Improved Differential Modeling and Performance Simulation of Slurry Spray Dryers as Verified by Industrial Data

Abstract

Process control of a spray dryer that is usually used as the last step of production is very crucial in obtaining a quality standard product. To this end, predicting the effect of various operating and environmental parameters on product properties is essential. Modeling has been done in microscopic and macroscopic scales by modifying the mass and heat transfer equations used in investigating the drying mechanism. However, as far as momentum transfer is concerned, the equations are the same as the ones used in the available literature models. Unlike conventional models that take only the two streams of hot air and sprayed droplets into account, a third stream is considered in our proposed model and this modification improves the results significantly. The model equations have been solved numerically and new simulation software has been developed using Visual C++ 6.0. The model results are in good agreement with industrial data obtained from a detergent-producing plant and show maximum errors of about 10%.

Keywords:

• Differential modeling
• Droplets
• Fines
• Hot air
• Nozzle
• Powder
• Slurry
• Spray dryer

ACKNOWLEDGEMENT

The authors thank the personnel and the director of the Research and Development Department of the Detergent Production Section of the Behdad Chemical Company.