Powder closed feeding device

Abstract

The utility model discloses a closed powder feeding device which comprises a steel frame platform, an upper-layer support, a main material metering system, a compensation feeding metering system, a vacuumizing pipeline, a microbead feeding system, a vacuum system, a weight sensor and a conveying pipeline. The main material metering system and the compensation feeding system are located on the uppermost portion of the whole device, and the microbead feeding system, the vacuum system and the steel frame platform are all installed on the ground. A main material transfer hopper in the main material metering system is connected with a vacuum system through a vacuumizing pipeline, the main material metering system and the compensation feeding metering system are both installed in a suspension mode and fixedly supported on a main material weight sensor on an upper-layer support, and the main material weight sensor is connected with the device control system and detects the feeding weight in real time. And the microbead feeding system is communicated with the main material metering system through a pneumatic valve and a conveying pipeline. A secondary feeding mode is adopted, the self-cleaning effect of the pipeline is achieved through simple valve layout and control, and a traditional mode that a feeding pipeline is cleaned through a draught fan is replaced.

Description

Technical Field

[0001] The utility model belongs to the technical field of powder metering, feeding and conveying, and relates to a powder closed feeding device. Background Art

[0002] In the field of powder engineering, the technical research on powder metering, feeding and conveying has been continuously concerned. Due to the unique flow characteristics of powders, the interaction between particles, and their sensitivity to environmental conditions, many technical challenges have emerged in the process of powder metering and conveying. These challenges are particularly obvious in fields such as chemical engineering, mining, and building materials, where powders are often used as key materials or raw materials.

[0003] For powder metering and feeding, different material properties, such as fluidity, uniformity, and density, have different requirements for metering and feeding methods. With the help of modern computer technology, combined with instruments such as electronic weighing and mass flow meters, and automatic control technology, modern powder metering systems have been able to achieve high-precision metering and control. For the feeding process, appropriate methods such as gravity feeding or screw conveyors are selected considering the material characteristics to ensure meeting specific process conditions.

[0004] In the link of powder conveying, in addition to considering the material characteristics, the selection of the conveying method is also closely related to the conveying distance and speed. Although traditional pneumatic conveying is favored due to its small floor area and relatively low energy consumption, it may cause problems such as dust generation, particle accumulation, and channel blockage during operation. For this reason, new conveying technologies such as dense-phase conveying and screw conveying have attracted the attention of engineers and researchers, aiming to improve the stability and efficiency of conveying.

[0005] Generally speaking, with the continuous evolution of technological progress and industrial demands, the continuous innovation of powder metering, feeding and conveying technology is crucial for improving the efficiency of industrial production and ensuring product quality. We look forward to more technological breakthroughs and application innovations in this field in the future.

[0006] The invention patent with the publication number of CN 109969798 A discloses a new type of powder feeding machine that can be used by connecting a negative pressure pump. The feeding machine consists of a control part, a filter barrel, a discharge door section, and a bottom section, which are connected in sequence from top to bottom by clamps, realizing the closed conveying of powder materials without manual contact, thus effectively avoiding the problem of powder overflow. Each part is connected by a clamp and adopts a cylindrical design, making disassembly more convenient. However, this device has deficiencies in the degree of feeding automation and does not fully consider the cleaning problem of the feeding pipeline, resulting in more laborious subsequent cleaning operations. Content of the Utility Model

[0007] In view of the limitations of the current mixing technology for powder materials, a powder closed feeding device is proposed. This system is designed specifically for powder materials with low density characteristics or prone to dust generation, aiming to achieve more accurate metering and feeding, effective premixing, and a stable dust-free conveying process.

[0008] The technical solution of the utility model is: a powder closed feeding device, which includes a steel frame platform, an upper layer support, a main material metering system, a compensation feeding metering system, a vacuum pumping pipeline, a microsphere feeding system, a vacuum system, a weight sensor, and a conveying pipeline. The main material metering system and the compensation feeding system are located at the top of the overall device, and the microsphere feeding system, the vacuum system, and the steel frame platform are all installed on the ground.

[0009] The main material transfer hopper in the main material metering system is connected to the vacuum system through the vacuum pumping pipeline, and the pipeline connection parts need to be sealed to ensure the vacuum degree of the system during the operation of the vacuum device. Both the main material metering system and the compensation feeding metering system adopt a suspension installation method, fixed on the main material weight sensor supported on the upper layer support. The main material weight sensor is connected to the device control system to detect the feeding weight in real time. The microsphere feeding system is connected to the main material metering system through a pneumatic valve and a conveying pipeline. In view of the shortcomings of the existing device, such as low feeding quality accuracy, high microsphere breakage rate, and easy dust generation, this system adopts a secondary feeding method, that is, the combination of main feeding and compensation feeding. The main feeding has a fast feeding speed and no damage to the microspheres, preferentially feeds and leaves a certain quality margin; the compensation feeding has high accuracy and is easy to control, and subsequently accurately supplements the material to the required quality. The feeding process is in a fully enclosed state to prevent microspheres from generating dust.

[0010] The weight ratio of the materials added in the main feeding and the compensation feeding depends on the specific requirements for the material weight ratio accuracy and the feeding time. When the requirement for the feeding weight accuracy is high, the weight ratio of the compensation feeding will increase accordingly; when the feeding time requirement is short, the weight ratio of the main feeding will increase.

[0011] The described main material metering system includes a main material metering and mixing chamber, a material stirring paddle, a motor, a bag clamping device, a main material transfer hopper, a main material blanking valve, a bag clamping device blanking valve, a main blanking valve, and a main material weight sensor. The main material metering system is designed with an upper and lower structure, and the main material transfer hopper and the bag clamping device are located above the main material metering and mixing chamber. The main material metering and mixing chamber is integrally fixed on the main material weight sensor, and a material stirring paddle is installed inside it. The stirring paddle adopts a frame structure, and the sizes of both sides of the paddle blades are asymmetric to ensure that the materials on the near side and the far side of the stirring shaft can be fully mixed. The stirring paddle is connected to the motor, and the rotational speed range is 10 - 50 r / min. This rotational speed range can effectively reduce the breakage rate of microspheres and improve the quality of the mixed materials. Too low a rotational speed will result in poor stirring effect and inability to fully mix the materials; while too high a rotational speed will increase the breakage rate of microspheres. The main material transfer hopper is integrally sealed, and the pipeline at its top is connected to the vacuum pumping pipeline. The lower end of the bag clamping device is designed as a flared structure, and its inclination angle should satisfy not less than the collapse angle of the materials inside the bag clamping device to ensure that the materials will not accumulate during the discharging process. The bottom of the main material transfer hopper and the bag clamping device are respectively connected to the main material metering and mixing chamber through the main material blanking valve and the bag clamping device blanking valve.

[0012] The described bag clamping device includes a bag clamping component A, a bag clamping component B, a rubber sealing strip, and a buckle. The diameters of the inner and outer cylindrical plates of the bag clamping device B are slightly larger than the corresponding hole and column diameters of the bag clamping device A, which facilitates installation and ensures the smooth falling of the materials, avoiding the phenomenon of stepped dust accumulation. Rubber sealing strips are used for sealing treatment at the contact positions of the bag clamping component A and the bag clamping component B, thereby preventing dust and ensuring a soft contact with the material bag to avoid damage to the material bag. In the initial state, the bag clamping component B is located above the bag clamping component A, and the bag clamping device is in an inverted state as a whole. When adding materials, first open the buckle to separate the bag clamping component A and the bag clamping component B, and keep the bag clamping component B in the position above the bag clamping component A. After separation, load the material bag filled with materials from the large opening below the bag clamping component A, make the bag mouth of the material bag located in the gap between the bag clamping component A and the bag clamping component B, then open the material bag, open the bag mouth of the material bag and put it over the upper cylindrical part of the bag clamping component A, and then press the bag clamping component A and the bag clamping component B together, and tightly fasten the two with the buckle to clamp the bag mouth of the material bag between the two components to achieve bag clamping; preventing the leakage and dust generation of the materials.

[0013] The described compensation feeding system includes a small material metering chamber, a motor reducer, a small hopper, a double-screw side feeding device, a compensation material dropping valve, and a compensation material weight sensor. The small hopper is located at the upper part of the system, adjacent to the double-screw side feeding device below. The small material metering and mixing chamber is located at the lower part of the system. The compensation feeding system as a whole is approximately symmetric in the left-right direction. The small material metering and mixing chamber is integrally fixed on the compensation material weight sensor and is connected to the compensation material dropping valve at the lower end. The double-screw side feeding device connects the small hopper and the small material metering chamber and is connected to the motor reducer at the side end. The number of double-screw side feeding devices depends on the types of materials to be mixed. Each double-screw side feeding device is responsible for compensating the feeding of different materials or trace materials, and determines the screw structure and feeding speed of the double-screw according to the physical and chemical properties of the added materials. While maintaining the feeding accuracy, it is necessary to control the breakage rate of the materials. In this patent, the number of double-screw side feeding devices is 4. The described microbead feeding system includes a feeding tank, a moving support, a material reflux valve, a feeding valve, and a conveying pipeline. The feeding valve is located in the feeding branch, and the material reflux valve is located at the end of the material reflux branch. One end of the feeding branch is connected to the bottom of the feeding tank, and the other end communicates with the main material transfer hopper to realize the conveying of materials. One end of the material reflux branch is connected to the middle of the feeding tank, and the other end is connected to the feeding and conveying pipeline to realize the cleaning and reflux of materials. In the initial state, both the feeding valve and the material reflux valve are in the closed state. After the vacuum negative pressure value in the main material transfer hopper is stable, the feeding valve is opened, and the material A enters the main material transfer hopper under the action of the pressure difference. After the main material weight sensor detects that the material quality reaches the preset value and closes the feeding valve, a large amount of materials will accumulate in the feeding and conveying pipeline. When it is necessary to clean the materials accumulated in the pipeline, opening the material reflux valve can re-form a pressure difference between the feeding tank and the main material transfer hopper, prompting the materials accumulated in the pipeline to continue to enter the main material transfer hopper, achieving the self-cleaning effect of the feeding pipeline, replacing the traditional method of using a fan to clean the feeding pipeline, without the need to install additional cleaning equipment, greatly simplifying the cleaning process and reducing the production cost.

[0014] The feeding device of a powder closed feeding device of the present utility model, its main working principle and process include:

[0015] The first step: Put material A into the feeding tank in the microbead feeding system, close the feeding valve and the material reflux valve of the microbead feeding system, start the vacuum system. After the vacuum system operates, it pumps out the air inside the main material metering system to form a negative pressure. After the vacuum negative pressure value in the main material transfer hopper is stable, open the feeding valve. Material A enters the main material transfer hopper under the action of the pressure difference. After the main material weight sensor detects that the material quality reaches the preset value and closes the feeding valve, a large amount of materials will accumulate in the feeding and conveying pipeline. When it is necessary to clean the materials accumulated in the pipeline, opening the material reflux valve can re-form a pressure difference between the feeding tank and the main material transfer hopper, prompting the materials accumulated in the pipeline to continue to enter the main material transfer hopper, realizing the self-cleaning of the feeding pipeline;

[0016] Step 2: Pour Material B into the material bag in the bag clamping device by the method of bag clamping and inversion. The specific operation steps are as follows: First, open the buckle to separate the bag clamping assembly A and the bag clamping assembly B, and keep the bag clamping assembly B above the bag clamping assembly A. After separation, load the material bag filled with materials under the bag clamping assembly A, make the bag mouth of the material bag located at the gap between the bag clamping assembly A and the bag clamping assembly B, then open the material bag, open the bag mouth of the material bag and put it over the upper cylindrical part of the bag clamping assembly A, and then press the bag clamping assembly A and the bag clamping assembly B to tightly fasten the two with the buckle, and clamp the bag mouth of the material bag through the clamping between the two parts to complete bag clamping; prevent the leakage and dust of materials. Then, use the inverter to restore the bag clamping device to the normal position, and use an external lifting platform or other lifting equipment to install the bag clamping device at the designated position of the main material feeding system;

[0017] Step 3: After starting the metering control program, automatically open the main material blanking valve and the bag clamping device blanking valve for preliminary main feeding. The accuracy requirement of the main feeding is relatively low, and it is not necessary to reach the target weight value at one time. After opening the valve, Material A and Material B enter the main material metering and mixing chamber in sequence. The main material metering system adopts the weight gain metering method, that is, the material gravity sensor of the main material is used to monitor the amount of materials falling into the main material metering and mixing chamber in real time, and the increased mass is the mass of the added materials. When the mass of the added materials reaches the preset value, the system feeds back a signal to close the main material blanking valve and the bag clamping device blanking valve. During the falling process of the materials, the material stirring paddle keeps working to ensure that Material A and Material B are fully mixed;

[0018] Step 4: Since there is still a certain quality margin after the preliminary main feeding, the difference part is supplemented by the compensation feeding metering system. The compensation feeding metering system uses a double-screw side feeding device for supplementary feeding, and the feeding weight is also controlled by the weight gain method. The two double-screw side feeding devices respectively supplement two kinds of materials, Material A and Material B. The screw speed ≤ 100 r / min. The low feeding speed is easy to control, so as to achieve high-precision feeding quality. If the speed is too high, it is easy to cause the supplementary feeding quality to exceed the preset value. After supplementing to the target weight value, the compensation feeding metering system stops running. The compensation feeding system includes but is not limited to material compensation, and can also directly feed trace amounts of materials.

[0019] The present utility model relates to a powder closed feeding device, and its advantages and positive effects are as follows: 1. It realizes the transformation of the material transportation and premixing processes from manual operation to mechanized operation, improving production efficiency; 2. The entire working process of the system is carried out under closed conditions, avoiding the occurrence of dusting phenomena and greatly reducing the harm and impact on operators and the environment; 3. By combining the vacuum feeding method with the bag clamping device feeding method, the feeding process is simple and efficient; 4. It innovatively realizes the bag clamping device feeding method, enabling workers to independently complete the feeding. The operation process is fast and efficient, avoiding dust generation of microbeads while ensuring the integrity of the microbead material and improving the mixing quality; 5. Adopting the secondary feeding method, combining the main feeding and compensation feeding, while ensuring the feeding efficiency, greatly improves the material weight measurement accuracy, ensuring that each component feeds strictly according to its preset weight ratio; 6. During the feeding process, consideration is given to avoiding the breakage of microbead materials, improving the mixing quality while ensuring the mixing efficiency. 7. Utilizing a simple valve layout and control to achieve the self-cleaning effect of the pipeline, replacing the traditional method of using a fan to clean the feeding pipeline, eliminating the need to install additional cleaning equipment, greatly simplifying the cleaning process and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a schematic diagram of the overall device of a powder closed feeding device of the present utility model.

[0021] Figure 2 FIG. is a schematic diagram of the main material metering system of a powder closed feeding device of the present utility model.

[0022] Figure 3 FIG. is a longitudinal sectional view of the bag clamping device of a powder closed feeding device of the present utility model.

[0023] Figure 4 FIG. is a schematic diagram of the bag clamping device of a powder closed feeding device of the present utility model.

[0024] Figure 5 FIG. is a schematic diagram of the initial separation position of the bag clamping device of a powder closed feeding device of the present utility model.

[0025] Figure 6 FIG. is a schematic diagram of the compensation feeding metering system of a powder closed feeding device of the present utility model.

[0026] Figure 7 FIG. is a schematic diagram of the microbead feeding system of a powder closed feeding device of the present utility model.

[0027] In the figure: 1. Steel frame platform, 2. Upper support, 3. Main material metering system, 4. Compensation feeding metering system, 5. Vacuum pumping pipeline, 6. Microsphere feeding system, 7. Vacuum system, 8. Conveying pipeline, 3-1. Main material metering and mixing chamber, 3-2. Material stirring paddle, 3-3. Motor, 3-4. Bag clamping device, 3-4-1. Bag clamping component A, 3-4-2. Bag clamping component B, 3-4-3. Rubber sealing strip, 3-4-4. Buckle, 3-5. Main material transfer hopper, 3-6. Main material dropping valve, 3-7. Bag clamping device dropping valve, 3-8. Main dropping valve, 3-9. Main material weight sensor, 4-1. Minor material metering and mixing chamber, 4-2. Motor reducer, 4-3. Minor material hopper, 4-4. Twin-screw side feeding device, 4-5. Compensation material dropping valve, 4-6. Compensation material weight sensor, 6-1. Feeding tank, 6-2. Moving support, 6-3. Material reflux valve, 6-4. Loading valve. Detailed implementation mode

[0028] For the purpose of making the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0029] A powder closed feeding device of the present utility model, as Figure 1 shown, includes a steel frame platform 1, an upper support 2, a main material metering system 3, a compensation feeding metering system 4, a vacuum pumping pipeline 5, a microsphere feeding system 6, a vacuum system 7 and a conveying pipeline 8. The main material metering system 3 and the compensation feeding system 4 are located at the uppermost part of the overall device, and the microsphere feeding system 6, the vacuum system 7 and the steel frame platform 1 are all installed on the ground.

[0030] The main material transfer hopper 3-5 in the main material metering system 3 is connected to the vacuum system 7 through the vacuum pumping pipeline 5, and the pipeline connection parts need to be sealed to ensure the vacuum degree of the system during the operation of the vacuum device. Both the main material metering system 3 and the compensation feeding metering system 4 adopt a suspension installation method, and are fixed on the main material weight sensor 3-9 fixed on the upper support 2. The main material weight sensor 3-9 is connected to the device control system to detect the feeding weight in real time. The microsphere feeding system 6 is connected to the main material metering system 3 through a pneumatic valve and a conveying pipeline 8. In view of the disadvantages of the existing device such as low feeding quality accuracy, difficult cleaning of the accumulated material in the feeding pipeline, high microsphere breakage rate and easy dust generation, this system adopts a secondary feeding method, that is, the combination of main feeding and compensation feeding. The main feeding has a fast feeding speed, preferentially feeds and leaves a certain quality margin; the compensation feeding has high accuracy and is easy to control, and accurately supplements the material to the required weight subsequently. The feeding process is in a fully enclosed state to prevent microspheres from generating dust. By using a simple valve layout and control, it replaces the traditional method of using a fan to clean the feeding pipeline, eliminates the need to install additional cleaning equipment, greatly simplifies the cleaning process, and reduces the production cost.

[0031] The described main material metering system 3 includes a main material metering and mixing chamber 3-1, a material stirring paddle 3-2, a motor 3-3, a bag clamping device 3-4, a main material transfer hopper 3-5, a main material blanking valve 3-6, a bag clamping device blanking valve 3-7, a main blanking valve 3-8, and a main material weight sensor 3-9, as Figure 2 shown. The main material metering system 3 adopts an up-and-down structure design. The main material transfer hopper 3-5 and the bag clamping device 3-4 are located above the main material metering and mixing chamber 3-1. The main material metering and mixing chamber 3-1 is integrally fixed on the main material weight sensor 3-8, and a material stirring paddle 3-2 is installed inside it. The material stirring paddle 3-2 is of a frame structure, and the paddle blades are asymmetric in size on both sides to ensure that the materials on the near side and the far side of the stirring shaft can be fully mixed; the material stirring paddle 3-2 is connected to the motor 3-3, and the rotational speed range is 10-50 r / min. This rotational speed range can effectively reduce the breakage rate of the microspheres and improve the mixing quality of the materials; too low a rotational speed will result in poor stirring effect and inability to fully mix the materials; while too high a rotational speed will increase the breakage rate of the microspheres; the main material transfer hopper 3-5 is integrally sealed, and its top pipeline is connected to the vacuum pipeline 5; the lower end of the bag clamping device 3-4 is designed as a flared structure, and its inclination angle should satisfy not less than the collapse angle of the materials inside the bag clamping device to ensure that the materials will not accumulate during the discharging process; the bottoms of the main material transfer hopper 3-5 and the bag clamping device 3-4 are respectively connected to the main material metering and mixing chamber 3-1 through the main material blanking valve 3-6 and the bag clamping device blanking valve 3-7.

[0032] The described bag clamping device 3-4 includes a bag clamping assembly A 3-4-1, a bag clamping assembly B 3-4-2, a rubber sealing strip 3-4-3, and a buckle 3-4-4, as Figures 3-5As shown in the figure. The diameters of the inner and outer cylindrical plates of the bag clamping device B3-4-2 are slightly larger than the corresponding hole and column diameters of the bag clamping device A3-4-1, which facilitates installation while ensuring the smooth falling of materials and avoiding the phenomenon of stepped dust accumulation. Rubber sealing strips 3-4-3 are used for sealing at the contact points of the bag clamping assemblies A and B, so as to prevent dust and ensure soft contact with the material bag to avoid damage to the material bag. In the initial state, the bag clamping assembly B3-4-2 is located above the bag clamping assembly A3-4-1, and the whole bag clamping device is in an inverted state. When adding materials, first open the buckle to separate the bag clamping assembly A3-4-1 and the bag clamping assembly B3-4-2, still maintaining the positional relationship that the bag clamping assembly B3-4-2 is located above the bag clamping assembly A3-4-1. After separation, load the material bag filled with materials from the large opening below the bag clamping assembly A3-4-1, make the bag mouth of the material bag located in the gap between the bag clamping assembly A3-4-1 and the bag clamping assembly B3-4-2, then open the material bag, open the bag mouth of the material bag and put it over the upper cylindrical part of the bag clamping assembly A3-4-1, and then press the bag clamping assembly A3-4-1 and the bag clamping assembly B3-4-2, and tightly fasten the two with the buckle 3-4-4 to clamp the material bag mouth between the two parts to realize bag clamping; prevent material leakage and dust.

[0033] The described compensation feeding system 4 includes a small material metering and mixing chamber 4-1, a motor reducer 4-2, a small hopper 4-3, a twin-screw side feeding device 4-4, a compensation material dropping valve 4-5 and a compensation material weight sensor 4-6, as Figure 6 shown in the figure. The small hopper 4-3 is located at the upper part of the system, adjacent to the twin-screw side feeding device 4-4 below. The small material metering and mixing chamber 4-1 is located at the lower part of the system. The compensation feeding system 4 is approximately symmetric in structure from left to right as a whole. The small material metering and mixing chamber 4-1 is fixedly supported on the compensation material weight sensor 4-6, and the lower end is connected to the compensation material dropping valve 4-5; the twin-screw side feeding device 4-4 connects the small hopper 4-3 and the small material metering and mixing chamber 4-1, and the side end is connected to the motor reducer 4-2. The number of twin-screw side feeding devices 4-4 depends on the types of materials to be mixed. Each twin-screw side feeding device 4-4 is responsible for compensating the feeding of different materials or trace materials, and determines the twin-screw feeding speed according to the physical and chemical properties of the added materials. While maintaining the feeding accuracy, it is necessary to control the breakage rate of the materials. In this patent, the number of twin-screw side feeding devices 4-4 is 4.

[0034] The described microbead feeding system 6 includes a feeding tank 6-1, a moving bracket 6-2, a material reflux valve 6-3, a feeding valve 6-4 and a conveying pipeline 8, as Figure 7As shown in the figure. The feeding valve 6-4 is located in the feeding branch, and the material reflux valve 6-3 is located at the end of the material reflux branch. One end of the feeding branch is connected to the bottom of the feeding tank 6-1, and the other end is connected to the main material total transfer hopper 3-5 to realize the transportation of materials. One end of the material reflux branch is connected to the middle of the feeding tank 6-1, and the other end is connected to the feeding pipeline 8 to realize the cleaning and reflux of materials. In the initial state, both the feeding valve 6-4 and the material reflux valve 6-3 are in the closed state. After the vacuum negative pressure value in the main material transfer hopper 3-5 is stable, the feeding valve 6-4 is opened, and the material enters the main material transfer hopper 3-5 under the action of the pressure difference. After the main material weight sensor 3-9 detects that the material quality reaches the preset value and closes the feeding valve 6-4, a large amount of materials will accumulate in the feeding pipeline 8. When it is necessary to clean the materials accumulated in the pipeline, opening the material reflux valve 6-3 can re-form a pressure difference between the feeding tank 6-1 and the main material transfer hopper 3-5, prompting the materials accumulated in the pipeline to continue to enter the main material transfer hopper 3-5. The self-cleaning effect of the pipeline is realized by using a simple valve layout and control, greatly simplifying the cleaning process and reducing the production cost.

[0035] A powder closed feeding device of the present utility model, its main working principle and process include:

[0036] The first step: Put the material A into the feeding tank 6-1 in the microsphere feeding system 6, close the feeding valve 6-4 and the material reflux valve 6-3 of the microsphere feeding system, start the vacuum system 7. After the vacuum system 7 operates, the air inside the main material metering system 3 is discharged to form a negative pressure. After the vacuum negative pressure value in the main material transfer hopper 3-5 is stable, open the feeding valve 6-4, and the material A enters the main material transfer hopper 3-5 under the action of the pressure difference. After the main material weight sensor 3-9 detects that the material quality reaches the preset value and closes the feeding valve 6-4, a large amount of materials will accumulate in the feeding pipeline 8. When it is necessary to clean the materials accumulated in the pipeline, opening the material reflux valve 6-3 can re-form a pressure difference between the feeding tank 6-1 and the main material transfer hopper 3-5, prompting the materials accumulated in the pipeline to continue to enter the main material transfer hopper 3-5, realizing the self-cleaning of the feeding pipeline;

[0037] Step 2: Pour material B into the material bag in the bag clamping device 3-4 by the bag clamping and reversing method. The specific operation steps are as follows: First, open the buckle 3-4-4 to separate the bag clamping assembly A 3-4-1 and the bag clamping assembly B 3-4-2, and keep the bag clamping assembly B 3-4-2 in the position above the bag clamping assembly A 3-4-1. After separation, load the material bag filled with materials from below the bag clamping assembly A 3-4-1. When the bag mouth of the material bag is located in the gap between the bag clamping assembly A 3-4-1 and the bag clamping assembly B 3-4-2, open the material bag, open the bag mouth of the material bag and put it over the upper cylindrical part of the bag clamping assembly A 3-4-1. Then, press the bag clamping assembly A 3-4-1 and the bag clamping assembly B 3-4-2, and tightly fasten the two with the buckle 3-4-4 to clamp the bag mouth of the material bag between the two parts to complete bag clamping; prevent the leakage and dust of the materials. Then, use the reversing machine to restore the bag clamping device 3-4 to the normal position, and then use the external lifting platform or other lifting equipment to install the bag clamping device 3-4 at the designated position of the main material feeding system 3;

[0038] Step 3: After starting the metering program, automatically open the main material blanking valve 3-6 and the bag clamping device blanking valve 3-7 for preliminary main feeding. The accuracy requirement of the main feeding is relatively low, and it is not necessary to reach the target weight value at one time. After opening the valves, materials A and B enter the main material metering and mixing chamber 3-1. The main material metering system 3 adopts the weight gain metering method, that is, uses the main material gravity sensor 3-9 to real-time monitor the mass change of the main material metering system when the materials are falling, and the increased mass is the mass of the added materials. When the mass of the added materials reaches the preset value, the system feeds back a signal to close the main material blanking valve 3-6 and the bag clamping device blanking valve 3-7. During the falling process of the materials, the material stirring paddle 3-2 keeps working to ensure that materials A and B are fully mixed;

[0039] Step 4: Since there is still a certain mass margin after the preliminary main feeding, the difference part is supplemented by the compensation feeding metering system 4. The compensation feeding metering system 4 uses the double-screw side feeding device 4-4 for supplementary feeding. The feeding quality is also controlled by the weight gain method. The two double-screw side feeding devices respectively supplement materials A and B. The screw rotation speed ≤ 100 r / min, and the feeding speed is relatively slow and easy to control, so as to achieve high-precision feeding quality. If the rotation speed is too high, it is easy to cause the supplementary feeding quality to exceed the preset value. After supplementing to the target mass value, the compensation feeding metering system 4 stops running. The compensation feeding system includes but is not limited to material compensation, and can also directly feed trace amounts of materials.

Claims

1. A powder closed feeding device, characterized in that: It includes a steel frame platform, an upper support, a main material metering system, a compensating feed metering system, a vacuum pipeline, a micro-bead feeding system, a vacuum system, a weight sensor and a conveying pipeline. The main material metering system and the compensating feed system are located at the uppermost part of the device. The micro-bead feeding system, the vacuum system and the steel frame platform are all installed on the ground. The main material transfer bucket in the main material metering system is connected to the vacuum system through a vacuum pipeline. The pipe connection parts must be sealed to ensure the vacuum degree of the system when the vacuum device is running. The main material metering system and the compensating feed metering system are both installed in a suspension manner and are fixed on the main material weight sensor on the upper support. The main material weight sensor is connected to the device control system to detect the feeding in real time. Weight, the microbead feeding system is connected to the main material metering system through a pneumatic valve and a conveying pipeline; the main material metering system includes a main material metering mixing chamber, a material stirring paddle, a motor, a bag clamp, a main material transfer bucket, a main material blanking valve, a bag clamp blanking valve, a main blanking valve and a main material weight sensor. The main material metering system adopts an upper and lower structure design. The main material transfer bucket and the bag clamp are located above the main material metering mixing chamber. The main material metering mixing chamber is fixed on the main material weight sensor as a whole, and a material stirring paddle is installed inside it. The stirring paddle adopts a frame structure, and the sizes of the two sides of the paddle are asymmetrical to ensure that the materials on the near and far sides of the stirring shaft can be fully mixed. The stirring paddle is connected to the motor; the main material transfer bucket is sealed as a whole , its top pipeline is connected with the vacuum pipeline; the lower end of the bag clamp is designed as a bell-mouth structure, and its inclination angle should meet the requirement of not less than the collapse angle of the material inside the bag clamp. The main material transfer hopper and the bottom of the bag clamp are respectively connected with the main material metering and mixing chamber through the main material blanking valve and the bag clamp blanking valve; the compensation feeding system includes a small material metering chamber, a motor reducer, a small hopper, a twin-screw side feeding device, a compensation material blanking valve and a compensation material weight sensor. The small hopper is located at the upper part of the system, adjacent to the twin-screw side feeding device below, and the small-amount metering mixing chamber is located at the lower part of the system. The overall compensation feeding system has a left-right approximately symmetrical structure. The small-amount metering mixing chamber is integrally fixed on the compensation material weight sensor, and the lower end is connected to the compensation material blanking valve ; The twin-screw side feeding device is connected to the small hopper and the small material metering chamber, and the side end is connected to the motor reducer. The number of twin-screw side feeding devices depends on the number of types of mixed materials. Each twin-screw side feeding device is responsible for compensating for the feeding of different materials or trace materials, and determining the screw structure and feeding speed of the twin screw according to the physicochemical properties of the added materials; The microbead feeding system includes a feeding tank, a movable bracket, a material reflux valve, a feeding valve and a conveying pipeline. The feeding valve is located in the feeding branch, and the material reflux valve is located at the end of the material reflux branch. One end of the feeding branch is connected to the bottom of the feeding tank, and the other end is connected to the main material main hopper. One end of the material reflux branch is connected to the middle of the feeding tank, and the other end is connected to the feeding conveying pipeline.

2. A powder closed feeding device according to claim 1, characterized in that: The stirring paddle is connected to the motor, and the speed range is 10-50r / min.

3. A powder closed feeding device according to claim 1, characterized in that: The bag clamp includes a bag clamp component A, a bag clamp component B, a rubber sealing strip and a buckle. The diameters of the inner and outer cylindrical plates of the bag clamp B are slightly larger than the corresponding hole and column diameters of the bag clamp A. Rubber sealing strips are used to seal the contact between the bag clamp component A and the bag clamp component B.

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