Muhammad Kunta Biddinika

Velocity Profile Measurements in Two-Phase Flow using Multi-wave Sensors

Two-phase flow has been recognized as one of the most important phenomena in fluid dynamics. In addition, gas-liquid two-phase flow appears in various industrial fields such as chemical industries and power generations. In order to clarify the flow structure, some flow parameters have been measured by using many effective measurement techniques. The velocity profile as one of the important flow parameter, has been measured by using ultrasonic velocity profile (UVP) technique. This technique can measure velocity distributions along a measuring line, which is a beam formed by pulse ultrasounds. Furthermore, a multi-wave sensor can measure the velocity profiles of both gas and liquid phase using UVP method. In this study, two types of multi-wave sensors are used. A sensor has cylindrical shape, and another one has square shape. The piezoelectric elements of each sensor have basic frequencies of 8 MHz for liquid phase and 2 MHz for gas phase, separately. The velocity profiles of air-water bubbly flow in a vertical rectangular channel were measured by using these multi-wave sensors, and the validation of the measuring accuracy was performed by the comparison between the velocity profiles measured by two multi-wave sensors.

Alternative solid biofuel production from palm oil residue wastes employing dry torrefaction

Indonesia is the biggest producer country of crude palm oil in the world so that the utilization of palm oil industry waste as a solid fuel via dry torrefaction is a very promising method to produce not only green energy sources but also resolve the waste problems. This study aims to investigate the effect of temperature and holding time on the torrefaction of palm oil residue waste. The feedstocks used in these experiments were palm kernel and palm kernel shell. The feedstocks collected contained high moisture fraction which was then sun-dried for three days in order to reduce the water content. The results show that the temperature of 250°C produced a highest solid product which is more than 80% yield for palm kernel shell. The increase of torrefaction temperature and holding time resulted in decreasing the solid yield for both feedstocks. The palm kernel torrefaction produced less solid fraction than those of palm kernel shell at 250°C. In contrast condition at the higher temperature, palm kernel torrefaction produced less solid fraction than palm kernel shell. The heating value of solid product increased as the increase of temperature and holding time, while the energy yield decreased.Indonesia is the biggest producer country of crude palm oil in the world so that the utilization of palm oil industry waste as a solid fuel via dry torrefaction is a very promising method to produce not only green energy sources but also resolve the waste problems. This study aims to investigate the effect of temperature and holding time on the torrefaction of palm oil residue waste. The feedstocks used in these experiments were palm kernel and palm kernel shell. The feedstocks collected contained high moisture fraction which was then sun-dried for three days in order to reduce the water content. The results show that the temperature of 250°C produced a highest solid product which is more than 80% yield for palm kernel shell. The increase of torrefaction temperature and holding time resulted in decreasing the solid yield for both feedstocks. The palm kernel torrefaction produced less solid fraction than those of palm kernel shell at 250°C. In contrast condition at the higher temperature, palm kernel torre...

Clarification of Ejection and Sweep in Rectangular Channel Turbulent Flow

The experimental study has been carried out to investigate the behavior of ejection and sweep events in a rectangular channel turbulent flow. The channel is a 1800 mm long vertical channel with a cross sectional area of 100 mm and 20 mm. The events are studied by obtaining velocity components of the flow by using the ultrasonic measurement method (UVP). This paper clarifies the capability of the UVP for investigating the sweep and ejection events.Copyright