The Determination of Quartz Percentages in Coal Dust Emission during the Anthracite Coal Cutting by Mechanical Cutting Tool

2014 ◽  
pp. 665-676
Author(s):  
Phan Quang Van ◽  
Carsten Drebenstedt
Keyword(s):  
Cutting Tool ◽  
Coal Dust ◽  
Dust Emission ◽  
Coal Cutting ◽  
Anthracite Coal ◽  
Mechanical Cutting

scholarly journals Potential of dust emission resources using small wind tunnel and GIS: case study of Bakhtegan playa, Iran

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Siroos Karimzadeh ◽  
Mohammad Mehdi Taghizadeh
Keyword(s):  
Wind Tunnel ◽  
Present Model ◽  
Low Cost ◽  
Dust Emission ◽  
High Potential ◽  
Wind Speeds ◽  
Desert Areas ◽  
Medium Potential

Abstract Determination of the high potential of dust emission is a requisite affair in the management of dusts emission and as well as avoiding its risks. Wind tunnel is among the most important approaches in the study of areas having high potential in emitting dusts. Extensive dried playas and desert areas require the making of low-cost, simple, and car-portable tunnels capable of presenting comparable data of various areas even supposing not having enough precision in the model of real wind motion. In this study, we first engaged in making a car-portable tunnel with a primarily semicircle section of 38 cm height, 50 cm diameter, and 110 cm length. A fan and key appliance with the ability to change speed were used along with a simple transformer launched with car battery. Then, concentration of the pm10 dusts was measured in the various wind speeds of 1, 2.5, 4, 5.5, and 7 m/s by the help of anemometer and digital equipments. The study of Bakhtegan playa was done, as the methodology of handling with this tunnel, in 35 positions, and zoning of the results was performed via ArcGIS software. Depending on the destructibility of the shell by wind, the areas under study were categorized as low potential (34%), medium potential (37%), and high potential (29%) in emitting dusts. The results of zoning spotted the high-potential areas on the map. The usage of small tunnels, as in the present model, may be applied in order for the low-cost and fast studies of vast areas to the purpose of playas management.

Deployment of Electro-Mechanical Cutting Tool on Intelligent Coiled Tubing for Horizontal Wells

2017 ◽  
Author(s):  
Ricardo de Paula Carvalho ◽  
Robledo Wakin Barros ◽  
Felipe Toloi Gastaldo ◽  
Alexandre Amorim ◽  
Jean Narlon Moreira ◽  
...  
Keyword(s):  
Cutting Tool ◽  
Horizontal Wells ◽  
Coiled Tubing ◽  
Mechanical Cutting

scholarly journals Determination of miscalibrated polarization angles from observed cosmic microwave background and foreground EB power spectra: Application to partial-sky observation

2020 ◽  
Vol 2020 (6) ◽  
Author(s):  
Yuto Minami
Keyword(s):  
Power Spectrum ◽  
Cosmic Microwave Background ◽  
Simultaneous Determination ◽  
Unbiased Estimate ◽  
Dust Emission ◽  
Power Spectra ◽  
Microwave Background ◽  
The Public ◽  
Polarization Power

Abstract We study a strategy to determine miscalibrated polarization angles of cosmic microwave background (CMB) experiments using the observed $EB$ polarization power spectra of CMB and Galactic foreground emission. We apply the methodology of Y. Minami et al. (Prog. Theor. Exp. Phys. 2019, 083E02, 2019), developed for full-sky observations to ground-based experiments such as Simons Observatory. We take into account the $E$-to-$B$ leakage and $\ell$-to-$\ell$ covariance due to partial sky coverage using the public code NaMaster. We show that our method yields an unbiased estimate of miscalibrated angles. Our method also enables simultaneous determination of miscalibrated angles and the intrinsic $EB$ power spectrum of polarized dust emission when the latter is proportional to $\sqrt{C_\ell^{EE}C_\ell^{BB}}$ and $C_\ell^{BB}$ is proportional to $C_\ell^{EE}$.

scholarly journals Wind tunnel investigation on the dust emission characteristics of high moisture coal piles

2020 ◽  
Vol 145 ◽  
pp. 02019
Author(s):  
Ningning Hong ◽  
Shitao Peng ◽  
Hongxin Zhao ◽  
Ning Su
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Moisture Content ◽  
Coal Dust ◽  
Dust Emission ◽  
Wind Tunnel Test ◽  
High Moisture Content ◽  
High Moisture ◽  
Emission Behavior ◽  
The Relationship

With the increasing requirements of environmental protection, a large number of new wet dust suppression technologies are used in the port in recent years, such as watering at the bottom of the Dumper Shed, etc. So the moisture content of coal is more than 10% often appear. Relevant studies show that the amount of dust from coal (conventional moisture content) pile is directly proportional to the high power of wind speed. But studies on high moisture content coal are rare. In this study, Wind tunnel test was carried out to study the dust emission behavior of coal with high moisture content (13.7% and 14.3%). The results show that the relationship between coal dust and wind speed tends to be linear under high moisture content. The study can provide a basis research for the estimation of coal dust emission in port.

Side Mill Tool Profiling for Generation of Helical Surfaces Determined by Reverse Engineering

2014 ◽  
Vol 657 ◽  
pp. 28-32
Author(s):  
Camelia Popa ◽  
Virgil Gabriel Teodor ◽  
Nicuşor Baroiu ◽  
Nicolae Oancea
Keyword(s):  
Reverse Engineering ◽  
Cutting Tool ◽  
Special Problem ◽  
Helical Surface ◽  
Surface Type ◽  
Axial Section ◽  
Compressor Rotor ◽  
Constant Pitch ◽  
Measuring Machine

The compressor rotors usually are helical surfaces with constant pitch and are composed crossing profiles. Frequently, for repair operations occurs the reconstruction necessity for one or both of the worms, drive and driven, from the helical compressors gear. The helical composed surface of rotor flank is generated usually with side mill. The knowledge of worm shape can not be made from geometrical conditions. In these conditions it is necessary to determine the flank form by actual measuring the crossing profiles of these parts. So, the theoretical helical surface of the worm is being substituted by an assembly of helical lines which together with crossing profiles forms points cloud resulted from measuring leads to a polyhedral expression of the flank rotor. Numerically, this surface type is expressed by a coordinate array which shows its discrete image. The profiling of cutting tool bounded by a revolution surface reciprocally enveloping with the substitutive surface of the helical one represents a special problem. In this paper is proposed an algorithm for polyhedral expression of the helical surface previously determined by reverse engineering methods and an algorithm for the determination of the specific enveloping condition at contact with a discrete surface.It is presented an example for a compressor rotor measured on a 3D measuring machine, the algorithm for the transformation of the gathered points cloud in a surface with polyhedral expression. Given these conditions there were determined the enveloping condition and the axial section of the side mill.

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