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Optimal sequence and heat integration for multicomponent distillation trains / Enwer Amara Korba 

Public ISBD Titre : Optimal sequence and heat integration for multicomponent distillation trains Type de document : texte imprimé Auteurs : Enwer Amara Korba, Auteur ; G. L. wells, Directeur de thèse Editeur : Sheffield : [s.n.] Année de publication : 1985 Importance : 156 f. Présentation : ill. Format : 30 cm. Note générale : PhD Thesis : Chemical Engineering : University of Sheffield: 1985 Bibliogr. f. 157 - 162 . Annexe f. 163 - 264 Langues : Anglais (eng) Mots-clés : Distillation  trains Optimal  distillation Near-optimal  distillation Heat  integration Index. décimale : D006785 Résumé : A synthesis strategy is developed for the design of distillation trains (columns in sequence) to separate milticomponent mixtures. The proposed schemes allow for the reduction of overall energy requirements using heat integration methods to give energy savings. The strategy is based on decomposing the problem into two distinct tasks. The first objective is to generate a number of optimal and near-optimal distillation tower sequences. This is achieved with the help of either of two heuristics which have been developed in this work. One is to select the schemes which produce the lowest value for the summation of column overhead vapour flowrates. The second heuristic, which is preferred, is to select the sequences with the lowest value for overall work potential lost. The latter is based on a simple analysis of the degradation of energy during the distillation process using the second law of thermodynamics. This lastn approach aims to present selected schemes which have the best prospect for exchange of energy. The second task in the synthesis strategy consists of organizing a heat exchanger network around the selected sequences in order to substantially reduce their operating costs. Appropriate methods have been studied in detail. Heat integration of a distillation train requires the modification of the operating pressure of its constituent columns to create sufficient temperature driving forces in the reboilers. Guidelines are given for the application of this concept of re-use of energy to water-cooled, steam-heated distillation systems. The main method used for heat integration is the heating of the bottom reboiler by condensing the overhead stream of another column. Other, more complex methods, include the use of intermediate reboilers, vapour re-compression scheme and double-effect distillation. A system of five components has been tested for eight different compositions. Every possible distillation tower sequence for earch feed has been completely evaluated so that a comparison can be made with the schemes generated by the design strategy. The results show that, in general, the most economic schemes were obtained when the increase in the operating pressure of the columns in a sequence was kept to a minimum. In this case, further reductions in operating costs are frequently possible by introducing an intermediate reboiler Optimal sequence and heat integration for multicomponent distillation trains [texte imprimé] / Enwer Amara Korba, Auteur ; G. L. wells, Directeur de thèse . - Sheffield : [s.n.], 1985 . - 156 f. : ill. ; 30 cm. PhD Thesis : Chemical Engineering : University of Sheffield: 1985 Bibliogr. f. 157 - 162 . Annexe f. 163 - 264 Langues : Anglais (eng) Mots-clés : Distillation  trains Optimal  distillation Near-optimal  distillation Heat  integration Index. décimale : D006785 Résumé : A synthesis strategy is developed for the design of distillation trains (columns in sequence) to separate milticomponent mixtures. The proposed schemes allow for the reduction of overall energy requirements using heat integration methods to give energy savings. The strategy is based on decomposing the problem into two distinct tasks. The first objective is to generate a number of optimal and near-optimal distillation tower sequences. This is achieved with the help of either of two heuristics which have been developed in this work. One is to select the schemes which produce the lowest value for the summation of column overhead vapour flowrates. The second heuristic, which is preferred, is to select the sequences with the lowest value for overall work potential lost. The latter is based on a simple analysis of the degradation of energy during the distillation process using the second law of thermodynamics. This lastn approach aims to present selected schemes which have the best prospect for exchange of energy. The second task in the synthesis strategy consists of organizing a heat exchanger network around the selected sequences in order to substantially reduce their operating costs. Appropriate methods have been studied in detail. Heat integration of a distillation train requires the modification of the operating pressure of its constituent columns to create sufficient temperature driving forces in the reboilers. Guidelines are given for the application of this concept of re-use of energy to water-cooled, steam-heated distillation systems. The main method used for heat integration is the heating of the bottom reboiler by condensing the overhead stream of another column. Other, more complex methods, include the use of intermediate reboilers, vapour re-compression scheme and double-effect distillation. A system of five components has been tested for eight different compositions. Every possible distillation tower sequence for earch feed has been completely evaluated so that a comparison can be made with the schemes generated by the design strategy. The results show that, in general, the most economic schemes were obtained when the increase in the operating pressure of the columns in a sequence was kept to a minimum. In this case, further reductions in operating costs are frequently possible by introducing an intermediate reboiler

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité	Spécialité	Etat_Exemplaire
D006785	D006785	Papier	Bibliothèque centrale	Thèse de Doctorat	Disponible

Documents numériques

AMARA-KORBA.Enwer.pdf URL

Development and implementation of an identification package for linear multivariable systems / Madina Hamiane

Public ISBD Titre : Development and implementation of an identification package for linear multivariable systems Type de document : texte imprimé Auteurs : Madina Hamiane, Auteur ; S.A. Morris, Directeur de thèse ; A.S. Billings, Directeur de thèse Editeur : Sheffield : [s.n.] Année de publication : 1984 Importance : 210 f. Présentation : ill. Format : 27 cm. Note générale : PhD Thesis : Mathematics : University of Sheffield : 1984 Bibliogr. f. 202 - 210 Langues : Anglais (eng) Mots-clés : Development Implementation Identification  package Linear Multivariable  systems Index. décimale : D004084 Résumé : The work presented in this thesis concerns the structural and parmetric identification of linear multivariable systems using an interactive software package developed and implemented on the perkin-Elmer 3220 minicomputer in the departement of control engineering at sheffield university. The choice of a suitable model representation is first investigated and a model, derived from a canonical state-space formulation for the system, is selected. This selected model divides the whole system into interconnected subsystems whose number equals the number of system outputs. This allows for the implementation of the parametric and structural identification procedures for each subsystem, independently of all other subsystems. A method for the determination of subsystem orders is derived, based on the triangularisation of a certain measurement matrix. Development and implementation of an identification package for linear multivariable systems [texte imprimé] / Madina Hamiane, Auteur ; S.A. Morris, Directeur de thèse ; A.S. Billings, Directeur de thèse . - Sheffield : [s.n.], 1984 . - 210 f. : ill. ; 27 cm. PhD Thesis : Mathematics : University of Sheffield : 1984 Bibliogr. f. 202 - 210 Langues : Anglais (eng) Mots-clés : Development Implementation Identification  package Linear Multivariable  systems Index. décimale : D004084 Résumé : The work presented in this thesis concerns the structural and parmetric identification of linear multivariable systems using an interactive software package developed and implemented on the perkin-Elmer 3220 minicomputer in the departement of control engineering at sheffield university. The choice of a suitable model representation is first investigated and a model, derived from a canonical state-space formulation for the system, is selected. This selected model divides the whole system into interconnected subsystems whose number equals the number of system outputs. This allows for the implementation of the parametric and structural identification procedures for each subsystem, independently of all other subsystems. A method for the determination of subsystem orders is derived, based on the triangularisation of a certain measurement matrix.

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité	Spécialité	Etat_Exemplaire
D004084	D004084	Papier	Bibliothèque centrale	Thèse de Doctorat	Disponible

Depth of field improvements and automatic focusing in long wavelength imaging systems / Ahmed Yamani

Public ISBD Titre : Depth of field improvements and automatic focusing in long wavelength imaging systems Type de document : texte imprimé Auteurs : Ahmed Yamani, Auteur ; Benson, F. A, Directeur de thèse Editeur : Sheffield : [s.n.] Année de publication : 1984 Importance : 168 f. Présentation : ill. Format : 30 cm. Note générale : PhD Thesis : Electronics : University of Sheffield : 1984 Bibliogr. f. 164 - 168 Langues : Anglais (eng) Mots-clés : Imaging  systems Field  improvements Long  wavelength Index. décimale : D004284 Résumé : A novel approach to the depth of field limitations associated with backward propagation techniques is developed. The new technique does not require prior object range information to reconstruct simultaneous in-focus images of targets situated at widely different ranges. furthermore, the distortion associated with backward wave propagation is removed when this technique is used. Although the proposed procedure is multifrequency in nature, the bandwidth used is shown to be well within that of a typical transducer and, thus, it can be used in other imaging systems operating in either the electromagnetic or acoustic regimes. Depth of field improvements and automatic focusing in long wavelength imaging systems [texte imprimé] / Ahmed Yamani, Auteur ; Benson, F. A, Directeur de thèse . - Sheffield : [s.n.], 1984 . - 168 f. : ill. ; 30 cm. PhD Thesis : Electronics : University of Sheffield : 1984 Bibliogr. f. 164 - 168 Langues : Anglais (eng) Mots-clés : Imaging  systems Field  improvements Long  wavelength Index. décimale : D004284 Résumé : A novel approach to the depth of field limitations associated with backward propagation techniques is developed. The new technique does not require prior object range information to reconstruct simultaneous in-focus images of targets situated at widely different ranges. furthermore, the distortion associated with backward wave propagation is removed when this technique is used. Although the proposed procedure is multifrequency in nature, the bandwidth used is shown to be well within that of a typical transducer and, thus, it can be used in other imaging systems operating in either the electromagnetic or acoustic regimes.

Exemplaires

Code-barres	Cote	Support	Localisation	Section	Disponibilité	Spécialité	Etat_Exemplaire
D004284B	D004284	Papier	Bibliothèque centrale	Thèse de Doctorat	Disponible
D004284A	D004284	Papier	Bibliothèque centrale	Thèse de Doctorat	Disponible