Simulation of Trough Withering of Tea using One Dimensional Heat and Mass Transfer Finite Difference Model

One-dimensional heat and mass transfer mathematical model was developed to simulate moisture content of tea leaves during trough withering. Model solutions were approached using finite difference method with appropriate boundary conditions. A computer program written in QBASIC was used to calculate the real time moisture content of tea leaves and other psychometric parameters of conditioned air during withering. Four experiments were performed using commercial type of withering trough to validate the developed model. Leaf samples were drawn from top, middle and bottom layers of the leaf bed in the trough for one-hour time interval for 12 h of the test period. Simulated moisture data calculated by the program was compared with the experimental data. Time and space increments of the model were chosen minimizing the estimation error of moisture content. Results showed that the experimental and simulated moisture data were in close agreement for top, middle and bottom layers of the withering trough with standard errors in the range of 0.2940–1.2872, 0.7148–1.1025 and 0.7106–4.5478, respectively on percent wet basis.

Keywords: Fresh tea leaves; one dimensional heat and mass transfer model; withering trough

DOI: http://dx.doi.org/10.4038/tar.v22i3.3701

Tropical Agricultural Research 22(3) (2011) 282-295