JP4422324B2 - Method and apparatus for separating and collecting waste plastics - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a method and an apparatus for separating waste plastics for separating, recovering and recycling waste plastics from a mixture of waste plastics and labels. In particular, it is suitable for separating labels from used PET bottles (polyethylene terephthalate containers) and collecting them as polyethylene terephthalate pieces.
[0002]
[Prior art]
Recovery of reusable resources from waste for resource protection, proper treatment and reuse, that is, recycling is a very important issue in modern society. In particular, plastics are not only recyclable, but also have a lot of environmental problems when used as waste as well as petroleum as a finite resource. By the way, waste plastics, including PET bottles that are being collected and collected, account for a large proportion of those used as containers for food, cosmetics, detergents, and the like. These collected waste plastics such as plastic bottles often contain labels and the like, so these mixed labels and the like are separated and recycled.
[0003]
[Problems to be solved by the invention]
The present invention researches the separation and recovery method and apparatus of rational waste plastics that have high separation efficiency and do not require equipment and operating costs when separating and recovering waste plastics from a mixture of waste plastics and labels. As a result, it was completed.
[0004]
[Means for Solving the Problems]
The present invention will be described with reference to the drawings illustrating the embodiments in order to help understanding thereof. In order to solve the above problems, the present invention is a method for separating and recovering waste plastic from a mixture of waste plastics and labels, etc., and first crushing the mixture to a required size by a dry crusher, Next, use a primary dry-type gravity classifier to separate and collect waste plastics on the heavy-weight side, and feed the mixture of labels, etc. separated on the light-weight side and the remaining waste plastics to the secondary dry-type gravity classifier. Labels are separated on the lighter side, labels on the lighter side are blown to a cyclone to discharge the labels from the lower part, and waste plastics and labels separated on the heavy side are dry crushed. Provided is a method for separating and recovering waste plastics, characterized by being refluxed in a machine. The labels separated on the light weight side in the secondary dry gravity classifier may be supplied to the second crusher, further crushed, reduced in volume, and recovered.
[0005]
Furthermore, the present invention is an apparatus for separating and recovering waste plastic from a mixture of waste plastics and labels, comprising a dry crusher 1 for crushing the mixture to a required size, and waste plastic in the crushed mixture. Primary dry gravity classifier 2 that separates and collects wastes on the heavy-weight side and separates the remaining waste plastics and labels, etc., on the light-weight side, and labels on the light-weight side. Secondary dry gravity classifier 3, cyclone 4 for separating and collecting separated labels from gas, waste plastics and labels separated on the heavy load side of secondary dry gravity classifier 3, etc. A separation / recovery device for waste plastics characterized by comprising a reflux piping system (5) that circulates to the supply side of the crusher (1). It is preferable to provide a second dry crusher 6 for crushing and reducing the volume of the separated labels on the light weight side of the secondary dry gravity classifier 3.
[0006]
As the primary dry gravity classifier 2 and / or the secondary dry gravity classifier, an upflow type can be preferably used. An aspirator type upflow gravity classifier is suitable as the primary dry gravity classifier, and a U-shaped duct type upflow gravity classifier is preferred as the secondary dry gravity classifier.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described with reference to the drawings illustrating the embodiments and examples. FIG. 1 is a flow sheet for explaining the configuration of a method (apparatus) for separating and recovering waste plastic from a mixture of waste plastics and labels according to the present invention. Waste plastics such as plastic bottles collected with the label or the like mixed can be separated and recovered from the label or the like using the present invention as it is or after being compressed and reduced in volume.
[0008]
Various means have been conventionally used for the separation of the two, but the present invention supplies waste plastic in order to make the mixture of waste plastics and labels collected for recycling easy to separate. After supplying the line crusher 1 to the dry crusher 1 and crushing, it separates both under a dry type using the wind kite efficiently. As the dry crusher 1 used in the present invention, one utilizing shearing is recommended, and a rotary cutter or the like can be preferably used. In order to efficiently carry out the wind blow, the screen 7 having an opening of about 30 mm is attached to the discharge side of the crusher 1 and the crushed material passed through may be sent to the primary dry gravity classifier 2 in the next step. In the present invention, there is no particular restriction on the workpiece transfer means between the processes, but it is convenient to provide a blower directly in the transfer path and carry the air flow. Depending on the situation, a screw conveyor or the like may be used.
[0009]
The crushed material transported by the air current is separated from the transported gas by a cyclone, and if necessary, it is supplied to the primary dry gravity classifier 2 using a wind fan using the rotary feeder 8. Wind separation is effective for separating waste plastics from labels, etc., especially wind flow due to upward flow. Waste plastics to be collected are on the heavy load side and labels are on the light load side. To separate. The recovered waste plastic is transported out of the system from the recovered plastic transport line 10. Examples of the dry gravity classifier 2 include an aspirator type used as a primary dry gravity classifier in the example of FIG. 1 and a U-shaped duct type upflow gravity classifier. In the present invention, it is important to adjust the operating conditions so that labels and the like are not mixed into the waste plastic separated and recovered on the heavy load side in the primary dry gravity classifier 2.
[0010]
An example of an aspirator-type dry gravity classifier is shown in a perspective view in FIG. In this dry gravity classifier, the cylinder 21 is conical, and a supply port 22 is provided in the middle of the cylinder 21. A blower 23 for an updraft is attached to the lower part of the body 21, and a blower 24 that also serves to transport a light-weight separated light is provided at the top, and gas is sucked into the body 21 from an intake port 25 provided near the bottom. An upward flow is formed. Since the upward flow becomes faster as it reaches the upper part in the cylinder 21, the crushed material introduced from the supply port 22 is taken out from the top part 26 of the cylinder by removing the light weight, that is, mainly the labels by the wind kite. Waste plastics are discharged from the heavy material outlet 27 at the bottom. Since the operating conditions are adjusted so that the labels do not mix with the heavy plastic waste plastic, the plastic waste enters the lightweight plastic. The crushing waste plastics taken out from the heavy material outlet 27 are transported to the next process outside the apparatus as recovered plastic. The labels and some residual crushing waste plastics are taken out from the light-weight outlet 26 and sent to the secondary dry gravity classifier 3.
[0011]
Labels and waste plastics sent to the secondary dry gravity classifier 3 are separated again by wind. The secondary dry gravity classifier 2 is preferably an upflow type as in the case of the primary dry gravity classifier 1. In the embodiment shown in FIG. 1, a U-shaped duct type upflow type gravity classifier 2 is used. Yes. In the secondary dry gravity classifier 3, labels are separated on the light weight side, and labels and crushed plastics are taken out from the heavy weight side. The separated labels are sent to the cyclone 4 to be separated from the carrier air current, and packed in, for example, the flexible container 9. The residual mixture taken out to the heavy material side is refluxed to the supply side of the dry pulverizer 1, and is crushed and separated again.
[0012]
FIG. 3 illustrates an outline of a U-shaped duct type upflow gravity classifier. This gravity classifier is composed of a cylindrical or rectangular tube duct whose body 31 is curved in a U shape, a supply port 32 at one end of the duct, and a heavy material outlet 33 separated at the bottom of the U shape at the other end. Is connected to the suction side of the suction blower 35 as a label outlet 34 in this example. A gas inlet 36 is provided upstream of the heavy object outlet 33, and an appropriate amount of gas is caused to flow from the gas inlet 36 into the U-shaped duct 31 by the suction blower 35. The object is separated mainly by wind. In the U-shaped duct, the labels rise to the straight pipe portion 37 by the rising gas, the heavy objects settle, and both are easily winded. The separated heavy article is taken out from the heavy article outlet 33, and the labels are taken out from the outlet 34 by the suction blower 35. Although it cannot be generally stated depending on the operating conditions, in a very general case, the gas flow rate in the U-shaped duct is preferably about 3 to 15 m / sec. Further, in a U-shaped duct type upflow gravity classifier, the separation efficiency can be improved by assembling U-shaped ducts in multiple stages.
[0013]
Furthermore, since the labels separated on the light weight side in the secondary dry gravity classifier 3 tend to be very bulky, a small second crusher 6 is provided for processing and volume reduction. It is good to carry to.
[0014]
【The invention's effect】
By utilizing the present invention, it is possible to separate and remove labels and the like from waste plastics in which label pieces and the like are mixed by a dry method, and efficiently and economically and efficiently recover and recycle the waste plastics. It is particularly suitable for recovering PET from waste PET bottles.
[Brief description of the drawings]
FIG. 1 is a flow sheet for explaining the configuration of a method (apparatus) for separating and recovering waste plastic from a mixture of waste plastics and labels according to the present invention. FIG. 2 is an aspirator type upflow gravity classifier. FIG. 3 is a perspective view showing an example of a U-shaped duct type upflow gravity classifier.
1: dry crusher 2: primary dry gravity classifier 3: secondary dry gravity classifier 4: cyclone 5: reflux piping system 6: second dry crusher 7: screen 8: rotary feeder 9: flexible container 10: recovered plastic Conveyance line 11: Waste plastic supply line 21: Cylinder 22: Supply port 23: Blower 24: Blower 25: Intake port 26: Lightweight material outlet 27: Heavy material outlet 31: Cylinder 32: Supply port 33: Removal of heavy material Outlet 34: Lightweight outlet 35: Suction blower 36: Gas inlet 37: Straight pipe

Claims (6)

A method of separating and recovering waste plastic from a mixture of waste plastics and labels, etc. First, the mixture is crushed to the required size by a dry crusher, and then the waste plastic etc. using a primary dry gravity classifier Is separated and collected on the heavy-weight side, and the label separated on the light-weight side and the mixture of the remaining waste plastics are sent to the secondary dry gravity classifier to separate the labels on the light-weight side. The waste side plastics are blown to a cyclone to discharge the labels from the lower part, and the waste plastics separated from the heavy load side and the labels are returned to the dry crusher. Separation and recovery methods. The method for separating and collecting waste plastics according to claim 1, wherein a label or the like separated on the light weight side in the secondary dry gravity classifier is supplied to the second crusher and further crushed and collected. A device for separating and recovering waste plastic from a mixture of waste plastics and labels, etc., which comprises a dry crusher (1) for crushing the mixture to a required size, and heavy waste plastics in the crushed mixture A primary dry gravity classifier (2) that separates and collects waste plastics and labels, etc., and separates the remaining waste plastics and labels into the lightweight object, and separates the labels into the lightweight object from the mixture on the lightweight object. The secondary dry gravity classifier (3), the cyclone (4) that separates and recovers the separated labels from the gas, the waste plastics and labels separated on the heavy load side of the secondary dry gravity classifier A separation / recovery device for waste plastics, characterized by comprising a reflux piping system (5) that circulates to the dry crusher supply side. Separation of waste plastics according to claim 3, characterized in that a second dry crusher (6) for crushing the separated labels is provided on the light weight side of the secondary dry gravity classifier. Recovery device. The apparatus for separating and collecting waste plastics according to claim 3 or 4, wherein an upflow type is used for the primary dry gravity classifier and / or the secondary dry gravity classifier. The aspirator type upflow type gravity classifier is used as the primary dry gravity classifier, and the U-shaped duct type upflow type gravity classifier is used as the secondary dry type gravity classifier. 4. A separation apparatus for waste plastics according to 4 or 5.

Images