JPH06104755B2 - Synthetic resin recovery method and recovery device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a synthetic resin recovery method and a recovery device used in various synthetic resin industries, molding industries using synthetic resins, and the like.

[Prior Art] A defective product of a conventional synthetic resin product, a used synthetic resin product, or the like is usually disposed of.

[Problems to be Solved by the Invention] However, defective products or used products of the abandoned synthetic resin described above are, for example, polystyrene, polyethylene,
Polypropylene does not corrode and remains semi-permanently at the disposal site, causing pollution. The present invention has been made to solve such a problem, and an object thereof is to provide a method and a recovery device for a synthetic resin from a defective product or a used product of the synthetic resin.

[Means for Solving the Problems] With regard to the present invention for achieving the above object, first, a method is described. It is a method of dissolving a synthetic resin 10 in an organic solvent to form a solution 17, and the solution 17 is added to a lower portion. Concentrated liquid 15 having a heater 16 and a concentrated liquid collecting passage 15a at the upper portion
Part of the solvent is evaporated by using the above to concentrate, the evaporated solvent is cooled and recovered, and the concentrated liquid is collected from the concentrated liquid collecting passage 15a at the upper part of the concentrated liquid 15, which is collected. , Having a spinning nozzle 27 consisting of a large number of fine holes at the bottom,
Further, the decompression chamber 25 is housed in a liquid tank 24 provided with a decompression chamber 25 below the bottom, and the decompression chamber 25 is decompressed by a vacuum pump 26, whereby the concentrated liquid is spun from the spinning nozzle 27 of the liquid tank 24.
A synthetic resin characterized by being spun as 28 and hanging down, and the solvent of the filament 28 is sucked and dried from the filament 28 by the vacuum pump 26, and the sucked solvent is recovered by a recovery device 29a. Is the method of collection.

Further, regarding the recovery device, it is a dissolution device 1 for dissolving a synthetic resin in an organic solvent, which is formed in communication with the dissolution device 1, has a heater 16 in the lower portion, and has a concentrated liquid collecting passage 15a in the upper portion. A concentrating device 14 having a concentrating tank 15 having; a cooling recovery device 18a for cooling and recovering the solvent evaporated from the concentrating device 14; provided in communication with the concentrated liquid collecting passage 15a of the concentrating tank 15 at the bottom. Spinning nozzle 27 consisting of many fine holes
And a liquid tank 24 having a decompression chamber 25 below the bottom; an organic solvent recovery device 29a provided in the decompression chamber 25 via a suction vacuum pump 26; This is a synthetic resin recovery device.

[Operation] The present invention is configured as described above, the solution 17 of the organic solvent in which the synthetic resin 10 is dissolved is heated and concentrated, and the spinning nozzle 27 provided at the bottom of the liquid tank 24 is provided with a large number of fine holes. Decompression chamber
25 A large number of yarns 28 are made to flow down, and in this decompression chamber 25, a solvent is suctioned and collected by a vacuum pump 26, and this is collected by a collecting device 29a. As a result of the concentrated solution 17 having an extremely large surface area with respect to the volume, the area where the solvent evaporates becomes extremely large, and the entire evaporation is effectively performed. Therefore, the recovery yield of the solvent is greatly increased. Can be increased to

Also, when the solution 17 concentrated as described above is made to flow down from the spinning nozzle, evaporation due to concentration is performed, and this can be recovered by distillation, which also improves the recovery yield.

Further, since the synthetic resin 10 to be recovered is formed into the filament body 28 all in an integral shape, it can be easily used as a raw material after recovery.

[Embodiment] In FIG. 1, reference numeral 1 denotes a dissolving device, which is composed of, for example, a conveyor 2, an injecting nozzle 3 of an injecting liquid, an injecting device 5 including a pump 4, an injecting chamber 6, and an air curtain device 7. The conveyor 2 is, for example, a meshless net conveyor, which is mounted between the drive pulley 8 and the driven pulley 9 and rotated in the direction of arrow A2.

As an example, 10 indicates a raw material for recovery such as expanded polystyrene. The injection nozzle 3 is connected to a pump 4 which is connected to a solvent tank 11. The tank 11 contains a chlorine-based organic solvent such as trichloroethane, trichloroethylene, and methylene chloride, and trichloroethylene is contained as an example. The tank 11 may contain not only the chlorine-based organic solvent as described above, but also a normal organic solvent, such as carbon dioxide and acetone. The reason why the chlorine-based organic solvent is used as an example as described above is that there is little risk of fire.

Further, 12 is a bottom portion of the injection chamber 6, and 13 is a collecting pipe. Raw material 10
Is dissolved by the injection of trichlorethylene injected from the injection nozzle 3, and is made to flow from the bottom 12 of the injection chamber 6 through the collecting pipe 13 into the concentration tank 15 of the concentration device 14. Reference numeral 16 denotes a heater provided in the concentrating tank 15. The heater 16 heats the synthetic resin solution 17 in the concentrating tank 15 to vaporize the solvent and concentrate the solution 17.

Reference numeral 18 denotes a heat exchanger for liquefaction, which is made of stainless steel and is connected to a cooler 19. 20 is an aggregator.

In the concentrating tank 15 above the boiling point of the solution 17, that is, in the case of trichloroethylene is heated by the heater 16 to about 40 ℃ ~ 80 ℃, the solution 17 is vaporized, the gas is cooled in the heat exchanger 18, It is liquefied there, dropped on the inclined agglomerator 20 and poured into the tank 11. This is also done with acetone, carbon difluoride and the like.

Next, 15a is a concentrated liquid collecting passage formed in the upper part of the concentrating tank 15, and one of its forms is an overflow device.
21 are formed. This is configured so that the overflowed solution 17 in the concentrating tank 15 flows out. The outflowing solution 17 is in a state where the synthetic resin is concentrated.

Further, when the concentration is carried out in this way, the concentration of the synthetic resin becomes higher toward the upper side. Therefore, a concentrated liquid having a high concentration can be obtained by this overflow. Reference numeral 22 indicates a suction pump.

Next, 23 is a separating device for separating the synthetic resin and the solvent. 24 is a liquid tank, 25 is a decompression chamber, and the chamber 25 is connected to a vacuum pump 26 for suction. 27 is a spinning nozzle having a large number of fine holes, and the fine holes are formed to have a size of 5 microns as an example, and 250 holes are formed as an example.

Then, when the vacuum pump 2 is operated and suction is made to about 10 torr, the decompression chamber 25 is decompressed, and the filament 28 of synthetic resin appears from the spinning nozzle 27 and is formed.

At that time, the solvent is sucked by the vacuum pump 26, and the recovery device 29a.
Sent to. 29 is an adsorption device using activated carbon as an example.

30 is an acid resistant turbo blower, and 31 is an inlet. Further, 32 indicates a collecting tray, and 33 indicates a take-out door.

Then, the spun yarn 28 stops the vacuum pump 26, opens the door 33, takes out the dish 32, and is taken out of the separating device 23. The spun form 28 becomes hard with the passage of time, and a raw material is formed by a crusher (not shown). Next, the recovery device 29a
The adsorbing device 29 is formed as shown in FIG. 2 and has a flexible tube 34 inside. 35 is activated carbon.

Next, 36 is a pipe line connected to the flexible pipe 34, to which the three-way valve 37
Is provided, and this pipe line 36 is connected to the cooler 19 shown in FIG.
And the heating device 38 are branched and communicated with each other.

In FIG. 1, 39 is a low pressure in-line compressor,
40 is a gas inlet, 41 is the same outlet, and these are each provided with a switchgear. In the meandering pipe 34, heat and refrigerant are circulated by being cooled by the cooler 19 shown in FIG. 1 or by being heated by the heating device 38 by operating the three-way valve 37. There is.

Next, in FIG. 1, 42 is the air supplied to the adsorption device 29,
It is a heater for the carrier air, in which the carrier air is heated and supplied to the adsorption device 29 through the inlet 43 of the carrier air. Reference numeral 45 is a carrier air discharge passage. Next, in FIG. 3, 46 is a cooling device, 47 is a casing, 48 is a flexible pipe, which is connected to a refrigerator 49, and a refrigerant such as CFC is circulated inside. 50
Is an example of a contact member made of stainless steel and made of steel wool for increasing the area of contact with gas.

51 indicates a stainless steel punching plate.
Reference numeral 52 is a supply port for a mixed gas of carrier air and gas. And the cooling device 46 is cooled to approximately -10 ° C,
As a result, most of trichloroethylene is liquefied and recovered. Next, 53 is a liquid level sensor, which is the control device shown in FIG.
Connected to 54. Incidentally, various devices described above and below,
It goes without saying that various power units and the like are connected to the control unit 54 so as to operate in a sequence.

Next, 55 is an upper communication pipe, 56 is a lower communication pipe, 57 is an upper valve, 58
Is a lower valve, 59 is a vacuum pump, and 60 is a liquefier. The liquefaction device 60 is connected to a second refrigerator 61, and its cooling head 62 is made of copper as an example, and is cooled to -90 ° C. by the second refrigerator 61 as an example. The liquefying device 60 can cool the target gas below the freezing point by the second refrigerator 61.

Reference numeral 63 is a cooler, and 64 is a side wall, which is composed of, for example, a large number of concentric copper cylinders. As shown in FIG. 5, the cylindrical side walls 64 are formed with passages 65 on opposite sides of the adjacent side walls 64 so that the gas passage becomes longer. The side wall 64 may also be formed in a spiral shape as shown in FIG. Next, 66 shown in FIG. 4 is a bottom wall, and a liquid flow-down port 67 is formed therein.

Further, 68 is a heating member, and a sheet heater is used as an example. The member 68 is wound around the cooling head 62 and connected to the control device 54.

A mixed gas composed of trichloroethylene and air is fed into the adsorption device 29 through the inlet 40. At that time, the activated carbon 35 in the adsorption device 29 is, for example, approximately -5 ° C to -10 ° C due to the heat and the refrigerant supplied from the cooler 19 circulating in the flexible pipe 34.
Therefore, trichloroethylene in the mixed gas is effectively adsorbed on the activated carbon 35. And this adsorption is performed for about 15 minutes as an example. The length of this adsorption time is determined by the control device 54 by a gas concentration sensor (not shown) provided at the inlet 40, and is executed. The temperature may be almost the same even when the solvent is an ordinary solvent such as acetone.

Next, the inlet 40 and the outlet 41 are closed, the three-way valve 37 is switched together with it, the heated heat from the heating device 38, the refrigerant is supplied to the flexible pipe 34, the activated carbon 35 is 120 ℃ as an example. To be heated.

At the same time, the vacuum pump 69 operates, and the inside of the adsorption device 29 is in a vacuum state of about 10 torr, for example. Then, in this state, from the inlet 43 of the carrier air to the heater 42
After that, as an example, the carrier layer heated to about 120 ° C. is supplied. In this case, the activated carbon 35 desorbs trichloroethylene, and the desorbed trichlorethylene is selected by the carrier air and supplied to the cooling device 46. Then, these controls are performed by the control device 54.

In FIG. 1, the acid-resistant turbo blower 30 can take in air from the outside as shown in the figure, so that the solvent gas does not leak out from the housing of the entire apparatus (not shown).

Next, the carrier air containing trichloroethylene is supplied from the supply port 52 of the cooling device 46 shown in FIG. In this case, the vacuum pump 59 is operated and is sucked.

The inside of the cooling device 46 is kept at about 0 ° C., which is a temperature below the boiling point of trichlorethylene, as an example. Therefore, the trichlorethylene in the mixed gas comes into contact with the flexible pipe 48 and the contact member 50 and is cooled and liquefied. , Drops onto the bottom of the casing 47 and is stored there as trichloroethylene liquid. When the trichloroethylene liquid reaches the sensor 53, the upper valve 57 is closed by the output from the controller 54,
The lower valve 58 is opened, and the trichloroethylene liquid enters the lower part of the liquefaction device 60 through the lower communication pipe 56 and is stored therein. In this part, water that has entered as atmospheric humidity is separated by specific gravity.

Note that the cooling device 46, as an example, is almost
It was about 400,000 PPM, but at the exit, it is almost 20,000 PPM.

Next, the mixed gas in the cooling device 46 is fed to the liquefying device 60 by the vacuum pump 59, and as an example there, -90 ° C.
And is solidified on the side wall 64 and the heating member 68. The operating time for this coagulation is, for example, about 15 minutes. The clean air that has lost trichloroethylene is adsorbed again.
It will be sent to 29. (Illustration is omitted) Then, the solidified trichlorethylene is a heating member.
The liquefier 60 is liquefied by the liquefier 60 by a temperature of not higher than the boiling point of trichlorethylene, for example, 0 ° C. to liquefy the solidified trichlorethylene, and the liquefied device 60 is liquefied and flowed down from a downflow port 67 to be sent to the tank 11. To be Although the above description has been given with respect to trichlorethylene as a chlorine-based organic solvent as an example, in the case of an ordinary organic solvent such as acetone or carbon difluide, it is performed in almost the same steps depending on the temperature while paying attention to fire.

Further, the object of the present invention is to recover the synthetic resin from the used synthetic resin product, the defective product of the synthetic resin and the like as described above, but as another example, a shell core is used in casting casting. A disappearing model is formed around polystyrene by using foamed polystyrene, and when this model is defective, this method can be used to recover the shell core. Polystyrene can also be collected.

EFFECTS OF THE INVENTION The present invention is configured as described above, the synthetic resin is dissolved in an organic solvent, the solution is heated and concentrated, and the concentrated solution is discharged from a spinning nozzle composed of a large number of fine holes to reduce a large number of particles. Since the concentrated solution as a whole is flowed down as a filament and the solvent is evaporated to be recovered, the concentration of the surface area with respect to the volume can be extremely increased as a whole, and thus the evaporation area of the solvent can be extremely increased. This makes it possible to effectively evaporate the solvent. Therefore, the yield of solvent recovery can be greatly increased.

Also, when heating and concentrating the solution in order to make it flow down from the spinning nozzle as described above, evaporation can be carried out by the concentration, and this can be recovered by distillation, so that the recovery yield can be increased.

Further, since the synthetic resin to be recovered has a constant shape as a filament body, it can be easily used as a raw material after recovery.

Further, since the heater 16 is provided in the lower part of the concentrating tank 15 and the concentrated liquid collecting passage 15a is formed in the upper part, and generally when the concentration by heating and evaporation is performed as described above, the concentration is higher in the upper part of the liquid. Since it is formed, the sampling passage 15 provided at the top
Although a simple mechanism can be obtained from a, only concentrated concentrates can be obtained.

Further, the concentrated liquid is hung down by the spinning nozzle 27 as a filament 28 and dried, but this droop can be retained in the air for a long time as compared with, for example, flushing, and therefore should be sufficiently dried. You can In the case of flushing or the like, there is a drawback that the amount of remaining solvent is large. Further, the thread body 28 can be immediately formed into pellets having the same thickness by a crusher or the like, which is easy to handle as a resin material.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a view showing an outline of a method for recovering synthetic resin, FIG. 2 is a detailed view of a portion of FIG. 1, and FIG. FIG. 4 is a detailed view of another portion, FIG. 4 is an enlarged detailed view of the portion shown in FIG. 3, FIG. 5 is a cross-sectional view of FIG. 4, and FIG. 6 shows another embodiment of the present invention. It is a figure equivalent to FIG. 1 ... Dissolution device 10 ... Synthetic resin 14 ... Concentration device 17 ... Solution 18a ... Cooling recovery device 14 ... Concentration device 23 ... Separation device 24 ... Liquid tank 25 ... Decompression chamber 26 ... Vacuum Pump 27 …… Spinning nozzle 28 …… Filament 29a …… Collection device

Claims (2)

[Claims] 1. A synthetic resin (10) is dissolved in an organic solvent to form a solution (17), and the solution (17) is placed at the bottom of a heater (1).
Using a concentrating tank (15) having 6) and having a concentrated liquid collecting passageway (15a) in the upper part, a part of the solvent is evaporated and concentrated, and the evaporated solvent is cooled and recovered, Further, the concentrated liquid is collected from the concentrated liquid collecting passageway (15a) in the upper part of the concentrating tank (15), and the concentrated liquid has a spinning nozzle (27) consisting of a large number of fine holes at the bottom thereof, and Decompression chamber below (25)
In the liquid tank (24), and the vacuum chamber (25) is decompressed by the vacuum pump (26), whereby the concentrated liquid is spun from the spinning nozzle (27) of the liquid tank (24). The yarn (28) is spun into a body (28) and hung down.
A method for recovering a synthetic resin, characterized in that the solvent of the filament (28) is sucked and dried by the vacuum pump (26), and the sucked solvent is recovered by a recovery device (29a). 2. A dissolving device (1) for dissolving a synthetic resin in an organic solvent; a heater (16) formed at a lower portion and connected to the dissolving device (1), and a concentrated liquid collecting portion at an upper portion. Concentrator (1) having a concentration tank (15) having a passage (15a)
4); a cooling recovery device (18a) for cooling and recovering the solvent evaporated from the concentrating device (14); a bottom portion provided in communication with the concentrated liquid collecting passage (15a) of the concentrating tank (15) A liquid tank (24) having a spinning nozzle 27 consisting of a large number of fine holes and a decompression chamber (25) provided below the bottom;
An organic solvent recovery device (29a) provided in 5) via a suction vacuum pump (26); a synthetic resin recovery device.