scholarly journals Performance of N95 elastomeric respirators in high humidity and high coal dust concentration environment

2021 ◽  
Author(s):  
Jintuo Zhu ◽  
Xinjian He ◽  
Liang Wang ◽  
Xiaoxue Liao ◽  
Guangping Teng ◽  
...  
Keyword(s):  
Coal Dust ◽  
Dust Concentration ◽  
High Humidity

scholarly journals Optical Estimation on Pollution Level of Respirable Dust Based on Infrared Transmitting Behavior in Coalmine Fully Mechanized Working Face

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Wen-Zheng Wang ◽  
Yan-Ming Wang ◽  
Guo-Qing Shi
Keyword(s):  
Coal Particle ◽  
Coal Dust ◽  
Operating Conditions ◽  
Dust Concentration ◽  
Optical Channel ◽  
Pollution Level ◽  
Engineering Practice ◽  
Dust Generation ◽  
Working Face ◽  
Comparison Results

Respirable coal particle generated during underground mining is the main cause for gas-dust explosions and coal workers’ pneumoconiosis (CWP) which needs accurate monitoring especially on its concentration. Focusing on the coal dust pollution in the fully mechanized working face of Huangbaici coalmine, coal particle was sampled for further industrial analysis and FT-IR test to obtain its chemical composition and optical constant. Combined with the simulated spatial distribution of airborne dust, the spectral transmission characteristics of coal dust within wavelengths of 2.5 to 25 μm under different operating conditions were obtained. The simulation results show that the transmittance and aerosol optical depth (AOD) of coal dust are closely linked and obviously influenced by the variation of dust generation source (intensity of dust release, position of coal cutting, and the wetting of the coal seam) and airflow field (wind speed and direction of ventilation). Furthermore, an optical channel of 1260–1280 cm−1(7.937–7.813 μm) which is almost only sensitive to the variation of dust concentration but dull to the diameter change of coal dust was selected to establish the correlation of dust concentration and infrared transmittance. The fitting curve was then applied to retrieve the equivalent dust concentration based on optical information, and the comparison results demonstrate that the estimated pollution level is consistent with field measurement data in engineering practice.

scholarly journals Experimental Research and Numerical Simulation of Ejector Precipitator in a Fully Mechanized Mining Face

2020 ◽  
Vol 45 (11) ◽  
pp. 9815-9833
Author(s):  
Guodong Zhai ◽  
Wentao Zhang ◽  
Yaozong Li ◽  
Xinghao Lu ◽  
Wenyuan Hu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Negative Pressure ◽  
Coal Dust ◽  
Structural Parameters ◽  
Dust Concentration ◽  
Dust Removal ◽  
Measuring Point ◽  
Mining Face ◽  
Supply Water

AbstractIn order to effectively reduce the coal dust concentration in a fully mechanized mining face, this research used laboratory experiment, numerical simulation, and field test to conduct an in-depth exploration of the ejector precipitator installed at the low-level caving coal hydraulic support. Firstly, through the experimental platform in the laboratory, the dust removal effect of the nozzle with different structural parameters was tested, and the 3D particle dynamic analyzer was adopted to verify its atomization characteristics; then, the structural parameters corresponding to the nozzle in the best test results were obtained. Secondly, by using Fluent, the negative pressure flow field in the ejector barrel was numerically simulated. The results indicated that when the pressure of supply water was 12 MPa, the negative pressure value formed in the flow field was the lowest and the inspiratory velocity was the largest, which was conducive to dust removal. Finally, the tests of liquid–gas ratio and dust removal ratio were carried out in a fully mechanized mining face. The results showed that when the nozzle specification recommended by the experiment and the pressure of supply water recommended by the numerical simulation were used, the removal ratios of the total coal dust and the respirable coal dust were 89.5% and 91.0%, respectively, at the measuring point of the highest coal dust concentration. It indicates that the ejector precipitator has a good application effect in reducing the coal dust concentration in a fully mechanized mining face and improving the work environment of coal mine workers.

The Application of Particle Motion Equation in Coal Handling System of Dissipation Dust Law

2013 ◽  
Vol 313-314 ◽  
pp. 702-705
Author(s):  
Shao Cheng Ge ◽  
Yao Xuan Feng ◽  
De Ji Jing
Keyword(s):  
Numerical Simulation ◽  
Field Test ◽  
Particle Motion ◽  
Theoretical Basis ◽  
Coal Dust ◽  
Motion Equation ◽  
Dust Concentration ◽  
Dust Particles ◽  
Space Application ◽  
Handling System

For getting the effectiveof application in dissipation dust law with particle motion equation atcoal handling system of belt machine tail, must be to proceed related numerical simulation in the way of dust particles motion incoal handling system of belt machine tail and dust concentration of diffusion inoperation space. Application particlemotion equation theory for numerical simulation to coal dustparticles, obtained dust coal dissipation law in coal handling system, at thesame time combine with the data of the field test of dust concentration andfallout dispersion for analyzing and comparing. The results of comparison showthat: the data of numerical simulation with particle motion equationin coal dust dissipation law is coincide with reality dissipation law. Accordingto the conclusion of this research, it is provides theoretical basis forprevention and treatment in coal mine of coal handling system of dustdissipation.

scholarly journals Laboratory Determination of Coal Dust Cleaning Efficacy of a Fibrous Filter for Flooded-Bed Dust Scrubber

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 295
Author(s):  
Neeraj Gupta ◽  
Ashish Ranjan Kumar ◽  
Steven Schafrik
Keyword(s):  
Water Flow ◽  
Coal Dust ◽  
Dust Concentration ◽  
Dust Particles ◽  
Fibrous Filter ◽  
Cleaning Efficiency ◽  
Variable Frequency Drive ◽  
Room And Pillar Mining ◽  
Set Up ◽  
Cleaning Efficacy

Fibrous-type dust filters are used in flooded-bed dust scrubbers to capture dust from underground room and pillar mining atmospheres. They have 10–30 layers of finely woven strands that trap particles through the interception and impaction process. A full-cone water spray is installed upstream of the filter, which floods the screen. A scrubber’s efficacy is usually measured and reported in terms of reduction in gravimetric dust concentration at a known location in a mine. This paper reports the particle-size-dependent dust removal efficiency of a fibrous filter obtained from an instrumented test-set up. A variable frequency drive and an inline flow control knob were used to control the airflow through the filter and water flow onto the filter. Optical particle counting of coal dust particles upstream and downstream was carried out to determine the cleaning efficacy. Experiments showed an increase in cleaning efficiency for all the dust particles with their size. A progressive decrease in dust concentration downstream of the filter with an increase in water flow through the nozzle affirmed the capture of dust particles by water sprays.

Development of electrostatic induction coal dust concentration sensor based on plate-ring detection electrode

2021 ◽  
Author(s):  
jiange chen ◽  
Dewen Li ◽  
Kequan Wang ◽  
Jie Wang ◽  
Guoqing Liu ◽  
...  
Keyword(s):  
Coal Dust ◽  
Three Dimensional ◽  
Element Model ◽  
Central Moment ◽  
Structure Design ◽  
Dust Concentration ◽  
Detection Accuracy ◽  
Induction Signal ◽  
Electrostatic Induction ◽  
Detection Electrode

Abstract In order to increase the detection accuracy of coal dust and reduce the maintenance of the coal dust concentration sensor, in this paper, the electrostatic sensor of the plate-ring detection electrode was developed for the detection of coal dust concentration. Through the establishment of the three-dimensional finite element model of the plate-ring detection electrode and the simulation results of COMSOL, the superiority of the plate-ring detection electrode was demonstrated, and the basis for the structure design of the plate-ring detection electrode was provided. The plate-ring detection electrode and the processing circuit of the tiny electrostatic induction signal were designed. Electrostatic induction dust concentration sensor with plate-ring detection electrode was developed. Experiments and data analysis proved that the 1.5-order central moment of the electrostatic induction signal had a high degree of fit with the dust concentration value. The mathematical relationship between the electrostatic induction signal and the dust concentration was determined. The detection error of coal mine dust concentration sensor based on plate-ring detection electrode did not exceed 10%.

Numerical Simulation Research on Gas-Dust Flow Field of Forced-Exhausted Hybrid Ventilation in Whole Rock Mechanized Heading Face

2013 ◽  
Vol 336-338 ◽  
pp. 873-879 ◽  
Author(s):  
Gang Zhou ◽  
De Ming Wang ◽  
Wei Min Cheng ◽  
Sen Cao
Keyword(s):  
Fluid Model ◽  
Coal Dust ◽  
Engineering Application ◽  
Simple Algorithm ◽  
Dust Concentration ◽  
Dust Control ◽  
High Concentration ◽  
Two Phase ◽  
Collocated Grid ◽  
Two Fluid Model

Euler-Euler two-fluid model was used to construct control equations of gas-solid two-phase flow, based on SIMPLE algorithm of collocated grid and FLUENT software, the pressure distribution of air-flowing field and dust field diffusion in fully-mechanized excavation face with different air-draft volume were simulated. The results show that with the increase of exhausted dust ability, diffusion intensity of producing dust pollution in driving head constantly decreases. Compared to air-draft volume of 320m3/min, when it is 600m3/min, the average dust concentration at the driver and whole section positions respectively decrease 51.28% and 56.51%, and high-concentration dust diffusion distance of the other workers position section decrease from 13.6m to 8.5m. Engineering Application indicates that the measured dust concentration is basically anastomosed with simulation result. When air-draft volume of dedusting fan is 600m3/min and dust control system with air curtain formed by forced fan drum is used, the dedusting rates of total coal dust and respirable dust on spot are respectively 95.1% and 96.1%, which achieves a great dedusting effect.

scholarly journals Empirical Models of Zones Protecting Against Coal Dust Explosion

2017 ◽  
Vol 62 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Dariusz Prostański
Keyword(s):  
Research And Development ◽  
Coal Dust ◽  
Empirical Models ◽  
Dust Concentration ◽  
Mining Institute ◽  
Dust Explosion ◽  
Dust Deposition ◽  
National Centre ◽  
Mine Workings ◽  
Methods Of Measurement

Abstract The paper presents predicted use of research’ results to specify relations between volume of dust deposition and changes of its concentration in air. These were used to shape zones protecting against coal dust explosion. Methodology of research was presented, including methods of measurement of dust concentration as well as deposition. Measurements were taken in the Brzeszcze Mine within framework of MEZAP, co-financed by The National Centre for Research and Development (NCBR) and performed by the Institute of Mining Technology KOMAG, the Central Mining Institute (GIG) and the Coal Company PLC. The project enables performing of research related to measurements of volume of dust deposition as well as its concentration in air in protective zones in a number of mine workings in the Brzeszcze Mine. Developed model may be supportive tool in form of system located directly in protective zones or as operator tool warning about increasing hazard of coal dust explosion.

Sign in / Sign up

Export Citation Format

Share Document