Multipoint negative pressure pneumatic conveying system based on powder conveying and control method

Abstract

The invention provides a multi-point negative pressure pneumatic conveying system based on powder conveying and a control method, and the system comprises a fan outlet which is connected into a powder conveying pipeline and is used for providing air inlet volume; a plurality of conveying points are distributed on the powder conveying pipe in the blowing-in direction of the air inlet volume, each conveying point comprises a buffer bin for storing powder and a discharging opening, the discharging openings are formed above the buffer bins, the buffer bins are provided with material level switches, the material level switches monitor that the material level reaches the preset material level, and the knife valves below the buffer bins are triggered to be opened in a power line carrier mode; the powder is unloaded to the powder conveying pipeline; the high negative pressure dust remover is communicated with the powder conveying pipeline to form negative pressure conveying, and the powder is collected in a sedimentation and filter material separation mode; and the weighing device is arranged at the lower end of the high negative pressure dust remover and is used for weighing the collected powder. Based on power line carrier communication, the system arrangement cost is greatly reduced, meanwhile, multiple conveying points are adopted for distributed discharging, the powder conveying efficiency is greatly improved, and the conveying time is also saved.

Description

Technical Field

[0001] The present application relates to the technical field of material conveying, and in particular to a multi-point negative pressure pneumatic conveying system and a control method based on powder material transmission. Background Art

[0002] Among the related technologies, pneumatic conveying is the mainstream technology for powder material transmission at present, which uses airflow energy to transport powder materials in a closed pipeline. Among them, the negative pressure pneumatic conveying system uses vacuum suction to suck in powder materials, which is suitable for short-distance powder material transportation.

[0003] However, for some powder materials, such as polysilicon, a long-distance and high-efficiency negative pressure pneumatic conveying system is required, which involves power lines and data lines to realize power supply and communication control respectively, with complex wiring and large amount of labor, which greatly increases the laying cost and labor of the system, and is also easy to cause unnecessary interference in signal transmission. Therefore, a new negative pressure pneumatic conveying system for powder materials is urgently needed. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a multi-point negative pressure pneumatic conveying system and control method based on powder transmission, which is used to solve the problems of low powder transmission efficiency and high laying cost in the prior art.

[0005] To achieve the above-mentioned purpose and other related purposes, the first aspect of the present application provides a multi-point negative pressure pneumatic conveying system based on powder transmission, the system adopts power carrier mode for data communication, and the system includes: a fan outlet, connected to the powder transmission pipeline, for providing an intake air volume of a preset air volume; a plurality of conveying points are distributed on the powder transmission pipe along the blowing direction of the intake air volume, each of the conveying points includes a buffer silo for storing powder and a discharge port, the discharge port is arranged above the buffer silo, the buffer silo is provided with a level switch to monitor the material level when the preset material level is reached, and the knife valve below the buffer silo is triggered to open by power carrier mode to discharge the material into the powder transmission pipeline; a high negative pressure dust collector is connected to the powder transmission pipeline to form negative pressure transmission, and the powder is collected by sedimentation and filtration separation; a weighing device is arranged at the lower end of the high negative pressure dust collector, weighs the collected powder, and reports it by power carrier mode.

[0006] In certain embodiments of the first aspect of the present application, the upper portion of the high negative pressure dust collector is connected to a first compressed air source, which is used to spray the filter material separated by sedimentation, clean the powder attached to the surface of the filter material, and output clean air; the lower portion of the high negative pressure dust collector is also connected to the first compressed air source, which is used to spray and fluidize the ash storage bin and ash unloading valve configured at the lower portion of the high negative pressure dust collector to evenly output the powder.

[0007] In certain embodiments of the first aspect of the present application, the multi-point negative pressure pneumatic conveying system also includes: a vacuum pump and an exhaust fan of the high negative pressure dust collector are connected in sequence by pipes on the upper part of the high negative pressure dust collector, the vacuum pump provides negative pressure for the high negative pressure dust collector, and the exhaust fan discharges the clean air.

[0008] In certain embodiments of the first aspect of the present application, the multi-point negative pressure pneumatic conveying system further comprises: a muffler is provided on the output duct of the exhaust fan.

[0009] In certain embodiments of the first aspect of the present application, the plurality of vacuum pumps are divided into main and standby pumps, forming pump groups with different negative pressure forces according to pressure requirements.

[0010] In certain embodiments of the first aspect of the present application, a second compressed air source, a pipeline is connected to the knife valve below the buffer silo, and reverse blowing is performed to clean the powder attached to the knife valve.

[0011] In certain embodiments of the first aspect of the present application, the multi-point negative pressure pneumatic conveying system further includes: an electric two-way valve, which is arranged between the fan outlet and the powder transmission pipeline, and controls the opening and closing of the intake air volume by means of an electric carrier.

[0012] In certain embodiments of the first aspect of the present application, the powder transport pipeline is a seamless steel pipe, and the inner lining of the seamless steel pipe is a ceramic wear-resistant part.

[0013] In certain embodiments of the first aspect of the present application, if there are two fan outlets and two high-negative pressure dust collectors, one fan outlet is connected to multiple delivery points under the ash hopper of the cartridge dust collector, and the other fan outlet is connected to multiple delivery points under the ash hopper of the cyclone dust collector, all of the delivery points are connected to the two high-negative pressure dust collectors respectively through the powder transmission pipeline, and the electric two-way valve controls the connection and disconnection between the high-negative pressure dust collector and the multiple delivery points based on the power carrier mode, forming two negative pressure pneumatic conveying systems of the same or different powders, or forming a negative pressure pneumatic conveying system.

[0014] The second aspect of the present application provides a control method for a multi-point negative pressure pneumatic conveying system based on powder transmission, wherein the multi-point negative pressure pneumatic conveying system performs data communication based on a power carrier mode, and the method comprises: in response to receiving a first power carrier signal and performing analysis, if it is monitored that the powder in the buffer bin reaches a preset material level threshold, a first carrier control signal is generated to turn on the fan unit and output an intake air volume of a preset air volume; at the same time, the knife valve at the lower end of the buffer bin is slowly opened to allow the powder to continue to fall into the powder transmission pipeline; the negative pressure transmission formed by a high negative pressure dust collector in the powder transmission pipeline is used to collect the powder by sedimentation and filter material separation, the filter material separated by sedimentation is sprayed, the powder attached to the surface of the filter material is cleaned, and clean air is output; in response to receiving a second power carrier signal And analyze it, if it is monitored that the powder in the high negative pressure dust collector reaches a preset weight, a second carrier control signal is generated to open the ash discharge valve to discharge the material to the outside; in response to receiving the third power carrier signal and analyzing it, if it is monitored that the powder concentration meets the preset concentration range, a third carrier control signal is generated to maintain the unloading speed of the buffer silo and maintain the air volume of the fan unit, wherein the unloading speed of the powder is matched with the air volume; or, if it is monitored that the powder concentration is higher than the preset concentration range, a fourth carrier control signal is generated to reduce the unloading speed of the buffer silo or / and increase the air volume of the fan unit; or, if it is monitored that the powder concentration is lower than the preset concentration range, a fifth carrier control signal is generated to increase the unloading speed of the buffer silo or / and reduce the air volume of the fan unit.

[0015] As described above, a technical solution of a multi-point negative pressure pneumatic conveying system and control method based on powder material transmission described in the present application has the following beneficial effects:

[0016] The present application connects the powder transmission pipeline to the fan outlet, utilizes the air intake volume and negative pressure as the power source, realizes the continuous and stable transmission of powder, which not only improves the transmission efficiency but also reduces the energy consumption; the use of multi-point distributed transmission points enables the powder to enter the transmission powder transmission pipeline evenly and continuously, avoiding the pipeline blockage or uneven powder distribution caused by single-point transmission, and at the same time, also improves the powder transmission efficiency and shortens the powder transmission time; the powder is efficiently collected by sedimentation and filter separation, which reduces environmental pollution and effectively prevents the flying and leakage of powder during the transportation process; the collected powder is accurately weighed, which is conducive to the precise control of powder collection in the production process, and the power carrier communication is used to realize the rapid transmission of data and the immediate response of control instructions, which is not only low in cost but also high in safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Shown is a structural block diagram of a multi-point negative pressure pneumatic conveying system based on powder material transmission provided by the present application;

[0018] Figure 2 Shown is a control flow chart of a multi-point negative pressure pneumatic conveying system based on powder material transmission provided by the present application. DETAILED DESCRIPTION

[0019] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0021] See also Figure 1 , is a structural block diagram of a multi-point negative pressure pneumatic conveying system based on powder material transmission provided by the present application. The system adopts a power carrier mode for data communication. The system is described in detail as follows:

[0022] The fan outlet 1 is connected to the powder transmission pipeline to provide a preset air volume for the intake air;

[0023] For example, the air volume generated by the fan is used as a power source to form an airflow field in the pipeline. By combining it with negative pressure transportation, the airflow intensity during long-distance transmission is enhanced, ensuring that the powder is evenly and continuously transmitted in the pipeline, reducing the risk of blockage, improving transmission efficiency, and reducing energy consumption.

[0024] A plurality of delivery points 2 are distributed on the powder transmission pipe along the blowing direction of the air intake volume. Each delivery point 2 includes a buffer silo for storing powder and a discharge port. The discharge port is arranged above the buffer silo. The buffer silo is provided with a material level switch to monitor the material level when it reaches a preset material level. The knife valve below the buffer silo is triggered by an electric carrier (i.e., Figure 1 The electric knife gate valve is opened to discharge the material into the powder transmission pipeline;

[0025] It should be noted that power carrier communication is a communication method unique to the power system. It uses existing power lines to transmit analog or digital signals at high speed through carriers.

[0026] Exemplarily, the buffer silo is used as temporary storage to balance the powder supply and the pipeline transmission rate to avoid direct impact on the pipeline causing wear or blockage. The level switch is linked with the knife valve to achieve automatic control to ensure that the powder is supplied on demand. On the powder transmission pipeline, multiple delivery points are evenly or unevenly distributed according to demand. A buffer silo is installed at each delivery point. The discharge port is located at the top of the buffer silo and is equipped with a level switch. When the level switch detects that the powder reaches a preset height, it generates a power carrier control signal as a trigger signal to control the knife valve below the buffer silo to open, allowing the powder to fall into the transmission pipeline, thereby enhancing the flexibility and stability of the system and adapting to different powder characteristics and transmission requirements.

[0027] High negative pressure dust collector 3, connected to the powder transmission pipeline to form negative pressure transmission, and collects powder by sedimentation and filter material separation;

[0028] Illustratively, negative pressure suction is used to introduce the airflow carrying powder into the dust collector, and the powder and air are separated by physical sedimentation and filtration mechanisms. The air inlet of the high negative pressure dust collector is connected to the end of the powder transmission pipeline to form a negative pressure environment. The large particles of powder are initially separated through the sedimentation chamber inside the high negative pressure dust collector, and then fine particles are further captured by filter materials (such as cloth bags and filter elements). By collecting powder, environmental pollution is reduced.

[0029] A weighing device is provided at the lower end of the high negative pressure dust collector to weigh the collected powder and report it in the form of a power carrier.

[0030] For example, a weighing sensor is used to sense the weight change of the powder and convert it into an electrical signal output to achieve precise measurement. A weighing device, such as an electronic scale, is installed below the outlet of the high negative pressure dust collector to measure the weight of the collected powder in real time. The precise measurement of the powder is achieved and reported in the form of a power carrier wave, providing accurate data for production management and quality control.

[0031] Through the above method, by connecting the powder transmission pipeline at the fan outlet, using the intake air volume and negative pressure as the power source, continuous and stable transportation of powder is achieved, which not only improves the transportation efficiency but also reduces energy consumption; the use of multi-point distributed delivery points allows the powder to enter the transmission powder transmission pipeline evenly and continuously, avoiding the pipeline blockage or uneven powder distribution caused by single-point delivery. At the same time, it also improves the powder transmission efficiency and shortens the powder transmission time; the powder is efficiently collected by sedimentation and filter separation, reducing environmental pollution and effectively preventing the flying and leakage of powder during transportation; the collected powder is accurately weighed, which is conducive to the precise control of powder collection in the production process. At the same time, the power carrier communication is used to achieve rapid data transmission and immediate response to control instructions, which is not only low in cost but also high in safety.

[0032] Optionally, in some embodiments, the upper part of the high negative pressure dust collector is connected to a first compressed air source to spray the filter material separated by sedimentation, clean the powder attached to the surface of the filter material, and output clean air; the lower part of the high negative pressure dust collector is also connected to the first compressed air source to evenly output the powder by spraying and fluidizing the ash storage bin and ash unloading valve configured at the lower part of the high negative pressure dust collector.

[0033] For example, compressed air is used to impact the filter material through an instantaneous high-pressure airflow, overcome the adhesion between the powder particles and the filter material, and remove the particles from the surface of the filter material. At the same time, the blowing action is usually synchronized with the dust cleaning cycle of the dust collector to ensure that the filter material remains clean and maintains high dust removal efficiency. For example, the first compressed air source is connected to the upper part of the high negative pressure dust collector through a pipe and a valve. A blowing device, such as a pulse blowing valve or an air bag, is installed in the filter material area of ​​the dust collector. The blowing action is triggered according to a preset time interval or according to the pressure drop change of the filter material. When the blowing device is activated, the compressed air is sprayed to the filter material in the form of a short and strong airflow pulse, and the powder particles attached to the surface of the filter material are blown off, thereby cleaning the filter material. In this way, the filter material can be kept clean, the service life of the filter material can be extended, and the dust removal efficiency can be improved; at the same time, the increase in system pressure drop caused by filter material blockage is reduced to ensure stable operation.

[0034] After the filter material is cleaned, the concentration of powder particles in the air is significantly reduced to meet the emission standards. The remaining tiny particles are further removed through an additional filter layer to ensure that the air quality meets the standards. After the filter material is cleaned, clean air carrying fewer powder particles is discharged through the outlet of the dust collector; an additional filter layer (such as a HEPA filter) can be set at the outlet to further purify the air; the clean air is then discharged into the atmosphere or recycled into the production process for reuse, reducing dust emissions and protecting the environment; improving air quality and ensuring the health of workers.

[0035] Specifically, the ash discharge valve accurately controls the outflow rate of the powder to ensure the uniformity of the powder during the transportation process. According to the characteristics of the powder and the transportation distance, the appropriate transportation method is selected to ensure that the powder can be stably and efficiently transported to the destination. For example, the powder that has been fluidized by the spray enters the transportation system through the ash discharge valve and is transported to the designated collection point, which improves the uniformity and continuity of the powder output, reduces the cost of manual operation, and improves production efficiency.

[0036] Optionally, in some embodiments, a second compressed air source is connected to a knife valve below the buffer silo through a pipeline, and reverse blowing is performed to clean the powder attached to the knife valve.

[0037] Specifically, the second compressed air source can be the same source as the first compressed air source, and the compressed air can be delivered to the knife valve position through the pipeline system to achieve remote and precise cleaning operations. For example, the second compressed air source is connected to the knife valve under the buffer silo to achieve remote delivery and precise control of compressed air, which improves the flexibility and efficiency of cleaning operations, reduces manual operations, and reduces labor intensity. Through the high-speed and high-pressure characteristics of compressed air and the shear force generated by reverse blowing, the powder attached to the knife valve is effectively removed, effectively removing the powder attached to the knife valve, preventing blockage and reduced delivery efficiency. At the same time, the cleaning process is fast and efficient, reducing downtime and maintenance costs.

[0038] Optionally, in certain embodiments, the multi-point negative pressure pneumatic conveying system further includes: an electric two-way valve, which is arranged between the blower outlet and the powder transmission pipeline, and controls the opening and closing of the air intake volume by means of an electric carrier.

[0039] For example, the electric two-way valve controls the on-and-off of the airflow in the pipeline through its opening and closing action, thereby adjusting the air volume. The selection of the installation position must ensure that the electric two-way valve can effectively control the air volume and at the same time, facilitate maintenance and operation. By reasonably determining the installation position of the electric two-way valve, the accuracy of air volume control and the stability of the system are ensured, thereby improving the powder transmission efficiency and reducing energy consumption.

[0040] It should be noted that the electric two-way valve realizes the opening and closing of the valve by driving the valve core to rotate or move through the motor, thereby improving the reliability and durability of the system. The air volume, pressure and other parameters in the powder transmission pipeline are monitored by sensors. According to the monitoring results and the preset control strategy, a control signal is sent to the electric two-way valve to adjust the air volume, thereby realizing precise control of the electric two-way valve, improving the powder transmission efficiency and system stability; reducing energy consumption and extending the service life of equipment; improving the degree of automation and intelligence of the system, and facilitating operation and maintenance management.

[0041] Optionally, in certain embodiments, if there are two fan outlets and two high-negative pressure dust collectors, one fan outlet is connected to multiple delivery points under the ash hopper of the cartridge dust collector, and the other fan outlet is connected to multiple delivery points under the ash hopper of the cyclone dust collector, all of the delivery points are connected to the two high-negative pressure dust collectors respectively through the powder transmission pipeline, and the electric two-way valve controls the connection and disconnection between the high-negative pressure dust collector and the multiple delivery points based on the power carrier mode, forming two negative pressure pneumatic conveying systems of the same or different powders, or forming one negative pressure pneumatic conveying system.

[0042] For example, according to the factory layout, powder characteristics, dust collector performance and transportation requirements, the system design is carried out to determine the fan outlet location, the number of delivery points, the pipeline layout and the electric two-way valve configuration, and the connection method and control logic between the two dust collectors and the delivery point are planned. The fan provides negative pressure power to suck the powder from the dust collector hopper and transport it to the high negative pressure dust collector. The dust collector is used to remove impurities and particles in the powder to ensure the quality of the transported powder. The powder transmission pipeline is used to transport the powder from the delivery point to the high negative pressure dust collector. The electric two-way valve controls the on and off of the airflow in the pipeline through opening and closing actions, thereby adjusting the powder delivery path. To ensure the stable and efficient operation of the system, the performance and reliability of the system are improved by adjusting the equipment parameters and control logic.

[0043] Through the above methods, the flexible configuration and control logic of the electric two-way valve can realize the independent or combined operation of two negative pressure pneumatic conveying systems of the same or different powders; the reasonable configuration of the fan and dust collector can ensure the efficient conveying and dust removal effect of the powder. In addition, the introduction of intelligent control system improves the automation degree and conveying efficiency of the system; through system optimization and data analysis technology, energy consumption and operation and maintenance costs are reduced.

[0044] Optionally, in some embodiments, a compressed air source is connected to the upper portion of the high negative pressure dust collector to spray the filter material separated by sedimentation, clean the powder attached to the surface of the filter material, and output clean air, wherein the filter material is a high-temperature filter material.

[0045] Among them, the filter material for sedimentation separation is sprayed with a compressed air source of 0.6MPa in the factory area to clean the powder attached to the surface of the filter material. The compressed air source can not only clear the powder, but also have a cooling effect and output clean air. It should be noted that the filter material is arranged at the upper end of the high negative pressure dust collector, or the filter material and the high negative pressure dust collector are integrated so that the cleaned powder can be collected together.

[0046] For example, a compressed air source is connected to the upper part of the high negative pressure dust collector. When cleaning the powder on the surface of the filter material, the compressed air source is turned on and the compressed air is transported to the blowing device inside the high negative pressure dust collector through the pipeline. The compressed air is sprayed out at a certain pressure and flow rate to clean the filter material. During the blowing process, the powder is blown off by the compressed air and discharged through the dust discharge device of the high negative pressure dust collector; at the same time, the clean air is filtered by the filter material and then output to the outside.

[0047] Through the above method, using compressed air for spray cleaning can quickly clean the powder on the surface of the filter material, improve the cleaning efficiency, and achieve the purpose of unblocking the powder and reducing the temperature of the powder; by cleaning the dust on the surface of the filter material, it can reduce the blockage and wear of the filter material, thereby extending the service life; the filter material can remove tiny particles and impurities in the air to ensure the quality of the output air. In addition, using compressed air for spray cleaning has simple equipment, convenient operation, and low maintenance cost.

[0048] Optionally, in some embodiments, it also includes: a vacuum pump 4 and an exhaust fan 5 of the high negative pressure dust collector are connected in sequence by pipes on the upper part of the high negative pressure dust collector 3, the vacuum pump 4 provides negative pressure for the high negative pressure dust collector, and the exhaust fan 5 discharges clean air.

[0049] Among them, the vacuum pump and the exhaust fan are arranged outside the high negative pressure dust collector. The vacuum pump extracts air through the mechanical movement generated by electricity, and discharges the extracted gas into the atmosphere through the exhaust port, thereby forming a negative pressure at the suction port. The vacuum pump can use multiple groups of vacuum pumps. For example, multiple groups of vacuum pumps are divided into main and standby pumps, and pump groups with different negative pressure forces are formed according to pressure requirements, such as the main vacuum pump and the standby vacuum pump, so as to improve the stable output capacity of the vacuum pump, or meet the needs of different negative pressures, such as Figure 1 As shown, three Roots vacuum pumps can freely form a main vacuum pump and a standby vacuum pump.

[0050] For example, the muffler 6 is usually installed on the exhaust duct of the exhaust fan, that is, near the exhaust port, to reduce the noise generated when the air is discharged. Since the muffler contains multiple chambers and duct structures, these structures can reflect, interfere and absorb sound waves, thereby reducing the propagation of noise; at the same time, the muffler is filled with sound-absorbing materials, such as foam plastics, glass fiber, etc., to enhance the noise reduction effect.

[0051] Optionally, in some embodiments, it also includes: a knife valve, which is arranged below the buffer silo and adaptively adjusts the discharge speed of the buffer silo according to the real-time temperature of the powder received by the high negative pressure dust collector.

[0052] Exemplarily, the knife valve is arranged below the buffer silo, and the knife valve is connected to the motor through a frequency converter, so as to realize accurate control of the material discharge speed. By monitoring the powder concentration of the powder material and feeding back to the control system, for example, according to the received powder concentration, the output frequency of the frequency converter is automatically adjusted, and then the speed of the motor is changed, so as to realize adaptive adjustment of the material discharge speed.

[0053] Through the above method, on the one hand, the frequency conversion speed regulation technology is used to automatically adjust the feeding speed according to the powder concentration, so as to achieve precise control of the feeding speed, thereby ensuring the stable output of the powder and the stable operation of the system; on the other hand, the knife valve can adjust the speed of the motor according to actual needs, so as to save energy.

[0054] Optionally, in some embodiments, the powder transport pipeline is a seamless steel pipe, and the inner lining of the seamless steel pipe is a ceramic wear-resistant part.

[0055] For example, the thickness of the steel pipe is greater than or equal to 3 mm, and a seamless steel pipe with a thickness of 8 mm is lined with ceramic wear-resistant parts, and elbows, tees, reducers, and valves are lined with ceramic wear-resistant parts.

[0056] Through the above method, since the seamless steel pipe has high mechanical strength and pressure bearing capacity, it can withstand greater pressure and load. Ceramic wear-resistant parts of preset thickness are arranged in the seamless steel pipe. The high hardness, high wear resistance and high corrosion resistance of the ceramic wear-resistant parts are utilized to combine the ceramic layer with the seamless steel pipe to form a composite pipeline. It should be noted that the ceramic layer can effectively reduce the wear and corrosion of the pipeline during the transportation process and extend its service life. At the same time, its service life is relatively long, which can reduce the frequency of replacement and maintenance.

[0057] Optionally, in practical applications, the implementation of a multi-point negative pressure pneumatic conveying system based on powder transmission is as follows:

[0058] The dust in the ash bin of the dust collector falls continuously and uninterruptedly into the lower ash bin through the lower star-shaped ash discharge valve. A level meter is installed in the ash bin, and an electric gate valve is installed at the bottom of the ash bin. When the level meter detects a high material level, it sends a power carrier control signal to control the electric two-way valve to open, and the air enters the negative pressure conveying pipe. The electric gate valve slowly opens, and the dust gradually falls and mixes with the air. The material is transported to the dust collector and ash storage bin through the dilute phase conveying pipe. The purified clean gas meets the discharge standards after passing through the vacuum pump and muffler. This application uses a vacuum pump as the power source to provide negative pressure. A high negative pressure bag dust collector is used for dust separation and is equipped with an ash storage bin, an ash discharge valve and a gate valve (integrated device), and a filter is used for ash mixing and air collection.

[0059] Considering that dust has a certain degree of abrasiveness on pneumatic conveying pipelines, 8mm thick-walled seamless steel pipes are lined with ceramic wear-resistant parts. Elbows, tees, reducers and valves are lined with ceramic wear-resistant parts. At the same time, because the working body of the equipment and the silicon powder belong to the same zone, all equipment must consider dust explosion-proof design.

[0060] In addition, the pneumatic conveying pipeline and some valves are installed on the roof, the main part of the pneumatic conveying dust removal unit is installed on the east side of the bottom of the building, and the middle part is all connected with seamless steel pipes.

[0061] For example, Figure 1 There are 36 and 24 delivery points under the ash hopper of the medium cyclone dust collector, and there are 4 delivery points under the ash hopper of the cartridge dust collector. The structure and construction of each delivery point are the same and will not be repeated here.

[0062] It should be noted that the filtration efficiency of the pleated filter bag should be ≥99.8%, and the dust concentration discharged to the outdoor air after treatment should be ≤10mg / m 3 , a detection port is reserved on the exhaust pipe. According to the dust characteristics, the filtration wind speed is designed to be less than 0.6m / min, and the wind speed of the box section is less than 2.5m / s. The advanced cleaning controller is adopted, and the spraying interval and pulse width can be adjusted; the cleaning controller has pressure difference, timing, and offline cleaning functions; the electromagnetic pulse valve is pilot-operated, and the pipelines are installed neatly and beautifully.

[0063] It should also be noted that the ash storage bin at the lower end of the negative pressure dust collector has a cyclone function. The shell material thickness of the cyclone dust collector is 5mm, and the wear resistance of the powder is fully considered (a 5mm ceramic lining needs to be installed). The straight cylinder and the conical cylinder are connected by flanges and cannot be directly welded. The legs must meet the strength and wind / vibration resistance requirements.

[0064] Through the above method, by controlling the powder concentration, the maximum utilization rate of the powder transmission pipeline is ensured, and explosion will not occur. At the same time, ventilation is carried out indoors, and there is no need to introduce outdoor wind source, which ensures that the outdoor wind source is not affected by weather or climate, thereby ensuring the stability of ash hopper dust removal. In addition, multiple conveying points are equipped with powder buffer silos, which can realize miniaturized and refined management.

[0065] See also Figure 2 , is a control flow chart of a multi-point negative pressure pneumatic conveying system based on powder material transmission provided by the present application, the multi-point negative pressure pneumatic conveying system performs data communication based on a power carrier mode, and the method includes:

[0066] Step S201, in response to receiving the first power carrier signal and analyzing it, if it is monitored that the powder in the buffer silo reaches a preset material level threshold, a first carrier control signal is generated to turn on the fan unit to output a preset air volume; at the same time, the knife valve at the lower end of the buffer silo is slowly opened to allow the powder to continue to fall into the powder transmission pipeline;

[0067] Specifically, the powder stock in the buffer silo is monitored in real time by a material level sensor installed in the buffer silo. The material level sensor transmits the power carrier to the controller for analysis. When it is detected that the powder stock reaches the preset material level threshold, a first carrier control signal is generated and sent to the fan unit and the knife valve, triggering the fan unit to start and output a preset air intake volume; at the same time, the knife valve at the lower end of the buffer silo is slowly opened to allow the powder to continue to fall into the powder transmission pipeline.

[0068] Step S202, using the negative pressure conveying formed by the high negative pressure dust collector in the powder conveying pipeline, collecting the powder by sedimentation and filter material separation, spraying the sedimentation separated filter material, cleaning the powder attached to the filter material surface, and outputting clean air;

[0069] Specifically, the powder is initially separated by sedimentation, and the impurities in the powder are further separated by filter material. During separation, the filter material is sprayed and cleaned with the help of a compressed air source to ensure that the filter material is unobstructed and clean air is output.

[0070] Step S203, in response to receiving and analyzing the second power carrier signal, if it is monitored that the powder in the high negative pressure dust collector reaches a preset weight, a second carrier control signal is generated to open the ash discharge valve to discharge the powder to the outside;

[0071] Specifically, the collected powder is weighed using an electronic scale or a floor scale, and the weighing information is loaded into a second power carrier signal in a carrier manner. By analyzing the second power carrier signal, if it is monitored that the powder collected in the high negative pressure dust collector reaches a preset weight, for example, when the weight of the powder reaches 1 ton, a second carrier control signal is generated and sent to the ash discharge valve, which opens the ash discharge valve to discharge the material to the outside, wherein the preset weight can be set according to user needs.

[0072] Step S204, in response to receiving and analyzing the third power carrier signal, if it is monitored that the powder concentration meets the preset concentration range, a third carrier control signal is generated to maintain the unloading speed of the buffer silo and the air volume of the fan unit, wherein the unloading speed of the powder is matched with the air volume; or, if it is monitored that the powder concentration is higher than the preset concentration range, a fourth carrier control signal is generated to reduce the unloading speed of the buffer silo and / or increase the air volume of the fan unit; or, if it is monitored that the powder concentration is lower than the preset concentration range, a fifth carrier control signal is generated to increase the unloading speed of the buffer silo and / or reduce the air volume of the fan unit.

[0073] Exemplarily, the capacitive sensor can reflect the change of powder concentration by measuring the change of equivalent dielectric constant of the fluid, and the real-time powder concentration is loaded with a third power carrier signal in the form of power carrier, and sent to the system controller (i.e., processor). By analyzing the third power carrier signal, the monitored real-time powder concentration is determined. If the powder concentration of the powder meets the preset concentration range, the feeding speed of the powder and the air volume of the cold air are matched, that is, once the feeding speed of the buffer silo is adjusted, the air volume of the fan unit also needs to be adjusted. For example, if the feeding speed is increased, the air volume of the fan unit should also be increased; similarly, if the feeding speed is reduced, the air volume of the fan unit should also be reduced.

[0074] Exemplarily, if the powder concentration is higher than the preset concentration range, a fourth carrier control signal is generated to control the negative pressure pneumatic conveying system by reducing the material discharge speed of the buffer silo or / and increasing the air volume of the fan unit. If the real-time temperature is lower than the preset concentration range, a fifth carrier control signal is generated to control the negative pressure pneumatic conveying system by increasing the material discharge speed of the buffer silo or / and reducing the air volume of the fan unit, wherein the third carrier control signal, the fourth carrier control signal, and the fifth carrier control signal are generated in the same manner, representing different control strategies respectively.

[0075] Optionally, based on blind recognition of OFDM (orthogonal frequency division multiplexing) communication signals on the power carrier line, the receiving end can have partial protocol information of the sending end before communication is established, thereby facilitating the establishment of a link between the receiving end and the sending end. For example, by blindly estimating the number of carriers, center frequency and subcarrier spacing of the OFDM signal received on the power carrier, some information about the communication protocol can be obtained. Based on this information, the receiving end selectively tries to establish a link with the sending end, thereby improving link efficiency.

[0076] Specifically, power carrier communication uses existing power lines as communication channels, and there is no need to lay additional communication lines. Since power carrier communication does not require laying additional communication lines, the trouble and cost of wiring can be eliminated, which not only reduces the initial investment cost of the system, but also reduces the subsequent maintenance workload. Power carrier communication transmits data through power lines and is not easily interfered with or eavesdropped on, so it has high security. In addition, power carrier communication usually chooses to transmit within a specific frequency band, which can effectively avoid interference from low-frequency power signals and further enhance its anti-interference ability. Power carrier communication can efficiently use power lines as communication channels, realize rapid data transmission and immediate response to control instructions, which not only improves the work efficiency of the system, but also realizes the comprehensive utilization of resources.

[0077] Through the above method, when the powder concentration meets the preset concentration range, maintaining a stable feeding speed and air volume can avoid unnecessary energy waste; at the same time, by accurately controlling the feeding speed and air volume, energy consumption can be further reduced and energy utilization efficiency can be improved; by adjusting the feeding speed and air volume, the suspension state and conveying speed of the material in the pipeline can be maintained, thereby avoiding problems such as blockage and powder explosion; if the powder concentration is higher or lower than the preset concentration range, different control strategies are used to accurately control the feeding speed and air volume, which can ensure the stability and continuity of the material during the conveying process, thereby improving production efficiency; at the same time, it can also reduce the downtime caused by equipment failure, further improving production efficiency.

[0078] It should be noted that according to the type of powder transported by each conveying point and the positional relationship corresponding to each conveying point, the power is turned on and off according to the priority of the powder type, and the corresponding powder is controlled to be transmitted to the high negative pressure dust collector, so as to save energy. For example, since the energy required to maintain the normal operation of a high negative pressure dust collector remains unchanged, if all conveying points are working, one or two high negative pressure dust collectors can be turned on as needed to improve the maximum utilization of the entire system.

[0079] Through the above method, the powder transmission pipeline is connected to the fan outlet, and the intake air volume and negative pressure are used as the power source to achieve continuous and stable transportation of powder, which not only improves the transportation efficiency but also reduces energy consumption; the use of multi-point distributed delivery points allows the powder to enter the transmission powder transmission pipeline evenly and continuously, avoiding pipeline blockage or uneven powder distribution caused by single-point delivery. At the same time, it also improves the powder transmission efficiency and shortens the powder transmission time; the powder is efficiently collected by sedimentation and filter separation, which reduces environmental pollution and effectively prevents the flying and leakage of powder during transportation; the collected powder is accurately weighed, which is conducive to the precise control of powder collection in the production process; at the same time, power carrier communication is used to achieve rapid data transmission and immediate response to control instructions, which is not only low in cost but also high in safety.

[0080] The specific definition of the control method of the multi-point negative pressure pneumatic conveying system based on powder transmission can be found in the above definition of the multi-point negative pressure pneumatic conveying system based on powder transmission, which will not be repeated here. Each module in the above-mentioned multi-point negative pressure pneumatic conveying system based on powder transmission can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the electronic device in the form of hardware, or can be stored in the memory of the electronic device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0081] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A multi-point negative pressure pneumatic conveying system based on powder transmission, characterized in that: The system adopts a power carrier mode for data communication, and the system comprises: The fan outlet is connected to the powder transmission pipeline to provide a preset air volume; A plurality of delivery points are distributed on the powder transmission pipe along the blowing direction of the air intake volume, each of the delivery points includes a buffer silo for storing powder and a discharge port, the discharge port is arranged above the buffer silo, the buffer silo is provided with a material level switch to monitor the material level when it reaches a preset material level, and the knife valve below the buffer silo is triggered to open through an electric carrier mode to discharge the powder into the powder transmission pipe; A high negative pressure dust collector is connected to the powder transmission pipeline to form negative pressure transmission, and collects the powder by sedimentation and filter material separation; A weighing device is arranged at the lower end of the high negative pressure dust collector to weigh the collected powder and report it in a power carrier mode.

2. The multi-point negative pressure pneumatic conveying system based on powder transmission according to claim 1 is characterized in that: The upper part of the high negative pressure dust collector is connected to the first compressed air source, which is used to spray the filter material separated by sedimentation, clean the powder attached to the surface of the filter material, and output clean air; the lower part of the high negative pressure dust collector is also connected to the first compressed air source, which is used to spray and fluidize the ash storage bin and ash unloading valve configured at the lower part of the high negative pressure dust collector to evenly output the powder.

3. The multi-point negative pressure pneumatic conveying system based on powder transmission according to claim 2 is characterized in that: Also includes: A vacuum pump and an exhaust fan of the high negative pressure dust collector are connected in sequence by pipelines on the upper part of the high negative pressure dust collector, wherein the vacuum pump provides negative pressure for the high negative pressure dust collector, and the exhaust fan discharges the clean air.

4. The multi-point negative pressure pneumatic conveying system based on powder transmission according to claim 3 is characterized in that: Also includes: A muffler is arranged on the output pipeline of the exhaust fan.

5. The multi-point negative pressure pneumatic conveying system based on powder material transmission according to claim 3 is characterized in that: The plurality of vacuum pumps are divided into main and standby pumps, and form pump groups with different negative pressure forces according to pressure requirements.

6. The multi-point negative pressure pneumatic conveying system based on powder material transmission according to claim 1 is characterized in that: The second compressed air source has a pipeline connected to the knife valve below the buffer silo, and reversely blows to clean the powder attached to the knife valve.

7. The multi-point negative pressure pneumatic conveying system based on powder transmission according to any one of claims 1 to 6, characterized in that: Also includes: The electric two-way valve is arranged between the blower outlet and the powder transmission pipeline, and controls the opening and closing of the air intake air volume through the power carrier mode.

8. The multi-point negative pressure pneumatic conveying system based on powder transmission according to any one of claims 1 to 6, characterized in that: The powder transmission pipeline is a seamless steel pipe, and the inner lining of the seamless steel pipe is a ceramic wear-resistant part.

9. The multi-point negative pressure pneumatic conveying system based on powder material transmission according to any one of claims 1 to 6, characterized in that: If there are two fan outlets and two high-negative-pressure dust collectors, one fan outlet is connected to multiple conveying points under the ash hopper of the cartridge dust collector, and the other fan outlet is connected to multiple conveying points under the ash hopper of the cyclone dust collector. All the conveying points are respectively connected to the two high-negative-pressure dust collectors through the powder transmission pipeline. The electric two-way valve controls the connection and disconnection between the high-negative-pressure dust collector and the multiple conveying points based on the power carrier mode, thereby forming two negative-pressure pneumatic conveying systems for the same or different powders, or forming one negative-pressure pneumatic conveying system.

10. A control method for a multi-point negative pressure pneumatic conveying system based on powder material transmission, characterized in that: The multi-point negative pressure pneumatic conveying system performs data communication based on a power carrier mode, and the method comprises: In response to receiving the first power carrier signal and analyzing it, if it is monitored that the powder in the buffer silo reaches a preset material level threshold, a first carrier control signal is generated to turn on the fan unit to output a preset air volume; at the same time, the knife valve at the lower end of the buffer silo is slowly opened to allow the powder to continue to fall into the powder transmission pipeline; The negative pressure conveying formed by the high negative pressure dust collector in the powder transmission pipeline is used to collect the powder by sedimentation and filter material separation, the filter material separated by sedimentation is sprayed, the powder attached to the surface of the filter material is cleaned, and clean air is output; In response to receiving and analyzing the second power carrier signal, if it is monitored that the powder in the high negative pressure dust collector reaches a preset weight, a second carrier control signal is generated to open the ash discharge valve to discharge the powder to the outside; In response to receiving the third power carrier signal and analyzing it, if it is monitored that the powder concentration meets the preset concentration range, a third carrier control signal is generated to maintain the unloading speed of the buffer silo and the air volume of the fan unit, wherein the unloading speed of the powder matches the air volume; or, if it is monitored that the powder concentration is higher than the preset concentration range, a fourth carrier control signal is generated to reduce the unloading speed of the buffer silo and / or increase the air volume of the fan unit; or, if it is monitored that the powder concentration is lower than the preset concentration range, a fifth carrier control signal is generated to increase the unloading speed of the buffer silo and / or reduce the air volume of the fan unit.

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