Theory and Operation of the Fourdrinier Paper Machine

641 Pages·1967·41.846 MB·English

by  Geoffrey H. Nuttall, M.A. (Cantab.)

THEORY AND OPERATION
OF THE FOURDRINIER
PAPER MACHINE

THEORY AND OPERATION
OF THE FOURDRINIER
PAPER MACHINE
BY
G. H. NUTTALL, M.A. (Cantab.)
LONDON:
S. C. PHILLIPS & CO. LTD.
© G. H. Nuttall
PRINTED IN GREAT BRITAIN BY
ADLARD & SON LTD., BARTHOLOMEW PRESS, DORKING
CONTENTS
Foreword ix
PART 1: THE WET-END FLOW SYSTEM
11 Introduction 3
CHAPTER lA: THEORETICAL CONSIDERATIONS.
lA. 1 Flow of Fibre Suspensions . 6
lA.2 Influence of Wet-end Design on Operational Stability 15
CHAPTER lB: OPERATING FACTORS AFFECTING PERFORMANCE.
lB. 1 Retention on the Wire 31
lB.2 Fresh Stuff Flow and Mixing 35
lB. 3 Backwater and Whitewater Systems 38
lB.4 Breast Box Approach System 40
lB. 5 Breast Box Design 46
1B. 6 Slice Design 54
1B. 7 Aeration of the Stock 59
lB. 8 Hydraulic Disturbances 63
CHAPTER lC: RUNNING THE WET-END FLOW SYSTEM.
1 C. 1 Daily Operation 66
lC.2 Maintenance 76
1C.3 Control of Substance . 80
1 C .4 Practical Points . 87
References 95
PART 2: SCREENS AND CLEANERS
21 Introduction 101
CHAPTER 2A: THEORETICAL CONSIDERATIONS.
2A. l Theory of Screening . 105
2A. 2 Theory of Cleaning . 117
2A. 3 Assessing Screen and Cleaner Efficiency 129
CHAPTER 2B: OPERATING FACTORS AFFECTING SCREENS AND CLEANERS.
2B. I Position in the Flow System 135
28. 2 Open Screening Equipment 140
2B . 3 Closed Pressure Screens 144
28. 4 Early Cleaning Equipment . 150
2B.5 Cylindrical Cleaners . 152
2B. 6 Cyclone Cleaners 154
CHAPTER 2C: RUNNING SCREENS AND CLEANERS.
2C. I Daily Operation 17 1
2C. 2 Maintenance 172
2C. 3 Practical Points 17 5
References 180
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CONTENTS
PART 3: THE WIRE SECTION
31 Introduction 185
CHAPTER 3A: THEORETICAL CONSIDERATIONS.
3A. l Drainage in the Table Roll Section 187
3A. 2 Forming the Sheet on the Wire 195
3A. 3 Drainage at the Suction Boxes 209
3A .4 Conditions for Couching . 219
CHAPTER 3B: OPERATING FACTORS AFFECTING THE WIRE SECTION.
3B.1 Early Drainage Conditions. 226
3B. 2 Table Rolls and other Dewatering Devices 232
3B. 3 Shake 237
3B . 4 Suction Boxes 241
3B. 5 The Dandy 247
3B. 6 Couching . 252
3B. 7 The Wire and Showers 262
3B. 8 Breast Box Stock Consistency and Temperature 268
38. 9 Machine Speed, Substance and Stuff Treatment 269
3B.10 Equipment 271
CHAPTER 3C: RUNNING THE WIRE SECTION.
3C. 1 Daily Operation 275
3C. 2 Maintenance 280
3C. 3 Practical Points 286
References 296
PART 4: THE PRESS SECTION
41 Introduction 303
CHAPTER 4A: GENERAL THEORY OF PRESSING.
4A. 1 Early Theory 306
4A.2 Modern Theory of Pressing 310
CHAPTER 4B: OPERA TING FACTORS AFFECTING PRESS PERFORMANCE.
4B. l Press Load and Nip Width 318
48.2 Felts and Felt Cleaning 320
4B. 3 Felt and Paper Runs . 325
4B .4 Suction Roll Conditions 332
4B. 5 Machine Speed and Draw Control 335
4B. 6 Moisture Content of Paper entering Press 337
4B. 7 Paper Properties 339
4B. 8 Temperature 340
4B. 9 Equipment 342
CHAPTER 4C: RUNNING THE PRESS SECTION.
4C. I Daily Operation 345
4C. 2 Maintenance 350
4C. 3 Cross-web Variations 355
4C. 4 Practical Points 360
References 366
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CONTENTS
PART 5: THE DRYING SECTION AND CALENDERS
SI Introduction 371
CHAPTER SA: THEORETICAL CONSIDERATIONS
SA.1 Removal of Water in Drying 373
SA. 2 Performance of the Drying Section 387
SA. 3 Effect of Drying on Paper Properties 394
SA.4 Calendering 411
CHAPTER SB: OPERATING FACTORS AFFECTING DRYING AND
CALENDERING.
SB. 1 Steam Heating and Condensate System 422
SB. 2 Felts and Felt Drying 434
SB. 3 Conditions inside the Dryers 444
SB.4 Ventilation 453
SB. 5 Auxiliary Drying Methods . 461
5B.6 Machine Speed and Draw Control 471
SB. 7 Paper Properties 475
SB.8 The M.G. Cylinder 476
SB. 9 Calenders 481
SB. 10 Equipment 487
CHAPTER SC: RUNNING THE DRYERS AND CALENDERS.
SC. 1 Daily Operation 497
SC. 2 Maintenance 506
SC. 3 Control of Moisture Content 515
SC .4 Control of Thickness . 528
SC. 5 Practical Points 535
References 546
PART 6: PRODUCTION CONTROL
61 Introduction 553
CHAPTER 6A: MONITORING MACHINE PERFORMANCE.
6A. 1 Analysis of Downtime 556
6A.2 Performance Data 561
6A. 3 Monitoring Quality . 570
CHAPTER 6B: IMPROVING MACHINE PERFORMANCE.
6B. l General Survey . 581
6B. 2 Financial Considerations 586
6B. 3 Performance under Different Operating Conditions 600
References 613
Index 615
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