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Faculty: Geotehnology and management of operations
Speciality: Safety of labour activity
Nowadays, because of extraction of coal deposits in great depth and under trying geological conditions, the complicated layout of mine workings has been formed. Under this layout, the ventilation objects are not supplied by calculated air consumption. Ventilation of mine influences greatly upon labor safety of workers, as well as it needs high power inputs of the main ventilators. Therefore it is essential to establish the reasons for ventilation worsening in order to elaborate the steps on efficiency increase of mine ventilation, economy of power and reduction of air waste.
Make an analysis of the present ventilation layout of mine workings and air distribution in workings of mine “Kurakhovskaya”, to study the project of deposits revision, to study the heat conditions, the mine ventilation stability. As well as to work out some steps on ventilation improvement for perspective period, ventilation stability, ventilation problems reduction and reduction of expenses for power, normalization of heat conditions in faces.
The mine “Kurakhovskaya” forms a part of state enterprise “Selidovugol”. Put into operation in 1940.
Productive capacity is 400,000 tons a year. Annual plan for 2009 is 355 tons a year. At present the system of transport is being reconstructed. The mine is also preparing for increasing output of coal to 1000 ton a year. The main factors suppressing the increase of coal output are: conducting of the stope works at the considerable depth and on the suggestive distance from the main transport workings and airways; complexity of mine working ventilation, situated below level – 475 meters.
Opening of the pit “Kurakhovskaja” has been made by tree sloping shafts, driven in the coal-bed l21 and by two sloping shafts, driven in the coal-bed k8 (southern part of the mine). Except the sloping workings the pit was opened by a vertical ventilation shaft and a prospecting shaft №1.
A method of preparing of the pit is panel. The order of base service is descending. The bedding is flat. Coal seam isn’t disposed to spontaneous combustion. The system of extraction applied-long chimneys along bedding.
The top possible depth of extraction in previous beds - 840 meters. Current depth - 320m and 790 m.
Total water inflow in mine is 800m3/h.
At present mining is being done in beds k8 and l2?. Stope works in mine are conducted with the help of mechanized complex КД-90. Preparatory workings are driven with the help of tunnel machine in КСП-21 and KSP-22. Wheeled and conveyer transport is used in the mine. Transport of men, load and materials is carried out by wheeled transport. Transport of rock from the 16th northern lava of bed K is carried out by conveyer SP – 250; in site conveyer workings – СП 202, conveyor belt 1L – 80; in all pit- by conveyor belts 1L-100, 1L-100Y, 1L-100K, 2LY-100, 3L-100Y, 2 LY-120V.
The mine ‘Kurakhovskaya’ is not gassed, but it is dangerous because of coal dust explosion and carbon dioxide isolation.
For aeration of mine workings the ventilation plants of main aeration are used. They are established in the vertical ventilation shaft and the pit shaft №1. The ventilation plant in the vertical aeration shaft equipped by two fans of the same kind VC- 31, 5 M2 with rotation frequency of working wheels 600 speeds a minute and engine with a power 800 kilowatt. The plant was put into operation in 1999, the last setting up took place in November 2006.
The ventilation plant in the pit-shaft №1 equipped with two fans of the same type VC-31, 5, with rotation frequency of working wheels 600speed a minute and engine with a power 800 kilowatt. The plant was put into operation in 1984; the last setting up took place in November 2006.
A mine ventilation layout is flanking, ventilation mode- sucking. The mine workings are ventilated by two VGP: ventilation plant of pit-shaft №1 equipped with a fan VC-31, 5: and ventilation plant of the vertical aeration shaft, equipped with a fan VC-31, 5 М2. Air quantity received in mine for ventilation – 119.0 m3/s.
As a result of analysis of air condition the following main disadvantages have been stated: lack of air for the objects of aeration in mine, improper condition of the ventilation plants, insufficient cross size of mine workings, undetached ventilation of some preparatory workings.
For analysis of heat conditions parameters, as well as depression quantity of natural draught the data of temperature survey were applied. At the moment of survey the air temperature in some main air supplying and ventilation workings wasn’t exceeding the permissible standard according to Safety Rules (p. 8.2.2).
The exceptions were the following workings, where exceeding the permissible standards was observed (Safety Rules p. 8.2.2.): men’s entry of northern pit slope-26,2° C, sloping cross-cut 16 of northern lava, bed k8-26,4 °C; the 16th northern conveyer drift of coal-bed k8-29, 4 °C; the 16th northern lava of coal-bed k8 – 29, 8 °C; the 16th northern ventilation drift of coal- bed k8-31,2 °C; ventilation cross-cut-30,6 °C; sloping conveyer cross-cut level 555m-30,4 °C; haulage cross-cut level 565m-31,2 °C; northern load entry of the coal-seam coal-bed k8– 26,4 °C; the 16th southern conveyer drift of the bed k8– 29,6 °C; the 16th southern lava of the coal-bed k8-32,6 °C; the 16th southern ventilation drift of the coal-bed k8– 33,0 °C; the 15th northern conveyer drift – 30,6 °C; northern pit slope-28,8 °C; slope №7of the coal-seam k8- 26,4 °C. The temperature of air in workings of the preparatory faces made: in the14 th southern conveyer drift of the coal-bed l21- 28, 8 °C; in the 14th ventilation drift of the coal-bed l21-29, 2 °C.
Relative humidity of air made; in the main air supplying workings - 88-92%; in stope and preparatory workings - 88-96%; in the main workings with outgoing air-blast-92-98%.
It is significant, that in blind pits: in the 14th southern conveyer drift of the coal-bed l21 the temperature made 28,2 °C at the beginning and at the end of the working, humidity- 925; in haulage cross-cut on the level 550m. – 24,2 °C, humidity-86%; in men’s entry of the northern slope of the coal-bed k8 the temperature at the beginning of the working made 16,6 °C, at the end – 24,6 °C, humidity – 92%. In the 16th northern lava of the coal-bed k8 these parameters accordingly the following: 29,4 °C and 29,8 °C, humidity made 94%, but in southern lava of the coal-bed k8 the temperature at the beginning of the working made 29,6 °C , at the end – 32,6 °C, humidity – 98%.
So, the heat conditions in the mine do not correspond to the requirements of the Safety Rules.
The immediate steps ensuring an increase of efficiency of mine ventilation, as well as the economy of electric power and unproductive air waste reduction for the next period are:
Annual economy of electric power under these circumstances will make 473 040 kwh a year.
The analysis of ventilation in the working mine ‘Kurakhovskaya’ of state enterprise ‘Selidovugol’ has been carried out, the lack of supply of the mine with necessary quantity of air has been stated as well as unsatisfying character of aerodynamic parameters of mine workings, unpractical use of the fresh air, substantial air leakage through ventilation constructions in mine workings and on the surface. The measures for normalization of climate conditions in the mine workings have been ordered as well as improving the mine aeration for the present.
At present the work for the magister degree is being carried out, in January 2010. For farther information ask the author Pshenichnyh Natalya and teacher Stukalo Vitaly.