Linear reciprocating high-efficiency intelligent environmentally friendly continuous chain bucket ship unloader

Abstract

The present invention relates to a linear reciprocating high-efficiency intelligent environmentally friendly continuous chain bucket ship unloader, comprising a chain bucket material taking mechanism, which is fixed on a trolley assembly and moves along a track on an arm frame mechanism with the trolley assembly, and an arm frame belt connected to a material outlet of the chain bucket material taking mechanism and a transfer belt docked with the arm frame belt are installed on the arm frame mechanism, and the output end of the transfer belt docks with the unloading belt through a transfer hopper, and the output end of the unloading belt docks with a dock belt conveyor arranged on the dock through a central hopper; and also includes a trolley walking system mechanism, a guide cylinder is vertically installed on the gantry, a slewing mechanism is installed on the arm frame mechanism and is sleeved on the guide cylinder and rotates around it, and a lifting mechanism for controlling it to slide up and down along the guide cylinder is also installed on the arm frame mechanism. The present invention meets the unloading requirements of different ship types and different working conditions, has high efficiency and low cost, is convenient to use and has a long service life, and improves the utilization rate of the unloading space on the dock shoreline.

Description

Technical Field

[0001] The invention relates to the technical field of ship unloading mechanical devices, in particular to a linear reciprocating high-efficiency, intelligent, and environment-friendly continuous chain bucket ship unloader. Background Art

[0002] For bulk cargoes with large bulk density or uneven and relatively large particles, such as coal and ore, the current dock unloading equipment includes intermittent and continuous types. Intermittent ship unloaders are mainly bridge-type grab ship unloaders, which are characterized by mature models and wide application. However, because they use grab unloading, they have always been unable to solve the problems of high energy consumption, poor environmental performance (material spillage, dust flying), low average efficiency, and difficulty in realizing intelligent operation.

[0003] The existing continuous ship unloaders are mainly L-type chain bucket ship unloaders, which have good environmental performance and high productivity, but their application is very limited. The main reason is the defects of their working mode: the L-type chain bucket ship unloader is a boom type. When working, it uses three circular motions, namely, boom rotation, amplitude change, and chain bucket reclaiming head rotation, to cover the cabin working surface in conjunction with the walking of a large vehicle. Too fast circular motion speed will cause the problem of significant increase in inertial load, so its speed cannot be too high, which makes the time required for the ship unloader to switch the reclaiming operation line long, reducing the unloading efficiency of the entire ship. The compound circular motion also makes it difficult to achieve the automated operation of the entire ship. When facing large ships, the dock shoreline occupied by multiple equipment for unloading together is long and difficult to arrange. In addition, the operation mode of the reclaiming head of the L-type chain bucket system is rotary reclaiming, and the reclaiming direction is exactly perpendicular to the traction direction of the chain and the bucket mouth direction of the chain bucket, which causes the material to have a relatively large pushing resistance to the bucket side baffle. This lateral force acts on the cylindrical arm of the chain bucket system, causing it to twist and bend, and is transmitted to the entire machine structure and the slewing mechanism, making the relevant parts easy to damage and accelerating the wear of the chain. Especially when unloading ore, the resistance is very large, so the L-type chain bucket ship unloader is rarely used in ore terminals. At the same time, for sticky materials, the material cannot be unloaded cleanly and the material will be returned. Moreover, due to the side feeding, it is impossible to clear the bottom of the cabin, which reduces the average production efficiency of the whole ship loading and unloading. Summary of the invention

[0004] In view of the shortcomings in the above-mentioned existing production technology, the applicant provides a linear reciprocating high-efficiency, intelligent, and environmentally friendly continuous chain bucket ship unloader with a reasonable structure, thereby solving the technical problems of low production efficiency, large space occupation, large rotary material retrieving and pushing resistance causing component damage, and incomplete warehouse clearing in the prior art dock ship unloader.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A linear reciprocating high-efficiency, intelligent, and environmentally friendly continuous chain bucket ship unloader comprises a chain bucket reclaiming mechanism, which is fixed on a trolley assembly and moves horizontally along an arm frame mechanism with the trolley assembly; an arm frame belt connected to a material outlet of the chain bucket reclaiming mechanism and a transfer belt docked with the arm frame belt are installed on the arm frame mechanism; the output end of the transfer belt docks with the unloading belt through a transfer hopper, and the output end of the unloading belt docks with a dock belt conveyor arranged on the dock through a center hopper; the trolley walking system is also included, on which a guide cylinder is vertically installed; the arm frame mechanism is equipped with a slewing mechanism and is sleeved on the guide cylinder to slew around it; the arm frame mechanism is also equipped with a lifting mechanism for controlling it to slide up and down along the guide cylinder.

[0007] As a further improvement of the above technical solution:

[0008] The trolley assembly includes a frame, and the frame moves along the arm mechanism through the rollers at the bottom thereof; the installation structure of the chain bucket material-retrieving mechanism is as follows: it includes a cylinder vertically arranged with the frame, a closed-loop digging chain is installed in the cylinder, and a plurality of chain buckets are evenly installed along the outer side of the digging chain, and an opening is provided on one side of each chain bucket; the portion of the digging chain extending out of the bottom of the cylinder is the digging end in contact with the material, and a tensioning device is provided inside the cylinder, and the tensioning device includes two tensioning wheels for tensioning the inner side of the digging chain; a discharging chute extends from the upper end of the cylinder, and the lower portion of the outlet thereof is butt-jointed with a receiving hopper installed on the frame of the trolley assembly.

[0009] The installation structure of the arm mechanism is as follows: it includes a sunken front beam, the sunken front beam is hinged to one end of the bent rear beam, a balancing arm is extended from the other end of the bent rear beam, the bent rear beam is in a Z-shaped structure, and its height is higher than the sunken front beam, a herringbone frame is installed on the bent rear beam, the top of the herringbone frame is respectively hinged to one end of the front pull rod and one end of the rear pull rod, the other end of the front pull rod is hinged to the sunken front beam, and the other end of the rear pull rod is hinged to the balancing arm.

[0010] The sunken front beam is connected to the bent rear beam by a floating hinge. The bent rear beam is provided with a support below the hinge, and the sunken front beam is provided with a joint surface matching the support on the corresponding end face. The front pull rod is composed of three sections, and two adjacent sections are hinged by two center hinges respectively.

[0011] The arm belt is installed on the upper surface of the sunken front beam, and the trolley assembly moves along the upper surface of the sunken front beam; a machine room is installed on the upper surface of the balancing arm away from the bent rear beam, and a winch is arranged inside the machine room, and the winch is connected to the pulley blocks respectively installed on the upper surface of the bent rear beam and the top of the guide cylinder through ropes.

[0012] One fixed end of the transfer belt and the transfer hopper is located at the end of the balance arm frame where the machine room is installed, and the other fixed end is located at the end where the bent rear beam and the sunken front beam are hinged. The transfer hopper is installed at the bottom of the balance arm frame below the machine room.

[0013] The structure of the trolley travel system is as follows: it includes a wheel mechanism, on which a door leg support frame is supported and installed, and the guide cylinder is installed in the middle of the upper surface; the center hopper is fixedly installed on the door leg support frame located on one side of the guide cylinder, one end of the unloading belt is hinged to the center hopper, and the other end of the unloading belt is hinged to the transfer hopper.

[0014] The slewing mechanism comprises a slewing support installed on the arm mechanism, and a motor and a planetary reducer for driving the slewing support to rotate.

[0015] The arm belt, transfer belt and unloading belt are all equipped with dustproof covers; the transfer hopper and center hopper are all equipped with protective covers.

[0016] The beneficial effects of the present invention are as follows:

[0017] The present invention has a compact and reasonable structure and is easy to operate. Through the lifting of the arm mechanism, the linear motion of the trolley assembly and the trolley travel mechanism on three coordinate axes in the spatial position, and the rotary motion of the arm mechanism, it can fully meet the unloading requirements of different docks, ship types and working planes under different working conditions. It has the advantages of high efficiency, long service life, high efficiency and environmental protection, and improves the utilization rate of the unloading space on the dock shoreline. At the same time, the present invention also has the following advantages:

[0018] 1. The chain bucket reclaiming mechanism of the present invention adopts a forward cutting reclaiming method, that is, the feeding opening direction of the chain bucket is consistent with the traveling direction of the trolley, and the bucket mouth faces the material, so that the chain bucket is easy to fill and unload, with less material return and high productivity; it can adapt to the loading and unloading of materials with different characteristics, especially convenient for loading and unloading of bulk materials with large particles and large bulk density; it reduces the external load acting on the whole machine structure due to the operation of the chain bucket system, and the material pile has almost no lateral force on the chain bucket, the chain bucket and chain are reasonably stressed, and the service life is long;

[0019] 2. The sunken front beam of the arm mechanism of the present invention can reduce the height of the chain bucket reclaiming mechanism while ensuring the operation requirements. Its advantages are: reducing the lifting height of the material and the lifting power; reducing the moving load, the weight of the whole machine and the wheel pressure;

[0020] 3. The bent rear beam of the present invention provides slewing support and lifting support for the entire boom mechanism. Taking into account the particularity of ship unloading operations under wave conditions, a double hinge point type is used for the connection between the bent rear beam and the sinking front beam: when the ship unloader is working normally, the load of the sinking front beam is transmitted to the bent rear beam through the support-joint surface. When the surge causes the ship to move upward, the joint surface and the support step are separated from each other, the front pull rod is bent, and the sinking front beam can rise and fall around the floating hinge point, thereby quickly unloading the jacking force, thereby avoiding damage to the chain bucket reclaiming mechanism and the entire machine structure, and also protecting the cabin;

[0021] 4. The balance arm of the present invention is located at the rear of the whole machine, and a machine room is installed at its tail. It can be used as a support for the transfer belt conveyor system, the transfer hopper system and the unloading belt conveyor system, and can also be used as a counterweight. The counterweight ensures that the center of gravity of the lifting part is close to the center of the guide column, reducing the deflection load of the lifting movement;

[0022] 5. The present invention can be operated by multiple unloaders. The operating surface of each unloader is consistent with the occupied dock shoreline. Multiple unloaders can unload the same ship without occupying too much dock shoreline, which can not only improve the unloading efficiency of a single ship, but also improve the utilization rate of the dock shoreline and shorten the unloading time at the port.

[0023] 6. The unloading process of the present invention is reasonable. All links are sealed in a closed space by the cylinder, belt conveyor cover, hopper protective cover, etc. for transportation. It can improve productivity and realize automatic unloading while ensuring no pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention.

[0025] Figure 2 It is a top view of the present invention.

[0026] Figure 3 It is a structural schematic diagram of the chain bucket reclaiming mechanism of the present invention.

[0027] Figure 4 It is a schematic diagram of the digging state of the digging end of the chain bucket reclaiming mechanism of the present invention.

[0028] Figure 5 for Figure 4 Section view along AA section.

[0029] Figure 6 It is a structural schematic diagram of the arm support mechanism of the present invention.

[0030] Figure 7 for Figure 6 Enlarged view of part A in the middle.

[0031] Figure 8It is a schematic diagram of the state when the sunken front beam of the present invention floats relative to the bent rear beam.

[0032] Fig. 9 It is a structural schematic diagram of the trolley traveling mechanism of the present invention.

[0033] Fig.10 It is a schematic diagram of the state of the present invention when cleaning the bottom of the cabin.

[0034] Fig.11 This is a schematic diagram of the state of multiple ship unloaders of the present invention unloading a ship simultaneously.

[0035] Fig.12 It is a schematic diagram of the state when the present invention is not working.

[0036] Among them: 1. Chain bucket reclaiming mechanism; 2. Trolley assembly; 3. Boom mechanism; 4. Boom belt; 5. Pulley block; 6. Guide cylinder; 8. Transfer belt; 9. Machine room; 10. Transfer hopper; 11. Discharge belt; 12. Trolley walking system mechanism; 13. Center hopper; 14. Wharf belt conveyor; 15. Door leg support frame; 101. Cylinder; 102. Chain bucket; 103. Discharge chute; 104. Receiving hopper; 105. Tensioning wheel; 106. Opening; 301. Sunken front beam; 302. Front pull rod; 303. Rear pull rod; 304. A-shaped frame; 305. Floating hinge; 307. Bending rear beam; 308. Balance arm; 309. Center hinge; 311. Joint surface; 312. Support; A. Cargo ship; B. Wharf; B1. Wharf shoreline. DETAILED DESCRIPTION

[0037] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0038] like Figure 1 and Figure 2 As shown, the linear reciprocating high-efficiency, intelligent and environmentally friendly continuous chain bucket ship unloader of this embodiment includes a chain bucket reclaiming mechanism 1, which is fixed on a trolley assembly 2 and moves horizontally along an arm mechanism 3 with the trolley assembly 2. An arm belt 4 connected to the discharge port of the chain bucket reclaiming mechanism 1 and a transfer belt 8 connected to the arm belt 4 are installed on the arm mechanism 3. The output end of the transfer belt 8 is connected to a discharge belt 11 through a transfer hopper 10, and the output end of the discharge belt 11 is connected to a dock belt conveyor 14 arranged on dock B through a central hopper 13; it also includes a trolley walking system 12, which includes a door leg support frame 15, on which a guide cylinder 6 is vertically installed, and a slewing mechanism (not shown in the figure) is installed on the arm mechanism 3, the arm mechanism 3 is sleeved on the guide cylinder 6 and rotates around it, and the arm mechanism 3 is also installed with a lifting mechanism for controlling it to slide up and down along the guide cylinder 6.

[0039] like Figure 3 , Figure 4 and Figure 5 As shown, the trolley assembly 2 includes a frame, and the frame moves along the arm mechanism 3 through the rollers at the bottom thereof; the installation structure of the chain bucket material taking mechanism 1 is as follows: it includes a cylinder 101 vertically arranged with the frame, a closed-loop digging chain is installed in the cylinder 101, and a plurality of chain buckets 102 are evenly installed along the outer side of the digging chain, and an opening 106 is provided on one side of each chain bucket 102; the portion of the digging chain extending out of the bottom of the cylinder 101 is the digging end in contact with the material, and a tensioning device is provided inside the cylinder, and the tensioning device includes two tensioning wheels 105 for tensioning the inner side of the digging chain; a discharging chute 103 extends from the upper end of the cylinder 101, and the lower end of the outlet thereof is butt-jointed with a receiving hopper 104 installed on the frame of the trolley assembly 2.

[0040] like Figure 6 , Figure 7 and Figure 8 As shown, the installation structure of the arm mechanism 3 is: including a sunken front beam 301, the sunken front beam 301 is hinged to one end of the bent rear beam 307, and a balancing arm 308 is extended from the other end of the bent rear beam 307. The bent rear beam 307 is in a Z-shaped structure, and its height is higher than the sunken front beam 301. A herringbone frame 304 is installed on the bent rear beam 307, and the top of the herringbone frame 304 is respectively hinged to one end of the front pull rod 302 and one end of the rear pull rod 303, the other end of the front pull rod 302 is hinged to the sunken front beam 301, and the other end of the rear pull rod 303 is hinged to the balancing arm 308.

[0041] The sunken front beam 301 is connected to the bent rear beam 307 by a floating hinge 305. The bent rear beam 307 is provided with a support 312 below the hinge with the sunken front beam 301. The sunken front beam 301 is provided with a joint surface 311 matching the support 312 at a corresponding position. The front pull rod 302 is composed of three sections, and two adjacent sections are hinged by two center hinges 309 respectively.

[0042] A boom belt 4 is installed on the upper surface of the sunken front beam 301, and the trolley assembly 2 moves along the track on the upper surface of the sunken front beam 301; a machine room 9 is installed on the upper surface of the balancing boom 308 away from the bent rear beam 307, and a winch 16 for controlling the lifting of the boom mechanism 3 is provided inside the machine room 9. The winch 16 is connected to the pulley blocks 5 respectively installed on the upper surface of the bent rear beam 307 and the top of the guide cylinder 6 in sequence through ropes.

[0043] One fixed end of the transfer belt 8 and the transfer hopper 10 is located at one end of the balance arm 308 where the machine room 9 is installed, and the other fixed end is located at one end where the bent rear beam 307 and the sunken front beam 301 are hinged. The transfer hopper 10 is installed at the bottom of the balance arm 308 below the machine room 9.

[0044] like Fig. 9As shown, the structure of the trolley travel system 12 is: it includes a wheel mechanism, on which a door leg support frame 15 is supported and installed, and a guide cylinder 6 is installed in the middle of the upper surface; a center hopper 13 is fixedly installed on the door leg support frame 15 located on one side of the guide cylinder 6, and the center hopper 13 is hinged to one end of the unloading belt 11, and the other end of the unloading belt 11 is hinged to the transfer hopper 10.

[0045] The slewing mechanism includes a slewing support installed on the arm mechanism 3, and a motor and a planetary reducer (not shown in the figure) for driving the slewing support to rotate.

[0046] The arm frame belt 4, the transfer belt 8 and the unloading belt 11 are all provided with dustproof covers; the transfer hopper 10 and the center hopper 13 are all provided with protective covers on their exteriors.

[0047] During implementation of the present invention:

[0048] The chain bucket reclaiming mechanism 1 digs the material from the cabin of the cargo ship A, unloads it to the arm belt 4, transfers it to the unloading belt 11 through the transfer belt 8 and the transfer hopper 10, and then transfers it to the wharf belt conveyor 14 through the central hopper 13. All links are sealed in a closed space by the cylinder 101, the cover of each belt conveyor, the hopper protective cover, etc. for transportation, thereby eliminating dust leakage in the material transportation link and the transfer link, ensuring the environmental protection of unloading and transportation.

[0049] like Figure 1 and Fig.10 As shown in the figure, the unloading states of the full and empty cabins are respectively achieved. The arm mechanism 3 moves up and down along the guide cylinder 6 to complete the unloading from the full cabin to the empty cabin state. The distance of the chain bucket reclaiming mechanism 1 relative to the dock shoreline B1 is adjusted by the left and right movement of the trolley assembly 2 to facilitate the reclaiming of materials at different positions in the cabin. The chain bucket reclaiming mechanism 1 moves with the movement of the trolley assembly 2, as shown in FIG. Figure 4 As shown in the direction of the middle arrow, the chain bucket opening direction is in line with the forward running direction of the trolley assembly 2 (to the left), so that the opening can cut the material from the front to achieve material collection. When the trolley assembly 2 moves in the reverse direction (to the right), under the condition that the trolley travel speed and the digging chain traction speed are reasonably matched, the chain bucket 102 can rake the material, thereby truly realizing reciprocating linear material collection, so as to improve the ship unloading efficiency and realize intelligent operation. In the stage of clearing the cabin, with the cooperation of the trolley assembly 2 and the trolley travel mechanism 12, the chain bucket 102 moves with its opening close to the cabin bottom plate, which can clear the materials on the cabin bottom on the travel path, reducing the amount of manual clearance and improving the average ship unloading efficiency.

[0050] like Fig.11As shown in the figure, the operating surface of each ship unloader is consistent with the dock shoreline B1 it occupies. Multiple ship unloaders can unload the same ship together without occupying too much dock shoreline B1, which can not only improve the unloading efficiency of a single ship, but also improve the utilization rate of the dock shoreline B1. Fig.12 As shown, when not in operation, the arm mechanism 3 and the guide cylinder 6 rotate to be parallel to the dock shoreline B1.

[0051] The chain bucket reclaiming mechanism 1 reclaims and lifts the materials, and the continuous conveying equipment such as belt conveyors lifts, transfers and transports the materials. The unloading process is continuous, the production efficiency is high, and the cost per ton of unloading materials, including power consumption and manpower, can be reduced. Therefore, the present invention is an efficient, green and environmentally friendly ship unloader.

[0052] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. Any form of modification may be made within the scope of protection of the present invention.

Claims

1. A linear reciprocating high-efficiency, intelligent and environmentally friendly continuous chain bucket ship unloader, characterized by: The invention comprises a chain bucket reclaiming mechanism (1), wherein the chain bucket reclaiming mechanism (1) is fixed on a trolley assembly (2) and moves along a track on an arm frame mechanism (3) with the trolley assembly (2); the arm frame mechanism (3) is provided with an arm frame belt (4) connected to a material outlet of the chain bucket reclaiming mechanism (1) and a transfer belt (8) connected to the arm frame belt (4); the output end of the transfer belt (8) is connected to a discharge belt (11) through a transfer hopper (10); the output end of the discharge belt (11) is connected to a dock belt conveyor (14) arranged on a dock (B) through a central hopper (13); and the invention also comprises a trolley walking system mechanism (12), wherein the trolley walking system mechanism (12) comprises a door leg support frame (15) on which a guide cylinder (6) is vertically mounted. The arm mechanism (3) is provided with a slewing mechanism and is sleeved on a guide cylinder (6) to slew around the guide cylinder (6). The arm mechanism (3) is also provided with a lifting mechanism to control the arm mechanism to slide up and down along the guide cylinder (6). The trolley assembly (2) includes a frame, and the frame moves along the arm mechanism (3) via rollers at the bottom thereof. The installation structure of the chain bucket reclaiming mechanism (1) comprises a cylinder (101) vertically arranged with the frame, a closed-loop digging chain is installed in the cylinder (101), and a plurality of chain buckets (102) are evenly spaced along the outer side of the digging chain, and an opening (106) is provided on one side surface of each chain bucket (102); the portion of the digging chain extending out of the bottom of the cylinder (101) is the digging end in contact with the material, and a tensioning device is provided inside the cylinder, and the tensioning device comprises Two tensioning wheels (105) for tensioning the inner side of the digging chain; a discharging chute (103) extends from the upper end of the cylinder (101), and the lower end of the discharge chute is butt-jointed with a receiving hopper (104) mounted on the frame of the trolley assembly (2); the mounting structure of the arm mechanism (3) comprises a sinking front beam (301), the sinking front beam (301) is hinged to one end of a bending rear beam (307), a balancing arm (308) extends from the other end of the bending rear beam (307), the bending rear beam (307) is in a Z-shaped structure, and its height is higher than the sinking front beam (301), a herringbone frame (304) is mounted on the bending rear beam (307), and the top of the herringbone frame (304) is respectively connected to one end of the front pull rod (302) and the rear pull rod (303). One end is hinged, the other end of the front pull rod (302) is hinged on the sunken front beam (301), and the other end of the rear pull rod (303) is hinged on the balance arm (308); the sunken front beam (301) is connected to the bent rear beam (307) through a floating hinge (305), the bent rear beam (307) is provided with a support (312) below the hinge, and the sunken front beam (301) is provided with a joint surface (311) that cooperates with the support (312); the front pull rod (302) is composed of three sections, and two adjacent sections are respectively hinged by two central hinges (309); the arm belt (4) is installed on the upper surface of the sunken front beam (301), and the trolley assembly (2) moves along the track on the upper surface of the sunken front beam (301);A machine room (9) is installed on the upper surface of one end of the balancing arm (308) away from the bent rear beam (307), and a winch (16) is arranged inside the machine room. The winch (16) is connected to pulley blocks (5) respectively installed on the upper surface of the bent rear beam (307) and the top of the guide cylinder (6) in sequence through ropes. ; 2. The linear reciprocating high-efficiency, intelligent and environmentally friendly continuous chain bucket ship unloader according to claim 1, characterized in that: One fixed end of the transfer belt (8) and the transfer hopper (10) is located at one end of the balance arm (308) where the machine room (9) is installed, and the other fixed end is located at one end where the bent rear beam (307) and the sunken front beam (301) are hinged, and the transfer hopper (10) is installed at the bottom of the balance arm (308) below the machine room (9).

3. The linear reciprocating high-efficiency, intelligent and environmentally friendly continuous chain bucket ship unloader according to claim 1, characterized in that: The slewing mechanism comprises a slewing support body mounted on the bent rear beam (307), and a motor and a planetary reducer for driving the slewing support body to slew.

4. The linear reciprocating high-efficiency, intelligent and environment-friendly continuous chain bucket ship unloader according to claim 1, characterized in that: The structure of the trolley travel system (12) is as follows: it includes a wheel mechanism, on which the door leg support frame (15) is supported and mounted, and the guide cylinder (6) is mounted in the middle of the upper surface; the center hopper (13) is fixedly mounted on the door leg support frame (15) located on one side of the guide cylinder (6), one end of the unloading belt (11) is hinged to the center hopper (13), and the other end is hinged to the transfer hopper (10).

5. The linear reciprocating high-efficiency, intelligent and environment-friendly continuous chain bucket ship unloader according to claim 1, characterized in that: The arm frame belt (4), the transfer belt (8) and the discharge belt (11) are all provided with dustproof covers on the outside; and the transfer hopper (10) and the center hopper (13) are all provided with protective covers on the outside.

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