AIChE Equipment Testing Procedure - Trayed and Packed Columns

100.0 PURPOSE & SCOPE 1 101.0 Purpose 1 102.0 Scope 1 200.0 DEFINITION AND DESCRIPTION OF TERMS 2 201.0 Flow Quantities 2 202.0 Key Components 3 203.0 Mass Transfer Efficiency 4 203.1 Theoretical Trays or Plates or Stages 4 203.2 Overall Column Efficiency 4 203.3 Apparent Murphree Tray Efficiency 4 203.4 Ideal Murphree Tray Efficiency 4 203.5 Murphree Point Efficiency 4 203.6 HETP 4 203.7 HTU 4 203.8 NTU 4 204.0 Operating Lines 5 205.0 Pinch 5 206.0 Maximum Throughput 5 206.1 Maximum Hydraulic Throughput 5 206.2 Maximum Operational Capacity 5 206.3 Maximum Efficient Capacity 5 207.0 Minimum Operating Rate 5 208.0 Operating Section 5 209.0 Hardware 6 209.1 Components of a Trayed Column 6 209.2 Components of a Packed Column 7 300.0 TEST PLANNING 9 301.0 Preliminary Preparation 9 301.1 Safety 10 301.2 Environmental Considerations 10 301.3 Test Objectives 10 301.4 Organizational Resources 10 301.5 Schedule 10 301.6 Review of Historic Operating Data 10 302.0 Column Control and Instrumentation 11 303.0 Peripheral Equipment 11 304.0 Pre-test Calculations 11 304.1 Process Simulation 11 304.2 Dry Run 11 305.0 Types of Tests 12 305.1 Performance Tests 12 305.2 Acceptance Tests 12 306.0 Specific Areas of Interest 12 306.1 Packing Efficiencies 12 306.2 Tray Efficiencies 12 306.3 Overall Column Efficiency 13 306.4 Capacity Limitations 13 307.0 Energy Consumption 14 308.0 Pressure Drop Restrictions 15 309.0 Data Collection Requirements 15 309.1 Process Operating Data 15 309.2 Gamma Scan Data 15 310.0 Conditions of External Streams 18 310.1 Overall and Component Material Balances 18 310.2 Overall Enthalpy Balances 18 311.0 Internal Temperatures 18 311.1 Heat Balances 18 311.2 Internal Profiles 18 312.0 Internal Samples 20 312.1 Internal Samples for Efficiency Checks 20 312.2 Internal Samples for Overall Performance 20 313.0 Pressure Profiles 20 314.0 Data Requirements-Physical Properties 20 314.1 Test Mixtures 20 314.2 Essential Data 21 315.0 Auxiliary Data 21 316.0 Test Procedure Documentation 21 400.0 METHODS OF MEASUREMENT AND SAMPLING 22 401.0 System Controls and Operating Stability 22 402.0 Measurement of Temperatures 22 402.1 Accuracy 22 402.2 Errors 22 403.0 Measurement of Flow Rates 24 403.1 Orifice Meters 24 403.2 Rotameters 25 403.3 Vortex Flow Meters 25 403.4 Coriolis Flow Meters 25 403.5 Magnetic Flow Meters 25 403.6 Pitot Tube (or Annubar) 25 403.7 Direct Volume or Weight Measurement 26 404.0 Measurement of Column Pressure Drop 26 404.1 Instrument 26 404.2 Pressure Taps 26 404.3 Seal Pots 33 404.4 Leakage Check 33 404.5 Accuracy 33 405.0 Sampling Procedure 34 405.1 General 34 405.2 Selection of Sampling Points 34 405.3 Sample Connections 35 405.4 Containers 35 405.5 Sampling of High Boiling Materials 36 405.6 Sampling of Intermediate Boiling Materials 37 405.7 Sampling of Materials Having Boiling Points Below -50°F (-46°C) 40 405.8 Leakage Check 41 405.9 Labeling and Handling the Samples 41 500.0 TEST PROCEDURE 43 501.0 Preliminary 43 502.0 Test Procedure for Maximum Hydraulic Throughput 43 502.1 Flood Symptoms 44 502.2 Performing Capacity Tests 45 502.3 Optional Test Technique - Gamma Scanning 48 503.0 Considerations Affecting Efficiency Test Procedure 48 503.1 Rigorous Versus Shortcut Efficiency Tests 48 503.2 Strategy of Efficiency Testing 49 503.3 Early Preparation for Efficiency Tests 50 503.4 Last-minute Preparations for Efficiency Tests 53 503.5 Establishment of Steady State Conditions 55 503.6 The Test Day 56 503.7 Concluding Test 56 600.0 COMPUTATION OF RESULTS 601.0 Verification of Test Data and Simulation Models 58 602.0 Material Balance 59 602.1 End Effects 59 603.0 Enthalpy Balance 59 603.1 Overall Balance 59 603.2 Internal Flow Rates 60 604.0 Hydraulic Performance 60 604.1 Trayed Column 60 604.2 Packed Column 61 605.0 Efficiency Performance 61 605.1 Trayed Column 62 605.2 Packed Column 69 700.0 INTERPRETATION OF RESULTS 76 701.0 Sources of Experimental Error 76 701.1 Material and Enthalpy Balances 77 702.0 Effects of Experimental Error 78 703.0 Design versus Performance 78 703.1 Mechanical/Tower Equipment 78 703.2 Process Conditions 78 704.0 Hydraulic Performance 79 704.1 Mechanical/Tower Equipment 79 704.2 Tray 79 704.3 Packing 80 704.4 Process Conditions 80 705.0 Mass Transfer Performance 81 705.1 Mechanical/Tower Equipment 81 705.2 Tray 81 705.3 Packing 82 705.4 Maldistribution 82 705.5 Process 84 706.0 Test Troubleshooting 85 706.1 Analysis Procedure 85 706.2 Sampling 85 706.3 Equilibrium Data 85 706.4 Temperature Measurements 85 706.5 Heat and Material Balances 86 706.6 Fluctuation of Process Conditions 86 706.7 Pressure Drop Measurements 86 706.8 Incorrect Prediction of Pressure Drop 86 706.9 Errors in Assumptions in Modeling Mass Transfer 86 706.10 Multicomponent Systems Deviate from Binary Data 87 706.11 High Purity Separation 87 706.12 Test and Design Conditions 87 800.0 APPENDIX 88 801.0 Notation 88 801.1 Greek Symbols 90 802.0 Sample Calculations 90 802.1 General Analysis of Test Data 90 802.2 Packed Column 91 802.3 Trayed Column 107 803.0 References 126