RU2787763C1 - Method for ventilation of extraction area when reverse order of mining of mineral seams - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention relates to the mining industry and can be used for ventilation of excavation areas (panels and blocks) of mines. The method includes the supply of fresh air to the extraction drift, the removal of exhaust air from the extraction area, the preliminary calculation of the minimum and maximum thermal depressions h _{e min} and h _{e max} that occur between the extraction and ventilation drifts h _e2 and h _e3 and between the extraction and conveyor drifts h _e1, respectively. A portable ventilation bulkhead is installed in the excavation drift behind a pair of through worked out chambers following the dead-end chamber, and during the subsequent mining of the excavation section in the excavation drift, it is moved behind the through worked out chambers following the dead-end chamber, and portable ventilation jumpers are installed in the through worked out chambers located in front of the first pair of end-to-end worked chambers. The number of insulated through exhaust chambers is determined depending on the air distribution, taking into account the effect of thermal depressions that occur during normal ventilation, taking into account the content of gases released from the surface of mine workings, and in the event of a fire. Air is supplied by a local ventilation fan through the main pipeline to the dead-end chamber and through an additional pipeline located in front of the dead-end chamber, in the excavation roadway, in the through exhaust chamber located immediately behind the dead-end chamber, or in the ventilation roadway. The exhaust air is removed through the excavation drift, through the exhaust chamber located behind the dead-end chamber, into the ventilation drift or through wells drilled in the pillar between the dead-end chamber and the adjacent through exhaust chamber located behind the dead-end chamber.

EFFECT: invention provides the possibility of using the method for ventilation of excavation areas located both along the fall and rise of the formation, and in ensuring the safety and efficiency of ventilation, including in the event of a fire in the conveyor drift, by creating additional conditions for the removal of polluted air and its exclusion recirculation, as well as the ingress of air containing methane into the conveyor roadway in which the miners are located.

2 cl, 5 dwg

Description

The invention relates to the mining industry and can be used for ventilation of excavation areas (panels and blocks) of mines.

A known method of ventilating a dead-end mine or mine, including the supply of air through a through mine working, the intake of part of the air by a local ventilation fan and its supply through a ventilation pipeline into a dead-end mine working. Part of the air flow passing through the local ventilation fan is directed through the ventilation tee to an additional pipeline located in the through mine working, equipped at the outlet with a confuser with a variable outlet section, with the help of the confuser an air stream is formed, which removes the ambient and polluted air outgoing due to the ejection effect. from a dead-end mine working in the direction of air flow in the through mine working, while the length of the additional pipeline is determined depending on the geometric dimensions of the through and dead-end mine workings necessary to ventilate the air volume and the characteristics of the local ventilation fan (patent RU No. 2648788, publ. 28.03 .2018).

Disadvantages of the known method:

1. In the air emanating from the dead end, methane (which is lighter than air) will accumulate near the roof in the upper part of the mine workings, therefore, the air emanating from the additional pipeline will remove part of the air that does not contain methane further into the excavation drift.

2. The method does not take into account the air distribution between other mine workings and in the mining area as a whole, and therefore it is impossible to determine the further entry of the methane-air mixture and polluted air into the area where people are located.

A known method of ventilating a dead end working, including the supply of fresh air to the bottom hole of the working through the injection pipeline and the removal of dust and gas through the ventilation stack connected to the dust extraction fan of the combine, through wells previously drilled in the pillar into the adjacent worked out working. When the combine moves, the flexible pipeline is pulled out of the well, ensuring the continuous removal of polluted air from the working zone of the mine to the previously passed one. At the moments when new wells are exposed by the combine, the flexible pipeline is passed into these opened wells, while the previously used ones are laid with rock (Zemskov A.N., Kondrashev P.I., Travnikova L.G. Natural gases of potash deposits and measures to combat them. Perm, 2008. pp. 323-325).

Disadvantages of the known method:

1. Mandatory presence and functioning of the dust cleaning system. In case of low efficiency of dust cleaning or deterioration of the dust cleaning system, the pipeline that discharges air from the working area may be clogged with dust, as a result of which the air will be stopped from the working area and the mining process will stop.

2. In the method, a dead-end development is considered separately, outside the entire ventilation system of the mining area. In this case, it is impossible to determine in which direction the air flowing through the pipeline will begin to flow and to exclude the option of reversing the contaminated jet back into the chamber, for example, due to the action of natural draft (thermal depression) acting between the ventilation and transport (excavation) drifts.

3. The need to place two pipelines along the entire length of the dead-end development, which complicates the movement of self-propelled vehicles.

4. Increase in the number of pipeline ventilation units used.

5. Mandatory availability and use of self-propelled drilling rigs.

и максимальной

величин разностей высотных отметок между местом отработки рабочих камер и местом выхода воздуха из выемочного штрека в уклон ΔH _min и ΔH _max , соответственно, при этом в процессе увеличения количества отработанных камер и при достижении величины тепловой депрессии, равной h _{e min} , перемычку демонтируют, а при достижении величины тепловой депрессии, равной h _{e max} , перемычку устанавливают вновь (патент RU №2529459, опубл. 27.09.2014). There is a known method of ventilating the extraction area in the reverse order of mining of mineral layers located along the fall of the reservoir, in which fresh air is supplied to the extraction drift, a ventilation jumper is installed on the extraction drift behind the working chambers, the exhaust air from which is removed through ventilation failures into the conveyor-ventilation drift , preliminarily calculate the minimum and maximum thermal depressions h _{e min} and h _{e max} , respectively, arising between the excavation roadway and ventilation hitches, as well as between the excavation and buried conveyor-ventilation roadways, as functions of the minimum

and maximum

values of differences in elevations between the place of working chambers mining and the place of air outlet from the extraction drift into the slope Δ H _min and Δ H _max , respectively, while in the process of increasing the number of worked chambers and upon reaching the thermal depression value equal to h _{e min} , the jumper is dismantled , and upon reaching the value of thermal depression, equal to h _{e max} , the jumper is installed again (patent RU No. 2529459, publ. 27.09.2014).

Disadvantages of the known method:

1. The method is applicable only for ventilation of excavation areas located along the dip of the formation.

2. Removal of polluted air is carried out through a conveyor (conveyor-ventilation) drift. In connection with the presence of people in this drift, there is a problem associated with the supply of polluted (including methane-containing) air.

3. When calculating the minimum ( h _{e min} ) and maximum ( h _{e max} ) thermal depressions, only the angle of inclination of the excavation area relative to the horizon is taken into account and the angle of inclination of the worked out and mined chambers relative to the axis of the excavation drift is not taken into account.

4. The calculation of thermal depressions that occur between the excavation roadway and ventilation hitches, between the excavation roadway and the buried conveyor roadway is made only taking into account changes in air temperature, without taking into account changes in its density during the "dilution" of methane released from the surface of mine workings.

5. The shaft ventilation bulkhead is installed only to prevent the passage of air into the conveyor drift, which is not required when fresh air is supplied to it, i.e. when it is not used for its intended purpose - as a ventilation.

The closest method of the same purpose to the claimed invention in terms of the combination of features is the method of ventilating the extraction area in the reverse order of mining the mineral layers located along the dip of the formation, including the supply of fresh air to the extraction drift, the removal of exhaust air through ventilation failures into the conveyor-ventilation drift, preliminary calculation of the minimum and maximum thermal depressions h _{e min} and h _{e max} , arising between the excavation roadway and ventilation hitches h _e2 and h _e3 and between the excavation and buried conveyor-ventilation roadways h _e1 , respectively. Calculations of each of the values h _e2 and h _e3 are carried out taking into account the angle γ of the inclination of the chambers relative to the axis of the excavation drift, according to the results of the calculations, the areas of mining of the excavation drift are selected, for which ventilation is required, and the conveyor-ventilation drift is driven parallel or at an angle to the axis of the excavation drift , while the injection of fresh air into the working chambers is carried out using local ventilation fans, made with the possibility of changing the performance as the chambers are worked out, depending on the maximum h _{e max} and minimum h _{e min} values of h _e2 and h _e3 , respectively, as well as at a dead end penetration of the chamber and during its through ventilation depending on the angle γ (patent RU No. 2569647, publ. 27.11.2015). This method is taken as a prototype.

The disadvantages of the known method, taken as a prototype:

1. The method is applicable only for ventilation of excavation areas located along the dip of the formation.

2. The use of a conveyor road as a ventilation road causes danger to people in it, due to the ingress of polluted air, including methane-containing air.

3. It is necessary to use a local ventilation fan made with the possibility of changing the performance (mainly a frequency drive), which significantly affects the price due to the need to use an explosion-proof drive.

4. The calculation of thermal depressions that occur between the excavation roadway and ventilation hitches, between the excavation roadway and the buried conveyor roadway is made only taking into account changes in air temperature, without taking into account changes in its density during the "dilution" of methane released from the surface of mine workings.

The objective of the invention is the development of a safe and effective method of ventilating the excavation area in the reverse order of mining the mineral layers, located both in the fall and in the rise of the layer.

The problem was solved due to the fact that in a known way

ventilation of the excavation area during the reverse order of mining of mineral layers, including the supply of fresh air to the excavation drift, the removal of exhaust air from the excavation area, preliminary calculation of the minimum and maximum thermal depressionsh _{e min} andh _{e max} arising between the excavation and ventilation driftsh _e2 andh _e3 and between the excavation and conveyor driftsh _e1 accordingly, according to the results of calculations, ventilation modes are selected, fresh air is injected into the working chamber using a local ventilation fan, according to the invention, a portable ventilation jumper is installed in the excavation road behind a pair of through-hole exhausted chambers following the dead-end chamber, and during subsequent mining of the excavation area in the excavation the drift is moved behind the through exhaust chambers following the dead end chamber, and portable ventilation jumpers are installed in the through exhaust chambers located in front of the first pair of through exhaust chambers, while the number of insulated through exhaust chambers is determined depending on the air distribution, taking into account the effect of thermal depressions that occur during normal ventilation mode, taking into account the content of gases released from the surface of mine workings, and in the event of a fire, air is supplied by a local ventilation fan through the main pipeline water into the dead end chamber and through an additional pipeline located in front of the dead end chamber, in the excavation roadway, in the through exhausted chamber located immediately after the dead end chamber, or in the ventilation roadway, the exhaust air is removed through the excavation roadway, through the exhausted chamber located immediately behind the dead end chamber , into the ventilation drift, or through wells drilled in the pillar between the dead-end chamber and the adjacent through-hole exhausted chamber located behind the dead-end chamber.

At the same time, the number, diameter of wells and the distance between them, as well as the diameter of the main and additional pipelines are determined by the results of calculations of air distribution between mine workings, taking into account the effect of thermal depressions that occur during normal ventilation, taking into account the concentration of gases released from the surface of mine workings, and when the occurrence of a fire.

The claimed method is applicable for ventilation of excavation areas located both along the fall and rise of the formation and allows in both cases to ensure efficiency and safety in the event of a fire in the conveyor drift by creating additional conditions for the removal of polluted air and the exclusion of its recirculation.

The essence of the invention is illustrated by the following figures.

In FIG. 1 shows a scheme of ventilation of the excavation area by the inventive method at the initial stage of mining the excavation area.

In FIG. 2 shows the scheme of ventilation of the excavation area by the claimed method with the number of worked chambers more than 2 pairs (in one direction and the other).

In FIG. 3 shows the method of supplying air to a dead-end opening and discharging air from an additional pipeline to the area in front of the dead-end chamber.

In FIG. 4 shows a method for supplying air to a dead-end mine and discharging air from an additional pipeline into a through exhaust chamber.

In FIG. 5 shows the method of supplying air to a dead-end mine and discharging air from an additional pipeline into a ventilation drift.

In FIG. marked:

1 - fresh air;

2 – excavation drift;

3 – local ventilation fan;

4 - main pipeline;

5 - slaughter;

6 - dead end chamber;

7 - polluted air;

8 - slope;

9 - conveyor drift;

10 - ventilation drift;

11 - a through chamber, located immediately behind the dead-end chamber 6;

12 - portable ventilation jumper;

13 – end-to-end exhaust chamber;

14 - additional pipeline;

15 - rear sight;

16 - well.

The method is applicable for ventilation of excavation areas located both along the fall and rise of the formation and is carried out as follows.

When ventilating the excavation area, fresh air 1 enters the excavation drift 2 (Fig. 1). Part of the air with the help of a local ventilation fan 3 through the main pipeline 4 is supplied to the face 5 of the dead-end chamber 6. After the face 5 is ventilated, the polluted air 7 again enters the excavation drift 2.

Also, fresh air 1 enters along the slope 8 into the conveyor drift 9 and further into the excavation drift 2.

To direct polluted air 7 into the ventilation drift 10 on the way of its movement in the excavation drift 2, behind the through exhausted chambers 11 located immediately behind the dead end chamber 6, a portable ventilation jumper 12 is installed. chamber 11 following the dead end chamber 6 (Fig. 2). When the number of waste chambers is more than 2 pairs (in one direction and the other), portable ventilation jumpers 12 are installed in through waste chambers 13 located in front of the first pair of through waste chambers.

Due to this, additional conditions are created for removing air from the conveyor roadway 9 into the ventilation roadway 10.

To create additional conditions for removing polluted air 7 and preventing its recirculation from the local ventilation fan 3, in addition to the main pipeline 4, an additional pipeline 14 comes out, which “throws” air either into the excavation drift 2 into the area in front of the dead-end chamber 6 (Fig. 3), or into the through worked chamber 11 located immediately behind the dead end chamber 6 (Fig. 4), or through it into the ventilation drift 10 (Fig. 5), or through the wells 16 drilled in the pillar 15 between the dead end chamber 6 and the through worked out chamber 11, located immediately behind the dead end chamber 6. In the presence of wells 16 for polluted air 7, the shortest path of movement appears through the through exhausted chamber 11 into the ventilation drift 10. Due to the absence of mechanical obstacles in the direction of movement of polluted air 7, the possibility of dust clogging of wells 16 is excluded. it is not required to place two pipelines in a dead-end development.

To improve the efficiency and safety of the ventilation method, the predicted value of thermal depressions is preliminarily calculatedh _{e min} andh _{e max} arising between the excavation and ventilation driftsh _e2 andh _e3 and between the excavation and conveyor driftsh _e1,respectively, in normal and emergency (in the event of a fire in the conveyor lane 9) ventilation modes.

When the excavation section is located along the rise of the formation, the thermal depressions h _e1 , h _e2 and h _e3 that occur between the excavation 2 and ventilation 10 drifts, as well as between the excavation 2 and conveyor 9 drifts contribute to ventilation (directed according to the required direction of air movement), however, in the event of a fire in the conveyor drift 9, the thermal depression h _e1 will change its direction to the opposite and increase several times, as a result of which the flue gases will begin to flow into the dead end chamber 6. In this regard, a portable ventilation jumper 12 is installed in the excavation drift 2 behind the through exhaust chambers 11, located immediately behind the dead end chamber 6.

Ventilation of the excavation area is carried out according to the same method, with the exception of the installation of portable ventilation lintels 12 in through-hole waste chambers 13 (Fig. 2). Jumpers 12 are installed in through exhaust chambers 13, if as a result of calculations it is established that, in their absence, flue gases will enter the dead-end chamber 6.

The values of thermal depressions h _e1 , h _e2 and h _e3 are calculated depending on the temperature, air pressure and the difference in elevation between the beginning and end of the mine workings. If it is possible to determine the amount and composition of gases released from the reservoir, their density is taken into account in the calculations, on which the values of h _e1 , h _e2 and h _e3 depend.

The performance of the local ventilation fan 3 is selected based on the ability to supply air to the dead-end mine 6 in the required volume and ensure the release of air from the additional pipeline 14, which can prevent the recirculation of polluted air 7 to the local ventilation fan 3 by placing an additional pipeline 14 in front of the dead-end chamber 6 in the excavation roadway 2 (Fig. 3), directing an air stream from it into a through exhaust chamber located immediately behind the dead-end chamber 6 (Fig. 4), or into a ventilation drift 10 (Fig. 5).

The location of portable ventilation lintels 12 is determined on the basis of the calculation for air distribution between mine workings.

The number, diameter of wells 16 and the distance between them, as well as the possibility of their application is determined by calculations.

The calculation is made depending on the calculated value of thermal depressions h _e1 , h _e2 and h _e3 .

If it is impossible to carry out calculations that determine the value of h _e1 , h _e2 and h _e3 portable ventilation jumpers 12 are installed in the indicated places throughout the entire process of mining the excavation area.

Modeling of air distribution in real conditions of mines showed that when using the proposed method of ventilation, polluted air is removed into the ventilation drift at a lower performance of the local ventilation fan and there is no recirculation of polluted air to a fresh stream. When modeling an emergency, it was found that when using the proposed method, flue gases will be removed into the ventilation drift without getting into the dead end chamber (where the miners are located).

Claims (2)

1. A method for ventilating an extraction area during the reverse order of mining of mineral layers, including supplying fresh air to the extraction drift, removing exhaust air from the extraction area, preliminary calculation of the minimum and maximum thermal depressions h _{e min} and h _{e max} arising between the extraction and ventilation drifts h _e2 and h _e3 and between the excavation and conveyor drifts h _e1 , respectively, according to the results of calculations, ventilation modes are selected, fresh air is injected into the working chamber using a local ventilation fan, characterized in that a portable ventilation bridge is installed in the excavation drift behind a pair of through exhaust chambers following the dead end chamber, and during the subsequent mining of the excavation area in the excavation drift, they are moved behind the through worked out chambers following the dead end chamber, and portable ventilation bridges are installed in the through worked out chambers located in front of the first th pair of through exhaust chambers, while the number of insulated through exhaust chambers is determined depending on the air distribution, taking into account the effect of thermal depressions that occur during normal ventilation, taking into account the content of gases released from the surface of mine workings, and in the event of a fire, air is supplied by a local ventilation fan through the main pipeline to the dead end chamber and through the additional pipeline located in front of the dead end chamber, in the excavation roadway, in the through exhausted chamber located immediately behind the dead end chamber, or in the ventilation roadway, the exhaust air is removed through the excavation roadway, through the exhausted chamber located immediately behind dead-end chamber, into the ventilation drift, or through wells drilled in the pillar between the dead-end chamber and the adjacent through-hole exhausted chamber located behind the dead-end chamber. 2. The method according to claim 1, characterized in that the number, diameter of wells and the distance between them, as well as the diameter of the main and additional pipelines are determined by the results of calculations of air distribution between mine workings, taking into account the effect of thermal depressions that occur during normal ventilation, taking into account the concentration gases released from the surface of mine workings, and in the event of a fire.

Images