CN107387060A - Method for guiding fully-mechanized coal mining machine to mine coal from top - Google Patents

Abstract

The invention discloses a method for guiding top coal mining of a fully mechanized mining machine, which is suitable for preventing damage to the fully mechanized mining machine from roof hard rock. It includes the following steps: (1) embedding the radiometer in the non-working position of the drill bit of the fully mechanized mining machine; Avoid mutual interference between the fully mechanized mining machine drill bit and the radiometer; (2) Before the fully mechanized mining machine works, preset the alarm rock density threshold; (3) When the fully mechanized mining machine works, the fully mechanized mining machine drill bit excavates the top coal seam, and at the same time The radiometer detects the geological density in the working area in front of the drill bit of the fully mechanized mining machine. When the detected geological density is greater than the alarm rock density threshold or changes suddenly, an alarm will be prompted. This method can realize that when the fully mechanized mining machine cuts coal at the junction of coal and rock on the roof, it can send an alarm especially when it is close to the rock, preventing the fully mechanized mining machine from blindly breaking the rock and causing damage to the fully mechanized mining machine equipment.

Description

A Method for Guiding Top Coal Mining of Fully Mechanized Mining Machine

technical field

The invention relates to a method for cutting coal seams by fully mechanized mining machines in coal mines and avoiding damage to the fully mechanized mining machines caused by rocks, which belongs to the coal mining technology and is especially suitable for roof areas with large differences in coal and rock densities.

Background technique

When the fully mechanized mining machine cuts the coal seam, it will inevitably touch the hard roof overlying rock at the coal-rock junction, which may easily cause damage to the head of the fully mechanized mining machine, and even affect the stability of the roof overlying rock, resulting in potential safety hazards.

When the coal seam is excavated, a certain thickness of top coal is always reserved in the roof area to prevent damage to the stability of the overlying rock caused by the fully mechanized mining machine and damage to the fully mechanized mining machine itself. Coal seams are affected by layer slip structures and other geological structures, which will lead to uneven thickness of coal seams and non-horizontal extension directions. At present, fully mechanized miners excavating coal seams are operated manually, mainly relying on the naked eye to identify the coal-rock junction to determine the boundary of coal seam mining, so as to prevent equipment damage caused by poor contact between the machine head and hard overlying rock, but this is easy to cause inaccurate identification and strongly relies on Subjective experience guides fully mechanized mining machine excavation.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a method for instructing a fully mechanized miner to mine top coal, by measuring the radioactive density of the roof area, and then guiding the mining of the fully mechanized miner according to the change of rock density in the roof area , to solve the problem that the head of the fully mechanized mining machine mistakenly cuts the hard overlying rock because of the inaccurate identification of the coal-rock boundary by the human eye.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the present invention is:

A method for instructing top-coal mining of a fully mechanized mining machine, comprising the steps of:

(1) Embed the radiometer in the non-working position of the drill bit of the fully mechanized mining machine to avoid mutual influence between the drill bit of the fully mechanized mining machine and the radiometer;

(2) Before the fully mechanized mining machine works, preset the alarm rock density threshold;

(3) When the fully mechanized mining machine is working, the drill bit of the fully mechanized mining machine excavates the top coal seam, and at the same time the radiometer detects the geological density of the working area in front of the fully mechanized mining machine bit. When the detected geological density is greater than the alarm rock density threshold or occurs When there is a sudden change, an alarm prompt will be given.

In the actual working engineering of fully mechanized mining machines, there are top coal seams and roof overlying rocks with large density differences in the roof area. When we detect that the geological density in the working area in front of the fully mechanized mining machine drill bit suddenly increases or exceeds the alarm rock density, it will be It can be considered that the roof is overlying rock in front, so as to prevent the accident of accidental cutting of the roof overlying rock by the fully mechanized mining machine blindly cutting the roof area.

Preferably, the radiometer keeps in contact with the top coal seam during work, and the detection direction is along the drill bit of the fully mechanized mining machine; so that the radiometer can measure the top coal seam as far as possible, and keep the measured value corresponding to the fully mechanized mining machine The direction of the drill bit, that is, the construction object of the drill bit of the fully mechanized mining machine can be predicted in advance.

Specifically, the radiometer includes a gamma source, a lead screen, a detector, a detection circuit and a housing, the gamma source, the lead screen, the detector and the detection circuit are all arranged in the housing, and the lead screen is arranged between the gamma source and the detection circuit. Between the detectors, a cylindrical structure with a tapered front end is formed as a whole; when working, the electrons radiated from the gamma source to the top coal seam have a Compton effect, forming a primary scattered Compton electron, and the detector is used to receive the primary scattering Compton electrons, the detection circuit converts the once-scattered Compton electrons into electrical pulses and amplifies them, and calculates the gamma ray intensity of the once-scattered Compton electrons based on the amplified electrical pulses to obtain the geological density; lead screen It is used to isolate the gamma source and the detector to prevent the electrons radiated by the gamma source from being directly received by the detector.

Preferably, the gamma source is a medium-energy gamma source, which radiates electrons to the surroundings during operation, and the detection major axis is 60-100 cm (preferably 80 cm), and the short axis is 15-35 cm (preferably 25 cm). The gamma source energy is about 1MeV. Theoretically, the radiation range of the gamma source is an ellipsoid range. Since the bottom of the top coal seam is directly in contact with the air and the radioactivity decays sharply, it can only detect half of the ellipsoid range, that is, the half ellipsoid on the side of the top coal seam that is in contact with the air. The geological density of the area is detected; in fact, in order to prevent the blind cutting of the roof area by the fully mechanized mining machine, it is very reasonable to reserve about ten centimeters of top coal residue, which just meets our preferred detection area.

Preferably, in order to prevent the electrons radiated by the gamma source from being directly received by the probe, considering the energy of the above-mentioned gamma source, the thickness of the lead screen is designed to be 10-20 cm, and the design of this size comprehensively considers the gamma source. The detection range and the overall size of the radiometer, although the thicker the lead screen, the better the effect, but the installation of a large-scale detector will be more troublesome, and it is difficult to ensure that it will not conflict with the drill bit of the fully mechanized mining machine.

Preferably, the alarm rock density threshold is αρ _max , ρ _max is the maximum density of the top coal seam, α is the evaluation weight, and generally α≥1. Generally, for a large continuous area, the density of the top coal seam is relatively stable, and we can even directly judge the coal content or rock content according to the density value; therefore, for a large continuous area, we generally only need to predict Set the alarm rock density in turn, considering the dramatic density difference between the top coal seam and the roof overlying rock, generally set the density slightly larger than the top coal seam as the alarm rock density threshold, when the density detected by the radiometer is greater than the alarm rock density, it indicates the detection area There is roof overlying rock in the interior, which may cause damage to the fully mechanized mining machine, and an alarm is issued to remind the fully mechanized mining machine to stop cutting this area.

Beneficial effects: the method for guiding the top-coal mining of fully-mechanized mining machines provided by the present invention has the following advantages compared with the prior art: 1. Since there is an obvious density difference between the coal seam and the rock formation in the coal-measure strata, radioactive density measurement is an efficient method, The detection range is small, the precision is high, and the equipment is light and simple; 2. The early warning value is set, and the distance between the machine head and the roof overburden is judged according to the program, so as to guide the fully mechanized mining machine to cut the coal seam, and avoid equipment damage caused by unclear identification with the naked eye , Improve work efficiency; 3. This technology can also be applied to iron ore or non-metallic ore and other mines with large differences in ore density to achieve safe and economical mining.

Description of drawings

Fig. 1 is the construction layout schematic diagram of radiometer of the present invention;

Fig. 2 is the structural representation of radiometer;

The figure includes: 1-gamma source, 2-lead screen, 3-detector, 4-detection circuit, 5-probe, 6-computer, 7-top coal seam, 8-roof overburden, 9-bottom coal, 10-base plate, 11-roadway.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

A method for guiding top-coal mining of fully mechanized mining machines, using gamma single source spacing density logging and Compton effect to measure rock density within the spatial distribution range of rays, so as to determine the coal content of the top coal and guide the mining of fully mechanized mining machines Top coal; comprising the steps of:

Step 1: Design the radiometer

The radiometer includes a gamma source, a lead screen, a detector, a detection circuit and a casing, the gamma source, the lead screen, the detector and the detection circuit are all arranged in the casing, and the lead screen is arranged between the gamma source and the detector, The overall form is a cylindrical structure with a conical contraction at the front end; when working, the electrons radiated from the gamma source to the top coal seam have a Compton effect, forming primary scattered Compton electrons, and the detector is used to receive the primary scattered Compton electrons. The detection circuit converts the once-scattered Compton electrons into electric pulses and amplifies them. Based on the amplified electrical pulses, the computer calculates the gamma-ray intensity of the once-scattered Compton electrons to obtain the geological density; the lead screen is used to isolate the gamma ray The gamma source and the detector avoid electrons radiated by the gamma source to be received by the detector directly.

The gamma source is a medium-energy gamma source of about 1 MeV, which radiates electrons to the surroundings when it works, and the long axis of detection is 80cm, and the short axis is 20cm; in order to avoid the gamma rays emitted by the gamma source from directly radiating to the detector The thickness of the design lead screen is 15 cm.

Step 2: Install the radiometer

The radiometer is embedded in the non-working position of the drill bit of the fully mechanized mining machine to avoid mutual influence between the drill bit of the fully mechanized mining machine and the radiometer; the radiometer keeps in contact with the top coal seam when it is working, and the direction of detection is along the direction of the drill bit of the fully mechanized mining machine; In operation, the radiometer is capable of detecting half an ellipsoid.

Step 3: Preset alarm rock density threshold

Before the fully mechanized miner works, the preset alarm rock density threshold is αρ _max , ρ _max is the maximum density of the top coal seam, and α is the evaluation weight, which is taken as 1 in this case.

Step 4: The radiometer monitors the geological density of the working area in front of the drill bit of the fully mechanized mining machine in real time

When the fully mechanized mining machine is working, the drill bit of the fully mechanized mining machine excavates the top coal seam, and at the same time the radiometer detects the geological density of the working area in front of the fully mechanized mining machine bit. The gamma source scatters with the top coal seam through the Compton effect. Receive a scattered Compton electron and record its gamma ray intensity to obtain the density of the measurement area.

As the fully mechanized mining machine digs deeper into the top coal seam, when there is a certain volume of roof overlying rock in the detection ellipse area, the intensity of the primary scattered gamma rays received by the probe decreases instantly, and the rock density in the space increases; The detected geological density and the alarm rock density threshold determine whether to continue cutting the coal seam: When the detected geological density is greater than the alarm rock density threshold, the staff is reminded not to continue cutting the coal seam upwards, otherwise the roof overburden will be cut by mistake.

Or when a sudden change occurs, an alarm prompt will be given.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (6)

1. a method for instructing fully mechanized mining machine top-coal mining, is characterized in that: comprise the steps: (1) Embed the radiometer in the non-working position of the drill bit of the fully mechanized mining machine to avoid mutual influence between the drill bit of the fully mechanized mining machine and the radiometer; (2) Before the fully mechanized mining machine works, preset the alarm rock density threshold; (3) When the fully mechanized mining machine is working, the drill bit of the fully mechanized mining machine excavates the top coal seam, and at the same time the radiometer detects the geological density of the working area in front of the fully mechanized mining machine bit. When the detected geological density is greater than the alarm rock density threshold or occurs When there is a sudden change, an alarm prompt will be given. 2. The method for instructing top-coal mining of a fully mechanized mining machine according to claim 1, characterized in that: the radiometer keeps in contact with the top coal seam during operation, and the direction of detection is along the drill bit of the fully mechanized mining machine. 3. the top-coal mining method of instructing fully mechanized mining machine according to claim 1, is characterized in that: said radiometer comprises gamma source, lead screen, detector, detection circuit and housing, gamma source, lead screen, Both the detector and the detection circuit are set in the casing, and the lead screen is set between the gamma source and the detector, forming a cylindrical structure with a tapered front end as a whole; when working, the electrons radiated from the gamma source to the top coal seam generate health. The Compton effect forms primary scattered Compton electrons, the detector is used to receive the primary scattered Compton electrons, the detection circuit converts the primary scattered Compton electrons into electrical pulses and amplifies them, and calculates the value based on the amplified electrical pulses The gamma ray intensity of the once-scattered Compton electrons is used to obtain the geological density; the lead screen is used to isolate the gamma source and the detector, preventing the electrons radiated by the gamma source from being directly received by the detector. 4. The method for instructing top-coal mining of fully mechanized miners according to claim 3, characterized in that: the gamma source is a medium-energy gamma source, which radiates electrons to the surroundings when it works, and the long axis of detection is 60-100 cm, The short axis is 15-35cm. 5. The method for guiding top-coal mining of fully mechanized mining machines according to claim 3, characterized in that: the thickness of the lead screen is 10-20 cm. 6. The method for instructing top-coal mining of fully mechanized miners according to claim 1, characterized in that: the alarm rock density threshold is αρ _max , ρ _max is the maximum density of the top coal seam, and α is the evaluation weight.