Pneumatic powder conveying system and control method

Abstract

The application discloses a kind of powder material pneumatic conveying systems, comprising: conveying unit, for pressurized delivery of powder to pipeline network, realize multiple pump parallel delivery;Gas source unit, for providing double independent air supply;Bin unit, for receiving and storing the powder delivered;Control unit, for centralized monitoring of pipeline pressure, valve state and material level, and trigger sound light alarm;Blockage removal unit, for automatic removal of pipeline and pump in the blockage;Electrical distribution unit, for each unit provides 380VAC power and control electricity;Wherein, conveying unit is connected by gas pipeline to gas source unit;Conveying unit is connected by conveying pipeline to bin unit;Control unit is connected by cable to the sensor of each unit, actuator and distribution unit.The application also discloses a kind of powder material pneumatic conveying system control method.The application solves the problem of air supply interference, pipeline blockage and material bridging, inaccurate control, poor environmental protection and insufficient structural safety and component wear resistance.

Description

Technical Field

[0001] This invention relates to a pneumatic conveying system and control method for powdery materials. Background Technology

[0002] Currently, dense-phase positive pressure pneumatic conveying systems are widely used in the pneumatic conveying field. These systems typically consist of a silo pump, conveying pipelines, an air source device, a silo, and a simple control system. They are mainly used for long-distance conveying of powdery materials and have been widely applied in chemical, building materials, and other fields. However, for conveying fine particulate materials, existing technologies often use a single air source to provide power for both conveying and instrumentation control. The silos are mostly made of ordinary stainless steel, conventional elbows are used at pipeline bends, and the control systems are mostly limited to single automatic or manual control modes, lacking specific anti-clogging and anti-clogging designs.

[0003] Specifically, it has the following defects:

[0004] 1. Unreasonable design of the gas source system (gas source interference problem: existing technologies generally use a single gas source to supply gas for both material conveying and instrument control at the same time, which leads to gas source pressure fluctuations during the conveying process, which in turn causes pneumatic valves to jam or even be damaged, seriously affecting the stability of system operation;

[0005] 2. Insufficient anti-blocking and anti-blocking capabilities (pipeline blockage and material bridging issues: existing technologies are not specifically designed for the characteristics of fine particles and strong adhesion of powdery materials, resulting in frequent pipeline blockages. Furthermore, there is a lack of accurate pipe blockage detection devices and efficient rapid anti-blockage solutions. At the same time, the silo pump does not have a targeted anti-blockage structure, making it easy for materials to bridge and block, affecting the continuity of conveying.

[0006] 3. Poor adaptability of the control system (inaccurate control problem: the existing control system has weak linkage, the switching between manual and automatic control modes is not smooth, and there is a lack of a complete fault alarm and interlock protection mechanism, which cannot meet the needs of continuous and stable operation of smart factories.

[0007] 4. Design flaws in the silo system (poor environmental performance and structural safety issues: the inner wall of the existing end silo is not treated with anti-adhesion, resulting in poor material discharge; the dust collection device on the top of the silo is inefficient and easily generates dust pollution; at the same time, the structural strength of the silo does not fully consider extreme working conditions (such as full load, wind and snow, earthquakes, etc., resulting in insufficient stability).

[0008] 5. Insufficient wear resistance of conveying components: Most elbows in existing conveying pipes are made of ordinary stainless steel with a small radius of curvature. They suffer severe wear during the conveying of powdery materials, which shortens the service life of the pipes and increases maintenance costs.

[0009] Therefore, to address the above problems, a pneumatic conveying system and control method for powdery materials are provided. Summary of the Invention

[0010] To address the aforementioned problems in the existing technology, this invention provides a pneumatic conveying system and control method for powdered materials, which solves the problems of air source interference, pipeline blockage and material bridging, inaccurate control, poor environmental performance, and insufficient structural safety and component wear resistance.

[0011] The technical solution to achieve the above objectives is:

[0012] One embodiment of the present invention is a pneumatic conveying system for powdered materials, comprising:

[0013] The conveying unit is used to pressurize and convey powder to the pipeline network, enabling parallel conveying by multiple pumps.

[0014] The gas supply unit is used to provide dual independent gas sources;

[0015] The hopper unit is used to receive and store conveyed powder materials;

[0016] The control unit is used to centrally monitor pipeline pressure, valve status, and material level, and to trigger audible and visual alarms.

[0017] The unblocking unit is used to automatically remove blockages from pipes and pumps;

[0018] Electrical distribution unit, used to provide 380VAC power and control power to each unit;

[0019] in,

[0020] The delivery unit is connected to the gas source unit via a gas pipeline;

[0021] The conveying unit is connected to the silo unit via a conveying pipeline;

[0022] The control unit is connected to the sensors, actuators and power distribution units of each unit via cables;

[0023] The air inlet of the unblocking unit is connected to the air source unit through a pipeline, and the electrical signal is connected to the control unit.

[0024] Preferably, the conveying unit includes: a 304 stainless steel dense-phase positive pressure chamber pump.

[0025] Multiple 304 stainless steel dense phase positive pressure chamber pumps in each phase are connected in parallel to the same conveying pipeline through a switching valve group, and the end of the conveying pipeline is connected to the silo unit.

[0026] The 304 stainless steel dense phase positive pressure chamber pump is equipped with an electrically controlled feed valve at the top, which is connected to the outlet of the front finished product silo via a flexible connection. It is also equipped with an electrically controlled discharge valve and an exhaust valve at the bottom, which are connected to the conveying pipeline.

[0027] The top pressurization port and bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump are both connected to the air source unit through pipelines.

[0028] A Toledo three-point weighing sensor is fixedly installed at the bottom support of the 304 stainless steel dense phase positive pressure chamber pump.

[0029] in,

[0030] The conveying pipeline is composed of seamless 304 stainless steel conveying pipes, wear-resistant elbows, and wear-resistant tees forming a pipeline network.

[0031] Preferably, the gas source unit includes: a gas supply branch pipeline for conveying gas and a gas supply branch for instrumentation, wherein the gas supply branch pipeline for conveying gas and the gas supply branch for instrumentation are a dual-line independent gas supply system;

[0032] The gas supply branch pipeline and the instrument gas supply branch pipeline are all connected in series with a 304 stainless steel gas storage tank, a pressure gauge, a safety valve and an automatic drainer.

[0033] The gas supply branch pipeline is connected to the top pressurization port, bottom air inlet and the unblocking unit of the 304 stainless steel dense phase positive pressure chamber pump via the 304 stainless steel gas storage tank, pressure gauge and safety valve.

[0034] The instrument air source branch is connected to all pneumatic valves and the control unit via the 304 stainless steel air tank, pressure gauge, and safety valve.

[0035] The automatic drainer is connected to a drain pipe at its bottom.

[0036] Preferably, the hopper unit includes: a 304 stainless steel end-point hopper.

[0037] The top inlet of the 304 stainless steel end-point silo is connected to the end of the conveying pipeline via a pipe.

[0038] The top of the 304 stainless steel terminal silo is fixedly equipped with a silo top dust collector, a safety valve, and a manhole door.

[0039] The bottom outlet of the 304 stainless steel end-point silo is connected to an inertial vibrating hopper.

[0040] A pneumatic hammer flow aid device is fixedly installed on the outer side of the cone of the 304 stainless steel end-point silo, and the inner wall of the cone is treated with 8K mirror finish.

[0041] A Toledo weighing sensor is fixedly installed at the bottom support leg of the 304 stainless steel end-point hopper.

[0042] The upper and lower parts of the inner wall of the 304 stainless steel end-point hopper are fixedly installed with material level switches, and all material level switches are connected to the control unit.

[0043] Preferably, the control unit includes: a PLC control cabinet, a 10-inch LCD touch screen, and a pressure transmitter, pressure switch, valve position switch, and audible and visual alarm controlled and triggered by a control system based on a Siemens S7-1200 PLC.

[0044] The PLC control cabinet is centrally installed in the central control room and is connected to each local control box via cable.

[0045] The local control box is installed next to each silo pump and is connected to the valves, weighing sensors and unblocking unit of the 304 stainless steel dense phase positive pressure silo pump via cables.

[0046] The 10-inch LCD touch screen is installed on the PLC control cabinet and is used for human-machine interaction.

[0047] The pressure transmitter and pressure switch are fixedly installed on the conveying pipeline and the gas source branch pipeline.

[0048] Each of the pneumatic valves is fixedly installed with a valve position switch at the valve stem.

[0049] The audible and visual alarm is fixedly installed on the central control room and the local control box.

[0050] Preferably, the unblocking unit includes: an unblocking auxiliary blowing device and a chamber pump pneumatic knocking device for breaking the blockage.

[0051] The blockage-clearing and blowing device is fixedly installed on the conveying pipeline, connected to the conveying gas source branch pipeline through the pipeline, and connected to the local control box through the control cable.

[0052] The pneumatic knocking and unblocking device for the silo pump is fixedly installed on the inner wall of the 304 stainless steel dense phase positive pressure silo pump. The air inlet is connected to the gas supply branch pipeline and connected to the local control box via a control cable.

[0053] Preferably, the electrical distribution unit includes: a 304 stainless steel main distribution cabinet, a hot-dip galvanized steel cable tray, and a motor.

[0054] The 304 stainless steel main distribution cabinet adopts a 380VAC three-phase four-wire power supply system, and supplies power to each unit equipment through the power cables and control cables in the hot-dip galvanized steel cable tray, and is connected to the power equipment of each unit through the motor.

[0055] A control method for a pneumatic conveying system for powdered materials according to the second aspect of the present invention includes:

[0056] System initialization:

[0057] Step S1: Start the PLC control cabinet and local control box. The system self-checks the status of each device, air source pressure, and instrument signals. Start the dust collector on the top of the silo. After it runs stably, it enters the standby state.

[0058] Feeding stage:

[0059] Step S2: The control unit selects the control mode. In automatic mode, the PLC issues a command to open the electrically controlled feed valve, and the powdered material enters the 304 stainless steel dense phase positive pressure chamber pump from the finished product silo.

[0060] Step S3: The feed rate is monitored in real time by the Toledo three-point weighing sensor at the bottom. When the set value is reached, the PLC sends a command to close the electronically controlled feed valve to complete the feeding process.

[0061] Fluidization pressurization stage:

[0062] Step S4: The PLC controls the opening of the top pressurization port and bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump. Compressed air from the conveying air source branch pipeline enters the pump body. The top pressurization creates a positive pressure environment inside the pump, and the bottom air inlet fluidizes the powdered material.

[0063] Step S5: Monitor the pressure inside the pump using the pressure transmitter. When the set delivery pressure is reached, enter the delivery preparation state.

[0064] Precision delivery stage:

[0065] Step S6: The PLC controls the switching valve group to operate according to the preset target silo, connecting the 304 stainless steel dense phase positive pressure chamber pump with the conveying pipeline of the target silo.

[0066] Step S7: Then, the electrically controlled discharge valve at the bottom is opened, and the fluidized powdered material is transported to the terminal silo through the conveying pipe and wear-resistant elbow under the push of compressed air.

[0067] Step S8: During the conveying process, the pressure transmitter monitors the pipeline pressure in real time, and the Toledo load cell monitors the conveying volume in real time.

[0068] Congestion relief and support phase:

[0069] Step S9: During the conveying process, the unblocking unit monitors the pipeline pressure and the material status inside the 304 stainless steel dense phase positive pressure chamber pump in real time.

[0070] Step S10: If the pipeline pressure exceeds the set threshold, it is determined to be a pipe blockage. Immediately close the electrically controlled discharge valve, start the anti-blockage blowing device at the corresponding position to perform high-pressure blowing to remove the blockage, and close the anti-blockage blowing device after the pressure returns to normal. Then reopen the electrically controlled discharge valve to continue conveying.

[0071] Step S11: If material bridging is detected in the 304 stainless steel dense phase positive pressure silo pump, start the pneumatic knocking and unblocking device of the silo pump, and continue feeding after the unblocking is completed;

[0072] Unloading and cleaning phase:

[0073] Step S12: When the weighing display of the 304 stainless steel dense phase positive pressure chamber pump shows that the remaining material amount is zero, it indicates that the conveying is completed. Continue to introduce compressed air for 60 seconds to clean the conveying pipeline.

[0074] Step S13: After cleaning is completed, close the pressurization port, air inlet and electrically controlled discharge valve, and open the exhaust valve to release the residual pressure in the pump body;

[0075] Cycle or stop:

[0076] Step S14: If continuous conveying is required, return to the feeding stage to repeat the process. If a stop command is received or an interlock protection condition is triggered, the system will immediately stop all equipment operation, issue an audible and visual alarm, and wait for fault handling.

[0077] Compared with the prior art, the beneficial effects of the present invention are:

[0078] 1. This invention adopts an independent design for the delivery air source and the instrument air source branch. The two branches are controlled by independent pipelines, air tanks and valves, which avoids the influence of the single air source on the instrument air source due to the fluctuation of the delivery pressure. It ensures the stability of the air source pressure required by the pneumatic valve, thereby avoiding the difficulty or damage of valve opening and closing, improving system stability and solving the defects of air source interference.

[0079] 2. This invention addresses the strong adhesion of powdered materials by integrating a pneumatic knocking and unblocking device within the silo pump to disrupt the material bridging structure through mechanical vibration. Furthermore, it evenly distributes intelligent unblocking and blowing devices along the conveying pipeline, using pressure sensors to monitor pipeline pressure in real time. When a blockage occurs, high-pressure blowing is quickly activated to remove the adhered material from the pipe using airflow impact force. Simultaneously, the conveying pipeline employs wear-resistant elbows with a large radius of curvature and is lined with ceramic to reduce material flow resistance and the probability of blockage, thus resolving the defects of blockage and bridging.

[0080] 3. This invention: It adopts Siemens S7-1200 PLC as the core, and designs three control modes: automatic, remote and local. The linkage of each unit is realized through bus. It is equipped with complete detection instruments (pressure, weighing, material level, position switch) to collect operating parameters in real time and connect to the central control platform. It sets up a multi-level interlock protection mechanism. When abnormal operating conditions occur, it automatically stops and alarms to ensure that the system meets the requirements of continuous operation of smart factories ≥8000 hours, and solves the defect of inaccurate control.

[0081] 4. The cone section of the final hopper in this invention is treated with an 8K mirror finish to reduce the adhesion of powdery materials. Combined with an inertial vibrating hopper and air hammer to aid flow, it ensures smooth material discharge. The dust collector on the hopper top uses flame-retardant and anti-static membrane filter media, with a processing air volume ≥6000m³. 3 / h, dust removal efficiency ≥99.9%, emission concentration ≤10mg / Nm 3 To achieve zero dust pollution, the design of the terminal silo fully considers extreme working conditions such as full material, wind and snow, and a magnitude 7 earthquake. The cylinder wall and cone hopper are made of thickened stainless steel plates to improve structural stability and solve the defects of poor environmental performance and structural safety.

[0082] 5. The conveying pipeline of this invention adopts 304 stainless steel seamless steel pipe (wall thickness ≥ 6mm). The elbow adopts a large curvature radius design and is lined with integral ceramic. The ceramic material has high hardness and strong wear resistance, which can significantly reduce the wear of powdery materials on the pipeline, extend the service life, and solve the defect of insufficient wear resistance of components. Attached Figure Description

[0083] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0084] Figure 1 This is a block diagram of a pneumatic conveying system for powdered materials according to the present invention;

[0085] Figure 2 This is a schematic diagram of some equipment and connection relationships of a pneumatic conveying system for powdered materials according to the present invention;

[0086] Figure 3 This is a flowchart of the system initialization and feeding stages in the control method of a pneumatic conveying system for powdered materials according to the present invention;

[0087] Figure 4 This is a flowchart of the fluidization pressurization stage and the precision conveying stage in the control method of a pneumatic conveying system for powdered materials according to the present invention;

[0088] Figure 5 This is a flowchart of the blockage prevention stage, unloading and cleaning stage, and cycle or shutdown in the control method of a pneumatic conveying system for powdered materials according to the present invention. Detailed Implementation

[0089] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0090] like Figure 1 As shown, a pneumatic conveying system for powdered materials includes: a conveying unit 1 for pressurizing and conveying powder to a pipeline network to achieve parallel conveying by multiple pumps; an air source unit 2 for providing dual independent air sources; a silo unit 3 for receiving and storing the conveyed powder; a control unit 4 for centrally monitoring pipeline pressure, valve status, and material level, and triggering audible and visual alarms; a blockage removal unit 5 for automatically clearing blockages in pipelines and pumps; and an electrical distribution unit 6 for providing 380VAC power and control power to each unit. The conveying unit 1 is connected to the air source unit 2 via an air pipeline; the conveying unit 1 is connected to the silo unit 3 via a conveying pipeline; the control unit 4 is connected to the sensors, actuators, and electrical distribution unit 6 of each unit via cables; the air inlet of the blockage removal unit 5 is connected to the air source unit 2 via a pipeline, and the electrical signal is connected to the control unit 4.

[0091] like Figure 1 , 2 As shown, the conveying unit includes: a 304 stainless steel dense-phase positive pressure chamber pump 101.

[0092] Multiple 304 stainless steel dense phase positive pressure chamber pumps 101 in each phase are connected in parallel to the same conveying pipeline 102 via switching valve groups. The end of the conveying pipeline 102 is connected to the silo unit. The top of the 304 stainless steel dense phase positive pressure chamber pump 101 is equipped with an electrically controlled feed valve, which is connected to the outlet of the front-end finished product silo via a flexible connection. The bottom is equipped with an electrically controlled discharge valve and an exhaust valve, which are connected to the conveying pipeline 102. The top pressurization port and the bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump 101 are both connected to the air source unit via pipelines. A Toledo three-point weighing sensor is fixedly installed at the bottom support of the 304 stainless steel dense phase positive pressure chamber pump 101.

[0093] in,

[0094] The conveying pipeline 102 is composed of seamless 304 stainless steel conveying pipes, wear-resistant elbows and wear-resistant tees forming a pipeline network.

[0095] like Figure 1 , 2 As shown, the gas source unit includes: a gas supply branch pipeline 201 for conveying gas and a gas supply branch pipeline 202 for instrumentation. The gas supply branch pipeline 201 and the gas supply branch pipeline 202 are dual independent gas supply systems. A 304 stainless steel gas storage tank, a pressure gauge, a safety valve, and an automatic drainer are connected in series on both the gas supply branch pipeline 201 and the gas supply branch pipeline 202. The gas supply branch pipeline 201 is connected to the top pressurization port, bottom air inlet, and unblocking unit of the 304 stainless steel dense phase positive pressure chamber pump 101 via the 304 stainless steel gas storage tank, pressure gauge, and safety valve. The gas supply branch pipeline 202 is connected to all pneumatic valves and control units via the 304 stainless steel gas storage tank, pressure gauge, and safety valve. The bottom of the automatic drainer is connected to a drain pipe.

[0096] like Figure 1 , 2 As shown, the silo unit includes: a 304 stainless steel end-point silo 301; the top inlet of the 304 stainless steel end-point silo 301 is connected to the end of the conveying pipe 102 via a pipe; a dust collector, a safety valve, and a manhole are fixedly installed on the top of the 304 stainless steel end-point silo 301; an inertial vibrating hopper is connected to the bottom outlet of the 304 stainless steel end-point silo 301; an air hammer flow aid device is fixedly installed on the outer side of the cone of the 304 stainless steel end-point silo 301; a Toledo load cell is fixedly installed at the bottom support leg of the 304 stainless steel end-point silo 301; and level switches are fixedly installed on the upper and lower parts of the inner wall of the 304 stainless steel end-point silo 301, all of which are connected to the control unit.

[0097] like Figure 1 , 2 As shown, the control unit includes: a PLC control cabinet, a 10-inch LCD touch screen, and a control system based on a Siemens S7-1200 PLC. It supports automatic, remote, and local control of pressure transmitters, pressure switches, valve position switches, and audible and visual alarms. The PLC control cabinet is centrally installed in the control room and communicates with each local control box via cables. Each local control box is installed next to a chamber pump and is connected via cables to the valves, weighing sensors, and unblocking unit of the 304 stainless steel dense-phase positive pressure chamber pump 101. The 10-inch LCD touch screen is mounted on the PLC control cabinet for human-machine interaction. Pressure transmitters and pressure switches are fixedly installed on the delivery pipeline 102 and the gas supply branch pipeline 201. Valve position switches are fixedly installed on the stems of each pneumatic valve. Audible and visual alarms are fixedly installed in the control room and on the local control boxes.

[0098] like Figure 1 , 2 As shown, the unblocking unit includes an unblocking auxiliary blowing device and a chamber pump pneumatic knocking unblocking device. The unblocking auxiliary blowing device is fixedly installed on the conveying pipeline 102, connected to the conveying air source branch pipeline 201 through the pipeline, and connected to the local control box through the control cable. The chamber pump pneumatic knocking unblocking device is fixedly installed on the inner wall of the 304 stainless steel dense phase positive pressure chamber pump 101, the air inlet is connected to the conveying air source branch pipeline 201, and connected to the local control box through the control cable.

[0099] like Figure 1 , 2 As shown, the electrical distribution unit includes: a 304 stainless steel main distribution cabinet, a hot-dip galvanized steel cable tray, and a motor. The 304 stainless steel main distribution cabinet is powered by a 380VAC three-phase four-wire system. It supplies power to each unit's equipment through the power cables and control cables in the hot-dip galvanized steel cable tray, and is connected to the power equipment of each unit through the motor.

[0100] like Figure 1-5As shown, a control method for a pneumatic conveying system for powdery materials includes:

[0101] System initialization: (Auxiliary equipment: PLC control cabinet, local control box, pressure transmitter, silo top dust collector)

[0102] Step S1: Start the PLC control cabinet and local control box. The system self-checks the status of each device, air source pressure, and instrument signals. Start the dust collector on the top of the silo and enter standby mode after it runs stably.

[0103] Feeding stage: (Auxiliary equipment: electrically controlled feed valve, Toledo three-point weighing sensor, local control box)

[0104] Step S2: Control unit 4 selects control mode. In automatic mode, PLC Siemens S7-1200 PLC issues a command to open the electrically controlled feed valve, and the powdered material enters the 304 stainless steel dense phase positive pressure chamber pump 101 from the finished product silo.

[0105] Step S3: The feed rate is monitored in real time by the bottom Toledo three-point weighing sensor. When the set value is reached, the PLC sends a command to close the electronically controlled feed valve to complete the feeding process.

[0106] Fluidization pressurization stage: (Auxiliary equipment: pressurization port valve, air inlet valve, pressure transmitter)

[0107] Step S4: The PLC controls the opening of the top pressurization port and bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump 101, and the compressed air from the air source branch pipeline 201 enters the pump body. The top pressurization creates a positive pressure environment inside the pump, and the bottom air inlet makes the powdery material fluidized.

[0108] Step S5: Monitor the pressure inside the pump using a pressure transmitter. When the set delivery pressure is reached, enter the delivery preparation state.

[0109] Precision conveying stage: (Auxiliary equipment: electrically controlled discharge valve, switching valve group, pressure transmitter, Toledo load cell)

[0110] Step S6: The PLC controls the switching valve group to connect the conveying pipeline of the 304 stainless steel dense phase positive pressure chamber pump 101 to the target silo according to the preset target silo.

[0111] Step S7: Then, the bottom electrically controlled discharge valve is opened, and the fluidized powdered material is conveyed to the terminal silo through the conveying pipe and wear-resistant elbow under the push of compressed air.

[0112] Step S8: During the conveying process, the pressure transmitter monitors the pipeline pressure in real time, and the Toledo load cell monitors the conveying volume in real time.

[0113] Blockage Clearing and Support Phase: (Auxiliary Equipment: Blockage Clearing and Blowing Device, Silo Pump Pneumatic Knocking and Blockage Breaking Device, Pressure Switch)

[0114] Step S9: During the conveying process, the unblocking unit 5 monitors the pipeline pressure and the material status inside the 304 stainless steel dense phase positive pressure chamber pump 101 in real time.

[0115] Step S10: If the pipeline pressure exceeds the set threshold, it is determined to be a pipe blockage. Immediately close the electrically controlled discharge valve, start the corresponding anti-blockage blowing device to perform high-pressure blowing to remove the blockage, and close the anti-blockage blowing device after the pressure returns to normal. Then reopen the electrically controlled discharge valve to continue conveying.

[0116] Step S11: If material bridging is detected in the 304 stainless steel dense phase positive pressure silo pump 101, start the pneumatic knocking and unblocking device of the silo pump, and continue feeding after the unblocking is completed.

[0117] Unloading and cleaning stage: (Auxiliary equipment: exhaust valve, compressed air valve)

[0118] Step S12: When the weighing display of the 304 stainless steel dense phase positive pressure chamber pump 101 shows that the remaining material quantity is zero, it indicates that the conveying is completed. Continue to introduce compressed air for 60 seconds to clean the conveying pipeline 102.

[0119] Step S13: After cleaning is completed, close the pressurization port, air inlet and electrically controlled discharge valve, and open the exhaust valve to release the residual pressure in the pump body;

[0120] Cyclic or shutdown: (Auxiliary equipment: audible and visual alarm, PLC control cabinet)

[0121] Step S14: If continuous conveying is required, return to the feeding stage to repeat the process. If a stop command is received or an interlock protection condition is triggered, the system will immediately stop all equipment operation, issue an audible and visual alarm, and wait for fault handling.

[0122] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pneumatic conveying system for powdered materials, characterized in that, include: The conveying unit is used to pressurize and convey powder to the pipeline network, enabling parallel conveying by multiple pumps. The gas supply unit is used to provide dual independent gas sources; The hopper unit is used to receive and store conveyed powder materials; The control unit is used to centrally monitor pipeline pressure, valve status, and material level, and to trigger audible and visual alarms. The unblocking unit is used to automatically remove blockages from pipes and pumps; Electrical distribution unit, used to provide 380VAC power and control power to each unit; in, The delivery unit is connected to the gas source unit via a gas pipeline; The conveying unit is connected to the silo unit via a conveying pipeline; The control unit is connected to the sensors, actuators and power distribution units of each unit via cables; The air inlet of the unblocking unit is connected to the air source unit through a pipeline, and the electrical signal is connected to the control unit.

2. The pneumatic conveying system for powdered materials according to claim 1, characterized in that, The conveying unit includes: a 304 stainless steel dense phase positive pressure chamber pump (101). Multiple 304 stainless steel dense phase positive pressure chamber pumps (101) in each phase are connected in parallel to the same conveying pipeline (102) through a switching valve group, and the end of the conveying pipeline (102) is connected to the silo unit. The 304 stainless steel dense phase positive pressure chamber pump (101) is equipped with an electrically controlled feed valve at the top, which is connected to the outlet of the front-end finished product silo via a flexible connection. It is also equipped with an electrically controlled discharge valve and an exhaust valve at the bottom, which are connected to the conveying pipeline (102). The top pressurization port and bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump (101) are both connected to the air source unit through pipelines. A Toledo three-point weighing sensor is fixedly installed at the bottom bracket of the 304 stainless steel dense phase positive pressure chamber pump (101). in, The conveying pipeline (102) is composed of seamless 304 stainless steel conveying pipes, wear-resistant elbows and wear-resistant tees forming a pipeline network.

3. The pneumatic conveying system for powdered materials according to claim 2, characterized in that, The gas source unit includes: a gas supply branch pipeline (201) and an instrument gas supply branch pipeline (202), wherein the gas supply branch pipeline (201) and the instrument gas supply branch pipeline (202) are dual independent gas supply systems; The gas supply branch pipeline (201) and the instrument gas supply branch pipeline (202) are connected in series with a 304 stainless steel gas storage tank, a pressure gauge, a safety valve and an automatic drain. The gas supply branch pipeline (201) is connected to the top pressurization port, bottom air inlet and the unblocking unit of the 304 stainless steel dense phase positive pressure chamber pump (101) via the 304 stainless steel gas storage tank, pressure gauge and safety valve. The instrument air supply branch (202) is connected to all pneumatic valves and the control unit via the 304 stainless steel air tank, pressure gauge, and safety valve. The automatic drainer is connected to a drain pipe at its bottom.

4. The pneumatic conveying system for powdered materials according to claim 3, characterized in that, The silo unit includes: a 304 stainless steel end-point silo (301). The top inlet of the 304 stainless steel end-point hopper (301) is connected to the end of the conveying pipe (102) via a pipe; The top of the 304 stainless steel terminal silo (301) is fixedly equipped with a silo top dust collector, a safety valve and a manhole door; The bottom outlet of the 304 stainless steel end-point hopper (301) is connected to an inertial vibrating hopper; The 304 stainless steel end-point hopper (301) is fixedly installed with an air hammer flow aid device on the outer side of the cone, and the inner wall of the cone is treated with 8K mirror finish. A Toledo weighing sensor is fixedly installed at the bottom support leg of the 304 stainless steel end-point hopper (301); The upper and lower parts of the inner wall of the 304 stainless steel end-point hopper (301) are fixedly installed with level switches, and the level switches are all connected to the control unit.

5. The pneumatic conveying system for powdered materials according to claim 4, characterized in that, The control unit includes: a PLC control cabinet, a 10-inch LCD touch screen, and a pressure transmitter, pressure switch, valve position switch, and audible and visual alarm controlled and triggered by a control system based on a Siemens S7-1200 PLC. The PLC control cabinet is centrally installed in the central control room and is connected to each local control box via cable. The local control box is installed next to each silo pump and is connected to the valves, weighing sensors and unblocking unit of the 304 stainless steel dense phase positive pressure silo pump (101) via cables. The 10-inch LCD touch screen is installed on the PLC control cabinet and is used for human-machine interaction. The pressure transmitter and pressure switch are fixedly installed on both the conveying pipeline (102) and the gas source branch pipeline (201); Each of the pneumatic valves is fixedly installed with a valve position switch at the valve stem. The audible and visual alarm is fixedly installed on the central control room and the local control box.

6. The pneumatic conveying system for powdered materials according to claim 5, characterized in that, The unblocking unit includes: an unblocking auxiliary blowing device and a chamber pump pneumatic knocking device for breaking up the blockage. The blockage-expelling and blowing device is fixedly installed on the conveying pipeline (102), connected to the conveying gas source branch pipeline (201) through the pipeline, and connected to the local control box through the control cable; The pneumatic knocking and unblocking device for the silo pump is fixedly installed on the inner wall of the 304 stainless steel dense phase positive pressure silo pump (101), and the air inlet is connected to the gas supply branch pipeline (201), and connected to the local control box through the control cable.

7. A pneumatic conveying system for powdered materials according to claim 6, characterized in that, The electrical distribution unit includes: a 304 stainless steel main distribution cabinet, a hot-dip galvanized steel cable tray, and a motor. The 304 stainless steel main distribution cabinet adopts a 380VAC three-phase four-wire power supply system, and supplies power to each unit equipment through the power cables and control cables in the hot-dip galvanized steel cable tray, and is connected to the power equipment of each unit through the motor.

8. A control method for a pneumatic conveying system for powdered materials based on claims 1-7, characterized in that, include: System initialization: Step S1: Start the PLC control cabinet and local control box. The system self-checks the status of each device, air source pressure, and instrument signals. Start the dust collector on the top of the silo. After it runs stably, it enters the standby state. Feeding stage: In step S2, the control unit selects the control mode. In automatic mode, the PLC issues a command to open the electrically controlled feed valve, and the powdered material enters the 304 stainless steel dense phase positive pressure chamber pump (101) from the finished product silo. Step S3: The feed rate is monitored in real time by the Toledo three-point weighing sensor at the bottom. When the set value is reached, the PLC sends a command to close the electronically controlled feed valve to complete the feeding process. Fluidization pressurization stage: Step S4: The PLC controls the opening of the top pressurization port and bottom air inlet of the 304 stainless steel dense phase positive pressure chamber pump (101). Compressed air from the conveying air source branch pipeline (201) enters the pump body. The top pressurization creates a positive pressure environment inside the pump, and the bottom air inlet makes the powdered material fluidized. Step S5: Monitor the pressure inside the pump using the pressure transmitter. When the set delivery pressure is reached, enter the delivery preparation state. Precision delivery stage: Step S6: The PLC controls the switching valve group to operate according to the preset target silo, connecting the 304 stainless steel dense phase positive pressure chamber pump (101) with the conveying pipeline of the target silo. Step S7: Then, the electrically controlled discharge valve at the bottom is opened, and the fluidized powdered material is transported to the terminal silo through the conveying pipe (102) and wear-resistant elbow under the push of compressed air. Step S8: During the conveying process, the pressure transmitter monitors the pipeline pressure in real time, and the Toledo load cell monitors the conveying volume in real time. Congestion relief and support phase: Step S9: During the conveying process, the unblocking unit monitors the pipeline pressure and the material status inside the 304 stainless steel dense phase positive pressure chamber pump (101) in real time. Step S10: If the pipeline pressure exceeds the set threshold, it is determined to be a pipe blockage. Immediately close the electrically controlled discharge valve, start the anti-blockage blowing device at the corresponding position to perform high-pressure blowing to remove the blockage, and close the anti-blockage blowing device after the pressure returns to normal. Then reopen the electrically controlled discharge valve to continue conveying. Step S11: If material bridging is detected in the 304 stainless steel dense phase positive pressure silo pump (101), start the pneumatic knocking and unblocking device of the silo pump, and continue feeding after the unblocking is completed; Unloading and cleaning phase: Step S12: When the weighing display of the 304 stainless steel dense phase positive pressure chamber pump (101) shows that the remaining material quantity is zero, it indicates that the conveying is completed. Continue to introduce compressed air for 60 seconds to clean the conveying pipeline (102). Step S13: After cleaning is completed, close the pressurization port, air inlet and electrically controlled discharge valve, and open the exhaust valve to release the residual pressure in the pump body; Cycle or stop: Step S14: If continuous conveying is required, return to the feeding stage to repeat the process. If a stop command is received or an interlock protection condition is triggered, the system will immediately stop all equipment operation, issue an audible and visual alarm, and wait for fault handling.

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