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Journal : Sinergi

DETECTING CLASSIFIER-COAL MILL DAMAGE USING A SIGNAL VIBRATION ANALYSIS Dedik Romahadi; Alief Avicenna Luthfie; L. B. Desti Dorion
SINERGI Vol 23, No 3 (2019)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (11403.501 KB) | DOI: 10.22441/sinergi.2019.3.001

Abstract

A classifier plays a crucial role in the cement industry. It is in charge of separating coal that has been smoothened out and is ready to be burned although the coal is still rough after going through the grinding process. It takes a long time to burn coal that is not perfectly processed with a classifier. Therefore, it will reduce the amount of cement production, and the factories will release more energy. The closed arrangement and the number of components in the unit classifier requires a sophisticated method to detect damage that occurs early. Vibration analysis is a method that has been effectively employed in detecting the initial damage that occurs to the engine, especially the classifier. This study was aimed at detecting the location of the damage occurring in the classifier by using a vibration signal analysis and by measuring the magnitude of vibration and presenting it to the frequency domain (spectrum) form using Fast Fourier Transform. Engine condition assessment referred to ISO 10816-3 standard in velocity and displacement modes. Based on data spectrum analysis, the dominant damage laid in the unbalanced rotor. Spectrum characteristics of the damage appeared to be in the spectrum line worth 438.01 μm at a 3.5-Hz frequency (1X) radially. This analysis proved to be supported by the decrease in vibration value to 18.65 μm after balancing the Classifier rotor.
NUMERICAL SIMULATION ON REAR SPOILER ANGLE OF MINI MPV CAR FOR CONDUCTING STABILITY AND SAFETY Alief Avicenna Luthfie; Dedik Romahadi; Hanif Ghufron; Solli Dwi Murtyas
SINERGI Vol 24, No 1 (2020)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (687.676 KB) | DOI: 10.22441/sinergi.2020.1.004

Abstract

Spoiler attached on the rear part of a car can generate drag force and negative lift force, called downforce. This drag force can increase air resistance to the car, meanwhile, a negative lift force can improve the car’s stability and safety. Refer to many researchers, the shape and the angle of the spoiler give different aerodynamic effects and therefore give a different value of drag force and lift force. Based on these facts, this study was focused on the analysis of different spoiler angle attached to a mini MPV car to drag and lift force generated by the spoiler. The method used in this study is a numerical simulation using the Computational Fluid Dynamics (CFD) technique. The analysis was carried out at different spoiler angle and car’s speed. The spoiler angles are -20o, -10o, 0o, 10o, and 20o. The car’s speeds are 40 km/h, 60 km/h, 80 km/h, 100 km/h, and 120 km/h. Then the drag and lift force and their coefficient generated by different spoiler angles were being investigated at specified speeds. The result shows that higher spoiler angles generate higher drag and lower lift. Spoiler angles higher than 0o generate negative lift force, otherwise generate positive lift force. Therefore, to increase a car’s stability and safety, it is recommended to use a spoiler angle higher than 0o. Based on the result, it is best to use spoiler angle 10o because it generates negative lift force with -0.05 lift coefficient and 0,68 drag coefficient.
Numerical analysis of the vortex flow effect on the thermal-hydraulic performance of spray dryer Fajar Anggara; Dedik Romahadi; Alief Luthfie Avicenna; Yosua Heru Irawan
SINERGI Vol 26, No 1 (2022)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/sinergi.2022.1.004

Abstract

The use of a spray-dryer is very popular in the drying process in the food and beverage industry. However, due to the properties of the sensitive product that the quality will degrade in drying at high temperature, the innovative design of spray-dryer is developed which can increase the heat transfer rate at moderate temperature. This research was conducted to develop a spray-dryer design to improve thermal-hydraulic performance, with a high transfer rate and low-pressure drop at such a temperature. The design varies by several inlets categorized as design A with one inlet, design B with two inlets, and design C with three inlets. This simulation uses ANSYS FLUENT17, and the independence of the mesh was evaluated to improve the result of the simulation. The efficient mesh number is obtained from the independence of the mesh at around one million. The result shows that design C has the lowest pressure loss and the highest transfer rate due to high vortex and swirl flow generation, improving the mixture quality and direct contact between droplet and dry-air.