Influence of Spray Drying Conditions on Residue Accumulation—Simulation Using CFD

Abstract The Computational Fluid Dynamics code FLUENT 5.3 is used to study how changes in spray drying operating conditions can affect the fouling of the equipment during drying. A set of experiments was conducted on a laboratory spray dryer keeping constant the feed rate, the feed temperature, the air inlet temperature and the atomizer pressure, and varying the compressed air flow rate and the flow rate of drying air. This set of data was simulated using the CFD package FLUENT 5.3. The same trends were observed between experimental data and the simulations in terms of the effects of the investigated parameters. Residue accumulation increased with decreases of compressed air flow rate and flow rate of drying air. The simulation results give a better understanding of several phenomena that appear during spray drying and can sharply reduce the number of experiments needed to find a solution to the fouling problem.

[1]  S. A. Morsi,et al.  An investigation of particle trajectories in two-phase flow systems , 1972, Journal of Fluid Mechanics.

[2]  P. Kerkhof,et al.  Air flow, temperature, and humidity patterns in a co-current spray dryer: modelling and measurements , 1997 .

[3]  A. Goula,et al.  Spray Drying Performance of a Laboratory Spray Dryer for Tomato Powder Preparation , 2003 .

[4]  Arun S. Mujumdar,et al.  Industrial Spray Drying Systems , 2006, Handbook of Industrial Drying.

[5]  David F. Fletcher,et al.  USE OF COMPUTATIONAL FLUID DYNAMICS TECHNIQUES TO ASSESS DESIGN ALTERNATIVES FOR THE PLENUM CHAMBER OF A SMALL SPRAY DRYER , 2001 .

[6]  Y. Maa,et al.  Spray-drying performance of a bench-top spray dryer for protein aerosol powder preparation. , 1998, Biotechnology and bioengineering.

[7]  Keith Masters,et al.  SCALE-UP OF SPRAY DRYERS , 1994 .

[8]  J. Vasseur,et al.  SIMULATION OF SPRAY DRYING IN SUPERHEATED STEAM USING COMPUTATIONAL FLUID DYNAMICS , 1999 .

[9]  Pjam Piet Kerkhof,et al.  Measurement and Modelling of the Air Flow Pattern in a Pilot-Plant Spray Dryer , 1997 .

[10]  T. Howes,et al.  A SEMI-EMPIRICAL APPROACH TO OPTIMISE THE QUANTITY OF DRYING AIDS REQUIRED TO SPRAY DRY SUGAR-RICH FOODS , 1997 .

[11]  C. Judson King,et al.  Air temperature and humidity profiles in spray drying. 1. Features predicted by the particle source in cell model , 1988 .

[12]  David F. Fletcher,et al.  Prospects for the Modelling and Design of Spray Dryers in the 21st Century , 2003 .

[13]  David F. Fletcher,et al.  Spray drying of food ingredients and applications of CFD in spray drying , 2001 .

[14]  Ireneusz Zbicinski,et al.  The effects of air inlet geometry and spray cone angle on the wall deposition rate in spray dryers , 1994 .

[15]  J. Straatsma,et al.  Spray drying of food products: 1. Simulation model , 1999 .