Optimizing the Design of the Spring Plate in the Girth Gear of a Rotary Cement Kiln

Abstract

In cement production, rotary kilns are essential, particularly in clinker manufacturing. The spring plates, fabricated from St37-2 steel, connect the girth gear to the kiln shell and play a crucial role in the structural integrity of the kiln. This study numerically analyzes and optimizes the stress distribution across spring plates used in the Kufa cement plant (Najaf, Iraq), under varying operational conditions. Using finite element modeling (ANSYS 2022/R1), stress distributions for the standard spring plate design (S), three existing designs (d1, d2, d3), and three proposed designs (P1, P2, P3) were compared. Sensitivity analysis was conducted across five filling conditions: (1) 100% design load, (2) 100% practical load, (3) 90% practical load, (4) 80% practical load, and (5) 70% practical load. The proposed P3 design demonstrated the best performance, reducing the maximum stress concentration at critical locations by 51.86% compared to the standard design, with maximum stress values of 154.06 MPa (P3) versus 320.08 MPa (S) under 100% design load. The sensitivity analysis confirmed that stress levels decreased with reduced kiln loads, enhancing the service life of the spring plates. This study underscores the importance of design modifications to minimize stress concentration and improve the operational durability of rotary kilns.