Numerical modeling of fluid and particle behaviors in impact pulverizer

Takeuchi, Hirohisa; Nakamura, Hideya; Iwasaki, Takashi; Watano, Satoru

doi:10.1016/j.powtec.2011.10.021

Cited by 15 publications

(6 citation statements)

References 21 publications

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“…In the simulation of a comminution process by CFD-DPM, more attention is paid to particle tracking and particle-wall interaction. For instance, in the impact crusher [44][45][46], the particle and flow behavior after the collision of high-speed particles accelerated by air flow with stator and wall were studied, which explained the mechanism of the particle impacting the wall to a certain extent. However, there are two problems that must be solved: On the one hand, the input of a large number of particles will inevitably produce collision.…”

Section: Comminutionmentioning

confidence: 99%

Computational Fluid Dynamics–Discrete Phase Method Simulations in Process Engineering: A Review of Recent Progress

Yang,

Xi,

Qin

et al. 2024

Applied Sciences

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Complex fluid–solid systems generally exist in process engineering. The cognition of complex flow systems depends on numerical and experimental methods. The computational fluid dynamics–discrete phase method simulation based on coarsening technology has potential application prospects in industrial-scale equipment. This review outlines the computational fluid dynamics–discrete phase method and its application in several typical types of process engineering. In the process research, more attention is paid to the dense condition and multiphase flow. Furthermore, the CFD-DPM and its extension method for comprehensive hydrodynamics modeling are introduced. Subsequently, the current challenges and future trends of the computational fluid dynamics–discrete phase method are proposed.

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Section: Comminutionmentioning

confidence: 99%

Computational Fluid Dynamics–Discrete Phase Method Simulations in Process Engineering: A Review of Recent Progress

Yang,

Xi,

Qin

et al. 2024

Applied Sciences

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“…36 Due to the large extrusion pressure of the high-speed rotating hammer in the crushing chamber, a highpressure region was formed at the tip of the hammer, and the static pressure value of the airflow at the tip of the hammer is the largest, which was similar to the research of Hirohisa Takeuchi and Yang Kang. 17,37 During extrusion, the mechanical energy of the airflow in the region increased to its peak, leading to the strongest thermal movement of gas molecules and the highest static pressure in the region. Figure 6 shows the effects of screen aperture size, rotor speed, hammer-screen clearance, hammer number, and mass flow rate on the static pressure distribution of the airflow field in Region I.…”

Section: Static Pressure Distribution In Region Imentioning

confidence: 99%

“…The results showed a distinct stratification and gradient distribution along the radial direction of the rotor in the static pressure within the crushing chamber, but there were few differences in the static pressure and velocity in the axial direction. From the tip of the hammer to the center of the rotor, the static pressure steadily decreased, with the biggest negative pressure value in the center of the rotor. ,− The airflow in the crushing chamber moves annularly with the rotor, and the airflow velocity gradually increases from the center of the rotor along the radial direction and reaches the maximum at the tip of the hammer. The airflow near the screen surface forms a high-speed and high-pressure circulation airflow (airflow circulation layer) with the high-speed rotating hammer.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Analysis of the Airflow Field in the Crushing Chamber of the Hammer Mill

Li,

Jiang,

Zeng

et al. 2024

ACS Omega

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The airflow dynamics within hammer mills' crushing chambers significantly affect material crushing and screening. Understanding the crushing mechanism necessitates studying the airflow distribution. Using a self-built crushing test platform and computational fluid dynamics (CFD) simulations, we investigated the impact of screen aperture size, rotor speed, hammer-screen clearance, hammer quantity, and mass flow rate on airflow distribution within the rotor region, circulation layer, and screen apertures. Results indicated generally uniform axial static pressure distribution within the rotor region, with radial gradients. Increased rotor speed improved radial static pressure gradients, while higher mass flow rates reduced them. The highest airflow velocity within the circulation layer reached approximately 83.46% of the hammer tip's tangential velocity. Greater rotor speed and hammer quantity intensified circulation airflow, whereas increased mass flow rate decreased it. Eddies formed within screen apertures with higher rotor speeds and hammer quantities but diminished with larger apertures and higher mass flow rates. Static pressure differences across screen apertures increased with mass flow rate and rotor speed but decreased significantly with larger apertures. This systematic examination provides insights into airflow distribution within hammer mill crushing chambers, offering a theoretical foundation for improving and designing hammer mills.

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“…At the same time, the variation in the velocity of the material particles under different working conditions, the number of collisions, and the amount of materials discharged with time was proved. Hirohisa et al [22] used the CFD-DPM coupling method to simulate the fluid flow and particle motion process in the impact mill and analyzed the velocity and frequency of the collisions between the particles and the whole grinding chamber wall under different rotor speeds and particle sizes. The research results can provide a theoretical basis for the structural optimization of the impact mill.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation and Experimental Study of Corn Straw Grinding Process Based on Computational Fluid Dynamics–Discrete Element Method

Wang,

Tian,

Xiao

et al. 2024

Agriculture

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To improve the operational efficiency of a hammer mill and delve into a high-efficiency, energy-saving grinding mechanism, the crucial parameters influencing the grinding of corn straw were identified as the spindle speed, hammer–sieve gap, and sieve pore diameter. According to the force analysis and kinematics analysis, the key factors affecting corn straw grinding were the spindle speed, the hammer–sieve gap, and the sieve pore diameter. The grinding process of corn straw was studied using computational fluid dynamics (CFDs) and the discrete element method (DEM) gas–solid coupling numerical simulation and experiment. The numerical simulation results showed that with the growth of time, the higher the spindle speed, the faster the bonds broke in each part, and the higher the grinding efficiency. When the energy loss of the hammer component was in the range of 985.6~1312.2 J, and the total collision force of the corn straw was greater than 47,032.5 N, the straw grinding effect was better, and the per kW·h yield was higher. The experimental results showed that the optimum combination of operating parameters was a spindle speed of 2625 r/min, a hammer-screen gap of 14 mm, and a sieve pore diameter of 8 mm. Finally, the CFD–DEM gas–solid coupling numerical simulation validation tests were performed based on the optimal combination of the operating parameters. The results showed that the energy loss of the hammer component was 1189.5 J, and the total collision force of the corn straw was 49,523.5 N, both of which were within the range of better results in terms of numerical simulation. Thus, the CFD–DEM gas–solid coupling numerical simulation could accurately predict the corn straw grinding process. This study provides a theoretical basis for improving a hammer mill’s key components and grinding performance. Meanwhile, the proposed gas–solid two-phase flow method provided theoretical references for other research in agricultural machinery.

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Numerical modeling of fluid and particle behaviors in impact pulverizer

Cited by 15 publications

References 21 publications

Computational Fluid Dynamics–Discrete Phase Method Simulations in Process Engineering: A Review of Recent Progress

Computational Fluid Dynamics–Discrete Phase Method Simulations in Process Engineering: A Review of Recent Progress

Numerical Simulation and Analysis of the Airflow Field in the Crushing Chamber of the Hammer Mill

Numerical Simulation and Experimental Study of Corn Straw Grinding Process Based on Computational Fluid Dynamics–Discrete Element Method

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