Better Instrumentation

Efficient and safe operation of sulfuric add plants depends on better instrumentation for indication and recording of the following  

Sulfuric acid plants are net exporters of energy. Since energy costs are rising worldwide it is imperative to maximize the heat recovery from the plants by addressing the following  

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The ASME, Performanee Test Code on Gas Turbines, ASME PTC 22 examines the overall performanee of the gas turbine. The ASME PTC 22 only examines the overall turbine and many turbines in the field are better instrumented for eomputation of the detail eharaeteristies of the gas turbine. Figure 20-6 shows the desired loeation of the measurement points for a fully instrumented turbine. The following are the various eomputations required to ealeulate the gas turbine overall performanee based on the eode ... 

All the scientific and engineering disciplines involved in materials research are in need of better instrumentation and facihties. Suitable equipment for chemical engineers interested in materials questions might include the following ... 

Actual development of intelligent batch process control systems, for lab, pilot plant, and plant, based on better process understanding and better instruments. 

Loss of cooling can be detected by measuring the temperature within the reactor and sounding an alarm. Frequently, by the time the alarm sounds, it is too late. Design a better instrumentation and alarm configuration to detect loss of cooling more directly. Draw the instrumentation diagram. 

There is constant development and change in the techniques and methods of analytical chemistry. Better instrument design and a fuller understanding of the mechanics of analytical processes enable steady improvements to be made in sensitivity, precision, and accuracy. These same changes contribute to more economic analysis as they frequently lead to the elimination of time-consuming separation steps. The ultimate development in this direction is a non-destructive method, which not only saves time but leaves the sample unchanged for further examination or processing. 

A mass accuracy better than 1 ppm is routinely obtained by the better instruments when they are operated in a peak matching mode. An interlaboratory study of mass accuracy of different instruments and operating modes can be found in Reference 231. 

The breadth of their research similarly reflects his diverse interests and abilities. Scientifically, the research at the Institute was a continuation of the Mark directed programs in Vienna and, to a lesser extent, in Hawkesbury. Yet the Brooklyn research was improved by better instrumentation, refinement in techniques, and a unique alliance of scientists with a broad range of experiences. 

Among the most effective of the modifications to Claus operating procedure is accurate temperature control of the catalyst beds. Gamson and Elkins (27) in the early 1950 s showed that equilibrium sulfur conversion efficiencies in the catalytic redox reaction rise dramatically as operating temperatures are lowered toward the dewpoint of sulfur. While some highly efficient subdewpoint Claus type processes are now in use the bulk of sulfur production from H2S still requires that the converters be operated above the dewpoint. Careful control of converter bed temperature has, however, contributed to improved efficiencies. This has in large part resulted from better instrumentation of the Claus train and effective information feed back systems. 

In the past the successful operation of batch processes depended mainly on the skill and accumulated experience of the operator. This operating experience was difficult to codify in a form that enabled full use to he made of it in developing new1 designs. The gradual evolution of better instrumentation, followed by the installation of sequence control systems, has enabled much more process data to be recorded, permitting maintenance ol process variations within the minimum possible limits. 

The most obvious solution to problems where both high and low frequency noises are embedded in the data are better instrumental practices. For example, by sufficient coaddition, the high frequency noise component of spectroscopic imaging data can be averaged out. However, when better instrumental practices are unavailable or impractical, other means must be found to enhance the spectroscopic imaging data so that information may be extracted. The method of using second-derivative spectra, shown in this section can be used with success if the high frequency noise in the data is limited. 

Other research areas that could improve the effectiveness and economics of flue gas treatment are (1) the development of better instrumentation for system control and (2) the evaluation of superior corrosion-resistant materials. System optimization cannot occur without a good means of system control. Many existing flue gas treatment systems are particularly sensitive to instrument feedback and response. The ability to control closely the operation of these systems could enhance their effectiveness and reliability. The presence of water in flue gas treatment systems... 

Although GC has become a mature analytical technique, improvements are still being made. New and better OT columns are becoming available so that their use has expanded, requiring new and better instrument designs. Multiple columns and column switching are becoming popular a series of papers on the subject of multidimensional GC describes the current developments.30... 

The reason why we are on a higher imaginative level is not because we have finer imagination, but because we have better instruments. 

Isotopic analysis separates isotopes on the basis of smaU but significant differences in mass (see Chapter 31 by Lipschultz, this volume). This can be done using an emission spectrometer or a mass spectrometer. With both types of instruments, the sample must be converted to a gas prior to analysis. Emission spectrometers operate based on the principle that a N2 gas molecule comprised of a and wiU fluoresce at a different frequency then a molecular comprised of two Ns or two Ns (reviewed in Preston, 1993). Isotope ratio mass spectrometers separate and quantify the different N2 gas molecules based on their behavior when they are accelerated through a magnetic field (reviewed in Mulvaney, 1993). Emission spectrometers seem to have faUen out of favor in the quest for bigger and better instruments. They do have advantages, however. Emission spectrometers are much cheaper to purchase and maintain, they are portable, they require smaUer masses of N for analysis than many mass spectrometers, and there is no possibility for carry over from sample to sample because each sample is sealed in an ampoule prior to analysis. 

By use of a monochromatized synchrotron radiation source it is possible to obtain better instrumental resolution, and the variable photon energy enables one to find the optimum cross section for valence and core ionization studies. These instrumental improvements are demonstrated by the XPS studies of a number of solid Sn, In, Sb and Pb organometallic and inorganic compounds . Sb 4d(3/2,5/2) binding energies were determined for Ph SbCl, the only Sb-organic derivative in the series, with improved instrumental resolution (0.43 eV) and line width (1.01 eV). The corresponding values are 36.12 and... 

A significant amount of work has gone into understanding the sources of radioxenon in the environment, as well as how to efficiently, selectively, and sensitively measure the isotopes. Major efforts are continuing to be made to better understand the global distribution of these isotopes, to learn how to attribute elevated levels to a specific source more precisely, and to develop better instrumentation for the measurement of the xenon isotopes. 

The annual cost of equipment includes depreciation and maintenance. In addition, an allowance should be made for the loss of interest which, if the instrument had not been purchased, would have accrued from investment of the capital. Depreciation is the difference between the capital cost and the secondhand value. In practice, the secondhand value of an instrument is usually small, not because it is worn out, but because there are newer and better instruments available for performing the same task. Few instruments cannot be replaced by faster and better ones after 5 years, although many continue to be used for long after this time despite progressively increasing maintenance costs. This built-in obsolescence makes rental attractive as this enables the user to change his instrument quickly without loss of capital it may also act as an incentive to manufacturers to improve their maintenance service. 

Still the workhorse of the analytical lab, grating instruments may be somewhat slow for modern process applications. Since most classical equations have been generated on grating instruments, there is a wealth of information available for the grating user. The better instruments are quite low in noise and have excellent reproducibility. 

A value of (A20)o greater than about 0.1° points to the need for better instrument alignment. The general alignment procedure stipulated by the diffractometer manufacturer should be carried out. Two further conditions must be satisfied ... 

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