1. |
On‐line model of gas distribution in the blast furnace |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 121-126
Mats Nikus,
Henrik Saxén,
Preview
|
PDF (473KB)
|
|
摘要:
In this paper a model for on‐line estimation of the radial gas distribution in blast furnaces is presented. The model is based on molar and energy flow balances for the blast furnace top, using the top gas temperature and gas temperature measurements from a fixed above‐burden probe. The radial distribution of the gas flux in the upper shaft is estimated by means of a Kaiman filter. Using measurement data from a Finnish blast furnace, the method is illustrated to capture short‐term dynamics and to detect sudden (larger) changes in the gas distribution.
ISSN:0003-8962
DOI:10.1002/srin.199605468
出版商:Wiley
年代:2016
数据来源: WILEY
|
2. |
Mathematical model for post combustion in smelting reduction |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 127-137
Ullrich Becker‐Lemgau,
Karl‐Hermann Tacke,
Preview
|
PDF (1305KB)
|
|
摘要:
Post combustion in the top space of iron bath smelting reduction furnaces is analysed with three‐dimensional mathematical modelling. Momentum transport and continuity equations in combination with ak‐ɛmodel of turbulence are numerically solved for the gas flow field. Combustion reactions are modelled by a set of transport equations based on the SCRS combustion model and its extension to thek‐ɛ‐gmodel. A two‐stage combustion scheme is formulated to include carbon transfer and combustion. Heat transfer to bath and droplets is approximated including radiation. Computation results for rectangular reactors are presented with velocity patterns and combustion fields. The complex shapes of post combustion flames are demonstrated. Process parameters are varied to study their influence on combustion and heat transfer to the bath. Effects of the injection geometry are illustrated.
ISSN:0003-8962
DOI:10.1002/srin.199605469
出版商:Wiley
年代:2016
数据来源: WILEY
|
3. |
Influence of carbon, silicon and molybdenum on the separating and emulsifying behaviour of steel and slag |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 138-143
Tarek El Gammal,
Hans‐Jörg Schrinner,
Erwin Wosch,
Preview
|
PDF (535KB)
|
|
摘要:
The influence of C, Si, and Mo on the surface tension of Armco iron, and on the interfacial tension between Armco iron and a 40%CaO/40%SiO2/20%Al2O3slag at 1550°C has been investigated. Surface tension was determined according to the drop weight method, and the interfacial tension by the drop detachment method. Based on these measurements, ternary interfacial tension diagrams are set up, which enable the separating and emulsifying tendencies of the related steel/slag/gas systems to be predicted. This is followed by the calculation of the meniscus radius as a function of interfacial tension in continuous casting, together with the assessment of its effect on lubrication.
ISSN:0003-8962
DOI:10.1002/srin.199605470
出版商:Wiley
年代:2016
数据来源: WILEY
|
4. |
Applicability of fractal concepts to surface roughness |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 144-148
Hartmut Pawelski,
Preview
|
PDF (380KB)
|
|
摘要:
The stochastic part of metal surface profiles can be described by means of fractal geometry. The scaling behaviour of the roughness‐depth as function of the basis length is related to the non‐integral fractal dimension. Regular fractals, which are constructed similarly to the Koch‐curve, are not capable of reproducing typical roughness‐depth distributions. More adequate is the Weierstraß‐Mandelbrot function. If the bearing area ratio approximately follows a power law, the parameters can be easily determined from the exponent and the form of the roughness‐depth distribution, as is shown for a technical surface after cold‐rolling. If the Weierstraß‐Mandelbrot function is used in two classical friction models, the influence of the parameters including the fractal dimension on the friction coefficient in the case of dry surfaces can qualitatively be estimated.
ISSN:0003-8962
DOI:10.1002/srin.199605471
出版商:Wiley
年代:2016
数据来源: WILEY
|
5. |
Contribution to the modelling of stretch reducing of tubes |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 149-155
Paul Bernardy,
Hermann Möltner,
Preview
|
PDF (627KB)
|
|
摘要:
Computer‐aided simulation is becoming more and more important for the further development of the stretch reducing mill (SRM). The available methods of calculation, however, are not satisfactory. The complete simulation of the process with a finite element method cannot yet be carried out within a reasonable time, whereas the results obtained with the help of simpler models are sometimes very inaccurate. The development of an efficient model aims at considerably improving the relation between expenditure and return as compared with the above‐mentioned methods of calculation. Based on today's knowledge of the process, fundamental extensions have been made to the known conventional SRM model. According to forming history the process model of the extended SRM model is composed of two partial models. The first partial model describes the forming process which takes place in the pass and approximates the real three‐dimensional rolling process with the help of axisymmetric elements. The second partial model describes the behaviour of the workpiece in the space between the stands. The gradual calculation of the deformation in the space between the passes is derived from the equilibrium of forces in axial direction and with the help of suitable hot stress‐strain curve functions. An efficient and fast SRM simulation program has been drawn up on the basis of this extended elementary model. The results obtained were found to correspond very well to the measuring results obtained in numerous rolling trials. The model approach described in this paper can also be applied to other longitudinal rolling processes.
ISSN:0003-8962
DOI:10.1002/srin.199605472
出版商:Wiley
年代:2016
数据来源: WILEY
|
6. |
Direct creep curve assessment and optimization of creep equations for high temperature alloys |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 156-162
Karl Heinz Kloos,
Joachim Granacher,
Andreas Pfenning,
Preview
|
PDF (596KB)
|
|
摘要:
The conventional use of a time temperature parameter method for the basic assessment of a multi‐heat creep data set facilitates the establishment of a creep equation for a material type. However, the parameter can introduce some distortion to the creep data and hence the creep equation. To avoid this disadvantage, a new method for the direct creep curve assessment of multi‐heat data was developed. Systematic deviations in creep behaviour of individual test materials in respect to the mean behaviour of the multi‐heat data set are reduced and the creep curves for individual stresses are transformed to mid creep curves of a limited number of stress classes. With this method large multi‐heat creep data sets of Alloy 100 and Alloy 738 LC could be reduced to mean creep curves. On this basis, existing parameter based creep equations were examined and optimized, if necessary. Further, the confidence limits of these equations were determined. With a stress modification the creep behaviour of a material similar in structure can be described. In finite element analyses some verification experiments which simulate typical loading conditions of components could be successfully recalculated with the optimized creep equations.
ISSN:0003-8962
DOI:10.1002/srin.199605473
出版商:Wiley
年代:2016
数据来源: WILEY
|
7. |
News from the Max‐Planck‐Institut für Eisenforschung GmbH |
|
Archiv für das Eisenhüttenwesen,
Volume 67,
Issue 4,
2016,
Page 163-177
Preview
|
PDF (2261KB)
|
|
ISSN:0003-8962
DOI:10.1002/srin.199605474
出版商:Wiley
年代:2016
数据来源: WILEY
|