DescriptionSpray Dryers: A Guide to Performance Evaluation, Second Edition discusses the reasons for spray drying. These reasons are usually to produce a product with certain desired properties or with better efficiency than other methods. The book discusses how to plan in light of these objectives and gives guidance on the variables affecting product properties and dryer performance, to decide which variables to evaluate. Technical spray dryer installations are briefly described. Checklists are given to aid in planning measurements and listing steps needed for a test.
Scope of Spray Drying.
Reasons for Testing Spray Dryers.
Design vs. Operational Variables.
Definitions and Descriptions of Terms.
Airflow Motive Force.
Description of Terms.
Dryer Controls and Instrumentation.
Cleaning and Inspection.
Types of Test.
Dryer System Capacity.
Heat and Material Balance.
Variables Affecting Product Properties.
Residual Moisture Content.
Prediction of Capacity and Rate Effects.
Data Requirements - Product Properties.
Complete Heat and Material.
Peripheral Equipment Limitations.
Product Quality Measurements.
Objective of Tests.
Test Data Sheet.
Planning Check List.
Methods of Measurement and Sampling.
Gas Temperature Humidity.
Selection of Temperature Sensors.
Installation of Temperature Sensors.
Duct Temperature and Velocity Profiles.
Accuracy of Dry Bulb Temperatures.
Dryer Exit Humidity.
Accuracy of Gas Wet Bulb Temperature.
Installed Flow Meters.
Exit Gas Measurement.
Material Temperature and Moisture Content.
Product Temperature Measurement.
Product Moisture Content.
Dust Flow Measurements.
Radiation and Convection Heat Losses.
Estimated Heat Loss.
Measuring Heat Loss.
Location of Pressure Sensors.
Electric Power Measurements.
Running a Definitive Test in a Plant-Scale Dryer.
Humidity and Moisture Measurements.
Computation of Results.
Psychrometric Chart Method.
Humid Air Volume.
Total Air Volume.
Air Material Balance.
Enthalpy or Heat Balances on the Dryer.
Interpretation of Results.
Exploratory or Troubleshooting Tests.
Material, Moisture, and Energy Balances.
Dryer Heat Losses and Thermal Efficiency.
Example: Evaluating Drying Capacity of Air Stream.
Example: Dryer Test With Psychrometric Chart Heat Balance.
Evaluate Product and Evaporation Rate.
Ambient Air Humidity, Enthalpy, and Humid Volume.
Humidity Added by Fuel.
Dryer Outlet Conditions.
Dry Air Flow Rate.
Total Air Flow Rates.
Burner Heat Input.
Check Driving Force for Evaporation.
Example: Typical Dryer Test.
Air Flows - Outlet.
Air Flows - Inlet.
Dry Solids Balance.
Moisture Balance - Evaporation Rates.
Heat Balances: Heat Duty and Fuel Consumption.
Heat Balance Over Dryer.
Test Data Sheet.
Tables and Figures.