Mining long-distance material pneumatic conveying system and control method

Abstract

The invention belongs to the technical field of mine material conveying, and particularly relates to a mine long-distance material pneumatic conveying system and a control method. The conveying system comprises a booster pump set and a conveying unit. One booster pump set is arranged between every two conveying units, the conveying units and the booster pump sets are connected to form a material pneumatic conveying chain, one booster pump set is arranged at the material receiving end of the material pneumatic conveying chain, and the discharging end of the material pneumatic conveying chain is an outlet of the conveying unit; according to the conveying system, the booster pump set is arranged between every two conveying units, a continuous pneumatic conveying chain is formed, the airflow pressure in a pipeline is effectively maintained, and the problems of material deposition and blockage caused by too long conveying distance or too large height difference are solved; according to the control method, accurate, efficient and safe control over the mining pneumatic conveying system is achieved in a graded response and multi-component cooperation mode.

Description

Technical Field

[0001] This invention belongs to the field of mining material conveying technology, specifically relating to a long-distance pneumatic material conveying system and control method for mining. Background Technology

[0002] Currently, during coal mine construction, bulk materials are typically transported underground from vertical or inclined shafts using mine cars. This process involves long transport distances and discontinuous material supply, leading to slow construction progress. Furthermore, the rapid movement of mine cars generates dust, resulting in persistent high concentrations of dust within the mine, impacting worker health and operational safety. Pneumatic conveying technology, as a conventional means of transporting bulk materials, has received widespread attention in mining, building materials, and chemical industries. However, traditional pneumatic conveying systems primarily employ straight-pipe structures. In vertical shafts, long-distance transport due to significant height differences causes a continuous increase in the kinetic energy of the bulk materials within the pipes, exacerbating pipe damage. Moreover, the impact of the bulk materials at the pipe outlet is severe, easily causing dust storms underground. In inclined shafts, long-distance transport over considerable distances leads to pipe blockages. Summary of the Invention

[0003] This invention addresses the problems of reduced pipe life in vertical shafts and blockages in inclined shafts caused by pneumatic conveying systems with straight pipe structures.

[0004] The present invention provides the following technical solution: a long-distance pneumatic material conveying system for mining, comprising a booster pump set and a conveying unit; there is a booster pump set between every two conveying units, the conveying units and the booster pump set are connected to form a material pneumatic conveying chain, there is a booster pump set at the receiving end of the material pneumatic conveying chain, and the discharge end of the material pneumatic conveying chain is the outlet of the conveying unit; Sensor groups and composite vibrating screens are distributed at intervals along the conveying direction on the conveying unit; each sensor group includes a material level sensor, an exhaust valve, a piezoelectric pressure sensor, and a differential pressure sensor; the sensor groups interact with the central control unit to form a closed-loop control.

[0005] Furthermore, the conveying unit includes a front straight pipe, a gradually expanding pipe, a corrugated pipe, a gradually contracting pipe, and a rear straight pipe connected in sequence along the material conveying direction.

[0006] Furthermore, the booster pump unit includes a negative pressure suction pipeline, a booster air pipeline, and a mixing component. The mixing component has a material channel with the same conveying direction as the conveying unit. One end of the material channel is connected to the booster air pipeline, and the other end of the material channel is connected to the conveying unit. The negative pressure suction pipeline is connected to the material channel from the side. When the high-speed airflow ejected from the booster air pipeline passes through the material channel, it forms a siphon effect to draw the material into the mixing component.

[0007] Furthermore, the booster air circuit includes an oil-water separator, a booster pump, and a high-pressure air pipe connected sequentially along the airflow direction; the negative pressure suction line includes a material conveying hose.

[0008] Furthermore, the mixing component includes a dust filter and a hopper, the cavities of which are connected to form a material channel. The dust filter is connected to a negative pressure suction pipeline and a pressurized air pipeline, and the hopper is connected to a conveying unit.

[0009] Furthermore, the expansion angle of the diffuser is 8°~12°; the contraction angle of the converging tube is 5°~8°.

[0010] Furthermore, the corrugated pipe is composed of alternating straight pipe sections and curved bends. The inclination angle of the straight pipe sections is 45° to 60°, and the curvature of the curved bends is 5 to 10 times the pipe diameter.

[0011] A control method for controlling a long-distance pneumatic material conveying system for mining, wherein the central control unit performs graded fault handling based on multi-source data fusion analysis; When the material pulse frequency detected by the level sensor drops by ≥20% from the safe frequency or the detection value of the piezoelectric pressure sensor exceeds the set threshold, the primary response is triggered: the exhaust valve at the current abnormal point is opened to release local high-pressure gas; the amplitude of the first composite vibrating screen upstream of the current abnormal point is increased by 15% compared with the rated amplitude to accelerate the material flow. When the 5-second trend slope K of the differential pressure sensor is greater than 2 kPa / s and the material pulse frequency detected by the level sensor decreases by ≥30% from the safe frequency, a secondary response is triggered: the exhaust valve of the current abnormal point and the exhaust valves of the two upstream sensor groups are opened, and the speed of the booster pump in the first booster pump group upstream of the current abnormal point is simultaneously increased to 115% of the rated value. When the 5-second trend slope K of the differential pressure sensor is greater than 20 kPa / s and the amplitude of the composite vibrating screen is abnormal, a level 3 response is triggered: the amplitude of the first composite vibrating screen upstream of the current abnormal point increases by 20% compared with the rated amplitude, the duty cycle is 0.3, and the load is reduced to 30% of the rated load.

[0012] Furthermore, when the secondary response is triggered, the opening degree of the exhaust valve at the current abnormal point is 70%, the opening degree of the exhaust valve of the first upstream sensor group is 60%, and the opening degree of the exhaust valve of the second upstream sensor group is 50%, thus forming a gradient pressure relief.

[0013] Compared with the prior art, the advantages of the present invention are: This invention provides a long-distance pneumatic material conveying system for mines. By installing booster pump sets between every two conveying units, a continuous pneumatic conveying chain is formed, effectively maintaining the airflow pressure within the pipeline and avoiding material deposition and blockage problems caused by excessive conveying distance or significant elevation differences. It is particularly suitable for long-distance conveying scenarios such as inclined shafts. The conveying unit adopts a combination structure of expanding, corrugated, and contracting pipes to gradually adjust the material flow rate and direction, significantly reducing the impact force of materials on the pipeline. Especially in environments with significant elevation differences, such as vertical shafts, this effectively extends the pipeline's service life. The dust filter in the booster pump set works in conjunction with the negative pressure suction pipeline to perform preliminary dust removal before the material enters the conveying system, reducing underground dust and ensuring personnel health and operational safety.

[0014] This invention provides a control method that achieves precise, efficient, and safe control of a mine pneumatic conveying system through graded response and multi-component coordination, significantly improving the system's operational reliability and continuity. The system only initiates the appropriate level of response when an anomaly is detected, avoiding prolonged high-load operation and reducing energy consumption. Attached Figure Description

[0015] Figure 1 A schematic diagram of a long-distance pneumatic material conveying system for mining; Figure 2 This is a schematic diagram of the conveying unit; Figure 3 This is a schematic diagram of a booster pump unit; Figure 4 This is a schematic diagram of the sensor assembly and the composite vibrating screen.

[0016] In the diagram: 1-Booster pump set; 1.1-Conveying hose; 1.2-Dust filter; 1.3-High-pressure air pipe; 1.4-Booster pump; 1.5-Oil-water separator; 1.6-Hopper; 2-Front straight pipe; 3-Expanding pipe; 4-Wave pipe; 4.1-Inclined straight pipe section; 4.2-Arc-shaped bend pipe section; 5-Converging pipe; 6-Rear straight pipe; 7-Sensor set; 8-Composite vibrating screen. Detailed Implementation

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Example 1 like Figure 1 , Figure 2As shown: A long-distance pneumatic material conveying system for mining includes a booster pump set 1 and a conveying unit; there is a booster pump set 1 between every two conveying units, and the conveying unit and the booster pump set 1 are connected to form a material pneumatic conveying chain. There is a booster pump set 1 at the receiving end of the material pneumatic conveying chain. The booster pump set 1 at the receiving end is used to draw in material from the source, and the discharge end of the material pneumatic conveying chain is the outlet of the conveying unit.

[0019] The conveying unit includes a front straight pipe 2, a gradually expanding pipe 3, a corrugated pipe 4, a gradually contracting pipe 5, and a rear straight pipe 6 connected sequentially along the material conveying direction.

[0020] The function of the front straight pipe 2 is to receive the material from the upstream booster pump group 1, provide an initial stable flow channel for the material, and make the material flow initially uniform in preparation for entering the subsequent reducing pipe.

[0021] The expansion angle of the diffuser 3 is 8°~12°. This angle ensures that the fluid (material + pressurized gas) will not separate excessively from the pipe wall during expansion, thus effectively avoiding the generation of eddies. Its working principle is to gradually increase the cross-sectional area of ​​the pipe, thereby effectively reducing the flow velocity and dynamic pressure of the material according to the principles of fluid mechanics.

[0022] The corrugated pipe 4 is composed of alternating inclined straight pipe sections 4.1 and curved bend sections 4.2. The inclination angle of the inclined straight pipe section 4.1 is 45°~60°, and the curvature of the curved bend section 4.2 is 5~10 times the pipe diameter. This curvature ensures smooth material turning with minimal resistance. Its function is to break the linear motion of materials in traditional straight pipe conveying. Its working principle is: through the alternating pipe section structure, the material continuously undergoes a "deceleration-turning-acceleration" cycle during the conveying process. This cycle effectively dissipates the excess kinetic energy accumulated by the material due to long-distance drop, preventing its energy from continuously accumulating.

[0023] The contraction angle of the tapered tube 5 is 5°~8°; its function is to smoothly accelerate and converge the material flow after the speed regulation and energy dissipation of the corrugated tube 4. Its working principle is to gradually reduce the cross-sectional area of ​​the pipe, so that the material flow velocity increases slowly, providing sufficient kinetic energy for the material to overcome the subsequent pipe resistance and avoiding the deposition problem caused by insufficient velocity.

[0024] The function of the rear straight pipe 6 is to stabilize the material flow after it has been accelerated by the tapered pipe 5, and to send it out of this conveying unit in a uniform flow state to the next stage booster pump group 1 or the final outlet, so as to ensure the continuity of the conveying.

[0025] like Figure 3As shown: The booster pump unit 1 includes a negative pressure suction pipeline, a booster air pipeline, and a mixing component. The mixing component has a material channel with the same conveying direction as the conveying unit. One end of the material channel is connected to the booster air pipeline, and the other end of the material channel is connected to the conveying unit. The negative pressure suction pipeline is connected to the material channel from the side. When the high-speed airflow ejected from the booster air pipeline passes through the material channel, it forms a siphon effect to draw the material into the mixing component. The negative pressure suction pipeline draws material from a material source (such as a storage tank) or the end of the upstream conveying unit. The negative pressure suction pipeline includes a conveying hose 1.1.

[0026] The function of the booster air circuit is to provide clean, high-pressure airflow. The booster air circuit includes an oil-water separator 1.5, a booster pump 1.4, and a high-pressure air pipe 1.3 connected sequentially along the airflow direction. The oil-water separator 1.5 removes oil and moisture from the compressed air, preventing clumping, blockage, or contamination of materials caused by the mixing of oily and humid air with the materials, thus ensuring the dryness and cleanliness of the conveyed airflow. The booster pump 1.4 pressurizes the clean air to generate the high-speed, high-pressure airflow required by the system.

[0027] The function of the mixing component is to mix the material with the high-pressure airflow and smoothly send the mixed two-phase flow into the downstream conveying unit. The mixing component includes a dust filter 1.2 and a hopper 1.6. The cavities of the dust filter 1.2 and the hopper 1.6 are connected to form a material channel. The dust filter 1.2 is connected to the negative pressure suction pipeline and the pressurized air pipeline, and the hopper 1.6 is connected to the conveying unit.

[0028] When the high-speed airflow ejected from the pressurized air circuit enters the material channel of the dust filter 1.2 through the high-pressure air pipe 1.3, a negative pressure zone (siphon effect) is formed in the channel according to Bernoulli's principle. This draws in the material from the conveying hose 1.1 at high speed and achieves preliminary mixing. Furthermore, the dust filter 1.2 filters the mixed gas-solid two-phase flow, capturing some of the dust, significantly reducing the dust concentration in the underground working environment and improving working conditions.

[0029] The hopper 1.6 is used to temporarily store materials that have undergone preliminary mixing and dust removal, and is connected to the downstream conveying unit (such as the front straight pipe 2) through its lower channel. Its volumetric design can buffer the material flow, making the material conveying more continuous and stable, avoiding pulsating conveying, and providing a smooth transition for the material to enter the conveying pipeline.

[0030] Example 2 A control method is provided for controlling a long-distance pneumatic material conveying system for mining as described in Example 1. The conveying unit is provided with sensor groups 7 and composite vibrating screens 8 spaced apart along the conveying direction. Each sensor group 7 includes a material level sensor, an exhaust valve, a piezoelectric pressure sensor, and a differential pressure sensor. The sensor groups 7 interact with the central control unit to form a closed-loop control.

[0031] The central control unit performs graded fault handling based on multi-source data fusion analysis. When the material pulse frequency detected by the level sensor drops by ≥20% from the safe frequency or the detection value of the piezoelectric pressure sensor exceeds the set threshold (>1.5MPa), a primary response is triggered: the exhaust valve at the current abnormal point is opened to release local high-pressure gas and prevent pipe rupture; the amplitude of the first composite vibrating screen 8 upstream of the current abnormal point is increased by 15% compared with the rated amplitude to accelerate material flow; the primary response is for minor blockage or pressure abnormality, and accelerates material flow through local exhaust and vibrating screen to prevent the problem from escalating.

[0032] When the 5-second trend slope K of the differential pressure sensor is greater than 2 kPa / s and the material pulse frequency detected by the level sensor decreases by ≥30% from the safe frequency, a secondary response is triggered: the exhaust valve of the current abnormal point and the exhaust valves of the two upstream sensor groups 7 are opened, the opening degree of the exhaust valve of the current abnormal point is 70%, the opening degree of the exhaust valve of the first upstream sensor group 7 is 60%, and the opening degree of the exhaust valve of the second upstream sensor group 7 is 50%, forming a gradient pressure relief, and simultaneously increasing the speed of the booster pump 1.4 in the first booster pump group 1 upstream of the current abnormal point to 115% of the rated value; effectively alleviating the risk of blockage.

[0033] When the 5-second trend slope K of the differential pressure sensor is greater than 20 kPa / s and the amplitude of the composite vibrating screen 8 is abnormal, a three-level response is triggered: the amplitude of the first composite vibrating screen 8 upstream of the current abnormal point increases by 20% compared with the rated amplitude, the duty cycle is 0.3, and the load is reduced to 30% of the rated load; the system further increases the vibration intensity and operates with reduced load to prevent system overload or pipe burst and ensure equipment safety.

[0034] The central control unit is connected to the booster pump group 1 and the composite vibrating screen 8 via wireless signals; the central control unit is connected to the 4-20mA signal output terminals of each sensor via an explosion-proof junction box; the central control unit controls the dual-frequency vibration motor of the composite vibrating screen 8 via a relay module, and drives the exhaust valve via a pneumatic solenoid valve.

[0035] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A long-distance pneumatic material conveying system for mining, characterized in that: It includes a booster pump set (1) and a conveying unit; there is a booster pump set (1) between every two conveying units, and the conveying unit and the booster pump set (1) are connected to form a material pneumatic conveying chain. There is a booster pump set (1) at the receiving end of the material pneumatic conveying chain, and the discharge end of the material pneumatic conveying chain is the outlet of the conveying unit. Sensor groups (7) and composite vibrating screens (8) are distributed at intervals along the conveying direction on the conveying unit; each sensor group (7) includes a material level sensor, an exhaust valve, a piezoelectric pressure sensor and a differential pressure sensor; the sensor group (7) interacts with the central control unit to form a closed-loop control.

2. The long-distance pneumatic material conveying system for mining according to claim 1, characterized in that: The conveying unit includes a front straight pipe (2), a gradually expanding pipe (3), a corrugated pipe (4), a gradually contracting pipe (5), and a rear straight pipe (6) connected in sequence along the material conveying direction.

3. The long-distance pneumatic material conveying system for mining according to claim 2, characterized in that: The booster pump set (1) includes a negative pressure suction pipeline, a booster air path and a mixing component. The mixing component has a material channel with the same conveying direction as the conveying unit. One end of the material channel is connected to the booster air path, and the other end of the material channel is connected to the conveying unit. The negative pressure suction pipeline is connected to the material channel from the side. When the high-speed airflow ejected from the booster air path passes through the material channel, it forms a siphon effect to draw the material into the mixing component.

4. A long-distance pneumatic material conveying system for mining according to claim 3, characterized in that: The pressurized air circuit includes an oil-water separator (1.5), a pressurized pump (1.4), and a high-pressure air pipe (1.3) connected in sequence along the airflow direction; the negative pressure suction line includes a material conveying hose (1.1).

5. A long-distance pneumatic material conveying system for mining according to claim 4, characterized in that: The mixing component includes a dust filter (1.2) and a hopper (1.6). The cavities of the dust filter (1.2) and the hopper (1.6) are connected to form a material channel. The dust filter (1.2) is connected to a negative pressure suction pipeline and a pressurized air pipeline, and the hopper (1.6) is connected to a conveying unit.

6. A long-distance pneumatic material conveying system for mining according to claim 2, characterized in that: The expansion angle of the expanding tube (3) is 8°~12°; the contraction angle of the contracting tube (5) is 5°~8°.

7. A long-distance pneumatic material conveying system for mining according to claim 2, characterized in that: The wave tube (4) is formed by alternating straight pipe sections (4.1) and curved pipe sections (4.2). The inclination angle of the straight pipe section (4.1) is 45°~60°, and the curvature of the curved pipe section (4.2) is 5~10 times the pipe diameter.

8. A control method for controlling the long-distance pneumatic material conveying system for mining as described in claim 4, characterized in that: The central control unit performs graded fault handling based on multi-source data fusion analysis. When the material pulse frequency detected by the level sensor drops by ≥20% from the safe frequency or the detection value of the piezoelectric pressure sensor exceeds the set threshold, the primary response is triggered: the exhaust valve of the current abnormal point is opened to release the local high-pressure gas; the amplitude of the first composite vibrating screen (8) upstream of the current abnormal point is increased by 15% from the rated amplitude to accelerate the material flow. When the 5-second trend slope K of the differential pressure sensor is greater than 2 kPa / s and the material pulse frequency detected by the level sensor decreases by ≥30% from the safe frequency, a secondary response is triggered: the exhaust valve of the current abnormal point and the exhaust valves of the two upstream sensor groups (7) are opened, and the speed of the booster pump (1.4) in the first booster pump group (1) upstream of the current abnormal point is simultaneously increased to 115% of the rated value. When the 5-second trend slope K of the differential pressure sensor is greater than 20 kPa / s and the amplitude of the composite vibrating screen (8) is abnormal, a three-level response is triggered: the amplitude of the first composite vibrating screen (8) upstream of the current abnormal point increases by 20% compared with the rated amplitude, the duty cycle is 0.3, and the load is reduced to 30% of the rated load.

9. The control method according to claim 8, characterized in that: When the secondary response is triggered, the opening degree of the exhaust valve at the current abnormal point is 70%, the opening degree of the exhaust valve of the first upstream sensor group (7) is 60%, and the opening degree of the exhaust valve of the second upstream sensor group (7) is 50%, forming a gradient pressure relief.

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