ISSN:0009-286X    

DOI:10.1002/cite.330610802

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractEquipment made of special materials.Errors in the planning phase of capital expenditure and major repairs often lead to particularly high costs in remedying them. The investigations that were necessary to ensure reliable manufacture are described with reference to a heat exchanger made of zirconium. In addition to design details, the testing of the explosiveclad tube sheets and the welding of the heat exchanger tubes are explained at length. In the repair sector a report is given on damage to an evaporating vessel made of nickel‐clad sheet. Particular attention is paid to the build‐up of tension in the cladding in relation to the support material. A second example of damage is used to show the influence of design details on the damage mechanism. In this case Monel 400 piping is invol

ISSN:0009-286X    

DOI:10.1002/cite.330610803

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractChoice of materials for air‐cooled heat exchangers.Air has many advantages as a coolant for industrial processes. It is available in any desired quantity and does not incur costs for supply and disposal. Although air is far less corrosive than water, there are limitations for certain materials and air contaminations. The possibility of using different materials for the process side and the cooling air side, with the latter preferably having an enlarged surface area, can be exploited to advantage to take account of material‐specific properties of the two sides. Process‐dictated limits of optimum surface area increase and temperature‐dictated limits of application and proven fin patterns, are demonstrated. Attention is drawn to actual cases of damage taken from practice and their lessons and also to some unexplaine

ISSN:0009-286X    

DOI:10.1002/cite.330610804

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610806

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractIs hydrodynamic modelling a sound approach for the design of gravity settlers without coalescing aids?Liquid/liquid dispersions occur in many chemical operations. Normally they have to be broken down again. This is accomplished by the flowing together of the droplets (coalescence) to a coherent phase. In practice simple gravity settlers without any coalescing aids are used for this purpose. In such settlers the dispersion is separated by the density difference between the phases, while a dense dispersion layer forms at the interface between the dispersion and the clear mother phase. The present paper deals with the modelling of such gravity settlers. First, the models describing the coalescence process of single drops are reviewed and analyzed. A physical notion of the coalescence process is derived thereform. Afterwards the models for the droplet coalescence in dense dispersions taken from the literature are presented and discussed. In conclusion the chances and limitations of the present settler models are indicated by quantitative comparison of selected models. A computer program specially developed for this purpose is presented.

ISSN:0009-286X    

DOI:10.1002/cite.330610807

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610809

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

摘要:

AbstractImmobilized enzymes – kinetics, efficiency, and applications.Immobilized enzymes represent an important class of catalysts. They are used in many industrial processes, some of which are economically significant. The introduction of other new processes is to be expected, and some examples are briefly described. Certain conditions have to be satisfied for their practical application. They can be summarized in a set of characteristic parameters or properties. The principal properties of a biocatalyst include its kinetics and its efficiency. Both of these are discussed at length. Possible catalyst designs permitting improvement of efficiency with mass transfer limitation are describe

ISSN:0009-286X    

DOI:10.1002/cite.330610810

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610811

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610812

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330610813

出版商:WILEY‐VCH Verlag    

年代:1989

数据来源: WILEY