JP2629111B2 - Waste 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 municipal solid waste, various industrial wastes, or intermediate products obtained by drying, incineration, crushing, etc., using a massive carbon-based combustible material such as coke as a heat source. The present invention relates to a waste melting furnace that is heated and melted and recovered as civil engineering material, concrete fine aggregate, and slag material for surface decorative aggregate.

[0002]

2. Description of the Related Art Conventionally, as a waste melting furnace, waste is charged from a top of a shaft furnace with a basicity adjusting agent such as limestone or silica stone, coke, and oxygen-containing gas or oxygen is introduced from a tuyere. The enriched gas is blown into the furnace, and the coke and carbonaceous matter generated by pyrolysis are burned at high temperature on the high-temperature hearth, and the furnace is sequentially lowered and melted in the drying zone, dry distillation gasification zone and combustion melting zone. Slag, high temperature combustion exhaust gas,
There is a structure in which the waste packed bed in the shaft rises as a counter flow, is discharged as a combustible gas, and is recovered as combustion heat.

[0003] The applicant of the present application has previously described Japanese Patent Application Laid-Open No. 2-3328.
In the No. 85 application, a tuyere is provided at a lower part of a furnace body in which an upper part is enlarged and an inner surface is formed at an angle equal to or larger than the angle of repose of the charged bulk carbonaceous fuel, and a tap hole is provided at a position lower than the tuyere. From the upper center, insert a cylinder of waste, bulk carbonaceous fuel and basicity adjuster so that its lower end reaches a position higher than the tuyere level, and further, around this insertion cylinder, the bulk carbonaceous fuel We applied for a waste melting furnace that has a charging port and discharges combustion gas from above. This makes it possible to reliably supply the bulk carbon-based fuel, which is a heat source, to the high-temperature hearth below the waste packed bed, and because the tuyere at the bottom is provided below the cone with a small inside diameter, Air or oxygen-enriched air for forming the hearth can reliably reach the core, and a high-temperature hearth can be reliably formed.
A melting furnace with good operation efficiency can be obtained.

Further, in a waste melting furnace having such a furnace body, a space region is formed above a bulk carbon-based fuel filling region surrounding a waste filling region formed above a hearth high temperature region, Thus, there has been proposed a melting furnace in which the permeability of the massive carbon-based fuel due to the mutual adhesion of dust and the deterioration of the unloading of the massive carbon-based fuel are prevented.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an improvement in such a waste melting furnace, which stably melts waste with poor air permeability while suppressing dust scattering, and preheat drying of exhaust gas. An object of the present invention is to provide a waste melting furnace with high thermal efficiency by improving the effect.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a tuyere is provided at a lower portion of a furnace body in which an upper portion is enlarged and an inner surface is formed at an angle equal to or larger than the angle of repose of the charged bulk carbonaceous fuel. A hot water outlet is provided, and a charging cylinder for charging the waste, the massive carbonaceous fuel and the basicity modifier from the upper center of the furnace body is inserted so that its lower end reaches a position higher than the tuyere level, and In a waste melting furnace in which a charging inlet for massive carbon-based fuel is provided around the insertion tube and the combustion gas is discharged from above , the furnace inner surface in a range from the tuyere to the lower end of the charging tube is substantially cylindrical. It is characterized by being formed in a shape.

[0007]

The high temperature exhaust gas from the high temperature hearth area at the lower part of the furnace is forced to flow in the vicinity of the waste packed bed because the furnace body in the packed area mainly composed of waste is narrowed down into a cylindrical shape. Therefore, the preheat drying of the waste is promoted by the high-temperature exhaust gas.

[0008]

FIG. 1 shows an embodiment of the present invention, in which a charging system is indicated by a solid line and an exhaust gas system is indicated by a broken line.

The waste melting furnace 10 has an inner upper surface having an inclination angle of 7 degrees.
It has a furnace body 1 formed wide at 0 degrees. The lower peripheral surface of the furnace body 1 is provided with two-stage tuyeres 2 and 3, and a melt outlet 4 is disposed below the tuyeres 2 and 3. A charging cylinder 5 for charging a charge mainly composed of waste is inserted from above the center of the furnace body 1, and coke charging inlets 6 are formed at a plurality of locations on the outer periphery of the furnace body 1. An exhaust gas outlet 7 is provided in the middle. Between the substantially lower end of the charging cylinder 5 of the furnace body 1 and the upper tuyere 2, a shaft portion 8 having a substantially cylindrical inner surface of the furnace is formed.

In operation of the waste melting furnace 10,
From the waste charging cylinder 5, as shown by the charging system shown by the solid line in the figure, waste A, 40 to 80% by weight of the total coke B, central coke B, and limestone C as a basicity adjusting agent Is mixed and charged, and immediately below the charging area 9 mainly composed of waste.
Is formed. In addition, lump coke having a diameter of 2 to 80 mm is charged from the coke charging inlet 6 around the furnace, and a coke charging area 11 by the charged coke is formed around the charging area 9 mainly composed of waste. Space 1 above
Form 2

The coke charged from the peripheral coke inlet 6 forms a coke filling zone 11 where heat exchange is performed while descending with the combustion exhaust gas discharged to the exhaust gas outlet 7, and the coke gradually increases. When the temperature rises to reach the upper tuyere 2, part of the CO gas in the combustion exhaust gas rising from below is preferentially burned, and the obtained heat is further heated to a higher temperature and the oxygen injected Some of them burn coke distributed around the inside of the charging cylinder.

At this point, softening and melting of ash and incombustibles have begun, and the rising gas is relatively difficult to pass through. However, the peripheral wall has a cylindrical shaft portion 8. Due to the narrowed ring-shaped coke layer formed on the shaft portion 8, the rising gas maintains a uniform flow in the circumferential direction, and the flow velocity is increased, so that the rising gas also passes through the waste filling area 9. This promotes heat transfer.

The charged coke is burned by the air from the upper tuyere 2, and 700 to 10 at the lower center of the charged cylinder 5.
A high-temperature furnace that reaches 00 ° C. and further uniformly burns the central coke of the coke supplied into the charging cylinder by the preheated air blown from the lower tuyere 3 to stably maintain a high-temperature coke grate. A floor 13 is formed. The charged coke becomes red-hot coke by the time it reaches the high-temperature hearth 13, and ash and incombustibles rapidly soften and melt the voids of the coke grate by radiant heat and high-temperature combustion exhaust gas resulting from the coke combustion. It is extracted from the gate 4.

Further, the amount of entrained dust in the exhaust gas E discharged from the exhaust gas discharge port 7 is reduced by the formation of the space 12, and passes through the system shown by the dotted line, through the secondary combustion chamber 14, the air preheater 15, Further, it is discharged into the atmosphere via a purifier (not shown). Reference numeral 16 denotes a blower for blowing air preheated by the air preheater 15 to the tuyeres 2 and 3.

[0015]

According to the present invention, the following effects can be obtained.

(1) A high-temperature hearth is reliably formed, and even if the air-impermeable material is poorly air-permeable, dust can be prevented from scattering while maintaining the air-permeability and the unloading in the furnace so that the melting process can be stably performed. By improving the drying effect, a waste melting furnace with high thermal efficiency can be realized.

(2) Since the pre-heating of the charged waste is sufficiently performed, the fuel cost can be reduced.

(3) Exhaust gas generated from the high-temperature hearth is passed through the bulk fuel zone around the waste-filled zone with good air permeability, so that dust scattering from waste can be minimized.
Even the dust once scattered is captured in the process of passing through the packed bed of massive carbon-based fuel, and accompanying dust can be suppressed, and the gas flow in the furnace is stabilized, so that the furnace can be operated stably.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the invention together with a charging system and an exhaust gas system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Furnace body 2 and 3 Tuyere 4 Hot tap 5 Waste charging cylinder 6 Coke charging inlet 7 Exhaust gas discharge 8 Approximately cylindrical shaft part 9 Waste filling area 10 Melting furnace 11 Coke filling area 12 Upper space area 13 High temperature Hearth 14 secondary combustion chamber 15 air preheater 16 push-in blower

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Sou Ono 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Shunji Kuezuka Kitakyushu-shi, Fukuoka 46-59 Ohara Nakahara, Tobata-ku Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Kunihiro Watanabe 59-46 Nakahara Oaza, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Plant Design Co., Ltd. (56) References JP-A-3-5611 (JP, A) JP-B-63-49128 (JP, B2) JP-B-53-16633 (JP, B2)

Claims (1)

(57) [Claims] 1. An enlarged upper part, an inner surface of which is formed at an angle equal to or greater than the angle of repose of the charged bulk carbonaceous fuel, a tuyere is provided at a lower position, a tap is provided at a position lower than the tuyere, and a center is provided. From the upper part, insert the charging cylinder for charging the waste, the bulk carbon-based fuel, and the basicity adjuster so that the lower end of the charging cylinder is higher than the tuyere level, and place the bulk carbon-based fuel around the charging cylinder. In a waste melting furnace having a furnace structure in which a fuel inlet is provided and an exhaust gas outlet is provided above, a furnace inner surface in a range from a tuyere above to a lower end of the charging cylinder is made substantially cylindrical. A waste melting furnace characterized by being formed.