Analysis of the Screw Flight Wear Model and Wear Regularity of the Bulk Transport in Screw Ship Unloader

Abstract

The screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under different working conditions. Hence, we established a new screw flight wear model based on the Archard wear model and Continuous Medium Hypothesis to predict the service life of the screw flight. Three influencing factors, including speed, filling rate, and pitch, were selected to study the wear law of the screw flight, and the wear law was verified by EDEM simulation. Results indicate that the simulation results affected by the changes in various factors were consistent with the calculation model. With the increase of rotation speed and filling rate, the screw flight wear rate increased. Nevertheless, with the increase of pitch, the screw flight wear rate first increased and then decreased. The screw flight wear model can be used to calculate the wear rate under different working conditions for the screw flight life prediction.

Innovative Approaches to Wear Reduction in Horizontal Powder Screw Conveyors: A Design of Experiments-Guided Numerical Study

“…Consequently, this leads to higher wear rates in the screw model. Similarly to the findings in [42], where the vertical screw conveyor was studied we can compare the relationship between the rotation speed and the wear rate of the screw flight. We noted that with the increase in rotation speed, the trend of the wear rate increases, confirming the reported observations.…”

“…Conversely, lower stiffness values, leading to overlaps exceeding 0.3%, resulted in smoother interaction and resistance. Due to computational limitations, the modulus was reduced, a decision supported by findings in articles [41,42], where a similar analysis was conducted with erosive sand of comparable sizes. Calibration based on these considerations provided a satisfactory approximation for entry data.…”

The vertical screw conveying characteristics of cohesive particle and optimization of design parameters

“…1 to obtain △t=2.32×10 -5 s. The Rayleigh time step is usually set in the time step range of 5% to 40%. Therefore, the simulation time step is set to 4.64×10 -6 s, and the total simulation time is set to 10s, with data saved every 0.05s [24].…”

“…Where, vz is the axis velocity of particles, n is the actual rotational speed, g is the acceleration of gravity, R is the external radius of screw blade, the friction coefficient of particles and internal cylinder wall μt is 0.4, the friction angle of particle and screw blade φk is 21.77° [24].…”

“…To study the wear regularity of the screw blade, Yang et al [23,24] established a new screw conveyor wear prediction model based on the Archard wear model and the continuous medium assumption, and the wear regularity of the screw blade was simulated and experimentally verified at different rotational speeds, filling rates, and pitches.…”