(55d) Influence of Swirl Flow on the Erosion of Pipe Bends of Pneumatic Conveying Pipeline Systems

Pneumatic conveying pipeline systems are widely employed in the industry for transporting the powder and granular materials such as pulverized coal, fly ash, food grains, cement etc. over long distances without any spillage and contamination of the material. The shrouded conveying of materials through pipeline system has specific advantages in the terms of flexibility in the pipe routing, reliability in conveying and associated safety issues. However, it is worth noting here that the pipe bends of pneumatic conveying pipeline system normally fail early due to the erosion caused by the impact of hard and abrasive particles. Therefore, need arises for the development of solutions for extending the life of pipe bends and consequently enhancing the reliability of the conveying system. The objective of the present paper is to explore the possibility of enhancing the life (by reducing the erosion) of pipe bends by employing a swirl flow in the pipeline toward the upstream side of the bend. Experimental investigations have been carried out for assessing the erosive wear of bend and attrition rate of conveyed sand. Effectiveness of the swirling of material (sand) on the reduction of bend erosion at different feeding rates has also been investigated and presented herein. Moreover, the influence of swirling flow on the erosion of another bend placed further down to the flow after the test bend is also investigated. The photographic views of the eroded areas of the pipe bends eroded in the conveying pipeline in presence and absence of swirl flow have been inspected and compared. Based on the experimental investigations, it has been observed that with the swirl flow, erosion rate of bends has reduced significantly varying in the range of 300-360%. Moreover, due to the existence of swirling effect, a significant reduction in attrition rate is achieved, which is of the order of about 114%. Uniform erosion surface topography with low depth of penetrations have been observed at the pipe bends in the presence of swirl flow imparted to the materials (sand) prior to entry in the bends.