Software for design of experiments and response modelling of cake ltration applications

摘要

Filtration is a widely used unit operation in chemical engineering. The hugevariation in the properties of materials to be ltered makes the study of ltration a challenging task. One of the objectives of this thesis was to showthat conventional ltration theories are di cult to use when the systemto be modelled contains all of the stages and features that are present in acomplete solid/liquid separation process. Furthermore, most of the ltrationtheories require experimental work to be performed in order to obtain criticalparameters required by the theoretical models.Creating a good overall understanding of how the variables a ect the nal product in ltration is somewhat impossible on a purely theoreticalbasis. The complexity of solid/liquid separation processes require experimentalwork and when tests are needed, it is advisable to use experimentaldesign techniques so that the goals can be achieved.The statistical design of experiments provides the necessary tools for recognisingthe e ects of variables. It also helps to perform experimental workmore economically. Design of experiments is a prerequisite for creating empiricalmodels that can describe how the measured response is related to thechanges in the values of the variable.A software package was developed that provides a ltration practitionerwith experimental designs and calculates the parameters for linear regressionmodels, along with the graphical representation of the responses. Thedeveloped software consists of two software modules. These modules areLTDoE and LTRead. The LTDoE module is used to create experimentaldesigns for di erent lter types. The lter types considered in the softwareare automatic vertical pressure lter, double-sided vertical pressure lter,horizontal membrane lter press, vacuum belt lter and ceramic capillaryaction disc lter. It is also possible to create experimental designs for thosecases where the variables are totally user de ned, say for a customized ltrationcycle or di erent piece of equipment. The LTRead-module is used toread the experimental data gathered from the experiments, to analyse thedata and to create models for each of the measured responses.Introducing the structure of the software more in detail and showing someof the practical applications is the main part of this thesis. This approachto the study of cake ltration processes, as presented in this thesis, has beenshown to have good practical value when making ltration tests.