Improvement of a rubber drying greenhouse with a parabolic cover and enhanced panels

Abstract

Two structures of a greenhouse for rubber drying: (1) parabolic greenhouse (PG) and (2) parabolic greenhouse with the additional area-enhanced panels (PGEP) have been designed and built in this work. The experiment was divided into two parts: (1) a test of the empty greenhouses; and (2) a test of the greenhouses with rubber sheets drying. The results from the first part revealed that the measured air temperature within the PGEP was 5°C higher than PG’s. The new-designed PGEP provides higher thermal efficiency than the PG. Mathematical model was utilized to predict the air temperatures inside the empty greenhouses and the results agreed well with the experimental data. In addition, the test of greenhouses with rubber sheets drying showed that the drying period in PGEP was only 1.5 days while the drying period in PG was up to 5days. The rubber sheets dried with this method were classified as grade 1 (the top quality) and there was no fungal growth found in the sheets. The finite difference was applied in the mathematical model to predict the reduction of moisture content of the rubber sheets. The results from the model agreed well with the results from the experiments. Other significant parameters were also discussed.