SU1681016A1 - Method for ventilation of quarry - Google Patents

Abstract

The invention relates to mining protémé and is intended for ventilation of quarries. The purpose of the invention is to increase the ventilation efficiency by increasing the mobility of the ventilation process and increasing the initial power of convective currents (KP). Along the perimeter of the pit (K), heat sources (IT) are placed, the thermal radiation of which is directed to the surface, which limits the amount of ventilation. Thermal radiation is absorbed by the rocks of the bottom and sides, as a result of which they are heated. carrying out airing K; Thermal radiation from IT is directed to the side opposite to IT and to the bottom of K. During deep inversions, the surface limiting the ventilated volume is irradiated to obtain an adiabatic temperature distribution in the ventilation volume. After that, the board K is irradiated, upon irradiation of which KP is formed, which performs the breakdown of the inversion layer. Simultaneously with the irradiation, substances that increase the absorptive capacity of air, such as water or water vapor, are sprayed at the bottom. 3 h. n. f-ly, 3 ill. cl

Description

The invention relates to industrial sanitation, in particular to ventilation in the conduct of open pit mining, and is intended for artificial ventilation of quarries.

The purpose of the invention is to increase the ventilation efficiency by increasing the mobility of the ventilation process and increasing the initial power of convective flows.

FIG. 1 depicts a pit ventilation pattern; in fig. 2 - diagram of the ventilation of the quarry with deep inversions,

initial stage; in fig. 3 - the same, the final stage.

Along the perimeter of the pit, heat sources 1 are located that generate thermal radiation 2. Positions 3-5 indicate convective currents that are formed when exposed to thermal radiation.

The method of ventilation is carried out as follows.

Sources of heat 1 install around the perimeter of the pit side above the ventilated volume and direct the heat radiation 2 generated by the heat sources 1 to the surface limiting

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the volume of ventilation, i.e., the bottom and sides of the pit, located below the level of their location. In this case, the thermal radiation 2 is absorbed by the rocks of the bottom and sides. As a result of the heating of the rocks, a convective flow 3 is formed along the side of the pit, which aerates the pit. The heat radiation generated by the heat sources is directed to the pit wall opposite to the heat source.

In order to ventilate quarries at deep inversions of air temperatures, considerable energy is required. In such cases, it is impractical to destroy the temperature inversion in the entire volume of the pit.

In this case, the radiation 2 generated by the heat sources 1 is directed to the bottom and sides of the quarry below their level, i.e., to the entire surface limiting the amount of ventilation. Radiation 2 is absorbed by rocks of the bottom and sides, as a result of which they are heated, thus forming convective currents 4 along the board of the quarry in the volume of the pit below the level of the sources of heat 1. Due to the mixing of air in this volume and as a result of its heating, the inversion is destroyed before the adiabatic temperature distribution in the pit volume below the level of the sources of heat 1. At the same time, the air in the pit volume, located below the level of placement of heat sources 1, is isolated in the deepest part of the pit by inversion layers. After that, the radiation 2 generated by the heat sources 1 is directed aboard the quarry, i.e., only a part of the surface, limiting the amount of ventilation. Upon irradiation of the pit side, a convective flow 3 is formed, which breaks the inversion layer in the quarry, which causes the formation of a powerful upward flow of 5 lower air layers heated to adiabatic temperature distribution upon irradiation of the surfaces limiting the volume of the pit located below the level of heat sources.

Simultaneously with the irradiation of the surface, which limits the volume of ventilation in the lower part of the pit, substances that increase the air absorption capacity are sprayed at the bottom. Such substances can be water, water vapor and m, p.

Example 1. It is necessary to ventilate a quarry with a depth of 500 m with a slope angle of 45 °, with a bottom diameter of 200 m. Meteorological conditions: temperature inversion at -0.02 ° / m, air temperature at the bottom te -20 ° C. Ventilation time 2 h. At a height of 100 m from the bottom of the pit above

ventilated volume evenly have heat sources. This ensures the uniform heating of polluted air at a height in the volume located below the heat sources,

increases the ventilation capacity and increases the initial ventilation flow through the board of the quarry both by ventilating individual contaminated zones and the entire contaminated

volume. The total area of the radiating surface of heat sources is 180 m2 with a heating temperature of 1000 ° C, which creates a total thermal power of 150 mW. Heat radiation generated by heat sources is directed to the bottom of the pit. Part of the radiation, the passage through the polluted air, is absorbed by it, which causes it to heat up. The other part is absorbed by rocks that limit the volume of ventilation, and due to the heating of the bottom and sides of the quarry, located below the heat sources, convective currents are formed on the side of the pit, which aerates it. When the intensity of the irradiation of rocks is 50–70 W / m2, their heating temperature exceeds the ambient air temperature by 1–2 ° C. The pit’s volume located below the level of heat sources is aired by convective currents emanating from both heat sources and airborne career from the bottom of the career. Irradiation of the lower part of the quarry with a reduced total heat output provides airing for two hours.

Example 2. The initial data as in example 1, only at -0.06 ° k / m. Radiation generated by heat sources is directed to the bottom of the pit. At the same time

with irradiation of the pit bottom, air temperature is measured over the depth of the pit. Temperature control is carried out as follows. In several places, evenly distributed around the perimeter

a pit, on its board, temperature sensors are installed at a height, the readings of which are recorded on one console. Based on sensor readings in coordinates (altitude, temperature), a temperature line is constructed.

in height and compared with the adiabatic distribution line. The deviation of the line towards the inversion state indicates the presence of an inversion layer. More progressive methods of control are possible.

temperature, for example, optical, laser, sensing and so on. Calculations determined that as a result of irradiation of the pit bottom after 1 h in the 100-meter layer from the pit bottom, which is most contaminated, the inversion is destroyed to adiabatic. In this case, the lower layers of air, heated by irradiating the bottom of the pit, are isolated in the deepest part of the pit by inversion layers. Thereafter, the radiation generated by the heat sources is sent on board the pit. When the pit wall is irradiated, a convective flow is formed which breaks the inversion layer in the pit, which causes the formation of a powerful upward flow of lower layers of air heated by irradiating the bottom of the pit, which exists and develops due to gravitational forces. After 0.5 h, the volume of the pit below the heat sources will be ventilated.

Example The initial data as in examples 1 and 2. The relative humidity of the air in the bottom of the pit is 60%.

Radiation generated by heat sources is directed to the bottom of the pit. Simultaneously with the irradiation, in the lower part of the pit, at the bottom, substances that increase the absorption capacity of air are sprayed. Such substances can be water, water vapor, etc., for spraying of which sprinkling installations, installations creating water-air steam jets (NK-12KV-1M UMP-1, etc.) can be used.

To increase the air absorption capacity by 30% (which reduces the total ventilation time by 0.5 hours), the UMP-1 unit, for example, sprays 10 tons of water for 1 hour. As a result of spraying water, the relative humidity at the bottom of the pit rises to 80%, which increases the direct absorption of radiation. Thus, a greenhouse effect is created at the bottom of the pit.

effect, and increased air humidity further increases the Archimedean force. For carrying out the method, electric infrared emitters, gas infrared emitters or emitters on a different type of fuel can be used. So, as the electric emitters can be used lamps of the type and short circuit and others, tubular electric heaters TEN, etc. As the gas emitters - Mars GI-IV-1A, GIIV-2A, GBPidr.

Claims (4)

1. A way to ventilate a quarry, including the formation of convective currents using heat sources, which, in order to increase the efficiency of ventilating the quarry by increasing the mobility of the ventilation process and increasing the initial power of convective streams, install heat sources over the ventilated volume around the perimeter the pit walls direct the thermal radiation generated by heat sources to the surface, which limits the amount of ventilation. 2. Method pop. 1, characterized in that the thermal radiation generated by the heat sources is directed to the side opposite to the heat source and to the bottom of the quarry. 3. Method according to paragraphs. 1 and 2, characterized in that, in order to reduce the energy consumption for ventilation with deep inversions, the surface limiting the ventilation volume is irradiated until an adiabatic temperature distribution is obtained in the ventilation volume, after which the pit walls are irradiated. 4. Method pop. 1, characterized in that. that, simultaneously with the irradiation of the surface limiting the volume of ventilation, substances that increase the air absorption capacity are sprayed at the bottom of the pit. 2  LJ / // 7 // 7 // 7 // U / L Figure 1 # # / # Fiyo.2 / S