Solid-Liquid Separation

Solid Liquid Separation includes important industrial processes used for recovery and processing of solids or purification of liquids. Most of the process industries in which particulate slurries are handled use some form of solid-liquid separation and yet the subject is not adequately covered in most higher education courses. This book is designed to bring the readers up-to-date on the principles and industrial practices of solid-liquid separation and washing technology. Particular attention is given to hardware and to its evaluation, application and selection. Whilst not exclusively concerned with filtration and sedimentation, these operations will be dealt with in depth. Important variations in the available equipment will be discussed throughout the book with emphasis on basic engineering concepts, equipment selection and evaluation, solids washing, methods of pre-treatment, filter aids and other practical aspects of mechanical separation. This book is intended for engineers and scientists of graduate status who are engaged in design, production for research and development. This book is designed to bring the readers up-to-date on the principles and industrial practices of solid-liquid separation and washing technology. Particular attention is given to hardware and to its evaluation, application and selection. Whilst not exclusively concerned with filtration and sedimentation, these operations are dealt with in depth. Important variations in the available equipment are discussed throughout the book with emphasis on basic engineering concepts, equipment selection and evaluation, solids washing, methods of pre-treatment, filter aids and other practical aspects of mechanical separation. This book is intended for engineers and scientists of graduate status who are engaged in design, production for research and development. Author is the top of his field, and knows well all the latest advances in his subject area Fourth edition of a title which is respected and admired in the world of Chemical Engineering Updated and revised to match the developments in the industry Contents......Page 5 Preface to the fourth edition......Page 11 Preface to the first edition......Page 13 1 Introduction to solid-liquid separation......Page 15 1.1 Pretreatment of suspensions......Page 18 1.2 Equipment and principles......Page 24 1.3 The spectrum of particle size......Page 40 2.1 Introduction, the reasons for particle characterization......Page 44 A2.2 Can the arithmetic mean of the surface distribution be determined from the mass distribution?......Page 77 A2.1 The choice of a mean particle size......Page 72 2.9 Statistical measurement control......Page 71 2.8 On-line measurement techniques......Page 70 2.7 Laboratory measurement of particle size......Page 65 2.6 Sampling......Page 63 2.5 Presentation of data......Page 55 2.4 Measures of central tendency......Page 51 2.3 Types of particle size distribution......Page 47 2.2 Definitions of particle size......Page 46 3.1 Introduction......Page 80 3.2 Basic definitions and mass balance equations......Page 81 3.3 Basic relationships between Er, G(x) and the particle size distributions of the products......Page 88 3.4 Modifications of efficiency definitions for applications with an appreciable underflow-to-throughput ratio......Page 103 3.5 A new method of testing separators......Page 107 Nomenclature......Page 115 4.1 Introduction......Page 118 4.6 Other considerations......Page 139 4.5 Flocculation by polyelectrolytes......Page 135 4.4 Practical applications of the zeta potential......Page 130 4.3 Electrokinetic phenomena and the zeta potential......Page 127 4.2 The colloidal model......Page 121 4 Coagulation and flocculation Part II - Orthokinetic flocculation......Page 144 4.8 Theory......Page 145 4.9 Laboratory testing......Page 152 4.10 Practical flocculators......Page 160 4.11 Current developments......Page 177 5 Gravity clarification and thickening......Page 180 5.1 Clarifiers......Page 181 5.2 Thickeners......Page 192 6 Hydrocyclones......Page 205 6.1 Introduction and description......Page 206 6.2 Liquid flow patterns......Page 207 6.3 Motion of suspended particles......Page 210 6.4 Pressure distribution within the flow, static pressure drop......Page 212 6.5 Hydrocyclone function, design and merits......Page 213 6.6 Theories of separation......Page 218 6.7 Hydrocyclone selection and scale-up......Page 234 6.8 Design variations, other design features......Page 245 6.9 Applications......Page 251 6.10 Conclusions......Page 256 7.1 Introduction......Page 260 7.2 Theoretical performance predictions......Page 261 7.3 Equipment......Page 270 7.4 Factors affecting the choice of centrifugal equipment......Page 283 7.5 Recent developments......Page 286 8.1 Introduction......Page 295 8.2 Filter media - general......Page 297 8.3 Cartridge filters......Page 298 8.4 Rigid porous media......Page 300 8.5 Non-woven media......Page 301 8.6 Woven wire......Page 303 8.7 Woven fabrics......Page 306 8.8 Material selection......Page 310 8.9 Filter rating......Page 312 8.10 Summary......Page 313 9 Filtration fundamentals......Page 316 9.1 Introduction......Page 317 9.2 Flow rate-pressure drop relationships......Page 319 9.3 Filtration operations - basic equations, incompressible cakes......Page 323 9.4 Filtration operations - basic equations, compressible cakes......Page 334 9.5 Relationship between specific cake resistence, porosity and specific surface......Page 337 9.6 Cake moisture correction - mass balance......Page 338 9.7 Further development of filtration theory......Page 339 9.8 The benefits of pre-thickening......Page 341 9.9 Filtration of non-Newtonian liquids......Page 344 10.1 Introduction, methods of washing solids......Page 349 10.2 Principle of cake washing, the washing curve......Page 350 10.4 How much wash liquid is needed?......Page 355 10.5 Can the washing curve be predicted?......Page 356 10.6 An example of a cake washing calculation......Page 357 10.7 Cake washing on continuous filters......Page 360 10.8 Practical considerations......Page 361 11.1 Introduction......Page 363 11.2 Removal of cake by mass forces......Page 364 11.4 Dislodging of cake by reverse flow......Page 365 11.5 Prevention of cake deposition by vibration......Page 366 11.6 Cross-flow filtration......Page 367 12.1 Introduction......Page 382 12.2 Batch pressure filtration......Page 383 12.3 Continuous pressure filtration......Page 407 13 Vacuum filtration......Page 423 13.1 Nutsche filter......Page 424 13.2 Enclosed agitated vacuum filters......Page 425 13.3 Vacuum leaf filter......Page 427 13.4 Tipping pan filter......Page 428 13.5 Horizontal rotating pan filters......Page 429 13.6 Horizontal belt vacuum filters......Page 430 13.7 Rotary vacuum drum filters......Page 432 13.8 Rotary vacuum disc filters......Page 437 13.9 Selection of continuous vacuum filters......Page 439 13.10 Improvement of filter performance by physical pretreatment of the slurry......Page 440 14 Centrifugal filtration......Page 446 14.1 Perforate basket centrifuge......Page 448 14.2 Peeler centrifuge......Page 450 14.3 Conical basket centrifuge......Page 451 14.4 Pusher centrifuge......Page 453 14.5 Scale-up and testing......Page 454 15.1 Introduction......Page 456 15.2 The pumping arrangements......Page 459 15.3 Advantages and capabilities of a counter current washing system......Page 461 15.4 Mass balance calculations for the solids......Page 462 15.5 Washing efficiency calculations......Page 470 15.6 Washing train design recommendations......Page 474 15.7 Applications, case studies......Page 478 15.8 Conclusions......Page 486 15.9 Appendix - Leaf testing for countercurrent washing of filter cakes......Page 487 16.1 Introduction......Page 490 16.2 Series connections on overflow......Page 492 16.3 Series connections on underflow......Page 501 16.4 Series connections on both outlets......Page 507 16.5 Mass balance calculations......Page 511 17.2 Sedimentation or filtration?......Page 526 17.3 Sedimentation equipment......Page 528 17.4 Filtration equipment......Page 531 17.5 A note from the editor......Page 538 18 Particle-fluid interation, thermodynamics of solid-liquid separation Part I - Particle-fluid interation......Page 540 18.2 Motion of particles in fluids......Page 541 18.3 Flow through packed beds......Page 548 18.4 Particles in non-Newtonian liquids......Page 551 18 Particle-fluid interaction, thermodynamics of solid-liquid separation Part II - Thermodynamics of solid-liquid separation......Page 555 18.6 Some notes on entropy......Page 556 18.7 Entropy index......Page 557 18.8 Criterion of separation......Page 559 18.10 Conclusions......Page 561 Index......Page 563 Contents 5 Preface to the fourth edition 11 Preface to the first edition 13 1 Introduction to solid-liquid separation 15 1.1 Pretreatment of suspensions 18 1.2 Equipment and principles 24 1.3 The spectrum of particle size 40 2 Characterization of particles suspended in liquids 44 A2.2 Can the arithmetic mean of the surface distribution be determined from the mass distribution? 77 A2.1 The choice of a mean particle size 72 2.9 Statistical measurement control 71 2.8 On-line measurement techniques 70 2.7 Laboratory measurement of particle size 65 2.6 Sampling 63 2.5 Presentation of data 55 2.4 Measures of central tendency 51 2.3 Types of particle size distribution 47 2.2 Definitions of particle size 46 2.1 Introduction, the reasons for particle characterization 44 3 Efficiency of separation of particles from fluids 80 3.1 Introduction 80 3.2 Basic definitions and mass balance equations 81 3.3 Basic relationships between Er, G(x) and the particle size distributions of the products 88 3.4 Modifications of efficiency definitions for applications with an appreciable underflow-to-throughput ratio 103 3.5 A new method of testing separators 107 Nomenclature 115 4 Coagulation and flocculation Part I 118 4.6 Other considerations 139 4.5 Flocculation by polyelectrolytes 135 4.4 Practical applications of the zeta potential 130 4.3 Electrokinetic phenomena and the zeta potential 127 4.2 The colloidal model 121 4.1 Introduction 118 4 Coagulation and flocculation Part II - Orthokinetic flocculation 144 4.7 Introduction 145 4.8 Theory 145 4.9 Laboratory testing 152 4.10 Practical flocculators 160 4.11 Current developments 177 5 Gravity clarification and thickening 180 5.1 Clarifiers 181 5.2 Thickeners 192 6 Hydrocyclones 205 6.1 Introduction and description 206 6.2 Liquid flow patterns 207 6.3 Motion of suspended particles 210 6.4 Pressure distribution within the flow, static pressure drop 212 6.5 Hydrocyclone function, design and merits 213 6.6 Theories of separation 218 6.7 Hydrocyclone selection and scale-up 234 6.8 Design variations, other design features 245 6.9 Applications 251 6.10 Conclusions 256 7 Separation by centrifugal sedimentation 260 7.1 Introduction 260 7.2 Theoretical performance predictions 261 7.3 Equipment 270 7.4 Factors affecting the choice of centrifugal equipment 283 7.5 Recent developments 286 8 Filter media, filter rating 295 8.1 Introduction 295 8.2 Filter media - general 297 8.3 Cartridge filters 298 8.4 Rigid porous media 300 8.5 Non-woven media 301 8.6 Woven wire 303 8.7 Woven fabrics 306 8.8 Material selection 310 8.9 Filter rating 312 8.10 Summary 313 9 Filtration fundamentals 316 9.1 Introduction 317 9.2 Flow rate-pressure drop relationships 319 9.3 Filtration operations - basic equations, incompressible cakes 323 9.4 Filtration operations - basic equations, compressible cakes 334 9.5 Relationship between specific cake resistence, porosity and specific surface 337 9.6 Cake moisture correction - mass balance 338 9.7 Further development of filtration theory 339 9.8 The benefits of pre-thickening 341 9.9 Filtration of non-Newtonian liquids 344 10 Cake washing 349 10.1 Introduction, methods of washing solids 349 10.2 Principle of cake washing, the washing curve 350 10.3 Is it always best to dewater before cake washing? 355 10.4 How much wash liquid is needed? 355 10.5 Can the washing curve be predicted? 356 10.6 An example of a cake washing calculation 357 10.7 Cake washing on continuous filters 360 10.8 Practical considerations 361 11 Methods for limiting cake growth 363 11.1 Introduction 363 11.2 Removal of cake by mass forces 364 11.3 Mechanical cake removal 365 11.4 Dislodging of cake by reverse flow 365 11.5 Prevention of cake deposition by vibration 366 11.6 Cross-flow filtration 367 12 Pressure filtration Part I - Batch pressure filtration 382 12.1 Introduction 382 12.2 Batch pressure filtration 383 12 Pressure filtration Part II - Continuous filtration 407 12.3 Continuous pressure filtration 407 13 Vacuum filtration 423 13.1 Nutsche filter 424 13.2 Enclosed agitated vacuum filters 425 13.3 Vacuum leaf filter 427 13.4 Tipping pan filter 428 13.5 Horizontal rotating pan filters 429 13.6 Horizontal belt vacuum filters 430 13.7 Rotary vacuum drum filters 432 13.8 Rotary vacuum disc filters 437 13.9 Selection of continuous vacuum filters 439 13.10 Improvement of filter performance by physical pretreatment of the slurry 440 14 Centrifugal filtration 446 14.1 Perforate basket centrifuge 448 14.2 Peeler centrifuge 450 14.3 Conical basket centrifuge 451 14.4 Pusher centrifuge 453 14.5 Scale-up and testing 454 15 Countercurrent washing of solids 456 15.1 Introduction 456 15.2 The pumping arrangements 459 15.3 Advantages and capabilities of a counter current washing system 461 15.4 Mass balance calculations for the solids 462 15.5 Washing efficiency calculations 470 15.6 Washing train design recommendations 474 15.7 Applications, case studies 478 15.8 Conclusions 486 15.9 Appendix - Leaf testing for countercurrent washing of filter cakes 487 16 Separator series and networks 490 16.1 Introduction 490 16.2 Series connections on overflow 492 16.3 Series connections on underflow 501 16.4 Series connections on both outlets 507 16.5 Mass balance calculations 511 17 The selection of solid-liquid separation equipment 526 17.1 Introduction 526 17.2 Sedimentation or filtration? 526 17.3 Sedimentation equipment 528 17.4 Filtration equipment 531 17.5 A note from the editor 538 18 Particle-fluid interation, thermodynamics of solid-liquid separation Part I - Particle-fluid interation 540 18.1 Introduction 541 18.2 Motion of particles in fluids 541 18.3 Flow through packed beds 548 18.4 Particles in non-Newtonian liquids 551 18 Particle-fluid interaction, thermodynamics of solid-liquid separation Part II - Thermodynamics of solid-liquid separation 555 18.5 Introduction 556 18.6 Some notes on entropy 556 18.7 Entropy index 557 18.8 Criterion of separation 559 18.9 Estimates of sediment porosity 561 18.10 Conclusions 561 Index 563 Referex Solid Liquid Separation includes important industrial processes used for recovery and processing of solids or purification of liquids. Most of the process industries in which particulate slurries are handled use some form of solid-liquid separation and yet the subject is not adequately covered in most higher education courses.

This book is designed to bring the readers up-to-date on the principles and industrial practices of solid-liquid separation and washing technology. Particular attention is given to hardware and to its evaluation, application and selection. Whilst not exclusively concerned with filtration and sedimentation, these operations will be dealt with in depth.

Important variations in the available equipment will be discussed throughout the book with emphasis on basic engineering concepts, equipment selection and evaluation, solids washing, methods of pre-treatment, filter aids and other practical aspects of mechanical separation.

This book is intended for engineers and scientists of graduate status who are engaged in design, production for research and development.


This book is designed to bring the readers up-to-date on the principles and industrial practices of solid-liquid separation and washing technology. Particular attention is given to hardware and to its evaluation, application and selection. Whilst not exclusively concerned with filtration and sedimentation, these operations are dealt with in depth.

Important variations in the available equipment are discussed throughout the book with emphasis on basic engineering concepts, equipment selection and evaluation, solids washing, methods of pre-treatment, filter aids and other practical aspects of mechanical separation.

This book is intended for engineers and scientists of graduate status who are engaged in design, production for research and development.


Author is the top of his field, and knows well all the latest advances in his subject area.

Fourth edition of a title which is respected and admired in the world of Chemical Engineering.

Updated and revised to match the developments in the industry.

Content: Preface to the fourth edition, __Pages xi-xii__, L.S.Preface to the first edition, __Pages xiii-xiv__, L.S.1 - Introduction to solid-liquid separation, __Pages 1-29__, L. Svarovsky2 - Characterization of particles suspended in liquids, __Pages 30-65__, L. Svarovsky3 - Efficiency of separation of particles from fluids, __Pages 66-103__, L. Svarovsky4 - Coagulation and flocculation: Part I, __Pages 104-129__, M.A. Hughes- Coagulation and flocculation: Part II—Orthokinetic flocculation, __Pages 130-165__, K.J. Ives5 - Gravity clarification and thickening, __Pages 166-190__, L. Svarovsky6 - Hydrocyclones, __Pages 191-245__, L. Svarovsky7 - Separation by centrifugal sedimentation, __Pages 246-280__, L. Svarovsky8 - Filter media, filter rating, __Pages 281-301__, Lawrence G. Loff9 - Filtration fundamentals, __Pages 302-334__, L. Svarovsky10 - Cake washing, __Pages 335-348__, L. Svarovsky11 - Methods for limiting cake growth, __Pages 349-367__, L. Svarovsky12 - Pressure filtration: Part I—Batch pressure filtration, __Pages 368-392__, L. Svarovsky- Pressure filtration: Part II—Continuous filtration, __Pages 393-408__13 - Vacuum filtration, __Pages 409-431__, L. Svarovsky14 - Centrifugal filtration, __Pages 432-441__, L. Svarovsky15 - Countercurrent washing of solids, __Pages 442-475__, L. Svarovsky16 - Separator series and networks, __Pages 476-511__, L. Svarovsky17 - The selection of solid - liquid separation equipment, __Pages 512-525__, H.G.W. Pierson18 - Particle-fluid interaction, thermodynamics of solid-liquid separation: Part I—Particle-fluid interaction, __Pages 526-540__, L. Svarovsky- Particle-fluid interaction, thermodynamics of solid-liquid separation: Part II—Thermodynamics of solid-liquid separation, __Pages 541-548__, L. SvarovskyIndex, __Pages 549-554__ Author is the top of his field, and knows well all the latest advances in his subject area. Fourth edition of a title which is respected and admired in the world of Chemical Engineering. Updated and revised to match the developments in the industry. Brand new chapters reflecting the growing interest in industry such as Cake Washing and Separator Series and Networks. Solid Liquid Separation includes important industrial processes used for recovery and processing of ... etc Includes important industrial processes used for recovery and processing of solids or purification of liquids. This book provides information on the principles and industrial practices of solid-liquid separation and washing technology. It pays particular attention to hardware and to its evaluation, application and selection