The primary purpose of this thesis is to find out the mechanism of cracking formation during filtration as well as improve the dewatering efficiency of Limestone and Vietnam coal. They are both fine materials, which negatively affect the filtration process. Experiments are executed by changing parameters like solid volume fraction of initial suspension, the height of filter cake and the applied pressure difference using the conventional pressure filtration. Permeability ratio is used as the relevance output parameter to quantify the degree of cracking. Otherwise, saturation and residual moisture content on filter cake are also calculated to evaluate the extent of dewatering. Almost the mechanism of cracking is assumpted and proved. Countermeasures are suggested to prevent the probability and degree of cracking on filter cake. Otherwise, steam pressure filtration is applied as a new method allow improve the dewatering efficiency and reduce the cracking.:Contents
Abstract iii
Acknowledgment v
Contents vi
List of Figure viii
List of Tables xvi
List of Symbols xvii
Abbreviation xix
1. Background 1
1.1. The Filtration process 1
1.2. Conventional pressure filtration and steam pressure filtration 3
1.3. Filtration theory 6
1.4. Cake deliquoring - immiscible fluid displacement in porous media 16
1.5. Tensile stress between particles 20
1.6. Coal processing/ washing 24
2. Literature review 34
2.1. Cracking on filter cake and the dewatering process with and without cracking 34
2.2. Summary and focus of research 47
3. Material, methods and the result of capillary pressure curve and tensile stress versus saturation 51
3.1. Material used 51
3.1.1. Limestone 51
3.1.2. Vietnam Coal 52
3.2. Conventional filtration rig and steam pressure filtration rig 55
3.2.1. Conventional filtration rig 55
3.2.2. Steam pressure filtration rig 57
3.3. Filtration experimental 58
3.4. Relevant parameter 59
3.5. Analyze technique 65
3.6. Tensile stresses depend on saturation during deliquoring 66
4. The influence of operating parameters on cracks formation in case of limestone 69
4.1. Capillary pressure curve and tensile stress during the filtration in the case of limestone 69
4.2. Test were conducted using conventional pressure filtration 76
4.2.1. Particle size distribution effect 76
4.2.2. The solid volume fraction of suspension effect 82
4.2.3. Height of filter cake (filter cake deep/ filter cake thickness) effect 92
4.2.4. Pressure difference effect 101
4.3. The difference in the crack formation by using steam pressure filtration 111
4.4. General conclusion 116
5. The influence of operating parameters on cracks formation in the case of Vietnam coal 118
5.1. Capillary pressure curve and tensile stress during filtration in case of Vietnam coal 118
5.2. Test were conducted using conventional pressure filtration 122
5.2.1. The influence of the solid volume fraction on crack formation and saturation 122
5.2.2. The influence of the height of filter cake on crack formation and saturation 127
5.2.3. The influence of pressure difference on crack formation and saturation 134
5.3. Estimate the efficiency dewatering as well as the crack formation using steam pressure filtration 139
5.4. General conclusion 146
6. Overall conclusion and recommendation 148
6.1. Overall conclusion 148
6.2. Recommendation 150
References 152
Appendices 156
Appendix A: Data from CCWP. 156
Appendix B: Data from the crack formation with various operation parameters using conventional pressure filtration (CPF). 159
Appendix C: Data from steam pressure filtration. 167
Appendix D: Miscellaneous Information. 177
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:74001 |
| Date | 01 April 2021 |
| Creators | Pham, Thanh Hai |
| Contributors | Peuker, Urs Alexander, Hoffner, Bernhard, Technische Universität Bergakademie Freiberg |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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