JP2005179466A - Recycling apparatus for foamed polystyrene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recover polystyrene resin in a simpler way by accelerating the solubilization of a wasted foamed poly styrene and evaporating the solvent with warm water of a relatively low temperature of ≥40°C. <P>SOLUTION: The recycling apparatus 1 of the foamed polystyrene is constituted of a charging section 11 where a foamed polystyrene product W is pushed in, a crusher 13 which crushes the foamed polystyrene product W received there into pieces, a dissolving tank 15 which, located below it, dissolves the pieces into a low boiling point solvent that, reserved, is a liquid at ordinary temperature of ≤39°C to create a gel, a gel tank 17, a hot water tank 18 which stores hot water subject to temperature control at about 60°C, a separation section 18a which, with the gel and the hot water supplied in the upper part of it from both the tanks of 17 and 18, lets them contact each other to produce a polystyrene solid material and evaporates the solvent, and a mesh belt conveyer 19 which conveys the solid material R received in the hot water tank 17. The apparatus is also equipped with a vaporized solvent recovering section 20 which collects the vaporized gas of the solvent, condenses and liquifies it to recover the solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an apparatus for recovering, reducing, and recycling polystyrene foam, which is used in large quantities in a wide range including packing of various products such as fish toro boxes and electrical products.

The expanded polystyrene has a volume ratio of about 98% of air, and the volume is very large for the weight. Especially, the transportation of the expanded polystyrene after disposal is economically very inefficient. . In order to improve this, reducing the volume of used polystyrene as a solid at the discharge site is also an important issue in conjunction with resource recovery.

As a conventional apparatus for volume reduction and recycling of expanded polystyrene, there is an apparatus using limonene as a solvent for dissolving expanded polystyrene (for example, see Non-Patent Document 1). This can be done by using a liquid “limonene” (C10H16, specific gravity: 0.84, boiling point: 175 ° C., flash point: 48 ° C.), which can be taken from orange peel, after dissolving the polystyrene foam at room temperature for about 3 minutes. It removes dirt with a filter, raises the temperature with a vacuum evaporating separator, vaporizes limonene, separates the polystyrene resin, and combines with the antioxidant function of limonene liquid itself to obtain high-quality recycled polystyrene. In addition, limonene can be condensed and reused in a condenser.
13 pages in all pages of "Sony Styrofoam High Quality Recycling System" developed by SONY and currently available on the Internet and having the registered trademark of "Orange R-net".

The problem to be solved is that limonene takes about 3 minutes to dissolve the expanded polystyrene, and the operation speed is slow when intensively recycling the expanded polystyrene, and vacuum evaporation separation is performed to separate the limonene from the polystyrene resin. In addition to generating a vacuum in the container, a boiler for heating is required, a cooling water tank is required to cool the high temperature polystyrene resin, etc. Since the flash point is as low as 48 ° C, attention must be paid to fire.

The present invention is a foamed polystyrene product input portion provided at the upper portion of the casing,
A crushing means that is provided subsequent to the charging unit and crushes the charged polystyrene product,
A dissolving tank for receiving foamed polystyrene fragments generated by crushing by the crushing means, and dissolving the foamed polystyrene fragments in a solvent having high chemical stability therein to form a gel;
A hot water tank containing hot water;
A separation unit for contacting the hot water from the hot water tank and the gel-like material generated in the dissolution tank to recycle the gel-like material into a polystyrene solid, and vaporize the solvent;
Unloading means for unloading the polystyrene solid matter generated in the separation unit to the outside of the apparatus;
And a discharge unit that collects and discharges the vaporized solvent vaporized in the separation unit.

 Furthermore, in the present polystyrene recycling apparatus, the separation unit is provided in the upper part of the hot water tank, and the gel-like material sent from the dissolution tank and the hot water sent from the hot water tank are internally contained. It strikes each other, produces | generates a polystyrene solid substance, vaporizes a solvent component, and is comprised so that the produced | generated polystyrene solid substance and warm water may be dropped to the said warm water tank. Further, the solvent vaporized gas discharge unit collects the solvent vaporized gas from the upper space of the hot water tank and the dissolution tank in addition to the separation unit, and cools the vaporized gas by a cooling means to condense and liquefy it. Further, a vaporized solvent recovery means for recovering the solvent can be provided. The vaporized solvent recovery means includes a heat exchanger supplied with at least the vaporized gas of the solvent collected from the upper space of the hot water tank and the dissolution tank, a cooler for cooling the heat exchanger, and a condensate liquefaction by the heat exchanger. A recovery solvent tank for storing the condensed solvent, a blower for sucking the vaporized gas of the solvent on the downstream side of the heat exchanger and releasing the air after separation of the condensed solvent to the atmosphere through a deodorizer, and a recovery solvent tank It is composed of a new solvent replenishment unit connected. In that case, the heat generated by the cooler that cools the heat exchanger is supplied to the temperature maintaining means by a heat pump system, and is used to maintain the temperature of the hot water in the hot water tank.

The above solvent is a low boiling point liquid at room temperature up to about 39 ° C. and has a large kauributanol value and a strong dissolving power, for example, a boiling point of 35 ° C. to less than 40 ° C. and a melting point of −20 Less than ℃, specific gravity (20 ℃) is 1.1 to 1.5, viscosity (20 ℃) has physical properties of 0.3 to 0.9 cP, non-flammable and has high dissolving power and stability The second type organic solvent is preferred.

The replenishing unit is connected to the vaporized solvent recovery means so as to form a substantially closed recovery circuit, and is configured to receive the solvent recovered by the vaporized solvent recovery means from the recovered solvent tank. . In addition, the solid matter carried out from the carrying-out means is further dehydrated by a dehydrator, then dried by a drier, stored in a temporary silo after drying, and sent from the silo to an extrusion molding machine, where it is in the form of a rod. It can be processed from extrusion to cutting into pellets by a cutting machine. The unloading means preferably comprises a mesh belt conveyor. Moreover, it is preferable that the said warm water tank has temperature maintenance means, such as a heater which maintains the temperature of warm water. The gel-like material is transferred from the dissolution tank to the gel-like material tank by a pump through a filter and stored, and is supplied from the gel-like material tank to the separation unit by a pump.

As an effect of the present invention, the solvent used is, for example, a liquid having a low boiling point such as 39.8 ° C. and a normal temperature of about 39 ° C. or less, which is a liquid in the dissolution tank, and has a large kauributanol value (KB value). Since it has a strong dissolving ability, it is possible to quickly dissolve the expanded polystyrene in the dissolution tank, and even a large amount of expanded polystyrene can be intensively dissolved in the gel-like material in a short time, and the recycling work speed and efficiency can be increased. Moreover, separation of the solvent from the gel-like material to obtain a polystyrene resin solid is achieved, for example, by simply evaporating the solvent by bringing warm water of about 40 ° C. or higher and the gel-like material into contact with each other at the separation part. Therefore, a relatively large-scale apparatus such as a vacuum evaporating separator, a boiler, and a cooling water tank is not required other than the heater for maintaining the temperature of the hot water, and the present polystyrene foam recycling apparatus can be made compact. Therefore, the present polystyrene foam recycling apparatus can be easily transported and installed in a place where a large amount of waste polystyrene foam comes out. Typical chlorinated solvents with a large Kauributanol (KB) value include Super M of methylene chloride. When this is used, there is no flash point, so there is no need to pay special attention to the fire, and chemical stability is further improved. Since it is excellent in performance, it does not damage the apparatus or polystyrene resin, and the use efficiency and regeneration rate of the solvent itself are increased, and the operation can be economically improved.

Further, in this polystyrene foam recycling apparatus, in the upper space of the hot water tank, the gel-like material sent from the dissolving tank and the hot water sent from the hot water tank collide with each other inside the separation unit, and the polystyrene solid material Can be finely formed into flakes, and the solvent can be sufficiently vaporized, and the produced polystyrene solids and hot water can be dropped into the lower hot water tank as they are. In addition to the separation unit, the solvent vaporized gas discharge unit collects the solvent vaporized gas from the upper space of the hot water tank and dissolution tank, cools the vaporized gas by the cooling means, condenses it, and collects the solvent. By providing the vaporized solvent recovery means having a substantially closed circuit, the worker is not exposed to the vapor of the solvent, and the allowable concentration of 100 ppm in the work environment can be easily achieved. By providing a blower that sucks the vaporized gas of the solvent on the downstream side of the heat exchanger and discharges the air after separation of the condensed solvent to the atmosphere through the deodorizer, the internal pressure of the apparatus is reduced to reduce the vaporized gas of the solvent. It is possible to prevent leakage to the outside. Furthermore, the heat generated by the cooler that cools the heat exchanger is supplied to the means for maintaining the temperature of the hot water tank by a heat pump system, and is used to maintain the hot water temperature of the hot water tank, thereby reducing the operating cost.

The solvent has a boiling point of 35 ° C. to less than 40 ° C., a melting point of −20 ° C. or less, a specific gravity (20 ° C.) of 1.1 to 1.5, and a viscosity (20 ° C.) of 0.3 to 0.9 cP. When using a second type organic solvent that has physical properties, is nonflammable and has high dissolving power and stability, it is in a liquid state at -20 ° C to 35 ° C which is commonly experienced on a daily basis. Since it evaporates, it is easy to dissolve and separate polystyrene foam and can be safely recycled. Since the dissolution tank mainly receives solvent supply from the recovery solvent tank of the vaporized solvent recovery means and only supplements the shortage with new solvent, the operating cost can be further reduced. Furthermore, the solid matter carried out from the carrying-out means is dehydrated, dried, temporarily stored in a silo, then formed into a rod shape by an extrusion molding machine, and cut into pellets by a cutting machine, so that a large amount of polystyrene is discarded. Can be processed into high added value pellets. Moreover, it can carry out, draining a solid substance by making a carrying means into a belt conveyor of a mesh, and can reduce the loss of warm water. The hot water tank has temperature maintaining means such as a heater for maintaining the temperature of the hot water, and can particularly reliably maintain a temperature of 40 ° C. or higher that promotes the vaporization of the solvent. Furthermore, the gel-like material is transferred from the dissolution tank through a filter to the gel-like material tank and stored by a pump, and the gel-like material from which foreign substances have been removed from the gel-like material tank is stably supplied to the separation unit by the pump. It can be supplied, and the contact with warm water can be stabilized to stabilize the production of polystyrene solids.

1 to 4, the polystyrene foam recycling apparatus 1 is provided above one end of a casing of the apparatus, and opens and closes a plurality of box-shaped polystyrene foam products W such as fish trolley boxes. From the loading unit 11 (which can of course be pushed in continuously or intermittently by a belt conveyor or the like), and the introduced polystyrene foam product provided after the loading unit 11. A crusher 13 such as a rotary cutter that crushes into pieces of about 3 cm cubic, and a crusher 13 provided below the crusher 13, receives pieces of foamed polystyrene, and is controlled to reach a substantially constant level via the replenishment unit 15A. Dissolving by dissolving foamed polystyrene fragments in a low boiling point solvent that is liquid at room temperature up to 39 ° C. 15, a gel-like material tank 17 that receives and stores the gel-like material supplied from the dissolution tank 15 through the filter 16 by the pump P1, and a temperature maintaining heater 18b in the range of 55 ° C. to 70 ° C., preferably 60 ° C. A hot water tank 18 containing hot water whose temperature is controlled before and after, and at the upper part of the hot water tank 18, the gel-like material is supplied from the gel-like material tank 17 by the pump P 2 and pumped from the hot water tank 18. Separation unit that receives the supply of hot water whose temperature is controlled at around 60 ° C. by P3, collides the gel-like material and the hot water with each other, solidifies into a flaky recovered polystyrene solid R, and vaporizes the solvent. 18a and the recovered polystyrene solid R falling together with the hot water from the separation unit 18a are carried out from the inside of the hot water tank 18 to the outside through a closure basket. And a Mesh belt conveyor 19.. The filter 16 removes foreign substances such as paper, cellophane, and labels from the gel-like material. Although the specific gravity of polystyrene is greater than that of water, the polystyrene solid matter produced in the hot water tank 18 still contains some air, so it floats in the hot water and can be easily carried out by the belt conveyor 19, and the volume can be greatly reduced. Therefore, the efficiency of transportation by truck will be greatly improved.

As an incidental facility, the present polystyrene recycling apparatus 1 generates solvent vapor gas from the upper space of the dissolution tank 15, that is, the upper space of the crusher 13, the gel material tank 17, the upper space of the hot water tank 18, and the separation part 18a. The vaporized solvent recovery unit 20 collects, condenses and liquefies, and recovers the solvent. The vaporized solvent recovery unit 20 includes a heat exchanger 21 to which the vaporized gas of the collected solvent is supplied, a cooler 22 that cools the heat exchanger, and a recovered solvent tank that stores the condensed solvent condensed and liquefied by the heat exchanger 21. 23, a blower 25 that sucks the vaporized gas of the solvent on the downstream side of the heat exchanger 21 and releases the air after separating the condensed solvent to the atmosphere through the deodorizer 24, and a new solvent supply connected to the recovered solvent tank 23 It is comprised from the pump P5. From the recovered solvent tank 23, the solvent is supplied to the dissolution tank 15 through the replenishing section 15A by the pump P4 that is controlled by the level control sensor S1, and is reused by substantially vaporizing and condensing the solvent. A closed recovery circuit is formed.

The separation part 18a does not need to be formed in a particularly protruding shape, and can be provided in the upper space of the hot water tank 18. Further, the separation unit is formed as a tank independent of the hot water tank 18, or may be configured such that the gel material is directly supplied to the warm water in the hot water tank 18 and stirred with a stirrer. The level of the hot water tank 18 is also managed, and the supply of clean water is received by a pump whose operation is controlled by the level control sensor S2. The hot water in the hot water tank 18 is managed by the heater 18 b at a temperature higher than that in the hot water tank 18. The heat generated by the cooler 22 of the vaporized solvent recovery unit 20 is supplied to the heater 18b by a heat pump system to effectively use the heat.

In order to increase the added value from the flake-shaped recovered polystyrene solid R to the pellet-shaped polystyrene resin, the flake-shaped solid carried out from the belt conveyor 19 is further dehydrated by the dehydrator 31 in the additional processing unit 30. Thereafter, it is dried by a dryer 32, and after drying, it is temporarily stored in a silo 33, sent from the silo to an extrusion molding machine 34, extruded into a bar shape, and then cut into pellets by a categorizing machine 35. This is suitable when a large amount of the expanded polystyrene product is continuously discarded.

Various juices and liquids such as blood and oil of fish scattered in a fish trout box are preferably washed in advance, but diatomaceous earth or white clay may be put in the filter 16 and adsorbed. Alternatively, the gel-like material tank 17 may be omitted, and the gel-like material may be directly supplied from the dissolution tank 15 via the filter 16 to the separation unit 18a via the pump P1. Further, in configuring the separation unit, the gel-like material is supplied to the hot water tank 18 in a pulsating or intermittent manner, supplied with a strong water flow with a hot water ejector, or as described above. The gel-like material can be formed as a flaky solid material by using a stirrer.

In Example 1 of the present invention, methylene chloride super M having the following characteristics is used as the solvent, and plays a major role in solving the problems in the polystyrene recycling apparatus 1 having the above-described configuration.
Boiling point: 39.8 ° C, melting point: -96.7 ° C, specific gravity (20 ° C): 1.326, viscosity (20 ° C): 0.441 cP, flash point: none, KB value: 135, surface tension (20 ° C ): 28.2 dyne / cm, specific heat (20 ° C.): 0.28 cal / g ° C., latent heat of vaporization: 78.7 cal / g, vapor pressure (20 ° C.): 349 mmHg, evaporation rate (ether = 100): 71, vapor Density: 3.37 g / l, air = 1.93, compatibility with water (solvent / water, 25 ° C.): 1.320 / 100, allowable concentration (Japan Society for Occupational Health): 100 ppm, organic Solvent poisoning regulations: Class 2 organic solvents.

Examples of the use of the present invention include the recycling of waste polystyrene used for packaging, packing of electrical products, etc., and various types of containers used for storing and transporting fish, fruits and vegetables, and foamed polystyrene discarded from foam polystyrene manufacturers. Used.

The flow block diagram of the recycling apparatus of the polystyrene foam which concerns on the representative example of this invention. It is a top view which shows the external appearance of the recycling apparatus of the polystyrene foam which concerns on a representative example. It is a front view which shows the external appearance of the recycling apparatus of the polystyrene foam which concerns on a representative example. It is a left view which shows the external appearance of the recycling apparatus of the polystyrene foam which concerns on a representative example.

Explanation of symbols

1: Styrofoam recycling device 11: input unit 13: crusher 15: dissolution tank 15A: replenishment unit 17: gelled material tank 18: hot water tank 18a: separation unit 18b: temperature maintaining means 19: carry-out means 20: vaporized solvent recovery Means 21: Heat exchanger 22: Cooler 23: Recovery solvent tank 24: Deodorizer 25: Blower 31: Dehydrator 32: Dryer 33: Silo 34: Extruder 35: Cutting machine W: Waste polystyrene foam product P1: Pump means P2: Pump P3: Pump R: Recovered polystyrene

Claims (11)

A styrofoam product input section provided at the top of the casing;
A crushing means that is provided subsequent to the charging unit and crushes the charged polystyrene product,
A dissolving tank for receiving foamed polystyrene fragments crushed by the crushing means, and dissolving the foamed polystyrene fragments in a highly chemically stable solvent to form a gel;
A hot water tank containing hot water;
A separation unit for contacting the hot water from the hot water tank and the gel-like material generated in the dissolution tank to recycle the gel-like material into a polystyrene solid, and vaporize the solvent;
Unloading means for unloading the polystyrene solid matter generated in the separation unit to the outside of the apparatus;
An apparatus for recycling foamed polystyrene, comprising: a discharge unit that collects and discharges the vaporized solvent vaporized in the separation unit.   The separation part is provided in the upper part of the hot water tank, and a gel-like substance sent from the dissolution tank and a hot water sent from the hot water tank collide with each other to generate a polystyrene solid. The apparatus of Claim 1 comprised so that a solvent content may be vaporized and the produced | generated polystyrene solid substance and warm water may be dropped to the said warm water tank.   The solvent vaporized gas discharge unit collects the solvent vaporized gas from the upper space of the hot water tank and the dissolution tank in addition to the separation unit, and the vaporized gas is cooled by a cooling means to be condensed and liquefied. The apparatus according to claim 1, further comprising a vaporized solvent recovery means for recovering water.   The vaporized solvent recovery means is a heat exchanger supplied with at least the vaporized gas of the solvent collected from the upper space of the hot water tank and the dissolution tank, a cooler for cooling the heat exchanger, and condensed and liquefied by the heat exchanger. It is connected to a recovery solvent tank that stores the condensed solvent, a blower that sucks the vaporized gas of the solvent on the downstream side of the heat exchanger and releases the air after separation of the condensed solvent to the atmosphere through a deodorizer, and a recovery solvent tank The apparatus according to claim 3, further comprising a new solvent replenishing section.   The apparatus according to claim 4, wherein the heat generated by the cooler that cools the heat exchanger is supplied to the temperature maintaining means by a heat pump method and used to maintain the temperature of the hot water in the hot water tank.   2. The apparatus according to claim 1, wherein the solvent is an organic solvent which is nonflammable, has a low boiling point and is liquid at room temperature up to about 39 [deg.] C., has a large kauributanol value, and has a strong dissolving power.   The replenishing unit is connected to the vaporized solvent recovery means so as to form a closed recovery circuit, and is configured to receive the solvent recovered by the vaporized solvent recovery means from the recovery solvent tank. The apparatus of claim 3.   The solid material unloaded from the unloading means is further dehydrated by a dehydrator, then dried by a dryer, stored in a temporary silo after drying, and sent from the silo to an extrusion molding machine where it is extruded into a rod shape. The apparatus according to claim 1, wherein the apparatus is subjected to a processing of cutting into pellets from a molding by a cutting machine.   9. The apparatus according to claim 1, wherein the carry-out means is constituted by a mesh belt conveyor.   The said hot water tank is an apparatus of Claim 1 which has the temperature maintenance means to maintain the temperature of warm water. The apparatus according to claim 1, wherein the gel-like material is transferred from the dissolution tank to a gel-like material tank by a pump through a filter and stored, and is supplied from the gel-like material tank to the separation unit by a pump.

Images