This research presents a case study of the rating heat transfer of a loop thermosyphon with a vapour chamber (LTVC). The dimensions of the evaporator chamber were 200 × 200 × 55, 200 × 200 × 65 and 200 × 200 × 75 mm ( × × ). The adiabatic and condenser section had an 8-loops thermosyphon. The length of the adiabatic and condenser section in each loop was 824 and 800 mm, respectively. The air velocity was 0.5, 1.0, and 1.5 m/s with the heat input being 600, 900, and 1,200 W. The three working fluids were: water, ethanol, and R-11 with filling ratios of 20, 40, and 60% with respect to the chamber volume. The experimental data showed that the LTVC yielded the value of the relative thermal efficiency of about 1 at R-11, a filling ratio of 60%, a velocity of 0.5 m/s, and an aspect ratio of 2.5 in the study conditions. It was further found that the larger vapour chamber was superior in the rating of the heat transfer over other vapour chambers in all experimental conditions in this study.

This research was aim to apply heat pipe in the small pasteurizing machine for fruit juice process. The orange juice was used as the sample. The container of the pasteurizing machine was made from 304 stainless steel with 1.5 millimeter of thickness, 300 millimeter of inside diameter, and 374 millimeter high, with 20 liters capacity. In order to control the temperature distribution in the test tank, four heat pipes, that made from same material, were used as heating device that heated from LPG gas. The heat pipe had 0.8 millimeters of thickness, 25millimeter of internal diameter, and the length of 650 millimeters. The result was found that the pasteurizing machine can be pasteurized the orange juice as 88 degree celsius with 32.5 minutes of come up time. The temperature distribution of the orange juice in the tank was  0.5 degree celsius.

This research aimed to study on the optimum condition for osmotic dehydration of pomelo. The experimental procedure was divided into 2 sections. For first section, the effect of sucrose solution concentration (50, 60, and 70 oBrix) on osmotic rate and moisture content of osmotic dehydrated pomelo were evaluated. After that, the effects of drying temperature (50, 65, and 80oC) on quality of osmotic dehydrated pomelo including, odor, texture, taste, and color were determined. The experimental results showed that the osmotic dehydration rate of pomelo were 6.4, 9.4, and 9.6 oBrix/hr when the pomelo was immersed in 50, 60, and 70 oBrix sucrose solutions, respectively. The moisture content of osmotic dehydrated pomelo which immersed in 70oBrix was lowest. The osmotic dehydrated pomelo that was immersed in 70 oBrix sucrose solutions and dried at 50oC has highest quality.

No abstract