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In order to address the problem of erosion failure of the reducer, numerical simulation of the reducer was carried out based on the DPM model, realizeble k-ε model and particle wear equation to analyse the flow velocity, particle diameter, mass flow rate, transition inclination, the improved transition angle of the reducer's erosion and wear law and the performance of the improved reducer. The results show that the erosion wear is most serious at the intersection of the transition section and the small pipe. The maximum erosion rate increases gradually with the increase of flow velocity, mass flow rate and the decrease of particle diameter. The transition Angle increases from 5° to 35°, and the maximum erosion rate fluctuates from 9. 32 × 10 - 5 kg/ (m 2·s). The maximum erosion rate increases from 35° to 85°, and then decreases significantly. When 80° ~ 85°, the maximum erosion rate is small and the influence of various factors is small, especially when 85°, the maximum erosion rate is reduced by 23. 5 times. The maximum erosion rate of the transition fillet 7. 5 ~ 15 mm is less than that of the transition fillet before the improvement, and the erosion distribution is more uniform. With the increase of the transition Angle, the difference of the maximum pressure in the modified 2. 5 ~ 15 mm transition reducer is gradually reduced, and the maximum pressure and stress in the modified pipe are lower than those in the modified pipe, and the maximum pressure in the pipe is reduced by 2. 25 times. The results can provide reference for the selection, structural design and optimization of the reducer in practice. [ABSTRACT FROM AUTHOR]

Aiming at the problem of working noise of drilling vibrating screen, a method of applying a damping layer to the side plate of the drilling vibrating screen box to reduce its noise radiation was proposed. Through the vibration model of the screen box, the vibration mode and the acoustic radiation of the side plate before and after the damping of the side plate were analyzed by the finite element method and the modal strain energy method, and the influence of different materials and different thicknesses of damping layers on the surface noise radiation of the screen box was compared and analyzed by using COMSOL. Studies have shown that the surface damping structure can reduce noise radiation. Applying harder materials can play a certain vibration restraining role on the side panels. It is necessary to select the best thickness according to the material properties to achieve the best vibration and noise reduction effect. [ABSTRACT FROM AUTHOR]

The geological sedimentation simulation platform is an important device for quantitatively studying geological sedimentation theory. In order to meet the research needs of large-scale, refined, and quantitative sedimentation simulation, a geological sedimentation simulation platform that can perform all-round attitude adjustment motion based on a 4-PSE parallel mechanism was designed, and its kinematic characteristics were studied. Combined with the working principle of the simulation platform, the degrees of freedom of the 4-PSE parallel mechanism were calculated, and the Kinematics equations of the simulation platform were derived. The virtual prototype model of the simulation platform was established in ADAMS software, and its Kinematics parameters were theoretically verified using the Kinematics simulation results. The workspace constraints of the simulation platform was analyzed, its workspace was obtainecl, and the influence curve of relevant structural parameters on the workspace was drawn. The research results provide a theoretical basis for the structural design optimization of subsequent geological sedimentation simulation platforms and the combination of multiple platforms. [ABSTRACT FROM AUTHOR]

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In order to improve the mixing uniformity of the double-layer stirring tank, ANSYS Fluent was used to simulate the solid-liquid mixing process in the double-layer blade stirring tank by using the Euler multiphase flow model and the standard k-ε turbulence model. The effects of different rotational speed, blade diameter and distance between blades on the solid-liquid mixing uniformity( σ ) in the stirring tank were analyzed, and the solid-liquid mixing process was quantitatively analyzed combined with the speed in the tank. The results show that there is no uniform suspension in the stirring tank when the rotational speed is lower than 300 r/ min, and completely off-bottom suspension when the rotational speed is 300, 400 r/ min, and when the speed continues to increase, the stirring effect decreases. When the blade diameter is 0. 5D(D is the inner diameter of the mixing tank), the solid phase distribution in the stirring tank is good. When the blade distance is 390 mm, the solid phase of J1 blade has better suspension, when the blade distance is 440 mm, the solid phase of J2 blade has better suspension. When the distance is greater than 440 mm, the solid phase is mostly deposited at the bottom of the stirring tank. The blade diameter and the number of blades have almost no effect on σ, but the rotational speed has a great influence on σ, in the J1 blade combination, the σ is the lowest when the speed is 400 r/ min and the blade distance is 390 mm. In the J2 blade combination, the σ is the lowest when the speed is 300 r/ min and the blade distance is 440 mm. The J1 blade stirs better when the speed is 300 r/ min and when the speed is 400 r/ min. Under the optimum combination of parameters, the best stirring effect can be achieved after stirring for 24 s. [ABSTRACT FROM AUTHOR]