JPH0558792B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Application of the Invention) The present invention relates to a volume reduction treatment device for waste plastics. (Background technology) Waste plastics are a mixture of thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, and polyethylene, and thermosetting resins such as phenolic resins and urea resins. In addition, in many cases, it contains earth and sand, waste paper,
Since it also includes other waste materials such as wood chips, cloth, and food scraps, in this specification, it is referred to as "waste plastics" to refer to the miscellaneous waste plastics that include these materials. Conventionally, equipment for reducing the volume of these waste plastics compresses the waste plastics at room temperature, applies induction heating to melt and soften the thermoplastic resin, and uses this as an adhesive to reduce the volume. In some cases, the waste plastics are placed in a hot air oven and hot air is blown to soften and melt the thermoplastic resin, and then this softened molten resin is used as an adhesive to produce thermosetting resins and other materials. There is a method in which the volume is reduced by compression molding together with the waste, and this invention belongs to the latter. In this case, in order to maintain the compression molded state of the processed material after treatment, it is necessary to mix the thermoplastic resin that melts at low temperatures uniformly, and to ensure that the temperature is uniformly applied to the processed material. It was necessary to ensure that the thermosetting resin, which does not soften with heat, can be smoothly discharged through a narrowed discharge port. In addition, the size of waste plastics is not constant, so if you use a funnel-shaped hot air stove with an outlet at the bottom, small waste plastics will be heated unless special measures are taken. There were cases where the liquid spilled out from the outlet without any problem.
However, if the diameter of the discharge port is made small, there is a problem in that relatively large waste plastics made of thermosetting resin may clog the discharge port and cannot be discharged. (Technical Problem) The purpose of this invention is to make it possible to stir the waste plastics stored in the hot air furnace and mix it well, and to make it possible to add hot air uniformly. It is an object of the present invention to provide a waste plastics volume reduction processing apparatus which can efficiently reduce the volume of waste plastics having various sizes and shapes and thermal characteristics even when using a hot blast furnace. (Technical Means) In order to achieve the above-mentioned technical problem, the present invention provides a funnel-shaped hot air stove with a plurality of nozzles on the outer periphery in a hot air storage chamber, and injects air into the upper part of the large diameter of this hot air stove. A discharge port is provided at the bottom with a small diameter, and a rotating shaft having a screw blade having an outer diameter that substantially matches the inner diameter of the discharge port is provided in the axial direction of the hot air stove, with a part of the rotating shaft facing the discharge port. At the same time, a shutter plate is provided at the discharge port so as to be openable and closable to prevent the material to be processed in the hot air stove from spilling out. A variety of miscellaneous waste plastics including thermoplastic resins, thermosetting resins, and other wastes are fed into the hot air oven and housed in the hot blast furnace, and the thermoplastic resins are heated to soften and melt the thermoplastic resins, and the softened and melted During this process, the screw blades are rotated in the forward or reverse direction as appropriate to stir the stored waste plastics in the hot blast furnace, and the shutter plate is opened to forcefully discharge the treated materials from the discharge port. It is something. (Function) By configuring as described above, by rotating the rotating shaft in the forward or reverse direction during heating in the hot air stove, the screw blades agitate the waste plastics, and the hot air is heated. Improves circulation and allows waste plastics to be heated evenly.
During discharge, by rotating in the forward direction, the semi-molten processed material can be forcibly sent toward the discharge port, and it also facilitates the discharge of large thermosetting resins and other waste. Even if the diameter of the hot air stove is increased, small waste plastics can be prevented from being heat-treated and falling out of the outlet. (Embodiment) An embodiment of the present invention will be described below in detail based on the drawings. Reference numeral 1 denotes a blower for taking in outside air, and a hot air generating furnace 3 equipped with an oil burner 2 that uses kerosene as fuel, for example. , are connected via a ventilation pipe 4. Adjacent to this hot air generating furnace 3, a hot air retention chamber 5 constructed with a heat insulating wall is provided. Inside this hot air storage chamber 5, a funnel-shaped hot air stove 6 is housed vertically. An input port 7 is provided at the large diameter upper portion of the hot air stove 6, an outlet port 8 is provided at the small diameter lower portion, and an exhaust pipe 9 is further provided at the upper portion. The hot air stove 6 further includes a plurality of nozzles 6 on the outer periphery.
a, 6a... are attached at random. Inside this hot air stove 6, screw blades 10 having an outer diameter substantially matching the inner diameter of the discharge port 8 are disposed from the top.
A rotary shaft 11 is rotatably suspended in the axial direction with the screw blade 10 facing the discharge port 8, and the rotary shaft 11 is rotated by a motor 12 in forward and reverse directions. For example, a hydraulically driven shutter plate 13 is attached to the discharge port 8 of the hot air stove 6 so as to be openable and closable.
A bucket 14 is placed facing this discharge port 8. Next, to explain the function and effect, when the burner 2, which uses kerosene as fuel, is ignited and the blower 1 is turned on, the high temperature combustion gas generated by the burner 2 is taken in by the blower 1. The hot air is diluted and the temperature is lowered by the outside air, and then introduced from the hot air generating furnace 3 into the hot air storage chamber 5, and then blown into the inside of the furnace through nozzles 6a, 6a, . . . provided on the outer periphery of the hot air furnace 6. Around this time, the motor 12 is turned on, the screw blade 10 is rotated in the opposite direction at an appropriate speed, and after confirming that the temperature inside the hot blast stove 6 has reached approximately 180°C to 200°C, the inlet port 7 is For example, maltprene, styrofoam,
When a mixture of various waste plastics including thermoplastic resins such as polyethylene, thermosetting resins such as phenolic resins and urea resins, and other waste materials is introduced, the heat that softens and melts at a relatively low temperature is generated. The plastic resin melts and penetrates between the other softened and unmelted resins and other waste materials, thereby bonding the entire treated object. At this time, as the input waste plastics are stirred by the rotating screw blade 10, thermoplastic resins that soften and melt at the temperature inside the furnace, thermosetting resins that do not soften and melt, and other wastes are well mixed. In addition to this, the hot air passes through the object uniformly, so there is no temperature unevenness and the object is heated almost uniformly. Furthermore, small pieces of waste plastic stored in the hot air stove 6 tend to spill into the bucket 14 through the gap between the screw blade 10 and the discharge port 8 before being heated; It is blocked by the plate 13 and accumulates on the upper part of the shutter plate 13, and the nozzles 6a, 6a...
It is heated by the hot air blown through it and is softened and melted. Depending on the situation, the screw blade 10 may be rotated alternately in the forward direction or in the reverse direction, or may be rotated intermittently as appropriate. In this way, after approximately 3 to 6 minutes have elapsed since the injection, the resin with a low melting point melts and permeates between other resins and other waste, so the shutter plate 13 is opened and the direction of rotation of the motor 12 is adjusted. When turned in the forward direction, the waste plastics are sent to the discharge port 8 by the screw blade 10, and are discharged from there into the interior of the bucket 14. At the same time, new waste plastics are inputted from the input port 7, subjected to the above-described treatment, and then discharged from the discharge port 8. In this way, the volume of waste plastics can be continuously reduced. It is possible. Although the screw blade 10 is convenient for performing such continuous processing, this does not mean that batch processing cannot be performed using the screw blade 10. Figure 2 compares the processing capacity of continuous processing and batch processing, and shows that as the volume of the hot blast stove increases, the processing capacity of continuous processing increases dramatically compared to batch processing. I understand. In either case, when the amount of waste plastics to be processed reaches an appropriate amount, one bucket is
4 to take out the contents, or instead of the bucket 14, compression molding is performed using a molding machine (not shown) installed at the location of the bucket 14 or at a different location to further reduce the volume. be. Even if a molding machine is not used, the molten resin penetrates between the unmelted resin and other waste and bonds them together, making it possible to reduce the volume to about one-tenth of the original size. . In any of the above cases, as the melted thermoplastic resin cools, it adheres the unmelted thermosetting resin and other waste materials, so that the material to be treated does not fall apart and decompose. Paper, cloth, and wood chips were found in the waste plastics.
If ignitable waste is mixed in, a fire may occur inside the hot blast furnace 6, but in this case, a sprayer (not shown) may be used to spray water into the inside of the furnace to extinguish the fire. Alternatively, ignition could be prevented by humidifying the hot air beforehand and blowing it into the hot air stove 6. The processing temperature in the hot air stove 6 has a large effect on the volume reduction performance of waste plastics, but as shown in the table below, most of the thermoplastic resins
Polyethylene, polypropylene, polyvinyl chloride, polystyrene, etc., which soften at 150℃ to 160℃ and are the main components of municipal waste plastics,
Since it becomes molten by 180℃, the processing temperature is 150℃.
It was found that it is desirable to keep the temperature above ℃.

【table】

[Table] On the other hand, if the processing temperature is raised too high, the waste plastics will thermally decompose, producing smoke and odors. The kind is
It has been found that a treatment temperature of about 180°C to 200°C is most desirable. This treatment temperature naturally varies depending on the type of waste plastics to be subjected to volume reduction treatment, the distribution ratio, etc., and is not constant. Next, the volume reduction performance also varies depending on the composition of waste plastics, but in the case of the above-mentioned municipal waste, the volume reduction rate in the hot blast furnace 6 is about 1/10, and the volume reduction rate is about 1/10 when molded using a molding press. Later, it was reduced to about 1/40. On the other hand, when Styrofoam was the main component, the strength was 1/100 after molding, and when a large amount of foreign matter or thermosetting resin was mixed in, it was about 1/20 to 1/30 after molding. . (Effects) As explained in detail above, according to the present invention,
By installing a rotating shaft equipped with screw blades inside the hot blast furnace, the input material is stirred during heating to ensure uniform heating, increasing processing efficiency and thermal efficiency, as well as reducing the volume of small processed materials. Alternatively, it is possible to prevent spilling from the discharge port without being melted, and furthermore, large-sized waste plastics, especially thermosetting plastics, and other waste can be easily discharged from the discharge port, and furthermore, it can be continuously disposed of. The effect of being able to perform volume reduction processing can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, FIG. 1 is a vertical sectional view schematically showing the invention, and FIG. 2 is a drawing showing the processing capacity of the waste plastics volume reduction processing apparatus according to the invention. . 1...Blower, 2...Oil burner, 3...
...Hot air generation furnace, 5...Hot air retention chamber, 6...Hot air furnace, 6a, 6a...Nozzle, 7...Inlet, 8...
...Discharge port, 10...Screw blade, 11...Rotating shaft, 12...Motor, 13...Shutter plate.

Claims (1)

[Claims] 1. A funnel-shaped hot air stove with a plurality of nozzles on the outer periphery is provided in a hot air storage chamber, an inlet is provided at the upper part of the large diameter of this hot air stove, and an outlet is provided at the lower part of the small diameter, and A rotary shaft equipped with a screw blade having an outer diameter that substantially matches the inner diameter of the outlet is installed with a part thereof facing the outlet, and a rotary shaft is installed with a part thereof facing the outlet, and the material to be processed in the hot blast furnace is not spilled into the outlet. A shutter plate is provided that can be opened and closed to prevent the hot air from burning, and the hot air stove is heated from the outside, while hot air is sent into the hot air stove through the nozzle, and the thermoplastic resin and thermosetting resin accommodated in the hot air stove are heated. Various miscellaneous waste plastics including resins and other wastes are heated to soften and melt the thermoplastic resin, and during this softening and melting, the screw blade is rotated in the forward or reverse direction as appropriate. A volume reduction processing apparatus for waste plastics, characterized in that the collected waste plastics are agitated in the hot blast furnace, and the waste plastics to be treated are forcibly discharged from the discharge port by opening the shutter plate.