Large-size processes

Microstructures on Macroscale MicroChannel Reactors for Medium- and Large-Size Processes... 

A list of fabrication jobs to be done at site shall be known such as storage tanks large-sized process vessels like converters, absorption towers (which need internal linings) distillation columns (with internal fittings of trays). 

In apphcations where the fraction of fine particles in the soHds of the feed slurry is low, a simple and relatively cheap vacuum filter can yield cakes with moisture contents comparable to those discharged by pressure filters. Vacuum filters include the only truly continuous filters built in large sizes that can provide for washing, drying, and other process requirements. 

When reactor-grade plutonium is left in spent fuel, the large size of the fuel assembhes and the lethal radiation fields make it extremely difficult to divert the material covertly. Once the reactor-grade plutonium is separated in the commercial reprocessing option, however, the radiation barrier is almost eliminated, and in certain steps of the process the plutonium is in powder or Hquid form, which is much more easily diverted than large, bulky fuel... 

There is, however, only a limited quantity of by-product power available, and for large process operations the demand for power is usually far greater than the simple steam cycle can produce. Many steam system design decisions fall back to the question of how to raise the ratio of by-product power to process heat. One simple approach is to limit the turbines that are used to extract power to large sizes, where high efficiency can be obtained. 

For most large-scale processes, adsorbent particle size varies from 0.06 to 6 mm (0.0025 to 0.25 in), but the adsorbent packed in a fixed bed will have a fairly narrow particle size range. Pressure drop in adsorbers can be changed by changing the diameter to bed depth ratio and by changing the particle size (see Sec. 5). Adsorbent size also determines separation performance of adsorbent columns—increasing efficiency with decreasing particle size. In hquid-phase process-... 

Commercial centrifuges of this type have bowl diameters ranging from 0.3 to 2.4 m (12 to 96 in). The large sizes are used on heavy-duty apphcations such as coal dewatering and are limited by stress considerations to operate at 300g. The intermediate sizes for chemical process service develop up to lOOOg (see Table 18-10). 

Mold This process is particularly suited economically to producing small production runs and large-sized products, because molds are not subjected to relatively any pressure during molding and inexpensive thin sheet metal molds can thus be used in many applications. Lightweight cast aluminum and... 

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