Multi-stage continuous screening device for machine-made sand

Abstract

The application relates to the technical field of machine-made sand production equipment, and specifically discloses a multi-stage continuous screening device for machine-made sand, which comprises a sorting mechanism including a shell provided with a fan, an air inlet and an air outlet arranged in sequence along an air inlet direction on the shell, a primary sorting mechanism and a secondary sorting mechanism, a primary feeding port arranged on the upper end of the shell of the primary sorting mechanism and close to the air inlet, a plurality of primary discharge ports arranged on the lower end of the shell, and the primary discharge ports including an unqualified discharge port and a qualified discharge port arranged in sequence along the air inlet direction; a secondary feeding port arranged on the upper end of the shell of the secondary sorting mechanism and close to the air inlet, the unqualified discharge port being communicated with the secondary feeding port of the secondary sorting mechanism, and the air inlets of the primary sorting mechanism and the secondary sorting mechanism being provided with flow guides in the horizontal direction. The patent aims to solve the problems that the existing machine-made sand screening adopts a vibrating screen with large energy consumption and easy hole blocking, and an ordinary air separation device cannot realize multi-stage sorting of machine-made sand.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machine-made sand production equipment, in particular to a multi-stage continuous screening device for machine-made sand. BACKGROUND

[0002] Machine-made sand is obtained by crushing and sand making process of rocks, and the particle shape and size distribution directly affect the quality of concrete. The screening device for machine-made sand is a key equipment specially used for particle size grading and impurity removal of machine-made sand, and is widely used in modern machine-made sand aggregate production lines.

[0003] The existing screening equipment for machine-made sand aggregate production line is mainly a vibrating screen. The energy consumption of using the vibrating screen is high. An ordinary vibrating screen can only screen 20-30 tons of machine-made sand per hour, and about 2-3 degrees of electricity are consumed for screening 1 ton of machine-made sand. The general vibrating screen is provided with three layers of screen meshes and can only screen four grades. If more grading is needed, multiple vibrating screens need to be set. In addition, the vibrating screen will appear hole blocking phenomenon with the increase of working time during screening of machine-made sand, especially in the screen mesh with smaller aperture, which is more prone to hole blocking, thereby causing rapid decline of production capacity of the vibrating screen. A small part of the screening is carried out by using air separation equipment. However, the existing air separation sorting mechanism mainly separates stone powder and fine sand, and the main purpose is to remove stone powder in fine sand. Generally, only 2-3 types of screening can be realized, and multi-stage sorting of machine-made sand cannot be realized. SUMMARY

[0004] In view of the deficiencies of the prior art, the technical problem solved by the present application is to provide a multi-stage continuous screening device for machine-made sand, which solves the problems of high energy consumption and easy hole blocking of the existing machine-made sand screening, and the ordinary air separation device cannot realize multi-stage sorting of machine-made sand.

[0005] In order to solve the above problems, the technical scheme adopted by the present application is: a multi-stage continuous screening device for machine-made sand, the sorting mechanism includes a shell provided with a fan, the shell is provided with an air inlet and an air outlet along the air inlet direction in sequence, the sorting mechanism includes a primary sorting mechanism and a secondary sorting mechanism, a primary feeding port is arranged on the upper end of the shell of the primary sorting mechanism close to the air inlet, a plurality of primary discharge ports are arranged on the lower end of the shell, and the primary discharge ports include unqualified discharge ports and qualified discharge ports arranged along the air inlet direction in sequence; a secondary feeding port is arranged on the upper end of the shell of the secondary sorting mechanism close to the air inlet, the unqualified discharge ports are communicated with the secondary feeding port of the secondary sorting mechanism; the air inlets of the primary sorting mechanism and the secondary sorting mechanism are provided with guide plates along the horizontal direction.

[0006] The technical principles and beneficial effects of the scheme are as follows: the gravity of the machine-made sand of different particle sizes is utilized, and air selection is performed by using wind power; the device can realize screening of 130-150 tons per hour; taking 140 tons as an example, the energy consumption of each ton of machine-made sand screening is about 0.6 degrees, which is reduced by more than 70% compared with the energy consumption of the traditional vibrating screen screening method, and the production capacity will not be reduced due to hole blockage. The device can realize long-time continuous separation of large quantities of machine-made sand. At the same time, the device can realize separation of multiple particle size ranges, and the main particle size in the range of different particle size ranges accounts for 97% or more.

[0007] Further, the primary discharge port comprises a discharge plate and a discharge pipe arranged from top to bottom and connected in sequence, and the discharge plates of the plurality of primary discharge ports gradually increase in height along the air inlet direction, and the included angle between the highest points of the plurality of discharge plates is 5-10°. By gradually increasing the height of the baffle, different particle sizes of machine-made sand can be separated, so that particles in different particle size ranges fall into different primary discharge ports.

[0008] Further, the secondary feed port is provided with a secondary feed pipe, the lower end of the feed pipe is curved towards the air outlet, and the housing of the secondary separation mechanism at the end of the feed pipe is provided with a baffle. The baffle can generate a rebound force on the sand hitting the baffle, and the larger the particle size, the greater the rebound force, so that the rebound of the larger particle size is closer to the air inlet side, improving the separation efficiency and separation effect.

[0009] Further, the top of the housing of the primary separation mechanism and the secondary separation mechanism is an inclined plate inclined upward along the direction from the air inlet to the air outlet. By cooperating the gradually increasing discharge plate and the discharge plate with the upwardly inclined inclined plate, an upwardly inclined air duct is formed in the housing, which is convenient for separation.

[0010] Further, the cross section of the end of the guide plate away from the air outlet is triangular. The front end is triangular to facilitate flow guiding.

[0011] Further, the guide plates are spaced apart in the vertical direction, and the gap size between the guide plates gradually increases from top to bottom. By controlling the gap of the guide plates from top to bottom, the gap gradually increases from top to bottom, according to Bernoulli's principle, when the air inlet narrows, the flow rate increases, thereby controlling the wind speed of the air inlet, so that the wind speed of the air inlet gradually increases from bottom to top.

[0012] Further, the air outlets of the primary sorting mechanism and the secondary sorting mechanism are connected together through an air outlet pipe, the fan is installed at the end of the air outlet pipe, and a dust collector is arranged between the air outlet and the fan. The fan is arranged at the air outlet, air is sucked into the air outlet through an air inlet, and air flow is formed in this way, so that negative pressure is formed in the shell, and the dust in the machine-made sand during sorting is not dispersed outward under the action of the negative pressure, thereby reducing the dust amount in the environment around the equipment; at the same time, the dust collector is used for dust removal, so that clean air is discharged, and the dust removal effect is realized at the same time.

[0013] Further, the secondary sorting mechanism is located at the lower end of the primary sorting mechanism, and the unqualified discharge port is communicated with the secondary feeding port through a flexible material. Because the inside of the shell of the primary sorting mechanism is in a negative pressure state, the bags are adsorbed together under the action of the negative pressure when the sorting starts, so that the discharge port is closed; air is not easily introduced from the primary discharge port, and when the machine-made sand accumulated in the discharge pipe increases, the flexible material is separated under the action of gravity, so that the machine-made sand can be discharged.

[0014] Further, a plurality of unqualified discharge ports are arranged, and a plurality of secondary sorting mechanisms are arranged corresponding to the unqualified discharge ports. The plurality of unqualified discharge ports and the plurality of secondary sorting mechanisms realize fine sorting of different levels and improve the particle size concentration of machine-made sand in different particle size ranges.

[0015] Further, the guide plate is provided with three guide plates, and four gaps are formed between the three guide plates and the shell. The proportion of the four gaps in the total gap ranges from top to bottom in sequence 15-20%, 18-24%, 22-30%, and 28-34%. The air volume control of different height gaps is realized by controlling the proportion of the gaps. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a combined view of the primary and secondary sorting mechanisms;

[0017] Figure 2 It is a combined side sectional view of the primary and secondary sorting mechanisms;

[0018] Figure 3 It is a sectional view of the primary sorting mechanism;

[0019] Figure 4 It is a sectional view of the secondary sorting mechanism. DETAILED DESCRIPTION

[0020] The following will be further described in detail through specific embodiments:

[0021] The reference numerals in the accompanying drawings include: primary sorting mechanism 1, primary feed inlet 11, discharge plate 12, discharge pipe 13, air inlet 2, guide plate 21, damper 3, air outlet pipe 4, dust collector 41, fan 42, secondary sorting mechanism 5, secondary feed inlet 51, discharge plate 52, discharge pipe 53, baffle 54, and air outlet 6.

[0022] Example 1 is as attached. Figure 1 The diagram shows a multi-stage continuous sorting device for manufactured sand. The sorting mechanism includes a housing with a blower 42. The housing has an air inlet 2 and an air outlet 6 arranged sequentially along the air inlet direction. The sorting mechanism includes a primary sorting mechanism 1 and a secondary sorting mechanism 5. The primary sorting mechanism 1 has a primary feed inlet 11 near the air inlet 2 at the upper end of its housing, and multiple primary discharge outlets at the lower end of the housing. The primary discharge outlets include unqualified discharge outlets and qualified discharge outlets arranged sequentially along the air inlet direction. The secondary sorting mechanism 5 has a secondary feed inlet 51 near the air inlet 2 at the upper end of its housing, and the unqualified discharge outlets are connected to the secondary feed inlet 51 of the secondary sorting mechanism 5. Both the primary sorting mechanism 1 and the secondary sorting mechanism 5 have horizontally arranged guide plates 21 at their air inlets 2. The air outlets 6 of the primary sorting mechanism 1 and the secondary sorting mechanism 5 are connected together by an air outlet pipe 4. The blower 42 is installed at the end of the air outlet pipe 4, and a dust collector 41 is provided between the air outlet 6 and the blower 42.

[0023] The primary feed inlet 11 is equipped with a primary feed pipe, and the end of the primary discharge outlet is an arc shape that curves towards the air inlet 2. This arc shape allows the manufactured sand to disperse parabolically towards the air inlet 2. Simultaneously, the primary feed pipe is designed as a long, rectangular tube along the longitudinal direction, making the discharge outlet of the arc-shaped plate long and narrow, thus causing the manufactured sand to fall in a waterfall-like manner, facilitating air separation. The primary discharge outlet includes a discharge plate 12 and a discharge pipe 13 arranged sequentially from top to bottom. One discharge pipe 13 is paired with two discharge plates 12, which are arranged in a V-shape. The discharge pipe 13 is a long, rectangular tube arranged longitudinally. The discharge plates 12 of the multiple primary discharge outlets gradually increase in height along the air inlet direction. The angle between the line connecting the highest points of the multiple discharge plates 12 and the horizontal line is 5-10°, preferably 7° in this embodiment. The gradually increasing height of the baffles facilitates the separation of manufactured sand of different particle sizes, allowing particles of different size ranges to fall into different primary discharge outlets.

[0024] The embodiment preferably designs six primary discharge ports, and sequentially numbers them as 1-1-1~1-1-6 along the air inlet direction. The two discharge plates 12 constituting the same primary discharge port are not equal in height, and gradually increase in height along the air inlet direction. For example, the included angle between the line connecting the highest points of the two discharge plates 12 constituting the primary discharge port 1-1-1 and the horizontal line is 7°. The heights of the discharge plates 12 connected by different primary discharge ports are consistent. The primary discharge ports numbered as 1-1-1~1-1-3 are unqualified discharge ports, and the primary discharge ports numbered as 1-1-4~1-1-6 are qualified discharge ports. After primary air separation, the particle size distribution range of the first three primary discharge ports is relatively disordered, and the mechanism sand of different particle size ranges is more concentrated through secondary air separation by means of the secondary discharge ports.

[0025] As shown in Figure 2 The secondary sorting mechanism 5 is arranged at the lower end of the primary discharge port, and three secondary sorting mechanisms 5 are distributed along the transverse direction, the middle one is numbered as 2-1, and the two on the sides are numbered as 2-2 and 2-3. The secondary feed ports 51 of the three secondary sorting mechanisms 5 are sequentially connected with the unqualified discharge ports numbered as 1-1, 1-2 and 1-3. The secondary feed port 51 is provided with a secondary feed pipe, the lower end of the feed pipe is curved into an arc shape toward the air outlet 6, and the housing of the secondary sorting mechanism 5 at the end of the feed pipe is provided with a baffle 54 arranged along the vertical direction. The baffle 54 can generate a rebound force on the sand hitting the baffle 54, and the rebound force increases with the particle size, so that the sand with larger particle size is rebounded to the side closer to the air inlet 2, thereby improving the sorting efficiency and effect.

[0026] The secondary sorting mechanism 5 is provided with a plurality of secondary discharge ports along the air inlet direction, and the embodiment preferably has three secondary discharge ports. The width of the discharge port in the middle is smaller than that of the other two discharge ports. Since the particle size in the middle range is relatively small compared to that at both ends, this arrangement facilitates discharging and further achieves better sorting. The secondary discharge port includes discharge plates 52 and discharge pipes 53 arranged from top to bottom and connected in sequence. The arrangement of the discharge plates 52 and the discharge pipes 53 is the same as that of the discharge plates 12 and the discharge pipes 13, except that the included angle between the line connecting the highest points of the discharge plates 52 and the horizontal line is 3°-5°, and the embodiment preferably has an included angle of 3°. The gradually increasing baffle 54 facilitates the sorting of mechanism sand of different particle sizes, so that particles of different particle size ranges fall into different secondary discharge ports.

[0027] The top of the housing of the primary sorting mechanism 1 and the secondary sorting mechanism 5 is a slope inclined upward from the air inlet 2 to the air outlet 6, and the inclination angle is 2°-8°. The inclination angles of the slopes of the primary sorting mechanism 1 and the secondary sorting mechanism 5 are 3° and 7°, respectively. The upwardly inclined slope in combination with the gradually increasing discharge plate and discharge plate forms an upwardly inclined air duct in the housing, which facilitates sorting.

[0028] The particle size range distribution of the six discharge outlets of the primary sorting mechanism and the nine discharge outlets of the three secondary sorting mechanisms is shown in Table 1 below.

[0029] Table 1 Particle size range of different equipment and different discharge outlets

[0030]

[0031] The air outlet 6 of the secondary sorting mechanism 5 and the primary sorting mechanism 1 is provided with an adjusting damper 3, the primary sorting mechanism 1 is numbered 1-1, and the air volume percentage of the primary sorting mechanism 1 and the three secondary sorting mechanisms 5, 2-1, 2-2 and 2-3, is 35-45%, 25-35%, 15-25% and 8-15% respectively, and the air volume percentage of the embodiment is 40%, 30%, 20% and 10% respectively. The air speed of different sorting mechanisms can be controlled by adjusting the damper 3, and the frequency conversion fan 42 is used, so that the size of the mechanism sand quantity to be processed can be adjusted synchronously according to the need. The unqualified material after the primary sorting is subjected to secondary sorting, and the fine sorting of six particle size ranges can be realized through two-stage continuous sorting.

[0032] Comparing the primary discharge outlet 1-1-1 and the secondary discharge outlet 2-1-1, the data of the two particle size discharge outlets after sorting is shown in Table 2.

[0033]

[0034] As shown in the above table, the primary discharge outlet 1-1-1 has a high proportion of each stage of discharge, and there are as many as four kinds of particle sizes with a proportion of more than 10%; after the mechanism sand of the primary discharge outlet 1-1-1 is sorted again by the secondary sorting mechanism, there are only two kinds of particle sizes with a proportion of more than 10%, and the proportion of the two kinds of particle sizes in the whole reaches 97%, the proportion of the mechanism sand with a particle size of 0.6 and below is not higher than 0.08%, and the mechanism sand particle size distribution concentration is high.

[0035] When the device is used, the belt feeder is used to feed the primary sorting mechanism 1, and when the primary sorting mechanism 1 and the secondary sorting mechanism 5 are not overlapped, the belt feeder is used to feed the secondary feeding port 51; the embodiment adopts an overlapping placement method; the unqualified discharge outlet can be directly communicated with the secondary feeding port 51 through a pipeline.

[0036] The same part of embodiment 2 as embodiment 1 is not repeated, and the difference is that; the cross section of the guide plate 21 away from the air outlet 6 is triangular, the cross section close to the inlet is rectangular, the ratio of the triangular and rectangular is 0.8:1-1.1:1, and the preferred ratio of this embodiment is 1:1; the front end is set to triangular to facilitate flow guide. The guide plate 21 is spaced apart along the vertical direction, and the gap size between the plurality of guide plates 21 gradually increases from top to bottom. The air inlet 2 of the primary sorting mechanism 1 is provided with 3 guide plates 21, and 4 gaps are formed between the 3 guide plates 21 and the shell. The percentage of the four gaps in the total gap ranges from top to bottom as follows: 15-20%, 18-24%, 22-30%, and 28-34%. The percentage of the total gap of this embodiment ranges from top to bottom as follows: 18%, 22%, 28%, and 32%. The air inlet 2 of the secondary sorting mechanism 5 is provided with 2 guide plates 21, and the gap distribution between the guide plates 21 of different sorting mechanisms is shown in Table 3.

[0037] Table 3 Gap distribution between guide plates of different sorting mechanisms

[0038]

[0039] By controlling the gap of the guide plate from top to bottom, the gap gradually increases from top to bottom. According to Bernoulli's principle, when the air inlet narrows, the flow rate increases, thereby controlling the wind speed of the air inlet, so that the wind speed of the air inlet gradually increases from bottom to top; thereby the manufactured sand can be blown away at a high wind speed at the top of the shell, so that the small particle size of the manufactured sand can fly to the discharge port close to the air outlet under the action of wind force.

[0040] The difference between embodiment 3 and embodiment 1, embodiment 2 is that; the discharge pipe 13 of the primary discharge port 11 is provided with a flexible material, and the unqualified discharge port is communicated with the secondary inlet 51 through the flexible material. The flexible material can be made of cloth bag and other wear-resistant flexible materials. Because the fan is arranged at the air outlet pipe 4, the entire device adopts air suction for air separation, so that the inside of the primary sorting mechanism shell is in a negative pressure state, thereby closing the discharge port under the action of negative pressure when starting to sort; it is not easy to enter the air from the primary discharge port, and when the manufactured sand accumulated in the discharge pipe increases, the flexible material is separated under the action of gravity, thereby discharging the manufactured sand. Similarly, the same setting can also be made at the secondary discharge port.

[0041] The above-mentioned are only embodiments of the present application, and the common knowledge of specific structures and characteristics in the scheme is not described too much. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope claimed in this application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A multi-stage continuous screening device for manufactured sand, characterized in that: The sorting mechanism includes a housing with a fan. The housing has an air inlet and an air outlet arranged sequentially along the air inlet direction. The sorting mechanism includes a primary sorting mechanism and a secondary sorting mechanism. The primary sorting mechanism has a primary feed inlet near the air inlet at the upper end of the housing, and multiple primary discharge outlets at the lower end of the housing. The primary discharge outlets include a defective discharge outlet and a qualified discharge outlet arranged sequentially along the air inlet direction. The secondary sorting mechanism has a secondary feed inlet near the air inlet at the upper end of the housing, and the defective discharge outlet is connected to the secondary feed inlet of the secondary sorting mechanism. Both the sorting mechanism and the secondary sorting mechanism have horizontally arranged guide plates at their air inlets. The secondary inlet has a feed pipe with its lower end curved towards the air outlet. The secondary sorting mechanism housing at the end of the feed pipe has a baffle. The baffle is arranged vertically and can generate a rebound force on the manufactured sand impacting the baffle, making it easier to rebound larger particles to the side closer to the air inlet. Multiple guide plates are distributed vertically at intervals, and the gap between the multiple guide plates gradually increases from top to bottom.

2. The multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The primary discharge port includes a feeding plate and a feeding pipe arranged from top to bottom and connected in sequence. The feeding plates of the multiple primary discharge ports gradually increase in height along the air inlet direction, and the angle between the line connecting the highest points of the multiple feeding plates and the horizontal line is 5-10°.

3. The multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The top of the housings of both the primary and secondary sorting mechanisms are inclined plates that slope upwards from the air inlet to the air outlet.

4. The multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The cross-section of the end of the air guide plate away from the air outlet is triangular.

5. A multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The air outlets of the primary sorting mechanism and the secondary sorting mechanism are connected together by an air outlet pipe. The fan is installed at the end of the air outlet pipe, and a dust collector is provided between the air outlet and the fan.

6. The multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The secondary sorting mechanism is located below the primary sorting mechanism, and the unqualified discharge port is connected to the secondary feed port through a flexible material.

7. A multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The non-conforming discharge port is provided in multiple ways, and the secondary sorting mechanism is provided in multiple ways corresponding to the non-conforming discharge port.

8. A multi-stage continuous screening device for manufactured sand according to claim 1, characterized in that: The guide plate is provided with 3, and the 3 guide plates form 4 gaps with the shell. The proportion of the 4 gaps to the total gaps ranges from top to bottom as follows: 15-20%, 18-24%, 22-30%, and 28-34%.

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