Effects of Infrared Heating Combined with Vibration Screen on Eliminating Rice Weevils in Paddy Storage

Abstract

The objective of this research was to study the effect of infrared heating combined with vibrated screen on eliminating rice weevils in paddy storage. The experimental unit was designed on a concept of allowing the paddy to move horizontally with thickness layer over a vibration screen operated by a cam giving vertical vibration. The paddy layer on the screen was heated using 3,600 W electric infrared bars at 5 levels of temperature:  120, 140, 160, 180 and 200 ^๐C. For a 1 kg of 3.1 mm paddy layer thickness and temperature upward of 120 ^๐C for 4-5 seconds, the adults death rate was 100%. But for a paddy layer thickness of 4.5 mm the adult death rate was nearly 100% for temperatures greater than 160 ^๐C for 4-5 seconds. Therefore, in order to conform with the practically work the 10 kg of paddy was continuously flowed. The study of the heating effect on the elimination of rice weevils in stored paddy showed the best results for a paddy layer thickness of 3.1 mm, a temperature between 160 and 200 ^๐C for 4-5 seconds. The results of the study show that the adults death rate was 100% at temperatures upward of 180 ^๐C. This does not make sense. For 2-3 months of paddy storage, the adults growth rate was1.1-5.3% and 1.1-3.7% at the temperatures of 180 ^๐C and 200 ^๐C respectively. However, the optimum temperature was 180 ^๐C because the value of the head rice yield was the highest.