For multi-phase separation, developing high-performance cyclone separators is highly demanded. In this study, different divergent or convergent insertion pipes bFelow the vortex finder are employed to improve the separation performance. The impacts of insertion pipe geometrical configurations on the flow characteristics, pressure drop, and separation efficiency are systematically analyzed. The results reveal that the employed insertion pipe can significantly affect the static pressure distribution inside the cyclone. A longer insertion pipe length and larger tilt angle result in a wider central low-pressure area and smaller overall static pressure. The divergent insertion pipes increase pressure loss, while the convergent insertion pipes augment pressure loss. A larger insertion pipe length significantly impacts the axial velocity distribution. For divergent insertion pipes, the maximum central axial velocity increases with increasing tilt angles and then decreases. For small particles (d_p ≤ 5 μm), a convergent insertion pipe exhibits a better separation performance. When the particle diameter d_p ≥ 5 μm, divergent insertion pipes with larger angles and lengths can significantly decrease the pressure drop while guaranteeing satisfied collection efficiency. When L = 75 mm and θ = 60°, the pressure drop is reduced by 7.8%. This study may contribute to rationally designing high performance cyclone separators and also paves ways for improving the existing cyclone separators.

During the operation of drilling rigs, bolts are subjected to significant loads, rendering bolt groups vulnerable to failure due to uneven load distribution. This study investigates the multi-bolt load distribution characteristics of eight-gear and four-gear symmetric transmission mechanisms in drilling rigs. The spring stiffness method is utilized to analyze multi-bolt load distribution. A finite element model of the bolted connection is developed by integrating the structural shape and transmission mechanism. The model’s accuracy is validated through a rack strain test under various loads. Based on the finite element analysis results, this study proposes an evaluation method for bolted connections using relative deformation difference. The impacts of bolt pitch, end distance, preload, and thickness of the derrick connection plate under different load positions on the connection are examined. This paper presents a methodology and conclusions that can inform the design of bolted connections for heavy-duty drive systems.