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Title: A study of a falling film evaporator for production gas chromatrography
Author: Shaikh, M. A.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1980
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A falling film evaporator for production gas chromatography was constructed and studied. The characteristics of the evaporator were that it was operated in the presence of an inert gas at sub-boiling temperatures for a heat sensitive liquid. Experiments were carried out and compared with theoretical predictions. The theoretical predictions were made by a mathematical model developed for the system. A steady state model was first considered but as the computational procedure suffered convergence difficulties, it was extended to include the unsteady state in which an initial distribution of temperature in the liquid and gas phases were taken and the changes with time of concentration and temperature were calculated until steady state distributions were obtained. Two consistent methods of estimating interface temperature were investigated in the computational scheme. Comparisons of experimental values were made with theoretically predicted values of different parameters. A good agreement was found in every case indicating the validity of the mathematical model for heat and mass transfer between liquid and gas stream in countercurrent laminar flow. The factors that enhance the vaporisation rate for heat sensitive materials at sub-boiling temperatures have been outlined. It is suggested that the computational procedure be used as the basis for a design procedure for a falling film evaporator, having specified the gas flow rate, degradation temperature and rate of vaporisation. Suggestions are also made as to how a falling film evaporator can be incorporated into a gas chromatograph for maximum throughput.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available