JPH111571A - Treatment for reducing volume of foamed polystyrene or the like, and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and efficiently subject foamed polystyrene, etc., to a volume-reducing treatment to easily recover the highly pure polystyrene, etc., by immersing the material to be treated in a specific volume-reducing agent heated at the softening temperature of the material or higher. SOLUTION: This method for subjecting foamed polystyrene, etc., to a volume-reducing treatment comprises immersing the material to be treated, such as the foamed polystyrene, in a volume-reducing agent which comprises an aliphatic polyhydric alcohol and which is heated at the softening temperature of the material of higher, preferably at a higher temperature by about 40-70 deg.C than the softening temperature. The aliphatic polyhydric alcohol is preferably e.g. glycerol, a polyethylene glycol including diethylene glycol and triethylene glycol, or trimethylol propane. The aliphatic polyhydric alcohol is preferably mixed with the carbonate, borate, sulfate or phosphate of an alkali metal, the chloride or borate of an alkali (ne earth) metal, triethanolamine, etc. E.g. when the foamed polystyrene is immersed in the heated volume-reducing agent, the foamed polystyrene is reduced into a volume of about 1/100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for efficiently reducing the volume of expanded polystyrene discharged in large quantities as industrial waste and recovering it as high-purity polystyrene. Regarding the device.

[0002]

2. Description of the Related Art Expanded polystyrene (so-called expanded polystyrene) discharged as industrial waste can be efficiently recovered and treated by mechanical crushing, melting with hot air, or dissolving with a solvent. It is necessary to reduce the volume as much as possible to reduce the volume.

As the chemical dissolution treatment using a solvent, a room temperature dissolution method using limonene and a high temperature dissolution method using a solvent such as glyceride containing glycerin ester as a main component are known. In the former, foamed polystyrene is dissolved in limonene at room temperature, and the solution is distilled to separate limonene and recover polystyrene. In the latter, polystyrene is dissolved in a solvent heated to about 100 ° C. or higher, and the solution is cooled to precipitate polystyrene, and the polystyrene is recovered by separating the solvent.

[0004]

According to the prior art, it is difficult to increase the volume reduction rate by mechanical crushing, and the melting by hot air is difficult due to the high heat insulation of the expanded polystyrene. However, there is a disadvantage that the surface temperature is too high and the quality of the recovered polystyrene tends to deteriorate. In addition, chemical dissolution requires a distillation step and a cooling step to separate the solvent, which results in a large-scale facility and an excessively low running cost due to poor energy efficiency. There is a problem that it is unsuitable for a proper processing.

Accordingly, an object of the present invention is to solve the problems of the prior art and to reduce the object to be processed quickly and efficiently by using a specific volume reducing agent and combining a heating tank and a processing frame. It is an object of the present invention to provide a method for reducing the volume of foamed polystyrene or the like, which can be subjected to volumetric treatment and can easily recover high-purity polystyrene even in a small-scale process, and an apparatus therefor.

[0006]

According to a first aspect of the present invention for achieving the above object, a volume reducing agent comprising an aliphatic polyhydric alcohol is heated to a temperature higher than a softening temperature of a material to be treated, The gist is to reduce the volume by immersing the object to be treated.

According to a second aspect of the present invention, there is provided a heating tank for heating a volume-reducing agent, and a processing frame disposed above the heating tank, wherein the processing frame contains an object to be processed contained therein. The essence of the method is to immerse the resin in a volume reducing agent in a heating tank and pull it up.

[0008] The heating tank is incorporated in the lower part of the vertically long main body frame, and the processing frame can be incorporated in the main body frame so as to be able to move up and down. A processing position in the heating tank and an intermediate recovery position can be taken.

Further, the main body frame may have an opening / closing shutter below the loading position of the processing frame and above the heating tank, and may have an opening / closing door in front of the recovery position of the processing frame.

Further, a movable perforated plate can be incorporated into the processing frame so as to be able to be turned upside down.

The processing frames may be arranged outwardly along the outer periphery of the rotating body that rotates vertically.

[0012]

According to the structure of the first aspect, the volume-reducing agent is heated to an appropriate volume-reducing temperature equal to or higher than the softening temperature of the object to be treated, and the object to be treated is charged and immersed. The treated product is quickly softened, and can be almost completely defoamed to reduce its volume. The material to be treated after volume reduction (hereinafter, referred to as a volume-reduced material) is taken out, washed with water to remove the adhering volume-reducing agent, and dried at high temperature to obtain a purity of about 96 to 99%. It can be recovered as the above solid. Further, the above processing steps are extremely simple and do not require any oversized equipment, so that they can be suitably used for small-scale processing.

When the material to be treated is expanded polystyrene, a preferable volume reducing agent is, for example, an aliphatic polyhydric alcohol such as glycerin, diethylene glycol, polyethylene glycol including triethylene glycol, and trimethylpropane. These materials have low softening temperature of expanded polystyrene, do not dissolve expanded polystyrene,
It is not easily adsorbed by polystyrene and has no flammability near the volume reduction treatment temperature above the softening temperature, low vapor pressure at high temperatures, little evaporation loss, chemically stable, no risk of deterioration, easy water solubility It has excellent properties such as easy removal from polystyrene after volume reduction by washing with water, non-toxicity to the human body, low cost and easy availability.

It is important that the volume-reducing agent does not dissolve polystyrene by itself and is hardly adsorbed by polystyrene. This is because, when polystyrene is dissolved in the volume reducing agent, the recovery efficiency of polystyrene is reduced, and the volume reducing agent is rapidly deteriorated, and the regeneration treatment is extremely troublesome. Further, if the volume reducing agent is adsorbed to the polystyrene, the purity of the recovered polystyrene decreases, and it becomes difficult to reuse the polystyrene as a recycled material, and the subsequent purification treatment is not easy. Therefore, by adopting an aliphatic polyhydric alcohol such as glycerin as the main agent of the volume-reducing agent, the impurities in the recovered polystyrene are limited to only water, and high-purity is achieved by removing the water by a high-temperature drying step. Can easily be recovered.

When the volume reducing agent absorbs a large amount of water or when the amount of water adsorbed on polystyrene is large, excessive water is likely to be contained as an impurity in the polystyrene after volume reduction. Therefore, the polystyrene after volume reduction is
Unnecessary moisture is removed by drying at high temperature, but even in that case, the water content in the polystyrene after volume reduction is
In order to shorten the drying time and reduce the required heat of drying,
It is preferred to keep it to a minimum.

Any one of alkali metal carbonates, borates, sulfates, phosphates, alkali metal or alkaline earth metal chlorides, and boric acid is added to the aliphatic polyhydric alcohol.
By adding the above, the water absorption of the aliphatic polyhydric alcohol itself is reduced, water is prevented from adsorbing to the polystyrene after volume reduction, and the boiling point of the aliphatic polyhydric alcohol is raised to reduce the evaporation. It is effective to reduce The same is true for boric acid.

For example, for glycerin, K ₂ CO
₃ , 1 to 5% by weight of either Na ₂ B ₄ O ₇ or boric acid
When the glycerin is added, the boiling point of glycerin increases by 20 to 50 ° C., and when 2 to 3% by weight of K ₂ CO ₃ is added, the flame retardancy of glycerin is improved.
When ₂ to 5% by weight of Na ₂ B ₄ O ₇ is added, the amount of water adsorbed on polystyrene after volume reduction is reduced by about 10% by weight.
To about 3%. further,
By K added ₂ CO ₃ or Na ₂ B ₄ O ₇ 2~5 wt%, reduce the water absorption of the glycerin itself in 10 days about 10 to 15% by weight to about 2 to 3% it can. One or more of these additives can be added, and the amount of each additive is
The content is preferably about 1 to 15% by weight, particularly preferably 1 to 5% by weight, based on the aliphatic polyhydric alcohol.

Further, one or more of triethanolamine and triisopropanolamine may be added to the aliphatic polyhydric alcohol. Triethanolamine,
Triisopropanolamine, like alkali metal carbonates, can reduce the water absorption of aliphatic polyhydric alcohols and the adsorption of water to polystyrene, and increase the boiling point of aliphatic polyhydric alcohols. It is effective in reducing evaporation loss. For example, when triethanolamine or triisopropanolamine is added to glycerin in an amount of 10 to 20% by weight, the water absorption of glycerin and the amount of water adsorbed by polystyrene are reduced by half respectively.
It can be reduced to 1/5. One or two of these additives can be added, and the amount added to the aliphatic polyhydric alcohol is about 1 to 20% by weight, particularly preferably 3 to 10% by weight.

The volume reducing agent is used at a temperature lower than the softening temperature of the material to be treated.
It is preferred that the heating be performed at a high temperature of about 0 to 70C. For example, if the softening temperature of the expanded polystyrene is about 110C, the volume reducing agent may be heated to about 150-180C. However, it may be preferable to heat the volume reducing agent to 200 ° C. or higher depending on the type of expanded polystyrene. Expanded polystyrene can be softened and defoamed quickly as soon as it is immersed in a volume-reducing agent, and its volume can be reduced to about 1/100.

According to the structure of the second aspect, the processing frame is formed by immersing the processing object in a volume reducing agent in a heating tank heated to a temperature higher than the softening temperature of the processing object. It can be softened quickly, defoamed and reduced in volume, and can be recovered as a high-purity volume-reduced product by pulling it out of the heating tank.

When the heating tank and the processing frame are incorporated in the vertically long main body frame, the processing frame accommodates the object to be processed, is lowered into the heating tank, and is processed by the volume reducing agent in the heating tank. It is possible to reduce the volume of the material, raise the material as it is, collect the reduced volume material, and batch-process the material to be processed.

The processing frame, which takes an upper loading position, a lower processing position, and an intermediate collecting position, receives a workpiece from the outside at the loading position and lowers it to the processing position to reduce the volume of the workpiece. Then, the volume-reduced material can be taken out by raising it to the collection position.

When the upper and lower shutters and the front door are provided on the main body frame, the upper shutter and the front door open the upper part of the heating tank to the outside when the processing frame is in the processing position. When the processing frame is in the recovery position and the charging position, the upper opening of the heating tank can be sealed, and the evaporation loss of the volume reducing agent in the heating tank can be minimized. it can.

When the movable plate is incorporated into the processing frame, the movable plate stands up and forms a slope when the processing frame is at the recovery position, and the volume-reduced material can be easily removed from the processing frame to the outside. Can be discharged.

When the processing frame is arranged on the outer periphery of a rotating body that rotates vertically, the processing frame is rotated by rotating the rotating body so that the object to be processed is charged and stored on one side, and the volume is reduced as it is. It can be immersed in an agent and discharged on the other hand, and the object can be continuously subjected to volume reduction.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

An apparatus for reducing the volume of expanded polystyrene or the like comprises a heating tank 21 and a processing frame 31 as main members (FIG. 1, FIG.
(Fig. 2). However, the heating tank 21 and the processing frame 31 are incorporated in the main body frame 10 together with the drive shaft 41 that moves the processing frame 31 up and down.

The main body frame 10 includes a lower frame 11,
Left and right side walls and rear side walls 12, 12,..., Upper frame 1
3, and are formed vertically long. However, FIG.
2 shows only the rear side wall 12. A collection chamber 14 is formed on the front surface of the lower frame 11,
Above the collection chamber 14, an inlet 10a is opened. A double door 14a, 1
4a, a perforated partition plate 14 is provided at the bottom.
b is provided. The container room 1 is located below the collection room 14.
4c is formed, and a container 14d for liquid recovery is housed in the container chamber 14c so as to be able to be taken out. A net lid 14d1 is provided on the upper surface of the container 14d. An opening / closing door 16 that can be opened downward toward the collection chamber 14 is attached to an intermediate portion of the main body frame 10.

An inspection door 17 is provided on the back of the main body frame 10.
Are provided so that they can be opened and closed freely.
Each is provided with a cover 12a. In addition, ventilation holes 12a1,
12a2 are formed, and the ventilation holes 12a1 and 12a2 are formed.
Is to introduce outside air between the cover 12a and the side wall 12, thereby preventing the cover 12a from becoming hot.

The heating tank 21 is formed in a box shape having an open top and is incorporated in the lower frame 11 of the main body frame 10. In addition, on the entire circumference including the bottom of the heating tank 21,
A heat insulating material 21a is provided. A heater 2 is provided at the rear of the heating tank 21 via left and right brackets 22a, 22a.
2, 22,... Are incorporated (FIGS. 2, 3).

The processing frame 31 is incorporated in the main body frame 10 via a drive shaft 41 so as to be able to move up and down (FIGS. 1 and 4).

The processing frame 31 is formed in a box shape with an open front through a perforated plate such as a punching metal, and a movable plate 32 is incorporated therein. Movable eye plate 32
Are formed by connecting thin bars bent in an L shape in a frame shape. The movable eye plate 32 includes left and right hinge pins 32b,
The processing frame 31 is rotatably mounted below the front portion of the processing frame 31 via one of the hinge pins 32b.
An operation rod 32c that is bent rearward outside the outside. However, the tip of the operation rod 32c is formed in a hook shape. Thus, the movable plate 32 can be erected forward in the processing frame 31 by rotating the operation rod 32c upward (two-dot chain line in FIG. 4). By driving it downward (solid line in the figure), it can be made parallel to the bottom surface of the processing frame 20.

A slide member 31a slidably engaged with the drive shaft 41 is provided on the back surface of the processing frame 31 (FIGS. 1 and 2). A pair of guide pieces 31a1 and 31a1 are rotatably incorporated in the upper and lower surfaces of the slide member 31a (FIGS. 2 and 4).
Reference numeral 31a1 slidably sandwiches both surfaces of the drive shaft 41. The drive shaft 41 is formed by spirally twisting a long band-shaped plate material.

The upper end of the drive shaft 41 is connected to a drive motor 41a mounted on the upper frame 13 (FIG. 1).
The lower end is rotatably supported by a holder 41b mounted on the bottom surface of the heating tank 21. Therefore, the processing frame 31
By rotating the drive shaft 41 in the normal and reverse directions via the drive motor 41a, the upper position of the main body frame 10 (solid line in FIG. 1) and the heating tank 2
1 can be freely moved up and down with respect to the processing position (dashed line in FIG. 1). In addition, the processing frame 31 includes the opening / closing door 1.
6 can also be stopped at an intermediate collection position (two-dot chain line in the same figure). The drive shaft 41 and the heater 2
2, 22,... Can perform necessary maintenance and inspection work by opening the inspection door 17 on the rear surface.

A drive rod 15 is vertically arranged on the main body frame 10 in order to raise and lower the movable plate 32 in the processing frame 31 at the collection position. However, the lower end of the driving rod 15 is bent in a hook shape so as to be able to engage with the operating rod 32c of the movable plate 32.
The upper frame 1 is connected via the rotary actuator 15c.
3 is connected to a cylinder 15b.

Therefore, the drive rod 15 can be rotated 90 ° in the normal and reverse directions via the rotary actuator 15c to disengage the bent portion at the lower end of the drive rod 32c (the solid line and the two-dot chain line in FIG. 2). ). In addition, the drive rod 15 engages the bent portion at the lower end with the operation rod 32c, and pulls it upward through the cylinder 15b, so that the movable perforated plate 32 in the processing frame 31 at the collection position is erected diagonally. (Two-dot chain line in FIG. 1).

The heating tank 21 contains a volume reducing agent L in such an amount that the processing frame 31 can be sufficiently sunk (FIG. 1). The volume-reducing agent L is heated to a predetermined temperature equal to or higher than the softening temperature of the product, and is kept on standby. However, the volume reducing agent L
Contains aliphatic polyhydric alcohol as a main component, and if necessary,
Adjust by mixing appropriate amounts of additives. Also, the processing frame 31
In the upper part of the main body frame 10, the workpiece is loaded onto the movable eyeglass 32 via the front loading port 10a (in the direction of the arrow Ka in FIG. 1). Thereafter, the processing frame 31 is moved to the heating tank 21 via the drive motor 41a and the drive shaft 41.
To the inside processing position, and the whole can be immersed in the volume reducing treatment agent L.

When the processing frame 31 is lowered to the processing position, the object to be processed in the processing frame 31 is heated by the volume reducing agent L to be quickly softened, and the volume is reduced while defoaming. It can be subjected to volume reduction as a high-purity, high-density volume reduction product. After a lapse of a predetermined time, the processing frame 31 is raised to the collection position.

Therefore, the driving rod 15 is engaged with the operating rod 32c via the rotary actuator 15c, and is lifted upward via the cylinder 15b, so that the movable perforated plate 32 in the processing frame 31 is inclined upright. . Therefore, the volume-reduced material on the movable plate 32 falls into the collection chamber 14 via the opening / closing door 16 (arrow Kb in FIG. 1).
Direction), and can be collected in the collection chamber 14. The volume-reduced material at this time can be removed through the perforated partition plate 14b to remove the volume-reducing agent adhering thereto and then taken out through the doors 14a, 14a (arrows in FIG. 2). Kc direction). The volume-reduced material taken out is washed with water and dried to recover high-purity polystyrene. Further, the processing frame 31 may be raised to the loading position as it is, and the same procedure may be repeated.

The opening / closing door 16 is supposed to be raised and opened at the collection position via a suitable connecting mechanism (not shown). However, the opening / closing door 16 may be provided with an opening / closing mechanism independent of the movable eye plate 32, and may be opened when the movable eye plate 32 is raised.

In the above description, the heating tank 21 may be controlled to energize the heaters 22 via a suitable temperature controller so as to keep the temperature of the volume reducing material L constant. Further, the drive shaft 41 may use a screw shaft or a drive mechanism such as a chain instead of the spiral plate. Further, the processing frame 31 may be formed of an appropriate net material instead of the punching metal.

[0042]

[Other Embodiments] A processing frame 3 is provided on a main body frame 10.
The shutters 19a, 19a are disposed below the loading position of the heating tank 21.
b, 19b may be provided (FIG. 5).

The opening / closing shutters 19a, 19a are attached to the main body frame 10 with both sides open upward.
The opening / closing shutters 19b, 19b are attached to the heating tank 21 so as to open downward at both sides. Open / close shutter 19
When the processing frame 31 is at the loading position, the processing frames 31a and 19a are opened upward (solid line in FIG. 5) and closed horizontally by lowering the processing frame 31 from the loading position (two-dot chain line in FIG. 5). . Further, the opening / closing shutters 19b, 19b open downward when the processing frame 31 descends to the processing position (two-dot chain line in the same figure) and close horizontally when the processing frame 31 rises (solid line in the same figure). . Therefore, the opening / closing shutters 19a, 19
a, 19b, and 19b, together with the opening and closing door 16, are opened only when necessary, and when unnecessary, the upper part of the heating tank 21 is sealed to suppress the evaporation loss of the volume reducing agent L in the heating tank 21. Can be.

The processing frame 31 is a rotating body 3 that rotates vertically.
Processing frames 3 arranged outwardly along the outer circumferences of 4, 34
3, 33... (FIGS. 6, 7).

The processing frames 33, 33... Are provided with partition plates 33a, 33a.
Is provided between the two rotating bodies 34, 34. The rotating bodies 34, 34 are fixed to a drive shaft 35 via bosses 34a, and can be rotated up and down via the drive shaft 35 (in the direction of arrow K1 in FIG. 6).
The lower portions of the rotating bodies 34 are immersed in the volume reducing agent L in the heating tank 21.

The main frame 10 has front and rear insertion ports 10.
a, an outlet 10b is formed, and a collection box 10c is disposed below the outlet 10b. Also,
The heating tank 21 is provided with front and rear guides 23 along the lower portions of the rotating bodies 34. When each processing frame 33 faces the input port 10a, the lower partition plate 33a becomes substantially horizontal, and when the processing frame body 33 faces the discharge port 10b, the lower partition plate 33a has an inclination angle θ from horizontal to downward.
Shall be taken.

The rotating frames 33, 33...
4 is rotated in the direction of the arrow K1 in FIG. 6, whereby the object to be processed is charged into the inside through the charging port 10a (in the direction of the arrow Kd in FIG. 6). It can be conveyed backward, the volume-reduced material can be pulled up from the volume-reducing agent L, and can be discharged to the external collection box 10c via the discharge port 10b (in the direction of the arrow Ke in the figure). In addition,
The guides 23, 23 prevent the object to be processed and the material to be reduced in the processing frame 33 from being inadvertently released to the outside at an unspecified position. However, the material to be processed and the volume reduced
In general, since the specific gravity is smaller than that of the volume reducing agent L, there is no possibility of falling from the downwardly facing processing frames 33 into the volume reducing agent L.

The heating tank 21 shown in FIG. 6 is provided with a level sensor 24. The level sensor 24 measures the level of the volume reducing agent L in the heating tank 21 and, together with a level controller (not shown), directs the downwardly directed processing frames 33, 3
The level of the volume reducing agent L can be controlled so that 3 is sufficiently sunk in the volume reducing agent L.

The present invention can be effectively applied to thermoplastic plastic foams other than expanded polystyrene. The volume-reduced material recovered in the recovery chamber 14 or the recovery box 10c may be mechanically removed from the volume-reducing agent adhering thereto by using an appropriate centrifugal separator.

[0050]

As described above, according to the first aspect of the present invention, the volume of the object to be treated is reduced by immersing the object in a volume reducing agent heated to a temperature higher than the softening temperature of the object. The volume-reducing agent does not dissolve the material to be treated, is hardly adsorbed on the material to be treated, and quickly softens the material to be treated, reduces the volume while defoaming, and can perform the volume-reducing treatment very efficiently. It is also suitably applied to small-scale processing steps, and has an excellent effect that high-purity polystyrene can be easily recovered.

According to the second aspect of the invention, the heating tank for heating the volume reducing agent is combined with the processing frame for immersing the object to be accommodated in the volume reducing agent and pulling it up. Can be implemented smoothly.

[Brief description of the drawings]

FIG. 1 is a side view of the overall configuration.

FIG. 2 is a sectional view taken along line XX of FIG. 1;

FIG. 3 is a sectional view taken along line YY of FIG. 2;

FIG. 4 is an enlarged perspective view of a main part.

FIG. 5 is an explanatory front view showing another embodiment.

FIG. 6 is an explanatory side view showing another embodiment.

FIG. 7 is an enlarged perspective view of a main part of FIG. 6;

[Explanation of symbols]

 L: Volume reducing agent 10: Body frame 16: Opening / closing door 19a, 19b: Opening / closing shutter 21: Heating tank 31, 33 ... Processing frame 32: Movable plate 34: Rotating body

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 26

Claims (7)

[Claims] 1. A volume reducing treatment for foamed polystyrene or the like, characterized in that a volume reducing agent composed of an aliphatic polyhydric alcohol is heated to a temperature higher than the softening temperature of an object to be treated and the object is immersed to reduce the volume. Method. 2. A heating tank for heating a volume-reducing agent, and a processing frame disposed above the heating tank, wherein the processing frame heats an object to be housed therein. A volume reduction device for foamed polystyrene or the like, characterized by being immersed in a volume reduction agent in a tank and raised. 3. The volume reduction processing of expanded polystyrene or the like according to claim 2, wherein the heating tank is incorporated in a lower part of a vertically long main body frame, and the processing frame is incorporated in the main body frame so as to be able to move up and down. apparatus. 4. The processing frame body has an upper charging position, a processing position in the heating tank, and an intermediate recovery position in the main body frame.
An apparatus for reducing the volume of the expanded polystyrene or the like. 5. The processing apparatus according to claim 1, wherein the main body frame includes an opening / closing shutter below the input position of the processing frame and an upper portion of the heating tank, and includes an opening / closing door in front of a recovery position of the processing frame. An apparatus for reducing the volume of the expanded polystyrene or the like according to claim 4. 6. The apparatus for reducing the volume of expanded polystyrene or the like according to claim 3, wherein a movable perforated plate is incorporated into the processing frame so as to be able to be turned upside down. 7. The apparatus for reducing the volume of polystyrene foam or the like according to claim 2, wherein the processing frames are arranged outwardly along the outer periphery of a rotating body that rotates vertically.