Proposal for improving of paddy rice drying process in dryers inclined pools

The operation of inclined type dryers for paddy rice is studied to improve their operation and efficiency, considering the variables of drying time, humidity distribution in the rice layer after drying and air velocities within the plenum. Simulating the distribution and velocities of the air flow before crossing the rice layer, the outlet ducts to the plenum are relocated and dampers are placed to distribute the flow evenly. On the other hand, it is proposed to replace the flat-type mesh with a zigzag-type mesh. To verify the proposed modifications, a scale model was built to determine the humidity and drying time variation inside the rice layer, obtaining more uniform moisture percentages within the rice layer and a decrease in drying time.

Development of a biomass energy dryer assisted with solar energy for farmers in off-grid communities

The objectives of this research are to design and construct a biomass energy dryer assisted with solar energy for farmers in off-grid communities and to evaluate the performance of the dryer. The dryer consists of a boiler, drying chamber and solar panels. A compressed sponge was used as a drying product. The air temperature distribution and product moisture uniformity inside the drying chamber were measured. The apparatus was tested in three energy modes, solar energy mode, biomass energy mode and biomass/solar energy assisted mode. Drying using biomass/solar energy assisted mode gave a better drying performance compared to the other modes due to the uniform moisture content and air temperature. The average temperature difference between the top and bottom tray was less than 3°C. The average moisture content between the top and bottom tray was very close, less than 0.8% db. In addition, this drying mode can reduce product contamination from smoke ash and combustion.

Effects of potassium fertilisation on late potato blight and yield – short communication

Potato yields and infestation by P. infestans are related to the supply of potassium. Potassium was applied as soil fertilisation combined with split foliar applications or only as split foliar treatments at a maximum dose of 150 kg/ha K₂O in both strategies, Lord and Ditta cultivars were used. Additionally, water spraying was included as an alternative treatment in order to maintain uniform moisture in the rows of plants. Plants fertilised with foliar spraying only were more infested than plants fertilised with combined methods. The fertiliser increased the protection impact of copper treatments against P. infestans. This may suggest a possible synergistic effect in reducing the symptoms of the disease, however not always statistically significant in both cultivars. Plants sprayed with water but without soil application of fertiliser showed a statistically significantly higher infestation rate, both in Lord and Ditta cultivars, compared to plants with soil application of fertiliser but without watering.

Development and Promotion of the Reversible Airflow Flatbed Dryer in the Philippines

A flatbed dryer with a reversible airflow was introduced in the Philippines through a collaborative project between Nong Lam University of Vietnam and the Philippine Rice Research Institute (PhilRice). In this design, airflow is reversed at some point during the drying period to achieve uniform drying without mixing the grain. An 8-ton capacity dryer was constructed at PhilRice Central Experiment Station in Nueva Ecija to evaluate its performance and adaptability under Philippine conditions. Appropriate and locally available materials were used in the construction of the pilot unit. Nine (9) additional dryers were then constructed at PhilRice stations (Nueva Ecija, Isabela, Negros, Agusan, Central Mindanao University, and Midsayap) that served as pilot units for technology promotion in their respective areas of coverage. Performance of the dryer was evaluated in terms of the following parameters: (1) drying; (2) quality of dried grains; and (3) economic analysis of using the dryer. The performance evaluation was conducted in three drying batches of newly harvested rice seeds. Paddy dried with the reversible airflow flatbed dryer at full load capacity has a uniform moisture content with one percent (1%) moisture gradient at different layers of the grain mass along the depth and across the drying bin. The drying rate was 1% moisture reduction per hour. The drying cost of using the reversible dryer is PhP0.74 per kg which is lower than the prevailing mechanical drying cost of PhP1.13 per kg. It has a payback period of 2.5 years and break-even point of 53.0 batches/year. To date, eight (8) privately-owned units have already been constructed and fully operational in the provinces of Nueva Ecija, Quirino, and Bukidnon, with PhilRice receiving inquiries from interested individuals here and abroad regarding the technology.