Evaluation of the Performance of a Custom-Made Fluidized Bed Drying System

Abstract. Laboratory and farm-scale fluidized bed dryers are not available to purchase. Additionally, a deliberation is presently continuing regarding the beneficial and damaging effects of drying grain in a fluidized bed. Therefore, the goal of this research was to develop and test a custom-made small-scale fluidized bed dryer, suitable for moderate farms and capable of drying small and large size grains from high moisture content to a safe storage moisture content. The customary fluidized bed dryer was developed and constructed in the Rice Research and Extension Center, Stuttgart, Arkansas. The fluidized bed dryer was used to dry wheat from an initial moisture content of 23.3% db. The effects of the aspect ratio (bed height to bed diameter ratio) of 2, 3, and 4 m/m, the furnace temperature of no heat, 100°C, 150°C, and 200°C and drying duration of 10, 20, 30, 40, 50, and 60 min on the wheat moisture content, drying rate, and dryer efficiency were investigated. The lowest wheat moisture content of 16.3% db was observed at the lowest aspect ratio of 2 m/m, the highest furnace temperature of 200°C, and the longest drying duration of 60 min. Conversely, the highest wheat moisture content of 19.0% db was observed at the highest aspect ratio of 4 m/m, and the no heat condition. The drying rate of 0.47%/min was observed at the lowest aspect ratio of 2 m/m and the furnace temperature of 200°C after 10 min. The maximum dryer efficiency of 63.2% was achieved at the aspect ratio of 4 m/m, the furnace temperature of 200°C. Two empirical models were developed to predict the moisture content of wheat and the dryer efficiency as affected by the aspect ratio, the furnace temperature and the drying duration with the adjusted coefficient of determination of 0.91 and 0.88, respectively. Although, the developed fluidized bed dryer is a lab-scale system, the experimental results provided an exceptional indication to scale up the drying system to dry grains.

[1]  Adnan Topuz,et al.  An experimental and numerical study of fluidized bed drying of hazelnuts , 2004 .

[2]  Sergio A. Giner,et al.  Modelling of Wheat Drying in Fluidized Beds , 1987 .

[3]  Stefan Heinrich,et al.  Fluidized Bed Air Drying: Experimental Study and Model Development , 2008 .

[4]  S. Iniyan,et al.  Fluidized bed drying of some agro products – A review , 2016 .

[5]  M. Yahya,et al.  Performance Analysis of Solar Assisted Fluidized Bed Dryer Integrated Biomass Furnace with and without Heat Pump for Drying of Paddy , 2016 .

[6]  Joseph M. Awika,et al.  Major Cereal Grains Production and Use around the World , 2011 .

[7]  K.S.M.S. Raghavarao,et al.  Studies on roasting of wheat using fluidized bed roaster , 2008 .

[8]  Edoun Marcel,et al.  Experimental Evaluation of the Thermal Performance of Dryer Airflow Configuration , 2015 .

[9]  Terry J. Siebenmorgen,et al.  EQUILIBRIUM MOISTURE CONTENTS OF ROUGH RICE DRIED USING HIGH-TEMPERATURE, FLUIDIZED-BED CONDITIONS , 2010 .

[10]  Arun S. Mujumdar,et al.  A Critical Assessment of Industrial Coal Drying Technologies: Role of Energy, Emissions, Risk and Sustainability , 2011 .

[11]  Didier Lecomte,et al.  High Temperature Convective Drying of a Packed Bed with Humid Air at Different Humidities , 2009 .

[12]  Sangeeta Prakash,et al.  Performance evaluation of blanched carrots dried by three different driers , 2004 .

[13]  K. Sandeepa,et al.  Studies on Drying of Sorghum Seeds in a Fluidized Bed Dryer , 2013 .

[14]  Sakamon Devahastin,et al.  Drying kinetics and quality of coconut dried in a fluidized bed dryer , 2005 .

[15]  Somchart Soponronnarit,et al.  EFFECTS OF DRYING ON HEAD RICE YIELD USING FLUIDIZATION TECHNIQUE , 1999 .

[16]  A.J.B. van Boxtel,et al.  Control of fluid bed tea dryers: controller performance under varying operating conditions , 2000 .

[17]  D. L. Proctor,et al.  Grain storage techniques: evolution and trends in developing countries , 1994 .

[18]  Bhesh Bhandari,et al.  Effects of High-Temperature Fluidized Bed Drying and Tempering on Kernel Cracking and Milling Quality of Vietnamese Rice Varieties , 2009 .

[19]  Mohammad Hadi Khoshtaghaza,et al.  Effects of fluidized bed drying on the quality of soybean kernels , 2015 .

[20]  Dariush Mowla,et al.  Experimental and theoretical investigation of drying behaviour of garlic in an inert medium fluidized bed assisted by microwave , 2008 .

[21]  Somchart Soponronnarit,et al.  Effect of Fluidized Bed Drying Temperature on Various Quality Attributes of Paddy , 2004 .

[22]  D. R. Mcgaw.  Heat transfer in shallow crossflow fluidized bed heat exchangers—I. A generalized theory , 1976 .

[23]  Arun S. Mujumdar,et al.  Applications for Fluidized Bed Drying , 2003 .

[24]  Banshi D. Shukla.  DRYING TECHNOLOGY AND EQUIPMENT IN INDIA , 2001 .

[25]  José M. Aragón,et al.  Fluidized Bed Drying of 2-Phase Olive Oil Mill By-Products , 2006 .

[26]  Z. V. P. Murthy,et al.  Fluidized Bed Drying of Aonla (Emblica officinalis) , 2007 .

[27]  C. Srinivasakannan,et al.  An Experimental and Modeling Investigation on Drying of Ragi (Eleusine corocana) in Fluidized Bed , 2006 .

[28]  Somchart Sopanronnarit,et al.  MOBILE FLUIDIZED BED PADDY DRYER , 1998 .

[29]  Griffiths G. Atungulu,et al.  Drying of Rough Rice Using Heated Husk for Heat Transfer and Moisture Adsorption , 2018 .

[30]  R. Gupta,et al.  Moisture Dependent Selected Postharvest Engineering Properties of Ragi (Eleusine Coracana) Grown in Northern Hills of India , 2015 .

[31]  Bande.  Determination of Selected Physical Properties of Egusi Melon (Citrullus colocynthis lanatus) Seeds , 2012 .

[32]  A. Tabatabaeefar.  Moisture-dependent physical properties of wheat , 2003 .

[33]  Abhay Kumar Thakur,et al.  Stationary versus Fluidized-Bed Drying of High-Moisture Paddy with Rest Period , 2006 .

[34]  Ahmad Mohsenimanesh,et al.  Modelling the Drying Kinetics of Canola in Fluidised Bed Dryer , 2018 .

[35]  Cedric Briens,et al.  Hydrodynamics and mass transfer in an upward venturi/bubble column combination , 1991 .

[36]  P. Golob,et al.  Reducing losses in small farm grain storage in the tropics , 1993 .

[37]  C O Anyaeche,et al.  Design and Fabrication of a Low Cost Fluidized Bed Reactor , 2012 .