The analysis on bio-drying potential of sewage sludge in the North of China
This paper analyzes the overview of northern sewage sludge, focusing on the potential of bio-drying of sewage sludge in northern China by adopting the technology of biological drying to dispose the sewage sludge. Owning great development potential is the conclusion obtained by the experimental study of the northern sludge.
Transport processes and unit operations
I. TRANSPORT PROCESSES: MOMENTUM, HEAT, AND MASS. 1. Introduction to Engineering Principles and Units. 2. Principles of Momentum Transfer and Overall Balances. 3. Principles of Momentum Transfer and Applications. 4. Principles of Steady-State Heat Transfer. 5. Principles of Unsteady-State Heat Transfer. 6. Principles of Mass Transfer. 7. Principles of Unsteady-State and Convective Mass Transfer. II. UNIT OPERATIONS. 8. Evaporation. 9. Drying of Process Materials. 10. Stage and Continuous Gas-Liquid Separation Processes. 11. Vapor-Liquid Separation Processes. 12. Liquid-Liquid and Liquid-Solid Separation Processes. 13. Membrane Separation Processes. 14. Mechanical-Physical Separation Processes. III. APPENDICES. A1. Fundamental Constants and Conversion Factors. A2. Physical Properties of Water. A3. Physical Properties of Inorganic and Organic Compounds. A4. Physical Properties of Foods and Biological Materials. A5. Properties of Pipes, Tubes, and Screens. Notation. Index.
Convective Drying of Wastewater Sludges: Influence of Air Temperature, Superficial Velocity, and Humidity on the Kinetics
Abstract The influence of air temperature, velocity, and humidity during convective drying of two different sludges (A and B) is investigated through a 33 factorial design. For sludge A, a constant drying flux period is observed, while sludge B is characterized by a long decreasing drying flux phase. A sensitivity analysis shows that temperature is the main operating parameter affecting the drying kinetics. Mass and heat transfer coefficients as well as water evaporation capacities are calculated from drying curves. Transfer coefficients are related to operating conditions through dimensionless relations. For both sludges, a linear relation is found between water evaporation capacity and the maximal measured drying flux.