Integrated system for heating rollers of conveyor belts for mining and three-chamber foaming and spraying dust suppression

Abstract

The present invention discloses an integrated system for heating and three-chamber foaming spray dust reduction of mining conveyor belt rollers, aiming to realize environmentally friendly dust reduction and deicing and antifreezing of mining coal / gangue conveyor belts in low temperature environments. The system mainly includes a preheating antifreeze foam spray device and a conveyor belt heating antifreeze device, wherein the preheating antifreeze foam spray device is mainly composed of a three-chamber foaming chamber, a self-spinning convex perforated nozzle, an edge anti-overflow cover, etc. The preheated foaming liquid is fully foamed by three different foaming methods in the three-chamber foaming chamber, and the foamed foaming liquid is evenly sprayed through the self-spinning convex perforated nozzle, and is prevented from overflowing by the edge anti-overflow cover. The conveyor belt heating antifreeze device is mainly composed of a middle section dual-purpose electric heating roller and two side electric heating rollers, and a double-helix electric heating tube is arranged in the roller, and the belt can be pulse-heated through the roller. The system modifies the belt conveyor body, and the installation and disassembly process is simple and easy, and the applicability and promotion are very strong.

Description

Technical Field

[0001] The invention discloses an integrated system for heating a mining conveyor belt roller and performing three-chamber foaming spraying to reduce dust, and relates to the field of environmentally friendly dust reduction and deicing and antifreezing of mining coal / gangue conveyor belts in a low-temperature environment. Technical Background

[0002] Dust is one of the main hazards of industrial production plants. Due to its variety, wide sources and difficulty in elimination, it is widely present in many places of modern mechanized production. In the process of mining, the harm of mine dust is also quite serious, especially in the process of coal / gangue being transported by conveyor belts. Due to the additional wind flow field generated when the material is dropped and the interference of the flow field in the space during the belt transportation process, a large amount of dust is generated. On the one hand, these dusts are widely spread in the workplace, causing environmental pollution. On the other hand, when workers inhale dust, they are prone to occupational health hazards such as pulmonary fibrosis, pneumoconiosis and silicosis, affecting the normal progress of production operations. At the same time, due to the characteristics of my country's energy endowment distribution, coal resources are concentrated in the northern region, which leads to low temperatures in the working environment during winter production, and the temperature in some areas may be below 20°C for a long time. This causes the water sprayed on the conveyor belt to easily cause the coal / gangue to condense together during traditional spray dust reduction operations. This not only reduces the belt's transportation efficiency, but also the ice produced by water solidification will affect the belt's service life. In severe cases, the belt may even slip or even get stuck at the end, which poses a huge safety hazard and brings a lot of inconvenience to the transportation process. Therefore, it is very necessary to heat and de-ice the belt in time while reducing dust on the coal transported on the belt.

[0003] At present, for the dust removal method of belt transport of coal / gangue, high-pressure spray dust removal is generally used in China, in which the spraying medium is mainly water. Although this method is economical and practical, it cannot solve the problem that water is easy to solidify in a low-temperature environment. Especially in northern my country, facing a long cold winter, the method of spraying water for dust removal can have a certain effect, but it will also cause coal / gangue blocks to condense and reduce transportation efficiency. Of course, some mines in northern China have tried to add antifreeze to water, but due to the limited antifreeze performance of antifreeze, there are certain limitations in some low-temperature environments, so it is difficult to effectively solve the problem by relying solely on this method. From the perspective of belt heating, this technology is less used in coal preparation plants. Therefore, in view of the dust control during belt transportation and the actual antifreeze problem of the belt, the present invention provides a set of mining conveyor belt roller heating and three-chamber foaming spray dust reduction integrated system, which can effectively solve the dust problem during belt transportation and the problem of belt icing, improve the transportation efficiency of the belt, and ensure the health and safety of workers in the operating area. Summary of the invention

[0004] In view of this, the present invention provides a set of integrated system for heating the conveyor belt rollers and three-chamber foaming spray dust reduction for mining, which can effectively reduce the dust concentration generated during the belt transportation process, and effectively solve the problem of icing of the coal / gangue conveyor belt in a low temperature environment, reduce the dust hazards, improve the transportation efficiency, and improve the working environment of the operators. To solve the above problems, the embodiments of the present invention adopt the following technical solutions:

[0005] An embodiment of the present invention provides an integrated system for heating and three-chamber foaming spraying dust reduction of mining conveyor belt rollers, comprising: a preheating antifreeze foam spraying device, which uses the foam spraying device to spray antifreeze foam onto the coal / gangue on the belt, and uses the unique properties of the antifreeze foam to remove dust; a conveyor belt heating and antifreeze device, which uses the heating effect of three electric heating rollers to pulse heat the belt to achieve the effect of antifreeze and deicing.

[0006] In the first aspect, the preheating antifreeze foam spraying device of the integrated system for heating the mining conveyor belt rollers and the three-chamber foaming spray dust reduction comprises: a Y-type air supply pipe, a check valve, a rice-grain-shaped outward-turned baffle, an antifreeze foaming liquid feed pipe, a mesh metal baffle, a three-chamber foaming cavity, a shrinkage-type foam output port, a self-spinning convex perforated nozzle, and an edge overflow prevention cover; the Y-type air supply pipe is respectively connected to the left side and the bottom side of the three-chamber foaming cavity to transport the high-pressure gas in the air compressor into the foaming cavity; the antifreeze foaming liquid The feed pipe is arranged on the top side of the three-chamber foaming chamber and is used to input antifreeze foaming liquid; the three-chamber foaming chamber is located in the middle of the device and contains three foaming methods inside, which can improve the foaming quality; the contraction type foam output port is located on the right side of the three-chamber foaming chamber and quickly outputs the foamed foam for dust reduction; the self-spinning convex perforated nozzle is connected to the output port; the edge overflow prevention cover is tightly attached to the foam output port and wraps the nozzle in the cover, which can effectively control the foam spraying angle and improve the utilization rate of the foam.

[0007] Antifreeze agent is mixed in the foaming liquid of the preheating antifreeze foam spraying device.

[0008] In combination with the first aspect, the antifreeze agent selects chloride salts or water-soluble organic compounds to lower the freezing point of the foaming liquid, prevent the coal / gangue blocks from freezing during the belt transportation of coal / gangue in a low temperature environment, facilitate the transportation of coal / gangue blocks, and effectively control the dust generated during the transfer of coal / gangue blocks.

[0009] In combination with the first aspect, a check valve is installed at one end of the Y-shaped air pipe of the preheating antifreeze foam injection device close to the three-chamber foaming chamber; a rice-grain-shaped outward-turned baffle is provided at the connection between the three-chamber foaming chamber and the Y-shaped air pipe, and the rice-grain-shaped outward-turned baffle has outward-turned small holes, which can prevent the foaming liquid from entering the air pipe without affecting the airflow; the presence of the check valve and the rice-grain-shaped outward-turned baffle can prevent the foaming liquid from flowing back into the air compressor, thereby improving the service life and working performance of the air compressor.

[0010] In combination with the first aspect, the three-chamber foaming cavity is composed of three parts, namely, a high-speed fan blade stirring foaming chamber, a radial structure porous metal foaming chamber, and a microporous ceramic ball foaming chamber.

[0011] In combination with the first aspect, there are two stirring blades inside the high-speed fan blade stirring foaming chamber, and a small driving blade is arranged near one end of the Y-shaped air pipe. The three blades are coaxially connected, and the air force in the air pipe can drive the small driving blade to drive the stirring blade to stir and perform preliminary foaming on the foaming liquid.

[0012] In combination with the first aspect, the radial structure porous metal foaming chamber is composed of a radial structure porous metal, and when the foaming liquid that has undergone preliminary foaming enters the chamber, the complex porous medium region inside the chamber can be used to further foam the foaming liquid.

[0013] In combination with the first aspect, there are a large number of small-particle microporous ceramic balls in the microporous ceramic ball foaming chamber. The porous structure of the ceramic balls themselves and the pores formed by accumulation can further foam the foaming liquid. The diameter of the ceramic balls is 4 to 6 mm, which makes the produced foam texture structure more delicate and the particle size more uniform, thereby improving the foaming quality.

[0014] In combination with the first aspect, mesh metal baffles are provided at different foaming chamber connection locations and shrinkage-type foam output ports in the three-chamber foaming cavity of the preheating antifreeze foam spray device, which can effectively isolate different foaming chambers and prevent microporous ceramic balls from entering other foaming chambers.

[0015] In combination with the first aspect, the antifreeze foaming liquid feed pipe adopts a funnel-shaped design at the bottom, and a mesh metal baffle is also provided at the opening part below the funnel, which can enable the foaming liquid entering the foaming cavity to effectively diffuse laterally while slowing down the speed of longitudinal diffusion, so that the foam enters the foaming cavity evenly through multiple dimensions, which helps to maintain the spatial shape of the foam, thereby maintaining the structural stability of the foam.

[0016] In combination with the first aspect, the shrinkage foam outlet adopts a closing design, and the relationship between the diameter Φ1 of the outlet and the diameter Φ2 of the foaming cavity is Φ1:Φ2=1:6, which can increase the speed of spraying foam outward under the condition of unchanged flow rate.

[0017] In combination with the first aspect, the self-spinning convex perforated nozzle has a fan blade structure inside, which is nested in the output port. The wind flow and liquid flow delivered by the air compressor can drive the nozzle to spin, and the antifreeze foam is evenly sprayed out through the centrifugal force brought by the rotation.

[0018] Combined with the first aspect, according to the change of airflow provided by the air compressor, the injection angle is between 60° and 150°. At the same time, the rotating fan blades driven by the airflow continuously stir the foam as it passes through, further improving the foaming quality of the foam and maintaining the shape of the foam well.

[0019] In combination with the first aspect, an edge overflow prevention cover is provided at the output port of the preheating antifreeze foam spraying device. One end of the edge overflow prevention cover is tightly attached to the output port to wrap the nozzle in the cover, and the other end is opened at 90° to 120°. The spraying angle of the foam can be effectively controlled to prevent the foam from spraying outside the belt, thereby improving the utilization rate of the foam.

[0020] Secondly, the conveyor belt heating and antifreeze device of the integrated system of mining conveyor belt roller heating and three-chamber foaming jet dust reduction includes: electric heating rollers on both sides and dual-purpose electric heating rollers in the middle section; the electric heating rollers on both sides are located on both sides of the upper end of the roller bracket, the axis is connected to the roller bracket, and an electric heating pipe is arranged inside the cylinder; the dual-purpose electric heating roller in the middle section is located in the middle of the upper end of the roller bracket, the axis is connected to the bracket, and an electric heating pipe is arranged inside the cylinder, and the axis is hollow to facilitate the passage of the antifreeze foam conveying pipe, so as to realize the preheating of the foam conveying pipe.

[0021] In combination with the second aspect, the electric heating roller shafts on both sides adopt a circular hollow structure to accommodate the passage of the electric heating tube; the electric heating rollers on both sides are equipped with temperature-controlled electric heating tubes with a double helix structure, and the wiring part of the electric heating tube is located on the roller shaft and connected to a safe power supply; the electric heating tube passes through the wiring end of the roller shaft, spirally wraps around the roller shaft and is connected at the other end. The double helix structure of the electric heating tube can increase the heating area in the narrow space inside the roller, thereby improving the heating efficiency.

[0022] In combination with the second aspect, inside the roller, there is a double-layer fast heat-conducting net made of fast heat-conducting metal material between the electric heating tube and the roller shell, which is connected to the roller body and can quickly transfer heat to the roller body by heat conduction.

[0023] In combination with the second aspect, the roller shaft of the middle-section dual-purpose electric heating roller adopts an annular hollow structure, which can accommodate the foaming liquid delivery pipe to pass through and preheat the pipeline.

[0024] In combination with the second aspect, the arrangement of the temperature-controlling electric heating tubes in the middle-section dual-purpose electric heating roller is similar to the arrangement of the electric heating tubes in the electric heating rollers on both sides. The temperature-controlling electric heating tubes pass through the roller shaft and are wound around the roller shaft in a double helix structure and are placed inside the roller. Inside the roller, a double-layer fast heat-conducting net made of fast heat-conducting metal material is provided between the electric heating tube and the roller shell and is connected to the roller shell, which further improves the heating stability.

[0025] In combination with the second aspect, the relationship between the radius R1 of the electric heating rollers on both sides and the radius R2 of the middle dual-purpose electric heating roller is R1:R2=1:2; the relationship between the radius R2 of the middle dual-purpose electric heating roller and the radius R3 of its roller shaft is R2:R3=3:1. The middle dual-purpose electric heating roller adopts a thickened design as a whole, which can facilitate the pipeline to pass through the roller shaft to achieve a preheating effect.

[0026] Combined with the second aspect, the diameter of the electric heating tube is 6 to 12 mm, which can effectively realize its double helix layout inside the roller and improve the heating efficiency.

[0027] Combined with the second aspect, the heating temperature of the temperature-controlled electric heating tubes in the electric heating rollers on both sides is maintained at 20-30°C, and a temperature controller is provided at the control end, and heating is automatically stopped when the temperature exceeds 30°C.

[0028] Combined with the second aspect, the heating temperature of the electric heating tube in the middle section dual-purpose electric heating roller is maintained at 30-40°C, and a temperature controller is provided at the control end. Heating is automatically stopped when the temperature exceeds 40°C. The control of the roller temperature can prevent excessive temperature from causing a decrease in belt transport performance and a shortened belt life.

[0029] In combination with the second aspect, a constant temperature detector is provided on the roller bracket. When the ambient temperature is detected to be lower than 2°C, the roller responds and starts heating. After the cumulative heating time reaches 5 hours, the heating is automatically stopped and restarted after 1 hour. The residual heat is used to continue heating during the period when the device is turned off. The heating device is turned on or off cyclically to realize pulse heating, so as to realize automatic control of the heating system and make good use of the residual heat of the long-term load of the electric heating tube, thereby achieving the purpose of reducing costs and saving resources.

[0030] The preheating antifreeze foam spraying device provided in the embodiment of the present invention is mainly arranged at the drop-off port, belt junction and belt tail of the belt conveyor. When the preheating antifreeze foam spraying device is set, the original bracket is modified, and the antifreeze foam spraying device bracket is welded in the vertical direction of the belt conveyor body. The antifreeze foam spraying device is installed above the bracket and an adjustable device is set with an adjustment range of 120° so as to control the foam spraying angle according to actual needs.

[0031] The preheating antifreeze foam injection device requires two parts of pipelines. The first part is the preheating antifreeze foaming liquid delivery pipeline. The preheating antifreeze foaming liquid delivery pipeline passes through the middle dual-purpose electric heating roller and then delivers liquid to the injection devices at both ends through the liquid separation valve. The liquid separation valve is set on the crossbeam below the roller bracket. After passing through the liquid separation valve, the pipeline is fixed to the crossbeam below the roller bracket through a fixing device, and goes up along the antifreeze foam injection device bracket to provide foaming liquid to the preheating antifreeze foam injection device; the second part is the air supply pipeline. The air supply pipeline has two air supply pipes that come out of the air compressor, and then go up along the injection device bracket, and stick to the foaming liquid delivery pipeline, and split at the top of the preheating antifreeze foam injection device bracket to supply air from the two air ports of the Y-shaped air pipe.

[0032] In an embodiment of the present invention, a pair of preheating antifreeze foam spray devices are arranged every 0.8 to 1.5 m on both sides of the material drop port, the belt junction and the tail of the belt conveyor, and the number of pairs of spray devices shall not exceed 6 pairs. The preheating antifreeze foam spray device shall surround the material drop port, the belt junction and the tail of the belt conveyor; a pair of spray devices are arranged every 2 m in other parts of the belt conveyor, and when the remaining distance is greater than 1 m and less than 2 m, a pair of preheating antifreeze foam spray devices may be added, and when the remaining distance is less than 1 m, the preheating antifreeze foam spray device may not be arranged.

[0033] In the embodiment of the present invention, a light scattering high-sensitivity dust sensor is arranged on the bracket. When light is irradiated on dust particles, scattered light occurs. The intensity of the scattered light is proportional to the particle concentration. At this time, the sensor can convert the optical signal into an electrical signal to monitor the dust concentration. When the respirable dust concentration is detected to be higher than 2.5 mg / m 3 When the dust is removed, the dust removal device is automatically turned on to achieve automatic control and reduce the contact between personnel and dust.

[0034] In an embodiment of the present invention, the antifreeze foaming liquid of the preheating antifreeze foam spray device will be preheated by the heating effect of the middle-section dual-purpose electric heating roller during preparation; the pipeline for transporting the foaming liquid will be wrapped with heat-insulating materials to further maintain the temperature of the foaming liquid and achieve a certain antifreeze effect.

[0035] The conveyor belt heating and antifreezing device provided in the embodiment of the present invention is a heating roller modified on the basis of the original roller, and the electric heating rollers on both sides replace the original rollers on both sides. The middle section dual-purpose electric heating roller needs to be re-drilled and installed on the bracket during installation and its top height remains the original height, thereby reducing production costs and maintaining the excellent performance of the original equipment.

[0036] In the embodiment of the present invention, a heating system consisting of a pair of electric heating rollers on both sides and a middle dual-purpose electric heating roller is set up for every other set of rollers to achieve continuous heating of the belt. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the examples of the present invention or the prior art, the drawings required to be used in the embodiments or the description of the prior art are briefly introduced below.

[0038] Figure 1 It is a schematic diagram of the integrated system for heating the conveyor belt rollers for mining use and the three-chamber foaming spray dust reduction of the present invention;

[0039] Figure 2 This is a schematic diagram of a preheating antifreeze foam spraying device according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a self-spinning convex perforated nozzle of a foam spraying device according to an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of a conveyor belt heating and antifreezing device according to an embodiment of the present invention;

[0042] Figure 5 Schematic diagram of the electric heating rollers on both sides of the heating device according to an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of a middle dual-purpose electric heating roller of a heating device according to an embodiment of the present invention;

[0044] Figure 7 This is a schematic diagram of the loading and working pipelines of the foam spraying device according to an embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram of an adjustable device at a connection of a foam spraying device according to an embodiment of the present invention;

[0046] Fig. 9 It is a layout diagram of the foam spraying device and the belt heating device according to an embodiment of the present invention;

[0047] In the figure: 1-Y-type air pipe; 2-check valve; 3-antifreeze foaming liquid feed pipe; 4-rice-grain-shaped outward-turned baffle; 5-mesh metal baffle; 6-three-chamber foaming chamber; 7-contractile foam output port; 8-spinning convex perforated nozzle; 9-edge overflow cover; 10-small driving fan blade; 11-mixing fan blade; 12-radial porous metal; 13-microporous ceramic ball. DETAILED DESCRIPTION

[0048] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] like Figure 1The figure shows a schematic diagram of the integrated system for heating the rollers and three-chamber foaming spray dust reduction for mining conveyor belts of the present invention. The system is mainly divided into two parts: preheating antifreeze foam dust reduction and roller heating deicing and antifreeze. The preheating antifreeze foam dust reduction process mainly monitors the dust concentration in the environment to cause the foam spray device to respond; in the response process of the foam spray device, antifreeze is added to the foaming liquid, the foaming liquid delivery pipeline is preheated, three foaming methods are foamed, and fully foamed foam is sprayed out in sequence; the sensor monitoring of external dust is mainly realized by a light scattering high-sensitivity dust concentration sensor; the antifreeze added to the foaming liquid is mainly chloride salts or water-soluble organic compounds; the heating of the foaming liquid delivery pipeline is realized by the middle section dual-purpose electric heating roller; the foaming liquid is completely foamed in the three-chamber foaming cavity; the foam is sprayed through a self-rotating convex perforated nozzle; the antifreeze foam spray device is densely arranged at the blanking port, the belt junction, and the belt machine tail to achieve a better dust reduction effect.

[0050] The belt antifreeze process mainly causes the heating antifreeze device to respond by monitoring the external temperature, among which the monitoring of the external temperature mainly relies on a constant temperature temperature detector; the response of the heating antifreeze device mainly refers to the response of the conveyor belt heating antifreeze device; the belt heating antifreeze device consists of a middle dual-purpose electric heating roller and two side electric heating rollers, and the installation is to set a set of heating device for every set of rollers on the original basis.

[0051] like Figure 2 As shown in the figure, an antifreeze foam spraying device provided by the present invention mainly comprises: a Y-shaped air delivery pipe 1; a check valve 2; an antifreeze foaming liquid feeding pipe 3; a rice-shaped outward-turned baffle 4; a mesh metal baffle 5; a three-chamber foaming chamber 6; a contraction-type foam output port 7; a self-spinning convex perforated nozzle 8; an edge overflow prevention cover 9; a small driving fan blade 10; a stirring fan blade 11; a radial porous metal 12; and a microporous ceramic ball 13. It can be seen from the figure that the preheated antifreeze foaming liquid enters the three-chamber foaming chamber 6 through the antifreeze foaming liquid feeding pipe 3, and the high-speed air compressor The airflow enters the three-chamber foaming chamber 6 through the Y-shaped air pipe 1. After the gas passes through the small driving blade 10, it will drive it to rotate and cause the stirring blade 11 to rotate, and the preheated foaming liquid is initially foamed by the stirring action; then the foaming liquid passes through the radial porous metal 12 area, and further foams in the porous area provided by it; then it enters the foaming area composed of microporous ceramic balls 13, and completes foaming in the porous structure of the microporous ceramic balls themselves and the porous area formed by their accumulation; finally, the self-spinning convex perforated nozzle 8 driven by the wind flow is used to spray the foam.

[0052] The foaming liquid of the antifreeze foam spray device is mixed with chloride salts or water-soluble organic compound antifreeze agents, which can reduce the freezing point of the foaming liquid and achieve dust removal effect at the same time; the antifreeze foaming liquid feed pipe 3 adopts a funnel-shaped design and is equipped with a mesh metal baffle 5, which can effectively ensure that the preheated foaming liquid is fully diffused after entering; the check valve 2 and the rice-grain-shaped outward baffle 4 can prevent the foaming liquid from backflowing into the air compressor, thereby improving the service life of the air compressor; the three-chamber foaming chamber 6 is divided into three parts, namely, a high-speed fan blade stirring foaming chamber, a radial structure porous metal foaming chamber, and a microporous ceramic ball foaming chamber. The preheated foaming liquid passes through the three foaming chambers in turn to complete the foaming. The diameter of the microporous ceramic ball 13 in the microporous ceramic ball foaming chamber is 4 to 6 mm. It can be understood that after three steps of foaming, the foaming effect is guaranteed; the foam after foaming is completed is sprayed out through a self-spinning convex perforated nozzle 8, and a fan blade structure is arranged inside the self-spinning convex perforated nozzle 8, which is nested in the output The outlet can rely on the wind flow delivered by the air compressor to drive the nozzle to spin, and the antifreeze foam is evenly sprayed out for dust prevention through the centrifugal force brought by the rotation. According to the change of the wind flow provided by the air compressor, the angle of the foam spraying is between 60° and 150°; the shrinkage foam outlet 7 used for preheating the antifreeze foam output adopts a closing design, and the relationship between the diameter Φ1 of the outlet and the diameter Φ2 of the foaming chamber is Φ1:Φ2=1:6. It can be understood that this can ensure that the flow rate remains unchanged while accelerating the flow rate, so that the foam can be sprayed out at a high speed; after the foam is sprayed, in order to ensure that the foam effectively covers the belt, an edge overflow prevention cover 9 is provided at the outlet of the antifreeze foam spraying device, and one end of the edge overflow prevention cover 9 is tightly fastened to the shrinkage foam outlet 7, and the self-spinning convex perforated nozzle 8 is wrapped in the cover, which can effectively control the spraying angle of the foam to prevent the foam from being sprayed to the outer area of ​​the belt. The opening angle is controlled at 90°~120° and adjusted according to the actual working conditions.

[0053] Figure 3 As shown, it is a schematic diagram of the self-spinning convex perforated nozzle of the preheating antifreeze foam spray device. The self-spinning convex perforated nozzle and the output port of the preheating antifreeze foam spray device adopt a nested structure. It can be seen that in the nested position, the perforated nozzle adopts a "convex" shaped structure, and the corresponding output port adopts a "concave" shaped structure. A certain gap is left between the connections, and the metal at the connection can be polished and wear-resistant according to actual needs to ensure normal rotation.

[0054] The fan-shaped structure in the self-spinning convex perforated nozzle has its blades fixed on the main body of the nozzle and is designed with a certain arc, so that it can rotate when the liquid flows through, thereby driving the nozzle to rotate to achieve self-spin, thereby ensuring that the preheated foam is sprayed out efficiently and evenly.

[0055] Figure 4As shown, the conveyor belt heating and antifreezing device includes a middle section dual-purpose electric heating roller and two side electric heating rollers. The electric heating rollers are installed on the original roller bracket. It can be understood that this can reduce costs while maintaining the superior performance of the original structure. It is not difficult to see that the electric heating rollers on both sides are the same size as the original electric heating rollers, and the electric heating rollers on both sides can be used to replace the rollers that originally have no heating function; for the installation of the middle section dual-purpose electric heating roller, the original structure needs to be modified, and the installation hole of the middle roller shaft on the original bracket needs to be enlarged to accommodate the annular hollow structure of the middle section electric heating roller shaft, so as to facilitate the passage of the foaming liquid transportation pipeline.

[0056] Preferably, the relationship between the radius R1 of the electric heating rollers on both sides and the radius R2 of the middle section dual-purpose electric heating roller is R1:R2=1:2; the relationship between the radius R2 of the middle section dual-purpose electric heating roller and the radius R3 of its roller shaft is R2:R3=3:1, and the upper end of the middle section dual-purpose electric heating roller needs to be kept at the original height. It can be understood that only in this way can the belt be able to transport coal / gangue normally during operation.

[0057] A constant temperature detector is provided on the roller bracket. When the ambient temperature is detected to be lower than 2°C, the roller responds and starts heating. After the cumulative heating time reaches 5 hours, the heating is automatically stopped and restarted after 1 hour. The residual heat is used to continue heating during the shutdown period of the device. The heating device is turned on or off cyclically to realize pulse heating, so as to realize automatic control of the heating system and make good use of the residual heat of the long-term load of the electric heating tube, thereby achieving the purpose of reducing costs and saving resources.

[0058] Figure 5 As shown in the figure, the electric heating rollers on both sides of the conveyor belt heating and antifreeze device are shown. It is not difficult to see that the roller shaft adopts a circular hollow structure, which can ensure that the electric heating tube passes through the center of the shaft body; the connection part of the temperature-controlled electric heating tube with a double helix structure is located on the roller shaft, connected to a safe power supply, and the electric heating tube passes through the inside of the roller shaft connection terminal and spirally wraps around the roller shaft and is connected at the other end. The overall structure presents a double helix structure. It can be understood that the existence of the double helix structure can make the electric heating tube increase the heating area as much as possible within the limited space inside the roller, and the space it occupies is small, which is more suitable for the narrow characteristics of the roller interior; inside the roller, there is a double-layer fast heat-conducting net made of fast heat-conducting metal material between the electric heating tube and the roller shell, and the heat-conducting net is tightly attached to the roller cylinder in an annular shape, which further improves the heating efficiency.

[0059] Figure 6As shown, the middle section dual-purpose electric heating roller in the conveyor belt heating and antifreeze device adopts an overall thickened design compared to the electric heating rollers on both sides. At the same time, in order to enable it to preheat the foam conveying pipeline, the roller shaft adopts a ring-shaped hollow design. The inner ring area reserved in the middle can allow the heating pipeline to pass normally to achieve preheating.

[0060] In the arrangement of the electric heating tube, it adopts a design similar to that of the middle-section dual-purpose electric heating roller. It can be understood that the electric heating tube passes through the wiring terminal, spirally winds around the roller shaft, and connects at the other end of the roller shaft to form a double helix structure, which makes good use of the narrow space inside the roller; the presence of the double-layer fast heat conduction network speeds up the efficiency of heat transfer, improves the heating speed, and can maintain the heating effect well.

[0061] Figure 7 The figure shows the schematic diagram of the loading and working pipeline of the preheating antifreeze foam spraying device. For the installation of the preheating antifreeze foam spraying device, it is necessary to add a bracket to the original belt conveyor body. The bracket can be welded to reduce the operating cost. The bracket is equipped with a light scattering high-sensitivity dust concentration sensor, which can monitor the dust concentration by using the light scattering effect. When the respirable dust concentration is detected to be higher than 2.5mg / m 3 When the dust removal device is turned on, automatic control is realized; an adjustable device is set at the connection between the bracket and the antifreeze foam spraying device to realize the adjustment of the spraying angle of the antifreeze foam spraying device. The adjustment range is 120°, which can be adjusted in time according to actual working conditions to adapt to different working conditions.

[0062] The working pipeline of the preheating antifreeze foam spray device is divided into two parts, namely the air supply pipeline and the antifreeze foaming liquid delivery pipeline. In the first part, the air supply pipeline extends from the air compressor under the bracket, and is divided into two routes through a liquid separator valve, respectively supplying air to the antifreeze foam spray devices at both ends. It goes up along the antifreeze foam spray device bracket, is fixed on the bracket, and is divided into two sections at the top of the bracket to supply air to the antifreeze foam spray device from the two air supply ports of the Y-shaped air pipe. In the second part, after the antifreeze foaming liquid delivery pipeline is pumped out by the pump, it first passes through the middle dual-purpose electric heating roller along the roller bracket, and is divided into two sections on the crossbeam under the roller bracket. It goes up along the antifreeze foam spray device bracket and is fixed on the bracket in parallel with the air supply pipeline, respectively providing foaming liquid to the preheating antifreeze foam spray devices at both ends. This not only ensures normal liquid supply, but also preheats the foaming liquid to better achieve antifreeze.

[0063] Figure 8As shown, it is an adjustable device at the connection of the preheating antifreeze foam spraying device, which is located at the top of the preheating antifreeze foam spraying device bracket, extending downward to be connected to the antifreeze foam spraying device. It is not difficult to see that the adjustable device adopts an "I"-shaped structure, with one end fixed on the spraying device and the other end fixed on the bracket. The protruding part at the outermost end can make it tightly buckled on the bracket while realizing the adjustment of the spraying device, so that the spraying device can be ensured to have an adjustment angle of 120°, can adapt to different working conditions, and make the antifreeze foam accurately and effectively sprayed on the coal / gangue to avoid waste of foam materials.

[0064] Fig. 9 As shown, a layout diagram of the preheating antifreeze foam spraying device and the conveying belt heating device of the present invention is provided. The layout method will be different depending on the structure of the belt conveyor, but the overall layout principle provided in the figure should be followed. It can be understood that the present invention mainly includes the layout of the foam spraying device and the arrangement of the heating device.

[0065] First, for the preheating antifreeze foam spraying device, it is not difficult to see that the preheating antifreeze foam spraying device is mainly arranged at the material drop port, belt intersection and belt tail of the belt conveyor. This is also due to the potential hazards caused by the special structure of these places. A pair of antifreeze foam spraying devices are set every 0.8 to 1.5 meters on both sides near the material drop port, belt intersection and belt tail. The number of pairs of antifreeze foam spraying devices is not more than 6 pairs, and the material drop port, belt intersection and belt tail should be surrounded; in other parts of the belt conveyor, due to its relatively stable operation, less dust is generated, and a pair of preheating antifreeze foam spraying devices are set every 2 meters. When the remaining distance is greater than 1m and less than 2m, a pair of preheating antifreeze foam spraying devices can be added. When the remaining distance is less than 1m, no preheating antifreeze foam spraying device is required. In this way, the dust control of the special parts such as the material drop port, belt intersection and belt tail of the belt conveyor is strengthened, while conventional dust control is adopted for other parts with relatively stable operation, so as to achieve hierarchical control, save resources and reduce costs.

[0066] Then, as for the arrangement of the conveyor belt heating device, it can be understood that since the middle section dual-purpose electric heating rollers and the electric heating rollers on both sides are modified on the original basis, in order to maintain the integrity of the original roller bracket and the belt conveyor, while taking into account the effectiveness and continuity of the heating, a heating system consisting of the middle section dual-purpose electric heating rollers and the electric heating rollers on both sides is set for every other set of rollers.

[0067] The integrated system of electric heating roller heating and three-chamber foaming dust reduction for mining belts provided by the present invention can be well applied to workplaces such as coal preparation plants, underground mines and open-pit mines where dust is generated due to the conveying of coal / gangue by belts, especially for most northern regions and a small part of southern regions that are prone to freezing in winter. This system can achieve a stable dust reduction effect. According to preliminary estimates, the dust reduction rate can reach more than 95%. At the same time, it can effectively solve the problem of belt freezing in winter, and effectively solve the hazards caused by belt freezing while achieving efficient dust reduction. Especially for some mines in northern regions, the presence of a heating device can effectively ensure that the belt will not be affected by the solidification of liquids such as water during operation in a low-temperature environment, greatly improving the transportation efficiency and effectively improving the service life of the belt. The system is modified on the basis of the original belt conveyor, does not need to dismantle the original structure and is easy to install, greatly reducing the installation cost, and has a very broad application prospect.

[0068] It should be understood that the system provided by the embodiment of the present invention is mainly composed of two devices, a foam spraying device and a belt heating antifreeze device, and the two devices can be integrated into one system or disassembled and used separately. Therefore, whether a device is used in an integrated manner or used alone, it should be within the scope of protection of this application.

Claims

1. The integrated system of heating rollers for conveyor belts and three-chamber foaming spray dust reduction for mining is characterized by: include: The preheating antifreeze foam spraying device relies on the three-chamber foaming chamber in the device to foam the preheated antifreeze foaming liquid. After the foaming is completed, the antifreeze foam is sprayed onto the coal / gangue body of the conveyor belt through the self-rotating convex perforated nozzle on the device, and the unique properties of the antifreeze foam are used to reduce dust; the conveyor belt heating antifreeze device heats the coal / gangue conveyor belt through three electric heating rollers, among which the middle dual-purpose electric heating roller heats the middle part of the coal / gangue conveyor belt, and the electric heating rollers on both sides heat the two sides of the coal / gangue conveyor belt. The heating method is pulse heating, which uses the waste heat of the long-term load of the electric heating tube to achieve continued heating after it is closed for a short period of time; Among them: The preheating antifreeze foam spraying device comprises: a Y-shaped air pipe, a check valve, a rice-shaped outward-turned baffle, an antifreeze foaming liquid feed pipe, a mesh metal baffle, a three-chamber foaming chamber, a contraction-type foam output port, a self-spinning convex perforated nozzle, and an edge anti-overflow cover; wherein the Y-shaped air pipe is respectively connected to the left side and the bottom side of the three-chamber foaming chamber; the antifreeze foaming liquid feed pipe is arranged on the top side of the three-chamber foaming chamber; the three-chamber foaming chamber is located in the middle of the device and contains three foaming methods; the contraction-type foam output port is located on the right side of the three-chamber foaming chamber; the self-spinning convex perforated nozzle is connected to the output port; the edge anti-overflow cover is tightly attached to the foam output port and wraps the nozzle in the cover; The three-chamber foaming chamber of the preheating antifreeze foam injection device is composed of three parts, namely, a high-speed fan blade stirring foaming chamber, a radial structure porous metal foaming chamber, and a microporous ceramic ball foaming chamber; the high-speed fan blade stirring foaming chamber has two stirring blades inside, and a small driving blade is near one end of the Y-shaped gas pipe, and the three blades are coaxially connected; the radial structure porous metal foaming chamber is composed of a radial structure porous metal, and its interior is a complex porous medium area; a large number of small-particle microporous ceramic balls exist in the microporous ceramic ball foaming chamber, and the diameter of the ceramic balls is 4 to 6 mm; mesh metal baffles are set at different foaming chamber connection parts and shrinkage foam output ports in the three-chamber foaming cavity; The self-rotating convex perforated nozzle of the preheating antifreeze foam injection device has a fan blade structure inside, which is nested in the output port and automatically rotates with the wind flow and liquid flow.

2. The system according to claim 1, characterized in that: The conveyor belt heating and antifreeze device includes: electric heating rollers on both sides and dual-purpose electric heating rollers in the middle section; wherein the electric heating rollers on both sides are located on both sides of the upper end of the roller bracket, the axis is connected to the roller bracket, and an electric heating pipe is arranged inside the cylinder; the dual-purpose electric heating roller in the middle section is located in the middle of the upper end of the roller bracket, the axis is connected to the bracket, and an electric heating pipe is arranged inside the cylinder, and the axis is hollow to facilitate the passage of the antifreeze foam transport pipeline to realize preheating of the antifreeze foaming liquid.

3. The system according to claim 1, characterized in that: The foaming liquid of the preheating antifreeze foam injection device is mixed with antifreeze, and the antifreeze is selected from chloride salts or water-soluble organic compounds; the antifreeze foaming liquid feed pipe is designed in a funnel shape below, and a mesh metal baffle is arranged at the opening part below the funnel, so that the foaming liquid enters the foaming cavity through multiple dimensions; a check valve is installed at one end of the Y-shaped gas pipe close to the three-chamber foaming cavity, and a rice-grain-shaped outward-turned baffle is arranged at the connection between the three-chamber foaming cavity and the Y-shaped gas pipe.

4. The system according to claim 1, characterized in that: The self-rotating convex perforated nozzle of the preheating antifreeze foam spraying device sprays at an angle of 60° to 150° according to the change of the airflow provided by the air compressor; at the same time, the rotating fan blades driven by the airflow continuously stir the foam as it passes through; the output port is provided with an edge overflow prevention cover, one end of the edge overflow prevention cover is tightly attached to the output port to wrap the nozzle in the cover, and the other end is open at 90° to 120°.

5. The system according to claim 2, characterized in that: The electric heating roller shafts on both sides of the conveyor belt heating and antifreeze device adopt a circular hollow structure; the electric heating rollers on both sides are provided with temperature-controlled electric heating tubes with a double helix structure, and the wiring part of the electric heating tubes is located on the roller shaft and connected to a safe power supply; the electric heating tubes pass through the wiring end of the roller shaft, spirally wrap around the roller shaft and are connected at the other end; inside the roller, a double-layer fast heat-conducting net made of a fast heat-conducting metal material is provided between the electric heating tube and the roller shell, and is connected to the roller cylinder; the roller shaft of the middle section dual-purpose electric heating roller adopts an annular hollow structure to accommodate the passage of the foaming liquid delivery pipeline to achieve preheating of the foaming liquid; the electric heating tube is wound around the roller shaft in a double helix structure and is placed inside the roller; inside the roller, a double-layer fast heat-conducting net made of a fast heat-conducting metal material is provided between the electric heating tube and the roller shell, and is connected to the roller cylinder.

6. The system according to claim 2, characterized in that: The relationship between the radius R1 of the electric heating rollers on both sides of the conveyor belt heating and antifreeze device and the radius R2 of the middle dual-purpose electric heating roller is R1:R2=1:2; the relationship between the radius R2 of the middle dual-purpose electric heating roller and the radius R3 of its roller shaft is R2:R3=3:1; the diameter of the temperature-controlled electric heating tube is 6-12mm; the heating temperature of the temperature-controlled electric heating tubes in the electric heating rollers on both sides is maintained at 20-30°C, and a temperature controller is provided at the control end. When the temperature exceeds 30°C, heating is automatically stopped; the heating temperature of the electric heating tube in the middle dual-purpose electric heating roller is maintained at 30-40°C, and heating is automatically stopped when the temperature exceeds 40°C; a fixed temperature temperature detector is provided on the roller bracket, and when the ambient temperature is detected to be lower than 2°C, the roller responds and starts heating; after the cumulative heating time reaches 5h, the heating is automatically stopped, and the heating is turned on again after stopping for 1h. When the device is closed, the residual heat is used to continue heating, and the heating device is turned on or off in a cycle to achieve pulse heating.

7. The system according to claim 1, characterized in that: The preheating antifreeze foam spraying device is arranged at the blanking port, belt intersection and belt tail of the belt conveyor. A pair of preheating antifreeze foam spraying devices is arranged every 0.8 to 1.5 m on both sides near the blanking port, belt intersection and belt tail. The number of pairs of spraying devices is not more than 6 pairs, surrounding the blanking port, belt intersection and belt tail; a pair of spraying devices is arranged every 2 m in other parts of the belt conveyor. When the remaining distance is greater than 1 m and less than 2 m, a pair of preheating antifreeze foam spraying devices is added. When the remaining distance is less than 1 m, no spraying device is arranged; when the preheating antifreeze foam spraying device is arranged, the original bracket is modified, and the preheating antifreeze foam spraying device bracket is welded on the belt conveyor body. The antifreeze foam spraying device and the bracket are provided with adjustment devices, and the adjustment range is 120°; a light scattering high-sensitivity dust concentration sensor is arranged on the bracket, which can monitor the dust concentration by using the scattering of light. When the respiratory dust concentration is detected to be higher than 2.5 mg / m 3 The dust removal device will be automatically turned on when 8. The system according to claim 1, characterized in that: The heating rollers in the conveyor belt heating and antifreeze device are modified on the basis of the original conveyor rollers. The electric heating rollers on both sides replace the original conveyor rollers on both sides. The middle section dual-purpose electric heating rollers need to be re-drilled and installed on the bracket during installation, and their top height maintains the original conveyor roller height; a set of heating devices is set for every set of rollers.

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