A device and method for adding dust-settling agent at a constant ratio under high pressure by using gas control in a mine

Abstract

The present application belongs to the technical field of coal mine dust prevention, and discloses a mine-used gas control type constant-ratio high-pressure self-adding dust-settling agent device and method. The system comprises a shell, a liquid adding cylinder, a pneumatic four-way ball valve and a two-position five-way reversing valve fixedly arranged in the shell. The liquid adding cylinder is divided into two cavities, each cavity is provided with a piston, and each piston divides the cavity into a water injection cavity and a liquid adding cavity. The water inlet of the pneumatic four-way ball valve is connected with a water source, two working outlets are connected with two water injection cavities, and the water inlet and drainage of the two water injection cavities are controlled through the pneumatic four-way ball valve. The dust-settling agent is divided into two paths and respectively communicated with the left liquid adding cavity and the right liquid adding cavity, and after being discharged, is mixed with the water source to form a mixed liquid passage. The two-position five-way reversing valve is connected with a gas source and controls the water passage reversing of the four-way ball valve. The method comprises the steps of initial shunting, alternating water injection driving, alternating dust-settling agent suction and drainage, constant-ratio mixing and magnetic control pneumatic reversing. The present application can realize continuous constant-ratio addition of dust-settling agent, uniform mixing, good dust-settling effect and high safety.

Description

Technical Field

[0001] This invention belongs to the field of coal mine dust control technology, and relates to a device for adding dust suppressant by a pneumatically controlled constant-pressure method, and also relates to a method for adding dust suppressant by a pneumatically controlled constant-pressure method. Background Technology

[0002] During coal mining, large amounts of dust are generated during coal crushing and transportation. Long-term inhalation of this dust can lead to pneumoconiosis, seriously endangering the health of workers. At the same time, high-concentration dust environments can easily trigger explosions, posing a significant threat to safe coal mine production.

[0003] Currently, coal mines mainly use methods such as spray dust suppression and ventilation dilution for dust control. However, simple spray dust suppression has prominent problems such as high water consumption and low capture efficiency for respirable dust (particle size <7μm). To solve these problems, existing technologies often add chemical dust suppressants (such as surfactants and polymers) to significantly reduce the surface tension of dust and improve its wettability and settling efficiency.

[0004] Regarding the addition of chemical dust suppressants, existing technologies mainly employ the following two methods:

[0005] (1) The dust suppressant is drawn into the pipeline and sprayed out with the water flow before spraying by utilizing the siphon phenomenon generated by the jet. This method has the following defects: the dust suppressant is sprayed out before it is fully mixed with water after being drawn in, resulting in unstable dust suppression effect; the dust suppressant flow rate caused by the siphon phenomenon fluctuates greatly, making it impossible to achieve precise proportion addition and affecting the consistency of dust suppression effect.

[0006] (2) High-pressure water and dust suppressant are mixed at atmospheric pressure in a large container, and then sprayed after being pressurized by a high-pressure pump. This method has the following drawbacks: the large mixing container requires a large installation space, which is difficult to apply, especially in the confined environment of the well. It also requires additional large mixing equipment and high-pressure pumps, making the system complex and energy-intensive. Furthermore, the batch mixing method is difficult to adapt to the needs of continuous operation. Summary of the Invention

[0007] The present invention aims to provide a device for mine-use pneumatically controlled constant-ratio high-pressure self-addition of dust suppressant, so as to achieve precise control of the addition ratio, improve dust suppression effect, reduce application space, and adapt to continuous operation.

[0008] The present invention also provides a method for adding dust suppressant by a pneumatically controlled constant-pressure method in mining, so as to improve the uniformity of mixing dust suppressant with high-pressure water.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A device for adding dust suppressant in a mine using a pneumatically controlled constant-pressure method includes a housing, and a liquid adding cylinder, a pneumatic four-way ball valve, and a two-position five-way directional valve are fixedly installed inside the housing.

[0011] The liquid filling cylinder is fixedly equipped with a partition block, which divides the liquid filling cylinder into two non-communicating chambers. A piston is slidably installed in each chamber. The two pistons are connected by a cylinder rod, and a magnet is fixedly installed on each of the two pistons. Each piston divides its chamber into a water injection chamber and a liquid filling chamber. A three-way valve is fixedly installed on each of the two liquid filling chambers. A one-way valve is fixedly installed on the other two ports of the three-way valve. A magnetically controlled pneumatic valve is fixedly installed at the ends of the two water injection chambers of the liquid filling cylinder.

[0012] The inlet of the pneumatic four-way ball valve is connected to the water source, and the two working outlets are respectively connected to the two water injection chambers of the liquid filling cylinder. Its drain outlet is connected to the drain pipe through the ball valve. The pneumatic four-way ball valve controls the water inlet and drain outlet of the two water injection chambers in the liquid filling cylinder, thereby changing the size of the two water injection chambers and forming a circulating control water circuit.

[0013] The dust suppressant is divided into two paths, which are connected to two liquid filling chambers on the liquid filling cylinder. The two liquid filling chambers are connected to two inlets of the four-way valve, and the third inlet of the four-way valve is connected to the water source. When the liquid filling chamber expands, it generates negative pressure to draw in the dust suppressant. When it shrinks, it pressurizes the dust suppressant. The pressurized dust suppressant mixes with the water source to form a mixed liquid passage.

[0014] The gas inlets of the two magnetically controlled pneumatic valves are connected to a gas source, and the gas outlets of the two magnetically controlled pneumatic valves are respectively connected to the two control ports of the two-position five-way directional valve to control the switching of the two-position five-way directional valve; the air inlet of the two-position five-way directional valve is connected to a gas source, and its two working air ports are respectively connected to the two air control ports of the pneumatic four-way ball valve to form a pneumatic control circuit.

[0015] As a limitation of the present invention, the ball valve connected to the drain outlet of the pneumatic four-way ball valve is a flow regulating ball valve, used to control the drainage speed of the water injection chamber, thereby adjusting the addition ratio of dust suppressant.

[0016] As a further limitation of the present invention, after the water source is connected to the filter, it is divided into two paths through a three-way valve. One path is connected to the inlet of the pneumatic four-way ball valve, and the other path is connected to the third inlet of the four-way valve.

[0017] As another limitation of the present invention, a Y-type filter and an air source processor are fixedly provided inside the housing. After the air source passes through the Y-type filter and the air source processor in sequence, it is connected to a two-position five-way reversing valve and a magnetically controlled pneumatic valve.

[0018] As a limitation of the present invention, the cylinder rod is slidably disposed on the partition block, with both ends of the cylinder rod located on both sides of the partition block, and two oil seals are nested in the part of the partition block where the cylinder rod is inserted, and the oil seals seal the cylinder rod.

[0019] As a further limitation of the present invention, two sealing rings are fitted on the outer walls of both pistons, and the sealing rings seal the inner wall of the liquid filling cylinder.

[0020] As a third limitation of the invention, wear-resistant strips are fitted on both pistons.

[0021] A method for adding dust suppressant using a pneumatically controlled, constant-pressure, self-dispensing dust suppressant device in mining includes the following steps:

[0022] S1, Initial diversion: The high-pressure water source is divided into two paths, one of which leads directly to the mixing point and the other leads to the pneumatic four-way ball valve;

[0023] S2, Alternating water injection drive: By switching the pneumatic four-way ball valve, high-pressure water is alternately sent into the two water injection chambers on both sides of the liquid injection cylinder, which pushes the two pistons connected by the cylinder rod to reciprocate.

[0024] S3, alternating suction and discharge of dust suppressant: When the piston moves, it causes the two liquid filling chambers in the liquid filling cylinder to alternately generate negative pressure and positive pressure. When the pressure is negative, the dust suppressant is sucked in, and when the pressure is positive, the dust suppressant that has been sucked in is forced out and sent to the mixing point.

[0025] S4, constant ratio mixing: The extruded dust suppressant and the high-pressure water in S1 that goes directly to the mixing point meet at the mixing point to form a set ratio of high-pressure water containing dust suppressant, which is then output to the spray device.

[0026] S5, Magnetic control pneumatic reversing: When the piston moves to the end of its stroke, the magnet fixed on the piston triggers the magnetic control pneumatic valve installed on the outer wall of the corresponding side cavity, causing the magnetic control pneumatic valve to output a pneumatic signal to the two-position five-way reversing valve, controlling the two-position five-way reversing valve to reverse, and then controlling the pneumatic four-way ball valve to switch the water flow direction, causing the piston to move in the opposite direction.

[0027] S6. Continuous Cyclic Operation: Repeat S2 to S5 to achieve continuous, automatic, and constant-proportion addition of dust suppressant.

[0028] As a limitation of the present invention on a method for adding dust suppressant in a mine using a pneumatically controlled constant-ratio high-pressure system, in S2, the drainage speed of the water injection chamber is changed by adjusting the opening of the ball valve connected to the drain port of the pneumatic four-way ball valve, thereby controlling the speed of the piston reciprocating motion and thus adjusting the addition ratio of the dust suppressant.

[0029] By adopting the above technical solution, the beneficial effects achieved by the present invention compared with the prior art are as follows:

[0030] (1) This invention solves the problem of flow fluctuation caused by jet siphon. It utilizes the reciprocating motion of two pistons in the liquid addition cylinder to form a fixed stroke, so that two reciprocating and changing chambers with fixed volumes are formed in the liquid addition cylinder. Each reciprocating motion results in a constant volume of dust suppressant being sucked in and expelled. With the help of a ball valve to adjust the piston speed, the dust suppressant and high-pressure water can be added in a constant ratio and kept constant for a long time, avoiding dosage runaway. At the same time, the dust suppressant is independently sucked in and expelled in the liquid addition chamber and is fully mixed with high-pressure water at the mixing point. The real-time small-dose mixing method significantly reduces the surface tension of water and greatly improves the uniformity of mixing. The capture efficiency of respirable dust (particle size <7μm) is greatly improved, and the dust suppression effect is significantly improved.

[0031] (2) The entire device of the present invention uses gas as the control power. The magnetic control pneumatic valve and the two-position five-way reversing valve are both pneumatic control elements, which do not require electric drive, completely eliminating the hidden danger of electric sparks, meeting the explosion-proof requirements of coal mines, and making it safer.

[0032] (3) This invention does not require a large atmospheric pressure mixing container. It can automatically and continuously add liquid by integrating a liquid adding cylinder, a pneumatic four-way ball valve and a small pneumatic control component. The overall size is small and the weight is light. It is especially suitable for narrow underground roadways and dust reduction applications for mobile equipment (such as tunneling machines and coal mining machines).

[0033] (4) This invention utilizes the energy of the high-pressure water itself to drive the piston to reciprocate. Through self-priming and pressurization, the dust suppressant is easily and labor-savingly injected into the high-pressure water in a quantitative manner. There is no need to configure a high-pressure pump or stirring equipment, and the energy consumption is low. Moreover, the reciprocating automatic reversal is achieved by triggering the magnetic control pneumatic valve with a magnet. No manual operation is required, and continuous and stable operation can be achieved around the clock, which greatly reduces the operation and maintenance costs.

[0034] (5) By adjusting the opening of the ball valve at the drain port of the pneumatic four-way ball valve, the speed of the piston reciprocating motion can be changed, thereby quantitatively changing the addition ratio of the dust suppressant. It can be flexibly adjusted according to different working conditions (coal type, dust concentration) and has a wide range of applications.

[0035] (6) The dust suppressant of the present invention is always sealed in the storage tank and the liquid filling chamber before addition, and is not mixed with high pressure water in advance. It is only quantitatively pressed out when spraying is required, which avoids the problem of dust suppressant precipitation, failure or waste due to long-term storage or pressure fluctuation in the traditional atmospheric pressure mixing method.

[0036] In summary, this invention enables continuous and constant addition of dust suppressant, resulting in uniform mixing, good dust suppression effect, and high safety. Attached Figure Description

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0038] Figure 1 This is the control loop diagram for Embodiment 1 of the present invention (red lines represent the circulating water circuit, green lines represent the mixed liquid circuit, and blue lines represent the pneumatic control circuit).

[0039] Figure 2 This is a cross-sectional structural diagram of the liquid addition cylinder in Embodiment 1 of the present invention;

[0040] Figure 3 This is a top view of the liquid addition cylinder in Embodiment 1 of the present invention.

[0041] In the diagram: 001, housing; 100, filling cylinder; 101, first cylinder barrel; 102, second cylinder barrel; 103, partition block; 104, cylinder rod; 105, O-ring seal; 106, cylinder head; 107, lead screw; 108, oil seal; 109, first piston; 110, second piston; 111, wear-resistant strip; 112, left water filling chamber; 113, right water filling chamber; 114, left filling chamber; 115, right filling chamber; 116, first tee; 117, second tee; 118, one-way valve; 119, magnet; 120, magnetically controlled pneumatic valve;

[0042] 200. Filter; 300. Pneumatic four-way ball valve; 301. Water inlet; 302. Working outlet; 303. Drain outlet; 304. Air control port; 400. Four-way valve; 500. Dust suppressant storage tank; 600. Y-type filter; 700. Air source processor; 800. Two-position five-way directional valve; 801. Control port; 802. Working air port; 803. Air inlet; 900. Flow regulating ball valve. Detailed Implementation

[0043] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and do not constitute a limitation thereof.

[0044] The use of terms such as "up" and "down" or positional relationships in the embodiments is based on the human body's position when using this embodiment. It is only for the purpose of describing the present invention and simplifying the description, and does not indicate or imply that the device or component must have a specific position, or that it is constructed and operated in a specific position. Therefore, it should not be construed as a limitation on the content protected by the present invention.

[0045] Example 1

[0046] like Figures 1-3As shown, this embodiment is a device for adding dust suppressant in a mine using a pneumatically controlled, constant-ratio, high-pressure system. It includes a housing 001, inside which is fixed a liquid adding cylinder 100, a pneumatic four-way ball valve 300, and a two-position five-way directional valve 800. The liquid adding cylinder 100 cooperates with various control valves to form a circulating control water path and a mixing liquid path. The circulating control water path switches the reciprocating path of the liquid adding cylinder 100 through a pneumatic control circuit to achieve continuous constant-ratio addition of dust suppressant, so that the dust suppressant is fully mixed with high-pressure water.

[0047] The liquid filling cylinder 100 is the actuating element in this embodiment. It is an overall elongated cylindrical structure, including a first cylinder 101, a second cylinder 102, a partition block 103, a cylinder rod 104, and a piston. Both the first cylinder 101 and the second cylinder 102 are cylindrical, while the partition block 103 is cylindrical with a larger diameter in the middle and smaller diameters at both ends. The diameter of the larger cylinder in the middle is the same as the outer diameter of both cylinders 101 and 102, while the diameters of the smaller cylinders at both ends are the same as the inner diameters of both cylinders 101 and 102. During installation, the first cylinder 101 and the second cylinder 102 are inserted into the two smaller-diameter cylinders, and the partition block 103 divides the liquid filling cylinder 100 into two non-communicating chambers. O-rings 105 are embedded in the partition block 103 at the positions where the first cylinder 101 and the second cylinder 102 are fitted, for sealing. The ends of the first cylinder 101 and the second cylinder 102 that are not connected to the separator 103 are both sealed by cylinder heads 106. The structure connecting the cylinder heads 106 to the first cylinder 101 and the second cylinder 102 is as follows: four lead screws 107 are fixed on the outer walls of both the first cylinder 101 and the second cylinder 102. After the two cylinder heads 106 pass through the lead screws 107, they abut against the end faces of the first cylinder 101 and the second cylinder 102, respectively. Nuts are screwed onto the lead screws 107. By tightening the nuts, the cylinder heads 106 are pressed tightly against the end faces of the first cylinder 101 and the second cylinder 102, thus achieving a seal. A magnetically controlled pneumatic valve 120 is fixed on each of the two cylinder heads 106.

[0048] The cylinder rod 104 is slidably and sealingly mounted on the partition block 103. Two oil seals 108 are embedded at the connection point between the partition block 103 and the cylinder rod 104, achieving a seal between the cylinder rod 104 and the partition block 103. A first piston 109 and a second piston 110 are fixedly mounted at both ends of the cylinder rod 104. The first piston 109 is slidably and sealingly connected to the inner wall of the first cylinder 101, and two O-rings 105 are fitted on the first piston 109, both fitting against the inner wall of the first cylinder 101 for sealing. The second piston 110 is slidably connected to the inner wall of the second cylinder 102, and two O-rings 105 are fitted on the second piston 110, both fitting against the inner wall of the second cylinder 102 for sealing. Wear-resistant strips 111 are fitted on both the first piston 109 and the second piston 110, and these strips rub against the inner walls of the first and second cylinders 101 and 102. The first piston 109 divides the first cylinder 101 into a left water injection chamber 112 and a left liquid filling chamber 114, and the second piston 110 divides the second cylinder 102 into a right water injection chamber 113 and a right liquid filling chamber 115.

[0049] A first three-way valve 116 is fixedly connected to the left filling chamber 114, and a second three-way valve 117 is fixedly connected to the right filling chamber 115. Taking the left filling chamber 114 as an example, the three ports of the first three-way valve 116 correspond to the left filling chamber 114, the outlet pipe of the dust suppressant storage tank 500, and one inlet of the four-way valve 400 at the water-liquid mixing point, respectively. A one-way valve 118 is installed on the inlet of the first three-way valve 116 connecting to the dust suppressant storage tank 500. This one-way valve 118 only allows the dust suppressant to flow from the storage tank to the left filling chamber 114 and cannot flow in the opposite direction. A one-way valve 118 is also installed on the outlet of the pipe connecting the first three-way valve 116 to the four-way valve 400 at the mixing point. This one-way valve 118 only allows the dust suppressant to flow from the left filling chamber 114 to the four-way valve 400 and cannot flow in the opposite direction. The connection method between the right filling chamber 115 and the dust suppressant storage tank 500 and the four-way valve 400 is exactly the same. Both liquid filling chambers can independently perform the two actions of "drawing in dust suppressant" and "discharging dust suppressant", and the flow direction is forcibly limited by the one-way valve 118.

[0050] The liquid addition cylinder 100 is connected to the water source, air source, and dust suppressant storage tank 500 to form a circulating control water circuit, a mixed liquid circuit, and an air control circuit. This will be explained in detail below.

[0051] I. Circulating water control circuit

[0052] The water source comes from a high-pressure water supply pipeline underground in the mine. A filter 200 is fixedly installed inside the casing 001. The water source first passes through a filter 200 to remove impurities in the water, and then is divided into two paths through a three-way valve:

[0053] First path (direct mixing path): The high-pressure water source is directly connected to one inlet of the four-way valve 400 at the mixing point, serving as the basic water flow for mixing with the dust suppressant.

[0054] The second path (drive and proportional control path): The high-pressure water source is connected to the inlet 301 of the pneumatic four-way ball valve 300, which is fixed on the housing 001.

[0055] The pneumatic four-way ball valve 300 is a pneumatically controlled directional valve with a double L-shaped flow channel structure. It has four internal ports: one inlet 301 (connected to a water source), two working outlets 302 (connected to the left and right water inlets 112 and 113 of the filling cylinder 100 respectively), and one drain outlet 303 (connected to a drain pipe or drain tank via a ball valve). The pneumatic four-way ball valve 300 also has two air ports 304 for introducing gas to control the opening and closing of the two working outlets 302. This ball valve uses a flow regulating ball valve 900; by adjusting its opening, the resistance to drainage from the water inlet chamber can be changed, thereby controlling the reciprocating speed of the piston.

[0056] II. Mixed Pathway

[0057] The dust suppressant storage tank 500 is located outside the housing 001. The dust suppressant storage tank 500 is connected to the first three-way inlet 116 of the left filling chamber 114 (via one-way valve 118) and the second three-way inlet 117 of the right filling chamber 115 (via one-way valve 118) via a three-way valve. The outlet of the first three-way valve 116 on the left filling chamber 114 (via another one-way valve 118) and the outlet of the second three-way valve 117 on the right filling chamber 115 (via another one-way valve 118) are both connected to the other two inlets of the four-way valve 400 at the mixing point via pipelines. The four-way valve 400 is fixed to the housing 001.

[0058] The four-way valve 400 has four ports: three inlets (receiving high-pressure water from the direct water supply channel, dust suppressant from the left filling chamber 114, and dust suppressant from the right filling chamber 115, respectively) and one outlet (connected to a spray device). Therefore, regardless of which filling chamber dispenses the dust suppressant, it can instantly merge with the direct high-pressure water within the four-way valve 400 to form a uniform mixture.

[0059] III. Pneumatic Control Circuit

[0060] The air source uses a compressed air pipeline commonly used in underground mines. A Y-type filter 600 and an air source processor 700 are fixedly installed inside the housing 001. After passing through the Y-type filter 600 (for filtering impurities) and the air source processor 700 (for pressure stabilization), the air source is divided into two paths. One path connects to a 2-position 5-way directional valve 800, and the other path connects to two magnetically controlled pneumatic valves 120. The 2-position 5-way directional valve 800 is a pneumatically controlled directional valve using existing technology, which has two control ports 801, two working air ports 802, and one inlet port 803. Specifically, after the air source is divided into two paths, one path connects to the inlet port 803 of the 2-position 5-way directional valve 800, and the two working air ports 802 of the 2-position 5-way directional valve 800 are respectively connected to the two pneumatic control ports 304 of the pneumatic 4-way ball valve 300. Another path of the air source is connected to the gas inlet of each of the two magnetically controlled pneumatic valves 120. The gas outlets of the two magnetically controlled pneumatic valves 120 are connected to the two control ports 801 of the two-position five-way directional valve 800, forming a pneumatic control circuit. The principle of the pneumatic control circuit in this embodiment is as follows: when the magnet 119 on the first piston 109 moves to a position close to the cylinder head 106, the cavity of the left water injection chamber 112 becomes smaller, and the magnetic force of the magnet 119 makes the gas inlet and gas outlet of the magnetically controlled pneumatic valve 120 on that side open. The air source enters the left control port 801 of the two-position five-way directional valve 800 from the magnetically controlled pneumatic valve 120, causing the working air port 802 on the left side of the two-position five-way directional valve 800 to open. Air enters the pneumatic four-way ball valve 300 through the air inlet 803 of the two-position five-way directional valve 800, controlling the opening of the upper working outlet 302 of the pneumatic four-way ball valve 300. This allows high-pressure water to enter the left water injection chamber 112, pushing the second piston 110 to the right. When the second piston 110 reaches its limit position near the cylinder head 106 on that side, the same principle activates the right-side magnetically controlled pneumatic valve 120, which in turn opens the lower working outlet 302 of the pneumatic four-way ball valve 300, allowing high-pressure water to enter the right water injection chamber 113. This cycle repeats. In other words, one air source controls the two-position five-way directional valve 800 to switch directions through the magnetically controlled pneumatic valve 120, while another air source enters the pneumatic four-way ball valve 300 through the air inlet 803 of the two-position five-way directional valve 800, controlling the pneumatic four-way ball valve 300 to switch the water flow direction (i.e., switch the conduction state of the two working outlets 302).

[0061] IV. Working Principle of this Embodiment

[0062] The piston reciprocates using the energy of the high-pressure water itself. Pneumatic reversal is triggered by a position sensor on magnet 119, enabling continuous automatic reciprocating motion. Simultaneously, the fixed stroke of the piston creates a fixed volume, ensuring a constant dust suppressant addition ratio. The addition ratio is quantitatively adjusted by changing the piston's reciprocating speed through regulating the drainage resistance. The entire working cycle is described in detail below.

[0063] (1) Initial state and first half of the stroke (piston moves from left to right)

[0064] Assuming the system starts up, the pneumatic four-way ball valve 300 is in the initial position with its upper working outlet 302 open. High-pressure water enters the pneumatic four-way ball valve 300 through the inlet 301 and is guided to the left water injection chamber 112. The pressure generated by the high-pressure water entering the left water injection chamber 112 pushes the first piston 109 to the right. Since the two pistons are rigidly connected by the cylinder rod 104, the second piston 110 also moves to the right synchronously. As the first piston 109 moves to the right, the volume of the left liquid injection chamber 114 gradually decreases, and the pressure increases. The dust suppressant previously stored in the left liquid injection chamber 114 is compressed. When the pressure exceeds the opening pressure of the one-way valve 118 at the outlet of the first three-way valve 116, the dust suppressant is forced out and flows to the four-way valve 400. As the second piston 110 moves to the right, the volume of the right liquid injection chamber 115 gradually increases, generating negative pressure. When the negative pressure exceeds the opening pressure of the inlet check valve 118 of the second three-way valve 117, the dust suppressant is drawn into the right liquid filling chamber 115. Simultaneously, the water in the right water injection chamber 113 is squeezed by the second piston 110 and discharged through the flow regulating ball valve 900 on the pneumatic four-way ball valve 300. High-pressure water continuously enters the left water injection chamber 112, pushing the first piston 109 to continue moving to the right.

[0065] (2) Reversal trigger (end of journey)

[0066] When the second piston 110 moves to its rightmost endpoint, the magnet 119 on the second piston 110 is just close to the sensing area of ​​the right-side magnetically controlled pneumatic valve 120, causing the gas inlet and outlet of the right-side magnetically controlled pneumatic valve 120 to open. The magnetically controlled pneumatic valve 120 changes from a normally closed state to an open state, delivering air to the right control port 801 of the two-position five-way directional valve 800. After receiving the air signal, the internal valve core of the two-position five-way directional valve 800 switches, changing the air output state, opening the working air port 802 on the right side of the two-position five-way directional valve 800, and consequently opening the working outlet 302 below the pneumatic four-way ball valve 300, allowing high-pressure water to enter the right water injection chamber 113.

[0067] (3) The second half of the stroke (the piston moves from right to left)

[0068] When the pneumatic four-way ball valve 300 reverses direction, high-pressure water enters the right water injection chamber 113. The high-pressure water pushes the second piston 110 to the left, and through the cylinder rod 104, it drives the first piston 109 to move to the left simultaneously. At this time, the volume of the right liquid filling chamber 115 decreases and the pressure increases, forcing the dust suppressant just drawn into the chamber out through the one-way valve 118 at the outlet of the second three-way valve 117, and sending it to the four-way valve 400 at the mixing point. Simultaneously, the volume of the left liquid filling chamber 114 increases, generating negative pressure and drawing in the dust suppressant. The water in the left water injection chamber 112 is squeezed by the first piston 109 and discharged through the flow regulating ball valve 900 on the pneumatic four-way ball valve 300. When the first piston 109 moves to its leftmost end point, the magnet 119 on the first piston 109 triggers the left-side magnetically controlled pneumatic valve 120. The left-side magnetically controlled pneumatic valve 120 is open, supplying air to the control port 801 on the left side of the two-position five-way directional valve 800, causing the two-position five-way directional valve 800 to switch. The working air port 802 on the left side of the two-position five-way directional valve 800 is open, and the air source entering through the air inlet 803 of the two-position five-way directional valve 800 controls the working outlet 302 above the pneumatic four-way valve 300 to open, allowing high-pressure water to enter the left water injection chamber 112. This process repeats, causing the two liquid filling chambers to alternately draw in and expel dust suppressant, ensuring that the dust suppressant is continuously supplied to the four-way valve 400 at the mixing point.

[0069] (4) Mixing and constant proportion

[0070] At the four-way valve 400 at the mixing point, high-pressure water from the direct-flow water supply line merges with dust suppressant from the filling chamber. Because the volume of dust suppressant expelled with each complete piston stroke (from one end to the other) is exactly equal to the volume of one filling chamber (which is fixed by the design dimensions of the filling cylinder 100), and the high-pressure water flow rate from the direct-flow line remains essentially constant under stable system conditions, and because the piston's reciprocating speed remains essentially constant at the given flow rate regulating ball valve 900 opening, the mixing ratio remains constant.

[0071] (5) Proportional adjustment principle

[0072] Adjusting the opening of the ball valve installed on the drain port of the pneumatic four-way ball valve 300 changes the resistance to drainage from the water injection chamber. When the ball valve opening decreases, the drainage resistance increases, and the piston reciprocating speed slows down; conversely, when the opening increases, the piston reciprocating speed increases. This change in piston speed directly alters the volumetric flow rate of the dust suppressant extruded per unit time, while the flow rate in the direct water path remains essentially constant (due to its fixed resistance). Therefore, the proportion of dust suppressant added will change accordingly. Because the ball valve allows for stepless adjustment, the addition ratio can be continuously adjusted within a certain range to suit different coal types and dust concentrations.

[0073] Example 2

[0074] This embodiment describes a method for adding dust suppressant using a pneumatically controlled constant-pressure self-addition method in mining. The method utilizes the apparatus of Embodiment 1 to add the dust suppressant and includes the following steps:

[0075] S1. The high-pressure water source first passes through filter 200 to remove impurities. The filtered high-pressure water enters a three-way valve, which divides the high-pressure water flow into two paths: one path is directly connected to an inlet of four-way valve 400 at the mixing point, serving as the basic water flow for mixing with the dust suppressant; the other path is connected to the inlet of pneumatic four-way ball valve 300, used to drive the piston of liquid adding cylinder 100 to reciprocate and control the intake and discharge of dust suppressant.

[0076] S2. Alternating water injection drive: Under the pneumatic control signal of the two-position five-way directional valve 800, the pneumatic four-way ball valve 300 periodically switches its internal flow channel to alternately send high-pressure water into the left water injection chamber 112 and the right water injection chamber 113 of the liquid filling cylinder 100, pushing the first piston 109 and the second piston 110 connected by the cylinder rod 104 to reciprocate.

[0077] S3, alternating suction and discharge of dust suppressant: When the two pistons move, the left liquid filling chamber 114 and the right liquid filling chamber 115 alternately increase and decrease. The increase of the chamber creates a negative pressure, and the decrease of the chamber creates a positive pressure. When the pressure is negative, the dust suppressant is drawn into the dust suppressant storage tank 500. When the pressure is positive, the dust suppressant that has been drawn in is pushed out and sent to the inlet of the four-way valve 400 at the mixing point.

[0078] S4, constant ratio mixing: The extruded dust suppressant and the high-pressure water in S1 that goes directly to the mixing point are combined at the four-way valve 400 at the mixing point to form a set ratio of high-pressure water containing dust suppressant, which is then output to the spray device.

[0079] S5. Magnetic-controlled pneumatic reversing: After passing through the Y-type filter 600 and the air source processor 700, one path of the air source is connected to the air inlet 803 of the two-position five-way reversing valve 800, and the other path is connected to the gas inlets of two magnetically controlled pneumatic valves 120. When one of the pistons moves to the end of its stroke, the magnet 119 fixed on the piston triggers the magnetically controlled pneumatic valve 120 on that side to open, outputting a gas signal to the two-position five-way reversing valve 800, driving the two-position five-way reversing valve 800 to reverse, thereby controlling the pneumatic four-way ball valve 300 to switch the water flow direction, causing the piston to move in the opposite direction, thereby controlling the switching path of the circulating water circuit, and switching the suction and discharge paths of the dust suppressant.

[0080] S6. Continuous Cyclic Operation: Repeat steps S2 to S5 above. The two pistons in the liquid addition cylinder 100 automatically and continuously reciprocate. The left liquid addition chamber 114 and the right liquid addition chamber 115 alternately draw in and expel the dust suppressant. The four-way valve 400 always receives a uniform mixture of dust suppressant and high-pressure water, which is finally delivered to the spraying device for dust suppression. The entire process requires no manual intervention and no electricity. It can achieve continuous and constant-ratio addition around the clock solely by the energy of the high-pressure water itself and the downhole compressed air.

[0081] In step S2, the flow regulating ball valve 900 installed on the drain port of the pneumatic four-way ball valve 300 can be adjusted to change the resistance of the water injection chamber drainage, thereby controlling the reciprocating speed of the piston and thus changing the addition ratio of the dust suppressant.

[0082] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for mine-use pneumatically controlled constant-pressure self-addition of dust suppressant, characterized in that, Includes a housing, within which a liquid filling cylinder, a pneumatic four-way ball valve, and a two-position five-way directional valve are fixedly installed; The liquid filling cylinder is fixedly equipped with a partition block, which divides the liquid filling cylinder into two non-communicating chambers. A piston is slidably installed in each chamber. The two pistons are connected by a cylinder rod, and a magnet is fixedly installed on each of the two pistons. Each piston divides its chamber into a water injection chamber and a liquid filling chamber. A three-way valve is fixedly installed on each of the two liquid filling chambers. A one-way valve is fixedly installed on the other two ports of the three-way valve. A magnetically controlled pneumatic valve is fixedly installed at the ends of the two water injection chambers of the liquid filling cylinder. The inlet of the pneumatic four-way ball valve is connected to the water source, and the two working outlets are respectively connected to the two water injection chambers of the liquid filling cylinder. Its drain outlet is connected to the drain pipe through the ball valve. The pneumatic four-way ball valve controls the water inlet and drain outlet of the two water injection chambers in the liquid filling cylinder, thereby changing the size of the two water injection chambers and forming a circulating control water circuit. The dust suppressant is divided into two paths, which are connected to two liquid filling chambers on the liquid filling cylinder. The two liquid filling chambers are connected to two inlets of the four-way valve, and the third inlet of the four-way valve is connected to the water source. When the liquid filling chamber expands, it generates negative pressure to draw in the dust suppressant. When it shrinks, it pressurizes the dust suppressant. The pressurized dust suppressant mixes with the water source to form a mixed liquid passage. The gas inlets of the two magnetically controlled pneumatic valves are connected to a gas source, and the gas outlets of the two magnetically controlled pneumatic valves are respectively connected to the two control ports of the two-position five-way directional valve to control the switching of the two-position five-way directional valve; the air inlet of the two-position five-way directional valve is connected to a gas source, and its two working air ports are respectively connected to the two air control ports of the pneumatic four-way ball valve to form a pneumatic control circuit.

2. The device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to claim 1, characterized in that, The ball valve connected to the drain outlet of the pneumatic four-way ball valve is a flow regulating ball valve, used to control the drainage speed of the water injection chamber, thereby adjusting the addition ratio of dust suppressant.

3. The device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to claim 2, characterized in that, After the water source is connected to the filter, it is divided into two paths through a three-way valve. One path is connected to the inlet of the pneumatic four-way ball valve, and the other path is connected to the third inlet of the four-way valve.

4. A device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to any one of claims 1-3, characterized in that, The housing is equipped with a Y-type filter and an air source processor. The air source passes through the Y-type filter and the air source processor in sequence and is then connected to a two-position five-way reversing valve and a magnetically controlled pneumatic valve.

5. The device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to claim 4, characterized in that, The cylinder rod is slidably mounted on the partition block, with both ends of the cylinder rod located on either side of the partition block. Two oil seals are nested at the part of the partition block where the cylinder rod is inserted, and the oil seals seal the cylinder rod.

6. The device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to claim 5, characterized in that, Two sealing rings are fitted on the outer walls of both pistons, which seal against the inner wall of the liquid filling cylinder.

7. A device for adding a mine-use pneumatically controlled constant-pressure self-dispensing dust suppressant according to any one of claims 1-3, 5, and 6, characterized in that, Both pistons are fitted with wear-resistant strips.

8. A method for adding a self-regulating, pneumatically controlled, constant-ratio, high-pressure dust suppressant for mining, characterized in that... A method for adding dust suppressant using a mine-use pneumatically controlled constant-pressure self-adding dust suppressant device according to any one of claims 1-7 includes the following steps: S1, Initial diversion: The high-pressure water source is divided into two paths, one of which leads directly to the mixing point and the other leads to the pneumatic four-way ball valve; S2, Alternating water injection drive: By switching the pneumatic four-way ball valve, high-pressure water is alternately sent into the two water injection chambers on both sides of the liquid injection cylinder, which pushes the two pistons connected by the cylinder rod to reciprocate. S3, alternating suction and discharge of dust suppressant: When the piston moves, it causes the two liquid filling chambers in the liquid filling cylinder to alternately generate negative pressure and positive pressure. When the pressure is negative, the dust suppressant is sucked in, and when the pressure is positive, the dust suppressant that has been sucked in is forced out and sent to the mixing point. S4, constant ratio mixing: The extruded dust suppressant and the high-pressure water in S1 that goes directly to the mixing point meet at the mixing point to form a set ratio of high-pressure water containing dust suppressant, which is then output to the spray device. S5, Magnetic control pneumatic reversing: When the piston moves to the end of its stroke, the magnet fixed on the piston triggers the corresponding magnetic control pneumatic valve to open, so that the magnetic control pneumatic valve outputs a pneumatic signal to the two-position five-way reversing valve, controls the two-position five-way reversing valve to reverse, and then controls the pneumatic four-way ball valve to switch the water flow direction, so that the piston moves in the opposite direction. S6. Continuous Cyclic Operation: Repeat S2 to S5 to achieve continuous, automatic, and constant-proportion addition of dust suppressant.

9. A method for adding a mine-use pneumatically controlled constant-pressure self-adding dust suppressant according to claim 8, characterized in that, In S2, by adjusting the opening of the ball valve connected to the drain port of the pneumatic four-way ball valve, the drainage speed of the water injection chamber is changed, thereby controlling the speed of the piston reciprocating motion and thus adjusting the addition ratio of dust suppressant.

Images