JP2003074818A - Waste melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste melting furnace including means for melting a solid substance by heating an upper portion of a slag outlet and discharging it to the outside of the furnace when heat in the furnace is insufficient. SOLUTION: The waste melting furnace is adapted such that a high temperature combustion zone 4 is formed at a lower portion of the furnace 1c, on which zone 4 a waste layer 3 is formed, and a twyer 10 is provided in the high temperature combustion zone 4, and further waste is thermally decomposed to melt an ash fraction and a noncombusted fraction in the waste, and a resulting molten substance 5 is discharged from the slag outlet 11. In the furnace, a blowing section 13 is provided between the twyer 10 and the outlet 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting furnace for gasifying and melting waste, and a melting furnace for melting waste by using coke as auxiliary fuel. More specifically, the present invention relates to a waste melting furnace. The present invention relates to a waste melting furnace with a blow-in portion such as air that can heat the upper part of the mouth to melt the solidified layer in the furnace and discharge it to the outside of the furnace.

[0002]

2. Description of the Related Art As a conventional waste melting furnace using a solid carbon fuel, there is a waste gasification melting furnace disclosed in, for example, Japanese Patent Laid-Open No. 9-60830. This waste gasification and melting furnace was equipped with an inlet for waste and carbon-based auxiliary fuel at the top of the furnace body, and a tuyere for blowing oxygen-containing gas at the side of the furnace body. A vertical melting furnace that thermally decomposes waste to generate combustible gas, melts ash and incombustibles in the waste, and discharges it from the outlet. The upper tuyeres are provided at a level equivalent to the upper surface of the deposited layer formed by the auxiliary fuel, the middle tuyeres are provided at a level equivalent to the upper portion of the deposited layer, and correspond to the lower portion of the deposited layer. The lower tuyere is provided at the level, and the temperature inside the furnace is adjusted by increasing or decreasing the charging amount of carbon-based fuel.

[0003]

According to the waste gasification and melting furnace configured as described above, when the scale is reduced, the heat removal from the outside becomes too large, and the melted material at the tuyere tip is discharged. There were problems such as solidification and solidification in the furnace before reaching the mouth. Also, when a large amount of waste with a low calorific value and a high ratio of incombustibles is charged, the amount of heat generated is insufficient, and ash and incombustibles are unmelted and solidify and adhere in the furnace, making operation impossible. Was causing problems. Once solidified in the furnace, the solidified layer was directly melted from outside the furnace using an oxygen lance, but the melted high-temperature melt is scattered around, which involves dangerous work. Was there.

There is also a method of compensating for the deficiency of heat by increasing the charging amount of carbon-based fuel, but in order to raise the temperature near the outlet, wait until the carbon-based fuel reaches the tuyere. There must be. Therefore, there was a time loss until it fell to the tuyere, it was not possible to cope with the rapid change due to the change in the property of the waste, and there was a problem that ash and incombustibles solidified in the furnace. .

The present invention has been made in order to solve the above problems, and in order to maintain stable operation, when the amount of heat generated in the furnace becomes insufficient, the inside of the furnace, especially the slag, is instantly discharged. An object of the present invention is to provide a waste melting furnace equipped with a means for heating the upper part of the mouth to melt the solidified material and discharge it to the outside of the furnace, which has a blower part or a blowing part such as an air blowing part such as a heating burner.

[0006]

The waste melting furnace according to the present invention is constructed as follows. (1) A high temperature combustion zone is formed in the lower part of the furnace, a waste layer is formed on the high temperature combustion zone, and a tuyere for blowing an oxygen-containing gas is provided in the high temperature combustion zone, and the waste is thermally decomposed and discarded. This is a waste melting furnace that melts ash and incombustibles in a product and discharges the melt from a slag spout, in which a blowing section for air or the like is provided between the tuyere and the slag spout.

(2) In the waste melting furnace of the above (1), the blowing section for air or the like is constituted by a heating burner,
At room temperature or preheated air or oxygen-enriched air and the fuel were blown from the heating burner. (3) In the waste melting furnace of the above (1), the blowing part for air or the like is constituted by a blower port, and air at room temperature or preheated or oxygen-enriched air is blown from the blower port.

(4) In the waste melting furnace of the above (1), (2), and (3), a blow-in portion for air or the like is provided in a range of 50 mm to 300 mm upward from the outlet. (5) In the waste melting furnace of (1), (2), and (4) above, the heating burner formed a flame base in the burner nozzle. (6) Above (1), (2), (3), (4), (5)
In the waste melting furnace of, the amount of melt discharged is monitored, and if the amount of melt discharged is less than the expected amount of melt discharged based on the input amount of waste, the blowing part of air etc. I tried to blow in air from it.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] FIG. 1 is a longitudinal sectional view showing a waste melting furnace with a heating burner according to a first embodiment of the present invention. In the figure, reference numeral 1 is a furnace body of a shaft-shaped waste melting furnace, and the furnace body 1 includes a cylindrical freeboard portion 1a located at an upper portion thereof and a bosh portion 1b having an upward diameter. And the furnace lower part 1c. Reference numeral 2 is a deposited layer formed by a carbon-based auxiliary fuel such as waste and coke, which is filled in the furnace body 1 and constitutes a waste layer 3, a high temperature combustion zone 4, and a melt 5 from top to bottom.

A waste and coke inlet 6 is provided at the top of the furnace body 1, and a tuyere 7 for blowing oxygen-containing gas is provided at the side of the furnace body 1. This tuyere 7
Are provided as one set on each of the three levels along the height direction of the furnace body 1. One set of tuyere is the upper three-stage tuyere 8 provided at a level corresponding to the upper side of the waste layer 3 and the other set of tuyere is the upper part of the waste layer 3. It is an auxiliary tuyere 9 in the middle stage provided at a level corresponding to. Still another set of tuyere is provided at a level corresponding to the high temperature combustion zone 4 formed under the waste layer 3, and the lower main tuyere 10 for blowing oxygen-containing gas into the high temperature combustion zone 4 is there. Reference numeral 11 denotes a slag outlet provided on a side wall near the bottom of the furnace body 1 for discharging the melt 5 accumulated in the furnace bottom from the furnace, and 12 a combustion exhaust gas provided on an upper side wall of the furnace body 1. It is the outlet of.

Reference numeral 13 is a heating burner which is provided between the main tuyere 10 and the outlet port 11 to directly heat the inside of the furnace, from which room temperature or preheated air or oxygen-enriched air and fuel are blown, A part of the solidified waste between the tuyere 10 and the outlet 11 is melted and smoothly discharged outside the furnace. More specifically, the gas blown from the heating burner 13 is room temperature or preheated air, or oxygen-enriched air, and gas fuels such as propane, butane, methane, ethane or mixed gas thereof, or liquid fuel of kerosene, heavy oil, or It is a pulverized coal or plastic powder of solid fuel, which makes it possible to heat the inside of the furnace at a high temperature even if there is nothing to burn in the furnace.

The position of the heating burner 13 in the circumferential direction of the furnace is to quickly heat the melted material near the outlet 11 when the melted material 5 is likely to be solidified because the temperature inside the furnace is lowered. Since it is necessary to discharge it outside the furnace, it is preferable to be as close to the outlet 11 as possible, and more preferably just above the outlet 11. The position of the heating burner 13 in the height direction is preferably installed within a range of 50 mm to 300 mm from the position of the outlet 11. This is because if the thickness is 50 mm or less, the water cooling structure of the heating burner 13 is damaged by the metal in the melt 5, water leaks into the furnace, the temperature inside the furnace decreases, and the operation becomes unstable. This is because when the thickness is 300 mm or more, the heat of the heating burner 13 is not sufficiently transmitted to the vicinity of the outlet 11, and there is no effect of preventing the solidification of the melt 22.

The heating burner 13 forms a flame base in the burner nozzle in order to prevent misfire of the heating burner 13 due to fluctuations in the furnace. More specifically, the heating burner 13
The outer cylinder is made longer than the injection valve nozzle (for example, 0.8 times the burner diameter D or more), and the flame base is formed in the cylinder to prevent the flame from being blown off by disturbance. When the fuel is fanned out from the injection valve, the flame base is held in a circulating vortex having a length of, for example, about 0.8 D to maintain the flame. The outer cylinder is lengthened downstream from the nozzle tip so that its base is stably (without being disturbed by disturbance) at a fixed position.

The operation of the first embodiment configured as described above will be described. When the waste is gasified and melted by a waste melting furnace equipped with a heating burner, first, the waste, the coke which is one of the carbon-based auxiliary fuels, and the slag modifier are charged from the charging port 6, and these A deposit 2 is formed by the charge. The charge forming the deposited layer 2 is appropriately fluidized by the air blown from the auxiliary tuyere 9 in the middle stage, and a part thereof burns together with the combustible gas generated in the lower part. The heat of combustion heats the waste materials and dry-distills them to generate combustible gas.
The dry-distilled wastes sequentially descend from the upper part of the sedimentary layer 2 to the lower part of the furnace, are burned by the oxygen-containing gas blown from the main tuyere 10 in the lower stage, are ashed, are melted, and are melted. And is discharged from the outlet 11.

The temperature of the waste in the waste melting furnace constantly fluctuates because the adhering water content, the calorific value, and the ratio of combustibles and non-combustibles are not constant. In particular, when a large amount of waste with a large amount of attached water and a low calorific value is used, the temperature inside the furnace will drop, and some of the ash and incombustibles may be solidified in the furnace without melting and may not be discharged. . Therefore, the discharge amount of the molten material from the outlet port 11 is reduced. At this time, the heating burner 13 provided between the main tuyere 10 and the slag spout 11 is ignited to dissolve the solidified material, and the melt 5 is smoothly discharged from the slag spout 11. In this case, the heating burner 13 uses propane or kerosene as fuel,
It is desirable to supply oxygen-based enriched air that is enriched with oxygen.

The temperature inside the furnace is adjusted by the heating burner 13 by constantly monitoring the discharge amount of the melt discharged from the outlet 11. That is, the discharge amount of the melt 5 is monitored, and when the actual discharge amount of the melt 5 is smaller than the discharge amount of the melt expected based on the input amount of the waste, the heating burner 13 outputs the normal temperature. Alternatively, preheat air or oxygen-enriched air and inject fuel. As a result, the temperature inside the furnace near the outlet is raised and the melt is smoothly discharged.

The amount of waste input is measured and controlled by a measuring instrument. On the other hand, the discharged melt amount is obtained by continuously measuring and monitoring the weight of the granulated slag obtained by flowing the melt 5 into the granulated water tank. In this way, when the discharge amount of the melt becomes small, the heating burner 13 is operated to increase the heating power,
Heating burner 13 if the input and output are balanced
To stop.

However, when the heating burner 13 is stopped,
Heating burner 1 by means of the atmosphere gas or melt 5 in the furnace
The main body of the heating burner 13 is prevented from being damaged due to high temperature by stopping the fuel supply only and continuing to blow the oxygen-enriched air from the tuyere 7. Further, when the scale of the furnace is small and the amount of heat removed is always large, if a heat amount corresponding to the insufficient amount of heat is supplied by the heating burner 13, stable operation is possible regardless of the scale of the furnace. When the heating burner 13 is used continuously for a long time, it is better to fix it permanently in the furnace and make it a water-cooled structure. When it is used only for a short time, it is always installed outside the furnace. The structure may be such that it is inserted into the furnace only when it is used.

[Second Embodiment] In the second embodiment, a ventilation port is provided in place of the heating burner 13 in the first embodiment (not shown). Main tuyere 10 and outlet 1
1 is provided with a blower port for directly heating the inside of the furnace, from which room temperature or preheated air or oxygen-enriched air is blown, and the ash content solidified between the main tuyere 10 and the outlet 11 and Part of incombustibles is melted and discharged smoothly outside the furnace. The gas blown from the blower port is room temperature or preheated air, or oxygen-enriched air, and heats the inside of the furnace by burning the waste or the carbonaceous fuel charged as a submaterial. Other configurations are the same as those of the first embodiment.
The description is omitted because it is substantially the same as the case described in.

The operation of the second embodiment is substantially the same as that described in the first embodiment. However, in the first embodiment, when the discharge amount of the melt 5 is monitored and the actual discharge amount of the melt 5 is smaller than the discharge amount of the melt expected based on the input amount of the waste, , From the heating burner 13 at room temperature or preheated air or oxygen-enriched air,
Although the fuel is blown, in the second embodiment, air at room temperature or preheated or oxygen-enriched air is blown from the blower port.

[0021]

As is apparent from the above description, according to the present invention, the high temperature combustion zone is formed in the lower part of the furnace, the waste layer is formed on the high temperature combustion zone, and the oxygen-containing gas is blown into the high temperature combustion zone. A waste melting furnace that has a tuyere, thermally decomposes waste to melt ash and incombustibles in the waste, and discharges this melt from the slag spout. Since a blow-in portion for air or the like is provided between the two, it is difficult for solidified substances to be generated due to insufficient temperature inside the furnace, and stable operation of the melting furnace can be continued. In addition, even in the melting furnace of a small furnace with a large amount of heat removal,
Stable operation is possible.

Further, as the waste, it is possible to input waste having a large amount of heat and a low calorific value, and there is no restriction on the input waste. Also, due to the dissolution of the solidified matter generated in the furnace, the work that had been melted using oxygen lance etc. is eliminated, the workload is reduced and the danger of high temperature work is avoided,
Also, the abnormal damage of the refractory on the furnace wall due to the oxygen lance is eliminated. Furthermore, the gas generated by burning with the heating burner flows upward, so that a gas passage is created in the packed bed in the furnace,
It becomes a way to easily drip the melt generated in the furnace,
Secure a stable runway. Further, when the discharge amount of the melt is monitored and the air or the like is blown from the blowing portion of the air or the like, efficient operation becomes possible.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a first embodiment of the present invention.

[Explanation of symbols]

1 Waste melting furnace main body 1c Lower part of furnace 3 waste layer 4 High temperature combustion zone 5 melt 7 tuyere 10 main tuyere 11 outlet 13 Air blowing part (heating burner, blower port)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F27B 1/16 F27B 1/28 4K063 1/28 F27D 7/02 A F27D 7/02 21/00 Z 21 / 00 B09B 3/00 303K (72) Inventor Nao Nakamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-Term (Reference) 3K061 AA16 AB03 BA06 CA07 DA12 DB12 DB16 NB03 3K065 AA16 AB03 BA06 GA13 GA32 4D004 AA46 AC04 CA27 CA29 CB34 CC02 DA03 DA12 4K045 AA01 BA10 DA07 GB08 GB10 GB16 4K056 AA05 CA20 FA01 4K063 AA04 BA13 CA01 CA02 DA13 DA14

Claims (6)

[Claims] 1. A high temperature combustion zone is formed in a lower part of a furnace, a waste layer is formed on the high temperature combustion zone, and a tuyere for blowing an oxygen-containing gas is provided in the high temperature combustion zone to heat the waste. A waste melting furnace that decomposes and melts ash and incombustibles in the waste, and discharges the melt from a slag spout, wherein a blower for air or the like is provided between the tuyere and the slag spout. A waste melting furnace characterized by being provided with. 2. A waste melting apparatus according to claim 1, wherein the blowing section for air or the like is constituted by a heating burner, and air or oxygen-enriched air at room temperature or preheated and fuel are blown from the heating burner. Furnace. 3. The waste melting furnace according to claim 1, wherein a blower for air or the like is formed by a blower port, and air at room temperature or preheated or oxygen-enriched air is blown from the blower port. 4. A blower for air or the like is moved upward from the outlet 5
The waste melting furnace according to claim 1, wherein the waste melting furnace is provided in a range of 0 mm to 300 mm. 5. The waste melting furnace according to claim 1, wherein the heating burner has a flame base formed in the burner nozzle. 6. The amount of melt discharged is monitored, and when the amount of melt discharged is smaller than the expected amount of melt discharged based on the amount of waste input, air is blown from the blowing section. Air, etc. are blown in, Claims 1, 2, 3, 4, 5 are characterized by the above-mentioned.
The waste melting furnace according to any one of 1.