JPH06116566A - Apparatus for converting waste plastics into oil - Google Patents

Abstract

PURPOSE:To obtain an apparatus capable of efficiently removing a heavy component from a pyrolytic fraction prepared by pyrolyzing waste plastics and recovering the resultant oil converted into a light substance. CONSTITUTION:The objective apparatus is obtained by connecting a pyrolytic vessel 1 through a riser communicating part 2 to a lead-out part 4, connecting the lead-out part to a cooling liquefier 5, further providing an air-cooled type heat exchanger 3 in the communicating part 2 and a feeding means 21 for feeding the heated air discharged from the heat exchanger 3 as combustion air to a combustion means 22 of the pyrolytic vessel 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oiling apparatus for thermally decomposing waste plastics and extracting the thermally decomposed fraction as oil content, and particularly to efficiently recover the oil content rich in light components by low energy consumption. The present invention relates to an oil liquefaction device for waste plastics.

[0002]

2. Description of the Related Art Conventionally, a thermal decomposition method has been known as a method for treating waste plastics and recovering active ingredients. In this method, the waste plastic that has been crushed into chips is pyrolyzed by a pyrolysis kettle, and the pyrolyzed fraction is taken out from the outlet and introduced into a cooling liquefier for cooling and condensation. Is a method of collecting. However, in general, the oil content obtained from waste plastic tends to become heavy, that is, an oil content with a large amount of components having a high boiling point, and when it becomes extremely heavy, it becomes a waxy oil content. Therefore, it has been conventionally desired to lighten the oil, that is, to make oil having a large amount of components having a low boiling point, and as a method for solving the problem, for example, a lightening method using a catalyst has been proposed.

[0003]

However, the method using a catalyst has a problem that the cost is increased. A method is also conceivable in which the outlet of the thermal cracker outlet is cooled with a liquid, the heavy components are condensed there, and then returned to the thermal cracker again. However, the thermal cracking fraction flowing out from the thermal cracker is 4
It is a high temperature around 00 ° C, and it is necessary to maintain the temperature of the cooling liquid at the outlet of the heat exchanger at about 200 to 300 ° C in order to condense the heavy components, but a large amount of such a high boiling point cooling liquid is used. It is practically difficult to use. Furthermore, in order to circulate and use the cooling liquid that has been heat-exchanged and has become hot,
There is a problem that a large amount of cooling energy is required.
Therefore, an object of the present invention is to provide an oilification device for waste plastic, which can efficiently reduce the weight of the pyrolysis fraction flowing out from the pyrolysis kettle and has a low energy consumption.

[0004]

The oil-oiling apparatus for waste plastics according to the present invention, which solves the above-mentioned problems, is an oiling apparatus for thermally decomposing waste plastics and collecting the thermally-decomposed fraction as oil fractions. In this device, a thermal decomposition vessel for thermally decomposing waste plastic with a heat source by combustion, a decomposing section for the thermal decomposition fraction connected to the pyrolysis vessel rising through a communication section, and a derivation section were connected. It has a cooling liquefier. Further, in this apparatus, an air-cooling type heat exchanger provided in the rising communication portion and air heated by a pyrolysis fraction flowing in the rising communication portion and discharged from the heat exchanger are used for combustion in the thermal decomposition kettle. It is characterized by comprising an air supply means for supplying as air.

[0005]

According to the waste plasticizer of the present invention,
The pyrolysis fraction obtained by heating in the pyrolysis kettle is cooled by an air-cooling type heat exchanger while rising from the pyrolysis kettle and flowing out through the communication part. By this cooling, the relatively heavy components contained in the pyrolysis fraction are preferentially condensed in the rising communication section. This condensed heavy component rises and flows down through the communication section and is returned to the pyrolysis kettle,
It is redeveloped and some are made lighter. Therefore, the pyrolysis fraction, which is relatively light, is discharged from the outlet, and the oil that has been lightened by the cooling liquefier can be recovered.

On the other hand, the air heated by exchanging heat with the pyrolysis fraction flowing through the rising communication portion of the heat exchanger is supplied as combustion air to the combustion chamber of the pyrolysis vessel by the air supply means, and the heat of the heat is removed. Is effectively recovered, so that the thermal efficiency of the thermal decomposition vessel can be improved. On the other hand, since the pyrolysis fraction flowing out from the outlet is cooled by the heat exchanger, the cooling energy in the cooling liquefier can be reduced by that amount and the cooling liquefier can be made compact. As described above, the oilification device of the present invention can be a system that exerts an overall remarkable energy reduction effect by improving the thermal efficiency of the thermal decomposition vessel and the energy efficiency of the cooling liquefier.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is a diagram for explaining an oily oil recycling apparatus of the present invention. The thermal decomposition vessel 1 is for thermally decomposing waste plastic with a heat source by combustion, and a rising communication portion 2 is connected to the upper portion of the thermal decomposition vessel 1. The rising communication portion 2 is formed of, for example, a tubular body that rises vertically from the upper portion of the pyrolysis pot 1. And this rising communication part 2
An air-cooling type heat exchanger 3 is provided in. Heat exchanger 3
For example, a double pipe type in which the rising communication portion 2 is an inner pipe and the cooling air passage is an outer pipe, or a cooling air passage is an outer pipe, and a large number of relatively thin rising communication lines arranged in parallel are provided therein. A multi-tube type or the like provided with the part 2 can be used. In addition, in order to improve the heat exchange efficiency of the heat exchanger 3, a heat dissipation fin may be provided on the outer peripheral surface of the rising communication portion 2 if necessary.

The downstream side of the rising communication portion 2 is connected to the outlet portion 4, and the cooling liquefier 5 is connected to the tip of the outlet portion 4. The thermally decomposed fraction introduced into the cooling liquefier 5 is heat-exchanged with a cooling medium such as water to be cooled and condensed. The outflow portion of the cooling liquefier 5 is connected to a gas-liquid separator 7 by a pipe 6.
It is connected to the. The gas-liquid separator 7 separates the gas component of the condensate flowing out from the cooling liquefier 5, and for example, a cyclone separator can be used. In addition, 7a is a drain pipe connected to the bottom thereof. The pipe 9 through which the condensate from which the gas component is separated flows out is connected to the oil tank 8, and the pipe 10 through which the separated gas component flows out is connected to the scrubber 11. The scrubber 11 removes harmful substances contained in the gas component, and the outflow portion thereof is connected to the gas tank 13 by the pipe 12.

The gas tank 13 is connected by a pipe 14 to a duct burner 16 provided in an exhaust pipe 15 for discharging to the atmosphere. A pipe 17 for supplying an auxiliary combustion gas from an auxiliary combustion gas supply source 18 is connected to the duct burner 16. For example, LPG gas can be used as the auxiliary combustion gas. In addition, the exhaust pipe 15 is further provided with the pyrolysis kettle 1
A pipe 20 is connected to discharge the exhaust gas discharged from the combustion chamber 19 into the atmosphere. On the other hand, cooling air from a blower (not shown) or the like is supplied to the cooling medium passage of the air-cooling type heat exchanger 3 and flows into the cooling medium passage in the direction opposite to the flow of the pyrolysis fraction of the rising communication part 2. Be done. The outflow side of this cooling medium passage is connected to the air inflow side of the air supply means 21 constituted by a duct, for example.

A combustion means 22 such as a burner is provided in the combustion chamber 19 of the pyrolysis kettle 1, and the combustion means 22 is supplied with fuel from a fuel supply source 23 and combustion air. Therefore, the outflow portion of the air supply means 21 is connected to the air intake of the combustion means 22. However, a part of the combustion air may be supplied from another. Next, the operation of the device shown in FIG. 1 will be described. The waste plastic supplied by a supply means (not shown) is thermally decomposed in the thermal decomposition vessel 1 and liquefied, and then evaporated from the upper part to become a thermal decomposition fraction. In the pyrolysis fraction, a heavy component is generally present together with a light component in a considerable ratio.

The thermal cracked fraction is discharged from the thermal cracker 1 through the rising communication section 2 to the discharge section 4, the temperature of which is cooled by the heat exchanger 3 while passing through the rising communication section 2, and, for example, The temperature decreases from around 400 ° C to about 200 to 250 ° C. By this cooling, heavy components are condensed preferentially,
It rises and flows down along the inner wall of the communication part 2. The condensate rich in heavy components that has flowed down returns to the pyrolysis kettle 1 where it is heated again and part of it becomes a pyrolysis fraction containing more lighter components, while the more concentrated heavy components become sludge. Precipitates in the pyrolysis kettle 1. This sludge is optionally removed from the bottom with pyrolysis residue. On the other hand, the air supplied to the cooling air passage of the heat exchanger 3 is heat-exchanged with the pyrolysis fraction and heated to 200 to 300 ° C. The heated air is supplied by the supply means 21 to the combustion means 22 of the thermal decomposition kettle 1 and consumed as combustion air.

The pyrolysis fraction whose heavy components have been reduced and lightened in the rising communication section 2 and whose temperature has decreased is introduced into the cooling liquefier 5 by the derivation section 4 and cooled and condensed there. The condensation temperature in the cooling liquefier 5 is usually about 20 to 30 ° C., which is introduced into the gas-liquid separator 7 through the pipe 6. The condensate is separated and removed from the gas component contained therein, flows into the oil tank 8 through the pipe 9, and is collected and stored as an oil component. On the other hand, the separated gas component is pipe 10
Is introduced into the scrubber 11 by means of which the slight residual liquid contained in the gas is removed, and then is introduced into the gas tank 13 through the pipe 12. The gas in the gas tank 13 is supplied to the duct burner 16 of the exhaust stack 15 through the pipe 14, where the gas is burned with the auxiliary combustion gas and released to the atmosphere.

[0013]

EFFECTS OF THE INVENTION The waste plastic oiling apparatus of the present invention constructed as described above has the following effects. (1) Since the air-cooling type heat exchanger was provided in addition to the rising and communicating portions of the pyrolysis kettle, while the pyrolysis fraction flowing out of the pyrolysis kettle was discharged through the rising and communicating portions. It is cooled by the heat exchanger, and relatively heavy components are condensed and efficiently lightened. Further, the condensed heavy component rises and flows down through the communication part, is returned to the pyrolysis vessel, and is re-decomposed to be partly lighter. Therefore, the pyrolysis fraction, which is relatively light, is discharged from the outlet, and the oil that has been lightened by the cooling liquefier can be recovered. (2) Since the air heated by the heat exchanger is supplied to the combustion chamber of the thermal decomposition vessel as combustion air by the air supply means, the heat is effectively recovered and the thermal efficiency of the thermal decomposition vessel is increased. You can

[Brief description of drawings]

FIG. 1 is a diagram for explaining an oily oil recycling apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pyrolysis kettle 2 Rising communication part 3 Heat exchanger 4 Outflow part 5 Cooling liquefier 6 Piping 7 Gas-liquid separator 7a Drain piping 8 Oil tank 9 Piping 10 Piping 11 Scrubber 12 Piping 13 Gas tank 14 Piping 15 Exhaust pipe 16 Duct burner 17 Piping 18 Combustion gas supply source 19 Combustion chamber 20 Piping 21 Supply means 22 Combustion means 23 Fuel supply source

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Claims (1)

[Claims] Claim: What is claimed is: 1. An oiling apparatus for thermally decomposing waste plastics, cooling and condensing the thermally decomposed fractions, and collecting the oils as oils. 1, a decomposing section 4 of the pyrolysis fraction connected to the rising communication section 2, a cooling liquefier 5 connected to the derivation section 4, and an air-cooling type heat exchange provided in the rising communication section 2. And an air supply means 21 for supplying the air heated by the pyrolysis fraction flowing through the rising communication portion 2 and flowing out of the heat exchanger 3 as combustion air for the pyrolysis kettle 1. Characterizing waste plasticizer.