CN114953259A

CN114953259A - Washing and charging integrated waste plastic reinforced electric separation system and method

Info

Publication number: CN114953259A
Application number: CN202210578030.5A
Authority: CN
Inventors: 何鑫; 王文峰; 周长春; 李海生; 孙浩
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-08-30
Anticipated expiration: 2042-05-25
Also published as: CN114953259B

Abstract

The invention discloses a washing and charging integrated waste plastic reinforced electric separation system and a washing and charging integrated waste plastic reinforced electric separation method, wherein the system comprises a feeding washing and charging module, a high-voltage electrostatic separation module, a charging reinforced cyclic separation module and a decontamination drying cyclic separation module; the feeding cleaning charging module is connected with the high-voltage electrostatic sorting module, the medium-purity product collecting device below the high-voltage electrostatic sorting module is connected with the charging reinforced circulating sorting module, the charging reinforced circulating sorting module is connected back to a high-flow-rate feeding pipeline of the feeding cleaning charging module, a discharging pipeline of the high-voltage electrostatic sorting module is connected with the decontamination drying circulating sorting module, and the decontamination drying circulating sorting module is connected back to a high-flow-rate recycling pipeline of the feeding cleaning charging module. The invention can be used for sorting the thermoplastic mixed waste plastics in the electronic waste, sorting the high-quality grains in agriculture and other processes, and has the characteristics of convenient operation, targeted treatment, cost and energy conservation, flexible regulation and control of product structure and the like.

Description

Washing and charging integrated waste plastic reinforced electric separation system and method

Technical Field

The invention belongs to the technical field of renewable energy recovery and mineral physical separation, and particularly relates to a system and a method for cleaning and charging integrated waste plastic reinforced electric separation.

Background

At present, a great deal of electronic equipment such as computers, televisions, refrigerators, washing machines, mobile phones and the like enter a scrapping period every year in China, and shells and internal components of the electronic waste contain a great deal of recycled plastics. Under the current situation that crude oil resources are in short supply and the oil price is high, the emission of 2 tons of CO can be reduced when 1 ton of waste plastics is recycled ₂ And 3-5 tons of crude oil are saved, and the economic, environmental and energy safety benefits are remarkable.

Most recyclable plastics in electronic waste are thermoplastic plastics. Thermoplastics have the characteristics of softening by heating, solidifying by cooling and such a process can be repeated. The waste plastics can be re-melted and granulated or processed into new products with high added value after the process flows of sorting, cleaning, crushing and the like, the cost is low, the pollution is small, and the method is the current main waste plastic recycling direction. However, the quality and economic value of the recycled plastics are seriously affected by the content of impurities, so the purity requirement of the recycled products is high.

Currently, electro-separation is receiving much attention as a dry electrostatic separation technique in the separation of mixed waste plastics. Firstly, dry separation avoids a large amount of sewage treatment; secondly, the energy consumption is mainly electric energy, and the method is clean and efficient; and can also be sorted in the face of low density difference mixed plastics which cannot be processed by density separation technology. In the electric separation, materials need to be pre-crushed and particle size controlled, different types of plastic surfaces are charged with opposite polarities through various charging means, and then the materials are separated by attraction forces of positive and negative plates in different directions in a high-voltage electrostatic field. The types of thermoplastic plastics widely used in the current electronic waste are mainly ABS (acrylonitrile-butadiene-styrene), PS (polystyrene), PP (polypropylene), PVC (polyvinyl chloride) and the like, wherein the ABS and the PS have extremely similar densities, and are all 1.05g/cm ³ On the left and right sides, the density sorting means cannot effectively separate. However, the ABS and the PS, as well as the PP and the PVC have obvious friction charge difference, and the charge sequence is as follows: the (positive electricity) ABS-PS-PP-PVC (negative electricity) pre-crushing before electric separation also provides convenience for remelting and granulating single kind of plastic after separation. Therefore, the above-mentioned characteristics of the thermoplastic waste plastics all provide favorable conditions for the electrical separation thereof.

However, dust and oil stains from electronic equipment which are often contaminated on the surface of the waste plastic can change the charge characteristics of the surface of the plastic, thereby affecting the charge quantity and the electric separation effect and reducing the purity of the recycled plastic. In the existing electric separation system, the negative influence of floating dust on the surface of plastic and plastic particles stained with oil stains on the separation effect is usually ignored, or a great amount of cost investment is increased because a wet cleaning and drying process is added at the front end of separation. Meanwhile, the control of the purity of the sorted products also stays in the sorting process, and the sorting process cannot be flexibly regulated and controlled, so that the problems exist in different degrees.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a cleaning and charging integrated waste plastic reinforced electric separation system and a method, which are mainly used for sorting thermoplastic mixed waste plastic in electronic waste, separating mixed metal, metal and plastic mixtures in the waste, and can also be used for processes such as powder engineering separation, sorting of high-quality grains in agriculture and the like. The method solves the problems of poor sorting effect caused by surface property change and insufficient charge due to dust and oil stains on the surfaces of plastic particles in the conventional process for electrically sorting and recycling the thermoplastic waste plastics, excessive dependence on the process on product purity, difficulty in regulation and control and the like, and has the characteristics of convenience in operation, targeted treatment, cost and energy conservation, flexible regulation and control of product structure and the like.

The invention is realized by the following technical scheme:

a washing and charging integrated waste plastic reinforced electric separation system comprises a feeding washing and charging module, a high-voltage electrostatic separation module, a charging reinforced circular separation module and a decontamination drying circular separation module;

the feeding cleaning charging module comprises a fan, a high-flow-rate recovery pipeline, an airflow pipeline, a feeding device, a high-flow-rate feeding pipeline and a cleaning charging device; the high-flow-rate recovery pipeline is designed as a three-way pipeline, two ends of the high-flow-rate recovery pipeline are respectively connected with a fan and an airflow pipeline, and the side surface of the high-flow-rate recovery pipeline is connected with a decontamination drying circulation sorting module; two ends of the airflow pipeline are respectively connected with a high-flow-rate recovery pipeline and a high-flow-rate feeding pipeline; the high-flow-speed feeding pipeline is designed as a four-way pipeline, two ends and one side of the high-flow-speed feeding pipeline are respectively connected with an airflow pipeline, a cleaning charging device and a feeding device, and one side of the high-flow-speed feeding pipeline, which is opposite to the feeding device, is connected to a charging reinforced circulation sorting module; two ends of the cleaning charging device are respectively connected with a high-flow-rate feeding pipeline and a high-voltage electrostatic separation module through flanges; the cleaning charging device comprises a cleaning area I, a cleaning charging area II and a charging area III, wherein the three areas are connected through a flange, more than one cleaning friction rod made of friction materials is arranged in each of the three areas in a staggered mode, and the surface work function of each friction material is between plastics to be selected; the cleaning friction rods are respectively externally connected with controllers and can rotate automatically, and the rotating speed can be controlled and adjusted;

the high-voltage electrostatic separation module comprises a high-voltage electrostatic separation chamber, a high-purity product collection device, a medium-purity product collection device, a low-purity product collection device and a discharge pipeline; the two ends of the high-voltage electrostatic separation chamber are respectively connected with a cleaning charging device and a discharging pipeline, the separation mode adopted by the high-voltage electrostatic separation chamber is a parallel plate type, and a positive plate and a negative plate which are loaded with high voltage are arranged in the high-voltage electrostatic separation chamber in parallel; two first slideways are respectively arranged on two short edges of the inner side of the positive plate along the short edges, a scraping rod is erected between the two first slideways and is externally connected with a controller, and the scraping rod slides back and forth along the first slideways at a low speed under the action of the controller to scrape particles adsorbed on the surface of the positive plate; two second slideways are respectively arranged on two long edges of the inner side of the positive plate along the long edges, a first ore separating plate and a second ore separating plate are erected between the two second slideways, the first ore separating plate and the second ore separating plate are both externally connected with a controller, and the first ore separating plate and the second ore separating plate slide along the second slideways and fix points under the action of the controller to classify products; the negative plate and the positive plate have the same structure; the high-purity product collecting device, the medium-purity product collecting device and the low-purity product collecting device are positioned below the high-voltage electrostatic separation chamber and respectively correspond to a high-purity product area, a medium-purity product area and a low-purity product area which are formed by sequentially separating a positive plate and a negative plate from one end close to the cleaning charging device through a first ore separating plate and a second ore separating plate; one end of the discharge pipeline is connected with the high-voltage electrostatic separation chamber through a flange, and the other end of the discharge pipeline is connected to the decontamination drying circulation separation module;

the charge strengthening circulating sorting module comprises a circulating pipeline and a corona strengthening charge device; two ends of the circulating pipeline are respectively connected with the medium-purity product collecting device and the corona strengthening charging device; the two circulating pipelines are respectively connected with one side of the positive plate and one side of the negative plate; more than one corona rod is arranged inside the corona charge strengthening device in a staggered mode, and two ends of the corona charge strengthening device are respectively connected with a circulating pipeline and a high-flow-rate feeding pipeline; the corona charge strengthening devices are provided with two circulating pipelines which are respectively and correspondingly connected with one side of the positive plate and one side of the negative plate, wherein a negative electrode corona rod is adopted as a circulating line corresponding to the positive plate, and a positive electrode corona rod is adopted as a circulating line corresponding to the negative plate;

the decontamination drying circulation sorting module comprises a cleaning pipeline, a conveying device, a drying device and a negative pressure recovery device; the cleaning pipeline is designed as a three-way pipeline, and two ends and the side surface of the cleaning pipeline are respectively connected with a low-purity product collecting device, a conveying device and a discharging pipeline; cleaning nozzles externally connected with a water source are respectively arranged on two sides of the vertical inner wall of the cleaning pipeline in a staggered mode, and a porous water outlet is formed in one end, connected to the conveying device, of the cleaning pipeline, close to the ground; the two ends of the conveying device are respectively connected with a cleaning pipeline and a negative pressure recovery device, and the whole middle section of the conveying device is covered by a drying device; and two ends of the negative pressure recovery device are respectively connected with the conveying device and the high-flow-rate recovery pipeline.

Preferably, the cleaning charging device is a square pipeline; the cleaning friction rods in the square pipeline are inserted, and the arrangement modes in the three areas are all in a regular triangle mode; the radius of washing friction stick is r, and the washing friction stick interval of arranging is D, and square pipeline width is X, and the three relation is: r is not less than 1/20X and not more than 1/16X, D is more than 2/5X and not more than 1/2X.

Preferably, the cleaning charging device is a circular pipeline; the embedding mode of cleaning friction rod in the circular pipeline is single-end embedded, and the embedding mode is A-square: the cleaning area I, the cleaning charged area II and the charged area III are respectively provided with two circles of cleaning friction rods, the first circle is sequentially arranged at 3 according to 120 degrees, and the second circle and the first circle are staggered at 60 degrees and are sequentially arranged at 3 according to 120 degrees; the radius of the cleaning friction rod is R, the embedding depth is L, the radius of the circular pipeline is R, and the relationship among the three is as follows: r is less than or equal to 1/8R, and L is 1/3R.

Preferably, the cleaning charging device is a circular pipeline; the embedding mode of cleaning friction rod in the circular pipeline is single-end embedded, and the embedding mode is B mode: the cleaning area I, the cleaning charged area II and the charged area III are respectively provided with two circles of cleaning friction rods, the first circle is sequentially arranged at 4 according to 90 degrees, and the second circle and the first circle are staggered at 45 degrees and are sequentially arranged at 4 according to 90 degrees; the radius of the cleaning friction rod is R, the embedding depth is L, the radius of the circular pipeline is R, and the relationship among the three is as follows: r is less than or equal to 1/8R, and L is 1/6R.

Preferably, the surface of the cleaning friction rod is divided into A, B and C;

the design A adopts more than one brush whiskers made of friction materials and arranged densely in a fiber shape along the rod surface of a cleaning friction rod, the diameter of the brush whiskers is 0.5mm, the length of the brush whiskers is equal to the radius r of the cleaning friction rod, and the distance between every two rows of brush whiskers along the horizontal direction and the vertical direction is less than 0.5 mm;

the design B adopts more than one high-friction tooth and low-friction tooth which are made of friction materials and are sequentially arranged along the rod surface of the cleaning friction rod according to the height, the diameters of the high-friction tooth and the low-friction tooth are both 1mm, the top ends of the high-friction tooth and the low-friction tooth are both provided with a round contact, the diameter of the round contact is 0.5mm, the length of the high-friction tooth is equal to the radius r of the cleaning friction rod, the length of the low-friction tooth is equal to 0.5r, and the distance between each row of friction teeth in the horizontal direction and the vertical direction is smaller than 1 mm;

the C design uses a smooth surface ground with a friction material.

Preferably, the design of the cleaning friction rods in the square pipeline and the circular pipeline are both of a uniform type: the surface of the cleaning friction rod in the cleaning area I is designed to be A, the surface of the cleaning friction rod in the cleaning charged area II is designed to be B, and the surface of the cleaning friction rod in the charged area III is designed to be C.

Preferably, the design of the cleaning friction rod in the square pipeline and the circular pipeline is combined: the cleaning friction rods in the three areas are divided into an upper section and a lower section, and the surfaces of the upper section and the lower section are any combination of A, B, C designs.

Preferably, the high-flow-rate recovery pipeline and the high-flow-rate feeding pipeline are designed by adopting Venturi tubes, and the two ends of the Venturi tubes are wide and the middle section of the Venturi tubes is narrow.

A washing and charging integrated waste plastic reinforced electric separation method comprises the following steps:

step 1), feeding the crushed waste plastic particles into a system through a feeding device, wrapping the crushed waste plastic particles into a cleaning charging device by air flow blown by a fan, brushing the particles by a cleaning friction rod in a cleaning area I to remove surface dust, further cleaning the surface in a cleaning charging area II, carrying out primary charging, and carrying out deep charging by collision friction with a cleaning friction rod in a charging area III; the surface of the plastic particles with the surface work function lower than that of the friction material is positively charged, and the surface work function of the plastic particles with the surface work function higher than that of the friction material is negatively charged;

step 2), after the particles enter a high-voltage electrostatic separation chamber from a cleaning charging device, the particles with positive electricity are adsorbed on a negative plate, and the particles with negative electricity are adsorbed on a positive plate; fully charged particles are scraped by a scraping rod and enter a high-purity product collecting device; the particles with common charging effects are scraped to a medium-purity product collecting device, enter a circulating pipeline, then enter a corona strengthening charging device, enter a high-flow-rate feeding pipeline again for secondary sorting after being subjected to charging strengthening by a corona rod; because the poor granule of greasy dirt pollution or other reasons electrified effect is scraped to low purity product collection device or is taken to the ejection of compact pipeline by the air current, is sent into the washing pipeline clearance surface in unison at last, falls into conveyer after the washing is accomplished and delivers to hot air drying in the drying device, and the granule after the washing drying gets into the system once more via negative pressure recovery unit and selects separately.

The invention has the following beneficial effects:

(1) the system and the method for cleaning and charging integrated waste plastic reinforced electric separation have the characteristics of convenience in operation, targeted treatment, cost and energy conservation, flexible regulation and control of product structures and the like.

(2) The cleaning charge module of the system integrates cleaning and charging, friction brushes, friction teeth and smooth friction surfaces are designed on the surfaces of cleaning friction rods and combined, and are coupled with various pipeline designs, partitions and friction rod autorotation settings, and the cleaning charge module sequentially cleans surface floating dust, deeply cleans particles, pre-charges and deeply charges to complete the cleaning and charging integration. Not only can be cleaned and replaced regularly. The targeted design of cleaning and charging can be carried out aiming at various aspects of the characteristics of the selected materials, and the separation effect is enhanced. A dust removal system at the front end is omitted, the cost is reduced, and the particles can be ensured to be fully charged through enough friction times.

(3) The high-voltage electrostatic separation module of the system comprises a product structure regulation design, a scraping rod and a mineral separation plate are arranged on the inner sides of a positive plate and a negative plate, the charged sufficient degree is divided into three structures of high purity, medium purity and low purity according to the adsorption position of particles from high to low on the polar plates, and the product structure can be flexibly regulated and controlled according to the actual collected product quality.

(4) The charge-enhanced circular sorting module and the decontamination drying circular sorting module of the system are designed aiming at particle groups with different sorting problems. Particles with relatively insufficient charge can be subjected to a corona electric field to enhance the charge effect, and particle groups which are almost incapable of charge due to surface property change (oil stains and the like) are uniformly cleaned, dried and separated again. The targeted treatment can effectively enhance the particle charging effect, reduce the cost and save the energy.

(5) The washing and charging integrated waste plastic reinforced electric separation system and the method have wide application range, are mainly used for recycling mixed plastics in electronic wastes, and only need to carry out sectional treatment on various mixed plastics. The method can also be used for separating plastic and metal parts in electronic waste, recovering mixed metal, separating powder engineering, sorting high-quality grains in agriculture and the like.

Drawings

FIG. 1 is a schematic flow diagram of a cleaning and charging integrated waste plastic intensified electric separation system;

fig. 2 is a structure diagram of a square pipeline of the cleaning charging device: a is a side view, B is a top view;

fig. 3 is a circular pipeline structure diagram of the cleaning charging device: a is a top view, B is a side view;

FIG. 4 is a schematic diagram of three designs of a cleaning rub bar: a is a top view of the design A, B is a side view of the design A, C is a top view of the design B, d is a side view of the design B, e is a top view of the design C, and f is a side view of the design C;

FIG. 5 is a schematic view of the inner side of the positive plate in the high-tension electrostatic separation chamber;

FIG. 6 is a structural view of a curved porous water outlet in the cleaning pipeline;

in the figure: 1. a fan; 2. a high flow rate recovery pipeline; 3. an air flow conduit; 4. a feeding device; 5. a high flow rate feed conduit; 6. cleaning the charging device; 6-1, cleaning the rubbing rod; firstly, a square pipeline; ②, a circular pipeline; i, a cleaning area; II, cleaning a charged area; III, a charged area; 7. a high-voltage electrostatic separation chamber; 7-1, a first slideway; 7-2, a scraping rod; 7-3, a second slideway; 7-4, a first mineral separation plate; 7-5, second ore dividing plate; 8. a high purity product collection device; 9. a medium-purity product collecting device; 10. a low purity product collection device; 11. a discharge pipeline; 12. a circulation pipe; 13. a corona strengthening charging device; 13-1, corona rod; 14. cleaning a pipeline; 14-1, cleaning a spray head; 14-2, a porous water outlet; 15. a conveying device; 16. a drying device; 17. a negative pressure recovery device.

Detailed Description

The invention will be further elucidated with reference to the embodiments described in the following, without however limiting the scope of the invention thereto.

Example 1

A washing and charging integrated waste plastic reinforced electric separation system is shown in figure 1 and comprises a feeding washing and charging module, a high-voltage electrostatic separation module, a charging reinforced circular separation module and a decontamination drying circular separation module.

As shown in fig. 1, the charging module for charging cleaning comprises a fan 1, a high-flow-rate recovery pipeline 2, an airflow pipeline 3, a feeding device 4, a high-flow-rate feeding pipeline 5 and a charging device for cleaning 6; the high-flow-rate recovery pipeline 2 is designed as a three-way pipeline, two ends of the high-flow-rate recovery pipeline are respectively connected with the fan 1 and the airflow pipeline 3, and the side surface of the high-flow-rate recovery pipeline is connected to a negative pressure recovery device 17 of the decontamination drying circular sorting module; the two ends of the airflow pipeline 3 are respectively connected with a high-flow-rate recovery pipeline 2 and a high-flow-rate feeding pipeline 5; the high-flow-rate feeding pipeline 5 is designed as a four-way pipeline, two ends and one side of the high-flow-rate feeding pipeline are respectively connected with the airflow pipeline 3, the cleaning charging device 6 and the feeding device 4, and one side of the high-flow-rate feeding pipeline, which is opposite to the feeding device 4, is connected to a corona strengthening charging device 13 of a charge strengthening circulating sorting module; and two ends of the cleaning charging device 6 are respectively connected with the high-flow-rate feeding pipeline 5 and the high-voltage electrostatic separation chamber 7 of the high-voltage electrostatic separation module through flanges.

As shown in fig. 2 and 3, the cleaning charging device 6 can be divided into a square pipeline (i) and a circular pipeline (ii), each pipeline comprises a cleaning area (i), a cleaning charging area (ii) and a charging area (iii), the three areas are connected through flanges, and more than one cleaning friction rod 6-1 made of friction materials (the surface work function of which is between the plastics to be selected) is arranged inside the three areas in a staggered manner. The three areas can be respectively disassembled to replace the cleaning friction rod 6-1 or clean the cleaning friction rod regularly.

As shown in fig. 2, the cleaning charging device 6 is a square pipeline (r); the cleaning friction rod 6-1 in the square pipeline is inserted, and the arrangement modes in the three areas are all in a regular triangle mode; the radius of the cleaning friction rods 6-1 is r, the distance between the cleaning friction rods 6-1 in the same row is D, the width of the square pipeline is X, and the relationship among the three is as follows: r is not less than 1/20X and not more than 1/16X, D is more than 2/5X and not more than 1/2X. The regular triangle arrangement can ensure that the cleaning friction rod 6-1 is vertically and horizontally symmetrical in a top view (figure 2) of the square pipeline, thereby promoting the flow characteristics of gas-solid two-phase fluid formed in the actual pipeline to be symmetrical and facilitating the control of the fluid movement mode; the radius smaller than 1/16X can ensure that enough space with the same width as the friction rods exists at the two ends of the friction rods when 2 cleaning friction rods 6-1 in the pipeline are parallel, and prevent the back of the friction rods from forming an overlarge negative pressure area to cause speed reduction and detention on particle groups, and the limitation larger than 1/20X not only ensures the cleaning friction effect of the cleaning friction rods 6-1 on the particles, but also leaves an action space for the surface design of the cleaning friction rods 6-1; the distance D smaller than 1/2X can reserve sufficient flowing space for the two sides of the same row of cleaning rubbing rods 6-1 to ensure the stable shunting flow of the air flow, and the distance larger than 2/5X can also avoid the cleaning rubbing action of the cleaning rubbing rods 6-1 on the particles in the fluid from being reduced by the excessively wide single-side space.

As shown in fig. 3, the cleaning charging device 6 is a circular pipeline (ii); the embedding mode of the cleaning friction rod 6-1 in the round pipeline II is a single-end embedded mode, and the embedding mode comprises a mode A and a mode B:

in the first mode, two circles of cleaning friction rods 6-1 are respectively distributed in a cleaning area I, a cleaning charged area II and a charged area III, the number of the first circles is 3 according to 120 degrees, and the number of the second circles and the number of the first circles are 3 according to 120 degrees and are staggered by 60 degrees; the radius of the cleaning friction rod 6-1 is R, the embedding depth is L, the radius of the circular pipeline is R, and the three relations are as follows: r is less than or equal to 1/8R, and L is 1/3R.

In the second mode, two circles of cleaning friction rods 6-1 are respectively distributed in the cleaning area I, the cleaning charged area II and the charged area III, 4 cleaning friction rods are sequentially arranged in the first circle according to 90 degrees, and 4 cleaning friction rods are sequentially arranged in the second circle and the first circle at 45-degree staggered positions and according to 90 degrees; the radius of the cleaning friction rod 6-1 is R, the embedding depth is L, the radius of the circular pipeline is R, and the relationship among the three is as follows: r is less than or equal to 1/8R, and L is 1/6R.

The cleaning friction rods 6-1 in the circular pipeline II are distributed in staggered circles, so that the cleaning friction effect on particles in fluid at different positions of the circular section can be ensured to a greater extent; the mode A and the mode B are respectively suitable for cleaning particles with relatively low friction requirements and relatively high friction requirements, the radius R smaller than 1/8R and the embedding depth below 1/3R can ensure that enough space exists on two sides of the friction rod 6-1 for cleaning in the mode A and the mode B to stably shunt fluid, and the lower embedding depth in the mode B can avoid excessive interference of the symmetrical friction rod on the fluid in the same plane.

As shown in FIG. 4, the surface of the cleaning friction bar 6-1 is divided into A, B and C designs:

as shown in fig. 4a and 4b, the design A adopts more than one brush whiskers made of friction materials and arranged densely along the rod surface of the cleaning friction rod 6-1 in a fiber shape, the diameter of the brush whiskers is 0.5mm, the length of the brush whiskers is equal to the radius r of the cleaning friction rod 6-1, and the distance between every two rows of the brush whiskers along the horizontal direction and the vertical direction is less than 0.5 mm. The spacing requirement is determined according to the preferable sorting particle size range (1-5 mm) of the plastic particles, so that the reduction of sorting efficiency caused by embedding the particles into the hairbrush under the action of air flow is avoided.

As shown in fig. 4c and 4d, the design B adopts more than one high-friction tooth and low-friction tooth made of friction materials and arranged in sequence along the rod surface of the cleaning friction rod 6-1 according to the height, the diameters of the high-friction tooth and the low-friction tooth are both 1mm, the top ends of the high-friction tooth and the low-friction tooth are both provided with round contacts, the diameter of each round contact is 0.5mm, the length of the high-friction tooth is equal to the radius r of the cleaning friction rod 6-1, the length of the low-friction tooth is equal to 0.5r, and the distance between each row of friction teeth in the horizontal direction and the vertical direction is smaller than 1 mm. The distance requirement is determined based on the preferable sorting particle size range (1-5 mm) of the plastic particles and the diameter of the round contact terminal is 0.5mm, and the particles are prevented from being embedded into friction teeth under the action of air flow to reduce sorting efficiency.

As shown in fig. 4e and 4f, the design C uses a smooth surface ground by a friction material.

The A, B, C design for cleaning the surface of the friction rod 6-1 can be combined at will, wherein the A design has the strongest cleaning effect on the surface of the particles, the B design has the simultaneous cleaning and charging effect on the surface of the particles, and the C design has the best charging effect on the particles. Therefore, personalized combination can be carried out according to the characteristics of the materials to be selected, if the surface of the plastic to be selected has more dust and the difference of the work function of the surface is small, charging needs to be enhanced, the surface of the friction rod 6-1 in the cleaning area I can be completely designed by A, the surface of the friction rod in the cleaning charging area II is designed by A + C, cleaning and charging are further enhanced, and charging is enhanced by C in the charging area III.

The A, B, C design for cleaning the surface of the friction rod 6-1 can be made of different friction materials, and as long as the surface work functions of the friction materials are all between the plastics to be selected, the separation effect can be enhanced by adopting different friction materials. If the design A focuses on cleaning, a friction material with high toughness is selected, the design B focuses on cleaning and charging, the friction material with high toughness and certain hardness is selected to resist collision for charging, and the design C focuses on charging, and the friction material with high hardness and the best charging effect of the plastics to be selected is selected to strengthen the charging effect.

The preferred scheme is that the surfaces of the cleaning friction rods 6-1 in the square pipeline (I) and the circular pipeline (II) are of a uniform type and a combined type: in the unified formula, the surface of a cleaning friction rod 6-1 in a cleaning area I is designed as A, the surface of a cleaning friction rod 6-1 in a cleaning charged area II is designed as B, and the surface of a cleaning friction rod 6-1 in a charged area III is designed as C; in the combined mode, the cleaning friction rods 6-1 in the 3 areas are divided into an upper section and a lower section, and the surfaces of the upper section and the lower section can be any combination of A, B and C.

According to a preferable scheme, cleaning friction rods 6-1 in a cleaning area I, a cleaning charged area II and a cleaning charged area III in a square pipeline and a circular pipeline are respectively externally connected with a controller, and can rotate automatically, and the rotating speed is controllable and adjustable. In the sorting process, if the circulating sorting amount in the charging reinforced circulating sorting module and the decontamination drying circulating sorting module is increased, the condition of insufficient charging in the sorting is prompted, the rotation of the cleaning friction rod 6-1 is increased aiming at the particle group with lower cleaning and collision friction times caused by the shunting and friction rod negative pressure area in the airflow, the particle group moving at relatively low speed in the friction rod negative pressure area is continuously introduced into the high-speed airflow again through the rotation, the cleaning collision times are increased, and the cleaning and charging effects are enhanced.

The utility model provides a preferred scheme, high flow rate recovery pipeline 2 with the venturi design that high flow rate charge-in pipeline 5 all adopted, the wide middle section in both ends is narrow, can increase the pipeline middle section velocity of flow, promotes negative pressure and retrieves material and feeding efficiency.

As shown in fig. 1, the high-voltage electrostatic separation module comprises a high-voltage electrostatic separation chamber 7, a high-purity product collection device 8, a medium-purity product collection device 9, a low-purity product collection device 10 and a discharge pipeline 11; and two ends of the high-voltage electrostatic separation chamber 7 are respectively connected with the cleaning charging device 6 and the discharging pipeline 11. One end of the discharge pipeline 11 is connected with the high-voltage electrostatic separation chamber through a flange, and the other end of the discharge pipeline is connected to a cleaning pipeline 14 of the decontamination drying circulation separation module.

The high-voltage electrostatic separation chamber 7 adopts a parallel plate type separation mode, and a positive plate and a negative plate which are loaded with high voltage are arranged in parallel in the high-voltage electrostatic separation chamber; the positive plate and the negative plate have the same structure, taking the positive plate as an example, as shown in fig. 5, two first slideways 7-1 are respectively arranged along the short edges on the two short edges of the inner side of the positive plate, a scraping rod 7-2 is erected between the two first slideways 7-1, the scraping rod 7-2 is externally connected with a controller, and the scraping rod 7-2 slides back and forth along the first slideways 7-1 at a low speed under the action of the controller to scrape particles adsorbed on the surface of the positive plate; two inboard two long edges of positive plate are provided with two second slides 7-3 respectively along long limit, erect between two second slides 7-3 and divide mineral board 7-4 and second to divide mineral board 7-5, first branch mineral board 7-4 and second divide mineral board 7-5 all external controller, and first branch mineral board 7-4 and second divide mineral board 7-5 to slide and fix a point along second slide 7-3 under the controller effect, carry out product classification. The high-purity product collecting device 8, the medium-purity product collecting device 9 and the low-purity product collecting device 10 are located below the high-voltage electrostatic separation chamber 7 and respectively correspond to a high-purity product area, a medium-purity product area and a low-purity product area, wherein the high-purity product area, the medium-purity product area and the low-purity product area are respectively formed by sequentially separating a positive plate and a negative plate from one end close to the cleaning charging device 6 through the first ore separating plate 7-4 and the second ore separating plate 7-5.

As shown in figure 5, the first ore separating plate 7-4 and the second ore separating plate 7-5 are provided with strip-shaped empty grooves on the surfaces, and the empty grooves can allow the scraping rods 7-2 to penetrate through the empty grooves and slide up and down along the two short sides of the polar plate without influencing the real-time adjustment of the ore separating plates.

As shown in fig. 1, the charge-enhanced cyclic sorting module includes a circulating pipe 12 and a corona-enhanced charging device 13; two ends of the circulating pipeline 12 are respectively connected with a medium-purity product collecting device 9 and a corona strengthening charging device 13; two circulation pipelines 12 are arranged and are respectively connected with one side of the positive plate and one side of the negative plate; more than one corona rod 13-1 is arranged in the corona charge strengthening device 13 in a staggered mode, and two ends of the corona charge strengthening device 13 are respectively connected with the circulating pipeline 12 and the high-flow-rate feeding pipeline 5; the corona charge strengthening devices 13 are provided with two circulation pipelines 12 which are respectively connected with one side of the positive plate and one side of the negative plate, wherein a negative electrode corona rod is adopted in a circulation line corresponding to the positive plate, and a positive electrode corona rod is adopted in a circulation line corresponding to the negative plate.

As shown in fig. 1, the decontamination drying cycle sorting module comprises a cleaning pipeline 14, a conveying device 15, a drying device 16 and a negative pressure recovery device 17; the cleaning pipeline 14 is designed as a three-way pipeline, and two ends and the side surface of the cleaning pipeline are respectively connected with the low-purity product collecting device 10, the conveying device 15 and the discharging pipeline 11; cleaning nozzles 14-1 externally connected with a water source are respectively arranged on two sides of the vertical inner wall of the cleaning pipeline 14 in a staggered manner, as shown in fig. 6, a porous water outlet 14-2 is arranged at one end, connected to the conveying device 15, of the cleaning pipeline 14, close to the ground; the two ends of the conveying device 15 are respectively connected with a cleaning pipeline 14 and a negative pressure recovery device 17, and the whole middle section of the conveying device is covered by a drying device 16; the two ends of the negative pressure recovery device 17 are respectively connected with the conveying device 15 and the high-flow-rate recovery pipeline 2.

In this embodiment, conveyer 15 can adopt the conveyer belt, and drying device 16 can adopt the assembly line oven, and negative pressure recovery unit 17 only needs the principle to satisfy the negative pressure, is convenient for install into the system, does benefit to the fluid motion of waiting to select separately the granule can.

A washing and charging integrated waste plastic reinforced electric separation method comprises the following specific steps:

(1) broken waste plastic particles enter a system through a feeding device 4, are entrained by airflow blown by a fan 1 and enter a cleaning charging device 6, the particles are scrubbed by a cleaning friction rod 6-1 in a cleaning area I to remove surface dust, the surface in a cleaning charging area II is further cleaned and is preliminarily charged, and the particles collide with the cleaning friction rod 6-1 in a charging area III to rub and deeply charge; the plastic particles with surface work function lower than that of the friction material have positive charges on the surface, and the plastic particles with surface work function higher than that of the friction material have negative charges on the surface.

(2) After the particles enter a high-voltage electrostatic sorting chamber 7 through a cleaning charging device 6, the positively charged particles are adsorbed on a negative plate, and the negatively charged particles are adsorbed on a positive plate; fully charged particles are scraped by the scraping rod 7-2 and enter a high-purity product collecting device 8; the particles with common charging effects are scraped to a medium-purity product collecting device 9, enter a circulating pipeline 12, then enter a corona strengthening charging device 13, enter a high-flow-rate feeding pipeline 5 again for secondary sorting after being subjected to charge strengthening by a corona rod 13-1; due to oil pollution or other reasons, particles with poor electrification effect are scraped to the low-purity product collecting device 10 or are brought to the discharging pipeline 11 by air flow, and finally are uniformly conveyed to the cleaning pipeline 14 to clean the surface, the particles fall into the conveying device 15 after cleaning, the particles are conveyed to the drying device 16 to be dried by hot air, and the particles after cleaning and drying enter the system again for sorting through the negative pressure recovery device 17.

Example 2 Recycling of renewable resources

The system and method described in example 1 is used for recycling of renewable resources such as mixed plastics, mixed metals and separation of plastic and metal mixtures from waste as follows:

as shown in fig. 1, a fan 1 introduces an air flow with a certain speed, and the air flow enters a cleaning charging device 6 together with mixed particles entering from a feeding device 4 through an air flow pipe 3 to a high-speed feeding pipe 5. The cleaning charging device 6 adopts a square pipeline (length is 96cm, width is 36cm) and an equilateral triangle cleaning friction rod 6-1 arrangement mode (radius r is 1/18X is 2cm, distance D between the side-by-side friction rods is 1/2X is 18cm), the cleaning friction rods 6-1 in the cleaning area I adopt a uniform A design (a high-toughness friction material with surface work function based on the plastics to be selected is adopted, the diameter of a single brush whisker is 0.5mm, the length is equal to the radius r of the friction rods is 2cm, the distance between the brush whiskers is less than 0.5mm), low-speed rotation is carried out through an external controller, the cleaning friction rods 6-1 in the cleaning charging area II adopt a combined B + C design (the B design and the A design adopt the same material, the diameter of a single friction tooth is 1mm, the diameter of a round contact is 0.5mm, the length of a high-friction tooth is 2cm, the length of a low-friction tooth is 0.5r, the surface work function of the high-hardness plastic to be selected is 1cm, the surface work function of the cleaning friction rod 6-1 cm, and the other high-hardness of the cleaning friction rod is between the high-hardness And the friction material with better charging effect) without autorotation, and the cleaning friction rod 6-1 in the charging area III adopts the same type C design (same as the cleaning charging area II) without autorotation. The surface floating dust content of general waste plastic particles is relatively low, and the requirement on cleaning strength is not high, so that the square pipeline I and the regular triangle cleaning friction rod 6-1 are arranged, and the shunting of particle group movement caused by staggered ring distribution of the friction rods in the circular pipeline II is avoided. Cleaning friction rod 6-1 in cleaning zone I adopts the design of unity formula A to carry out centralized processing to granule surface dust to constantly introduce the granule crowd in friction rod back negative pressure zone in the reposition of redundant personnel through friction rod low-speed rotation and carry out deep cleaning. The cleaning friction rod 6-1 in the cleaning charging area II adopts a B + C combined design, the characteristic of the combination of B design cleaning and charging is utilized to carry out final dust removal and preliminary charging on particles before charging, and meanwhile, the stirring effect of the B design on the particles is utilized to continuously stir particle groups into fluid to carry out collision friction with the other half C design of the friction rod, so that a certain charging effect is achieved. And finally, all particle groups in the airflow enter a charging area III, and continuously collide with a friction rod with a smooth surface C under the high-speed action of the airflow, so that the charging times and the charging quantity are intensively improved, and the full charging is completed.

The particles having a surface work function greater than that of the friction material (the particles located at the back of the friction material in the triboelectric order table) are negatively charged on the surface, and the particles having a surface work function less than that of the friction material (the particles located at the front of the friction material in the triboelectric order table) are positively charged on the surface. After the charging is finished, the mixed particles enter a high-voltage electrostatic separation chamber 7, the particles with little dust and sufficient charge on the surface are quickly attracted by a high-voltage polar plate, the particles with positive charges are adsorbed to the front end of a negative polar plate, the particles with negative charges are adsorbed to the front end of a positive polar plate, and the particles are scraped into a high-purity product collection device 8 by a scraping rod 7-2 which reciprocates at a low speed in a first slideway 7-1; the particles with less electric quantity due to more surface dust which are not rubbed and charged for a few times in the dust removal and charging device 6 are correspondingly adsorbed on the middle sections of the positive plate and the negative plate, are scraped into the medium-purity product collecting device 9 and enter the corona strengthening and charging device 13 through the circulating pipeline 12, wherein a positive electrode corona rod is arranged on a pipeline through which the products are collected by the negative plate, a negative electrode corona rod is arranged on a pipeline through which the products are collected by the positive plate, so that the electric charges with corresponding polarities on the surfaces of the particles are strengthened, and the particles enter the sorting device again through the high-flow-rate feeding pipeline 5 for sorting; the low-charge-quantity particles or basically non-charged particles with surface dust and scale or oil stains are uniformly conveyed into a cleaning pipeline 14 through a low-purity product collecting device 10 and a discharging pipeline 11 respectively, the surface is washed by water jet flow for multiple times, then the water on the surface is drained through a bent porous water outlet 14-2, then the water enters a conveying device 15, slowly passes through a drying device 16 to dry the surface, and is conveyed to a negative pressure recovery device 17 to enter a system again for separation. Along with the increase of the sorting time, the amount of medium-purity products and low-purity products is reduced, the first ore separating plate 7-4 and the second ore separating plate 7-5 in the second slideway 7-3 can be regulated and controlled to improve the yield of high-purity product sections, reduce and even close medium-purity and low-purity product circulating sections, reduce the cost and improve the productivity.

Example 3 sorting of premium grains in agriculture

The system and method described in example 1 was used for sorting of quality grain in agriculture as follows:

as shown in fig. 1, the connection mode and the operation principle of embodiment 3 are the same as those of embodiment 2, and the following differences exist:

(1) since the grains are easy to have a large amount of floating dust in the natural environment for a long time, and the grains have low density and shells, the floating dust on the surface needs to be cleaned and the shells need to be prevented from falling off. The cleaning charging device 6 adopts a circular pipeline A mode, the cleaning friction rod 6-1 in the cleaning area I adopts a unified type A design and performs autorotation through an external controller, the cleaning friction rod 6-1 in the cleaning charged area II adopts a combined type A + C non-autorotation, and the cleaning friction rod 6-1 in the charged area III adopts a unified type C design and performs autorotation. The surface dust of the grains is fully removed under the cleaning of the friction hairbrushes in the cleaning area I and the cleaning charged area II, the design of friction teeth B which are easy to peel off grain shells is abandoned, the charging is fully enhanced by adopting the design C in the cleaning charged area II and the cleaning charged area III, and the sorting effect is improved.

(2) Because inferior grain such as shrivelled, rotten grain particle have the condition poor, the granule is lighter etc. and very easily be blown out high-voltage electrostatic separation room 7 directly and get into ejection of compact pipeline 11, retrieve the washing cost height, can directly collect the processing, close the circuit of washing pipeline 14, close washing shower nozzle 14-1 in the pipeline promptly and make it no longer spray water.

(3) The positions of the first ore separating plate 7-4 and the second ore separating plate 7-5 can be changed according to the parameter requirements of grain products, and the separation efficiency is improved.

(4) Because the grain product is special in property, the drying mode of the drying device needs to be adjusted to be normal-temperature cold-air drying, so that the grain is prevented from deteriorating.

The above-described embodiments are merely preferred embodiments of the present invention, and it should be noted that, for those skilled in the art, improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be construed as the scope of the present invention.

Claims

1. A washing and charging integrated waste plastic reinforced electric separation system is characterized by comprising a feeding washing and charging module, a high-voltage electrostatic separation module, a charging reinforced circular separation module and a decontamination drying circular separation module; the feeding and cleaning charging module comprises a fan, a high-flow-rate recovery pipeline, an airflow pipeline, a feeding device, a high-flow-rate feeding pipeline and a cleaning charging device; the high-flow-rate recovery pipeline is designed as a three-way pipeline, two ends of the high-flow-rate recovery pipeline are respectively connected with a fan and an airflow pipeline, and the side surface of the high-flow-rate recovery pipeline is connected with a decontamination drying circulation sorting module; two ends of the airflow pipeline are respectively connected with a high-flow-rate recovery pipeline and a high-flow-rate feeding pipeline; the high-flow-speed feeding pipeline is designed as a four-way pipeline, two ends and one side of the high-flow-speed feeding pipeline are respectively connected with an airflow pipeline, a cleaning charging device and a feeding device, and one side of the high-flow-speed feeding pipeline, which is opposite to the feeding device, is connected to a charging reinforced circulation sorting module; two ends of the cleaning charging device are respectively connected with a high-flow-rate feeding pipeline and a high-voltage electrostatic separation module through flanges; the cleaning charging device comprises a cleaning area I, a cleaning charging area II and a charging area III, wherein the three areas are connected through a flange, more than one cleaning friction rod made of friction materials is arranged in each of the three areas in a staggered mode, and the surface work function of each friction material is between plastics to be selected; the cleaning friction rods are respectively externally connected with a controller, can rotate automatically, and can be controlled and adjusted in rotation speed;

the high-voltage electrostatic separation module comprises a high-voltage electrostatic separation chamber, a high-purity product collection device, a medium-purity product collection device, a low-purity product collection device and a discharge pipeline; the two ends of the high-voltage electrostatic separation chamber are respectively connected with a cleaning charging device and a discharging pipeline, the separation mode adopted by the high-voltage electrostatic separation chamber is a parallel plate type, and a positive plate and a negative plate which are loaded with high voltage are arranged in parallel in the high-voltage electrostatic separation chamber; two first slideways are respectively arranged on two short edges of the inner side of the positive plate along the short edges, a scraping rod is erected between the two first slideways and is externally connected with a controller, and the scraping rod slides back and forth along the first slideways at a low speed under the action of the controller to scrape particles adsorbed on the surface of the positive plate; two second slideways are respectively arranged on two long edges of the inner side of the positive plate along the long edges, a first ore separating plate and a second ore separating plate are erected between the two second slideways, the first ore separating plate and the second ore separating plate are both externally connected with a controller, and the first ore separating plate and the second ore separating plate slide along the second slideways and fix points under the action of the controller to classify products; the negative plate and the positive plate have the same structure; the high-purity product collecting device, the medium-purity product collecting device and the low-purity product collecting device are positioned below the high-voltage electrostatic separation chamber and respectively correspond to a high-purity product area, a medium-purity product area and a low-purity product area which are formed by sequentially separating a positive plate and a negative plate from one end close to the cleaning charging device through a first ore separating plate and a second ore separating plate; one end of the discharge pipeline is connected with the high-voltage electrostatic separation chamber through a flange, and the other end of the discharge pipeline is connected to the decontamination drying circulation separation module;

2. The cleaning and charging integrated waste plastic reinforced electric separation system as claimed in claim 1, wherein the cleaning and charging device is a square pipe; the cleaning friction rods in the square pipeline are inserted, and the arrangement modes in the three areas are all in a regular triangle mode; the radius of washing friction stick is r, and the washing friction stick interval of arranging is D, and square pipeline width is X, and the three relation is: r is not less than 1/20X and not more than 1/16X, D is more than 2/5X and not more than 1/2X.

3. The cleaning and charging integrated waste plastic reinforced electric separation system as claimed in claim 1, wherein the cleaning and charging device is a circular pipeline; the embedding mode of cleaning friction rod in the circular pipeline is single-end embedded, and the embedding mode is A mode: the cleaning area I, the cleaning charged area II and the charged area III are respectively provided with two circles of cleaning friction rods, the first circle is sequentially arranged at 3 according to 120 degrees, and the second circle and the first circle are staggered at 60 degrees and are sequentially arranged at 3 according to 120 degrees; the radius of the cleaning friction rod is R, the embedding depth is L, the radius of the circular pipeline is R, and the relationship among the three is as follows: r is less than or equal to 1/8R, and L is 1/3R.

4. The cleaning and charging integrated waste plastic reinforced electric separation system as claimed in claim 1, wherein the cleaning and charging device is a circular pipeline; the embedding mode of cleaning friction rod in the circular pipeline is single-end embedded, and the embedding mode is B mode: the cleaning area I, the cleaning charged area II and the charged area III are respectively provided with two circles of cleaning friction rods, the first circle is sequentially arranged at 4 according to 90 degrees, and the second circle and the first circle are staggered at 45 degrees and are sequentially arranged at 4 according to 90 degrees; the radius of the cleaning friction rod is R, the embedding depth is L, the radius of the circular pipeline is R, and the relationship among the three is as follows: r is less than or equal to 1/8R, and L is 1/6R.

5. The system for strengthening and electrically separating charged integrated waste plastics according to any one of claims 2-4, wherein the surface of the cleaning friction rod is divided into A, B and C designs;

the C design uses a smooth surface ground with a friction material.

6. The washing charge-integrated waste plastic reinforced electric separation system as claimed in claim 5, wherein the design of the washing friction bars in the square pipe and the circular pipe are all of a uniform type: the surface of the cleaning friction rod in the cleaning area I is designed to be A, the surface of the cleaning friction rod in the cleaning charged area II is designed to be B, and the surface of the cleaning friction rod in the charged area III is designed to be C.

7. The system for cleaning, charging and integrating waste plastic reinforced electric separation as claimed in claim 5, wherein the cleaning friction bars in the square pipeline and the circular pipeline are designed in a combined manner: the cleaning friction rods in the three areas are divided into an upper section and a lower section, and the surfaces of the upper section and the lower section are any combination of A, B, C designs.

8. The system of claim 1, wherein the high flow rate recycling pipeline and the high flow rate feeding pipeline are both designed as venturi tubes with wide ends and narrow middle section.

9. The method for cleaning charged integrated waste plastic for strengthening electric separation based on the system of claim 1 is characterized by comprising the following steps:

step 2), after the particles enter a high-voltage electrostatic separation chamber from a cleaning charging device, the positively charged particles are adsorbed on a negative plate, and the negatively charged particles are adsorbed on a positive plate; fully charged particles are scraped by a scraping rod and enter a high-purity product collecting device; the particles with common charging effects are scraped to a medium-purity product collecting device, enter a circulating pipeline, then enter a corona strengthening charging device, enter a high-flow-rate feeding pipeline again after being subjected to charging strengthening through a corona rod and are separated again; because the poor granule of greasy dirt pollution or other reasons electrified effect is scraped to low purity product collection device or is taken to the ejection of compact pipeline by the air current, is sent into the washing pipeline clearance surface in unison at last, falls into conveyer after the washing is accomplished and delivers to hot air drying in the drying device, and the granule after the washing drying gets into the system once more via negative pressure recovery unit and selects separately.