Effect of Air Inlet Speed Variations on Oil Palm Loose Fruit Collector

Abstract

Oil palm is one of the largest economic sectors in Malaysia. Among the problems faced in the estates is oil palm loose fruit deposition, which is currently being collected manually in the industry. Hence, an oil palm loose fruit collector was designed using a cyclone separator mechanism and was studied using computational fluid dynamics (CFD). In the current study, Reynold’s stress model (RSM) and the discrete phase model (DPM) were employed to navigate numerical simulations where air speed intake of the designed machine was varied at 13, 30, and 46 m/s, respectively. The wall was set to a no-slip condition with standard wall functions. The hydraulic diameter of the gas outlet was Bc = 0.1 m. The hydraulic diameters of the particle’s outlet were Jc = 0.15 m and 0.2 m, respectively. Turbulence intensity at the gas and particle outlet was specified at 5%. An injection with density of 995.7 kg/m3 and a diameter of 0.04 m was set to simulate oil palm loose fruit collection into the system. Effects of air speed variations on the pressure drop and collection efficiency were then analyzed. It was found that increasing the inlet air speed from 13 m/s to 30 m/s reduced the collection efficiency by 14.92 % from 80.05% to 66.13%, while a 54.444% collection was recorded at 46 m/s inlet air speed. Ultimately, results indicate that a lower air speed is favorable in terms of pressure drop and collection efficiency.

Keywords

• computational fluid dynamics; cyclone separator; discrete phase model; oil palm loose fruits; reynold’s stress model