Positioning the Erosion Wear of Bend Pipes in the Pneumatic Conveying System
1. State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China;
2. University of Chinese Academy of Sciences, Beijing 100039, China;
3. Hefei General Machinery Research Institute, Hefei 230088, China
Abstract Pneumatic conveying technologies are widely used in various industrial processes. Erosion wear is the key factor affecting the safety and economical efficiency of the conveying processes. It is of great significance to determine the erosion position of the bend pipes for the prevention from pipeline erosion wear. In order to investigate the impact of the superficial gas velocity, solid flow rate and particle diameter on the erosion position of the bend pipe with different ratios bending diameter (R/D), a thin coating layer was applied on the inner wall of the bend pipe to determine the erosion position. Additionally, electrical capacitance tomography (ECT) measurements were also performed to detect the solid concentration distribution on the cross-section of the bend pipe inlet. Erosion position was defined using height definition and the ratio of height of erosion position to pipediameter (h/D) as a unit. It was found that the erosion position may be located at h/D 0.5 when the gas velocity was about 11 m/s or more. As the gas velocity grew above a critical gas velocity, the erosion position started to descend and finally reached h/D 0.2. The solid flow rate, the diameter of particle and the R/D ratio could affect the critical gas velocity. The critical gas velocity had a negative correlation with the solid flow rate and the R/D ratio, while it had a positive correlation with the diameter of particle. When the gas velocity was in a certain range, increase of the solid flow rate could lead to the downward movement of the erosion position.
