Experimental study the effect of angle of blade inclination on coal swirl fluidized bed drying

Boilers in Indonesia's power plants generally are designed using high range coal. The lack of supply for this coal leads consumption switched to the low range coal that will gives impact to decrease plant performance, increase in pollution, operating and maintenance cost. To face this problem, coal must be upgrading before use in boiler. Drying process is one of method to upgrade quality of coal where swirl fluidized bed drying is one of most efficient of fluidized bed drying. This research was conducted with variation for angle of blade inclination 10°, 20° and 30° with drying time 5 minutes. The temperature and RH air dryer inlet was 55 °C and 10.5 % and mass sample was 600 gr. For the five minute period of drying, moisture content was decreased from 25.17 to 10.28 %, 11.47 % and 13.67 % based on air dryer calculation and decreased to 9.57%, 11.20 and 13.77% based on coal measurement. Average mass transfer coefficient was 0.058 m/s, 0.052 m/s and 0.043 m/s respectively. Air dryer temperature at outlet for five minute period of drying was 53.1 °C, 51.7 °C and 50.6 °C and relative humidity was 18.13 %, 15.25 % and 15.16% respectively.