RU1809115C - Method to control gas emission by district retreating longwall heading without pillar stopping - Google Patents

Abstract

Usage: the development of gas beds. SUMMARY OF THE INVENTION: a mining field is being prepared for mining by twin drifts. The ventilation output of the next working column is carried out at a distance of 10-20 m from the unsupported conveyor working of the spent column, which is isolated from the existing workings by means of a jumper. A pipeline is connected through the jumper connected to the gas-suction unit, and part of the methane-air mixture is removed from the worked-out space of the worked-out column through the worked-out space of the worked-out column and an unsupported conveyor working in the direction of movement of the treatment face. 2 ill.

Description

FIELD: mining. SUBSTANCE: invention can be used in gas emission control in mining areas during aimless mining of coal seams. . The aim of the present invention is to prevent dangerous accumulations of methane at the interface of the mine working with ventilation (unsupported) during the aimless mining of excavation fields without maintaining previously worked lava mine workings (without additional drainage excavations) and eliminating the above-mentioned disadvantages.

The goal is achieved in that in the known method of controlling gas evolution, which includes preparing the excavation fields for mining by twin drifts; sequential dilution of harmful substances

according to the sources of their receipt; ventilation of the mine working area between the conveyor and ventilation drifts due to mine depression ;, removal of an air stream emanating from the mine working along the ventilation mine, guarded by pillars on both sides, in the direction of the mine face; MVS removal by drainage generation using GOU (centrifugal fan - CV), - the prevention of dangerous accumulations of methane at the interface of the production with ventilation (unsupported) is carried out due to the fact that part of the methane with a dangerous concentration is discharged into the worked out space of the mine excavation column in the worked-out space of the overlying waste mining site using own00

about

Yu

with

the methane lifting force and the presence of the aerodynamic connection of the worked out spaces, which is ensured by aimless mining of the excavation field (without leaving any artificial obstacles in the worked-out space - pillars of coal or rubble strips), the other part, together with No. B C, is discharged to the section of the treatment mine located in the inter-track range, due to the depression created by the GOU (CV), in the direction of the unsupported output and is diverted through it and the pipeline in isolation using the GOU (CV) within the limits of the worked mochno column in a direction coinciding with the direction of movement of the stope.

The fundamental difference between the proposed method of gas evolution control and the existing one is that the MVS is discharged within the extraction column in the direction of movement of the treatment face, and not in the opposite direction, while preventing dangerous accumulations of methane at the interface of the treatment production with ventilation (unsupported) due to the prevention of methane getting into the treatment space due to its free flow into the overlying waste space (which is ensured by the presence of aero ynamic communication goaf) and intense motion of the air flow on the cleaning portion to generate mezhshtrekovom entirely by the discharge voltage generated on the mated cleaning produce an unsupported depression SEI (CV).

Using the proposed method of managing the gas case it will allow to provide the following advantages compared to existing methods:

- mining of excavation fields without pillars of coal left in the worked out space, which eliminates coal losses and increases the reliability of endogenous fire safety;

- exclude the cost of additional drainage workings or preservation and maintenance of the latter in the worked out space. In turn, eliminating the need to maintain workings will reduce the time for end operations and thereby increase the load on the working face or free up additional numbers;

- ventilation of the excavation sections is carried out on the front bremsbergs (slopes), which can significantly reduce leakage through the worked out space and increase the fire safety of formations prone to spontaneous combustion;

- there is no need for flanking workings or for drilling large diameter wells from the surface, which is associated with large capital costs;

- the application of the method is practically not limited to mining conditions;

- provides high and reliable safety of mining operations;

- significantly improves the aerodynamic characteristics of ventilation networks, allows you to control the distribution of air over a wide range.

5 FIG. 1 shows a method for controlling gas evolution using a GOU; Figure 2 is a specific embodiment.

In the method shown in FIG. 1, at least. lava movement 1, that part of the conveyor

0 drift 2, which goes into the worked-out space 3, is fully or partially extinguished (which depends mainly on the strength of the host rocks and the mining and geological parameters of the excavation site) ..

5 With stable host rocks, the mine fastening is removed in whole or in part (due to production necessity and adopted mining technology), and for unstable

The surrounding rocks are reinforced by fires (not shown in the drawing to increase the efficiency of gas extraction).

At the end of lava 1 mining, it is isolated from the active workings by jumpers 4 and 5 in the zone of the security pillar 6. For the subsequent isolated withdrawal of the MVS from the unsupported mine 2 through the jumper 5, isolating the unsupported mine 2 from the existing

0 18, lay a rigid pipeline 7. In preparation for mining the excavation section 8, the ventilation output 9 is carried out 10-20 m from the unsupported output 2 and is interdependent, the distance is connected to it

failures 10.

In the same period, an electric machine chamber is equipped in which

GOU 11 and the inlet is connected to a rigid pipe

0 by piping 7. On the discharge side, a flexible (or rigid) discharge pipe 12 is connected. The end of the pipe 12, through which the MVS is discharged, is led into the mixing chamber 13 and is equipped with a bend allowing the MVS to exit the pipeline at an angle of 45 ° to the direction of the main valve tional, on-1 current. The mixing chamber 13 is a part of the working sewn by a continuous longitudinal partition of non-combustible

material. The length of the mixing chamber is 5-6 m, the width is at least 1.5 m. The entrance to and exit from the chamber is enclosed by metal bars. The excavation at the construction site of the chamber 5 m to both sides of it must be secured by non-combustible support. When methane is removed to the surface, measures are taken to ensure its safe release into the atmosphere.

The parameters of the isolated discharge of MB C to the mine workings or to the surface are determined by calculation.

The method is carried out as follows.

Fresh air from the central Bremsbergs (slopes) 18 enters the conveyor drift 19 to the net production .16. Part of the air (80-90%) enters the lava 16, the other part of the air, together with leaks 20, into the mined space 21, the methane 22 is pushed out from the lava 16. Under the influence of the mine shaft depression, own lifting force, air leaks 20, the presence of free the aerodynamic connection between the mined spaces 21 and 3, methane 22 is discharged into the overlying waste space, and due to the vacuum created by the depression, GOU 11 is directed to unsupported mine 2.

Part of the air entering the lava 16 is directed to the section of the mine workout 23 located in the inter-track whole 17 with the help of the depression created by GOU 11 and is diverted to the unsupported mine 2. Mixing with methane 22, formed MBC 24 with a dangerous concentration of methane is diverted in isolation by producing 2 and pipeline 7 using GOU 11 through the mixing chamber 13 (or directly to the day surface - not shown in the drawing) into a common downstream jet of a mine or excavation section.

Another part of the air, which is the difference between the amount of air entering the lava 16 and discharged from the unsupported mine 2 using GOU 11, with the allowable methane content due to the mine shaft depression, is diverted through the ventilation mine 9 to the common downstream stream of the excavation section and the shaft.

The air flow rate for ventilation of the section of the mine workings 23 is determined from the conditions for ensuring the concentration of methane at the interface of the lava 16 with unsupported production 2 not more than 1% by the formula

O. OT8 -

100 1Vp Kn S -Co

where QOTB is the required air flow rate of 5 discharged from unsupported production, m3 / min;

VP-gas emission from the worked out space (determined by the forecast or from the actual gas balance of an existing or similar extraction site), m3 / min;

 % permissible methane content in the air discharged to unsupported production;

5 Co - methane content in the stream of air entering the extraction section,%.

The resulting air flow rate is checked against the permissible air velocity.

0 The direction of air movement in the ventilation outlet 9 and the conveyor 19 may differ from that shown in FIG. 1, which depends on the order of ventilation of the treatment mine 16 (upward or downward ventilation) and the location of the mine with a common air stream.

PRI me R. In July 1990, an experimental testing of the proposed method for controlling gas evolution in the lava 4-7-17 was carried out at the Raspadsk mine of the USSR Unitary Enterprise, as shown in Fig. 2. The length of the lava was 120 m, the area of the treatment mine between the ventilation and unsupported 20 m, the column length 700. m, the thickness of coal packs 4-4.5 m, the angle of incidence of the formation 6-8 °, natural gas content 12-15 m3 / t, the strength of the host rocks 6-9 on the scale of prof. The arch is a cone, the management of the roof is a complete collapse.

In the process of mining the excavation column 1, the conveyor mine 2 was maintained for subsequent use in the mining of lava 3. However, during the mining period

5 by lava 3, due to increased mountain pressure, partial heaving of the soil and other natural factors, the preserved mine 2 could not be fully maintained and maintained in the section 560-700 m from the central slope 4, as a result of which the mine was completely crushed, and in the region 80 -560 m section was preserved only by 15-20% and amounted to 2-2.5 m2.

With this position of mining in

5 lava 3 received an average of 600-650 m3 / min of air, which almost all (90-95%), ventilating lava 3 was discharged through the vent. lation production of 8 with a methane content of 0.6-0.8%. Outgassing ate

the wet area was 5-6 m / min. The air almost did not pass through the purification section 9, as a result of which methane accumulated in this section and in conjunction with unsupported production 2, the concentration of which varied from 0.6% at the ventilation output of 8 to 2% or more at the end section 10 , which accordingly led to the triggering of automatic gas protection and frequent halting of coal mining operations.

Then, according to an example similar to Fig. 1, a GOU 5 (centrifugal fan VMTsG-7) was mounted, a pressure flexible ventilation pipe 6 was connected, and through a fault, it was brought into the mixing chamber 7, which was equipped with a common outlet stream of the extraction section.

Immediately after switching on GOU 5, the methane content at the outlet of the mixing chamber 7 increased to 2.5-3%, and at 15-20 m at point 11 from 0.5-0.6% to 1.0-1.5%, at the end section 10, it fell to 0.2-0.4% at an air flow rate of 280-300 m3 / min.

After 3 hours, after the aerodynamic parameters of the excavation section were stabilized, the following results were established: the incoming air into the lava 3 was 900-1000 m / min, 600-700 m3 / min with a methane content of 0.2-0 were discharged from the ventilation output 8 , 4%, in the area of the treatment mine 9 - 300-350 m / min with a methane content of 0.3-0.4%. At the outlet of the mixing chamber 7, the methane content was 0.4-0.6%, the total gas emission in the area was less than 5 m / min. In this mode, the extraction column was worked out over a length of 140 m. Moreover, over the entire period, the permissible methane content was never exceeded. An increase in the air flow in the area indicates a decrease in the total aerodynamic resistance of the ventilation network, which is very important when working out coal prone to spontaneous combustion. And although it was possible to significantly reduce the total air flow in the area, such experiments were not conducted.

The measures taken made it possible to significantly improve the gas situation and work on coal extraction in the regime without reducing production. As a result, the monthly advance of the treatment face amounted to 140 m or more than 90 thousand tons of coal.

FORMULA AND SECTION

A method of controlling gas evolution during the aimless mining of the excavation floor by pillars, including preparing the excavation floor for mining by twin drifts, ventilating the treatment mine section between the conveyor and ventilation drifts due to general shaft depression, and draining the air stream emanating from the treatment generation through the ventilation generation protected by pillars on both sides, the removal of the methane-air mixture using a gas suction unit, characterized in that, in order to prevent dangerous accumulations of methane on After cleaning the treatment plant with ventilation and unsupported production, the ventilation production of the next worked column is carried out at a distance of 10-20 m from the unsupported conveyor working of the worked column, which is isolated from the existing workings by means of a jumper, while a hard pipeline connected through the jumper is laid to the gas-suction unit, and part of the methane-air mixture is removed from the worked-out space of the worked-out column through the worked-out space of the spent column and the aforementioned unsupported conveyor mine in the direction of movement of the mine face, and the other part of the methane-air mixture is discharged through the ventilation mine of the worked column, both of which

The exhausted methane-air mixture is sent to a mixing chamber equipped in a production with an outgoing air stream.