JP2008284789A - Device and method for sorting pulverized plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for and a method of efficiently and accurately sorting a great amount of pulverized plastics without being affected by the properties, size and bulkiness of plastic raw materials. <P>SOLUTION: The sorting device 1 for the pulverized plastics includes a pneumatic sorting apparatus 3 which is provided with a suction blower 13 for making a suction wind C act on a raw material A and roughly divides the raw material into sucked lightweight plastics D and non-sucked heavy plastics E, a volumetric feed apparatus 5 provided with a metering drum 23 capable of storing a definite amount of lightweight plastic pieces D and a freely openable damper 25 installed at the bottom of the metering drum 23, a granulator 7 which is provided in such a state as to communicate with the volumetric feeder 5 and granulates the low-melting point lightweight plastic pieces D after melting, and a gravitational sorting apparatus 11 which utilizes the vibration of a slanted vibrating air table to classify the lightweight plastic pieces D into a granulated pieces and non-granulated ones. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pulverized plastic sorting apparatus and a sorting method for sorting crushed plastic into plastics of the same type in an environment where different types of plastic pieces are crushed and mixed.

Recently, plastic containers made from polyethylene terephthalate (hereinafter referred to as PET) called “pet bottles” as beverage bottle containers have become widespread, and used garbage disposal has become a problem.
PET bottles are made of PET, caps are mainly polypropylene (hereinafter referred to as PP), some are polyethylene, labels are mainly polystyrene (hereinafter referred to as PS), and some are PET. It is made of plastic material.
Some PET bottles are separated and collected into bottle bodies, caps, and labels in the state of bottle containers, and are reused as individual recycled plastic raw materials.

However, in reality, many PET bottles exist as pulverized plastics that are discarded as bottle containers and are processed by a pulverizer to be processed into plastic pieces in which the above three types of plastics are mixed.
And in order to take out individual recycled plastic raw materials from such crushed plastic, a sorting method using air blowing that separates into those that soar by blowing and those that do not soar, those that float on the water and those that sink in the water A plastic piece is sorted by independently or appropriately combining a sorting method using a wet method, a sorting method using a specific gravity difference, and the like.
Recently, a part of the sorting method using the difference in melting point of plastic raw materials has been adopted.

On the other hand, the above-mentioned three types of plastic materials constituting the plastic bottle have the property of being easily charged and sticking. In addition, used PET bottles have a high moisture content, and since the label is in the form of a film, it has the property of being easily adsorbed by the influence of moisture.
In addition, the crushed plastic has a mixture of coarsely pulverized and coarsely pulverized levels, and there is a difference in the bulkiness due to the difference in the content of the above three types of plastic materials contained in the PET bottles. It was.
Therefore, because of such properties of pulverized plastics, it is not easy to take out individual recycled plastic raw materials from the pulverized plastics even when the above three types of sorting methods are combined. In addition to the large amount of residue, these were incinerated and used as a heat source.

According to the conventional method for selecting pulverized plastic, there are the following problems.
First, the sorting method using air blowing has a problem that it is difficult to make a difference in the state of a plastic piece. Moreover, the wet sorting method for separating the pulverized plastic by floating it in water is applicable when the size of the pulverized plastic is usually about 8 to 12 mm, and there is a problem that it is difficult to make a difference when the pulverized plastic becomes smaller. .
Further, the sorting method using the difference in specific gravity is not easy to take out individual recycled plastic materials from the pulverized plastic mixed with PET, PP, and PS because of the property of being easily charged with static electricity and easily adsorbed by moisture.

On the other hand, since the sorting method using the difference in melting point of the plastic raw material is performed in a dry method, there is no problem of adsorption due to moisture as described above, but there is a problem in terms of processing capacity because it becomes a complete batch method, and further, PET, It was easily affected by the difference in bulkiness due to the difference in PP and PS contents, and had a problem that the granulation was likely to vary.
In addition, since the sizes of the granulated material and the non-granulated material vary, there is also a problem that it is difficult to accurately separate them.

  The present invention has been made on the basis of these points, and the object of the present invention is to select a large amount of pulverized plastic efficiently and accurately without being affected by differences in properties, size and bulkiness of the plastic raw material. It is an object of the present invention to provide a ground plastic sorting apparatus and sorting method that can be carried out.

  In order to achieve the above object, the pulverized plastic sorting apparatus according to claim 1 of the present invention uses a mixture of different types of plastic pieces in a pulverized state as raw materials, and sorts the raw materials into plastics of the same type. In the pulverized plastic sorting device, which can be taken out as an individual recycled plastic raw material, it is provided with an intake blower that causes suction air to act on the raw material, and is roughly divided into a lightweight plastic piece that is sucked and a heavy plastic piece that is not sucked. Provided in communication with the wind power sorter, a metering drum capable of storing a certain amount of the lightweight plastic piece, an openable / closable damper provided on the bottom surface of the metering drum, and in communication with the metering feeder , Stir while heating the supplied lightweight plastic pieces, melting temperature of low melting lightweight plastic pieces A granulator that melts and granulates only a low-melting light-weight plastic piece by quenching in the vicinity, and a granulated low-melting-point lightweight plastic piece and a non-granulated high-melting-point lightweight plastic piece are inclined. And a specific gravity difference sorting device that performs classification using vibration of a vibration air table provided in a posture.

  A ground plastic sorting device according to claim 2 is the ground plastic sorting device according to claim 1, wherein the ground plastic sorting device is not granulated with the granulated low melting point lightweight plastic piece. Further, the present invention is characterized in that a vibration sieve sorting device for classifying high-melting-point lightweight plastic pieces according to size is provided.

  According to a third aspect of the present invention, there is provided the ground plastic sorting apparatus according to the first or second aspect, wherein the weighing drum includes an opening / closing driving means for performing an opening / closing operation of a damper and the opening / closing driving means. A timer that measures the time since the damper is in the open state and closes the damper after a predetermined time has elapsed, and a lower level switch that sets the level of the lightweight plastic piece placed in the granulator It is characterized by being.

  According to a fourth aspect of the present invention, there is provided a pulverized plastic sorting device according to any one of the first to third aspects, wherein the weighing drum is configured to blow off a lightweight plastic piece deposited near the rotation fulcrum of the damper. The air jetting means for removing is provided.

  A ground plastic sorting device according to claim 5 is the ground plastic sorting device according to any one of claims 1 to 4, wherein the different types of plastic pieces are high melting point polyethylene terephthalate and polypropylene, and low melting point. This is a plastic piece made of polystyrene, and is characterized in that the melting temperature of polystyrene is set to 105 ° C to 120 ° C.

  According to a sixth aspect of the present invention, there is provided a method for sorting pulverized plastics, wherein different types of plastic pieces are mixed in a pulverized state as raw materials, and the raw materials are sorted into the same types of plastics to obtain individual recycled plastic raw materials. In the method of sorting pulverized plastic that can be taken out as follows, a wind power sorting step roughly divided into a lightweight plastic piece sucked by applying suction air to the raw material and a heavy plastic piece not sucked, and the lightweight plastic piece A fixed quantity supply that feeds a fixed amount at a time, stirs the supplied lightweight plastic pieces while heating them, and rapidly cools them around the melting temperature of the low melting point lightweight plastic pieces, thereby melting and granulating only the low melting point lightweight plastic pieces. Granulation process, granulated low-melting light-weight plastic pieces and non-granulated high And it is characterized in that it comprises a gravity difference sorting step of classifying by utilizing the vibration of the vibrating air table provided a lightweight plastic pieces of the point in an inclined position, the.

  A method for sorting ground plastic according to claim 7 is the method for sorting ground plastic according to claim 6, wherein the granulated low melting point is provided between the quantitative supply / granulation step and the specific gravity difference sorting step. The light-weight plastic piece and a high-melting-point light weight plastic piece that has not been granulated are classified by size using a vibration sieve.

  Further, the method for sorting ground plastic according to claim 8 is the method for sorting ground plastic according to claim 6 or 7, wherein the level of the lightweight plastic piece charged in the granulating device is set in the quantitative supply / granulation step. After detection, agitation of the lightweight plastic piece is started, and when heated to the predetermined temperature, water is injected and rapidly cooled to perform granulation. During this time, supply of the lightweight plastic piece to the granulator is continued. Then, after discharging the lightweight plastic pieces in the granulating apparatus after granulation, the supply of the lightweight plastic pieces to the granulating apparatus is resumed.

  A method for sorting ground plastic according to claim 9 is the ground plastic sorting method according to any one of claims 6 to 8, wherein the different types of plastic pieces are high melting point polyethylene terephthalate and polypropylene, and low melting point. This is a plastic piece made of polystyrene, and is characterized in that the melting temperature of polystyrene is set to 105 ° C to 120 ° C.

  The following actions are obtained by the above means. First, it is divided roughly into a lightweight plastic piece that is sucked by applying suction air to a raw material in which different types of plastic pieces are mixed, and a heavy plastic piece that is not sucked. When the plastic pieces mixed in the raw material are PET, PP, and PS, the light plastic pieces contain a lot of PS, and the PS contains a little amount of PET. On the other hand, heavy plastic pieces contain a large amount of PET and PP, and some of these contain PS.

  Next, the above-mentioned lightweight plastic piece is put into a fixed amount supply device, and a certain amount of the lightweight plastic piece is supplied to the granulating device. When the lightweight plastic piece charged in the metering supply device reaches a predetermined level of the granulating device, the stirring blade of the granulating device starts to rotate, and the supplied lightweight plastic piece is heated and stirred. . To supply a certain amount of lightweight plastic pieces to the granulator, first, the damper is opened, the timer is activated when the lower limit level switch reacts, and the lightweight plastic pieces deposited near the rotation fulcrum of the damper when the timer expires. The air is jetted and blown off, and then the damper is closed to supply a predetermined amount of a lightweight plastic piece to the granulator. The temperature inside the heating tank rises due to frictional heat generated by stirring, and when the lightweight plastic piece in the heating tank is heated to near the melting temperature of the low-melting lightweight plastic piece, water is poured into the heating tank and rapidly cooled. . By the above operation, only the low-melting-point lightweight plastic piece is melted and granulated. In addition, when a lot of PS is contained in the lightweight plastic piece and PET is contained in the PS, only PS having a melting point lower than that of PET is granulated.

The lightweight plastic piece after the granulation is performed is discharged from the heating tank and supplied to the next step. At the same time, the damper opens and the next lightweight plastic piece is supplied into the heating tank.
Therefore, since the lightweight plastic pieces are always continuously supplied in the measuring drum, a small amount of the lightweight plastic pieces is temporarily stored in the measuring drum, and bridges due to a large amount of accumulation are prevented. A certain amount of lightweight plastic pieces are continuously supplied to the granulator successively, and the granulation of the low melting point lightweight plastic pieces and the discharge of the lightweight plastic pieces are repeated.

  Next, the granulated low-melting-point lightweight plastic piece and the non-granulated high-melting-point lightweight plastic piece are supplied to the specific gravity difference sorting device, and the vibration of the vibrating air table provided in an inclined posture is used. It classify | categorizes into the said lightweight plastic piece granulated and the lightweight plastic piece which was not granulated. In addition, the above-mentioned two types of lightweight plastic pieces supplied into the vibration air table moved upward so that the granulated low-melting-point lightweight plastic pieces with a high specific gravity climbed the hill, and were not granulated with a low specific gravity. A high-melting-point lightweight plastic piece moves down on a slope.

It is also possible to apply the light plastic piece after granulation to the vibration sieve sorting device before carrying out the above specific gravity difference sorting. In this case, the lightweight plastic pieces are classified according to size by the sieve provided in the vibration sieve sorting device.
Therefore, it becomes possible to supply a lightweight plastic piece having a uniform size to the specific gravity difference sorting device, and the accuracy of sorting by the specific gravity difference sorting device is improved.

According to the pulverized plastic sorting apparatus of the present invention, by first applying a suction air to the raw material, it can be roughly classified into a lightweight plastic piece and a heavy plastic piece, and the subsequent sorting is performed using the lightweight plastic piece. Since it did in this way, the precision of the sorting by the granulation performed after that and specific gravity improves.
In addition, the lightweight plastic pieces are supplied to the granulator by a fixed amount by a fixed quantity supply device, so that granulation can be performed efficiently while keeping the amount of the lightweight plastic pieces in the measuring drum small. The processing amount of the obtained lightweight plastic piece can be remarkably increased.

In addition, when the light weight plastic pieces after granulation are applied to the vibrating screen sorter prior to the specific gravity difference sorting, the light weight plastic pieces are classified according to size, so the accuracy of sorting in the specific gravity difference sorter Can be improved.
In particular, it becomes possible to efficiently and accurately carry out sorting of pulverized plastics from a large number of bet bottles without being affected by differences in properties, sizes, and bulkiness of the plastic raw materials PET, PP, and PS.
The same effect is also achieved by the method for sorting pulverized plastics of the present invention, and a large amount of crushed plastics can be sorted efficiently and accurately without being affected by differences in properties, sizes and bulkiness of the plastic raw materials. It becomes possible to execute.

  The best mode for carrying out the present invention will be described below by taking the illustrated embodiment as an example. FIG. 1 is a front view showing the overall configuration of a pulverized plastic sorting apparatus of the present invention, FIG. 2 is the same as above, a plan view, FIG. 3 is a front view showing a wind power sorting apparatus, FIG. 4 is the same as above, and is a plan view. FIG. 6 is a front view showing the fixed amount supply device, FIG. 7 is the same as above, a side view, FIG. 8 is the same as above, FIG. 8 is a front view showing the periphery of the opening / closing drive means, and FIG. FIG. 10 is a plan view showing the arrangement of the vibrating screen sorting device and the specific gravity difference sorting device, FIG. 11 is a front view showing the vibrating screen sorting device, FIG. 12 is the same as the above, a side view, and FIG. 13 is the specific gravity difference sorting device. FIG. 14 is a side view, FIG. 14 is an explanatory view showing a piping route from the wind power sorting device to the granulation device, and FIG. 15 is a combination of the piping route from the vibration sieve sorting device to the specific gravity difference sorting device and the sorting route of the sorted plastic pieces. It is explanatory drawing shown. FIG. 16 is an explanatory view schematically showing how the crushed plastic selected by the pulverized plastic sorting method of the present invention is selected. FIG. 17 is a flowchart showing an operation sequence of the pulverized plastic sorting apparatus.

The pulverized plastic sorting device 1 of the present invention uses a mixture of different types of plastic pieces in a pulverized state as a raw material A, and sorts the raw material A into plastics of the same type to obtain individual recycled plastic raw materials. It can be taken out as B.
In the following description, three types of plastic pieces of PET, PP, and PS constituting a plastic bottle will be described as an example of the different types of plastic pieces. As shown in FIG. 16, the raw material A includes a coarse raw material A1, pulverized by a pulverizer or the like (not shown), a fine raw material A2, or a residue that could not be sorted by another sorting device or the like.

The ground plastic sorting device 1 according to the present embodiment includes a wind power sorting device 3, a quantitative supply device 5, a granulating device 7, a vibrating sieve sorting device 9, and a specific gravity difference sorting device 11. Has been.
The wind power sorter 3 includes an intake blower 13 that causes the suction air C to act on the raw material A, a transport portion 15 through which the sucked lightweight plastic piece D passes, and a discharge portion through which the heavy plastic piece E that is not sucked and falls by its own weight passes. 17. A suction port 19 is provided on the side surface of the discharge unit 17, and the transport unit 15 and the intake blower 13 are connected by a relay duct 21. Further, a pre-duster cyclone (not shown) is provided between the relay duct 21 and the transport unit 15 to prevent the sucked lightweight plastic piece D from entering the relay duct 21 side.

In the present embodiment, a large amount of PS is contained as the lightweight plastic piece D, and a plastic piece in which PET is mixed somewhat in the PS is taken out. Further, as the heavy plastic piece E, a lot of PET and PP are contained, and a plastic piece in which PS is somewhat mixed is taken out.
In addition, since most of the heavy plastic pieces E are PET and PP and PS are only slightly contained, they can be reused as recycled plastic raw materials B as they are, or further sorted, and more PET Recycled as recycled plastic material B with increased purity.
On the other hand, the lightweight plastic piece D is continuously fed into the quantitative supply device 5 described below.

The fixed amount supply device 5 includes a measuring drum 23 that can store a certain amount of the lightweight plastic piece D to be charged, and an openable and closable damper 25 provided on the bottom surface of the measuring drum 23.
The measuring drum 23 is a cylindrical member having an upper surface constituted by a closed surface connected to the cyclone 24 and an open lower surface. The heating drum in the granulating device 7 is provided in the peripheral drum portion of the lower portion of the measuring drum 23 from the measuring drum 23. There is provided a lower limit level switch 27 for setting the level of the lightweight plastic piece D put into the 45.
In addition, an upper limit level switch 29 for setting an upper limit level of the lightweight plastic piece D put into the measuring drum 23 is provided on the upper peripheral drum portion of the measuring drum 23.

The lower limit level switch 27 and the upper limit level switch 29 are constituted by a torque type level sensor with a rotating blade at the tip, and in a state where the lightweight plastic piece D continues to rotate in a state of falling and flowing from above, It is set so that the lightweight plastic piece D is accumulated and the rotating blades are loaded and turned on.
Note that the position of the lower limit level is set near the lower end of the measuring drum 23. When the lightweight plastic piece D accumulates to the lower limit level, the weight becomes approximately 30 kg, and then a predetermined time (200 to 240 seconds) is set by a timer. About 10 kg is added to a total weight of about 40 kg. Further, when the lightweight plastic pieces D are accumulated up to the upper limit level, the lightweight plastic pieces D are clogged in the measuring drum 23 and a bridge is formed. Therefore, the quantitative supply is continuously performed to the granulating apparatus 7 while maintaining a range not exceeding this. It has come to be.

In addition, an opening / closing driving means 31 for performing an opening / closing operation of the damper 25 is provided on the peripheral body portion on the front side of the measuring drum 23. The opening / closing drive means 31 includes an air cylinder 33 attached downward, a cylinder rod 35 protruding and retracting from the air cylinder 33, and a link mechanism 37 that converts linear motion of the cylinder rod 35 into rotational motion of the damper 25. It is configured.
The link mechanism 37 has a fixed link 39 fixedly attached to the tip of the cylinder rod 35 and a first movable link 41 having one end rotatably connected to the fixed link 39 and extending downward. And one end of the first movable link 41 is rotatably connected to the other end of the first movable link 41, and the other end is connected to the rotation fulcrum O of the damper 25 to rotate together with the damper 25. Yes.

In addition to this, the measuring drum 23 is supplied with a timer T1 (not shown) for measuring the time after the lower limit level switch 27 reacts, and water W for rapid cooling in a heating tank 45 in the granulating apparatus 7 described below. A water supply tank 47 for supplying water and a nozzle 49 serving as an inlet for water W are provided.
In addition, a steam exhaust device 51 for discharging steam S generated by supplying water W to the outside is connected.
Further, the damper 25 is constituted by two wing pieces having a semi-disc shape, and closes the bottom surface of the measuring drum 23 in a horizontally opened state, and covers the bottom surface of the measuring drum 23 in a folded state. It is designed to expand.

  The measuring drum 23 is provided with air injection means 115 for blowing away and removing the lightweight plastic pieces D deposited near the rotation fulcrum O of the damper 25. The air injection means 115 distributes the compressed air supplied from the air tank 117 and the air tank 117 installed in the peripheral drum portion on one side surface of the measuring drum 23 in two directions, and suppresses supply of compressed air and stoppage of supply. For example, four introduction pipes 121 for introducing the compressed air supplied from the air tank 117 through the electromagnetic valve 119 into the measuring drum 23, and four pipes for directing the introduction pipe 121 downward. The nozzle 123 is provided.

  The granulating device 7 includes a heating tank 45 provided below the measuring drum 23 so as to communicate with the measuring drum 23, a stirring blade 53 for stirring the lightweight plastic piece D in the heating tank 45, and the stirring A rotation drive mechanism 55 for rotating the blades 53, a discharge port 57 for discharging the lightweight plastic piece D after granulation, a shutter plate 59 for opening and closing the discharge port 57, and an operation for operating the shutter plate 59 Means 61. Further, the water supply tank 47, the nozzle 49 and the steam exhaust device 51 are also part of the constituent members constituting the granulating device 7.

The heating tank 45 has a two-tank structure, and oil heated to 100 ° C. to 120 ° C. is constantly circulated in the space formed between them.
A temperature sensor 113 is attached to the heating tank 45. Further, a timer T2 (not shown) for measuring the time after the temperature sensor 113 has reacted is provided.
The operating means 61 that operates the shutter plate 59 that opens and closes the discharge port 57 is provided with a timer T3 (not shown) that measures the time after the operating means 61 opens.
The stirring blade 53 has two blades that are somewhat curved in the plane direction and the vertical direction and are arranged with a phase difference of 180 °, and the stirring blade 53 having the same configuration has a phase difference of 90 °. The upper and lower two are provided. The two stirring blades 53 are attached to the upper portion of the rotating shaft 63 that penetrates the bottom surface of the heating tank 45.
The rotation drive mechanism 55 includes a drive motor 65, an output shaft of the drive motor 65, and a drive transmission mechanism 67 provided between the rotation shaft 63.

  The vibration sieve sorting device 9 includes a hopper 71 provided at the upper part of the machine frame 69, a vibration trough 73 provided in an inclined posture, and two sieves 75, 77 provided in two stages in the vibration trough 73. And a vibration device 79 for vibrating the vibration trough 73, and three kinds of lightweight plastic pieces D having different particle sizes or sizes, which are screened by the two sieves 75, 77, are accommodated in a bag body 81, Or it is comprised by providing the three types of discharge chute 83, 85, 87 for supplying to the specific gravity difference sorting apparatus 11 described below.

The sieves 75 and 77 are formed as an example by a rectangular flat plate punching metal, and the sieve 75 arranged in the upper stage is for coarse and has many holes (not shown) having a diameter of 4 to 5 mm, for example, 4.5 mm. . On the other hand, the sieve 77 arranged in the lower stage is for fine use and has a number of holes (not shown) having a diameter of 1 to 3 mm, for example, 2.9 mm. Of course, the sieves 75 and 77 may be mesh-shaped in place of the rectangular flat plate punching metal.
Accordingly, the light-weight plastic piece D having a particle diameter or a size larger than 4.5 mm is supplied to the coarse discharge chute 83 arranged in the upper stage, and the medium discharge chute arranged in the middle stage. 85 is supplied with a lightweight plastic piece D having a particle size or size larger than 2.9 mm but not larger than 4.5 mm, and the fine discharge chute 87 arranged at the lower stage has a particle size or size 2. A lightweight plastic piece D of 9 mm or less is supplied.

  The specific gravity difference sorting device 11 includes a hopper 91 provided at the upper part of the machine casing 89, a vibration air table 93 provided in an inclined posture, a vibration generator 95 for vibrating the vibration air table 93, and a vibration air table 93. A wind tunnel 97 disposed below, a fan motor 99 for driving a fan (not shown) provided in the wind tunnel 97, and a granulation with a high melting point and a low specific gravity connected to the downstream end of the vibration air table 93. A discharge chute 101 for low specific gravity for discharging the light weight plastic piece D that has not been connected, and an upstream end of the vibration air table 93, and a granulated lightweight plastic piece D having a large specific gravity and a low melting point is discharged. And a discharge chute 103 for high specific gravity.

In addition, although the lightweight plastic piece D cannot pass through the bottom part of the said vibration air table 93, the ventilation structure which is not shown in figure through which the ventilation F blown up from the said wind tunnel 97 can pass is provided. In addition, a quantitative supply feeder 88 for introducing a lightweight plastic piece D discharged from the medium-sized discharge chute 85 of the vibrating screen sorting device 9 is provided in the front stage of the hopper 91, and there is a slight change in the amount by vibrating screen sorting. The specific gravity difference sorting is stabilized by quantitatively supplying the generated lightweight plastic pieces D.
The upper surface of the vibration air table 93 is covered with a hood 105. The hood 105 is provided with the hopper 91, a dust collection duct 107, and an inspection window 109 for inspection. The dust collection duct 107 is connected to the dust collector 108, sucks and discharges the air in the hood 105, and the residue is stored in the bag body 81.

Next, the pulverized plastic sorting method of the present invention, which is executed by using the pulverized plastic sorting apparatus 1 of the present invention configured as described above, will be described.
In the following description, as in the above-described pulverized plastic sorting apparatus 1, three types of plastic pieces of PET, PP, and PS mainly constituting a plastic bottle will be described as examples of different types of plastic pieces. As shown in FIG. 16, the raw material A to be selected includes coarse raw material A1, pulverized by a pulverizer (not shown), fine raw material A2, or residue that could not be selected by other sorting devices. It is.

The method for sorting pulverized plastic according to the present embodiment includes (1) wind sorting process, (2) quantitative supply / granulation process, (3) vibrating sieve sorting process, and (4) specific gravity difference sorting process in order. It is configured by executing.
(1) Wind power selection process (see FIGS. 3-5, 14, 16)
The wind sorting process is a process roughly classified into a lightweight plastic piece D sucked by applying a suction wind C to the raw material A and a heavy plastic piece E not sucked.
In this step, the above-described wind sorting device 3 is used. The raw material A put into the wind power sorter 3 is sucked by the action of the suction wind C formed by driving the intake blower 13, and the lightweight plastic piece D containing a large amount of PS with a low specific gravity is sucked. It is supplied to the quantitative supply and granulation process of the next process.
On the other hand, the heavy plastic piece E containing a lot of heavy PET is dropped downward by its own weight, and is discharged to the outside through the discharge portion 17.

(2) Quantitative supply / granulation process (see FIGS. 6-9, 14, 16)
In the quantitative supply / granulation process, a small amount of light plastic pieces D containing a large amount of PS roughly classified by the above-described wind sorting process are supplied in a certain amount, and the supplied light plastic pieces D are stirred while being heated to a predetermined temperature. Then, it is a step of granulating after melting the lightweight plastic piece D having a low melting point by rapid cooling.
In this step, the above-described quantitative supply device 5 and granulation device 7 are used, and the operation thereof is shown in the flowchart of FIG. First, the damper 25 is opened. The lightweight plastic piece D supplied by pneumatic feeding from the previous process is continuously charged into the measuring drum 23, and the damper 25 is added to the granulating device 7 positioned below through the opened lower surface of the measuring drum 23 in the open state. It is supplied into the warm bath 45.

When the supply of the lightweight plastic piece D proceeds and the lightweight plastic piece D reaches the lower limit level of the measuring drum 23, the lower limit level switch 27 reacts, the rotation drive mechanism 55 starts to be driven, and is attached to the upper part of the rotating shaft 63. The two stirring blades 53 and 53 are rotated.
The lightweight plastic piece D in the heating tank 45 is heated to about 114 ° C. by the heat from the heating tank 45 and the frictional heat generated by rotating the stirring blade 53.
In addition, the timer T1 is activated simultaneously with the reaction of the lower limit level switch 27, and after about 200 seconds (can be arbitrarily set in 200 to 240 seconds as described above), the cylinder rod 35 of the air cylinder 33 is extended to be a damper. 25 is closed and the supply of the lightweight plastic piece D to the heating tank 45 is temporarily stopped. The amount of the lightweight plastic piece D in the heating tank 45 is set to about 40 kg. Even when the damper 25 is closed, the lightweight plastic piece D is continuously fed until the upper limit level switch 29 reacts.

  Simultaneously with the time-up of the timer T1, compressed air is supplied from the air tank 117 to the nozzle 123 through the electromagnetic valve 119 and the introduction pipe 121, and is applied to the lightweight plastic piece D accumulated near the rotation fulcrum O of the damper 25. Air is jetted towards. Along with this, the lightweight plastic piece D deposited near the rotation fulcrum O of the damper 25 is blown off and falls downward, and the damper 25 is prevented from being caught by the lightweight plastic piece D near the rotation fulcrum O. In the state, it shifts to the closing operation.

And when the temperature in the heating tank 45 rises and it is confirmed by the temperature sensor 113 that the lightweight plastic piece D in the heating tank 45 is heated to about 114 ° C., 5-10 as an example in the heating tank 45. Injecting liters of water, the temperature in the heating tank 45 is rapidly cooled. The low melting point PS is melted and semi-gelled by the above operation, and then solidified and granulated by rapid cooling.
At the same time, when the timer T2 (not shown) is turned on and the timer T2 is turned off after a predetermined time has elapsed, the lightweight plastic piece D after the granulation is performed operates the operating means 61 in a predetermined direction to move the shutter plate 59. Is opened to the outside through the discharge port 57, conveyed upward by the vertical conveyor 111, and guided to the next vibration sieve selection step.

At the same time when the shutter plate 59 is opened, a timer T3 (not shown) is turned on. When the timer T3 is turned off after a predetermined time has elapsed, the operation means 61 is operated in the reverse direction to close the shutter plate 59. State. Normally, this closed state is detected, an open signal is output to the damper 25, and the next lightweight plastic piece D is supplied into the heating tank 45.
Therefore, a small amount of light plastic pieces D continuously supplied during the granulation step are temporarily stored in the measuring drum 23, and a large amount of light plastic pieces D are accumulated at a time. Bridging is prevented, and a certain amount of the lightweight plastic piece D is supplied into the heating tank 45 almost continuously, and the granulation of the low melting point lightweight plastic piece D and the discharge of the lightweight plastic piece D are repeated. ing.
When the amount of the lightweight plastic piece D in the measuring drum 23 is inadvertently increased and reaches the upper limit level, the upper limit level switch 29 is turned on, and the introduction of the lightweight plastic piece D into the measuring drum 23 is stopped. It is supposed to be.

(3) Vibrating sieve selection process (see FIGS. 10-12, 15, 16)
Vibrating sieve sorting process uses vibrating sieve of PS, which is a low-melting-point lightweight plastic piece D granulated by the above quantitative supply / granulation process, and PET, which is a high-melting-point lightweight plastic piece D, that has not been granulated Then, it is a process of classifying by size.
In this step, the above-described vibrating screen sorting device 9 is used. That is, the lightweight plastic piece D conveyed upward by the vertical conveyor 111 is put into the hopper 71 and supplied into the vibration trough 73 that is vibrated by the vibration generator 79.

The light plastic piece D supplied into the vibration trough 73 is screened by a coarse screen 75 and a fine screen 77. For example, the light plastic piece D having a particle diameter or size exceeding 4.5 mm is used for the coarse screen. It is temporarily stored in the bag 81 through the discharge chute 83.
Further, as an example, a lightweight plastic piece D having a particle size or size exceeding 2.9 mm and not more than 4.5 mm is directly supplied to the next specific gravity difference sorting step through the discharge chute 85 for the medium mesh. A lightweight plastic piece D having a particle size or size of 2.9 mm or less is stored in another bag body 81 through a fine discharge chute 87. In addition, what is not selected (which cannot be a raw material) is separately stored in the same bag 81 as the coarse discharge chute 83.

(4) Specific gravity difference selection process (see FIGS. 13, 15, and 16)
The specific gravity difference sorting step classifies the granulated low-melting-point lightweight plastic piece D and the non-granulated high-melting-point lightweight plastic piece D using the vibration of the vibrating air table 93 provided in an inclined posture. It is a process.
In this step, the above-described specific gravity difference sorting device 11 is used. A lightweight plastic piece D having a particle size or size of more than 2.9 mm and not more than 4.5 mm discharged through a discharge chute 85 for medium eyes passes through a quantitative supply feeder 88 and is a hopper in the specific gravity difference sorting device 11. A fixed amount is supplied in 91.
The lightweight plastic piece D put into the hopper 91 falls into the lower vibration air table 93 and is lifted up somewhat by the air blow F from the wind tunnel 97. Further, the vibration from the vibration generator 95 causes the following. To move.

That is, the above-mentioned two kinds of lightweight plastic pieces D supplied into the vibrating air table 93 moved upward so that the granulated low melting point PS having a high specific gravity climbs the slope, and was not granulated with a low specific gravity. The high melting point PET moves downward so as to slide down the slope.
The PS is stored in the bag 81 through the discharge chute 103 for high specific gravity, and the PET is stored in another bag 81 through the discharge chute 101 for low specific gravity.
The lightweight plastic piece D taken out from the middle-eye discharge chute 85 was taken out from the coarse-grain discharge chute 83 temporarily stored in the bag 81 by the vibration sieve sorting step after the specific gravity difference sorting. The lightweight plastic piece D is put into the hopper 91 of the specific gravity difference sorter 11, and the specific gravity difference sort is executed by the same procedure to sort into PS and PET.

As described above, according to the present embodiment, the following effects can be obtained.
According to the pulverized plastic sorting apparatus 1 according to the present embodiment, by first applying the suction air C to the raw material A, it can be roughly divided into a lightweight plastic piece D and a heavy plastic piece E, and among these, the lightweight plastic piece D Since the subsequent sorting is performed using the above, the accuracy of sorting by the subsequent granulation, vibration sieve and specific gravity difference is improved.
Further, the lightweight plastic pieces D are supplied to the granulating device 7 by a fixed amount by the fixed amount supply device 5 so that the granulation can be efficiently performed in a state where the amount of the lightweight plastic pieces D in the measuring drum 23 is kept small. Therefore, it is possible to prevent a bridge resulting from the accumulation of a large amount of lightweight plastic pieces D in the measuring drum 23, and as a result, the processing amount of the lightweight plastic pieces D that can be selected can be significantly increased.

Further, by applying the light weight plastic piece D after granulation execution to the vibration sieve sorting device 9 prior to the specific gravity difference sorting, the light weight plastic piece D is classified according to the size. Sorting accuracy is improved.
In particular, according to the pulverized plastic sorting apparatus 1 of the present invention, the selection of crushed plastic from a large amount of PET bottles is affected by differences in the properties, sizes, and bulkiness of the plastic raw materials PET, PP, and PS. Can be executed efficiently and accurately.
In addition, the same effect is obtained by the method for selecting pulverized plastic according to the present embodiment, and a large amount of pulverized plastic is selected by the difference in properties, sizes, and bulkiness of each of the plastic raw materials PET, PP, and PS. It can be executed efficiently and accurately without being affected by.

The pulverized plastic sorting apparatus 1 and the crushed plastic sorting method of the present invention are not limited to those of the above-described embodiments, and design changes can be made within the scope of the invention. For example, when there is no variation in the size of the raw material A and the shapes are uniform, the vibration sieve sorting device 9 or the vibration sieve sorting process can be omitted.
Further, a part of the light weight plastic piece D having a different size, which has been screened in the vibration screen sorting device 9 or the vibration screen sorting process, is not temporarily stored in the bag body 81 but temporarily stored in a stock tank or the like (not shown). In this case, it is also possible to sequentially supply the specific gravity difference sorting device 11 to the specific gravity difference sorting process.
In addition, the sensor for setting the lower limit level and the upper limit level of the measuring drum 23 is not limited to the torque type sensor described above, and various types of sensors can be applied.

  INDUSTRIAL APPLICABILITY The present invention can be used in the manufacture and field of use of a pulverized plastic sorting apparatus that sorts pulverized plastic into the same type of plastic in an environment where different types of plastic pieces are pulverized and mixed. It has applicability in the field of sorting and recycling for bottles.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows embodiment of this invention, and is a front view which shows the whole structure of the sorting apparatus of a grinding | pulverization plastic. It is a figure which shows embodiment of this invention, and is a top view which shows the whole structure of the grinding | pulverization plastics sorting apparatus. It is a figure which shows embodiment of this invention, and is a front view which shows a wind power sorter. It is a figure which shows embodiment of this invention, and is a top view which shows a wind power sorter. It is a figure which shows embodiment of this invention, and is a side view which shows a wind power sorter. It is a figure which shows embodiment of this invention, and is a front view which shows a fixed quantity supply apparatus. It is a figure which shows embodiment of this invention, and is a side view which shows a fixed_quantity | feed_rate supply apparatus. It is a figure which shows embodiment of this invention, and is a front view which expands and shows the rotation drive means periphery in a fixed quantity supply apparatus. It is a figure which shows embodiment of this invention and is a side view which shows a granulation apparatus. It is a figure which shows embodiment of this invention, and is a top view which shows the arrangement | positioning aspect of a vibration sieve sorting device and a specific gravity difference sorting device. It is a figure which shows embodiment of this invention, and is a front view which shows a vibration sieve selection apparatus. It is a figure which shows embodiment of this invention, and is a side view which shows a vibration sieve selection apparatus. It is a figure which shows embodiment of this invention, and is a side view which shows a specific gravity difference selection apparatus. It is a figure which shows embodiment of this invention, and is explanatory drawing which shows the piping path | route from a wind power sorter to a granulator. It is a figure which shows embodiment of this invention, and is explanatory drawing which shows together the piping path | route from a vibration sieve sorting apparatus to a specific gravity difference sorting apparatus, and the classification | category path | route of the sorted plastic piece. It is a figure which shows embodiment of this invention and is explanatory drawing which shows typically the mode of selection of a grinding | pulverization plastic. It is a figure which shows embodiment of this invention, and is a flowchart which shows the operation | movement order of the sorting apparatus of a grinding | pulverization plastic.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sorting device of pulverized plastic 3 Wind power sorting device 5 Constant supply device 7 Granulating device 9 Vibrating sieve sorting device 11 Specific gravity difference sorting device 13 Intake blower 15 Transport unit 17 Discharge unit 19 Suction port 21 Relay duct 23 Weighing drum 25 Damper 27 Lower limit Level switch 29 Upper limit level switch 31 Open / close drive means 33 Air cylinder 35 Cylinder rod 37 Link mechanism 39 Fixed link 41 First movable link 43 Second movable link 45 Heating tank 47 Water supply tank 49 Nozzle 51 Steam exhaust device 53 Stirring blade 55 Rotation drive mechanism 57 Discharge port 59 Shutter plate 61 Operating means 63 Rotating shaft 65 Drive motor 67 Drive transmission mechanism 69 Machine frame 71 Hopper 73 Vibration trough 75 Sieve (for coarse)
77 Sieve (for fine grain)
79 Exciter 81 Bag 83 Discharge chute (for coarse)
85 Discharge chute (for middle eyes)
87 Discharge chute (for fine)
89 Machine frame 91 Hopper 93 Vibrating air table 95 Shaking device 97 Wind tunnel 99 Fan motor 101 Discharge chute (for low specific gravity)
103 Discharge chute (for high specific gravity)
105 Hood 107 Dust collection duct 109 Inspection window 111 Vertical conveyor 113 Temperature sensor 115 Air injection means 117 Air tank 119 Solenoid valve 121 Introduction pipe 123 Nozzle A Raw material A1 Rough raw material A2 Fine raw material B Recycled plastic raw material C Suction air D Light weight plastic Fragment E Heavy plastic fragment F Air blow O Rotating fulcrum W Water S Steam

Claims (9)

In a pulverized plastic sorting device that uses a mixture of different types of plastic pieces in a pulverized state as raw materials, sorts the raw materials into plastics of the same type and can be taken out as individual recycled plastic raw materials,
A wind power sorter that includes an intake blower that causes suction air to act on the raw material, and that is broadly divided into a lightweight plastic piece that is sucked and a heavy plastic piece that is not sucked,
A metering supply device comprising a measuring drum capable of storing a certain amount of the lightweight plastic piece, and an openable and closable damper provided on the bottom surface of the measuring drum;
It is provided in communication with the above-mentioned quantitative supply device. The supplied lightweight plastic piece is stirred while heated, and only the low melting point lightweight plastic piece is melted by quenching near the melting temperature of the low melting point lightweight plastic piece. A granulating device for granulating;
A specific gravity difference sorting device that classifies a granulated low-melting-point lightweight plastic piece and a non-granulated high-melting-point lightweight plastic piece using vibration of a vibrating air table provided in an inclined posture;
An apparatus for sorting pulverized plastics, comprising:   The pulverized plastic sorting device is equipped with a vibrating sieve sorting device that classifies the granulated low-melting-point lightweight plastic pieces and the non-granulated high-melting-point lightweight plastic pieces according to size. 2. The apparatus for sorting pulverized plastics according to claim 1.   The measuring drum includes an opening / closing driving means for performing an opening / closing operation of the damper, a timer for measuring a time after the damper is opened by the opening / closing driving means, and closing the damper after a predetermined time has elapsed, The ground plastic sorting device according to claim 1 or 2, further comprising a lower limit level switch for setting a level of a lightweight plastic piece charged in the granulating device.   4. The pulverized plastic sorting apparatus according to claim 1, wherein the weighing drum is provided with an air injection means for blowing off and removing a lightweight plastic piece deposited near the rotation fulcrum of the damper. apparatus.   The different types of plastic pieces are plastic pieces made of high melting point polyethylene terephthalate and polypropylene and low melting point polystyrene, and the melting temperature of polystyrene is set to 105 ° C to 120 ° C. The apparatus for sorting ground plastics according to any one of 1 to 4. In a method for sorting pulverized plastics, in which different types of plastic pieces are mixed in a pulverized state as raw materials, the raw materials are sorted into plastics of the same type and can be taken out as individual recycled plastic raw materials.
A wind power sorting step roughly divided into lightweight plastic pieces sucked by acting suction air on the raw material and heavy plastic pieces not sucked;
Supply a small amount of the above-mentioned lightweight plastic pieces, stir the supplied lightweight plastic pieces while heating them, and quench and cool them near the melting temperature of the low-melting-point lightweight plastic pieces to melt and manufacture only the low-melting-point lightweight plastic pieces. A quantitative supply and granulation process to granulate;
A specific gravity difference sorting step for classifying a granulated low-melting-point lightweight plastic piece and a non-granulated high-melting-point lightweight plastic piece using vibrations of a vibrating air table provided in an inclined posture. A method for sorting pulverized plastics.   Between the above-mentioned quantitative supply / granulation step and the specific gravity difference sorting step, the granulated low-melting-point lightweight plastic piece and the non-granulated high-melting-point lightweight plastic piece are sized using a vibration sieve. 7. The method for sorting ground plastic according to claim 6, further comprising a vibration sieve sorting step for classifying each of them.   In the above quantitative supply / granulation step, after detecting the level of the light plastic piece charged in the granulator, the stirring of the light plastic piece is started, and when heated to the predetermined temperature, water is injected and rapidly cooled. During this period, the supply of the lightweight plastic pieces to the granulator is continued, and after the lightweight plastic pieces in the granulator are discharged, the lightweight plastic pieces are supplied to the granulator. The method for sorting crushed plastics according to claim 6 or 7, wherein the supply of slag is resumed.   The different types of plastic pieces are plastic pieces made of high melting point polyethylene terephthalate and polypropylene and low melting point polystyrene, and the melting temperature of polystyrene is set to 105 ° C to 120 ° C. The method for selecting ground plastic according to any one of 6 to 8.

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