JP2634735B2 - Plastic processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating plastic, which can be used for disposal of plastic waste by combustion and energy saving measures by utilizing it as a fuel resource.

[0002]

2. Description of the Related Art In recent years, the amount of plastic waste generated has increased dramatically, and has become a major social problem over its disposal as municipal waste or industrial waste. Until now, landfilling, incineration and the like have been performed as such plastic waste disposal methods.

In the landfill process, plastic waste is landfilled as is in a landfill site,
A method of reducing the volume by pressurizing or the like and then burying it has been adopted. On the other hand, in the case of incineration, it is difficult to classify and collect plastic wastes as other general wastes.

[0004]

However, the conventional methods for treating plastic waste as described above have caused various problems including environmental problems and resource problems. In other words, landfills have a problem of lack of landfill land, and the plastic waste does not decay, softening the ground, or polluting the surrounding environment due to elution of harmful substances from the landfilled plastic waste. There was a problem that was. Further, in this landfill treatment, only plastic waste is landfilled, and energy is not reused such as heat recovery, so that there is a problem that resources are wasted.

On the other hand, in the incineration treatment, there is no problem such as the shortage of the landfill site and the pollution of the surrounding environment due to the landfill, but the plastic waste remains solid and is co-fired with the general waste. However, there is a problem that stable combustion cannot be obtained due to local high heat generation due to solid combustion or fluctuation in heat generation due to co-firing, thereby damaging the furnace wall refractory.
And, in order to perform incineration treatment under such conditions, a high heat value, or a special furnace or a special boiler or the like that can cope with a drastic fluctuation of the heat value must be used.
There was a problem that high cost was required.

In addition, there is a problem that load fluctuations become large due to co-firing with general waste, resulting in unstable combustion, which makes it difficult to increase operating efficiency. In addition, there is a problem that it is difficult to completely burn due to co-firing, soot and unburned matter remain, or sophisticated exhaust gas treatment equipment is required because harmful gas is generated.

Further, in the case of solid combustion, since the plastic waste is treated as a solid, its handling becomes difficult, the transport equipment and the supply equipment become large, and a large site and space are required. However, when the finely pulverized material is handled as powder, dust and the like are liable to be generated during the transportation, and there is a problem that the entire combustion plant tends to become a dirty image.

[0008] In general, solid processing requires labor, but it is difficult to secure human resources in combination with the dirty image of the entire factory as described above, and even if automation and labor saving are promoted, solid processing is difficult. Since automation and labor saving increase the cost, there is a problem that it can be used only for large facilities such as business thermal power.

In the case of solid combustion, existing large and small heavy oil furnaces and boilers using petroleum fuel as a liquid fuel cannot be used. There was such a problem.

[0010] It is an object of the present invention to provide a method for treating plastic, which can burn the plastic in a stable state and can obtain a fuel excellent in handling properties such as transportation and storage.

[0011]

According to the method for treating plastic of the present invention, a plastic is coarsely pulverized, and the plastic coarsely pulverized product and a liquid containing a surfactant are charged into a fine pulverizer. The method is characterized in that the coarsely pulverized plastic is finely pulverized and mixed with the liquid containing the surfactant to form a slurry fuel.

[0012]

According to the present invention, the plastic is coarsely pulverized and then finely pulverized, so that the plastic is finally fine and uniform, and the plastic waste can be disposed of by stable combustion. Like
It is possible to solve various problems that occur when the plastic waste is mixed and treated as it is as described above.

In addition, since energy is reused using plastic waste as fuel, oil fuel can be saved, resource problems can be solved, and fuel costs can be stabilized. become.

Further, since a liquid containing a surfactant is mixed with the plastic to form a slurry-like fuel, it can be handled as a liquid. In particular, when slurrying plastic waste, it is possible to uniformly mix finely pulverized plastic fines with a liquid by using a surfactant.

[0015] Since the slurry fuel is used, stable fuel supply can be performed, and stable combustion can be achieved by spray combustion. Therefore, in combination with the above-mentioned stabilization due to the atomization of plastic, the load fluctuation in the furnace can be reduced, the furnace load per unit time can be improved, and the furnace can be operated efficiently, and the solid fuel can be further improved. than in the case of, significant reduction in unburned, after which it is possible to perform the low NO _X reduction, it is possible to easily perform the handling operations in the combustion process.

Further, since the slurry fuel is used, it can be supplied to existing large and small heavy oil furnaces and boilers as an alternative to petroleum fuel, and the existing furnace can be used by a simple change such as a change of a burner portion. Become.

Further, since the slurry fuel is used, the fuel can be stored in a storage tank, transported by a tank truck, or transported by a pipeline. By improving their storage and transport properties, automation and labor saving of the raw material supply system to the combustion furnace can be promoted, and the cost can be reduced significantly in terms of equipment and labor. Thereby, the above object is achieved.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a plastic processing apparatus 10 includes:
A coarse crusher 20 such as a jaw crusher for coarsely crushing the plastic waste 11 to obtain a coarsely crushed plastic material 12; a quantitative feeder 21 which is a powder supply mechanism provided downstream of the coarse crusher 20; Liquid tank 30 for mixing the liquid 40 containing the agent, a flow rate adjusting mechanism 31 provided downstream of the mixed liquid tank 30, and an interface between the plastic coarsely pulverized material 12 from the quantitative feeder 21 and the flow rate adjusting mechanism 31. And a wet pulverizer 50 into which a liquid 40 containing an activator is charged.

Further, the plastic processing apparatus 10 is provided with a plastic finely pulverized material 13 finely pulverized by the wet fine pulverizer 50 and a liquid 40 containing a surfactant downstream of the wet fine pulverizer 50 described above. Slurry tank 60 for more thorough mixing
And a pipeline 70 for feeding the slurry fuel 14 generated here to the combustion furnace 80, and a slurry pump 71 such as a mono pump provided in the middle of the pipeline 70.

Here, the plastic waste 11 is, for example, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET).
), Polyvinyl chloride (PVC) and the like.
The coarsely pulverized plastic 12 is a plastic waste 11 pulverized to about 10 mm or less, and the finely pulverized plastic 13 has an average particle size of 100 μm or less (preferably 30 μm or less).
m) of plastic waste.

The liquid 40 containing a surfactant is a liquid obtained by mixing a fuel oil 41 and water 42 with a nonionic surfactant 43 for homogenizing the mixing with the plastic waste 11. The mixing ratio (% by weight) of the fuel oil: water: surfactant = 0: 100: 1 or less to 100: 0: 1 or less, preferably the ratio = 10: 90: 1 to 30:70: 1
It is as follows.

The mixed liquid tank 30 is well stirred and mixed with a fuel oil 41, water 42 and a surfactant 43 by a stirrer 32 provided therein, and a liquid 40 containing the mixed surfactant is mixed.
The wet pulverizer by the pump 33 provided on the downstream side
It is configured to send to 50.

The fixed-quantity feeder 21 is configured to continuously feed the plastic coarsely pulverized material 12 coarsely pulverized by the coarse pulverizer 20 to the wet fine pulverizer 50 by a predetermined amount. The flow rate adjusting mechanism 31 is configured to adjust the flow rate of the liquid 40 containing the surfactant mixed in the mixed liquid tank 30 to the wet pulverizer 50. Then, the flow rate adjusting mechanism 31 converts the liquid 40 containing a surfactant into the wet fine pulverizer 50 based on a signal 22 corresponding to the supply amount of the plastic coarsely pulverized material 12 to the wet fine pulverizer 50 by the quantitative feeder 21. To be supplied to

The wet pulverizer 50 is an apparatus for finely pulverizing the plastic coarsely pulverized material 12 in a state where the liquid 40 containing a surfactant is mixed into a so-called wet state to obtain a plastic finely pulverized material 13. In this embodiment, a ball mill is used. The particle size of the plastic coarsely pulverized material 12 pulverized by this ball mill is determined by
It can be appropriately adjusted by setting the particle size, amount, or grinding time of No. 51. The mixing ratio of the coarsely pulverized plastic 12 and the liquid 40 containing a surfactant is such that the liquid 40 containing a surfactant is mixed with 30 to 50 (preferably 40) parts by weight of the coarsely pulverized plastic 12. 70-50 (preferably
60) Parts by weight.

The slurry tank 60 stirs the plastic finely pulverized material 13 and the liquid 40 containing a surfactant sent from the wet finely pulverizer 50 by a stirrer 61 provided therein to mix them more thoroughly. Thus, the slurry-like fuel 14 is formed.

The combustion furnace 80 is an existing combustion furnace and has a burner
Supply steam for atomizing or air 82 to 81,
The burner 81 is configured to eject the slurry-like fuel 14 in the form of a spray to perform spray combustion.

In this embodiment, the treatment of plastic waste is performed as follows. First, a plastic waste 11 is roughly pulverized by a coarse pulverizer 20 to obtain a plastic coarsely pulverized product 12. On the other hand, the liquid 40 containing the surfactant is mixed in the mixed liquid tank 30 in advance.

Next, the plastic coarsely pulverized material 12 is continuously supplied from the coarse pulverizer 20 to the wet fine pulverizer 50 by a predetermined amount by the quantitative feeder 21. At the same time, the flow adjustment mechanism 31
Receives the signal 22 from the fixed-quantity feeder 21 and supplies the liquid 40 containing the surfactant to the wet-type fine pulverizer 50 from the mixed liquid tank 30 by an amount corresponding to the supplied predetermined amount of the plastic coarsely pulverized material 12. Then, the plastic coarsely pulverized product 12 is finely pulverized by the wet fine pulverizer 50 in a state where the liquid 40 containing the surfactant is mixed, to obtain the plastic finely pulverized product 13.

Thereafter, in the slurry tank 60, the finely pulverized plastic 13 and the liquid 40 containing a surfactant are further sufficiently mixed to obtain a slurry fuel 14. And
The generated slurry fuel 14 is sent to a combustion furnace 80 through a pipeline 70 by a slurry pump 71, and the combustion furnace 80
Spray and burn. Here, when the distance from the slurry tank 60 to the combustion furnace is long, the slurry fuel 14 is carried to the combustion furnace by a tank truck 72 or the like, and when the slurry fuel 14 is not used immediately, the storage tank 73 is used. Store in

According to this embodiment, the plastic waste 11 is coarsely pulverized and then finely pulverized, so that the plastic component is finally made finer and uniform, and the plastic waste 11 is stably burned. Can be disposed of as described above, leaving the solid plastic waste 11
Various inconveniences that occur when treating by co-firing can be solved.

Further, since energy is reused using the plastic waste 11 as fuel, oil fuel can be saved, resource problems can be solved, and fuel costs can be stabilized.

Further, since the plastic waste 11 is mixed with the liquid 40 containing a surfactant to form the slurry-like fuel 14, the liquid waste can be handled. Especially,
In making the plastic waste 11 into a slurry, the use of the surfactant 43 allows the finely pulverized plastic fines 13 to be uniformly mixed with the liquid.

Since the slurry-like fuel 14 is used, stable fuel supply can be performed, and stable combustion can be achieved by spray combustion. Therefore, in combination with the above-mentioned stabilization by atomization of the plastic waste 11, the load fluctuation in the combustion furnace 80 can be reduced, the furnace load per unit time can be improved, and the furnace can be operated efficiently. compared with the case of the solid fuel, significant reduction in unburned, upon which it is possible to perform the low NO _X reduction, it is possible to easily perform the handling operations in the combustion process.

Further, since the slurry-like fuel 14 is used, it can be supplied to existing large and small heavy oil furnaces and boilers as an alternative to oil, and the existing furnace can be used with simple changes such as changing the burner portion.

Further, since the slurry fuel 14 is used, the fuel is stored in the storage tank 73, transported by the tank truck 72,
Alternatively, conveyance by the pipeline 70 or the like can be performed. And, by improving these storage and transport properties, automation and labor saving of the raw material supply system to the combustion furnace 80 can be promoted, and thereby, the cost can be significantly reduced in terms of facilities and labor.

Further, since the plastic waste 11 is incinerated as the slurry fuel 14, there is no need to perform a landfill treatment as in the prior art, and the plastic waste 11 can be disposed without any problems associated with the landfill. it can.

By the way, a combustion experiment was conducted on the present embodiment. Table 1 shows the conditions and results at that time.

[0038]

[Table 1]

In the same table, although the particle size of the coarse pulverization is the same in Experimental Example 1 and Experimental Example 2, plastic waste
The conditions of the composition 11, the mixed liquid composition of the plastic waste 11 and the liquid 40 containing the surfactant, and the particle size of the fine pulverization are different. And the result of each experimental example is favorable.

Further, in Experimental Example 2, compared to Example 1, it is finely pulverized and therefore the slurry viscosity is increased, although higher slurry spray combustion pressure and combustion calories, amount generated NO _X is It has increased. Therefore, in actual application, it is desirable to appropriately select each condition according to the condition of the furnace, required calories, and the like.

It should be noted that the present invention is not limited to the above-described embodiment, and for example, the following modifications are included in the present invention. That is, in the above embodiment, the plastic to be treated is the plastic waste 11, but the plastic is actively generated, and the slurry fuel
May produce 14.

The signal 22 for adjusting the supply amount sent from the fixed-quantity feeder 21 to the flow rate adjusting mechanism 31 in the above embodiment is used.
Is a signal automatically generated, may be manually, may be a signal sent in the opposite direction, in short, the plastic coarsely pulverized material 12 and the liquid 40 containing a surfactant It is sufficient that the supply ratio of the liquid to the wet pulverizer 50 can be set to a predetermined value.

Further, in the above embodiment, the surfactant 43 is of a nonionic type. However, the surfactant 43 may be appropriately selected as long as it can promote the mixing of the plastic finely pulverized material 13 and the liquid. Good.

In the above embodiment, a slurry tank 60 is provided downstream of the wet pulverizer 50, and the plastic pulverized material 13 and the liquid 40 containing a surfactant are further sufficiently mixed to form a slurry. Although the fuel 14 is used, without providing the slurry tank 60, the plastic coarsely pulverized material 12 is finely pulverized into the plastic finely pulverized material 13 in the wet fine pulverizer 50, and simultaneously with the plastic finely pulverized material 13, Mixing with the liquid 40 containing a surfactant may also be performed.

Further, in the above embodiment, the wet pulverizer 50 is used.
Although a ball mill is used, other devices such as a rod mill and a roller mill may be used as long as they can perform wet pulverization.

[0046]

As described above, according to the present invention, the plastic is used as the slurry fuel, so that the plastic can be burned in a stable state and a fuel excellent in handling properties such as transportation and storage can be obtained. be able to.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

[Explanation of symbols]

 10 Plastic processing equipment 11 Plastic waste 12 Plastic coarsely pulverized 13 Plastic finely pulverized 14 Slurry fuel 20 Coarse pulverizer 30 Mixed liquid tank 40 Liquid containing surfactant 50 Wet pulverizer 60 Slurry tank 80 Combustion furnace

Claims (1)

(57) [Claims] 1. A plastic material is coarsely pulverized, and the plastic coarsely pulverized product and a liquid containing a surfactant are charged into a fine pulverizer. A method for treating plastic, comprising mixing with a liquid containing an agent to form a slurry fuel.