摘要:

AbstractMeasures for intensifying heat transfer.Various approaches to the intensification of heat transfer have occupied engineers for many years. Many proposals failed to be accepted while others have been adopted in practice and have led to considerable savings in energy and materials. This article considers a number of topical developments in the improvement of convective heat transfer, heat transfer on evaporation, and heat transfer on condensation. The authors cite primarily review articles from among the extensive body of literature pertaining to this field of study.

ISSN:0009-286X    

DOI:10.1002/cite.330560602

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330560603

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractEconomic aspects of heat exchanger design.The economic design of a heat exchanger results in the minimum total cost over the expected lifetime. This needs a balance between the two groups of costs, capital investment and running costs. However, a general quantitative description of these cost groups is not possible due to the large number of variables, in practice one is limited to approximating analyses. In some cases a mere capital cost minimization will suffice; often, however, operating costs due to pumping power or price of heat have to be considered additionally. Further, it is important to note that the annual operating hours and the plant availability cannot be predetermined exactly and yet have a large effect on total cost. Therefore, and since one cannot take into account all the optimization parameters, one has to examine each individual case and devise a rational optimization routine. This paper illustrates the various levels of optimization and should facilitate the selection and hence promote the economic design of heat exchange equipment.

ISSN:0009-286X    

DOI:10.1002/cite.330560604

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractCauses and effects of fouling and scaling of heat transfer surfaces.Fouling and scaling of heat transfer surfaces may lead to considerable performance losses of heat exchangers. During design compensation is made by overdimensioning based on estimated fouling factors, with varying degrees of success. A proper knowledge of the causes of fouling and of the time dependency of the fouling resistance would be better because the fouling effect could then adopting limited by reasonable preventative measures. At present, continuously operating cleaning systems are predominantly applied. A general description of the fouling process – deposition and removal – would require an analytic fouling mo

ISSN:0009-286X    

DOI:10.1002/cite.330560605

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractThe significance of biotechnology for industrial chemistry.In the next few decades biotechnology will bring about fundamental innovations in the fields of health, nutrition, and agriculture as well as in important branches of industrial production, such as chemistry, which may well be comparable in importance with the present revolutionary technical progress based on electronics. Justification for these forecasts comes mainly from pioneering scientific advances in the fields of molecular biology, biochemistry, and microbiology. Particular mention should be made here of the fascinating potential of genetic engineering methods presently undergoing rapid development. However, less spectacular techniques, such as cell fusion and the immobilization of enzymes or whole living cells on polymeric substrates to give manageable, long‐lived biocatalysts, will also contribute to this wave of innovation. Some of these new developments are now gaining acceptance in industrial productio

ISSN:0009-286X    

DOI:10.1002/cite.330560606

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

摘要:

AbstractFabrication of pellets with defined pore‐size distribution.The fabrication of porous alumina‐pellets of high mechanical strength and with a well defined pore‐size distribution by pelletization and by extrusion is described. Macropores can be introduced through solid material which is vaporized after agglomeration; the content of macropores can thereby be chosen within a rather wide range. The amount of micropores in the pellets can be controlled by thermal treatment (sintering). Mechanical strength is obtained if the primary particles are connected by bridges of solid material, generated from substances dissolved in the liquid which fills the pores before drying. The mechanism and the procedure leading to the formation of porous alumina‐pellets are also applicable if silica or zeolites are to be agglomerated into porous pellets of high mechanical s

ISSN:0009-286X    

DOI:10.1002/cite.330560607

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330560608

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330560609

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330560610

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330560611

出版商:WILEY‐VCH Verlag    

年代:1984

数据来源: WILEY