Multistage winnowing system for wood chip impurity removal

Abstract

A multi-stage winnowing system for wood chip impurity removal relates to the technical field of impurity removal equipment and comprises a multi-stage screening device, a multi-stage winnowing device, a first cyclone separator and a second cyclone separator. The multi-stage screening device classifies the initial materials according to the size, and a foundation is laid for subsequent screening; the multi-stage winnowing device separates large-size materials and heavy impurities through airflow, and the purity of the materials is improved. The first cyclone separator is used for separating target materials from dust by utilizing centrifugal force, and the second cyclone separator is used for further treating the dust to prevent environmental pollution; a buffer storage device is further arranged in the multi-stage winnowing system, the material supply rhythm can be adjusted, blockage is prevented, and the number of multi-stage winnowing devices is reduced; the air volume adjusting device adjusts the air inlet volume according to the material size, and system adaptability and energy saving performance are improved. The device is reasonable in design, impurities in wood chips can be effectively removed, the material purity is improved, and the large-scale material treatment requirement is met; and the discharged gas is cleaner through the electrostatic dust collection device.

Description

Technical Field

[0001] The present invention relates to the technical field of impurity removal equipment, and in particular to a multi-stage air separation system for wood chip impurity removal. Background Art

[0002] In the processing of fiberboard, after the wood is chipped by a chipper, it is necessary to pass through air separation to separate large wood chips, and remove impurities such as small stones, iron blocks, and sand and gravel, and then transport the qualified wood chips to a hot grinder for cooking and softening and then separate the fibers. In the field of material processing, air separation is a common purification method for separating impurities and target materials in mixed materials. Traditional air separation systems usually include a screening device and a multi-stage air separation device. The screening device conducts preliminary classification according to the size of the materials, and the multi-stage air separation device uses air flow to separate materials with different densities or suspension velocities. However, there are some deficiencies in the traditional system: it is difficult for the multi-stage air separation device to effectively separate the target material from the dust with a smaller specific gravity, resulting in limited improvement in material purity, and the direct discharge of dust will pollute the environment. In addition, when the mixed material contains various components such as wood chips, sand, stones, and iron filings, the density and particle size of these materials vary greatly, and it is difficult for traditional air separation technology to precisely control the separation process, resulting in poor separation effect, and the materials are prone to accumulate in groups, thereby affecting the air separation efficiency and quality. The above defects are problems that need to be solved urgently by those skilled in the art. Summary of the Invention

[0003] In order to overcome the deficiencies in the background art, the present invention discloses a multi-stage air separation system for wood chip impurity removal; aiming to achieve an efficient and environmentally friendly material screening and purification process through the organic combination and reasonable layout of components such as a multi-stage screening device, a multi-stage air separation device, a first cyclone separator, a second cyclone separator, and related blowers, and can meet the material separation requirements under various complex working conditions.

[0004] To achieve the above invention purpose, the present invention adopts the following technical solutions:

[0005] A multi-stage air separation system for wood chip impurity removal, comprising:

[0006] A multi-stage screening device for classifying the mixed material according to the size;

[0007] A multi-stage air separation device, whose multiple feed ports are respectively in one-to-one correspondence and communication with the multiple discharge ports of the multi-stage screening device, for removing impurities after dispersing the mixed material;

[0008] A first cyclone separator, whose feed port is in corresponding communication with the material outlet of the multi-stage air separation device;

[0009] The first fan has its intake air path and outlet air path both divided into two paths. One path of the intake air path is correspondingly connected to the outlet of the first cyclone separator, and the other path is connected to the external environment. One path of the outlet air path of the first fan is correspondingly connected to the multi-stage air separation device to provide air separation airflow for the multi-stage air separation device.

[0010] The second fan has its intake air path correspondingly connected to the other path of the outlet air path of the first fan.

[0011] The second cyclone separator has its feed inlet correspondingly connected to the outlet air path of the second fan and is used to separate dust from air.

[0012] Preferably, the multi-stage air separation device includes:

[0013] Multiple air separation boxes, the intake port of each air separation box is correspondingly connected to the outlet air path of the first fan, and the material outlet of each air separation box is correspondingly connected to the feed inlet of the first cyclone separator;

[0014] Multiple first airtight flow devices are respectively installed at the material inlets of the multiple air separation boxes;

[0015] Multiple feeding devices, the feed inlets of the multiple feeding devices are respectively correspondingly connected to the discharge port of one stage of the multi-stage screening device, and the discharge outlets of the multiple feeding devices are respectively correspondingly connected to a first airtight flow device;

[0016] Multiple second airtight flow devices are respectively installed at the impurity outlets of the multiple air separation boxes.

[0017] Preferably, the air separation box includes:

[0018] A box body;

[0019] A material channel is arranged at the top on one side of the box body;

[0020] A buffer groove is arranged inside the box body and is located below the material channel;

[0021] A hollow stirring shaft is located in the buffer groove and is correspondingly rotatably connected to the side wall of the box body. A motor for driving the hollow stirring shaft is installed on one side of the box body. Multiple stirring blades are arranged at intervals on the shaft body of the hollow stirring shaft;

[0022] A jet nozzle is correspondingly connected to the cavity of the shaft body of the hollow stirring shaft, and a jet nozzle is installed between adjacent two stirring blades;

[0023] An arc-shaped baffle is arranged on one side of the buffer groove and is correspondingly fixedly connected to the side wall of the box body;

[0024] A guide plate is arranged below the buffer groove, and there is a material dropping opening between the guide plate and the arc-shaped baffle;

[0025] The air separation channel is located below the arc-shaped baffle, and its feed inlet is correspondingly connected to the blanking port;

[0026] The air inlet channel is located on one side of the feed inlet of the air separation channel;

[0027] The impurity channel is located at the bottom of the air separation channel;

[0028] The material channel is located on one side of the air separation channel.

[0029] Preferably, a plurality of slots are provided on one side of the buffer groove corresponding to the arc-shaped baffle.

[0030] Preferably, a buffer storage device is provided at the discharge port of each stage of the multi-stage screening device.

[0031] Preferably, both the first airtight flow device and the second airtight flow device are rotary valves.

[0032] Preferably, the feeding device is a screw feeder.

[0033] Preferably, an air volume regulating device is installed on the air outlet gas path where the first fan is correspondingly connected to the multi-stage air separation device.

[0034] Preferably, a conveyor belt is provided at the feed inlet of the multi-stage screening device; the multi-stage screening device is a swing sieve.

[0035] Preferably, an electrostatic dust removal device is further included at the air outlet of the second cyclone separator; the electrostatic dust removal device includes:

[0036] A rotating dust collection barrel, which is correspondingly rotatably connected to the air outlet of the second cyclone separator;

[0037] Hexagonal ventilation holes, a plurality of hexagonal ventilation holes are arranged in an array on the barrel body of the rotating dust collection barrel, so that the barrel body of the rotating dust collection barrel has a honeycomb-shaped structure, and the hexagonal ventilation holes are inclined downward;

[0038] A discharge grid electrode, which is arranged inside the rotating dust collection barrel and is insulatedly connected to the top of the rotating dust collection barrel; the discharge grid electrode includes a plurality of grid bars arranged at intervals along the circumferential direction, and a plurality of discharge needles are arranged at intervals on the rod body of the grid bar from top to bottom;

[0039] A rotating shaft, the top of which is correspondingly coaxially and firmly connected to the rotating dust collection barrel, and the bottom extends into the air outlet of the second cyclone separator; the shaft body of the rotating shaft inside the rotating dust collection barrel has a conical structure with the tip facing downwards, and an arc-shaped baffle is provided at the top of the conical structure;

[0040] An impeller, which is installed at the bottom of the rotating shaft and is driven to rotate by the upward airflow inside the air outlet of the second cyclone separator;

[0041] A dust collection cover, which covers the outside of the rotating dust collection barrel and is detachably connected to the air outlet of the second cyclone separator.

[0042] Due to the technical solution described above, the present invention has the following beneficial effects:

[0043] (1) The structure of the present invention is simple. The multi-stage screening device accurately screens the materials, making the sizes of the mixed materials discharged from each discharge port uniform, laying a foundation for subsequent air separation. The multi-stage air separation device uses a specific airflow to separate large-sized materials and heavy impurities. The first cyclone separator uses centrifugal force to separate the target materials and dust. The two work together to effectively improve the material purity and separation efficiency, and solve the problem that it is difficult for traditional multi-stage air separation devices to effectively separate the target materials and dust.

[0044] (2) The present invention further configures a second cyclone separator to handle the dust that is not completely separated by the first cyclone separator, avoiding direct discharge of dust to pollute the environment and meeting the environmental protection requirements. The second fan provides additional power for the second cyclone separator to ensure its separation effect and enhance the system's dust treatment capacity and environmental protection performance. The air outlet of the first cyclone separator is connected to the air intake path of the first fan. While the first fan sucks in ambient air to maintain the airflow circulation, it also sucks in the dust-containing gas discharged from the first cyclone separator, enhancing the internal airflow movement of the first cyclone separator and improving the dust separation effect and treatment efficiency.

[0045] (3) The present invention further sets up buffer storage devices at the discharge ports of each stage of the multi-stage screening device to temporarily store the screened mixed materials, balance the speed difference between screening and air separation, and enable a multi-stage air separation device to process different levels of materials at different times, reducing the number of multi-stage air separation devices, and lowering the equipment procurement, maintenance costs, and production space occupation.

[0046] (4) The present invention further sets up a hollow stirring shaft and jet nozzles in the air separation box and is driven by a motor, effectively preventing the mixed materials from accumulating and forming lumps in the buffer grooves. The pulsed airflow provided by the jet nozzles blows the materials apart, ensuring that the materials are in a loose state before air separation, thereby improving the accuracy and effect of air separation.

[0047] (5) The present invention further adds an electrostatic dust removal device, which is installed at the air outlet of the second cyclone separator. It further improves the dust removal efficiency and quality of the entire wood chip impurity removal system, making the discharged gas cleaner and meeting higher environmental protection standards. The rotating design of the rotating dust collection barrel and the guiding effects of the conical rotating shaft and arc-shaped edges enable the airflow to better diffuse and pass through the hexagonal ventilation holes, further improving the electrostatic dust removal effect and ensuring that more dust particles are adsorbed and collected. The dust collection cover adopts a detachable connection method, allowing operators to conveniently remove the dust collection cover regularly for cleaning, and at the same time cleaning the rotating dust collection barrel, ensuring the efficient operation of the electrostatic dust removal device, reducing the maintenance difficulty and frequency caused by excessive dust accumulation on the equipment surface, lowering the maintenance cost and equipment failure rate, and improving the service life and operation reliability of the equipment.

[0048] (6) The present invention further adds a dispersion device between the first airtight flow device and the buffer groove in the box body, effectively improving the uniformity and efficiency of system processing. Inside the dispersion box of the dispersion device, a dispersion shaft with two sets of helical blades with opposite rotation directions is rotatably connected, which can evenly push the mixed materials piled up in the center of the dispersion box to both sides, avoiding the materials being concentrated only in the middle of the buffer groove, ensuring that the stirring blades can fully exert their dispersing performance, thereby improving the system processing effect. The bottom of the dispersion box is designed as a semi-circular opening structure to adapt to the flow characteristics of the materials. The intermittently opened double-leaf door installed at the bottom is composed of a linkage structure including two arc-shaped door panels and their connected extension arms, connecting rods, pull rods, hinge shafts, tension springs, etc. It cooperates with the intermittent drive mechanism to achieve the intermittent feeding of the mixed materials in the dispersion box, leaving sufficient time for the stirring blades to perform the dispersing operation, further improving the dispersing effect, enhancing the processing efficiency and quality of the multi-stage air separation system for wood chip impurity removal, and meeting the actual production requirements. When the push rod presses down the right-angle bending part of the pull rod to the limit position and then disengages, the elastic force of the tension spring can make the pull rod automatically move upward, driving the arc-shaped door panel to close, preventing the leakage of the mixed materials in the non-working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic structural diagram of the connection frame of the present invention;

[0050] Figure 2 is a schematic structural diagram of the air separation box;

[0051] Figure 3 is a cross-sectional view of the air separation box;

[0052] Figure 4 is a schematic structural diagram of the hollow stirring shaft;

[0053] Figure 5 is a schematic structural diagram of the buffer groove;

[0054] Figure 6 is a schematic installation structure diagram of the electrostatic dust removal device;

[0055] Figure 7 is a cross-sectional view of the electrostatic dust removal device;

[0056] Figure 8 is a schematic structural diagram of the rotating dust collection bucket;

[0057] Figure 9 is a schematic structural diagram of the discharge grid;

[0058] Figure 10 is a schematic installation structure diagram of the dispersion device;

[0059] Figure 11 is a three-dimensional structural diagram of the dispersion device;

[0060] Figure 12 It is a structural schematic diagram of a dispersion device.

[0061] In the figure: 1. Conveyor belt; 2. Multi-stage screening device; 3. Buffer storage device; 4. Feeding device; 5. First airtight flow device; 6. Second airtight flow device; 7. First cyclone separator; 8. Second cyclone separator; 9. First fan; 10. Second fan; 11. Air volume regulating device; 12. Air separation box; 12-1. Box body; 12-2. Material channel; 12-3. Buffer groove; 12-4. Hollow stirring shaft; 12-5. Stirring blades; 12-6. Jet nozzles; 12-7. Arc-shaped baffle; 12-8. Deflector; 12-9. Air separation channel; 12-10. Discharge opening; 12-11. Air inlet channel; 12-12. Impurity channel; 12-13. Material channel; 13. Electrostatic dust removal device; 13-1. Rotating dust collection barrel; 13-2. Hexagonal ventilation holes; 13-3. Discharge grid; 13-4. Rotating shaft; 13-5. Impeller; 13-6. Dust collection hood; 14. Dispersion device; 14-1. Dispersion box; 14-2. Dispersion shaft; 14-3. Spiral blades; 14-4. Arc-shaped door panel; 14-5. Extension arm; 14-6. Connecting rod; 14-7. Pull rod; 14-8. Fixed seat; 14-9. Hinge shaft; 14-10. Pulleys; 14-11. Grooved pulleys; 14-12. Poking rods; 14-13. Tension springs. Specific embodiments

[0062] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0063] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0064] In this application, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0065] Example 1:

[0066] Combined with the attached Figure 1 , a multi-stage air separation system for wood chip impurity removal, comprising a multi-stage screening device 2, a multi-stage air separation device, a first cyclone separator 7, and a second cyclone separator 8. Its working process is as follows:

[0067] The multi-stage screening device 2 is the basic link of the whole system and is responsible for the preliminary treatment of the initial materials mixed with various impurities. When the materials enter the multi-stage screening device 2, they will be accurately classified and screened according to their sizes, ensuring that the mixed materials discharged from each stage outlet have high uniformity in size. This process lays a good foundation for the subsequent fine screening operation, enabling the subsequent processes to more efficiently screen and separate according to the physical properties of the materials such as density and suspension velocity. According to actual needs, the multi-stage screening device 2 is a vibrating screen, which can screen the mixed materials in 1 to 6 stages. To reduce the labor intensity of the operators, a conveyor belt 1 is configured at the feed inlet of the multi-stage screening device 2, and the materials are fed into the multi-stage screening device 2 through the conveyor belt 1.

[0068] Each stage outlet of the multi-stage screening device 2 is connected to the multi-stage air separation device through a communication structure. The main function of the multi-stage air separation device is to further purify the materials that have been screened by size. It first breaks up the mixed materials, and then through the action of a specific air flow, separates the unqualified materials with relatively large sizes and impurities such as sand, stones, and iron filings with relatively large specific gravities in the mixed materials, thereby improving the purity of the materials. The first fan 9 provides power support for the multi-stage air separation device, and its air outlet gas path is correspondingly connected to the air inlet of the multi-stage air separation device, which can stably provide the required air flow for the air separation process and ensure the continuity and effectiveness of the air separation operation.

[0069] However, although the multi-stage air separation device can perform well in removing large-size materials and heavy impurities, it has certain limitations, that is, it cannot effectively separate the target materials from the dust with relatively small specific gravities. To solve this technical problem, a communication structure is established between the material outlet of the multi-stage air separation device and the first cyclone separator 7 in this example.

[0070] Under the action of the airflow generated by the first fan 9, the target material carrying dust is blown into the first cyclone separator 7. The first cyclone separator 7 utilizes the physical principle of centrifugal force to separate the target material and dust inside. The separated target material is discharged from the discharge port of the first cyclone separator 7 and continues to enter the subsequent processing or treatment links; while the dust is carried out from the exhaust port of the first cyclone separator 7 with the airflow, realizing the further purification of the material.

[0071] It should be noted that the air outlet of the first cyclone separator 7 is correspondingly connected to the intake air path of the first fan 9 through a branch pipeline. This air path layout enables the first fan 9 during operation to not only extract the gas in the environment to maintain the normal air circulation of the system, but also simultaneously suck the gas carrying dust discharged from the exhaust port of the first cyclone separator 7. In this way, through the suction effect of the first fan 9, the airflow movement inside the first cyclone separator 7 can be enhanced, thereby improving its separation effect, ensuring that more dust can be effectively separated, and improving the efficiency and quality of the first cyclone separator 7 in separating and treating dust.

[0072] Although the first cyclone separator 7 can separate dust to a certain extent, in order to prevent dust from being directly discharged into the atmosphere and causing environmental pollution, a second cyclone separator 8 is additionally configured in this embodiment. On the air outlet path of the first fan 9, two branches are separated through a pipeline. One branch is correspondingly connected to the multi-stage air separation device according to the established design to ensure the normal air supply for the air separation operation; the other branch is correspondingly connected to the feed port of the second cyclone separator 8. After the gas carrying dust enters the second cyclone separator 8 under the guidance of the airflow, the dust and gas are also separated by means of centrifugal force and other effects. The separated clean gas meets the environmental protection emission standards and is smoothly discharged from the exhaust port of the second cyclone separator 8; while the dust is discharged from the discharge port of the second cyclone separator 8 and is usually collected for special treatment, thus effectively avoiding the pollution to the environment caused by the disordered discharge of dust and meeting the environmental protection requirements.

[0073] In order to ensure that the second cyclone separator 8 can achieve a good separation effect on its air path, a second fan 10 is installed on the connecting air path between the first fan 9 and the second cyclone separator 8. The setting of the second fan 10 can provide additional power support for this air path, ensure that the airflow passes through the second cyclone separator 8 at an appropriate speed and pressure, so that the dust separation process inside it is more efficient and thorough, and further enhances the performance and environmental protection of the second cyclone separator 8 in dust treatment.

[0074] Embodiment 2:

[0075] Combined with the attached Figures 1 - 5, A multi-stage air separation system for removing impurities from wood chips. Different from Embodiment 1, on the basis of Embodiment 1, the multi-stage air separation device includes multiple air separation boxes for separating impurities from the target material in the mixed material. Its core function is to separate impurities from the target material in the mixed material by using air flow. The air inlets of the multiple air separation boxes are respectively connected in correspondence with the air outlet pipeline of the first fan 9 through pipelines, ensuring a stable and sufficient air flow supply and providing stable power support for the air separation operation. The material outlets of the multiple air separation boxes are respectively connected in correspondence with the feed inlets of the first cyclone separator 7 through pipelines, preparing for the subsequent dust separation link.

[0076] At the material inlet of the air separation box, a feeding device 4 is connected through a first airtight flow device 5. Among them, the first airtight flow device 5 adopts a rotary valve, which can effectively control the gas flow during the material transportation process, ensuring the air flow stability of the system and the accuracy of material transportation. The feed inlet of the feeding device 4 is connected in correspondence with one of the discharge outlets of the multi-stage screening device 2, responsible for quantitatively transporting the mixed material with relatively uniform size after screening into the air separation box. According to the actual working conditions and material characteristics, the feeding device 4 is preferably a screw feeder, and this structure can ensure that the material does not get blocked during transportation, realizing continuous and stable feeding, thus ensuring the efficient progress of the air separation operation.

[0077] In addition, a second airtight flow device 6 is installed at the impurity outlet of the air separation box, also adopting the design of a rotary valve. This device can prevent the disorderly entry of external gas while discharging impurities, maintaining the stability of the internal air flow of the system and the pressure balance, and ensuring the stability of the air separation effect.

[0078] Through the coordinated action of the first airtight flow device 5 and the second airtight flow device 6, this embodiment can achieve continuous feeding and discharging during the air separation process, thereby performing continuous air separation operations, greatly improving production efficiency, and meeting the needs of large-scale material processing.

[0079] During the material processing process, especially for the air separation operation of mixed materials containing wood chips, sand, stones, iron filings, etc., some technical problems are often encountered. When the mixed material passes through the first airtight flow device 5, it is extremely easy to accumulate into a mass, and the mass of material often wraps impurities. If the air separation air flow is large, the impurities are easily carried out; if the air separation air flow is small, the target material is easily discharged from the impurity outlet, which both lead to poor air separation effects. To solve this technical defect, this embodiment has been further improved and optimized.

[0080] Specifically, in combination with the attached Figures 2 - 5The air separation box 12 includes a box body 12-1. A material channel 12-2 is provided at the top of one side of the box body 12-1, and a first airtight flow device 5 is installed at the discharge port of the material channel 12-2, so that the mixed material can enter the box body 12-1 in an orderly manner. A buffer groove 12-3 is provided below the material channel 12-2 in the box body 12-1, and the mixed material can first fall into the buffer groove 12-3 after passing through the first airtight flow device 5.

[0081] To prevent the mixed material from accumulating and forming a mass in the buffer groove 12-3, a hollow stirring shaft 12-4 is rotatably connected in the buffer groove 12-3. A motor for driving the hollow stirring shaft 12-4 is installed on one side of the box body 12-1, and a plurality of stirring blades 12-5 are arranged at intervals on the shaft body of the hollow stirring shaft 12-4. An air jet nozzle 12-6 is installed between adjacent two stirring blades 12-5, and the air jet nozzle 12-6 is correspondingly communicated with the cavity of the shaft body of the hollow stirring shaft 12-4. During the air separation operation, the cavity of the shaft body of the hollow stirring shaft 12-4 is correspondingly rotationally connected to the air source pipeline, and the air source provides pulsed air flow for the air jet nozzle 12-6. The motor drives the hollow stirring shaft 12-4 to rotate, picks up the mixed material in the buffer groove 12-3, and then the air jet nozzle 12-6 jets pulsed air flow to disperse the picked-up mixed material and blow it out of the buffer groove 12-3, thus effectively preventing the mixed material from accumulating and forming a mass and avoiding affecting the air separation effect.

[0082] In addition, an arc-shaped baffle 12-7 is provided on one side of the buffer groove 12-3 and is fixedly connected to the side wall of the box body 12-1 correspondingly. A diversion plate 12-8 is provided below the buffer groove 12-3, and a blanking port 12-10 is left between the diversion plate 12-8 and the arc-shaped baffle 12-7. The mixed material blown by the pulsed air flow jetted by the air jet nozzle 12-6 enters the cavity between the arc-shaped baffle 12-7 and the diversion plate 12-8 and freely scatters under its own gravity without falling in a mass.

[0083] The blanking port 12-10 is communicated with an air separation channel 12-9. An air inlet channel 12-11 is provided on one side of the feed port of the air separation channel 12-9, and the air inlet channel 12-11 is correspondingly communicated with the air outlet pipeline of the first fan 9 through a pipeline. An impurity channel 12-12 is provided at the bottom of the air separation channel 12-9, and a material channel 12-13 is provided on one side of the air separation channel 12-9. The freely scattered mixed material enters from the feed port of the air separation channel 12-9, and the target material is separated from the impurities under the action of the air separation air flow. The impurities are discharged from the impurity channel 12-12, and the target material is discharged from the material channel 12-13 along with the air separation air flow and enters the first cyclone separator 7.

[0084] Furthermore, considering that the impurities such as stones and iron filings in the mixed material are difficult to be blown up by the pulse airflow due to their large specific gravity, in order to prevent these impurities from accumulating in the buffer groove 12-3, a plurality of slots are provided on one side of the buffer groove 12-3 corresponding to the arc-shaped baffle 12-7. In this way, the stirring blade 12-5 can pick up the impurities such as stones and iron filings and discharge them from the slots of the buffer groove 12-3, thereby ensuring the smooth progress of the air selection process and improving the stability and reliability of the air selection effect.

[0085] Embodiment three:

[0086] Combined with Figures 10 - 12 As shown, a multi-stage air separation system for wood chip removal is optimized and upgraded on the basis of the second embodiment. Specifically, a dispersion device 14 capable of evenly dispersing the mixed material into the buffer groove 12-3 is added between the first air-tight circulation device 5 and the buffer groove 12-3 in the box body 12-1. This improvement helps to improve the uniformity and efficiency of subsequent processing.

[0087] The main component of the dispersion device 14 is a dispersion box 14-1, the top of which corresponds to and is connected to the discharge port of the first air-tight circulation device 5. A dispersion shaft 14-2 is rotatably connected inside the dispersion box 14-1, and two sets of spiral blades 14-3 with opposite rotation directions are arranged on the shaft of the dispersion shaft 14-2. When the spiral blades 14-3 rotate, the mixed material accumulated at the center of the dispersion box 14-1 can be evenly pushed to both sides of the dispersion box 14-1, so as to achieve the purpose of evenly dispersing the mixed material. In this way, it can be avoided that the mixed material is only concentrated in the middle area of the buffer groove 12-3, thereby ensuring that the stirring blade 12-5 can give full play to its dispersing performance and improve the processing effect of the entire system.

[0088] The driving method of the dispersion shaft 14-2 has a certain flexibility. It can be driven by an independent motor to ensure its independence and stability of operation; it can also be connected to the motor that drives the hollow stirring shaft 12-4 through a transmission mechanism. Common transmission mechanisms include chain transmission mechanisms or belt transmission mechanisms. This design facilitates the integration and efficient operation of the system.

[0089] The bottom of the dispersion box 14-1 is designed as a semicircular opening structure to adapt to the flow characteristics of the mixed material. A set of double doors that can realize the intermittent opening function are installed at the bottom of the dispersion box 14-1. When the double doors are opened, the semicircular opening at the bottom of the dispersion box 14-1 opens accordingly, so that the mixed material in the dispersion box 14-1 can smoothly fall into the buffer groove 12-3 under the action of gravity, preparing for the subsequent processing process.

[0090] The structure of the double-leaf door mainly consists of two arc-shaped door panels 14-4 whose tops are hinged to the dispersion tank 14-1 correspondingly, and these two arc-shaped door panels 14-4 are installed in a double-leaf opening structure to effectively control the bottom opening of the dispersion tank 14-1. On one side of each arc-shaped door panel 14-4, an extension arm 14-5 extends, and a connecting rod 14-6 is hinged to the extension arm 14-5. At the ends of the two connecting rods 14-6 away from the extension arms 14-5, strip-shaped openings are respectively provided, and between the corresponding two connecting rods 14-6, a pull rod 14-7 is installed. A convex shaft capable of slidingly mating with the two strip-shaped openings is provided on the rod body of the pull rod 14-7, thus realizing the linkage between various components. At the same time, the rod bodies of the two connecting rods 14-6 are hinged to the dispersion tank 14-1 through a hinge shaft 14-9, ensuring the stability and reliability of the entire structure.

[0091] Below the dispersion tank 14-1 corresponding to the two connecting rods 14-6, a fixed seat 14-8 is connected. The pull rod 14-7 passes through the fixed seat 14-8 and forms a vertical sliding fit relationship with it, that is, the pull rod 14-7 can freely move along the vertical direction of the fixed seat 14-8. When the pull rod 14-7 moves vertically downward along the fixed seat 14-8, it will pull the two connecting rods 14-6, and then cause the two connecting rods 14-6 to deflect around their respective hinge shafts 14-9, thereby controlling the opening of the two arc-shaped door panels 14-4 and enabling the mixed material in the dispersion tank 14-1 to smoothly fall into the buffer groove 12-3. On the contrary, when the pull rod 14-7 moves vertically upward along the fixed seat 14-8, it will control the closing of the two arc-shaped door panels 14-4 to prevent the material from leaking in the non-working state. In addition, a tension spring 14-13 is installed between the bottom of the pull rod 14-7 and the fixed seat 14-8, and its main function is to drive the pull rod 14-7 to move upward during the non-working or state reset process of the system, thereby realizing the automatic closing function of the arc-shaped door panel 14-4. A right-angled bending part is also designed at the bottom of the pull rod 14-7 for cooperation with the subsequent driving mechanism.

[0092] On the side of the pull rod 14-7 corresponding to the dispersion box 14-1, an intermittent drive mechanism is installed to drive the pull rod 14-7 to move downward along the fixed seat 14-8. The mechanism can control the opening timing and frequency of the arc door plate 14-4, so as to achieve intermittent delivery of the mixed material and improve the operating efficiency and processing effect of the entire system. The intermittent drive mechanism mainly includes a thumbwheel 14-10 rotatably connected to the dispersion box 14-1, and a groove wheel 14-11 rotatably connected to one side of the thumbwheel 14-10. When the thumbwheel 14-10 rotates one circle, it can drive the groove wheel 14-11 to rotate 90°. The groove wheel 14-11 is a cross-shaped structure, and each branch thereof is provided with a slide groove. The dial wheel 14-10 is provided with a lever that can slide and cooperate with the slide groove. There is an arc-shaped structure between two adjacent branches. The dial wheel 14-10 is provided with a disc that is adapted to the arc-shaped structure of the groove wheel 14-11, and a notch that avoids the groove wheel 14-11 is provided at the position of the disc corresponding to the lever. When the disc is adapted to the arc-shaped structure, the groove wheel 14-11 is in a locked state, and the groove wheel 14-11 cannot rotate. When the lever of the dial wheel 14-10 cooperates with the slide groove of the groove wheel 14-11, the notch of the disc faces the arc-shaped structure, the groove wheel 14-11 is unlocked, and the dial wheel 14-10 can drive the groove wheel 14-11 to rotate. A lever 14-12 is connected to the groove wheel 14-11, and its main function is to press down the right-angled bend of the pull rod 14-7.

[0093] The specific working process is as follows: when the thumbwheel 14-10 rotates one circle and drives the groove wheel 14-11 to rotate 90°, the lever 14-12 also rotates 90°. When the lever 14-12 rotates to the top position of the right-angled bend of the pull rod 14-7, the opening condition is met. At this time, the thumbwheel 14-10 continues to rotate one circle, further driving the groove wheel 14-11 and the lever 14-12 to rotate another 90°, and the lever 14-12 begins to press down the right-angled bend of the pull rod 14-7, thereby driving the pull rod 14-7 to move downward, and then controlling the two arc door panels 14-4 to open, so that the mixed material in the dispersion box 14-1 falls into the buffer groove 12-3. Through such a design, the thumbwheel 14-10 needs to rotate four circles to control the two arc door panels 14-4 to open once, thereby reserving sufficient time for the work of the spiral blade 14-3 and ensuring the coordinated operation of the entire system.

[0094] In addition, the driving method of the thumbwheel 14-10 also has a certain degree of flexibility. It can be controlled by an independent motor to ensure the independence and stability of its operation; it can also be connected to the dispersion shaft 14-2 through a transmission mechanism. Common transmission mechanisms also include chain transmission mechanisms or belt transmission mechanisms. This design facilitates the integration and efficient operation of the system.

[0095] During the process of the lever 14-12 rotating and pressing down the right-angle bending part of the pull rod 14-7, when the lever 14-12 presses the pull rod 14-7 to the limit position, the lever 14-12 will disengage from the right-angle bending part of the pull rod 14-7. At this time, driven by the elastic force of the tension spring 14-13, the pull rod 14-7 can automatically move upward, thereby driving the two arc-shaped door panels 14-4 to close, preventing the leakage of materials in the non-working state, and ensuring the normal operation of the system and the effective management of materials.

[0096] Due to the intermittent opening of the two arc-shaped door panels 14-4, the mixed materials can evenly fall into the buffer groove 12-3 in an intermittent manner. In this way, sufficient time is reserved for the dispersing operation of the stirring blades 12-5, further improving the dispersing effect, enhancing the processing efficiency and quality of the entire multi-stage air separation system for wood chip impurity removal, and enabling it to better meet the production requirements in practical applications.

[0097] Embodiment 4:

[0098] Combined with the attached Figure 1 , for a multi-stage air separation system for wood chip impurity removal, on the basis of any one of Embodiments 1 to 3, a buffer storage device 3 is provided at the discharge ports of each stage of the multi-stage screening device 2. When the mixed materials are screened by the multi-stage screening device 2, materials of different sizes will be discharged from the discharge ports of each stage. At this time, the buffer storage device 3 can temporarily store these screened mixed materials.

[0099] This design has many advantages. On the one hand, the buffer storage device 3 is like a buffer link that can adjust the supply rhythm of the materials. It provides sufficient material reserves for the multi-stage air separation device, ensuring that the multi-stage air separation device will not experience phenomena such as idling due to untimely material supply during operation, thus achieving continuous and stable material supply. On the other hand, through the temporary storage function of the buffer storage device 3, it can effectively prevent the multi-stage air separation device from being blocked due to material accumulation. In actual production, the screening speed of the materials and the air separation processing speed may be inconsistent. Without the buffer storage device 3, when the screening speed is faster than the air separation processing speed, the materials will quickly accumulate at the feed port of the multi-stage air separation device, ultimately resulting in blockage and affecting the normal operation of the entire system. The buffer storage device 3 can balance this speed difference, enabling the mixed materials at each stage to enter the multi-stage air separation device for air separation in an orderly manner.

[0100] From a cost perspective, this design can also effectively reduce the number of multi-stage air separation devices. In the absence of the buffer storage device 3, in order to meet the simultaneous air separation requirements of different levels of materials, multiple multi-stage air separation devices may need to be configured. However, through the temporary storage and adjustment functions of the buffer storage device 3, the mixed materials at each level can enter the multi-stage air separation device for air separation in a certain order, so as to achieve the time-sharing processing of different levels of materials by one multi-stage air separation device. This not only reduces the procurement and maintenance costs of the equipment, but also saves production space.

[0101] In addition, in this embodiment, an air volume adjustment device 11 is installed on the air outlet gas path corresponding to the connection between the first fan 9 and the multi-stage air separation device. The air volume adjustment device 11 can accurately adjust the air intake volume of the multi-stage air separation device according to the size of the mixed materials.

[0102] Specifically, when the size of the mixed materials is large, in order to ensure the air separation effect, it is necessary to increase the air intake volume through the air volume adjustment device 11. This is because materials with larger sizes usually have larger mass and inertia, and stronger airflows are required to fully suspend and separate them. On the contrary, if the size of the mixed materials is small, their mass and inertia are relatively small. At this time, the air intake volume can be reduced through the air volume adjustment device 11. This can not only ensure the air separation effect, but also avoid unnecessary impacts of excessive airflows on small-sized materials, such as accidentally blowing the target materials as impurities.

[0103] This air volume adjustment function has important practical significance. When processing different types and specifications of materials, the system can flexibly adjust the air separation parameters according to the specific characteristics of the materials, improving the versatility and adaptability of the system. At the same time, through precise air volume control, energy can be effectively saved and production costs can be reduced. For example, when processing small-sized materials, reducing the air intake volume can reduce the energy consumption of the fan, and at the same time reduce the wear of the equipment by the airflows and extend the service life of the equipment.

[0104] Embodiment Five:

[0105] Combined with the attached Figures 6 - 9 , a multi-stage air separation system for wood chip impurity removal, on the basis of any one of Embodiments One to Four, further adds an electrostatic dust removal device 13, and the electrostatic dust removal device 13 is installed at the air outlet of the second cyclone separator 8. The electrostatic dust removal device 13 is mainly composed of a rotating dust collection barrel 13-1, which is rotatably connected to the air outlet of the second cyclone separator 8 and is insulated from each other. The rotating dust collection barrel 13-1 is connected to the positive pole of the power supply through a slip ring, and its barrel body is arranged with a plurality of inclined downward hexagonal ventilation holes 13-2 in an array form, and these hexagonal ventilation holes 13-2 make the overall structure of the rotating dust collection barrel 13-1 present a honeycomb-like structural feature.

[0106] Inside the rotating dust collection barrel 13-1, a discharge grid 13-3 is provided. The discharge grid 13-3 is connected to the negative pole of the power supply via a conductive slip ring, and its top is in an insulated connection state with the rotating dust collection barrel 13-1. The discharge grid 13-3 is composed of multiple grid bars arranged at equal intervals in the circumferential direction. Several discharge needles are arranged on the rod body of each grid bar from top to bottom.

[0107] When a DC high voltage of tens of thousands of volts is applied between the two poles, the high voltage causes the air molecules around the discharge electrode to be ionized, and then a large number of free electrons and positive ions are generated in the air, forming a corona discharge phenomenon. It should be noted that the structure of the hexagonal ventilation hole 13-2 can increase the area of the discharge region, enabling more gas molecules to come into contact with the discharge electrode, thereby improving the ionization efficiency. When the dust-containing gas passes through the hexagonal ventilation hole 13-2, it can come into contact with the discharge region more fully, making it easier for the dust particles to be attached by the ionized free electrons and positive ions, thus improving the charging efficiency of the dust. This helps to enhance the migration and trapping effect of the dust in the electric field.

[0108] When the dust particles in the gas discharged from the air outlet of the second cyclone separator 8 pass through the ionization region, free electrons will attach to the surface of the dust particles, making them carry a negative charge. Driven by the electric field force, these negatively charged dust particles will move towards the rotating dust collection barrel 13-1 with the opposite polarity. Once the dust particles hit the rotating dust collection barrel 13-1, they will release the charges they carry and, due to the influence of electrostatic adsorption and van der Waals forces, firmly attach to the surface of the rotating dust collection barrel 13-1. Over time, they gradually accumulate to form an ash layer.

[0109] A rotating shaft 13-4 is fixedly connected coaxially inside the rotating dust collection barrel 13-1. The bottom of the rotating shaft 13-4 extends into the air outlet of the second cyclone separator 8. The shaft body part of the rotating shaft 13-4 inside the rotating dust collection barrel 13-1 is designed as a conical structure with the tip facing downwards, and an arc-shaped baffle is provided at the top of this conical structure. This conical structure and its arc-shaped baffle can play a good guiding role, enabling the gas discharged from the air outlet of the second cyclone separator 8 to spread towards the rotating dust collection barrel 13-1 and smoothly pass through the hexagonal ventilation hole 13-2. In addition, the hexagonal ventilation hole 13-2 is arranged to slope downwards, which can further slow down the flow velocity of the air flow, thereby enhancing the overall effect of electrostatic dust removal and making the discharged gas cleaner.

[0110] An impeller 13-5 is installed at the bottom of the rotating shaft 13-4, and its function is to drive the rotation of the rotating shaft 13-4 by means of the airflow flowing upward from the air outlet of the second cyclone separator 8. Since the second cyclone separator 8 generates vibrations during normal operation, these vibrations are transmitted to the rotating dust collection barrel 13-1, causing it to vibrate. When the ash layer accumulated on the surface of the rotating dust collection barrel 13-1 reaches a certain thickness, under the action of vibration, the ash layer will separate from the surface of the rotating dust collection barrel 13-1. At the same time, since the rotating dust collection barrel 13-1 is in a rotating state, the separated ash layer can be effectively thrown out.

[0111] In order to collect the thrown-out ash layer, a dust collection hood 13-6 is provided outside the rotating dust collection barrel 13-1, and the dust collection hood 13-6 is detachably connected to the air outlet of the second cyclone separator 8. In this way, the ash layer thrown out by the rotating dust collection barrel 13-1 can converge inside the dust collection hood 13-6. The operator can regularly remove the dust collection hood 13-6 for cleaning. After removing the dust collection hood 13-6, the rotating dust collection barrel 13-1 will also be exposed, facilitating its cleaning, so as to ensure that the electrostatic dust removal device 13 can continuously maintain good dust removal performance.

[0112] The parts not detailed in the present invention are prior art. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, aiming to include all changes falling within the meaning and scope of the equivalent elements within the present invention.

Claims

1. A multi-stage air separation system for removing impurities from wood chips, characterized in that, Comprising: A multi-stage screening device (2) for classifying the mixed materials according to the size. A multi-stage air separation device, the multiple feed ports of which are respectively in one-to-one correspondence and communication with the multiple discharge ports of the multi-stage screening device (2), for removing impurities after the mixed materials are dispersed. A first cyclone separator (7), the feed port of which is in corresponding communication with the material outlet of the multi-stage air separation device. A first fan (9), the intake air path and the outlet air path of which are both divided into two paths. One of the intake air paths is in corresponding communication with the outlet of the first cyclone separator (7), and the other is in communication with the external environment. One of the outlet air paths of the first fan (9) is in corresponding communication with the air inlet of the multi-stage air separation device to provide air separation airflow for the multi-stage air separation device. A second fan (10), the intake air path of which is in corresponding communication with the other outlet air path of the first fan (9). A second cyclone separator (8), the feed port of which is in corresponding communication with the outlet air path of the second fan (10) for separating dust from air.

2. The multi-stage air separation system for wood chip impurity removal according to claim 1, characterized in that, The multi-stage air separation device includes: Multiple air separation boxes (12), the air inlet of each air separation box (12) is in corresponding communication with the outlet air path of the first fan (9), and the material outlet of each air separation box (12) is in corresponding communication with the feed port of the first cyclone separator (7). Multiple first airtight flow devices (5) respectively installed at the material inlets of the multiple air separation boxes (12). Multiple feeding devices (4), the feed ports of the multiple feeding devices (4) are respectively in corresponding communication with one of the discharge ports of one stage of the multi-stage screening device (2), and the discharge ports of the multiple feeding devices (4) are respectively in corresponding communication with a first airtight flow device (5). Multiple second airtight flow devices (6) respectively installed at the impurity outlets of the multiple air separation boxes (12).

3. The multi-stage air separation system for wood chip impurity removal according to claim 2, characterized in that, The air separation box (12) includes: A box body (12-1); A material channel (12-2) provided at the top of one side of the box body (12-1). A buffer groove (12-3) provided inside the box body (12-1) and located below the material channel (12-2). A hollow stirring shaft (12-4) located in the buffer groove (12-3) and rotatably connected to the side wall of the box body (12-1) correspondingly. A motor for driving the hollow stirring shaft (12-4) is installed on one side of the box body (12-1). A plurality of stirring blades (12-5) are arranged at intervals on the shaft body of the hollow stirring shaft (12-4). A jet nozzle (12-6) in corresponding communication with the cavity of the shaft body of the hollow stirring shaft (12-4), and a jet nozzle (12-6) is installed between adjacent two stirring blades (12-5). An arc-shaped baffle (12-7) provided on one side of the buffer groove (12-3) and fixedly connected to the side wall of the box body (12-1) correspondingly. A guide plate (12-8) provided below the buffer groove (12-3), and a material dropping opening (12-10) is left between the guide plate (12-8) and the arc-shaped baffle (12-7). An air separation channel (12-9) located below the arc-shaped baffle (12-7), and its feed port is in corresponding communication with the material dropping opening (12-10). An air inlet channel (12-11) located on one side of the feed port of the air separation channel (12-9). The impurity channel (12 - 12) is located at the bottom of the air - separation channel (12 - 9); The material channel (12 - 13) is located on one side of the air - separation channel (12 - 9).

4. The multi-stage air separation system for removing impurities from wood chips according to claim 3, wherein: On one side of the buffer groove (12 - 3) corresponding to the arc - shaped baffle (12 - 7), a plurality of slots are provided.

5. The multi - stage air - separation system for wood chip impurity removal according to claim 2, characterized in that: Slow - storage devices (3) are provided at the discharge ports of each stage of the multi - stage screening device (2).

6. The multi-stage air separation system for wood chip impurity removal according to claim 2, wherein: Both the first air - tight flow device (5) and the second air - tight flow device (6) are rotary valves.

7. The multi-stage air separation system for wood chip impurity removal according to claim 2, wherein: The feeding device (4) is a screw feeder.

8. The multi - stage air - separation system for wood chip impurity removal according to claim 1, characterized in that: An air volume regulating device (11) is installed on the air outlet air path where the first fan (9) is correspondingly connected to the multi - stage air - separation device.

9. The multi - stage air - separation system for wood chip impurity removal according to claim 1, characterized in that: A conveyor belt (1) is provided at the feeding port of the multi - stage screening device (2); the multi - stage screening device (2) is a shaking screen.

10. The multi-stage air separation system for wood chip impurity removal according to claim 1, characterized in that: It further includes an electrostatic dust - removal device (13) provided at the air outlet of the second cyclone separator (8); the electrostatic dust - removal device (13) includes: A rotating dust - collection barrel (13 - 1), which is rotatably connected corresponding to the air outlet of the second cyclone separator (8); Hexagonal ventilation holes (13 - 2), and a plurality of hexagonal ventilation holes (13 - 2) are arranged in an array on the barrel body of the rotating dust - collection barrel (13 - 1), making the barrel body of the rotating dust - collection barrel (13 - 1) in a honeycomb - shaped structure, and the hexagonal ventilation holes (13 - 2) are inclined downward; A discharge grid (13 - 3), which is arranged inside the rotating dust - collection barrel (13 - 1) and is insulatedly connected to the top of the rotating dust - collection barrel (13 - 1); the discharge grid (13 - 3) includes a plurality of grid bars arranged at intervals along the circumferential direction, and a plurality of discharge needles are arranged at intervals on the rod body of the grid bar from top to bottom; A rotating shaft (13 - 4), the top of which is coaxially and firmly connected to the rotating dust - collection barrel (13 - 1) correspondingly, and the bottom extends into the air outlet of the second cyclone separator (8); the shaft body of the rotating shaft (13 - 4) inside the rotating dust - collection barrel (13 - 1) is in a conical structure with the tip facing downwards, and an arc - shaped edge is provided at the top of the conical structure; An impeller (13 - 5), which is installed at the bottom of the rotating shaft (13 - 4) and drives the rotating shaft (13 - 4) to rotate through the upward airflow inside the air outlet of the second cyclone separator (8); A dust - collection cover (13 - 6), which covers the outside of the rotating dust - collection barrel (13 - 1) and is detachably connected to the air outlet of the second cyclone separator (8).

Images