JPH0972530A - Volume reducing apparatus for waste plastic and the like and treating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently, safely and completely continue the combustion while satably maintaining the environment in a burning furnace by burning waste plastic and the like, simultaneously sucking the combustion gas to the bottom of a conveyor, and blowing, on the other hand, the gas from the gas blowing nozzle of a combustion chamber into the chamber. SOLUTION: Shredder dust 21 (waste plastic) is fed from a supply hopper 16 into a circulating and moving conveyor 22, and continuously supplied in a predetermined thickness. The dust 21 layer is ignited from above by an igniter 13 and burned. Combustion exhaust gas is sucked from a burning furnace 24 of the lower surface side of the conveyor 22 to a combustion chamber 26 via a window box 15. The dust 21 is continuously burned by this operation, and the air is blown to the chamber 26 from a gas blowing nozzle 29 to the floor or sidewall of the chamber 26. Thus, since the exhaust gas in the chamber 26 is further agitated, combustible material can be completely burned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for reducing the volume of waste plastics, and more particularly to waste plastics such as vinyl chloride, polyethylene, shredder dust, or industrial wastes containing waste plastics and general wastes. We propose a technology that can be effectively used when burning and incinerating materials for volume reduction.

[0002]

2. Description of the Related Art In recent years, disposal of waste plastics such as vinyl chloride, polyethylene, shredder dust, etc., or municipal wastes or industrial wastes containing waste plastics (hereinafter collectively referred to as "waste plastics") has become a problem. There is. In particular, so-called shredder dust generated from abandoned automobiles and home electric appliances containing a large amount of waste plastics has a problem such as secondary pollution due to harmful substances contained therein. Furthermore, in recent years, there are laws and regulations concerning landfill, and remoteness and depletion of landfill sites and rising landfill costs are becoming a major social problem. Therefore, as a breakthrough measure, a new technology is required to detoxify waste plastics such as shredder dust and perform volume reduction processing.

In response to such demands, recently, as a technique for reducing the volume of waste plastics such as shredder dust, a technique of burning the waste plastics and melting the incinerated ash produced after the combustion has been tried. Has been.
For example, there is a method of burning waste plastics in a fluidized furnace or a rotary kiln and then melting the incinerated ash produced in an electric furnace or a burner furnace.

[0004]

However, the processing method according to the above-mentioned conventional technique has technical drawbacks as described below and has not been realized yet. . The fluidized-bed method can burn waste plastics, but it is extremely difficult to separate the incineration residue and unburned dust in the fluidized furnace. If the air flow rate is increased to increase the combustion speed, the local area inside the furnace The temperature is high, the refractory is significantly damaged, and continuous operation for a long time is impossible, and the construction cost is enormous. . A rotary kiln can burn waste plastics, but since the occupation rate in the furnace is limited, it is necessary to enlarge the equipment in order to increase the throughput, and to completely seal the rotating body. However, it is difficult to burn harmful gases to the outside of the kiln, and it is difficult to control combustion and complete combustion is not possible.

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and in particular, to efficiently and safely burn combustible substances contained in waste plastics while maintaining a stable environment in the combustion furnace. An object of the present invention is to provide an apparatus capable of completely burning and a method for treating the apparatus. Another object of the present invention is to detoxify and reduce the volume of waste plastics and to smoothly recycle waste automobiles and home appliances.

[0006]

Means for Solving the Problems The inventor has conducted extensive research to realize the above object. As a result, by controlling the environment of the combustion chamber, the waste plastics are completely burned, and effective volume reduction processing can be realized. That is, the apparatus for reducing the volume of waste plastics according to the present invention is (1) an apparatus for reducing the volume by burning and incinerating waste plastics. On the conveyor whose bottom is a rustle, waste plastics are continuously charged to form a deposited layer, and the waste plastics are ignited from above and the waste plastics are sequentially burned at the same time, By sucking the combustion gas toward the lower surface of the conveyor at the bottom of the conveyor, it is configured to assist the self-combustion of the waste plastic deposition layer. One or more gas blowing nozzles are arranged on the floor surface or the side wall surface of the combustion chamber formed under the roster, and the gas is intermittently or continuously blown from this nozzle. This is a volume reduction processing device for waste plastics. Then, the method for reducing the volume of waste plastics according to the present invention is (2) by burning and incinerating the waste plastics in a combustion furnace to reduce the volume of the waste plastics.
Combustion and incineration of waste plastics. Waste plastics are continuously charged while being continuously charged on a conveyor that is operated intermittently or continuously while the bottom portion is a rustle, and is adjusted according to the movement of the conveyor from the top of the layer thus obtained. Then, the waste plastics are sequentially ignited to sequentially burn, and at the same time, the combustion gas is sucked to the lower surface side of the conveyor at the bottom of the conveyor to assist self-combustion of the waste plastic deposited layer. On the other hand, from the gas blowing nozzle provided on the floor surface or the side wall surface of the combustion chamber formed under the conveyor loss, the gas is intermittently or continuously blown into the combustion chamber. This is a volume reduction treatment method for waste plastics. (3) In the volume reduction treatment method described in (2) above,
The waste plastics are characterized in that they are charged and deposited on the bottom portion of the conveyor with a bedding interposed. As the bedding, it is desirable to use lumpy quicklime or limestone. (4) Further, in the volume reduction treatment method according to the above (2) or (3), the waste plastics are mixed with at least one of quick lime, limestone and slaked lime in advance. .

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The volume reduction technology for waste plastics according to the present invention is a conveyor having a bottom at the bottom, or an endless type having a bottom at the bottom intermittently or continuously. The waste plastics are continuously charged and deposited on the conveyor which is operated in a continuous manner according to the movement of the conveyor, and the waste plastics are sequentially ignited by sequentially igniting from the deposit layer thus obtained. At the same time, the combustion gas is sucked to the bottom surface of the conveyor at the bottom of the conveyor. That is, the entire deposited layer is burned by the end of the conveyor by igniting the surface of the deposited layer and sequentially expanding the combustion region after ignition with the movement of the conveyor downward and backward. At this time, the present invention is configured to assist self-combustion of the deposited layer after ignition by suctioning toward the combustion chamber under the rostr.

Particularly, in the processing technique of the present invention, one or more gas blowing nozzles are provided on the floor surface or the side wall surface of the high temperature combustion chamber, and the gas is blown intermittently or continuously from this nozzle. Therefore, the type of gas used here is, for example, air alone, steam or water,
By arbitrarily selecting from air containing ammonia, urea, NaOH, lime milk (Ca (OH) ₂ ), other combustion gas, boiler waste gas, etc., It is possible to stir the exhaust gas in the combustion chamber more effectively and achieve more complete combustion of combustible materials, and also to prevent the emission of pollutants such as NO _X , SO _X , chlorine and dioxin in the combustion exhaust gas. it can. For example, by blowing air or other gas containing ammonia gas, denitration of the combustion gas is possible while maintaining complete combustion. . By eliminating the fly ash that accumulates at the bottom of the combustion chamber,
It is possible to maintain a stable furnace environment. Has the advantage.

According to the volume reduction technology of the present invention as described above, it is possible to completely burn the combustible substances contained in the waste plastics and incinerate them while maintaining the environment in the combustion furnace stable. It is possible to improve the combustion processing efficiency of waste plastics and further improve the volume reduction achievement rate.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.
FIG. 1 is a process flow explanatory view showing an example of a process of shredder dust representing waste plastics, using a volume reduction processing apparatus for waste plastics according to the present invention.
In FIG. 1, reference numeral 1 is a volume reduction processing device for burning shredder dust, 2 is a sorter for separating irons 3 and non-ferrous metals 4 from an incineration residue, and collecting incinerated ash 5, 6 Is a furnace bottle for supplying the incinerated ash 5 to the electric furnace 7, and 8 is a melt recovered from the electric furnace 7. Further, 9 is a dust collector, 10 is a chimney, 11 is a heavy metal recovery device, and 12 is a detoxification treatment device.
The fumes generated from are processed. On the other hand, 17 is a heat exchanger, 18 is a generator, 19 is an exhaust gas treatment device, and 20 is a dehydrator, and these devices generate electricity using the exhaust gas generated from the volume reduction treatment device 1 (heat exchange). At the same time, the exhaust gas is detoxified. In addition, in FIG. 1, the incineration residue reduced in volume by the volume reduction processing apparatus is melt-processed by the electric furnace, but the present invention is not limited to the method according to this flow. For example, the incineration ash generated by the combustion by the volume reducing apparatus can be solidified by using cement or the like, or can be melted by the combustion energy of oil or gas.

FIG. 2 is an explanatory view showing an example of the volume reduction processing apparatus of the present invention, and FIG. 3 is a sectional view taken along line AA of the volume reduction processing apparatus. As is apparent in FIG. 2, the main part of the device is constituted by the conveyor 22. A preferred embodiment of the conveyer 22 has a form in which vessels for accommodating shredder dust are endlessly connected in order to burn and incinerate the shredder dust. And this conveyor 2
2. That is, the bottom of the vessel has a loss 25, which is configured to endlessly circulate around a combustion furnace 24 described later. If the conveyor 22 is not in the shape of a vessel, it is necessary to provide a shredder dust dropout prevention plate 28 on at least both side walls thereof. Also, Lost 25
The opening structure may be either parallel or orthogonal to the moving direction of the conveyor 22, or may be a grid-like opening, and the opening interval can be set arbitrarily.

The conveyor 22 circulates, and a combustion furnace body 24 is arranged just inside thereof. The combustion furnace main body 24 includes a wind box 15 and a combustion chamber 26. The wind box is a specific area of the conveyor 22, that is, a waste plastics supply hopper-16.
And a parallel moving part starting from the ignition device 13 (combustion area)
Is provided as a combustion gas suction wind box 15. A combustion chamber 26 is connected to the lower side of the wind box 15. In the combustion chamber 26, one or more gas blowing nozzles 29 are arranged on the floor surface or the side wall surface, and the gas is intermittently or continuously blown from the nozzles 29. The arrow 23 in the figure indicates the flow direction of the combustion gas, and this combustion gas is a combustion exhaust gas suction hole.
Sucked from 27. In addition, in the wind box 15,
A secondary ignition device 14 is provided.

An example of the processing method of the present invention for reducing the volume of waste plastics such as shredder dust by using such a volume reducing apparatus will be described with reference to FIG. First, in the circulating conveyor 22, the supply hopper
Shredder dust 21 is cut out from 16 and continuously deposited to a predetermined thickness. Next, the shredder dust 21 is ignited and burned by the ignition device 13 from the accumulated shredder dust 21 layer, and at the same time, the wind box 15 is discharged from the combustion furnace main body 24 provided on the lower surface side of the conveyor 22.
The combustion exhaust gas is sucked into the combustion chamber 26 through. By this operation, the shredder dust 21 is combusted continuously by receiving the forced supply of air. At the same time, for the combustion exhaust gas (combustion gas including unburned gas) sucked into the combustion chamber 26, air is supplied from one or more gas blowing nozzles 29 provided on the floor surface or side wall surface of the combustion chamber 26. It is blown into the combustion chamber 26 intermittently or continuously. As a result, the exhaust gas in the combustion chamber 26 is further agitated, and complete combustion of the combustible material can be realized. Further, if the air containing ammonia is used here, denitration becomes possible at the same time as complete combustion.

As described above, the present invention replaces the conventional fluidized-bed furnace as a combustion furnace and replaces it with the above-mentioned volume reduction processing apparatus 1
Is adopted, and has the following effects. (1) The combustible material contained in the shredder dust can be completely burned. As shown in FIG. 2, the volume reduction processing apparatus according to the present invention ignites and burns the surface layer of shredder dust charged and accumulated on a conveyor by an igniter, and at the same time, burns the combustion gas through a wind box. It is configured to suck on the bottom side of the bottom of the rostrul, and one or more gas blowing nozzles are provided on the floor surface or side wall surface of the combustion chamber formed under the rostrut, and intermittently or from this nozzle. The exhaust gas in the combustion chamber is agitated by continuously blowing the gas. With such a configuration, the shredder dust that has ignited is burned at the stage where the plastics with a lower ignition temperature in the upper layer are burned and liquefied and vaporized, and the plastics and rubbers with a higher ignition temperature are gradually burned. While changing
The combustion position moves to the lower part of the deposited layer in sequence. When such a combustion furnace system is adopted, the amount of air required for the combustion of shredder dust can be arbitrarily selected, so that stable combustion processing can be performed.

In the present invention, the combustion chamber of the combustion furnace body is divided into a plurality of chambers (a gasification combustion chamber, an alternate combustion chamber, a cooling chamber) corresponding to the combustion region of the conveyor, and each chamber has a temperature It can also be adopted in a method of sucking different combustion exhaust gases.

In the present invention, when supplying waste plastics, a substance having a high melting point may be interposed as a bedding just above the rostrur for the purpose of heat resistance protection. As the bedding, it is preferable to use quicklime or limestone. Such quick lime or limestone is the NO in the combustion exhaust gas.
_This is because gases such as _{X 2} , SO _X , chlorine, and dioxin can be reduced, and when a melting process using an electric furnace as a subsequent process is adopted, it becomes an effective flux for incineration ash melting. The quicklime or limestone or slaked lime can also be premixed with shredder dust.

In the present invention, in order to perform the combustion of the shredder dust more completely, a secondary ignition device is installed in the wind box according to the components and the amount of the organic matter contained in the shredder dust, and the secondary ignition device is installed in the wind box. The flue gas may be burned more completely. This 2
As the next ignition device, a burner is inserted in the side wall of the wind box, and an oil pan is installed in the wind box, and the oil is gasified while continuously supplying oil to this oil pan. It is possible to use a burnable type.

(2) No problem occurs in the shredder dust combustion environment. As described above, in the combustion process by the volume reduction processing device, since the combustion exhaust gas is sucked into the wind box of the combustion furnace body, the vicinity of the surface layer of the shredder dust in the conveyor is constantly in a negative pressure state compared to the atmosphere. , The combustion exhaust gas does not leak to the atmosphere. Therefore, the harmful gases such as NO _X , SO _X , chlorine and dioxin contained in the combustion exhaust gas flow into the combustion chamber body equipped with the wind box without leaking to the atmosphere.

(3) Shredder dust can be incinerated continuously. The volume reduction processing apparatus as described above can be put to practical use in a batch type combustion furnace composed of a single conveyor, a wind box and a combustion chamber.
It is more preferable to be configured by a combustion furnace of a type in which a plurality of conveyors are connected and circulated in an endless manner as shown in FIG. The reason for this is that this type of combustion furnace can continuously incinerate waste plastics. Further, in this type of combustion furnace, in addition to improving the combustion efficiency, the temperature of the combustion exhaust gas becomes constant, which facilitates energy recovery and detoxification treatment of exhaust gas in the post process. further,
This type of combustion furnace has a structure in which waste plastics are ignited and burned until they are discharged as incineration ash, because the heat generated by combustion is easily dispersed, so the maximum combustion temperature can be kept low. Therefore, it is possible to reduce the burden on the refractory material forming the wind box and the combustion chamber. In addition, in this type of combustion furnace, it is desirable to appropriately adjust the connecting length of the wind box and the moving speed of the conveyor according to the amount of waste plastics to be processed.
Install one or more secondary ignition devices.

[0020]

As described above, according to the present invention, it is possible to efficiently and safely completely combustible substances contained in shredder dust while maintaining a stable furnace environment, and to significantly reduce shredder dust. The volume reduction can be achieved. Further, according to the present invention, by stirring the exhaust gas in the combustion chamber, it is possible to promote complete combustion and prevent the generation of harmful substances such as dioxins. That is, the present invention is most effective as a volume reduction treatment system for shredder dust, and is extremely useful industrially.

[Brief description of drawings]

FIG. 1 is a process flow explanatory view showing an example of shredder dust processing using a volume reduction processing apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a volume reduction processing device of the present invention.

FIG. 3 is a sectional view taken along line AA of the volume reduction processing apparatus of the present invention shown in FIG.

[Explanation of symbols]

 1 Volume Reduction Processing Device 2 Sorting Machine 13 Ignition Device 14 Secondary Ignition Device 15 Wind Box 16 Waste Plastic Supply Hopper 21 Shredder Dust 22 Conveyor 24 Combustion Furnace Main Body 25 Lostru 26 Combustion Chamber 27 Combustion Exhaust Gas Suction Hole 29 Gas Injection nozzle

Claims (5)

[Claims] 1. A device for reducing the volume by burning and incinerating waste plastics, which comprises: On the conveyor whose bottom is a rustle, waste plastics are continuously charged to form a deposited layer, and the waste plastics are ignited from above and the waste plastics are sequentially burned at the same time, By sucking the combustion gas toward the lower surface of the conveyor at the bottom of the conveyor, it is configured to assist the self-combustion of the waste plastic deposition layer, and One or more gas blowing nozzles are arranged on the floor surface or the side wall surface of the combustion chamber formed under the roster, and the gas is intermittently or continuously blown from this nozzle. Waste plastics volume reduction processing equipment. 2. A method for reducing the volume of waste plastics by incinerating the waste plastics in a combustion furnace, wherein the combustion and incineration of the waste plastics comprises: Waste plastics are continuously charged while being continuously charged on a conveyor that is operated intermittently or continuously while the bottom portion is a rustle, and is adjusted according to the movement of the conveyor from the top of the layer thus obtained. Then, the waste plastics are sequentially ignited to sequentially burn, and at the same time, the combustion gas is sucked to the lower surface side of the conveyor at the bottom of the conveyor to assist self-combustion of the waste plastic deposition layer ,. On the other hand, from the gas blowing nozzle provided on the floor surface or the side wall surface of the combustion chamber formed under the conveyor loss, the gas is intermittently or continuously blown into the combustion chamber. Volume reduction treatment method for waste plastics. 3. The volume-reducing method according to claim 2, wherein the waste plastics are charged and deposited on the bottom portion of the conveyor with a bedding. 4. The volume-reducing method according to claim 3, wherein lumpy quicklime or limestone is used as the bedding. 5. The volume reduction treatment according to claim 2, wherein the waste plastics are mixed with at least one of quick lime, limestone, and slaked lime in advance. Method.