JP2002037915A - Recycling equipment for recovered polyester container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively provide a polyester material for recycling having a sufficient degree of polymerization. SOLUTION: This equipment installs drying means to dry polyester materials obtained by crushing polyester containers to recycle the recovered polyester containers, a heating means to heat the polyester material to the polymerization temperature t3 of the polyester and a polymerization reacting means to carry out a solid phase polymerization of the polyester material heated to the polymerization temperature t3, and the polyester material is a flaky material and at least one of the drying means and the heating means installs stirring means having a rotating axis elongated in horizontal direction and the conveying direction of the polyester material is set along the direction of the elongating direction of the rotating axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for recycling a recovered polyester (polyethylene terephthalate) container.

[0002]

2. Description of the Related Art Conventionally, in order to reuse an unnecessary PET bottle for beverages, for example, a PET bottle is crushed and then heated and melted to form a pellet. The pellets are manufactured by temporarily melting a crushed PET bottle, cutting the PET bottle into a predetermined length while stretching the extruder. Such pellets have, for example, a columnar shape, an elliptical shape, and a spherical shape, and are relatively easy to handle during drying and heating. Therefore, if the polyester container is to be recycled and a PET bottle or the like is to be manufactured again, it is possible to purchase the pellets that have been regenerated and commercialized as described above, and then melt it again to manufacture an arbitrary polyester container or the like. There were many.

[0003]

However, as described above, when the recovered polyester container or the like is reused, moisture often adheres to the polyester container when the polyester container is crushed or washed. When such moisture is attached, when the above-mentioned pulverized material is heated to produce pellets again, there is a disadvantage that the molten polyester reacts with the moisture to cause hydrolysis. When such hydrolysis occurs, the IV value of the produced pellet becomes insufficient. Here, the IV value is
It is a value generally called intrinsic viscosity, and is a value that indirectly indicates the degree of polymerization of polyester by viscosity. That is, since it has been found that the intrinsic viscosity and the molecular weight are directly proportional, the IV value is generally used as a standard representing the molecular weight (degree of polymerization). The higher the IV value, the higher the degree of polymerization. When the IV value of the pellets is low, containers and the like manufactured using the material also have a low IV value. In particular, a PET bottle for storing carbonated drinking water or the like has insufficient strength. In some cases, the recycled products formed by the above do not have sufficient product quality.

Further, when heating the polyester material to increase the IV value of the polyester material, if the amorphous polyester material remains, the viscosity of the surface of the material increases, and the polyester materials become very different from each other. It may be in a state where it easily adheres. However, if the high temperature state is maintained to some extent and the crystallization is completed, the tendency to adhere easily decreases. However, for example, if the polyester materials in the form of pellets adhere to each other at the initial stage of polymerization, the surface area of each polyester material fluctuates during the subsequent solid phase polymerization reaction, and the heating degree differs, and the obtained pellets are obtained. There has been a problem that the IV value of the product is not uniform.

[0005] Further, in order to obtain a regenerated polyester material in the form of pellets from a collected PET bottle or the like, it is necessary to pulverize and melt the collected polyester material as described above. If so, not only the melting operation itself is troublesome, but also a facility for melting is required, and the recovered polyester container was not necessarily regenerated efficiently.

[0006] An object of the present invention is to solve the above-mentioned problems of the prior art and to efficiently provide a regenerated polyester material having a sufficient degree of polymerization.

[0007]

Means for Solving the Problems [Structure 1] A recycling apparatus for a recovered polyester container according to the present invention is obtained by pulverizing the polyester container in order to reuse the recovered polyester container. Drying means for drying the polyester material, heating means for raising the polyester material to a polymerization temperature, and polymerization reaction means for solid-state polymerization of the polyester material raised to the polymerization temperature, wherein the polyester material is in the form of flakes. Wherein at least one of the drying unit and the heating unit includes a stirring unit having a rotating shaft extending in a lateral direction, and the conveying direction of the polyester material is set in the extending direction of the rotating shaft. It is characterized in that it is configured along. [Operation and effect] As in the present configuration, if a drying unit, a heating unit, and a polymerization reaction unit are provided, for example, when the polyester material is heated to the polymerization temperature, the temperature of the polyester material can be increased stepwise. Becomes possible. Therefore, it is possible to first remove the moisture of the polyester material without fail, and then to heat to the polymerization temperature,
A polyester material having a high IV value and a small variation in the IV value can be obtained.

Further, in the present configuration, a flake-like polyester material is used, and the flakes are, for example, those obtained by pulverizing a collected polyester container. Therefore, a melting step for pelletization is not required as in the related art, so that a regenerated polyester material can be obtained extremely efficiently.

Further, in the regenerating equipment of this configuration, at least one of the drying means and the heating means includes a stirring means having a rotating shaft extending in a lateral direction, and the conveying direction of the polyester material is changed. It is configured along the extending direction of the rotating shaft. In this way, if the rotating shaft of the stirring device is extended in the lateral direction, and if the conveying direction of the polyester material is along the extending direction of the rotating shaft, the deposition height of the polyester material is usually It will be low. Therefore, it is possible to prevent the lower portion of the deposited polyester material from being compacted by the load. Even if the polyester material is deposited relatively high above the stirring means, the compaction can be eliminated because the polyester material is stirred by the stirrer. If the drying means is provided with the stirring device, compaction can be prevented, the flow of the carrier gas can be maintained well, and the drying can be reliably performed. That is, since the effect of removing water can be enhanced and heating to the polymerization temperature can be performed appropriately,
High value polyester material can be obtained. on the other hand,
If the heating means is provided with the stirring device, since it prevents the polyester materials heated near the polymerization temperature from adhering to each other, for example, all of the flake-like polyester materials are substantially uniform. It will be heated. As a result, a polyester material having a uniform IV value can be obtained. Of course, when both the drying unit and the heating unit are configured as described above, a polyester material having a high IV value and uniformity can be obtained.

[Structure 2] In the recycling apparatus for a recovered polyester container according to the present invention, the drying means and the heating means are integrally formed, and the temperature of the drying means is controlled as described above. The temperature of the drying unit and the temperature of the heating unit can be independently adjusted while maintaining the temperature of the drying unit lower than the temperature of the heating unit. (Effect) When solid-phase polymerization of polyester material,
It is necessary to raise the temperature to the polymerization temperature in a state where the water contained in the material is surely removed. This is because if the polyester material contains water at the polymerization temperature, hydrolysis occurs and the IV value cannot be increased. The removal of water is sufficiently possible even at a lower temperature than the polymerization temperature. In the polymerization facility of the present configuration, the temperature of the drying unit and the temperature of the heating unit are configured to be independently adjustable, and the temperature of the drying unit is maintained lower than the temperature of the heating unit. Drying can be performed while maximally preventing the above-mentioned hydrolysis from occurring.
Further, since the temperature adjustment of both means can be set to any temperature, it is possible to set optimal heating conditions suitable for the polyester material to be treated. Further, since the drying unit and the heating unit are integrally configured, heat loss when the polyester material is transported between the drying unit and the heating unit can be minimized, and the thermal efficiency can be reduced. Excellent facilities can be obtained. In addition, the solid-state polymerization equipment can be made compact by integrally forming the drying unit and the heating unit.

[Structure 3] In the recycling apparatus for a recovered polyester container according to the present invention, as described in claim 3, the first stirring means and the second stirring means having a heat medium flow passage formed therein are provided with the drying means. Means and the heating means are provided separately, and the temperature of the heating medium supplied to the first stirring means is set lower than the temperature of the heating medium supplied to the second stirring means, and the first stirring An intermediate stirring means provided between the means and the second stirring means, the intermediate stirring means being capable of reaching an intermediate temperature between the drying means and the heating means under the influence of the temperature inside the heating means. can do. [Effect] By providing the first stirring means and the second stirring means as in the present configuration, it is possible to prevent the adhesion of the polyester materials and to allow the carrier gas to smoothly flow through the gaps between the polyester materials. And water can be reliably removed. In addition, if a heating medium flow passage through which a heating medium can flow is formed in each of the stirring means, heating can be performed from the inside of the polyester material deposition layer, so that heating of the polyester material can be promoted. In addition, the temperature of the entire polyester material existing in the heating container can be maintained more uniformly. Furthermore, by providing an intermediate stirring means capable of reaching an intermediate temperature between the two, under the influence of the temperature inside the drying means and the temperature inside the heating means, the temperature difference between the two means can be reliably ensured. This can be maintained, and the heat treatment by each means can be appropriately performed.

[Structure 4] In the recycling apparatus for a recovered polyester container according to the present invention, as set forth in claim 4, the polymerization reaction means has an upper portion for charging the polyester material and has a storage space therein. With a formed cylinder,
A table feeder for carrying out the polyester material is provided at a lower portion of the cylindrical body, and the table feeder includes a table on which the polyester material is placed, and an extruding member that pushes the polyester material toward an outer peripheral portion. In addition, the table and the pushing member can be configured to have a rotation drive mechanism for rotating the table and the pushing member relative to each other. [Effects] As in the present configuration, a cylindrical body having a charging portion for a polyester material at an upper portion is provided, and a storage space inside the cylindrical body is configured such that the polyester material is conveyed downward. In addition, if a table feeder having a table and an extruding member that are relatively rotatable relative to each other is provided, the flat flake-shaped polyester material conveyed from the upper part of the storage space is tentatively compacted underneath. Also, the extrusion member can reliably push the polyester material out of the table, and the discharge of the polyester material can be performed smoothly. Therefore, for all the polyester materials, the time held in the cylindrical body is constant, and a polyester material having a uniform IV value can be obtained.

[Structure 5] The recycling apparatus for a recovered polyester container according to the present invention can be configured by including a cooling mechanism in the rotary drive mechanism. [Function and Effect] If the rotation drive mechanism is provided with a cooling mechanism, it is possible to prevent overheating of the rotation drive mechanism and prevent problems such as thermal distortion or burning of the rotation drive mechanism from occurring. The relative rotation between the table and the pushing member is always kept smooth. As a result, the apparatus can be continuously operated, and the high-temperature polyester material immediately after the completion of the solid-state polymerization step can be continuously discharged. That is, the discharge of the polyester material is performed at a constant efficiency, the time during which the individual polyester materials are maintained in the solid-state polymerization step is made uniform, and a polyester material for regeneration having a uniform IV value can be obtained.

[Structure 6] In the recycling apparatus for a recovered polyester container according to the present invention, as described in claim 6, a gas supply for supplying an inert gas from below to above inside the polymerization reaction means. A first supply port for supplying an inert gas to the inside of the polymerization reaction means from a central position of the lower portion related to the polymerization reaction means, and a periphery of the lower portion. A second supply port for supplying an inert gas into the polymerization reaction tower from a nearby position. [Effects] As in this configuration, a first supply port is provided at the lower central position of the polymerization reaction means and a second supply port is provided around the lower side to supply the inert gas into the polymerization reaction means. Thereby, the inert gas can be uniformly supplied to the inside of the polymerization reaction means. With this configuration, even if the type of the polymerization reaction means is a vertical type and the polyester material is caused to flow downward from above in the interior thereof, the polymerization reaction means does not have a stirring function. Even in this case, since the inert gas can be supplied evenly to the deposited polyester material, it is possible to obtain a recycled polyester material having a uniform IV value.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Summary) The present invention relates to a flake-like recycled polyester material obtained from an unnecessary pet product in order to reuse the collected beverage PET bottle or the like as a beverage PET bottle or the like. Is subjected to various treatments and used as polyester material flakes for reproduction. In the present invention, the flakes F (hereinafter simply referred to as “flakes F”) of recycled polyester material obtained by pulverizing waste PET bottles and the like are washed with alkali and water, dried, and held at a predetermined temperature for a predetermined time to polymerize. Increase the degree. That is, the flakes F obtained by pulverization are not reprocessed into pellets,
This is to increase the V value. The regeneration equipment according to the present invention mainly includes a pre-dryer 1 as a part of a drying unit for drying the washed flakes F, and the dried flakes F
And a polymerization reaction tower 3 as a polymerization reaction means for subjecting the regenerated polyester material to the polymerization temperature to a solid-state polymerization. In the present embodiment, the heater 2 has both a function as a drying unit and a function as a heating unit.

(Preliminary dryer) Not only does some moisture adhere to the surface of the recovered polyester container such as a PET bottle, but also to the surface of the flakes F when crushing and washing. I do. The predryer 1 removes such moisture. In the present embodiment, an example in which a hopper dryer is used as the preliminary dryer 1 will be described. The hopper dryer has a substantially cylindrical drying chamber 11.
The flakes F charged in the upper part are caused to flow downward, and drying is performed during that. The drying temperature t1 is approximately 100 to 200 ° C.

At the outlet of the pre-dryer 1, a table feeder 4 is provided as means for facilitating the transport of the flakes F. The table feeder 4 includes a table on which a regenerated polyester material is placed, and an extruding member that pushes the flakes F toward an outer peripheral portion. The flakes F placed on the table can be extruded by relative rotation between the table and the pushing member. The table feeder has the same configuration as that provided in the polymerization reaction tower 3 described later, and thus the details will be described later.

(Heating Device) The flakes F that have been subjected to the predrying described above are conveyed to the heating device 2. Here, the degree of drying of the flake F after the preliminary drying is further increased, and the flake F is raised to the polymerization temperature in order to smoothly shift to the next solid-phase polymerization step. That is, the heater 2 has both a function as another drying means for further drying the flakes F which have been subjected to the preliminary drying and a function as the heating means.

The heater 2 used in the present invention is arranged horizontally. The heater 2 is provided with stirring means 21, and the rotation shaft 22 of the stirring means 21 extends in a substantially horizontal direction. A nitrogen gas is circulated as a carrier gas inside the heater 2. The carrier gas mainly has a function of heating the flakes F and a function of removing volatile components generated from the flakes F. With such a horizontal configuration, inconveniences that are likely to occur when the flakes F flow downward, for example, the area below the deposited flakes F is compacted by a load or the flow of the carrier gas is obstructed. Inconvenience is unlikely to occur. That is, as in the present configuration, in the horizontal heater 2, compaction due to the accumulation of the flakes F does not easily occur, and the carrier gas is easily circulated, so that moisture removal of the flakes F is performed smoothly. Further, if the heater 2 is of the horizontal type as in the present configuration, the plant equipment can be configured to be low, and the regeneration equipment can be made compact and the construction cost of the factory equipment can be reduced. You can also.

As shown in FIG. 2, the inside of the heater 2 of this embodiment is divided into two regions. That is, a region from which water remaining without being removed by the preliminary dryer 1 is further removed is defined as a first heating region A1. The first heating area A1 has a function of the drying unit. In the first heating area A1, the temperature is set to be lower by a predetermined temperature than the polymerization temperature t3 of the polyester material for regeneration. The reason for setting the temperature lower than the polymerization temperature t3 is to prevent the flakes F from being hydrolyzed. This temperature is referred to as prepolymerization temperature t2. Specifically, the temperature is set at 100 to 200 ° C. and maintained for 30 minutes or more. This step is particularly called a first heating step. For example, flake F
The water concentration immediately after being put into the heating area A1 is about 40
Although it is about 00 ppm to 6000 ppm, at the time when the first heating step is completed, water is removed to about 30 ppm.

On the other hand, it is the second heating area A2 that heats the flake F from which the removal of water has been completed to the polymerization temperature t3.
The second heating region functions as the heating unit. Here, the flakes F are mixed at a polymerization temperature t3 of 150 to 2
Set to 50 ° C. and hold this temperature for 30 minutes or more. As a result, the water concentration can be reduced to 20 to 30 ppm. Since the temperature is the polymerization temperature t3 of the polyester material for regeneration, the polymerization of the flakes F is also started inside the heater 2. However, at this stage, since the water contained in the flakes F has been removed, the hydrolysis does not proceed.

As the heater 2, for example, a torus disk (product name of Hosokawa Micron) can be used. The heater 2 has a substantially cylindrical main body 23 placed horizontally, and a plurality of disks or paddle-shaped stirring means 21 is rotated inside the heater 2 to stir the flakes F while polymerizing in the next step. The flakes F are transported to the reaction tower 3.

In the heater 2 according to the present embodiment, the first
The temperature of the heating area A1 and the temperature of the second heating area A2 can be adjusted independently. As shown in FIG. 2, the first heating area A1 and the second heating area A2 include:
The first stirring means 21a and the second stirring means 21b are separately provided. In the present embodiment, the first stirring means 21a and the second stirring means 21b have the same disk shape, and the inside of each is hollow. Inside these stirring means 21, a heat medium flow passage 24 through which a heat medium for temperature adjustment flows is formed. As the heat medium, for example, oil is used. As described above, the first stirring means 21
a and oil to be supplied to the second stirring means 21b
And the temperature of the oil supplied to it. Although not shown, the heater 2 includes a heater body 2
A heat medium supply passage for supplying a heat medium is also formed outside the heat medium 3. Thus, the flakes F supplied into the heater 2 are uniformly and efficiently heated from the surroundings.

An intermediate stirring means 21c is provided between the first stirring means 21a and the second stirring means 21b.
The intermediate stirring means 21c is for maintaining a difference between the temperature of the first heating area A1 and the temperature of the second heating area A2. For example, a heat medium is not allowed to flow through the intermediate stirring means 21c, and the temperature is intermediate between the two regions under the influence of both the heating regions.

The first stirring means 21a, the second stirring means 21b, and the intermediate stirring means 21c are provided with paddles 21d for stirring and flowing the flakes F on their respective outer peripheral portions.
The transport condition of the flakes F can be appropriately adjusted by changing the size of the paddle 21d, the inclination angle with respect to the rotation direction of each stirring means 21, or the rotation speed of each stirring means 21.

(Solid State Polymerization) In this embodiment, as shown in FIG. 1, for example, a hopper reactor (product name of Hosokawa Micron) is used as the polymerization reaction tower 3 as the polymerization reaction means. The polymerization reaction tower 3 has a cylindrical body 3A extending vertically. A storage space 3B capable of maintaining a predetermined polymerization temperature t3 of 150 ° C. to 200 ° C. is formed inside the cylindrical body 3A. The flakes F to be subjected to the solid-state polymerization reaction are charged into the storage space 3B from a charging portion 3C formed above the cylindrical body 3A. Flake F
Is gradually conveyed downward. The transfer speed is appropriately set by changing the discharge speed of the flakes F by the below-described table feeder provided below the polymerization reaction tower 3. This allows the flake F to proceed with the polymerization reaction for a predetermined time.

The inside of the polymerization reaction tower 3 is shown in FIG.
As shown in FIG. 3, a nitrogen gas as a carrier gas G is supplied from a gas supply mechanism 5 provided at a lower portion thereof.
No stirring means is provided inside the polymerization reaction tower 3. However, the flakes F can be extremely stably conveyed below the polymerization reaction tower 3 to increase the IV value.

As described above, nitrogen gas is used as the carrier gas G. The carrier gas G contains the flakes F
In addition to preventing oxidation of the polyester, it has a function of controlling the temperature in the polymerization reaction tower 3 and discharging volatile components from the polyester material accompanying the solid-phase polymerization. In particular, when the polyester material is oxidized, it is colored yellow, and the quality of the product is inferior particularly when used as a PET bottle for beverages. Nitrogen gas has the above functions and is also very economical. Of course, an inert gas such as argon and helium can be used as the carrier gas G.

In the present embodiment, the gas supply mechanism 5 is configured as shown in FIG. That is, a first supply port 51 is provided at a central position of a lower portion of the polymerization reaction tower 3, and an annular second supply port 52 is provided at a position near the periphery of the lower portion. The first supply port 51 is provided with a cone member 53 above the first supply port 51 so as not to prevent the flake F from flowing down. With this configuration, the carrier gas G can be evenly supplied to the inside of the polymerization reaction tower 3, and the IV value of the flakes F can be uniformly increased.

A table feeder 6 is provided below the polymerization reaction tower 3 as means for transporting the polyester material after polymerization to the next cooler. As shown in FIG. 4, the table feeder 6 includes a table 61 on which the flakes F can be placed, and has a configuration in which the pushing member 62 rotates just above the table 61. A front edge portion 63 of the pushing member 62, which comes into contact with the flake F and applies an extruding force, is configured in a curved shape, for example, as shown in FIG. With this configuration, it is possible to maintain a constant inclination angle with respect to the direction of relative movement with respect to the table 61 at any part of the front edge portion 63. As a result, the flakes F can be reliably pushed to the outer peripheral side. In addition, the front edge 63
Is provided with an eaves member 64. That is, table 6
The flakes F, which are mainly located at the lowermost position among the flakes F placed on the top 1, are pushed out by the front edge 63 while being sandwiched between the surface of the table 61 and the eaves member 64. It is. Therefore, the flakes F in the middle of being extruded do not come off from the front edge 63, and the flakes F can be reliably pushed out of the table 61. The extruded flakes F are applied to the main body 6 of the table feeder 6.
The liquid drops from the gap between the table 8 and the table 61, slides on the inner peripheral inclined surface 68 a of the main body 68 having a substantially conical shape, and deposits on the discharge port 69.

The table feeder 6 is provided with a cooling mechanism 67 for cooling a rotating shaft 65 of the pushing member 62 and a bearing 66 for supporting the rotating shaft 65. As the cooling mechanism 67, for example, a water cooling jacket that can circulate cooling water is provided around the rotation shaft 65 and the like. Of course, a cooling mechanism 67 may be provided on the main body 68 side of the table feeder 6 in addition to the above.

By using the polymerization reaction tower 3, the IV value of the flake F can be increased to about 1.5.
A flake F having such an IV value can be sufficiently reused as a beverage PET bottle or the like.

(Cooling) The polyester material after the solid phase polymerization treatment is cooled and packed as recycled polyester flakes to produce a product. In the present embodiment, as shown in FIG. 1, a horizontal type cooler 7 used as the heater 2 is used for the cooling. Although not shown, the cooler 7 is also provided with a stirring means, and the rotation axis of the stirring means extends in a substantially horizontal direction. A cooling medium can be supplied inside the stirring means, and a jacket through which the cooling medium can flow is provided outside the main body of the cooler 7.

For this reason, it is possible to supply cold heat to the polyester material from both the inside and the outside of the cooler 7 to quickly cool it. Also in the cooler 7, the flakes F stored in the cooler 7 are not compacted, and the carrier gas G is interposed between the flakes F.
And the individual flakes F can be cooled quickly. Furthermore, by using the horizontal cooler 7, the plant equipment can be configured to be low, and the entire regeneration equipment can be made compact, and advantages such as reduction in the construction cost of the factory equipment can be obtained. it can.

(Other Facilities) In addition to the above-mentioned facilities, for example, E
A G scrubber 8 is provided. The EG scrubber 8 is for removing EG (ethylene glycol) generated particularly during solid-phase polymerization. However, according to the experiment described later, when flake F, which is a polyester material for regeneration, is polymerized as in the present invention, the influence of the difference in EG partial pressure on the IV value was small. For this reason, an ordinary adsorption device may be used rather than using the EG scrubber 8.

(Effect) The recycling apparatus for a recovered polyester container according to the present invention is configured such that at least one of a drying means for removing water from the polyester material and a heating means for raising the polyester material to the polymerization temperature are arranged horizontally. If the rotation axis of the stirring means provided in these means is extended in the lateral direction, the height of the deposited polyester material can be set low, and the lower part of the deposited polyester material is compacted by the load. Can be prevented. And, since the stirring effect of the polyester material by the stirring main stage is exhibited, even when using a flaky polyester material which is easy to overlap, moisture removal of the polyester material, and reliably preventing adhesion of the polyester materials. Thus, a polyester material having a high IV and uniformity can be obtained. In particular, if the drying means is provided with the stirring device, the compaction is prevented, the flow of the carrier gas is maintained favorably, the drying can be reliably performed, and the effect of removing moisture is enhanced. Therefore, a polyester material having a higher IV value can be obtained. On the other hand, if the heating means is provided with the stirrer, since the polyester materials heated near the polymerization temperature are prevented from adhering to each other, for example, all of the flake-like polyester materials are substantially uniform. It will be heated on condition. As a result, IV
A polyester material having a uniform value can be obtained. Furthermore, in the present invention, for example, since the flake-shaped polyester material obtained by pulverizing the recovered polyester container is used as it is, a melting step for pelletizing is not required as in the related art, and the recycling polyester material is extremely efficiently used. Can be obtained.

In addition, if the drying means or the heating means is of a horizontal type as in the present configuration, the height of the equipment can be reduced, and the entire regeneration equipment can be made compact, and the equipment of the factory can be reduced. Advantages such as a reduction in construction costs can also be obtained.

Another Embodiment <1> In the above embodiment, an example in which one horizontal heater 2 is used has been described. However, a plurality of horizontal heaters 2 may be used. In this case, it is possible to distinguish between those used exclusively for the drying means and those used exclusively for the heating means, and it is possible to more accurately set the processing temperature in each means. In addition, a horizontal heater 2
If a plurality of are used, it is also possible to replace the vertical pre-dryer 1 shown in FIG. 1 with the horizontal heater 2, so that the entire solid-state polymerization facility can be made compact. Becomes The horizontal heater 2 has good agitation even if it is a flake-like polyester material, and as described above, the bridging phenomenon of the flakes F hardly occurs. In addition, such a heater 2 has a more complicated device configuration than a general polymerization reaction tower 3 and the like, and requires time and labor for maintenance. However, since all of the polyester material for regeneration can be heated uniformly and the polyester material for regeneration can be sufficiently polymerized, a recycling facility for the recovered polyester container is constituted using only the horizontal heater 2. It is also possible.

[Experimental results] The experimental results performed to evaluate the characteristics of the polyester material for recycling obtained by using the recycling equipment according to the present invention are shown below. The experiment is a comparison between the case where a flake-like polyester material for regeneration is used and the case where a pellet-like polyester material for regeneration is used.

Table 1 shows the quality standards of the flake-like recycled polyester material. The quality standards are
This is an excerpt from the product quality standard of recycled PET resin from used PET bottles by Bottle Recycle Co., Ltd.

[0041]

[Table 1]

The flake F had an IV value of 0.6
5 to 0.75 dl / g. Since various kinds are mixed in the recovered polyester container as a raw material, such a degree of variation is inevitably generated. The water content was 0.6% or less. The size of the flake F was passed through a sieve having an 8 mmφ screen. Table 2 shows the size distribution of the flakes that passed through the sieve.

[0043]

[Table 2]

On the other hand, a pellet-like polyester material for regeneration was also used in the experiment for comparison. The pellet is I
The V value was 0.66 ± 0.22 dl / g. Since such regenerated pellets are to be extruded into pellets after once melting the recovered polyester container, etc.,
The variation in IV value was extremely small. Moisture is 0.4
% Or less. The regenerated pellets were substantially cylindrical, and the pellet size was 2.5 to 3.0 mmφ × 2.5 to 3.0 mmL. More specifically, there were those having a size of a major axis of 3.45 × a minor axis of 2.25 × a length of 2.60 mm. The weight of the regenerated pellet is 0.0223 g /
It was about a grain.

FIG. 5 shows the effect of the reaction temperature of the regenerating polyester material on the IV value. That is, it was found that the higher the reaction temperature, the higher the IV value. However, if the reaction temperature is too high, the flakes may increase in tackiness, decrease the fluidity, and eventually make the operation of the polymerization equipment impossible.

FIG. 6 shows the influence of the flow rate of the carrier gas flowing inside the polymerization reaction tower on the IV value. It can be seen that the higher the flow rate, the higher the reached IV value. That is, by increasing the flow rate, the flake I
The V value can be increased.

In general, in the solid phase polymerization of virgin pellets, it is known that the partial pressure of EG (ethylene glycol) in the flowing carrier gas has a large effect on the IV value. However, as a result, in the solid phase polymerization of flakes, the influence of the EG partial pressure in the carrier gas on the IV value was small.

FIG. 7 shows the difference in the degree of increase in the IV value depending on the type of raw material used, and FIG. 8 also shows the difference in the IV increase rate depending on the type of raw material. These figures show that the flakes have a higher absolute value of the IV value when the flakes and pellets are compared. This is because during the production of regenerated pellets, the recovered polyester container is once melted, so that hydrolysis proceeds and IV
This is considered to be due to a decrease in the absolute value of the value.

The rate of increase and the rate of increase of the IV value were slightly higher in the flakes than in the regenerated pellets. That is, it is considered that the difference in shape between the two influences that the specific surface area of the flake is larger than the specific surface area of the pellet.

As described above, in consideration of the fact that flakes are more advantageous from the viewpoint of an increase in the IV value and that the labor for processing into pellets can be omitted, a flake-like recycled polyester material is used. It can be said that it is more advantageous.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a recycling facility for a recovered polyester container according to the present invention.

FIG. 2 is an explanatory diagram showing details of a heater.

FIG. 3 is an explanatory diagram showing details of a gas supply mechanism.

FIG. 4 is an explanatory diagram showing details of a table feeder.

FIG. 5 is an explanatory diagram showing a relationship between a temperature of a polyester raw material and an IV value.

FIG. 6 is an explanatory diagram showing a relationship between a carrier gas flow rate and an IV value.

FIG. 7 is an explanatory diagram showing a relationship between a difference in polyester raw material and an IV value.

FIG. 8 is an explanatory diagram showing the relationship between differences in polyester raw materials and the rate of increase in IV value.

[Explanation of symbols]

 Reference Signs List 21 stirrer 21a first stirrer 21b second stirrer 21c intermediate stirrer 5 gas supply mechanism 51 first supply port 52 second supply port 6 table feeder 61 table 62 extrusion member 65 rotation shaft 67 cooling mechanism t3 polymerization temperature

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F301 AA25 CA09 CA32 CA41 CA51 CA62 CA63 CA64 CA72 4J029 AA03 AB07 AC01 AE01 BA03 CB06A KE07 KE08 KE12 KF09 LA06 LA17

Claims (6)

[Claims] 1. A drying unit for drying a polyester material obtained by pulverizing the polyester container so as to reuse the collected polyester container, a heating unit for increasing the polyester material to a polymerization temperature, A polymerization reaction means for solid-state polymerization of the raised polyester material, wherein the polyester material is in the form of flakes, and at least one of the drying means and the heating means has a rotation extending in a lateral direction. Recycling equipment for a recovered polyester container, comprising stirring means having a shaft, and configured so that a conveying direction of the polyester material is set along an extending direction of the rotating shaft. 2. The temperature of the drying unit and the temperature of the heating unit while the drying unit and the heating unit are integrally formed, and the temperature of the drying unit is maintained lower than the temperature of the heating unit. The recycling facility for a recovered polyester container according to claim 1, wherein the apparatus is configured to be independently adjustable. 3. A first stirring means and a second stirring means each having a heat medium flow passage formed therein are separately provided for the drying means and the heating means, and the heating medium is supplied to the first stirring means. The temperature is set lower than the temperature of the heat medium supplied to the second stirring means, and the temperature inside the drying means and the heating between the first stirring means and the second stirring means are set. The recycling equipment for a recovered polyester container according to claim 2, further comprising an intermediate stirring means capable of reaching an intermediate temperature between the two by being affected by the temperature inside the means. 4. The polymerization reaction means includes a charging section for the polyester material at an upper portion thereof, a cylindrical body having a storage space formed therein, and a table feeder for unloading the polyester material at a lower portion of the cylindrical body. The table feeder includes a table on which the polyester material is placed, and an extruding member for extruding the polyester material toward an outer peripheral portion, and a rotary drive for rotating the table and the extruding member relative to each other. The recycling facility for a recovered polyester container according to any one of claims 1 to 3, further comprising a mechanism. 5. The facility for recycling a recovered polyester container according to claim 4, wherein said rotary drive mechanism is provided with a cooling mechanism. 6. A gas supply mechanism for supplying an inert gas to the inside of the polymerization reaction means from below to above the polymerization reaction means, wherein the gas supply mechanism comprises a lower portion of the polymerization reaction means. A first supply port for supplying an inert gas to the inside of the polymerization reaction means from a central position, and a second supply port for supplying an inert gas to the inside of the polymerization reaction means from a position near the periphery of the lower portion. The recycling facility for a recovered polyester container according to any one of claims 1 to 5, further comprising: