The objective of this research was to design and development of a continuous flow paddy dryer with infrared radial radiation technique. The prototype of dryer consists of two concentric circular cylinders cylinders which the paddy drying chamber is height of 1 m. The inner cylinder has diameter of 26.5 cm made from glasses and outer cylinder has diameter of 29.5 cm made from perforated (1.75 mm) steel sheet. At the center of cylinders installed 1200 w of electric infrared heater. A hopper was installed on the top of the chamber while 120 w of blower and paddy flow control were installed at bottom of chamber. The performance of the dryer in terms of specific energy consumption (SED) drying rate (DR) and quality of paddy i.e. head rice yield (HRY) and whiteness index (WI) were evaluated by drying 15 kg of paddy with initial moisture content of 23-26% (w.b.) by using the drying conditions of 80oC of drying chamber temperature 1.075 m3/min of air flow rate and 0.837 1.228 1.875 and 2.308 kg/min of paddy flow rate. The results found that paddy flow rate at 1.875 kg/min is the optimum condition because gave the highest DR lowest SEC and rice qualities (HRY and WI) closely to control.

This research objective was to apply thermoelectric module model TEC12710 as a preheater and dehumidifier for red chilies dryer. The heat side and cool side of Thermoelectric module affected by supplied electricity were used to produces the low humidity and warm air in preheater before charging to the main electric heater of dryer. Fresh red chilies were selected as a sample in the prototype testing during the use of preheater assisted main heater and using only main heater. The test results are compared with the sample dried under the natural sun drying. The experimental results show that the preheater can condense the moisture in air with the highest MER of 0.083 kgwaterh-1 at cold side of thermoelectric module and can heat the air up in 10°C of temperature with hot side of thermoelectric module. The final moisture content of sample is only 10%wb with the slightly changed in color when compared with the sample from sun drying. The using of preheater with main heater gives a higher specific moisture extraction rate lower specific energy consumption 14 MJ energy used and can dry faster than 10 h when compared with the using of only main heater.