Technikatörténeti szemle 19. (1992)

KÖNYVISMERTETÉS - Papers of the First „MINERALKONTOR” International Conference on the History of Chemistry and Chemical Industry (Veszprém, 12-16 August, 1991)

JÁNOS INCZÉDY* CONTRIBUTIONS TO THE HISTORY OF PROCESS ANALYTICAL CHEMISTRY Introduction The regulation and control received a special significance in the modern high tech industrial technologies, where the technological parameters may change only between very narrow limits, and the product itself is a sophisticated one, with a structure controlled uniform composition. Today the development of special instruments for process control is an extra field of the analytical chemical research activities, because the requirements against the process analytical instruments are different from the usual analytical instruments used in laboratories. Some of the special requirements are: ruggedness, long term stability, low cost of maintenance, relatively short dead and/or response time, and automatic operation. It is interesting to note, that the ambition to develope automatic measurement systems for the continuous control of the industrial process streams is fairly old. It was strongly bound to the development of the chemical industry, and therefore its history goes back to ca 100 years, when there were no any traces of the new modern computerised control and management systems. In the next two paragraphs some examples of the early automatic measuring systems, as well as some early regulating systems are introduced. Early automatic measuring systems Gas-analysers. One of the very first instrument by which the composition of a gas stream could be followed was patented by F. Lux (Ludwigshafen) (1) in 1886. This was the early version of the gas density balances used also today. It was suggested for the continuous control of the composition of lighting gas. It is interesting to note, that the device was suggested also for the continuous measurement of the density of liquids (e. g. alcohol-water mixture). By an improved version of the instrument (2) certain gas components could be selectively determined. Two bulbs were posed on the ends of the two arms of the balance, and the gas stream, which is investigated was introduced first to bulb A, and after passing an absorbing liquid containing device, to the second bulb denoted with B. If one component of the original gas mixture was absorbed in the absorption device selectively and its own density was different from that of the bulk, a chan•University of Veszprém, H-8200 Veszprém, Pf. 158.