Closed combined type belt conveying system capable of discharging at multiple points

Abstract

The invention relates to a multi-point unloading closed combined type belt conveying system which comprises a closed shell, at least one conveyor arranged in the closed shell and at least one multi-point unloading belt conveyor which are randomly combined and connected in series, unloading of materials is achieved through an unloader or conveying of the materials along the next conveyor, feeding of a plurality of granaries is achieved, and meanwhile the multi-point unloading closed combined type belt conveying system is arranged in the closed shell. The unloader is obliquely arranged, so that the throwing track of grain materials is close to the plane of a material receiving plate of a material receiving hopper of the unloader, the throwing kinetic energy of grain particles is more converted into sliding in the direction of the material receiving plate, collision is less, collision dust is less, the dust movement trend is downward in the direction of the material receiving plate, and therefore diffusion of the dust in the environment is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of grain material conveying equipment, and particularly relates to a closed combined belt conveying system with multi-point discharging. Background Art

[0002] A closed belt conveyor is a transportation equipment that conveys bulk materials to a predetermined target by means of a conveyor belt moving in a closed housing. It has the advantages of low cost, mature technology, strong sealing performance, less dust pollution, simple and easy operation, etc. Therefore, closed belt conveyors are widely used in the processes of grain transfer, loading, warehousing, and outloading.

[0003] With the continuous expansion of the scale of grain depots, a grain depot usually consists of multiple granaries. When storing grain in the granaries, it is usually fed into the granaries from the top of the granaries. Currently, when feeding grain into the granaries, multiple closed belt conveyors are usually inclined and lapped one by one to achieve multi-bin feeding. The overall height is very large when lapping to the end, and the pedestrian corridor also needs to be made inclined, which is cumbersome, has poor safety, and is inconvenient. For this reason, technicians have developed a discharge device that is convenient for multi-point discharging, such as a Chinese invention patent with the patent number ZL2016107624541 and the patent name "Belt conveyor throwing and distributing discharge device", and a Chinese invention patent application with the application number 2020102188650 and the name "Four-way discharge device for belt conveyor". The discharge device can achieve intermediate discharge of the belt conveyor, so as to realize that one conveyor can simultaneously store grain in multiple granaries. That is, one belt conveyor is arranged on the tops of multiple granaries, and multiple discharge devices are arranged on the belt conveyor. One discharge device corresponds to one granary, realizing multi-point discharging of one belt conveyor. When a certain granary needs to store grain, only the discharge device corresponding to this granary needs to be opened, and the grain transported on the belt conveyor enters the granary from this discharge device.

[0004] However, the existing closed belt conveyors with multi-point discharging used for grain warehousing have the following defects when in use: 1. When the grain material falls from the high-position roller into the discharge device, the grain material collides with the wall plate of the discharge device, generating a large amount of dust diffusion. Since the belt conveyor is located in a closed space, the dust generated by the collision of the grain material and the discharge device is easy to accumulate inside the conveyor, posing a safety hazard, easily accelerating the wear of the conveyor belt and other mechanical equipment, increasing the maintenance cost, affecting the service life of the closed belt conveyor. In addition, the dust in the closed environment also has an explosion risk.

[0005] 2. The discharge devices of the existing closed belt conveyors with multi-point discharging are large in volume, and the production manufacturing cost, transportation cost, and installation cost are all very high.

[0006] 3. When the existing enclosed belt conveyor with multi-point unloading is in use, at the lap joint of two adjacent conveyor belts, when the front conveyor belt unloads grain into the granary or throws materials onto the rear conveyor belt, it is inevitable that grain materials will be scattered on the bottom plate of the enclosed housing. In addition, when transporting grain materials with high humidity and moisture content, it is inevitable that grain particles and dust impurities in the grain will adhere to the surface of the conveyor belt. When the conveyor belt moves to the lap joint of the two conveyor belts, due to the reversal of the conveyor belt, some of the adhered materials will fall off under the action of gravity. Some of the fallen materials will be transported on the rear conveyor belt, and some of the fallen materials will also be scattered on the bottom plate of the enclosed housing. This results in serious material accumulation on the bottom plate at the lap joint of two adjacent conveyor belts and is difficult to clean. Especially when the conveyor is installed on top of the granary, the cleaning operation is even more difficult. And the long-term accumulation of grain materials is prone to mildew and deterioration, affecting the quality of grain materials.

[0007] 4. Materials that are firmly adhered to the conveyor belt will move under the carrying of the return conveyor belt. During the movement of the return conveyor belt, it will contact, collide, and rub against the bottom plate of the enclosed belt conveyor. The materials adhered to the conveyor belt will fall onto the bottom plate due to the collision and friction. In addition, during the transportation process of the enclosed belt conveyor, it is inevitable that grain materials and dust impurities will leak from the upper layer of the belt to the lower layer or onto the bottom plate of the enclosed housing. The materials scattered on the bottom plate will increase the wear of the conveyor belt and the running resistance of the conveyor belt. At the same time, the return conveyor belt will also carry the materials on the bottom plate to the tail part of the machine, resulting in serious accumulation of materials and dust impurities at the tail part, affecting the normal operation of the conveyor belt and being difficult to clean. Especially for the enclosed belt conveyor installed above the granary, the high-altitude operation for cleaning is even more difficult.

[0008] 5. When the existing enclosed belt conveyor is in use, the return conveyor belt contacts and rubs against the bottom plate of the enclosed housing, the conveyor belt friction is relatively large, the conveyor requires a large amount of power, the operating cost is relatively high, and the conveyor belt wears relatively fast, seriously affecting the service life of the conveyor belt. Summary of the Invention

[0009] In summary, in order to overcome the deficiencies of the prior art problems, the present invention provides a multi-point unloading enclosed combined belt conveyor system.

[0010] To solve the above technical problems, the technical solution provided by the present invention is realized as follows: A closed combined belt conveyor system with multi-point discharging, comprising: a closed housing, at least one conveyor and at least one discharger arranged in the closed housing, the conveyor being a belt conveyor and / or a multi-point discharging belt conveyor, all the conveyors in the closed housing being connected in series, the discharging end of the front conveyor being located above the feeding end of the rear conveyor, a drop being formed between the discharging end of the front conveyor and the feeding end of the rear conveyor, and a discharger being arranged between the discharging end of the front conveyor and the feeding end of the rear conveyor. The discharging points of the multi-point discharging belt conveyor have a high-position roller and a low-position roller, the high-position roller being arranged above the low-position roller, a drop being formed between the high-position roller and the low-position roller, the high-position roller being located at the discharging end of the high-position conveyor belt of the multi-point discharging belt conveyor, the low-position roller being located at the starting end of the low-position conveyor belt of the multi-point discharging belt conveyor, and a discharger being arranged between the high-position roller and the low-position roller. Wherein: the discharger is arranged obliquely, including a discharging housing, a feeding port at the upper end of the discharging housing, a discharging port at the lower end of the discharging housing and discharging ports on both sides of the discharging housing, the feeding port corresponding to the high-position roller or the discharging end of the front conveyor, the discharging port corresponding to the low-position conveyor belt or the feeding end of the rear conveyor, the discharging ports on both sides of the discharging housing being respectively communicated with the discharging boxes on both sides of the closed housing, two inclined receiving hoppers being arranged in the feeding port, the inner cavities of the two receiving hoppers being communicated with the discharging port to form a discharging channel, and the inner cavities of the two receiving hoppers being respectively communicated with the discharging ports to form discharging channels, a discharging hopper capable of flipping relative to the discharging housing and a driving device for driving the discharging hopper to flip being arranged in the discharging housing, the flipping of the discharging hopper realizing the switching between the discharging channel and the discharging channels, the receiving plate of the receiving hopper having an angle a with the horizontal line, and the height difference between the receiving plate and the upper end of the high-position roller or the upper end of the discharging end of the front conveyor being h.

[0011] Preferably, the angle a is 45-60°, and the height h is 200-300 mm.

[0012] Preferably, the discharging hopper includes a bottom plate and arc-shaped baffles fixed on both sides of the bottom plate, rotating shafts being arranged on the outer sides of the two arc-shaped baffles, the rotating shafts outside the two arc-shaped baffles being coaxially arranged, and one of the rotating shafts passing through the closed housing and being connected to a driving device arranged outside the closed housing, the driving device driving the rotating shaft to drive the arc-shaped baffles and the bottom plate to flip.

[0013] Preferably, two receiving hoppers inside the feed inlet of the discharge housing are arranged side by side. The lower openings of the two receiving hoppers respectively extend into the inner cavities of the two discharge hoppers. The receiving hopper is a funnel-shaped structure formed by a receiving plate, an inner wall plate, an outer wall plate and a baffle plate. The receiving plate and the baffle plate are arranged opposite to each other, and the inner wall plate and the outer wall plate are arranged opposite to each other. The inner cavity of the receiving hopper forms a feed channel. On both sides of the discharge outlet of the discharge housing, there are discharge plates arranged obliquely downward from outside to inside. The two discharge plates respectively correspond to the outer wall plates of the two receiving hoppers. The discharge opening of the discharge housing is provided with a discharge plate arranged obliquely downward from inside to outside. The discharge plates of the two discharge openings respectively correspond to the inner wall plates of the two receiving hoppers. When the discharger discharges, the bottom plate of the discharge hopper fits with the inner wall plate and the discharge plate to form a discharge channel, and the feed inlet of the discharge housing is communicated with the discharge outlet. When the discharger discharges materials, the bottom plate of the discharge hopper fits with the outer wall plate and the discharge plate to form a discharge channel, and the feed inlet of the discharge housing is communicated with the discharge outlet.

[0014] Preferably, a dust collection port is provided on the bottom plate of the closed housing at the connection between the discharge end of the front conveyor and the feed end of the rear conveyor. A dust cleaning housing is provided below the dust collection port. A dust cleaning feed port communicated with the dust collection port is provided on the top plate of the dust cleaning housing. A dust collection plate is arranged in the dust cleaning housing. Both sides of the dust collection plate are connected to the side plates of the dust cleaning housing. A dust cleaning conveying device is arranged in the dust cleaning housing. The dust cleaning conveying device is used to convey the materials received by the dust collection plate to the dust cleaning discharge port. The dust cleaning discharge port is located at the lower end on one side of the dust cleaning housing. The dust cleaning discharge port is communicated with the dust return feed port of the dust return housing. The dust return housing is a square annular hollow housing. The feed end of the rear conveyor passes through the inner ring square hole of the square annular housing. On one side of the dust return housing above the rear conveyor, there is a dust return discharge port with an opening downward. The dust return discharge port corresponds to the upper conveyor belt of the rear conveyor. A dust return conveying device is arranged in the dust return housing. The dust return conveying device conveys the materials conveyed by the dust cleaning conveying device to the upper conveyor belt of the low-position conveyor belt. The return material conveying device is a scraper conveying mechanism.

[0015] Preferably, the dust cleaning conveying device is a dust cleaning scraper and a dust cleaning chain mechanism arranged in the dust cleaning housing. Both ends of the dust cleaning scraper are respectively connected to the chains of the two dust cleaning chain mechanisms. The lower end of the dust cleaning scraper contacts the top surface of the dust collection plate. The two dust cleaning chain mechanisms drive the dust cleaning scraper to move, and the dust cleaning scraper pushes the materials on the dust collection plate.

[0016] Preferably, an air vent groove is arranged on the inner side of the bottom plate of the closed housing. Air holes are densely arranged on the air vent groove. The air holes correspond to the bottom surface of the return conveyor belt of the conveyor. Air outlets are arranged on the closed housing at the connection of the discharge end of the front conveyor and the feed end of the rear conveyor and at the discharge points of the belt conveyor with multi-point discharging. The air outlets are communicated with the air inlet of the dust collector. The air outlet of the dust collector is communicated with the air inlet of the fan. The air outlet of the fan is communicated with the air inlet of the air vent groove through a pipeline.

[0017] Preferably, the driven roller of the first conveyor in the series-connected conveyors is arranged in the movable housing. A tailstock support is arranged at the lower end of the movable housing. One side of the tailstock support is connected with the closed housing. A supporting roller is arranged on the other side of the tailstock support. The supporting roller contacts with the lower end of the movable housing. The movable housing is inserted and connected with the closed housing. The outer side of the movable housing and the outer side of the closed housing are connected through an adjusting screw rod. The distance between the movable housing and the closed housing is adjusted through the adjusting screw rod to realize the tensioning of the tail end of the conveyor belt of the first conveyor in the series-connected conveyors.

[0018] Preferably, a gravity tensioning device is further included. The gravity tensioning device is connected with the return conveyor belt of the conveyor. The gravity tensioning device is arranged in the closed housing. A door is arranged on the closed housing.

[0019] Preferably, a tailstock ash return device is arranged at one end where the driven roller of the first conveyor in the series-connected conveyors is located. The tailstock ash return device includes a tailstock ash return housing and a tailstock ash return device. The tailstock ash return housing is a square annular hollow structure. The closed housing passes through the inner ring square hole of the tailstock ash return housing. The inner ring of the tailstock ash return housing is connected with the outer side of the closed housing. A tailstock ash outlet is arranged on the bottom plate of the closed housing. A tailstock ash return inlet with an upward opening is arranged at the bottom edge of the inner ring of the tailstock ash return housing. A tailstock ash return outlet with a downward opening is arranged at the top edge of the inner ring of the tailstock ash return housing. A tailstock ash inlet is arranged on the top plate of the closed housing. The tailstock ash outlet is communicated with the tailstock ash return inlet. The tailstock ash return outlet is communicated with the tailstock ash inlet. A tailstock ash return conveying device is arranged in the inner cavity between the inner ring and the outer ring of the tailstock ash return housing. The tailstock ash return conveying device is a scraper conveyor mechanism.

[0020] Preferably, in the series-connected conveyors, a scraping device is provided at the discharging end of the front conveyor. The scraping device includes a scraper, a scraping support plate for supporting the scraper, and a scraping shaft. The scraper is closely attached to the surface of the return conveyor belt on the driving roller at the discharging end of the front conveyor. The scraper is connected to one side of the scraping support plate, and the other side of the scraping support plate is connected to the scraping shaft. The scraping shaft is rotatably connected to the closed housing. A pressing mechanism is provided outside the closed housing. The pressing mechanism includes a scraping swing rod, a pressing connecting rod, and a pressing spring. One end of the scraping swing rod is connected to the scraping shaft, and the other end of the scraping swing rod is hinged to the pressing connecting rod. A pressing spring is provided between the pressing connecting rod and the closed housing, and the elastic force of the pressing spring is used to keep the scraper always closely attached to the surface of the conveyor belt.

[0021] Preferably, a feed hopper is provided on the closed housing at the end where the driven roller of the first conveyor in the series-connected conveyors is located. The feed hopper includes a hopper body. The hopper body has a feed section, a discharge section, and a buffer section. The feed section has a feed inlet, the discharge section has a discharge outlet, and a guide plate inclined from outside to inside is provided at the discharge outlet of the discharge section. The axis of the feed section is arranged parallel and offset to the axis of the discharge section. The feed section and the discharge section are connected by an inclined buffer section. An inclined chute is provided in the buffer section. The cross-sectional shape of the inclined chute is "V" shaped. The inclined chute has a narrow discharge opening, and the narrow discharge opening is located at the center of the bottom of the chute on the side of the inclined chute close to the feed section. On the inner walls of the two side plates of the buffer section, inwardly protruding guide bumps are provided, and the two guide bumps are arranged oppositely, and there is a passage for the material to flow through between the two guide bumps. The guide bumps are located at the end of the inclined chute close to the discharge section. The side of the guide bump close to the feed section has a guide inclined surface, and the guide inclined surface is inclined from outside to inside along the material flow direction from the feed section to the discharge section.

[0022] Preferably, the first conveyor in the series-connected conveyors is arranged at an angle b with the horizontal plane, -110° ≤ b ≤ -180°, and the last conveyor in the series-connected conveyors is arranged at an angle c with the horizontal plane, 0 ≤ c ≤ 70°.

[0023] The beneficial effects of the present invention are as follows: 1. The receiving hopper and the discharging device of the present invention are arranged obliquely. The included angle between the receiving plate of the receiving hopper and the horizontal line is a, and the included angle a is 45° to 60°. Within this range, when discharging at the discharging end of the previous belt conveyor, the throwing trajectory of the grain material is close to the plane of the receiving plate. More of the throwing kinetic energy of the grain particles is converted into sliding along the direction of the receiving plate, with less collision and less generation of collision dust. The dust is mainly in the form of floating dust, and the movement trend of the dust is downward along the direction of the receiving plate, thereby reducing the diffusion of dust in the environment.

[0024] 2. The height difference between the material receiving plate of the material receiving hopper of the present invention and the upper end of the high-position roller or the upper end of the discharging end of the front conveyor is 200 - 300 mm. With this installation height difference, when the grain material is discharged, the kinetic energy of the grain particles is relatively low, and there is less collision dust generated when hitting the material receiving plate, and the amount of dust flying is also less, and the dust diffusion range is small. As the height difference increases, when the belt conveyor discharges materials, the falling height of the grain material increases, the kinetic energy of the grain particles will increase, and more collision dust and dust flying will be generated. If the height difference is too small, it is not conducive to the installation and maintenance of the discharging device.

[0025] 3. The inclined arrangement of the material receiving hopper and the discharging device of the present invention can effectively reduce the volume of the discharging point of the multi-point discharging closed belt conveyor, thereby reducing the equipment installation space, saving the production and transportation costs, and improving the market competitiveness of the product.

[0026] 4. A dust collection port is provided at the connection of the conveyors connected in series of the present invention, and a material receiving plate and a dust cleaning and transporting device are provided below the dust collection port. The leakage of materials during the discharging or feeding process of the front conveyor in the conveyors connected in series and the materials carried by the return conveyor belt of the rear conveyor to the connection are all dropped from the dust collection port onto the dust collection plate, and then enter the ash return shell under the action of the dust cleaning and transporting device, and then re-enter the upper conveyor belt of the rear conveyor under the action of the ash return transporting device and are transported by the rear conveyor, thereby effectively solving the problem of material accumulation at the connection, enabling the conveyor to operate normally and stably, reducing the wear of the conveyor belt, lowering the operation and maintenance costs, and ensuring the service life.

[0027] 5. The present invention uses a scraping device to scrape off the grains, dust and impurities adhered to the conveyor belt, effectively cleaning the materials such as grains, dust and impurities adhered to the conveyor belt. The scraped materials fall onto the aggregate plate and are re-transported to the upper conveyor belt of the rear conveyor, thereby effectively reducing the material accumulation on the bottom plate of the closed housing, reducing the wear of the conveyor belt, reducing the shutdown maintenance cost of the conveyor, and ensuring the service life of the conveyor belt.

[0028] 6. A tailstock return device is provided at one end where the driven roller of the first conveyor in the conveyors connected in series of the present invention is located. The tailstock return device can send the accumulated materials at the tailstock into the first conveyor for re-transportation, thereby effectively avoiding the influence of the accumulated materials at the tailstock on the conveyor, reducing the shutdown maintenance cost of the belt conveyor, and ensuring the service life of the conveyor belt.

[0029] 7. In the tandem-connected conveyors of the present invention, the driven roller of the first conveyor is arranged inside the movable housing. The movable housing is inserted and connected to the closed housing. The distance between the movable housing and the closed housing is adjusted by the adjusting screw to achieve the tensioning of the conveyor belt of the first conveyor in the tandem-connected conveyors. For the other conveyors except the first conveyor of the present invention, a gravity tensioning device is provided, and the conveyor belt is tensioned through the gravity tensioning device, thereby effectively solving the automatic adjustment of the tension degree of the conveyor belt of the conveyor. The gravity tensioning device is arranged inside the closed housing, and the upper end of the closed housing is connected to the closed housing, which can effectively prevent the dust generated during the conveying process of the grain material from leaking and spreading from the gravity tensioning device.

[0030] 8. The hopper body of the feed hopper of the present invention has an inclined chute arranged obliquely. The center of the bottom of the chute on one side of the feed section close to the hopper body is provided with a narrow discharge opening. A guide convex block is arranged at one end of the discharge section of the chute close to the hopper body. After the grain material enters the hopper body, a small part of the material converges through the chute and flows out from the narrow discharge opening, falling to the central area in the width direction of the conveyor belt of the belt conveyor. The material exerts pressure on the conveyor belt, making the conveyor belt centered and pressed correctly, thereby avoiding the material scattering caused by the deviation of the conveyor belt. The rest of the majority of the material is buffered and converged under the action of the chute and the guide convex block to form a slow-speed and dense material flow. The flow rate of the material is reduced, which can reduce the impact of the material on the conveyor belt, prevent the conveyor belt from deviating due to impact and the material from splashing. At the same time, in the dense material flow, there is less air between the material particles, which can reduce the diffusion and flying of dust and reduce dust pollution.

[0031] 9. A guide plate arranged obliquely from the outside to the inside is provided at the discharge opening of the discharge section of the feed hopper of the present invention. When the grain material falls from the discharge opening onto the conveyor belt, the arrangement of the guide plate can make the material converge from the outside to the inside, so that the material falls to the middle area of the conveyor belt, which can further prevent material scattering.

[0032] 10. An air outlet and a dust collector are provided on the closed housing at the connection between the discharge end of the front conveyor and the feed end of the rear conveyor and at the discharge points of the belt conveyor with multi-point discharge. The dust generated during the conveying process of the grain material flows out from the air outlet under the action of the fan. After being dust-removed by the dust collector, the clean air flow enters the ventilation groove arranged inside the bottom plate of the closed housing under the action of the fan. Then, the air flow flows out from the air holes on the wear-resistant plate to form an air cushion between the return conveyor belt and the bottom plate of the closed housing and the return conveyor belt, thereby reducing the friction between the return conveyor belt and the bottom plate of the closed housing, ensuring the service life of the conveyor belt, and reducing the energy consumption of the conveyor.

[0033] 11. In the series-connected conveyors of the present invention, the first conveyor is arranged at an angle with the horizontal plane, and the last conveyor in the series-connected conveyors is arranged at an angle with the horizontal plane. The angular arrangements of the first conveyor and the last conveyor can effectively expand the application range of the present invention, enabling the present invention to be applicable to grain bins at different angles.

[0034] 12. In the series-connected conveyors of the present invention, the front conveyor and the rear conveyor are connected by a discharge device. The discharge points of the belt conveyors with multi-point discharge are provided with discharge devices. The discharge of materials or the conveyance along the next conveyor is achieved through the discharge devices. At least one belt conveyor and at least one multi-point discharge belt conveyor are combined in series arbitrarily to realize the feeding of multiple grain bins. When feeding a certain grain bin is required, only the conveyor corresponding to that grain bin needs to be started, and the conveyors after that grain bin do not need to be started, realizing the sectional use of the conveyors, thereby achieving the purpose of saving power energy and reducing wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is of the present invention Figure 1 amplified schematic diagram of part A; Figure 3 is of the present invention Figure 2 schematic structural diagram in the B direction; Figure 4 is a schematic structural diagram of the discharge state of the discharge device of the present invention; Figure 5 is of the present invention Figure 4 schematic diagram of the C-C structure; Figure 6 is a schematic diagram of the discharge state of the discharge device of the present invention; Figure 7 is a schematic structural diagram of the feed hopper of the present invention; Figure 8 is a schematic side view structural diagram of the feed hopper of the present invention; Figure 9 is of the present invention Figure 1 amplified schematic diagram of part D; Figure 10 is of the present invention Figure 1 amplified schematic diagram of part E; Figure 11 is a schematic structural diagram of the scraping device of the present invention; Figure 12 is a schematic structural diagram of the dust cleaning and conveying device of the present invention; Figure 13 is a schematic structural diagram of the ash return and conveying device of the present invention; Figure 14Schematic diagram of the structure of the tail ash return device of the present invention; Figure 15 Optical photos of the corn sample colliding with the baffle when the installation angles of the baffle are 30°, 45°, 60°, 120°, 135°, and 150° respectively; Figure 16 Velocity trace diagrams of the dust when the corn sample collides with the baffle when the installation angles of the baffle are 30°, 45°, 60°, 120°, 135°, and 150° respectively; Figure 17 Optical photos of the corn sample colliding with the baffle when the conveying speeds of the belt conveyor are 2.1 m / s, 3.1 m / s, 4.1 m / s, and 4.9 m / s respectively; Figure 18 Velocity trace diagrams of the diffused dust during the collision when the corn sample collides with the baffle when the conveying speeds of the belt conveyor are 2.1 m / s, 3.1 m / s, 4.1 m / s, and 4.9 m / s respectively; Figure 19 Optical photos of the corn sample colliding with the baffle when the conveying speeds of the belt conveyor are 200 mm, 350 mm, and 500 mm respectively; Figure 20 Velocity trace diagrams of the diffused dust during the collision when the corn sample collides with the baffle when the conveying speeds of the belt conveyor are 200 mm, 350 mm, and 500 mm respectively; Figure 21 Another schematic diagram of the structure of the present invention. Detailed implementation manners

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Embodiment 1

[0037] As Figure 1 、 Figure 2 and Figure 9As shown in the figure, a closed combined belt conveyor system with multi-point discharging, comprising: a closed housing 16, at least one conveyor and at least one discharger 23 arranged in the closed housing 16. In this embodiment, two belt conveyors with multi-point discharging are arranged in the closed housing 16. Each belt conveyor with multi-point discharging has two discharging points, a total of four discharging points, corresponding to four grain bins. The two belt conveyors with multi-point discharging are connected in series. The discharging end 17 of the first conveyor 5 is located above the feeding end 18 of the second conveyor 6, and a drop is formed between the discharging end 17 of the first conveyor 5 and the feeding end 18 of the second conveyor 6. An inclined discharger 23 is arranged between the discharging end 17 of the first conveyor 5 and the feeding end 18 of the second conveyor 6. The discharging points of the belt conveyor with multi-point discharging have a high-position roller 19 and a low-position roller 20. The high-position roller 19 is arranged above the low-position roller 20, and a drop is formed between the high-position roller 19 and the low-position roller 20. The high-position roller 19 is located at the discharging end 17 of the high-position conveyor belt 21 of the belt conveyor with multi-point discharging, and the low-position roller 20 is located at the starting end of the low-position conveyor belt 22 of the belt conveyor with multi-point discharging. An inclined discharger 23 is arranged between the high-position roller 19 and the low-position roller 20. As Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, the unloader 23 is arranged obliquely, including an unloading housing 231, a feed inlet 235 at the upper end of the unloading housing 231, a discharge outlet 236 at the lower end of the unloading housing 231, and discharge openings 237 on both sides of the unloading housing 231. The feed inlet 235 corresponds to the high-position drum 19 or the discharge end of the front conveyor. The discharge outlet 236 corresponds to the low-position conveyor belt 22 or the feed end 18 of the rear conveyor. The discharge openings 237 on both sides of the unloading housing 231 are respectively communicated with the discharge boxes 24 on both sides of the closed housing 16. Two inclined receiving hoppers 232 are arranged in the feed inlet 235. The inner cavities of the two receiving hoppers 232 are communicated with the discharge outlet 236 to form a discharge channel, and the inner cavities of the two receiving hoppers 232 are respectively communicated with the two discharge openings 237 to form a discharge channel. An unloading hopper 233 capable of flipping relative to the unloading housing 231 and a driving device 234 for driving the flipping of the unloading hopper 233 are arranged in the unloading housing 231. The flipping of the unloading hopper 233 realizes the switching between the discharge channel and the discharge channel. The included angle between the receiving plate 2321 of the receiving hopper 232 and the horizontal line is a, and the included angle a is 45° to 60°. The height difference between the receiving plate 2321 and the upper end of the high-position drum 19 or the upper end of the discharge end 17 of the front conveyor is h, and the height h is 200 to 300 mm. The unloading hopper 233 includes a bottom plate 2331 and arc-shaped baffles 2332 fixed on both sides of the bottom plate 2331. Rotating shafts 2333 are arranged on the outer sides of the two arc-shaped baffles 2332. The rotating shafts 2333 outside the two arc-shaped baffles 2332 are coaxially arranged, and one of the rotating shafts 2333 passes through the closed housing 16 and is connected to the driving device 234 arranged outside the closed housing 16. The driving device 234 drives the rotating shaft 2333 to drive the arc-shaped baffle 2332 and the bottom plate 2331 to flip.

[0038] Two receiving hoppers 232 are arranged in parallel in the feed port 235 of the discharge shell 231. The lower end openings of the two receiving hoppers 232 are respectively extended into the inner cavities of the two discharge hoppers 233, which can effectively prevent the grain materials entering from the receiving hoppers 232 from being scattered during the discharge or discharging process. The receiving hopper 232 is a funnel-shaped structure surrounded by a receiving plate 2321, an inner wall plate 2322, an outer wall plate 2323 and a baffle plate 2324. The receiving plate 2321 and the baffle plate 2324 are arranged opposite to each other, and the inner wall plate 2322 and the outer wall plate 2323 are arranged opposite to each other. The inner cavity of the receiving hopper 232 forms a feed channel. The two sides of the discharge port 236 of the discharge shell 231 have discharge plates 2321 arranged from outside to inside and tilted downward. 8. The two discharge plates 238 correspond to the outer wall plates 2323 of the two receiving hoppers 232 respectively. The discharge port 237 of the discharge shell 231 is provided with a discharge plate 239 which is arranged downwardly and inclined from the inside to the outside. The discharge plates 239 of the two discharge ports 237 correspond to the inner wall plates 2322 of the two receiving hoppers 232 respectively. When the discharger 23 discharges, the bottom plate of the discharge hopper 233 fits with the inner wall plate 2322 and the discharge plate 239 to form a discharge channel. The feed port 235 of the discharge shell 231 is communicated with the discharge port 237. When the discharger 23 discharges, the bottom plate of the discharge hopper 233 fits with the outer wall plate 2323 and the discharge plate 238 to form a discharge channel. The feed port 235 of the discharge shell 231 is communicated with the discharge port 236.

[0039] like Figure 10 As shown, the driven roller of the first conveyor 5 is arranged in a movable housing 25, a tail bracket 26 is arranged at the lower end of the movable housing 25, one side of the tail bracket 26 is connected to the closed housing 16, and a roller 27 is arranged on the other side of the tail bracket 26, and the roller 27 contacts the lower end of the movable housing 25, the movable housing 25 is plug-connected with the closed housing 16, the outer side of the movable housing 25 is connected with the outer side of the closed housing 16 through an adjusting screw 28, and the distance between the movable housing 25 and the closed housing 16 is adjusted by adjusting the screw 28 to achieve the tail tensioning of the conveyor belt of the first conveyor 5. The return conveyor belts of the first conveyor 5 and the second conveyor 6 are respectively connected to the gravity tensioning device 14, and the gravity tensioning device 14 is arranged in the closed housing 15, and the closed housing 15 is provided with a door.

[0040] The gravity tensioning device 14 includes a tensioning fixed frame, a tensioning movable frame, a front tensioning roller, a rear tensioning roller, a tensioning counterweight and a gravity tensioning roller. A tensioning opening is provided on the bottom plate of the closed housing 16. Below the tensioning opening is provided a tensioning fixed frame. On one side of the tensioning fixed frame are provided a front tensioning roller and a rear tensioning roller that can rotate relative to the tensioning fixed frame. At the lower end of the tensioning fixed frame is provided a tensioning movable frame that can move up and down relative to the tensioning fixed frame. The gravity tensioning roller is provided with a gravity tensioning roller that can rotate relative to the tensioning movable frame. A tensioning counterweight is provided on the tensioning movable frame. The return conveyor belt of the conveyor provided with the gravity tensioning device 14 is sequentially connected to the front tensioning roller, the gravity tensioning roller and the rear tensioning roller. Under the action of gravity, the tensioning counterweight pulls down the tensioning movable frame. The tensioning movable frame moves downward. The gravity tensioning roller on the tensioning movable frame pulls down the return conveyor belt, thereby tensioning the conveyor belt of the conveyor.

[0041] As Figure 12 and Figure 13 shown, a dust collecting port 29 is provided on the bottom plate of the closed housing 16 at the connection between the discharge end 17 of the first conveyor 5 and the feed end 18 of the second conveyor 6. Below the dust collecting port 29 is provided a dust cleaning housing 30. On the top plate of the dust cleaning housing 30 is provided a dust cleaning feed port 31 communicating with the dust collecting port 29. A dust collecting plate 32 is provided in the dust cleaning housing 30. Both sides of the dust collecting plate 32 are connected to the side plates of the dust cleaning housing 30. A dust cleaning conveying device is provided in the dust cleaning housing 30. The dust cleaning conveying device is used to convey the materials received by the dust collecting plate 32 to the dust cleaning discharge port 33. The dust cleaning discharge port 33 is located at the lower end on one side of the dust cleaning housing 30. The dust cleaning discharge port 33 communicates with the return ash feed port 35 of the return ash housing 34. The return ash housing 34 is a square annular hollow housing. The feed end 18 of the rear conveyor passes through the inner ring square hole of the square annular housing. On one side of the return ash housing 34 above the rear conveyor is provided a return ash discharge port 36 opening downward. The return ash discharge port 36 corresponds to the upper conveyor belt of the rear conveyor. A return ash conveying device is provided in the return ash housing 34. The return ash conveying device conveys the materials conveyed by the dust cleaning conveying device to the upper conveyor belt of the low-position conveyor belt 22. The dust cleaning conveying device is a dust cleaning scraper 37 and a dust cleaning chain mechanism 38 provided in the dust cleaning housing 30. Both ends of the dust cleaning scraper 37 are respectively connected to the chains of the two dust cleaning chain mechanisms 38. The lower end of the dust cleaning scraper 37 contacts the top surface of the dust collecting plate 32. The two dust cleaning chain mechanisms 38 drive the dust cleaning scraper 37 to move. The dust cleaning scraper 37 pushes the materials on the dust collecting plate 32.

[0042] During the discharging or out-feeding process of the discharging end 17 of the first conveyor 5, the materials scattered on the bottom plate of the closed housing 16 and the materials carried by the return conveyor belt of the second conveyor 6 flow out from the ash collection port 29, and then fall onto the ash collection plate 32. The ash cleaning and conveying device is started. Under the pushing action of the ash cleaning scraper 37, the materials on the ash collection plate 32 are pushed to flow out from the ash cleaning discharge port 33, and then enter the ash return housing 34. Under the action of the ash return conveying device, they are conveyed to the upper conveyor belt of the second conveyor 6 and re-conveyed, which can effectively reduce the accumulation of materials at the discharging point.

[0043] As Figure 14 shown, at one end where the driven roller of the first conveyor 5 is located, there is a tail ash return device 49. The tail ash return device 49 includes a tail ash return housing 491 and a tail material return conveying device. The tail ash return housing 491 is a square-ring-shaped hollow structure. The closed housing 16 passes through the inner-ring square hole of the tail ash return housing 491. The inner ring of the tail ash return housing 491 is connected to the outer side of the closed housing 16. There is a tail ash outlet 492 on the bottom plate of the closed housing 16. There is a tail ash return inlet 493 with an upward opening at the bottom edge of the inner ring of the tail ash return housing 491. There is a tail ash return outlet 494 with a downward opening at the top edge of the inner ring of the tail ash return housing 491. There is a tail ash inlet 495 on the top plate of the closed housing 16. The tail ash outlet 492 is communicated with the tail ash return inlet 493. The tail ash return outlet 494 is communicated with the tail ash inlet 495. A tail material return conveying device is arranged in the inner cavity between the inner ring and the outer ring of the tail ash return housing 491. The materials accumulated at the tail of the first conveyor 5 enter the tail ash return housing 491 from the tail ash outlet 492, and then are re-fallen onto the upper conveyor belt of the first conveyor 5 under the drive of the tail material return conveying device and re-conveyed, which can effectively reduce the accumulation of materials at the tail.

[0044] Both the tail return material conveying device and the return ash conveying device are scraper conveying mechanisms. Taking the return ash conveying device as an example to illustrate the specific structure of the scraper conveying mechanism, the return ash conveying device includes a return material drive shaft, a return material driving sprocket 39, a return material tensioning shaft, a return material tensioning sprocket 40, a return material redirecting shaft, a return material redirecting sprocket 41 and a return material power device 42. The return material drive shaft is arranged in the return ash housing 34, located at a corner of the square return ash housing 34. Inside the square return ash housing 34, a return material driven shaft, a return material tensioning shaft and a return material redirecting shaft are respectively arranged at the other three corners. A return material power device 42 is provided outside the return ash housing 34. The return material power device 42 is connected to the return material drive shaft to drive the return material drive shaft to rotate relative to the return ash housing 34. A return material driving sprocket 39 is provided on the return material drive shaft. A return material driven sprocket 43 is provided on the return material driven shaft. A return material redirecting sprocket 41 is provided on the return material redirecting shaft. A return material tensioning sprocket 40 is provided on the return material tensioning shaft. The return material driving sprocket 39, the return material driven sprocket 43, the return material redirecting sprocket 41 and the return material tensioning sprocket 40 are connected by a return material chain 45. A plurality of return material scrapers 44 are fixedly connected to the return material chain 45. Under the action of the return material power device 42, the return material chain 45 drives the return material scrapers 44 to move inside the square annular return ash housing 34. The material flowing out from the ash cleaning outlet 33 of the ash cleaning housing 30 enters the return ash housing 34, and then is transported to the return ash outlet 36 under the action of the return material scrapers 44, and falls from the return ash outlet 36 onto the upper conveyor belt of the low-position conveyor belt 22.

[0045] An air vent groove 46 is arranged on the inner side of the bottom plate of the closed housing 16. Air holes are densely arranged on the air vent groove 46. The air holes correspond to the bottom surface of the return conveyor belt of the conveyor. Air outlets are arranged on the closed housing 16 at the connection of the discharging end 17 of the front conveyor and the feeding end 18 of the rear conveyor and at the discharging points of the belt conveyor with multi-point discharging. The air outlets are communicated with the air inlet of the dust collector 12. The air outlet of the dust collector 12 is communicated with the air inlet of the fan 13. The air outlet of the fan 13 is communicated with the air inlet of the air vent groove 46 through a pipeline.

[0046] As Figure 11As shown in the figure, a scraping device 48 is provided at the discharging end 17 of the first conveyor. The scraping device 48 includes a scraper 481, a scraping support plate 482 for supporting the scraper 481, and a scraping shaft 483. The scraper 481 is in close contact with the surface of the return conveyor belt on the driving roller at the discharging end 17 of the first conveyor 5. The scraper 481 is connected to one side of the scraping support plate 482, and the other side of the scraping support plate 482 is connected to the scraping shaft 483. The scraping shaft 483 is rotatably connected to the closed housing 16. A pressing mechanism is provided outside the closed housing 16. The pressing mechanism includes a scraping swing rod 484, a pressing connecting rod 485, and a pressing spring 486. One end of the scraping swing rod 484 is connected to the scraping shaft 483, and the other end of the scraping swing rod 484 is hinged to the pressing connecting rod 485. A pressing spring 486 is provided between the pressing connecting rod 485 and the closed housing 16. The elastic force of the pressing spring 486 is used to keep the scraper 481 always in close contact with the surface of the conveyor belt of the driving roller of the first conveyor 5. The scraper 481 is in close contact with the conveyor belt. During operation, the materials or dust adhered to the conveyor belt are separated from the conveyor belt under the action of the scraper 481, which can effectively reduce the amount of materials carried by the return conveyor belt, thereby reducing the accumulation of materials on the inner bottom plate of the closed housing 16. At the same time, the scraper 481 of the present invention is in close contact with the surface of the return conveyor belt at the driving roller. The dust and materials scraped off by the scraper 481 directly fall onto the second conveyor 6 and are continuously conveyed by the second conveyor 6.

[0047] As Figure 7 and Figure 8 shown in the figure, a feed hopper 7 is provided on the closed housing 16 at the end where the driven roller of the first conveyor 5 is located. The feed hopper 7 includes a hopper body 71. The hopper body 71 has a feed section 72, a discharge section 73, and a buffer section 74. The feed section 72 has a feed port, the discharge section 73 has a discharge port, and a guide plate 75 inclined from outside to inside is provided at the discharge port of the discharge section 73. The axis of the feed section 71 is arranged parallel and offset with the axis of the discharge section 73. The feed section 71 and the discharge section 73 are connected by an inclined buffer section 74. An inclined chute 76 is provided in the buffer section 74. The cross-sectional shape of the inclined chute 76 is "V" shaped. The inclined chute 76 has a discharge narrow opening 77. The discharge narrow opening 77 is located at the center of the bottom of the inclined chute 76 on the side close to the feed section 72. On the inner walls of the two side plates of the buffer section 74, inwardly protruding guide bumps 78 are provided, and the two guide bumps 78 are arranged oppositely, and there is a passage for materials to flow through between the two guide bumps 78. The guide bumps 78 are located at one end of the inclined chute 76 close to the discharge section 73. The side of the guide bump 78 close to the feed section 72 has a guide inclined surface 79. The guide inclined surface 79 is inclined from outside to inside along the material flow direction from the feed section to the discharge section 73.

[0048] During use, in this embodiment, grain feeding operations are performed on four grain bins. The first discharge point 8 of the first conveyor 5 corresponds to the first grain bin 1, the second discharge point 9 of the first conveyor 5 corresponds to the second grain bin 2, the first discharge point 10 of the second conveyor 6 corresponds to the third grain bin 3, and the second discharge point 11 of the second conveyor 6 corresponds to the fourth grain bin 4.

[0049] Grain materials enter from the feed hopper 7. When feeding the first grain bin 1, start the first conveyor 5 and start the driving device 234 of the discharger 23 at the first discharge point 8 of the first conveyor 5. The driving device 234 is a motor, and the motor drives the rotating shaft 2333 to rotate, thereby driving the arc-shaped baffle 2332 and the bottom plate 2331 of the discharge hopper 233 to flip, so that the two feed channels of the discharger 23 are respectively communicated with the two discharge channels. The grain materials flowing out from the high-position roller at the first discharge point 8 of the first conveyor 5 enter from the feed port 235 of the discharger 23, and then under the action of the discharge hopper 233, flow out from the discharge ports 237 on both sides, respectively enter the discharge boxes 24 on both sides of the closed housing 16, and then discharge along the discharge box 24 and enter the first grain bin 1 along the feed port of the first grain bin 1, realizing the feeding of the first grain bin 1.

[0050] When feeding the second grain bin 2, start the driving device 234 of the discharger 23 at the first discharge point 8 of the first conveyor 5 again. The motor drives the rotating shaft 2333 to rotate in the reverse direction, thereby driving the discharge hopper 233 to flip, and both feed channels are communicated with the discharge channel. The grain materials flowing out from the high-position roller at the first discharge point 8 of the first conveyor 5 enter from the feed port 235 of the discharger 23, and then under the action of the discharge hopper 233, flow out from the middle discharge port, fall onto the lower conveyor belt at the first discharge point 8 of the first conveyor 5, and then continue to be conveyed. At this time, the first discharge point 8 of the first conveyor 5 does not discharge.

[0051] Start the driving device 234 of the discharger 23 at the connection between the first conveyor 5 and the second conveyor 6. The connection between the first conveyor 5 and the second conveyor 6 is the second discharge point 9, so that the discharge hopper 233 at the second discharge point 9 flips, and the feed channel in the discharge hopper 233 at this place is communicated with the discharge channel. The grain materials conveyed by the first conveyor 5 fall from the discharge end 17 of the first conveyor 5 and enter the discharger 23 inside the second discharge point 9, enter the discharge channel along the feed channel of the discharge hopper 233 at the second discharge point 9, and then enter the second grain bin 2 from the discharge box 24 and the feed port of the second grain bin 2, realizing the feeding of the second grain bin 2. Similarly, when it is necessary to feed the third grain bin 3 or the fourth grain bin 4, only need to adjust the discharger 23 at the discharge point corresponding to the bin to be fed to the discharging state, and adjust the discharger 23 at other discharge points to the discharging state.

[0052] During the use of the present invention, the blower 13 is started. During the conveying process, discharging process, or unloading process of the grain material, the generated dust flows out from the air outlet under the action of the blower 13, and then enters the dust collector 12 for dust removal. The air flow after dust removal enters the ventilation groove 46 provided on the inner side of the bottom plate of the closed housing 16 under the action of the blower 13. Then, the air flow flows out from the air holes on the ventilation groove 46 to form an air cushion between the return conveyor belt and the bottom plate of the closed housing 16 and the return conveyor belt, thereby reducing the friction between the return conveyor belt and the bottom plate of the closed housing 16, ensuring the service life of the conveyor belt, and reducing the energy consumption of the conveyor.

[0053] Taking the transportation of corn by a belt conveyor as an example. Through the belt conveyor discharging collision dust-raising experiment carried out in the laboratory, the collision dust-raising at the discharging point of the multi-point discharging closed belt conveyor is reduced by setting the conveying speed, collision angle, and unloading height of the belt conveyor.

[0054] The belt conveyor discharging collision dust-raising experiment includes the following steps: S1. Build a belt conveyor discharging collision dust-raising experimental device in the laboratory, and conduct a belt conveyor discharging collision dust-raising experiment to determine the conveying speed, collision angle, and unloading height of the belt conveyor with the least collision dust-raising.

[0055] S11. Prepare experimental grain samples S111. Prepare a certain amount of corn grains, requiring that the corn grains are plump, without shriveled grains and broken grains; S112. Add an equal amount of tracer particles to the grain particles in step S111 and mix them evenly. The tracer particles are made of glutinous rice flour.

[0056] S12. Build the experimental device, and the experimental device is built in a constant temperature and humidity chamber.

[0057] S121. Arrange a belt conveyor with adjustable height and speed; The height adjustment range of the belt conveyor is 1.0 m to 2.0 m, and the speed adjustment range is 2.1 m / s to 4.1 m / s.

[0058] S122. Set an angle-adjustable baffle at the discharging end of the belt conveyor and adjust the installation angle of the baffle; The angle adjustment range of the included angle between the baffle and the horizontal plane is 0 to 180°.

[0059] S123. Arrange a PIV test system; The PIV test system includes a laser illumination device, a CCD camera, a synchronization controller, and a computer equipped with an image analysis system. The lens of the CCD camera faces the baffle directly, the laser illumination device faces the baffle directly, the synchronization controller is communicatively connected to the CCD camera and the laser illumination device, and the CCD camera is communicatively connected to the computer equipped with the image analysis system.

[0060] S13. Obtain the baffle installation angle with the least collision dust S131. Set the height difference between the discharge end of the belt conveyor and the baffle plane to 200 mm, set the motor frequency corresponding to the conveying speed of 2.1 m / s, set the installation angle of the baffle to 30°, calibrate the PIV test system, and start the belt conveyor.

[0061] S132. After the belt conveyor runs stably, add a certain amount of the grain sample obtained in step S1 to the belt conveyor.

[0062] S133. When the grain sample is discharged and collides with the baffle at the discharge end of the belt conveyor, the PIV test system conducts an experimental shooting to obtain multiple corresponding optical photos of the grain sample colliding with the baffle.

[0063] S134. Adjust the baffle installation angles to 45°, 60°, 120°, 135°, and 150° respectively, calibrate the PIV test system, and repeat steps S132 - S134 to obtain multiple groups of optical photos of the grain sample colliding with the baffle with the same height difference between the discharge end of the belt conveyor and the baffle plane, the same conveying speed of the belt conveyor, and different baffle installation angles; as Figure 15 Shown are the optical photos of the corn sample colliding with the baffle when the baffle installation angles are 30°, 45°, 60°, 120°, 135°, and 150° respectively.

[0064] S135. Use the visualization post - processing software Tecplot to conduct a comparative analysis of the optical photos obtained in step S134 to obtain the velocity trace map of the dust collision and diffusion when the grain sample collides with the baffle; as Figure 16 Shown are the velocity trace maps of the corn sample colliding with the baffle dust when the baffle installation angles are 30°, 45°, 60°, 120°, 135°, and 150° respectively.

[0065] S136. Conduct a comparative analysis of the optical photos obtained in step S134 and the velocity trace maps obtained in step S135 to obtain the baffle installation angle with the least collision dust when the height difference between the discharge end of the belt conveyor and the baffle plane is the same and the conveying speed of the belt conveyor is the same. By Figure 15 and Figure 16As shown, the installation angle of the baffle is adjusted from 30° to 150°, and the proportion of collision dust shows a trend of first decreasing and then increasing. When the installation angle of the baffle is 60°, the generation of collision dust is the least. This indicates that at 60°, more kinetic energy of the grain particles is converted into sliding along the baffle direction rather than generating collision dust. At other angles, the kinetic energy conversion efficiency is relatively low. Especially when the inclination angle is greater than 60°, the rebound kinetic energy increases, resulting in an expanded dust diffusion range. When the baffle angle changes from 120° to 150°, the dust diffusion range and the amount of dust flying increase gradually. The horizontal kinetic energy is gradually converted into vertical kinetic energy, leading to a significant increase in both dust flying and collision dust. The dust diffusion trajectory is complex and the diffusion range is wide. Therefore, when the height difference between the discharge end of the belt conveyor and the baffle plane is the same and the conveying speed of the belt conveyor is the same, the installation angle of the baffle with the minimum collision dust flying is 60°.

[0066] S14. Obtain the conveying speed with the minimum collision dust flying S141. Set the height difference between the discharge end of the belt conveyor and the baffle plane to 200 mm, set the motor frequency corresponding to the conveying speed of 2.1 m / s, set the installation angle of the baffle to 30°, calibrate the PIV test system, and start the belt conveyor.

[0067] S142. Repeat steps S132 - S133 to obtain multiple optical photos of the grain sample colliding with the baffle when the height difference between the discharge end of the belt conveyor and the baffle plane is 200 mm, the conveying speed is 2.1 m / s, and the installation angle of the baffle is 30°.

[0068] S143. Adjust the motor frequencies of the belt conveyor to 3.1 m / s, 4.1 m / s, and 4.9 m / s respectively, calibrate the PIV test system, and repeat steps S132 - S134 to obtain multiple optical photos of different groups of grain samples colliding with the baffle when the height difference between the discharge end of the belt conveyor and the baffle plane is the same, the installation angle of the baffle is the same, and the conveying speed of the belt conveyor is different. As Figure 17 shown are the optical photos of the corn sample colliding with the baffle when the conveying speeds of the belt conveyor are 2.1 m / s, 3.1 m / s, 4.1 m / s, and 4.9 m / s respectively. As Figure 18 shown is the velocity trace diagram of the collision - diffused dust when the corn sample collides with the baffle when the conveying speeds of the belt conveyor are 2.1 m / s, 3.1 m / s, 4.1 m / s, and 4.9 m / s respectively.

[0069] S144. Repeat steps S135 - S136 to obtain the conveying speed of the belt conveyor with the minimum collision dust flying when the height difference between the discharge end of the belt conveyor and the baffle plane is the same and the installation angle of the baffle is the same.

[0070] When the conveying speed of the belt conveyor is 2.1 m / s, the dust diffusion speed generated by the impact of the grain sample on the baffle is mostly controlled below 0.3 m / s; when the conveying speed is 3.1 m / s, the generated dust diffusion speed is mostly below 0.6 m / s; when the conveying speed is 4.1 m / s, the generated dust diffusion speed is about 1.1 m / s; when the conveying speed is 4.9 m / s, the generated dust diffusion speed is about 1.3 m / s. From Figure 17 and Figure 18 it can be seen that when the conveying speed is low, the proportion of dust raised by the conveyor is larger than that of the collision dust. The dust diffusion trajectory mainly moves along the direction of contacting the baffle, showing a strong tendency to diffuse along the baffle. When the conveyor belt speed is high, the proportion of collision dust is larger than that of the dust raised by the conveyor. The diffusion effect of the collision dust is obvious. The dust diffuses and moves perpendicular to the baffle direction, and the eddy current distribution is significant. It can be seen from this that as the conveying speed of the belt conveyor increases, the greater the dust diffusion speed of the grain dust, the more obvious the eddy current distribution. The dust diffusion range also increases with the increase of the speed. Therefore, when the height difference between the discharge end of the belt conveyor and the baffle plane is the same and the baffle installation angle is the same, the conveying speed of the belt conveyor with the least collision dust raising is 2.1 m / s.

[0071] S15. Obtain the height difference between the discharge end of the belt conveyor with the least collision dust raising and the baffle plane S151. Set the height difference between the discharge end of the belt conveyor and the baffle plane to 200 mm, set the motor frequency corresponding to the conveying speed of 2.1 m / s, set the installation angle of the baffle to 30°, calibrate the PIV test system, and start the belt conveyor.

[0072] S152. Repeat steps S132 - S133 to obtain multiple optical photos of the grain sample colliding with the baffle when the height difference between the discharge end of the belt conveyor and the baffle plane is 200 mm, the conveying speed is 2.1 m / s, and the installation angle of the baffle is 30°.

[0073] S153. Adjust the height difference between the discharge end of the belt conveyor and the baffle plane to 350 mm and 500 mm respectively, calibrate the PIV test system, and repeat steps S132 - S134 to obtain multiple groups of optical photos of the grain sample colliding with the baffle with the same conveying speed, the same baffle installation angle, and different height differences between the discharge end of the belt conveyor and the baffle plane. As Figure 19 shown are the optical photos of the corn sample colliding with the baffle when the conveying speeds of the belt conveyor are 200 mm, 350 mm, and 500 mm respectively. As Figure 20 shown are the velocity trace diagrams of the collision-diffused dust when the corn sample collides with the baffle when the conveying speeds of the belt conveyor are 200 mm, 350 mm, and 500 mm respectively.

[0074] S154. Repeat steps S135 - S136 to obtain the height difference between the discharge end of the belt conveyor and the baffle plane when the baffle installation angles are the same and the collision dust generation is minimized at the same baffle installation angle.

[0075] The height difference between the discharge end of the belt conveyor and the baffle plane is the falling height of the grain. As shown in Figure 19 and Figure 20 , different falling heights of the grain have a significant impact on dust diffusion. At a lower falling height, the kinetic energy of the grain particles is lower, less collision dust is generated when hitting the baffle, and the amount of dust raised is also less. The dust diffusion range is smaller. As the falling height increases, the kinetic energy of the grain particles increases, and a large amount of collision dust and dust raised are generated. The dust diffusion range is the largest, the diffusion trajectory is complex, mainly diffusing along the baffle direction and the vertical direction, and a vortex effect is generated. In addition, as the falling height of the grain increases, the dust diffusion concentration continues to increase. This phenomenon is because as the falling height increases, the kinetic energy of the grain increases, and the intensity of the induced air flow also increases accordingly. After the collision, the speed of the grain changes rapidly, resulting in a greater collision intensity. And the larger induced air flow also increases the probability of dust diffusion on the grain surface, promoting the phenomenon of secondary dust raising, thus leading to more obvious dust diffusion as the height increases. As can be seen from the Figure 20 velocity trace diagram, as the falling height of the grain increases, the vertical component velocity of the dust increases, the dust diffusion speed increases significantly, the dust diffusion range and concentration increase, and the diffusion trajectory becomes more complex, making it easy to generate dust vortices. Therefore, when the baffle installation angles are the same, the height difference between the discharge end of the belt conveyor and the baffle plane with the minimum collision dust generation is 200 mm. Example 2

[0076] As Figure 21 shown, repeat Example 1 with the following differences: the first conveyor is arranged at an angle b with the horizontal plane, b = -170°, and the last conveyor is arranged at an angle c with the horizontal plane, c = 10°.

[0077] It should be noted that the above embodiments are illustrative rather than restrictive of the technical solutions of the present invention. Equivalent substitutions by those of ordinary skill in the art or other modifications based on the existing technology, as long as they do not exceed the scope and spirit of the technical solutions of the present invention, should be included within the scope of the rights required by the present invention.

Claims

1. A closed combined belt conveyor system with multi-point unloading, comprising a closed shell, at least one conveyor and at least one unloader arranged in the closed shell, wherein the conveyor is a belt conveyor or / and a multi-point unloading belt conveyor, all the conveyors in the closed shell are connected in series, the unloading end of the front conveyor is located above the feeding end of the rear conveyor, a height difference is formed between the unloading end of the front conveyor and the feeding end of the rear conveyor, and a unloader is arranged between the unloading end of the front conveyor and the feeding end of the rear conveyor, The unloading point of the multi-point unloading belt conveyor has a high roller and a low roller. The high roller is arranged above the low roller, and a height difference is formed between the high roller and the low roller. The high roller is located at the unloading end of the high conveyor belt of the multi-point unloading belt conveyor, and the low roller is located at the starting end of the low conveyor belt of the multi-point unloading belt conveyor. A discharger is arranged between the high roller and the low roller. Features: The discharger is arranged at an angle, and includes a discharge shell, a feed port at the upper end of the discharge shell, a discharge port at the lower end of the discharge shell and discharge ports on both sides of the discharge shell, the feed port corresponds to the high-position roller or the discharge end of the front conveyor, the discharge port corresponds to the low-position conveyor belt or the feed end of the rear conveyor, the discharge ports on both sides of the discharge shell are respectively connected with the discharge boxes on both sides of the closed shell, two inclined receiving hoppers are provided in the feed port, the inner cavities of the two receiving hoppers are connected with the discharge port to form a discharge channel, the inner cavities of the two receiving hoppers are respectively connected with the discharge port to form a discharge channel, a discharge hopper capable of flipping relative to the discharge shell and a driving device for driving the flipping of the discharge hopper are provided in the discharge shell, the flipping of the discharge hopper realizes the switching of the discharge channel and the discharge channel, the angle between the receiving plate of the receiving hopper and the horizontal line is a, and the height difference between the receiving plate and the upper end of the high-position roller or the upper end of the discharge end of the front conveyor is h.

2. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The angle a is 45-60°, and the height h is 200-300 mm.

3. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The discharge hopper includes a bottom plate and arc-shaped baffles fixed on both sides of the bottom plate. A rotating shaft is provided on the outer sides of the two arc-shaped baffles. The rotating shafts outside the two arc-shaped baffles are coaxially arranged, and one of the rotating shafts passes through the closed shell and is connected to a driving device arranged outside the closed shell. The driving device drives the rotating shaft to drive the arc-shaped baffle and the bottom plate to flip.

4. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The two receiving hoppers in the feed port of the discharge shell are arranged in parallel, and the lower end openings of the two receiving hoppers are respectively deep into the inner cavities of the two discharge hoppers. The receiving hopper is a funnel-shaped structure surrounded by a receiving plate, an inner wall plate, an outer wall plate and a baffle plate. The receiving plate and the baffle plate are arranged opposite to each other, and the inner wall plate and the outer wall plate are arranged opposite to each other. The inner cavity of the receiving hopper forms a feeding channel. The two sides of the discharge port of the discharge shell are provided with discharge plates arranged downward from the outside to the inside, and the two discharge plates are respectively connected to the two receiving Corresponding to the outer wall plate of the hopper, the discharge port of the discharge shell is provided with a discharge plate which is arranged downwardly and inclined from the inside to the outside, and the discharge plates of the two discharge ports respectively correspond to the inner wall plates of the two receiving hoppers. When the discharger is unloading, the bottom plate of the discharge hopper fits with the inner wall plate and the discharge plate to form a discharge channel, and the feed port of the discharge shell is connected with the discharge port. When the discharger is discharging, the bottom plate of the discharge hopper fits with the outer wall plate and the discharge plate to form a discharge channel, and the feed port of the discharge shell is connected with the discharge port.

5. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The ash collecting port is arranged on the bottom plate of the closed shell at the connection between the discharge end of the front conveyor and the feed end of the rear conveyor, a cleaning shell is arranged below the ash collecting port, a cleaning feed port connected to the ash collecting port is arranged on the top plate of the cleaning shell, an ash collecting plate is arranged in the cleaning shell, both sides of the ash collecting plate are connected to the side plates of the cleaning shell, a cleaning conveying device is arranged in the cleaning shell, the cleaning conveying device is used to convey the material received by the ash collecting plate to the cleaning discharge port, the cleaning discharge port is located at the lower end of one side of the cleaning shell, and the cleaning The ash discharge port is connected to the ash return feed port of the ash return shell, and the ash return shell is a square annular hollow shell. The feed end of the rear conveyor passes through the inner ring square hole of the square annular shell, and the ash return shell is located on one side above the rear conveyor and is provided with an ash return discharge port opening downward, and the ash return discharge port corresponds to the upper conveyor belt of the rear conveyor. An ash return conveying device is arranged in the ash return shell, and the ash return conveying device conveys the material conveyed by the ash cleaning conveying device to the upper conveyor belt of the low-position conveyor belt, and the return material operation device is a scraper conveying mechanism.

6. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The dust cleaning and conveying device is a dust cleaning scraper and a dust cleaning chain mechanism arranged in a dust cleaning shell. The two ends of the dust cleaning scraper are respectively connected to the chains of two dust cleaning chain mechanisms. The lower end of the dust cleaning scraper contacts the top surface of the dust collecting plate. The two dust cleaning chain mechanisms drive the dust cleaning scraper to move, and the dust cleaning scraper pushes the material on the dust collecting plate.

7. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: A ventilation groove is arranged on the inner side of the bottom plate of the closed shell, and air holes are densely arranged on the ventilation groove, and the air holes correspond to the bottom surface of the return conveyor belt of the conveyor. An air outlet is arranged on the closed shell at the connection between the unloading end of the front conveyor and the feeding end of the rear conveyor and the unloading point of the multi-point unloading belt conveyor, and the air outlet is connected to the air inlet of the dust collector, and the air outlet of the dust collector is connected to the air inlet of the fan, and the air outlet of the fan is connected to the air inlet of the ventilation groove through a pipeline.

8. The closed combined belt conveyor system with multi-point unloading according to claim 1 is characterized in that: The driven roller of the first conveyor in the series-connected conveyors is arranged in a movable shell, a tail bracket is arranged at the lower end of the movable shell, one side of the tail bracket is connected to the closed shell, and a roller is arranged on the other side of the tail bracket, and the roller contacts the lower end of the movable shell, the movable shell is plug-connected to the closed shell, the outer side of the movable shell is connected to the outer side of the closed shell by an adjusting screw, and the distance between the movable shell and the closed shell is adjusted by the adjusting screw to realize the tensioning of the tail end of the conveyor belt of the first conveyor in the series-connected conveyors.

9. The closed combined belt conveyor system with multi-point unloading according to claim 1, characterized in that: In the conveyors connected in series, a scraper device is provided at the discharge end of the front conveyor, and the scraper device includes a scraper, a scraper support plate supporting the scraper and a scraper shaft. The scraper is pressed against the surface of the return conveyor belt on the driving roller at the discharge end of the front conveyor, and the scraper is connected to one side of the scraper support plate, and the other side of the scraper support plate is connected to the scraper shaft, and the scraper shaft is rotatably connected to the closed shell, and a holding mechanism is provided outside the closed shell, and the holding mechanism includes a scraper rocker, a holding connecting rod and a holding spring, one end of the scraper rocker is connected to the scraper shaft, and the other end of the scraper rocker is hinged to the holding connecting rod, and a holding spring is provided between the holding connecting rod and the closed shell, and the elasticity of the holding spring is utilized to keep the scraper always in close contact with the surface of the conveyor belt.

10. The closed combined belt conveyor system with multi-point unloading according to claim 1, characterized in that: The first conveyor in the series-connected conveyors is arranged at an angle b with the horizontal plane, -170°≤b≤-180°, and the last conveyor in the series-connected conveyors is arranged at an angle c with the horizontal plane, 0≤c≤10°.

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