JPH08110024A - Heat treatment method of rubber waste - Google Patents

Abstract

PURPOSE: To effectually utilize excessive energy by selecting carbon residue of rubber residue subjected to a thermal decomposition processing from metal residue and thereafter burning it and recovering waste heat from combusted waste gas. CONSTITUTION: Rubber waste W in which a metal is mixed is ground in a grounding process 1 to a predetermined size and is thermally decomposed in a thermal decomposition process 2 to produce thermally decomposed gas G and produce carbon residue W4 and metal residue W3. The thermally decomposed gas G is purified in a gas processing process and hence is separated to purified gas G1 and recovery oil K, and the carbon residue 4 W4 and the metal residue W3 are selected in a selection process 3. Only the carbon residue W4 is ground in a carbon grounding process 4 and is thereafter supplied to a combustion processing process 6. Powder carbon residue W5 supplied to the combustion processing process 6 is combusted with the recovery oil K yielded in the gas processing process 5 as a mixing fuel. In a waste heat recovery process 7 waste heat is recovered from the combusted waste gases G3, G4 produced in the thermal treatment process 6 and the thermal decomposition process 2 to produce vapor G5 in a boiler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method for rubber-based waste containing a mixture of metals such as tires and rubber belts for transferring articles.

[0002]

2. Description of the Related Art Vehicle tires and tubes, high-pressure rubber hoses, rubber belts for transferring articles, and even footwear made of rubber are usually filled with a metal material such as steel wire for reinforcement. Such waste of rubber products mixed with metals (hereinafter referred to as rubber waste), for example, when it is a tire, is recycled into a recycled tire by using the original shape, or it is submerged in the sea as it is and used for fish reef. Or, it is cut into a predetermined size, metal is removed, and then rubber powder is heat-molded and used as a paving block laid on the sidewalk, etc., but the application amount for such applications is Very few and most are subject to incineration.

It is known that various types of waste incinerators as shown in FIGS. 7 and 8 are conventionally applied as the above-mentioned heat treatment device for rubber waste. 7 (a), (b) and (c) show a so-called direct combustion type device for directly burning rubber waste, and (a) and (b) of FIG. 8 show rubber waste. The apparatus of the carbonization system which carries out the carbonization of the thing is shown.

The incinerator 10a shown in FIG. 7 (a) is the most general so-called grate type,
A grate 102a is provided inside the main body 101a, and the rubber-based waste W is supplied onto the grate 102a. Combustion air is introduced from below the grate 102a.

Since the combustion air is supplied to the rubber waste W above it from the gap of the grate 102a and the side wall of the main body 101a, the rubber waste W in contact with the grate 102a.
Burns well. The combustion residue is accumulated in the lower part of the grate 102a and the lower gutter 103a, and is appropriately taken out. An example of this type of incinerator is Japanese Patent Laid-Open No. 56-113.
Those disclosed by Japanese Patent Laid-Open No. 919 and Japanese Patent Laid-Open No. 58-150708 are known.

The incinerator 10b shown in FIG. 7 (b) is a so-called rotary kiln system in which a main body 101b is placed obliquely laterally so as to be rotatable about its axis, and a combustion chamber 102b is formed in the main body 101b. ing. An inlet 103b is provided on one side of the combustion chamber 102b,
A burner 104b and a combustion air supply port are provided on the other side portion. The rubber-based waste W is transferred from the charging port 103b of the combustion chamber 102b rotating around the axis to the combustion chamber 102b.
It is thrown into the interior of the burner 104b and comes into countercurrent contact with the flame of the burner 104b to burn.

Since the rubber waste W in the combustion chamber 102b is agitated by the rotation of the main body 101b about its axis, the rubber waste W is well contacted with the flame and the combustion air, and the rubber waste W is uniform. Burns well and satisfactorily. The combustion residue is discharged out of the system through a discharge port provided on the other side of the main body 101b. Usually, a cement kiln for producing cement is used as the incinerator 10b, and in most cases, the rubber waste W is incinerated while producing cement.

In the incinerator 10c shown in FIG. 7 (c), the combustion chamber 102c formed inside the main body 101c is filled with sand, and the sand forms the fluidized bed 103c. Combustion air is supplied into the combustion chamber 102c from the lower portion of the fluidized bed 103c, and the crushed rubber-based waste W is introduced into the combustion chamber 102c from the upper inlet 104c. . Then, the rubber-based waste W put into the combustion chamber 102c is burned by obtaining the combustion air supplied through the fluidized bed 103c, and the combustion exhaust gas is discharged from the discharge port 105c to the outside of the system. ing.

Thus, the combustion bed is a fluidized bed 103c of sand.
Even if a viscous material having fluidity is generated by combustion, the viscous material diffuses in the sand, so that the flow of combustion air is not hindered. Since the combustion residue remains in the sand of the fluidized bed 103c, the sand is replaced appropriately.

FIG. 8A shows an indirect heating type dry distillation apparatus 1.
0d is shown. The carbonization device 10d includes an externally heated main body 101d and a combustion chamber 102d surrounding the main body. The rubber waste W loaded in the main body 101d is dry-distilled by burning the fuel with the burner 103d provided in the combustion chamber 102d. The dry distillation gas generated in the main body 101d is recovered by the recovery device 10
4d, where recycled oil and the like are collected. The solid dry distillation residue remaining in the main body 101d is taken out of the system by temporarily stopping the operation of the dry distillation apparatus 10d. Useful recycled oil and the like are recovered from the rubber waste W. Further, since the recovered residue is not oxidized, it has an advantage that it can be used as carbon black or activated carbon.

FIG. 2B shows a direct heating type carbonization device 1
0e is shown. The dry distillation apparatus 10e burns the rubber-based waste W loaded in the interior thereof in a state where combustion air is insufficient, and carries out a dry distillation of the main body 101e and the dry distillation gas derived from the main body 101e. Furnace 1
02e and. A heat exchanger 103e for recovering waste heat by exchanging heat with the combustion exhaust gas is provided above the combustion furnace 102e, and the waste heat can be effectively used. A dry distillation apparatus for treating rubber waste of this type is disclosed in, for example, Japanese Patent Laid-Open No.
There are known ones disclosed in Japanese Patent Laid-Open No. 141638/1993, Japanese Patent Laid-Open No. 5-141639, Japanese Patent Laid-Open No. 5-296427 and the like.

[0012]

By the way, in the grate incinerator 10a shown in FIG. 7 (a), since the combustion temperature is as low as 600 ° C. to 900 ° C., the rubber waste W is completely removed. It is extremely difficult to burn. For example, when the rubber waste W is a waste tire, carbon black occupying about 33% of the total weight in the tire,
Steel wires occupying up to 25% are included, the total amount thereof corresponds to about half of the tire, and there is a problem that they remain as combustion residues in the incinerator 10a. When a large amount of combustion residue is generated in this way, a secondary treatment is required for handling it.

Further, in the rotary kiln type incinerator 10b shown in FIG. 7B, the rubber-based waste W is used.
However, in the case of simultaneously performing cement production and incineration treatment of rubber waste W in a cement kiln, it is necessary to make combustion treatment of rubber waste W and cement production compatible with each other. However, there is a problem in that combustion management such as furnace temperature and pressure control becomes difficult, and the quality of the cement deteriorates because the combustion residue of the rubber waste W is mixed into the cement.

In the fluidized bed type incinerator 10c shown in FIG. 7 (c), if the rubber waste W is crushed pieces or small tires, the combustor forms a fluidized bed. It does not hinder the flow of combustion air because it diffuses into the sand that is present, but large tires such as trucks and buses do not flow well because they are buried in the sand, and as a result, the flow of combustion air However, there is a problem in that it does not burn well. Further, steel wires and the like are entangled with each other to form large pills, which causes a problem of blocking the inside of the furnace. And this kind of furnace is usually 800-900
Since low-temperature combustion at a temperature of ℃ is performed, carbon in the rubber hardly burns, a large amount of carbon residue is generated, and there is a problem that the operation cost increases due to the treatment.

Further, in the carbonization devices 10d and 10e shown in (a) and (b) of FIG. 8, the rubber-based waste W is used.
Although the advantages of being able to effectively use the dry distillation gas and oil are common, in the dry distillation apparatus 10d, the dry distillation residue of the rubber-based waste W remains on the bottom of the kettle, which makes the removal work extremely difficult and the workability is improved. In addition, the dry distillation apparatus 10e has a problem that a large amount of carbon residue whose quality is deteriorated due to oxidation is generated, which makes it difficult to process the carbon residue.

Then, (a) to (b) of FIG. 7 and FIG. 8 described above.
None of the conventional incinerators for rubber-based waste W as shown in (B) is configured so that the energy balance and the material balance are self-contained within the system.
For example, fuel must be introduced from outside the system,
There is a problem that the secondary treatment of the combustion residue is necessary, resulting in an increase in energy cost and work cost.

The present invention has been made to solve the above-mentioned problems, in which the energy balance and the material balance in the system are effectively set, surplus energy can be effectively used, and in turn, in the system. It is an object of the present invention to provide a heat treatment method for rubber waste that can treat rubber waste so as to be self-sufficient, and as a result can reduce treatment costs.

[0018]

The heat treatment method for rubber waste according to claim 1 of the present invention is a heat treatment method for rubber waste in which a metal is mixed, and the rubber waste is crushed. Crushing step, a pyrolysis step of pyrolyzing the crushed material crushed in this crushing step, a sorting step of sorting the pyrolysis residue obtained in this pyrolysis step into a metal residue and a carbon residue, in this sorting step A carbon crushing step of crushing the selected carbon residue, a gas treatment step of sending out a purified gas obtained by refining the pyrolysis gas generated in the pyrolysis step as a fuel of the pyrolysis step, and a crushed in the carbon crushing step Combustion treatment step of combusting the pulverized carbon with the recovered oil obtained in the gas treatment step as fuel, and recovering waste heat from the combustion exhaust gas generated in the combustion treatment step and the thermal decomposition step. It is composed from the waste heat recovery step of is characterized in.

The heat treatment method for rubber waste according to claim 2 of the present invention is the heat treatment method for rubber waste according to claim 1, wherein in the heat decomposition step, a cylindrical heat decomposition chamber has an outer periphery. An external heating type rotary kiln type pyrolysis furnace configured to rotate about an axis while being surrounded by heating means is applied.

The heat treatment method for rubber waste according to claim 3 of the present invention is the heat treatment method for rubber waste according to claim 1 or 2, wherein a swirl flow is generated in the furnace in the combustion treatment step. The swirl flow type melting furnace of the shaft furnace type configured as described above is applied.

The heat treatment method for rubber waste according to claim 4 of the present invention is the heat treatment method for rubber waste according to any one of claims 1 to 3, wherein the waste derived from the waste heat recovery step is used. The heat-recovered gas is configured to be subjected to dust removal and deflow treatment.

[0022]

According to the heat treatment method for rubber waste according to the first aspect, the rubber waste mixed with metal is first crushed to a predetermined size in the crushing step, and then heat-treated in the next thermal decomposition step. The decomposition treatment is performed to generate thermal decomposition gas, and carbon residue and metal residue are generated.
The pyrolysis gas is refined in the gas treatment step to be separated into refined gas and recovered oil, the carbon residue and the metal residue are selected in the selection step, and only the carbon residue is crushed in the carbon crushing step. Then, it is supplied to the combustion treatment process.

The powdery carbon residue supplied to the combustion treatment step is burned with the recovered oil obtained in the gas treatment step as a mixed fuel, and the waste heat is recovered from the combustion exhaust gas in the waste heat recovery step. Done.

As described above, the carbon residue of the rubber waste which has been once subjected to the thermal decomposition treatment in the thermal decomposition step is separated from the non-combustible metal residue in the selection step and subjected to the combustion processing in the combustion processing step. Therefore, such a two-step process enables a more complete combustion process than the case where only a conventional one-step combustion process is performed.

As described above, this is a self-contained treatment method in which energy is balanced in the entire system from the crushing process to the waste heat recovery process, and there is no need to perform secondary treatment, and the waste heat By recovering, it is possible to effectively use the surplus energy, and the operating cost is reduced.

According to the heat treatment method for rubber waste according to the second aspect, in the thermal decomposition step, the supplied rubber waste is stored in the furnace by the rotation of the pyrolysis furnace of the external heating rotary kiln system. The rubber-based waste is thermally decomposed uniformly, reliably and efficiently because it is uniformly stirred and the heat is uniformly supplied.

According to the heat treatment method for rubber waste according to the third aspect, in the combustion treatment step, the carbon residue introduced from the thermal decomposition step is swirling flow in the swirling flow type melting furnace of the shaft furnace type. Since it is swirled and stirred in the furnace by the above, the carbon content is surely contacted and the carbon content is completely burned, and the metal residue and the like entrained in the carbon residue are reliably separated and removed as slag by centrifugal force.

According to the heat treatment method for rubber waste according to the above-mentioned claim 4, since the waste heat-recovered gas derived from the waste heat recovery step is subjected to dust removal and defluent treatment, The purified exhaust gas is discharged out of the system.

[0029]

EXAMPLE FIG. 1 is a process chart showing an example of a heat treatment method for rubber waste according to the present invention. As shown in this figure,
The heat treatment method for rubber waste according to the present invention comprises a crushing step 1,
Pyrolysis step 2, Sorting step 3, Carbon crushing step 4
And a gas treatment step 5 and a combustion treatment step 6. In the figure, the arrows connecting these steps show the flow of substances moving in the system, the thick solid arrows show the flow of solids, the white arrows show the flow of gas, and the dotted arrows show the flow of liquid. The dotted arrows indicate the flow of the gas-liquid mixture, and the hatched arrows indicate the flow of the mixture of gas and solid.

The crushing step 1 is a step of crushing the rubber waste to be treated. To this crushing step 1, the rubber waste W in its original form is supplied, which is crushed to a predetermined size by a crusher, and the crushed material W1 obtained as a result is supplied to the thermal decomposition step 2 of the next step. It has become so. Incidentally, in this embodiment, the rubber waste W is crushed to a size of about 10 to 20 cm.

Examples of the rubber waste W include tires and tubes for vehicles, rubber hoses, rubber belts for transferring articles, and footwear made of rubber. In the present embodiment, tires for vehicles are It has been selected for processing.

The thermal decomposition step 2 is a step of thermally decomposing the crushed material W1 obtained by crushing in the crushing step on the upstream side, and a predetermined external heat type thermal decomposition furnace is used for combustion heating state. The crushed material W1 is loaded into the thermal decomposition furnace of No. 1 to thermally decompose it. The refined gas G1 refined in the gas treatment step 5 is used as a fuel for thermal decomposition. This purified gas G1 is approximately 8500 kcal / Nm ³
It has a high calorific value and is suitable as a fuel for thermal decomposition. In the thermal decomposition step 2, the sludge W7 generated in the gas treatment step 5 is also fed back together with the crushed material W1.

In this thermal decomposition step 2, crushed material W1
As a result, a pyrolysis gas G is generated, and a pyrolysis residue W2 that has not been pyrolyzed is produced. The thermal decomposition gas G is in a gas-liquid mixed state containing liquid decomposition oil. Most of the thermal decomposition residue W2 is generated due to the steel wire embedded in the tire, the carbon black mixed in the rubber, and various additives. Therefore, the thermal decomposition residue W2 is in a state in which metal and carbon are mixed.

In the sorting step 3, the thermal decomposition residue W2 produced in the thermal decomposition step 2 is converted into a metal residue W3 and a carbon residue W.
This is a process of selecting 4 items. In this step, a magnetic separator using an electromagnet is used to remove the metal residue W3 made of a magnetic material such as iron from the thermal decomposition residue W2 during the belt transfer. Metal residue W3 removed
Is stored in the metal residue yard 3a, and the carbon residue W4 is sent to the next carbon crushing step 4.

Since the metal residue W3 is heated in a substantially reducing atmosphere in the thermal decomposition step 2, it is not oxidized at all and becomes good quality metal scrap. The carbon residue W4 is similar to carbon black or oil coke, and has a small volatile content of 5 to 10% by weight.
About 85% by weight is composed of carbon. Such carbon residue W4 is a flame-retardant substance that is extremely difficult to burn,
In the conventional normal incinerator, complete combustion cannot be performed unless the temperature is high and a long combustion residence time is applied.

The carbon crushing step 4 is a step for crushing the carbon residue W4 selected in the selecting step 3. In this carbon crushing step 4, the carbon residue W4 is once stored in the coarse coal silo, and is sequentially cut out from the bottom by a crusher and crushed to about 200 mesh. By this pulverization, the total surface area of the carbon residue W4 increases, the contact area with the combustion air increases, and the carbon residue W4 easily burns. Crushed carbon W formed by crushing
5 is sent to the combustion processing step 6 of the next step by air transportation.

The gas treatment step 5 is a step of purifying the pyrolysis gas G generated in the pyrolysis step 2. In the gas treatment step 5, first, in the cooling tower, the hot pyrolysis gas G is brought into contact with cooling oil to be cooled to condense liquid components, and the separated purified gas G1 is used as fuel in the pyrolysis step 2. I try to send it out. The condensed liquid component is separated into a cracked oil component and a sludge oil, and the cracked oil component is used as the cooling oil, and the sludge oil becomes a recovered oil K after being subjected to a predetermined refining operation. The fuel is sent to the combustion process 6 as the next process.

The combustion treatment step 6 is a step in which the pulverized carbon W5 pulverized in the carbon pulverization step 4 and the recovered oil K obtained in the gas treatment step 5 are combusted as a mixed fuel. In this step, a high-performance swirl-flow melting furnace is used, and the crushed carbon W5 fed by air flow from the carbon crushing step 4 burns with the recovered oil K from the gas processing step 5 as an auxiliary fuel, and as a result, The obtained combustion residue slag W6 is stored in the slag yard 6a, and the combustion exhaust gas G3 is sent to the waste heat recovery step 7 of the next step.

The waste heat recovery step 7 is a step of recovering waste heat from the combustion exhaust gas G3, G4 generated in the combustion treatment step 6 and the thermal decomposition step 2. In this waste heat recovery step 7,
A waste heat boiler is used as the waste heat recovery equipment, and steam G5 is generated by this boiler. This steam G5 is supplied to the power generation facility 8 to perform waste heat power generation.

Further, the exhaust gas G6 derived from the waste heat recovery process 7 is supplied to the exhaust gas treatment process 9, where a predetermined exhaust gas cleaning process is performed, and the exhaust gas G6 is discharged to the outside of the system as a clean gas G7. It has become. An electric dust collector and a wet degassing device are applied to the exhaust gas treatment step 9.

The details of each of the above steps will be described below with reference to FIGS.
This will be described in detail with reference to FIG. FIG. 2 is an explanatory diagram showing an example of the crushing step 1. As shown in this figure, crushing step 1
The tire yard 11 for storing the tire W0 which is the rubber waste W, the tire lifter 12 provided on the downstream side thereof, the crusher 13 for crushing the tire W0 fed by the tire lifter 12, and the crusher A quantitative supply device 14 for introducing the crushed material W1 crushed by the machine 13 into the thermal decomposition step 2 is provided.

In the case of the present embodiment, the tire lifter 12 is a so-called hook conveyor in which hooks for preventing slippage are provided on the surface of the chain belt at a predetermined pitch. The tire W0 stored in the tire yard 11 is sequentially supplied to the base end side of the tire lifter 12 by a predetermined cargo handling machine, raised by circulation movement of the conveyor, and supplied from the top into the crusher 13. There is.

In the case of the present embodiment, the crusher 13 is a biaxial shear type rotary shredder. The tire W0 supplied to the crusher 13 is crushed to a size of about 10 to 20 cm square by a human or by a circular tooth rotating around the axis while descending from above, and becomes a crushed material W1. It is designed to be released downward. A conveyor belt 13a is provided below the crusher 13, and the crushed material W1 dropped from above is conveyed to the conveyor belt 13a and supplied to the constant quantity supply device 14.

The fixed amount supply device 14 is provided with a storage portion 14a at the upper portion thereof, a screw feeder 14b at the lower portion of the storage portion 14a, and a leveler 14c for uniformizing the height of the crushed pieces. Has been. The crushed material W1 discharged from the screw feeder 14b is carried to the conveyor belt 14d provided on the downstream side and introduced into the subsequent thermal decomposition step 2.

FIG. 3 is an explanatory view showing the thermal decomposition step 2 and the sorting step 3. In this figure, the thermal decomposition step 2 is shown on the left side of the alternate long and short dash line, and the sorting step 3 is shown on the right side thereof. The thermal decomposition step 2 is provided with an external heat type rotary kiln type thermal decomposition furnace 21. This pyrolysis furnace 21
Is composed of a cylindrical furnace body 22 that rotates around an axis by a rotation driving means (not shown), and an annular outer cylinder portion 23 that is provided so as to surround the outer peripheral surface of the furnace body 22. .

The outer cylinder portion 23 is fixed to a support member (not shown) so that it does not rotate even if the furnace body 22 rotates about its axis. And inside the furnace body 22, the crushed material W
A thermal decomposition chamber 22a for thermally decomposing 1 is formed, and a combustion chamber 23a is formed between the outer peripheral surface of the furnace body 22 and the inner peripheral surface of the heating furnace 23.

At the upstream end of the furnace body 22 (on the left side of the drawing),
A crushed material charging cylinder 24 is provided concentrically, and a screw feeder 24a extending in the longitudinal direction is provided inside the crushed material charging cylinder 24. Then, the screw feeder 24a is rotationally driven around the axis by a drive means (not shown), and the crushed material W1 supplied into the crushed material charging cylinder 24 is introduced into the thermal decomposition chamber 22a. In addition to the crushed material W1, the sludge W7 obtained in the gas treatment step 5 is also supplied to the crushed material input cylinder 24.

At the downstream end of the pyrolysis furnace 21, there is provided a residue discharge tube 25 for discharging the pyrolysis residue W2 to the outside. The residue discharge cylinder 25 has a screw feeder 25a that rotates around an axis by rotational driving of a driving means (not shown).
Is internally provided, and the thermal decomposition residue W2 in the thermal decomposition chamber 22a is led out by the rotation of the screw feeder 25a.

On the other hand, the heating furnace 23 is provided with a combustion burner 23b penetrating the outer peripheral wall surface. The purified gas G1 purified in the gas treatment step 5 is the combustion burner 23b.
The combustion air introduced into the combustion chamber 23a via a fan (not shown) is burned, and the combustion heat causes the crushed material W1 filled in the thermal decomposition chamber 22a to be thermally decomposed. ing.

Further, a pyrolysis gas discharge part 26 is provided on the upstream side of the furnace main body 22, and the pyrolysis gas G generated in the pyrolysis chamber 22a via the pyrolysis gas discharge part 26 is treated in the gas treatment step 5 The combustion exhaust gas G4 generated in the combustion chamber 23a is discharged toward the waste heat recovery step 7 through the combustion exhaust gas discharge pipe provided in the heating furnace 23. .

In the sorting step 3, the transfer belt 31 for transferring the pyrolysis residue W2 discharged from the pyrolysis furnace 21 and the magnetic separator for magnetically selecting the metal residue W3 from the pyrolysis residue W2 on the transfer belt 31 during the transfer. 32 and 32. The magnetic separator 32 is adapted to selectively remove a magnetic substance such as iron from the thermal decomposition residue W2. Predetermined amount of metal residue W3
When is removed, the magnetic separator 32 moves to the metal residue yard 3a and drops the metal residue W3 into the metal residue yard 3a.

A suction hood 33 is provided below the transfer belt 31. The suction hood 33 is for sucking dust generated from the carbon residue W4 after magnetic separation and introducing it as a powder air flow G8 into the carbon crushing step 4 of the next step.

FIG. 4 is an explanatory view showing an example of the carbon crushing step 4. As shown in this figure, in the carbon crushing step 4, the coarse coal silo 4 for temporarily storing the carbon residue W4 is used.
1, a first bag filter dust collector 42 provided above the crude coal silo 41, a quantitative feeder 43 connected to the bottom of the crude coal silo 41, and a pulverizer connected to the downstream side of the quantitative feeder 43. A machine 44 and a second bag filter dust collector 45 provided on the downstream side of the crusher 44 are provided.

The powder airflow G8 sucked by the suction hood 33 in the sorting step 3 is introduced into the first bag filter dust collector 42, and only the airflow in the powder airflow G8 is filtered. And is discharged to the outside through the suction blower 42a.
On the other hand, the fine powder captured by the filter of the first bag filter dust collector 42 is temporarily stored in the coarse coal silo 41.

Then, the carbon residue W4 in which fine powder is mixed is sequentially extracted from the bottom of the crude coal silo 41 and supplied to the quantitative feeder 43. The quantitative feeder 43 has a table feeder 43a built-in,
By controlling the rotation speed of the table feeder 43a, a fixed amount of carbon residue W4 is supplied to the pulverizer 44 on the downstream side. In this embodiment, the crusher 44 is an impact type hammer crusher.
Then, the crushed carbon W5 crushed and generated by the crusher 44 is supplied to the second bag filter dust collector 45 on the downstream side by air transportation.

The air that has passed through the filter in the second bag filter dust collector 45 is discharged to the outside through the suction blower 45a, and the crushed carbon W5 captured by the filter is discharged from the lower portion of the second bag filter dust collector 45. The air is discharged, introduced into an air pipe 46 provided for feeding the combustion air A, and supplied to the combustion treatment step 6 by air flow transportation.

FIG. 5 is an explanatory view showing an example of the gas treatment process 5. As shown in this figure, in the gas treatment step 5,
A cooling tower 51 for cooling the pyrolysis gas G, and this cooling tower 51
Pump 5 for extracting cracked oil K1 stored at the bottom of
2 and the decomposed oil K extracted by the extraction pump 52
Thickener 53 that separates 1 into circulating oil K2 and sludge oil K3, centrifuge 56 that separates and collects recovered oil K by centrifuging sludge oil K3, and recovery that is separated and recovered by this centrifugal separator 56. Oil tank 57 for storing the oil K
And are provided.

The cooling tower 51 is a so-called gas-liquid separator, which directly exchanges heat of the pyrolysis gas G in the hot gas state introduced from the pyrolysis step 2 with the cooling oil supplied from the top. It is then cooled to remove the oil component. The oil component removed from the pyrolysis gas G is stored as the cracked oil K1 at the bottom of the cooling tower 51, and the pyrolysis gas G from which the oil component has been removed becomes the purified gas G1 and undergoes the pyrolysis step 2
The fuel is supplied to the thermal decomposition furnace 21 as a fuel.

Circulating oil K2 separated by the thickener 53
Is cooled by indirect heat exchange with cooling water by a circulating oil cooler 54 provided in the middle of the flow path, and is supplied as cooling oil into the cooling tower 51 from the top. Also,
The sludge oil K3 separated in the thickener 53 is also cooled in the oil cooler 55 by indirect heat exchange with cooling water. Then, in the centrifugal separator 56, the sludge W7 separated as a result of the centrifugal separation is
It is returned to the thermal decomposition step 2 and loaded into the thermal decomposition furnace 21 together with the crushed material W1.

The recovered oil K derived from the centrifuge 56 is temporarily stored in the oil tank 57, is sequentially withdrawn by the drive of the pressure pump 58 provided on the downstream side, and is supplied as fuel to the combustion treatment process 6. It is supposed to be done.

FIG. 6 shows a combustion treatment process 6 and a waste heat recovery process 7.
It is an explanatory view showing an example of and exhaust gas processing process 9.
In this figure, a combustion treatment process 6 is drawn on the left side, a waste heat recovery process 7 is drawn in the center, and an exhaust gas treatment process 9 is drawn on the right side, which is separated by a one-dot chain line. As shown in this figure, a swirling flow melting furnace 61 is provided in the combustion processing step 6. This swirling flow melting furnace 61 is a shaft furnace similar to the blast furnace,
A furnace main body 62 having a combustion chamber 61a formed therein and a furnace bottom 63 provided at the bottom of the furnace main body 62 are basically configured.

At the top of the furnace body 62, a fuel supply port 62a for receiving the recovered oil K from the gas treatment step 5 and a crushed carbon W5 from the carbon crushing step 4 are burned with air A.
And an air carbon supply port 62b for supplying the air into the combustion chamber 61a. Further, a combustion exhaust gas discharge port 62c is provided in the body of the furnace body 62.

The recovered oil K supplied into the combustion chamber 61a through the fuel supply port 62a is the combustion air A supplied into the combustion chamber 61a through the carbon air flow supply port 62b.
Then, the pulverized carbon W5 introduced into the combustion chamber 61a is burned in the combustion air A by being combusted in a swirling flow.

Due to the combustion, the temperature in the combustion chamber 61a is raised to 1200 to 1600 ° C., and the combustion is performed in a state where a swirl flow is formed along the inner wall surface of the combustion chamber 61a. The crushed carbon W5 made of carbon black, which is a flame-retardant substance that is difficult to burn normally with a swirling flow, completely burns within a few seconds, and the resulting combustion exhaust gas G3 is directed from the combustion exhaust gas outlet 62c to the waste heat recovery process 7. Slag W6 which is a combustion residue
Is designed to fall onto the furnace bottom 63. The zinc oxide with the highest content contained in the crushed carbon W5 does not melt unless it is 1900 ° C. or higher, but it is taken into other melts by setting the temperature of the combustion chamber 61a to 1200 to 1500 ° C. The removed state is removed as slag W6.

A discharge conveyor 64 is provided inside the furnace bottom 63, and the slag W6 is discharged to the outside from a discharge port 63a provided at the side of the furnace bottom 63 by driving the discharge conveyor 64. It has become so.

The waste heat recovery step 7 is provided with a waste heat boiler 71. The waste heat boiler 71 is formed of a cylindrical body or a box-shaped body having a heat exchange chamber 70 inside. A steam generator 72 having a large number of heat exchange pipes arranged in parallel is provided in the heat exchange chamber 70, and the softened ion-exchanged water K4 is supplied to the steam generator 72. A mortar-shaped hopper portion 71 a is formed below the waste heat boiler 71.

Then, in the waste heat boiler 71, the combustion exhaust gas G3 discharged from the swirling flow melting furnace 61 on the upstream side,
The combustion exhaust gas G4 discharged from the thermal decomposition furnace 21 in the thermal decomposition step 2 is introduced, and these combustion exhaust gases G3, G4 and the ion exchange water K4 are heat-exchanged in the steam generator 72 to generate steam G5. . This steam G5 is supplied to the power generation facility 8 for power generation. The combustion exhaust gas G3 used for generating the steam G5 is reduced in temperature by heat exchange with the ion-exchanged water K4 and becomes exhaust gas G6, which is led to the exhaust gas treatment step 9 of the next step.

The heat exchange chamber 7 is entrained in the combustion exhaust gas G3.
The dust W8 introduced into 0 is gravity-dropped while slowly moving in the large-capacity heat exchange chamber 70, is stored in the hopper portion 71a, and is appropriately extracted to the outside.

The exhaust gas treatment step 9 is provided with an electric dust collector 91 and a wet degassing device 93. The exhaust gas G6 derived from the waste heat boiler 71 is supplied to the electric dust collector 91, and the dust remaining in the exhaust gas G6 is removed. A push-down blower 92 is provided on the lower side of the electric dust collector 91.
1 and the ventilation passage A1 for air flow transportation are sent to the air passages provided under the waste heat boiler 71. Then, the dust W9 extracted from the electrostatic precipitator 91 is supplied to the ventilation A1.

Further, dust W8 derived from the hopper portion 71a of the waste heat boiler 71 is supplied to the ventilation A1. Then, the dust W8, W captured by the waste heat boiler 71 and the electric dust collector 91
9 is mixed in the combustion air A of the combustion processing step 6 by being accompanied by the ventilation A1 by air flow transportation and supplied to the swirling flow melting furnace 61.

In the case of this embodiment, the wet degassing device 93 has a function of countercurrently contacting a liquid and a gas so as to physically transfer dust contained in the gas to the liquid and remove the dust. It has a function that chemically removes contained harmful substances and removes them. Then, the wet degassing device 93 is formed by the absorption tower 93a, uses an alkaline liquid in which caustic soda or the like is dissolved in water as the cleaning liquid K5, and sprays the cleaning liquid K5 from the top of the absorption tower 93a. And the exhaust gas G6 'from the electrostatic precipitator 91 introduced into the lower part of the absorption tower 93a are brought into countercurrent contact with each other.

By this countercurrent contact, the dust remaining in the exhaust gas G6 'is removed and the exhaust gas G6' is removed.
Sulfur oxides present in 6'are alkali cleaning solution K5
Are neutralized and removed by. The cleaning liquid K5 is recycled. Then, the exhaust gas G6 'cleaned by the wet degassing device 93 becomes a clean gas G7, which is discharged from the top of the absorption tower 93a by the discharge blower 94 and discharged to the outside through the stack 95.

As described in detail above, the heat treatment method for rubber waste according to the present invention is a rubber waste W containing a mixture of metals.
Crushing step 1 for crushing the crushed material, pyrolysis step 2 for pyrolyzing the crushed material W1, sorting step 3 for sorting the thermal decomposition residue W2 into metal residue W3 and carbon residue W4, and selected carbon residue W4 Carbon crushing step 4 for crushing
The gas treatment step of purifying the pyrolysis gas G generated in the pyrolysis step 2 and sending the purified gas G1 as the fuel of the pyrolysis step 2 and the crushed carbon W5 crushed in the carbon crushing step 4 are performed in the gas treatment step. Combustion treatment step 6 in which the recovered oil K obtained in 5 is used as fuel for combustion treatment, and this combustion treatment step 6
And a waste heat recovery step 7 for recovering waste heat from the combustion exhaust gas G3, G4 generated in the thermal decomposition step 2, and an exhaust gas treatment step 9 for cleaning the exhaust gas G6 after the waste heat recovery.

Therefore, the rubber-based waste W crushed in the crushing step 1 is thermally decomposed in the thermal decomposition step 2, and as a result, the thermal decomposition gas G and the thermal decomposition residue W2 are produced, and the thermal decomposition gas G is generated. Purified gas G purified in the gas treatment step 5
1 and the recovered oil K, the pyrolysis residue W2 becomes a carbon residue W4 which is selected in the selection step 3 to remove the metal residue W3, and the carbon residue W4 is crushed in the next carbon crushing step 4. Combustion exhaust gas G3 obtained as a result of the combustion treatment after that in combustion treatment step 6
Is recovered in a waste heat recovery step 7, is then cleaned in an exhaust gas treatment step 9, and is discharged outside the system as a clean gas G7.

In the present invention, the refined gas G1 refined in the gas treatment step 5 is used as the fuel in the thermal decomposition step 2, and the recovered oil K separated in the gas treatment step 5 is used in the combustion treatment step. Combustion exhaust gas G generated in the thermal decomposition step 2 and the combustion treatment step 6
Since the waste heat recovery processes 3 and G4 are designed to recover waste heat in the waste heat recovery step 7, the system is in a self-contained energy balance state without supplementing energy from the outside. It is possible to reduce the processing cost of the system waste W.

Further, in the thermal decomposition step 2, since the high-performance external heat rotary kiln type thermal decomposition furnace 21 is used, the thermal decomposition efficiency is improved, and in the combustion treatment step 6, the inside of the furnace is increased. 1200 ℃ ~ 1600
Since the swirl-flow melting furnace 61 of the shaft furnace type capable of raising the temperature to ℃ is applied, the crushed carbon W5 made of carbon black which could not be easily completely burned by the conventional incinerator in the past is instantly used. Can be completely combusted, and is extremely effective in completely treating the rubber waste W.

Further, in the swirl flow melting furnace 61, since the temperature inside the furnace is high as described above, the rubber waste W contains about 5 parts.
Heavy metals such as zinc and oxides thereof, which are contained by weight, are melted and taken out in a state of being confined in the slag W6. Therefore, the scattering of heavy metals is effectively suppressed, which is convenient for environmental protection.

By the way, when the material composition of the rubber waste W consisting of waste tires is 55% by weight of the rubber component, 30% by weight of the carbon black component and 15% by weight of the steel component, in the conventional ordinary incineration facility, Since the carbon black component was not burned, waste tires from burning 1
The calorific value per kg was 5500 kcal / kg (rubber calorific value 10000 kcal / kg × 0.55), whereas in the present invention, since the carbon black component is also burned, 7750 kcal / kg (rubber The calorific value is 10,000 kcal / kg × 0.55 + the calorific value of carbon black is 7500 kcal / kg × 0.30), and 1.4 times the combustion heat of the conventional case can be obtained. If the combustion heat of 1.4 times that in the conventional case is recovered, the heat recovery rate will also be 1.4 times that in the conventional case, and it can be seen how the present invention is excellent in terms of heat recovery.

In the above embodiment, the combustion treatment step 6
In the swirling flow melting furnace 61, the recovered oil K obtained in the gas processing step 5 is used as a fuel to burn the crushed carbon W5 in the swirling flow melting furnace 61. It is not limited to applying the swirling flow melting furnace 61 to No. 6, but the crushed carbon W5 and the recovered oil K are directly mixed into sludge-like fuel, and this sludge-like fuel is injected and supplied to a dedicated boiler. It is also possible to provide combustion equipment similar to the so-called COM (Coal-Oil-Mixture) combustion method in which the fuel is burned in the same manner, and to perform combustion treatment with this.

However, when the same combustion equipment as the COM combustion system is used, the combustion temperature as high as that of the swirling flow melting furnace 61 cannot be obtained, and therefore the possibility of incomplete combustion is high, and the exhaust gas is correspondingly increased. Many harmful components such as unburned carbon and dust may remain inside. Therefore, when the COM combustion method is adopted, it is necessary to enhance the post-treatment such as enhancing the exhaust gas treatment process 9.

[0081]

According to the heat treatment method for a rubber-based waste according to claim 1, the rubber-based waste containing a mixture of metals is
First, it is crushed to a predetermined size in the crushing step, and is subjected to a thermal decomposition treatment in the next thermal decomposition step to generate a thermal decomposition gas and a carbon residue and a metal residue. Then, the pyrolysis gas is refined in the gas treatment step and separated into refined gas and recovered oil,
The carbon residue and the metal residue are sorted in the sorting step, and only the carbon residue is crushed in the carbon crushing step and then supplied to the combustion treatment step.

The powdery carbon residue supplied to the combustion treatment step is burned with the recovered oil obtained in the gas treatment step as fuel, and the waste heat is recovered from the combustion exhaust gas in the waste heat recovery step. Be seen.

As described above, the carbon residue of the rubber waste which has been once subjected to the thermal decomposition treatment in the thermal decomposition step is separated from the non-combustible metal residue in the selection step and subjected to the combustion processing in the combustion processing step. Therefore, such a two-step process enables a more complete combustion process than the case where only a conventional one-step combustion process is performed.

As described above, the invention of claim 1 is a self-contained treatment method in which the energy balance and the material flow are balanced in the entire system from the crushing process to the waste heat recovery process. The heat treatment gas and combustion residue do not need to be subjected to a secondary treatment, and the excess energy can be effectively used by recovering the waste heat, reducing the treatment cost of rubber waste. It is extremely effective in making it happen.

According to the heat treatment method for rubber waste according to claim 2, in the thermal decomposition step, the supplied rubber waste is uniformly distributed in the furnace by the rotation of the rotary kiln type thermal decomposition furnace. Since the mixture is agitated and the heat is uniformly supplied, it is uniformly, reliably and efficiently pyrolyzed, which is convenient for performing a more complete pyrolysis process.

According to the heat treatment method for rubber waste according to claim 3, in the combustion treatment step, the carbon residue introduced from the pyrolysis step is swirling flow in the swirling flow type melting furnace of the shaft furnace system. Since it is swirled and stirred in the furnace by the above, the carbon content is surely contacted and the carbon content is completely burned, and the metal residue and the like entrained in the carbon residue are reliably separated and removed as slag by centrifugal force.

According to the heat treatment method for rubber waste according to the above-mentioned claim 4, the waste heat recovered gas derived from the waste heat recovery step is subjected to dust removal and defluent treatment. The purified exhaust gas is discharged out of the system, which is convenient for environmental protection.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example of a heat treatment method for rubber waste according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a crushing step.

FIG. 3 is an explanatory diagram showing a thermal decomposition step and a sorting step.

FIG. 4 is an explanatory diagram showing an example of a carbon crushing step.

FIG. 5 is an explanatory diagram showing an example of a gas treatment process.

FIG. 6 is an explanatory diagram showing an example of each of a combustion treatment process, a waste heat recovery process, and an exhaust gas treatment process.

FIG. 7 is an explanatory view showing a conventional direct combustion type waste incinerator, (a) shows a lattice type, (b) shows a rotary kiln type, and (c) shows a fluidized bed type. .

FIG. 8 is an explanatory view showing a conventional dry distillation type waste treatment device, in which (a) shows an external heating type and (b) shows an internal heating type.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crushing process 11 Tire yard 12 Tire lifter 13 Crusher 14 Quantitative supply device 14a Storage part 14b Table feeder 14c Leveler 14d Conveyor belt 2 Pyrolysis process 21 Pyrolysis furnace 22 Furnace body 22a Pyrolysis chamber 23 Heating furnace 23a Combustion chamber 23b Combustion burner 23c Air hole 24 Crushed material input cylinder 24a Screw feeder 25 Residue discharge cylinder 25a Screw feeder 26 Pyrolysis gas discharge part 3 Sorting process 3a Metal residue yard 31 Transfer belt 32 Magnetic separator 33 Suction hood 4 Carbon crushing process 41 Coarse carbon silo 42 No. 1 Bag filter dust collector 43 Quantitative feeder 44 Crusher 45 Second bag filter dust collector 46 Air piping 5 Gas treatment process 51 Cooling tower 52 Extraction pump 53 Thickener 54 Circulating oil cooler 55 Oil cooler 56 Centrifugal separation 57 Oil Tank 58 Pressure Pump 6 Combustion Treatment Process 6a Slab Yard 61 Swirling Flow Melting Furnace 61a Combustion Chamber 62 Furnace Main Body 62a Fuel Supply Port 62b Carbon Air Flow Supply Port 62c Combustion Exhaust Gas Exhaust Port 63 Furnace Bottom 63a Discharge Port 7 Waste Heat Recovery Process 70 Heat exchange room 71 Waste heat boiler 71a Hopper part 72 Steam generator 8 Power generation equipment 9 Exhaust gas treatment process 91 Electrostatic precipitator 92 Indentation blower 93 Wet degasser 93a Absorption tower 94 Discharge blower 95 Stack W Rubber waste W1 Crushed product W2 Pyrolysis residue W3 Metal residue W4 Carbon residue W5 Crushed carbon W6 Slag W7 Sludge W8, W9 Dust G Pyrolysis gas G1 Purified gas G3 Combustion exhaust gas G4 Combustion exhaust gas G5 Steam G6 Exhaust gas G7 Clean gas K2 Circulating oil K3 Circulating oil K2 Sludge oil 4 ion exchange water K5 cleaning solution

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F23G 5/46 ZAB A

Claims (4)

[Claims] 1. A heat treatment method for rubber-based waste containing a mixture of metals, which comprises a crushing step for crushing the rubber-based waste, and a thermal decomposition step for thermally decomposing the crushed material crushed in this crushing step. A sorting step of sorting the thermal decomposition residue obtained in this thermal decomposition step into a metal residue and a carbon residue, a carbon crushing step of crushing the carbon residue selected in this sorting step, a thermal decomposition generated in the thermal decomposition step A gas treatment process in which a purified gas obtained by refining the gas is delivered as a fuel for a pyrolysis process, and the pulverized carbon pulverized in the carbon pulverization process is burned using the recovered oil obtained in the gas treatment process as a fuel. A rubber waste comprising a combustion treatment step, and a waste heat recovery step for recovering waste heat from combustion exhaust gas generated in the combustion treatment step and the thermal decomposition step. Heat treatment method. 2. In the thermal decomposition step, an external heat type rotary kiln type heat is constructed in which a cylindrical thermal decomposition chamber is configured to rotate around its axis with its outer peripheral surface surrounded by heating means. The heat treatment method for rubber waste according to claim 1, wherein a decomposition furnace is applied. 3. The rubber according to claim 1, wherein a shaft furnace type swirl flow type melting furnace configured to generate a swirl flow is applied to the combustion treatment step. Of heat treatment of waste materials. 4. The waste heat recovered gas derived from the waste heat recovery step is configured to be subjected to dust removal and deflow treatment. Method of heat treatment of rubber waste in Japan.