JP2000146144A - Molten discharger and discharging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molten discharger for discharging molten, produced in a waste treatment furnace for melting unburnt components in waste and recovering in the form slag metal, continuously and stably to the outside of the furnace. SOLUTION: A molten discharger comprises a molten furnace 1 for melting waste and delivering produced molten slag metal 4 from a slag delivery opening 2, and a heating means disposed at the outlet part of the slag delivery opening 2 in order to heat up the delivered molten slag metal 4 locally wherein the heating means has a burner 3 for forming a heating flame using a combustion accelerating gas having oxygen concentration of 75 or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a waste treatment furnace for melting incombustibles in waste and recovering it as slag metal so that the produced molten material can be continuously and stably discharged outside the furnace. And a method for discharging the melt.

[0002]

2. Description of the Related Art In a method of discharging molten slag and metal in a waste melting furnace, there is a conventional technique of intermittently opening a slag outlet at a lower part of the furnace as disclosed in Japanese Patent Application Laid-Open No. 1-184313. The method of tapping periodically by repeating the opening and closing, and the method of tapping continuously from the tap at the bottom of the furnace as disclosed in JP-A-55-102815 and JP-A-1-117435. Separated. Considering practical use, long-term durability of the slag port that discharges the molten material is important, and the former is periodically opened and closed,
We repair the slag outlet. On the other hand, the continuous slagging method such as the latter does not require periodic opening and closing as in the former case, and is easy to handle. In the vicinity of the outlet, there is a problem that blockage and solidification due to a decrease in temperature proceeds, and it is difficult to stably remove slag. Therefore, the present inventors have patented a device in which a heating furnace is installed at the outlet of the melting furnace (Japanese Patent Application Laid-Open Nos. 9-196355 and 9-19).
No. 6356) was also proposed and implemented, and the stability of the slag during continuous slag was confirmed.

[0003]

In the heating furnace system, a multi-burner is mounted on the upper surface of a slag outlet of a melting furnace as in Japanese Patent Application Laid-Open No. 5-322139, and heating is performed. Some are designed to prevent scattering. However, these inventions require a heating furnace, a furnace for holding heat. Therefore, despite the fact that stable continuation of continuous slag was possible in the test of the present inventors, (1) it took about one and a half days to preheat the heating furnace, and (2) slag outlet exit. It was difficult to open part of the heating furnace immediately when the flow of the melt in
Challenges remained. SUMMARY OF THE INVENTION An object of the present invention is to provide a waste treatment furnace that melts incombustibles in waste and collects it as slag metal. It is an object of the present invention to provide a melt discharge device and a method thereof.

[0004]

In order to solve the above problems and achieve the object, the present invention uses the following means.

[0005] (1) The apparatus of the present invention is a melting furnace for melting waste and discharging the generated molten slag metal from a slag port, and is disposed at an outlet of the slag port. And heating means for locally heating the discharged molten slag metal, wherein the heating means has a burner for forming a heating flame using a supporting gas having an oxygen concentration of 75% or more. It is a melt discharge device.

(2) The apparatus according to the present invention is characterized in that the burner has means for forming a long flame and locally burning the molten slag metal discharged. A melt discharge device according to 1).

(3) The apparatus according to the above (1) or (2), wherein the burner is provided with a means for forming a flame in a reducing atmosphere. is there.

(4) In the method of the present invention, the waste is melted in a melting furnace, and the generated molten slag metal is discharged from a slag port, and the slag is discharged at an outlet of the slag port. A step of locally heating the molten slag metal with a flame using a supporting gas having an oxygen concentration of 75% or more.

(5) In the method of the present invention, the local heating step comprises:
The molten material discharging method according to the above (4), characterized in that a long flame is formed and the molten slag metal discharged is locally roasted.

(6) In the method of the present invention, the local heating step includes:
The melt discharging method according to the above (4) or (5), wherein a flame in a reducing atmosphere is formed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above problems, it is necessary to maintain a molten state so that a molten substance flows smoothly from an outlet of a slag outlet to a slow cooling pot or a quench water tank.

The present invention is characterized in that by installing a burner for locally heating the outlet of the slag outlet of the melting furnace instead of the heating furnace, the slag can be stably continued without preheating the entire furnace. . As a burner to be used, a combustion supporting gas having an oxygen concentration of 75% or more and kerosene, propane or natural gas fuel are used. The burner forms a long flame with high oxygen concentration oxygen-enriched air and liquid or gaseous fuel. As a result, the tip temperature of the flame was increased to 2000
When the temperature is at least ° C, only the vicinity of the slag outlet and the melt can be locally heated, and it is not necessary to heat the entire furnace as in the conventional heating furnace structure. As a result, effects such as shortening of the preheating time, the possibility of partial opening, and easy adjustment were obtained.

Based on the above findings, the present inventors have provided a means for locally heating the vicinity of the outlet of a slag outlet in a high-temperature reducing atmosphere using an oxygen kerosene burner having an oxygen concentration within a certain range. In a waste treatment furnace that melts incombustibles in the waste and collects it as slag metal, the generated melt can be continuously and stably discharged outside the furnace without preheating the entire furnace. The present inventors have found a melt discharge device and a method thereof, and have completed the present invention.

An embodiment of the present invention will be described below.

FIG. 1 shows an apparatus configuration of the present invention. In the conventional heating furnace system, as shown in FIG. 2, the entire heating furnace, that is, between the outlet of the continuous slag port 2 and the water tank 5 for dropping the melt 4 so as to maintain the molten state of the melt 4. Are covered with a refractory, and a plurality of general kerosene air burners 7 are provided for the purpose of warming the entire heating furnace. In the present invention, the use of the kerosene oxygen burner 3 increases the flame temperature, and the use of the burner 3 capable of forming a long flame makes it possible to locally heat the outlet of the slag outlet 2.

FIG. 3 shows a temperature condition calculated by a heat conduction analysis from the entrance of the slag port 2 to the exit of the slag port 2 on the side of the melting furnace 1 when the outlet of the slag port 2 is heated. The results of a partial measurement with a thermometer during long-term operation in a demonstration reactor are shown. By heating the refractory in the slag port 2 to 1800 ° C. or higher, the refractory inside the slag port 2 can be maintained at 1400 ° C.
It was found that the slag in the demonstration furnace was also stable.

FIG. 4 shows the relationship between the flame tip temperature and the refractory surface temperature. The horizontal axis is the oxygen concentration of the oxygen-enriched air. By setting the oxygen concentration to 75% or more, the flame tip temperature could be made 2000 ° C or more, and the refractory temperature at the slag outlet could be heated to 1800 ° C or more. . For this reason, in the present invention, the oxygen concentration of the air used in the burner is set to 75% or more. FIG. 5 shows the amount of oxygen used for the burner and the flame tip temperature. When the value obtained by dividing the supplied oxygen amount by the amount of oxygen required by the fuel (hereinafter referred to as oxygen ratio) is plotted on the horizontal axis, the flame temperature becomes maximum at almost the theoretical oxygen amount (number 1.0).
For maintaining the molten state, it is desirable that the flame temperature be high. However, in order to prevent oxidation of the effluent and improve the quality, it is better to perform reduction combustion (burning at less than the required oxygen amount of fuel). It was found from the analysis results of the generated slag. In the test, the oxygen ratio was set in the range of 0.4 to 1.2.
When the temperature is set to 0 or less, although the flame front temperature decreases, the oxidation of the molten material is suppressed.

[0018]

As described above, according to the present invention, the vicinity of the slag outlet is locally heated in a high-temperature reducing atmosphere using an oxygen kerosene burner. The inside of the mouth could be maintained at a sufficiently high temperature, and continuous slag removal was possible in a stable manner. (2) Since a required portion could be locally heated, a high temperature steady state could be reached in a short time, and the preheating time could be shortened.

(3) Since high-concentration oxygen is used, reduction combustion can be performed at a high temperature, oxidation of the molten material discharged can be prevented, and quality is improved.

(4) Since heating is performed locally, the amount of fuel used can be minimized.

It is an invention which is very useful for the world's demand for stabilization, simplification, and harmlessness to the next-generation waste disposal method.

[Brief description of the drawings]

FIG. 1 is an example of an apparatus for carrying out the present invention, which is an explanatory view of an apparatus in which an oxygen kerosene burner is arranged above an outlet of a continuous tapping port and the center of the tapping port can be heated by the burner. .

FIG. 2 is an explanatory view of a conventional type device in which a space from an outlet of a continuous slag port to a water tank for dropping a molten material is covered with a refractory, and the inside of the heat retention furnace is heated by a plurality of air kerosene burners. .

FIG. 3 shows a temperature condition calculated by a heat conduction analysis from an inlet portion of a melting furnace to an outlet portion of the smelting port when the outlet of the smelting port is heated, and a long-term operation of the demonstration furnace. The figure which shows the result of having measured partly with the thermometer.

FIG. 4 is a diagram showing a relationship between a flame tip temperature and an oxygen concentration of an oxygen kerosene burner.

FIG. 5 is a diagram showing a relationship between a value (oxygen ratio) obtained by dividing the amount of oxygen supplied to the burner by the amount of oxygen required by the fuel and the temperature of the flame tip.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Melting furnace main body, 2 ... Continuous slag port, 3 ... Oxygen kerosene burner, 4 ... Melt, 5 ... Water tank, 6 ... Heat retention furnace, 7 ... Air kerosene burner.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohiro Yoshida 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Masahiro Sudo 1-2-1-2 Marunouchi, Chiyoda-ku, Tokyo Sun Inside the Kokan Co., Ltd. (72) Inventor Yuichi Yamakawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term within Nihon Kokan Co., Ltd. 3K061 NB08 4D004 AA43 BA05 CA29 CA37 CB03 CB34 4K045 AA04 BA10 RB12 RC11

Claims (6)

[Claims] 1. A melting furnace which melts waste and discharges the generated molten slag metal from a slag outlet. The melting furnace is disposed at an outlet of the slag outlet.
Heating means for locally heating the discharged molten slag metal, wherein the heating means has a burner for forming a heating flame using a supporting gas having an oxygen concentration of 75% or more. , Melt discharger. 2. The burner forms a long flame,
2. The melt discharger according to claim 1, further comprising means for locally burning the discharged molten slag metal. 3. The melt discharger according to claim 1, wherein the burner includes a means for forming a flame in a reducing atmosphere. 4. A process in which waste is melted in a melting furnace and the generated molten slag metal is discharged from a slag port. At the outlet of the slag port, 75% of the discharged slag metal is discharged. A step of locally heating with a flame using a supporting gas having the above-mentioned oxygen concentration. 5. The molten metal discharging method according to claim 4, wherein the local heating step forms a long flame and locally burns the discharged molten slag metal. 6. The method according to claim 4, wherein the local heating step forms a flame in a reducing atmosphere.