摘要:

AbstractTransport phenomena in three‐phase reactors with fluidized solids.Three‐phase reactors with fluidized solids have a wide range of application. It extends from catalytic hydrogenation, oxidations, polymerizations, and reactions of synthesis gas to coal liquefaction plant and applications in biotechnology. Considerable advantages of these reactors lie in the intense degree of contact between the phases and in their high thermal stability relative to other types of reactors. Pertinent model concepts of fluid dynamics are treated qualitatively, and our present knowledge about transport phenomena within and between the phases is reviewed. Modelling of these reactors is considered in conclus

ISSN:0009-286X    

DOI:10.1002/cite.330550802

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractChemical engineering and economic aspects of converting dilute SO2gases into sulphuric acid.In the contact process for production of concentrated sulphuric acid the lowest limit for the autothermal processing of dilute SO2gases lies at around 2 vol.‐% SO2provided that a pre‐drying concentrating system is in use. Yet more dilute SO2gases can be processed by Ciba Geigy's nitrogen oxide/sulphuric acid process – a modern version of the well‐known lead chamber process – which is already producing 70 to 75% H2SO4from molybdenum disulfide roasting waste gases of ca. 1 vol.‐% SO2on an industrial scale. The paper considers not only the specific boundary conditions, and chemical engineering characteristics of the two fundamentally different processes but considers above all the economics of processing low‐concentration SO2gases for s

ISSN:0009-286X    

DOI:10.1002/cite.330550803

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractElementary processes in the production and stabilization of emulsions.When developing new emulsifying agents with a specially low environmental impact, when using emulsifying agents in various branches of industry, and when breaking down emulsions (a very frequent requirement), an understanding of the elementary processes which take place is of great help. The paper provides a comprehensive account of the various elementary processes involved in the production and stabilization of emulsions otherwise scattered throughout the literature. The interplay of the individual elementary processes shows how emulsifying agents and stabilizers differ in their modes of operation. In discussing the structures which occur in aqueous tenside systems, it is pointed out that the swelling of micelles is an elementary process responsible for solubilization and cream formation.

ISSN:0009-286X    

DOI:10.1002/cite.330550804

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractApplications of variable speed three‐phase motors in the chemical industry.For good reasons, three‐phase motors are used very widely in the chemical industry. Their considerable operation advantages have formerly been offset by the drawback of an invariant speed. Since the use of variable‐speed three phase motors (with transistor and thyristor technology) has become economical in various applications, new opportunities are opening up for chemical engineering. In order to demonstrate the wide application of this new technology, the article first surveys the electric motors used in a large chemical plant. The two principal motivations for using variable speed three‐phase motors are then considered, viz. energy saving and chemical engineering improvements, and the attainable advantages are set out against the technical and economical limitations on use. In conclusion, the risk of breakdown of variable speed three‐phase motors is discussed in relation to conventional t

ISSN:0009-286X    

DOI:10.1002/cite.330550805

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractCost reduction by planned maintenance, paying attention to required plant availability.Availability, plant utilisation, plant safety and maintenance are interrelated. The intensity and degree of planning of maintenance has to be within given conditions – and reduction of the degree of planning can also lead to a remarkable cost reduction in maintenance. Planned maintenance signifies not only optimization of the above relations, but also the performance of work in a highest amount of planning. Because maintenance costs are largely personnel costs, the planning and control of work have to lead mainly to an increase of effectivity of maintenance personnel. The following examples and numbers may show how organisational and technical measures can effect an increase of planning possibilities, and hence a cost favourable situatio

ISSN:0009-286X    

DOI:10.1002/cite.330550806

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330550807

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330550808

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330550809

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330550810

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330550811

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY