Foam fluid preparation system with solid phase particles and material addition ratio control method

Abstract

This invention discloses a system for preparing foamed fluid containing solid particles and a method for controlling the material addition ratio. The system includes: a slurry supply unit for metering and mixing solid raw materials and liquids to form and output a slurry containing solid particles with adjustable flow rate; a foaming liquid supply unit for storing and outputting a foaming liquid with adjustable flow rate; a gas supply unit for providing gas with adjustable pressure and flow rate; a mixing output unit for receiving and mixing the slurry from the slurry supply unit, the foaming liquid from the foaming liquid supply unit, and the gas from the gas supply unit to form and output a foamed fluid containing solid particles; and a control unit for receiving the flow rate or weight signals of each material and controlling the output of each supply unit according to preset material ratio parameters to achieve proportional preparation of the foamed fluid. This system can prepare foamed fluid materials containing solid particles with different material addition ratios, achieving efficient prevention and control of coal spontaneous combustion disasters in mines.

Description

Technical Field

[0001] This invention relates to the field of coal spontaneous combustion prevention technology in mine goaf areas, and particularly to a foam fluid preparation system containing solid particles and a method for controlling the addition ratio of foam fluid containing solid particles. Background Technology

[0002] my country's coal mining primarily targets spontaneously combustible and self-igniting coal seams. With increasing mining intensity and depth, coal fire accidents are becoming more frequent. Spontaneous combustion of coal is one of the major hazards encountered during mining. It not only destroys coal resources, causing enormous economic losses, but also produces large amounts of harmful gases such as CO, polluting the air and environment. Furthermore, spontaneous combustion often triggers gas explosions and dust explosions, seriously threatening the lives of underground personnel.

[0003] The foam fluid fire extinguishing technology containing solid particles involves quantitatively adding a foaming liquid composed of various chemical reagents to fly ash or yellow mud slurry. This foaming liquid is then mixed with a large flow of gas to produce a continuous foam fluid material that is output to the goaf in underground coal mines. The foam fluid, produced by this specific mixing ratio, can cover large areas of residual coal in the goaf for extended periods, effectively preventing spontaneous combustion accidents. The mixing ratio of the slurry to the foaming liquid in the solid particle-containing foam fluid significantly affects performance parameters such as foam retention time. Currently used foam proportioners operate on the principle of negative pressure suction. A pump delivers pressurized water at high speed through the throat of a venturi tube, creating a negative pressure zone at the throat. Simultaneously, the throat is connected to the foam liquid outlet via a pipe. Driven by the pressure difference, the foam liquid is automatically and continuously drawn into the venturi tube, thus mixing proportionally with the pressurized water. However, the structure of the venturi tube dictates that the flow rate of the added foam liquid must always maintain a constant ratio with the flow rate of the pressurized water; the ratio of foam liquid to slurry cannot be adjusted within a certain range according to actual usage conditions. In addition, the mixing of foam proportions relies on system pressure, and when the flow rate changes too much, it is difficult to ensure the accuracy of the addition ratio, which reduces the fire extinguishing effect of the prepared foam fluid.

[0004] To prepare foam with a fixed ratio, Chinese patent CN116570865B proposes a foam proportioning mixing device and mixing control unit for fire fighting. This device uses a pump to extract foam liquid and water from a storage tank to achieve a quantitative proportion of fire-fighting foam. However, it can only be used for two-phase foam preparation and its application effect in preventing spontaneous combustion in coal mines is poor. Chinese patent CN110354422B proposes a negative pressure mobile foam generator, which achieves the preparation and output of large-flow solids-containing foam. However, its foam mixing ratio is fixed, making it difficult to automatically adjust the addition ratio of foaming liquid and slurry for different application conditions. Therefore, the foaming performance of the prepared foam cannot meet the needs of coal mine fire prevention and extinguishing.

[0005] In summary, existing fire prevention and extinguishing measures and materials have the following problems: 1. Traditional fire prevention and extinguishing measures in coal mines, such as injecting yellow mud slurry, injecting nitrogen, liquid carbon dioxide, and adding chemical inhibitors, have problems such as poor fire extinguishing effect, small control area, and difficulty in covering high-level fire sources, making it difficult to effectively prevent coal spontaneous combustion disasters in coal mine goaf areas; 2. Currently, fire-fighting foam materials are mainly two-phase foams. Foams are easily affected by the external environment, which can lead to thinning and cracking. They have a short stability time, poor accumulation effect, and are not effective in covering coal residues in goaf areas. Therefore, it is difficult to effectively prevent and control coal spontaneous combustion disasters in underground goaf areas. 3. The expansion ratio and stabilization time of foam fluids containing solid particles are affected by the mixing ratio of foaming liquid and slurry. Currently, foam proportioning devices use a negative pressure proportioning method. The pressurized water generated by the pump flows through the Venturi tube in the mixer to create negative pressure, causing the foam liquid to be automatically drawn into the mixer and mixed in proportion. However, the mixing ratio is determined by the device's structural parameters and is difficult to adjust within a certain range. Furthermore, the addition ratio is driven by pressure, resulting in low proportioning accuracy. Summary of the Invention This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to propose a foam fluid preparation system containing solid particles, capable of preparing solid-containing foam fluid materials with different material addition ratios for various applications such as coal mine fire prevention and extinguishing injection sealing and pile spraying, thereby achieving efficient prevention and control of coal spontaneous combustion disasters in mines.

[0006] The second objective of this invention is to provide a method for controlling the addition ratio of foam fluid materials containing solid particles.

[0007] To achieve the above objectives, a first aspect of the present invention provides a foam fluid preparation system containing solid particles, comprising: a slurry supply unit, a foaming liquid supply unit, a gas supply unit, a mixing output unit, and a control unit; wherein, The slurry supply unit is used to meter and mix solid raw materials and liquids to form and output a slurry containing solid particles with adjustable flow rate. A foaming liquid supply unit is used to store and output foaming liquid with adjustable flow rate; A gas supply unit is used to provide gas with adjustable pressure and flow rate; The mixing output unit has a mixing chamber for receiving and mixing slurry from the slurry supply unit, foaming liquid from the foaming liquid supply unit, and gas from the gas supply unit to form and output a foam fluid containing solid particles. The control unit is connected to the slurry supply unit, foaming liquid supply unit, and gas supply unit respectively. It is used to receive the flow rate or weight signal of each material and control the output of each supply unit according to the preset material ratio parameters to achieve the proportional preparation of foam fluid.

[0008] In addition, the foam fluid preparation system containing solid particles according to the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the slurry supply unit includes a slurry preparation tank, a solid raw material metering and adding module, and a liquid metering and adding module; The solid raw material metering and adding module includes a hopper, a screw conveyor, and an on / off valve connected in sequence. A weighing sensor is installed between the screw conveyor and the on / off valve. The weighing sensor is used to measure the weight of the solid raw material entering the pulping tank. The control unit is connected to the weighing sensor and the on / off valve respectively. The control unit is used to control the on / off valve to open when the solid raw material conveyed by the screw conveyor reaches the required weight, so as to convey a certain amount of solid raw material to the pulping tank. The liquid metering and adding module includes a water tank, a water tank screw pump, and a water tank electromagnetic flow regulating valve connected in sequence. The water tank screw pump is connected to a water tank screw pump speed regulating motor, and a water flow sensor is installed between the water tank screw pump and the water tank electromagnetic flow regulating valve. The control unit is connected to the water tank screw pump speed regulating motor, the water flow sensor, and the water tank electromagnetic flow regulating valve respectively. The water tank screw pump speed is controlled by the water tank screw pump speed regulating motor to achieve a wide range of flow rate adjustment. The control unit controls the opening degree of the water tank electromagnetic flow regulating valve to fine-tune the output water flow rate, so as to provide a quantitative amount of liquid to the pulping tank and mix it with the solid raw materials.

[0009] According to one embodiment of the present invention, the slurry supply unit further includes a mud pump and a slurry electromagnetic flow regulating valve located at the outlet of the slurry tank. A filter screen is provided between the outlet of the slurry tank and the mud pump. The mud pump is connected to a mud pump speed regulating motor. A slurry flow sensor is provided between the mud pump and the slurry electromagnetic flow regulating valve. The control unit is connected to the slurry flow sensor, the slurry electromagnetic flow regulating valve, and the mud pump speed regulating motor respectively. The control unit is used to control the mud pump speed regulating motor and the slurry electromagnetic flow regulating valve in real time according to the slurry flow rate, so as to control the magnitude of the slurry input flow rate.

[0010] According to one embodiment of the present invention, the foaming liquid supply unit includes a foaming liquid storage tank, a foaming liquid screw pump, and a foaming liquid electromagnetic flow regulating valve connected in sequence. The foaming liquid screw pump is connected to a foaming liquid screw pump speed regulating motor. A foaming liquid flow sensor is provided between the foaming liquid screw pump and the foaming liquid electromagnetic flow regulating valve. The control unit is connected to the foaming liquid screw pump speed regulating motor, the foaming liquid flow sensor, and the foaming liquid electromagnetic flow regulating valve respectively. The control unit is used to control the foaming liquid screw pump speed regulating motor and the foaming liquid electromagnetic flow regulating valve according to the foaming liquid flow rate, so as to realize the quantitative control input of the foaming liquid addition flow rate.

[0011] According to one embodiment of the present invention, the gas supply unit includes an air compressor, an electric regulating valve, and a gas flow meter. The control unit is connected to the electric regulating valve and the gas flow meter by signal. The control unit is used to control the opening degree of the electric regulating valve to realize real-time control of the gas flow.

[0012] According to one embodiment of the present invention, the mixing output unit includes a mixer, which is connected to a slurry supply unit via a slurry input pipeline, a foaming liquid supply unit via a foaming liquid input pipeline, and a gas supply unit via an air inlet pipeline. A pressure gauge is installed on the air inlet pipeline for real-time monitoring of the pressure value of the input gas.

[0013] According to one embodiment of the present invention, the control unit is configured to adjust the output flow rate of the foaming liquid supply unit so that the volume ratio of foaming liquid to slurry added is precisely adjustable within the range of 0.3% to 6%, with an adjustment accuracy of 0.1%; wherein the control unit is a PLC controller, which has preset values ​​for the mixing ratio of foaming liquid and slurry, including at least 1%, 3%, and 6%.

[0014] To achieve the above objectives, a second aspect of the present invention provides a method for controlling the addition ratio of solid-phase particle-containing foam fluid materials. This method, based on the solid-phase particle-containing foam fluid preparation system described in the above embodiment, includes the following steps: S1, through the control unit, sets the target parameters for solid raw materials, water, slurry, foaming liquid and gas; S2, control the slurry supply unit to prepare slurry, and adjust its output flow rate according to the target parameters; S3, control the foaming liquid supply unit to adjust the output flow rate of the foaming liquid according to the target parameters; S4, the gas supply unit adjusts the gas output flow rate and / or pressure according to the target parameters; S5 mixes the proportionally output slurry, foaming liquid, and gas in the mixing output unit to form and output a foam fluid containing solid particles.

[0015] According to an embodiment of the present invention, adjusting the slurry output flow rate in step S2 includes: firstly, coarsely adjusting the flow rate by adjusting the speed of the drive motor, and then finely adjusting the flow rate by adjusting the opening of the electromagnetic flow regulating valve on the pipeline; the same control strategy combining coarse and fine adjustment is adopted in adjusting the foaming liquid output flow rate in step S3; wherein, when finely adjusting the flow rate, a PID control algorithm with flow deviation as input is adopted.

[0016] According to an embodiment of the present invention, the above-described method for controlling the addition ratio of solid-phase particle-containing foam fluid materials further includes: S6. After preparation is completed, first stop the gas supply unit, then stop the foaming liquid supply unit, and finally stop the slurry supply unit. During the stopping process, each flow regulating valve is closed in sequence.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) In view of the problem that current coal mine fire prevention and extinguishing materials are difficult to effectively prevent coal spontaneous combustion disasters, the present invention designs a foam fluid preparation system containing solid particles. Through a slurry supply unit, a foam liquid supply unit, a gas supply unit and a mixing output unit, the preparation and output of foam fluid fire prevention and extinguishing materials containing solid particles are realized. The generated solid foam fluid can be transported through pipelines to the goaf area in the mine where there is a risk of coal spontaneous combustion, so as to achieve efficient prevention and control of coal mine fires.

[0018] (2) In view of the problem of low material addition ratio accuracy in the preparation of solid foam fluid, the present invention designs a material addition ratio control method. Solid particles, water, foam liquid and gas are transported to the mixer through different pipelines. The precise ratio mixing of foam liquid, slurry and gas is achieved by controlling the pump speed and opening and closing of electromagnetic flow regulating valve. At the same time, the addition ratio of each material can be continuously and linearly adjusted according to the application to prepare solid foam fluid with different performance parameters.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 This is a block diagram of a foam fluid preparation system containing solid particles according to an embodiment of the present invention; Figure 2 This is a flowchart of a method for controlling the addition ratio of solid-phase particle foam fluid materials according to an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Slurry supply unit; 2. Silo; 3. Screw conveyor; 4. Weighing sensor; 5. Opening / closing valve; 6. Water tank; 7. Water tank screw pump; 8. Water tank screw pump speed control motor; 9. Water flow sensor; 10. Water tank electromagnetic flow regulating valve; 11. Slurry tank; 12. Filter screen; 13. Mud pump speed control motor; 14. Mud pump; 15. Slurry flow sensor; 16. Slurry electromagnetic flow regulating valve; 17. Foaming liquid supply unit; 18. Foaming liquid 19. Storage tank; 20. Foaming liquid screw pump; 21. Foaming liquid screw pump speed control motor; 22. Foaming liquid flow sensor; 23. Foaming liquid electromagnetic flow regulating valve; 24. Gas supply unit; 25. Air compressor; 26. Electric regulating valve; 27. Gas flow meter; 28. Proportional mixing unit; 29. ​​Slurry input pipeline; 30. Foaming liquid input pipeline; 31. Pressure gauge; 32. Air inlet pipeline; 33. Mixer; 34. Outlet pipeline; 35. Control unit. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The following description, with reference to the accompanying drawings, illustrates the foam fluid preparation system containing solid particles and the method for controlling the addition ratio of foam fluid materials containing solid particles, as proposed in embodiments of the present invention.

[0024] like Figure 1 As shown, the foam fluid preparation system containing solid particles according to an embodiment of the present invention includes: a slurry supply unit 1, a foaming liquid supply unit 17, a gas supply unit 23, a mixing output unit 27, and a control unit 34.

[0025] The system includes: a slurry supply unit 1 for metering and mixing solid raw materials and liquids to form and output a slurry containing solid particles (such as fly ash) with adjustable flow rate; a foaming liquid supply unit 17 for storing and outputting foaming liquid with adjustable flow rate; a gas supply unit 23 for providing gas with adjustable pressure and flow rate; a mixing output unit 27 having a mixing chamber for receiving and mixing the slurry from the slurry supply unit 1, the foaming liquid from the foaming liquid supply unit 17, and the gas from the gas supply unit 23 to form and output a foam fluid containing solid particles; and a control unit 34 connected to the slurry supply unit 1, the foaming liquid supply unit 17, and the gas supply unit 23 for receiving the flow rate or weight signals of each material and controlling the output of each supply unit according to preset material ratio parameters to achieve proportional preparation of the foam fluid.

[0026] Specifically, this foam fluid preparation system containing solid particles is a highly integrated and automated multiphase flow precision mixing device. It precisely measures and mixes solid raw materials (such as fire extinguishing powder) and liquids (such as water or fire extinguishing solution) through a slurry supply unit 1, forming a uniform and flow-controllable suspension slurry. Simultaneously, a foaming liquid supply unit 17 independently provides a stable surfactant solution, while a gas supply unit 23 provides compressed air or inert gas (such as nitrogen) with precise pressure and flow rate. These three materials are independently controlled and transported to the core mixing output unit 27. Within the mixing chamber, through dynamic shearing and turbulent mixing mechanisms, the gas is enveloped by the foaming liquid to form a stable foam skeleton, and solid particles are simultaneously and uniformly loaded into the foam wall membrane, ultimately generating a three-phase composite foam fluid with high stacking capacity, strong adhesion, and specific chemical functions.

[0027] The control unit 34 acts as the central hub, collecting real-time flow or weight signals of various materials. Based on preset solid-liquid-gas ratio parameters (such as foam ratio, solid content, and stability indicators), it dynamically adjusts the actuators (such as pump speed, valve opening, and air pressure) of each supply unit through a closed-loop control algorithm to ensure high consistency of the foam fluid formulation and process repeatability. This technical solution is specifically designed for the prevention and control of spontaneous combustion of coal in goaf areas of mines. The output foam containing solid particles can not only efficiently fill the fissures in the goaf and isolate oxygen, but also allow solid particles (such as inhibitors and sealing materials) to be stably transported to the fire area with the foam, achieving long-term coverage and chemical inhibition. This greatly improves fire prevention and extinguishing efficiency and material utilization, reflecting the cutting-edge direction of intelligent preparation and precise engineering application of multifunctional fluids under complex working conditions.

[0028] According to one embodiment of the present invention, the slurry supply unit 1 includes a slurry tank 11, a solid raw material metering and adding module, and a liquid metering and adding module. The solid raw material metering and adding module includes a silo 2, a screw conveyor 3, and an on / off valve 5 connected in sequence. A weighing sensor 4 is provided between the screw conveyor 3 and the on / off valve 5. The weighing sensor 4 is used to measure the weight of the solid raw material entering the slurry tank 11. The control unit 34 is connected to the weighing sensor 4 and the on / off valve 5 respectively. The control unit 34 is used to control the on / off valve 5 to open when the solid raw material conveyed by the screw conveyor 3 reaches the required weight, so as to convey a quantitative amount of solid raw material to the slurry tank 11. For example, the feeding rate of the screw conveyor 3 is 0~15t / h, the water tank screw pump 7 has a water supply rate of 0~60m³ / h, the output rate of the slurry mud pump 14 is 0~30m³ / h, and the flow rate range of the foaming liquid screw pump 19 is 0~3m³ / h.

[0029] Furthermore, the liquid metering and adding module includes a water tank 6, a water tank screw pump 7, and a water tank electromagnetic flow regulating valve 10 connected in sequence. The water tank screw pump 7 is connected to a water tank screw pump speed regulating motor 8. A water flow sensor 9 is installed between the water tank screw pump 7 and the water tank electromagnetic flow regulating valve 10. The control unit 34 is connected to the water tank screw pump speed regulating motor 8, the water flow sensor 9, and the water tank electromagnetic flow regulating valve 10 respectively. The water tank screw pump 7 controls the speed through the water tank screw pump speed regulating motor 8 to achieve a wide range of flow rate adjustment. The control unit 34 controls the opening degree of the water tank electromagnetic flow regulating valve 10 to fine-tune the output water flow rate, so as to provide a quantitative amount of liquid to the pulping tank 11 and mix it with the solid raw materials.

[0030] According to one embodiment of the present invention, the slurry supply unit 1 further includes a mud pump 14 and a slurry electromagnetic flow regulating valve 16 disposed at the discharge port of the slurry tank 11. A filter screen 12 is provided between the discharge port of the slurry tank 11 and the mud pump 14 to filter out excessively large or insoluble particles in the slurry containing solids, preventing blockage of the output pipeline. The mud pump 14 is connected to a mud pump speed regulating motor 13. A slurry flow sensor 15 is disposed between the mud pump 14 and the slurry electromagnetic flow regulating valve 16. The control unit 34 is connected to the slurry flow sensor 15, the slurry electromagnetic flow regulating valve 16, and the mud pump speed regulating motor 13 respectively. The control unit 34 is used to control the mud pump speed regulating motor 13 and the slurry electromagnetic flow regulating valve 16 in real time according to the slurry flow rate, so as to control the magnitude of the slurry input flow rate.

[0031] Specifically, solid raw materials such as fly ash used in the preparation of foam fluid are conveyed from silo 2 by screw conveyor 3. The solid raw materials are weighed using weighing sensor 4. Once the input raw materials reach the required weight, valve 5 is opened to pour the fly ash and other solid raw materials into slurry tank 11. Water is drawn from water tank 6 into slurry tank 11 via water tank screw pump 7 and mixed evenly with the solid raw materials. The real-time output flow rate is monitored by water flow sensor 9. The speed of water tank screw pump 7 is controlled by water tank screw pump speed-regulating motor 8 to achieve a wide range of flow rate adjustment. The opening degree of water tank electromagnetic flow regulating valve 10 is controlled by control unit 34 to fine-tune the output water flow rate. A filter screen 12 is installed at the output port of slurry tank 11 to filter out excessively large or insoluble particles in the solid-containing slurry, preventing blockage of the output pipeline. Slurry tank 11 is connected to mud pump 14, which can transport the slurry to mixer 32 through slurry input pipeline 28 during solid-containing foam fluid preparation.

[0032] According to one embodiment of the present invention, the foaming liquid supply unit 17 includes a foaming liquid storage tank 18, a foaming liquid screw pump 19, and a foaming liquid electromagnetic flow regulating valve 22 connected in sequence. The foaming liquid screw pump 19 is connected to a foaming liquid screw pump speed regulating motor 20. A foaming liquid flow sensor 21 is provided between the foaming liquid screw pump 19 and the foaming liquid electromagnetic flow regulating valve 22. The control unit 34 is connected to the foaming liquid screw pump speed regulating motor 20, the foaming liquid flow sensor 21, and the foaming liquid electromagnetic flow regulating valve 22 respectively. The control unit 34 is used to control the foaming liquid screw pump speed regulating motor 20 and the foaming liquid electromagnetic flow regulating valve 22 according to the foaming liquid flow rate, so as to realize the quantitative control input of the foaming liquid addition flow rate. The foaming liquid is output from the foaming liquid storage tank 18 through the foaming liquid screw pump 19, and enters the mixer 32 through the foaming liquid input pipeline 29 to mix with the slurry.

[0033] According to one embodiment of the present invention, the gas supply unit 23 includes an air compressor 24, an electric regulating valve 25, and a gas flow meter 26. A control unit 34 is connected to the electric regulating valve 25 and the gas flow meter 26 via signals. The control unit 34 is used to control the opening degree of the electric regulating valve 25 to achieve real-time control of the gas flow rate. The gas generated by the air compressor 24 enters the mixer 32 through the inlet pipe 31 and mixes with the slurry containing foaming liquid to create foam. For example, the operating pressure range of the air compressor 24 is 0.2 MPa to 0.8 MPa, and the gas mass flow rate range is 0 to 100 m³ / h.

[0034] According to one embodiment of the present invention, the mixing output unit 27 includes a mixer 32, which is connected to the slurry supply unit 1 via a slurry input pipe 28, to the foaming liquid supply unit 17 via a foaming liquid input pipe 29, and to the gas supply unit 23 via an air inlet pipe 31. A pressure gauge 30 is installed on the air inlet pipe 31 for real-time monitoring of the pressure value of the input gas. The end of the mixer 32 is connected to the outlet pipe 33 to realize the output of foam fluid material containing solid particles.

[0035] Specifically, such as Figure 1 As shown, one end of the slurry input pipeline 28 is connected to the electromagnetic flow regulating valve of the mud pump 14, and the other end is connected to the mixer 32; the foaming liquid input pipeline 29 is connected to the foaming liquid electromagnetic flow regulating valve 22 and the mixer 32; one end of the air inlet pipeline 31 is connected to the rear end of the mixer 32, and the other end is connected to the gas flow meter 26.

[0036] It should be noted that the slurry inlet pipe 28, the foaming liquid inlet pipe 29, the air inlet pipe 31, and the mixer 32 are all made of high-chromium alloy, which has good corrosion resistance and wear resistance.

[0037] According to one embodiment of the present invention, the control unit 34 is configured to adjust the output flow rate of the foaming liquid supply unit 17 so that the volume ratio of the foaming liquid to the slurry is precisely adjustable within the range of 0.3% to 6%, with an adjustment accuracy of 0.1%; wherein the control unit 34 is a PLC controller, which has preset values ​​for the mixing ratio of foaming liquid and slurry, including at least 1%, 3%, and 6%.

[0038] In other words, the control unit 34 can control the addition ratio of foaming liquid to slurry within the range of 0.3% to 6%, with a control accuracy of up to 0.1%; at the same time, it can control and output preset values ​​of foam and slurry mixing ratio of 1%, 3%, and 6%.

[0039] The following two specific examples illustrate in detail the specific process of the foam fluid preparation system containing solid particles.

[0040] Example 1 This operating condition is designed for situations where there are significant high-temperature areas in the goaf of a coal mine. Control unit 34 prioritizes the activation of a high-flow-rate, high-expansion-ratio foam fluid material containing solid particles to cover a large area of ​​the goaf and prevent further coal spontaneous combustion. The material conveying rate of the screw conveyor 3 in silo 2 is controlled at 10 t / h, the water supply rate of the screw pump 7 in the water tank is set to 40 m³ / h, the water-cement ratio for preparing the solid-containing slurry in the slurry tank 11 is 4:1, and the output flow rate of the slurry pump is set to 20 m³ / h. The proportion of foaming liquid added is set to 6%, the flow rate output of the foaming liquid screw pump is set to 1.2 m³ / h, and the slurry and foaming liquid are simultaneously introduced into the mixer 32 for mixing. The air flow rate generated by the air compressor 24 is set to 480 m³ / h. The gas is mixed and reacted with the foaming liquid in the mixer 32 through the air inlet pipe 31, and the solid foam fluid is generated from the outlet pipe 33 with a flow rate of 600 m³ / h. It is connected to the external grouting pipeline and outputs the foam fluid to the underground goaf.

[0041] The present invention discloses a method for controlling the material addition ratio in a foam fluid preparation system containing solid particles: First, the control unit 34 sets various flow parameters for the preparation of foam fluid containing solid particles, including the discharge mass from the silo, the discharge mass from the water silo, the target flow rate of the slurry, the target flow rate of the foaming liquid, and the gas flow rate. Simultaneously, the initial states of each electrical control device are set, including the opening status of the water silo electromagnetic flow regulating valve 10, the foaming liquid electromagnetic flow regulating valve 22, and the electric regulating valve 25; the initial speeds of the water silo screw pump speed regulating motor 8, the mud pump speed regulating motor 13, and the foaming liquid screw pump speed regulating motor 20; and the signal displays of the weighing sensor 4, the water silo flow sensor 9, the slurry flow sensor 15, the foaming liquid flow sensor 21, and the pressure gauge 30 are checked.

[0042] Next: Start the screw conveyor 3 to transport solid raw materials from the hopper 2. When the weighing sensor 4 detects that the raw materials have reached the preset weight, shut off the screw conveyor 3 and open / close the valve 5 to feed the raw materials into the pulping tank. Start the water tank screw pump 7 and its speed regulating motor 8. Based on the feedback value from the water flow sensor 9, the control unit 34 adjusts the speed of the water tank screw pump speed regulating motor 8 to quickly bring the water flow close to the target value, completing the coarse adjustment of the water flow. Then, fine-tune the opening of the water tank electromagnetic flow regulating valve 10 to achieve precise control of the water flow.

[0043] Next: Start the mixing device in the slurry tank 11 for mixing. After the slurry is prepared, start the mud pump 14 and its speed-regulating motor 13. The control unit 34, based on the feedback value from the slurry flow sensor 15, adjusts the speed of the mud pump speed-regulating motor 13 to quickly bring the output flow rate close to the target slurry flow rate, completing the coarse adjustment of the slurry flow rate. Based on the reading of the foaming liquid flow sensor 21, the control unit 34 adjusts the speed of the foaming liquid screw pump speed-regulating motor 20 to complete the coarse adjustment of the foaming liquid flow rate. After the coarse adjustment of the flow rate is basically stable, the control unit 34 fine-tunes the output flow rate. Using the deviation between the real-time detection value of the slurry flow sensor 15 and the target flow rate as input, a PID control algorithm is used to fine-tune the opening of the slurry electromagnetic flow regulating valve 16 to precisely stabilize the slurry flow rate at the target preset value. Based on the real-time detection value of the foaming liquid flow sensor 21, the control unit 34 fine-tunes the opening of the foaming liquid electromagnetic flow regulating valve 22 to achieve precise control of the foaming liquid flow rate.

[0044] Next: After the slurry stabilizes and enters the mixer 32, the air compressor 24 is started. Based on the reading detected by the gas flow meter 26, the opening of the electric regulating valve 25 is adjusted to ensure that the gas output flow rate is precisely stabilized at the target set value. At the same time, the reading of the pressure gauge 30 on the air inlet pipe 31 is monitored to ensure that it is within the safe range. By eliminating interference from fluctuations in material characteristics and changes in pipeline pressure through the electrically controlled valves, the addition ratio of materials for preparing solid-phase foam fluid is kept stable and adjustable. Finally, after the raw materials are fully mixed and reacted in the mixer 32, the prepared foam fluid containing solid particles is output through the outlet pipe 33.

[0045] Finally: After the solid-containing foam fluid is prepared, stop each supply system in sequence. First, shut down the air compressor 24 and the electric regulating valve 25, then shut down the foaming liquid screw pump 19, and finally shut down the mud pump 14. During the shutdown process, gradually close each regulating valve to prevent water hammer or pressure surges.

[0046] Example 2 Compared to Example 1, this example differs in that, for situations where there is a risk of spontaneous combustion of residual coal in the goaf of a coal mine but no obvious anomalies have yet appeared, a highly stable foam fluid material containing solid particles with a medium foaming ratio is injected to prevent spontaneous combustion of coal. The material conveying rate of the screw conveyor 3 in the silo 2 is controlled at 2t / h, the water supply rate of the screw pump 7 in the water tank is set to 8m³ / h, the water-cement ratio of the solid-containing slurry prepared in the slurry tank 11 is 4:1, and the output flow rate of the slurry pump is set to 8m³ / h. The proportion of foaming liquid added is set to 3%, the flow rate output of the foaming liquid screw pump is set to 0.24m³ / h, the slurry and foaming liquid are simultaneously introduced into the mixer 32 for mixing and reaction, and the air flow rate generated by the air compressor 24 is set to 80m³ / h. The gas is mixed and reacted with the slurry containing foaming liquid in the mixer 32 through the air inlet pipe 31, and the flow rate of the solid-containing foam fluid generated from the outlet pipe 33 is 120m³ / h. In this embodiment, the slurry preparation rate, foaming ratio of the foam fluid, and amount of foaming liquid added are all lower than in Example 1, but the stabilization time of the solid-containing foam fluid is greater than in Example 1. While reducing the cost of fire prevention and extinguishing in coal mine goaf areas, it can effectively prevent and control the hidden danger of spontaneous combustion of coal.

[0047] Corresponding to the above embodiments, the present invention also proposes a method for controlling the addition ratio of foam fluid materials containing solid particles.

[0048] The method for controlling the addition ratio of solid-phase particle-containing foam fluid materials according to embodiments of the present invention, based on the solid-phase particle-containing foam fluid preparation system of the above embodiments, includes the following steps: S1, through the control unit, sets the target parameters for solid raw materials, water, slurry, foaming liquid and gas; S2, control the slurry supply unit to prepare slurry, and adjust its output flow rate according to the target parameters; S3, control the foaming liquid supply unit to adjust the output flow rate of the foaming liquid according to the target parameters; S4, the gas supply unit adjusts the gas output flow rate and / or pressure according to the target parameters; S5 mixes the proportionally output slurry, foaming liquid, and gas in the mixing output unit to form and output a foam fluid containing solid particles.

[0049] According to an embodiment of the present invention, adjusting the slurry output flow rate in step S2 includes: firstly, coarsely adjusting the flow rate by adjusting the speed of the drive motor, and then finely adjusting the flow rate by adjusting the opening of the electromagnetic flow regulating valve on the pipeline; the same control strategy combining coarse and fine adjustment is adopted in adjusting the foaming liquid output flow rate in step S3; wherein, when finely adjusting the flow rate, a PID control algorithm with flow deviation as input is adopted.

[0050] According to an embodiment of the present invention, the above-mentioned method for controlling the addition ratio of foam fluid containing solid particles further includes: S6, after preparation is completed, first stop the gas supply unit, then stop the foaming liquid supply unit, and finally stop the slurry supply unit, and during the stopping process, each flow regulating valve is gradually closed in sequence.

[0051] Specifically, the first step is to set the target parameters for preparing the foam fluid containing solid particles through the control unit, including the discharge mass from the silo, the discharge mass from the water silo, the target flow rate of the slurry, the target flow rate of the foaming liquid, and the gas flow rate. Simultaneously, the initial states of each electrical control device are set, including the opening status of the electromagnetic flow regulating valves of the water silo, the foaming liquid, and the electric regulating valves; the initial speeds of the variable speed motors of the water silo screw pump, the mud pump, and the foaming liquid screw pump; and the signal displays of the weighing sensors, water silo flow sensors, slurry flow sensors, foaming liquid flow sensors, and pressure gauges are checked. Then, the screw conveyor is started to transport solid raw materials from the hopper. When the weighing sensor detects that the raw materials have reached the preset weight, the screw conveyor is shut down and the valve is opened to feed the raw materials into the pulping tank. The water tank screw pump and its speed-regulating motor are started. Based on the feedback value from the water flow sensor, the control unit adjusts the speed of the water tank screw pump speed-regulating motor to quickly bring the water flow close to the target value, completing the coarse adjustment of the water flow. Afterwards, the opening of the water tank electromagnetic flow regulating valve is finely adjusted to achieve precise control of the water flow.

[0052] Further, the mixing device in the slurry preparation tank is started for mixing. Once the slurry is prepared, the mud pump and its speed-regulating motor are started. Based on the feedback value from the slurry flow sensor, the control unit adjusts the speed of the mud pump's speed-regulating motor to quickly bring the output flow rate close to the target slurry flow rate, completing the coarse adjustment of the slurry flow rate. Based on the reading of the foaming liquid flow sensor, the speed of the foaming liquid screw pump's speed-regulating motor is adjusted to complete the coarse adjustment of the foaming liquid flow rate. After the coarse adjustment of the flow rate is basically stable, the control unit fine-tunes the output flow rate. Using the deviation between the real-time detection value of the slurry flow sensor and the target flow rate as input, a PID control algorithm is used to fine-tune the opening of the slurry electromagnetic flow regulating valve to precisely stabilize the slurry flow rate at the target preset value. Based on the real-time detection value of the foaming liquid flow sensor, the opening of the foaming liquid electromagnetic flow regulating valve is fine-tuned to achieve precise control of the foaming liquid flow rate.

[0053] After the slurry enters the mixer stably, the air compressor is started. Based on the gas flow meter reading, the opening of the electric regulating valve is adjusted to ensure the gas output flow rate is precisely stabilized at the target set value. Simultaneously, the pressure gauge reading on the inlet pipe is monitored to ensure it remains within a safe range. Interference from material transport fluctuations and pipeline pressure changes is eliminated through electrically controlled valves, maintaining a stable and adjustable addition ratio of materials for preparing solid-phase foam fluid. Finally, after the raw materials are fully mixed and reacted in the mixer, the prepared foam fluid containing solid particles is output through the outlet pipe.

[0054] Finally, once the solid-containing foam fluid is prepared, shut down each supply system in sequence. First, turn off the air compressor and electric regulating valve; second, turn off the foaming liquid screw pump; and finally, turn off the mud pump. During shutdown, gradually close each regulating valve to prevent water hammer or pressure surges.

[0055] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A foam fluid preparation system containing solid particles, characterized in that, include: The system includes a slurry supply unit, a foaming liquid supply unit, a gas supply unit, a mixing and output unit, and a control unit; among which, The slurry supply unit is used to meter and mix solid raw materials and liquids to form and output a slurry containing solid particles with adjustable flow rate. The foaming liquid supply unit is used to store and output foaming liquid with adjustable flow rate; The gas supply unit is used to provide gas with adjustable pressure and flow rate; The mixing output unit has a mixing chamber for receiving and mixing slurry from the slurry supply unit, foaming liquid from the foaming liquid supply unit, and gas from the gas supply unit to form and output a foam fluid containing solid particles. The control unit is connected to the slurry supply unit, the foaming liquid supply unit, and the gas supply unit respectively. It is used to receive the flow rate or weight signal of each material and control the output of each supply unit according to the preset material ratio parameters to realize the proportional preparation of foam fluid.

2. The foam fluid preparation system containing solid particles according to claim 1, characterized in that, The slurry supply unit includes a slurry preparation tank, a solid raw material metering and adding module, and a liquid metering and adding module; The solid raw material metering and adding module includes a hopper, a screw conveyor, and an on / off valve connected in sequence. A weighing sensor is installed between the screw conveyor and the on / off valve. The weighing sensor is used to measure the weight of the solid raw material entering the pulping tank. The control unit is connected to the weighing sensor and the on / off valve respectively. The control unit is used to control the on / off valve to open when the solid raw material conveyed by the screw conveyor reaches the required weight, so as to convey a certain amount of solid raw material to the pulping tank. The liquid metering and adding module includes a water tank, a water tank screw pump, and a water tank electromagnetic flow regulating valve connected in sequence. The water tank screw pump is connected to a water tank screw pump speed-regulating motor. A water flow sensor is installed between the water tank screw pump and the water tank electromagnetic flow regulating valve. The control unit is connected to the water tank screw pump speed-regulating motor, the water flow sensor, and the water tank electromagnetic flow regulating valve. The water tank screw pump's speed is controlled by the water tank screw pump speed-regulating motor to achieve a wide range of flow rate adjustment. The control unit controls the opening degree of the water tank electromagnetic flow regulating valve to fine-tune the output water flow rate, thereby providing a quantitative amount of liquid to the pulping tank and mixing it with the solid raw materials.

3. The foam fluid preparation system containing solid particles according to claim 2, characterized in that, The slurry supply unit also includes a mud pump and a slurry electromagnetic flow regulating valve located at the outlet of the slurry tank. A filter screen is installed between the outlet of the slurry tank and the mud pump. The mud pump is connected to a mud pump speed regulating motor. A slurry flow sensor is installed between the mud pump and the slurry electromagnetic flow regulating valve. The control unit is connected to the slurry flow sensor, the slurry electromagnetic flow regulating valve, and the mud pump speed regulating motor. The control unit is used to control the mud pump speed regulating motor and the slurry electromagnetic flow regulating valve in real time according to the slurry flow rate to control the magnitude of the slurry input flow rate.

4. The foam fluid preparation system containing solid particles according to claim 1, characterized in that, The foaming liquid supply unit includes a foaming liquid storage tank, a foaming liquid screw pump, and a foaming liquid electromagnetic flow regulating valve connected in sequence. The foaming liquid screw pump is connected to a foaming liquid screw pump speed regulating motor. A foaming liquid flow sensor is installed between the foaming liquid screw pump and the foaming liquid electromagnetic flow regulating valve. The control unit is connected to the foaming liquid screw pump speed regulating motor, the foaming liquid flow sensor, and the foaming liquid electromagnetic flow regulating valve respectively. The control unit is used to control the foaming liquid screw pump speed regulating motor and the foaming liquid electromagnetic flow regulating valve according to the foaming liquid flow rate, so as to realize the quantitative control input of the foaming liquid addition flow rate.

5. The foam fluid preparation system containing solid particles according to claim 1, characterized in that, The gas supply unit includes an air compressor, an electric regulating valve, and a gas flow meter. The control unit is connected to the electric regulating valve and the gas flow meter via signals. The control unit is used to control the opening degree of the electric regulating valve to achieve real-time control of the gas flow.

6. The foam fluid preparation system containing solid particles according to claim 1, characterized in that, The mixing output unit includes a mixer, which is connected to the slurry supply unit via a slurry input pipeline, to the foaming liquid supply unit via a foaming liquid input pipeline, and to the gas supply unit via an air inlet pipeline. A pressure gauge is installed on the air inlet pipeline to monitor the pressure value of the input gas in real time.

7. The foam fluid preparation system containing solid particles according to any one of claims 1 to 6, characterized in that, The control unit is configured to adjust the output flow rate of the foaming liquid supply unit so that the volume ratio of foaming liquid to slurry added is precisely adjustable within the range of 0.3% to 6%, with an adjustment accuracy of 0.1%; wherein the control unit is a PLC controller, which has preset values ​​for the mixing ratio of foaming liquid and slurry, including at least 1%, 3%, and 6%.

8. A method for controlling the addition ratio of solid-phase particle-containing foam fluid materials, characterized in that, The method for controlling the addition ratio of solid-phase particle-containing foam fluid materials is based on the foam fluid preparation system containing solid-phase particles as described in any one of claims 1 to 7, and includes the following steps: S1, through the control unit, sets the target parameters for solid raw materials, water, slurry, foaming liquid and gas; S2, control the slurry supply unit to prepare slurry, and adjust its output flow rate according to the target parameters; S3, control the foaming liquid supply unit to adjust the output flow rate of the foaming liquid according to the target parameters; S4, the gas supply unit adjusts the gas output flow rate and / or pressure according to the target parameters; S5 mixes the proportionally output slurry, foaming liquid, and gas in the mixing output unit to form and output a foam fluid containing solid particles.

9. The method for controlling the addition ratio of solid-phase particle-containing foam fluid materials according to claim 8, characterized in that, The adjustment of the slurry output flow rate in step S2 includes: firstly, coarse adjustment of the flow rate by adjusting the speed of the drive motor, and then fine adjustment of the flow rate by adjusting the opening of the electromagnetic flow regulating valve on the pipeline; the adjustment of the foaming liquid output flow rate in step S3 adopts the same control strategy of combining coarse and fine adjustment; wherein, when fine-tuning the flow rate, a PID control algorithm with the flow deviation as input is used.

10. The method for controlling the addition ratio of solid-phase particle-containing foam fluid materials according to claim 8, characterized in that, Also includes: S6. After preparation is completed, first stop the gas supply unit, then stop the foaming liquid supply unit, and finally stop the slurry supply unit. During the stopping process, each flow regulating valve is closed in sequence.

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