Intelligent Working Face Scraper Conveyor Straight Line Positioning and Pushing Technology

Abstract This study provides a new permanent magnetic eddy current drive system to solve the ener-gy-saving drive problem of the scraper conveyor working under bad conditions, including overload startup, severe abrasion and pollution. Considering the practical conveying conditions of the scraper chain on a fully mechanised coal mining face, this study creates a mathematical model for the new permanent magnetic eddy current drive system of the scraper conveyor based on its characteristics and indicates the motion characteristics of the scraper chain driven by two wheels. This study verifies the model accuracy with a pre-startup technology depending on the scraper conveyor on the No. 12318 working face of the 8th coal mine in the West No. 1 mining area of the Pansan Coal Mine of the Huainan Mining Group. According to the results, the motion acceleration of the scraper chain based on the new permanent magnetic eddy current drive is lower than that of the scraper chain with a hydraulic coupler under the same running condition and load during startup and acceleration and declines by approximately 14.7%. Consequently, this can decline the startup impact due to the serious abrasion and frequent overload of the scraper chain working under bad conditions.

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Friction and wear of the middle trough in scraper conveyors

Industrial Lubrication and Tribology ◽

10.1108/ilt-08-2017-0231 ◽

2018 ◽

Vol 70 (6) ◽

pp. 1072-1077 ◽

Cited By ~ 2

Author(s):

Junxia Li ◽

Shaowei Liang

Keyword(s):

Friction And Wear ◽

Economic Benefits ◽

Social Significance ◽

Treatment Technology ◽

Coking Coal ◽

Content Type ◽

Theoretical Support ◽

Working Face ◽

Scraper Conveyor ◽

Industrial Adjustment

Purpose The study of the friction law and wear characteristics of the middle trough material can better select the appropriate material for the scraper conveyor of fully mechanized working face and provide theoretical support for the wear-resistant treatment technology. Design/methodology/approach This paper investigated friction and wear of the middle trough in a scraper conveyor under different media. Lignite, coking coal and anthracite were selected media, and middle trough wear was maximum for anthracite and minimum for lignite, with coking coal being intermediate. Findings Wear increased linearly with increasing load nonlinearly with increasing sliding speed. Middle trough wear also increased with increasing media granularity up to approximately 0.4 mm (40 mesh), but had little effect beyond that. Originality/value It can provide a reference for the scraper conveyor running resistance. At the same time, it has great social significance and economic benefits for the safe, green and efficient coal mine industrial adjustment, etc.

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A Study of Fractal Deep-Hole Blasting and Its Induced Stress Behavior of Hard Roof Strata in Bayangaole Coal Mine, China

Advances in Civil Engineering ◽

10.1155/2019/9504101 ◽

2019 ◽

Vol 2019 ◽

pp. 1-14 ◽

Cited By ~ 6

Author(s):

Jianping Zuo ◽

Zhengdai Li ◽

Shankun Zhao ◽

Yunqian Jiang ◽

Haiyan Liu ◽

...

Keyword(s):

Fractal Dimension ◽

Coal Mine ◽

Fractal Dimensions ◽

Simulation Software ◽

Deep Hole ◽

Hard Roof ◽

Working Face ◽

Straight Line ◽

Line Design ◽

Roof Strata

The phenomena of strong pressure occurrences have been observed many times in the #311103 working face of the Bayangaole Coal Mine. Deep-hole blasting measures were used to relieve the pressure in order to decrease the danger levels of these strong pressure occurrences on the working face. The blasting layouts proposed in this study differed from the conventional blasting layouts of a “straight-line” design by instead utilizing “triangular-fractal” and “deep-shallow-fractal” for the purpose of successfully driving the explosive efficiency and enlarging the roof-blasting range. The fractal dimension of the “triangular-fractal” blasting layout was calculated as 1.1274. The fractal dimension of the “deep-shallow-fractal” was calculated to be 1.556. The fractal dimensions of both improved layouts were found to be larger than that of the “straight-line” blasting layout (1.0). In addition, the Mises stress evolution and the changed trend of the effective stress and strain of the observation points around the hole of the three layouts are analyzed and compared by LS-DYNA numerical simulation software. The results indicated that the “deep-shallow-fractal” blasting layout had the most effective blasting effects, followed by the “triangular-fractal” blasting layout. It was determined that the traditional “straight-linear” blasting layout had the least effective blasting effects of the three examined layouts. In summary, the implementations of the improved fractal blasting layouts in this study were found to be conducive to the enhancement of the blasting effects.

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Microdensitometer—computer correlation analysis of ultrastructural periodicity

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081024 ◽

1978 ◽

Vol 36 (2) ◽

pp. 32-33

Author(s):

D.R. Ensor ◽

C.G. Jensen ◽

J.A. Fillery ◽

R.J.K. Baker

Keyword(s):

Correlation Analysis ◽

Background Noise ◽

Computer Control ◽

Optical Diffraction ◽

Screw Thread ◽

Straight Line ◽

Computer Storage ◽

Correlation Process ◽

Electron Microscope Image ◽

Fixed Beam

Because periodicity is a major indicator of structural organisation numerous methods have been devised to demonstrate periodicity masked by background “noise” in the electron microscope image (e.g. photographic image reinforcement, Markham et al, 1964; optical diffraction techniques, Horne, 1977; McIntosh,1974). Computer correlation analysis of a densitometer tracing provides another means of minimising "noise". The correlation process uncovers periodic information by cancelling random elements. The technique is easily executed, the results are readily interpreted and the computer removes tedium, lends accuracy and assists in impartiality.A scanning densitometer was adapted to allow computer control of the scan and to give direct computer storage of the data. A photographic transparency of the image to be scanned is mounted on a stage coupled directly to an accurate screw thread driven by a stepping motor. The stage is moved so that the fixed beam of the densitometer (which is directed normal to the transparency) traces a straight line along the structure of interest in the image.

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Freeze fracture imaging and computer simulation of liposome structure: Membrane geometry and defects

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076834 ◽

1983 ◽

Vol 41 ◽

pp. 646-647

Author(s):

Joseph A. Zasadzinski

Keyword(s):

Liquid Crystalline ◽

Freeze Fracture ◽

Continuum Theory ◽

Closed Surfaces ◽

Straight Line ◽

Low Weight ◽

Concentric Spheres ◽

Membrane Geometry ◽

Dupin Cyclides ◽

Limiting Case

At low weight fractions, many surfactant and biological amphiphiles form dispersions of lamellar liquid crystalline liposomes in water. Amphiphile molecules tend to align themselves in parallel bilayers which are free to bend. Bilayers must form closed surfaces to separate hydrophobic and hydrophilic domains completely. Continuum theory of liquid crystals requires that the constant spacing of bilayer surfaces be maintained except at singularities of no more than line extent. Maxwell demonstrated that only two types of closed surfaces can satisfy this constraint: concentric spheres and Dupin cyclides. Dupin cyclides (Figure 1) are parallel closed surfaces which have a conjugate ellipse (r1) and hyperbola (r2) as singularities in the bilayer spacing. Any straight line drawn from a point on the ellipse to a point on the hyperbola is normal to every surface it intersects (broken lines in Figure 1). A simple example, and limiting case, is a family of concentric tori (Figure 1b).To distinguish between the allowable arrangements, freeze fracture TEM micrographs of representative biological (L-α phosphotidylcholine: L-α PC) and surfactant (sodium heptylnonyl benzenesulfonate: SHBS)liposomes are compared to mathematically derived sections of Dupin cyclides and concentric spheres.

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Human Enamel Replication

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090889 ◽

1976 ◽

Vol 34 ◽

pp. 180-181

Author(s):

Norman L. Dockum ◽

John G. Dockum

Keyword(s):

Organic Matrix ◽

Human Teeth ◽

Human Enamel ◽

Straight Line ◽

Ultrastructural Characteristics

Ultrastructural characteristics of fractured human enamel and acid-etched enamel were compared using acetate replicas shadowed with platinum and palladium. Shadowed replications of acid-etched surfaces were also obtained by the same method.Enamel from human teeth has a rod structure within which there are crystals of hydroxyapatite contained within a structureless organic matrix composed of keratin. The rods which run at right angles from the dentino-enamel junction are considered to run in a straight line perpendicular to the perimeter of the enamel, however, in many areas these enamel rods overlap, interlacing and intertwining with one another.

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