JPH10183139A - Apparatus for oiling and reducing waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extremely reduce a cost, to facilitate maintenance and raise productivity and economic efficiency by actualizing simplification, miniaturization and compacting of the whole apparatus. SOLUTION: This apparatus 1 for oiling and reducing a waste plastic P is equipped with a thermal decomposition tank 2 for heating and thermally decomposing a waste plastic. Especially the thermal decomposition tank 2 is provided with a tank main body 3 having a shape in width narrower at a lower side than in an upper side, plural horizontal heating pipes 4a, 4b and 4c arranged at fixed intervals in the vertical direction along the inside of the tank main body 3 in the interior of the tank main body 3 and a heating mechanism 5 for setting the temperature of the heating pipe 4a arranged at a high position higher than that of the heating pipe 4c laid at a low position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste plastic oil reduction apparatus for recycling waste plastic.

[0002]

2. Description of the Related Art Conventionally, waste plastic (polymer waste)
There is known an oil-reducing device that heats and thermally decomposes and then reduces it to heavy oil (corresponding to heavy oil A).

[0003] This type of oil-reducing device is made of polyethylene,
Solid waste plastics such as polysterol and vinyl chloride are melted in a melting tank heated at a relatively low temperature of around 250 ° C. (70 ° C. for vinyl chloride), and then 400 ° C.
The waste plastic dissolved in a pyrolysis tank heated to a high temperature (around 170 ° C. for vinyl chloride) is thermally decomposed, and the decomposed gas is cooled to obtain heavy oil. In addition,
If solid waste plastic is directly injected into the pyrolysis tank, not only will the waste plastic be carbonized and the reduction efficiency will be greatly reduced, but also the treatment of carbides will be difficult. Dissolves solid waste plastic.

[0004]

However, the above-mentioned conventional waste plastic oil reduction apparatus has the following problems to be solved.

First, since a separate dissolving tank is required in addition to the thermal decomposition tank, the entire apparatus becomes complicated and large, the cost is greatly increased, and the maintenance is extremely disadvantageous. .

[0006] Second, the processing speed of waste plastics is reduced, the productivity of heavy oil is reduced, and the economical efficiency during production is poor.

The present invention has been made to solve the problems existing in the prior art, and realizes simplification and downsizing of the whole apparatus, drastic cost reduction and ease of maintenance, and production. It is an object of the present invention to provide a waste plastic oil reduction apparatus capable of dramatically improving efficiency and economy.

[0008]

SUMMARY OF THE INVENTION The present invention relates to the construction of a waste plastic oil reduction apparatus 1 including a pyrolysis tank 2 for heating and thermally decomposing waste plastics P. And a tank body 3 having a shape in which the width on the lower side is narrower, and the tank body 3 is provided inside the tank body 3.
, 4b... 4c... Arranged at predetermined intervals in the vertical direction along the inner surface of the heater, and a heater arranged below the temperature of the heating tubes 4a. It is characterized by comprising a pyrolysis tank 2 having a heating mechanism 5 in which the temperature of the tubes 4c is set low.

In this case, according to a preferred embodiment, it is desirable that the tank body 3 be formed in a semi-cylindrical shape having semicircular end surfaces 3s, 3t. The heating tube 4c arranged below
Are set to a temperature at which the waste plastics P are melted, and the temperature of the heating pipes 4a arranged above is
The temperature is set at a temperature at which the dissolved waste plastic L is thermally decomposed. The plurality of heating tubes 4a, 4b, 4c are constituted by a plurality of linear portions formed by bending one continuous tube 6 in a zigzag shape, and the heating tube 4a arranged at the uppermost portion is formed. , And is exhausted from the heating pipes 4c arranged at the bottom. It is desirable that this continuous pipe 6 be provided in a pair on the left and right. On the other hand, at the upper end of the tank body 3, there is provided a rotary screw 7 arranged in the axial direction of the tank body 3 and arranged so that the lower part 7d is immersed in the dissolved waste plastic L. At this time, a rotary screw 7 is attached to one end of the tank body 3.
A supply section 8 of waste plastic P... Accommodating one side of the rotary screw 7 is provided, and a foreign substance recovery section 9 accommodating the other side of the rotary screw 7 is provided at the other end of the tank body 3.

As a result, the solid waste plastic P supplied to the supply section 8 is removed by the rotary screw 7 from the tank body 3.
Supplied inside. And waste plastic P…
First, it is heated and melted by the relatively low-temperature heating tubes 4c arranged below. On the other hand, dissolved waste plastic L
Are increased, and the high-temperature heating tubes 4a whose upper surfaces are arranged upward are provided.
Is reached, the mixture is heated by the heating tubes 4a and vaporized by thermal decomposition. The vaporized cracked gas is cooled and liquefied into heavy oil (equivalent to heavy oil A). Also,
Foreign matter such as carbide floating on the upper surface of the waste plastic L dissolved by the rotary screw 7 is collected by the foreign matter recovery unit 9, and the upper surface of the waste plastic L is agitated and purified, thereby increasing the generation efficiency of the decomposition gas. .

Therefore, since the pyrolysis tank 2 also serves as a melting tank, simplification of the whole apparatus and downsizing can be realized.
In addition to greatly reducing costs, facilitating maintenance and increasing the processing speed of waste plastic, the productivity of heavy oil and the economics during production are improved.

[0012]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, the configuration of the waste plastic oil reduction apparatus 1 according to the present embodiment will be described with reference to FIGS.

In the figure, reference numeral 2 denotes a pyrolysis tank which constitutes a main part of the oil reduction device 1. This pyrolysis tank 2 has a tank body 3 in which the width of the lower side is narrower than the upper side, that is, FIGS.
The tank body 3 is formed in a semi-cylindrical shape having semicircular end surfaces 3s and 3t as shown in FIG.

At the center of the upper end of the tank body 3, a rotary screw 7 arranged in the axial direction of the tank body 3 is provided. This rotary screw 7 is rotated by a rotation drive unit 11. In addition, a supply section 8 extending outward is integrally provided above the end face 3s of the tank body 3, and a foreign substance collection section 9 extending outward is provided integrally above the end face 3t. 7
One side and the other side are accommodated in a supply unit 8 and a foreign matter collection unit 9, respectively. At this time, the lower part 7d of the rotary screw 7 is disposed so as to be immersed in the dissolved waste plastic L. Further, a hopper 12 for charging solid waste plastics P is provided above the supply unit 8, and an outlet 13 for removing collected foreign matter is provided above the foreign matter collection unit 9. Reference numeral 13c denotes an opening / closing lid for opening and closing the outlet 13.

The outer surface of the tank main body 3 is substantially entirely surrounded by an outer plate 14, and a heat retaining section 32 having a closed space S between the outer plate 14 and the tank main body 3 is provided. This heat retaining part 32
Is supplied from a heating device 31 to be described later. In this case, the space S between the peripheral surface 3f of the tank body 3 and the outer plate 14 may be relatively narrow because the space S may be filled with the oil C for keeping heat. The space S is filled with a heat retaining oil C, and also accommodates a curved portion of the continuous pipe 6 described later, so that an interval for accommodating the curved portion is ensured. Reference numeral 15 denotes a cover that covers the upper surface of the tank body 3, and a duct 16 that collects decomposition gas is connected to the upper center of the cover 15. This duct 16 is connected to a scrubber 52 described later.

Further, the tank body 3 is provided with a heating mechanism 5. The heating mechanism 5 has a plurality of horizontal heating tubes 4a, 4a, 4b, 4b, 4c, 4c provided inside the tank body 3.
Each of the heating tubes 4a, 4b, 4c is arranged at predetermined intervals in the vertical direction along the inner surface of the tank body 3, preferably 10 to 15 cm.
Place at intervals. In this case, each heating tube 4a, 4b, 4c
Is constituted by a plurality of straight portions formed by bending one continuous pipe 6 in a zigzag manner. That is, a plurality of straight portions in the continuous pipe 6 bent in a zigzag shape are arranged inside the tank body 3, and the curved portions are accommodated in the space S between the outer plate 14 and the tank body 3. As shown in FIG. 2, a pair of continuous pipes 6 are provided on the left and right.

On the other hand, the top openings of the heating tubes 4a, 4a arranged at the top are connected to the hot air generator 21 and the top openings of the heating tubes 4c, 4c arranged at the bottom are provided with blowers 23. Connect to chimneys 22,22. Thereby, the hot air supplied from the hot air generator 21 is supplied to the uppermost heating pipes 4a, then passes through the intermediate heating pipes 4b, and thereafter, from the lowermost heating pipes 4c to the outside. Is discharged. At this time, the temperature of the heating pipes 4c... Disposed below the heating pipes 4c.
It gradually decreases due to heat dissipation when passing through. Therefore, when the temperature of the heating pipes 4a arranged at the top reaches the temperature at which the dissolved waste plastic L is thermally decomposed, the temperature of the heating pipes 4c arranged below melts the waste plastic P. Conditions such as the diameter and length of the continuous tubes 6 (the number of the heating tubes 4a) are selected so that the temperature is reached.

The surfaces of the heating pipes 4a..., The inner surface of the tank body 3 and the outer surface of the rotary screw 7 that are in contact with the dissolved waste plastic L and the decomposition gas are made of liquefied glass having heat resistance (room temperature glass). Is applied. The heating pipes 4a, the tank body 3, the rotary screw 7, and the like are usually made of a metal material such as steel, so that corrosion is likely to occur. In particular, when vinyl chloride is used as the waste plastic, corrosion and oxidation of the metal proceed at a considerable rate due to the generated chlorine. For this reason, the surface of the heating tube 4a and the like is coated with liquefied glass 25a to enhance chemical resistance, corrosion resistance, durability, and the like. In this case, as shown in FIG.
For example, liquefied glass 25a, 25
It is desirable to apply b ... repeatedly to provide a multilayer glass layer.

The thermal decomposition tank 2 is provided with a heat retaining device 30 shown in FIG. The heat retaining device 30 includes a heating device 31. The heating device 31 includes a heating unit 33, and the heating unit 3
As shown in FIGS. 2 and 5, the discharge part 3 is connected to one upper side of the heat retaining part 32 via a pipe 35 having a valve 34, and the suction part of the heating part 33 is connected to a pipe 37 having a valve 36. Is connected to the other side on the upper side of the heat retaining section 32. Thereby, after the heat retaining oil C is heated by the heating unit 33, the oil C is supplied to the space S between the outer plate 14 and the tank body 3 constituting the heat retaining unit 32 via the pipe 35, The heating oil C is returned to the heating unit 33 via the pipe 37 to form a heating circuit. In addition, 3
Reference numeral 8 denotes an oil tank connected to the heating unit 33 via a valve 39; 40, a control unit for controlling the operation of the heating unit 33 and various controls such as heating temperature; and 41, an extension unit including a function of liquefying the vaporized heat retaining oil. It is.

FIG. 4 shows an oil-reducing apparatus 1 having a pyrolysis tank 2.
1 shows the entire configuration. In the figure, 51 is a crusher for crushing large waste plastics into small pieces, 52 is a scrubber for neutralizing chlorine gas, 53 is a PH adjustment tank attached to the scrubber, and 54 is a condenser for liquefying decomposed gas. And 55, a cooler (cooling tower) for cooling the condenser 54, 56, a pump, 57, an oil / water separation tank for separating the obtained heavy oil and water, 58, a filter, and 59, a heavy oil storage tank.

Next, the overall operation of the liquefaction and reduction apparatus 1 including the function of the pyrolysis tank 2 constituting the main part of the present embodiment will be described with reference to the drawings.

First, hot air is supplied by the hot air generator 21 to the heating tubes 4a, 4a arranged at the top. This allows
400 ° C for the heating tubes 4a, 4a (170 ° C for vinyl chloride)
Heated back and forth. Also, the heating tube 4c arranged at the lowermost part,
4c is heated to around 250 ° C (70 ° C for vinyl chloride). The diameter and length of the continuous tubes 6 (the number of the heating tubes 4a) are selected so as to obtain such a temperature. Then, the hot air is discharged from the chimneys 22 and 22 to the outside. At this time, air is also sucked in by the blower 23.

On the other hand, solid waste plastics (polyethylene, polysterol, vinyl chloride, etc.)
It is thrown into 2. At this time, the large waste plastic is crushed into small pieces by the crusher 51. In addition, the rotation drive unit 1
1 is operated to rotate the rotary screw 7. Thereby, the solid waste plastic P put into the hopper 12
Are transferred by the rotary screw 7 and supplied into the tank body 2. By controlling the rotation speed of the rotary screw 7 arbitrarily, the supply amount of the waste plastics P to the tank body 2 can be adjusted.

The waste plastic P supplied to the inside of the tank body 2 falls to the bottom of the tank body 2 and is heated by the relatively low-temperature heating pipes 4c, 4c arranged at the bottom of the tank body 2. Dissolve. The dissolved waste plastic L is stored in the tank main body 2, and the liquid level of the dissolved waste plastic L rises with the increase. Then, when the raised liquid level reaches the uppermost heating pipes 4a, 4a, it is heated by the high-temperature heating pipes 4b, 4a, and the waste plastic L is vaporized by being thermally decomposed. In addition, waste plastic L
Foreign matter such as carbides floating on the upper surface of the waste plastic L is collected by the foreign matter recovery unit 9 by the rotating screw 7, and the upper surface of the waste plastic L is agitated and purified, thereby increasing the generation efficiency of the decomposition gas.

On the other hand, the vaporized decomposition gas is supplied to the scrubber 52 through the duct 16, and the mixed chlorine gas is neutralized. Further, the cracked gas is supplied from the scrubber 52 to the condenser 54 and cooled to be liquefied into heavy oil (equivalent to heavy oil A). The condenser 54 is constantly cooled by the cooling liquid sent from the cooler 55. Then, the obtained heavy oil is supplied to the oil / water separation tank 57. In the oil / water separation tank 57, water and heavy oil are separated, and the heavy oil is filtered by the filter 5.
After the impurities are removed by the hot air generator 8, the hot air generator 2 is supplied to and stored in the storage tank 59.
1 and used as fuel for the hot air generator 21.

During the period when the operation of the liquefaction and reduction apparatus 1 is stopped at night or the like, the thermal decomposition tank 2 is kept warm by the heat keeping apparatus 30. In this case, the heating oil C is heated by the heating unit 33 to a temperature of 70 to 400 ° C.
5, the oil C is supplied to the space S between the outer plate 14 and the tank main body 3 that constitute the heat retaining unit 32, and the heat retaining oil C in the space S is returned to the heating unit 33 via the pipe 37. Thereby, the waste plastic L remaining in the tank main body 3 is kept warm, and the start-up time at the time of restarting the operation can be greatly reduced.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment, and can be arbitrarily changed in the detailed configuration, shape, material, quantity, method, and the like without departing from the gist of the present invention.

For example, the tank body has been illustrated as having a semi-cylindrical shape. However, for example, a tank body having an arbitrary shape in which the width on the lower side is narrower than that on the upper side, such as an inverted triangle or an inverted trapezoid, is used. Available. Further, the plurality of heating tubes are constituted by a plurality of straight portions formed by bending a single continuous tube in a zigzag shape, but a plurality of heating tubes may be arranged literally. Furthermore, although the case of one rotating screw has been illustrated, a plurality of rotating screws may be arranged in parallel.

[0030]

As described above, the oil-reducing apparatus for waste plastic according to the present invention comprises a tank body having a shape in which the lower side is narrower than the upper side, and the inside of the tank body is provided with the tank body. A heating mechanism provided with a plurality of horizontal heating tubes arranged at predetermined intervals in the vertical direction along the inner surface, and the temperature of the heating tube arranged below is set lower than the temperature of the heating tube arranged above. The following remarkable effects are exhibited by providing the thermal decomposition tank having the above.

Since the thermal decomposition tank also serves as a dissolving tank, it is possible to realize simplification and downsizing of the entire apparatus, and also to achieve drastic cost reduction and easy maintenance.

Since the processing speed for waste plastics is increased, the productivity of heavy oil and the economics during production can be dramatically improved.

According to a preferred embodiment, if a rotary screw is provided at the upper end of the tank body in the axial direction of the tank body and the lower part is soaked in the melted waste plastic, the supply of waste plastic is provided. As a result, the efficiency of generation of the decomposition gas can be increased by stirring and purifying the upper surface of the dissolved waste plastic.

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a pyrolysis tank constituting a main part of an oil reduction apparatus according to the present embodiment,

FIG. 2 is a sectional front view of the pyrolysis tank,

FIG. 3 is a partial cross-sectional view of a heating tube in the pyrolysis tank,

FIG. 4 is a block diagram showing an overall configuration of the oil-reducing device.

FIG. 5 is a block diagram of a heat retaining device provided in the oil-reducing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil reduction apparatus 2 Pyrolysis tank 3 Tank main body 3s End face of tank main body 3t End face of tank main body 4a Heating pipe 4b Heating pipe 4c Heating pipe 5 Heating mechanism 6 Continuous pipe 7 Rotating screw 7d Lower part of rotary screw 8 Supply part 9 Foreign matter Collection section P… Waste plastic

Claims (9)

[Claims] 1. A waste plastic oil reduction apparatus comprising a pyrolysis tank that heats and thermally decomposes waste plastic, wherein a lower tank body has a shape in which a lower side is narrower than an upper side.
Inside the tank body, a plurality of horizontal heating tubes arranged at predetermined intervals in the vertical direction along the inner surface of the tank body are provided, and heating is arranged below the temperature of the heating tube arranged above. An oil-reducing device for waste plastics, comprising: a pyrolysis tank having a heating mechanism for setting a temperature of a pipe low. 2. The waste plastic oil reduction apparatus according to claim 1, wherein the tank body is formed in a semi-cylindrical shape having semicircular both end surfaces. 3. The waste plastic oil reduction apparatus according to claim 1, wherein the temperature of the heating pipe disposed below is set to a temperature at which the waste plastic is melted. 4. The waste plastic oil reduction apparatus according to claim 1, wherein the temperature of the heating pipe disposed above is set to a temperature at which the dissolved waste plastic is thermally decomposed. 5. A plurality of heating tubes are constituted by a plurality of linear portions formed by bending a single continuous tube in a zigzag manner. The waste plastic oil reduction apparatus according to claim 1, wherein air is exhausted from a heating pipe disposed at a lower portion. 6. The waste plastic oil reduction apparatus according to claim 5, wherein a pair of said continuous pipes are disposed on the left and right. 7. The rotary screw according to claim 1, wherein an upper end of the tank main body is provided with a rotary screw arranged in an axial direction of the tank main body and a lower part arranged to be immersed in melted waste plastic. Oil reduction device for waste plastic. 8. The waste plastic oil reduction apparatus according to claim 7, wherein a waste plastic supply part accommodating one side of the rotary screw is provided at one end of the tank main body. 9. The waste plastic oil reduction apparatus according to claim 7, wherein a foreign matter collecting portion accommodating the other side of the rotary screw is provided at the other end of the tank body.