JP2004223353A - Solvent recovery apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent recovery apparatus which can recycle a solvent used for reducing the volume of a styrene resin foam. <P>SOLUTION: This solvent recovery apparatus 1 is mainly composed of an agitation tank 6 in which the styrene resin foam is dissolved by the solvent S into gel G to reduce the volume, and the gel G is agitated while being heated preliminarily, an impurity removing tank 5 which is connected to the agitation tank 6, settles impurities E contained in the gel G by using the difference in specific gravities, and removes the impurities E, and a recovery body part 2 which is connected to the tank 5 through a feed pump 7 for feeding the gel G at a constant rate, evaporates the solvent S contained in the gel G, and recovers the solvent S. In an inclined flowing part of the recovery body part 2, the inclined surface 9 is set so that the inclination angle θ is 30° to an installation floor surface F. An oil circulation tank installed below the inclined surface 9 is adjusted at 280°C. The flowing-down gel G is heated, and the solvent S is evaporated. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solvent recovery apparatus, and more particularly to a solvent recovery apparatus for dissolving a styrene resin foam made of polystyrene or the like, recovering and reusing a gelling solvent for reducing the volume. .
[0002]
[Prior art]
Conventionally, resource recycling activities have been particularly active, in which products made of plastic materials that have already been manufactured as products are collected and reused as raw materials that can be used for new products for the purpose of effectively using petroleum resources. It has become. For example, PET bottles and the like, which are widely used as containers for beverages, are separated and collected at a convenience store or the like, and then are converted into pellets of polyethylene terephthalate, which is the main raw material, and are newly converted from such pellets. 2. Description of the Related Art Polyester fibers and the like are manufactured and used as raw materials for various products such as clothing.
[0003]
On the other hand, in retail stores such as supermarkets handling foods and the like, trays made of white styrofoam resin (styrene-based resin foam) may be used when selling meat and fish. Furthermore, home electric appliance manufacturers and the like sometimes use a packing body or a filler made of styrene foam resin for the purpose of absorbing an impact applied when an electric appliance is transported.
[0004]
Here, the styrofoam resin has a structure in which a large number of air bubbles are provided inside by greatly expanding the resin beads during molding. Therefore, the transfer of heat is suppressed by air, the material has excellent heat insulating properties, and is one of the materials having a small specific gravity. However, contrary to the above-mentioned excellent advantages, it is known that post-use processing and recycling take time and effort.
[0005]
That is, as described above, since the material is relatively small in specific gravity, there is a disadvantage that the material becomes bulky with respect to weight. That is, when the styrofoam resin is recycled and reused due to the bulkiness, the amount of the styrofoam resin that can be placed on the truck bed at one time in the state of the tray or the package is limited. As a result, the cost of transporting the styrofoam resin for processing has increased significantly, and the processing cost for recycling has tended to be higher than other plastic resins.
[0006]
Therefore, the recovered styrofoam resin is once dissolved by using an aromatic hydrocarbon solvent, a solvent such as limonene (also called a gelling solvent), or by using various other ether or ester solvents. In order to reduce the volume of styrofoam resin, recycling has been performed (for example, see Patent Document 1 and Patent Document 2). As a result, the amount of styrene foam resin transported is increased, and the above-mentioned transport cost does not significantly differ from other plastic resins and the like.
[0007]
The Styrofoam resin reduced in volume by the solvent is transported to the respective recycling plants, where the solvent is removed by evaporating it by heating or the like, processed into pellets such as styrene resin, etc. It is being reused as
[0008]
[Patent Document 1]
Japanese Patent No. 3236213
[Patent Document 2]
JP 2002-105237 A
[Problems to be solved by the invention]
However, in the above-mentioned technology for recycling a styrene foam resin, the solvent (gelling solvent) used at the time of volume reduction is hardly recovered and reused. Therefore, the solvent evaporated by heating is often released as it is into the atmosphere. As a result, despite the fact that the recycling technology promotes the effective use of petroleum resources, petrochemical solvents are newly consumed, and the petroleum resources are wasted and wasted. Furthermore, there is a high possibility that the surrounding environment will be adversely affected by releasing the solvent into the atmosphere, and the environment may be deteriorated. In addition, the cost of purchasing a solvent for reducing the volume is required each time, which has been a factor of increasing the cost of recycling the styrene resin foam.
[0009]
In view of the above circumstances, an object of the present invention is to provide a solvent recovery device that can recover and reuse a solvent used for reducing the volume of a styrene-based resin foam.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the solvent recovery apparatus according to the first aspect of the present invention forms a gel-like styrene gel obtained by reducing the volume of a styrene-based resin foam with a solvent to a predetermined thickness and flows out. A slit portion having a slit groove to be held, an inclined surface which is held in a state of being inclined at a predetermined inclination angle, has an inclined surface for allowing the styrene gel to flow naturally by its own weight, and an inclined downstream portion in which a substantially closed occlusion space is formed. Heating and evaporating means for heating the inclined surface of the inclined flow-down portion and evaporating the solvent from the styrene gel naturally flowing down on the inclined surface; and communicating with the closed space at the inclined-flow lower portion, the styrene gel A solvent recovery unit that sucks the solvent evaporated from the liquid, recovers the liquefied liquid, and a styrene resin that is provided at the end of the inclined surface below the inclined flow and collects the styrene resin from which the solvent has been removed. Those comprising a resin collection portion.
[0011]
Here, the styrene-based resin foam includes a white tray used for selling foodstuffs and the like, or a styrene foam resin package used for the purpose of absorbing shock when packing electric products. . Further, a solvent is a substance that, when contacted with a styrene-based resin foam, dissolves the solid styrene-based resin foam and turns it into a liquid (gel-like) having fluidity, such as an aromatic hydrocarbon. Are known.
[0012]
Therefore, the solvent recovery device according to the first aspect of the present invention forms a styrene gel which is gelled by a solvent and has fluidity into a predetermined thickness from the slit groove of the slit portion and flows out. Then, the outflowing film-like styrene gel naturally flows down according to its own weight along the inclined surface below the inclined flow. At this time, heat is supplied to the inclined surface below the inclined flow by the heating and evaporating means, and heat relating to the styrene gel on the inclined surface is transmitted. As a result, the solvent component (having a lower boiling point than the styrene resin body) contained therein evaporates from the styrene gel to which heat has been transmitted, and the styrene gel flowing down the inclined surface flows from the slit to the end of the inclined surface. The solvent is almost completely removed from the styrene gel before reaching the provided styrene resin recovery section.
[0013]
Further, the solvent evaporated from the styrene gel becomes a gas and stays in the substantially closed closed space below the inclined flow. Then, the solvent is sucked together with the atmosphere and collected by suction means such as a fan of a solvent recovery unit connected to and connected to the closed space. Then, by liquefying the solvent in a gaseous state by cooling or the like in the solvent recovery section, a liquid solvent capable of re-dissolving the styrene-based resin foam is generated. On the other hand, the solvent is removed from the styrene gel which naturally flows down along the inclined surface and reaches the end of the inclined surface, and is collected as a styrene resin in a styrene resin collecting section. Accordingly, it is possible to perform solid-liquid separation of the solvent and the styrene resin while allowing the styrene gel to flow naturally along the inclined surface.
[0014]
The solvent recovery device according to a second aspect of the present invention is the solvent recovery device according to the first aspect, wherein the inclined downstream portion has a plurality of partition plates on the inclined surface along a flow direction in which the styrene gel naturally flows. Is provided.
[0015]
Therefore, according to the solvent recovery device of the second aspect, in addition to the operation of the solvent recovery device of the first aspect, the inclined surface at the lower portion of the inclined flow is partitioned by the plurality of partition plates. Thereby, the styrene gel naturally flowing down the inclined surface is restricted from flowing down while spreading in the direction perpendicular to the flowing direction of the inclined surface by the partition plate. For this reason, the film flows down the inclined surface while almost maintaining the film thickness when it flows out of the slit groove, and the heat is uniformly transmitted to the styrene gel by the heating and evaporating means. Therefore, uneven heating at each part of the inclined surface is suppressed, the solvent is evaporated in a stable state from the entire inclined surface, and the solvent can be efficiently recovered.
[0016]
According to a third aspect of the present invention, in the solvent recovery apparatus according to the first or second aspect, the heating and evaporating means uses oil heated to a high temperature as a heat medium, An oil circulation tank, which is installed in contact with the inclined surface below and is filled with the oil therein, and the oil filled in the oil circulation tank is disposed near the end of the inclined surface below the inclined flow. And an oil circulating means for circulating in a direction of the slit portion from the oil passage.
[0017]
Therefore, according to the solvent recovery device of the third aspect of the present invention, in addition to the operation of the solvent recovery device of the first or second aspect of the invention, oil is used as a heat medium for heating the styrene gel, and An oil circulation tank is provided so as to be in contact with the inclined surface. Furthermore, the high-temperature oil filled in the oil circulation tank is circulated from near the end of the inclined surface toward the slit. Thus, the entire inclined surface can be heated at a substantially constant temperature, and the solvent can be efficiently recovered. Here, as the configuration of the oil circulation tank, even if the oil circulation tank circulates linearly from the end of the inclined surface toward the vicinity of the slit, in other words, the oil circulation tank is used as a heat medium, The space through which the oil flows may be partitioned in the oil circulation tank, and the oil may be circulated in a meandering manner in the flowing direction of the styrene gel flowing down the inclined surface. In particular, in order to uniformly supply heat to the entire inclined surface, it is preferable to circulate the oil described below while meandering.
[0018]
According to a fourth aspect of the present invention, in the solvent recovery apparatus according to any one of the first to third aspects, the width of the slit groove of the slit portion is 0.5 mm or more. It is set within a range of 0 mm or less.
[0019]
Therefore, according to the solvent recovery device of the fourth aspect, in addition to the operation of the solvent recovery device of any one of the first to third aspects, the width of the slit groove of the slit portion is 0.5 mm or more. It is set to be 3.0 mm or less, more preferably, 1.0 mm or more and 2.0 mm or less. Thereby, the thickness of the styrene gel formed and flown out from the slit portion is regulated within the above range. Here, when the slit groove is narrower than 0.5 mm, it is assumed that the styrene gel having a relatively high viscosity does not flow well from the slit groove. On the other hand, if the groove width is increased to 3.0 mm or more, it is assumed that the thickness of the styrene gel which naturally flows down the inclined surface increases, and that the heat given by the heating and evaporating means is not completely transmitted to the upper surface of the styrene gel film. Is done. As a result, heat enough to evaporate the solvent contained in the styrene gel is not supplied, and reaches the styrene-based resin recovery section in a state where the solvent is contained, and the recovery of the solvent is incomplete.
[0020]
According to a fifth aspect of the present invention, in the solvent recovery apparatus according to the third or fourth aspect, the oil temperature of the oil filled in the oil circulation tank is in a range of 230 ° C or more and 300 ° C or less. It is set.
[0021]
Therefore, in the solvent recovery apparatus according to the fifth aspect of the present invention, in addition to the operation of the solvent recovery apparatus according to the third or fourth aspect, the temperature of the heating medium is 230 ° C. or more and 300 ° C. or less, more preferably 240 The temperature is set in the range of not less than 280 ° C. Thereby, the styrene-based resin collected from the lower end of the slope is prevented from being damaged by heat and the quality is suppressed from being reduced, and the solvent contained in the styrene gel can be completely evaporated.
[0022]
According to a sixth aspect of the present invention, in the solvent recovery apparatus according to any one of the first to fifth aspects, the inclination angle of the inclined surface is 15 degrees or more and 45 degrees with respect to an installation surface. It is set in the following range.
[0023]
Therefore, the solvent recovery device according to the sixth aspect of the present invention provides the solvent recovery device according to any one of the first to fifth aspects of the present invention, in addition to the operation of the solvent recovery device according to any one of the first to fifth aspects. The angle is set in the range of 15 to 45 degrees, more preferably 25 to 35 degrees with respect to the plane. Here, since the styrene gel having fluidity naturally flows down the inclined surface by its own weight, the inclination angle of the inclined surface is a particularly important factor. That is, when the inclination angle is less than 15 degrees, it takes a long time to flow down the styrene gel, and it is assumed that the throughput of the solvent recovery device is reduced. On the other hand, if the inclination angle is larger than 45 degrees, the time for natural flow decreases, and in such a short time, the solvent contained in the styrene gel cannot be completely removed.
[0024]
According to a seventh aspect of the present invention, in the solvent recovery apparatus according to any one of the first to sixth aspects, the solvent recovery apparatus is included in the styrene gel by utilizing a difference in specific gravity with the styrene gel. The apparatus further includes a settling removing means for removing impurities by settling.
[0025]
Therefore, according to the solvent recovery apparatus of the seventh aspect of the present invention, in addition to the operation of the solvent recovery apparatus of any one of the first to sixth aspects, the impurities contained in the styrene gel have a specific gravity lower than that of the styrene gel. Removed using the difference. Here, foreign substances are often mixed in the styrene-based resin foam used as a tray or a package collected at a supermarket or the like. In the collection operation, the removal of foreign substances (impurities) is performed mainly by hand or the like by visual inspection or the like as much as possible. However, such an operation is not perfect, and foreign substances may be mixed in the gelled styrene gel. In addition, the contaminated foreign matters include a large amount of sand, mud, iron scrap, and the like, and generally have a higher specific gravity than styrene gel.
[0026]
Therefore, the impurities are removed by utilizing the difference in specific gravity. Here, as an example of the impurity removing means, the impurity is removed by temporarily storing the styrene gel in the previous stage supplied to the slit portion and providing an impurity precipitation tank for precipitating the impurities. In addition, such an impurity precipitation tank is provided with a shielding plate provided with a gap only in the vicinity of the bottom end of the impurity precipitation tank, facing the direction in which the styrene gel is delivered to the slit portion, and the delivery direction of the styrene gel is changed from a substantially horizontal direction. It is desirable that the conversion be made in the drooping direction in a corrective manner so as to more efficiently settle the impurities. In addition, in order to maintain the fluidity of the styrene gel, the impurity precipitation tank is desirably heated to about 80 ° C. Furthermore, it is of course possible to remove large foreign substances and the like contained in the styrene gel using a filter, a strainer, or the like, which is a well-known technique.
[0027]
The solvent recovery device according to claim 8 is the solvent recovery device according to any one of claims 1 to 7, wherein the solvent recovery unit removes the residual gas component after the solvent is recovered, The apparatus further includes a residual gas introduction unit for introducing the residual gas into the closed space below the inclined flow.
[0028]
Therefore, the solvent recovery apparatus according to the eighth aspect of the present invention provides the residual gas introduction means for introducing the residual gas component to the lower portion of the inclined flow again in addition to the operation of the solvent recovery apparatus according to any one of the first to seventh aspects. have. That is, the solvent evaporated from the styrene gel by the solvent recovery unit is sucked together with the air in the closed space and liquefied by a cooling process or the like. At this time, the closed space below the inclined flow may be in a reduced pressure state due to the continuous suction of the atmosphere. For this reason, the evaporation efficiency of the solvent under reduced pressure changes, and the solvent cannot be recovered in a stable state. Further, when the closed space is decompressed, the entire solvent recovery device including the lower part of the inclined flow may be deformed, and may be in a dangerous state. Therefore, the above-mentioned problem is avoided by providing the residual gas introducing means to make the closed section at the lower part of the inclined flow substantially under atmospheric pressure (there is a possibility that the pressure is slightly reduced by suction).
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a solvent recovery apparatus 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing the overall schematic configuration of a solvent recovery device 1 of the present embodiment, and FIG. 2 is a cross-sectional view showing the configuration of a slanted flow lower portion 3 of a recovery main body 2 as viewed from above. FIG. 4 is a cross-sectional view of the configuration of the oil circulation tank 4 of the recovery main body 2 viewed from above, and FIG. 4 is a cross-sectional view of the configuration of the impurity removal tank 5.
[0030]
As shown in FIG. 1, the solvent recovery apparatus 1 of the present embodiment dissolves a styrene-based resin foam such as a styrene foam resin with a solvent S, and converts the styrene gel G into a gel to reduce the volume thereof at about 80 ° C. At a steam temperature, a stirring tank 6 for stirring while preliminarily heating so as to exhibit a fluidity state, and an impurity E such as dust, which is connected to the stirring tank 6 and contained in the preheated styrene gel G, are subjected to a difference in specific gravity. An impurity removing tank 5 to be settled and removed by utilizing, a delivery pump 7 for delivering the styrene gel G from which the impurities E have been removed by the impurity removing tank 5 at a predetermined delivery speed, and styrene delivered from the delivery pump 7 It mainly comprises a recovery main body 2 for heating the gel G and evaporating and recovering the solvent S. Here, the impurity removing tank 5 corresponds to the impurity removing means in the present invention.
[0031]
More specifically, the recovery main body 2 has a slit W set to a slit width of 2 mm in order to adjust the flowable styrene gel G delivered from the delivery pump 7 to a constant film thickness. Styrene gel G having a thickness of about 2 mm flowing out of the slit portion 8 is supported by the supporting legs R while maintaining the slit portion 8 and the installation floor surface F of the collection main body portion 2 at an inclination angle θ of about 30 degrees. Is allowed to flow naturally along the inclined surface 9, and the inclined surface 9 is in contact with the inclined lower portion 3 formed with the substantially closed occlusion space 10 and the inclined surface 9 of the inclined lower portion 3. Circulating tank 4 filled with oil 11 in oil filling space 12 as a heat medium for heating oil, heating burner unit 13 for heating oil 11 filled in oil circulating tank 4 to a high temperature, and heated oil 11 In the vicinity of the lower end M of the slope 9 The oil circulation pipe 14 and the oil circulation pump 15 circulating obliquely upward toward the slit portion 8 are connected to the closed space 10 of the inclined flow lower portion 3 so as to be connected, and the styrene gel G is evaporated by being heated. A suction / discharge fan 16 for sucking the gaseous solvent S, a liquefaction unit 17 for liquefying the sucked solvent S, and a solvent recovery unit 19 having a storage unit 18 for storing the liquefied solvent S; A return pipe 20 for returning the residual gas component Z after the solvent S is recovered by liquefaction to the closed space 10 of the inclined flow lower part 3, and recovery holes 21 formed at three places at the lower end M of the inclined surface 9. And a styrene resin recovery section 22 for recovering the styrene resin PS from which the solvent S has been removed. Here, the oil circulation tank 4, the oil 11, and the heating burner 13 correspond to the heating and evaporating means in the present invention, and the oil circulation pipe 14 and the oil circulation pump 15 correspond to the oil circulating means in the present invention. The tube 20 corresponds to the residual gas introducing means in the present invention.
[0032]
Further, the inclined downstream portion 3 will be described. As shown in FIG. 2, five partition plates 23 are provided on the surface of the inclined surface 9 at equal intervals along the flowing direction D of the styrene gel G. Further, as shown in FIG. 3, the oil circulation tank 4, when circulating the oil 11 from the vicinity of the lower end M of the inclined surface 9 toward the slit portion 8, causes the flow of the oil 11 to flow downward of the styrene gel G. Rectifying plates 24 for adjusting to meander in a direction orthogonal to D are alternately protruded from the side surface 25 of the oil circulation tank 4 toward the oil filling space 12.
[0033]
Further, as shown in FIG. 4, the impurity removing tank 5 is formed opposite to the styrene gel G sent out from the stirring tank 6 in a substantially horizontal direction, and the sending direction of the styrene gel G is substantially drooped from substantially horizontal. It has a hanging plate 26 forcibly changing in the direction. Therefore, the flow of the styrene gel G sent from the stirring tank 6 is controlled from the substantially horizontal direction to the substantially hanging direction by the hanging plate 26, and flows toward the bottom surface 27 of the impurity removing tank 5. Here, since a clearance 29 through which the styrene gel G can flow is formed between the tip of the hanging plate 26 and the bottom surface 27 of the impurity removing tank 5, the styrene gel G reaching the vicinity of the bottom surface 27 is Rise again. At this time, the impurity E contained in the styrene gel G cannot often rise together with the styrene gel G due to a difference in specific gravity. As a result, the impurity E sinks near the bottom surface 27 of the impurity removing tank 5. Thereby, the impurities E can be removed from the styrene gel G. In addition, a drain 28 for extracting the settled impurity E from the inside of the impurity removing tank 5 is provided on the bottom surface 27.
[0034]
Next, a method of using the solvent recovery device 1 of the present embodiment will be described. First, a styrene gel G in a gel state, which is collected at a supermarket or the like for the purpose of recycling and reduced in volume by the solvent S, is charged from a hopper 30 provided above the stirring tank 6. At this time, large impurities contained in the styrene gel G are removed before the hopper 30 is charged or when the hopper 30 is charged, but the description is omitted here.
[0035]
A steam pipe (not shown) connected to a boiler (not shown) is provided inside the stirring tank 6 into which the styrene gel G is charged from the hopper 30, and is heated to a temperature of about 80 ° C. Then, by rotating the stirring propeller 31 provided inside the stirring tank 6, kneading is performed while further increasing the fluidity in a warmed state. This makes it possible to easily send the styrene gel G to the impurity removal tank 5 and the recovery main body 2 thereafter.
[0036]
Then, the styrene gel G preliminarily heated by the stirring tank 6 is sent to the impurity removing tank 5 thereafter. Here, a steam pipe (not shown) is arranged around the impurity removing tank 5, and is heated to a temperature of about 80 ° C. like the stirring tank 6. Therefore, the fluidity of the styrene gel G is not impaired inside the impurity removing tank 5.
[0037]
The sending direction of the styrene gel G sent to the impurity removing tank 5 is forcibly changed from substantially horizontal to substantially hanging by the hanging plate 26 provided therein as described above, and is regulated toward the bottom surface 27. . Thereafter, the styrene gel G that has reached the bottom surface 27 rises through the clearance 29 between the hanging plate 26 and the bottom surface 27. The effect of removing the impurity E from the styrene gel G by utilizing the difference in specific gravity has already been described, and therefore a detailed description is omitted here.
[0038]
Thereafter, the styrene gel G that has reached the open end 32 of the impurity removal tank 5 is sent out by the sending pump 7 to the slit portion 8 of the collecting main body 2 by a predetermined amount. Here, the delivery pump 7 and the slit portion 8 are connected by a connection pipe 33. Here, in the connection pipe 33, one pipe 34a connected to the delivery pump 7 is branched into two near the slit portion 8, and is connected to the slit portion 8 at two locations by branch pipes 34b and 34c. . Thereby, the styrene gel G can be supplied at a constant delivery amount without being biased in the width direction of the slit portion 8. Here, as shown in FIG. 2, the slit portion 8 has a substantially cylindrical cross section, and a slit W having a slit width of 2 mm is formed at a position where the slit portion 8 substantially abuts the inclined surface 9 of the inclined flow lower portion 3. ing. Then, the styrene gel G flows out of the slit W to the inclined surface 9 from the slit W by a predetermined amount from the delivery pump 7. As a result, a styrene gel G having a thickness of about 2 mm, which is substantially the same as the slit width, is formed on the inclined surface 9.
[0039]
The styrene gel G flowing out with a film thickness of about 2 mm flows down the inclined surface 9 according to its own weight because the inclined downstream portion 3 is formed in a state where the inclined angle θ is maintained at 30 degrees. At this time, the speed of the natural flow is set very slowly by the viscosity of the styrene gel G, and in the present embodiment, from the start of the outflow of the slit portion 8 to the arrival at the styrene resin recovery portion 22 until it is recovered. Is about 1 hour.
[0040]
As described above, the inclined surfaces 9 are provided with the partition plates 23 at equal intervals. Therefore, the styrene gel G flowing out of the slit portion 8 flows down each section 35 divided by the partition plate 23. That is, when the styrene gel G flows down the inclined surface 9, the styrene gel G tends to spread and flow in a lateral direction (corresponding to the vertical direction in FIG. 2) perpendicular to the flowing direction D. This increases the likelihood that the film thickness will vary at each point on the inclined surface 9 in the process of flowing down, even though the film thickness is adjusted to be constant in the slit portion 8 and flows out. As a result, when the styrene gel G is heated by the oil 11 circulating in the oil circulating tank 4, uneven heating tends to occur due to differences in heat transfer at each location. Thereby, it is assumed that the solvent S contained in the styrene gel G cannot be stably recovered. Thus, as shown in the present embodiment, by providing the partition plate 23 on the inclined surface 9, the spread of the styrene gel G in the lateral direction is suppressed within an allowable range, and the inclined surface 9 is formed in a state where the film thickness is uniform. The styrene gel G flowing down can be heated.
[0041]
An oil circulation tank 4 that circulates in an oil filling space 12 filled with high-temperature (here, set to 280 ° C.) oil 11 is provided below the inclined surface 9. Thereby, the styrene gel G flowing down each section 35 of the inclined surface 9 is heated with the oil 11 serving as a heat medium, and the solvent S contained in the styrene gel G evaporates gradually in the process. . At this time, the flow of circulation is regulated by the above-mentioned current plate 24 so as to meander in a direction perpendicular to the flowing direction D of the styrene gel G. As a result, the heat of the oil 11 is transmitted uniformly over the entire inclined surface 9, and there is no difference in the evaporation efficiency of the solvent S of the styrene gel G flowing down the inclined surface 9. As a result, the recovery of the solvent S is performed more stably.
[0042]
Here, the solvent S of the gas component evaporated from the styrene gel G by the heat transmitted by the oil 11 in the oil circulation tank 4 stays in the closed space 10 above the inclined surface 9. At this time, the solvent S is sucked together with the atmosphere by the suction / discharge fan 16 of the solvent recovery unit 19 connected to and connected to the closed space 10. The sucked solvent S is liquefied by being cooled by the liquefaction unit 17, and is stored in the storage unit 18 as the liquid solvent S. As a result, the solvent S used for the volume reduction processing during recycling and recovery of the styrene resin foam can be liquefied and recovered, and the recovered solvent S is again used for the volume reduction processing of the styrene resin foam. Can be used.
[0043]
The residual gas component Z after liquefying and recovering the solvent S is again introduced into the closed space 10 of the inclined flow lower part 3 through the return pipe 20. Thereby, the suction by the suction / discharge fan 16 is continued, so that the pressure in the closed space 10 is suppressed, and the evaporation efficiency is not unstable. Further, the equipment such as the inclined flow lower part 3 is not deformed due to the continuous over-pressure reduction state.
[0044]
Thereafter, the styrene gel G that has flowed down along the inclined surface 9 is in a state where the solvent S is almost completely removed as it approaches the lower end M of the flow. Then, the styrene resin PS is collected by the styrene resin collection unit 22 from the collection hole 21 provided at the lower end M of the flow.
[0045]
As described above, according to the solvent recovery apparatus 1 of the present embodiment, the impurities E are settled and removed from the pre-heated styrene gel G by utilizing the difference in specific gravity, and the styrene gel G is removed by a predetermined film. By allowing the styrene gel G to flow naturally along the inclined surface 9 with the thickness adjusted, the styrene gel G is separated into the liquid component solvent S and the solid component styrene resin PS, and the styrene resin PS and the solvent S are combined and collected. be able to. Furthermore, the recovered solvent S can be reused when the volume of the styrene resin foam is reduced again during recycling. Furthermore, since the temperature of the oil 11 for heating and evaporating the solvent S is set to 280 ° C., it does not affect the composition of the recovered solvent S and the styrene resin PS, and can be used without hindrance to subsequent recycling. it can.
[0046]
As a result, the solvent S that has been conventionally released into the atmosphere and has a strong possibility of adversely affecting the global environment can be repeatedly used a plurality of times, thereby reducing the risk of damaging the environment. Further, since the cost of the solvent S can be reduced, it is possible to suppress the processing cost required for recycling the styrene resin foam.
[0047]
As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and various improvements can be made without departing from the gist of the present invention as described below. And design changes are possible.
[0048]
That is, in the solvent recovery apparatus 1 of the present embodiment, the processing conditions for recovering the solvent S from the styrene gel G are set such that the oil temperature is set to 280 ° C. and the inclination angle θ is set to 30 degrees. The processing conditions for solvent recovery are not limited, and may be changed within a predetermined range depending on the viscosity of styrene gel G, component ratio, and the like.
[0049]
Furthermore, although the heating and evaporating means is described as using an oil and an oil circulation tank, the present invention is not limited to this, and other heating means such as electric heating can be used.
[0050]
【The invention's effect】
As described above, the solvent recovery apparatus according to the first aspect of the present invention allows the styrene gel to flow down the inclined surface held at a predetermined inclination angle so that the styrene gel has a substantially uniform film thickness. Can be heated. For this reason, the evaporation efficiency of the solvent contained in the styrene gel is stabilized, and the solvent can be favorably recovered. Then, the recovered solvent can be reused for the volume reduction treatment of the styrene resin foam. As a result, the cost of recycling the styrene resin foam is reduced, and since the solvent is not released into the atmosphere, the possibility of adversely affecting the global environment is reduced.
[0051]
According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, by providing a plurality of partition plates on the inclined surface, the thickness of the styrene gel flowing down the inclined surface can be made uniform. And the evaporation efficiency is further improved.
[0052]
According to a third aspect of the present invention, in addition to the effect of the first or second aspect of the present invention, a high temperature oil is used as a heat medium, and the oil is circulated under a slope. In addition, the inclined surface can be uniformly heated. Thereby, the evaporation efficiency of the solvent can be stabilized.
[0053]
According to a fourth aspect of the present invention, in addition to the effect of the first aspect of the present invention, the width of the slit groove is set to a range of 0.5 mm or more and 3.0 mm or less. By setting, the heat given by the heating and evaporating means can be efficiently absorbed and the solvent in the styrene gel can be evaporated.
[0054]
According to a fifth aspect of the present invention, in addition to the effects of the third or fourth aspect of the present invention, the solvent and styrene recovered by setting the oil temperature to 230 ° C. or more and 300 ° C. or less. The resin is prevented from being thermally destroyed, and no trouble occurs during subsequent reuse.
[0055]
According to a sixth aspect of the present invention, in addition to the effect of the first aspect of the present invention, the solvent recovery apparatus is set at an inclination angle of 15 to 45 degrees with respect to the installation surface. Therefore, the flow speed of the styrene gel flowing down the inclined surface can be adjusted, and the time required for evaporating the solvent can be secured.
[0056]
The solvent recovery device according to the seventh aspect of the present invention can remove impurities from the styrene gel by utilizing the difference in specific gravity in addition to the effect of the solvent recovery device according to any one of the first to sixth aspects of the invention. . Thus, impurities are removed with a simple configuration, and no impurities or the like are mixed in the styrene gel to be further flowed down, so that uneven heating or the like does not occur on the inclined surface.
[0057]
The solvent recovery apparatus according to the eighth aspect of the present invention provides the same effect as the solvent recovery apparatus according to any one of the first to seventh aspects, and further comprises removing the residual gas component after the solvent is recovered from the closed space below the inclined flow. By returning to the above, it is possible to prevent the inside of the closed space from being decompressed, and to prevent a decrease in evaporation efficiency and a deformation of the lower portion of the inclined flow.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the overall schematic configuration of a solvent recovery device.
FIG. 2 is an explanatory view showing a configuration of a lower portion of an inclined flow of a recovery main body.
FIG. 3 is an explanatory diagram illustrating a configuration of an oil circulation tank of a recovery main body.
FIG. 4 is a sectional view showing a configuration of an impurity removing tank.
[Explanation of symbols]
1 Solvent recovery device
2 Collection body
3 Lower slope
4 Oil circulation tank (oil circulation means)
5 Impurity removal tank (impurity removal means)
6 stirring tank
8 slit part
9 Slope
10 Closed space
11 oil (heating evaporation means)
13. Heating burner (heating evaporating means)
14 Oil circulation pipe (oil circulation means)
15 Oil circulation pump (oil circulation means)
19 Solvent recovery section
20 Return pipe (residual gas introduction means)
22 Styrene resin recovery section
23 Partition plate
24 Rectifier plate
26 Hanging plate (impurity removing means)
D Downward direction
E impurity
G styrene gel
PS styrene resin
S solvent
Z residual gas component
θ tilt angle

Claims (8)

A slit portion having a slit groove for allowing a gel-like styrene gel obtained by reducing the volume of the styrene-based resin foam by a solvent to flow into a film having a predetermined thickness,
An inclined flow lower portion, which is held in a state of being inclined at a predetermined inclination angle, has an inclined surface for allowing the styrene gel to flow naturally by its own weight, and a substantially closed closed space is formed,
Heating and evaporating means for heating the inclined surface of the inclined flow lower portion and evaporating the solvent from the styrene gel naturally flowing down on the inclined surface;
A solvent recovery unit that communicates with the closed space below the inclined flow, suctions the solvent evaporated from the styrene gel, liquefies and recovers the solvent,
A styrene resin recovery unit provided at the end of the inclined surface below the inclined flow, for recovering the styrene resin from which the solvent has been removed. The inclined flow lower part,
2. The solvent recovery device according to claim 1, wherein a plurality of partition plates are provided on the inclined surface along a flowing direction in which the styrene gel flows naturally. 3. The heating and evaporating means includes:
Oil heated to a high temperature is used as a heat medium,
An oil circulation tank that is installed in contact with the inclined surface below the inclined flow lower portion and is filled with the oil therein,
2. An oil circulating means for circulating the oil filled in the oil circulating tank from near the end of the inclined surface below the inclined flow toward the slit portion. Or the solvent recovery device according to claim 2. The groove width of the slit groove provided in the slit portion,
The solvent recovery device according to any one of claims 1 to 3, wherein the length is set in a range of 0.5 mm or more and 3.0 mm or less. The oil temperature of the oil filled in the oil circulation tank is:
The solvent recovery device according to claim 3, wherein the temperature is set in a range of 230 ° C. or more and 300 ° C. or less. The inclination angle of the inclined surface,
The solvent recovery device according to any one of claims 1 to 5, wherein the angle is set in a range of 15 degrees or more and 45 degrees or less with respect to the installation surface. 7. The method according to claim 1, further comprising: a settling removing unit configured to settle and remove impurities contained in the styrene gel by utilizing a difference in specific gravity from the styrene gel. The solvent recovery device according to claim 1. The solvent recovery section,
The residual gas introducing means for introducing the residual gas component after the solvent is recovered into the closed space below the inclined flow, further comprising: a residual gas introducing unit. Solvent recovery equipment.

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