JP2002340313A - Purging method for intermediate hopper in inserting apparatus of waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the facility of an inert gas supplying apparatus and reduce running cost by a method wherein the using amount of inert gas necessary for purging gas in an intermediate hopper is reduced as much as possible and gas in the intermediate hopper is efficiently purged by suppressing the generation of circulating current. SOLUTION: The intermediate hopper 2 is provided at the top of a waste melting furnace 3, and an upper sealing damper 10 for opening and closing the upper end opening unit is provided in the upper end opening unit of the intermediate hopper 2, while a lower sealing damper 11 for opening and closing a lower end opening unit is provided in the lower end opening unit communicated with the inside of a waste processing furnace. In the method of purging furnace gas in the intermediate hopper by the inert gas, the temperature of the inert gas is raised to approximate the density of the same to that of furnace gas in the intermediate hopper and purge the furnace gas from the upper part of the intermediate hopper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for charging a waste melting furnace for thermally decomposing and melting waste such as general waste and industrial waste.

[0002]

2. Description of the Related Art As a method of treating general waste and industrial waste, waste is charged into a shaft furnace type waste melting furnace, and the waste is dried, preheated, pyrolyzed, burned, and melted. And
There is known a thermal decomposition / melting method for extracting slag or metal.

[0003] As a charging device for a waste treatment furnace, an upper seal damper is used to seal pyrolysis gas generated in the furnace when waste conveyed by a waste crane from a waste pit or the like is loaded. And a lower seal damper. The intermediate hopper, a space surrounded by double dampers,
An inert gas is supplied to prevent the flammable gas inside the furnace from leaking out of the furnace and to prevent the atmosphere outside the furnace from entering the furnace. The supply of the inert gas to the charging device of the waste treatment furnace is described in, for example, Japanese Patent Application Laid-Open No. 2000-2000 filed by the present applicant.
No. 3,104,411.

FIG. 2 is a view showing a conventional charging apparatus for a waste treatment furnace.

[0005] In FIG. 2 (a), waste is charged from an input hopper 1 into an intermediate hopper 2, and dried in a waste melting furnace 3.
Pyrolyzes, burns, melts. The waste is temporarily stored in an intermediate hopper 2 provided at an upper part of the melting furnace 3, and the intermediate hopper 2 provided with an upper seal damper 10 and a lower seal damper 11 is provided.
By purging inert gas, steam, or combustion exhaust gas, the outflow of the gas in the furnace to the atmosphere and the intrusion of the atmosphere into the furnace are prevented.

In the charging device shown in FIG. 2B, an intermediate hopper 2 is provided at the top of the waste melting furnace 3, and an upper seal damper 10 for opening and closing the upper end opening is provided at the upper end opening of the intermediate hopper 2. A lower seal damper 11 that opens and closes the lower end opening is provided at a lower end opening communicating with the waste treatment furnace, and the waste loaded in the intermediate hopper is placed in the melting furnace in the intermediate hopper. , And a scraping damper 12 for sealing the inside of the intermediate hopper and the waste melting furnace is rotatably provided.

[0007]

In the conventional charging device,
An inert gas supply device is provided to supply the inert gas, and exhaust gas generated in the waste treatment furnace is piped. Therefore, a huge facility cost and a running cost for supplying the inert gas are required.

[0008] Further, CO, N invading the intermediate hopper.
_{2. A} circulating flow is formed by the density difference between the furnace gas, which is a mixed gas such as steam and H _2, and the inert gas to be purged,
The gas in the intermediate hopper could not be efficiently expelled.

Therefore, the present invention reduces the amount of inert gas required for purging the gas in the intermediate hopper surrounded by the double damper as much as possible, and suppresses the generation of a circulating flow to efficiently reduce the amount of inert gas in the intermediate hopper. It is an object of the present invention to expel gas, reduce the size of equipment of an inert gas supply device, and reduce running costs.

[0010]

According to the method of purging an intermediate hopper of a waste melting furnace according to the present invention, an intermediate hopper is provided at a furnace top of a waste treatment furnace, and an upper end opening is opened and closed at an upper end opening of the intermediate hopper. An upper seal damper is provided, and a lower seal damper that opens and closes a lower end opening is provided at a lower end opening communicating with the waste treatment furnace, and a method of purging furnace gas in an intermediate hopper with an inert gas. The temperature of the inert gas is increased to make the density of the inert gas at least approximate to the density of the gas in the furnace in the intermediate hopper, and the inert gas is purged from above the intermediate hopper.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention is at least warmed by the heat exchanger and an electric heater or the like with steam for generating inert gas in waste treatment furnace such as N ₂ to a density of gas in the intermediate hopper Supply by approximation. In addition, by purging from the upper part of the intermediate hopper, effective purging of the gas in the intermediate hopper can be realized. Further, in a facility having a damper for scraping waste in the intermediate hopper (referred to as a scraping damper), the purge may be performed from the scraping damper.

FIG. 1 is an overall view of a waste melting facility for carrying out the present invention.

In the waste melting furnace 3, waste, coke and limestone as auxiliary materials are charged from the charging hopper 1 at the upper part of the furnace into the intermediate hopper 2 provided with the upper seal damper 10 and the lower seal damper 11, and discarded. It is dried, thermally decomposed, burned and melted in the material melting furnace 3. The combustibles from the furnace are exhausted from a duct at the upper part of the furnace as pyrolysis gas, burned in a combustion chamber 4, and then used as heat and electric energy by auxiliary equipment such as a boiler 5 and a turbine generator. Thereafter, the exhaust gas is cooled by a gas cooler, passes through a dust collecting device 6, and is discharged from a chimney 7 by an induced blower.

[0014] At the lower part of the waste melting furnace, there is provided a blowing tuyere for blowing oxygen-enriched air, which is a mixture of air and oxygen, and ash is taken out of the slag outlet as slag and metal. The oxygen-enriched air blown from the tuyere burns the coke in the furnace and the char generated by pyrolysis, and the heat of combustion is used to dry the waste loaded in the furnace, pyrolyze it, and melt incombustibles. Used for

As the inert gas blown into the intermediate hopper 2 of the charging apparatus, for example, nitrogen generated by the nitrogen generator 8 is pressurized steam generated by the boiler 4 (for example, about 200
(° C.) and is blown into the intermediate hopper 2 from a blowing port 13 formed in the intermediate hopper 2. The air inlet 13 may be formed on the lower surface of the upper seal damper 10. The inert gas is heated to bring its gas density close to that of the furnace gas. Even if the temperature is further increased in anticipation of the expansion effect and the inert gas density becomes smaller than the gas density in the furnace, the inert gas tends to stagnate above the intermediate hopper 2, so that a purging effect is expected.

The gas expands in volume depending on the temperature and decreases in density. Table 1 shows the furnace gases (CO, N ₂ , CO ₂ , H ₂
It shows the relationship between the temperature and density of a mixed gas containing O, H ₂ , CH _{4 and the} like as main components) and the gas density at the N ₂ temperature blown into the intermediate hopper.

[0017]

[Table 1] From Table 1, for example, when the furnace gas temperature is 80 ° C., N ₂
It can be seen that the same gas density is obtained when the temperature is set to 146 ° C. Therefore, the density can be approximated by heating the purge gas in accordance with the gas temperature in the furnace in the intermediate hopper.

Therefore, by raising the temperature of the inert gas to be supplied, the volume of the inert gas can be expanded, and the amount of gas supplied from the inert gas supply device can be reduced.
The formation of a circulating flow due to the density difference can be suppressed. At this time, even if the density of the inert gas becomes lower than the density of the gas in the furnace, the purging effect can be expected as described above.

[0019]

According to the present invention, the amount of inert gas supplied from the inert gas supply device can be greatly reduced by raising the temperature of the inert gas. It is possible to reduce equipment costs and running costs by downsizing. In addition, by heating the purge gas in accordance with the gas temperature in the furnace in the intermediate hopper, the density is approximated, and purging from the upper part of the intermediate hopper suppresses the formation of a circulating flow due to the density difference,
The gas in the intermediate hopper can be efficiently expelled.

[Brief description of the drawings]

FIG. 1 is an overall view of a waste melting facility for carrying out the present invention.

FIG. 2 is a diagram showing a conventional charging apparatus for a waste treatment furnace.

[Explanation of symbols]

 1: Input hopper 2: Intermediate hopper 3: Melting furnace 4: Combustion chamber 5: Boiler 6: Dust collector 7: Chimney 8: Nitrogen generator 9: Heat exchanger 10: Upper seal damper 11: Lower seal damper 12: Scavenging Damper 13: Purge inlet

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[Procedure amendment]

[Submission date] June 18, 2001 (2001.6.1)
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

In the charging device shown in FIG. 2 (b), an intermediate hopper 2 is provided at the top of the waste melting furnace 3, and an upper seal damper 10 is provided at the upper end opening of the intermediate hopper 2 to open and close the upper end opening. A lower seal damper 11 that opens and closes a lower end opening is provided at a lower end opening communicating with the waste treatment furnace, and a waste loaded in the intermediate hopper is disposed in the melting furnace in the intermediate hopper. the take can out damper 12 you charged is rotatably provided on.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) F27D 17/00 101 F27D 17/00 101Z (72) Inventor Mitsumasa Todaka 46-59, Nakahara, Tobata-ku, Kitakyushu-shi (72) Inventor Masafumi Yamada 46-59 Ohara Nakahara, Tobata-ku, Kitakyushu Nippon Steel Plant Design Co., Ltd.F-term (reference) MA00 4K056 AA05 BA01 CA20 DA31

Claims (3)

[Claims] An intermediate hopper is provided at the furnace top of the waste treatment furnace, and an upper seal damper for opening and closing the upper end opening is provided at an upper end opening of the intermediate hopper. Is provided with a lower seal damper for opening and closing the lower end opening, and in a method of purging the furnace gas in the intermediate hopper with the inert gas, the inert gas is heated to reduce the density of the inert gas at least in the intermediate hopper. Purging from the upper part of the intermediate hopper by approximating the density of the gas in the furnace. 2. An inert gas is purged from a scraping damper disposed in an intermediate hopper.
A method for purging an intermediate hopper in an insertion device of a waste melting furnace as described in the above. 3. The waste according to claim 1, wherein the temperature of the inert gas is raised by a heat exchanger using pressurized steam generated in a boiler of an exhaust gas treatment system of the waste treatment furnace. A method for purging an intermediate hopper in an insertion device of a melting furnace.