Studi Eksperimen Performansi Heat Exchanger Crossflow Unmixed, Finned Tube 4 Passes Dengan Variasi Putaran Dan Volume Flow Rate Pada Rotary Dryer Untuk Mengeringkan Singkong

Abstract

A heat exchanger is a device used to transfer heat between two or more fluids and which function either as a heater or a coolant. The unit of Heat Exchanger is consist of air heater and rotary dryer. This research is aimed to get the optimum value of rotary dryer rotation and volume flow rate in cassava’s drying process. Matters from the cassava’s drying process were cassava’s mass reduction, cassava’s heat accepted, rotary dryer’s efficiency, and heat exchanger’s efficiency. The rotary dryer variatons used were 26,1 rpm; 33,9 rpm; and 44,2 rpm then the volume flow rate variations used were 0,023 m³/s; 0,027 m³/s; and 0,029m³/s. The way this heat exchanger works is the air as the cold fluid coming out from the blower then entering the air heater. Inside of the air heater the cold fluid receives heat from the hot fluid that flowing between the air heater shells. The heat source used comes from a simple stove under the air heater. After receiving the heat, the hot air has entered the rotary dryer which functions as a dryer. The optimum drying drying results when the pully of rotary dryer was setting at a speed of 26.1 rpm and the volume of cold fluid flow rate was 0.029 m³ / s is 0.235kg. The heat received by cassava from the optimum drying process when pully of the rotary dryer was setting at a speed of 26.1 rpm and the volume of cold fluid flow rate was 0.029 m³ / s is 521300.7 J. The optimal value of the efficiency of the rotary dryer and heat exchanger respectively 14.541% and 4.158% when pully in the rotary dryer was setting at a speed of 26.1 rpm and the volume of cold fluid flow rate was 0.029 m³ / s. Pully rotation in the best rotary dryer is when the pully was rotating at a speed of 26.1 rpm and the cold fluid volume was 0.029 m³ / s. Keywords : heat exchanger, air heater, rotary dryer, mass, efficiency