Effect of operating conditions on the particle size distribution and specific energy input of fine grinding in a stirred mill: Modeling cumulative undersize distribution

2022 ◽  
Vol 176 ◽  
pp. 107347
Author(s):  
Wang Guo ◽  
Yuexin Han ◽  
Peng Gao ◽  
Zhidong Tang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Specific Energy ◽  
Energy Input ◽  
Operating Conditions ◽  
Specific Energy Input ◽  
Fine Grinding

scholarly journals Influence of grinding method and grinding intensity of corn on mill energy consumption and pellet quality

2016 ◽  
Vol 70 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Djuro Vukmirovic ◽  
Jovanka Levic ◽  
Aleksandar Fistes ◽  
Radmilo Colovic ◽  
Tea Brlek ◽  
...  
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Hammer Mill ◽  
Pellet Quality ◽  
Roller Mill ◽  
Grinding Method

In recent years there is an emerging trend of coarse grinding of cereals in production of poultry feed due to positive influence of coarse particles on poultry digestive system. Influence of grinding method (hammer mill vs. roller mill) and grinding intensity of corn (coarseness of grinding) on mill specific energy consumption and pellet quality was investigated. By decreasing grinding intensity of corn (coarser grinding), specific energy consumption of both hammer mill and roller mill was significantly decreased (p < 0.05). When comparing similar grinding intensities on hammer mill and roller mill (similar geometric mean diameter or similar particle size distribution), specific energy consumption was higher for the hammer mill. Pellet quality decreased with coarser grinding on hammer mill but, however, this effect was not observed for the roller mill. Generally, pellet quality was better when roller mill was used. It can be concluded that significant energy savings could be achieved by coarser grinding of corn before pelleting and by using roller mill instead of hammer mill. From the aspect of pellet quality, if coarser grinding is applied it is better to use roller mill, concerning that more uniform particle size distribution of corn ground on roller mill probably results in more uniform particle size distribution in pellets and this provides better pellet quality.

scholarly journals Influence of the Feed Moisture, Rotor Speed, and Blades Gap on the Performances of a Biomass Pulverization Technology

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Siyi Luo ◽  
Yangmin Zhou ◽  
Chuijie Yi ◽  
Yin Luo ◽  
Jie Fu
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Specific Energy ◽  
Rotor Speed ◽  
Operational Parameters ◽  
Product Particle ◽  
Dry Conditions ◽  
Feed Moisture

Recently, a novel biomass pulverization technology was proposed by our group. In this paper, further detailed studies of this technology were carried out. The effects of feed moisture and crusher operational parameters (rotor speed and blades gap) on product particle size distribution and energy consumption were investigated. The results showed that higher rotor speed and smaller blades gap could improve the hit probability between blades and materials and enhance the impacting and grinding effects to generate finer products, however, resulting in the increase of energy consumption. Under dry conditions finer particles were much more easily achieved, and there was a tendency for the specific energy to increase with increasing feed moisture. Therefore, it is necessary for the raw biomass material to be dried before pulverization.

Effect of Particle Size Distribution on the Deep-Bed Capture Efficiency of an Exhaust Particulate Filter

2014 ◽  
Author(s):  
Sandeep Viswanathan ◽  
Stephen S. Sakai ◽  
Mitchell Hageman ◽  
David E. Foster ◽  
Todd Fansler ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Particle Deposition ◽  
Operating Conditions ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Filter Loading ◽  
Particle Sizer ◽  
The Impact

The exhaust filtration analysis system (EFA) developed at the University of Wisconsin – Madison was used to perform micro-scale filtration experiments on cordierite filter samples using particulate matter (PM) generated by a spark-ignition direct injection (SIDI) engine fueled with gasoline. A scanning mobility particle sizer (SMPS) was used to characterize running conditions with four distinct particle size distributions (PSDs). The distributions selected differed in the relative number of accumulation versus nucleation mode particles. The SMPS and an engine exhaust particle sizer (EEPS) were used to simultaneously measure the PSD downstream of the EFA and the real-time particulate emissions from the SIDI engine to determine the evolution of filtration efficiency during filter loading. Cordierite filter samples with properties representative of diesel particulate filters (DPFs) were loaded with PM from the different engine operating conditions. The results were compared to understand the impact of particle size distribution on filtration performance as well as the role of accumulation mode particles on the diffusion capture of PM. The most penetrating particle size (MPPS) was observed to decrease as a result of particle deposition within the filter substrate. In the absence of a soot cake, the penetration of particles smaller than 70 nm was seen to gradually increase with time, potentially due to increased velocities in the filter as flow area reduces during filter loading, or due to decreasing wall area for capture of particles by diffusion. Particle re-entrainment was not observed for any of the operating conditions.

Hydrodynamics of Multiple Size Particles in a Liquid Fluidized Bed Classifier

2003 ◽  
Author(s):  
Dinesh Gera ◽  
Madhava Syamlal ◽  
Thomas J. O’Brien
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Volume Fraction ◽  
Fluid Model ◽  
Operating Conditions ◽  
Particle Sizes ◽  
Two Fluid Model ◽  
Predicted Values

A two fluid model is extended to an N-phase, multi-fluid model, in which each particulate phase represents a collection of particles with identical diameter and density. The current N-phase model is applied to a fluidized bed classifier with six different particle sizes to investigate the effects of different operating conditions—fluidizing liquid flow rate, feed voidage, and particle size distribution in the feed stream—on the particle size distribution inside the classifier and the discharge streams. The predicted volume fraction of different particle sizes is compared with the experimental data reported by Chen et al. (2002) for two columns, 191 mm and 292 mm in diameter, each having different geometries and containing glass beads of different sizes fluidized with water. A fairly good agreement is observed between the measured and predicted values for mono- and poly-dispersed systems.

Monitoring Fluidization Dynamics for Detection of Changes in Fluidized Bed Composition and Operating Conditions

1999 ◽  
Vol 121 (4) ◽  
pp. 887-894 ◽  
Author(s):  
J. Ruud van Ommen ◽  
Jaap C. Schouten ◽  
Cor M. van den Bleek
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Pressure Fluctuations ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Gradual Change ◽  
Monitoring Method ◽  
Superficial Gas Velocity

In many industrial applications of gas-solids fluidized beds, it is worthwhile to have an on-line monitoring method for detecting changes in the hydrodynamics of the bed (due for example to agglomeration) quickly. In this paper, such a method, based on the short-term predictability of fluidized bed pressure fluctuations, is examined. Its sensitivity is shown by experiments with small step changes in the superficial gas velocity and by experiments with a gradual change in the particle size distribution of the solids in the bed. Furthermore, it is demonstrated that the method is well able to indicate if a stationary hydrodynamic state has been reached after a change in the particle size distribution (a ‘grade change’).

Development of the Bed Particle Size Distribution in a Circulating Fluidized Bed Combustor

2005 ◽  
Author(s):  
Cornelis Klett ◽  
Ernst-Ulrich Hartge ◽  
Joachim Werther
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Calculated Data ◽  
Operating Conditions ◽  
Attrition Rate ◽  
Balance Model ◽  
Fluidized Bed Combustor

In the present work a particle population balance model for a circulating fluidized bed combustor (CFBC) is developed that allows a description of the fate of individual particles in terms of attrition and transport effects. Besides the operating conditions and the particle size distribution the residence time of particles in the system is considered in the modeling of abrasion and shrinking of particles. The model takes account of the fact that fresh particles have a higher attrition rate than particles which have stayed for some time already in the system. The model aims at the description of the dynamic adjustment of the particle size distributions in a given system. The model has been validated with experimental data from a pilot-plant combustor, i.e. a CFBC with an inner diameter of 0.1 m and a height of 15 m. A comparison between experimental and calculated data shows the applicability of the model.

scholarly journals The influence of energy input on the particle size of disintegrated excess sludge in the ultrasonic disintegration process

2018 ◽  
Vol 2017 (3) ◽  
pp. 679-685
Author(s):  
Łukasz Skórkowski ◽  
Ewa Zielewicz
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Energy Input ◽  
Oxygen Demand ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Disintegration Process ◽  
Most Significant Change ◽  
Measured Particle

Abstract The objective of this research was to examine the influence of energy input on the particle size distribution of disintegrated sludge. The change of particle size distribution indicates the deagglomeration of flocs and disruption of micro-colonies. As the digestibility of sludge increases with dispersion, particle size analysis is an important factor in evaluating the disintegration process. Four different levels of energy input were used in the research: 10–100 kWh·m−3. All samples showed significant changes as far as dispersion (kdCST = 22.98–74.67, kdFCOD = 3.23–18.46), lysis (kdSCOD = 4.22–12.09), acidification (kdVFAs = 1.78–12.61), nitrogen release (kdTN = 4.02–21.61) indicators were concerned. Results indicate the gradual decrease of measured particle size with increasing energy input. The energy supplied to the disintegration process primarily promotes deagglomeration and with the rise of energy input, the destruction of cells. For EV = 50 and 100 kWh·m−3 an increased occurrence of lysis effects and increase in particle fraction &lt;99.9 μm was noted. The highest efficiency evaluated by increase of filtered chemical oxygen demand (FCOD) and soluble COD (SCOD) per unit of volumetric energy – ΔCOD and ΔSCOD (mgO2·Wh−1) was obtained for Ev = 10 WhL−1, which corresponds to the most significant change in particle size distribution. The volume of particles &lt;99.9 μm rose from 1.92% for non-disintegrated sludge to 26.62% for volumetric energy 100 kWh·m−3.

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