ISSN:0009-286X    

DOI:10.1002/cite.330610302

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractNew converter systems for methanol synthesis.Far‐reaching energy savings in equilibrium reactions requires development not only of better catalysts but also processes with higher conversions in the reactor; wherever possible, so high that recirculation of residual gases is unnecessary. With this aim in mind, two new processes have been developed for methanol production and this paper represents the first report about the second of these processes. The two new reactor concepts are based on the gas/solid/solid‐trickling film reactor GSSTFR and the reactor with intermediate product removal RSIPR. In the case of the GSSTFR, the product formed at the catalyst is removed directly from the reactor with a solid adsorbent which moves down through the catalyst bed. Conversions of 100% are achieved in the simplest way – recirculation becomes unnecessary. Savings in investment costs, energy, and raw materials are discussed and compared with the Lurgi process. With the RISPR, high conversions are achieved by selective absorption of the methanol at the temperature of reaction. Tetraethylene glycoldimethylether, TEGDME, is selected as solvent for this purpose. A possible flow scheme is also shown for this process and savings are estimated. Possible savings are so promising that further development on a semi‐industrial scale is reco

ISSN:0009-286X    

DOI:10.1002/cite.330610303

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractThe role of sensors in process engineering.The principal function of sensors in process engineering is to obtain information about an ongoing process in order to ensure optimum management of that process in terms of process engineering. New methods of measuring conventional parameters, and recent advances in instrumentation technology, have improved ways of obtaining information and so influenced the interpretation of process engineering installations. Statistical evidence confirms a sharp increase in the number of sensors, and the increasing tendency to record flow and level measurements and product composition. Changes occurring in process engineering determine the requirements sensors have to meet and the ways in which they can be used. Microelectronics makes it possible to extend the range of functions available and the information content. This is giving rise to an new generation of sensors which are not only helping to meet the higher measurement standards required but are also making modern sensor technology more „user friendly”︁, specially for mainte

ISSN:0009-286X    

DOI:10.1002/cite.330610304

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractEquilibria and technical equipment for neutralization of alkaline water with CO2.Alkaline water can be neutralized by means of carbonic acid. The particular advantages of this method are that there is no increase in the content of neutral salts and that the product water is well buffered and therefore does not favour corrosion. Furthermore, neutralization can easily be combined with an aeration. The paper discusses physico‐chemical fundamentals and presents some neutralization device

ISSN:0009-286X    

DOI:10.1002/cite.330610305

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractPolymerization engineering.Polyreactions are complex chemical reactions which are generally conducted in liquid phase. The characteristic feature of polyreactions is the pronounced increase in viscosity of the reactants during the reaction. The increase in viscosity influences numerous reaction and process parameters, such as the reaction kinetics, the transfer of mass, heat, and momentum, the degree of mixing of the reactants, and the residence time distribution of continuous reactors. Thus the increase in viscosity influences the performance, selectivity, and safety of the reactor. The choice of reactor for performing polyreactions can be based on various aspects. Of decisive importance are the performance and selectivity of the reactor. For the cases of simple and complex polyreactors, various kinds of reactors are compared with respect to their performance and selectivity, with the molar mass distribution of the resulting polymers serving as example of the selectivity of polyreactions. In the case of simple polymerizations, the molar mass distribution of the polymers depends unequivocally on the type of reactor and the various reactor types can be arranged in appropriate order. This is no longer the case for more complex polymerizations because the concentration conditions in the reactors play an increasingly important role.

ISSN:0009-286X    

DOI:10.1002/cite.330610306

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractCorrosion phenomena in flowing media, illustrated for chemical pumps.It is shown how centrifugal pumps in chemical plant are exposed to a complex superposition of (static and dynamic) mechanical and thermal stresses, of corrosion, erosion/abrasion and cavitation. Then examples of pump parts that have been operated under service conditions are shown to demonstrate appearance and origin of flow‐induced, erosion‐ and cavitation‐corrosion. Materials concepts are discussed that are able to avoid or reduce these phenomena. Several pump‐like test methods are introduced that permit selection of pump materials in accordance with the practical service conditions, where hydraulic, design, and materials criteria have to be optimized to guarantee long pum

ISSN:0009-286X    

DOI:10.1002/cite.330610307

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610308

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractApplication of the QuaT temperature measuring system in process measurement engineering.Resistance thermometers and thermocouples are today's standard in industrial electrical temperature‐measurement techniques. Their weaknesses, which were not so important, have become obvious with the advanced application of digital data loggers and data control units. These weaknesses include: uncertainty wether such a measuring line is predictable; the transmitter has to be defined with regard to the parameter, for each individual application; and transfer of the measured signal from the field to the central unit needs considerable effort. A temperatur measurement system has now been introduced which does not have these disdvantages, because it is using a piezoelectric resonator as a sensor element. Thus signal processing is „digital”︁. Advantages and disadvantages of both kinds of instrumentation are presented. The suitability of the new system, also regarding costs, is confirmed by the results from five industrial test p

ISSN:0009-286X    

DOI:10.1002/cite.330610309

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610310

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610311

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY