JP2002173690A - Apparatus for disposal of waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste plastic disposal apparatus capable of safely treating a noncondensable light gas component while recovering the cracked oil composed of condensed oil gas as a recovered oil. SOLUTION: The waste plastic disposal apparatus 1 is provided with a thermal cracking apparatus 12 to generate an oil gas and a residue by the thermal cracking of a waste plastic material and recovered oil separating apparatuses 15, 16 to separate a light gas and a recovered oil by condensing the oil gas discharged from the thermal cracking apparatus 12. The light gas discharged from the recovered oil separation apparatuses 15, 16 is burned in a heating and burning apparatus 20. The thermal cracking apparatus 12 carries out the thermal cracking of the waste plastic by burning the recovered oil and the heating and burning apparatus 20 performs the burning treatment of the light gas by burning the recovered oil. The burned exhaust gas of the thermal cracking apparatus 12 is subjected to afterburning treatment together with the light gas in the heating and burning apparatus 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste plastic processing apparatus for thermally decomposing and processing waste plastic.

[0002]

2. Description of the Related Art In a conventional waste plastic processing apparatus, waste plastic is melted and thermally decomposed in a pyrolysis apparatus to generate oil gas and residues. The oil gas becomes product oil by a product oil recovery tower and the like, and is reused as fuel. Residues are collected in a residue collection container and reused as solid fuel or the like.

[0003]

In a conventional waste plastic processing apparatus, a generated oil recovery system for recovering generated oil from oil gas is a very expensive plant because it has a distillation column facility. Therefore, it is preferable that the oil gas is simply condensed to form cracked oil, that is, the oil is not subjected to generation (fractionation) on site, but to be concentrated and processed by a generated oil recovery system in another place.

However, when condensing oil gas into cracked oil, it is necessary to safely treat light gas components (including off-gas components) that do not condense as cracked oil.

[0005] The present invention has been made in view of such a point, and while recovering cracked oil obtained by condensing oil gas as recovered oil, it is possible to safely treat light gas that is not condensed. It is an object to provide a plastic processing apparatus.

[0006]

SUMMARY OF THE INVENTION The present invention provides a pyrolysis apparatus for pyrolyzing waste plastic to generate oil gas and residues, and a light gas by condensing oil gas generated by the pyrolysis apparatus. It has a recovered oil separation device that separates recovered oil, and a heating combustion device that burns light gas separated by the recovered oil separation device.The pyrolysis device burns fuel to remove waste plastic. It is designed to thermally decompose, and the heating combustion device burns fuel,
Light gas is burned, and at least a part of the recovered oil separated by the recovered oil separation device is
It has been used as a fuel for a pyrolysis device and as a fuel for a heating combustion device, and the combustion exhaust gas of the pyrolysis device has been reburned together with light gas in the heating combustion device. A waste plastic processing apparatus.

According to the present invention, while the recovered oil can be recovered from the recovered oil separation device, the light gas discharged from the recovered oil separation device is subjected to the combustion treatment by the heating combustion device, so that the safe operation of the device is achieved. It is possible.

[0008] Preferably, the heating and combustion device is configured to decompose the combustion exhaust gas and the light gas of the thermal decomposition device by performing a combustion treatment. In this case, environmental pollution due to the operation of the waste plastic processing device can be suppressed.

[0009] Preferably, the heating and combustion apparatus includes a processing furnace for combustion processing, a temperature sensor for measuring a temperature in the processing furnace, and a fuel supply amount adjusting unit for adjusting a fuel supply amount of the heating and combustion apparatus. A fuel supply amount control unit that controls the fuel supply amount preparation unit based on the temperature in the processing furnace measured by the temperature sensor. In this case, since the fuel supply amount can be controlled in accordance with the amount of light gas to be burned, the inside of the processing furnace can always be brought into a complete combustion state.

[0010] When the waste plastic processing apparatus includes a heat treatment apparatus using a high-temperature gas, it is preferable that high-temperature exhaust gas discharged from the heating and burning apparatus is used for the heat treatment apparatus. In this case, energy efficiency is good. The high-temperature exhaust gas is preferably diluted to an appropriate temperature with air or the like in accordance with the processing mode of the heat treatment apparatus.
For example, the heat treatment apparatus is a boiler that generates steam or hot water using a high-temperature gas. In this case, steam or hot water generated in the boiler can be used as a heat source of another heat treatment apparatus.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a waste plastic processing apparatus according to the present invention will be described below with reference to FIG.

As shown in FIG. 1, a waste plastic processing apparatus 1 according to the present embodiment includes a pyrolysis apparatus 12 that pyrolyzes waste plastic to generate oil gas and residues. The input device 11 for supplying waste plastic to the pyrolysis device 12 is connected to the pyrolysis device 12.

The pyrolysis device 12 heats waste plastic from the outside with a combustion gas generated by burning fuel (in this case, recovered oil: described later) in a burner section 12b, and also includes a rotation provided inside. The waste plastic is stirred by the screw 12s to decompose the waste plastic into oil gas and residue.

The pyrolysis device 12 is provided with a residue discharge port 12d for discharging a residue, and is connected to an oil gas pipe 13 for discharging an oil gas. Oil and gas piping 13
Is connected to the condensing device 15 (recovered oil separating device). Further, an exhaust gas pipe 14 for discharging combustion gas generated by burning fuel for heating is provided in the pyrolysis device 12.
Is connected. The exhaust gas pipe 14 is connected to the heating combustion device 2
0 so that the combustion exhaust gas is sent to the heating combustion device 20.

The condensing device 15 is configured to inject a liquid oil (in this case, a recovered oil: described later) into the oil gas to condense the oil gas. A cracking oil drum 16 (recovered oil separating device) is connected to the condensing device 15 so that the injected liquid oil and the condensed oil gas are temporarily stored.

Here, the oil gas portion includes a light gas portion which is not condensed even by the condensing device 15. A light gas pipe 17 is provided above the cracked oil drum 16 to discharge the light gas. The light gas pipe 17 is
It is connected to the heating and burning device 20 and sends light gas to the heating and burning device 20.

The disassembled oil drum 16 is provided with a discharge pipe 30 for discharging temporarily stored oil and gas as recovered oil. The discharge pipe 30 may be provided with a pump 35 for controlling a discharge amount of the recovered oil.

From the discharge pipe 30, an oil circulation pipe 31 leading to the condenser 15 is branched. The recovered oil is supplied to the condenser 15 by the oil circulation pipe 31. Further, fuel supply pipes 32 and 33 are branched from the discharge pipe 30, and are connected to the thermal decomposition device 12 (burner portion 12b) and the heating and burning device 20, respectively. The fuel supply pipes 32 and 33 allow the recovered oil to be supplied as fuel to the pyrolysis device 12 and the heating combustion device 20. Such fuel supply is also possible at the time of starting and stopping the waste plastic processing apparatus 1.

The heating and burning apparatus 20 burns the recovered oil sent through the fuel supply pipe 33 to burn off the combustion exhaust gas sent from the exhaust gas pipe 14 and the light gas sent from the light gas pipe 17. Has become. in this case,
The heating and burning device 20 is configured to burn the combustion exhaust gas and the light gas to make them harmless.

The heating and burning apparatus 20 of the present embodiment includes a processing furnace 21 for combustion processing, a temperature sensor 22 for measuring the temperature in the processing furnace 21, and a valve for adjusting the fuel supply amount of the heating and burning apparatus 20. And the like, and a fuel supply amount adjusting unit 23. Then, the fuel supply amount control unit 24 controls the temperature sensor 2
The fuel supply amount adjusting unit 23 is controlled based on the temperature inside the processing furnace 21 measured by 2.

Further, a boiler 40 for generating steam or hot water by using high-temperature exhaust gas discharged from the heating and burning device 20 is connected to the heating and burning device 20. The final exhaust gas (detoxified) from the boiler 40 is
The air is discharged to the atmosphere via a blower 41 and an exhaust duct 42.

Next, the operation of the waste plastic processing apparatus 1 according to the present embodiment will be described.

The waste plastic pulverized and granulated to an appropriate size is supplied into a pyrolysis unit 12 through a charging machine 11. The pyrolysis device 12 heats the waste plastic with the combustion gas generated by the burner section 12b and agitates the waste plastic with the rotary screw 12s. As a result, the waste plastic is pyrolyzed,
This produces oil and gas and residues.

The residue is appropriately discharged from the residue discharge port 12d and is reused as a solid fuel or the like. On the other hand, the oil gas is sent to the condensing device 15 via the oil gas pipe 13 and is separated into the recovered oil condensed and liquid and the gaseous light gas component (to be precise, the main light gas component is Once condensed and re-evolved as a gas). Both the recovered oil and the light gas are sent to the cracked oil drum 16, where the recovered oil is stored in the lower part and the light gas is retained in the upper part. When impurities are present in the oil gas, the impurities can be settled and separated at the bottom of the cracked oil drum 16.

The recovered oil is discharged through a discharge pipe 30, but a part of the recovered oil is circulated to a condenser 15 through an oil circulation pipe 31. Further, a part of the recovered oil is supplied to the fuel supply pipes 32 and 3.
3, the fuel is supplied to the burner section 12 b of the thermal decomposition device 12 and the heated combustion device 20 as fuel.

The light gas is sent to the processing furnace 21 of the heating and burning device 20 through the light gas pipe 17 and is subjected to combustion processing. Here, the temperature in the processing furnace 21 is constantly measured by the temperature sensor 22, and the fuel supply amount control unit 24 controls the fuel supply amount preparation unit 23 according to the measured value, so that the fuel supply amount is always an appropriate amount. Adjusted. Therefore, even when the amount of the light gas sent into the processing furnace 21 fluctuates, the light gas can always be completely burned. For complete combustion of light gas, it is preferable to control the temperature in the processing furnace 21 to be substantially constant.

The high temperature exhaust gas discharged from the heating and burning device 20 is used by the boiler 40. Boiler 40
The steam or hot water generated in the above can be used as a heat source for various devices (not shown) of the waste plastic device. Therefore, energy loss can be suppressed.

Of course, the hot exhaust gas can be used in any other heat treatment apparatus. In this case, the high-temperature exhaust gas is preferably diluted to an appropriate temperature with air or the like in accordance with the processing mode of each heat treatment apparatus.

As described above, according to the present embodiment, the recovered oil can be recovered from the cracked oil drum 16, while the light gas discharged from the cracked oil drum 16 is subjected to the combustion processing by the heating combustion device 20. Therefore, safe device operation is possible.

In particular, the heating and burning device 20 includes the thermal decomposition device 1
Since the combustion exhaust gas and the light gas of No. 2 are burned and made harmless, environmental pollution due to the operation of the waste plastic processing apparatus 1 can be suppressed.

[0031]

As described above, in the waste plastic processing apparatus of the present invention, the recovered oil can be recovered from the recovered oil separation apparatus, while the light gas discharged from the recovered oil separation apparatus is heated by the heating and combustion apparatus. Because it is burned,
Safe device operation is possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a waste plastic processing apparatus showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Waste plastic processing apparatus 11 Input machine 12 Pyrolysis apparatus 12b Burner part 12d Residual discharge port 12s Rotary screw 13 Oil gas pipe 14 Exhaust gas pipe 15 Condenser 16 Cracked oil drum 17 Light gas pipe 20 Heating and combustion apparatus 21 Processing furnace 22 Temperature sensor 23 fuel supply amount adjustment unit 24 fuel supply amount control unit 30 delivery pipe 31 oil circulation pipe 32, 33 fuel supply pipe 35 pump 40 boiler 41 blower 42 waste duct

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) F23G 5/027 ZAB F23G 5/027 ZABA 4H015 5/16 ZAB 5/16 ZABB 4H029 7/12 ZAB 7/12 ZABZ F term (Reference) 3K061 AA24 AB02 AB03 AC13 CA02 FA02 FA21 3K065 AA24 AB02 AB03 AC13 CA01 3K078 BA08 BA13 CA02 CA07 CA21 4F301 CA02 CA03 CA24 CA41 CA52 CA72 4H013 AA02 4H015 AA02 AA17 AB01 BA12 BB03 CB01 4H029 CA01

Claims (5)

[Claims] 1. A pyrolysis apparatus for thermally decomposing waste plastic to generate oil gas and residue, and a recovered oil for condensing oil gas generated by the pyrolysis apparatus to separate light gas and recovered oil. A separation device, and a heating and burning device that burns the light gas separated by the recovered oil separation device. At least a part of the recovered oil separated by the recovered oil separation device is A waste plastic processing apparatus characterized by being used as a fuel and as a fuel for a heating and burning apparatus. 2. A pyrolysis apparatus for thermally decomposing waste plastic to generate oil gas and residue, and a recovered oil for condensing oil gas generated by the pyrolysis apparatus to separate light gas and recovered oil. A separation device, and a heating combustion device that burns light gas separated by the recovered oil separation device, so that the combustion exhaust gas of the pyrolysis device is reburned together with the light gas by the heating combustion device. Waste plastic processing equipment characterized in that: 3. The waste plastic processing apparatus according to claim 1, wherein the heating combustion apparatus is configured to burn off combustion exhaust gas and light gas from the pyrolysis apparatus to make them harmless. 4. A heating combustion apparatus, comprising: a processing furnace for combustion processing; a temperature sensor for measuring a temperature in the processing furnace; a fuel supply amount adjusting unit for adjusting a fuel supply amount of the heating combustion apparatus; A fuel supply amount control unit that controls the fuel supply amount preparation unit based on the temperature in the processing furnace measured by
The waste plastic processing apparatus according to any one of claims 1 to 3, further comprising: 5. The apparatus according to claim 1, further comprising a heat treatment apparatus using a high-temperature gas, wherein high-temperature exhaust gas discharged from the heating and combustion apparatus is used for the heat treatment apparatus. A waste plastic processing apparatus according to any one of the above.