JPH09290229A - Thermal decomposition device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously thermally decompose objects to be treated without pollution and to efficiently recover residue components by providing the device with rotary vanes which move the objects to be treated by rotating nearly around the central axis of a flat plate member for stagnating the objects to be treated in contact with this flat member. SOLUTION: Waste plastic is crushed by a crushing machine and is taken into the agitating section 6 in the device from a plastic feed port 2. A heating furnace 5 is heated at a prescribed temp. by a heating gas and the rotary vanes 9 rotates therein. The plastic pieces charged into the agitating section 6 stagnate on a heating disk 7 and are gradually moved by the rotary vanes 9 which rotate slowly at the number of revolutions meeting a reaction rate. The plastic pieces are heated by the heating disk 7 and the thermal decomposition progresses. The generated cracking gases are discharged outside the device from cracking gas outlet nozzles 3, 4 and the molten plastic is discharged outside the device from a drain nozzle 11. Further, the residue components are dropped to a residue discharge port 10 and are discharged outside the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal decomposition apparatus capable of efficiently and safely thermally decomposing waste plastic or the like.

[0002]

2. Description of the Related Art In recent years, as the use of plastics has increased, the amount of plastics to be disposed of has grown enormous, and the annual amount of discarded plastics exceeds 6 million tons.
Therefore, it is one of the causes of environmental problems such as shortage of landfill disposal site and generation of harmful gas by incineration. Therefore, as a recycling treatment of a plastic material, a method of converting it into a solid fuel or a pyrolysis oil has been proposed.

There are various types of plastics to be treated, such as polypropylene, polyethylene, polystyrene, polyvinyl chloride, etc., and their shapes are also various such as bottles, sheets and films. Therefore, crushing,
After cutting, etc., they were transferred to a processing device for melting and solidification or thermal decomposition.

[0004]

However, when polyvinyl chloride or the like is mixed when the plastic is melted and solidified or pyrolyzed for the purpose of volume reduction and recycling, chlorine gas or polyvinyl chloride is mixed. The added plasticizer such as dioctyl phthalate decomposes to generate phthalic acid. In order to remove these chlorine gas and phthalic acid, it is desirable to heat them in stages, and it is necessary to continuously discharge the residue generated after decomposition. The device that does this has not yet been developed.

The present invention has been made in view of the above circumstances, and an object thereof is to continuously pyrolyze an object to be treated, such as plastic waste, in a pollution-free state, and efficiently recover the residue. An object of the present invention is to provide a thermal decomposition device that can be used.

[0006]

In order to achieve the above object, the invention of claim 1 is a flat plate for accommodating an input port for inputting a processing target and a processing target input from the input port. A member, a rotary blade that is provided in contact with the flat plate member, and that rotates about the central axis of the flat plate member to move the accumulated object to be processed at a predetermined speed; Heating means for heating the treated object to a predetermined temperature, and a decomposed gas discharge nozzle for discharging decomposed gas generated during thermal decomposition of the treated object to the outside of the apparatus,
And a residue discharge port for discharging the thermally decomposed residue conveyed on the flat plate member to the outside of the apparatus.

According to the above construction, the object to be treated such as plastic dust can be continuously pyrolyzed in a pollution-free state, and the residue can be efficiently recovered.

According to a second aspect of the present invention, in the thermal decomposition apparatus according to the first aspect, the heating means is a heating furnace provided on the lower surface side of the flat plate member, and the heating gas is introduced into the heating furnace. The flat plate member is heated.

According to the above construction, since the heating means is composed of a simple heating furnace, the pyrolysis temperature can be easily changed by changing the temperature of the heating gas introduced. According to a third aspect of the present invention, a flat plate member for accumulating the objects to be processed, a flat plate member provided in contact with the flat plate member, and rotating about the central axis of the flat plate member, the accumulated objects to be processed are predetermined. A rotary blade that moves at a speed, a heating unit that heats the object to be processed accumulated on the flat plate member to a predetermined temperature, and a thermally decomposed object to be processed carried on the flat plate member outside the flat plate member. It is configured by assembling multiple stages of thermal decomposition tanks that have at least a discharge port for discharging to the The product is put into the next-stage thermal decomposition tank through the discharge port and thermally decomposed again, and the lowermost thermal decomposition tank discharges the residue after thermal decomposition outside the apparatus through the discharge port. It is a thing.

According to the above construction, since the pyrolysis tanks can be combined in multiple stages, it is possible to carry out multistage pyrolysis treatment with a simple apparatus configuration.

According to a fourth aspect of the present invention, in the thermal decomposition apparatus according to the third aspect, the heating means is a heating furnace provided on the lower surface side of the flat plate member, and is provided in the heating furnace of the lowermost thermal decomposition apparatus. While the heating gas is introduced from the outside of the apparatus, the exhaust heat gas from the lower pyrolysis tank is introduced into the heating furnace of the pyrolysis apparatus located in the upper stage. According to the above configuration, the heating gas is introduced only into the lowermost thermal decomposition tank, and the exhaust heat gas is introduced into the next stage to heat, so that the stepwise thermal decomposition treatment with a temperature difference is minimized. Can be run with energy efficiency.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> FIG. 1 is a plan view and a front view showing an embodiment (first embodiment) of a thermal decomposition apparatus according to the present invention. This thermal decomposition device is a device for thermally decomposing waste plastic.

As shown in the figure, the waste plastic thermal decomposition apparatus 1 is formed in a cylindrical shape, and has a plastic injection port 2 and two decomposition gas outlet nozzles 3 and 4 at appropriate positions on the upper surface thereof. Is provided. The cylindrical portion of the thermal decomposition apparatus 1 is composed of a heating furnace 5 and a stirring section 6 formed on the heating furnace 5. The heating furnace 5 and the stirring section 6 are separated by a heating disk 7. ing. At the bottom of the heating furnace 5,
A heating gas introduction port 8 is provided, and heating gas having a predetermined temperature is introduced from the introduction port 8 to heat the heating disk 7.

The heating disk 7 is formed of an umbrella-shaped thin disk. Further, a part of the heating disc 7 is cut out, and the residue discharge port 10 is attached to the cutout portion. In the figure, a portion corresponding to approximately 1/4 of the heating disc 7 is cut out and the residue discharge port 10 is attached here, but this is an example and may be of an appropriate size.

A motor M is arranged on the central axis of the upper surface of the thermal decomposition apparatus 1. A rotary blade 9 having four blades is attached to the rotary shaft of the motor M. The rotary blade 9 is arranged near the inner diameter of the cylinder and in contact with the heating disk 7. The rotary blades 9 may be of any suitable number such as three blades.

A molten plastic drain nozzle 11 is attached to a side surface of the heating furnace 5 near the stirring section 6 so that the molten plastic is discharged to the outside of the apparatus.

Next, the operation of the plastic thermal decomposition apparatus 1 having the above structure will be described.

Waste plastic such as vinyl chloride to be subjected to thermal decomposition is crushed to a predetermined size by a crusher (not shown). The waste plastic pieces after crushing are taken into the stirring section 6 in the apparatus through the plastic input port 2. In this case, the heating furnace 5 has already been heated to a predetermined temperature by the heating gas,
For example, while being heated to 350 to 450 ° C., the rotary blade 9 is rotating at a predetermined speed, for example, 0.5 to 1.0 hours / rotation. The plastic pieces charged into the stirring section 6 are accumulated on the heating disk 7 and gradually moved by the rotating blade 9 which slowly rotates at a rotation speed corresponding to the reaction speed. During the movement, the waste plastic piece is heated by the heating disk 7 on the lower surface, and thermal decomposition proceeds. Plastics such as polypropylene, polystyrene, and polyethylene are decomposed by heating at a temperature of about 350 to 450 ° C, and polyvinyl chloride is decomposed by heating at a temperature of about 270 to 350 ° C.

By this thermal decomposition treatment, waste plastic that has been introduced, for example, chlorine gas from vinyl chloride resin pieces,
And fumaric acid, which is a plasticizer, is separated and discharged from the decomposition gas outlet nozzles 3 and 4 to the outside of the apparatus. The decomposed gas outlet nozzle 3.4 communicates with a hydrochloric acid treatment device (not shown),
This hydrochloric acid treatment device collects hydrochloric acid, and
The unrecovered gas components in this hydrochloric acid treatment device are made pollution-free by an exhaust gas treatment device (not shown) and then discharged into the atmosphere. On the other hand, the molten plastic melted by heating is discharged from the drain nozzle 11 to the outside of the apparatus.

In this way, the chlorine content, the plasticizer content, and the residue content after the oil content are collected are carried by the rotation of the rotary blades 9 and fall to the residue discharge port 10 to be discharged outside the apparatus.
The residue discharge port 10 communicates with a residue treatment device (not shown). In this residue treatment apparatus, for example, the residue is put into an inclined heating furnace and rotated while being heated to continuously perform thermal decomposition and crushing of the residue, and the powdery residue is discharged.

As described above, according to the embodiment of the present invention, only by injecting the waste plastic piece to be treated from the plastic input port 2, the thermal decomposition is automatically proceeded to separate the oil gas and the residue. It becomes possible to separate and collect.

<Second Embodiment> FIG. 2 is a front view showing the configuration of another embodiment (second embodiment) of the thermal decomposition apparatus according to the present invention. The same components as those of the apparatus shown in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

This apparatus has a structure in which heating furnaces are stacked in three stages. That is, the first heating furnace 5A is connected to the second heating furnace 5B provided at the upper stage thereof via the first damper 12, and the second heating furnace 5B is provided at the upper stage thereof. It is connected to the 3 heating furnace 5C via the second damper 13. The upper surfaces of the heating furnaces 5A, 5B and 5C are a first heating disk 7A, a second heating disk 7B and a third heating disk 7C, respectively. A first rotor 9A, a second rotor 9B, and a third rotor 9C are coaxially arranged in each stirring section. Further, the first heating disc 7A has the first residue discharge port 10A, the second heating disc 7B has the second residue discharge port 10B, and the third heating disc 7C has the third residue discharge port 10B.
Residue discharge ports 10C are provided respectively. An oil gas discharge nozzle 14 is attached to the lower portion of the second heating furnace 5B.

In the above structure, the heating gas introduced from the heating gas inlet 8 is introduced from the first heating furnace 5A to the second heating furnace 5B through the first damper 12. The heating gas introduced into the second heating furnace 5B is further fed to the second damper 1
3 is introduced into the first heating furnace 5C. The temperature of the heating gas thus introduced into the heating furnaces 5A to 5C is highest in the first heating furnace 5A, which is the first-stage heating furnace, and highest in the third heating furnace 5C, which is the last-stage heating furnace. ing. Also,
Each rotor 7A-7C is also rotating slowly.

In this state, the waste plastic pieces charged from the plastic charging port 2 are collected by the third stirring section 6C in the apparatus.
Is taken in. In this case, each heating furnace 5A-5C has already been
Are heated to a predetermined temperature by the heating gas. For example, in the first heating furnace 5A, the first heating disk 7A is
The second heating furnace 5B heats the second heating disk 7B to about 300 to 350 ° C.
C heats the third heating disk 7C to about 270 ° C.

The plastic pieces put into the third stirring section 6C move slowly by the rotational movement of the rotary blade 9C, and during the movement, they are heated by the third heating disk 7C on the lower surface, and thermal decomposition progresses. To do. By this thermal decomposition treatment, chlorine gas and fumaric acid, which is a plasticizer, are separated from the input waste plastic, for example, vinyl chloride resin pieces, and discharged from the decomposition gas outlet nozzles 3 and 4 to the outside of the apparatus. The decomposed gas outlet nozzle 3.4 communicates with a hydrochloric acid treatment device (not shown), and the hydrochloric acid component is recovered by this hydrochloric acid treatment device.
After being made pollution-free by an exhaust gas treatment device not shown,
Emitted into the atmosphere. On the other hand, the molten plastic melted by heating is discharged from the drain nozzle 11 to the outside of the apparatus.

The waste plastic from which the chlorine content and the plasticizer content have been recovered is carried by the rotation of the rotary blade 9C and dropped from the third residue discharge port 10C into the second stirring section 6B.

Similarly, in the second stirring section 6B, the waste plastic is heated by the second heating disk 7B which is heated to a temperature higher than that of the third heating disk 7C, and chlorine which cannot be recovered by the third stirring section 6C. Minutes and other organic gases are recovered.
The waste plastic from which chlorine, etc. has been collected is the second rotor blade 9B.
Is carried by the rotation of the second residue discharge port 10B and dropped into the first stirring section 6A.

Similarly, in the first stirring section 6A, the first heating disk 7 heated to a temperature higher than that of the second heating disk 7B.
The waste plastic is heated by A, and the second stirring section 6B
The organic gas generated from the waste plastic that could not be recovered in step 1 is recovered, and the residue is carried by the rotation of the first rotary blade 9A and discharged from the first residue discharge port 10A to the outside of the apparatus. The residue discharge port 10 communicates with a residue treatment device (not shown). In this residue treatment apparatus, for example, the residue is put into an inclined heating furnace and rotated while being heated to continuously perform thermal decomposition and crushing of the residue, and the powdery residue is discharged.

Further, in the first stirring section 6A, oil gas is also collected, taken out of the apparatus through the oil gas discharge nozzle 14 and used as fuel oil.

As described above, according to this embodiment, the heating furnaces are stacked in three stages, and three-stage heat treatment is possible. Further, since the heating gas is introduced only into the first heating furnace 5A and the heating furnaces 7B and 7C use the waste heat thereof, the heating energy can be achieved with a minimum amount and the efficiency can be improved. It becomes a waste plastic decomposer.

As described above, according to each embodiment, in order to reduce the volume of plastic waste and to recycle it, in order to recover chlorine gas and phthalic acid generated when melting and decomposing plastic containing polyvinyl chloride, It is possible to provide a thermal decomposition apparatus capable of continuously discharging a residue while maintaining a predetermined heating temperature and residence time.

In each of the above-mentioned embodiments, the object of thermal decomposition is waste plastic, but the present invention is not limited to this, and the thermal decomposition apparatus according to the present invention is used in the case of thermally decomposing sludge to dry and solidify it. , Its target may be any object.

Further, as the heating means, the heating disc is heated by the heating gas introduced into the heating furnace, but the heating disc may be directly heated by an electric heater or a gas burner. Alternatively, heating may be performed from above the waste plastic placed on the heating disc.

[0035]

As described above, according to the first aspect of the present invention, the object to be treated such as plastic waste can be continuously thermally decomposed in a pollution-free state, and the residue can be efficiently recovered.

According to the second aspect of the present invention, the heating means is composed of a heating furnace having a simple structure. Therefore, the thermal decomposition temperature can be easily changed by changing the temperature of the heating gas introduced.

According to the third aspect of the invention, since the thermal decomposition tanks can be combined in multiple stages, it is possible to perform multiple stages of thermal decomposition treatment with a simple apparatus configuration.

According to the invention of claim 4, the heating gas is introduced only into the lowermost thermal decomposition tank, and the exhaust heat gas is introduced into the next stage for heating, so that there is a stepwise difference in temperature. The thermal decomposition process can be performed with minimum energy efficiency.

[Brief description of drawings]

FIG. 1 is a plan view and a front view showing a configuration of a waste plastic thermal decomposition apparatus to which the present invention is applied.

FIG. 2 is a front view showing the configuration of another embodiment of the waste plastic thermal decomposition apparatus to which the present invention is applied.

[Explanation of symbols]

 1 Plastic Thermal Decomposition Device 2 Plastic Input Port 3,4 Decomposition Gas Outlet Nozzle 5 Heating Furnace 5A 1st Heating Furnace 5B 2nd Heating Furnace 5C 3rd Heating Furnace 6 Stirring Part 6A 1st Stirring Part 6B 2nd Stirring Part 6C 3rd Stirring part 7 Heating disc 7A First heating disc 7B Second heating disc 7C Third heating disc 8 Heating gas inlet 9 Rotor blade 9A First rotor blade 9B Second rotor blade 9C Third rotor blade 10 Residue discharge Outlet 10A First residue discharge port 10B Second residue discharge port 10C Third residue discharge port 11 Molten plastic drain nozzle 12 First damper 13 Second damper 14 Oil gas discharge nozzle

Claims (4)

[Claims] 1. A charging port for charging a processing target, a flat plate member for accumulating the processing target charged from the charging port, a flat plate member provided in contact with the flat plate member, and substantially the flat plate member. A rotating blade that rotates around the central axis to move the accumulated processing object at a predetermined speed, a heating unit that heats the processing object accumulated on the flat plate member to a predetermined temperature, and the processing. A decomposition gas discharge nozzle that discharges decomposition gas generated during thermal decomposition of an object to the outside of the device, and a residue discharge port that discharges the residue after thermal decomposition conveyed on the flat plate member to the outside of the device. Pyrolysis device. 2. The thermal decomposition apparatus according to claim 1, wherein the heating means is a heating furnace provided on a lower surface side of the flat plate member, and the flat plate member is heated by a heating gas introduced into the heating furnace. A thermal decomposition device characterized by: 3. A flat plate member for accumulating objects to be processed, and a plate member provided in contact with the plate member and rotating about the central axis of the plate member so that the accumulated objects are accumulated at a predetermined speed. A moving rotary blade, and heating means for heating the object to be treated accumulated on the flat plate member to a predetermined temperature,
The thermal decomposition tank is configured to have at least a discharge port for discharging the processing object after thermal decomposition conveyed on the flat plate member to the outside of the flat plate member. A charging port for charging the target object is provided, and the decomposed processing target object is charged into the thermal decomposition tank of the next stage through the discharge port and thermally decomposed again.
The thermal decomposition tank at the bottom stage discharges the residue after thermal decomposition to the outside of the apparatus through a discharge port. 4. The thermal decomposition apparatus according to claim 3, wherein the heating means is a heating furnace provided on the lower surface side of the flat plate member, and the heating furnace of the lowermost thermal decomposition apparatus is heated from outside the apparatus. While the gas is being introduced, the exhaust heat gas from the lower pyrolysis tank is introduced into the heating furnace of the upper pyrolysis device.