Estimation of the Thermal Diffusivity of Beans Using a Simple Apparatus

A simple apparatus for the determination of the thermal diffusivity of black-eyed beans samples, using the transient heat conduction method is presented. This apparatus is a stainless steel cylindrical tube, containing the sample, placed into a constant temperature water bath. The variation of the temperature at the center of the tube with time is recorded. The thermal diffusivities were determined from the temperature-time relationship data of the sample, and the dimensions of the equipment.  The estimated thermal diffusivity values of the samples varied between 4.70 x 10 -8 to 6.94 x 10 -8 and 5.26 x 10 -8 to 7.68 x 10 -8 when the temperature in the water bath was 50 o C and 60 o C, respectively.  Also, the thermal diffusivity was higher when the water bath temperature was 60 o C rather than 50 o C for the sample range of particle sizes studied. As black-eyed beans are a staple food in many parts of West African, they are grown, harvested, and stored. The thermal diffusivity information is useful in determining the behaviour of this Argo-product when stored. Keywords : Beans, Thermal Diffusivity, Transient Heat Conduction Method.