Equipment improvements INDEX

For use with process-equipment estimates and chemical-plant investment estimates, the Marshall and Swift equipment cost indexes and the Chemical Engineering plant cost indexes are recommended. These two cost indexes give very similar results, while the Engineering News-Record construction cost index, relative with time, has increased much more rapidly than the other two because it does not include a productivity improvement factor. Similarly, the Nelson-Farrar refinery construction index has shown a very large increase with time and should be used with caution and only for refinery construction. 

The development of a continuous grinding index was the focus of work in the late 1970s (59). The laboratory test equipment used is similar to that for the Hardgrove test but permits classifying the product and recycling the oversize material. An improved correlation is obtained that may, however, need to be corrected for the relative sizes of the test grinding balls versus those used in commercial-scale equipment. The continuous grinding index is especially useful for lower rank coals. 

Figure 14 illustrates a comparison between solvent extraction yields predicted from adsorption analyses and actual raffinate yields in commercial solvent extraction plants. Few commercial yields have ever equaled those obtained by adsorption analyses and none has exceeded those values hence, curve A (45° angle) represents the ultimate in solvent extraction. Curve B represents solvent extraction in commercial equipment on stocks ranging in viscosity index from +25 to +110, and for viscosity index improvements ranging from 30 to 130. Extremely viscous stocks or those which require a very large viscosity index improvement have been observed to follow more closely lines C and D. 

Where possible, commercial sources of reagents, kits, and equipment are listed throughout the text instead of in a separate index. Extensive references are provided to facilitate the task for those readers who may wish to consult the literature for additional information on specific topics. All books can be improved, and this volume is no exception. I welcome constructive criticism from my colleagues and students. With this help I look forward to offering a greatly improved second edition. 

OCP OEM Olefin copolymer viscosity modifier or viscosity index improver. Original equipment manufacturer. The company that makes the vehicle or unit, e.g., Ford, GM. 

In a quite different but very important industrial area, free-radical polymerizations have made great inroads In the optimization of the desired commercial properties of impact-modified poly(vinyl chloride) (PVC). In a most sophisticated variation, grafted impact modifiers based on the quaterpolymerization of acrylic esters, butadiene, styrene, and acrylonitrile have been produced and almost precisely match the refractive index of PVC. The blending of the Impact modifier with PVC yields a completely clear polymer suitable for shampoo bottles and food containers. In addition to excellent clarity these polymers have extremely good impact strength combined with improved fabricability by flow molding equipment. 

To improve the accuracy of measurement on short sub-sections of a road, a microprocessor-based integrator unit has been developed and has replaced the mechanical integrator fitted to the trailer of the standard bump integrator. The new equipment enabled the unevenness index of sub-sections as short as 30 m to be measured with an accuracy of better than 3%. This accuracy on short sub-sections made the bump integrator suitable for use with the CHART highway maintenance system (Still et al. 1983). 

Pre-emphasis is employed in an FM broadcast transmitter to improve the received signal-to-noise ratio. The pre-emphasis upper-frequency limit is based on a time constant of 75 /ts as required by the FCC for FM broadcast transmitters. Audio frequencies from 50 to 2120 Hz are transmitted with normal FM whereas audio frequencies from 2120 Hz to 15 kHz are emphasized with a larger modulation index. There is significant signal-to-noise improvement at the receiver, which is equipped with a matching de-emphasis circuit. 

As demand for polyethylene has increased, there has been a continuous effort to improve catalyst activity. This was important to achieve high productivity at relatively short residence times. These properties have avoided the need to remove catalyst residues from the product It was also important for polypropylene to have a high isotactic index to ehminate the need for equipment for the extraction of atactic polymer. 

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