SCHOOL OF CHEMICAL ENGINEERING AND ADVANCED MATERIALS Control of Detergent Properties in a Spray Dryer Process Mark Jonathan Crosby March 2017 Table of Contents INTRODUCTION ................................................................................................................... 0 Spray Drying ........................................................................................................................................... 1 Background ............................................................................................................................................ 1 Objectives ................................................................................................................................................. 2 Scope of project ....................................................................................................................................... 2 Control of Spray dryers ........................................................................................................................... 3 Structure of Thesis .................................................................................................................................. 4 Literature & Materials .............................................................................................................................. 5 The influence of the process on the powder properties .......................................................................... 5 Development of the process model ......................................................................................................... 5 Conclusions & References ........................................................................................................................ 6 LITERATURE REVIEW ........................................................................................................... 7 Introduction ........................................................................................................................................... 8 Detergent Production ............................................................................................................................. 8 Bulk Density .............................................................................................................................................. 9 Particle Size Distribution ........................................................................................................................ 10 Moisture ................................................................................................................................................. 10 Spray Drying ......................................................................................................................................... 11 Principles of Spray drying ....................................................................................................................... 12 Liquid Atomization ........................................................................................................................ 12 Gas-Droplet Mixing ....................................................................................................................... 16 Drying of Liquid Droplets .............................................................................................................. 18 i Modelling of drying .............................................................................................................................. 26 Formation of droplets ............................................................................................................................ 26 Particle motion ....................................................................................................................................... 29 Drying ..................................................................................................................................................... 31 Level 0: Heat and Mass Balances .................................................................................................. 31 Level 1: Heat and Mass Balances with Equilibrium Models .......................................................... 33 Level 2: Rate-Based Models .......................................................................................................... 34 Morphology ............................................................................................................................................ 41 Shrinkage ...................................................................................................................................... 42 Agglomeration and Attrition ......................................................................................................... 43 Conclusions........................................................................................................................................... 44 MATERIALS & METHODS ................................................................................................... 45 Introduction ......................................................................................................................................... 46 Small Scale Mixed Flow Spray dryer ..................................................................................................... 47 Spray Dryer Chamber ............................................................................................................................. 48 Fluid Bed ................................................................................................................................................. 49 Measurements and Estimations ........................................................................................................... 50 Slurry Measurements/Estimations ......................................................................................................... 51 Air Measurements .................................................................................................................................. 56 Powder Measurements .......................................................................................................................... 58 Atomization Rig .................................................................................................................................... 60 Nozzle Modifications .............................................................................................................................. 62 Slurry flow measurements ..................................................................................................................... 64 Air flow measurements .......................................................................................................................... 64 Droplet Distribution Measurements ...................................................................................................... 65 ii Processing Issues & Solutions ............................................................................................................... 65 Mixed Flow Spray dryer .......................................................................................................................... 66 Slurry flow ..................................................................................................................................... 66 Powder flow .................................................................................................................................. 69 Air measurements......................................................................................................................... 72 Particle size measurement ............................................................................................................ 77 Atomization Rig ...................................................................................................................................... 78 Air flow manipulation ................................................................................................................... 78 Nozzle set up ................................................................................................................................. 80 MOISTURE CONTENT ........................................................................................................ 83 1 Introduction ......................................................................................................................................... 84 2 Empirical approach ............................................................................................................................... 86 2.1 Model Performance ............................................................................................................................... 87 3 Mass Balance ........................................................................................................................................ 90 3.1 Modelling Approach ............................................................................................................................... 90 3.2 Model Performance ............................................................................................................................... 94 4 Heat balance ......................................................................................................................................... 98 4.1 Modelling Approach ..............................................................................................................................