Increase In Rotational Speed Research Articles

Nanofibers of PMMA/TiO2 Produced by Electrospinning

The method of electrospinning with a rotating cylinder collector was used to prepare PMM/TiO2 nanofibers. The effect of the collector rotation speed on the diameters, morphology, and structural properties of the prepared PMM/TiO2 nanofibers was studied, with the remaining parameters of the electrospinning system held constant. relied on the FE-SEM to study the diameters and regularity of the prepared nanofibers, which showed that the obtained nanofibers with diameters of 366 nm decreased to 127 nm and their regularity increased as the collector speed increased. The X-ray diffraction spectra showed that the prepared PMM/TiO2 nanofibers have an amorphous structure and begin to transform into a polycrystalline structure with increasing collector speed. Functional groups identified through FTIR tests have been shown to not be affected by the increase in rotation speed, regularity, or decrease in the diameter of the prepared PMM/TiO2 nanofibers.

Effect of Rotation Speed and Feed on the Surface of ST 41 Steel on a Lathe Machine

This study discusses the effect of feed rate and machine rotation speed on the surface roughness of ST 41 steel in the flat turning process. The aim is to determine the relationship between variations in rotation speed (100 rpm, 300 rpm, and 500 rpm) and feed rate on the final surface results of the workpiece. The method involves cutting tests on ST 41 steel specimens with a diameter of 25 mm and a length of 400 mm with various rotation speed variations. The results show that at low rotation speed (100 rpm), the surface of the workpiece tends to be rough. The surface becomes better at medium speed (300 rpm), while at high speed (500 rpm), the surface results are smoother. These findings indicate that increasing rotation speed contributes to a decrease in surface roughness. Thus, higher rotation speeds can improve the quality of turning results.

Influence of centrifugal casting parameters on Al-Mg alloy castings microstructure and mechanical properties

The paper is dedicated to the process of obtaining hollow castings on a horizontal centrifugal casting machine. The influence of mold rotation speed and the melt pouring process mechanical properties of as-cast parts made of AlMg5, alloyed by small amount of transition and rare earth metals, is represented. Mold pouring processes and crystallization kinetics depend on mold rotational speeds 1100, 1500 and 2000 rpm were studied by using numerical modeling. The influence of the specified mold rotation speeds on the structure and mechanical properties of castings is shown. It is also determined that the installation of a foam ceramic filter in the pouring cup of a centrifugal casting machine ensures melt laminar flow when pouring it into a mold. It was determined that 1500 rpm is the most favorable rotating speed from the points of optimal hydrodynamic mold filling processes and casting crystallization kinetics. It was also shown that with the increase of a mold rotation speed from 1100 to 2000 rpm, the thickness of the defective inner layer decreases, the alloy structure refines, and the mechanical properties of as-cast detail increase the next way: at 1500 rpm (σ0.2–by 10%, σB − by 25%, δ − 3 times), at 2000 rpm (σ0.2–by 18%, σB − by 31%, δ − 4 times), compared to products obtained by steel mold gravity casting. Centrifugal casting technology ensures the mechanical properties of cast blanks even higher than those of deformed AlMg5 alloys, the values of which approach those of AlMg6 alloy products.

Experimental Investigation of the Dynamic Deformation of Wind Turbine Blades Based on 3D-Digital Image Correlation

A wind turbine is a rigid–flexible coupling system, and its blades will be deformed under the action of aerodynamic force, inertia force, and elastic force. To monitor the deformation of the blades, this paper builds a dynamic deformation measurement system for wind turbine blades based on 3D-DIC and directly measures the three-dimensional displacement distribution of different blades under different operating conditions to obtain the dynamic deformation of the blades. The experimental results show that the dynamic waving deformation of the blade shows the trend of increasing and then decreasing with the increase in wind turbine rotational speed and incoming wind speed, and when the rotational speed reaches 500 r/min and the incoming wind speed reaches 9 m/s, the blade deformation reaches the maximum value; the dynamic waving deformation of wind turbine blade decreases with the increase in the elastic modulus of the blade and the degree of the decrease decreases gradually; the dynamic deformation of is predicted by the multiple displacement distribution of different blades under different operating conditions, and is obtained by the fitting of the experimental data. This paper develops a 3D-DIC-based dynamic testing system for wind turbine blades, conducts experimental studies to verify and prove the practicality of the system, and finally obtains the prediction polynomials for the dynamic deformation of wind turbine blades under different operating conditions.

The Investigation of Graphene Oxide-Enhanced Hybrid Slurry Preparation and Its Polishing Characteristic on CVD Single Crystal Diamond.

As an environment-friendly material, graphene oxide nanosheet can effectively improve the polishing surface quality of single crystal diamond workpieces. However, the lubricating and chemical effects of graphene oxide nanosheets have an uncertain impact on the polishing material removal rate. In this paper, the graphene oxide-enhanced hybrid slurry was prepared with good stability. The femtosecond laser etching and contour measurement method was adopted to analyze the polishing material removal rate of the CVD single crystal diamond workpiece. The surface damage of the workpiece polished with SiC abrasive grains is minimal, while the workpiece with diamond abrasive grains has the largest material removal rate. With an increase in abrasive grain size, the polishing material removal rate increases, but new surface scratches and pits can be introduced if the grain size is too large. Therefore, a grain size of 2.5 μm was selected to improve the surface quality. The surface roughness first decreases and then increases with the increase in polishing rotation speed. At a speed of 4000 rpm, the surface roughness reached its minimum with a relatively high material removal rate simultaneously. A series of CVD single crystal diamond scratching experiments were conducted with different scratching speeds, which proved that graphene oxide can help facilitate material surface micro-protrusion removal.

Levitation Performance of Radial Film Riding Seals for Gas Turbine Engines

Turbomachinery in gas turbines uses seals to control the leakage between regions of high and low pressure, consequently enhancing engine efficiency and performance. A film riding seal hybridizes the advantages of contact and non-contact seals, i.e., low leakage and low friction and wear. The literature focuses on the leakage performance of these seals; however, one of their fundamental characteristics, i.e., the gap between the rotor and seal surface, is scarcely presented. The seal pad levitates due to the deflection of the springs at its back under the influence of hydrodynamic forces. This study develops a test rig to measure the levitation of film riding seals. A high-speed motor rotates the rotor and gap sensors measure the levitation of the seal pads. Measurements are also compared with the predictions from a Reynolds equation-based theoretical model. Tests performed for the increasing rotor speed indicated that, initially, until a certain rotor speed, the pads adjust their position, then rub against the rotor until another rotor speed is reached, before finally starting levitating with further increased rotor speeds. Moreover, both the measured and predicted results show that pads levitated the most when located 90° clockwise from the positive horizontal axis (bottom of seal housing) compared to other circumferential positions.

Analysis of the effect of roughness on the sealing performance of end faces of microporous friction pairs

To study the influence of surface roughness on the sealing performance of the end face of microporous weaving friction vice, approximate simulation of end face roughness based on fractal theory is carried out, and a calculation model of gap lubrication film flow involving surface roughness is established, and the influence of different surface roughness on the sealing performance parameter of the end face of microporous weaving is investigated, and the influence of the parameters of the microporous weaving on the sealing performance of the end face under the same roughness is analyzed. The findings indicate that as surface roughness and rotational speed rise, so do the liquid film opening force and friction coefficient. Conversely, leakage somewhat decreases as surface roughness increases and increases as rotational speed increases. In the case of surface roughness Sa = 0.6 μm, the friction coefficient is smaller. The leakage is larger in the case of microporous weave compared with that of non-microporous weave. The friction coefficient tends to decrease with the increase of weave depth and area ratio, and the leakage tends to increase with the increase of weave depth and area ratio.

Experimental Study on the Influence of Rotational Speed on Grinding Efficiency for the Vertical Stirred Mill

The rotational speed of the agitator is one of the important parameters that affect the grinding efficiency of the vertical stirred mill. Increasing the speed will improve the grinding effect, but it will increase energy consumption, and determining a reasonable speed setting is a system issue. The effects of different speeds on energy consumption, product particle size, and grinding efficiency were analyzed in this study. An experimental vertical stirred mill was used to grind iron ore, and five different speed parameters from 175 rpm to 350 rpm were set as variables. It was found that increasing the rotational speed will increase the grinding effect, but it will trigger more energy consumption. A new evaluation index to comprehensively reflect the grinding efficiency of the mill, which was defined as the ability of a mill to grind the same product per unit of time and energy consumption, was proposed. The grinding efficiency was calculated when the particle size of iron ore powder decreased to −45, −38, and −28 μm at different speeds. It can be seen that the growth rate of energy consumption is faster than that of the percentage of particle size, which leads to a continuous decrease in grinding efficiency with the increase in rotational speed. If high processing capacity is pursued within a certain period of time, high speed can be chosen, but it will result in energy loss. On the contrary, the low speed can be chosen, if considering grinding economy.

Research on magnetic force of magnetic seal in aero-engine

Aiming at the magnetic seal in an aero-engine accessory, the range of magnetic force required for the normal operation of the magnetic seal is analyzed. The finite element analysis method based on the Maxwell stress tensor method is used to calculate the magnetic force between the dynamic ring and the magnetic static ring in the magnetic sealing system. The magnetic force under different magnetization modes and gaps is tested by the magnetic measuring test bench, which verifies the correctness of the magnetic calculation method. The effects of permanent magnet material, permanent magnet magnetization direction, magnetic seal structural parameters, and working conditions on the magnetic force between the dynamic ring/magnetic static ring in the magnetic seal are analyzed. Under the same structure, the magnetic force of NeFeB35, SmCo28, Alnico5, and Ferrite as magnetic static rings is compared. The results show that NdFeB35 has the largest magnetic force, SmCo28 is second, Alnico5 and Ferrite are relatively small, and their magnetic forces are about 1/4 to 1/5 of the first two materials. When the rotor or the casing is moving axially, NeFeB35 and SmCo28 materials with large magnetic force should be selected to meet the normal working requirements. Under the same material, the magnetic forces of axial, radial, and radiative magnetization modes are compared. the ratio of magnetic force under axial, radiative, and radial magnetization is about 2.3:1.1:1. If NeFeB35 and SmCo28 materials are axially magnetized, their magnetic forces will exceed the allowable range, which will increase the seal wear. The increase in the inner diameter of the dynamic ring and the gap between the dynamic ring and the magnetic static ring causes a decrease in the magnetic force. The increase in temperature affects the magnetic properties of permanent magnetic material, which leads to the decline of magnetic force between the dynamic ring and the magnetic static ring. The increase in rotor speed leads to the acceleration of the fluctuation frequency of the magnetic force. Still, the maximum and minimum values of the magnetic force under different speeds remain unchanged, and the maximum fluctuation rate is less than 3%. According to the analysis results, the fitting formula of magnetic force calculation is presented by the orthogonal test and the least squares method.

Micromechanical study of core barrel drilling for rotary drilling rigs based on the discrete element method

Abstract This study developed a gravel soil granular bed model using the discrete element method, elaborating on the core barrel drilling process by integrating bond-breaking and particle flow patterns. A quantitative description of the drilling process is achieved by defining bond-breaking efficiency. The results indicate that the force on particles near the drill tooth is the greatest, and this force increases with the core barrel feed rate, which enhances drilling efficiency and exacerbates wear on the drill tooth and guide bars. An increase in rotational speed raises the force on the particles in the boundary region, leading to deeper wear of the guide bar; however, the enlargement of particle voids near the drill tooth mitigates wear. Additionally, a coupled discrete element method and finite element method are developed to analyse the effects of drilling parameters on drill tooth deformation, revealing that the design of the open hole at the top of the drill can effectively reduce the maximum equivalent stress and wear depth. The conclusions drawn contribute to understanding particle mechanics, the particle bonding damage mechanism, and drilling mechanical behavior, providing a reference for optimizing drilling operations and drill design.

Research on the Sealing Performance of Segmented Annular Seals Based on Fluid–Solid–Thermal Coupling Model

High-speed segmented annular seals are often subjected to friction and wear, and the groove design on the sealing surface can effectively suppress this loss. For the purpose of improving the sealing performance, the segmented annular seal models of three structures are established, and the accuracy of the calculation model is verified by comparing with the previous results. Through fluid–solid–thermal coupled analysis, the flow field characteristics, opening characteristics, and leakage characteristics of the segmented annular seal under high working condition parameters were studied. The results show that the setting of the shallow groove forms the hydrodynamic effect by squeezing and hindering the flow of fluid in the clearance. The increase in rotational speed and pressure difference can promote the increase in the opening force, while the temperature has no significant effect on the opening of the seal. Seals with ladder-like grooves have the best opening performance, and seals without shallow grooves are already difficult to open under conditions of high pressure difference and large spring forces. Temperature and pressure difference are the main factors affecting the leakage of the seal, while the influence of the rotation speed is small. When the sealed pressure increases from 0.15 MPa to 0.4 MPa, the maximum increase in the leakage of the seal with specific groove design is 4.657 times the original. As the temperature rises from 420 K to 620 K, the maximum decrease in the three structures is up to 22.9%. Among the seals of the three structures, seals with ladder-like grooves have medium leakage. This research will contribute to the improvement of research methods for the sealing performance of segmented annular rings, especially for the evaluation of groove design and opening characteristics.

CFD-based unsteady simulation and performance analysis of scroll compressor

The scroll compressor is an essential part of the heat pump air conditioning system in electric vehicles, with its performance and efficiency having a significant impact on the vehicle's range. This paper employs a combination of experimental and numerical simulations (using the dynamic mesh method) to study the scroll compressor in electric vehicles, exploring the effects of rotational speed and pressure ratio on compressor performance. The results reveal a significantly uneven temperature distribution across the chambers, primarily due to tangential leakage, which results in elevated temperatures in the central areas of the chambers and reduced temperatures near the meshing points. As the rotational speed increases, both the mass flow rate and the isentropic efficiency of the scroll compressor rise, whereas the discharge temperature declines; notably, discharge temperature drops by an average of 1.6 % for 600 r·min-1 increase in rotational speed. For each unit increase in the pressure ratio, the discharge temperature increases by an average of 12.22 K, while the mass flow rate decreases by 7.95 %. The study also shows that the isentropic efficiency initially rises with increasing pressure ratio, reaching a maximum of 67.06 % before starting to decline. These findings provide valuable insights into the performance characteristics of scroll compressors and offer theoretical support for optimizing compressor efficiency in practical applications.

A heat transfer model for thermal distortions in high speed spiral groove gas lubricated face seals

The thermal distortions of seal face caused by heat transfer directly affect the stability of seal operation. Here, a heat transfer analysis model of spiral groove gas face seal is established taking account of gas compressibility and choked flow effect. Then, a thermoelastohydrodynamic lubrication (TEHL) analysis is carried out based on the proposed heat transfer model, frictional heat flux, surface conduction heat flux, and film adsorption heat flux are calculated, and face distortions are also analyzed under different operating parameters including rotational speed, seal temperature and seal pressure. It is shown that, the adsorption heat induced by gas expansion makes the film cooling, which often leads complex temperature distributions and plays an important and non-ignored role in thermal distortions. For the spiral groove face seal, the increase of seal pressure and rotational speed makes the adsorption heat increase significantly due to pumping effect of grooves. The more important is that the thermal distortions may be controlled by changing seal width. Here, for the spiral groove face seal, the clearance can transfer divergent to convergent with increasing seal width from 5 mm to 13.1 mm. This provides a potential way for distortion control in gas face seal design.

Study on the excess seeds removing performance of a potato precision seed metering device

In the potato mechanical planting industry, the high multi-seeding rate and miss-seeding rate are problems that exist in many potato precision seed metering devices. The main potato seeds in China are cut potatoes with different shapes and sizes. However, there is a lack of research on precision seeding technology for cut potatoes, and the adaptability of many existing potato seeding devices on cut potato is poor. The mechanized precision seeding of potato can effectively reduce labor consumption, improve the seeding effect (decrease multi-seeding rate and miss-seeding rate), improve the improve production of potato per acre and improve the quality commodity potatoes. In response to the above issues, a precision seed metering device with novel scoops, which can adapt to various sizes and shapes of cut potatoes, was developed. In this study, the different seed collecting scenarios (SCSs) were constructed. Through the statics and kinematic analysis, the excess seeds removing (ESR) process was divided in to three areas. The kinematic model of seed potato was established to study the influence of different SCSs and sprocket rotational speeds on the ESR performance, and preliminary determined the appropriate sprocket rotational speed range for ESR process. Then, the coupled simulation results of EDEM and RecurDyn revealed that different sprocket speeds and SCSs had a significant influence on the ESR performance. Finally, the bench tests and field tests were conducted to verify the actual performance of the precision seed metering device. The results showed that, with the increase of the sprocket rotational speed, the ESR performance of the device improved, the multi-seeding rate significantly decreased, but the miss-seeding rate increased. High sprocket rotational speed will remove more seed potatoes and cause high miss-seeding rate. The bench tests showed the appropriate sprocket rotational speed for medium and large potato was 35 r/ min. The field tests obtained the best qualified-seeding rate of 91.54%, the miss-seeding rate of 3.08% and the multi-seeding rate of 5.38%. This study can provide theoretical reference for the design of potato precision seed metering device.

Effects of Coriolis force on the aero-thermal performance of stator-rotor purge flow

The hot-end components of gas turbines necessitate efficient cooling strategies to enhance performance and durability. This research focuses on how the Coriolis force affects the purge flow’s cooling effectiveness on the turbine endwall. Utilizing both experimental and numerical methods, the study examines various rotational speeds and Mach numbers to understand the Coriolis force’s impact on aerodynamic losses and cooling effectiveness. This study’s methodological innovations are demonstrated in the following aspects: The implementation of a deflector plate within the rim seal ensures that the circumferential velocity of the purge flow relative to the rotor remains constant at any cascade speed, thereby guaranteeing that the focus of this research is on the “Coriolis effect” rather than the “rotational effect.” The development of a dual-coordinate analysis method allows for a clear presentation of the mechanism by which the Coriolis force influences the vortex’s motion characteristics. Increasing the rotational speed of the cascade enhances the adiabatic cooling effectiveness of the endwall. Similarly, increasing the Mach number of both the main flow and the purge flow under the same blowing ratio also enhances the endwall’s adiabatic cooling effectiveness. This study demonstrates that the underlying mechanisms of these effects are essentially the same, as both alter the Coriolis forces acting on the fluid. Coriolis forces expand the pressure leg of the horseshoe vortex and the passage vortex while reducing the suction leg of the horseshoe vortex. Given that vortex cores are low-pressure regions, the purge flow is entrained into the cores of the pressure leg of the horseshoe vortex and the passage vortex. The increase in rotational speed and Mach number results in greater Coriolis forces, inducing a movement away from the vortex core that expels the denser cooling air from the core. The conclusions of this study can provide insights for the design of gas turbines. Furthermore, the research methodology employed here can serve as a reference for studies on the interaction between purge flow and main flow.

The Study of Water Content on the Coal Loading Performance of Thin Coal Seam Shearer Drum by Discrete Element Method (DEM)

ABSTRACTAs the main component of thin coal seam shearers, the drum bears the functions of loading and cutting, and its performance has become an important factor restricting mining efficiency and production safety. In response to the problem of low efficiency in installing thin coal seam shearers, this paper uses the Discrete Element Method (DEM) to study the effects of loading methods, helical angle of drum, drum rotation speed, and particle water content on coal loading rate. Research has found that the coal loading performance of the ejection loading method is much higher than that of the pushing loading method. As the helical angle increases, the average loading rate increases. As the rotation speed increases, the loading rate of wet coal particles gradually decreases. During production and thin coal seam mining, special attentions should be paid to the control of helical angle of drum and drum rotation speed. This study has guiding importance for improving the efficiency of thin coal seam mining.

Movement Characteristics of Droplet Deposition in Flat Spray Nozzle for Agricultural UAVs

At present, research on aerial spraying operations with UAVs mainly focuses on the deposition outcomes of droplets, with insufficient depth in the exploration of the movement process of droplet deposition. The movement characteristics of droplet deposition as the most fundamental factors affecting the effectiveness of pesticide application by UAVs are of great significance for improving droplet deposition. This study takes flat spray nozzles as the research object, uses the Particle Image Velocimetry (PIV) technique to obtain movement data of water droplet deposition under the influence of rotor flow fields, and investigates the variation characteristics of droplet deposition speed under different influencing factors. The results show that the deposition speed and the distribution area of high-speed (>12 m/s) particles increase with the increase of rotor speed, spraying pressure, and nozzle size. When the rotor speed increases from 0 r/min to 1800 r/min, the average increase in maximum droplet deposition speed for nozzle models LU120-02, LU120-03 and LU120-04 is 33.26%, 19.02%, and 7.62%, respectively. The rotor flow field significantly increases the number of high-speed droplets, making the dispersed droplet velocity distribution more concentrated. When the rotor speed is 0, 1000, 1500, and 1800 r/min, the average decay rates of droplet deposition speed are 36.72%, 20.00%, 15.47%, and 13.21%, respectively, indicating that the rotor flow field helps to reduce the decrease in droplet deposition speed, enabling droplets to deposit on the target area at a higher speed, reducing drift risk and evaporation loss. This study’s results are beneficial for revealing the mechanism of droplet deposition movement in aerial spraying by plant protection UAVs, improving the understanding of droplet movement, and providing data support and guidance for precise spraying operations.

A Numerical Simulation of the Effect of Drilling Fluid Rheology on Cutting Migration in Horizontal Wells at Different Drilling Fluid Temperatures

In recent years, significant breakthroughs have been made in the exploration of deep to ultra-deep oil and gas reserves onshore in China. These conventional deep to ultra-deep reservoirs are typically buried at depths exceeding 4500 m, with bottom-hole temperatures surpassing 150 °C. The high temperatures at the bottom of the well are more likely to cause deterioration in drilling fluid properties, altering its rheological properties and reducing cutting transport efficiency, which can lead to wellbore cleaning issues. In this paper, the numerical simulation method is used to analyze the influence of cutting particle size, drilling fluid flow rate, drill pipe rotation speed, and drill pipe eccentricity on the annular cutting concentration under different wellbore drilling fluid temperature conditions. The results show that at the same cutting particle size, as the drilling fluid temperature increases, the cutting concentration in the annulus increases sharply. The increase is the largest when the particle size is 3 mm, and when the drilling fluid temperature is 220 °C, the cutting concentration increases by 79.7% compared to at 200 °C and by 279% compared to at 180 °C. When the flow rate increases from 0.5 m/s to 1.0 m/s, the annular cutting concentration at drilling fluid temperatures of 220 °C and 200 °C decreases by 70.5% and 50.4%, respectively. The higher the drilling fluid temperature, the better the cutting removal effect when increasing the drill pipe rotation speed. However, when the rotation speed exceeds 120 rpm, the change in cutting concentration with increasing rotation speed becomes insignificant. When the drill pipe eccentricity is small, an increase in drilling fluid temperature leads to a significant rise in annular cutting concentration. However, when the drill pipe eccentricity is large, changes in drilling fluid temperature have a smaller impact on cutting concentration. The research findings can provide engineering guidance and theoretical support for the design of drilling fluid hydraulic parameters for cutting transport and rheological parameters in high-temperature wellbores.

Characterizing the contact force of a high-speed rotating fluid on brush wire

Abstract To study the effect of coolant fluid on rotor-brush wire contact in high-speed conductive slip rings, the rotor-brush wire contact model is simplified to two cylindrical vertical contacts. The theoretical formula of the force on the near-wall surface of the brush wire is derived by combining the distribution of the characteristics of the cylindrical rotating fluid domain. A three-dimensional model of high-speed rotor-brush wire fluid-solid coupling is created. The initial preload and coolant disturbance on the near-wall surface of the brush wire is considered to analyze the force characteristics of the brush wire. The force characteristics of the near-wall surface and the three-dimensional surface velocity cloud diagram of the fluid domain are obtained. The results show that the growth rate of the fluid domain force on the wall surface of the brush wire increases with the increase of rotational speed. A change of only 0.5 mm near the wall leads to a change of nearly 40% in the speed.

DEM simulation of an impact crusher using the fast-cutting breakage model

The impact crusher that exploits impact rather than pressure to break down materials has been widely used in the mineral industry. To further improve its performance in material crushing, numerical simulation capable of providing a deeper insight into the complicated dynamics of feed materials than experimental study has emerged as a promising tool. However, the field of the accurate prediction of product quality and explicit simulation of breakage events inside an industrial-scale crusher remains underexplored on account of the absence of a robust breakage model and heavy computational cost. In this study, a numerical investigation of an industrial-scale crusher using the fast-cutting breakage model is conducted within the DEM (Discrete Element Method) framework. The accuracy of the breakage simulation is quantitatively validated by comparing the predicted results with the measurements from actual production. Furthermore, the influence of operating conditions including the rotation speed of the rotor and the feeding rate on the interested parameters, i.e., the power consumption of the equipment, the size distribution of the products, and the impact-induced wear is investigated comprehensively. The results illustrate that (i) the size of the product increases with the rotor speed until a critical value, after which a further increase in rotor speed will exert no significant influence on the size distribution; (ii) The feeding rate is not a critical operating condition that largely determines the fineness of the product and the efficiency of the equipment almost remain stable under a certain range of feeding rates; (iii) The wear of the devices concentrates on the rotor and the impact plates, and the distribution of the wear exhibits different characteristics in different parts, caused by the complex collision between the particles and the devices.