摘要:

AbstractImpact abrasion.Our present knowledge concerning impact abrasion is surveyed. Impact abrasion of a wall is taken to mean its destruction as a result of collisions with solid particles. The article first presents a phenomenology of abrasion based on experimental studies and observations with a scanning electron microscope. Abrasion occurs in three phases: wear, lamellation, and destruction. Based on this phenomenology the wear of planar plates is examined as a function of the principal variables, i.e. the angle of incidence of the particles, their velocity, the duration of the experiment, concentration of solids in the particle beam, and the mechanical properties of the particles and the plate. Plate abrasion, which can be determined experimentally with relative case, serves as the starting point for a consideration of wear in pipe elbows. Differential analysis of the wear of curved surfaces is employed. The paper closes with a consideration of wear in components of equipment and machinery.

ISSN:0009-286X    

DOI:10.1002/cite.330500702

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractEnergy evaluation of incorporating heat pumps (vapour compressors) in chemical plant.Both the prevailing tendency of steeper price‐hikes for fuel than for equipment and the imminent shortage of conventional fuels are stipulating measures aimed at decreasing energy consumption. The energy requirements of different variants of a particular process can be compared by using an efficiency based on availability, if the lowest process temperature is used instead of the commonly applied ambient temperature. The method is explained with reference to two example

ISSN:0009-286X    

DOI:10.1002/cite.330500703

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractInfluence of thermodynamic and fluid dynamic mechanisms upon the emergency pressure relief of chemical reactors.The cross‐sectional areas of pressure relief devices for storage tanks and reactor vessels containing liquids under vapour pressure, which might undergo dangerous heating up, have so far been estimated on the basis of physically questionable procedures. This report analyses the pressure relief process using several extreme assumptions with regard to momentum and heat transfer in two phase flow. A conservative method of estimation is found under the assumptions of homogeneous flow and vapour‐liquid equilibrium. Using this procedure, a parametric study of the pressure relief process for a runaway polymerisation reaction has been carried out. Finally, recommendations are given concerning design of the vent line and control of the atmospheric dispersion of the relief stream via the jet exit momen

ISSN:0009-286X    

DOI:10.1002/cite.330500704

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractWaste water purification at BASF, Ludwigshafen/Rh.The manifold problems encountered in the field of waste water treatment in the chemical industry are considered, together with the tasks involved, possible solutions, and costs incurred, for the example of BASF AG in Ludwigshafen. This example is particularly interesting because it shows how the waste water problems of a chemical factory that has been in existence for over a centurvey could be solved in the course of a ten‐year plan. Twenty years after the inception of this plan, costs and success can now be quantifie

ISSN:0009-286X    

DOI:10.1002/cite.330500705

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractDisign of granulating plates and granulating drums.Equations relating mechanical and geometrical parameters have been derived for use in calculating the power requirements of granulating plates and granulating drums. An attempt is made to maintain the same product properties, especially the porosity and size of the agglomerates, on scale‐up of the granulating equipment. This condition considerably limits the possible operational parameters. In order to define the operating conditions on scaling‐up from model experiments, their influences are described in terms of theoretical models and empirical results. The utility of the expressions derived is illustrated using the design of a granulation plate as exam

ISSN:0009-286X    

DOI:10.1002/cite.330500706

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractPartial condensation and non‐adiabatic rectification of binary mixtures in packed columns.Vertical tube assemblies are preferred for partial condensation of vapour mixtures. The mixture of vapours is fed through the tubes in countercurrent flow to the falling condensate, while coolant flows through the jacket. Only with very large ratios of length L to diameter d of the tubes, i.e. L/d 200, does the separatory effect of partial condensation, owing to rectification mass transfer between the phases, exceed the enrichment effect of partial condensation. Use of ring‐shaped packings drastically reduces the characteristic diameter, so that the additional separatory effect occurs at relatively short tube lengths. In the present paper, experimental results concerning the separation efficiency of tubes packed with Raschig rings for non‐adiabatic rectification and partial condensation of the “negative” binary mixture n‐heptane/benzene are reported and evaluated with the aid of the extended two‐film theory. It is found that the resistance to mass transfer averaged over the length of the tube lies entirely on the liquid side on non‐adiabatic rectification. Correlation of the Sherwood number of the condensate taken over the length of the tube and the condensate loading clearly shows that the usual calculation of partial condensation with average total mass transfer coefficients does not give physically meaningful results in the case of liquid‐side resistance to transport. Calculating procedures which account for the variation of the partial mass transfer coefficients along the tube should lead to improved evaluation or prediction of sepa

ISSN:0009-286X    

DOI:10.1002/cite.330500707

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330500708

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330500709

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330500710

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

ISSN:0009-286X    

DOI:10.1002/cite.330500711

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY