A comprehensive evaluation of the anti-erosion characteristics of several new structural elbows in the pneumatic conveying system

Abstract

The anti-erosion design of elbows is a critical issue, which is directly related to the life of the pipeline. To improve the anti-erosion characteristics of elbows, three types of elbow structure with circumferentially distributed bionic transverse grooves, bionic ribs, and a single rib on the inner wall are proposed. The forms of the grooves or ribs in each type of structure described are selected as square or triangular shapes. The anti-erosion performances of the proposed three types of structures under different working conditions are evaluated using a numerical simulation method. The results show that all types of structures have certain anti-erosion properties because they can change the particle trajectory and affect the flow in the near-wall region. The shape of the grooves or ribs has a significant effect on the anti-erosion properties. The structure with triangular grooves or ribs shows better erosion resistance than the structure with square grooves or ribs, due to lower impact frequency between the particles and the wall. Among several structures, the triangle single rib has the best erosion resistance at 20°, and the maximum erosion rate is 47% lower than that of the ordinary elbow. The bionic triangle transverse grooves structure ranks second, followed by the bionic triangle ribs structure, the bionic square transverse grooves, and the bionic square ribs, respectively. With changes in velocities and particle mass flow rates, the order of erosion resistance does not vary. The conclusion provides a new concept for optimizing the design of erosion-resistant elbows. • Three new types of anti-erosion elbow structures are proposed. • Three types of anti-erosion elbow structures were evaluated comprehensively. • The triangular single rib has the best erosion resistance at 20°which increases 47%. • The single rib is resistant to erosion only before 35°.