JP2000192050A - Discharge port structure of carbonization oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge port structure whereby the carbonization product discharged from a carbonization oven can be cooled without being oxidized. SOLUTION: To cool a carbonization product a', the lower end of a cylindrical discharge chute 15 of a carbonization rotary kiln 1 is submerged in a cistern 16 so as to directly feed the product a' into the cistern. A slurry b in the cistern 16 is introduced into the chute 15 in the peripheral tangential direction by a pump 19 to thereby prevent the deposition of the product a' on the inside surface of the chute 15 and to evolve a vortex on the surface of water in the cistern 16. The product a' is caught up in the vortex and is immersed in the water. Thus, in spite of its low specific gravity and high hydrophobicity, the product a' can be smoothly introduced into the cistern 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge structure of a carbonization furnace for carbonizing a material to be carbonized such as RDF or combustible waste to obtain charcoal.

[0002]

2. Description of the Related Art Conventionally, many technologies have been developed for selectively collecting combustible waste from general waste (garbage) and reducing or further shaping the combustible waste into fuel or solid fuel (RDF). I have. This RDF is burned in a combustion boiler and used for power generation and the like.

By the way, the above combustible wastes are composed of various kinds, and especially, plastics are contained in the combustible wastes, and among the plastics, vinyl chloride and polypropylene are often contained in a relatively large amount. . This vinyl chloride-based plastic can be semi-molten during the volume reduction process, which is convenient for obtaining a molded product.

On the other hand, since vinyl chloride plastics generate a large amount of chlorine gas during combustion, the combustion exhaust gas is usually treated by an exhaust gas treatment device. That is, slaked lime is supplied to neutralize and collect chlorine gas.

[0005] Therefore, an exhaust gas treatment device using a large amount of slaked lime is required, which results in an increase in the size of the exhaust gas treatment device, an increase in equipment costs, and an increase in running costs. Further, since the piping to the combustion furnace or the exhaust gas treatment device or the heat exchange tube of the combustion boiler is exposed to a large amount of chlorine hydrogen, there is a problem that corrosion progresses quickly and hinders long-term stable operation.

[0006] In order to solve these problems, a method has recently been proposed for producing a directly dechlorinated carbide from combustible waste or a dechlorinated carbide from RDF.

There are various types of carbonization furnaces, such as a batch type and a continuous type. In the case of the continuous type, there are a type in which the furnace body is fixed and does not rotate, and a type in which the furnace body rotates. In the case of the former fixed type, the furnace is provided with transfer means such as an apron conveyor for placing and transferring the material to be carbonized and a screw conveyor for transferring the material to be rotated by rotation. The carbonized material is discharged while being transported inside. In the latter case, a rotary kiln is generally used, and by rotating the furnace body, the carbide is transferred while rolling the carbide to be transferred to the discharge side. As a heating method, there are a direct heating method in which a high-temperature gas is supplied into a furnace and a combustion gas generated by a burner in the furnace, and an indirect heating method in which a heating jacket or a heating tube is provided.

As an example of the continuous carbonization apparatus, Japanese Patent Application Laid-Open No. 6-307772 can be cited. This is a rotary kiln, which is of a direct heating type using a burner, and is provided with an inlet hood and an outlet hood at an inlet end and an outlet end of a furnace body, respectively. Inlet hood has feeder (carbonized material) supply device, outlet hood has burner,
A product (carbide) discharge device is provided. And
The discharge device is provided with a steam supply pipe.

In this carbonization furnace, the kiln body is maintained at a high temperature (several hundred degrees Celsius) by a burner, and the raw material is steamed in a low oxygen state to produce carbide, and the obtained carbide is discharged by a discharge device. Discharging. Also, at the time of discharge, steam is supplied by a steam supply pipe in the discharge device to cool the carbide.

[0010] At this time, if the carbide is exposed to air at a high temperature, it burns and becomes ash, but since it is cooled by steam, it hardly oxidizes even when it comes into contact with air. Further, even if the inside of the discharge device becomes negative pressure, since the steam is continuously supplied into the discharge device, no outside air flows into the main body and the raw material is not excessively oxidized. I have.

Japanese Patent Publication No. 55-5005 discloses a discharge chute provided at a discharge opening of the incinerator main body and a water seal of the discharge chute in order to reliably prevent outside air from flowing into the incinerator main body. It is disclosed.

[0012]

The prior art described in the above-mentioned publication discloses that cooling is carried out by steam, so that it is hardly oxidized. However, steam cannot provide sufficient and smooth cooling, and is not a little. It keeps the oxidation, and if it is oxidized, the quality is deteriorated, and in some cases, there is a risk of fire. For this reason, since the water in the water tank has a large heat capacity, it is conceivable that the conventional technique is combined with the technique described in the above-mentioned publication to discharge the carbide into the water by the discharge chute.

However, a new problem arises here. That is, since the carbide has a low specific gravity and has hydrophobicity, a new problem arises in that the carbide floats on the water surface and the discharge chute is blocked. Particularly, in a rotary kiln, the raw material is transported to the outlet side by rolling, so that the raw material is broken and fined at that time, and the carbide as a product is more likely to float on the water surface.

An object of the present invention is to smoothly cool carbides discharged from a carbonization furnace without being oxidized.

[0015]

Means for Solving the Problems To solve the above-mentioned problems, according to the present invention, first, carbides discharged from a carbonization furnace are cooled in a water tank. The cooling of the water tank with water is performed with water having a large heat capacity as compared with steam, so that the efficiency of the cooling is high, and therefore the water is cooled smoothly without being oxidized.

Next, according to the present invention, the carbide sent to the water tank is wetted to form a slurry. If it is in a slurry state, it is guided smoothly into the water tank.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, a discharge means of a carbonization furnace for heating and carbonizing a material to be carbonized at a high temperature is provided with a means for discharging the carbide of the material to be carbonized. In a discharge structure of a carbonization furnace provided with cooling means, the discharge means has a tubular discharge chute downward from the discharge port, and the cooling means comprises a water tank in which a lower end of the discharge chute is submerged, and a discharge tank for discharging the water. And a pipe for supplying water for wetting the carbide into the chute.

In this configuration, the supply pipe is connected to the water tank, and a circulation pump is interposed in the supply pipe so that the slurry in the water tank is supplied to the discharge chute as the wet water by the circulation pump. In this case, new carbide passing through the discharge chute is entangled with the carbide already adjusted to water, and the carbide sinks more smoothly in the water tank.

If the discharge chute has a circular cross section and the direction of water supply from the supply pipe is tangential to the periphery of the discharge chute, the supply slurry or water is fed along the inner surface of the discharge chute. In addition to preventing the carbide from adhering to the inner surface of the tank, a vortex is generated on the water surface of the water tank, and this vortex entrains the carbide and sinks in the water. Get in.

[0020]

1 to 3 show an embodiment in which a rotary kiln is used to perform indirect heating. In the figure, reference numeral 1 denotes a rotary kiln, which is provided with a body portion 2, an entrance side plate 3, and an exit side plate 4. The inlet side plate 3 is rotatably supported by a driving roller 5, and the outlet side plate 4 is rotatably supported by a driven roller 6. 7 is an apparatus for supplying a raw material (carbonized substance) a provided through the side plate 3 on the inlet side, and 8 is a side plate 4 on the outlet side.
A discharge device 9 for carbides a ′ provided through the cylindrical body 9 is a cylindrical body that covers the body 2.

The supply device 7 and the discharge device 8 can maintain a sealed state of a screw conveyor or the like.
The rotating shaft is hollow, and nitrogen gas t is introduced from the hollow shaft and discharged into the body 2. The cylindrical body 9
Is provided with a high-temperature gas inlet 10 and a high-temperature gas outlet 11, and the high-temperature gas s indirectly heats the carbonized material a in the body 2. If the heating heat is insufficient, a small amount of air is supplied into the rotary kiln 1 to
Alternatively, a calorific value may be supplemented by burning a pyrolysis gas described later. At this time, although not shown, an auxiliary air inlet is provided in the casing 7a of the supply device 7.

Although not shown, a heat-resistant material is provided on the inner surface of the cylindrical body 9 and a lifter is provided on the inner surface of the body portion 2 as in the prior art. At the end of the body unit 2 on the side of the discharge device 8, a plurality of scraping plates 12 having an L-shaped cross section are provided at equal intervals in the circumferential direction, and the discharge device 8 is scraped up by the scraping plate 12. Notch 13 for receiving carbide a '
Is provided. The discharge device 8 is provided with a gas outlet 14 for discharging the nitrogen gas t and the carbonized gas generated in the body 2 and a cylindrical discharge chute 15 for discharging the carbide downward. .

Next to the rotary kiln 1, that is, below the discharge device 8, there is provided a cooling device 16 composed of a water tank for storing a slurry b consisting of the carbide a ′ and water discharged from the rotary kiln 1. Discharge chute 15
Is sealed by the slurry (water) in the cooling device 16.

The cooling device 16 is, as shown in FIG.
It has a stirrer 17 for stirring the slurry b, a screw conveyor 18 for discharging carbide in the slurry, and a pump 19 for circulating the slurry b. Further, the discharge chute 15 is provided with a cooling water inlet pipe 20 and a slurry inlet pipe 21.
9 is connected. As shown in FIG. 3, the discharge ports of the inlet pipes 20 and 21 have discharge chutes 15 having a circular cross section.
Are arranged in a tangential direction. The discharge port may be a jet nozzle.

This embodiment has the above configuration.
The effect will be described for the case where the material to be carbide a is RDF. RDF is a solid fuel produced from refuse, and its size varies depending on the type of refuse used, the production apparatus, and the like. In this case, the size is 20mm in diameter x 3 in length
One having a thickness of about 0 mm was used. The components contained metals and chlorine.

A nitrogen gas t is introduced into the rotary kiln 1 and the rotary kiln rotates while maintaining a state of high temperature (about 400 to 650 ° C.) substantially without oxygen. That is, a high-temperature gas s is supplied from the gas inlet 10 of the cylinder 9 and discharged from the gas outlet 11 to maintain a high-temperature state, and is substantially controlled by the nitrogen gas t introduced through the supply device 7 and the discharge device 8. The rotary kiln 1 is rotated by keeping the oxygen-free state and rotating the driving roller 5.

In such a state, the RDF is
When (carbonized material a) is supplied into the body portion 2, the RDF is lifted by a lifter (not shown) and gradually moves toward the discharge device 8 while rolling in the body portion 2.

Here, the RDF is roasted because the inside of the rotary kiln 1 is high-temperature and oxygen-free, and becomes a pyrolysis gas (CO, hydrocarbon gas, etc.) and a solid carbide a '. The refuse that is the source of RDF contains organic chlorides such as vinyl chloride containers and vinylidene chloride wraps, and inorganic chlorides such as salt.
Organic chlorides are thermally decomposed into chlorine gas or hydrogen chloride gas g, and inorganic chlorides remain in the carbide a '. Also, RD
F or the carbide a 'is broken and fine during rolling.

The pyrolysis gas g is discharged from a gas outlet provided in the discharge device 8 together with the nitrogen gas t, and is burned by an exhaust gas combustion device outside the system. The gas s discharged from the gas outlet of the cylinder 9 is also introduced into the combustion device, and after the gas temperature is increased, the high-temperature gas in the cylinder 9 is directly or through an exhaust gas treatment device. Entrance 1
Cycled to zero.

On the other hand, the solid carbide a ′ is
2, the liquid enters the discharge device 8, is transferred by a screw through the device 8, and drops from the discharge chute 15 to the cooling device 16. The lower end of the discharge chute 15 is sealed with water (slurry b) in the cooling device 16 as described above.

At this time, since the carbide a 'is light and hydrophobic, it does not sink into the water, and the discharge chute 15 may be closed. However, the discharge chute 15 is provided with a cooling water inlet pipe 20. Cooling water c is added from here, and the carbide a 'is cooled in advance and mixed with the water c, so that there is no danger of clogging. Further, a slurry inlet pipe 21 is provided in the discharge chute 15, and the cooling device 1 is
Since the slurry b in 6 is supplied, a new carbide a 'is involved by the carbide a' already mixed with the water c and sinks in the cooling water tank 16, so that the risk of the blockage is further reduced. Further, the cross section of the discharge chute 15 is circular, and the cooling water inlet pipe 20 and the slurry inlet pipe 21 are
Since it is arranged tangentially around the discharge chute 15,
The cooling water c and the slurry b fall in the chute 1 as a swirling flow to prevent the carbide a 'from adhering to the inner surface of the chute 15 and the possibility of clogging is further reduced. For this reason, even if it is a lightweight and hydrophobic carbide a ', since it is a swirling flow,
The swirling flow is forcibly involved and sinks below the surface of the water, so that there is no danger of blockage.

The carbide a ′ made from RDF contains chlorides and metals, but since the slurry b is at a high temperature, the chlorides are easily dissolved in water and the carbides a ′ having a low chloride content are used. 'Can get. In addition, among metals, eluted metals (eg, zinc, copper, aluminum, etc.) also dissolve in water, so that the content of metals can be reduced. In addition, since the carbide a 'is broken and made fine by being rolled by the rotary kiln 1, it is convenient for removing chlorides and elutable metals. The slurry b
Since the cooling water c is supplied from the cooling water inlet pipe 20, the chloride concentration in the slurry b is suppressed, and the chloride is easily dissolved in the slurry b.

The carbide a ′ from which chlorides and leaching metals have been removed in this way is discharged from the cooling device 6 by the screw conveyor 18. The fine carbide a ′ is
Since it is difficult for the screw conveyor 18 to discharge the slurry b, a part of the slurry b circulated by the circulation pump 19 is discharged to discharge the fine carbide a ′. Exhausted carbide a '
Still has a lot of water, it is separated by a solid-liquid separator, the liquid containing chlorides and eluting metals is sent to a water treatment unit, and the carbide a 'is sent to a dehydration unit and a drying unit. It is sent to remove water.

The carbide a 'can be sent from the cooling device 16 to a wet pulverizer, and the carbide a' can be further finely pulverized to more completely remove chlorides and elutable metals (Japanese Patent Application No. Hei 10 (1998) -108). -23795).

Although only the indirect heating type rotary kiln 1 has been described above, a fixed continuous carbonizing furnace or a batch type carbonizing furnace can be used, and the heating type is also limited to the indirect heating type. Nor. For example, as shown in FIG. 4, the present invention can also be adopted in a fixed-type continuous carbonization furnace 30 in which the material to be carbonized a is stirred by the stirring blade 31. In the figure, the same symbols as those described above are the same, and the carbide a ′ is continuously fed into the water tank 16 in a sealed state by the rotary valve 32.

Further, a forcible feeder such as a screw conveyor may be arranged in the discharge device 8 in the vertical direction, and the carbide a 'may be forcibly pushed downward by the forcible feed and fed into the cooling device 16. .

[0037]

According to the present invention, as described above, the carbide is made into a slurry (wet state) and sent into the water tank to be cooled, so that the carbide is smoothly fed into the water tank and cooled smoothly. . Therefore, high-quality carbide can be obtained without oxidation during cooling.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of one embodiment.

FIG. 2 is an enlarged schematic view of a main part of the embodiment.

FIG. 3 is a plan view of a main part cut away from FIG. 2;

FIG. 4 is a schematic view of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary kiln 2 Body part 3 Inlet side plate 4 Outlet side plate 5 Driving roller 6 Follower roller 7 Supply device 8 Discharge device 9 Cylindrical body 10 Gas inlet 11 Gas outlet 12 Raised plate 13 Notch 14 Gas outlet 15 Discharge Chute 16 Cooling device (water tank) 17 Stirrer 18 Screw conveyor 19 Pump 20 Cooling water inlet pipe 21 Slurry inlet pipe a Carbide a 'Carbide b Slurry c Water g Pyrolysis gas s Hot gas t Nitrogen gas

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C10L 5/48 F27B 7/33 4K063 F27B 7/33 F27D 3/08 F27D 3/08 15/02 H 15 / 02 B09B 3/00 302F (72) Inventor Haruyuki Ono 1-112-19 Kitahorie, Nishi-ku, Osaka-shi Inside Kurimoto Iron Works Co., Ltd. (72) Inventor Kazuhiko Hizuka 1-12-19, Kitahorie, Nishi-ku, Osaka-shi Shares Company Kurimoto Iron Works F-term (reference) 4D004 AA07 AA46 AC04 BA03 CA15 CA26 CA32 CB09 CB26 CB31 CB42 CB43 CB45 CC03 4H012 HA01 HA06 HB01 HB07 HB09 HB10 4H015 AA01 AA02 AA17 AB01 BA03 BA12 ABA4A03 BA03 BB00 4K063 AA01 AA18 BA13 CA02 CA03 HA61

Claims (3)

[Claims] 1. A discharge means (8) for a carbide (a ′) of a material to be carbide (a) is provided at an outlet of a carbonization furnace (1) and a carbonization furnace (30) for heating and carbonizing the material to be carbide (a) at a high temperature. The discharge means 8 has a tubular discharge chute 15 directed downward from the discharge port, and the cooling means 16 is provided with a cooling means 16 of the discharge chute 15. A water tank 16 whose lower end is submerged, and a pipe 2 for supplying water for wetting the carbide a ′ into its discharge chute 15
0, 21. An outlet structure for a carbonization furnace. 2. The supply pipe 21 is connected to the water tank 16 and a circulation pump 19 is provided in the supply pipe 21. The circulation pump 19 turns the slurry in the water tank 16 into the discharge chute 15 as the wet water. The outlet structure of a carbonization furnace according to claim 1, wherein the supply is supplied to the inside of the furnace. 3. The discharge chute 15 has a circular cross section, and the direction of water supply from the supply pipes 20 and 21 is tangential to the periphery of the discharge chute. 2. The outlet structure of the carbonization furnace according to 1.