ISSN:0009-286X    

DOI:10.1002/cite.330700102

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

摘要:

AbstractIn the era of globalization, the speed of change is closely related to both the population growth in developing countries and their desire to close the economic gap with the western hemisphere. Chemical engineering is considered a significant contributor in finding solutions to the subsequent challenges of food supply, energy demand and environmental impact. National economies and their constituent enterprises require qualified engineers to meet these urgent and economically demanding challenges. At present however, neither the number of engineering students nor the national focus of university education seem appropriate to cover future requirements. On the scientific level, new modelling techniques, CFD and novel system orientied methods provide a perpective for both product and process improvements. In addition to their technical ability, professional engineers must emply a flexible approach as well as soft skills to put innovative solutions into practice. This paper illustrates and details the contents of the „Memorandum Verfahrenstechnik”︁ [3], a list of recommendations which was prepared by representatives of both industry and unive

ISSN:0009-286X    

DOI:10.1002/cite.330700103

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

摘要:

AbstractProperly implemented environmental protection can prove to be an economically sound and profitable approach for processing and manufacturing industry. This requires an integrated approach with a systematic consideration, and consequent reduction, of the formation of waste products and emissions. This paper proposes a system for categorisation of the starting materials of production and for classification of waste and emission flows, and an answering strategy based thereon. Avoid ance and reduction of emissions can be achieved in four ways: increasing efficiency, increasing effectiveness, utilisation of by‐products, and substitution of starting materials. Combination of material‐flow analysis with a complete plant environmental cost calculation helps to clarify the economic benefits of production‐integrated environmental protection. More than 100 case studies conducted within the framework of cleaner production programs in Austria demonstrated the soundness and feasibility of thes app

ISSN:0009-286X    

DOI:10.1002/cite.330700104

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

摘要:

AbstractThe water management law (WHG) and the plant regulations of the German federal states stipulate boundary conditions which must be observed during work on plants handling substances which are hazardous to water. There are various possibilities for the implementation of the legal provisions. During maintenance and cleaning work on chemical plants, our aim must be to provide effective protection of our waterways and to ensure that the operating procedures are also efficient in economic terms. Procedures which have been tried and tested in practice are described. The annex gives a compilation and explanations of extracts from legal texts from the field of water legislation which are of relevance in carrying out such work.

ISSN:0009-286X    

DOI:10.1002/cite.330700105

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

摘要:

AbstractFor the design of tube bundle heat exchangers avoiding tube bundle damage caused by vibration, fluidelastic instability is the most important vibration excitation mechanism. In order to present a guideline in the VDI‐Wärmeatlas the existing recommendations ofCHEN,WEAVERandFITZPATRICKandPETTIGREWandTAYLORwere examined. They differ in the suggested equations for calculating critical velocities for single phase crossflow. With an extensive evaluation and test of consistency of the these and newly available data on this topic, better correlations could be derived. Consistent definitions of critical flow velocity, damping, natural frequency and hydrodynamic mass are used; their values are to be determined in the still fluid with the density ρ. Confident documented data show only a small scatter. The other data deviate more, but mainly to the safe s

ISSN:0009-286X    

DOI:10.1002/cite.330700106

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

摘要:

AbstractDynamic interfacial tensions provide insight into the mechanism of surfactant adsorption at and transport across an interface. As an example, the adsorption kinetics and the distribution of a surfactant (alkyl dimethyl phosphine oxide with an alkyl chain length of 13) was studied at the water/hexane interface. The drop shape method used yields dynamic interfacial tensions that pass through a minimum under certain conditions. Model calculations show that depth, width and location of the minimum and the equilibrium adsorption state depend on several parameters: the diffusion coefficients of the surfactant in the two liquids, the distribution coefficient between the phases, the liquids volume ratio, and the total surfactant concentration in the system. One can conclude that surfactants are often soluble in both liquid phases, and transfer across the interface between them has to be considered. If a surfactant is to be optimized in a liquid‐liquid system to achieve maximum efficiency of a technological process, the surfactant distribution coefficient plays a significant rol

ISSN:0009-286X    

DOI:10.1002/cite.330700107

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330700108

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330700109

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330700110

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330700111

出版商:WILEY‐VCH Verlag    

年代:1998

数据来源: WILEY