JP2008308652A - Solvent separation/recovery method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent separation/recovery method capable of increasing a separation efficiency of a solvent and a styrene resin when the solvent is separated/recovered from a gel-like solvent-styrene mixed solution obtained by dissolving the foamed polystyrene by the solvent, recovering the solvent and the styrene resin of high quality and attaining miniaturization of an apparatus, and an apparatus. <P>SOLUTION: The solvent separation/recovery apparatus for separating the solvent from the gel-like solvent-styrene mixed solution 105 obtained by dissolving the foamed polystyrene by the solvent is provided with a solvent separator 25 for performing separation by vaporizing the solvent by heating the mixed solution, and a liquefying machine 34 for liquefying/recovering the vaporized solvent. The solvent is methylene chloride of a single component, and the solvent separator is the apparatus maintained to an ordinary pressure atmosphere and heating the mixed solution at a temperature of 100°C or lower. An addition means for adding a styrene monomer to the mixed solution is provided on the solvent separator or at a front stage side than the solvent separator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solvent separation and recovery method and apparatus for separating and recovering the solvent from a gel-like solvent / styrene mixed solution obtained by dissolving polystyrene foam with a solvent, and particularly to separating and recovering high-quality styrene oil and solvent. The present invention relates to a method and apparatus for solvent separation and recovery.

  Styrofoam (expanded polystyrene) has excellent properties such as high heat insulation and buffering, water-impervious, light, easy to mold, and inexpensive, so it has been buffered for agricultural and marine product containers as well. It is used in a wide range of fields such as wood and heat insulating building materials. In addition, since most of the polystyrene foam is a single material, separation is easy, volume reduction can be achieved by heat, compression, and solvent, and recycling characteristics are also excellent. However, the expanded polystyrene is formed by foaming and curing a synthetic resin with fine foam, and is expanded 50 to 100 times. Therefore, when storing and transporting used waste expanded polystyrene, storage space and transportation cost are reduced. It will increase. In particular, when transporting waste foamed polystyrene from the discharge site to the treatment plant, if it is transported as it is, much energy will be consumed for the weight to be carried.

Thus, various proposals and practical applications have been made on the technology for reducing the volume of polystyrene foam.
As shown in FIG. 10, conventional volume reduction methods include 1) dissolution by heat, 2) compression by pressure, and 3) volume reduction by a solvent. At present, 1) melting by heat has become the mainstream of the volume reduction method. This is because hot air around 240 ° C. is sent to a hot box containing foamed polystyrene, the foamed polystyrene is melted and poured into a tray, and an ingot is poured. To manufacture. However, this method may cause secondary pollution due to bad odor and black smoke generated by heating, and polystyrene is denatured and colored, so it is not suitable for reuse. 2) Compression by pressure is to produce an ingot by compression-molding polystyrene foam under pressure, but it becomes hard when compression-molded and can be used only for limited applications. The same applies to ingots manufactured by melting with heat.

On the other hand, the 3) volume reduction method using a solvent is a method in which a solvent such as limonene and foamed polystyrene are brought into contact with each other to dissolve and volume reduction.
Each of the volume reduction methods described above has advantages and disadvantages, and the problems to be solved in the commercialization of waste expanded polystyrene treatment are as follows: 1) Treatment of foreign matter, 2) Recovery of solvent (in case of solvent volume reduction), 3) Polystyrene recycling Method 4, 5) Reduction of initial equipment cost investment, 6) Reduction of running cost, 7) Ensuring raw materials suitable for the plant scale and maintenance of operation efficiency. The current situation is not done.

3) As an apparatus using a solvent dissolution method, Patent Document 1 (Japanese Patent Laid-Open No. 2002-338732) discloses a synthetic resin dissolution / regeneration apparatus equipped with a dissolution apparatus using this volume reduction method. ing. A solvent layer and a water tank are formed, and a dissolving device in which a synthetic resin is poured into the solvent layer through the water tank and dissolved, an evaporation device that solidifies and recovers the synthetic resin by evaporating the dissolved resin solution, and the evaporation container And a solvent separator for separating water and solvent from a mixture of water and solvent taken out from the vacuum generator. Here, the volume-reduced polystyrene foam was solidified and recovered. On the other hand, the solvent is separated and recovered and reused.
Further, examples of the solvent used for volume reduction include methylene chloride and xylene as described in Patent Document 2 (JP-A-9-272755) and Patent Document 3 (JP-A 2001-220461), for example. And a solvent in which a nonionic surfactant is mixed and a solvent in which methylene chloride and an aliphatic alcohol are mixed have been proposed.

When the above-described dissolution method using a solvent is used, it is required to separate and recover the solvent in order to reuse it.
As a method for separating and recovering the solvent, conventionally, as shown in FIG. 11, the solvent / styrene mixed solution is heated by a heater 52 in a solvent separator 51, which is reduced in pressure by a vacuum pump 53, and evaporated to be a styrene resin solution. After the separation, the vaporized solvent was cooled by the heat exchanger 55 with the cold brine produced by the Blainchler 54 and liquefied by the liquefier 56 to be regenerated. The styrene resin liquid separated from the solvent has been conveyed to a subsequent process such as an ingot production apparatus or an oil converting apparatus.

JP 2002-338732 A Japanese Patent Laid-Open No. 9-272755 JP 2001-220461 A

The conventional solvent volume reduction system uses a considerable amount of energy and a complicated and highly functional system such as distillation under reduced pressure to separate the solvent from the gel-like volume reduction material, but the recovery rate is also high. Since it is low and the separation efficiency is low, it is necessary to apply high-temperature heat, the solvent is altered, and the number of reuses is limited depending on the type of solvent.
In addition, the quality of polystyrene deteriorates due to the application of high temperature heat, making it difficult to use as a recycled material. Furthermore, in the process from solvent separation to polystyrene extraction, since polystyrene is solid at room temperature, solidification progresses from the separation surface and the solvent is enclosed inside when the solvent is separated from the gel volume-reduced product. Therefore, there was a problem that the solvent and styrene could not be completely separated.
Furthermore, since polystyrene alone is a solid, it is extremely difficult to carry it to the subsequent process, and it has not been possible to separate the waste from the gel-like volume-reduced material.

  Therefore, in view of the above-mentioned problems of the prior art, the present invention improves the separation efficiency of the solvent and the styrene resin when separating and recovering the solvent from the gel-like solvent / styrene mixed solution obtained by dissolving the polystyrene foam with the solvent. It is an object of the present invention to provide a solvent separation and recovery method and apparatus that can be made higher, can recover a high-quality solvent and styrene resin, and can further reduce the size of the apparatus.

Accordingly, in order to solve such problems, the present invention is a solvent separation and recovery method for separating the solvent from a gel-like solvent / styrene mixed solution obtained by dissolving foamed polystyrene with a solvent, and heating the mixed solution In the solvent separation and recovery method, after the solvent is vaporized and separated, the vaporized solvent is liquefied and recovered.
The solvent is a single component methylene chloride, and after adding a styrene monomer to the mixed solution, the methylene chloride is vaporized by heating the mixed solution at a temperature of 100 ° C. or lower under normal pressure. And
The styrene monomer is preferably a styrene oil obtained by separating and removing the methylene chloride from the mixed solution and then oiling.

According to the present invention, since a styrene monomer is added to a gel-like solvent / styrene mixed solution, the mixed solution is in a liquid state with high fluidity, and the intermediate product obtained by separating the solvent is also a liquid product. It is easy to separate the solvent, and high separation efficiency can be achieved.
Further, since only styrene is dissolved in methylene chloride, foreign matters can be removed in a solvent separation / recovery device. Furthermore, since the solvent can be separated at a low temperature, the solvent can be reused any number of times, and there is no deterioration in polystyrene quality.
Furthermore, since styrene oil is added to the liquid mixture, the intermediate product from which the solvent has been separated becomes liquid and can be pumped from the solvent separator to the oiling device. In addition, since the intermediate product has a high density, it is possible to reduce the size and increase the efficiency of the oil refiner.

Also, a solvent separation and recovery device for separating the solvent from the gel-like solvent / styrene mixed solution obtained by dissolving the polystyrene foam with a solvent, the solvent separating the solvent by heating the mixed solution to vaporize the solvent In a solvent separation and recovery device comprising a separator and a liquefier that liquefies and recovers the vaporized solvent,
The solvent is a single component methylene chloride, and the solvent separator is an apparatus for heating the mixed liquid at a temperature of 100 ° C. or less maintained in an atmospheric pressure, the solvent separator or the solvent separator An addition means for adding a styrene monomer to the mixed solution is further provided on the front side.

Furthermore, an oiling apparatus is provided in the subsequent stage of the solvent separator to oilize the styrene-treated product from which methylene chloride has been separated and removed from the mixed solution.
The addition means is characterized in that at least a part of the styrene oil obtained in the oil converting apparatus is the solvent separator or a return line that returns the upstream side of the solvent separator.

  As described above, according to the present invention, the reduced product is made into a liquid state with high fluidity, and the intermediate product from which the solvent is separated is also a liquid, so that the solvent can be easily separated and a separation efficiency of 95% or more is obtained. It is possible. Further, foreign substances can be removed in the solvent separation / recovery device. Furthermore, since the solvent can be separated at a low temperature, the solvent can be reused any number of times, and there is no deterioration in polystyrene quality. Furthermore, it can be pumped from the solvent separator to the oil generator. In addition, since the intermediate product has a high density, there are advantages such as downsizing and high efficiency of the oil generator.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
FIG. 1 is an overall configuration diagram showing an example of a processing system to which a solvent separation and recovery apparatus of the present invention is applied, FIG. 2 is a configuration diagram of a solvent separation and recovery apparatus according to an embodiment of the present invention, and FIG. 4 is a schematic configuration diagram showing an example of a volume reduction device applied to a solvent separation and recovery device, FIG. 4 is a detailed view of the volume reduction device of FIG. 3, (a) is a side sectional view, (b) is a plane sectional view, FIG. 5 is a cross-sectional view when waste foamed polystyrene is accommodated in the volume reduction device of the present embodiment, FIG. 6 is a cross-sectional view of waste foamed polystyrene dissolved in the volume reduction device of the present embodiment, and FIG. FIG. 8 is a cross-sectional view showing an example of a retry in the volume reduction device of the present embodiment, FIG. 9 is a graph (a) showing the correlation between the number of retries and the immersion time, and the immersion time. It is a graph (b) which shows the correlation of the frequency | count of immersion.

The apparatus which concerns on this embodiment is an apparatus which isolate | separates and collects a solvent from the solvent and styrene mixed liquid obtained by volume-reducing waste polystyrene using the single solvent which consists of a methylene chloride.
Referring to FIG. 10, in the prior art, as shown in FIGS. 10 (1) to (4), a method of manufacturing an ingot by heat or compression, or an ingot, a pellet, an adhesive, etc. using limonene or a mixed volume reducing solvent. The manufacturing method or the method of manufacturing a mixed oil using a large-sized oil refiner was used. However, these methods have left various problems as shown in the prior art.

On the other hand, in the apparatus according to this embodiment, a volume reduction treatment is performed in a sealed space using a solvent in which a single methylene chloride is sealed with a water film, and the solvent / styrene mixture obtained by volume reduction is used. The solvent is separated and recovered by heating the liquid at a temperature of 100 ° C. or lower under normal pressure.
Therefore, the solvent can be separated with high efficiency, foreign substances such as dust can be easily separated, and high quality polystyrene and styrene oil can be produced.

Specific examples will be described below.
First, with reference to FIG. 1, a recycling system for waste expanded polystyrene to which the volume reduction device 1 according to the present embodiment is applied will be described.
Each discharge point A, B, C, D,... From which the waste foamed polystyrene is discharged is equipped with a volume reducing device A, B, C, D,. To reduce the volume to a gel-like solvent / styrene mixed solution 10. The solvent 110 used at this time is preferably a solvent regenerated by a solvent separation and recovery apparatus. The solvent / styrene mixed solution 10 from the volume reduction device (volume reduction machine) 1 is temporarily stored in the storage tank 11 and sent to the solvent separation / recovery / oilification facility 15.
The solvent separation / recovery / oilification equipment 15 heats the mixed liquid 105 to 100 ° C. or lower under normal pressure to vaporize only the solvent, separates the styrene resin liquid from the solvent separation / recovery unit 200, and the vaporized solvent. A liquefying solvent liquefying and regenerating unit 300, a regenerated solvent storage tank 35, and an liquefier 4 for liquefying the styrene resin liquid separated by the solvent separation and recovery unit 200 are configured. Further, the regenerated solvent 110 is sent to each of the discharge points A, B, C, D,.

FIGS. 3 to 9 show views relating to the volume reduction device 1 of the present embodiment.
As shown in FIG. 3, in the volume reduction device 1 of this embodiment, a cylindrical dissolution tank 3 is installed in a sealed casing 2, and a single component methylene chloride 102 is placed in the dissolution tank 3. The solvent is introduced, water 101 is further introduced to form a water film 104 above the methylene chloride 102, and the methylene chloride 102 is sealed with water.
A weight mechanism 5 is installed above the dissolution tank 3. The weight mechanism 5 includes a plate-like weight 5a, a suspension line 5b for suspending the weight 5a from the ceiling of the casing 2, and a control unit 5c that adjusts the length of the suspension line 5b to control the lifting / lowering drive of the weight 5a. With. The weight 5a is movable up and down and comes into contact with the upper end opening of the dissolution tank 3 at the lowest position so as to seal the opening. The weight of the weight 5a is the buoyancy of the waste foamed polystyrene 100 with respect to the solvent 102. Slightly heavier. Moreover, it is preferable to provide the cylindrical guide part 4 for positioning when the weight 5a raises / lowers. The shape of the dissolution tank 3 is not limited to a cylindrical shape, and any shape such as a barrel shape or a square shape may be used. Further, the shape of the weight 5a is not limited, and the upper opening of the dissolution tank 3 is sealed to provide a sealed space. Any size and shape can be used.

In the casing 2, a position sensor 7 for detecting the vertical position of the weight 5a is provided. As the position sensor 7, a proximity sensor that detects that the detection object has approached without contact is preferably used, but any other sensor that detects the vertical position of the weight 5 a may be used. It is good also as a structure detected by the feeding length of 5b.
Further, the casing 2 is provided with a cooling means 6 for keeping the solvent in the dissolution tank 3 at 35 ° C. or lower. The cooling means 6 measures the solvent temperature or the space temperature in the casing 2, and operates when the estimated solvent temperature from the measured temperature or the space temperature of the solvent reaches 35 ° C. As the cooling means 6, a wind cooler that blows cooling air into the casing 2 is preferably used.

4 (a) and 4 (b) show detailed views of the volume reducing device. Although the basic configuration is the same as that of FIG. 3, the casing 2 is provided with opening / closing doors 2 </ b> A and 2 </ b> B at an upper portion and a lower portion of one side surface. The upper opening / closing door 2A is a door into which waste foamed polystyrene is introduced. A transparent viewing window 2a is provided so that the state of the waste foamed polystyrene inside can be visually confirmed. Further, a gripping portion 2b having a lock mechanism for the opening / closing door 2A is provided. Is provided. The lower opening / closing door 2B is a door for taking in and out the dissolution tank 3 and introducing the solvent 102 and water 101. Like the upper opening / closing door 2A, the lower opening / closing door 2B is provided with a grip portion 3b having a lock mechanism.
Further, a notification lamp 8 is provided at the upper part of the casing 2 so as to notify the operation / state of the melting apparatus 1. The notification lamp 8 is preferably a triple lamp. For example, when one of the open / close doors 2A and 2B is open, a green lamp is turned on, and the open / close doors 2A and 2B are closed and a safety lock is applied. Sometimes, the status of the melting apparatus is notified by turning on a red lamp or the like. It should be noted that the safety lock is always applied while the weight is being driven.

Here, the operation of the volume reduction device 1 described above will be described. In this embodiment, the case where the volume reduction device 1 is automated is shown.
It is assumed that the dissolution tank 3 in which the solvent 102 and water 101 are stored is already installed in the casing 2.
First, when the operation switch of the casing 2 is turned ON, the weight 5a is raised to the uppermost position by the control unit 5c and stopped. At this time, it is preferable to confirm that the weight 5a is at the uppermost position by the uppermost position sensor 7 (see FIG. 5).
Next, the upper opening / closing door 2A is opened, and the waste foamed polystyrene 100 is introduced. At this time, the notification lamp 8 is lit in green.

When the introduction of the waste foamed polystyrene 100 is completed, the upper opening / closing door 2A is closed and the grip portion 2b is locked. At this time, the notification lamp 8 is lit red.
When the controller 5c detects that the lock mechanism of the grip 2b has been activated, the controller 5c lowers the weight 5a. The lifting speed of the weight 5a is, for example, 15 to 35 mm / sec, and preferably about 25 mm / sec.
As the weight 5a is lowered, the waste foamed polystyrene 100 is pushed into the dissolution tank 3 and immersed in the solvent and begins to dissolve. When the weight 5a is lowered to the lowest position, it is preferable to confirm that the weight 5a is at the lowest position by the lowest position sensor 7 (see FIG. 6).

When it is detected that the weight 5a is at the lowest lowered position, counting of the immersion time is started. It is preferable to adjust the immersion time of the polystyrene foam according to the number of times the solvent is used.
FIG. 7 shows a graph of the number of times the solvent is immersed and the volume reduction rate. As shown in the figure, the volume reduction rate decreases with the number of times the solvent is immersed (number of times of use).
Therefore, the immersion time is minimized when the number of times of use of the solvent is small, and the immersion time is lengthened when the number of uses is large. For example, as shown in FIG. 9 (b), when using a solvent with 10 to 20 immersion times, the immersion time is 30 seconds, and when using a solvent with 70 to 80 immersion times, the immersion time is used. Is 60 seconds.
Thereby, a polystyrene foam can be melt | dissolved reliably. The number of immersions may be input to the control unit 5c, and the control unit 5c may measure the weight rising timing based on the number of immersions.

Further, when the lowermost position sensor 7 does not detect when the weight 5a is lowered, it is determined that the waste foamed polystyrene 100 is caught or the dissolution rate is worse than expected, and the weight 5a is raised again and then lowered. Try again. When the waste foamed polystyrene 100 is caught, it may stick to the side surface of the dissolution tank 3 and be fixed as shown in FIG. Therefore, it is possible to start dipping smoothly by pulling up again and retrying. It is preferable to set an upper limit for the number of retries. For example, retry is made up to 3 times.
Furthermore, as shown in FIG. 7, since the volume reduction rate decreases with the number of immersions of the solvent, it is preferable to adjust the retry time according to the number of immersions as shown in FIG. For example, when using a solvent with 10 to 20 immersion times, the retry time is 45 seconds, and when using a solvent with 70 to 80 times, the retry time is 90 seconds.

  If the door 2A does not open for a longer time than the required processing time with the operation switch ON, it is considered that the operation has been stopped, the operation is automatically stopped, the weight 5a is lowered to the lowest position, and the lid of the dissolution tank 3 is closed. It is preferable that the dissolution tank 3 be taken out.

According to the present example, a single methylene chloride having high volatility is used as a solvent, but since a water film is formed above the methylene chloride and sealed with water, the volatilization of the solvent is prevented. Can do. Further, since the dissolution treatment is performed in the hermetic casing 2 and the dissolution tank 3 is hermetically sealed by the weight 5a, it is possible to prevent volatilization of the solvent as a double sealed structure. Moreover, since it cools with a cooling means when the inside of a casing becomes 35 degreeC or more, it can maintain a solvent at the temperature below a boiling point, and can prevent volatilization.
Furthermore, the casing 2 and / or the dissolution tank 3 may be formed of a heat insulating material, and preferably further heat insulating paint may be applied. This makes it possible to prevent the temperature of the solvent from rising.

Further, according to the present embodiment, a single methylene chloride is used as a solvent, and foreign matters other than styrene remain undissolved, so that the foreign matters can be easily selected.
Since the dissolution apparatus 1 is configured to perform the treatment in the sealed casing 2, it can be an outdoor type, can secure the safety of the user, does not enter from the outside, and has an advantage of improving the solvent recovery rate. .
In this embodiment, no odor is generated as in the heat volume reduction treatment, and there is almost no noise compared to the compression volume reduction and the crushing solvent volume reduction.
Furthermore, if the waste foamed polystyrene 100 is large enough to enter the opening / closing door 2A, it is not necessary to perform pre-treatment such as crushing.

Next, a solvent separation and recovery apparatus according to an embodiment of the present invention will be described with reference to FIG.
The solvent separation and recovery apparatus according to this embodiment is an apparatus that separates, recovers, and recycles the solvent from the gel-like solvent / styrene mixed solution 105 obtained by the volume reduction device 1 shown in FIG.
This solvent separation / recovery device includes a charging unit 21 into which a solvent / styrene mixed liquid 105 is charged, a mixing tank 23 for mixing the mixed liquid and styrene monomer, and the mixed liquid 106 at 100 ° C. or lower under normal pressure. And a solvent separator 25 that evaporates methylene chloride and separates it into a styrene resin liquid and the solvent 107.

Filters 21a and 23a such as oil filters are preferably provided at the bottom of the charging unit 21 and the mixing tank 23, where foreign substances are removed. Pumps 22, 24, and 27 are provided between the charging unit 21 and the mixing tank 23, between the mixing tank 23 and the solvent separator 25, and subsequent to the solvent separator 25, respectively.
The solvent separator 25 includes a heater 26, and the heater 26 heats the temperature of the mixed solution to 100 ° C. or less, preferably about 80 ° C. to vaporize the solvent. The vaporized solvent 107 is sent to the solvent liquefaction regeneration unit 3.
The solvent liquefying and regenerating unit 3 includes a brachinler 31 that generates cold brine, a pump 32 that supplies the cold brine, a heat exchanger 33 that cools the gaseous solvent 107 with cold brine, and the solvent 107. And a liquefier 34 for liquefying. The solvent 108 liquefied by the liquefier 34 is reused as a solvent liquid. Further, a line may be connected from the upper space of the liquefier 34 toward the upper space of the solvent separator 25, and the methylogas fan 28 may be installed on the line.

  From the solvent separator 25, the styrene resin liquid (mixture of polystyrene and styrene oil) from which the solvent has been separated is discharged in a liquid state and introduced into the oil converting apparatus 4. The oil making apparatus 4 is a well-known apparatus. For example, a styrene resin liquid is thermally decomposed in a nitrogen atmosphere and styrene monomer is recovered as a gas. The gaseous styrene monomer is cooled with water or air to form a liquid styrene monomer (styrene). Oil).

Furthermore, in this embodiment, at least a part of the styrene oil produced by the oil generator 4 is returned to the solvent separator 25 or the mixing tank 23 via the return line 110.
In this manner, by adding styrene oil to the gel solvent / styrene mixed solution 105, the mixed solution can be made into a liquid state with high fluidity. A commercially available styrene monomer may be used for the styrene oil.
Thus, if the solvent / styrene mixed liquid 105 is heated at a low temperature of about 80 ° C. under normal pressure, only the solvent evaporates, so that it is energy-saving and separated from the solvent while maintaining the polystyrene quality (molecular weight). It is possible.
In addition, since styrene oil is added to the liquid mixture, the intermediate product from which the solvent has been separated is also in a liquid state and can be transported to the subsequent process with a normal oil pump, which is simple and requires a complicated mechanism. Has the advantage of not.

  According to the present example, the reduced product is made into a liquid state with high fluidity, and the intermediate product obtained by separating the solvent is also a liquid material. Therefore, the solvent can be easily separated, and a separation efficiency of 95% or more can be obtained. It is. Further, foreign substances can be removed in the solvent separation / recovery device. Furthermore, since the solvent can be separated at a low temperature, the solvent can be reused any number of times, and there is no deterioration in polystyrene quality. Furthermore, it can be pumped from the solvent separator to the oil generator. In addition, since the intermediate product has a high density, there are advantages such as downsizing and high efficiency of the oil generator.

It is a whole lineblock diagram showing an example of a processing system to which a solvent separation collection device of the present invention is applied. It is a lineblock diagram of a solvent separation recovery device concerning one example of the present invention. It is a schematic block diagram which shows an example of the volume reduction apparatus applied to the solvent separation collection | recovery apparatus of a present Example. FIG. 4 is a detailed view of the volume reducing device of FIG. 3, (a) is a side sectional view, and (b) is a plan sectional view. It is sectional drawing when waste foam polystyrene is accommodated in the volume reduction apparatus of a present Example. It is sectional drawing at the time of waste foaming styrene melt | dissolution in the volume reduction apparatus of a present Example. It is a graph which shows the correlation of the frequency | count of volume reduction, and the immersion frequency of the waste expanded polystyrene in a melt | dissolution process. It is sectional drawing which shows an example at the time of a retry in the volume reduction apparatus of a present Example. It is a graph (a) which shows the correlation of the frequency | count of retry and immersion time, and the graph (b) which shows the correlation of immersion time and immersion frequency. It is a figure explaining the comparison of the conventional waste polystyrene treatment and the waste polystyrene treatment of this invention. It is a block diagram of the conventional solvent separation collection | recovery apparatus.

Explanation of symbols

1 Volume reduction device (volume reduction machine)
3 Dissolving tank 4 Oil generator 5 Weight mechanism 6 Cooling means 7 Position sensor 23 Mixing tank 25 Solvent separator 26 Heater 31 Blinchler 33 Heat exchanger 34 Liquefier 100 Waste foam polystyrene 105 Solvent / styrene mixed liquid 110 Styrene oil return line 200 Solvent separation and recovery unit 300 Solvent liquefaction regeneration unit

Claims (4)

A solvent separation and recovery method for separating the solvent from a gel-like solvent / styrene mixed solution obtained by dissolving polystyrene foam with a solvent, after the solvent is vaporized and separated by heating the mixed solution, In the solvent separation and recovery method for recovering the vaporized solvent by liquefying,
The solvent is a single component methylene chloride, and after adding a styrene monomer to the mixed solution, the methylene chloride is vaporized by heating the mixed solution at a temperature of 100 ° C. or lower under normal pressure. Solvent separation and recovery method.   The solvent separation and recovery method according to claim 1, wherein the styrene monomer is a styrene oil obtained by separating and removing the methylene chloride from the mixed solution and then oiling. A solvent separation / recovery device for separating the solvent from a gel-like solvent / styrene mixed solution obtained by dissolving polystyrene foam with a solvent, wherein the solvent is heated to vaporize the solvent to separate the solvent. And a solvent separation and recovery device comprising a liquefier for liquefying and recovering the vaporized solvent,
The solvent is a single component methylene chloride, and the solvent separator is an apparatus for heating the mixed liquid at a temperature of 100 ° C. or less maintained in an atmospheric pressure, the solvent separator or the solvent separator A solvent separation / recovery device characterized by further comprising an adding means for adding a styrene monomer to the mixed solution on the upstream side. An oiling apparatus is provided in the latter stage of the solvent separator for oiling the styrene-treated product from which methylene chloride has been separated and removed from the mixture.
The said addition means is the return line which returns at least one part of the styrene oil obtained in the said oil-ized apparatus to the preceding stage side from the said solvent separator or this solvent separator. Solvent separation and recovery device.

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