A new study on dynamic adjustment of vibration direction angle for dual-motor-driven vibrating screen

2020 ◽  
pp. 095440892095260 ◽  
Author(s):  
Bing Chen ◽  
Jiwei Yan ◽  
Zhongjun Yin ◽  
Kumar K Tamma
Keyword(s):  
Driving Frequency ◽  
Frequency Range ◽  
Dynamic Adjustment ◽  
Vibration Direction ◽  
Vibrating Screen ◽  
Synchronous System ◽  
Direction Angle ◽  
System A ◽  
New Concepts ◽  
Important Significance

For a dual-motor-driven elliptical vibrating screen, the driving frequencies of the two motors are studied in this paper and it exposes the significant influences of different driving frequencies on the vibration direction angle of the self-synchronous system. A dynamic model is established to demonstrate the new concepts and innovative ideas put forth in this paper. Simulink and prototype experiments are implemented to further study the influences of different driving frequencies on the phase angle and the vibration direction angle. The results of simulation and experiments shows that vibrating screen driven by the two motors can not only achieve a stable synchronization within a certain frequency range by changing the driving frequency of either of the two motors, but also the vibration direction angle significantly changes at similar but different driving frequencies. This is an important finding that has important significance for the future operations of dual-motor-driven vibrating screen in industry. The method developed in this study would be a valuable engineering tool which can be used in design and application of the screens and the screening operations.

Study on Impact of Vibration Direction on Linear Vibration Screening Effect

2012 ◽  
Vol 226-228 ◽  
pp. 186-190
Author(s):  
Yue Min Zhao ◽  
Ke Wang ◽  
Liang Dong ◽  
Bo Zhang ◽  
Xu Liang Yang ◽  
...  
Keyword(s):  
Sieve Plate ◽  
Test Results ◽  
Simulation Test ◽  
Screening Process ◽  
Vibration Direction ◽  
Screening Effect ◽  
Direction Angle ◽  
Movement Characteristics ◽  
Screening Efficiency ◽  
Dip Angle

Based on Hertz-Mindlin contact model in software EDEM by discrete element method, using linear vibrating screen 360 mm×600 mm, movement characteristics of particle group on sieve plate and law of particles going through sieve plate were studied in screening process of coal in certain conditions, which were as follows: dip angle was 0 °, amplitude was 5 mm, frequency was 11 Hz. The simulation test results show that there are important influences of vibration direction on screening process. And influence law of vibration direction on screening effect was revealed finally. The paper also gained mathematical model between particle group’s screening efficiency and vibration direction angle, and mathematical models of particles easy or hard to sieve and material between average movement speeds and vibration direction angle.

scholarly journals Numerical Investigation on the Sieving Performance of Elliptical Vibrating Screen

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1151
Author(s):  
Zhiquan Chen ◽  
Xin Tong ◽  
Zhanfu Li
Keyword(s):  
Major Axis ◽  
The Finite Element Method ◽  
Semi Major Axis ◽  
Vibration Direction ◽  
Maximum Deformation ◽  
Vibrating Screen ◽  
Performance Indexes ◽  
Screening Efficiency ◽  
Axis Length ◽  
Element Method

Screening techniques have been widely deployed in industrial production for the size-separation of granular materials such as coal. The elliptical vibrating screen has been regarded as an excellent screening apparatus in terms of its high screening efficiency and large processing capacity. However, its fundamental mechanisms and operational principles remain poorly understood. In this paper, the sieving process of an elliptical vibrating screen was numerically simulated based on the discrete element method (DEM), and an approach coupling the DEM and the finite element method (DEM–FEM) was introduced to further explore the collision impact of materials on the screen deck. The screening time, screening efficiency, maximum stress and maximum deformation were examined for the evaluation of sieving performance. The effects of six parameters—length of the semi-major axis, length ratio between two semi-axes, vibration frequency, inclination angle, vibration direction angle and vibration direction—on different sieving results were systematically investigated in univariate and multivariate experiments. Additionally, the relationships among the four performance indexes were discussed and the relational functions were obtained. The conclusions and methodologies presented in this work could be of great significance for the design and improvement of elliptical vibrating screens.

The Experiment Study on Flash Spectrum Produced by Hypervelocity Impact

2015 ◽  
Vol 782 ◽  
pp. 197-203
Author(s):  
Kai Zhang ◽  
Qing Ming Zhang ◽  
Ren Rong Long
Keyword(s):  
Space Debris ◽  
Hypervelocity Impact ◽  
Spectral Lines ◽  
Line Spectrum ◽  
Weapon System ◽  
Flash Intensity ◽  
System A ◽  
Flash Spectrum ◽  
The Relationship ◽  
Important Significance

It is an inevitable phenomenon that flash is generated in the process of hypervelocity impact. The research on impact flash is of important significance for assessing the collision between space debris and spacecraft, identifying the material properties on the surface of planet, evaluating the damage of weapon system. A measurement system was built in order to acquire flash spectrum ranging in wavelength from 200 to 1100nm. The relationship between flash intensity and impact velocity was studied. The spectrum consists of line spectrum and continuous spectrum. Line spectrum mainly concentrates in the range of 200-500nm. The spectral lines of the elements were identified. The strong flash happens within 2.2ms after beginning to impact. In addition, the electron temperature of plasma produced in hypervelocity impact is calculated by spectral method, and compared with the temperature measured by Langmuir three probes.

Thermal Annealing Dependence of High-Frequency Magnetoimpedance in Amorphous and Nanocrystalline FeSiBCuNb Ribbons

2008 ◽  
Vol 8 (6) ◽  
pp. 2873-2882 ◽  
Author(s):  
B. Hernando ◽  
V. M. Prida ◽  
M. L. Sanchez ◽  
J. Olivera ◽  
C. Garcia ◽  
...  
Keyword(s):  
High Frequency ◽  
Annealing Temperature ◽  
Driving Frequency ◽  
Network Analyzer ◽  
Frequency Range ◽  
Isothermal Heating ◽  
Amorphous Ribbons ◽  
Maximum Value ◽  
Different Temperatures ◽  
Nanocrystalline Sample

The magnetoimpedance (MI) effect in Fe73.5Si13.5B9Nb3Cu1 melt-spun amorphous ribbons has been studied in the frequency range (1–500 MHz). Isothermal heating treatments in a furnace have been employed to nanocrystallize the ribbons (1 h at 565 °C in a vacuum of 10–3 mbar), while other samples were annealed at lower temperatures (400 and 475 °C during 1 h), in order to evaluate the influence of the annealing temperature on the MI effect. The high-frequency impedance was measured using a technique based on the reflection coefficient measurements of a specific transmission line by using a network analyzer. Frequency dependence of the MI ratio, ΔZ/Z, and both resistive, ΔR/R, and reactive, ΔX/X, components of magnetoimpedance were measured in the amorphous and annealed states, at different temperatures. A maximum value of the MI ratio of about 50% at a driving frequency of 18 MHz is obtained in the nanocrystalline (annealed at 565 °C) ribbon. Maxima for R/R of about 81% at 85 MHz and ΔX/X around 140% at 5 MHz were also achieved. It is revealed that the microstructural evolution in the nanocrystalline sample leads to a magnetic softening, an optimum domain structure and a permeability which is sensitive to frequency and applied magnetic field, generating a large MI response.

The Drag Reduction Mechanism of Vibration Digging Shovel

2013 ◽  
Vol 288 ◽  
pp. 41-47
Author(s):  
Wang Yun Ning ◽  
Ying Chen ◽  
Yu Lan Kuang ◽  
Yong Hua Zhang
Keyword(s):  
Drag Reduction ◽  
Cutting Speed ◽  
Viscous Friction ◽  
Vibration Direction ◽  
Friction Resistance ◽  
Direction Angle ◽  
Reduction Mechanisms ◽  
The Impact ◽  
The Relationship ◽  
The Ideal

In order to investigate the drag reduction mechanisms of vibration digging shovel from the kinematics and mechanical aspects, and to estimate the magnitude of its traction resistance, we performed kinematic analysis when the velocity of the digging shovel was undergoing sinusoidal changes. Based on the analysis of the relationship between vibration direction angle, ascending direction angle and the edge motion curve, we evaluated the efficacy of different mining modes and proposed the ideal working conditions. We found that when the vibration direction angle φ <0 it could produce favorable cutting conditions. When the cutting direction angle θ was slightly less than or equal to the buried angle α and the ascending direction angle λ <π/2, the traction resistance was the least and soil-crushing effect was enhanced. The application of the moving viscous friction resistance model of mining shovel to analyze the force, including the impact of cutting speed on vibration viscous friction, could optimize the ideal working state and deduce the horizontal traction resistance formula of cutting and ascending. This model will be conducive to the structural design of vibration digging shovel and the estimation of its traction resistance.

scholarly journals Studying of movement kinematics of dynamically active sieve

2019 ◽  
Vol 23 (1) ◽  
pp. 94-97 ◽  
Author(s):  
Dmitry Popolov ◽  
Sergey Shved ◽  
Igor Zaselskiy ◽  
Igor Pelykh
Keyword(s):  
Mechanical Properties ◽  
Frequency Range ◽  
Technological Parameters ◽  
Movement Kinematics ◽  
Vibrating Screen ◽  
Amplitude Component ◽  
Working Frequency ◽  
Element Movement ◽  
The Mathematical Model ◽  
Research Show

Abstract The article presents the movement kinematics of the modular bar element of a dynamically active polymer sieve of a vibrating screen. On the basis of analytical methods, the mathematical model was obtained, which makes it possible to determine the law and trajectory of the modular bar element movement depending on its geometric characteristics, physico-mechanical properties of the polymer material, the regime and technological parameters of the vibrating screen. The results of this research show that in the working frequency range of the vibrating screen grate, modular bar element of the dynamically active sieve moves along the trajectories, the envelope of which is represented by Cassini’s ovals, which along with the generation of the amplitude component in the horizontal and vertical directions allows one to obtain the selfcleaning effect of the sowing surface.

The Dipole Antenna with Photonic Crystal Structure Used for Mobile Communication

2013 ◽  
Vol 448-453 ◽  
pp. 2163-2166
Author(s):  
Bin Lin ◽  
Ting Lin ◽  
Yang Ge ◽  
Rong Rong Wang ◽  
Yong Ping Guo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Photonic Crystal ◽  
Mobile Communication ◽  
Communication System ◽  
Return Loss ◽  
Dipole Antenna ◽  
Photonic Crystal Structure ◽  
Frequency Range ◽  
Mobile Communication System ◽  
Important Significance

The antenna design and its manufacturing technology is one of the gordian technique in mobile communication system, the performance of antenna influences the performance of the mobile communication system directly. To mobile communication system, the study of antenna has important significance. The development of mobile communication system brings a new request to the antennas design. This paper start from dipole antenna and the structural theory of photonic crystal, bat around the superiority of the two, and make a combination, design a dipole antenna with photonic crystal structure which can work in 2GHz frequency range, small size, return loss in low and bandwidth is suitable for CDMA2000 mobile communication system, and we simulate and test the performance of this antenna, discuss how the parametric variation will influence the performance of antenna.

ON THE STATISTICAL PROPERTIES OF SOME TRANSPORT EQUATIONS

1961 ◽  
Vol 39 (11) ◽  
pp. 1573-1582 ◽  
Author(s):  
Adrian E. Scheidegger
Keyword(s):  
Suspended Sediment Transport ◽  
Frequency Range ◽  
General Statement ◽  
Microscopic Reversibility ◽  
Equilibrium Conditions ◽  
System A ◽  
Component Systems ◽  
Diffusivity Equation ◽  
Diffusivity Tensor ◽  
Statistical Theory Of Turbulence

It is shown that, whenever a system is a linear combination of a large number of fluctuating component systems and in the "large" system a certain quantity is a constant of the motion, under equilibrium conditions that quantity is canonically distributed in the component systems and, under non-equilibrium conditions (assuming linear regression of the fluctuations and microscopic reversibility), the quantity in question is subject to a diffusivity equation with a symmetric diffusivity tensor. Application of the above to porous media hydrodynamics immediately yields the equations for miscible displacement which were laboriously obtained earlier from a special statistical model. Similarly, the corresponding equations for suspended sediment transport in rivers and for the mixing of a pollutant in air are shown to be the result of an application of the above general statement. Finally, the theory is also applied to the inertial frequency range in the statistical theory of turbulence.

Validation of Clicking-type Noise and Vibration in Automotive HVAC System

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
M.H.A. Satar ◽  
A. Z. A. Mazlan ◽  
M.H. Hamdan ◽  
M.S. Md. Isa ◽  
M.A.R. Paiman ◽  
...  
Keyword(s):  
Scale Model ◽  
Hvac System ◽  
Frequency Range ◽  
Similar Frequency ◽  
Noise And Vibration ◽  
System A ◽  
Vehicle System ◽  
Operating Frequency Range ◽  
Expansion Valve ◽  
Good Agreement

In this study, the characteristics of clicking-type noise and vibration occurring in the automotive heating, ventilation and air conditional (HVAC) systems are investigated. A lab-scale model of HVAC system is developed, and validation is carried out with a vehicle system. A fixed blower speed of 1 (at an airflow of 2.53 m/s) with alternated air conditional (AC) was implied in this study. Three different sensors namely as tachometer, accelerometer, and microphone were used to measure and prove the existing noise in the HVAC system. The study inferred that the compressor contributed significantly to the total vibration and noise in the HVAC system. Other components such as AC pipe, evaporator, and thermal expansion valve (TXV) also contributed to a slight extent. The clicking noise was observed in the operating frequency range of 200 ~ 300 Hz. This noise and vibration issues are partly influenced by the running conditions of the AC and the effect was significant when the AC was turned on. The validation of the findings in the model shows a good agreement with the results obtained in the vehicle system, whereby the clicking noise and vibration can be observed at a similar frequency range.

A MEMS Doubly Decoupled Gyroscope With Wide Driving Frequency Range

2012 ◽  
Vol 59 (12) ◽  
pp. 4921-4929 ◽  
Author(s):  
Chun-Wei Tsai ◽  
Kai-hsin Chen ◽  
Ching-Kai Shen ◽  
Jui-che Tsai
Keyword(s):  
Driving Frequency ◽  
Frequency Range
Sign in / Sign up

Export Citation Format

Share Document