Khao Tan, a kind of Northern Thai dessert, is one of the famous and money-making OTOPs of Lampang province.
Making Khao Tan process is not complicated. After sticky rice was steamed, it was molded in a disc shape of about 4 cms diameters, then let the discs dry in sunshine to get ready for being fried. It was found that the 1 to 2-day drying period would be longer on overcast days, especially in the rainy season.
To solve this problem, three students of Mechanical Technology, Faculty of Engineering, Rajamangala University of Technology Lanna, Lampang: Mr. Chalermpon Katasai, Mr. Tanawat wongchairat, and Mr. Prapot Deemak, developed a Khao Tan dryer which employs two sources of energy, sunshine and liquid petroleum gas (LPG), under Mr Chatchai Worapat’s supervision, their lecturer.
The size-of 120 x 220 x 110-cms machine which costs 30,000baht is blanketed with zinc sheets, lined with stainless sheets, and topped with two 6-mm pieces of glass. It is operated either by sunshine or LPG.
From the study of drying 1,260 pieces of Khao Tan with 3.7cms diameter, it took 10 hours to dry them in the sunshine, 6 hours to use this drying machine with the sunshine, and 5 hours with LP, consuming 3.8kg/hr. of gas.
This machine is a sample of applying mechanic energy which lessens both capital and operating cost.