A dust suppression processing method for sand and gravel

Abstract

This invention relates to the field of sand and gravel processing technology, and more particularly to a dust-reducing processing method for sand and gravel. The steps sequentially include primary crushing, a first vibrating screen, intermediate crushing, a second vibrating screen, sand making, and a third vibrating screen. During primary crushing, a coarse crushing dust purification device, including a cyclone dust collector, is used for dust removal. The finished materials obtained from the first and second vibrating screens are respectively conveyed to the first and second finished material bins via multi-stage belt conveyors. Enclosed dust removal devices are installed at the transition points between adjacent belt conveyors. A stair-type material discharge device is installed at the material discharge point of the last belt conveyor to slow down the material discharge speed. The finished material obtained from the third vibrating screen is conveyed to the third finished material bin by an enclosed screw conveyor. This invention effectively reduces dust pollution during the sand and gravel processing and transportation process, preventing dust emission and its environmental impact.

Description

Technical Field

[0001] This invention relates to the field of sand and gravel processing technology, and in particular to a dust suppression processing method for sand and gravel. Background Technology

[0002] Sand and gravel refer to rock particles or similar artificially manufactured particles obtained through natural or artificial crushing and screening. It is mainly produced from natural rocks through crushing and screening processes and is used in construction and civil engineering. Currently, the most commonly used sand and gravel is artificial sand and gravel, which is similar to particles obtained by artificially crushing rocks.

[0003] The sand and gravel processing process includes primary crushing, intermediate crushing, sand making, and multiple vibrating screening stages. The finished material obtained after vibrating screening is conveyed to the finished material silo for storage via multi-stage belt conveyors.

[0004] However, at the junction of 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, which can easily generate a lot of dust.

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

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

[0007] Currently, the usual practice is to use a combination of induced draft and bag filter dust collection. However, due to inadequate environmental protection design at the primary crushing site, the conveyor belt transfer junction, and the silo discharge point, a large amount of dust is emitted without organization and drifts with the wind, causing pollutants such as TSP and PM10 in the air to exceed the standards, which endangers the ambient air quality of the surrounding local area. Summary of the Invention

[0008] The main objective of this invention is to propose a dust reduction processing method for sand and gravel, which aims to reduce dust at the primary crushing stage, the overlapping area of ​​the belt conveyor, and the material discharge point of the silo.

[0009] To achieve the above objectives, this invention proposes a dust-reduction processing method for sand and gravel, comprising the following steps in sequence: primary crushing, first vibrating screening, intermediate crushing, second vibrating screening, sand making, and third vibrating screening. During primary crushing, a coarse crushing dust purification device, including a cyclone dust collector, is used for dust removal. The finished materials obtained from the first and second vibrating screenings are respectively conveyed to the first and second finished material bins via multi-stage belt conveyors. A closed dust removal device is installed at the junction of adjacent belt conveyors. A stair-type material discharge device is installed at the material discharge point of the last belt conveyor to slow down the material discharge speed. The finished material obtained from the third vibrating screening is conveyed to the third finished material bin by a closed screw conveyor.

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

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

[0012] Preferably, the enclosed dust removal device includes a hollow tank; 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, and the discharge end of the upper belt conveyor is located above the feed end of the lower belt conveyor; multiple inclined first discharge plates are provided inside the tank, and the multiple first discharge plates are staggered in the vertical direction; and the multiple first discharge plates are located between the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor.

[0013] Preferably, a second induced draft fan duct is provided at the top of the tank for connection to the dust removal equipment, and a first valve is provided on the second induced draft fan duct; multiple air inlet pipes are provided on the side wall of the tank, and a second staggered perforated dust suppressor is installed on each air inlet pipe; a dust suppression protective cover is provided at 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 cleaning devices are installed on the inner wall of the tank body; one cleaning device is located below the discharge end of the previous stage belt conveyor for cleaning the belt of that stage belt conveyor; the other cleaning device is located below the feed end of the next stage belt conveyor for cleaning the belt of that stage belt conveyor.

[0015] Preferably, the cleaning device includes a support plate and multiple scrapers; the scrapers are made of polyurethane, the upper end of the scraper is brush-shaped for contacting the belt on the conveyor belt, and the lower end is fixedly installed on the support plate, which is welded to the inside of the tank.

[0016] Preferably, the enclosed screw conveyor includes a conveyor housing, a screw rod, and a drive motor; screw rod mounting seats are provided at both ends of the conveyor housing, the screw rod is disposed inside the conveyor housing, and both ends of the screw rod are rotatably installed in the inner holes of the screw rod mounting seats; one end of the screw rod is connected to the drive motor; and an inlet and an outlet are provided on the conveyor housing.

[0017] Preferably, the stair-type material dropping device includes a concrete foundation, an angle steel bracket, a steel plate enclosure, and multiple second material dropping plates; the angle steel bracket is welded from connecting steel bars and four angle steels; the four angle steels are arranged in a rectangular shape, and the lower ends of the angle steels are pre-embedded in the concrete foundation; the connecting steel bars are welded between two adjacent columns; the steel plate enclosure is fitted over the outside of the upper half of the angle steel bracket; the multiple second material dropping plates are staggered in the vertical direction and installed obliquely inside the lower half of the angle steel bracket; the discharge end of the last stage conveyor belt 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 perforated dust suppressor and a polyester needle-punched felt dust suppressor cloth are provided inside the exhaust hood; and the polyester needle-punched felt dust suppressor cloth is spaced above the third staggered perforated dust suppressor.

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

[0020] In this invention, the dust reduction measures include: ① using a coarse crushing dust purification device for dust removal during primary crushing; ② installing a closed dust removal device at the transfer point between adjacent belt conveyors; ③ installing a stair-type material discharge device at the material discharge point of the last belt conveyor to slow down the material discharge speed; and ④ using a closed screw conveyor to transport the finished material obtained from the third vibrating screen to the third finished material silo. By adopting the above dust reduction measures, dust pollution during the processing and transportation of sand and gravel is effectively reduced, preventing the environmental impact of dust emission. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 A flowchart illustrating the dust suppression processing method for sand and gravel provided by this invention;

[0023] Figure 2 This is a schematic diagram of the coarse crushing dust purification device in this invention;

[0024] Figure 3 for Figure 2 Detailed cross-sectional view of CC;

[0025] Figure 4 This is a schematic diagram of a closed dust removal device installed at the junction of two adjacent belt conveyors in this invention.

[0026] Figure 5 This is a schematic diagram of the cleaning and scraping device in this invention;

[0027] Figure 6 This is a schematic diagram of the enclosed screw conveyor in this invention;

[0028] Figure 7 This is a schematic diagram of a stair-type material discharge device installed at the material discharge point of the last stage conveyor belt in this invention.

[0029] Figure 8 for Figure 7 Detailed cross-section of AA;

[0030] Figure 9 for Figure 7 Detailed cross-sectional view of BB;

[0031] Figure 10 This is a schematic diagram of the perforated plate in the present invention. Figure 1 ;

[0032] Figure 11 This is a schematic diagram of the perforated plate in the present invention. Figure 2 .

[0033] Reference numerals: 1. Belt conveyor; 2. Support; 3. First discharge plate; 4. Air inlet pipe; 4a. Dust suppression protective cover; 5. First valve; 6. Second induced draft fan duct; 7. Second valve; 8. Belt conveyor support; 9a. First staggered perforated dust suppressor; 9b. Second staggered perforated dust suppressor; 9c. Third staggered perforated dust suppressor; 10. Scraping device; 11. Polyester needle-punched felt dust suppressant cloth; 12. Steel plate enclosure; 13. Connecting steel bar; 14. Concrete base 15. Foundation; 16. Angle steel; 17. Support column; 18. Crossbeam; 19. Exhaust fan; 20. First exhaust fan duct; 21. Cyclone dust collector; 22. Exhaust pipe; 23. Unloading pipe; 24. Feed inlet; 25. Discharge outlet; 26. Conveyor housing; 27. Crusher; 28. Exhaust duct; 29. ​​Tank; 30. Screw rod; 31. Drive motor; 32. Screw rod mounting base; 33. Angle steel bracket; 34. Second discharge plate; 35. Exhaust hood. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort 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 various 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] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0037] Combination Figures 1 to 11As shown, a dust suppression processing method for sand and gravel includes the following steps in sequence: primary crushing, first vibrating screening, intermediate crushing, second vibrating screening, sand making, and third vibrating screening. During primary crushing, a coarse crushing dust purification device is used for dust removal. The finished materials obtained from the first and second vibrating screenings are respectively conveyed to the first and second finished material bins via multi-stage belt conveyors. A closed dust removal device is installed at the junction of adjacent belt conveyors. A stair-type material drop device is installed at the drop point of the last belt conveyor to slow down the material drop speed. The finished material obtained from the third vibrating screening is conveyed to the third finished material bin by a closed screw conveyor.

[0038] In this embodiment, the belt conveyor mainly includes a belt 1, a support 2, and a belt conveyor bracket 8 installed on the support 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 gravel raw materials; the crusher 26 is supported on the ground by four support columns 16; multiple crossbeams 17 are connected between adjacent support columns 16; the support columns 16 and crossbeams 17 together form a support frame; an exhaust pipe 27 is installed horizontally inside the support frame; one end of the exhaust pipe 27 is connected to the cyclone dust collector 20 through a first induced draft fan pipe 19; an induced draft fan 18 is installed on the first induced draft fan pipe 19; and an exhaust pipe 21 is connected to the outlet of the cyclone dust collector 20. Further, the lower part of the exhaust pipe 27 and the end away from the first induced draft fan pipe 19 are set as air inlets; and a first staggered perforated 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 draw air, a negative pressure can be created within the exhaust duct 27, which draws fine dust near the crusher 26 through the exhaust duct 27 and the first induced draft fan duct 19 into the cyclone dust collector 20 for dust removal, preventing dust from scattering and causing air pollution. The working principle of the cyclone dust collector 20 is to rotate the dust-laden airflow, using centrifugal force to separate dust particles from the airflow and collect them on the wall of the collector, and then using gravity to make the dust particles fall into the ash hopper. The cyclone dust collector 20 is conventional existing equipment and will not be described in detail here. By setting up the first staggered opening dust suppressor 9a, dust escape can be prevented.

[0041] Combination Figure 4As shown, the enclosed dust removal device includes a hollow tank 28. The discharge end of the upper-level conveyor belt and the inlet end of the lower-level conveyor belt both extend into the tank 28, with the discharge end of the upper-level conveyor belt located above the inlet end of the lower-level conveyor belt. Multiple inclined first drop plates 3 are arranged inside the tank 28, staggered vertically, and positioned between the discharge end of the upper-level conveyor belt and the inlet end of the lower-level conveyor belt. The sand and gravel conveyed by the upper-level conveyor belt are buffered by the multiple first drop plates 3 before falling onto the belt of the lower-level conveyor belt. By utilizing the multiple first drop plates 3 to buffer the material, the falling speed of the sand and gravel is reduced, thereby reducing the amount of dust falling at the conveyor belt transfer point. Simultaneously, since the discharge end of the upper-level conveyor belt and the inlet end of the lower-level conveyor belt both extend into the tank 28, the enclosed structure formed by the tank 28 prevents dust generation.

[0042] Furthermore, a second induced draft fan duct 6 is provided at the top of the tank 28 for connection to a dust removal device, which can be a cyclone dust collector. A first valve 5 is provided on the second induced draft fan duct 6; multiple air inlet pipes 4 are provided on the side wall of the tank 28, and a second staggered perforated dust suppressor 9b is installed on each air inlet pipe 4; a dust suppression protective cover 4a is provided at the inlet of the air inlet pipe 4, which serves both as an air intake and prevents dust inside the tank 28 from drifting and polluting the environment through the air inlet. The fine dust inside the tank is transported to the dust removal device for dust removal 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 cleaning devices 10 are installed on the inner wall of the tank body 28; one cleaning device 10 is located below the discharge end of the previous stage belt conveyor for cleaning the belt of that stage belt conveyor; the other cleaning device 10 is located below the feed end of the next stage belt conveyor for cleaning the belt of that stage belt conveyor. By using the cleaning devices 10, the sand and gravel residues attached to the belt conveyor are effectively removed. After being cleaned by the cleaning devices 10, the residues fall into the tank body 28, and the sand and gravel residues and deposited dust are periodically discharged through the lower discharge pipe 22 and the second valve 7, avoiding the pollution of the environment caused by the sand and gravel residues falling and being blown away by the wind.

[0044] Combination Figure 5 As shown, the cleaning and scraping device 10 includes a support plate 10a and multiple scraper blades 10b; the scraper blades 10b are made of polyurethane, the upper end of the scraper blades 10b is brush-shaped for contacting the belt on the conveyor belt, and the lower end is fixedly installed on the support plate 10a. The support plate 10a is welded to the inside of the tank body 28.

[0045] Combination Figure 6 As shown, the enclosed 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 disposed 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. An inlet 23 and an outlet 24 are provided on the conveyor housing 25. Using an enclosed screw conveyor can effectively reduce dust generation.

[0046] Combination Figures 7 to 9 As shown, the stair-type material drop device includes a concrete foundation 14, an angle steel bracket 32, a steel plate enclosure 12, and multiple second material drop plates 33. The angle steel bracket 32 ​​is welded from connecting steel bars 13 and four angle steels 15. The four angle steels 15 are arranged in a rectangular shape, and the lower ends of the angle steels 15 are embedded in the concrete foundation 14. The connecting steel bars 13 are welded between two adjacent columns. The steel plate enclosure 12 is fitted over the outside of the upper half of the angle steel bracket 32. The multiple second material drop plates 33 are staggered vertically and installed obliquely inside the lower half of the angle steel bracket 32. The discharge end of the last-stage conveyor belt passes through the steel plate enclosure 12 and extends into the interior of the angle steel bracket 32. By using a stair-type material drop device, the material drop height and speed can be effectively reduced, the amount of material drop dust generated can be reduced, and the environmental pollution caused by material drop dust can be mitigated. As the height of the finished materials piles up, part of the angle steel support 32 is buried. However, the falling materials can still enter the finished goods warehouse through the gaps between the connecting steel bars 13 on the angle steel support 32. Moreover, as the height of the finished products piles up increases and the vertical drop height decreases, the amount of dust generated by the falling materials will also decrease, and the impact on the environment will also decrease.

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

[0048] Combination Figure 10 , Figure 11 As shown, in this embodiment, the first staggered opening dust suppressor 9a, the second staggered opening dust suppressor 9b, and the third staggered opening dust suppressor 9c are all composed of multiple perforated plates, and each perforated plate has multiple through holes evenly distributed; adjacent perforated plates are spaced apart, and the through holes on adjacent perforated plates are staggered.

[0049] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for dust suppression processing of sand and gravel, comprising the steps of primary crushing, first vibrating screening, intermediate crushing, second vibrating screening, sand making, and third vibrating screening in sequence; characterized in that: During primary crushing, a coarse crushing dust purification device is used for dust removal, which includes a cyclone dust collector (20). The finished materials obtained from the first and second vibrating screenings are conveyed to the first and second finished material bins via multi-stage belt conveyors, respectively; a closed dust removal device is installed at the junction of two adjacent belt conveyors; and a stair-type material dropping device is installed at the material dropping point of the last belt conveyor to slow down the material dropping speed. The finished material obtained from the third vibrating screen is transported to the third finished material silo by a closed screw conveyor; The enclosed dust removal device includes a hollow tank (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 (28), and the discharge end of the upper belt conveyor is located above the feed end of the lower belt conveyor; multiple inclined first drop plates (3) are provided inside the tank (28), and the multiple first drop plates (3) are staggered in the vertical direction; and the multiple first drop plates (3) are located between the discharge end of the upper belt conveyor and the feed end of the lower belt conveyor. A second induced draft fan duct (6) is provided at the top of the tank (28) for connecting to the dust removal equipment, and a first valve (5) is provided on the second induced draft fan duct (6); multiple air inlet pipes (4) are provided on the side wall of the tank (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 at the inlet of the air inlet pipe (4); The stair-type material dropping device includes a concrete foundation (14), an angle steel bracket (32), a steel plate enclosure (12), and multiple second material dropping plates (33); the angle steel bracket (32) is welded from connecting steel bars (13) and four angle steels (15); the four angle steels (15) are arranged in a rectangular shape, and the lower ends of the angle steels (15) are embedded in the concrete foundation (14); the connecting steel bars (13) are welded between two adjacent columns. The steel plate enclosure (12) is fitted onto the outside of the upper half of the angle steel bracket (32); multiple second drop plates (33) are staggered in the vertical direction and installed at an angle 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 inside of the angle steel bracket (32).

2. The dust suppression processing method for sand and gravel as described in claim 1, characterized in that, During primary crushing, a crusher (26) is used to crush the sand and gravel raw materials; the crusher (26) is supported on the ground by four support columns (16); multiple crossbeams (17) are connected between two adjacent support columns (16); the support columns (16) and crossbeams (17) together form a support frame; an exhaust pipe (27) is installed horizontally 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 pipe (19); an induced draft fan (18) is installed on the first induced draft fan pipe (19); an exhaust pipe (21) is connected to the outlet of the cyclone dust collector (20).

3. The dust suppression processing method for sand and gravel as described in claim 2, characterized in that, The lower part of the exhaust pipe (27) and the end away from the first induced draft fan pipe (19) are set as air inlets; and a first staggered opening dust suppressor (9a) is installed on the air inlet at the end of the exhaust pipe (27).

4. The dust suppression processing method for sand and gravel as described in claim 1, characterized in that, A discharge pipe (22) is provided at the lower end of the tank (28), and the lower end of the tank (28) and the discharge pipe (22) together form a funnel-shaped structure; a second valve (7) is provided on the discharge pipe (22); two cleaning devices (10) are installed on the inner wall of the tank (28); one of the cleaning devices (10) is located below the discharge end of the upper-level belt conveyor for cleaning the belt of that level of belt conveyor; the other cleaning device (10) is located below the feed end of the lower-level belt conveyor for cleaning the belt of that level of belt conveyor.

5. The dust suppression processing method for sand and gravel as described in claim 4, characterized in that, The cleaning device (10) includes a support plate (10a) and multiple scrapers (10b); the scrapers (10b) are made of polyurethane, the upper end of the scrapers (10b) is brush-shaped for contacting the belt on the conveyor belt, and the lower end is fixedly installed on the support plate (10a). The support plate (10a) is welded to the inside of the tank (28).

6. The dust suppression processing method for sand and gravel as described in claim 1, characterized in that, The enclosed 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 located inside the conveyor housing (25), and both ends of the screw rod (29) are rotatably installed in the inner hole of the screw rod mounting seat (31); one end of the screw rod (29) is connected to the drive motor (30); a feed inlet (23) and a discharge outlet (24) are provided on the conveyor housing (25).

7. The dust suppression processing method for sand and gravel as described in claim 1, characterized in that, An exhaust hood (34) is provided on the top of the angle steel bracket (32), and a third staggered perforated dust suppressor (9c) and a polyester needle-punched felt dust suppressor cloth (11) are provided inside the exhaust hood (34); and the polyester needle-punched felt dust suppressor cloth (11) is spaced above the third staggered perforated dust suppressor (9c).

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