scholarly journals Research on Dust Suppression Technology of Shotcrete Based on New Spray Equipment and Process Optimization

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Pengcheng Li ◽  
Zhi Zhou ◽  
Lianjun Chen ◽  
Guoming Liu ◽  
Wei Xiao
Keyword(s):  
Process Optimization ◽  
Dust Concentration ◽  
Wind Pressure ◽  
Respirable Dust ◽  
Dust Production ◽  
Dust Suppression ◽  
Small Section ◽  
Root Cause ◽  
Dust Sources ◽  
Dust Distribution

In order to reduce the dust hazard of shotcrete, the paper analyzed the mechanism of dust production from the perspective of various dust sources and developed the plunger-type wet spraying machinery and wet mixer which can be applied in the small-section tunnel for reducing dust on the root cause. The dust concentration between dry-mix shotcrete and wet-mix shotcrete was compared and analyzed. The results showed that the average total dust concentration and respirable dust concentration in the process of dry spraying were 99.4 mg/m3 and 52 mg/m3, respectively, while 9.8 mg/m3 and 4.08 mg/m3 in the wet-mix shotcrete process, and the average dust concentration decreased by more than 90% after applying new wet-mix shotcrete outfits. The clean zone of dust was divided according to the dust distribution. Finally, the dust suppression technology was optimized by using an accelerator and adjusting wind pressure and spraying angle. Results indicated that the application of the accelerator reduced the dust production efficiently; moreover, when the wind pressure was 0.2 MPa with 1 m spraying distance and 90° angle of spraying, the dust concentration and rebound reached the minimum.

scholarly journals Dust Concentration Changing Regularities and Dust Reduction Technology by Spray Negative Pressure in Fully Mechanized Mining Face

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lirong Wu ◽  
Hongxuan Chen ◽  
Jiamin Li ◽  
Shican Fu ◽  
Yuyan Zhuang
Keyword(s):  
Negative Pressure ◽  
Flow Characteristics ◽  
Dust Concentration ◽  
Inlet Section ◽  
Coal Face ◽  
Dust Suppression ◽  
Mining Face ◽  
Dust Distribution ◽  
Dust Reduction ◽  
Ventilation Velocity

The dust concentration changing regularities are the basis to take dust depression measures, which is greatly influenced by the airflow. In the software of FLUENT, the value of ventilation velocity is set as a constant, which cannot express the real ventilation. According to the flow characteristics of the sublayer and data from Nicholas’ experiment, the ventilation velocity distribution formula of sublayer in the inlet section of fully mechanized caving coal face is deduced. The boundary condition of velocity is given by UDF. Taking the 3top1110 fully mechanized caving coal face as an example, the dust distribution in the process of coal mining and hydraulic support shifting was studied. According to the dust-spray coupling experiment, three types of nozzle are chosen based on the efficiency of dust suppression. Combining the dust migration rule and the characteristics of nozzles, the negative pressure-secondary dust suppression devices of spray were developed and applied. And the above measures have lowered the dust concentration effectively.

Research on Dust Suppression of a Copper Mine Underground Middle Level Crushing Station

2013 ◽  
Vol 726-731 ◽  
pp. 907-912
Author(s):  
Zong Yin Duan
Keyword(s):  
High Pressure ◽  
Middle Level ◽  
Dust Concentration ◽  
Dust Suppression ◽  
Copper Mine ◽  
Safety And Health

With long-term mining and new orebodies proved to be in the deep, the dust concentration of each mine underground operation site increased sharply, which is a serious threat to safety and health of workers in workspace. In this paper, a high pressure spray technology was put forward for dedusting on a mine underground middle crushing station[, and achieved the desired dedusting effect.

scholarly journals Analisis Debu Respirable terhadap Masyarakat di Kawasan Perumahan Sekitar Lokasi Pabrik PT. Semen Padang

Jurnal Dampak ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
Vera Surtia Bachtiar ◽  
Puspa Safitri Sanggar Rani
Keyword(s):  
Air Quality ◽  
Negative Impact ◽  
Ambient Air ◽  
Quality Standard ◽  
Residential Area ◽  
Dust Concentration ◽  
Respirable Dust ◽  
Ambient Air Quality ◽  
Housing Complex ◽  
Ambient Air Quality Standard

The purpose of this research are to analysis air quality and dust impact to people that came from factory activities at residential area around factory location of PT. Semen Padang. Measuring of air quality conducted in 3 residential area that are Komplek RW 1, RT 3 Batu Gadang district, Perumnas Indarung RW. VII, and housing of UNAND Blok D Gadut, using Personal Dust Sampler. The result is respirable dust concentration at housing complex RW. 1 RT. 3 Batu Gadang district that is 0,33 mg/m, the Perumnas Indarung RW.VII that is 0,55 mg/m along with housing of UNAND Blok D Gadut that is 0,44 mg/m. Concentration of dust respirable at all are still below ambient air quality standard that exist on PP RI No. 41 Tahun 1999, 3 mg/m. Based on quesioner and puskesmas data proximate with use univariat analysis, negative impact who feels people are impact of health is eyes irritation disease and impact of environment especially community-owned material. Keywords: air quality, negative impact, residential area, respirable dust, PT. Semen Padang ABSTRAKPenelitian ini bermaksud untuk menganalisis kualitas udara dan dampak negatif yang dirasakan masyarakat dari debu yang berasal dari aktivitas pabrik di kawasan perumahan sekitar lokasi pabrik PT. Semen Padang. Pengukuran kualitas udara dilakukan di 3 kawasan perumahan yaitu komplek perumahan RW. 1 RT. 3 Kelurahan Batu Gadang, Perumnas Indarung RW. VII, dan Perumahan UNAND Blok D Gadut dengan menggunakan alat Personal Dust Sampler. Diperoleh hasil konsentrasi debu respirable pada komplek perumahan RT.3 RW.1 Kelurahan Batu Gadang sebesar 0,33 mg/m, pada Perumnas Indarung RW.VII sebesar 0,55 mg/m serta pada Perumahan UNAND Blok D Gadut sebesar 0,44 mg/m. Konsentrasi debu respirable pada ketiga lokasi masih berada di bawah ambang batas baku mutu udara di lingkungan, 3 mg/m. Berdasarkan kuesioner dan data puskesmas terdekat dengan menggunakan analisis univariat, dampak negatif yang dirasakan masyarakat adalah dampak terhadap kesehatan berupa penyakit iritasi mata dan dampak terhadap lingkungan khususnya pada kondisi material yang dimiliki masyarakat.Kata kunci: kualitas udara, dampak negatif, kawasan perumahan, debu respirable, PT. Semen Padang

New Respirable Dust Suppression Systems for Coal Mines

2007 ◽  
Vol 17 (3) ◽  
pp. 321-325 ◽  
Author(s):  
Yao-she XIE ◽  
Gao-xian FAN ◽  
Jun-wei DAI ◽  
Xiao-bo SONG
Keyword(s):  
Coal Mines ◽  
Respirable Dust ◽  
Dust Suppression ◽  
Suppression Systems

scholarly journals Exposure Assessment To Inhalable And Respirable Dust In The Post-Earthquake Construction Sites In The City Of L’aquila 

2019 ◽  
Author(s):  
Riccardo Mastrantonio ◽  
Angela Civisca ◽  
Tamara Lippolis ◽  
Enrica Inglese ◽  
Eugenio Siciliano ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Crystalline Silica ◽  
Dust Concentration ◽  
Respirable Dust ◽  
Construction Sites ◽  
Mean Values ◽  
Silica Dust ◽  
Work Tasks ◽  
Inhalable Dust ◽  
The City

Abstract Following an earthquake occurred in the middle Italy in 2009, the involved territory hosted in ten years thousands of construction sites. The aim of this study is to assess the chemical exposure of the construction workers involved in the reconstruction of the city. To assess the exposure we collected 91 air samples to quantify the occupational exposure to airborne dusts and free crystalline silica dusts. Six construction companies joined the study and hosted the air sampling activities. We identified 4 work tasks: bricklayer and similar; scaffolder and carpenter; manual demolition; other tasks. Personal air sampling was performed by using the SKC AirCheck XR5000 sample pumps. Respirable dust and respirable crystalline silica dusts were collected by using a GS-3 Cyclones and 25 mm PVC filters; inhalable dust was collected by using a I.O.M. sampler and 25 mm PVC filters. The analyses were carried out by using gravimetric determination. Sampling time varied from 4 to 8 hours. The geometric mean values of inhalable dust concentration for the work tasks was: 3,65 mg/m 3 for scaffolder and carpenter; 18,16 mg/m 3 for manual demolition workers; 8,76 mg/m 3 for bricklayer and similar; 6,33 mg/m 3 for other work tasks. The geometric mean values of respirable dust concentration for the work tasks was: 0,67 mg/m 3 for scaffolder and carpenter; 0,92 mg/m 3 for manual demolition workers; 0,72 mg/m 3 for bricklayer and similar; 0,45 mg/m 3 for other work tasks. About the Crystalline Free Silica dust exposure, the average concentration in mg/m 3 was: 0,0038 for manual demolition workers, 0,0057 for scaffolder and carpenter, 0,004 for bricklayer and similar, 0,0035 for other tasks. The comparison of the results shows that manual demolition workers are exposed to considerably high levels of inhalable dusts, exceeding the ACGIH TLV-TWA limit of 10 mg/m 3 . About the respirable dust concentration, none of the work tasks dust concentration exceeded the ACGIH TLV-TWA limit of 3 mg/m 3 . Measurements of crystalline silica dust have shown levels below the threshold limit value of 0,025 mg/m 3 . This is in line with the average concentrations of respirable dust.

scholarly journals Global Dust Budgets of the Magellanic Clouds

2012 ◽  
Vol 8 (S292) ◽  
pp. 267-270 ◽  
Author(s):  
Mikako Matsuura
Keyword(s):  
Life Cycle ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Agb Stars ◽  
Dust Production ◽  
Space Observatory ◽  
Great Opportunity ◽  
Dust Sources ◽  
Nearby Galaxies

AbstractWithin galaxies, gas and dust are constantly exchanged between stars and the interstellar medium (ISM). The life-cycle of gas and dust is the key to the evolution of galaxies. Despite its importance, it is has been very difficult to trace the life-cycle of gas and dust via observations. The Spitzer Space Telescope and Herschel Space Observatory have provided a great opportunity to study the life-cycle of the gas and dust in very nearby galaxies, the Magellanic Clouds. AGB stars are more important contributors to the dust budget in the Large Magellanic Cloud (LMC), while in the Small Magellanic Cloud (SMC), SNe are dominant. However, it seems that the current estimates of the total dust production from AGB stars is insufficient to account for dust present in the ISM. Other dust sources are needed, and supernovae are promising sources. Alternatively the time scale of dust lifetime itself needs some revisions, potentially because they could be unevenly distributed in the ISM or clumps.

scholarly journals Martian Self-Sustaining Dust Torus

1996 ◽  
Vol 150 ◽  
pp. 187-190 ◽  
Author(s):  
Sho Sasaki
Keyword(s):  
Solar Radiation ◽  
Radiation Pressure ◽  
Production Efficiency ◽  
Solar Radiation Pressure ◽  
Dust Particles ◽  
Theoretical Studies ◽  
Orbital Eccentricity ◽  
Dust Production ◽  
Upper Limit ◽  
Dust Sources

AbstractRecent theoretical studies show that orbits of circummartian dust particles are controlled by solar radiation pressure and the Martian oblateness. Smaller dust particles (< 22μm) with enhanced orbital eccentricity are quickly captured by Mars. We find that the collisions of ring particles with Phobos and Deimos are the most important dust sources. Erosion of Phobos should set the upper limit on the dust production efficiency controlling this self-sustaining mechanism, and then the ring dust abundance.

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