A feeding device and control method suitable for 6~8 μm oxidant powder

Abstract

The application discloses a feeding device and control method suitable for 6-8 mu m oxidant powder, and particularly relates to the field of feeding equipment. The feeding device is used for transporting the oxidant powder in a material bucket to a mixing pot, and comprises a feeding hopper, a feeding end of the feeding hopper being communicated with a vacuum pump, a first control valve being arranged at a discharging port of the feeding hopper, a feeding hopper being connected to the discharging port of the feeding hopper through a soft connection section, a second control valve being arranged at a discharging port of the feeding hopper, a feeding chute being connected to the discharging port of the feeding hopper, and the discharging port of the feeding chute being communicated with the mixing pot, a vibrating feeder being arranged at the bottom of the feeding chute, a weight sensor being arranged below the vibrating feeder, a vacuum suction cavity, an outlet end of the vacuum suction cavity being connected to a feeding port of the feeding hopper through a conveying pipeline, a third control valve being arranged in the conveying pipeline, and a controller being connected to the weight sensor and the vibrating feeder and used for controlling the vibrating feeder. Based on the above device and method, the feeding precision can be improved.

Description

Technical Field

[0001] This invention relates to the field of feeding equipment, and in particular to a feeding device and control method suitable for 6-8μm oxidant powder. Background Technology

[0002] During the mixing of solid rocket engine propellant slurry, powdered raw materials, typically oxidizer powder, need to be added to the mixing pot. Oxidizer powder with a particle size of 6-8 μm is particularly difficult to add due to its small size, which makes it prone to agglomeration and arching. Furthermore, this type of oxidizer powder is flammable and explosive. Currently, the method of adding oxidizer powder in the solid rocket engine propellant loading industry involves pouring a sufficient amount of weighed powder into a hopper, then hoisting the hopper to a second-level platform and adding it to the mixing pot via a chute. In this method, the oxidizer collides and rubs against the inner wall of the chute, generating static electricity, posing a potential hazard during the mixing process. Simultaneously, the adding speed is uncontrollable and uneven. Especially at the moment the valve is opened, a large amount of oxidizer is added to the mixing pot in a very short time under gravity, causing a sharp increase in mixing torque and posing a safety risk during the mixing process. Summary of the Invention

[0003] The main purpose of this application is to provide a feeding device and control method suitable for 6~8μm oxidant powder, aiming to solve the problem of uncontrollable feeding speed in existing feeding methods.

[0004] To achieve the above objectives, this application provides a feeding device suitable for 6-8μm oxidant powder, used to transport oxidant powder from a hopper to a mixing pot, comprising: a feeding hopper, the inlet of which is connected to a vacuum pump, and the outlet of which is equipped with a first control valve; the outlet of the feeding hopper is connected to a feeding hopper via a flexible connection section; a level gauge is installed inside the feeding hopper; a second control valve is installed at the outlet of the feeding hopper, and the outlet of the feeding hopper is connected to a feeding chute, the outlet of which is connected to the mixing pot; a vibrating feeder is installed at the bottom of the feeding chute, and a weight sensor is installed below the vibrating feeder; a vacuum suction chamber, the outlet of which is connected to the inlet of the feeding hopper via a transport pipe, and a third control valve is installed inside the transport pipe; the inlet of the vacuum suction chamber is located inside the hopper, and a first filter screen is installed inside the vacuum suction chamber; the feeding hopper and the feeding hopper are also included. The hopper, feeding chute, and conveying pipes are all coated with an anti-static coating. The controller, connected to the weight sensor and the vibrating feeder, controls the vibrating feeder. The control process is as follows: The weight sensor collects the weight at each moment; based on the weight at the current moment and the previous moment, the weight difference and actual feeding amount are determined; the feeding speed at the current moment is determined based on the weight difference; if the feeding speed at the current moment does not meet the preset conditions, the feeding speed deviation at the current moment and the feeding speed deviation at historical moments are determined based on the feeding speed at the current moment and the preset feeding speed; the vibration frequency at the current moment is acquired; based on the vibration frequency at the current moment, the feeding speed deviation, and the feeding speed deviation at historical moments, the vibration frequency and vibration amplitude at the next moment are determined; the vibrating feeder is controlled based on the vibration frequency and vibration amplitude at the next moment.

[0005] Optionally, the feeding rate deviation at a historical moment includes the feeding rate deviation at the previous moment and the feeding rate deviation between the two moments before that.

[0006] Optionally, the actual feeding amount is determined based on the weight collected by the weight sensor at the current moment and the weight at the initial moment. After determining the weight difference and the actual feeding amount, the control process further includes determining the difference between the preset total feeding amount and the actual feeding amount, comparing the difference with a first preset feeding amount, and when the difference is determined to be greater than the first preset feeding amount, determining the vibration frequency of the next moment based on the vibration frequency and feeding speed deviation at the current moment and the feeding speed deviation at historical moments, including: determining a first vibration frequency increment based on the feeding speed deviations of the previous two moments, the previous moment, and the current moment, and determining the vibration frequency of the next moment based on the sum of the first vibration frequency increment and the vibration frequency at the current moment; wherein, the expression for the first vibration frequency increment is: ; In the formula, n is the number of time points. This represents the deviation in feeding speed at the current moment. This is the increment of the first vibration frequency. This represents the deviation in feeding speed from the previous moment. This represents the deviation in feeding speed between the first two moments.

[0007] If the difference is determined to be less than the first preset feeding amount, the vibration amplitude at the next moment is determined by the sum of the vibration amplitude at the current moment and the first vibration amplitude increment. The expression for the first vibration amplitude increment is: ; In the formula, This is the increment of the first vibration amplitude.

[0008] Optionally, when the difference is determined to be less than the first preset feeding amount, the vibration frequency at the next moment is determined based on the vibration frequency and feeding speed deviation at the current moment, and the feeding speed deviation at historical moments. This includes: determining the second vibration frequency increment based on the feeding speed deviations at the previous two moments, the previous moment, and the current moment; and determining the vibration frequency at the next moment based on the sum of the second vibration frequency increment and the vibration frequency at the current moment. The expression for the second vibration frequency increment is: ; In the formula, This represents the second vibration frequency increment.

[0009] Optionally, the vibration amplitude at the next moment is determined based on the sum of the vibration amplitude at the current moment and the increment of the second vibration amplitude. The expression for the increment of the second vibration amplitude is: ; In the formula, This represents the second vibration amplitude increment.

[0010] Optionally, the first control valve is a pneumatic ball valve, and the second and third control valves are both pneumatic clamp valves; the first, second, and third control valves are all connected to the controller.

[0011] Optionally, the flexible connecting section is made of anti-static cloth; the inside of the feeding chute forms an inclined surface.

[0012] To achieve the above objectives, this application also provides a feeding control method suitable for 6-8μm oxidant powder, employing a feeding device suitable for 6-8μm oxidant powder, comprising: opening a first control valve and a vacuum pump; collecting the volume of oxidant powder in the feeding hopper through a level gauge and sending it to a controller; when the volume reaches a preset volume, the controller closes the first control valve and the vacuum pump; opening a second control valve; collecting the weight through a weight sensor and sending it to the controller; when the weight exceeds a second preset feeding amount, the controller closes the second control valve; opening a third control valve and a vibrating feeder; setting a preset feeding speed, an initial vibration frequency and an initial amplitude of the vibrating feeder; controlling the vibrating feeder through the controller to discharge the oxidant powder in the feeding hopper through a feeding chute; and closing the third control valve and the vibrating feeder when the actual feeding amount reaches the third preset feeding amount.

[0013] Optionally, the expression for the initial preset feeding rate is: ; In the formula, The preset feeding speed is T, where T is the PID control cycle of the controller and n is the number of time points.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: This invention relates to a feeding device for 6-8μm oxidant powders. The feeding hopper, chute, and transport pipes are all coated with an antistatic coating to prevent safety hazards caused by friction. The discharge port of the feeding hopper is connected to the chute via a flexible connection section, ensuring accurate weighing of the powder material. The controller acquires the weight collected by the weight sensor at each moment in real time, determines the weight difference between the current and previous weights, and determines the feeding speed based on this difference. If the feeding speed at the current moment does not meet the preset conditions, the vibration frequency and amplitude for the next moment are determined based on the current feeding speed deviation, historical feeding speed deviations, and the current vibration frequency. This real-time control of the vibrating feeder ensures accurate feeding speed. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a feeding device suitable for 6-8μm oxidant powder according to this application; Figure 2 for Figure 1 Schematic diagram of the structure of the vacuum suction cavity; In the diagram, 1. Material bucket, 2. Mixing pot, 3. Feeding hopper, 4. Vacuum suction chamber, 41. Sleeve, 42. Cover plate, 5. First control valve, 6. Flexible connection section, 7. Feeding hopper, 8. Second control valve, 9. Feeding chute, 10. Vibrating feeder, 11. Weight sensor, 12. Transport pipeline, 13. Third control valve, 14. First filter screen, 15. Second filter screen, 16. Transition section, 17. Support frame, 18. Vacuum pump; Figure 3 This is a schematic diagram of a feeding control method applicable to 6-8μm oxidant powder according to this application; Figure 4 This is a schematic flowchart of the control process in a feeding control method applicable to 6~8μm oxidant powder according to this application; Figure 5 This is a graph showing the variation in feeding speed accuracy in Example 1 of a feeding control method applicable to 6-8μm oxidant powder according to this application; Figure 6 This is a graph showing the variation in feeding speed accuracy in Example 2 of a feeding control method applicable to 6-8μm oxidant powder according to this application.

[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The first embodiment of the present invention provides a feeding device suitable for 6-8 μm oxidant powder, such as... Figure 1As shown, the device used to transport oxidant powder from hopper 1 to mixing pot 2 includes a feeding hopper 3, a vacuum suction chamber 4, and a controller. The feeding hopper 3 has a vacuum pump 18 connected to its inlet via a pipeline, a first control valve 5 at its outlet, and a feeding hopper 7 connected to its outlet via a flexible connector 6. A level gauge is installed inside the feeding hopper 3. A second control valve 8 is installed at the outlet of the feeding hopper 7, which is connected to a feeding chute 9. The outlet of the feeding chute 9 is connected to the mixing pot 2. A vibrating feeder 10 is installed at the bottom of the feeding chute 9 for vibrating feeding. A weight sensor 11 is installed below the machine 10; the outlet of the vacuum suction chamber 4 is connected to the inlet of the feeding hopper 3 via a transport pipe 12, and a third control valve 13 is installed inside the transport pipe 12; the inlet of the vacuum suction chamber 4 is located inside the material bucket 1, and a first filter screen 14 is installed inside the vacuum suction chamber 4, with a screen aperture diameter slightly larger than 6~8μm; the feeding hopper 3, the feeding hopper 7, the feeding chute 9, and the transport pipe 12 are all coated with an antistatic coating; a controller is connected to the weight sensor 11 and the vibrating feeder 10, and is used to control the vibrating feeder 10; the control process is as follows: The system acquires the weight collected by the weight sensor 11 at each moment, determines the weight difference and actual feeding amount based on the weight at the current moment and the weight at the previous moment, determines the feeding speed at the current moment based on the weight difference, determines the feeding speed deviation at the current moment and the feeding speed deviation at the historical moment if the feeding speed at the current moment does not meet the preset conditions, acquires the vibration frequency at the current moment, determines the vibration frequency and vibration amplitude at the next moment based on the vibration frequency at the current moment, the feeding speed deviation, and the feeding speed deviation at the historical moment, and controls the vibrating feeder 10 based on the vibration frequency and vibration amplitude at the next moment.

[0019] In this embodiment, oxidant powder with a particle size of 6-8 μm is filtered out by the first filter screen 14. Combined with the adsorption force generated by the vacuum pump 18 at the feed inlet of the feeding hopper 3, 6-8 μm oxidant powder enters the feeding hopper 3, preventing foreign objects from entering the feeding hopper 3. The feeding hopper 3, the feeding hopper 7, the feeding chute 9, and the transport pipe 12 are all coated with an antistatic coating to avoid safety hazards caused by friction. When the oxidant powder does not enter the feeding hopper 7, the weight sensor 11 obtains the total weight of the feeding hopper 7, the vibrating feeder 10, the feeding chute 9, and the additional components. Therefore, a soft connection is set to reduce errors. Specifically, the transition section 16 is softly connected to the feeding hopper 7 through the soft connection section 6, and the feeding chute 9 is softly connected to the feeding port of the mixing pot 2 to ensure the weighing accuracy of the powder material. The controller acquires the weight collected by the weight sensor 11 at each moment in real time. Based on the weight at the current moment and the weight at the previous moment, the weight difference is determined. The feeding speed at the current moment is determined based on the weight difference. If the feeding speed at the current moment does not meet the preset conditions, the vibration frequency and vibration amplitude at the next moment are determined based on the feeding speed deviation at the current moment and the feeding speed deviation at historical moments, as well as the vibration frequency at the current moment. The vibrating feeder 10 is controlled in real time to ensure the accuracy of the feeding speed.

[0020] For example, such as Figure 2As shown, the vacuum suction chamber 4 includes a frustum-shaped sleeve 41, with a cover plate 42 at the bottom. The first filter screen 14 is located inside the sleeve 41. Both the cover plate 42 and the side wall of the sleeve 41 have through holes to facilitate material adsorption. The cover plate 42 is pressed tightly against the bottom of the material tank 1 to prevent the plastic liner inside the material tank 1 from being adsorbed and stuck near the first filter screen 14. The outlet of the sleeve 41 is fitted onto the pipe and connected by a cable tie. In use, the sleeve 41 is completely inserted into the material tank 1 containing fine-particle oxidant. The transport pipe 12 is made of 316L stainless steel. The first control valve 5 is located at the end of the transport pipe 12 near the feeding hopper 3, and the transport pipe 12 is inserted into the feeding hopper 3. Two second filter screens 15 are provided between the feed end of the feeding hopper 3 and the vacuum pump 18. The screen aperture diameter is smaller than the oxidant powder particle size of 6~8μm to prevent the powder from being drawn away. The discharge port of the feeding hopper 3 is connected to a transition section 16, which serves as a powder material feeding channel. The other end of the transition section 16 is connected to the flexible connection section 6 via a flange. The flexible connection section 6 is made of anti-static cloth. The flexible connection section 6 has a two-layer design; the outer layer is connected to the flange of the transition section 16 and the flange of the feeding hopper 7 via cable ties, and the inner layer is inserted into the feeding hopper 7, serving as a material conveying channel. The feeding hopper 7 and the feeding chute 9 are connected by bolts, with steel wire threaded through the bolts to prevent loosening. The feeding chute 9 includes a long channel, one end of which has a feed inlet connected to the outlet of the feeding hopper 7 via a flange, and the other end has a discharge outlet connected to the feeding port of the mixing pot 2 via a flange. The interior of the feeding chute 9 forms an inclined surface, with the clockwise angle between the inclined surface and the horizontal plane being less than 5°. Because the oxidant powder in this embodiment is explosive, the weight sensor 11 is an explosion-proof electronic scale. Furthermore, the feeding hopper 3 and the feeding hopper 7 are fixed by the support frame 17. In addition, the feeding hopper 3 has 4 lugs in the middle, which are connected to the support frame 17 for fixing. The weight sensor 11 is fixed on the support frame 17.

[0021] The first control valve 5 is a pneumatic ball valve, and the second control valve 8 and the third control valve 13 are both pneumatic clamp valves; the first control valve 5, the second control valve 8, and the third control valve 13 are all connected to the controller. The controller controls the opening and closing of the first control valve 5, the second control valve 8, and the third control valve 13.

[0022] In one embodiment, the actual feeding amount is determined based on the weight collected by the weight sensor 11 at the current moment and a first preset feeding amount. After determining the weight difference and the actual feeding amount, the control process further includes determining the difference between the preset total feeding amount and the actual feeding amount, comparing the difference with the first preset feeding amount, and when the difference is determined to be greater than the first preset feeding amount, determining a first vibration frequency increment based on the feeding speed deviations of the previous two moments, the previous moment, and the current moment, and determining the vibration frequency of the next moment based on the sum of the first vibration frequency increment and the vibration frequency at the current moment; wherein, the expression for the first vibration frequency increment is: ; In the formula, n is the number of time points. This represents the deviation in feeding speed at the current moment. This is the increment of the first vibration frequency.

[0023] The vibration amplitude at the next moment is determined by the sum of the vibration amplitude at the current moment and the increment of the first vibration amplitude. The expression for the increment of the first vibration amplitude is: ; In the formula, This is the increment of the first vibration amplitude.

[0024] Once the difference is determined to be less than the first preset feeding amount, the vibration frequency for the next moment is determined based on the current vibration frequency and feeding speed deviation, and the feeding speed deviation at historical moments, including: Based on the feeding rate deviations of the previous two moments, the previous moment, and the current moment, the second vibration frequency increment is determined. The vibration frequency at the next moment is determined by summing the second vibration frequency increment and the vibration frequency at the current moment. The expression for the second vibration frequency increment is as follows: ; In the formula, This represents the second vibration frequency increment.

[0025] The vibration amplitude at the next moment is determined by the sum of the vibration amplitude at the current moment and the increment of the second vibration amplitude. The expression for the increment of the second vibration amplitude is: ; In the formula, This represents the second vibration amplitude increment.

[0026] The second embodiment of the present invention provides a feeding control method suitable for 6-8 μm oxidant powder, employing a feeding device suitable for 6-8 μm oxidant powder, such as... Figure 3-4 As shown, the specific steps include: Step S1: Open the first control valve 5 and vacuum pump 18 to feed materials. During the feeding process, the volume of oxidant powder in the feeding hopper 3 is collected by the level gauge and sent to the controller. When the volume reaches the preset volume, the controller closes the first control valve 5 and vacuum pump 18. The preset volume is 80% of the total volume of the feeding hopper 3.

[0027] It is worth noting that when the oxidant powder has not entered the feeding hopper 7, the weight sensor 11 obtains the total weight of the feeding hopper 7, the vibrating feeder 10, the feeding chute 9, and the additional components. Therefore, the weight of the oxidant powder in the feeding hopper 7 is determined by zeroing the weight sensor 11. When the oxidant powder has completely entered the feeding hopper 7, the weight collected at this time is the weight W0 of the oxidant powder in the feeding hopper 7.

[0028] Step S2: Open the second control valve 8 and the vibrating feeder 10 to feed the material into the feeding hopper 7. During the feeding process, the weight sensor 11 collects the weight at each moment, that is, the weight signal is collected to obtain the real-time weight and send it to the controller. When the weight is greater than the first preset feeding amount (the first preset feeding amount is 20% of the preset total feeding amount), the controller closes the second control valve 8 and the vibrating feeder 10, and takes the weight at this time, that is, the initial weight of the oxidant powder in the feeding hopper 7, as the first weight W0.

[0029] Step S3: Open the third control valve 13 and the vibrating feeder 10, and set the preset feeding speed, the initial vibration frequency and the initial vibration amplitude of the vibrating feeder 10. Control the vibrating feeder 10 via the controller. The oxidant powder in the feeding hopper 7 is subjected to longitudinal vibration and discharged through the feeding chute 9 under the action of the inclination angle, entering the mixing pot 2. The expression for the preset feeding speed is: ; In the formula, The preset feeding speed is T, where T is the PID control cycle of the controller, and n is the number of time points; specifically, during acceleration... When decelerating T is the PID control period, set to 3600ms.

[0030] Specifically, in step S31, the third control valve 13 and the vibrating feeder 10 are opened, and the initial vibration frequency is set to 50Hz. The initial vibration amplitude is proportional to the preset feeding speed. The initial vibration amplitude is calculated from the preset feeding speed. The expression for vibration amplitude A is: In the formula, f The vibration frequency, This represents the density of the oxidant powder.

[0031] In step S32, the oxidant powder in the feeding hopper 7 is subjected to longitudinal vibration and discharged through the feeding chute 9 under the action of the inclination angle, entering the mixing pot 2; the weight sensor 11 collects the weight at each moment, and the weight collected at the current moment is used as the basis for the calculation. Weight collected at the previous moment Determine the weight difference and the actual amount of material added. , The feeding rate at the current moment is determined based on the weight difference. , ; If the current feeding speed does not meet the preset conditions, the feeding speed deviation at the current moment is determined based on the difference between the current feeding speed and the preset feeding speed. The deviation from the feeding speed at historical moments Among them, the preset conditions are: Minimum feeding speed and maximum feeding speed It is set based on experience. When the feeding speed at the current moment reaches the preset condition, the parameters of the vibrating feeder 10 will not be adjusted.

[0032] Step S33: Obtain the vibration frequency at the current moment; determine the vibration frequency and vibration amplitude at the next moment based on the vibration frequency and feeding speed deviation at the current moment and the feeding speed deviation at historical moments; control the vibrating feeder 10 based on the vibration frequency and vibration amplitude at the next moment.

[0033] Understandably, if the same control logic is used to control the vibrating feeder 10 throughout the feeding process, the feeding accuracy will be affected when the content of oxidant powder in the feeding hopper 7 is low. Therefore, in this embodiment, the entire process is divided into two stages according to the content of oxidant powder in the feeding hopper 7, and the vibrating feeder 10 is controlled separately, as follows.

[0034] Step S331: Determine the preset total amount of material to be added. The difference between the weight of the oxidant powder to be added to mixing pot 2 and the actual amount added. The difference is compared with the first preset feeding amount. If the difference is greater than the first preset feeding amount, the first vibration frequency increment is determined based on the feeding speed deviations of the previous two moments, the previous moment, and the current moment. The vibration frequency of the next moment is determined based on the sum of the first vibration frequency increment and the vibration frequency of the current moment. The expression for the first vibration frequency increment is as follows: ; In the formula, n is the number of time points. This represents the deviation in feeding speed at the current moment. This is the increment of the first vibration frequency; The vibration amplitude at the next moment is determined by the sum of the current vibration amplitude and the first vibration amplitude increment. The expression for the first vibration amplitude increment is as follows: ; In the formula, This is the increment of the first vibration amplitude.

[0035] Step S332: When the difference is determined to be less than the first preset feeding amount, the second vibration frequency increment is determined based on the feeding speed deviations of the previous two moments, the previous moment, and the current moment. The vibration frequency at the next moment is determined based on the sum of the second vibration frequency increment and the vibration frequency at the current moment. The expression for the second vibration frequency increment is: ; In the formula, This is the increment of the second vibration frequency; The vibration amplitude at the next moment is determined by the sum of the current vibration amplitude and the increment of the second vibration amplitude. The expression for the increment of the second vibration amplitude is: ; In the formula, This represents the second vibration amplitude increment.

[0036] Additionally, when the difference is determined to be less than the first preset feeding amount, the preset feeding speed also needs to be reduced. Specifically, the preset feeding speed is set to one-third of the original preset feeding speed to obtain the new preset feeding speed. ,Right now At the same time, judge Is it greater than ,like Then modify the preset feeding speed to ,like Then modify the preset feeding speed to .

[0037] Step S4: When the actual feeding amount reaches the preset total feeding amount, close the third control valve 13 and the vibrating feeder 10 to complete the feeding.

[0038] Because the transported raw material is an oxidant powder with a small particle size, it is prone to powder flying and explosion. During transportation, the powder is prone to static electricity and collisions. If static electricity accumulates or the collision energy reaches the ignition value, a combustion and explosion accident will occur. Therefore, this embodiment uses the aforementioned specialized feeding device and corresponding control method to set different preset feeding speeds according to the content of oxidant powder in the feeding hopper 7, and adjusts the vibration parameters of the vibrating feeder 10 to match the feeding speed, thereby ensuring the accuracy of the feeding speed.

[0039] Example 1 Based on the above-described feeding device, the control method of steps S1-4 is executed, treating the entire process as a single stage. The feeding rate is set to 0.7 kg / min, and feeding continues continuously for 1 hour, totaling 42 kg. The variation of feeding accuracy over time during a single feeding process in this embodiment is monitored, and the results are shown below. Figure 5 As can be seen from the figure, the feeding accuracy is within ±0.5%, which is significantly improved compared to the existing feeding technology with an accuracy of ±5%.

[0040] In addition, the total amount of material added in each process was calculated with 5 additions. The total amount of material added was set to 1950g, and the materials were added 5 times. The added weights were 1958g, 1956g, 1946g, 1947g, and 1952g, with addition accuracies of 0.41%, 0.31%, -0.21%, -0.15%, and 0.1%, respectively. The addition accuracy was within ±0.5%.

[0041] Example 2 Based on the above feeding device, the control method of steps S1-4 is executed, and the whole process is divided into two stages. The feeding speed in the first stage is set to 0.7 kg / min, and the feeding speed in the second stage is set to 0.22 kg / min, with a total feeding of 42 kg. Figure 6 The variation of the feeding speed accuracy over time was observed in Example 2, with the feeding accuracy within ±0.5%. Simultaneously, the accuracy of the total feeding volume was calculated. The total feeding volume was set at 1950g, with five feeding cycles: 1952g, 1953g, 1948g, 1951g, and 1952g. The feeding accuracies were 0.1%, 0.15%, -0.1%, 0.05%, and 0.1%, respectively, all within ±0.2%, representing an improvement over Example 1. Therefore, it can be seen that by controlling the feeding process in stages based on the oxidant powder content in the feeding hopper 7 and adjusting the preset feeding speed and the parameters of the vibrating feeder 10, the feeding accuracy can be further improved.

[0042] Existing 6-8μm oxidant powder feeding technology controls the feeding rate into the mixing pot 2 by controlling the valve opening. This control method is a variable-speed adjustment; the material is added to the mixing pot 2 rapidly and instantaneously the moment the valve is opened, rather than continuously and uniformly, thus affecting the uniformity of material mixing. Table 1 compares the uniformity of the existing technology and Example 2 5 minutes after feeding, with 5 samples taken for each. The results show that the feeding device and control method of the present invention can significantly improve the uniformity of mixing, reduce the effective mixing time, further improve mixing safety, and improve product quality consistency.

[0043] Table 1 Uniformity test results

[0044] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A feeding device suitable for 6-8μm oxidant powder, characterized in that, Used for transporting oxidant powder from a hopper to a mixing pot, including: The feeding hopper has a vacuum pump connected to the inlet end and a first control valve installed at the outlet. The outlet of the feeding hopper is connected to a feeding hopper via a flexible connection section. A level gauge is installed inside the feeding hopper. The discharge port of the feeding hopper is equipped with a second control valve, and the discharge port of the feeding hopper is connected to a feeding chute, the discharge port of the feeding chute being connected to a mixing pot. A vibrating feeder is installed at the bottom of the feeding chute, and a weight sensor is installed below the vibrating feeder; The vacuum suction chamber has its outlet end connected to the feed inlet of the feeding hopper via a transport pipe, and a third control valve is installed inside the transport pipe; the inlet end of the vacuum suction chamber is located inside the material bucket, and a first filter screen is installed inside the vacuum suction chamber. The feeding hopper, material hopper, material chute, and conveying pipeline are all coated with an anti-static coating; The controller, connected to the weight sensor and the vibrating feeder, is used to control the vibrating feeder; the control process is as follows: The system acquires the weight collected by the weight sensor at each moment, determines the weight difference and the actual feeding amount based on the weight at the current moment and the weight at the previous moment, and determines the feeding speed at the current moment based on the weight difference. If the feeding speed at the current moment does not meet the preset conditions, the feeding speed deviation at the current moment and the feeding speed deviation at the historical moment are determined based on the feeding speed at the current moment and the preset feeding speed. The vibration frequency at the current moment is obtained. Based on the vibration frequency and feeding speed deviation at the current moment, and the feeding speed deviation at historical moments, the vibration frequency and vibration amplitude at the next moment are determined. The vibrating feeder is then controlled based on the vibration frequency and vibration amplitude at the next moment.

2. The feeding device for 6-8 μm oxidant powder according to claim 1, characterized in that, The feeding rate deviation at a historical moment includes the feeding rate deviation at the previous moment and the feeding rate deviation between the two moments before that.

3. The feeding device for 6-8 μm oxidant powder according to claim 2, characterized in that, The actual feeding amount is determined based on the weight collected by the weight sensor at the current moment and the weight at the initial moment. After determining the weight difference and the actual feeding amount, the control process also includes determining the difference between the preset total feeding amount and the actual feeding amount, comparing the difference with a first preset feeding amount, and if the difference is greater than the first preset feeding amount, determining the vibration frequency for the next moment based on the vibration frequency and feeding speed deviation at the current moment and the feeding speed deviation at historical moments, including: Based on the feeding rate deviations of the previous two moments, the previous moment, and the current moment, the first vibration frequency increment is determined. The vibration frequency of the next moment is determined by summing the first vibration frequency increment and the vibration frequency of the current moment. The expression for the first vibration frequency increment is: ； In the formula, n is the number of time points. This represents the deviation in feeding speed at the current moment. This is the increment of the first vibration frequency. This represents the deviation in feeding speed from the previous moment. This represents the deviation in feeding speed between the first two moments.

4. The feeding device for 6-8 μm oxidant powder according to claim 3, characterized in that, The vibration amplitude at the next moment is determined by the sum of the vibration amplitude at the current moment and the increment of the first vibration amplitude. The expression for the increment of the first vibration amplitude is: ； In the formula, This is the increment of the first vibration amplitude.

5. The feeding device for 6-8 μm oxidant powder according to claim 3, characterized in that, Once the difference is determined to be less than the first preset feeding amount, the vibration frequency for the next moment is determined based on the current vibration frequency and feeding speed deviation, and the feeding speed deviation at historical moments, including: Based on the feeding rate deviations of the previous two moments, the previous moment, and the current moment, the second vibration frequency increment is determined. The vibration frequency at the next moment is determined by summing the second vibration frequency increment and the vibration frequency at the current moment. The expression for the second vibration frequency increment is as follows: ； In the formula, This represents the second vibration frequency increment.

6. The feeding device for 6-8 μm oxidant powder according to claim 5, characterized in that, The vibration amplitude at the next moment is determined by the sum of the vibration amplitude at the current moment and the increment of the second vibration amplitude. The expression for the increment of the second vibration amplitude is: ； In the formula, This represents the second vibration amplitude increment.

7. The feeding device for 6-8 μm oxidant powder according to claim 1, characterized in that, The first control valve is a pneumatic ball valve, and the second and third control valves are both pneumatic clamp valves. The first control valve, the second control valve, and the third control valve are all connected to the controller.

8. The feeding device for 6-8 μm oxidant powder according to claim 1, characterized in that, The flexible connection section is made of anti-static cloth; the inside of the feeding chute is formed with an incline.

9. A feeding control method suitable for 6-8 μm oxidant powder, characterized in that, The feeding device for 6-8 μm oxidant powder according to any one of claims 1-8 comprises: The first control valve and vacuum pump are opened, and the volume of oxidant powder in the feeding hopper is collected by the level gauge and sent to the controller. When the volume reaches the preset volume, the controller closes the first control valve and vacuum pump. The second control valve is opened, the weight is collected by the weight sensor and sent to the controller. When the weight is greater than the second preset feeding amount, the controller closes the second control valve. Open the third control valve and the vibrating feeder, and set the preset feeding speed, the initial vibration frequency and the initial vibration amplitude of the vibrating feeder. Control the vibrating feeder through the controller so that the oxidant powder in the feeding hopper is discharged through the feeding chute. When the actual feeding amount reaches the third preset feeding amount, the third control valve and the vibrating feeder are closed.

10. The feeding control method for 6-8 μm oxidant powder according to claim 9, characterized in that, The expression for the initial preset feeding rate is: ； In the formula, The preset feeding speed is T, where T is the PID control cycle of the controller and n is the number of time points.

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