JP3889124B2 - Waste plastic continuous oil making equipment, waste plastic continuous oil making method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a technique for thermally decomposing waste plastic to make it oily, and particularly to an oiling technique for efficiently obtaining an oily product having a composition suitable for a fuel oil such as an industrial burner.
[0002]
[Prior art]
Various ideas and device forms have already been proposed for the oily treatment of waste plastics. However, the reality is that there is still nothing that enables practical operation.
[0003]
For example, a technology that applies the mechanism of an extrusion molding machine, that is, a technique that continuously performs hydrocracking while heating while performing continuous conveyance using a continuous conveyance means such as a screw conveyor, which is a feature of the extrusion molding machine. It is. As for the mechanism of the extrusion molding machine, since the mechanism is a highly completed technology, a relatively large amount of processing is possible in a compact device form, and continuous automatic processing is possible. A lot of research and development has been promoted around the world. However, the practical use has not been made as described above.
[0004]
The large amount of carbides (carbon) generated during the decomposition process is one of the major reasons why conventional oil production technologies, including extrusion molding machines, do not come into practical use. In other words, when a large amount of carbon is generated, it adheres to the inner wall of the decomposition reactor and hinders heat conduction, making it difficult to stably control the decomposition reaction. Therefore, a recovered material having a desired composition can be obtained efficiently. In addition, the maintenance of the apparatus requires a great amount of labor and time, and further increases the risk of the reaction process, which requires a lot of monitoring personnel. As a result, it is inferior in economic efficiency and cannot be linked to operation as a practical machine.
[0005]
In addition, the fact that the composition of the collected product cannot be sufficiently controlled is also a factor impeding practical operation. That is, it is practically most desirable that the recovered material has a component composition suitable as a fuel oil such as an industrial burner. However, in the case of the conventional technology, the recovered material is inferior in quality due to carbon contamination, or on the contrary, the gasoline is excessively decomposed due to excessive decomposition and lacks suitability as a fuel oil. In reality, it is impossible to increase the added value of the collected material, and it cannot be linked to operation as a practical system.
[0006]
As described above, prevention of carbon generation and composition control of recovered materials are indispensable for making the plasticizing technology for waste plastic into a practical system. To that end, it is natural that accurate knowledge about the mechanism of polymer decomposition and carbon generation and appropriate measures based on this are required. However, all of the conventional techniques are insufficient for these points. It is considered that the generation of carbon could not be effectively prevented and the composition control of the recovered material could not be effectively performed.
[0007]
From this point of view, the inventor of the present application conducted a deeper research and analysis on the mechanism of polymer decomposition and carbon generation, and obtained the following knowledge. First, the oily decomposition of the polymer is that the solid polymer of the waste plastic melts into a liquid phase polymer, and then the liquid phase polymer is further heated to break the higher order structure of the polymer into a lower order structure. In this state, decomposition begins for the first time, and when decomposition occurs, vaporized substances with various molecular weight distributions depending on the decomposition temperature, etc. are generated, and this is cooled and recovered with a certain composition. It is generated through a series of processes that can be obtained. The greatest influence on the composition of the recovered material is the control of the heating temperature or the decomposition reaction for the liquid phase polymer. Therefore, the temperature control or the decomposition reaction control for the liquid phase polymer is the most important factor for the composition of the recovered material. Become.
[0008]
Next, most of the carbon is generated when the vapor generated by the decomposition, particularly the vaporized with a low molecular weight, is further subjected to excessive heating. However, all of the conventional technologies perform the treatment under conditions where the vaporized material is trapped or encapsulated in a solid polymer or liquid phase polymer and cannot escape excessive heating. It is the biggest cause. Therefore, it is most important to quickly separate the vapor generated from the liquid phase polymer from the liquid phase polymer and the like so as to eliminate the state of being exposed to excessive heating.
[0009]
In particular, in the conventional technology that applies the extruder mechanism, the compression force and shear force due to the powerful conveyance of the screw are also used as a heating source, so that the compression is compressed to a high density state even after liquefaction. As a result, the vaporized substance is confined to easily generate a large amount of carbon, and a thick layer is formed on the liquid phase polymer having low thermal conductivity. Thus, it was difficult to control the temperature uniformly, and the composition control of the recovered material could not be performed effectively.
[0010]
[Problems to be solved by the invention]
The present invention has been made on the basis of the above-described knowledge, and it is possible to generate carbon in an oil plasticizing device for waste plastics, particularly in a continuous oiling device that applies an extruder mechanism that can be expected to have the advantages described above. It is an object of the present invention to effectively prevent decomposition and to effectively carry out decomposition control for efficiently obtaining a recovered material having a desired composition.
[0011]
[Means for Solving the Problems]
The continuous oil making apparatus according to the present invention for realizing the above object is an outer cylinder that is provided with a conveying blade on its outer periphery and is rotatable, and an outer cylinder that forms a reaction chamber with the outer periphery of the inner cylinder. A cylinder, a core cylinder provided inside the inner cylinder, and a rotating shaft with a conveying blade provided inside the core cylinder are provided. In order to perform oiling with this continuous oil generator, the waste plastic supplied to the inside of the core cylinder is conveyed from one side of the core cylinder to the other side by the conveying blades of the rotating shaft, and the waste during the conveyance is discarded. The plastic is subjected to a pretreatment such as dehydrochlorination or decyanide by heating with heating energy supplied from the inside of the inner cylinder to the core cylinder, and a pretreatment product obtained by this pretreatment is supplied to the reaction chamber, The pretreatment material supplied to the reaction chamber is transported from one side to the other side in the reaction chamber by the rotation of the inner cylinder, and is melted by the heating energy supplied from the inner side of the inner cylinder to the reaction chamber. A liquid layer having a shallow liquid depth is formed at the bottom of the reaction chamber in the liquid phase polymer, and the liquid phase polymer is scraped from the liquid layer on the outer peripheral surface of the inner cylinder according to the rotation of the inner cylinder. With liquid phase polymer While forming a thin film on the outer peripheral surface of the tube causes decomposition and vaporization of the liquid phase polymer.
[0012]
One of the features of the continuous oil making apparatus according to the present invention is that a thin film is formed on the liquid phase polymer on the outer peripheral surface of the inner cylinder, and the thinned liquid phase polymer is decomposed by heating energy from the inside of the inner cylinder.・ I was trying to vaporize. For this reason, the liquid phase polymer which is going to cause decomposition and vaporization comes into contact with the heating source with a thin film of, for example, 0.5 mm or less, and the whole can always be kept at a uniform temperature. Further, it is possible to quickly remove the vapor generated from the liquid phase polymer from the liquid phase polymer, thereby eliminating the state in which the vapor is exposed to excessive heating, thereby effectively preventing the generation of carbon. Furthermore, the heating efficiency for the liquid phase polymer for decomposition and vaporization is remarkably increased, and the decomposition efficiency can be greatly improved. As a result, the decomposition reaction of the polymer can be effectively controlled, and a high-quality oily product having a desired composition can be efficiently recovered. Further, the burden on the maintenance of the apparatus can be greatly reduced, and further, the monitoring of the reaction process is substantially unnecessary, and the unmanned operation can be enabled.
[0013]
In addition to the above-described features, the continuous oil making apparatus according to the present invention is an oil treatment for mixed waste plastic in which plastics that release hydrogen chloride and cyanide are mixed by heating, such as polyvinyl chloride and polyacrylonitrile. Has the feature that it can be continuously performed in a pretreatment such as dehydrochlorination. In particular, it is characterized by the fact that pretreatment is performed using the inside of the inner cylinder. Therefore, it is a device that can perform pretreatment and oily treatment continuously, but the whole is greatly downsized, and heating energy for oily decomposition is also available. It is also possible to achieve significant energy savings by using this for pretreatment.
[0014]
[Embodiment]
Hereinafter, an embodiment of the present invention will be described. As shown in FIG. 1, the continuous oil making apparatus according to this embodiment is a reactor 1 that is entirely cylindrical and installed in a horizontal state or a slightly inclined state, a feeder 2 that supplies waste plastic to the reactor 1, The main component is a transfer feeder 3 for transferring waste plastic from a pretreatment chamber (described later) provided in the reactor 1 to the reaction chamber.
[0015]
The reactor 1 has a structure in which an outer cylinder 5, an inner cylinder 6, a core cylinder 7, and a rotating shaft 8 are concentrically combined in order from the outside. A predetermined space is provided between the outer cylinder 5 and the inner cylinder 6 to form a reaction chamber 10. The reaction chamber 10 has a structure composed of a melting zone M in which the distance between the outer cylinder 5 and the inner cylinder 6 is relatively narrowed and a reaction zone R in which the distance is widened. Further, a vaporized substance outlet 11 is provided in the reaction chamber 10 so that the vaporized substance can be sent out from the vaporized substance outlet 11 to a recovery device (not shown). A predetermined interval is also provided between the inner cylinder 6 and the core cylinder 7 to form a hot air passage 12 so that hot hot air blown from a heating burner (not shown) can be blown. Further, a predetermined interval is also provided between the core cylinder 7 and the rotary shaft 8 to form a preliminary processing chamber 14, the starting end portion of the preliminary processing chamber 14 is connected to the feeder 2, and the terminal end portion is connected to the transfer feeder 3. The pretreatment chamber 14 is provided with a degassing port 15 for exhausting gas generated by dehydrochlorination.
[0016]
The inner cylinder 6 is provided with screw conveyor-like conveying blades 16 on the outer periphery thereof, and can be rotated by driving means 18 via gears 17 and 17 provided on the outer periphery thereof. In this way, the waste plastic and its liquid phase polymer supplied can be transported as indicated by an arrow X in the reaction chamber.
[0017]
Similarly, the rotary shaft 8 is also provided with screw conveyor-like conveying blades 20 on the outer periphery thereof, and can be rotated by the driving means 21, and waste plastic supplied from the feeder 2 to the pretreatment chamber 14 is disposed in the pretreatment chamber. It can be transported as indicated by arrow Y.
[0018]
The transfer feeder 3 enables the waste plastic taken in from the pretreatment chamber 14 to be supplied to the reaction chamber 10 while storing an appropriate amount. For this purpose, the screw conveyor 23 for intake, the screw conveyor 24 for supply, and a storage tank 25 having a predetermined capacity are used. Further, the transfer feeder 3 is provided with a branch hot air passage 12b communicating with the hot air passage 12 of the inner cylinder 6 around the transfer feeder 3, so that the temperature of the waste plastic being moved can be maintained.
[0019]
The plasticizing process of waste plastic by such a continuous oil converting apparatus proceeds as follows. The solid waste plastic supplied from the feeder 2 to the pretreatment chamber 14 is continuously conveyed in the direction of arrow Y by the conveying blade 20 of the rotating shaft 8. And during this conveyance, the waste plastic is heated to 250 to 300 ° C. by the heating energy supplied from the hot hot air in the hot air passage 12 through the core cylinder 7, and polyvinyl chloride and polyacrylonitrile mixed in the waste plastic Reactions such as dehydrochlorination and desiccation occur. The generated gas is discharged to the outside through the deaeration port 15.
[0020]
When the preliminary processed material thus subjected to the preliminary processing reaches the end of the preliminary processing chamber 14, the transfer feeder 3 takes in the storage tank 25 by the screw conveyor 23. On the other hand, the transfer feeder 3 quantitatively supplies the preprocessed material from the storage tank 25 to the reaction chamber 10 by the screw conveyor 24. The pre-treatment product supplied to the reaction chamber 10 is continuously conveyed in the direction of arrow X by the conveying blade 16 of the inner cylinder 6. And during this conveyance, a preliminary-processed material is heated with the heating energy supplied through the inner cylinder 6 from the hot hot air of the hot air path 12. FIG. The heating temperature in the reaction chamber 10 is made different between the melting zone M and the reaction zone R. For this purpose, the thermal conductivity of the inner cylinder 6 is made different between a portion corresponding to the melting zone M and a portion corresponding to the reaction zone R. The heating temperature varies depending on whether the waste plastic is mainly composed of, for example, polystyrene or polyethylene. For example, when a catalyst is not used, the melting zone is usually 400 to 500 ° C and the reaction zone is 450 to 600 ° C. It is.
[0021]
In the melting zone M, the pre-processed material that has already been softened by being heated in the pre-processing chamber 14 is heated to the above temperature to melt and become a liquid phase polymer. The liquid phase polymer gradually forms a shallow layer as the conveyance proceeds, and in the reaction zone R, a liquid layer L having a shallow liquid depth is formed at the bottom of the reaction chamber 10 as shown in FIG. It becomes. In this state, the liquid phase polymer is scraped up according to the rotation of the inner cylinder 6. Therefore, the liquid phase polymer forms a thin film F on the outer peripheral surface of the inner cylinder 6. And in the state of this thin film F, it is heated and decomposed | disassembled and vaporized by the hot air of the hot air path 12 via the inner cylinder 6. FIG. The vaporized material generated thereby is sequentially sent out from the vaporized material delivery port 11 while filling the entire reaction chamber 10 except for the shallow liquid layer L.
[0022]
【The invention's effect】
As described above, according to the present invention, the generation of carbon can be effectively prevented, the decomposition reaction can be effectively controlled, and a high-quality oily product having a desired composition can be efficiently recovered. Also, mixed waste plastic mixed with polyvinyl chloride or the like can be processed efficiently, and a high-quality oily product having a desirable composition can be efficiently recovered.
[Brief description of the drawings]
FIG. 1 is a side view including a partial cross-section showing a simplified continuous oil making apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the reactor in FIG.
[Explanation of symbols]
5 Outer cylinder 6 Inner cylinder 7 Core cylinder 8 Rotating shaft 10 Reaction chamber 16 Conveying blade 20 Conveying blade F Thin film L Liquid layer

Claims (2)

And inner cylinder transport blade is a and rotatable provided on an outer periphery,
So as to form a reaction chamber between the outer periphery of the inner cylinder, an outer cylinder disposed so as the longitudinal direction in the longitudinal direction of the inner tube to the outside of the inner cylinder is along,
A hot air path is formed between the inner cylinder and the inner circumference of the inner cylinder, and the inner cylinder is arranged so that its longitudinal direction is along the longitudinal direction of the inner cylinder. A core cylinder and
A rotating shaft with conveying blades and is rotatable arranged that as the longitudinal direction along the interior of the core tube in the longitudinal direction of the core tube,
A burner for heating the pretreatment chamber and the reaction chamber by blowing hot air into the hot air path;
A feeder that is connected to one side of the core cylinder so as to communicate with the pretreatment chamber, and that supplies waste plastic that becomes a pretreatment object by performing pretreatment by heating to the pretreatment chamber;
It is connected to the other side of the core cylinder so as to communicate with the pretreatment chamber, and is connected to the other side of the outer cylinder so as to communicate with the reaction chamber, where it is decomposed and vaporized by heating. A transfer feeder for removing the pretreated material from the pretreatment chamber and supplying the pretreated material to the reaction chamber;
An outlet that is connected to the outer cylinder so as to communicate with the reaction chamber, and takes out the vaporized components generated by the decomposition and vaporization of the pretreated material in the reaction chamber;
With
The rotating shaft is configured to convey the waste plastic from one side of the inner cylinder to the other side in the pretreatment chamber by a conveying blade provided in the rotating shaft.
The inner cylinder is configured to convey the preliminary processed material from the other side of the inner cylinder to the one side by a conveyance blade included in the inner cylinder as it rotates.
Continuous plasticizing equipment for waste plastic . And inner cylinder transport blade is a and rotatable provided on the outer periphery, so as to form a reaction chamber between the outer periphery of the inner tube, a longitudinal direction in a longitudinal of the inner tube to the outside of the inner tube A hot air path is formed between the outer cylinder arranged in the direction and the inner periphery of the inner cylinder, and the longitudinal direction of the inner cylinder is aligned with the longitudinal direction of the inner cylinder. manner arranged a core barrel for the inner and pretreatment chamber, the interior longitudinally to the conveying blades whose longitudinal direction is the way arranged with and rotatable along the core tube of the core barrel A method of being carried out in a continuous plasticizer for waste plastic comprising a rotating shaft with
It is connected to one side of the core cylinder so as to communicate with the pretreatment chamber, and from the feeder that supplies waste plastic as a pretreatment material to the pretreatment chamber by performing pretreatment by heating there. Supply waste plastic to the pretreatment chamber,
By blowing hot air into the hot air path, the pretreatment chamber and the reaction chamber are heated,
While conveying toward the one side of the core tube on the other side by a waste plastic which is supplied to the inside of the core tube carrying blade of the rotary shaft, heating by hot air blown into the waste plastic in the conveying said heated air path Pre-treatment by
The pretreatment product obtained by this pretreatment is taken out by a transfer feeder and supplied to the reaction chamber,
A liquid phase polymer having a shallow liquid depth is formed at the bottom of the reaction chamber on the liquid phase polymer generated from the pretreatment product , and the liquid phase polymer is scraped up from the liquid layer on the outer peripheral surface of the inner cylinder according to the rotation of the inner cylinder. By causing the liquid phase polymer to form a thin film on the outer peripheral surface of the inner cylinder, by heating with the hot air blown into the hot air path, the liquid phase polymer is decomposed and vaporized ,
In taking out the decomposed and vaporized components from the outlet connected to the outer cylinder so as to communicate with the reaction chamber,
In the pretreatment chamber, the waste plastic is transported from one side of the inner cylinder to the other side,
Wherein in the reaction chamber, to transport the waste plastic from the other side of the inner tube to one side,
A method for continuously converting waste plastic to oil.

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