Heat exchanger Design for Longan Drying

Abstract

The objective of the research was to design heat exchanger of longan dryer and to study the efficiency. The experiment was conducted at the Agricultural Engineer Operating. Chiang Mai province during October 2006–November 2007. The machine consists of a furnace, heat exchanger venting duct, hot air piping set and venture. The test of open of hot air pipe indicated that the volume of air which flew through the venture, related to the opening gap which had linear regression of R2 =98%. The average mean air flow at the entrance was 0.87 m3/second. The efficiency of hot air chamber system was 33%. It was found that there were 73% of good product and 27% of defect. The average volume was reducing 4% from fresh longan.