Study of the discharge behavior of Rosin-Rammler particle-size distributions from hopper by discrete element method: A systematic analysis of mass flow rate, segregation and velocity profiles

2020 ◽  
Vol 360 ◽  
pp. 818-834
Author(s):  
Raj Kumar ◽  
Srikanth R. Gopireddy ◽  
Arun K. Jana ◽  
Chetan M. Patel
Keyword(s):  
Particle Size ◽  
Discrete Element Method ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Discrete Element ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Systematic Analysis ◽  
Discharge Behavior

Continuous Particle Size Distributions in a Bubbling Fluidized Bed Using Discrete Element Method

2012 ◽  
Author(s):  
Meire Pereira de Souza Braun ◽  
Alice Jordam Caserta ◽  
Helio Aparecido Navarro
Keyword(s):  
Particle Size ◽  
Discrete Element Method ◽  
Fluidized Bed ◽  
Gas Bubbles ◽  
Discrete Element ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Bubbling Fluidized Bed ◽  
Continuous Particle ◽  
Element Method

The focus of this paper is to study the behavior of systems with continuous particle size distributions over a gas-solid flow in a bubbling fluidized bed. A lognormal distribution with particle-size range between 800 micrometers and 900 micrometers was used to perform numerical simulations to investigate gas bubbles formation for a polydispersed system. Different drag models were used to predict the bubbles. Species segregation for a binary mixture and a monodispersed system were also studied. Discrete Element Method (DEM) simulations were performed using the source code MFIX (“Multiphase Flow with Interphase eXchanges”) [1] developed at NETL (“National Energy Technology Laboratory”). The bubble size of a single injected bubble depended strongly on gas-particle drag model used. The influence of the gas bubbles in the mixture and segregation was analyzed and discussed. The results were compared with experimental results from the literature and a good agreement were obtained.

scholarly journals Predicting the Particle Size Distributions of Spherical Particle Sets from Synthetic Images: A Comparison of 9 Classic Image Features

2021 ◽  
Author(s):  
javad Manashti ◽  
Francois Duhaime ◽  
Matthew Toews ◽  
Pouyan Pirnia
Keyword(s):  
Particle Size ◽  
Feature Extraction ◽  
Spherical Particle ◽  
Discrete Element ◽  
Local Binary Patterns ◽  
Extraction Methods ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Histograms Of Oriented Gradients ◽  
Synthetic Images

The two objectives of this paper were to demonstrate use the of the discrete element method for generating synthetic images of spherical particle configurations, and to compare the performance of 9 classic feature extraction methods for predicting the particle size distributions (PSD) from these images. The discrete element code YADE was used to generate synthetic images of granular materials to build the dataset. Nine feature extraction methods were compared: Haralick features, Histograms of Oriented Gradients, Entropy, Local Binary Patterns, Local Configuration Pattern, Complete Local Binary Patterns, the Fast Fourier transform, Gabor filters, and Discrete Haar Wavelets. The feature extraction methods were used to generate the inputs of neural networks to predict the PSD. The results show that feature extraction methods can predict the percentage passing with a root-mean-square error (RMSE) on the percentage passing as low as 1.7%. CLBP showed the best result for all particle sizes with a RMSE of 3.8 %. Better RMSE were obtained for the finest sieve (2.1%) compared to coarsest sieve (5.2%).

scholarly journals Pressure drop characteristics of reverse circulation pneumatic cuttings removal during coal seam drilling

2020 ◽  
Vol 103 (2) ◽  
pp. 003685042092523 ◽  
Author(s):  
Xiaoming Han ◽  
Songnan Song ◽  
Jialiang Li
Keyword(s):  
Particle Size ◽  
Pressure Drop ◽  
Coal Seam ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
New Technology ◽  
Drill Pipe ◽  
Air Velocity ◽  
Reverse Circulation

To solve the problems that the borehole depth is shallow and the drilling efficiency is low during the gas drainage drilling in soft coal seam with current cuttings removal method, a new technology of reverse circulation pneumatic cuttings removal is proposed. The working principle of reverse circulation pneumatic cuttings removal is analyzed, and the kinetic equation of cuttings in the inner hole of the drill pipe is established. Through experiments, the pressure drop in the drill pipe is measured to reveal the effects of air velocity, cuttings mass flow rate, and cuttings particle size on the pressure drop in inner hole of the drill pipe. When the cuttings mass flow rate is constant, the pressure drop increases with the increase in air velocity. When the air velocity is constant, the pressure drop increases with the increase in cuttings mass flow rate. At low air velocity, the pressure drop of cuttings is primary. As the air velocity increases, the pressure drop ratio of cuttings decreases. Under the same conditions, the order of pressure drop with different particle size cuttings is coarse cuttings > medium cuttings > fine cuttings. Empirical equation of pressure drop coefficient of cuttings is established, which is in good agreement with the actual data.

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