Patent Application
20140209715
This application claims priority to Chinese Application No. 201310039088.3, “FLOTATION TYPE SYSTEM AND METHOD FOR CRUSHING, SEPARATING AND WASHING WASTE PLASTICS”, filed on Jan. 31, 2013, which is hereby incorporated by reference in its entirety.
The present disclosure relates to the technical field of waste plastics recycling, and more particularly to a flotation type system and method for crushing, separating and washing waste plastics.
Equipment for crushing, separating and washing waste plastics is commonly used in the field of waste plastics recycling, and due to lower gross profit rate of this industry, it is difficult to apply higher-priced production and process control equipment. In current equipment for crushing, separating and washing waste plastics, static fluid medium is commonly applied, and fragments of the waste plastics floating on surface of the fluid medium are mechanically stirred to realize the purpose of washing and separating. However, the prior art method herein has disadvantages of lower efficiency, incomplete separation, and higher water consumption.
In view of defects existing in the prior art mentioned above, in one aspect, the present disclosure provides a flotation type system for crushing, separating and washing waste plastics, wherein, by means of applying fluid medium, fragments of the waste plastics are driven to move, and in the entire washing process, multiple means such as turbulent flow, plug flow, throwing and striking and so on are applied by the fluid medium to the fragments at one time or another, thereby improving the separating effect and separating speed, and improving the quality of products.
The flotation type system for crushing, separating and washing waste plastics, in a direction of transporting materials, includes a crusher, a flotation tank, a multi-functional rubbing and separating device, a washing tank and a dehydrator which are connected in turn; the flotation tank and the washing tank are disposed abreast; a discharge port of the flotation tank and a feeding port of the washing tank are disposed on the same end of the flotation type system; and the discharge port of the flotation tank and the feeding port of said washing tank are connected via said multi-functional rubbing and separating device.
Preferably, the flotation tank is a straight launder, and the washing tank is a U-shaped launder; the discharge port of the flotation tank, the feeding port of the washing tank and the discharge port of the washing tank are disposed on one end of the flotation type system, and the feeding port of the flotation tank is disposed on the other end of the flotation tank; the multi-functional rubbing and separating device is disposed between the discharge port of the flotation tank and the feeding port of the washing tank; the feeding port of the flotation tank connects with the crusher, and the discharge port of the washing tank connects with the dehydrator
A collecting and recycling system may be disposed under the dehydrator of the flotation type system, thereby effectively reducing the consumption of the fluid medium.
The washing tank includes a tank-body and a division plate; the tank-body is a U-shaped box, one end of the tank-body is a curve end, and the other end of the tank-body is a flat end, and the division plate is disposed at the intermediate position inside the tank-body; one end of the division plate is fixedly connected to the flat end of the tank-body, and a third flow channel is disposed between the other end of the division plate and the curve end of the tank-body, so that a first flow channel on one side of the division plate, a second flow channel on the other side of the division plate and the third flow channel form a continuous U-shaped washing flow channel. Both of the feeding port and discharge port of the washing tank are disposed on the flat end of the tank-body, and respectively disposed at two sides of the division plate. The entire U-shaped washing flow channel starts from the flat end of the washing tank at one side of the division plate; materials firstly pass the first flow channel at one side of the division plate, then pass the third flow channel between the end of the division plate and the curve end of the washing tank, and then pass the second flow channel at the other side of the division plate, finally the materials are sent out from the discharge port on the flat end of the washing tank at the other side of the division plate. The total length of the flow channels can be set according to actual processing requirements. The washing tank having the structure herein can effectively shorten the length of equipment for washing process, so that the entire flotation type system for crushing, separating and washing waste plastics is more compact in equipment structure.
According to actual situation of equipment, the washing tank may either be a straight flow channel. However, the washing tank with U-shaped flow channel can effectively shorten the length of equipment for washing process, so that the entire flotation type system for crushing, separating and washing waste plastics is more compact in equipment structure.
Preferably, the flotation tank and/or washing tank are respectively equipped with at least one boost straightening device;
Wherein the boost straightening device includes a straightening roller, radial diversion vanes and axial diversion vanes; the radial diversion vanes and axial diversion vanes are cross distributed on the outer cylindrical surface of the straightening roller. The straightening roller is a closed hollow cylinder with a roller rotating axle disposed in the central part thereof, the radial diversion vane is a vertical baffle radially disposed on the outer cylindrical surface of the straightening roller, and the axial diversion vane is an arc-shaped baffle axially disposed on the outer cylindrical surface of the straightening roller. When using, simply install the boost straightening device on the flotation tank or the washing tank; the central axis of the boost straightening device is perpendicular to the flow direction of the fluid in the flow channels, the quantity of boost straightening devices can be set flexibly according to actual requirements. The working principle of the boost straightening device herein is as follows: when the straightening roller is rotating, the lowest point of the outer cylindrical surface is lower than the fluid surface in the flow channels, therefore, the fluid and fragments of waste plastics contained therein will be pushed downwards to a certain water level, so as to reduce the rising distance of the floating materials and the settling distance of the sinking materials; wherein, the function of the axial diversion vanes distributed on the straightening roller is to push materials downwards, so that the materials will not billow out but will flow smoothly with the fluid medium; the function of the radial diversion vanes distributed on the straightening roller is to convert the fluid flow from the status of turbulent flow to the status of plug flow, thereby avoiding the materials going up and down with the fluid medium to reduce the effect of flotation separating.
Preferably, the flotation tank and/or washing tank are equipped with at lest one beater;
Wherein the beater includes a beater rotating axle and multiple rotating blades, the multiple rotating blades are uniformly distributed on the outer cylindrical surface of the beater rotating axle, and each of rotating blades is disposed axially along the central axis of the beater rotating. When a using, simply install the beater on the flotation tank or the washing tank; the central axis of the beater is perpendicular to the flow direction of the fluid in flow channel, according to actual requirements, the quantity of the beaters also can be set up flexibly. When the beater is working, the rotating axle of the beater drives rotating blades to rotate, flapping materials in the flotation tank or the washing tank, so as to overcome the surface tension between fragments of the waste plastics, thereby achieving the effect of separating impurities from fragments of waste plastics effectively and accelerating the separating speed of the materials in fluid medium.
The crusher and the feeding port of the flotation tank are connected through a screw conveyor; alternatively, the crusher is high placed to form a gravity self-falling mechanism, so that the crushed fragments of the waste plastics fall in the flotation tank automatically.
Preferably, the multi-functional rubbing and separating device includes a main body, a rotating axle of the device and lapping blades; a feeding port is disposed on one end of the main body and a discharge port is disposed on the other end; the rotating axle and lapping blades are disposed inside the main body; and the lapping blades are distributed on outer cylindrical surface of the rotating axle; inner space of the main body close to the feeding port forms a rubbing section, and inner space close to the discharge port forms a separating and dehydrating section; the main body is a hollow cylinder with both ends closed, and there are multiple through-holes distributed on the sidewall of the main body. The external rotary driving mechanism, connected to the multi-functional rubbing and separating device, drives the rotating axle to drive the lapping blades to rotate at a high speed, after the materials, containing waste plastics and fluid medium which may be water and saline and so on, are transported into the main body from the feeding port, along with the high-speed revolution of the lapping blades, the impurities attaching on the surface of the waste plastics are separated preliminarily in the rubbing section, and in the separating dehydration section, after the materials are flapped by the lapping blades, the impurities are thrown, along with the fluid medium, out of the main body through through-holes. The waste plastics, because of the kinetic energy provided by the lapping blades, will bounce off the discharge port of the multi-functional rubbing and separating device.
Preferably, a material limiting device is disposed between the flotation tank and the multi-functional rubbing and separating device. To be specific, the material limiting device includes a material transporting pipe and an impeller; the material transporting pipe (which may either be a material transporting trough) is disposed at the feeding port of the multi-functional rubbing and separating device, the impeller is disposed inside the material transporting pipe, the axial central axis of the impeller is perpendicular to the central axis of the material transporting pipe, and the central axle of the impeller connects with an external impeller driving mechanism. Blades on the impeller divide the cross-section of the material transporting pipe into multiple relatively independent spaces; after being fed into the material transporting pipe, the materials are distributed, at the impeller, into every relatively independent spaces; along with rotation of the impeller, materials in every relatively independent spaces are transported into the feeding port of the rubbing and separating device. Since the materials are fed into the feeding port of the rubbing and separating device uniformly in batches, the material feeding flow is uniform, thereby avoiding the multi-functional rubbing and separating device being blocked due to over-load materials.
Preferably, the dehydrator is a vertical dehydrator, and a cyclone separator (namely, the thick/thin piece separator) is connected in the discharge port of the dehydrator;
The cyclone separator includes a rotary type cyclone separating body and a discharge pipe disposed on the top of the cyclone separating body for discharging thin pieces; a material-air feeding pipe connected to the discharge port of the dehydrator is disposed on the upper part of the cyclone separating body, blowing direction of the material-air feeding pipe is tangent to an inner wall of the cyclone separating body, and a material-air feeding port is formed on a wall of the cyclone separating body; a discharge port for thick pieces is disposed on the bottom of the cyclone separating body; the discharge pipe extends inside the cyclone separating body from a head cover of the cyclone separating body, and a lower end of the discharge pipe extends downward below the material-air feeding port. The thick/thin pieces (namely the pieces of the waste plastics being dehydrated by the dehydrator) are fed, with high air volume, from the material-air feeding pipe into the cyclone separating body to rotate at a high-speed; the thick pieces with smaller specific surface area, due to a higher centrifugal force being generated, are thrown to the inner wall of the cyclone separating body, and as the effect of gravity, the thick pieces sliding down to the bottom of the cyclone separating body are discharged out of the discharge port; the wind flow entering the cyclone separating body is discharged from the discharge pipe because of pressure difference, the thin pieces with larger specific surface area, overcoming the gravity due to the effect of wind force, are carried by the wind flow and discharged out of the discharge pipe, thereby achieving the effect of separating the thick pieces and thin pieces in the waste plastics, and collecting the thick pieces and thin pieces separately.
Preferably, a first circulating water mechanism is disposed between the flotation tank and multi-functional rubbing and separating device, and a second circulating water mechanism is disposed between the washing tank and the dehydrator. The first circulating water mechanism includes a circulating pipe disposed between the flotation tank and multi-functional rubbing and separating device, thereby, the flotation medium obtained after the processing by the multi-functional rubbing and separating device is conveyed back to the flotation tank for recycling utilization; the second circulating water mechanism includes a circulating pipe disposed between the washing tank and the dehydrator, thereby, the washing medium obtained after the processing by the dehydrator is conveyed back to the washing tank for recycling utilization. By means of applying the first circulating water mechanism and the second circulating water mechanism, the high quality control of the fluid medium is realized, which is capable of effectively reducing the consumption and wastage of the flotation medium and washing medium in the crushing, separating and washing processes for the waste plastics.
By means of the system mentioned above, a flotation type method for crushing, separating and washing waste plastics is realized, which includes following steps:
(1) waste plastics are transported into the crusher of the flotation type system to be crushed, so as to form fragments of the waste plastics which are transported to the flotation tank of the flotation type system;
(2) there is fluid flotation medium pre-placed in the flotation tank, and after being fed into the flotation tank, the fragments of the waste plastics are separated primarily along with flowing of the flotation medium, thereby removing heavy impurities;
Wherein those fragments of waste plastics, of which specific gravity is less than specific gravity of the flotation medium, float upward and are transported to the multi-functional rubbing and separating device of the flotation type system; while those fragments of waste plastics, of which specific gravity is heavier than the specific gravity of the flotation medium, and heavy impurities sink downward and remain in the flotation tank;
(3) after being fed to the multi-functional rubbing and separating device, the fragments of waste plastics are beaten and stirred by force for separation, thereby removing light impurities preliminarily, and then pieces separated are transported to the washing tank of the flotation type system;
(4) there is fluid washing medium pre-placed in the washing tank, and after being fed into the washing tank, the pieces of the waste plastics are secondarily separated along with flowing of the washing medium, thereby further removing light impurities;
Wherein those pieces of waste plastics, of which specific gravity is less than specific gravity of the washing medium, float upward and are transported to the dehydrator of the flotation type system; while those pieces of waste plastics, of which specific gravity is heavier than specific gravity of the washing medium, and light impurities sink downward and remain in the washing tank; and
(5) the pieces of the waste plastics are fed into the dehydrator to be dried and dehydrated, so as to remove the washing medium attaching to surface thereof, thereby forming recycled pieces.
Preferably, in the step (1), said crusher crushes the waste plastics by means of dry-crushing or wet-crushing; wherein the dry-crushing is performed by crushing the waste plastics directly by the crusher without adding any fluid medium; and the wet-crushing is performed by crushing the waste plastics in a fluid medium environment by the crusher with the fluid medium added into the crusher simultaneously when the waste plastics are fed into the crusher;
In the step (2), the heavy impurities include metals and sediments contained in the fragments of the waste plastics, and the flotation medium is water or halide salt water;
And in the step (4), the light impurities include label paper, greasy dirt and flotation medium attaching on surface of the waste plastics; and the washing medium is water or halide salt water.
As compared to the prior art, the present disclosure has following advantages:
The working principle of the flotation type method for crushing, separating and washing waste plastics herein is simple, which is to crush the waste plastics first and then execute multiple stages of washing and separating. The flotation type system and method herein are capable of improving the effect of washing waste plastics effectively and improving the quality of products.
In the flotation type system for crushing, separating and washing waste plastics, the washing tank is a U-shaped structure, which effectively shortens the length of equipment for washing process, so that the entire flotation type system for crushing, separating and washing waste plastics is more compact in equipment structure, and the floor area of the equipment is reduced, which is beneficial to control the cost of the waste plastics recycling; and the feeding port and discharge port of the washing tank are disposed on the same end of the launder for further shortening the length of the entire equipment. Meanwhile, according to actual process requirements, the length or width of the launder can be set flexibly, and the material of the launder can be selected according to the process requirements as well; in addition, the washing tank with the U-shaped structure herein further may be as a launder unit, if the process requires, multiple launder units can be joined in use, which is simple in structure and convenient in use.
In the flotation type system herein, boost straightening devices are added on both of the flotation tank and the washing tank, which are simple in structure and convenient in use. When using, simply install the boost straightening device on the flotation tank or the washing tank, and the quantity of boost straightening devices can be set flexibly according to the actual requirements. The boost straightening device can convert the fluid flow from the status of turbulent flow to the status of plug flow, thereby avoiding the materials going up and down with fluid, and achieving the effect of straightening; meanwhile, when the straightening roller is rotating, the fluid and fragments of waste plastics contained therein will be pushed downwards to a certain water level, so as to reduce the rising distance of the floating materials and the settling distance of the sinking materials. The combined effects herein can effectively improve the flotation speed or washing speed; shorten the flotation time or washing time and the length of the launder, so as to achieve the effect of high-efficient washing, and reducing the floor area of the equipment.
The crusher and the feeding port of the flotation tank are connected through a screw conveyor; alternatively, the crusher is high placed to form a gravity self-falling mechanism, so that the crushed fragments of the waste plastics fall in the flotation tank automatically. The working principle of the system herein is simple, and the feeding efficiency of the system herein is higher.
In the flotation type system herein, a multi-functional rubbing and separating device is added between a flotation tank and a washing tank, which can effectively improve the quality of rubbing waste plastics, so as to separate waste plastics and impurities more thoroughly and improve the quality of recycled products. With the multi-functional rubbing and separating device herein, by means of high-speed revolution of the lapping blades, the lapping blades simultaneously agitate, flap and separate the materials, furthermore, the rubbing section, and separating and dehydrating section are arranged inside the main body, thereby achieving a rather good separating effect. The impurities such as label paper, greasy dirt, fluid medium from the flotation tank, and so on, attaching to the surface of the waste plastics can all be separated, therefore, after the materials enter the washing tank, the impurities thereof are reduced greatly, which can simplify the subsequent washing process.
A material limiting device is disposed between the flotation tank and the multi-functional rubbing and separating device. The material limiting device has advantages of simple structure, lower price and convenient in use; and the material limiting device, disposed between the material transporting mechanism and the mechanism for subsequent washing process, can control the feeding quantity of waste plastics washing mechanism to make the feeding flow uniform, thereby avoiding equipment for subsequent process being blocked due to over-load materials, and effectively improving the washing speed of waste plastics and improving the washing effect.
In the flotation type system for crushing, separating and washing waste plastics, a cyclone separator is connected in the discharge port of the dehydrator; the cyclone separator is adopted to cyclone separate thick pieces and thin pieces in the dehydrated waste plastics, and after being separated, the thick pieces and thin pieces are respectively fed out from independent discharge pipes and then collected separately, thereby increasing the recovery rate of waste plastics, and avoiding the thin pieces floating in the air to pollute the environment.
a is a structure diagram illustrating the material transporting pipe of the flotation type system for crushing, separating and washing waste plastics as shown in
b is a cross-section view taken along A-A line of
c is a structure diagram illustrating the material transporting trough of the flotation type system for crushing, separating and washing waste plastics according to another embodiment of the present invention;
In order to make the purpose, technical solutions and advantages of the present disclosure to be understood more clearly, the present disclosure will be described in further details with the accompanying drawings and the following embodiments. It should be understood that the specific embodiments described herein are merely examples to illustrate the invention, not to limit the present disclosure.
In one embodiment as shown in
The flotation tank 2 is a straight launder, and the washing tank 4 is a U-shaped launder; the discharge port of the flotation tank 2, the feeding port of the washing tank 4 and the discharge port of the washing tank 4 are disposed on one end of the flotation type system, and the feeding port of the flotation tank 2 is disposed on the other end of the flotation tank 2; the multi-functional rubbing and separating device 3 is disposed between the discharge port of the flotation tank 2 and the feeding port of the washing tank 4; the feeding port of the flotation tank 2 connects with the crusher 1, and the discharge port of the washing tank 4 connects with the dehydrator 5.
As shown in
As shown in
As shown in
As shown in
The beater 7 includes a beater rotating axle and multiple rotating blades, the multiple rotating blades are uniformly distributed on the outer cylindrical surface of the beater rotating axle, and each of rotating blades is disposed axially along the central axis of the beater rotating axle. When using, simply install the beater 7 on the flotation tank 2 or the washing tank 4; the central axis of the beater 7 is perpendicular to the direction of the fluid flow in the flow channels, the quantity of the beaters 7 also can be set flexibly according to actual requirements. When the beater 7 is working, the rotating axle of the beater 7 drives rotating blades to rotate, flapping materials in the flotation tank 2 or the washing tank 4, thereby accelerating the separating speed of the materials in the fluid medium.
As shown in
As shown in
A material limiting device is disposed between the flotation tank 2 and the multi-functional rubbing and separating device 3. To be specific, the material limiting device includes a material transporting pipe 81 and an impeller 82; the material transporting pipe 81 (which may either be a material transporting trough) is disposed at the feeding port 34 of the multi-functional rubbing and separating device 3, the structure of the material transporting pipe 81 is shown in
The dehydrator 5 is a vertical dehydrator, and a cyclone separator is connected in the discharge port of the dehydrator 5.
As shown in
A first circulating water mechanism is disposed between the flotation tank 2 and multi-functional rubbing and separating device 3, and a second circulating water mechanism is disposed between the washing tank 4 and the dehydrator 5. The first circulating water mechanism includes a circulating pipe disposed between the flotation tank 2 and multi-functional rubbing and separating device 3, thereby, the flotation medium obtained after the processing by the multi-functional rubbing and separating device 3 is conveyed back to the flotation tank 2 for recycling utilization; the second circulating water mechanism includes a circulating pipe disposed between the washing tank 4 and the dehydrator 5, thereby, the washing medium obtained after the processing by the dehydrator 5 is conveyed back to the washing tank 4 for recycling utilization. By means of applying the first circulating water mechanism and the second circulating water mechanism, the high quality control of the fluid medium is realized, which is capable of effectively reducing the consumption and wastage of the flotation medium and washing medium in the crushing, separating and washing processes for the waste plastics.
By means of the system mentioned above, a flotation type method for crushing, separating and washing waste plastics is realized, which includes following steps:
(1) Waste plastics are transported into the crusher 1 to be crushed, so as to form fragments of the waste plastics which are transported to the flotation tank 2;
(2) There is fluid flotation medium pre-placed in the flotation tank 2, and after being fed into the flotation tank 2, the fragments of the waste plastics are separated primarily along with the flowing of the flotation medium, thereby removing heavy impurities;
Those fragments of waste plastics, of which specific gravity is less than the specific gravity of the flotation medium, float upward and are transported to the multi-functional rubbing and separating device 3; while those fragments of waste plastics, of which specific gravity is heavier than the specific gravity of the flotation medium, and heavy impurities sink downward and remain in the flotation tank 2;
(3) After being fed to the multi-functional rubbing and separating device 3, the fragments of waste plastics are beaten and stirred by force for separation, thereby removing light impurities preliminarily, and then the pieces separated are transported to the washing tank 4;
(4) There is fluid washing medium pre-placed in the washing tank 4, and after being fed into the washing tank 4, the pieces of the waste plastics are secondarily separated along with the flowing of the washing medium, thereby further removing light impurities;
Those pieces of waste plastics, of which specific gravity is less than the specific gravity of the washing medium, float upward and are transported to the dehydrator 5; while those pieces of waste plastics, of which specific gravity is heavier than the specific gravity of the washing medium, and light impurities sink downward and remain in the washing tank 4; and
(5) The pieces of the waste plastics are fed into the dehydrator 5 to be dried and dehydrated, so as to remove the washing medium attaching to the surface thereof, thereby forming recycled pieces.
In the step (1), the crusher 1 crushes the waste plastics by means of dry-crushing or wet-crushing; wherein the dry-crushing is performed by crushing the waste plastics directly by the crusher 1 without adding any fluid medium; and the wet-crushing is performed by crushing the waste plastics in a fluid medium environment by the crusher 1 with the fluid medium added into the crusher 1 simultaneously when the waste plastics are fed into the crusher 1;
In the step (2), the heavy impurities include metals and sediments contained in the fragments of the waste plastics, and the flotation medium is water or halide salt water;
And in the step (4), the light impurities include label paper, greasy dirt and flotation medium attaching on the surface of the waste plastics; and the washing medium is water or halide salt water;
The flotation medium and the washing medium, which generally are different kinds of fluid medium, can be converted to each other; and
In the step (5), when there is a cyclone separator connected to the dehydrator, pieces of waste plastics form recycling pieces by dehydration in advance, and then pass the cyclone separator to separate thick pieces and thin pieces which are collected respectively.
It should be understood by those skilled in the art that what described above are preferred embodiments of the present disclosure. Various modifications and replacements may be made therein without departing from the theory of the present disclosure, which should also be seen in the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201310039088.3 | Jan 2013 | CN | national |
