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More About This Title Vacuum Technology in the Chemical Industry
English
All of the authors work or did work at a selection of the most important German companies involved in vacuum technology, and their expertise is disseminated here for engineers working in vacuum technology, chemical process design, plant operation, and mechanical engineering.
English
English
List of Contributors XV
1 Fundamentals of Vacuum Technology 1
Wolfgang Jorisch
1.1 Introduction 1
1.2 Fundamentals of Vacuum Technology 2
1.2.1 Fundamentals of Gas Kinetics 3
1.2.2 Equation of State for Ideal Gases 6
1.2.3 Flow of Gases through Pipes in a Vacuum 7
1.2.4 Vacuum Pumps Overview 12
References 14
2 Condensation under Vacuum 15
Harald Grave
2.1 What Is Condensation? 15
2.2 Condensation under Vacuum without Inert 16
2.3 Condensation with Inert Gases 17
2.4 Saturated Inert Gas–Vapour Mixtures 19
2.5 Vapour–Liquid Equilibrium 20
2.6 Types of Condensers 21
2.7 Heat Transfer and Condensation Temperature in a Surface Condenser 24
2.8 Vacuum Control in Condensers 30
2.9 Installation of Condensers 30
2.10 Special Condenser Types 32
Further Reading 34
3 Liquid Ring Vacuum Pumps in Industrial Process Applications 35
Pierre Hähre
3.1 Design and Functional Principle of Liquid Ring Vacuum Pumps 35
3.1.1 Functional Principle 35
3.1.2 Design Details 37
3.2 Operating Behaviour and Design of Liquid Ring Vacuum Pumps 40
3.2.1 Hydraulics 40
3.2.2 Thermodynamics 41
3.2.3 Counterpressure, Air Pressure 45
3.2.4 Design Data 47
3.3 Vibration and Noise Emission with Liquid Ring Vacuum Pumps 48
3.3.1 Vibration Stimulation by Imbalance of Rotary Solids 48
3.3.2 Vibration Stimulation by Pulsation 49
3.3.3 Vibration Stimulation by Flow Separations 50
3.3.4 Measures for Vibration Damping 50
3.4 Selection of Suitable Liquid Ring Vacuum Pumps 51
3.4.1 Simple, Robust and Suitable for the Entire Pressure Range 52
3.4.2 The Vacuum Pump for the Delivery of Liquid 52
3.4.3 Quiet and Compact for a Vacuum Close to the Vapour Pressure 57
3.4.4 A Compact Unit 59
3.4.5 The Right Sealing Concept 59
3.4.6 Vacuum Control 63
3.4.7 Valve Control 63
3.4.8 Power Adjustment 64
3.5 Process Connection and Plant Construction 67
3.5.1 Set-Up and Operation of Liquid Ring Vacuum Pumps 67
3.5.2 Conveyance of the Operating Liquid 68
3.5.3 Precompression 69
3.6 Main Damage Symptoms 73
3.6.1 Water Impact 73
3.6.2 Cavitation 73
3.6.3 Calcareous Deposits and How to Avoid Them 75
3.7 Table of Symbols 78
4 Steam Jet Vacuum Pumps 81
Harald Grave
4.1 Design and Function of a Jet Pump 81
4.2 Operating Behaviour and Characteristic 84
4.3 Control of Jet Compressors 87
4.4 Multi-Stage Steam Jet Vacuum Pumps 90
4.5 Comparison of Steam, Air and Other Motive Media 93
Further Reading 95
5 Mechanical Vacuum Pumps 97
Wolfgang Jorisch
5.1 Introduction 97
5.2 The Different Types of Mechanical Vacuum Pumps 99
5.2.1 Reciprocating Piston Vacuum Pump 100
5.2.2 Diaphragm Vacuum Pump 100
5.2.3 Rotary Vane Vacuum Pump 101
5.2.4 Rotary Plunger Vacuum Pump 102
5.2.5 Roots Vacuum Pump 103
5.2.6 Dry Compressing Vacuum Pump 104
5.3 When Using Various Vacuum Pump Designs in the Chemical or Pharmaceutical Process Industry, the Following Must Be Observed 104
5.3.1 Circulatory-Lubricated Rotary Vane and Rotary Plunger Vacuum Pumps 104
5.3.2 Fresh-Oil-Lubricated Rotary Vane Vacuum Pumps 108
5.3.3 Dry, Respectively Oil-Free Compressing Vacuum Pumps 110
5.3.4 Roots Vacuum Pumps 111
5.3.5 Dry Compressing Vacuum Pumps for Chemistry Applications 118
References 128
6 Basics of the Explosion Protection and Safety-Technical Requirements on Vacuum Pumps for Manufacturers and Operating Companies 129
Hartmut Härtel
6.1 Introduction 129
6.2 Explosion Protection 130
6.2.1 General Basics 130
6.2.2 Explosive Atmosphere and Safety Characteristics 131
6.2.3 Measures of the Explosion Protection 144
6.3 Directive 99/92/EC 146
6.3.1 Requirements on Operating Companies of Vacuum Pumps 146
6.3.2 Classification of Hazardous Areas into Zones 149
6.4 Directive 94/9/EC 150
6.4.1 Equipment Groups and Categories 150
6.4.2 Assignment between Equipment Categories and Zones 152
6.4.3 Requirements on Manufacturers of Vacuum Pumps 153
6.4.4 Conformity Assessment Procedure 154
6.4.5 Application of the Regulations of the Directive 155
6.5 Summary 157
References 158
Further Reading 159
7 Measurement Methods for Gross and Fine Vacuum 161
Werner Große Bley
7.1 Pressure Units and Vacuum Ranges 161
7.2 Directly and Indirectly Measuring Vacuum Gauges and Their Measurement Ranges 162
7.3 Hydrostatic Manometers 163
7.4 Mechanical and Electromechanical Vacuum Gauges 164
7.4.1 Sensors with Strain Gauges 165
7.4.2 Thermal Conductivity Gauges 167
7.4.3 Thermal Conductivity Gauges with Constant Filament Heating Power 169
7.4.4 Thermal Conductivity Gauges with Constant Filament Temperature 170
7.4.5 Environmental and Process Impacts on Thermal Conductivity Gauges 170
References 172
Further Reading 172
8 Leak Detection Methods 173
Werner Große Bley
8.1 Definition of Leakage Rates 173
8.2 Acceptable Leakage Rate of Chemical Plants 174
8.3 Methods of Leak Detection 175
8.4 Helium as a Tracer Gas 176
8.5 Leak Detection with Helium Leak Detector 176
8.6 Leak Detection of Systems in the Medium-Vacuum Range 177
8.6.1 Connection of Leak Detector to the Vacuum System of a Plant 177
8.6.2 Detection Limit for Leakage Rates at Different Connection Positions of a Multistage Pumping System 179
8.7 Leak Detection on Systems in the Rough Vacuum Range 180
8.7.1 Connection of Leak Detector Directly to the Process Vacuum 180
8.7.2 Connection of Leak Detector at the Exhaust of the Vacuum System 180
8.8 Leak Detection and Signal Response Time 181
8.9 Properties and Specifications of Helium Leak Detectors 182
8.10 Helium Leak Detection in Industrial Rough Vacuum Applications without Need of a Mass Spectrometer 183
8.10.1 Principle of theWise Technology® Sensor 185
8.10.2 Application 186
References 187
Further Reading 187
European Standards 187
9 Vacuum Crystallisation 189
Guenter Hofmann
9.1 Introduction 189
9.2 Crystallisation Theory for Practice 189
9.3 Types of Crystallisers 195
9.4 Periphery 203
9.5 Process Particularities 205
9.5.1 Surface-Cooling Crystallisation 206
9.5.2 Vacuum-Cooling Crystallisation 207
9.5.3 Evaporation Crystallisation 207
9.6 Example – Crystallisation of Sodium Chloride 207
References 209
10 Why Evaporation under Vacuum? 211
Gregor Klinke
Summary 211
10.1 Introduction 211
10.2 Thermodynamics of Evaporation 211
10.3 Pressure/Vacuum Evaporation Comparison 213
10.3.1 Vapour Utilisation 214
10.3.2 Design of the Apparatuses 214
10.3.3 Machine Equipment 214
10.3.4 Corrosion 215
10.3.5 Insulation 215
10.3.6 Safety Aspects 215
10.3.7 Product Properties 215
10.3.8 Boiling Range 216
10.4 Possibility of Vapour Utilization 217
10.4.1 External Utilization 217
10.4.2 Multi-Stage Evaporation 217
10.4.3 Mechanical Vapour Recompression 217
Further Reading 220
11 Evaporators for Coarse Vacuum 221
Gregor Klinke
Summary 221
11.1 Introduction 221
11.2 Criteria for the Selection of an Evaporator 221
11.2.1 Suitability for the Product 221
11.2.2 Cleaning 222
11.2.3 Quality of Heat Transfer 222
11.2.4 Required Space 222
11.2.5 Cost Efficiency 223
11.3 Evaporator Types 223
11.3.1 Agitator Evaporator 223
11.3.2 Natural Circulation Evaporator 223
11.3.3 Climbing-Film Evaporator 225
11.3.4 Falling-Film Evaporator 226
11.3.5 Forced-Circulation Evaporator 228
11.3.6 Fluidised-Bed Evaporator 230
11.3.7 Plate Evaporator 231
Further Reading 233
12 Basics of Drying Technology 235
Jürgen Oess
12.1 Basics of Solids–Liquid Separation Technology 235
12.2 Basics of Drying Technology 235
12.2.1 Convection Drying 236
12.2.2 Radiation Drying 237
12.2.3 Contact Drying 237
12.2.4 Advantages of the Vacuum Drying 242
12.3 Discontinuous Vacuum Drying 244
12.3.1 Setup of a Batch Vacuum Drying System 244
12.3.2 Operation of Discontinuous Vacuum Dryers 244
12.4 Continuous Vacuum Drying 246
12.4.1 Setup of a Batch Vacuum Drying System 246
12.4.2 Operation of Continuous Vacuum Dryers 246
12.4.3 Inlet- and Outlet Systems 247
12.5 Dryer Designs 248
Reference 249
13 Vacuum Technology Bed 251
Michael Jacob
13.1 Introduction to Fluidized Bed Technology 251
13.1.1 Open or Once-through Fluidized Bed Plants 251
13.1.2 Normal Pressure Fluidized Bed Units with Closed-Loop Systems 251
13.2 Vacuum Fluidized Bed Technology 253
13.2.1 Layout 253
13.2.2 Sequence of Operation 255
13.2.3 Fluidization at Vacuum Conditions 255
13.2.4 Heat Energy Transfer under Vacuum Conditions 256
13.2.5 Applications 257
References 258
14 Pharmaceutical Freeze-Drying Systems 259
Manfred Heldner
14.1 General Information 259
14.2 Phases of a Freeze-Drying Process 260
14.2.1 Freezing 260
14.2.2 Primary Drying – Sublimation 261
14.2.3 Secondary Drying 264
14.2.4 Final Treatment 264
14.2.5 Process Control 265
14.3 Production Freeze-Drying Systems 266
14.3.1 Drying Chamber and Shelf Assembly 267
14.3.2 Ice Condenser 270
14.3.3 Refrigerating System 271
14.3.4 Vacuum System 273
14.3.5 Cleaning of the Freeze-Drying System 274
14.3.6 Sterilisation 276
14.3.7 VHP Sterilisation 277
14.4 Final Comments 278
Further Reading 279
15 Short Path and Molecular Distillation 281
Daniel Bethge
15.1 Introduction 281
15.2 Some History 281
15.2.1 Vacuum Distillation 282
15.2.2 Short Path Evaporator 285
15.2.3 The Vacuum System 286
15.2.4 Distillation Plant 288
15.2.5 Application Examples 289
15.2.6 New Developments 292
15.3 Outlook 293
References 293
16 Rectification under Vacuum 295
Thorsten Hugen
16.1 Fundamentals of Distillation and Rectification 295
16.2 Rectification under Vacuum Conditions 298
16.3 Vacuum Rectification Design 302
16.3.1 Liquid and Gas Load 303
16.3.2 Pressure Drop 303
16.3.3 Separation Efficiency 303
16.4 Structured Packings for Vacuum Rectification 305
Nomenclature, Applied Units 309
Greek Symbols 310
Subscripts and Superscripts 310
References 310
17 Vacuum Conveying of Powders and Bulk Materials 311
Thomas Ramme
17.1 Introduction 311
17.2 BasicTheory 312
17.2.1 General 312
17.2.2 Typical Conditions in a Vacuum Conveying Line 315
17.3 Principle Function and Design of a Vacuum Conveying System 318
17.3.1 Multiple-Stage, Compressed-Air Driven Vacuum Generators 319
17.3.2 Conveying and Receiver Vessels 322
17.3.3 Filter Systems 324
17.4 Continuous Vacuum Conveying 325
17.5 Reactor- and Stirring Vessel Loading in the Chemical Industry 325
17.6 Conveying,Weighing, Dosing and Big-Bag Filling and Discharging 330
17.7 Application Parameters 330
References 330
18 Vacuum Filtration – Systemand Equipment Technology, Range and Examples of Applications, Designs 331
Franz Tomasko
18.1 Vacuum Filtration, a Mechanical Separation Process 331
18.1.1 On theTheory of Filtration and Significance of the Laboratory Experiment 332
18.1.2 Guide to Filter-Type Selection 333
18.2 Design of an Industrial Vacuum Filter Station 335
18.3 Methods of Continuous Vacuum Filtration, Types of Design and Examples of Application 337
18.3.1 Vacuum Filtration on a Curved Convex Surface, the Drum Filter 337
18.3.2 Vacuum Filtration on a Curved Concave Surface, the Internal Filter 351
18.3.3 Vacuum Filtration on a Flat Horizontal Surface 352
18.3.4 Vacuum Filtration on a Vertical Flat Surface, the Disc Filter 358
References 361
Index 363
