CN114602807B - A kind of dry classification and dust removal integrated screening equipment and method for fine granular materials - Google Patents

Abstract

The invention discloses an integrated dry classification and dust removal screening equipment and method for fine-grained materials, which belongs to the technical field of fine-grained material screening and solves the problem of particles blocking the screen surface when screening materials of 1 mm and below in the prior art. , screening the problem of environmental degradation. The screening equipment of the present invention includes a classification excitation device, a negative pressure adsorption device and a material collection device under the screen; the classification excitation device includes a vibrator, a screen frame and an elastic screen surface; the mesh size of the elastic screen surface is 1 mm; the negative pressure adsorption device The device is used to force materials below 1mm in the area above the screen to enter the area below the screen; the material collection device under the screen is used to collect fine particles of 1mm and below that enter the area under the screen. The invention realizes dry screening of materials of 1 mm and below, and avoids environmental pollution and material loss caused by dust during the screening process.

Description

A kind of dry classification and dust removal integrated screening equipment and method for fine granular materials

Technical field

The invention relates to the technical field of fine material screening, and in particular to a screening equipment and method integrating dry classification and dust removal of fine particles.

Background technique

Screening is a grading process in which loose mixed materials are passed through the sieve holes of a single or multi-layer screen surface and divided into several different grades of products according to particle size.

In the traditional dry screening process, the screen surface can easily cause particles to get stuck; for sticky and wet materials, the content of sticky fine particles is large and the external moisture is high, which can easily form a covering film and block the screen surface. The screening process gradually worsens. Seriously affects the screen surface opening rate and screening effect. During the dry screening process of fine-grained materials, due to the large content of powder materials, a large amount of dust will be generated during the screening process, causing environmental pollution and material loss.

Contents of the invention

In view of the above analysis, the present invention aims to provide an integrated equipment for 1mm dry classification and electrostatic precipitating of fine particle materials to solve the following existing problems:

(1) As the lower limit of screening particle size decreases, the content of particles close to the mesh size increases, especially for materials with a particle size range of 1mm and below, which is difficult to solve with traditional screening methods.

(2) During the dry screening process of fine-grained materials, due to the large content of powder materials, a large amount of dust will be generated during the screening process, causing environmental pollution and material loss.

The purpose of the present invention is mainly achieved through the following technical solutions:

The invention provides an integrated screening equipment for dry classification and dust removal of fine granular materials, including a classification excitation device, a negative pressure adsorption device and a material collection device under the screen;

The graded excitation device includes a vibrator, a screen frame and an elastic screen surface; the vibrator and the elastic screen surface are both located on the screen frame; the vibrator is used to provide exciting force to the screen frame; the mesh size of the elastic screen surface is 1mm ;

The negative pressure adsorption device is softly connected to the screen frame. The negative pressure adsorption device is located below the elastic screen surface. The negative pressure adsorption device is used to create a pressure difference between the upper and lower areas of the elastic screen surface, forcing 1mm of the upper area of the screen to The following materials enter the area under the screen;

The under-screen material collection device is located under the elastic screen surface and is used to collect fine particles of 1mm and below that enter the under-screen area.

In one possible design, the graded excitation device also includes a bracket and an elastic support; one end of the bracket is in contact with the fixed platform or the ground, and the other end is connected to the screen frame through the elastic support.

In one possible design, the negative pressure adsorption device includes an air flow generating unit, an air flow storage unit, an electrostatic precipitator unit, an adsorbed material collection unit and an air flow conveying unit;

The air flow generation unit, air flow storage unit, electrostatic precipitator unit, and adsorption material collection unit are all connected in sequence through the air flow transport unit; and the adsorption material collection unit is also softly connected to the screen frame through the air flow transport unit; the air flow generation unit generates negative pressure air flow, and passes through the air flow The storage unit, electrostatic precipitator unit and adsorbed material collection unit then enter the under-screen area of the elastic screen surface through the air transport unit.

In a possible design, the adsorbed material collection unit includes a first collector and a second collector connected in sequence; the first collector is located above the second collector;

The first collector includes a hollow first upper cone and a first lower cone. The first upper cone and the first lower cone are connected to form a closed space. An inclined first filter is provided in the closed space; the second collector The device includes a hollow second upper cone and a second lower cone. The second upper cone and the second lower cone are connected to form a closed space. An inclined second filter screen is provided in the closed space.

In a possible design, the mesh diameter of the first filter screen and the second filter screen is less than or equal to 0.05mm;

Based on the horizontal plane, the inclination angle of the first filter screen is greater than the inclination angle of the second filter screen.

In one possible design, an electrostatic field area is provided above the first collector, and the fine particles adsorbed by the negative pressure airflow generated by the negative pressure adsorption device first pass through the electrostatic field area;

The electrostatic field area is used to make dust particles negatively charged, and then separate the dust particles after adsorption.

In one possible design, the elastic screen surface includes multiple rectangular unit screen surfaces, the multiple rectangular unit screen surfaces are placed in parallel, and the long side direction of the rectangular unit screen surface is perpendicular to the flow direction of fine granular materials;

Along the feeding direction of fine-grained materials, the opening rate of the unit screen surface gradually decreases.

In one possible design, the elastic screen surface is tilted along the feeding direction, and the inclination angle of the elastic screen surface is 3-8° based on the horizontal plane.

In one possible design, multiple unit screen surfaces are made of polyurethane material.

In one possible design, the integrated screening equipment for dry classification and dust removal of fine-grained materials also includes an upper-screen material processing unit;

The over-the-sieve material processing unit is used to process the over-the-sieve material on the elastic screen surface and turn it into fine particles of 1 mm and below.

On the other hand, the present invention also provides an integrated dry classification and dust removal screening method for micro-fine materials, using the above-mentioned integrated dry classification and dust removal screening equipment for micro-fine materials. The screening method includes the following steps:

Step 1. Put the fine-grained materials into the classification excitation device. The fine-grained materials pass through the screen surface of the 1mm elastic screen. The fine-grained materials with 1mm and below pass through the elastic screen and enter the under-sieve material collection device; the above-sieve materials enter the above-sieve material processing unit;

Step 2: After being processed by the material processing unit on the screen, all the fine particles of 1mm and below formed by the materials on the screen will be removed.

Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

(1) By setting up a negative pressure adsorption device, the present invention can be used to increase the amount of fine-grained materials passing through the screen, strengthen the screening effect, and optimize the screening environment. By setting up a material collection unit, fine-grained materials can be recycled to avoid material loss.

(2) The present invention sets an electrostatic field above the first collector and sets an electrostatic precipitator below the second collector. The dual electrostatic precipitator design that combines dust removal during transportation and terminal dust removal can not only achieve efficient dust removal, but also And it can enhance the effective separation of dust particles and fine minerals on the screen surface to avoid environmental pollution.

(3) The integrated equipment for classification and dust removal of fine-grained materials provided by the present invention can achieve effective separation of fine-grained minerals and dust particles.

In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Additional features and advantages of the invention will be set forth in the description which follows, and in part, some advantages will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and obtained by the embodiments particularly pointed out in the description and drawings.

Description of drawings

The drawings are for the purpose of illustrating specific embodiments only and are not to be construed as limitations of the invention. Throughout the drawings, the same reference characters represent the same components.

Figure 1 is a left view of the hierarchical excitation device of the present invention;

Figure 2 is a front view of the hierarchical excitation device of the present invention;

Figure 3 is a schematic diagram of the overall structure of the hierarchical excitation device and adsorption device of the present invention;

Figure 4 is a process flow chart for processing the material above the sieve of the present invention, in which + represents the material above the sieve, and - represents the material below the sieve.

Reference signs:

1-Grading excitation device; 2-Elastic screen surface; 3-Air duct; 4-First collector; 5-Second collector; 6-First upper cone; 7-First filter; 8-First Lower cone; 9-second upper cone; 10 second filter; 11-second lower cone; 12-electrostatic precipitator; 13-air chamber; 14-fan; 15-vibrator; 16-sieve Frame; 17-elastic support; 18-bracket; 19-material on the screen; 20-material collection device under the screen; 21-feeding direction.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention and are not intended to limit the scope of the present invention.

The methods of material separation mainly include dry classification and wet classification according to particle size; among them, dry classification mainly includes dry screening and air cyclone force field classification (air flow classification); dry screening mainly uses screening equipment For classification, air flow classification is mainly performed through the air cyclone force field. The latter has small processing capacity and huge energy consumption, which restricts the industrial application of large-scale dry classification. Therefore, dry screening is an important way to solve the dry classification of industrial large-scale materials. The problem with dry screening is that the lower limit of the classification particle size of the existing technology is only 3mm or 2mm, and dry screening of 1mm cannot be achieved.

Compared with the previous 3mm or 2mm dry screening, this invention simultaneously utilizes negative pressure adsorption and electrostatic effect to perform 1mm dry screening.

As shown in Figures 1 to 4, the present invention provides an integrated screening equipment for dry classification and dust removal of fine-grained materials. The equipment includes a classification excitation device 1, a negative pressure adsorption device and a material collection device under the screen; classification excitation The device 1 includes a vibrator 15, a screen frame 16 and an elastic screen surface 2; the vibrator 15 and the elastic screen surface 2 are both located on the screen frame 16; the vibrator 15 is used to provide exciting force to the screen frame 16; the elasticity The mesh size of the screen surface 2 is 1mm; the negative pressure adsorption device is softly connected to the screen frame 16. The negative pressure adsorption device is located below the elastic screen surface 2. The negative pressure adsorption device is used to connect the upper screen area of the elastic screen surface 2 to the screen frame 16. A pressure difference is generated in the area under the screen, forcing materials below 1 mm in the area above the screen to enter the area under the screen; the under-screen material collection device 20 is located below the elastic screen surface 2 and is used to collect fine particles of 1 mm and below that enter the area under the screen.

Specifically, the present invention provides a negative pressure adsorption device below the elastic screen surface 2. The negative pressure adsorption device can introduce negative pressure airflow from below the elastic screen surface 2 to create a pressure difference between the upper screen area and the lower screen area of the elastic screen surface 2. , forcing the materials 1mm and below on the screen to pass through the screen downward; at the same time, due to the extrusion of the material particles and the deformation of the screen holes of the elastic screen surface 2, the particles blocking the screen holes are accelerated to pass through the screen holes. Due to the influence of moisture, in the traditional screening process, 1mm fine particles tend to adhere to large particles and cannot pass through the sieve. Compared with the existing technology, the present invention can promote the removal of fine particles through the air flow force field generated by the negative pressure adsorption device. The loss of moisture in the material causes the fine particles to desorb and pass through the screen.

Compared with the existing technology, the present invention can provide excitation force to the elastic screen surface 2 by arranging the graded excitation device 1 to promote materials with a diameter of 1mm and below to pass through the screen holes. In addition, since the screen surface of the present invention is an elastic screen surface 2, when the classification excitation device 1 provides excitation force to the screen frame 16, the screen holes will produce micro-deformation when stressed, which can promote the penetration of fine particles into the screen surface and promote the Screening of fine-grained materials.

The graded excitation device 1 of the present invention also includes a bracket 18 and an elastic support 17; one end of the bracket 18 is in contact with the fixed platform or the ground, and the other end is connected to the screen frame 16 through the elastic support 17.

Specifically, as shown in Figures 1 and 2, the graded excitation device 1 of the present invention also includes a bracket 18. The bracket 18 includes a plurality of support legs, for example, four support legs. The support legs are used to support the screen frame 16 and the screen surface. and its screening components; the bottom ends of the plurality of support legs are in contact with the ground or a fixed platform, and their top ends are connected with elastic supports 17, and the elastic supports 17 are connected with the screen frame 16.

In order to further ensure that fine-grained minerals of 1 mm and below can smoothly pass through the elastic screen surface 2, the negative pressure adsorption device of the present invention includes an air flow generating unit, an air flow storage unit, an electrostatic precipitator unit, an adsorbed material collection unit and an air flow conveying unit; the air flow generating unit, The airflow storage unit, electrostatic precipitator unit, and adsorbed material collection unit are all connected in sequence through the airflow conveying unit; and the adsorbed material collection unit is also softly connected to the screen frame 16 through the airflow conveying unit; the airflow generating unit generates negative pressure airflow, which passes through the airflow storage unit, The electrostatic precipitator unit and the adsorbed material collection unit then enter the under-screen area of the elastic screen surface 2 through the air flow conveying unit.

Specifically, the airflow generating unit of the present invention includes a fan 14, the first electrostatic precipitator unit includes a dust collector, the airflow storage unit includes an air chamber 13 or an air bag (equivalent to a buffer device with a buffering effect), and the airflow transport unit includes an air duct 3 The specific working process of the negative pressure adsorption device is: the fan 14 generates negative pressure airflow, which passes through the air chamber 13 or air bag, the electrostatic precipitator 12, and the adsorbed material collection unit and then is fed under the elastic screen surface 2 of the classification excitation device 1, so that A pressure difference is formed between the upper part of the elastic screen surface 2 and the lower part of the elastic screen surface 2. The granular materials 1mm and below are affected by the negative pressure air flow (downward adsorption force), thereby prompting these particles to pass through the screen and move toward the elastic screen. The lower part of surface 2 moves and becomes the object under the sieve. During the adsorption process of the negative pressure adsorption device, the flow direction of the adsorbed fine particles is: through the elastic screen surface, through the air duct 3 and into the electrostatic field area. After dust removal, it passes through the material adsorption unit respectively, and is collected after adsorption. The negative pressure airflow is discharged.

It should be emphasized that during the process of negative pressure airflow adsorption, materials with a diameter of 1 mm or less will inevitably be adsorbed. The present invention collects these materials by setting up an adsorption material collection unit. In addition, in order to avoid contaminating the air, the present invention collects the adsorbed materials The next link of the collection unit is equipped with an electrostatic precipitator 12. The electrostatic precipitator 12 is used to remove fine particles that are still adsorbed in the negative pressure airflow after being processed by the adsorbed material collection unit, and then the negative pressure airflow generated by the fan 14 can be discharged into atmosphere while avoiding air pollution.

In order to ensure the material collection effect and reduce the materials in the negative pressure air flow as much as possible, the material collection unit of the present invention includes a first collector 4 and a second collector 5 connected in sequence; the first collector 4 is located on the second collector Above the container 5; the first collector 4 includes a hollow first upper cone 6 and a first lower cone 8. The first upper cone 6 and the first lower cone 8 are connected to form a closed space, and there are The inclined first filter screen 7; the second collector 5 includes a hollow second upper cone 9 and a second lower cone 11. The second upper cone 9 and the second lower cone are connected to form a closed space. The closed space An inclined second filter screen 10 is provided inside.

Specifically, as shown in Figure 2, the material collection unit of the present invention includes a connected first collector 4 and a second collector 5, wherein the first collector 4 is located above the second collector 5, and the first collector 4 is disposed above the second collector 5. The collector 4 includes a first upper cone 6 and a first lower cone 8 that are both hollow. The first upper cone 6 and the first lower cone 8 are butted together to form a first hollow cavity. In the first hollow cavity A first filter screen 7 is provided with an inner slope. A first scraper collector and a first separation port are provided on the first filter screen 7. The first scraper collector passes the material above the first filter screen 7 through the first separation port. Remove the first upper cone 6 respectively. Similarly, the second collector 5 includes a second upper cone 9 and a second lower cone 11 that are both hollow. The second upper cone 9 and the second lower cone 11 are butted together to form a second hollow cavity. A second filter screen 10 is provided at an angle in the second hollow cavity. A second scraper collector and a second separation port are provided on the second filter screen 10. The second scraper collector collects the materials above the second filter screen 10. The first upper cones 6 are respectively removed through the second separation opening.

Since the material adsorbed by the negative pressure airflow first passes through the first collector 4, part of the material is collected through the first filter 7, which will reduce the concentration of the material in the negative pressure airflow. Therefore, when setting the first filter 7 and When the second filter screen 10 is used, the inclination angle of the first filter screen 7 is greater than the inclination angle of the second filter screen 10 .

In addition, since the particle size of materials in the negative pressure airflow is 1 mm and below, the mesh apertures of the first filter screen 7 and the second filter screen 10 of the present invention are less than or equal to 0.05 mm, and materials less than or equal to 0.05 mm are The electrostatic precipitator 12 is used for adsorption, and the negative pressure airflow after dust removal by the first electrostatic precipitator can be directly discharged into the atmosphere without causing environmental pollution.

It should be noted that the above-mentioned first filter screen 7 and the second filter screen 10 are both elastic filters, and the first collector 4 and the second collector 5 are both connected to power equipment, and the power equipment is used for the first filter screen 7 And the second filter screen 10 provides power to vibrate during the working process, thereby filtering and separating the materials more efficiently.

Compared with the prior art, the first collector 4 and the second collector 5 of the present invention use upper cones and lower cones to butt together to form a cavity, which can reduce the internal space of the first collector 4 and the second collector 5. To reduce the void volume, the first filter screen 7 and the second filter screen 10 are tilted to facilitate scraping.

It should be noted that the pressure difference between the upper screen area and the lower screen area of the elastic screen surface of the present invention is 500Pa-3000Pa. In addition, in order to ensure this pressure difference range, the mesh openings of the second filter mesh of the present invention are smaller than the mesh openings of the first filter mesh, and the mesh opening diameter of the second filter mesh is 65%-99% of the mesh opening diameter of the first filter mesh.

It should be emphasized that the present invention is provided with an electrostatic field area above the first collector 4, which is the previous link of the material collection unit. The fine particles adsorbed by the negative pressure airflow first pass through the electrostatic field area; the electrostatic field area is used to Dust particles are negatively charged and are separated after adsorption.

Specifically, the purpose of setting an electrostatic field above the adsorbed material collection unit in the present invention is to make the dust particles negatively charged by adjusting the intensity of the electrostatic field to prevent fine minerals from being charged, thereby causing the charged dust particles to be adsorbed by the collector wall, reducing The amount of particles entering the filter enhances the dust removal effect while avoiding clogging of the filter.

It should be noted that when adjusting the strength of the electrostatic field, the basis for the adjustment is: the surface charge density of fine-grained minerals and dust particles is different. The surface charge density of dust particles is greater than the surface charge density of fine-grained materials, and the force exerted by the electric field is greater. Strong, and at the same time, the mass of dust particles is smaller than the mass of fine particles. The dust particles are less affected by gravity, which causes them to be mainly subject to stronger electrostatic force, thus causing the two to separate.

It should be noted that the cleaning process of dust particles in fine particles of 1mm and below is: after the integrated screening equipment has been running for a period of time, the feeding is stopped, and at the same time the electric field intensity in the electrostatic field area is reduced, thereby causing the adsorbed dust particles to Desorption realizes the cleaning of this part of dust particles.

In order to improve the screening effect of the elastic screen surface 2, the elastic screen surface 2 of the present invention includes multiple rectangular unit screen surfaces. The multiple rectangular unit screen surfaces are placed in parallel. The long side direction of the rectangular unit screen surface is consistent with the flow direction of the fine particles. Vertical; along the feeding direction of fine-grained materials, the opening rate of the unit screen surface gradually decreases.

Compared with the prior art, the elastic screen surface 2 of the present invention is composed of multiple rectangular unit screen surfaces. According to the properties of the screened materials, it is easier to replace and adjust the screen plate, thereby adjusting the screen hole size. Specifically, the size of the sieve holes of the elastic screen surface 2 can be changed according to actual production needs. When the proportion of fine particles under the screen is to be higher, the sieve plate can be replaced to reduce the size of the sieve holes to adapt to production. demand; when the proportion of coarse particles on the screen is required to be high, the screen hole size can be increased by replacing the screen plate.

It should be noted that in order to improve the screening effect, the elastic screen surface 2 of the present invention uses polyurethane material. Compared with the existing technology, the elastic screen surface 2 of the present invention uses polyurethane because polyurethane is an elastic material, which can ensure that the mesh holes of the elastic screen surface 2 can be deformed during screening, thereby preventing fine particles from blocking the screen. hole.

It should be pointed out that the elastic screen surface 2 of the present invention is inclined along the material feeding direction, and the inclination angle of the elastic screen surface 2 is 3-8°. The inclination angle of the elastic screen surface 2 is controlled within the range of 3-8° because: the inclination angle of the elastic screen surface 2 is too small, which is not conducive to the forward movement of materials during the screening process; when the inclination angle of the elastic screen surface 2 is too large, , the material stays on the screen surface for a short time, and it is discharged as the product on the screen before it can pass through the screen.

Compared with the prior art, the present invention has the following beneficial effects:

(1) By setting up a negative pressure adsorption device, the present invention can be used to increase the amount of fine-grained materials passing through the screen, strengthen the screening effect, and optimize the screening environment. By setting up a material collection unit, fine-grained materials can be recycled to avoid material loss.

(2) The present invention sets an electrostatic field above the first collector 4 and sets an electrostatic precipitator 12 below the second collector 5. The dual electrostatic precipitator design that combines dust removal during transportation and terminal dust removal can not only achieve efficient dust removal At the same time, it can enhance the effective separation of dust particles and fine minerals on the screen surface to avoid environmental pollution.

(3) The integrated equipment for classification and dust removal of fine-grained materials provided by the present invention can achieve effective separation of fine-grained minerals and dust particles.

It should be noted that the dry classification and dust removal integrated screening equipment for fine-grained materials of the present invention also includes a processing unit for the over-the-sieve material 19; the over-the-sieve material 19 processing unit is used to process the over-the-sieve material on the elastic screen surface 2. Make it into fine particles of 1mm and below.

On the other hand, the present invention also provides an integrated dry classification and dust removal screening method for micro-fine materials, using the above-mentioned integrated dry classification and dust removal screening equipment for micro-fine materials. The screening method includes the following steps:

Step 1. Put the fine-grained materials into the classification excitation device 1, turn on the negative pressure adsorption device, and the fine-grained materials pass through the screen surface of the 1mm elastic screen. Under the adsorption action of the negative pressure airflow generated by the negative pressure adsorption device, the fine particles 1mm and below The material passes through the elastic screen and enters the material collection device under the screen; the material above the screen enters the material processing unit above the screen;

Step 2: After being processed by the material processing unit on the screen, all the fine particles of 1mm and below formed by the material 19 on the screen are processed.

In the above step 2, please refer to the following embodiment 1 for the specific processing process of the screened material 19 processing unit.

Example 1

This embodiment provides a possible design of the above-screen material processing unit. Specifically, the above-screen material processing unit includes a jaw crusher, and the above-screen material 19 needs to be processed by the jaw crusher before being processed.

The material processing unit on the screen of the present invention also includes a first-stage screening mechanism, a second-stage screening mechanism and a third-stage screening mechanism; the first-stage screening mechanism is also directly connected to the third-stage screening mechanism; the first-stage screening mechanism is also directly connected to the third-stage screening mechanism. The first-stage screening mechanism includes a first double-layer screening equipment, which includes a first upper screen and a first lower screen; the second-stage screening mechanism includes a second double-layer screening equipment, and the second double-layer screening equipment includes a first upper screen and a first lower screen. The layer screening equipment includes a second upper layer screen and a second lower layer screen; the third level screening mechanism includes a single layer screening equipment, and the single layer screening equipment includes a third single layer screen; the first lower layer screen, the second lower layer screen The mesh size of the third single-layer sieve is 1 mm.

It should be noted that the first double-layer screening equipment includes a first upper layer sieve and a first lower layer sieve. The mesh size of the first lower layer sieve is 1 mm; the second double-layer screening equipment includes a second upper layer sieve. and a second lower sieve, the sieve particle size of the second lower sieve is 1 mm; the single-layer screening equipment includes a third single-layer sieve, and the sieve particle size of the third single-layer sieve is also 1 mm. The screen surface size, inclination angle and vibration frequency of the first upper screen and the first lower screen, the second upper screen and the second lower screen, and the third single-layer screen are all equal.

The particle size limits of dry screening of fine-grained minerals in the prior art are mainly 3mm and 2mm, and wet screening is mostly used for fine-grained minerals. Wet screening requires a large amount of water, and when classifying clay minerals, it is easy to block the screen surface and worsen the screening environment. In addition, when traditional minerals are used for raw ore crushing and screening, a single vibrating screen is often used, and the screening efficiency is low; fine-grained minerals enter the crushing and grinding mechanism multiple times, which is prone to over-grinding, and additional crushing and grinding equipment are required. of power consumption.

Compared with the existing technology, the first-stage screening mechanism, the second-stage screening mechanism and the third-stage screening mechanism provided by the present invention constitute a multi-stage screening mechanism. The multi-stage screening mechanism adopts the first double-layer screen. The multi-stage combination of sub-equipment, second double-layer screening equipment and third single-layer screening equipment can achieve 1mm multi-stage depth screening of fine-grained minerals, effectively avoiding over-grinding of fine-grained minerals.

In order to crush the objects on the first upper screen so that the objects on the first upper screen finally pass through the third-stage screening mechanism, the first-stage screening mechanism of the present invention also includes a crusher; The products above the screen enter the crusher, and the crushed products are mixed with the products above the first lower screen and enter the second-stage screening mechanism. The products under the 1mm sieve obtained from the first lower screen enter the third-stage screening mechanism.

Specifically, the crusher is connected to the first upper screen, and the objects above the first upper screen enter the crusher for crushing. The obtained crushed products are mixed with the products above the first lower screen and enter the second-stage screening mechanism. , and the products under 1mm screened by the first lower screen directly enter the third-stage screening mechanism, preventing this part of fine-grained minerals less than or equal to 1mm from entering the second-stage screening mechanism and third-stage screening. mechanism, thereby avoiding over-grinding and reducing the power consumption of the crusher and grinding equipment.

In order to finely crush the products on the second upper screen, form a closed-circuit dry screening process on the products on the second upper screen, and finally allow the products on the second upper screen to pass through the third-stage screening mechanism, the invention The second-stage screening mechanism also includes a cone tertiary crusher. The products above the second upper sieve enter the cone tertiary crusher, and the crushed products return to the second upper sieve. The second double-layer screening equipment and the cone tertiary crusher form the first closed-circuit dryer. method of screening.

Specifically, the second-stage screening mechanism of the present invention also includes a cone crusher. The cone crusher, the inlet channel and the outlet channel are all connected to the second upper screen. The products on the second upper screen enter through the inlet channel. Cone crusher, after fine crushing, returns to the second upper screen through the discharge channel for screening. The products above the screen obtained by the second upper screen continue to enter the cone crusher, and the above process is repeated, while the products under the second upper screen are Then it enters the second lower sieve for 1mm screening, and the 1mm screened products enter the third-level screening mechanism.

Compared with the existing technology, the present invention sets up a cone crusher so that the cone crusher and the second double-layer screening equipment form the first closed-circuit dry screening, ensuring that the products on the second upper screen can be finely crushed. Then it returns to the second upper screen, and then enters the third-level screening mechanism after screening.

In order to make the raw ore entering the multi-stage dry screening system eventually become fine-grained minerals less than or equal to 1mm, the third-stage screening mechanism of the present invention also includes a grinding machine, which is connected to the second lower screen and the third-level screen respectively. The three single-layer screens are connected; the products above the second lower screen enter the grinding machine, and the ground products are mixed with the products under the second lower screen and enter the third-stage screening mechanism; the third single-layer screen performs a 1mm sieve After separation, the products above the third single-layer screen return to the grinding machine, and the products below the screen enter the sorting operation; the third single-layer screening equipment and the grinding machine form a second closed-circuit dry screening.

Compared with the existing technology, the grinding machine provided by the present invention and the third single-layer screening equipment constitute a second closed-circuit dry screening, and the products above the third single-layer screen enter the grinding machine for grinding. The final product returns to the third single-layer sieve. After the third single-layer sieve performs 1mm screening, the products under the sieve are fine-grained minerals less than or equal to 1mm. This part of the fine-grained minerals enters the sorting operation, while the objects on the sieve are Enter the grinding machine again; using the multi-stage dry screening system of the present invention, after multi-stage screening, the obtained products have no fine minerals with a particle size less than or equal to 1 mm. The system has a compact process and high screening efficiency. high.

It should be noted that the sieve particle size of the first upper sieve and the second upper sieve is 100mm, 50mm, 25mm, 13mm, 6mm or 3mm; the sieve particle size of the first upper sieve is larger than that of the second upper sieve. Pore size.

In order to ensure that fine-grained materials with a particle size less than or equal to 1 mm can smoothly pass through the sieve holes with a particle size of 1 mm and avoid clogging, the first double-layer screening equipment and the second double-layer screening equipment of the present invention both adopt double-layer screening equipment. The single-layer screening equipment uses a single-layer relaxation screen; the screen surfaces of the double-layer relaxation screen and the single-layer relaxation screen adopt elastic screen surface 2, and the elastic screen surface 2 is connected to the power device respectively.

Compared with the prior art, the screen surfaces of the double-layer relaxation screen and the single-layer relaxation screen of the present invention are connected to a power device. The power device is used to provide power to each relaxation screen to deform its mesh holes. The coal dust less than or equal to 1mm can pass through the screen surface of the elastic screen smoothly.

It should be emphasized that the screen surfaces of the double-layer relaxation screen and the single-layer relaxation screen of the present invention are all inclined, and the inclination angle of the elastic screen surface 2 is 3-8°. The inclination angle of the elastic screen surface 2 is controlled at The reason for the range of 3-8° is that: the inclination angle of the elastic screen surface 2 is too small, which is not conducive to the forward movement of the material during the screening process; when the inclination angle of the elastic screen surface 2 is too large, the material stays on the screen surface for a short time and is too late. After passing through the sieve, it becomes the product on the sieve and is discharged.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention. All substitutions are within the scope of the present invention.

Claims (10)

1. An integrated dry classification and dust removal screening equipment for fine-grained materials, which is characterized in that it includes a classification excitation device, a negative pressure adsorption device, an under-sieve material collection device and an over-sieve material processing unit; The grading excitation device includes a vibrator, a screen frame and an elastic screen surface; the vibrator and the elastic screen surface are both located on the screen frame; the vibrator is used to provide exciting force to the screen frame; The mesh size of the elastic screen surface is 1mm; The negative pressure adsorption device is softly connected to the screen frame. The negative pressure adsorption device is located below the elastic screen surface. The negative pressure adsorption device is used to generate pressure between the upper screen area and the lower screen area of the elastic screen surface. Poor, forcing materials below 1 mm in the upper screen area to enter the under screen area; the under screen material collection device is located below the elastic screen surface and is used to collect fine particles of 1 mm and below that enter the under screen area; The screening process using the integrated dry classification and dust removal screening equipment for fine-grained materials includes: Step 1. Put the fine-grained materials into the classification excitation device. The fine-grained materials pass through the screen surface of the 1mm elastic screen. The fine-grained materials with 1mm and below pass through the elastic screen and enter the under-sieve material collection device; the above-sieve materials enter the above-sieve material processing unit; Step 2. After being processed by the material processing unit on the screen, all the materials on the screen are fine particles of 1mm and below; The above-screen material processing unit includes a first-stage screening mechanism, a second-stage screening mechanism and a third-stage screening mechanism; the first-stage screening mechanism is also directly connected to the third-stage screening mechanism; the first-stage screening mechanism The sub-mechanism includes a first double-layer screening equipment, the first double-layer screening equipment includes a first upper screen and a first lower screen; the second-stage screening mechanism includes a second double-layer screening equipment, the second double-layer screen The screening equipment includes a second upper screen and a second lower screen; the third screening mechanism includes a single-layer screening equipment, and the single-layer screening equipment includes a third single-layer screen; the first lower screen, the second lower screen and the third The mesh size of the three single-layer sieves is all 1mm; The first-level screening mechanism also includes a crusher; the oversized objects from the first upper screen enter the crusher, and the crushed products are mixed with the over-screened products from the first lower screen and enter the second-level screening mechanism. The products under the 1mm sieve obtained from the layer sieve enter the third-stage screening mechanism; The second-stage screening mechanism also includes a cone tertiary crusher. The products above the second upper sieve enter the cone tertiary crusher, and the finely crushed products return to the second upper sieve; the second double-layer screening equipment and the cone tertiary crusher form the first Closed circuit dry screening; The third-level screening mechanism also includes a grinding machine, which is connected to the second lower screen and the third single-layer screen respectively; the products above the second lower screen enter the grinding machine, and the grinded products are mixed with the third single-layer screen. The products under the second lower screen are mixed and enter the third-level screening mechanism; after the third single-layer screen performs 1mm screening, the products above the third single-layer screen return to the grinding machine, and the products under the screen enter the sorting operation; The third single-layer screening equipment and the grinding machine form the second closed-circuit dry screening. 2. The integrated screening equipment for dry classification and dust removal of fine granular materials according to claim 1, characterized in that the classification excitation device further includes a bracket and an elastic support; one end of the bracket is in contact with a fixed platform or the ground. , the other end is connected to the screen frame through elastic support. 3. The integrated screening equipment for dry classification and dust removal of fine granular materials according to claim 2, characterized in that the negative pressure adsorption device includes an air flow generating unit, an air flow storage unit, an electrostatic dust removal unit, and an adsorbed material collection unit. and air delivery unit; The air flow generation unit, air flow storage unit, electrostatic precipitator unit, and adsorption material collection unit are all connected in sequence through an air flow transport unit; and the adsorption material collection unit is also softly connected to the screen frame through an air flow transport unit; the air flow generation unit generates The negative pressure airflow passes through the airflow storage unit, the electrostatic precipitator unit, and the adsorbed material collection unit, and then enters the under-screen area of the elastic screen surface through the airflow transport unit. 4. The integrated screening equipment for dry classification and dust removal of fine particle materials according to claim 3, characterized in that the adsorbed material collection unit includes a first collector and a second collector connected in sequence; A collector is located above the second collector; The first collector includes a hollow first upper cone and a first lower cone. The first upper cone and the first lower cone are connected to form a closed space. An inclined first cone is provided in the closed space. Filter; the second collector includes a hollow second upper cone and a second lower cone, the second upper cone and the second lower cone are connected to form a closed space, and an inclined space is provided in the closed space. of the second filter. 5. The integrated dry classification and dust removal screening equipment for fine-grained materials according to claim 4, characterized in that the mesh aperture of the first filter screen and the second filter screen is less than or equal to 0.05mm; Taking the horizontal plane as a reference, the inclination angle of the first filter screen is greater than the inclination angle of the second filter screen. 6. The integrated screening equipment for dry classification and dust removal of fine granular materials according to claim 4 or 5, characterized in that an electrostatic field area is provided above the first collector, and the electrostatic field area generated by the negative pressure adsorption device The fine particles adsorbed by the negative pressure airflow first pass through the electrostatic field area; The electrostatic field area is used to make dust particles negatively charged, and then separate the dust particles after adsorbing them. 7. The integrated screening equipment for dry classification and dust removal of fine granular materials according to claim 1, characterized in that the elastic screen surface includes a plurality of rectangular unit screen surfaces, and the plurality of rectangular unit screen surfaces are placed in parallel. , the long side direction of the rectangular unit screen surface is perpendicular to the flow direction of the fine particle material; Along the feeding direction of fine-grained materials, the opening rate of the unit screen surface gradually decreases. 8. The integrated screening equipment for dry classification and dust removal of fine-grained materials according to claim 7, characterized in that the elastic screen surface is arranged at an angle along the feeding direction, and the elastic screen surface is based on the horizontal plane. The tilt angle is 3-8°. 9. The integrated screening equipment for dry classification and dust removal of fine granular materials according to claim 8, characterized in that the above-screen material processing unit is used to process the above-screen materials on the elastic screen surface, and after processing, it becomes Fine particles of 1mm and below. 10. An integrated dry classification and dust removal screening method for fine-grained materials, which is characterized in that the dry classification and dust-removal integrated screening equipment for fine-grained materials according to any one of claims 1 to 9 is used, including the following step: Step 1. Put the fine-grained materials into the classification excitation device. The fine-grained materials pass through the screen surface of the 1mm elastic screen. The fine-grained materials with 1mm and below pass through the elastic screen and enter the under-sieve material collection device; The material on the screen enters the material processing unit on the screen; Step 2: After being processed by the material processing unit on the screen, all the fine particles of 1mm and below formed by the materials on the screen will be removed.