JP3096623B2 - Melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical melting furnace such as a waste melting furnace and a blast furnace.

[0002]

2. Description of the Related Art Conventionally, a furnace body for burning and melting waste injected from above at the bottom is formed in a lower constriction to form a funnel, and a furnace is provided below the funnel toward a melting part. A vertical melting furnace having a tuyere for blowing a working gas has been used.

[0003]

Conventionally, in a melting furnace, when wastes are caught on a furnace wall of a funnel and a so-called hanging of a shelf is caused, a support from a lower tuyere is used until the hanging of the shelf is canceled. The fuel was increased and the temperature of the lower melt was maintained. Since high-temperature exhaust gas rises from the lower part of the shelf made of waste, it gradually undergoes a reaction such as combustion, and the shelf is disintegrated naturally without being able to support the upper waste. However, collapsing the shelves in such a way requires a large amount of auxiliary fuel, and during that time the capacity of the waste is reduced. Therefore, an object of the present invention is to provide a vertical melting furnace capable of solving the above-mentioned problems and enabling the stable operation of the melting furnace and reducing the amount of auxiliary fuel used, while preventing the occurrence of hanging on a shelf. is there.

[0004]

SUMMARY OF THE INVENTION A feature of the present invention for the above purpose is to provide a furnace at the upper end of a funnel above a tuyere.
Supplying combustion gas to an auxiliary combustion zone near the wall,
Burning the nearby charge, the site of the funnel (S)
(2 ) A second tuyere for losing the support of the shelf to be generated in (1) (corresponding to claim 1). In addition, the second
The tuyere, blow the fluid along the inner wall of the funnel portion
It may be formed so as to be deflected in the same direction so as to fit (corresponding to claim 2).

[0005]

Therefore, according to the characteristic structure of the melting furnace of the present invention,
The ease of hanging the shelves varies depending on the moisture, properties, shape, etc. of the charge, but the shape of the furnace becomes narrower below the furnace, so that the hanging of the shelves is likely to occur at the narrowed portion. Bridging receives the frictional force of the refractory surface waste funnel section, since it is the resulting to not fall down, may destabilize the frictional <br/> friction force of the refractory surface. Therefore, it is provided at the upper end of the funnel near the charge of the part where the shelves are hanging.
And the second oxygen-containing gas from the tuyere, the furnace wall near the auxiliary combustion
Near the furnace wall near the second tuyere when blown into the area
In the auxiliary combustion zone, the charge is burned, the shelf to be produced loses its support, and the charge descends again in the furnace (corresponding to claim 1). In addition, the second
The combustion gas blown from the tuyere of the inside of the inner wall
Lever is blown along the side, charge of the portion proximate to the funnel portion to the inner wall of the auxiliary combustion zone of the furnace wall near
Portion along burns, charge in the auxiliary combustion zone is released from the compacted, removed the frictional force against falling, have a hanging shelf
Can be effectively prevented (corresponding to claim 2).

[0006]

As a result of the above, with the melting furnace having the structure according to the first aspect of the present invention, the hanging of shelves can be prevented, so that it is possible to provide a stable furnace operation and a technique with less auxiliary fuel as a melting furnace. . Further, by adding the configuration according to the second aspect, it becomes possible to provide a melting furnace that is easy to operate for preventing hanging from a shelf.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a melting furnace according to the present invention is applied to a waste melting apparatus will be described below with reference to the drawings. As shown in FIG. 1, the waste melting treatment apparatus blows a combustion gas such as air or an oxygen-enriched gas for 2 minutes.
Waste melting furnace F provided with a plurality of tuyeres 3
A boiler 12 that burns and uses generated gas in the waste melting furnace F, a flue 11 that supplies the generated gas to the boiler 12, and a power generator 16 that generates power using steam generated by the boiler 12; A waste gas treatment device 13 for treating waste gas discharged from the boiler 12 is provided. In the waste melting furnace F, the furnace main body 1 that burns and melts a charge introduced from above at the bottom is formed in a lower constriction, and the inner wall of the waste melting furnace F is opened upward. A vertical furnace formed by forming a tapered part S as a funnel part having a shape and forming a pool 6 below the melting part 2, wherein a drying zone Z 1, a pyrolysis zone Z 2, Three treatment zones, a combustion melting zone Z3, are sequentially arranged from the upper side to the lower side. The region where the melting portion 2 is formed and the pool 6 form the combustion melting zone Z3. Each tuyere 3 is provided with a wind box 4 composed of an annular tube for receiving the supply of oxygen-enriched air preheated as the combustion gas and distributing it to each tuyere 3. Mouth 3
A tuyere tube 5 for blowing oxygen-enriched air is connected to each of them. A first tuyere 3a is disposed below the tapered portion S so as to supply the combustion gas to the melting portion 2; At the upper end of the section S, a second tuyere 3b is arranged to supply the combustion gas to an auxiliary combustion area A formed along the furnace wall by the supplied combustion gas. The first tuyere 3a is located near the upper surface of the pool 6 so as to blow the combustion gas toward the melting portion 2 so as to be inward of the tapered portion S and slightly below. The taper portion S is provided at a plurality of locations in the circumferential direction. Further, an auxiliary fuel supply pipe capable of supplying gaseous fuel such as propane is connected to the tuyere pipe 5 for supplying oxygen-enriched air to the first tuyere 3a. In the case where the combustible component is insufficient, it can be added and supplied as auxiliary fuel. As shown in FIG. 2, the second tuyere 3b is inclined in a horizontal plane toward the inside of the tapered portion S so that the fluid to be blown is swirled and blown along the inner wall of the tapered portion S. The taper portion S is provided at a plurality of locations in the circumferential direction. Since it is formed in this manner, the second
The oxygen-enriched air blown from the tuyere 3b is effectively supplied to the portion of the auxiliary combustion zone A along the furnace wall. The tuyere tube 5 for supplying oxygen-enriched air to the second tuyere 3b
Are connected to the auxiliary fuel supply pipes respectively.
If the combustion in the auxiliary combustion area A near the tuyere 3b is insufficient, auxiliary fuel can be added and supplied.
In addition, the combustion temperature in the auxiliary combustion area A is kept lower than that of the melting portion 2 to perform only partial combustion, thereby exhibiting the effect of preventing shelving and preventing damage to the furnace wall.

[0008] The waste collected by the garbage truck is put into a hopper 9 provided above the waste melting furnace F,
By alternately opening and closing the double damper mechanism 10 including the upper damper 10a and the lower damper 10b provided in the lower part of the hopper 9, the generated gas in the waste melting furnace F is prevented from blowing up to the hopper 9. While being fed into the waste melting furnace F. The waste put into the waste melting furnace F is dried in a drying zone Z1 maintained at about 300 ° C. to 500 ° C., and further descends in a pyrolysis zone Z2 maintained at about 500 ° C. to 800 ° C. Most of the volatile organic matter contained in the wastes rises and flows out of the pyrolysis zone Z2 through the drying zone Z1 as a combustible gas such as methane, hydrogen, carbon monoxide and the like as a generated gas thermally decomposed into carbon dioxide, and is gasified. The remaining residue is a combustion melting zone Z3 maintained at about 1500 ° C.
The combustibles in the residue are burned in the melting section 2 of the above, and are melted. Corrosive gas such as hydrogen chloride generated in the process of decomposing vinyl chloride and the like contained in the waste in the thermal decomposition zone Z2 passes through the boiler 12 and is supplied thereto in a reaction chamber also serving as a flue. After being neutralized with an alkali agent such as lime powder and fixed as salts such as calcium chloride, it is captured and removed by a bag filter following the reaction chamber. In the combustion / melting zone Z3, the combustible components of the pyrolysis residue of the waste which has been thrown in from the upper part of the waste melting furnace F and which has been dried and thermally decomposed are mainly injected into the combustion section 2 at the side of the combustion / melting zone Z3. The first tuyere 3a formed in the portion contacts the combustion gas supplied toward the upper surface of the pool 6 and performs a combustion reaction,
A high temperature and a high heat are generated, and at the same time, the combustibles remaining in the basin 6 also burn in the liquid. The heat causes non-combustible components in the pyrolysis residue, such as ash and inorganic substances, to be melted, and the molten slag flows down and accumulates in the pool 6, and at the same time, the pool 6 is kept warm. The molten slag overflows from an overflow port 7 a of a slag discharge section 7 provided on a side of the pool 6 and is discharged into a slag recovery device 8. At the same time, the heat generated in the combustion unit 2 is
It is subjected to a thermal decomposition process in the thermal decomposition zone Z2 and a drying process in the drying zone Z1. When the calorific value due to the combustion reaction is insufficient for the pyrolysis treatment and the drying treatment, a gas fuel such as methane gas or a fine powder fuel such as carbon powder is further added to the combustion gas as a tuyere. The first tuyere 3 is supplied and added to the pipe 5 from the auxiliary fuel supply pipe.
a to the melting portion 2. Further, the second tuyere 3b is provided at an upper end portion of the tapered portion S, and the combustion gas is thermally decomposed in the pyrolysis zone Z2 at this portion, and the second gas is contained in the pyrolysis residue. The combustible component in the pyrolysis residue in the auxiliary combustion region A in contact with the combustion gas is supplied to the portion of the furnace wall of the tapered portion S,
Since the waste there is destroyed, the hanging of the loaded waste is prevented. That is, the second tuyere 3b is compacted at the furnace wall where the waste moving from the upper part to the lower part is constricted, and the auxiliary combustion in the vicinity of the compacted part is prevented in order to prevent the shelf from hanging. The combustion gas is supplied to the region A, and the portion to be compacted, which causes the hanging of the shelf, is released from the compaction by the combustion reaction. As described above, since the shelves are prevented by providing the second tuyere 3b, the downward movement of the waste in the furnace becomes smooth, that is, the carbon of the gasification residue smoothly flows into the high temperature combustion section. Supplied to Oxygen or an oxygen-enriched gas is supplied thereto, and as a result, the melting furnace of the present invention can perform high-temperature combustion with little or no need of auxiliary fuel.

A slag discharge section 7 is provided on the side of the pool 6 and the molten slag overflows from an overflow port 7a and drops into a water cooling tank 8b storing cooling water from the slag discharge section 7. It is quenched and becomes granulated slag. A slag conveying device is provided at the bottom of the water cooling tank 8b to carry out the granulated slag, and the granulated slag is taken out by the slag conveying device at any time. The slag discharge section 7
The tip of the bottom of the overflow 7a is formed so as to protrude from the side wall 8a of the slag recovery device 8 immediately below the overflow slag, and the molten slag flows down from the overflow 7a continuously to the side wall 8a immediately below. Adhesion is prevented.

The boiler 12 has a water chamber 12c disposed in a combustion chamber 12b provided with a combustor 12a, and has a temperature of about 300 ° C. to 500 ° C. generated in the waste melting furnace F.
The combustible gas of the waste melting furnace F and the combustor 12
The high-temperature combustion gas which is supplied through the flue 11 formed between the a.
The exhaust gas is exhausted from the chimney 15 through an exhaust gas treatment device 13 such as d and a bag filter. The flue 11 is provided with a controllable oxygen or oxygen-containing gas supply port 11a for combustion for partially burning the generated gas inside the flue 11 so that the inflow air flows downstream of the flue 11. For example, when air is supplied from the supply port 11a, the flue 1
Part of the generated gas passing through 1 burns, and the temperature of the generated gas is avoided by the combustion heat generated at that time, so that the vaporized tar condenses in the flue 11 and adheres to the inner wall. To prevent that. The steam generated by the boiler 12 is stably supplied to a power generator 16 having a steam turbine 16a for driving a generator 16b.
The electric power generated in the above is used as electric power for operating the waste melting treatment apparatus, and surplus electric power is supplied to the outside.

[Another embodiment] Hereinafter, another embodiment will be described. The first tuyere 3a may be provided at a position where the first tuyere 3a blows directly into the well 6 or a position where the first tuyere 3a blows into a space formed between the melting portion 2 and the well 6. The first tuyere 3a may be provided at a position where the first tuyere 3a is directly blown into the melting part 2 above the lower end of the melting part 2. When providing at the first position,
The combustibles in the basin 6 can be burned in liquid, and when provided in the second position, the combustion gas is sprayed on the surface of the basin 6 to stir the basin 6. In addition, it is possible to further promote the maintenance of the temperature of the molten slag. If the molten slag is provided at the third position, the waste is high in calories, and the molten portion 2 can be expanded to a larger area. Further, the first tuyere 3a may be provided in a horizontal direction, and may be directed to the center of the furnace. Although the second tuyere 3b is provided in the horizontal plane in the above embodiment, it may be provided slightly downward.
Further, these may be provided so as to be blown toward the reactor core without swirling the combustion gas to be blown. That is, if the auxiliary combustion region A of the pyrolysis residue in contact with the combustion gas blown from the second tuyere 3b is formed discontinuously with the melting region 2 and at a portion close to the furnace wall. Good. Note that the second tuyere 3b may be arranged in a horizontal plane or slightly downward and inward of the tapered portion S to burn wastes in contact with the tapered portion S to form a gap. Since the hanging on the shelf can be prevented, the auxiliary combustion area A is formed along the furnace wall to eliminate the consolidation. The second tuyere 3b
Is such that the oxygen-enriched air to be blown is swirled and blown along the inner wall of the tapered portion S at a portion of the tapered portion S near a boundary between the thermal decomposition zone Z2 and the combustion and melting zone Z3. It may be provided obliquely downward toward the inside of the tapered portion S. Further, these may be provided in a horizontal plane toward the inside of the tapered portion S so that the oxygen-enriched air to be blown is swirled and blown inside the inner wall of the tapered portion S. May be provided.
Further, the second tuyere 3b is configured such that the oxygen-enriched air or air blown to the portion of the tapered portion S near the boundary between the thermal decomposition zone Z2 and the combustion / melting zone Z3 is formed at the center of the tapered portion S. May be provided in a horizontal plane or slightly downward toward the inside of the tapered portion S so as to be blown toward. In this case, the blowing of the oxygen-enriched air or air is performed along the furnace wall along the auxiliary combustion zone A.
The object of the present invention can be achieved by adjusting so that is formed at least partially. In the embodiment, auxiliary fuel such as gas or oil is added to the combustion gas blown from the first tuyere 3a. Alternatively, coke may be added to the input material. further,
As the combustion gas, air may be blown instead of the oxygen-enriched gas. In addition, the second tuyere 3b
Although the combustion gas blown from above is also preheated, it is also possible to blow it without preheating, and it is also possible to add auxiliary fuel and blow it in. When the auxiliary fuel is added and blown from the second tuyere 3b in this way, it is possible to sufficiently cope with a case where the temperature is abnormally lowered and the shelf is about to be suspended, such as when the calories of the waste are low.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a block diagram of a waste melting apparatus.

FIG. 2 is a cross-sectional view showing another embodiment of the second tuyere.

[Explanation of symbols]

 Reference Signs List 1 Furnace main body of melting furnace 2 Melting part of melting furnace 3a Tuyere 3b Second tuyere S Taper part of melting furnace

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23G 5/24 F23G 5/00

Claims (2)

(57) [Claims] 1. A furnace body (1), which burns and melts a charge charged from above at a bottom portion, is formed in a lower constriction to form a funnel portion (S) and a portion below the funnel portion (S). A vertical melting furnace provided with a tuyere (3a) for blowing a combustion gas toward a melting part (2), wherein an upper end of the funnel (S) above the tuyere (3a). The combustion gas is supplied to the auxiliary combustion area (A) near the furnace wall.
Then, the charge near the furnace wall is burned, and the funnel
Loses support of shelf to be created in part (S)
Melting furnace with the second tuyere to (3b) to. Wherein the second tuyere (3b), so as to blow the fluid along the inside of the inner wall of the funnel portion (S)
2. The melting furnace according to claim 1, wherein the melting furnace is formed so as to be deflected in the same direction.