Automation controllers

Zinc. The electrowinning of zinc on a commercial scale started in 1915. Most newer faciUties are electrolytic plants. The success of the process results from the abiUty to handle complex ores and to produce, after purification of the electrolyte, high purity zinc cathodes at an acceptable cost. Over the years, there have been only minor changes in the chemistry of the process to improve zinc recovery and solution purification. Improvements have been made in the areas of process instmmentation and control, automation, and prevention of water pollution. 

Also important is the interplay between different sensors, controllers, automation equipment, and objects regulated by the control equipment. The requirements of pumps, fans, batteries, heat exchanger, valves, motors, etc. in standard sizes may greatly differ from the theoretical calculations. Because of this fact, the control equipment, in addition to satisfactory control, must be capable of correcting the differences between the calculated and delivered subproducts. 

Figure 7.20 Computer-controlled automated scanning densitometer for quantitative TLC.

Hollow-cathode lamps are currently available for over sixty elements. Several multi-element lamps have been constructed and are useful for routine determinations, but they have proved to be of doubtful performance up to now. More successful with regard to multi-element analysis have been computer controlled automated systems, which enable a programme of sequential measurements to be made with instrumental parameters being adjusted to the optimum for each element to be measured. 

Effective collaboration among the core four PA disciplines analytical, chemometrics, process engineering and control automation along with other disciplines (e.g., pharmacist, chemist, analyst, product formulators, etc.) is imperative to realize effective PAT solutions that are consistent with the intended lean manufacturing or QbD objectives. 

As with any process analytical application, instrument selection is based on the required analytical merits (sensitivity, dynamic range, precision and accuracy, etc.), process and enviromnental conditions, integration complexities (mechanical and controls automation) and operational and maintenance requirements. Because of the wide disparity in analytical performance and functionalities among photometric and spectroscopic LIE process instruments, selection should be carefully weighed on the basis of the technical problem, instrumental cost, implementation complexities, ease of use, conunercial and legacy maturity, level of vendor support and cost of ownership. 

The HP 6890 series GC gas-samphng valve technology, in conjunction with programmed interval sampling, makes this type of GC-based quahty-control automation a reahty. The GC can control and sense the position of multi-position valves to make it possible to automate sample-stream selection. Each sample, which is downloaded automatically, can then be analysed by a different method. Automated analysis of multiple process streams is especially attractive and cost-effective for complex chemical and petrochemical operations in which raw materials for product streams need to be assessed at regular intervals. 

This analyser is a computer-controlled automated batch analyser, using a stop-flow principle to analyse for pH, conductivity, turbidity and colour. TTie principle of analysis for each module is based on the recommended methods as detailed in the Examination of Waters and Associated Materials issued by the Standing Committee of Analysts of the Department of the Environment. The temperature of the sample hquid flow is measured in order that temperature-compensated results of pH and conductivity can be quoted. 

Finally, radiopharmaceuticals are often prepared on a daily basis within the framework of clinical studies which often last several months or years. They demand a viable and reproducible production chain, leading to a sterile- and pyrogen-free radiopharmaceutical of high radiochemical purity. Therefore, microprocessor-controlled automated synthesis devices [31] are developed in order to ensure routine pharmaceutical production. They are becoming mandatory in order to meet the demands related to Good Laboratory Practice (GLP) and Good Manufacturing Practice (GMP). 

New to the industry is the requirement that all electronically kept records be validated in accordance with the CFR (Title 21, Volume 1, part 11 revised April 1, 2003 requirement. This is particularly true of instances in which the systems are custom-designed and, furthermore, where computer-controlled automated processes are used. There remain many misconceptions about makes up computer validation. The CFR guideline as listed below should be well understood ... 

In a DSC experiment the difference in energy input to a sample and a reference material is measured while the sample and reference are subjected to a controlled temperature program. DSC requires two cells equipped with thermocouples in addition to a programmable furnace, recorder, and gas controller. Automation is even more extensive than in TA due to the more complicated nature of the instrumentation and calculations. 

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As in the LPCVD reactor discussed earlier, allowing the electrode structure to touch the tube wall as it is inserted leads to considerable particle contamination. Therefore, cantilever loaders are available here also, and a typical unit on an ASM reactor is shown in Figure 23. Again, in contrast to the AMP-3300, this system is operated under computer control. Automated handling of wafers is more difficult to achieve, and is not generally available. 

The Millilab 1A workstation is a personal computer-controlled automated robotic system which performs sample extraction from filters and SPE devices according to user-defined programs. This was used to compare the efficiency of different SPE materials, as manual error is substantially reduced. The results are listed in Table 26.1. 

Furthermore, radiopharmaceutical synthesis must be reliable and efficient and result in pharmaceutical-quality products. In addition, the processes must be well documented and controlled. Automated systems may support all these challenges and requirements. 

FIGURE 8 Production laboratory for PET radiopharmaceuticals. The 10-cm lead shielded hot cells contain computer-controlled automated synthesis modules. (Photo courtesy of PET-CUN Center, University of Navarra.)... 

Determine if the computerized system can be operated manually. How is this controlled Automated CIP (cleaning in place)... 

Robert Fretz joined F. Hoffmann-Fa Roche more than 30 years ago as a chemical engineer. He is presently responsible for Process Automation in all chemical and galenical manufacturing sites and leads the corporate Mamrfacturing Execution systems program. Mr. Fretz has broad international experience in all levels of control/automation projects from instrumentation to the enterprise level. Many of these projects included computerized system validation. He co-authored the Hoffmann-Fa Roche corporate guideline on Process Automation Qualification. 

He was elected to the National Academy of Public Administration in 1985, and he was a fellow at the Woodrow Wilson International Center for Scholars, Smithsonian Institution, and a research fellow at the Wissenschaftszentrum (Sciences Center) Berlin and the Max Planck Institute for Social Research, Cologne. He has been a member of the Board on Radioactive Waste Management and panels of the Committee on Human Factors and the Transportation Research Board of the National Academy of Sciences. He served on the Secretary of Energy Advisory Board, Department of Energy, and chaired its Task Eorce on Radioactive Waste Management, examining questions of institutional trustworthiness. He was a member of the National Research Council s panel on Human Eactors in Air Traffic Control Automation and the Technical Review Committee for the Nuclear Materials Technology Division, Los Alamos National Laboratory. 

For routine syntheses of labelled compounds, automated procedures have been developed which enable fast, safe, reproducible and reliable production. Automation has found broad application for the synthesis of radiopharmaceuticals. All steps must be as efficient as possible. For that purpose, target positioning and cooling, irradiation, removal of the target after irradiation, addition of chemicals, temperature and reaction time, purification of the product and dispensing are remotely controlled. Automation may be aided by computers and robotics may be apphed. 

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