Dust Reduction Efficiency of a Single-Row Vegetative Barrier (Maclura pomifera)

2018 ◽  
Vol 61 (6) ◽  
pp. 1907-1914
Author(s):  
Howell B. Gonzales ◽  
John Tatarko ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
Lawrence J. Hagen ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Great Plains ◽  
Wind Erosion ◽  
Dust Removal ◽  
Dust Particles ◽  
Deciduous Tree ◽  
Single Row ◽  
Osage Orange ◽  
Reduction Efficiency ◽  
Dust Reduction

Little is known about the dust removal efficiency of common vegetative barriers. This study of blowing dust reduction was conducted on one of the most common vegetative barriers used for wind erosion control in Kansas and the U.S. Great Plains, the deciduous tree species (Osage orange). A dust generator and distributor were fabricated to generate dust particles for determining the dust removal efficiency of a single-row Osage orange barrier. Simultaneous upwind and downwind dust concentrations were measured using mini-vol samplers for total suspended particulates (TSP) at heights of 1.5, 3.0, 4.5, and 6.0 m above the ground. Measurements were made using two towers located at upwind and downwind distances equal to the height of the barrier. Particle size distribution (PSD) analysis of the initial generated dust showed that most particles were large (GMD = 102.8 µm), while about 5% of the dust was particulate matter less than 2.5 µm in diameter (PM2.5) and 15% was less than 10 µm (PM10). Laser diffraction analysis of particles from the sample filters was used to determine the dust reduction efficiency of the barrier. Results showed that dust reduction was significantly related to reduction in wind speed at lower heights, causing an overall decrease in dust concentration as particles passed through the barrier. Concentrations of larger particles (~100 µm) were also reduced relative to smaller particles when dust passed through the barrier. The data also showed that 4.5 m above the ground, near the crown of the canopy, was most efficient at removing the PM2.5 (15% to 54%) and PM10 (23% to 65%) fractions of the generated dust. Keywords: Generated dust, Osage orange, PM2.5, PM10, TSP, Wind erosion.

Porosity and Drag Determination of a Single-Row Vegetative Barrier (Maclura pomifera)

2018 ◽  
Vol 61 (2) ◽  
pp. 641-652 ◽  
Author(s):  
Howell B. Gonzales ◽  
Mark E. Casada ◽  
Lawrence J. Hagen ◽  
John Tatarko ◽  
Ronaldo G. Maghirang ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Great Plains ◽  
Wind Erosion ◽  
Mean Values ◽  
Single Row ◽  
Wind Speeds ◽  
Osage Orange ◽  
Vegetative Barrier ◽  
Different Seasons ◽  
Calm Wind

Abstract. Deciduous trees of the species (Osage orange) are commonly established as vegetative barriers for wind erosion control throughout the U.S. Great Plains. Because there is no previous research on the aerodynamic effectiveness of these vegetative barriers during different seasons (leaf-on and leaf-off conditions), this study focused on determining the porosity and drag characteristics of this tree species. Digital image analyses were used to determine optical porosities that were then correlated with barrier drag coefficients. Images were taken in the field during calm wind conditions when the sunlight was suitable for digital imaging. Wind speeds were measured at different heights for a single-row Osage orange barrier using cup anemometers. Two anemometer towers were positioned relative to the barrier. One was located windward at 10H distance from the barrier; the other was located leeward and was movable to distances of 1H, 2H, 4H, 7H, 10H, 12H, 15H, and 20H from the barrier, where H is the average barrier height. The wind speeds measured in the field ranged from 4 to 7 m s-1, with lower wind speeds encountered during the leaf-off condition. As expected, wind speed reductions were greater for the leaf-on condition and ranged from 40% to 80% at 1H from the barrier, while the reduction was 20% to 38% for the leaf-off condition. The crown portion of the barrier was found to be responsible for much of the reduction. Mean values of the drag coefficient were 1.3 for the leaf-on condition, decreasing to 0.9 for the leaf-off condition of the Osage orange barrier, which corresponded to mean optical porosities of 20% and 61%, respectively Keywords: Drag coefficient, Image analysis, Osage orange, Porosity, Vegetative barrier, Wind erosion.

scholarly journals Synergistic removal of dust using the wet flue gas desulfurization systems

2019 ◽  
Vol 6 (7) ◽  
pp. 181696 ◽  
Author(s):  
Qirong Wu ◽  
Min Gu ◽  
Yungui Du ◽  
Hanxiao Zeng
Keyword(s):  
Removal Efficiency ◽  
Flue Gas ◽  
Power Plants ◽  
Flue Gas Desulfurization ◽  
Dust Removal ◽  
Dust Particles ◽  
Experimental Conditions ◽  
Collision Model ◽  
Sieve Tray ◽  
Spray Scrubber

Coal is still a major energy source, mostly used in power plants. However, the coal combustion emits harmful SO 2 and fly ash. Wet flue gas desulfurization (WFGD) technology is extensively used to control SO 2 emissions in power plants. However, only limited studies have investigated the synergistic dust removal by the WFGD system. Spray scrubbers and sieve-tray spray scrubbers are often used in WFGD systems to improve the SO 2 removal efficiency. In this study, the synergistic dust removal of WFGD systems for a spray scrubber and a sieve-tray spray scrubber was investigated using the experimental and modelling approaches, respectively. For the spray scrubber, the influence of parameters, including dust particle diameters and inlet concentrations of dust particles, and the flow rates of flue gas and slurry of limestone/gypsum on the dust removal efficiency, was investigated. For the sieve-tray spray scrubber, the influence of parameters such as the pore diameter and porosity of sieve trays on the dust removal efficiency was examined. The study found that the dust removal efficiency in the sieve-tray spray scrubber was approximately 1.1–10.6% higher than that of the spray scrubber for the same experimental conditions. Based on the parameters investigated and geometric parameters of a scrubber, a novel droplets swarm model for dust removal efficiency was developed from the single droplet model. The enhanced dust removal efficiency of sieve tray was expressed by introducing a strength coefficient to an inertial collision model. The dust removal efficiency model for the sieve-tray spray scrubber was developed by combining the droplets swarm model for the spray scrubber with the modified inertial collision model for the sieve tray. The results simulated using both models are consistent with the experimental data obtained.

scholarly journals Study on the Atomization and Dust-Reduction Performance of a New Type of External Pneumatic Vortex Fog Curtain Dust Removal Device in Fully Mechanized Excavation Face

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Deji Jing ◽  
Rina An ◽  
Jingxu Chen ◽  
Shaocheng Ge ◽  
Liying Sun
Keyword(s):  
Wind Speed ◽  
Dust Removal ◽  
Air Volume ◽  
Reduction Experiment ◽  
Reduction Efficiency ◽  
New Type ◽  
Atomization Performance ◽  
Relationship Of ◽  
Atomization Pressure ◽  
Dust Reduction

To solve the problem of dust pollution in the heading face, a new type of external pneumatic vortex fog curtain dust removal device suitable for a fully mechanized excavation face is designed in this paper. Firstly, dust migration laws at different times are simulated and analyzed by COMSOL software, and the functional relationship of dust concentration distribution above 50 mg/m3 at different heights and different wind speed is derived. Aiming at the dust migration laws of the heading face, a new dust removal device was proposed, and the atomization performance of the new type of external pneumatic vortex fog curtain dust removal device under different jet wind speed, different atomization pressure, and different nozzle working angle is explored through atomization performance experiment. It is found that when jet wind speed is 30 m/s, atomization pressure is 4 MPa, and nozzle working angle is 75°, the atomization performance of the new type of external pneumatic vortex fog curtain dust removal device is the best. Through the simulation of COMSOL software, the influence of air volume on the new type of external pneumatic vortex fog curtain dust removal device is analyzed. It is found that the new type of external pneumatic vortex fog curtain dust removal device is relatively stable when the air volume at the pressure outlet is less than 400 m3/min. The dust-reduction efficiency of the new type of external pneumatic vortex fog curtain dust removal device was investigated through the dust-reduction experiment, and it is found that the new type of external pneumatic vortex fog curtain dust removal device had better dust removal performance under the condition that the ventilation conditions did not interfere with the integrity of the vortex fog curtain.

scholarly journals DESIGN OF PULSED HIGH-VOLTAGE POWER FOR ELECTROSTATIC PRECIPITATOR

2018 ◽  
Vol 48 (3) ◽  
pp. 193-198
Author(s):  
L. J. FAN ◽  
X. C. PAN ◽  
Z. X. HUANG ◽  
X. D. ZU
Keyword(s):  
Physical Model ◽  
Removal Efficiency ◽  
High Voltage ◽  
Pulse Width ◽  
Electrostatic Precipitator ◽  
High Voltage Pulse ◽  
Pulse Frequency ◽  
Dust Removal ◽  
Dust Particles ◽  
The Relationship

In this paper, the physical model of anti-corona phenomenon was established, the theoretical model of anti-corona suppression powered by an electrostatic precipitator (ESP) pulse has been obtained. A dust collecting method was suggested in which a gas has ionized by an electrostatic field to adsorb dust particles to an electrode. The relationship between pulse frequency, amplitude pulse width and dust removal efficiency were tested. Research results showed that the physical model of anti-corona phenomenon could reflect the process of corona generation. The circuit scheme of superimposing high-voltage pulse based on direct current high voltage can effectively suppress the anti-corona phenomenon and improve the dust removal efficiency

Numerical Simulation on Improving NOx Reduction Efficiency of SNCR by Regulating the 3-D Temperature Field in a Furnace

2013 ◽  
Vol 807-809 ◽  
pp. 1505-1513 ◽  
Author(s):  
Amir A.B. Musa ◽  
Xiong Wei Zeng ◽  
Qing Yan Fang ◽  
Huai Chun Zhou
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Removal Efficiency ◽  
Pulverized Coal ◽  
Measuring System ◽  
Optimum Temperature ◽  
Utility Boiler ◽  
Coal Particles ◽  
Injection Zone ◽  
Reduction Efficiency

The optimum temperature within the reagent injection zone is between 900 and 1150°C for the NOX reduction by SNCR (selective non-catalytic reduction) in coal-fired utility boiler furnaces. As the load and the fuel property changes, the temperature within the reagent injection zone will bias from the optimum range, which will reduces significantly the de-NOX efficiency, and consequently the applicability of SNCR technology. An idea to improve the NOX reduction efficiency of SNCR by regulating the 3-D temperature field in a furnace is proposed in this paper. In order to study the new method, Computational fluid dynamics (CFD) model of a 200 MW multi-fuel tangentially fired boiler have been developed using Fluent 6.3.26 to investigate the three-fuel combustion system of coal, blast furnace gas (BFG), and coke oven gas (COG) with an eddy-dissipation model for simulating the gas-phase combustion, and to examine the NOX reduction by SNCR using urea-water solution. The current CFD models have been validated by the experimental data obtained from the boiler for case study. The results show that, with the improved coal and air feed method, average residence time of coal particles increases 0.3s, burnout degree of pulverized coal increases 2%, the average temperature at the furnace nose decreases 61K from 1496K to 1435K, the NO emission at the exit (without SNCR) decreases 58 ppm from 528 to 470 ppm, the SNCR NO removal efficiency increases 10% from 36.1 to 46.1%. The numerical simulation results show that this combustion adjustment method based on 3-D temperature field reconstruction measuring system in a 200 MW multi-fuel tangentially fired utility boiler co-firing pulverized coal with BFG and COG is timely and effective to maintain the temperature of reagent injection zone at optimum temperature range and high NOX removal efficiency of SNCR.

scholarly journals Experimental study on production and emission characteristics of PM2.5 from industrial fluidized bed boilers

2020 ◽  
Vol 24 (5 Part A) ◽  
pp. 2665-2675
Author(s):  
Songsong Zhang ◽  
Qian Du ◽  
Guoli Qi
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Mass Concentration ◽  
Great Influence ◽  
Chemical Properties ◽  
Dust Removal ◽  
Dust Collector ◽  
Bag Filter ◽  
Physical And Chemical ◽  
Fluidized Bed Boilers

Particle size distributions, concentrations, morphological characteristics, and elemental compositions of eight fluidized bed boilers with different capacities and different dust collectors were determined experimentally. The PM2.5 particle concentration and mass concentration were monitored in real-time before and after the boiler dust collector by electric low pressure impactor, and the physical and chemical properties of PM2.5 were analyzed by membrane sampling. We found that the PM2.5 particle concentration produced by industrial fluidized bed boilers displayed bimodal distributions, peaking at 0.2 ?m and 0.76 ?m, the formed mechanism of these two parts particles is vaporization-condensation of mineral matter and residual ash particles and the adsorbent wear or tear. Mass concentration exhibits a single peak characteristic with a peak at 0.12 ?m. The removal efficiency for PM2.5 of dust collectors varies with different dust removal mechanisms. The electrostatic precipitator and bag filter have high dust removal efficiency, and the water film dust collector has low dust removal efficiency. The normal operation of the bag filter has a great influence on the dust removal efficiency. The physical and chemical properties of PM2.5 showed that the single-particle morphology was mainly composed of irregular particles, containing a small amount of solid spherical particles and more agglomerates. The content of Si and Al in PM2.5 elemental analysis is the highest, which decreases after a dust collector. Some fluidized bed boilers use desulfurization in the furnace, which has great influence on the mass concentration of Ca and S elements, and the lowest Hg content in trace elements, about a few ppm. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI200901242E">10.2298/TSCI200901242E</a><u></b></font>

Study on a Photovoltaic Lunar Dust Removal System Based on the Photovoltaic Effect of PLZT

2017 ◽  
Author(s):  
Jing Jiang ◽  
Hong-Yue Zhao ◽  
Jin-Cheng Ding ◽  
Hong-Hao Yue ◽  
Xu-Yan Hou
Keyword(s):  
Ultraviolet Light ◽  
Removal Efficiency ◽  
Electrostatic Force ◽  
Photovoltaic Effect ◽  
Dust Removal ◽  
Dust Collector ◽  
Optical Elements ◽  
Lunar Dust ◽  
Protected Surface ◽  
Removal System

The deposition of lunar dust on the surface of solar panels and optical elements is one of the most important problems need to be solved in lunar exploration. This paper will propose an initiative lunar dust removal system based on the photovoltaic effect of PbLaZrTi (PLZT), which is activated by the ultraviolet light extracted from sun light at the lunar surface. When ultraviolet light with a wavelength near 365nm illuminates on polarized PLZT materials, high voltages of several kilovolt per centimeter can be generated between two electrodes of PLZT. When two electrodes of PLZT are connected to a lunar dust collector (LDC) and the ITO film of protected surface respectively, an electrostatic field forms between LDC and the protected surface. Coulomb forces over particles will overcome gravitational force and surface forces, so the particles can be absorbed to LDC and removed by LDC finally. Based on the equivalent electrical model, mathematical model of electrostatic force is derived when the lunar removal electric field is acted either by single piece PLZT or by multi-pieces PLZT which are connected in parallel. Experimental platform is set up to prove the feasibility of this lunar dust removal system. In order to improve the removal efficiency, a novel configuration design of LDC based on multi-PLZT patched is proposed and its removal efficiency is evaluated by experiments.

scholarly journals Design and Optimum of Dust Collector with Corrugated Plate for Underground Mine

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Ming Li ◽  
Chao Wu ◽  
Zhi-yong Zhou ◽  
Wei-chun Lian ◽  
Zhi-xiong Chen
Keyword(s):  
Removal Efficiency ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Dust Removal ◽  
Dust Collector ◽  
Dust Collection ◽  
Ansys Fluent ◽  
Metal Mine ◽  
Lead Zinc ◽  
Dimensional Simulation

A set of dust collectors was designed with corrugated plate for an underground metal mine, which has low ventilation resistance, simple maintenance, and strong environmental adaptability. A three-dimensional simulation model was built based on ANSYS-Fluent software, and it was used to analyze the influence law of key parameters on the comprehensive dust removal efficiency; the angle of corrugated plate to the horizontal plane, the surface characteristics of plate, pressure loss and dust removal efficiency were discussed. The optimal design scheme of the dust collector was determined according to the simulation results. The dust collection was carried out in the Fankou lead-zinc underground metal mine in China, and the total dust removal efficiency was more than 95%, and for respiratory dust, it was more than 85%. This dust collector can be widely used in similar underground metal mines.

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