摘要:

AbstractPresentation or various noise‐limitation measures and their significance. The task of noise limitation is becoming increasingly important within the general framework of environmental protection. Legislation prescribing certain maximum noise levels at the place of work and in the neighbourhood requires means of reducing noise levels by 20 to 30 dB (A), and in some cases by 40 dB (A). This applies both to individual units and to complete plants. It is nowadays no longer possible to achieve the stipulated noise protection solely by secondary measures since this would impose too great a burden on the operator. Instead low‐noise units and technologies should be developed. This requires the use of primary measures for noise reduction at sou

ISSN:0009-286X    

DOI:10.1002/cite.330540302

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractDevelopment of crystallizers. The control of the crystallization kinetics and the spatial variation of the crystal mass are of decisive importance for the operation of industrial crystallizers. The influence of micro‐ and macro‐attrition is demonstrated with particular reference to collisions with impeller blades and to breakage of crystals between impeller and draft tube. Spatial variations of supersaturation and crystal mass within the crystallizer have been shown to influence crystal size distribution. These variations are described by physical and mathematical models. Crystal size distributions measured in both pilot and industrial crystallizers show that simulation with the proposed models is very reliable. A model approach provides valuable support for the development of industrial crystallizers and also for the development of control using microprocess

ISSN:0009-286X    

DOI:10.1002/cite.330540303

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540304

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractMomentum and mass transfer in packed beds subject to gas flow in high‐temperature reactors and shaft furnaces. Dependable design of fixed and traveling bed reactors operating at high temperatures requires a detailed knowledge of heat and mass transfer at the solid surface and precise information about the pressure and gas velocity distribution inside the fixed bed. Special interest is focussed on the mixing of different component streams in some packed beds. The mixing depends on several parameters, such as particle size, bed length and diameter, configuration of junction points, and mass flow ratio of the individual gas streams. A general view summarizes our present knowledge of physical models of momentum and mass transfer and of mathematical descriptions of processes occurring in packed beds in terms of technical geometry (three‐dimensional array). In particular, possibilities of calculating the dispersion in complex packed beds through which flow take place are displayed. In this connection it is shown there are still some unsolved probl

ISSN:0009-286X    

DOI:10.1002/cite.330540305

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractInfluence of polymers on the flow of liquids – mechanisms and practical uses. The effect of high polymer additives in laminar and turbulent flow is presented. The publication shows that just a few ppm of high molecular substances can drastically alter the properties of flowing systems when these flows exhibit regions of high expansion rates. The effect of polymers in laminar flow leads to an increase in pressure drop compared to the flow of Newtonian media. In turbulent flow, on the other hand, use of high polymers reduces the pressure drop. The article shows that both the increase and the decrease in pressure drop can be attributed to the same molecular effects. Potential applications of high polymer additives (polyarylamides) in technical flow systems are described, and their benefits discusse

ISSN:0009-286X    

DOI:10.1002/cite.330540306

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractPrinciples of material flow in anaerobic methane production processes. Rising prices of fossil energy are upgrading the importance of processes for generating fuels from organic wastes and from renewable biomass. Anaerobic digestion is a suitable approach for the production of fuel gas rich in methane from wet or liquid organic feedstock. Depending upon the biochemical characteristics of the digestion process and upon the physical conditions for an optimal mass transport, specific technical solutions have been found for treating typical substrates differing in chemical composition, digestability, and fluid mechanical behaviour; such substrates are waste water, sludges, and organic solids with a high liquid content. A survey is given on the principal systems now used for conducting material to be digested through the whole process and in particular through the bioreactor.

ISSN:0009-286X    

DOI:10.1002/cite.330540307

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSeparation by membranes. The paper reviews membrane processes in general, excluding the electro‐membrane processes. The authors' aim is to discuss the aspects common to all membrane processes as well as the essential differences between them. The following processes will be examined: Reverse osmosis, ultrafiltration, gas permeation through porous or diffusion type membranes, pervaporation and liquid membrane techniques. In liquid systems, mass transport at the membrane surface proves to be the limiting factor. Conditions on the permeate side tend to influence flux and quality of the permeate only when a considerable pressure drop occurs. A typical example is that of hollow‐fiber modules. It is shown how the permeability and dimensions of the membrane require selective adjustment in order to establish maximum f

ISSN:0009-286X    

DOI:10.1002/cite.330540308

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractComputer‐assisted pipe routing in three‐dimensional space. For the past twelve years, the management of materials and the production of isometric drawings have been supported by computer programs. With the aim of expanding computer assistance, a long‐term joint systematic study of design activities during the planning of chemical plant performed by BASF and the engineering design department of the Technical University of Braunschweig has led on to a study of the use of computer gra

ISSN:0009-286X    

DOI:10.1002/cite.330540309

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540310

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330540311

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY