A quantitative feeding system and quantitative feeding control method for powder material of asphalt mixing equipment

Abstract

The present invention discloses a powder quantitative feeding system and a quantitative feeding control method for asphalt mixing equipment. The powder quantitative feeding system includes a quantitative feeding device and a control device. The quantitative feeding device includes a powder bin, a pulse dust collector installed on the top of the powder bin and a powder feeding mechanism. The pulse dust collector includes a pulse dust collector body and an air supply mechanism. The powder feeding mechanism includes a powder feeding pipeline, a tube bag valve assembly installed on the powder feeding pipeline and a pressure detection assembly. The control method includes: 1. conveying of powder-containing conveying gas; 2. precipitation and filtration of powder; 3. opening of the pulse dust collector; 4. detection of the height of the powder pile; 5. closing of the pulse dust collector. The present invention can achieve the purpose of quantitatively filling powder into the powder bin, can enable the conveying gas to achieve the purpose of pollution-free emission, can avoid dust pollution to the outside air caused by the powder-containing conveying gas, and at the same time, can reduce the consumption rate of powder during the transmission process.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt mixing, and relates to a powder quantitative feeding system for asphalt mixing equipment and a quantitative feeding control method. Background Art

[0002] When mixing asphalt concrete mixture, it is necessary to add an appropriate amount of powder to fill between large, medium and small aggregates and sand to reduce the void ratio of the mixture and improve the strength of the mixture. The powder feeding system is an important part of the asphalt mixing equipment. The powder feeding system can be used to transport the powder in the powder tank on the powder tanker to the powder silo. At present, the existing powder feeding system has the following defects in actual use: 1. The pressure in the powder delivery pipeline is difficult to control. When the pressure in the powder delivery pipeline is insufficient, the powder delivery amount is reduced and the time is too long. When the pressure in the powder delivery pipeline is too high, the powder delivery pipeline and the powder silo are greatly worn, especially the wear of the elbow part is rapidly aggravated; 2. It is impossible to achieve fixed production and quantity , it is easy to have insufficient powder in the powder bin during the production process, resulting in production interruption, or there is excess powder in the powder bin, which is agglomerated after being left for a long time; 3. Overflow occurs frequently, and the excess powder is discharged out of the bin at high pressure, seriously polluting the surrounding environment, and the source of the powder cannot be turned off immediately; 4. The opening and closing of the pulse dust collector in the powder feeding system relies on time control, which cannot be automated, and cannot efficiently and thoroughly remove the conveying gas in the powder bin. The pulse dust collector needs to be connected to an external compressed air pipeline, and the air intake point is uncertain and randomly selected. In addition, the wiring of the pulse dust collector is complicated, and it needs to be connected to the control line, power line and high-pressure purge gas pipeline, which requires a lot of manpower and material resources. Therefore, a quantitative feeding system and quantitative feeding control method for asphalt mixing equipment powder should be provided. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a powder quantitative feeding system for asphalt mixing equipment in view of the deficiencies in the above-mentioned prior art. The system has a simple structure and a reasonable design, can achieve the purpose of quantitatively filling powder into the powder bin, can enable the conveying gas to achieve the purpose of pollution-free emission, can avoid dust pollution to the outside air caused by the powder-containing conveying gas, and at the same time, can reduce the consumption rate of powder during the transmission process.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a quantitative feeding system for powder of asphalt mixing equipment, characterized in that: it includes a quantitative feeding device and a control device connected to the quantitative feeding device, the quantitative feeding device includes a powder bin, a pulse dust collector installed at the top of the powder bin and a powder feeding mechanism for introducing powder into the powder bin, the pulse dust collector includes a pulse dust collector body and an air supply mechanism for filling gas into the pulse dust collector body, the pulse dust collector body includes a pulse dust collector cylinder, a top cover installed at the top of the pulse dust collector cylinder, and a top cover fixedly installed on the pulse dust collector. A fixing plate on the inner wall of the cylinder and a plurality of filter bags mounted on the fixing plate, a connecting flange for mounting the top cover is provided on the cylinder of the pulse dust collector, a plurality of exhaust holes are provided on the connecting flange, a pressure balancing safety valve for controlling the pressure in the pulse dust collector body is installed on the cylinder of the pulse dust collector, the air supply mechanism comprises a first air compressor, an air storage tank connected to the first air compressor, an air pipeline installed at the outlet end of the air storage tank and a pulse valve group installed on the air pipeline, the air pipeline passes through the side wall of the top cover and is arranged on the top surface inside the top cover, and a pulse valve group is provided on the air pipeline There are multiple ventilation holes, the number of which is consistent with the number of the filter bags and corresponds one to one. The powder feeding mechanism includes a powder feeding pipeline for connecting the powder tank and the powder silo, a tube bag valve assembly and a pressure detection assembly installed on the powder feeding pipeline, the tube bag valve assembly includes a tube bag valve installed on the powder feeding pipeline, a second air compressor and an electromagnetic valve for controlling the on and off of the tube bag valve, the pressure detection assembly includes a first pressure sensor installed on the powder feeding pipeline for detecting the pressure in the powder feeding pipeline, a compressed air pressure regulator for reducing the pressure in the powder feeding pipeline and a pressure regulator for increasing the pressure in the powder feeding pipeline. A third air compressor with force, a heavy hammer type continuous level meter for detecting the height of the powder pile in the powder bin and a second pressure sensor for detecting the pressure in the powder bin are fixedly installed on the top of the powder bin, the control device includes a main controller and an auxiliary controller connected to the main controller, the heavy hammer type continuous level meter, the first pressure sensor and the second pressure sensor are all connected to the input end of the main controller, the second air compressor, the solenoid valve, the compressed air pressure regulator and the third air compressor are all connected to the output end of the main controller, and the first air compressor and the pulse valve group are all connected to the output end of the auxiliary controller.

[0005] The above-mentioned asphalt mixing equipment powder quantitative feeding system is characterized in that: the pulse dust collector cylinder includes a first circular cylinder, a second circular cylinder and a third circular cylinder connected in sequence from bottom to top, the second circular cylinder is a split type, and the second circular cylinder includes a first semicircular cylinder and a second semicircular cylinder that are interlocked, and an inspection hole is opened on the top cover, and the inspection hole is sealed by a sealing cover.

[0006] The above-mentioned asphalt mixing equipment powder quantitative feeding system is characterized in that: the air storage tank and the first air compressor are connected through a first air path connecting pipe, the air path pipeline includes a first air path branch pipeline, a second air path branch pipeline and a third air path branch pipeline arranged in parallel, and the first air path branch pipeline and the air storage tank, the second air path branch pipeline and the air storage tank, and the third air path branch pipeline and the air storage tank are respectively connected through three second air path connecting pipes.

[0007] The above-mentioned asphalt mixing equipment powder quantitative feeding system is characterized in that: the pulse valve group includes a first pulse valve installed on the first air branch pipeline, a second pulse valve installed on the second air branch pipeline and a third pulse valve installed on the third air branch pipeline, and a pressure regulating valve is installed at the outlet end of the air storage tank, and the first pulse valve, the second pulse valve, the third pulse valve and the pressure regulating valve are all connected to the output end of the auxiliary controller.

[0008] The above-mentioned powder quantitative feeding system for asphalt mixing equipment is characterized in that the exhaust hole is a waist-shaped exhaust hole, and a plurality of the waist-shaped exhaust holes are evenly distributed on the connecting flange.

[0009] The above-mentioned asphalt mixing equipment powder quantitative feeding system is characterized in that a first mounting seat for installing the first air compressor and a second mounting seat for installing the pressure balance safety valve are provided on the side wall of the third circular cylinder, and a pressure relief channel communicating with the inner cavity of the third circular cylinder is opened in the second mounting seat.

[0010] The present invention also provides a method for controlling the quantitative feeding of powder material in an asphalt mixing equipment, characterized in that the control method comprises:

[0011] Step 1: Transportation of powder-containing conveying gas:

[0012] One end of the powder delivery pipeline is connected to the powder tank on the powder tank truck, and the main controller controls the second air compressor and the solenoid valve to open, so that the powder-containing conveying gas in the powder tank enters the powder delivery pipeline and enters the powder bin through the tube bag valve, wherein the particle size of the powder particles in the powder-containing conveying gas is less than 0.5 mm;

[0013] Step 2: Precipitation and filtration of powder:

[0014] Step 201: In the process of the powder-containing conveying gas entering the powder bin from the outlet of the powder conveying pipeline, large-diameter powder particles in the powder-containing conveying gas are separated from the conveying gas and deposited at the bottom of the powder bin under the action of gravity to form a powder pile, wherein the large-diameter powder particles refer to powder particles with a particle size greater than 0.075 mm;

[0015] Step 202: During the process of the powder-containing conveying gas entering the powder bin from the outlet of the powder conveying pipeline, the small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector cylinder along with the conveying gas, and are adsorbed on the outer surfaces of multiple filter bags to form a dust layer. The clean gas generated after filtration is discharged through multiple exhaust holes, wherein the small-sized powder particles refer to powder particles with a particle size not greater than 0.075 mm, and the concentration of the small-sized powder particles in the clean gas is not greater than 20 mg / m 3 ;

[0016] Step 3: Start the pulse dust collector:

[0017] During the precipitation and filtration of the powder, the second pressure sensor detects the pressure in the powder bin in real time and sends it to the main controller. The main controller compares the measured pressure in the powder bin received with the first pressure setting value. When the measured pressure in the powder bin received by the main controller meets the first pressure setting value, the main controller sends a command to start the pulse dust collector to the auxiliary controller. The auxiliary controller receives the command to start the pulse dust collector and controls the opening of the first air compressor, the air storage tank and the pulse valve group. The dust-removing compressed air in the air storage tank enters the multiple filter bags through the air pipeline, removes the dust layer on the outer surface of the filter bag, and makes the small-size powder particles in the dust layer deposit on the powder pile from top to bottom. The value range of the first pressure setting value is 700Pa~784Pa;

[0018] Step 4: Detection of powder pile height:

[0019] The weight-type continuous material level meter detects the height of the powder pile in the powder silo in real time and sends it to the main controller, which compares the received measured height of the powder pile with the set value of the powder pile height. When the received measured height of the powder pile meets the set value of the powder pile height, the main controller controls the second air compressor and the tube bag valve to close, and stops conveying the powder-containing conveying gas into the powder silo;

[0020] Step 5: Shut down the pulse dust collector:

[0021] The second pressure sensor detects the pressure in the powder silo in real time and sends it to the main controller, which compares the measured pressure in the powder silo received with the second pressure setting value. When the measured pressure in the powder silo received by the main controller meets the second pressure setting value, the main controller sends a command to shut down the pulse dust collector to the auxiliary controller, and the auxiliary controller receives the command to shut down the pulse dust collector and controls the shutdown of the first air compressor, the air storage tank and the pulse valve group, and the pulse dust collector stops working. The value range of the second pressure setting value is 90Pa~100Pa.

[0022] The control method of the powder quantitative feeding system of the above-mentioned asphalt mixing equipment is characterized in that: in step one, during the process of conveying the powder-containing conveying gas, the first pressure sensor detects the pressure in the powder conveying pipeline in real time and transmits it to the main controller, the main controller compares the received measured pressure in the powder conveying pipeline with the set pressure value of the powder conveying pipeline, and when the received measured pressure in the powder conveying pipeline meets the set pressure value of the powder conveying pipeline, the powder-containing conveying gas is continuously introduced into the powder conveying pipeline; when the received measured pressure in the powder conveying pipeline is less than the set pressure value of the powder conveying pipeline, the main controller controls the third air compressor to start, increase the pressure in the powder conveying pipeline, until the measured pressure in the powder conveying pipeline meets the set pressure value of the powder conveying pipeline; when the received measured pressure in the powder conveying pipeline is greater than the set pressure value of the powder conveying pipeline, the main controller controls the compressed air pressure regulator to start, reduce the pressure in the powder conveying pipeline, until the measured pressure in the powder conveying pipeline meets the set pressure value of the powder conveying pipeline; wherein, the value range of the set pressure value of the powder conveying pipeline is 0.2MPa to 0.25MPa.

[0023] The control method of the powder quantitative feeding system of the above-mentioned asphalt mixing equipment is characterized in that: in step three, during the process of the second pressure sensor performing real-time detection of the pressure in the powder silo, when the pressure in the powder silo detected by the second pressure sensor meets the third pressure setting value, the pressure balance safety valve opens to realize the pressure relief of the powder silo, wherein the value range of the third pressure setting value is 785Pa~900Pa.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The quantitative feeding device of the powder quantitative feeding system of the present invention comprises a powder bin, a pulse dust collector and a powder feeding mechanism, wherein the powder feeding mechanism comprises a powder feeding pipeline for connecting the powder tank and the powder bin, and a tube bag valve assembly is installed on the powder feeding pipeline, and the tube bag valve assembly comprises a tube bag valve, a second air compressor and a solenoid valve for controlling the on and off of the tube bag valve. When actually used, after one end of the powder feeding pipeline is connected to the powder tank on the powder tank truck, the second air compressor and the solenoid valve are turned on to put the tube bag valve in an on state. At this time, the powder-containing conveying gas in the powder tank enters the powder feeding pipeline and enters the powder bin through the tube bag valve. In the process of gas entering the powder silo, large-sized powder particles in the powder-containing conveying gas are separated from the conveying gas and deposited at the bottom of the powder silo under the action of gravity to form a powder pile. Small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector along with the conveying gas. The pulse dust collector filters the small-sized powder particles in the powder-containing conveying gas entering the powder silo, and discharges the clean air obtained after filtration into the outside air, which can achieve the purpose of filling the powder silo with powder, achieve the purpose of pollution-free emission of the conveying gas, and avoid dust pollution of the outside air by the powder-containing conveying gas.

[0026] 2. The pulse dust collector of the present invention comprises a pulse dust collector body and an air supply mechanism. The pulse dust collector body comprises a pulse dust collector cylinder, a top cover, a fixing plate and a plurality of filter bags. The air supply mechanism comprises a first air compressor, an air storage tank, an air pipeline and a pulse valve group. In actual use, the first air compressor serves as a power source for the air supply mechanism. The air storage tank can cool and store the compressed air output by the first air compressor and can adjust the stability of the compressed air pressure. The first air compressor and the air storage tank together constitute a self-contained power source for the pulse dust collector, which solves the technical problem of complex wiring of the pulse dust collector in the prior art. It only needs to connect the first air compressor to the power supply. That is, it can ensure the normal operation of the pulse dust collector, reduce the failure rate of the pulse dust collector, and facilitate maintenance; by passing the air path pipeline through the side wall of the top cover and arranging it on the top surface inside the top cover, and by opening a plurality of air holes on the air path pipeline, the number of the air holes is consistent with the number of filter bags, and they correspond one to one. In actual use, when the pulse valve group is opened, compressed air will flow into the air path pipeline and enter the plurality of filter bags through the plurality of air holes, so as to remove the dust layer adsorbed on the outer surface of the plurality of filter bags, so as to make the small-size powder particles in the dust layer gradually deposit in the powder bin, so as to realize the dust removal of the plurality of filter bags and reduce the consumption rate of the powder during the transmission process.

[0027] 3. The control device of the powder quantitative feeding system of the present invention includes a main controller and an auxiliary controller. A heavy hammer type continuous material level meter is fixedly installed on the top of the powder silo, and the heavy hammer type continuous material level meter is connected to the input end of the main controller, and the second air compressor and the solenoid valve are both connected to the output end of the main controller. In actual use, during the precipitation and filtration of the powder-containing conveying gas, the heavy hammer type continuous material level meter detects the height of the powder pile in the powder silo in real time and sends it to the main controller. The main controller compares the received measured height of the powder pile with the set value of the powder pile height. When the measured height of the powder pile received by the main controller meets the set value of the powder pile height, the main controller controls to close the second air compressor and the solenoid valve, so that the tube bag valve is in a disconnected state, and the conveying of the powder-containing conveying gas into the powder silo is stopped, thereby achieving the purpose of quantitative feeding into the powder silo, achieving the purpose of fixed production and quantity and reducing inventory, and at the same time, it can avoid the phenomenon of excessive powder in the powder silo being agglomerated for a long time, thereby avoiding the phenomenon of poor powder discharge from the powder silo.

[0028] 4. The powder quantitative feeding system of the present invention installs a pressure detection component on the powder delivery pipeline, and the pressure detection component includes a first pressure sensor, a compressed air pressure regulator and a third air compressor, and the first pressure sensor is connected to the input end of the main controller, and the second air compressor, the solenoid valve, the compressed air pressure regulator and the third air compressor are all connected to the output end of the main controller. In actual use, during the process of conveying the powder-containing conveying gas, the first pressure sensor can detect the pressure in the powder delivery pipeline in real time and transmit it to the main controller. The main controller compares the measured pressure in the powder delivery pipeline with the set pressure value of the powder delivery pipeline. When the measured pressure in the powder delivery pipeline meets the set pressure value, the main controller will detect the pressure in the powder delivery pipeline in real time. When the pressure value of the powder pipeline is set, powder-containing conveying gas is continuously introduced into the powder delivery pipeline; when the measured pressure received in the powder delivery pipeline is less than the set pressure value of the powder delivery pipeline, the main controller controls the third air compressor to start, and increases the pressure in the powder delivery pipeline until the measured pressure in the powder delivery pipeline meets the set pressure value of the powder delivery pipeline; when the measured pressure received in the powder delivery pipeline is greater than the set pressure value of the powder delivery pipeline, the main controller controls the compressed air pressure regulator to start, and reduces the pressure in the powder delivery pipeline until the measured pressure in the powder delivery pipeline meets the set pressure value of the powder delivery pipeline. This can ensure the stability of the pressure in the powder delivery pipeline, reduce the impact of the powder-containing conveying gas on the powder silo and the pulse dust collector, and has a good use effect.

[0029] 5. The control method of the present invention is reasonably designed, can realize automatic control of the quantitative feeding system, can achieve the purpose of quantitative production, and is easy to promote and apply.

[0030] In summary, the powder quantitative feeding system of the present invention can achieve the purpose of quantitatively filling powder into the powder silo, can enable the conveying gas to achieve the purpose of pollution-free emission, can avoid the powder-containing conveying gas from causing dust pollution to the outside air, and at the same time, can reduce the consumption rate of powder in the transmission process; the control method of the powder quantitative feeding system can realize automatic control of the quantitative feeding system, can achieve the purpose of quantitative production, and is convenient for promotion and application.

[0031] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the use status of the powder quantitative feeding system of the asphalt mixing equipment of the present invention.

[0033] Figure 2 It is a schematic diagram of the structure of the pulse dust collector of the present invention.

[0034] Figure 3 for Figure 2 Left view of .

[0035] Figure 4 It is a schematic structural diagram of the pulse dust collector body of the present invention.

[0036] Figure 5 for Figure 4 AA section view.

[0037] Figure 6 The figure is a circuit principle block diagram of the control device of the powder quantitative feeding system of the present invention.

[0038] Figure 7 The figure is a flow chart of the powder quantitative feeding control method of the present invention.

[0039] Description of reference numerals:

[0040] 1-1—first circular cylinder; 1-2-1—first semicircular cylinder;

[0041] 1-2-2—the second semicircular cylinder; 1-3—the third circular cylinder;

[0042] 2—top cover; 3—connecting flange; 3-1—exhaust hole;

[0043] 4—sealing cover; 5—fixing plate; 6—filter bag;

[0044] 7—first mounting seat; 8—first air compressor; 9—air storage tank;

[0045] 10—pressure balance safety valve; 11—second mounting seat; 11-1—pressure relief channel;

[0046] 12-1—first gas branch pipeline; 12-2—second gas branch pipeline;

[0047] 12-3—the third gas branch pipe; 13—the vent hole;

[0048] 14-1—first pulse valve; 14-2—second pulse valve; 14-3—third pulse valve;

[0049] 15-1—First gas line connection; 15-2—Second gas line connection; 16—Pressure regulating valve;

[0050] 17—powder silo; 18—powder delivery pipeline; 19—main controller;

[0051] 20—auxiliary controller; 21—weight-type continuous material level meter; 22—tube bag valve;

[0052] 23—second air compressor; 24—solenoid valve;

[0053] 25—compressed air pressure regulator; 26—third air compressor;

[0054] 27—first pressure sensor; 28—second pressure sensor;

[0055] 29—Alarm; 30—Powder tank. DETAILED DESCRIPTION

[0056] like Figures 1 to 6The asphalt mixing equipment powder quantitative feeding system shown in the figure includes a quantitative feeding device and a control device connected to the quantitative feeding device, the quantitative feeding device includes a powder bin 17, a pulse dust collector installed on the top of the powder bin 17 and a powder feeding mechanism for introducing powder into the powder bin 17, the pulse dust collector includes a pulse dust collector body and an air supply mechanism for filling gas into the pulse dust collector body, the pulse dust collector body includes a pulse dust collector cylinder, a top cover 2 installed on the top of the pulse dust collector cylinder, a fixing plate 5 fixedly installed on the inner wall of the pulse dust collector cylinder and a plurality of filter bags 6 installed on the fixing plate 5, the pulse dust collector A connecting flange 3 for mounting the top cover 2 is provided on the cylinder, and a plurality of exhaust holes 3-1 are provided on the connecting flange 3. A pressure balancing safety valve 10 for controlling the internal pressure of the pulse dust collector body is installed on the cylinder of the pulse dust collector. The air supply mechanism includes a first air compressor 8, an air storage tank 9 connected to the first air compressor 8, an air pipeline installed at the outlet end of the air storage tank 9, and a pulse valve group installed on the air pipeline. The air pipeline passes through the side wall of the top cover 2 and is arranged on the top surface inside the top cover 2. A plurality of air vents 13 are provided on the air pipeline. The number of the air vents 13 is consistent with the number of the filter bags 6, and they are one-to-one. The powder feeding mechanism includes a powder feeding pipeline 18 for connecting the powder tank 30 and the powder silo 17, a tube bag valve assembly and a pressure detection assembly installed on the powder feeding pipeline 18, the tube bag valve assembly includes a tube bag valve 22 installed on the powder feeding pipeline 18, a second air compressor 23 and a solenoid valve 24 for controlling the on and off of the tube bag valve 22, the pressure detection assembly includes a first pressure sensor 27 installed on the powder feeding pipeline 18 for detecting the pressure in the powder feeding pipeline 18, a compressed air pressure regulator 25 for reducing the pressure in the powder feeding pipeline 18 and a third air compressor 26 for increasing the pressure in the powder feeding pipeline 18, and the top of the powder silo 17 A weight-type continuous level meter 21 for detecting the height of the powder pile in the powder bin 17 and a second pressure sensor 28 for detecting the pressure in the powder bin 17 are fixedly installed at the end, and the control device includes a main controller 19 and an auxiliary controller 20 connected to the main controller 19, the weight-type continuous level meter 21, the first pressure sensor 27 and the second pressure sensor 28 are all connected to the input end of the main controller 19, the second air compressor 23, the solenoid valve 24, the compressed air pressure regulator 25 and the third air compressor 26 are all connected to the output end of the main controller 19, and the first air compressor 8 and the pulse valve group are all connected to the output end of the auxiliary controller 20.

[0057] In this embodiment, the quantitative feeding device includes a powder bin 17, a pulse dust collector and a powder feeding mechanism, the powder feeding mechanism includes a powder feeding pipe 18 for connecting the powder tank 30 and the powder bin 17, and a tube bag valve assembly is installed on the powder feeding pipe 18, and the tube bag valve assembly includes a tube bag valve 22, a second air compressor 23 and a solenoid valve 24 for controlling the on and off of the tube bag valve 22. In actual use, after one end of the powder feeding pipe 18 is connected to the powder tank 30 on the powder tank truck, the second air compressor 23 and the solenoid valve 24 are turned on to put the tube bag valve 22 in an on state. At this time, the powder-containing conveying gas in the powder tank 30 enters the powder feeding pipe 18 and enters the powder tank through the tube bag valve 22. In the silo 17, during the process of the powder-containing conveying gas entering the powder silo 17, the large-sized powder particles in the powder-containing conveying gas are separated from the conveying gas, and are deposited at the bottom of the powder silo 17 under the action of gravity to form a powder pile, and the small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector along with the conveying gas, and the pulse dust collector filters the small-sized powder particles in the powder-containing conveying gas entering the powder silo 17, and discharges the clean air obtained after filtration into the outside air, thereby achieving the purpose of filling the powder silo 17 with powder, achieving the purpose of pollution-free emission of the conveying gas, and avoiding dust pollution of the outside air by the powder-containing conveying gas.

[0058] In this embodiment, the pulse dust collector includes a pulse dust collector body and an air supply mechanism. The pulse dust collector body includes a pulse dust collector barrel, a top cover 2, a fixing plate 5 and a plurality of filter bags 6. At this time, the pulse dust collector barrel and the top cover 2 together constitute a container with a top seal. The fixing plate 5 plays a role in fixing and supporting the plurality of filter bags 6. In actual use, when the small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector along with the conveying gas, the small-sized powder particles in the powder-containing conveying gas will gradually be adsorbed on the plurality of filter bags. The outer surface of the bag 6. At this time, a dust layer is formed on the outer surface of the multiple filter bags 6. The clean gas generated after filtration flows from bottom to top into the top cover 2 through the multiple filter bags 6. Since the pulse dust collector cylinder is provided with a connecting flange 3 for installing the top cover 2, and the connecting flange 3 is provided with a plurality of exhaust holes 3-1, the clean air entering the top cover 2 is discharged to the outside air through the multiple exhaust holes 3-1. The structure of the pulse dust collector body is simple, the capacity of the pulse dust collector cylinder is large, the filtration efficiency is good, and it is easy to remove dust and maintain.

[0059] In this embodiment, the air supply mechanism includes a first air compressor 8, an air storage tank 9, an air pipeline and a pulse valve group. In actual use, the first air compressor 8 serves as the power source of the air supply mechanism, and the air storage tank 9 can cool and store the dust-removing compressed air output by the first air compressor 8, and can also adjust the stability of the compressed air pressure. The first air compressor 8 and the air storage tank 9 together constitute a self-contained power source for the pulse dust collector, which solves the technical problem of complex wiring of the pulse dust collector in the prior art. It only needs to connect the first air compressor 8 to the power supply to ensure the normal operation of the pulse dust collector, reduce the failure rate of the pulse dust collector, and facilitate Maintenance: The air pipeline is arranged through the side wall of the top cover 2 on the top surface inside the top cover 2, and a plurality of air vents 13 are opened on the air pipeline. The number of the air vents 13 is consistent with the number of the filter bags 6 and corresponds one to one. In actual use, the pulse valve group is opened, and compressed air will flow into the air pipeline and enter the plurality of filter bags 6 through the plurality of air vents 13, thereby removing the dust layer adsorbed on the outer surface of the plurality of filter bags 6, and gradually depositing the small-size powder particles in the dust layer in the powder bin 17, thereby realizing dust removal of the plurality of filter bags 6 and reducing the consumption rate of the powder during the transmission process.

[0060] In this embodiment, a pressure balancing safety valve 10 for controlling the pressure in the pulse dust collector body is installed on the pulse dust collector cylinder. Its purpose is to prevent the filter bag 6 from being blocked and causing the pulse dust collector body to expand, so as to avoid safety accidents. In actual use, when the pressure in the pulse dust collector body is higher than the safety valve setting value, the pressure balancing safety valve 10 will automatically open to release the pressure. When the pressure in the pulse dust collector body is lower than the safety valve setting value, the pressure balancing safety valve 10 will automatically balance the pressure in the pulse dust collector body to prevent the pressure in the pulse dust collector body from being too low and causing poor powder circulation.

[0061] In this embodiment, the control device includes a main controller 19 and an auxiliary controller 20 connected to the main controller 19. The weight-type continuous material level meter 21 is fixedly installed on the top of the powder bin 17, and the weight-type continuous material level meter 21 is connected to the input end of the main controller 19. The second air compressor 23 and the solenoid valve 24 are both connected to the output end of the main controller 19. In actual use, during the precipitation and filtration of the powder-containing conveying gas, the weight-type continuous material level meter 21 detects the height of the powder pile in the powder bin 17 in real time and sends it to the main controller 19. The main controller The device 19 compares the received actual height of the powder pile with the set value of the powder pile height. When the actual height of the powder pile received by the main controller 19 meets the set value of the powder pile height, the main controller 19 controls to close the second air compressor 23 and the solenoid valve 24, so that the tube bag valve 22 is in a disconnected state, and stops conveying the powder-containing conveying gas into the powder bin 17, thereby achieving the purpose of quantitative feeding into the powder bin 17, achieving the purpose of fixed production and quantitative reduction of inventory, and at the same time, it can avoid the phenomenon of excessive powder in the powder bin 17 being agglomerated due to long-term storage, thereby avoiding the phenomenon of poor powder discharge from the powder bin 17.

[0062] In this embodiment, a pressure detection component is installed on the powder delivery pipeline 18, and the pressure detection component includes a first pressure sensor 27, a compressed air pressure regulator 25 and a third air compressor 26. The first pressure sensor 27 is connected to the input end of the main controller 19, and the second air compressor 23, the solenoid valve 24, the compressed air pressure regulator 25 and the third air compressor 26 are all connected to the output end of the main controller 19. In actual use, in the process of conveying the powder-containing conveying gas, the first pressure sensor 27 can detect the pressure in the powder delivery pipeline 18 in real time and transmit it to the main controller 19. The main controller 19 compares the received measured pressure in the powder delivery pipeline 18 with the set pressure value of the powder delivery pipeline. When the received measured pressure in the powder delivery pipeline 18 is When the set pressure value of the powder delivery pipeline is met, the powder-containing conveying gas is continuously introduced into the powder delivery pipeline 18; when the measured pressure received in the powder delivery pipeline 18 is less than the set pressure value of the powder delivery pipeline, the main controller 19 controls the third air compressor 26 to open, and increases the pressure in the powder delivery pipeline 18 until the measured pressure in the powder delivery pipeline 18 meets the set pressure value of the powder delivery pipeline; when the measured pressure received in the powder delivery pipeline 18 is greater than the set pressure value of the powder delivery pipeline, the main controller 19 controls the compressed air pressure regulator 25 to open, and reduces the pressure in the powder delivery pipeline 18 until the measured pressure in the powder delivery pipeline 18 meets the set pressure value of the powder delivery pipeline, which can ensure the stability of the pressure in the powder delivery pipeline 18, reduce the impact of the powder-containing conveying gas on the powder silo 17 and the pulse dust collector, and has a good use effect.

[0063] In this embodiment, the main controller 19 and the auxiliary controller 20 both use a single chip microcomputer of model STM32F103ZET6, and the first pressure sensor 27 and the second pressure sensor 28 both use a SIN-P350 series planar membrane structure pressure transmitter.

[0064] In this embodiment, the first air compressor 8 adopts a silent oil-free air compressor head of model FX680J, the second air compressor 23 adopts an air compressor of model TA-100, and the third air compressor 26 adopts an air compressor of model TA-120.

[0065] In this embodiment, the weight-type continuous material level meter 21 is a weight-type continuous material level meter of model CRV100B.

[0066] like Figure 3 , Figure 4 and Figure 5 As shown, in this embodiment, the pulse dust collector cylinder includes a first circular cylinder 1-1, a second circular cylinder and a third circular cylinder 1-3 connected in sequence from bottom to top, the second circular cylinder is a split type, and the second circular cylinder includes a first semicircular cylinder 1-2-1 and a second semicircular cylinder 1-2-2 that are interlocked, and an inspection hole is opened on the top cover 2, and the inspection hole is blocked by a sealing cover 4.

[0067] In this embodiment, the air storage tank 9 is connected to the first air compressor 8 through a first air path connecting pipe 15-1, and the air path pipeline includes a first air path branch pipeline 12-1, a second air path branch pipeline 12-2 and a third air path branch pipeline 12-3 arranged in parallel, and the first air path branch pipeline 12-1 and the air storage tank 9, the second air path branch pipeline 12-2 and the air storage tank 9, and the third air path branch pipeline 12-3 and the air storage tank 9 are respectively connected through three second air path connecting pipes 15-2.

[0068] In this embodiment, the dust-removing compressed air output by the first air compressor 8 enters the air storage tank 9 through the first air path pipe 15-1. The air storage tank 9 can store the dust-removing compressed air. At the same time, the air storage tank 9 can cool the dust-removing compressed air to keep the air pressure of the dust-removing compressed air stable.

[0069] In this embodiment, the parallel first air branch pipe 12-1, the second air branch pipe 12-2 and the third air branch pipe 12-3 together form an air pipe arranged directly above the multiple filter bags 6. The first air branch pipe 12-1, the second air branch pipe 12-2 and the third air branch pipe 12-3 together provide sufficient circulation space for the dust-removed compressed air to enter the multiple filter bags 6. The first air branch pipe 12-1, the second air branch pipe 12-2 and the third air branch pipe 12-3 are all arranged horizontally. The vent 13 on the first air branch pipe 12-1 is vertically opened on the pipe wall on the side of the first air branch pipe 12-1 close to the filter bags 6, and the vent 13 on the first air branch pipe 12-1 is vertically opened on the pipe wall on the side of the first air branch pipe 12-1 close to the filter bags 6. The air vents 13 on the second air branch pipe 12-2 are vertically opened on the pipe wall of the second air branch pipe 12-2 on the side close to the filter bag 6, and the air vents 13 on the third air branch pipe 12-3 are vertically opened on the pipe wall of the third air branch pipe 12-3 on the side close to the filter bag 6. The second air branch pipe 12-2 and the third air branch pipe 12-3 have the same structure, so that the multiple air vents 13 correspond one-to-one with the multiple filter bags 6, that is, there is an air vent 13 directly above each filter bag 6, so that the dust-removed compressed air in the air pipe can flow into the filter bag 6 through the air vents 13. The structure is simple and can ensure the smooth circulation of the dust-removed compressed air.

[0070] like Figure 3 and Figure 6 As shown, in this embodiment, the pulse valve group includes a first pulse valve 14-1 installed on the first air branch pipeline 12-1, a second pulse valve 14-2 installed on the second air branch pipeline 12-2 and a third pulse valve 14-3 installed on the third air branch pipeline 12-3, and a pressure regulating valve 16 is installed at the outlet end of the gas storage tank 9, and the first pulse valve 14-1, the second pulse valve 14-2, the third pulse valve 14-3 and the pressure regulating valve 16 are all connected to the output end of the auxiliary controller 20.

[0071] In this embodiment, the first pulse valve 14 - 1 , the second pulse valve 14 - 2 and the third pulse valve 14 - 3 are all pulse valves of model LPDA20.

[0072] In this embodiment, the pressure regulating valve 16 adopts an intelligent pressure controller of model number red-y smart.

[0073] like Figure 5 As shown, in this embodiment, the exhaust hole 3 - 1 is a waist-shaped exhaust hole, and a plurality of the waist-shaped exhaust holes are evenly distributed on the connecting flange 3 .

[0074] like Figure 2As shown, in this embodiment, a first mounting seat 7 for installing the first air compressor 8 and a second mounting seat 11 for installing the pressure balance safety valve 10 are provided on the side wall of the third circular cylinder 1-3, and a pressure relief channel 11-1 communicating with the inner cavity of the third circular cylinder 1-3 is provided in the second mounting seat 11.

[0075] like Figure 1 and Figure 6 As shown, in this embodiment, an alarm 29 is also installed on the powder delivery pipeline 18, and the alarm 29 is connected to the output end of the main controller 19. The alarm 29 adopts an alarm model of S100LR-BZ 220V.

[0076] In actual use, when the weight-type continuous material level meter 21 detects that the height of the powder pile in the powder silo 17 has reached the upper limit of the powder pile, and transmits it to the main controller 19, the main controller 19 controls the alarm 29 to sound an alarm, and controls the second air compressor 23 and the tube bag valve 22 to close, and stops conveying the powder-containing conveying gas into the powder silo 17 to prevent the powder in the powder silo 17 from overflowing.

[0077] like Figure 7 The asphalt mixing equipment powder quantitative feeding control method shown in FIG. Figures 1 to 6 , the control method comprises:

[0078] Step 1: Transportation of powder-containing conveying gas:

[0079] One end of the powder delivery pipeline 18 is connected to the powder tank 30 on the powder tanker, and the main controller 19 controls the second air compressor 23 and the electromagnetic valve 24 to open, so that the powder-containing conveying gas in the powder tank 30 enters the powder delivery pipeline 18 and enters the powder bin 17 through the tube bag valve 22, wherein the particle size of the powder particles in the powder-containing conveying gas is less than 0.5 mm;

[0080] Step 2: Precipitation and filtration of powder:

[0081] Step 201: When the powder-containing conveying gas enters the powder bin 17 from the outlet of the powder conveying pipe 18, large-diameter powder particles in the powder-containing conveying gas are separated from the conveying gas and deposited at the bottom of the powder bin 17 under the action of gravity to form a powder pile, wherein large-diameter powder particles refer to powder particles with a particle size greater than 0.075 mm;

[0082] Step 202: During the process of the powder-containing conveying gas entering the powder bin 17 from the outlet of the powder conveying pipe 18, the small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector cylinder along with the conveying gas, and are adsorbed on the outer surfaces of the plurality of filter bags 6 to form a dust layer. The clean gas generated after filtration is discharged through the plurality of exhaust holes 3-1, wherein the small-sized powder particles refer to the powder particles with a particle size not greater than 0.075 mm, and the concentration of the small-sized powder particles in the clean gas is not greater than 20 mg / m 3 ;

[0083] In this embodiment, by settling the large-diameter powder particles in step 201 and filtering the small-diameter powder particles in step 202, it is possible to prevent the small-diameter powder particles from being discharged into the outside air, and at the same time, the consumption rate of the powder during the transmission process can be reduced.

[0084] Step 3: Start the pulse dust collector:

[0085] During the precipitation and filtration of the powder, the second pressure sensor 28 detects the pressure in the powder bin 17 in real time and sends it to the main controller 19. The main controller 19 compares the measured pressure in the powder bin 17 received with the first pressure setting value. When the measured pressure in the powder bin 17 received by the main controller 19 meets the first pressure setting value, the main controller 19 sends a command to start the pulse dust collector to the auxiliary controller 20. The auxiliary controller 20 receives the command to start the pulse dust collector and controls the opening of the first air compressor 8, the air storage tank 9 and the pulse valve group. The dust-removing compressed air in the air storage tank 9 enters the multiple filter bags 6 through the air pipeline, removes the dust layer on the outer surface of the filter bags 6, and makes the small-size powder particles in the dust layer deposit on the powder pile from top to bottom. The value range of the first pressure setting value is 700Pa~784Pa;

[0086] During actual use, as the thickness of the dust layer on the outer surface of the filter bag 6 continues to increase, the filter bag 6 is in a gradually sealed state. At this time, while continuously feeding powder into the powder bin 17, the pressure in the powder bin 17 will continue to increase. When the pressure in the powder bin 17 rises to within the value range of 700Pa to 784Pa, the pulse dust collector must be turned on to remove the dust layer on the outer surface of the filter bag 6 to prevent the powder bin 17 from exploding and ensure safe production.

[0087] Step 4: Detection of powder pile height:

[0088] The weight-type continuous material level meter 21 detects the height of the powder pile in the powder bin 17 in real time and sends it to the main controller 19. The main controller 19 compares the received measured height of the powder pile with the set value of the powder pile height. When the received measured height of the powder pile meets the set value of the powder pile height, the main controller 19 controls the second air compressor 23 and the tube bag valve 22 to close, and stops conveying the powder-containing conveying gas into the powder bin 17.

[0089] In this embodiment, by using a heavy hammer type continuous material level meter 21 to detect the height of the powder pile in the powder bin 17 in real time, and by controlling the second air compressor 23 and the tube bag valve 22 through the main controller 19, the purpose of quantitatively delivering powder into the powder bin 17 can be achieved. The control circuit is simple, the response is fast, and the use effect is good.

[0090] Step 5: Shut down the pulse dust collector:

[0091] The second pressure sensor 28 detects the pressure in the powder silo 17 in real time and sends it to the main controller 19. The main controller 19 compares the measured pressure in the powder silo 17 received by the main controller 19 with the second pressure setting value. When the measured pressure in the powder silo 17 received by the main controller 19 meets the second pressure setting value, the main controller 19 sends a command to close the pulse dust collector to the auxiliary controller 20. The auxiliary controller 20 receives the command to close the pulse dust collector and controls the closing of the first air compressor 8, the air storage tank 9 and the pulse valve group, and the pulse dust collector stops working. The value range of the second pressure setting value is 90Pa~100Pa.

[0092] In this embodiment, by real-time detection of the pressure in the powder bin 17, under the joint control of the main controller 19 and the auxiliary controller 20, the opening of the pulse dust collector in step three and the closing of the pulse dust collector in step five are no longer manually controlled by relying on traditional empirical values, so that the opening and closing of the pulse dust collector can respond more quickly and efficiently, which is convenient for promotion and application.

[0093] In this embodiment, in step 1, during the process of conveying the powder-containing conveying gas, the first pressure sensor 27 detects the pressure in the powder delivery pipeline 18 in real time and transmits it to the main controller 19. The main controller 19 compares the received measured pressure in the powder delivery pipeline 18 with the set pressure value of the powder delivery pipeline. When the received measured pressure in the powder delivery pipeline 18 meets the set pressure value of the powder delivery pipeline, the powder-containing conveying gas is continuously introduced into the powder delivery pipeline 18. When the received measured pressure in the powder delivery pipeline 18 is less than the set pressure value of the powder delivery pipeline, The main controller 19 controls the third air compressor 26 to turn on, increasing the pressure in the powder delivery pipeline 18 until the measured pressure in the powder delivery pipeline 18 meets the set pressure value of the powder delivery pipeline; when the received measured pressure in the powder delivery pipeline 18 is greater than the set pressure value of the powder delivery pipeline, the main controller 19 controls the compressed air pressure regulator 25 to turn on, reducing the pressure in the powder delivery pipeline 18 until the measured pressure in the powder delivery pipeline 18 meets the set pressure value of the powder delivery pipeline; wherein the value range of the set pressure value of the powder delivery pipeline is 0.2MPa to 0.25MPa.

[0094] In actual use, under the joint action of the first pressure sensor 27, the main controller 19, the compressed air pressure regulator 25 and the third air compressor 26, not only can the real-time detection of the pressure in the powder delivery pipeline 18 be achieved, but also the purpose of adjusting the pressure in the powder delivery pipeline 18 can be achieved, so that the pressure in the powder delivery pipeline 18 always remains in a stable state, which can prevent the powder from generating unstable impact force on the inner surface of the powder delivery pipeline 18 and the inner surface of the powder silo 17, and avoid the phenomenon of uneven wear of the inner surface of the powder delivery pipeline 18 and the inner surface of the powder silo 17.

[0095] In this embodiment, in step three, during the process of the second pressure sensor 28 performing real-time detection of the pressure in the powder silo 17, when the pressure in the powder silo 17 detected by the second pressure sensor 28 meets the third pressure setting value, the pressure balance safety valve 10 opens to achieve pressure relief of the powder silo 17, wherein the value range of the third pressure setting value is 785Pa to 900Pa.

[0096] During actual use, the pressure in the powder silo 17 is detected in real time through the second pressure sensor 28. When the pressure in the powder silo 17 detected by the second pressure sensor 28 meets the pressure range of 785Pa to 900Pa, the powder-containing conveying gas in the powder silo 17 enters the pressure balance safety valve 10 through the pressure relief channel 11-1, and the pressure balance safety valve 10 is opened to achieve pressure relief of the powder silo 17, thereby avoiding the occurrence of safety accidents caused by excessive pressure in the powder silo 17. The pressure balance safety valve 10 can play an important protective role in personal safety and equipment operation.

[0097] In this embodiment, the pressure-balanced safety valve 10 adopts the pressure-balanced safety valve disclosed in the utility model patent with application number 201821153005.8 and invention name “A Pressure-Balanced Safety Valve”.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A powder quantitative feeding system for asphalt mixing equipment, characterized by: The invention comprises a quantitative feeding device and a control device connected to the quantitative feeding device, wherein the quantitative feeding device comprises a powder bin (17), a pulse dust collector installed at the top of the powder bin (17) and a powder feeding mechanism for introducing powder into the powder bin (17), the pulse dust collector comprises a pulse dust collector body and an air supply mechanism for filling gas into the pulse dust collector body, the pulse dust collector body comprises a pulse dust collector cylinder, a top cover (2) installed at the top of the pulse dust collector cylinder, a fixing plate (5) fixedly installed on the inner wall of the pulse dust collector cylinder and a plurality of filter bags (6) installed on the fixing plate (5), and a connection for installing the top cover (2) is provided on the pulse dust collector cylinder. A flange (3), wherein the connecting flange (3) is provided with a plurality of exhaust holes (3-1), the pulse dust collector cylinder is provided with a pressure balancing safety valve (10) for controlling the pressure inside the pulse dust collector body, the air supply mechanism comprises a first air compressor (8), an air storage tank (9) connected to the first air compressor (8), an air pipeline installed at the outlet end of the air storage tank (9), and a pulse valve group installed on the air pipeline, the air pipeline passes through the side wall of the top cover (2) and is arranged on the top surface inside the top cover (2), the air pipeline is provided with a plurality of ventilation holes (13), the number of the ventilation holes (13) is consistent with the number of the filter bags (6), and they correspond one to one, the air supply mechanism comprises a first air compressor (8), an air storage tank (9) connected to the first air compressor (8), an air pipeline installed at the outlet end of the air storage tank (9), and a pulse valve group installed on the air pipeline, the air pipeline passes through the side wall of the top cover (2) and is arranged on the top surface inside the top cover (2), the air pipeline is provided with a plurality of ventilation holes (13), the number of the ventilation holes (13) is consistent with the number of the filter bags (6), and the number of the ventilation holes (13) is one to one. The powder mechanism comprises a powder delivery pipeline (18) for connecting a powder tank (30) and the powder silo (17), a tube bag valve assembly and a pressure detection assembly installed on the powder delivery pipeline (18); the tube bag valve assembly comprises a tube bag valve (22) installed on the powder delivery pipeline (18), a second air compressor (23) and a solenoid valve (24) for controlling the on and off of the tube bag valve (22); the pressure detection assembly comprises a first pressure sensor (27) installed on the powder delivery pipeline (18) for detecting the pressure in the powder delivery pipeline (18), a compressed air pressure regulator (25) for reducing the pressure in the powder delivery pipeline (18), and a third air compressor for increasing the pressure in the powder delivery pipeline (18). (26), a weight-type continuous material level meter (21) for detecting the height of the powder pile in the powder bin (17) and a second pressure sensor (28) for detecting the pressure in the powder bin (17) are fixedly installed on the top of the powder bin (17), the control device comprises a main controller (19) and an auxiliary controller (20) connected to the main controller (19), the weight-type continuous material level meter (21), the first pressure sensor (27) and the second pressure sensor (28) are all connected to the input end of the main controller (19), and the second air compressor (23), the solenoid valve (24), the compressed air pressure regulator (25) and the third air compressor (26) are all connected to the output end of the main controller (19),The first air compressor (8) and the pulse valve group are both connected to the output end of the auxiliary controller (20); The gas storage tank (9) and the first air compressor (8) are connected via a first gas pipeline (15-1); the gas pipeline comprises a first gas branch pipeline (12-1), a second gas branch pipeline (12-2) and a third gas branch pipeline (12-3) arranged in parallel; the first gas branch pipeline (12-1) and the gas storage tank (9), the second gas branch pipeline (12-2) and the gas storage tank (9), and the third gas branch pipeline (12-3) and the gas storage tank (9) are respectively connected via three second gas pipelines (15-2); The pulse valve group comprises a first pulse valve (14-1) installed on a first gas branch pipeline (12-1), a second pulse valve (14-2) installed on a second gas branch pipeline (12-2), and a third pulse valve (14-3) installed on a third gas branch pipeline (12-3); a pressure regulating valve (16) is installed at the outlet end of the gas storage tank (9); the first pulse valve (14-1), the second pulse valve (14-2), the third pulse valve (14-3), and the pressure regulating valve (16) are all connected to the output end of the auxiliary controller (20); The pulse dust collector cylinder comprises a first circular cylinder (1-1), a second circular cylinder and a third circular cylinder (1-3) which are connected in sequence from bottom to top; the second circular cylinder is a split type; the second circular cylinder comprises a first semicircular cylinder (1-2-1) and a second semicircular cylinder (1-2-2) which are interlocked; an inspection hole is provided on the top cover (2), and the inspection hole is blocked by a sealing cover (4).

2. A powder quantitative feeding system for asphalt mixing equipment according to claim 1, characterized in that: The exhaust hole (3-1) is a waist-shaped exhaust hole, and a plurality of the waist-shaped exhaust holes are evenly distributed on the connecting flange (3).

3. A powder quantitative feeding system for asphalt mixing equipment according to claim 1, characterized in that: A first mounting seat (7) for mounting the first air compressor (8) and a second mounting seat (11) for mounting the pressure balance safety valve (10) are provided on the side wall of the third circular cylinder (1-3); a pressure relief passage (11-1) is provided in the second mounting seat (11) and is in communication with the inner cavity of the third circular cylinder (1-3).

4. A method for controlling quantitative powder feeding of an asphalt mixing plant using the quantitative powder feeding system of claim 1, characterized in that: The control method includes: Step 1: Transportation of powder-containing conveying gas: One end of the powder delivery pipeline (18) is connected to the powder tank (30) on the powder tank truck, and the main controller (19) controls the second air compressor (23) and the electromagnetic valve (24) to open, so that the powder-containing conveying gas in the powder tank (30) enters the powder delivery pipeline (18) and enters the powder bin (17) through the tube bag valve (22), wherein the particle size of the powder particles in the powder-containing conveying gas is less than 0.5 mm; Step 2: Precipitation and filtration of powder: Step 201, when the powder-containing conveying gas enters the powder bin (17) from the outlet of the powder conveying pipeline (18), large-diameter powder particles in the powder-containing conveying gas are separated from the conveying gas and deposited at the bottom of the powder bin (17) under the action of gravity to form a powder pile, wherein the large-diameter powder particles refer to powder particles with a particle size greater than 0.075 mm; Step 202: During the process of the powder-containing conveying gas entering the powder bin (17) from the outlet of the powder conveying pipeline (18), the small-sized powder particles in the powder-containing conveying gas flow from bottom to top into the pulse dust collector cylinder along with the conveying gas, and are adsorbed on the outer surfaces of the plurality of filter bags (6) to form a dust layer. The clean gas generated after filtration is discharged through the plurality of exhaust holes (3-1), wherein the small-sized powder particles refer to powder particles with a particle size not greater than 0.075 mm, and the concentration of the small-sized powder particles in the clean gas is not greater than 20 mg / m 3 ; Step 3: Start the pulse dust collector: During the precipitation and filtration of the powder, the second pressure sensor (28) detects the pressure in the powder bin (17) in real time and sends it to the main controller (19). The main controller (19) compares the measured pressure in the powder bin (17) received by the main controller (19) with the first pressure setting value. When the measured pressure in the powder bin (17) received by the main controller (19) satisfies the first pressure setting value, the main controller (19) sends a command to start the pulse dust collector to the auxiliary controller (20). The auxiliary controller (20) receives the command to start the pulse dust collector and controls the opening of the first air compressor (8), the air storage tank (9) and the pulse valve group. The dust-removing compressed air in the air storage tank (9) enters the plurality of filter bags (6) through the air pipeline, removes the dust layer on the outer surface of the filter bags (6), and causes the small-diameter powder particles in the dust layer to be deposited on the powder pile from top to bottom. The value range of the first pressure setting value is 700 Pa to 784 Pa. Step 4: Detection of powder pile height: The weight-type continuous material level meter (21) detects the height of the powder pile in the powder bin (17) in real time and sends the height to the main controller (19). The main controller (19) compares the received measured height of the powder pile with the set value of the height of the powder pile. When the received measured height of the powder pile satisfies the set value of the height of the powder pile, the main controller (19) controls the second air compressor (23) and the tube bag valve (22) to close, and stops conveying the powder-containing conveying gas into the powder bin (17). Step 5: Shut down the pulse dust collector: The second pressure sensor (28) detects the pressure in the powder bin (17) in real time and sends it to the main controller (19). The main controller (19) compares the measured pressure in the powder bin (17) received by the main controller (19) with the second pressure setting value. When the measured pressure in the powder bin (17) received by the main controller (19) satisfies the second pressure setting value, the main controller (19) sends a command to turn off the pulse dust collector to the auxiliary controller (20). The auxiliary controller (20) receives the command to turn off the pulse dust collector and controls the first air compressor (8), the air storage tank (9) and the pulse valve group to turn off, and the pulse dust collector stops working. The value range of the second pressure setting value is 90Pa to 100Pa.

5. The control method according to claim 4, characterized in that: In step 1, during the process of conveying the powder-containing conveying gas, the first pressure sensor (27) detects the pressure in the powder delivery pipeline (18) in real time and transmits it to the main controller (19). The main controller (19) compares the received measured pressure in the powder delivery pipeline (18) with the set pressure value of the powder delivery pipeline. When the received measured pressure in the powder delivery pipeline (18) satisfies the set pressure value of the powder delivery pipeline, the powder-containing conveying gas is continuously introduced into the powder delivery pipeline (18); when the received measured pressure in the powder delivery pipeline (18) is less than the set pressure value of the powder delivery pipeline, the main controller (19) (19) controlling the third air compressor (26) to start, increasing the pressure in the powder delivery pipeline (18) until the measured pressure in the powder delivery pipeline (18) satisfies the set pressure value of the powder delivery pipeline; when the received measured pressure in the powder delivery pipeline (18) is greater than the set pressure value of the powder delivery pipeline, the main controller (19) controls the compressed air pressure regulator (25) to start, reducing the pressure in the powder delivery pipeline (18) until the measured pressure in the powder delivery pipeline (18) satisfies the set pressure value of the powder delivery pipeline; wherein the set pressure value of the powder delivery pipeline ranges from 0.2 MPa to 0.25 MPa.

6. The control method according to claim 4, characterized in that: In step three, during the process of the second pressure sensor (28) detecting the pressure in the powder bin (17) in real time, when the pressure in the powder bin (17) detected by the second pressure sensor (28) satisfies a third pressure setting value, the pressure balance safety valve (10) opens to release the pressure of the powder bin (17), wherein the third pressure setting value has a value range of 785 Pa to 900 Pa.

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