EFFECT OF PIPELINE DECLINATION AND PARTICLE SIZE IN ANALYSIS OF WEAR RATE & FLOW MODELLING USING CFD FOR OFFSHORE TAILING HDPE TYPE PIPELINE PT. NEWMONT NUSA TENGGARA

• Main Author: GUNAWAN (NIM : 12105015); Pembimbing : Dr. Akhmad Ardian Korda, ST., MT., ARWIN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18082
• Institution: Institut Teknologi Bandung

Pipelines have become an important and cost-effective means of transporting solids over long distances. The copper industries like PT. Newmont Nusa Tenggara (PT. <br /> <br /> <br /> NNT), has been using slurry offshore pipelines for slurry tailing disposal in Senunu bay. This offshore pipeline located beneath Senunu bay with 3.114 km in length and the pipeline declines coherent with the contour of Senunu bay. The typical service life <br /> <br /> <br /> for this pipeline is 5 years with 2mm/year wear rate. Unfortunately this pipeline eroded more than expected with wear rate more than 20mm/year. Determination of <br /> <br /> <br /> wear rate for pipeline could have a high economic impact on this pipeline project. Wear is a combination of chemical corrosion and erosion. Since PT.NNT uses High <br /> <br /> <br /> Density Polyethylene (HDPE) for offshore pipeline, this material will not corroded, so the wear of the pipeline only be affected by erosion. A significant erosion problem is found to occur on HDPE pipes in tailing pipeline system. <br /> <br /> <br /> Analysis had been conducted to determine behaviour slurry flow with Reynolds number and critical slurry velocity or minimum speed to start the flow with Durand <br /> <br /> <br /> equation based on d50 (sieve passage diameter for 50% of the particles). A 2-D Computational Fluid Dynamics (CFD) model is developed to predict the flow and wear rate by the affect of pipeline declination (0.29o; 1.09o; 1.26o; 2o; 2.29o; 4.57o; 5.03o; 14.68o) and particle size of slurry (28.65&#956;m, 152 &#956;m, 213 &#956;m). <br /> <br /> <br /> The slurry flows with turbulence that is determined by the Reynolds number that valued 4,912,603. Critical slurry velocity that has been calculated showed that the <br /> <br /> <br /> operational slurry velocity that valued 6.02m/s is higher than critical slurry which valued 1.07m/s. In modelling with CFD, showed that wear rate increases when <br /> <br /> <br /> declination increases and the highest declination (14.681o) at the end of pipeline, wear rate is in the highest that valued 37.76 mm/year. CFD also showed that 213 &#956;m particles size, wear rate is higher than wear rate of 152 &#956;m and 213 &#956;m particles size.