Full-automatic gas dust pumping and discharging device and method for ground coal storage silo

Abstract

The invention discloses a full-automatic gas dust pumping and discharging device and method for a ground coal storage silo. The full-automatic gas dust pumping and discharging device comprises a silo, a recognition alarm system, a control system, a pumping and discharging fan and a damping hole ventilation pipeline device. A recognition alarm system is arranged on the inner wall of a top plate of the silo, damping hole ventilation pipeline devices are arranged on the two sides of the silo respectively, each damping hole ventilation pipeline device comprises two air pipes, hoop type supports are evenly arranged on the air pipes to fix the air pipes, damping holes are evenly formed in the air pipes, and filter screens are installed on the damping holes. The top ends of the two air pipes are respectively connected with an exhaust fan, the bottom ends of the air pipes are close to the bottom of the silo, and the exhaust fan is fixed on a roof of a transportation and maintenance workshop of a silo top plate; the recognition alarm system comprises a methane sensor and a dust sensor, the gas concentration and the dust concentration in the silo are detected in real time, and the control system controls the local ventilator to operate to pump and discharge gas and dust. The device is simple in structure and flexible to operate, gas and dust in the coal storage silo can be fully automatically and effectively pumped and discharged, and the safety of personnel and equipment is guaranteed.

Description

Technical Field

[0001] The invention relates to a fully automatic extraction device and method for gas dust in a ground coal storage silo, belonging to the technical field of gas dust control. Background Art

[0002] Gas is a flammable and explosive gas with a relative density of 0.554 to air. Under standard conditions, the density of gas is 0.716 kg / m 3 , which is lighter than air. In places such as coal mines, when gas leakage reaches a certain concentration, it can cause people to suffocate due to lack of oxygen, and combustion and explosion can occur, causing serious casualties and property losses. Dust also has explosion risks. When the dust concentration in the air reaches a certain level, it may explode when it encounters a fire source. Investigations have found that most explosions in coal mines are gas-coal dust mixed explosions, and mixed explosions can cause more serious explosion accidents than single explosions. Because a large amount of coal is stored in the ground coal bunker, gas and a large amount of coal dust will accumulate in the silo, which is prone to explosions, resulting in casualties and equipment damage.

[0003] Chinese patent CN218392713U discloses a high-efficiency gas treatment device for ground coal storage bunkers. The high-efficiency gas treatment device for ground coal storage bunkers provided by the patent drives the cam to rotate through a motor, the cam makes the rack move back and forth horizontally, the rack drives the gear to rotate forward and backward, the gear drives the L-shaped pipe to rotate forward and backward, the L-shaped pipe drives the arc cover to swing back and forth to suck gas, and at the same time, the swing of the arc cover drives the arc filter to rub against the brush to clean dust; however, the gas treatment device has a small extraction range and poor effect, and cannot detect the gas concentration in the bunker in real time. Excessive accumulation of coal dust in the bunker affects the service life of the equipment. Therefore, there is an urgent need for a fully automatic extraction device with good extraction effect, wide range, and easy handling of gas and coal dust. Summary of the invention

[0004] The present invention aims to provide a fully automatic gas and dust extraction device and method for ground coal storage silo, which has a simple structure and is easy to operate. It can fully automatically and effectively extract gas and dust in the coal storage silo, reduce the concentration of gas and coal dust, and ensure the safety of personnel and equipment.

[0005] The present invention monitors the gas and dust concentration in the silo in real time by setting up an identification alarm system. When the concentration exceeds the limit, the control system is used to automatically control the operation of the exhaust fan. The exhaust fan adopts a one-pressure-in-one-extraction cycle working mode. According to the change of wind direction, the gas and dust extraction effect is ensured and the filter is avoided from being blocked. The air volume and wind speed are adjusted with the help of the damping hole ventilation pipeline device to realize the comprehensive and efficient extraction of gas and dust in the coal bunker.

[0006] The present invention provides a fully automatic gas and dust extraction device for a ground coal storage silo, comprising a silo, an identification alarm system, a control system, an extraction and exhaust fan, and a damping hole ventilation pipeline device;

[0007] The silo is a common container for storing coal on the ground of a coal mine. It is a cylindrical building cast with reinforced concrete. An identification alarm system is arranged on the inner wall of the silo roof. Damping hole ventilation pipeline devices are arranged on both sides of the silo. The damping hole ventilation pipeline device includes two air ducts. Hoop-type brackets are evenly arranged on the air ducts to fix the air ducts. Damping holes are evenly arranged on the air ducts, and filters are installed on the damping holes. The top ends of the two air ducts are respectively connected to the exhaust fans, and the bottom ends of the air ducts are close to the bottom of the silo. The exhaust fans are fixed on the roof of the transportation and maintenance workshop on the top plate of the silo. The damping hole ventilation pipeline device can adjust the air volume and wind speed at each position in the silo, so that the air volume and wind speed at each position are balanced, so as to achieve the purpose of comprehensive exhaust of gas and dust.

[0008] The identification and alarm system includes a methane sensor and a dust sensor, which are installed on the top of the silo. The system detects the gas concentration and dust concentration in the silo in real time. Once the gas concentration exceeds 0.5% or the dust concentration exceeds 5g / m 3 , a signal is sent to the control system, which in turn controls the local ventilation fan to operate and extract gas and dust.

[0009] Furthermore, the methane sensor and dust sensor are respectively set 1m below the coal inlet, and the sensors are stably installed using a hanging fixed bracket. The methane sensor and dust sensor are respectively set on both sides of the coal inlet, and the distance between the methane sensor and the dust sensor is 1m. The stability and safety of the sensor are ensured during installation. Connect the sensor to the power supply and ensure that the voltage is stable. Connect the 4-20mA signal line of the sensor to the PLC control system to achieve real-time monitoring and alarm functions.

[0010] Furthermore, the above-mentioned methane sensor uses the GJC4 model, and the dust sensor uses the GCG1000 model. This type of sensor is easy to connect with other systems to achieve remote monitoring and control, can be used in environments where there is a risk of gas or coal dust explosion, and meets the explosion-proof requirements of coal mines.

[0011] Furthermore, the hanging fixed bracket includes a hanging ring, a hanging chain, and a hanging bracket. The structure of the hanging bracket is a triangular bracket. A frame of the triangular bracket is arranged to fit the bottom of the silo top plate. The hanging ring is a semicircular ring, which is fixed below the frame of the hanging bracket. The bottom of the hanging ring is connected to the hanging chain, and the bottom of the hanging chain is connected to the methane sensor or the dust sensor. Specifically, each component of the hanging fixed bracket is made of rigid material. The hanging ring and the hanging bracket are installed 1m below the coal inlet with fixing bolts, and methane sensors and dust sensors are installed on both sides respectively. One end of the hanging chain is connected to the hanging ring, and the other end is connected to the hanging bracket, and the methane sensor and the dust sensor are connected below. During the connection process, pay attention to adjusting the height and levelness of the bracket to ensure its stability.

[0012] The control system includes: a CPU module, an input module, an output module, a communication module, a power module, and a bus module;

[0013] (1) The CPU module is the core module of the PLC control system, which is mainly responsible for processing input signals, executing program instructions, controlling output signals, and providing monitoring;

[0014] (2) The input module is used to detect various sensor signals, receive the concentration over-limit alarm signal sent by the methane sensor or the dust sensor, and transmit the signal sent by the sensor to the output module;

[0015] (3) Output module: Receives the signal from the input module and converts it into a format that can be recognized by the PLC. It converts the signal processed by the PLC into a signal suitable for executing the fan operation and controls the local fan to start working;

[0016] (4) Communication module: Transmits the gas concentration, wind speed, temperature, and humidity data of the silo in the PLC system to the superior control center, realizes the communication between the PLC and the local ventilator, and can also store and record the data in the server to provide support for future safety management and decision-making; the PLC control system is connected to the superior control center via wireless signals;

[0017] (5) The power module provides power support for the PLC system to ensure that the PLC system can work normally;

[0018] (6) The bus module is used to expand the number of input and output points of the PLC system and realize data transmission and coordination between different nodes. The four-way self-sensing valve can be connected to the bus module to improve system performance.

[0019] Furthermore, the exhaust fans are two flameproof local ventilators for mining, which are respectively installed on the roof of the silo top transport and maintenance workshop by fixing bolts, and the joints are sealed with sealant. The air duct connected to it extends into the silo top transport and maintenance workshop and extends to the bottom of the main part of the silo. The power cord of the ventilator is connected to the PLC control system to ensure that the power wiring is correct to prevent short circuit or power supply abnormality. After the methane sensor or dust sensor sends a signal, the control system receives the signal and outputs a command to operate the local ventilator to exhaust the gas and dust in the silo.

[0020] Furthermore, the air duct is a stainless steel circular air duct, and the two air ducts are respectively connected to the two ventilators and extend downward to the bottom of the main part of the silo, and the joints are sealed with sealant. Secondly, the two air ducts are respectively fixed on the left and right sides of the inner wall of the silo using a clamp-type bracket, and a number of damping holes are opened on both sides of the air duct inside the silo to adjust the flow and wind speed.

[0021] The clamp-type bracket includes a clamp and a support structure, and the whole is made of rigid material. The support structure is installed on the inner wall of the silo by expansion bolts, and the clamp is connected to the support structure by fixing bolts. The clamp is formed by two semicircular steel belts connected by bolts, which can tightly hold the circular air duct. Its inner diameter is 578mm and its thickness is 3mm. The support structure includes a hanger, a basket nut, and a connecting piece. The hanger is a cylindrical rod structure made of high-strength round steel. The hanger is installed on the inner wall of the silo by expansion bolts. It has sufficient strength and rigidity to bear the load. The diameter of the hanger is 20mm; the basket nut is connected to the hanger and is used to adjust the length of the hanger; the connecting piece is a circular orifice plate, and the connecting rod is set at the end of the hanger and connected to the clamp by fixing bolts.

[0022] The damping holes are arranged on both sides of the air duct, and a filter is installed on the damping holes to prevent coal blocks from entering the air duct and affecting the ventilation performance; the filter is a uniformly distributed metal wire mesh, which is fixed on the damping hole with a sealant. Specifically, the filter is made of stainless steel, with a specification of 35 mesh, a pore size of 0.5mm, and a thickness of 0.2mm.

[0023] The present invention provides a method for using the above-mentioned ground coal storage silo gas dust automatic extraction device, comprising the following steps:

[0024] (1) First, connect all electrical equipment of the device to the power supply. When the operation starts, the sorting and sorting silo belt transports the coal blocks to the coal inlet of the silo. When there is a large amount of coal in the silo, the gas contained in the coal accumulates on the top of the silo and adheres to the inner wall of the silo;

[0025] (2) Use methane sensors and dust sensors to monitor gas concentration and dust in real time. When the gas concentration or dust concentration in the silo exceeds the limit, the sensor transmits an electrical signal to the PLC control system;

[0026] (3) The PLC control system converts the signal transmitted by the sensor into a signal that adapts to the operation of the fan, and then controls the exhaust fan to start working. The two local exhaust fans adopt a cycle working mode of one pressure in and one extraction;

[0027] (4) During the first hour of operation of the device, the left ventilator performs forced ventilation, and the right ventilator performs exhaust ventilation. The airflow flows in from the damping holes on the left air duct and flows out from the damping holes on the right air duct, making the airflow rotate;

[0028] (5) When the device is turned to the second hour, the wind direction is reversed, that is, the left fan is turned into exhaust ventilation, and the right fan is turned into pressure ventilation, so that the gas and dust extraction effect can be guaranteed, and the filter on the damping hole can be prevented from being blocked;

[0029] (6) The device operates in this cyclic manner. When the gas concentration and dust concentration are reduced to a safe range, the device stops operating and the gas and dust are effectively extracted, ensuring the safety of personnel and equipment.

[0030] Beneficial effects of the present invention:

[0031] (1) The methane sensor and dust sensor cooperate with the ventilator through the PLC control system. When the gas concentration or dust concentration exceeds the limit, the local ventilator is automatically started for extraction, which can effectively reduce the concentration of gas and coal dust in the silo, reduce the risk of explosion, and ensure the safety of personnel and equipment;

[0032] (2) Installing a filter can effectively prevent coal from entering the air duct, thereby ensuring that ventilation performance is not affected;

[0033] (3) Two explosion-proof local ventilators for mining use are used, one in a compression-in and one in an extraction cycle mode. Together with the damping ventilation holes on both sides of the air duct, the airflow can rotate in the silo, thereby increasing the extraction range and improving the extraction effect of gas and dust, while preventing the filter on the damping hole from becoming clogged.

[0034] (4) The damping ventilation holes on both sides of the air duct can evenly adjust the flow rate and wind speed to ensure that gas and dust are fully exhausted;

[0035] (5) The overall structure of the device provided by the present invention is clear, the functions of each component are clear, and the entire device can be fully automatic and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is the aerodynamic performance curve of the explosion-proof local exhaust fan for mining;

[0037] Figure 2 It is a schematic diagram of the velocity magnitude of the damping vents on both sides of the air duct;

[0038] Figure 3 It is a schematic diagram of the velocity of the wind flowing out of each damping vent;

[0039] Figure 4 This is a schematic diagram of the structure of the fully automatic gas and dust extraction device for the ground coal storage silo of the present invention;

[0040] Figure 5 for Figure 4 A magnified view of part A;

[0041] Figure 6 for Figure 4 A magnified view of part B;

[0042] Figure 7 for Figure 4 Enlarged view of part C;

[0043] Figure 8 This is the main view of the wind flow direction inside the silo;

[0044] Fig. 9 This is a top view of the wind flow direction inside the silo;

[0045] Fig.10 This is a top view of the clamp-type bracket.

[0046] In the figure: 1. Silo; 2. Silo roof transport and maintenance workshop; 3. Exhaust fan; 4. Sorting and distribution silo belt; 5. Coal inlet; 6. Coal discharge port; 7. Air duct; 8. Damping hole; 9. Hoop bracket; 10. Coal block; 11. Filter; 12. Hanging rod; 13. Basket nut; 14. Connector; 15. Hoop; 16. Methane sensor; 17. Dust sensor; 18. Lifting bracket; 19. Lifting chain; 20. Lifting ring. DETAILED DESCRIPTION

[0047] The present invention is further illustrated by the following examples, but is not limited to the following examples.

[0048] Embodiment 1:

[0049] like Figures 1 to 10 As shown, a fully automatic gas and dust extraction device for a ground coal storage silo includes a silo 1, an identification alarm system, a control system, an extraction fan 3, and a damping hole ventilation pipeline device;

[0050] The silo is a common container for storing coal on the ground in coal mines. It is a cylindrical building made of reinforced concrete. The conventional size is 30m in diameter and 50m in height (the main part is 35m high). The volume is about 28260m 3 A coal inlet 5 is provided at the center of the top of the silo 1, an identification alarm system is provided on the inner wall of the top plate of the silo 1, and a sorting and distributing silo belt 4 is provided above the top plate; damping hole ventilation pipeline devices are provided on both sides of the silo 1, respectively, and the damping hole ventilation pipeline device comprises two air ducts 7, and the air ducts 7 are evenly provided with clamp-type brackets 9 to fix the air ducts, and damping holes 8 are evenly provided on the air ducts, and filters 11 are installed on the damping holes 8; the top ends of the two air ducts 7 are respectively connected to the exhaust fans 3, and the bottom ends of the air ducts 7 are close to the bottom of the silo 1, and the exhaust fans 3 are fixed on the roof of the silo top transportation and maintenance workshop 2; the damping hole ventilation pipeline device can adjust the air volume and wind speed at each position in the silo, so that the air volume and wind speed at each position are balanced, so as to achieve the purpose of comprehensive exhaust of gas and dust;

[0051] The identification and alarm system includes a methane sensor 16 and a dust sensor 17, which are arranged on the top of the silo 1. The system detects the gas concentration and dust concentration in the silo in real time. Once the gas concentration exceeds 0.5% or the dust concentration exceeds 5g / m 3 , a signal is sent to the control system, which in turn controls the local ventilation fan to operate and extract gas and dust.

[0052] Furthermore, the methane sensor 16 and the dust sensor 17 are respectively arranged 1m below the coal inlet 5, and the sensors are stably installed using a hanging fixed bracket. The methane sensor and the dust sensor are respectively arranged on both sides of the coal inlet, and the distance between the right end methane sensor and the left end dust sensor is 1m, and the stability and safety of the sensors are ensured during installation. The sensor is connected to the power supply and the voltage is ensured to be stable, and the 4-20mA signal line of the sensor is connected to the PLC control system to realize real-time monitoring and alarm functions.

[0053] Furthermore, the methane sensor 16 is of the GJC4 model, and the dust sensor 17 is of the GCG1000 model. This type of sensor is convenient for connection with other systems to achieve remote monitoring and control, and can be used in environments where there is a risk of gas or coal dust explosion, meeting the explosion-proof requirements of coal mines.

[0054] Furthermore, the hanging fixed bracket includes a hanging ring 20, a hanging chain 19, and a hanging bracket 18. The structure of the hanging bracket 18 is a triangular bracket. A frame of the triangular bracket is arranged to fit the bottom of the silo top plate. The hanging ring 20 is a semicircular ring fixed below the frame of the hanging bracket 18. The bottom of the hanging ring 20 is connected to the hanging chain 19, and the bottom of the hanging chain 19 is connected to the methane sensor or the dust sensor. Specifically, each component of the hanging fixed bracket is made of rigid material. The hanging ring and the hanging bracket are installed 1m below the coal inlet with fixing bolts, and the methane sensor and the dust sensor are installed on both sides respectively. One end of the hanging chain is connected to the hanging ring, and the other end is connected to the hanging bracket, and the methane sensor and the dust sensor are connected below. During the connection process, it is necessary to pay attention to adjusting the height and levelness of the bracket to ensure its stability.

[0055] The control system includes: CPU module, input module, output module, communication module, power module, bus module; the PLC control system model uses Siemens S7-400 series: it has strong anti-interference ability; the number of input and output points can be flexibly increased through expansion modules to meet the connection requirements of a large number of sensors and actuators in the coal bunker; it supports multiple communication protocols and can easily communicate with the host computer, other PLCs or intelligent devices to achieve remote monitoring and centralized management. The functions of the control system are described as follows:

[0056] (1) The CPU module is the core module of the PLC, which is mainly responsible for processing input signals, executing program instructions, controlling output signals, and providing monitoring;

[0057] (2) The input module is used to detect various sensor signals, receive the concentration over-limit alarm signal sent by the methane sensor or the dust sensor, and transmit the signal sent by the sensor to the output module;

[0058] (3) Output module: Receives the signal from the input module and converts it into a format that can be recognized by the PLC. It converts the signal processed by the PLC into a signal suitable for executing the fan operation and controls the local fan to start working;

[0059] (4) Communication module: Transmits data information such as gas concentration, wind speed, temperature, and humidity of the silo in the PLC system to the superior control center, realizes communication between the PLC and the local ventilator, and can also store and record the data in the server to provide support for future safety management and decision-making; the PLC control system is connected to the superior control center via wireless signals;

[0060] (5) The power module provides power support for the PLC system to ensure that the PLC system can work normally;

[0061] (6) The bus module is used to expand the number of input and output points of the PLC system and realize data transmission and coordination between different nodes. The four-way self-sensing valve can be connected to the bus module to improve system performance.

[0062] Furthermore, the exhaust fans 3 are two flameproof local ventilators for mining, which are respectively installed on the roof of the silo top transport and maintenance workshop by fixing bolts, and the joints are sealed with sealant. The air duct connected to them extends into the silo top transport and maintenance workshop and extends to the bottom of the main part of the silo. The power cord of the ventilator is connected to the PLC control system to ensure that the power wiring is correct to prevent short circuit or power supply abnormality. After the methane sensor or dust sensor sends a signal, the control system receives the signal and outputs a command to operate the local ventilator to exhaust the gas and dust in the silo.

[0063] Specifically, the model of the flameproof local ventilator for mining in the present invention is determined by the following formula:

[0064] The required ventilation volume is calculated based on factors such as the silo volume and gas outflow volume. The air volume of the selected fan should be greater than the calculated required ventilation volume, with a margin of 1.1-1.2 times.

[0065]

[0066] In the formula: V is the volume of the silo; m is the number of ventilation times per hour; 2 refers to two air ducts; 60 refers to 60 minutes; the above formula represents the air volume required per minute for each air duct.

[0067] Furthermore, the friction resistance and local resistance of the air duct are calculated using relevant formulas of fluid mechanics. The wind pressure of the fan should be greater than the total resistance of the ventilation system, and a margin of 1.2-1.3 times is usually considered.

[0068]

[0069] Where: l is the length of the air duct;

[0070] d—pipe diameter;

[0071] v—wind speed;

[0072] g—acceleration due to gravity;

[0073] h f — friction resistance;

[0074] λ—friction resistance coefficient.

[0075]

[0076] Where: Re—Reynolds coefficient;

[0077] ν—The kinematic viscosity of air is about 1.46×10 -5 m 2 / s.

[0078]

[0079] Where: h j — local resistance;

[0080] ε—local resistance coefficient.

[0081] Specifically, in general, the ground coal storage silo is ventilated once an hour. Taking m as 1, the minimum ventilation volume required for a ventilator is about 188.4m 3 / min; calculated by the above formula, the total resistance of the ventilation system is approximately 831Pa.

[0082] The selected mining explosion-proof local ventilator is FBD-No.5.0 / 2×7.5.

[0083] Furthermore, the air volume of FBD-No.5.0 / 2×7.5 explosion-proof local ventilator for mining is 240-170m 3 / min, full pressure of 360-3280pa, power of 2×7.5kW, full pressure efficiency ≥75%, noise ≤30dB. It can be seen that the selection of FBD-No.5.0 / 2×7.5 explosion-proof local ventilation fan for mining can meet the requirements of required air volume and air pressure, and also meet the requirements of explosion-proof performance, noise and power during operation. Figure 1 It can be seen that the aerodynamic performance curve of FBD-No.5.0 / 2×7.5 mining explosion-proof local ventilation fan.

[0084] Furthermore, the air duct 7 is a stainless steel circular air duct, and the two air ducts are respectively connected to the two ventilators, extending downward to the bottom of the main part of the silo, and the joints are sealed with sealant. Secondly, the two air ducts are respectively fixed on the left and right sides of the inner wall of the silo using a clamp-type bracket, and a number of damping holes are opened on both sides of the air duct inside the silo to adjust the flow rate and wind speed.

[0085] Furthermore, the above duct size is determined by the following formula:

[0086] Q=πr 2 v

[0087] Specifically, the appropriate ventilation speed is about 10-15m / s. Through calculation, a stainless steel circular air duct with a diameter of 576mm and a thickness of 2mm can be selected.

[0088] The clamp-type bracket 9 includes a clamp 15 and a supporting structure, and the whole is made of rigid material. The supporting structure is installed on the inner wall of the silo by expansion bolts, and the clamp 15 is connected to the supporting structure by fixing bolts. The clamp is formed by two semicircular steel belts connected by bolts, and can tightly hold the circular air duct. Its inner diameter is 578mm and its thickness is 3mm. The supporting structure includes a hanger 12, a basket nut 13, and a connecting piece 14. The hanger 12 is a cylindrical rod structure made of high-strength round steel. The hanger 12 is installed on the inner wall of the silo by expansion bolts. It has sufficient strength and rigidity to bear the load. The diameter of the hanger is 20mm; the basket nut 13 is connected to the hanger 12 and is used to adjust the length of the hanger; the connecting piece 14 is a circular orifice plate, and the connecting rod is set at the end of the hanger and is connected to the clamp by fixing bolts.

[0089] The damping holes 8 are arranged on both sides of the air duct, and the filter screen 11 is installed on the damping holes to prevent the coal blocks 10 from entering the air duct and affecting the ventilation performance. Furthermore, the size of the damping holes is determined by the following formula combined with CFD software simulation calculation:

[0090] Using the continuity equation:

[0091] Q=vA

[0092] In the formula: Q is flow rate; v is flow velocity; A is pipe cross-sectional area.

[0093] Furthermore, according to Poiseuille's law, for laminar flow in a circular tube, the relationship between flow rate and pressure difference is:

[0094]

[0095] Where: r—pipe radius;

[0096] △p—pressure difference between the two ends of the pipeline;

[0097] μ—fluid viscosity;

[0098] L—Pipeline length.

[0099] Furthermore, for the damping hole, it can be assumed that its flow formula is:

[0100]

[0101] Where: C d —Flow coefficient of damping hole; A d —The area of ​​the damping hole; ρ—fluid density.

[0102] Furthermore, in order to achieve equal flow regulation, the pipeline flow Q can be equal to the sum of the flow rates of all damping holes:

[0103] Q=nQ d

[0104] Where: n is the number of damping holes.

[0105] Furthermore, the expression for the damping hole area can be derived:

[0106]

[0107] A d =πr 2

[0108] Furthermore, by combining the above formula and trying different numbers of damping holes and flow coefficients, the range of the damping hole diameter can be estimated, and CFD software can be used for simulation calculations.

[0109] Specifically, the range of values ​​of the damping hole diameter under the above conditions was initially calculated using a formula. Then, CFD software was used for three-dimensional simulation calculations. First, a circular stainless steel duct with a diameter of 576mm and a height of 40m was established. Damping ventilation holes were opened from high to low on both sides of the duct at a height of 35m, and two holes were opened every 1.5m from the center of the holes. The initial diameter of the damping ventilation holes is 60mm, and the diameter increases by 2mm each time according to the principle of increasing in sequence. 24 damping ventilation holes are opened on one side from high to low, and a total of 48 damping ventilation holes are opened on one duct (two are set at the center of the holes on the same horizontal line). The diameter of the last two damping ventilation holes is 106mm; secondly, a laminar flow physical field is added, the fluid properties are set to air, and a fan is added to the top of the duct with a fan volume of 300m 3 / min, the wind direction is downward, and 48 damping vents are set as wind outlets; finally, the speed of wind flowing out of the holes after overcoming friction resistance and local resistance is simulated and calculated, such as Figure 2 shown.

[0110] The above calculation results are as follows Figure 3 As shown, Figure 3 Schematic diagram of the velocity of air flowing out of each damping vent. Figure 3 It shows that when the wind flows out of the left and right holes, the change trends and speed magnitudes of the maximum and average speeds are almost the same. When the wind flows out of the damping hole, the average speed fluctuates in the range of 5-6m / s, and the maximum speed fluctuates between 10-13m / s, and neither of them changes significantly, achieving the purpose of adjusting the wind speed and flow rate through the damping vents.

[0111] Further, according to the above calculations, damping ventilation holes are opened on the air duct of the main part of the silo in order with an initial diameter of 60mm and a gradual increase of 2mm on both sides of the air duct from high to low, with the center of the hole between the holes 1.5m apart. There are 24 damping holes on one side of the air duct, and a total of 96 damping holes for the two air ducts. The diameter of the 4 damping holes at the bottom is 106mm.

[0112] The filter is a uniformly distributed metal wire mesh, which is fixed on the damping hole with a sealant to prevent coal blocks from entering the ventilation duct and affecting the ventilation performance. Specifically, the filter is made of stainless steel, with a specification of 35 mesh, a pore size of 0.5 mm, and a thickness of 0.2 mm.

[0113] The present invention provides a method for using the above-mentioned ground coal storage silo gas dust fully automatic extraction device, which is performed according to the following steps:

[0114] (1) First, install all equipment and instruments at the preset position and turn on the power. During normal operation, the sorting and distribution belt 4 transports the coal blocks 10 to the coal inlet 5 of the silo 1. A large number of coal blocks 10 fall into the silo 1 from the coal inlet 5. When they fall to the bottom of the silo 1, the coal blocks 10 break and produce fine coal dust. When there are a large number of coal blocks 10 in the silo, the gas contained in the coal will accumulate on the top of the silo 1 and adhere to the inner wall of the silo 1. As the operation proceeds, a sufficient concentration of gas and coal dust will accumulate in the silo 1, which is prone to explosion accidents;

[0115] (2) The methane sensor 16 and dust sensor 17 installed on the top plate of the silo 1 can effectively monitor the changes in the gas concentration and dust concentration in the silo 1. Once the gas concentration exceeds 0.5% or the dust concentration exceeds 5g / m 3 The methane sensor 16 or the dust sensor 17 transmits an electrical signal to the PLC control system, and the PLC control system transmits data information such as the gas concentration in the silo 1 to the monitoring and detection system.

[0116] (3) The PLC control system converts the signal transmitted by the methane sensor 16 or the dust sensor 17 into a signal adapted to the operation of the exhaust fan 3, and then controls the two local fans 3 to start working. The two local fans adopt a cycle working mode of one compression and one extraction.

[0117] (4) In the first hour of the operation of the device, the left exhaust fan 3 implements forced ventilation, and the right exhaust fan 3 implements exhaust ventilation. The wind flows in from the damping hole 8 on the left air duct 7 and flows out from the damping hole 8 on the right air duct 7, so that the wind flow is in a rotating form, and most of the wind flow flows along the inner wall of the silo 1, and only a small part of the wind flow flows in the internal space of the silo 1, ensuring the exhaust effect of gas and coal dust attached to the inner wall of the silo.

[0118] (5) When the device is turned to the second hour, the wind direction is reversed, that is, the left exhaust fan 3 is changed to exhaust ventilation, and the right exhaust fan 3 is changed to pressure ventilation, so that the exhaust effect of gas and dust can be guaranteed, and at the same time, the filter 11 on the damping hole 8 is prevented from being blocked.

[0119] (6) The gas and dust are discharged into the atmosphere in such a cyclic operation. When the gas concentration in silo 1 drops to a safe range, the device stops operating and the gas and dust are effectively extracted, thus ensuring the safety of personnel and equipment.

Claims

1. A fully automatic gas and dust extraction device for ground coal storage silos, characterized by: It includes a silo, an identification alarm system, a control system, an exhaust fan, and a damping hole ventilation pipeline device; an identification alarm system is arranged on the inner wall of the silo top plate, and damping hole ventilation pipeline devices are arranged on both sides of the silo respectively, the damping hole ventilation pipeline device includes two air ducts, the air ducts are evenly provided with clamp-type brackets to fix the air ducts, the air ducts are evenly provided with damping holes, and filters are installed on the damping holes; the top ends of the two air ducts are respectively connected to the exhaust fans, and the bottom ends of the air ducts are close to the bottom of the silo, and the exhaust fans are fixed on the roof of the transportation and maintenance workshop on the top plate of the silo; the identification alarm system includes a methane sensor and a dust sensor, which are arranged on the top of the silo. The system detects the gas concentration and dust concentration in the silo in real time. If the gas concentration exceeds 0.5% or the dust concentration exceeds 5g / m 3 , a signal is sent to the control system, which includes: a CPU module, an input module, an output module, a communication module, a power module, and a bus module to control the operation of the local ventilation fan to extract gas and dust.

2. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 1 is characterized by: The methane sensor and dust sensor are respectively set at 1m below the coal inlet. The sensors are firmly installed using a hoisting fixed bracket. Methane sensors and dust sensors are respectively set on both sides of the coal inlet. The distance between the methane sensor and the dust sensor is 1m. The sensor is connected to the power supply and the voltage is ensured to be stable. The 4-20mA signal line of the sensor is connected to the control system to realize real-time monitoring and alarm functions.

3. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 2 is characterized by: The methane sensor uses the GJC4 model, and the dust sensor uses the GCG1000 model to achieve remote monitoring and control; the lifting fixed bracket includes a lifting ring, a lifting chain, and a lifting bracket. The structure of the lifting bracket is a triangular bracket, and one frame of the triangular bracket is set in contact with the bottom of the silo top plate. The lifting ring is a semicircular ring, which is fixed under the frame of the lifting bracket. The bottom of the lifting ring is connected to the lifting chain, and the bottom of the lifting chain is connected to the methane sensor or the dust sensor.

4. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 1 is characterized by: The exhaust fans are two flameproof local ventilators for mining, which are respectively installed on the roof of the warehouse top transport and maintenance workshop by fixing bolts. The joints are sealed with sealant, and the power cord of the ventilator is connected to the control system.

5. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 1 is characterized by: The air duct is a stainless steel circular air duct, and the two air ducts are respectively connected to the two ventilators and extend downward to the bottom of the main part of the silo. The joints are sealed with sealant. The two air ducts are respectively fixed on the left and right sides of the inner wall of the silo using a clamp-type bracket. A number of damping holes of different diameters are opened on both sides of the air duct to adjust the flow rate and wind speed. A filter is installed on the damping hole to prevent coal blocks from entering the air duct and affecting the ventilation performance. The filter is a uniformly distributed metal wire mesh, which is fixed on the damping hole with sealant.

6. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 5 is characterized by: The clamp-type bracket includes a clamp and a support structure, which are made of rigid materials; the clamp is formed by two semicircular steel belts connected by bolts; the support structure includes a hanger rod, a basket nut, and a connecting piece. The hanger rod is a cylindrical rod structure made of high-strength round steel, and the hanger rod is installed on the inner wall of the silo through expansion bolts. The basket nut is connected to the hanger rod and is used to adjust the length of the hanger rod; the connecting piece is a circular orifice plate, and the connecting rod is arranged at the end of the hanger rod and is connected to the clamp through a fixing bolt.

7. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 5 is characterized by: The diameter of the air duct is 576mm, the thickness is 2mm and the height is 40m; each air duct has 24 damping holes on one side from top to bottom, and a total of 48 damping holes are set on both sides of an air duct. Two damping holes are set at the center of the same horizontal hole on an air duct, and the upper and lower spacing between two adjacent damping holes is 1.5m.

8. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 7 is characterized by: The initial diameter of the damping hole is 60 mm. According to the principle of increasing in sequence, the diameters of two adjacent damping holes from top to bottom increase by 2 mm each time.

9. The fully automatic gas and dust extraction device for ground coal storage silo according to claim 5 is characterized by: The filter is made of stainless steel with a pore size of 0.5mm and a thickness of 0.2mm.

10. A method for using the fully automatic gas and dust extraction device for a ground coal storage silo according to any one of claims 1 to 9, characterized in that The following steps are involved: (1) First, connect all electrical equipment of the device to the power supply. When the operation starts, the sorting and sorting silo belt transports the coal blocks to the coal inlet of the silo. When there is a large amount of coal in the silo, the gas contained in the coal accumulates on the top of the silo and adheres to the inner wall of the silo; (2) Use methane sensors and dust sensors to monitor gas concentration and dust in real time. When the gas concentration or dust concentration in the silo exceeds the limit, the sensor transmits an electrical signal to the PLC control system; (3) The control system converts the signal transmitted by the sensor into a signal that adapts to the operation of the fan, and then controls the exhaust fan to start working. The two local exhaust fans adopt a cycle working mode of one pressure in and one extraction; (4) In the first hour of the device operation, the left ventilator implements forced ventilation, and the right ventilator implements exhaust ventilation. The airflow flows in from the damping hole on the left air duct and flows out from the damping hole on the right air duct, making the airflow rotate; (5) When the device is turned to the second hour, the wind direction is reversed, that is, the left fan becomes exhaust ventilation, and the right fan is turned into pressure ventilation, so that the gas and dust extraction effect can be guaranteed, and at the same time, the filter on the damping hole is prevented from being blocked; (6) The device operates in this cyclic manner. When the gas concentration and dust concentration are reduced to a safe range, the device stops operating and the gas and dust are effectively extracted, ensuring the safety of personnel and equipment.

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