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The performance of a newly developed cyclone dryer is investigated using RANS-based single-phase computational fluid dynamics (CFD) and experimental model studies. The cyclone dryer is a cylindrical tower, divided by conical orifices into several chambers; recirculation of the flow within individual chambers ensures adequate retention time for drying of the transported solid material. Numerical calculations are performed using the commercial CFD code CFX5.7 for different mesh types, turbulence models, advection schemes, and mesh resolution. Results of the simulation are compared with data from experimental model studies. The RNG k-ε turbulence model with hexahedral mesh gives satisfactory results. A significant improvement in CFD prediction is obtained when using a second order accurate advection scheme. Useful descriptions of the axial and tangential velocity distributions are obtained, and the pressure drop across the cyclone dryer chamber is predicted with an error of approximately 10%. The optimized numerical model is used to predict the influence of orifice diameter and chamber height on total pressure drop coefficient.

After the harvest, the paddy would contain high and unequal initial moisture content, depending on the season and harvest time. As a result, the dehydration was caused by using the dryer while feeding the paddy grain unequal moisture content, the dryer should be properly adjusted to retain the final moisture content as per the rice mill and storage requirements and low specific energy consumption (SEC) were used for the drying operation per one cycle product. The objective of this paper was to study the paddy drying operation by using a continuous cross-flow dryer at a different initial grain moisture content. The research was divided into two steps, the first step began with the drying operation with levels of the initial moisture content 20.0%wb that involved the adjustment of the parameters of an average hot-air temperature 150°C, the speed rotation of an eccentric set of 11.52 rad s–1, the airflow rate 0.016 m3 s–1, and speed rotation of rotary valve 0.21 rad s–1 (approximately feed rate 36 kg h–1), by the application of these parameters, from the obtained results, it was found that grain moisture content of paddy was reduced from 20.0%wb to 14.3%wb as desired, and SEC of 3.60 MJ kg–1 water was evaporated. Then the second step, these parameters were tested in terms of the drying operation that the initial grain moisture content decreased and increased 18.1%wb and 23.0%wb, respectively. The results showed that when the initial grain moisture content decreased, the paddy drying operation reduced the moisture of the paddy until the final grain moisture content became 12.9%wb which was lower than the desired expectation, On the contrary, when the initial moisture content increased, the final grain moisture content became 16.1%wb. This was not sufficient for storage or planting in the next crop year which required re-drying operation as well. Furthermore, the results can be used as reference data and a guideline for small communities in Thailand to appropriate decisions with the drying cost and the value-added tax.

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This research aims are to design, build and analyze the performance of concentrated solar energy onto a simple calorimeter, made of copper and stainless steel. A scrapped yard antenna dish with a diameter of 1.68 meters was lined with aluminum foil reflector sheet. The average dish aperture area of 2.21 m2, the system uses water as a heat transfer fluid distributed from overhead tank. Absorbed energy was investigated at a water flow rate of 0.5 L/min were performed in the experiment and the maximum useful energy was determined. Parabolic dish concentrator displacement angle was adjusted in every 15 degrees per hour, with the used of electric controlled sun tracking system. The experimental tests carried out in Faculty of Industrial Technology, Vallaya Alongkorn Rajabhat University Pathum Thani, under Thailand climatic conditions (14.134°N, 100.611°E) during 2 selected days of the months April 2013. The performance of a paraboloidal concentrator was assessed using open-air experimental measurements including the incoming heat, the energy absorbed by the water, and the concentrator efficiency. The experimental results shown the maximum thermal efficiency was 89.73%. It was also found that copper calorimeter can simply attain during operation relatively high water temperature levels oncoming 97 °C. The concentrated solar flux at the focal point was 442,073.11W/m2 for stainless steel calorimeter and 619,448.66 W/m2 for copper calorimeter, respectively.