylene mbbers are introduced as a discrete phase in heterophasic copolymers to improve toughness and low temperature impact resistance (see Elastomers, ETHYLENE-PROPYLENE rubber). This is done by sequential polymerisation of homopolymer polypropylene and ethylene—propylene mbber in a multistage reactor process or by the extmsion compounding of ethylene—propylene mbber with a homopolymer. Addition of high density polyethylene, by polymerisation or compounding, is sometimes used to reduce stress whitening. In all cases, a superior balance of properties is obtained when the sise of the discrete mbber phase is approximately one micrometer. Examples of these polymers and their properties are shown in Table 2. Mineral fillers, such as talc or calcium carbonate, can be added to polypropylene to increase stiffness and high temperature properties, as shown in Table 3. 

Motor-driven, multistage reciprocating compressors have reportedly been the most popular choice for aeroderivatives. Motor-driven, oil-fiooded screw compressors are also used in some cases. High horsepower, multistage centrifugal compressors, similar to those used at many pipeline compressor stations, may be required for the newer heavy-duty units if the distribution pipeline pressure is insufficient (see Pipelines). Gas turbines have more stringent fuel-gas specifications in terms of cleanliness than do gas-fired boilers. Thus oil- and water-knockout systems, coalescing filters, and fine-mesh filters are used. 

Multistage pumps may be of the volute type (Fig. 10-41), with single- or double-suc tion impehers (Fig. 10-42), or of the diffuser type (Fig. 10-43). They may have horizontahy split casings or, for... 

As the feed-to-steam ratio is increased in the flow sheet of Fig. 11-125 7, a point is reached where all the vapor is needed to preheat the feed and none is available for the evaporator tubes. This limiting case is the multistage flash evaporator, shown in its simplest form in Fig. 11-125 7. Seawater is treated as before and then pumped through a number of feed heaters in series. It is given a final boost in temperature with prime steam in a brine heater before it is flashed down in series to provide the vapor needed by the feed heaters. The amount of steam required depends on the approach-temperature difference in the feed heaters and the flash range per stage. Condensate from the feed heaters is flashed down in the same manner as the brine. 

When it is desired to compute, with rigorous methods, actual rather than equilibrium stages, Eqs. (13-69) and (13-94) can be modified to include the Murphree vapor-phase efficiency T ij, defined by Eq. (13-29). This is particularly desirable for multistage operations involving feeds containing components of a wide range ol volatility and/or concentration, in which only a rectification (absorption) or stripping action is provided and all components are not sharply separated. In those cases, the use of a different Murphree efficiency for each component and each tray may be necessary to compute recovery accurately. 

The centrifugal compressor is composed of a casing containing a rotating element, rotor, which is supported by a set of bearings. For most multistage compressors, shaft end seals are located in-board of the bearings. 

In almost all cases the molecules have a higher value as liquid than as gas. Crude oil streams typically contain a low percentage of intermediate components. Thus, it is not normally economically attractive to consider other alternatives to multistage separation to stabilize the crude. In addition, the requirement to treat the oil at high temperature is more important than stabilizing the liquid and may require the flashing of both intermediate and heavy components to the gas stream. 

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