Dust fall processing method for sand-gravel materials

Abstract

The invention relates to the technical field of sandstone material processing, in particular to a sandstone material dust fall processing method which sequentially comprises the steps of primary crushing, first-time vibration screening, intermediate crushing, second-time vibration screening, sand making and third-time vibration screening. When primary crushing is carried out, a coarse crushing dust purification device is adopted for dust removal, and the coarse crushing dust purification device comprises a cyclone dust collector; finished product materials obtained through the first-time vibration screening and the second-time vibration screening are conveyed to a first finished product bin and a second finished product bin through a multi-stage belt conveyor respectively; a closed dust removal device is arranged at the joint of every two adjacent stages of belt conveyors; a stair type blanking device used for slowing down the blanking speed is arranged at the blanking point position of the last-stage belt conveyor; and a finished product material obtained through third-time vibration screening is conveyed to a third finished product bin through the closed spiral conveyor. Dust pollution in the sand and stone material processing and transferring process is effectively reduced, and the influence of dust dissipation on the environment is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of sand and gravel processing, and in particular to a dust reduction processing method for sand and gravel. Background Art

[0002] Sand and gravel refers to rock particles obtained by natural or artificial crushing and screening, or similar artificial particles. It is mainly processed by natural rocks through crushing, screening and other processes, and is used in construction and civil engineering. At present, the sand and gravel commonly used is mainly artificial sand and gravel, which is similar particles obtained by artificially crushing rocks.

[0003] The sand and gravel processing process includes primary crushing, secondary crushing, sand making and multiple vibration screening links. The finished materials obtained after vibration screening are conveyed to the finished product silo for storage through a multi-stage belt conveyor.

[0004] However, at the transition point between two adjacent belt conveyors, the finished sand and gravel will fall from the belt of the upper belt conveyor to the belt of the lower belt conveyor, and a large amount of dust is easily generated at the transition point between the two adjacent belt conveyors.

[0005] In addition, the finished sand and gravel transported by the last stage of the belt conveyor falls directly from the belt to the ground of the finished product silo. Due to the fast falling speed, a large amount of dust is easily generated.

[0006] When using a crusher to perform primary crushing of sand and gravel raw materials, a large amount of dust is also easily generated.

[0007] At present, induced draft + bag dust removal measures are usually adopted. However, due to imperfect design of environmental protection measures at primary crushing, belt conveyor transfer joints, and silo unloading points, a large amount of dust is emitted in an unorganized manner and blown away by the wind, causing TSP, PM10 and other pollutants in the air to exceed the standard, endangering the environmental air quality in the surrounding local areas. Summary of the invention

[0008] The main purpose of the invention is to provide a dust reduction processing method for sand and gravel materials, aiming at reducing dust at primary crushing, belt conveyor transfer overlap, and silo drop-out.

[0009] To achieve the above-mentioned purpose, the present invention proposes a dust reduction processing method for sand and gravel, the steps of which include primary crushing, first vibration screening, intermediate crushing, second vibration screening, sand making and third vibration screening in sequence; when performing primary crushing, a coarse crushing dust purification device is used for dust removal, and the coarse crushing dust purification device includes a cyclone dust collector; the finished materials obtained by the first vibration screening and the second vibration screening are respectively conveyed to the first finished product bin and the second finished product bin through a multi-stage belt conveyor; a closed dust removal device is arranged at the transition point of two adjacent belt conveyors; a staircase-type dropping device for slowing down the dropping speed is arranged at the dropping point of the last belt conveyor; the finished materials obtained by the third vibration screening are conveyed to the third finished product bin by a closed screw conveyor.

[0010] Preferably, during primary crushing, a crusher is used to crush sand and gravel raw materials; the crusher is supported on the ground by four support columns; a plurality of cross beams are connected between two adjacent support columns; the support columns and cross beams together constitute a support frame; an exhaust pipe is horizontally installed in the support frame; one end of the exhaust pipe is connected to the cyclone dust collector through a first induced draft fan duct; an induced draft fan is arranged on the first induced draft fan duct; an exhaust pipe is connected to the outlet of the cyclone dust collector.

[0011] Preferably, the lower part of the exhaust duct and the end away from the first induced draft fan duct are arranged as air inlets; and a first staggered open-hole dust suppressor is installed on the air inlet at the end of the exhaust duct.

[0012] Preferably, the closed dust removal device includes a hollow tank body; the discharge end of the upper-level belt conveyor and the feed end of the lower-level belt conveyor both extend into the interior of the tank body, and the discharge end of the upper-level belt conveyor is located above the feed end of the lower-level belt conveyor; a plurality of inclined first blanking plates are arranged in the tank body, and the plurality of first blanking plates are staggered and spaced in the vertical direction; and the plurality of first blanking plates are located between the discharge end of the upper-level belt conveyor and the feed end of the lower-level belt conveyor.

[0013] Preferably, a second induced draft fan duct is arranged on the top of the tank body for connecting to the dust removal equipment, and a first valve is arranged on the second induced draft fan duct; a plurality of air inlet pipes are arranged on the side wall of the tank body, and a second staggered opening dust suppressor is installed on each air inlet pipe; a dust suppression protective cover is arranged on the inlet of the air inlet pipe.

[0014] Preferably, a discharge pipe is provided at the lower end of the tank body, and the lower end of the tank body and the discharge pipe together form a funnel-shaped structure; a second valve is provided on the discharge pipe; two scraping devices are installed on the inner wall of the tank body; one of the scraping devices is provided below the discharge end of the upper-level belt conveyor and is used for scraping the belt of the belt conveyor at this level; the other scraping device is provided below the feed end of the lower-level belt conveyor and is used for scraping the belt of the belt conveyor at this level.

[0015] Preferably, the scraping device includes a support plate and multiple scrapers; the scraper is made of polyurethane, the upper end of the scraper is in the shape of a brush for contacting the belt on the belt conveyor, and the lower end is fixedly mounted on the support plate, and the support plate is welded to the inside of the tank body.

[0016] Preferably, the closed screw conveyor includes a conveyor housing, a screw rod, and a driving motor; screw rod mounting seats are provided at both ends of the conveyor housing, the screw rod is arranged inside the conveyor housing, and both ends of the screw rod are rotatably mounted in the inner holes of the screw rod mounting seats; one end of the screw rod is connected to the driving motor; and a feed port and a discharge port are provided on the conveyor housing.

[0017] Preferably, the staircase blanking device includes a concrete foundation, an angle steel bracket, a steel plate enclosure and a plurality of second blanking plates; the angle steel bracket is welded from a connecting steel bar and four angle steels; the four angle steels are distributed in a rectangular shape, and the lower ends of the angle steels are pre-buried in the concrete foundation; the connecting steel bars are welded between two adjacent columns; the steel plate enclosure is sleeved on the outside of the upper half of the angle steel bracket; a plurality of second blanking plates are staggered and spaced in the vertical direction, and are obliquely installed on the inside of the lower half of the angle steel bracket; the discharge end of the last-stage belt conveyor passes through the steel plate enclosure and extends into the interior of the angle steel bracket.

[0018] Preferably, an exhaust hood is provided on the top of the angle steel bracket, and a third staggered open-hole dust suppressor and a polyester needle felt dust suppression cloth are provided inside the exhaust hood; and the polyester needle felt dust suppression cloth is arranged above the third staggered open-hole dust suppressor at intervals.

[0019] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0020] In the present invention, the dust reduction measures adopted include: ① using a coarse crushing dust purification device to remove dust during primary crushing; ② setting a closed dust removal device at the transition point of two adjacent belt conveyors; ③ setting a staircase-type drop device for slowing down the drop speed at the drop point of the last belt conveyor; ④ using a closed screw conveyor to transport the finished material obtained by the third vibration screening to the third finished material bin. By adopting the above dust reduction measures, dust pollution in the sand and gravel processing and transportation process is effectively reduced, and the impact of dust escape on the environment is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 This is a flow chart of the dust reduction processing method for sand and gravel provided by the present invention;

[0023] Figure 2 It is a structural schematic diagram of the coarse dust purification device in the present invention;

[0024] Figure 3 for Figure 2 The cross-section drawing of the middle CC;

[0025] Figure 4 A schematic diagram of a closed dust removal device provided at the transition point of two adjacent belt conveyors in the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the scraping device in the present invention;

[0027] Figure 6 It is a structural schematic diagram of the closed screw conveyor in the present invention;

[0028] Figure 7 It is a schematic diagram of a staircase-type material-dropping device provided at the material-dropping point of the last-stage belt conveyor in the present invention;

[0029] Figure 8 for Figure 7 The detailed drawing of the cross section of AA;

[0030] Fig. 9 for Figure 7 The cross-section drawing of the middle BB;

[0031] Fig.10 Schematic diagram of the orifice plate in the present invention Figure 1 ;

[0032] Fig.11 Schematic diagram of the orifice plate in the present invention Figure 2 .

[0033] Explanation of the numbers in the figures: 1. belt; 2. buttress; 3. first blanking plate; 4. air inlet pipe; 4a. dust suppression protective cover; 5. first valve; 6. second induced draft fan pipe; 7. second valve; 8. belt conveyor support; 9a. first staggered hole dust suppressor; 9b. second staggered hole dust suppressor; 9c. third staggered hole dust suppressor; 10. scraping device; 11. polyester needle felt dust suppression cloth; 12. steel plate enclosure; 13. connecting steel bar; 14. concrete foundation Foundation; 15. Angle steel; 16. Support column; 17. Crossbeam; 18. induced draft fan; 19. First induced draft fan duct; 20. Cyclone dust collector; 21. Exhaust pipe; 22. Discharge pipe; 23. Feed inlet; 24. Discharge outlet; 25. Conveyor housing; 26. Crusher; 27. Exhaust pipe; 28. Tank body; 29. ​​Screw rod; 30. Drive motor; 31. Screw rod mounting seat; 32. Angle steel bracket; 33. Second blanking plate; 34. Exhaust hood. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] Combination Figures 1 to 11As shown, a dust reduction processing method for sand and gravel materials comprises the following steps in sequence: primary crushing, first vibration screening, intermediate crushing, second vibration screening, sand making and third vibration screening; during primary crushing, a coarse crushing dust purification device is used for dust removal; the finished materials obtained by the first vibration screening and the second vibration screening are respectively conveyed to the first finished product bin and the second finished product bin through multi-stage belt conveyors; a closed dust removal device is arranged at the junction of two adjacent belt conveyors; a staircase-type dropping device for slowing down the dropping speed is arranged at the dropping point of the last belt conveyor; the finished materials obtained by the third vibration screening are conveyed to the third finished product bin by a closed screw conveyor.

[0038] In this embodiment, the belt conveyor mainly includes a belt 1, a pier 2 and a belt conveyor support 8 arranged on the pier 2. The belt conveyor is a conventional existing equipment and will not be described in detail here.

[0039] Combination Figure 2 , Figure 3 As shown, the coarse crushing dust purification device includes a cyclone dust collector 20. Specifically, during primary crushing, a crusher 26 is used to crush the sand and stone raw materials; the crusher 26 is supported on the ground by four support columns 16; a plurality of cross beams 17 are connected between two adjacent support columns 16; the support columns 16 and the cross beams 17 together constitute a support frame; an exhaust pipe 27 is transversely installed in the support frame; one end of the exhaust pipe 27 is connected to the cyclone dust collector 20 through a first induced draft fan duct 19; an induced draft fan 18 is arranged on the first induced draft fan duct 19; an exhaust pipe 21 is connected to the outlet of the cyclone dust collector 20. Furthermore, the lower part of the exhaust pipe 27 and the end away from the first induced draft fan duct 19 are set as air inlets; and a first offset open-hole dust suppressor 9a is installed on the air inlet at the end of the exhaust pipe 27.

[0040] By using the induced draft fan 18 to extract air, a negative pressure can be formed in the exhaust pipe 27, and fine dust near the crusher 26 can be sucked into the cyclone dust collector 20 through the exhaust pipe 27 and the first induced draft fan pipe 19 for dust removal, thereby preventing dust from flying and causing air pollution. The working principle of the cyclone dust collector 20 is to make the dust-laden airflow rotate, separate the dust particles from the airflow and capture them on the wall of the device by centrifugal force, and then make the dust particles fall into the ash hopper by gravity. The cyclone dust collector 20 is a conventional existing equipment and will not be described in detail here. By setting the first staggered opening dust suppressor 9a, dust can be prevented from escaping.

[0041] Combination Figure 4As shown, the closed dust removal device includes a hollow tank body 28; the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor are both extended into the tank body 28, and the discharge end of the upper belt conveyor is located above the feed end of the lower belt conveyor; a plurality of inclined first blanking plates 3 are arranged in the tank body 28, and the plurality of first blanking plates 3 are arranged at intervals in the vertical direction; and the plurality of first blanking plates 3 are located between the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor. The sand and gravel conveyed by the upper belt conveyor falls onto the belt of the lower belt conveyor after being buffered by the plurality of first blanking plates 3. By utilizing the plurality of first blanking plates 3 to play a buffering role, the dropping speed of the sand and gravel is reduced, thereby reducing the amount of dust at the belt conveyor transfer point. At the same time, since the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor are both extended into the tank body 28, the tank body 28 is used to form a closed structure to avoid dust.

[0042] Furthermore, a second induced draft fan duct 6 is provided on the top of the tank body 28 for connecting to a dust removal device, which may be a cyclone dust collector. A first valve 5 is provided on the second induced draft fan duct 6; a plurality of air inlet pipes 4 are provided on the side wall of the tank body 28, and a second staggered opening dust suppressor 9b is installed on each air inlet pipe 4; a dust suppression protective cover 4a is provided on the inlet of the air inlet pipe 4, which not only plays an air intake role, but also prevents dust in the tank body 28 from floating through the air inlet and polluting the environment. The fine dust in the tank body is transported to the dust removal device for dust removal by using the second induced draft fan duct 6.

[0043] Furthermore, a discharge pipe 22 is provided at the lower end of the tank body 28, and the lower end of the tank body 28 and the discharge pipe 22 together form a funnel-shaped structure; a second valve 7 is provided on the discharge pipe 22; two scraping devices 10 are installed on the inner wall of the tank body 28; one of the scraping devices 10 is provided below the discharge end of the upper belt conveyor for scraping the belt of the belt conveyor at that level; the other scraping device 10 is provided below the feed end of the lower belt conveyor for scraping the belt of the belt conveyor at that level. The scraping device 10 is used to effectively remove the residual sand and gravel attached to the belt conveyor, which falls into the tank body 28 after being scraped by the scraping device 10, and the residual sand and gravel and the deposited dust are regularly discharged through the lower discharge pipe 22 and the second valve 7, thereby avoiding the residual sand and gravel falling and drifting with the wind to pollute the environment.

[0044] Combination Figure 5 As shown, the scraping device 10 includes a support plate 10a and multiple scrapers 10b; the scraper 10b is made of polyurethane, the upper end of the scraper 10b is in the shape of a brush for contacting the belt on the belt conveyor, and the lower end is fixedly mounted on the support plate 10a, and the support plate 10a is welded to the inside of the tank body 28.

[0045] Combination Figure 6 As shown, the closed screw conveyor includes a conveyor housing 25, a screw rod 29, and a drive motor 30; screw rod mounting seats 31 are provided at both ends of the conveyor housing 25, the screw rod 29 is provided inside the conveyor housing 25, and both ends of the screw rod 29 are rotatably mounted in the inner holes of the screw rod mounting seats 31; one end of the screw rod 29 is connected to the drive motor 30; a feed port 23 and a discharge port 24 are provided on the conveyor housing 25. Using a closed screw conveyor for transportation can effectively reduce dust.

[0046] Combination Figures 7 to 9 As shown, the stair-type blanking device includes a concrete foundation 14, an angle steel bracket 32, a steel plate enclosure 12, and a plurality of second blanking plates 33; the angle steel bracket 32 ​​is welded by connecting steel bars 13 and four angle steels 15; the four angle steels 15 are distributed in a rectangular shape, and the lower ends of the angle steels 15 are pre-buried in the concrete foundation 14; the connecting steel bars 13 are welded between two adjacent columns; the steel plate enclosure 12 is sleeved on the outside of the upper half of the angle steel bracket 32; a plurality of second blanking plates 33 are staggered and spaced in the vertical direction, and are obliquely installed inside the lower half of the angle steel bracket 32; the discharge end of the last-stage belt conveyor passes through the steel plate enclosure 12 and extends into the interior of the angle steel bracket 32. By adopting a stair-type blanking device, the blanking height and speed can be effectively reduced, the amount of blanking dust generated can be reduced, and the blanking dust environmental pollution can be reduced. As the finished material stacking height increases, part of the angle steel bracket 32 ​​is buried, but the falling material can still enter the finished product warehouse through the gap between the connecting steel bars 13 on the angle steel bracket 32. Moreover, as the finished product stacking height increases and the vertical drop height decreases, the amount of dust generated by the drop will also decrease, and the impact on the environment will also be reduced.

[0047] Furthermore, an exhaust hood 34 is provided on the top of the angle steel bracket 32, and a third staggered open-hole dust suppressor 9c and a polyester needle felt dust suppression cloth 11 are provided inside the exhaust hood 34; and the polyester needle felt dust suppression cloth 11 is arranged at intervals above the third staggered open-hole dust suppressor 9c, further effectively reducing dust pollution at the finished product drop point.

[0048] Combination Fig.10 , Fig.11 As shown, in this embodiment, the first staggered hole dust suppressor 9a, the second staggered hole dust suppressor 9b, and the third staggered hole dust suppressor 9c are all composed of multiple layers of perforated plates, each layer of the perforated plates is provided with multiple through holes; two adjacent layers of perforated plates are arranged at intervals, and the through holes on the two adjacent layers of perforated plates are staggered.

[0049] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A dust reduction processing method for sand and gravel, the steps sequentially comprising primary crushing, first vibration screening, intermediate crushing, second vibration screening, sand making and third vibration screening; characterized in that: During primary crushing, a coarse crushing dust purification device is used to remove dust, and the coarse crushing dust purification device includes a cyclone dust collector (20); The finished products obtained from the first vibration screening and the second vibration screening are respectively conveyed to the first finished product bin and the second finished product bin through multi-stage belt conveyors; a closed dust removal device is provided at the transition point of two adjacent belt conveyors; a staircase-type drop device for slowing down the drop speed is provided at the drop point of the last belt conveyor; The finished product obtained from the third vibration screening is transported to the third finished product silo by a closed screw conveyor.

2. A dust reduction processing method for sand and gravel as claimed in claim 1, characterized in that: During primary crushing, a crusher (26) is used to crush sand and stone raw materials; the crusher (26) is supported on the ground by four support columns (16); a plurality of cross beams (17) are connected between two adjacent support columns (16); the support columns (16) and the cross beams (17) together form a support frame; an exhaust pipe (27) is transversely installed in the support frame; one end of the exhaust pipe (27) is connected to the cyclone dust collector (20) through a first induced draft fan pipeline (19); an induced draft fan (18) is arranged on the first induced draft fan pipeline (19); and an exhaust pipe (21) is connected to the outlet of the cyclone dust collector (20).

3. A dust reduction processing method for sand and gravel as claimed in claim 2, characterized in that: The lower part of the exhaust pipe (27) and one end away from the first induced draft fan duct (19) are arranged as air inlets; and a first staggered open-hole dust suppressor (9a) is installed on the air inlet at the end of the exhaust pipe (27).

4. The dust reduction processing method for sand and gravel as claimed in claim 1, characterized in that: The closed dust removal device comprises a hollow tank body (28); the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor both extend into the interior of the tank body (28), and the discharge end of the upper belt conveyor is located above the feed end of the lower belt conveyor; a plurality of inclined first blanking plates (3) are arranged in the tank body (28), and the plurality of first blanking plates (3) are arranged at staggered intervals in the vertical direction; and the plurality of first blanking plates (3) are located between the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor.

5. A dust reduction processing method for sand and gravel as claimed in claim 4, characterized in that: A second induced draft fan duct (6) is arranged on the top of the tank body (28) for connecting to a dust removal device, and a first valve (5) is arranged on the second induced draft fan duct (6); a plurality of air inlet pipes (4) are arranged on the side wall of the tank body (28), and a second staggered opening dust suppressor (9b) is installed on each air inlet pipe (4); and a dust suppression protective cover (4a) is arranged on the inlet of the air inlet pipe (4).

6. A dust reduction processing method for sand and gravel as claimed in claim 4, characterized in that: A discharge pipe (22) is arranged at the lower end of the tank body (28), and the lower end of the tank body (28) and the discharge pipe (22) together form a funnel-shaped structure; a second valve (7) is arranged on the discharge pipe (22); two scraping devices (10) are installed on the inner wall of the tank body (28); one of the scraping devices (10) is arranged below the discharge end of the upper-level belt conveyor for scraping the belt of the belt conveyor at that level; and the other scraping device (10) is arranged below the feed end of the lower-level belt conveyor for scraping the belt of the belt conveyor at that level.

7. A dust reduction processing method for sand and gravel as claimed in claim 6, characterized in that: The scraping device (10) comprises a support plate (10a) and a plurality of scrapers (10b); the scraper (10b) is made of polyurethane, the upper end of the scraper (10b) is in the shape of a brush for contacting the belt on the belt conveyor, and the lower end is fixedly mounted on the support plate (10a); the support plate (10a) is welded to the inside of the tank body (28).

8. The dust reduction processing method for sand and gravel as claimed in claim 1, characterized in that: The closed screw conveyor comprises a conveyor housing (25), a screw rod (29), and a driving motor (30); screw rod mounting seats (31) are arranged at both ends of the conveyor housing (25); the screw rod (29) is arranged inside the conveyor housing (25), and both ends of the screw rod (29) are rotatably mounted in the inner holes of the screw rod mounting seats (31); one end of the screw rod (29) is connected to the driving motor (30); and a feed port (23) and a discharge port (24) are arranged on the conveyor housing (25).

9. The dust reduction processing method for sand and gravel according to claim 1, characterized in that: The stair-type blanking device comprises a concrete foundation (14), an angle steel bracket (32), a steel plate enclosure (12), and a plurality of second blanking plates (33); the angle steel bracket (32) is welded from a connecting steel bar (13) and four angle steels (15); the four angle steels (15) are distributed in a rectangular shape, and the lower ends of the angle steels (15) are pre-buried in the concrete foundation (14); the connecting steel bar (13) is welded between two adjacent columns; The steel plate enclosure (12) is sleeved on the outside of the upper half of the angle steel bracket (32); a plurality of second blanking plates (33) are arranged at staggered intervals in the vertical direction and are obliquely installed inside the lower half of the angle steel bracket (32); the discharge end of the last-stage belt conveyor passes through the steel plate enclosure (12) and extends into the interior of the angle steel bracket (32).

10. A dust reduction processing method for sand and gravel as claimed in claim 9, characterized in that: An exhaust hood (34) is arranged on the top of the angle steel bracket (32), and a third staggered open-hole dust suppressor (9c) and a polyester needle-punched felt dust suppressor cloth (11) are arranged inside the exhaust hood (34); and the polyester needle-punched felt dust suppressor cloth (11) is arranged above the third staggered open-hole dust suppressor (9c) at intervals.

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