JPH11172259A - Apparatus for converting waste plastic into oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to realize the simplification of an apparatus and its compaction into a smaller size and to thereby realize marked cost down and the facilitation of maintenance and enhancement in productivity and economical profitability. SOLUTION: A partition 7 is provided inside the body 3 of an apparatus 1 used for converting waste plastics P into an oil and having a pyrolysis tank 2 where waste plastics P are pyrolyzed by heating. The front of the partition 7 is assigned to a pyrolysis room Rf, the rear of the partition 7 is assigned to a dissolution room Rr, the lower part of the partition 7 constitutes a communication room Rc between the pyrolysis room Rf and the dissolution room Rr, and heating tubes are arranged in the body 3 so that hot air may pass the pyrolysis room, the communication room, and the dissolution room in the given order. Thus, it is possible to set the temperatures of the respective rooms at values suitable for the pyrolysis and dissolution of the plastics.

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]

Means for Solving the Problems In order to achieve the above-mentioned object, the construction of the present invention comprises a waste plastic P. provided with a pyrolysis tank 2 for heating and thermally decomposing waste plastic P.
In the oil-reducing device 1, the partition 7 is provided inside the tank body 3, so that the front of the partition 7 is a pyrolysis chamber Rf, and the rear of the partition 7 is a melting chamber Rr. The lower portion of the partition 7 is formed as a communication space Rc between the thermal decomposition chamber Rf and the melting chamber Rr, and the heating pipe 4a is formed.
, 4b, 4c, 4d, 4e
.., 4f... Are sequentially communicated from the hot air generator to the thermal decomposition chamber, from the thermal decomposition chamber to the communication space, from the communication space to the melting chamber, and from the melting chamber to the chimney communicating with the outside. It consists of a waste plastic oil reduction device based on

[0009]

FIGS. 1 and 6 show an embodiment of the means for solving the above-mentioned problems. In the embodiment shown in FIG. 1, a plurality of heating tubes 4 a...
..., 4b ..., 4c ..., 4d ..., 4e ...
., 4f... Between the front communication space Cf of the tank body 3 which is isolated from the outside and the partition 7 (4a.
.), Between the tank body rear communication space Cr and the partition 7 which are isolated from the outside (4e ..., 4f ...), and the partition 7
Communication space C at the lower part of the tank, which is isolated from the outside
f, 4c..., 4d... between the f and the tank body rear communication space Cr, which is cut off from the outside, and heating between the tank body front communication space Cf and the partition 7. The pipe is connected to the hot air generator 21, and the heating pipe between the rear communication space Cr of the tank main body and the partition 7 (4 e, 4 f) is connected to an external chimney. I have.

On the other hand, in the embodiment of FIG. 6, one or more heating tubes 4a..., 4b.
, 4d, 4e, 4f, ... are connected in a bent state in the order of hot air generator, melting chamber, and chimney.

According to the connection state according to the embodiment shown in FIGS. 1 and 6, the heating pipe of the pyrolysis chamber is set to a temperature suitable for pyrolysis, and the heating pipe of the melting chamber is set to a temperature suitable for melting. However, the heating pipe in the communication space can be set to the intermediate temperature.

Based on such a temperature setting, the melting chamber Rr
, 4c..., 4c.
Heated by d ... dissolves. On the other hand, the dissolved waste plastic L reaches the thermal decomposition chamber Rf through the communication space Rc. As the level of the dissolved waste plastic L increases, the liquid level reaches the upper part of the pyrolysis chamber Rf. If the liquid level reaches the high-temperature heating pipes 4a,. 4a, and is vaporized by thermal decomposition. The vaporized cracked gas is cooled and liquefied into heavy oil (equivalent to heavy oil A).

Therefore, since the pyrolysis tank 2 also serves as a dissolving tank, simplification of the entire apparatus and downsizing are 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 can be improved.

In FIG. 1, the tank body 3 has a front portion 3f inclined so as to narrow the bottom portion side. This is because even when the apparatus is not operating, the molten waste plastic L is melted.
When the heat is kept from below the bottom part, the amount of heat required for keeping the heat is reduced by designing the area of the bottom part to be small, and in the stage where the apparatus is operating, the communication space Rc is formed in the front pyrolysis chamber Rf. Considering that the specific gravity decreases as the molten waste plastic L moving through the thermal storage reaches the pyrolysis chamber Rf and then changes from the molten state to the pyrolysis state, and that the volume expands when rising. It is derived from that. In FIG. 6, the front surface 3f is in the vertical direction, and the bottom surface is not particularly narrow. However, it is naturally possible to adopt the same design as in FIG. However, such a design does not correspond to an essential component of the present invention.

[0015]

Embodiment 1 FIGS. 2 to 5 show the embodiment shown in FIG.
It will be described according to.

In the figure, reference numeral 2 denotes a thermal cracking tank which constitutes a main part of the oil reduction device 1. As shown in FIGS. 1 and 2, the pyrolysis tank 2 includes a tank main body 3 having a front surface 3f, a rear surface 3r, and a bottom surface 3d.

A partition 7 is provided between the left surface 3p and the right surface 3q at an intermediate position in the front-rear direction inside the tank body 3.
Erection. The partition 7 is formed as a closed body having a hollow inside. A partition 9 is provided inside the partition 7, and the partition 9
Before and after are formed a front space Sf and a rear space Sr. Therefore,
A pyrolysis chamber Rf is formed in front of the partition 7, a melting chamber Rr is formed in the rear of the partition 7, and a communication space Rc is formed below the partition 7.

On the other hand, a lower portion of the outer surface of the tank body 3 is surrounded by an outer plate 4, and a heat retaining portion 32 having a closed space between the outer plate 14 and the tank body 3 is provided. Heat retaining oil w is supplied to the heat retaining section 32 from a heating device 31 described later. Further, in the first embodiment, as shown in FIG.
, The front communication space Cf and the rear communication space Cr are covered by the outer housing 13, and the front communication space Cf
Is located between the front surface 3f of the tank body 3 and the outer housing 13, and the rear communication space Cr is located between the rear surface 3r of the tank body 3 and the outer housing 13.

At the uppermost stage of the thermal decomposition chamber Rf, four heating tubes 4a... Arranged at predetermined intervals in the left-right direction are provided, and the front end openings of the heating tubes 4a. At the same time, the rear end opening (inner end opening) communicates with the front space Sf in the partition 7. Further, in the second stage from the top of the pyrolysis chamber Rf, four heating pipes 4b... Arranged at predetermined intervals in the left-right direction are provided, and the front end openings of the heating pipes 4b. At the same time, the rear end opening (inner end opening) communicates with the front space Sf. Further, the thermal decomposition chamber R
f, four heating tubes 4c... and 4d... arranged at predetermined intervals in the left-right direction, respectively.
・ ・ Is provided. In this case, the heating tubes 4c.
. Penetrates the thermal decomposition chamber Rf, the communication space Rc and the melting chamber Rr, and the openings at both ends of the heating tubes 4c... And 4d. Each faces the communication space Cr.

Further, at the uppermost stage of the melting chamber Rr, four heating tubes 4f... Arranged at predetermined intervals in the left-right direction are provided, and the front end openings (inner end openings) of the heating tubes 4f. It is connected to the rear space Sr in the part 7 and the rear end opening faces the outside of the outer housing 13. Further, four heating tubes 4e... Arranged at predetermined intervals in the left-right direction are provided at the second stage from the top of the melting chamber Rr, and the front end openings (inner end openings) of the heating tubes 4e. In addition to being connected to the rear space Sr in the portion 7, the rear end opening faces the rear communication space Cr. In addition, each heating tube 4a ..., 4b ..., 4c ..., 4
The distance between d..., 4e.
Set to about 15 cm.

Thus, in the case of the configuration (1), as shown in FIG. 1, the heating tubes 4a.
→ heating tube 4b ... → front communication space Cf → heating tube 4c
・ ・ And 4d ・ ・ ・ → Back communication space Cr → Heating tube 4e ・
.. → the rear space Sr → the heating pipe 4f.

In FIG. 1, the uppermost heating pipes (4a..., 4f.
Are connected to the hot air generator 21 and the chimney 22, respectively, but such a connection state does not necessarily correspond to the constituent requirements of the present invention, and in short, the thermal decomposition chamber, the melting chamber, and the lens space In this case, the connection state may be such that the temperature becomes appropriate.

At the upper end of the melting chamber Rr, a hopper 1 for feeding solid waste plastics P.
2 is provided. Further, reference numeral 15 denotes a cover for covering the upper surface of the tank main body 3, and a duct 16 for collecting the decomposition gas is connected to the upper center of the cover 15. This duct 16 is connected to a scrubber 52 described later.

On the other hand, the outer end openings of the heating tubes 4a... Arranged at the top are connected to the hot air generator 21 and the heating tubes 4a.
are connected to a chimney 22 provided with blowers 23. Thereby, the hot air H supplied from the hot air generator 21 is discharged to the outside from the chimney 22 via the ventilation path 8. At this time, the temperature of the heating tubes 4a... Arranged above the thermal decomposition chamber Rf is set to the heating tubes 4d... 4c.
To be higher. That is, the heating pipe 4a arranged on the upstream side
The heating pipe 4f arranged downstream with respect to the temperature of ...
Are gradually lowered due to heat radiation when the hot air H passes through the ventilation paths 8.

Therefore, the heating tube 4a
When the temperature reaches a temperature at which the dissolved waste plastic L is thermally decomposed (usually 400 ° C., 170 ° C. for vinyl chloride), the temperature of the heating pipes 4c,. , 4b..., 4d..., 4d.
.., 4e..., 4f.

Particularly, in the thermal decomposition chamber, not only the temperature but also a large amount of heat is required, so that the heating pipes (4a..., 4b.
, 4d, 4e, 4f, etc., the diameter of which is designed to be larger, and further, the heating tubes (4a, 4b, ...) of the pyrolysis chamber. Can be designed to be bent in a zigzag shape in order to increase the contact area with the surroundings.

The outer peripheral surface of the heating tubes 4a,.
The surface that is in contact with the dissolved waste plastic L and the decomposed gas, such as the inner surface, is heat-resistant liquefied glass (normal temperature glass).
Is applied. Since the heating pipes 4a,... And the tank body 3 are usually made of a metal material such as steel, corrosion is likely to occur due to oxidation or the like accompanying heating. 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 surfaces of the heating tubes 4a, etc. are coated with liquefied glass 25a, and the chemical resistance, corrosion resistance, durability and the like are improved. In this case, as shown in FIG. 3, for example, the liquefied glass 2 is placed on the surface of the heating tube 4a.
It is desirable to apply 5a, 25b,.

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
2 and 5, the discharge section 3 is connected to one side of the heat retaining section 32 via a pipe 35 having a valve 34, and the suction section of the heating section 33 is connected to a pipe 37 having a valve 36. It connects to the other side of the heat retaining section 32 through the above. Thus, after the heat retaining oil W is heated by the heating unit 33, the outer plate 1 forming the heat retaining unit 32 via the pipe 35.
While being supplied to the space between the tank body 4 and the tank body 3, the heating oil W in the space is returned to the heating unit 33 through the pipe 37 to form a heating circulation circuit. 38 is a valve 39
, An oil tank connected to the heating unit 33, a control unit 40 for controlling the operation of the heating unit 33 and various controls such as a heating temperature, and an extension unit 41 having a function of liquefying the vaporized heat retaining oil.

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 first embodiment will be described.
The description will be made with reference to the drawings.

First, the hot air H is supplied by the hot air generator 21 to the heating tubes 4a. FIG. 1 shows the path of the hot air H by arrows. Thereby, the heating tubes 4a...
Is heated to around 400 ° C (170 ° C for vinyl chloride). Also, heating tubes 4c..., 4d.
Is heated to around 250 ° C. (70 ° C. for vinyl chloride). Then, the hot air H that has passed through the ventilation path 8 is discharged from the chimney 22 to the outside. At this time, the air is sucked by the blower 23.

On the other hand, solid waste plastics (polyethylene, polysterol, vinyl chloride, etc.) P are put into the hopper 12. At this time, the large waste plastic is crushed into small pieces by the crusher 51. The solid waste plastics P... Charged in the hopper 12 are in the melting chamber Rr.
Supplied inside.

The waste plastic P supplied into the melting chamber Rr falls to the bottom of the melting chamber Rr and is heated by the relatively low-temperature heating pipes 4c, 4d,. Dissolve. Dissolved waste plastic L is connected to communication space R
c and into the pyrolysis chamber Rf,
Stored inside. As the dissolved waste plastic L increases, the liquid level reaches the upper part of the pyrolysis chamber Rf, so that the liquid level rises to the high-temperature heating pipe 4a disposed above the pyrolysis chamber Rf.
.. Are heated by the heating tubes 4a and vaporized by thermal decomposition.

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 in which the operation of the liquefaction reduction device 1 is stopped at night or the like, the temperature of the tank body 3 is maintained by the heat retaining device 30. In this case, the heat retaining oil W is heated by the heating unit 33 to a temperature of 70 to 400 ° C.
5 and is supplied to the space between the outer plate 14 and the tank main body 3 constituting the heat retaining section 32 and the oil W for heat retention in the space.
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 operation reunion can be greatly reduced.

[0036]

Embodiment 2 The embodiment shown in FIG.
The description based on FIGS. 2 to 5 basically applies.

However, in the second embodiment, as shown in FIG. 6, the heating tubes 4a..., 4b.
, 4e, 4f, ... are sequentially connected in a bent state. In FIG. 6, the heating tubes 4a,.
b are bent in a state of protruding from the front surface 3f and the rear surface 3r of the tank body 3, and the front space S of the partition 7 is bent.
Also in the f and the rear space Sr, they are bent in a protruding state, respectively. Such protrusions make it possible for the heating tube to come into contact with the outside air, thereby sequentially lowering the temperature of the hot air.

However, due to such protrusion, the temperature of the heating tube can be gradually reduced depending on the amount and speed of the hot air without contacting the outside air. To protrude outside,
It does not fall under the constituent requirements of the present invention.

Further, apart from the case of FIG. 6, the heating pipes 4a..., 4b. Tube 4e ...
.., 4f... Are the front space Sf and the back space S, respectively.
Naturally, it is also possible to adopt a design in which communication is established via r, that is, a configuration in which the embodiment of FIG. 1 is partially adopted.

[0040]

Embodiment 3-1 In Embodiment 3-1 as shown in FIG. 7, the lower part of the tank main body 3 than the partition part 7 (the melting chamber R
r and the position of the thermal decomposition chamber Rf, or the position of the communication space Rc), and transports between the front surface 3f and the rear surface 3r the waste plastic that has been melted or is being melted or is being melted. The case where the screw conveyor 30 is provided is shown.

By providing such a screw conveyor 30, the waste plastic moves quickly from the rear to the front, and the heat transfer by each heating tube is efficiently performed by the stirring in the tank body 3 of the screw conveyor 30. The dissolution and thermal decomposition efficiency of the present invention can be further increased.

[0042]

Embodiment 3-2 Embodiment 3-2 is as shown in FIG.
A configuration in which one or more rotating blades that rotate in the horizontal direction are provided instead of the screw conveyor of Example 3-1 is shown.

[0043] Then, by rotating the blade so as to be concave with respect to the rotation direction, the rotor moves waste plastic that has been melted or is being melted forward as in the case of the screw conveyor, and Tank body 3
Since the inside is agitated, the same effective effect as in the case of Example 3-1 can be achieved.

While the embodiments have been described in detail, the present invention is not limited to such embodiments.
The details of the configuration, shape, material, quantity, method, and the like can be arbitrarily changed without departing from the gist of the present invention.

[0045]

As described above, the oil-reducing apparatus for waste plastic according to the present invention has a tank body having a front portion inclined and a bottom portion narrowed, and a partition portion is provided inside the tank body. Thereby, a pyrolysis chamber is formed forward from the partition, a melting chamber is formed rearward from the partition, and a communication space is formed below the partition, and a predetermined space is formed inside the tank body in the vertical and horizontal directions. A plurality of heating pipes having a ventilation path in the front-rear direction and provided in each of the heating pipes, and the temperature of the heating pipes arranged in the upper part of the thermal decomposition chamber is set higher than the heating pipes arranged in the melting chamber. The provision of the tank has the following remarkable effects.

Since the thermal decomposition tank also serves as a dissolving tank, simplification of the entire apparatus and reduction in size and size can be realized, and also significant cost reduction and easy maintenance can be achieved.

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

[Brief description of the drawings]

FIG. 1 is a cross-sectional side view of a pyrolysis tank constituting a main part of a configuration (1) and an oil reduction device according to a first embodiment.

FIG. 2 is a sectional front view taken along line XX in FIG.

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

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

FIG. 5 is a block diagram of a heat retention device provided in the oil-reduction device.

FIG. 6 is a cross-sectional side view of a pyrolysis tank that constitutes a main part of a configuration (2) and an oil reduction device according to a second embodiment.

FIG. 7 is a cross-sectional top view of the tank main body showing a state where the screw conveyor according to Example 3-1 is provided.

FIG. 8 is a cross-sectional top view of the tank main body of the tank main body showing a state in which the rotor according to the example 3-2 is provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil reduction apparatus 2 Pyrolysis tank 3 Tank main body 3f Front part of tank main body 3d Bottom part of tank main body 4a ・ ・ ・ Heating tube 4b ・ ・ ・ Heating tube 4c ・ ・ ・ Heating tube 4d ・ ・ ・ Heating tube 4e ・..Heating tube 4f ・ ・ ・ Heating tube 7 Partition 8 Air passage P ・ ・ ・ Waste plastic Rf Pyrolysis room Rr Melting room Rc Communication space L Melted waste plastic H Hot air

Claims (11)

[Claims] 1. A waste plastic oil-reducing apparatus having a pyrolysis tank for heating and thermally decomposing waste plastic, wherein a partition section is provided inside the tank body so that the front of the partition section becomes a pyrolysis chamber. The rear of the partition is a melting chamber, the lower part of the partition is formed as a communication space between the thermal decomposition chamber and the melting chamber, and the heating pipe is connected from the hot air generator to the thermal decomposition chamber and from the thermal decomposition chamber. From the space and communication space to the melting chamber and from the melting chamber to the chimney communicating with the outside,
An oil-reduction device for waste plastic based on sequential communication. 2. A plurality of heating pipes having a ventilation path in the front-rear direction and extending in a vertical direction are provided between the front communication space of the tank main body and the partition part, which are cut off from the outside, and after the tank main body cut off from the outside. Between the side communication space and the partition, and between the tank body front communication space and the outside of the tank body, which is isolated from the outside below the partition, and the tank body rear communication space, which is isolated from the outside. The heating pipe between the communication space and the partition is connected to the hot air generator, and the heating pipe between the tank body rear communication space and the partition is connected to an external chimney. An apparatus for liquefying and reducing waste plastic according to claim 1, wherein: 3. One or more heating pipes are sequentially arranged from a hot air generator to a thermal decomposition chamber, a thermal decomposition chamber to a communication space, a communication space to a melting chamber, and a chimney communicating from the melting chamber to the outside. The waste plastic oil reduction apparatus according to claim 1, wherein the connection is made in a bent state. 4. The waste plastic oil reduction device according to claim 1, wherein a screw conveyor for transporting the waste plastic is provided from a rear side to a front side below the partition part of the tank body. 5. The waste plastic oil reduction apparatus according to claim 1, wherein one or a plurality of horizontal rotating blades are provided below the partition in the tank body. 6. The upper part of the pyrolysis chamber is connected to a scrubber for neutralizing chlorine gas, and the scrubber is connected to a condenser interlocked with a cooling device, and the condenser is connected to an oil / water separation tank. The waste plastic oil reduction apparatus according to claim 1, wherein: 7. The waste plastic oil reduction apparatus according to claim 1, wherein the oil / water separation tank is connected to the storage tank and the hot air generator via a filter. 8. The apparatus for reducing liquefaction of waste plastic according to claim 1, wherein a metal surface contacted by a gas decomposed by thermal decomposition of the waste plastic is coated with liquefied glass having heat resistance. 9. The apparatus for reducing liquefaction of waste plastic according to claim 8, wherein the liquefied glass is coated on the metal surface contacted with the decomposed gas by applying a multi-layered glass layer. 10. The waste plastic oil reduction apparatus according to claim 1, wherein the diameter of the heating tube in the thermal decomposition chamber is designed to be larger than the diameter of the heating tube in the communication space and the melting chamber. 11. The waste plastic oil reduction apparatus according to claim 1, wherein the heating pipe in the thermal decomposition chamber is designed in a zigzag bent state.