JP2007244945A - Specific gravity fractionation device, fractional recovery method using the same, specific gravity fractionation method, waste disposal system, recycled plastic raw material and recycled plastic molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-size specific gravity fractionation device capable of improving fractional precision of plastic waste material according to a specific gravity separation method. <P>SOLUTION: The specific gravity fractionation device which fractionates an object to be sorted into a fractionated object having low specific gravity and a fractionated object having high specific gravity and recovers the fractionated objects is provided with: a fractionation vessel (a) for storing specific gravity separation liquid; a supply means (b) for supplying the object to be sorted; a liquid flow generating means (c) for generating a liquid flow of substantially horizontal direction in the specific gravity separation liquid; a first conveyance means (d) for moving the fractionated object which has low specific gravity in the liquid flow direction; and a second conveyance means (e) for moving the fractionated object having high specific gravity which is precipitated under the specific gravity separation liquid, in the direction reverse to the liquid flow. Therein, the second conveyance means has a function of refloating the fractionated object having low specific gravity which is precipitated under the specific gravity separation liquid. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a specific gravity separation device and a specific gravity separation method for separating and collecting a sorting object such as plastic waste. The present invention also relates to a method for separating and collecting using the specific gravity separation apparatus, and a waste treatment system incorporating the method. The present invention also relates to a recycled plastic material or a recycled plastic molded body.

  2. Description of the Related Art In recent years, in Japan, as income levels have improved, general households have an air conditioner (also referred to as “air conditioner” in the following description), a television receiver (also referred to as “TV” in the following description), a refrigerator. Or, household appliances such as washing machines, information equipment such as personal computers or word processors, office equipment such as printers or fax machines, and various other furniture, stationery, and toys are provided at a high penetration rate. . Convenience in home life has been dramatically improved by providing the above-mentioned various supplies in ordinary households.

  Since the above-mentioned various supplies are provided in ordinary households, the amount of disposal of these various supplies tends to increase year by year. Conventionally, recycling of these various materials has often been carried out through a scrap recovery route.

  Among the constituent materials of these various materials, the proportion of metals including iron tends to decrease, and the proportion of plastic compositions (also referred to as “plastic members”) tends to increase. Plastic members have a greater degree of design freedom than metals such as iron, can be imparted with various properties that are difficult to achieve with metals by preparing components and using additives, and are lightweight and durable This is because it has many advantages such as high performance.

  However, the plastic member has low value. In addition, the processing of the plastic member requires a lot of labor and cost as long as it is a conventional method. In the conventional iron scrap recovery route, it is not profitable to recycle such waste. From the viewpoint described below, it is becoming an important and urgent task to recycle waste of products including these plastic members (referred to as “plastic products” in the following description). The first point of view is to make effective use of resources. This is because many plastic members are based on fossil fuels such as crude oil. The second viewpoint is to prevent environmental destruction such as global warming and acid rain. This is because global warming and acid rain are caused by combustion of plastic members. A third viewpoint is to prevent environmental pollution such as generation and scattering of dioxins. This is because generation and scattering of dioxins are caused by incineration of a plastic member containing a chlorine compound. The fourth viewpoint is to suppress problems such as a shortage of landfill disposal sites. Since the plastic product waste is bulky, if the plastic product waste increases, the landfill disposal site will become insufficient.

  In order to solve the problems described above, the Home Appliance Recycling Law was enacted in April 2001. The Home Appliance Recycling Law requires that air conditioners, televisions, refrigerators, and washing machines be regenerated. The Home Appliance Recycling Law stipulates the legal standard values for air conditioners of 60% or more, TVs of 55% or more, refrigerators of 50% or more, and washing machines of 50% or more as re-commercialization rates of those products. The term “re-commercialization” refers to one of the following two types of actions. The first act is an act of separating parts and materials from the above-mentioned waste of household electrical appliances and using them as product parts or raw materials. The second action is an action that separates parts and materials from the above-mentioned household electrical appliance waste, and makes them ready for transfer to a person who uses them as product parts or raw materials for a fee or free of charge.

  Among them, as a method of separating a mixture composed of multiple types of plastics with different specific gravities at the time of recycling plastic waste materials, the difference in specific gravity of the mixture is used to separate the plastic composition in liquid. The method of separating each system has been widely used.

  In particular, by separating a plastic with a specific gravity of 1.0 that is submerged in water with a liquid having a specific gravity of 1.1, for example, ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05), polyurethane resin (specific gravity) : 1.2), polyvinyl chloride (specific gravity: 1.3), polyvinylidene chloride (specific gravity: 1.7), and the like, ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05) can be separated, and material recycling and thermal recycling are possible.

  Patent Document 1 discloses a method of separating and recovering specific gravity water other than water as a conventional technique for separating and recovering plastic having a specific gravity greater than 1.

  On the other hand, what is separated using water which is easy to handle has been proposed. Patent Document 2 and Patent Document 3 disclose a specific gravity sorting device that creates a constant water flow and separates and collects it using a difference in settling speed.

  However, in the specific gravity sorting devices disclosed in Patent Document 2 and Patent Document 3, it is necessary to provide a plurality of receiving boxes in order to separately collect the settled objects to be sorted. Along with the sediment carry-out device to be carried out, the specific gravity sorting device itself becomes complicated and large.

  Furthermore, since the collection tank is provided in the horizontal direction with respect to the water flow of the sorting tank and the sediment discharge device for carrying out the sorted object in the horizontal direction is provided, the receiving box adjacent to the collection tank has the sorting object. The transport distance is short, the sorting time is shortened, and the sorting accuracy is lowered.

  For this reason, in Patent Document 3, a non-sorting prevention device is provided on a partition plate that separates the collection tank and the sorting tank provided laterally with respect to the water flow of the sorting tank, so that the sorting tank is transported with insufficient sorting. Sorting is performed again by pushing the sorted product back to the sorting tank.

  However, since the above-described non-sorting prevention device is provided on the partition plate that partitions the sorting tank and the collection tank, the work area for pushing back the object to be sorted that is transported with insufficient sorting to the sorting tank is narrow. Also, the working distance for pushing back is short. For this reason, when an object to be sorted that is insufficiently sorted passes through the sorting preventing apparatus, it cannot be pushed back to the sorting tank, and as a result, the sorting accuracy is lowered.

In addition, when a plurality of the non-sorting prevention devices described above are provided, the specific gravity separation device itself is further complicated.
JP 2003-225646 A JP-A-9-57146 JP-A-9-108590

  The present invention has been made to solve the above-described problems, and the object of the present invention is to separate the mixed plastic member with high accuracy for each system of the plastic composition with a simple configuration. A specific gravity separation device and a specific gravity separation method are provided.

  Another object of the present invention is to provide a small specific gravity separation device capable of producing plastic raw materials or recycled plastic moldings by material recycling from the plastic composition and capable of recycling plastic waste materials efficiently and at low cost.

  Another object of the present invention is to establish a waste treatment system that separates and collects plastic waste materials collected from the market with the specific gravity separation device, and is obtained by material recycling. Is to provide.

  The present invention relates to a specific gravity separation apparatus that separates and collects a low specific gravity target and a high specific gravity target according to a difference in specific gravity, (a) a separation tank storing a specific gravity separation liquid; and (b) A supply means for supplying an object to be sorted into the separation tank; (c) a liquid flow generating means for generating a substantially horizontal liquid flow in the specific gravity separation liquid; and (d) a low specific gravity in the liquid flow direction. The specific gravity separation comprising: a first conveying means for moving the object to be sorted; and (e) a second conveying means for moving the object to be sorted having a high specific gravity that has settled below the specific gravity separation liquid in a direction opposite to the liquid flow. Providing the device.

  In the present invention, it is preferable that the second transporting unit has a function of re-floating a low-specific gravity sorting object that has settled below the specific gravity separation liquid.

  Moreover, the said specific gravity fractionation apparatus whose said to-be-sorted material is the crushed material of several types of plastic waste materials and / or metal waste materials from which specific gravity differs is preferable.

  In the present invention, the specific gravity separation device is preferably a waste product pulverized product of household electrical appliances selected from the group consisting of an air conditioner, a television, a refrigerator, and a washing machine.

  In the present invention, the specific gravity fractionation device in which the specific gravity of the object to be sorted is 1.0 or more is preferable.

  Moreover, the said specific gravity fractionation apparatus with which this invention generate | occur | produces the said liquid flow with the negative pressure of the discharge port attached to the said separation tank is preferable.

  In the present invention, it is preferable that the specific gravity separation device generate the liquid flow in a tunnel-type guide provided substantially horizontally in the separation tank.

  Moreover, the said specific gravity fractionation apparatus whose 2nd conveying apparatus is a screw conveyor is preferable for this invention.

  Moreover, the said specific gravity fractionation apparatus with which the screw of the said screw conveyor wound the ribbon-shaped blade | wing spirally is preferable for this invention.

  In the present invention, the specific gravity separation device provided with one or more stirring plates that synchronize with the screw and rotate along the inner peripheral surface of the screw guide is preferable.

  In the present invention, the specific gravity fractionating device is preferably such that the length from the rotating shaft to the tip of the stirring plate is longer than the radius of the outer circumference of the screw blade.

  Moreover, the specific gravity fractionation apparatus incorporating the dehydrator for dehydrating the collect | recovered specific gravity fractions is preferable for this invention.

In addition, the present invention provides a method for collecting a product to be sorted using the specific gravity sorting device.
The present invention also relates to a specific gravity separation method for separating and collecting a low-specific gravity target and a high specific gravity target according to a difference in specific gravity, wherein the target is separated into a liquid flow flowing from one specific gravity separation liquid to the other. A supply step for supplying sorting, a first transport step for transporting a low-specific gravity sorting object in the sorting object that moves to the other side by the liquid flow, and the sorting object that has settled below the specific gravity separation liquid There is provided a specific gravity separation method including a second transport step for transporting a high-specific gravity object to be sorted in an object in a direction opposite to the flow of the liquid flow.

  In the second conveying step of the specific gravity separation method according to the present invention, it is preferable that the low specific gravity to-be-sorted material included in the sedimented to-be-sorted material is re-floated to the liquid flow.

In addition, the present invention provides a waste treatment system incorporating the separation and recovery method.
The present invention also provides a recycled plastic raw material and a recycled plastic molded body made of plastic recovered by a waste treatment system.

  Plastic waste materials composed of mixed plastic members and the like can be separated with high accuracy by a simple configuration for each plastic composition system.

  In addition, it is possible to provide a specific gravity separation device that can perform specific gravity separation with high efficiency and small equipment.

  In addition, the specific gravity separation device of the present invention can be provided with a small means for re-floating the object to be separated that has settled in the specific gravity separation liquid several times, and by increasing the number of times to re-float the object to be separated, The accuracy of specific gravity separation can be increased.

  Moreover, a recycled plastic raw material or a recycled plastic molded article obtained by material recycling can be provided by using a specific gravity separation apparatus in a waste treatment system.

<Specific gravity separation device>
FIG. 1 is a diagram showing an example of a preferred specific gravity separation device of the present invention. Hereinafter, based on FIG. 1, the structure of the specific gravity separation apparatus of this invention is demonstrated.

  This specific gravity separation device puts a material to be sorted 5 in which plastic waste material and / or metal waste material is crushed into a separation tank 1 in which specific gravity separation liquid 2 is stored, and low specific gravity based on specific gravity separation liquid 2 by a specific gravity separation means. This is a device that separates high-specific gravity objects to be separated and collects them one after another by means of transport. The sorting tank 1 is provided with a loading port 7 as a supply means for supplying the material to be sorted 5, and the material to be sorted 5 is fed from the loading port 7. Further, the separation tank 1 is provided with a liquid flow generating means for generating a liquid flow in the horizontal direction, and a first transport means for transporting a low specific gravity sorting object in the horizontal water flow direction, and a specific gravity. There is provided a second transport means for transporting a high-specific gravity object to be settled below the separation liquid 2 in a direction opposite to the liquid flow by a screw conveyor 10 or the like provided below the separation tank 1.

  In addition, the specific gravity fractionating apparatus has a low specific gravity to-be-sorted object having a specific gravity larger than that of the specific gravity separation liquid 2 and a low specific gravity that is smaller than the predetermined specific gravity and close to the specific gravity of the specific gravity separation liquid 2. It is possible to separate the objects to be sorted with specific gravity and collect them separately.

  That is, the sorting tank 1 is provided with a loading port 7 as a supply means for supplying the material to be sorted 5, and the material to be sorted 5 is fed from the loading port 7. In the separation tank 1, a liquid flow generating means for generating a liquid flow in the horizontal direction is provided, and the liquid having a specific gravity larger than the specific gravity separation liquid 2 settles faster due to the liquid flow generated thereby. A first transport means is provided for transporting the object to be sorted that does not sink using the time difference of the sedimentation.

  However, there is a limit to the recovery rate of the object to be sorted having a specific gravity in a desired range only by the time difference of sedimentation.

  Therefore, the second conveying means for re-floating the re-levitated object to be re-floated on the liquid flow by re-levitating the object to be sorted out of the settled object to be re-levitated, It has.

  In addition, the conveyance direction of the to-be-sorted object of a 1st conveyance means and a 2nd conveyance means is mutually reverse direction, and the mutual conveyance path | route has overlapped up and down.

  According to this configuration, an object to be sorted having a fast settling speed and a large specific gravity is quickly transported and collected by the second transporting means, so that the chance of re-floating is reduced. On the other hand, the object to be sorted having a low specific gravity with a slow settling speed has a chance to sufficiently re-float on the transfer path of the second transfer means even when settling, and the first transfer located above the second transfer means. It will be conveyed by means.

  Although the specific gravity separation liquid 2 is not particularly limited, it is preferable to use water. In addition, for example, salt water or the like can be used. A liquid having a specific gravity between the material to be sorted is preferable.

  Alternatively, it may be any liquid that is smaller than the specific gravity of all the objects to be sorted and has a small specific gravity difference from the objects to be transported by the first transport means. In this case, the specific gravity difference is about 0.00-2. Differences are preferred.

≪Liquid flow generation means≫
This will be described below with reference to FIG. The liquid flow generating means refers to means for generating a substantially horizontal liquid flow in the specific gravity separation liquid 2 in the separation tank 1. In FIG. 1, the specific gravity separation liquid 2 in the separation tank 1 flows toward the drain port 6, and this liquid flow means a flow that occurs in the direction of the arrow shown in the figure, and the upper end of the screw conveyor. It means a flow from one side to the other (horizontal direction) within a range of a predetermined height, for example, within a range of height H in the guide 3, and it is preferable that the flow rate of the liquid flow is faster than the other.

  The inside of the separation tank 1 storing the specific gravity separation liquid 2 is preferably partitioned by a tunnel-type guide 3 so that water at a constant speed flows through the inside. This is because when a liquid flow is caused in the entire inside of the separation tank 1, a turbulent flow is generated at the water inlet. And the top | upper surface of the guide 3 is cut out and the cylindrical insertion port 7 is formed in the part. Further, the vicinity of the drainage port 6 of the guide 3 has a tapered structure so that no vortex is generated due to a sudden change in the liquid flow. By using the tunnel-type guide 3, the specific gravity separation liquid 2 is once put in the separation tank 1, and the specific gravity separation liquid 2 is sent into the guide 3 in a stable state. Occurrence can be minimized.

  Here, the liquid flow can create a flow with few vortices by connecting a pump or the like to the liquid discharge port 6 to create a negative pressure. However, depending on the object to be sorted, there is a long thing, and the long object to be sorted is clogged in the pump and the pump may not operate. Therefore, the separation tank 1 can be connected from the drainage port 6 without using the pump. A method of creating a liquid flow by using the potential energy of the specific gravity separation liquid 2 connected to the water tank 4 below the water surface and the large-diameter pipe 16 from the inner guide 3 is preferable.

  The liquid flow generating means is configured by the above-described pump for generating a liquid flow or a drainage path using positional energy, but the guide 3 may be included in the configuration.

  Further, in order to collect the object to be sorted 5 floating on the liquid surface of the specific gravity separation liquid 2, the top surface of the guide 3 is cut out in the downstream direction of the input port 7, and the object to be sorted 5 is separated around the separation tank 1. A PP (polypropylene) guide 15 surrounded by a cylindrical guide protruding to a level higher than the liquid level may be attached so as not to escape to a place other than the guide 3.

  Moreover, the optimum value of the flow rate of the specific gravity separation liquid 2 in the guide 3 is the size of the object 5 to be sorted, the distance L shown in FIG. 1 from the inlet 7 to the inlet of the drain 6, and the top of the guide 3. It varies depending on the height of H from the surface to the bottom. As for the relationship between L and H, for example, the longer L is, the higher the sorting accuracy is, and it is necessary to increase the flow velocity. Further, as H is increased, the sorting accuracy is increased, and the flow rate must be decreased. In consideration of the above, the flow velocity is selected so that the specific gravity accuracy of the discharged sorting object is high and the minimum specific gravity of the settled sorting object becomes a certain value of 1.0 to 1.1. Specifically, a speed in the range of about 100 to 300 mm / sec is preferable.

  Moreover, it is preferable to circulate the to-be-sorted object 5 by the volume of 0.1 to 5% with respect to the volume of the specific gravity separation liquid 2 in the guide 3 from viewpoints, such as circulation efficiency.

<< First conveying means >>
The first conveying means is a means for moving and collecting the low-specific gravity objects to be sorted by pushing the low-specific gravity objects to be drained into the drainage port 6 using the sedimentation speed due to the specific gravity difference in the liquid flow direction. .

  In the above-described liquid flow, an object to be sorted having a low specific gravity is conveyed. The specific gravity separation liquid 2 including the low specific gravity to-be-sorted material flowing out from the drain port 6 is once accumulated in the water tank 4. Thereafter, the material having a low specific gravity is separated from the specific gravity separation liquid 2 by a strainer 8 or the like, and then sent to a centrifugal dehydrator 9 for dehydration.

  On the other hand, the specific gravity separation liquid 2 separated from the plastic by the strainer 8 and the dehydrator 9 is returned to the separation tank 1 by a pump or the like. As a result, the specific gravity separation liquid 2 circulates.

  The first conveying means is constituted by the liquid flow generated by the liquid flow generating means, and the conveying path such as the pipe 16 that conveys the object to be sorted together with the liquid flow and / or the object to be sorted and the specific gravity separation liquid 2. The strainer 8 to be separated may be included in the configuration.

<< Second conveying means >>
The second transport unit is a unit that moves and collects a high-specific gravity sorting object that has settled below the specific gravity separation liquid 2 in a direction opposite to the liquid flow.

  The specific gravity that is heavier than the specific gravity separation liquid 2 is lighter than the specific gravity separation liquid, or is heavier than the specific gravity separation liquid, but is pushed away by the liquid flow due to the settling time difference, that is, in the above-described first conveying means. It must be collected separately from what is transported. Therefore, in the present invention, in the object to be separated, the object having a high specific gravity in the direction opposite to the direction in which the object having a low specific gravity is conveyed (direction of the liquid flow as the first conveying means). Transport. In order to convey in the reverse direction, the horizontal screw conveyor 10 is preferable because of the ease of creating the sediment re-floating mechanism and the length of the maintenance cycle.

  Further, the horizontal screw conveyor 10 is preferably a ribbon type so as not to cause a liquid flow. Moreover, it is preferable that the screw pitch and the width have a size that can sufficiently convey a high-specific gravity sorting object and can insert a stirring plate 13 described later. Specifically, the ribbon screw conveyor 10 having a width of 10 to 40 mm, a pitch of 50 to 300 mm, and an outer diameter of 100 to 200 mm is preferable.

From here, it demonstrates based on FIG. 2 which is sectional drawing of II-II in FIG.
As shown in FIG. 2, the horizontal screw conveyor 10 having a drive motor is disposed in a semicircular concave recess provided at the bottom of the separation tank 1, and is disposed below the guide 3. The rotation axis of the screw conveyor 10 is located at the approximate center of the lateral width of the guide 3 and is arranged to be parallel to the longitudinal direction of the guide 3.

  Moreover, as shown in FIG. 1, the upper part of the screw conveyor 10 and the lower part of the guide 3 are each comprised so that a mutual opening part may oppose along a longitudinal direction. That is, the liquid flow (first conveying means) flowing toward the other end from the one end of the guide 3 to the drainage port 6 and the screw conveyor 10 (second conveying means) are positioned so that their conveying paths overlap each other. To do.

  Thereby, a sufficient distance can be secured for repeatedly sorting the low-specific gravity sorting object and the high specific gravity sorting object because the sedimented sorting object floats again. In addition, since the object to be sorted can be re-floated over a length substantially equal to the length of the guide 3 in the longitudinal direction, the specific gravity separation device can be downsized.

  An object to be sorted having a high specific gravity moves in a direction opposite to the liquid flow by a horizontal screw conveyor 10 having a drive motor. Thereafter, the high specific gravity to-be-sorted material falls to the input port of the vertical screw conveyor 11 just below the discharge port of the horizontal screw conveyor 10. At this time, as shown in FIG. 2, the discharge port of the horizontal screw conveyor 10 and the input port of the vertical screw conveyor 11 having the drive motor are cylindrical in which both sides are sealed so that water does not leak. It must be connected.

  Next, the high specific gravity sorting object is drained by the vertical screw conveyor 11 and discharged from the discharge port 12. At this time, it is preferable that the screw conveyor 11 is inclined 30 to 80 degrees in the vertical direction with respect to the horizontal direction.

  In place of the vertical screw conveyor 11, a conveyor with a sun may be used.

≪Function to re-float sedimented objects to be sorted≫
Here, it is preferable that the second transport means simultaneously re-floats the sedimented low specific gravity to-be-sorted material when transporting the to-be-sorted material having a high specific gravity in the direction opposite to the liquid flow direction.
<Example 1>
Low specific gravity sorting from plastic waste materials that have a low specific gravity smaller than the specific gravity of the specific gravity separation liquid 2 and a high specific gravity larger than the specific gravity of the specific gravity separation liquid 2. The case where a thing is separated is demonstrated.

  For example, plastic waste materials are polypropylene (specific gravity: 0.9), polyethylene (specific gravity: 0.9), ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05), polyurethane resin (specific gravity: 1. 12), a mixture of different plastics such as polyvinyl chloride (specific gravity: 1.3) and polyvinylidene chloride (specific gravity: 1.7). When separating polypropylene and polyethylene from this, the specific gravity separation liquid 2 Use water. The flow rate of the liquid flow is preferably 1 mm or more and less than 100 mm / sec.

  Polypropylene and polyethylene having a specific gravity smaller than that of water are conveyed by being pushed away to the drain 6 by the first conveying means. The others settle and are transported by the second transport means.

  However, when plastic waste is put into the separation tank 1, plastics having different specific gravities may adhere to each other.

Also, if a low specific gravity target (polypropylene, polyethylene) having a specific gravity of less than 1 and a high specific gravity target (copper wire, etc.) greater than 1 are attached, the low specific gravity will settle. End up. Even in such a case, the objects to be sorted can be separated from each other by refloating the objects to be sorted by the second transport unit, and the objects having a low specific gravity can be transported by the first transport unit.
<Example 2>
The case where a low-specific gravity sorting object is separated from a plastic waste material having a larger specific gravity than the specific gravity separation liquid 2 will be described.

  For example, in Example 1, it demonstrates using the plastic waste material isolate | separated by the 2nd conveyance means. This plastic waste material includes ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05), polyurethane resin (specific gravity: 1.12), polyvinyl chloride (specific gravity: 1.3), and polyvinylidene chloride (specific gravity). A mixture of different types of plastics such as 1.7), from which ABS resin and polystyrene are separated as a low-specific gravity material to be sorted. Water is used for the specific gravity separation liquid 2. The flow rate of the liquid flow is preferably 100 mm or more and 300 mm or less / sec.

  Depending on the time difference of settling, a low-specific gravity sorting object such as ABS resin or polystyrene that is close to the specific gravity of water is pushed to the liquid discharge port 6 by the first carrying means and is carried, but a part of it falls. Even in such a case, it is possible to transport the object having a low specific gravity by the second transport unit, so that it can be transported by the first transport unit. The others settle and are transported by the second transport means.

  In this way, by changing the speed of the liquid flow, separation is made into a low-specific gravity sorting object smaller than the specific gravity of the specific gravity separation liquid 2 and a high specific gravity sorting object having a specific gravity larger than the specific gravity of the specific gravity separation liquid 2. Can do. Furthermore, the object to be sorted having a specific gravity greater than that of the specific gravity separation liquid 2 can be separated into a substance having a low specific gravity and a material having a high specific gravity.

  As described above, the objects to be sorted settled in the specific gravity separation liquid 2 include not only high specific gravity but also low specific gravity.

  In particular, when the plastic waste material shown in Example 2 is selected as a sorting target, the first settling object to be sorted, that is, the sorting object collected from the discharge port 12 without performing re-levitation once, has a specific gravity of 1. Since it contains 30 to 60% of 0 to 1.1 to-be-sorted items, it is lifted again while moving in the direction opposite to the liquid flow, and the to-be-sorted items having a specific gravity of 1.0 to 1.1 are collected. It is necessary to increase the recovery rate.

  Therefore, in the present invention, the sedimentation of the high-specific gravity sorting object and the fractionation of the sedimented low-specific gravity sorting object by re-floating are simultaneously performed several times. This is because the efficiency of the specific gravity separation is increased, and at the same time, the sediment to be sorted can be taken out and the efficiency as a whole is good. The re-levitation is preferably performed by the stirring plate 13 attached to the screw conveyor 10.

  Hereinafter, the detailed configuration of the second conveying means will be described based on FIG. 3 in which the screw conveyor 10 in FIG. 2 is enlarged. In the present invention, it is preferable to perform re-levitation by the stirring plate 13 attached to the screw conveyor 10.

  The stirring plate 13 is made of an elastic member such as a metal. As shown in FIG. 3, the tip of the stirring plate 13 is stopped when the stirring plate 13 becomes horizontal by the rib 14 attached to the guide at a position of 90 degrees. Therefore, the stirring plate 13 bends, and when the subsequent shaft is slightly rotated, the tip is released from the rib 14 and the tip rotates at a high speed. Since the length from the rotating shaft to the tip of the stirring plate 13 is longer than the radius of the outer circumference of the screw blade, the rib 14 does not interfere with the screw and affects only the stirring plate 13. Moreover, the height of the rib 14 should just be able to stop the stirring board 13 temporarily, for example, a 2-5 mm stainless steel square bar can be used. Moreover, the stirring plate 13 can use a stainless steel plate having a thickness of 0.1 to 0.5 mm and a width of 20 to 100 mm.

  The sediment to be sorted is raised to a portion where the liquid flow is present in the guide 3, and the material to be sorted having a low specific gravity rides on the liquid flow and is discharged from the drain port 6. On the other hand, the high-specific gravity sorting object re-floats, rides a little on the liquid flow, flows in the downstream direction of the liquid flow, and sinks again. Since the high-specific gravity sorting object settles faster than the low-specific gravity sorting object even if it floats again, it gradually moves in the direction opposite to the liquid flow by the screw.

  By repeating the re-levitation, the accuracy of the specific gravity fractionation of the sediment to be sorted is improved. In addition, when the number of re-levitation exceeds 20 times, the accuracy is almost saturated, so the number of re-levitation is preferably about 20 times.

  Here, re-levitation about 20 times makes the gap between the stirring plate 13 and the screw on the feed direction side about 1.5 to 3 times the size of the object to be selected 5, and a part of the object to be selected 5 Is allowed to pass through, the discharge amount is controlled, and the stirring plates 13 are arranged at a pitch of 45 to 70 degrees.

  In addition, in order to prevent the object to be sorted having a high specific gravity from rising and flowing in the downstream direction by the stirring plate 13 and being floated again by the stirring plate 13 before settling, and flowing out from the drainage port 6, The stirring plate 13 needs to be installed at a certain distance or more on the downstream side of the liquid flow from the inlet 7. When the liquid flow is 100 to 300 mm / sec, an interval of 100 to 200 mm or more can be provided to prevent an object having a high specific gravity from flowing out of the drainage port 6.

  Also, the rotational speed of the shaft is preferably 20 rpm or less for the ribbon screw blade to operate without greatly disturbing the liquid flow in the sorting section, and in order to ensure the discharge amount of the sediment having a high specific gravity that has settled. 10 rpm or more is required.

In addition, you may perform this levitation | floating by installing the means to generate | occur | produce a bubble below the separation tank 1 separately from the said screw conveyor. Alternatively, the liquid may be re-levitated by generating a liquid flow by injecting air vertically from the lower side of the separation tank 1.
<Selected materials to be sorted by specific gravity sorting device>
The objects to be sorted in the specific gravity separation apparatus of the present invention are a plurality of types of plastic waste materials and / or metal waste materials having different specific gravities. Plastic waste is a mixture of various types of plastic. This plastic waste material includes, in addition to polypropylene (specific gravity: 0.9) and polyethylene (specific gravity: 0.9), ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05), acrylic resin (specific gravity 1. 19), polycarbonate resin (specific gravity: 1.20), polyurethane resin (specific gravity: 1.12), polyvinyl chloride (specific gravity: 1.3), POM (polyoxymethylene, specific gravity: 1.41), poly It is a dissimilar plastic such as vinylidene chloride (specific gravity: 1.7). Some metal waste materials include copper wire (specific gravity: 9), stainless steel screws (specific gravity: 8), aluminum (specific gravity: 2.7), etc. Can be mentioned.

  Moreover, it is preferable that the to-be-sorted item is a crushed material of the waste of household electrical appliances selected from air conditioners, televisions, refrigerators, and washing machines of four items of household electrical appliances.

  The material to be sorted put into the specific gravity separation device of the present invention is a mixture of any two or more of the above-mentioned plastics and metal waste materials. The content of the material to be sorted depends on the content of the crushed waste. Also changes.

  The material to be sorted 5 from which the polyolefin-based plastic has been recovered in the static specific gravity separation step is introduced from the introduction port 7 into the guide 3 in which a constant liquid flow is made. The inputted sorting object 5 rides on the liquid flow and is carried to the drainage port 6 in the downstream direction.

  At this time, the high-specific gravity sorting object sinks due to the difference in buoyancy, and the low-specific gravity sorting object flows along with the specific gravity separation liquid 2 from the drainage port 6 without sinking to the bottom.

The to-be-sorted material 5 to be input preferably has a specific gravity of 1.0 or more. For a to-be-sorted material having a low specific gravity, an ABS resin having a specific gravity of less than 1.1 (specific gravity: 1.05), polystyrene (specific gravity: 1.05) One of these is mentioned. In addition, for an object to be sorted having high specific gravity, acrylic resin (specific gravity 1.19) having a specific gravity of 1.1 or more, polycarbonate resin (specific gravity: 1.20), polyurethane resin (specific gravity: 1.12), polychlorinated Plastics such as vinyl (specific gravity: 1.3), POM (polyoxymethylene, specific gravity: 1.41), polyvinylidene chloride (specific gravity: 1.7) and any of copper wire, stainless steel screw, and aluminum include.
<Waste treatment system>
FIG. 4 is a process diagram showing a preferred example of the waste treatment system of the present invention. The waste treatment system is a series of unified waste treatment flows that incorporate separation and collection by the specific gravity separation device.

  An example is shown in which this apparatus is used for recovering PS (polystyrene) and ABS resin from wastes of 4 items of household appliances. In addition, the mixture which passed through step 107 is equivalent to "the to-be-sorted object 5" in FIG. 1 said by this invention.

  In this specific example, first, as shown in FIG. 4, four items of used home appliances discarded from homes and the like are collected (step 101). Then, the household appliance waste is disassembled, and large metal parts such as a compressor and a heat exchanger, and large plastic molded articles such as a water tank of a washing machine and a vegetable case of a refrigerator are collected for each part (step 102). . In the present invention, it is preferable that the plastic waste material can be selectively recovered in the dismantling of step 102.

  Next, the remaining members of the wastes of the four home appliances from which the large metal members and the like have been collected are roughly crushed with a large crusher such as an impact crusher or a shear crusher (step 103). The particle size of the crushed material in step 103 is not particularly limited, but is preferably 10 mm or more, and more preferably 40 mm or more. Moreover, it is preferable that the particle size of a crushed material is 80 mm or less, and it is more preferable that it is 60 mm or less. If the particle size of the crushed material is less than 10 mm or more than 80 mm, the metal selection accuracy in the next process tends to be reduced, and if the particle size is less than 10 mm, it takes a long time for crushing. The plastic tends to melt or undergo thermal oxidative degradation, and when the particle size exceeds 80 mm, the bulk specific gravity tends to be small and the workability in the subsequent processes tends to be adversely affected. Specifically, it is particularly preferable to crush so that the particle size is about 60 mm. In addition, members that are difficult to crush, such as a large metal member such as a compressor and a heat exchanger, may be disassembled in advance and removed from the waste including the plastic member.

  Subsequently, the crushed waste of the home appliance is separated into a metal crushed material and a plastic crushed material formed of iron, copper, aluminum or the like (step 104). In order to separate the crushed waste in this step into metal crushed material and plastic crushed material, for example, a separation device using magnetic force suitable for iron separation, eddy current suitable for sorting aluminum and copper is used. The fractionation apparatus used, the trommel apparatus which makes a particle size uniform and sifts, etc. can be used suitably.

  Next, it is preferable to further separate the low bulk specific gravity crushed material from the plastic crushed material after the metal crushed material is separated (step 104). Here, the low bulk specific gravity crushed material means a crushed material having a bulk specific gravity of 0.3 or less. Specific examples of the low bulk specific gravity crushed material include a polyurethane heat-insulating material crushed material and a polystyrene foam-based crushed material. Although this low bulk specific gravity crushed material is not specifically limited, It is preferable to perform selection by wind power. Therefore, it is preferable to use an air separation device. Other devices that can be used include vibration sieving devices. When sorting the crushed waste into metal-based crushed material, plastic-based crushed material and low-bulk specific gravity crushed material, the order is used when sorting by wind, sorting by magnetic force, and sorting by eddy current. Is not particularly limited, but from the viewpoint of efficiency of separation, first, iron-based metal fragments are separated by magnetic force, then aluminum-based metal and copper-based metal fragments are separated by eddy current, and then It is preferable that the low bulk specific gravity crushed material is separated by wind force, and the remaining mixed plastic crushed material is subjected to the following steps.

  The mixed plastic-based crushed material obtained above is subjected to a fine crushing step (step 106). This fine crushing can be performed using, for example, a shearing type crushing apparatus (the one after the fine crushing is hereinafter referred to as “finely crushed material”). Although there is no restriction | limiting in particular in the magnitude | size of a finely crushed material, It is preferable that it is 5 mm or more, and it is more preferable that it is especially 8 mm or more. The particle size is preferably 30 mm or less, particularly preferably 20 mm or less. If this particle size is less than 5 mm, it takes a long time for crushing, so the plastic tends to melt or undergo thermal oxidative degradation. If this particle size exceeds 30 mm, the workability in the thermoforming process is adversely affected. This is because there is a tendency to exert an effect.

  In the specific gravity separation method of the present invention, a large plastic molded product such as a water tank recovered by manual disassembly (step 102), a vegetable case of a refrigerator, or the like, without undergoing steps 103 to 105 described above. You may make it use for a fine crushing process (step 106).

  Next, wet specific gravity separation is performed in order to subject the mixture to be sorted to specific gravity separation (step 107). The wet specific gravity separation method is not particularly limited, and a known technique may be used. Moreover, you may implement by using the liquid of specific gravity 1.0 or less like kerosene etc. for the specific gravity separation liquid of the specific gravity separation apparatus of this invention. In this step, a polyolefin plastic composition (polypropylene and polyethylene) having a specific gravity of 1.0 or less is recovered. Or you may use the specific gravity separation apparatus of this invention like Example 1 mentioned above.

  Next, the remaining plastics recovered from the polyolefin-based plastic composition (plastic waste other than polypropylene (specific gravity: 0.9) and polyethylene (specific gravity: 0.9), ABS resin (specific gravity: 1.05)) , Polystyrene (specific gravity: 1.05), acrylic resin (specific gravity 1.19), polycarbonate resin (specific gravity: 1.20), polyurethane resin (specific gravity: 1.12), polyvinyl chloride (specific gravity: 1.3) ), POM (polyoxymethylene, specific gravity: 1.41), polyvinylidene chloride (specific gravity: 1.7), etc., and some copper wire (specific gravity: 9), stainless steel screws (Specific gravity: 8) Polystyrene-based plastic composition (ABS resin, polystyrene) from aluminum (specific gravity: 2.7) is separated and collected by the specific gravity separation device of the present invention. That.

  PS (polystyrene) having a specific gravity of 1.0 to 1.1, having a liquid flow generating means and charging the remaining sorting object by a supply means into a separation tank storing water (specific gravity 1) as a specific gravity separation liquid. A material to be sorted having a low specific gravity close to the specific gravity of the specific gravity separation liquid 1 such as ABS resin is transported by the first transport means and collected. An object to be sorted having a higher specific gravity than a specific gravity of 1.1 is transported and collected by the second transport means. The object to be sorted having a specific gravity of 1.0 to 1.1 that has settled below the specific gravity separation liquid is re-floated several times by the second conveying means, and the specific gravity separation is repeated, thereby increasing the specific gravity accuracy (step 108). ).

  Further, the specific gravity separation method of the present invention does not have to include all the steps shown in FIG. 3, and steps not shown in FIG. 3 may be added or deleted as necessary. Moreover, it is not necessary for the materials to be sorted to include all the plastic waste materials and metal waste materials described above.

  In addition, by increasing the flow rate of the liquid flow in the specific gravity separation device of the present invention, from the above-mentioned polyolefin-based plastic composition and the remaining material to be sorted from which the polystyrene-based plastic composition (ABS resin, polystyrene) was recovered. It is also possible to recover the metal. Here, when the specific gravity separation device of the present invention is used and the flow rate of the liquid flow is set to about 400 to 600 mm / sec, for example, the remaining plastic waste materials (acrylic resin, polycarbonate resin, polyurethane resin, polyvinyl chloride, POM ( Polyoxymethylene) and polyvinylidene chloride) can be transported by the first transporting means, and a metal such as copper can be transported by the second transporting means as a high specific gravity sort and recovered with a purity of 60%. The rest of the collected material is resin (polyvinyl chloride) that is covered with copper wire.

As another embodiment of the specific gravity separation method of the present invention, a first waste material (polyolefin-based plastic composition) comprising a plurality of types of plastic waste materials and / or metal waste materials having different specific gravities using the specific gravity separation device of the present invention. (One or more of polypropylene, polyethylene, etc.), polystyrene plastic composition (any one or more of ABS resin, polystyrene, etc.), other plastic compositions (acrylic resin, polycarbonate resin, polyurethane resin, polychlorinated) Vinyl, POM (polyoxymethylene), polyvinylidene chloride, etc.)), metal waste (one or more of copper wire, stainless steel screws, aluminum, etc.) Water) with a first flow rate (e.g., 1 mm to 100 mm) (Full / sec), the polyolefin plastic composition can be transported and collected by the first transport means. (First collection step)
Next, with respect to the second waste material from which the polyolefin-based plastic composition has been separated and recovered, the same specific gravity separation liquid (for example, water) is used, and a second flow rate (for example, higher than the first flow rate) (for example, By generating a liquid flow of 100 mm or more and 300 mm or less / sec), the polystyrene-based plastic composition can be transported and collected by the first transport means. (Second collection step)
Next, with respect to the third waste material from which the polystyrene-based plastic composition has been separated and recovered, a third flow rate (for example, higher than the second flow rate) is used by using the same specific gravity separation liquid (for example, water). By generating a liquid flow of 400 to 600 mm / sec, the waste metal material can be transported and collected by the second transport means. (Third recovery step)
In the specific gravity separation method, the above steps may be configured independently or may be configured in a continuous manner. In addition, any one of the above steps may be performed using one specific gravity separation device of the present invention, or may be performed in order. Alternatively, any one of the transport paths (first or second transport means) of the plurality of specific gravity separation devices may be connected to the input port of each specific gravity separation device, which may be carried out continuously.

  From the above, according to the specific gravity separation device or specific gravity separation method of the present invention, by using the same specific gravity separation liquid and by changing the liquid flow, a plurality of types of plastic waste materials and / or metal waste materials having different specific gravity are used. Can be separated from the waste material consisting of, for each series of plastic compositions and / or into metals.

  Therefore, with a simple configuration, valuable materials (for example, polyolefin-based plastic compositions, polystyrene-based plastic compositions, metals) as raw materials for re-commercial use can be separated and collected with high accuracy.

≪Recycled plastic raw material / molded body≫
INDUSTRIAL APPLICABILITY The present invention can provide a recycled plastic raw material and a recycled plastic molded body manufactured from a collected material (plastic) by a waste treatment system.

  The recycled plastic material is preferably in the form of pellets. At this time, the particle diameter of the pellet is preferably 1 mm or more, and more preferably 2 mm or more. Further, the particle diameter of the pellet is preferably 8 mm or less, and more preferably 5 mm or less. When the particle size of the pellet is less than 1 mm, there is a tendency that workability is lowered because it floats. When the particle size of the pellet exceeds 8 mm, the pellet does not melt sufficiently in the cylinder of the molding machine, so that it is uniformly kneaded. This is because they tend not to be.

  In addition, when shape | molding the pellet-shaped recycled plastic raw material, you may granulate by any methods, such as a sheet cut, a strand cut, a hot air cut, an underwater cut, after extrusion molding. Among these granulation methods, when forming into a specific shape by injection molding later, an underwater cut that can smoothly supply resin raw material and can cope with a large amount of processing is particularly preferable.

  The shape of the recycled plastic raw material of the present invention is not particularly limited to a pellet shape, and may be any form such as a sheet shape, a film shape, a pipe shape, and the type and use of an extruder. What is necessary is just to determine suitably from the aspect of this, or the characteristic calculated | required.

  Further, the recycled plastic raw material of the present invention may contain additives such as a heat stabilizer, a light stabilizer, an antistatic agent, a lubricant, a filler, a copper damage inhibitor, an antibacterial agent, and a colorant, if necessary. You may add in the quantity of the range which does not harm.

  The recycled plastic molded body may be a member made of plastic (plastic member). In this case, the plastic member is preferably used for a product selected from the group consisting of an air conditioner, a television, a refrigerator, and a washing machine.

  The plastic member can be molded from the recycled plastic raw material using a method such as injection molding. Although it does not specifically limit as an injection molding machine used at this time, For example, a screw in-line type injection molding machine, a plunger type injection molding machine, etc. are mentioned.

  In order to further simplify the molding step of the plastic member, the crushed plastic is directly put into an injection molding machine without producing a recycled plastic raw material having a shape such as a pellet, and a member made of plastic is added. You may produce directly.

  Furthermore, this plastic member may contain additives such as heat stabilizers, light stabilizers, antistatic agents, lubricants, fillers, copper damage inhibitors, antibacterial agents, colorants, etc. It may be produced by adding the amount in a range not to be formed. The step of adding these additives is preferably performed when the recycled plastic raw material or the crushed plastic is put into an extrusion molding machine or an injection molding machine.

<Example 1>
The following embodiment will be described with reference to FIG.

  The mixed plastic-based crushed material having a particle size of 14 mm or less was used as the material to be sorted 5, and fractionation was performed using the specific gravity separation device of the present invention. The objects to be sorted are ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.05), polyurethane resin (specific gravity: 1.12), polyvinyl chloride (specific gravity: 1.3), polyvinylidene chloride (specific gravity). 1) and other plastics and some copper wire, stainless steel screws, aluminum. As the specific gravity separation liquid 2, water (specific gravity: 1) was used.

  When the distance L from the inlet 7 to the inlet of the drain 6 was 330 mm and the height of the guide 3 was 130 mm, the optimum flow rate was 251 mm / sec.

  At this time, the crushed pieces discharged from the drainage port 6 without sinking were 55% of the total amount of plastic having a specific gravity of 1.0 to 1.1, and the specific gravity accuracy was 98%. .

  Accordingly, the first sedimented object, that is, the object collected from the discharge port 12 contains 45% of crushed pieces having a specific gravity of 1.0 to 1.1, and thus moves in the direction opposite to the liquid flow. In the meantime, it was floated again, and fragments having a specific gravity of 1.0 to 1.1 were collected to increase the recovery rate.

  Here, the horizontal screw conveyor 10 is a ribbon type having a width of 30 mm, a pitch of 150 mm, and an outer diameter of 200 mm.

  Here, the re-levitation was performed by the stirring plate 13 attached to the screw conveyor 10. The stirring plate 13 was attached to the shaft of the screw conveyor 10. The gap between the stirring plate 13 and the screw on the feed direction side is about twice the size of the crushed pieces, a part of the crushed pieces is passed as it is, the discharge amount is controlled, and the number of the stirring plates 13 is eight. By setting the pitch at 60 degrees, the sediment to be sorted could be re-levitated 20 times efficiently.

  In addition, in order to prevent the object to be sorted having a high specific gravity from rising and flowing in the downstream direction by the stirring plate 13 and being floated again by the stirring plate 13 before settling, and flowing out from the drainage port 6, The stirring plate 13 was installed at a distance of 150 mm or more on the downstream side from the charging port.

  Further, the rotational speed of the shaft was set to 15 rpm so that the ribbon screw blade could operate without greatly disturbing the liquid flow and the discharged amount of the high specific gravity sedimented material was ensured.

  The stirring plate 13 was a stainless steel plate having a thickness of 0.3 mm and a width of 40 mm, and a 3 mm stainless steel square bar was used for the rib.

  By using a specific gravity separation device under the above conditions, plastic (ABS resin, polystyrene) having a specific gravity of 1.0 to 1.1 is discharged from the drain port 6 and recovered with a specific gravity accuracy of 98% and a recovery rate of 85%. We were able to.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the specific gravity separation apparatus of the present invention, it is possible to increase the number of times that the sedimented objects to be re-floated with a small-scale re-levitation means, and energy-saving, space-saving and high-precision specific gravity separation can be achieved. In addition, since water that is easy to handle can be used, a low-cost device can be supplied.

  Another object of the present invention is to provide a highly accurate recycled plastic raw material or recycled plastic molded body obtained by material recycling from plastic waste materials collected from the market by using the specific gravity separation device.

It is sectional drawing of the specific gravity separation apparatus which is one Embodiment of this invention. It is II-II sectional drawing in FIG. It is the figure which expanded the screw conveyor 10 in FIG. It is process drawing which shows one Embodiment of the specific gravity classification method of this invention.

Explanation of symbols

  1 Separation tank, 2 Specific gravity separation liquid, 3 Guide, 4 Water tank, 5 Sorted object, 6 Drainage port, 7 Input port, 8 Strainer, 9 Dehydrator, 10, 11 Screw conveyor, 12 Discharge port, 13 Stirring plate, 14 ribs, 15 PP guide, 16 pipes.

Claims (20)

In a specific gravity separation device that separates and collects a low specific gravity target and a high specific gravity target according to the difference in specific gravity,
(A) a separation tank storing the specific gravity separation liquid;
(B) supply means for supplying an object to be sorted to the separation tank;
(C) a liquid flow generating means for generating a substantially horizontal liquid flow in the specific gravity separation liquid;
(D) first conveying means for moving an object to be sorted having a low specific gravity in the liquid flow direction;
(E) A specific gravity separation device comprising second conveying means for moving a high-specific gravity sorting object that has settled below the specific gravity separation liquid in a direction opposite to the liquid flow.   2. The specific gravity separation device according to claim 1, which has a function of re-floating a low-specific gravity object to be settled below the specific gravity separation liquid.   The specific gravity separation device according to claim 1, wherein the object to be sorted is a crushed material of a plurality of types of plastic waste materials and / or metal waste materials having different specific gravities.   The specific gravity separation device according to claim 1, wherein the object to be sorted is a pulverized product of household electrical appliance waste selected from the group consisting of an air conditioner, a television, a refrigerator, and a washing machine. Each specific gravity difference between the specific gravity separation liquid, the low specific gravity target and the high specific gravity target is:
The specific gravity separation device according to claim 1, wherein a low specific gravity target <a specific gravity separation liquid <a high specific gravity target, or a specific gravity separation liquid <a low specific gravity target <a high specific gravity target.   The specific gravity separation device according to claim 1, wherein the liquid flow is generated by a negative pressure at a discharge port attached to the separation layer.   The specific gravity separation device according to claim 1, wherein the liquid flow is generated in a tunnel-type guide provided substantially horizontally in the separation tank.   The specific gravity separation device according to claim 1 or 2, wherein the second conveying means is a screw conveyor.   The specific gravity separation device according to claim 8, wherein the screw of the screw conveyor is a spirally wound ribbon-like blade.   The specific gravity separation device according to claim 9, wherein one or more stirring plates that synchronize with the screw and rotate along the inner peripheral surface of the screw guide are provided.   The specific gravity separation device according to claim 10, wherein a length from a rotation shaft to a tip of the stirring plate is longer than a radius of an outer peripheral circle of the screw blade.   The specific gravity separation apparatus according to claim 1, wherein a dehydrator for dehydrating the collected sorting object is incorporated.   A method for separating and collecting sorted objects using the specific gravity separation device according to claim 1. In a specific gravity separation method for separating and collecting a low specific gravity target and a high specific gravity target according to the difference in specific gravity,
A supply step of supplying the object to be sorted into a liquid flow flowing from one of the specific gravity separation liquids to the other;
A first transport step for transporting a low-specific gravity object to be sorted in the material to be moved to the other by the liquid flow;
A specific gravity separation method comprising: a second transporting step of transporting a high-specific gravity sorting object in the sorting object that has settled below the specific gravity separation liquid in a direction opposite to the flow of the liquid flow.   The specific gravity separation method according to claim 14, wherein in the second conveying step, the low-specific gravity sorting object included in the sedimented sorting object is re-floated to the liquid flow.   A waste disposal system incorporating the specific gravity separation device according to claim 1. In a waste disposal system incorporating the specific gravity separation device according to claim 16,
A sorting and collecting method, wherein the specific gravity sorting device according to claim 1 is incorporated after sorting objects to be sorted by wind power. In a waste disposal system incorporating the specific gravity separation device according to claim 16,
A separation and recovery method, wherein the specific gravity separation device according to claim 1 is incorporated after another wet specific gravity sorting of the object to be sorted.   A recycled plastic material made of plastic collected by the waste treatment system according to claim 16.   A recycled plastic molded body made of plastic recovered by the waste treatment system according to claim 16.

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