ON-LINE WEB-BASED DESIGN SIMULATOR OF A PLUG FLOW FLUIDISED BED CROSS-FLOW DRYER

In the past, engineering design of dryers have always been a tedious affair involving rules of thumbs derived from experience and pilot scale experimental data with few available dryer simulator software to speed up the scaling up of the dryer to industrial scale. A few simulators have appeared in the market but they are not readily accessible to most dryer-design practitioners especially in the developing world. To solve the accessibility problem, the paper proposes to use a web-base design tool for simulating an industrial dryer. The plug flow fluidized bed dryer with cross flow drying medium (hot air or flue gas) for drying paddy was simulated using a new cross flow model that was developed by the drying technology research group at Universiti Kebangsaan Malaysia. A website program which is accessible over the internet and user-friendly has been developed using LAMP combination that allows preliminary parametric studies to be undertaken for this type of dryer. The model was solved using Runge-Kutta 4th order method. Various operating parameters of the dryer such as the air consumption (G/F), initial hot air temperature (T_i), initial solid temperature (T_si) initial hot air humidity (Y_i), initial solid moisture (X_i), length of dryer (L), step size length (Δz) and width of dryer (w) can be manipulated to explore the performance of the dryer. The web-based simulator calculates the conditions of the outlet streams of the dryer which are the solids temperature (T_s), exhaust air temperature (T), solids moisture content (X) and exhaust air humidity (Y) as a function of fluidized bed length which are shown on the web page. The model was verified by comparing experimental data on paddy using a pilot scale fluidized bed cross-flow dryer.