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Actuality of work and scientific significance
The goal and tasks of master's work
A summary of the master's work
Development of Ukraine's coal industry as a basis for national energy independence is impossible without addressing the important issues of occupational safety. Alarming is the statistic of occupational diseases of miners, as well as the consequences of sudden explosions pyleuglemetanovyh mixtures, leading to an annual social and economic losses (approximately 1 billion hryvnia). Especially important social problem is the fight against dust in the coal industry. One of the most common occupational diseases of miners are respiratory dust etiology: pneumoconiosis, chronic bronchitis, bronchial asthma, chronic rinofaringolaringit and others. The treatment of these diseases is an urgent task of preventive medicine, and their prevention – an important task of service safety of the coal enterprises. Study of the problem involved in domestic and foreign scientists [1–13]. However, a number of issues remain unexplored, and this is due to the relevance of the chosen topic.
The purpose of master's thesis is to study the dust suppression for the development of evidence–based interventions to normalize the conditions for dust factor. In this paper we solve the problem:
In the current situation to achieve a substantial reduction of occupational diseases of miners is possible with a corresponding decrease particulate air pollution in mines in all processes of dust formation by selecting the optimum number of nozzles and their hydraulic and geometric parameters. Using the new development of coal industry enterprises will significantly reduce the risk of occupational diseases in miners.
Integrated dust removal mine air is implemented in three, to some extent interrelated areas: reducing dust, reducing pylepostupleniya (junction formed dust in suspension) and cleaning the air of a soaring dust.
Moistening of coal contributes to adhesion–cohesion forces between the surfaces of dust particles and the formation of these large aggregates, rapidly deposited from the air by the force of gravity. Established that the increase in humidity by 1–3% of coal reduces dust by 75–80%. With humidity over 12% of coal dust formation is virtually absent.
To improve the wettability of coal during its pre–moistened used surface–active agents (surfactants). Surfactant molecules adsorbed on the surface of liquid films and thereby reduce the surface tension of water and increase wetting ability of it due to the adsorption of surfactant molecules on the surface of dust particles.
In addition to pre–wetting the coal seam in the lava apply dust suppression measures and dust control air through irrigation.
The essence of the dust control spraying is that the interaction of liquid droplets with a particle of dust is its wetting, capture drop and the resulting deposition of the unit – a particle of dust – the water.
For dust control air flow curtain found the greatest application: water, air / water (pnevmogidrooroshenie), mist with water–air ejectors.
Effective dust control, which includes both cleaning dust–laden air and rock mass irrigation water is achieved using cylindrical and conical water–air ejectors. The principle of water–air ejector (Pic. 1) lies in the fact that due to the dilution created by the water torch nozzle is sucked dust–laden air, forming a dispersed shlamovidnuyu water mixture, which, in turn, sent to suppress dust. Water–air ejectors are used, inter alia, for dust control during shifting sections mechanized system.
On the principle of ejection is also based on dust control loading and transfer points of coal through its irrigation under cover using cone atomizers.
Mine named Mikhail Kalinin was built by the Institute Dongiproshaht and put into operation in 1961 with a design capacity of 1200 tons of coal per year. At present, the installed capacity of the mine 400 thousand tons of coal a year.
The field of mine named. Kalinin is located in south–eastern part of south wing Kalmius–Donets Basin Toretskoy–Makeyevka coal–bearing area and is located in north–eastern city of Donetsk. In the administrative division of a planned withdrawal of the mountain mine is located in the Kalinin, Kiev, Voroshilov district of the city of Donetsk and Chervonogvardeyskom district Makiivka Donetsk region.
The dimensions of a mine field along the strike – 8,0 km down–dip – 4,5 km.
Mine is classified as extremely dangerous to sudden outbursts of coal and gas–hazardous coal dust explosion. All coal seams are not prone to spontaneous combustion. Reservoir Depth 1285m (h10)
The angle of dip within the mine field ranges from 15 to 27 degrees. Airing mine done by a combined scheme with two main fans suction method. Group dustiness layer VI
To prevent the selection and spread of dust in the cleansing slaughter should be applied:
For dust control air jet emanating from the lava in the mines, where there is swelling of wall rocks, apply mist curtains with a reduced liquid flow rate. Consumption of liquid mist curtains – 0.05 liters per 1m3 of passing air at a pressure of 0,3–0,4 MPa.
Curtains for dust control air flow set at a maximum distance of 20m from the windows of lava in the direction of air movement.
Sprinklers mist curtains are installed so that the section making it completely blocked torches sprayed liquid, as shown in animation.
Per 500 m 3 / min flowing air to be set at a veil. When the actual amount of air passing by the group vent a pass equal to 1130 m 3 / min should be set two mist curtain at a distance of 3–5m apart.
Hangings must act at all times coal mining or any other process, accompanied by dust emission. Inclusion of the water supply must be carried when starting the combine.
In NIIGD a laboratory setup (Pic. 2), a model of the network of mine workings with a horizontal and an inclined part of the permanent section (80 * 80 sm), made in a scale of 1 to 4 of original size shaft mining them. Bazhanov. With the special dust feeder (pos. 1 Pic. 2), construction NIIGD pre–prepared at the mill, coal dust with a given dispersion of particles fed into the associated flow of air to the fan (pos.8 Fig. 2) inside the installation, where using a node dosing, it was created by mixing the given concentration with the calculated amount of air.
The volume concentration was determined using standard devices such as "EIA–5. After working regimes run dust alternately include water jets, and compared the effectiveness of dust suppression with serial sprays, such as UVPK Krasnoarmeyskiy plant dust suppression. In this case, sprinklers size was tested on three schemes.
A complex of studies have shown that the greatest effect gidroobespylivanie is at the direction of flames sprayed water on the course of the ventilation flow, and the least effect when the torches are directed against the flow of air.
To regulate, depending on the loading conveyor, the direction and amount of drip fed finely concentrated layer tested a new device that is protected by a patent of Ukraine. Full–scale testing in the six mines of Donbass have shown high efficiency of the new jets and confirmed the feasibility of mass production applications. Conclusion.
Package of measures to prevent diseases dust bronchitis and pneumoconiosis includes socio–legal, medical and organizational–technical measures and means of dust control and dust control of mine air.
Development of new methods and ways of dealing with dust, and the application of modern technologies to reduce the dust emission in the mines and protect miners from occupational diseases such as pneumoconiosis, bronchitis, as well as many others associated with damage to the respiratory tract.
Analysis of the results shows that the greatest effect gidroobespylivanie occurs at the direction of flames sprayed water on the course of the ventilation flow, and the least effect when the torches are directed against the flow of air.
The master's work hasn’t been finished yet while this author’s abstract was written. The final version is planned on December 2010 – January 2012. The whole text and materials on the master's work or data concerning this topic are available from the author or the scientific adviser after defending the thesis master's degree.