JP2002005421A - Flying ash melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the stabilized melting of flying ash of incineration with a low fuel ratio in a flying ash melting furnace for treating the flying ash generated upon incinerating treatment of waste through an incinerator. SOLUTION: In the flying ash melting furnace 1, equipped with a vertical type cylindrical melting furnace main body 2, having the slag hole 2d of molten slag as well as a waste gas outlet port 2f at the lower end of the same and structured by a refractory structure, and an oxygen burner 3, provided on the ceiling wall 2b of the melting furnace main body 2 with a downward posture, the flying ash of incineration A, collected by the waste gas treating facility of the incinerator, is carried by oxygen B supplied to the oxygen burner 3 through gas transportation while the flying ash of incineration A is blown into the high-temperature flame of the oxygen burner 3 together with the oxygen B to burn and melt the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for melting incineration fly ash collected in an exhaust gas treatment facility of a stoker type incinerator or a fluidized bed type incinerator for incinerating waste such as municipal solid waste and industrial waste. More particularly, the present invention relates to a fuel combustion type fly ash melting furnace in which incinerated fly ash is melted independently by the combustion heat of fossil fuel such as kerosene or natural gas.

[0002]

2. Description of the Related Art Generally, most waste such as municipal waste is incinerated by a stoker type incinerator or a fluidized bed type incinerator. In the former stoker-type incinerator, incineration ash remaining in the furnace as incineration residue and incineration fly ash taken out of the exhaust gas and collected by an exhaust gas treatment facility such as a dust collector are generated. On the other hand, in the latter fluidized bed incinerator, due to its structure, all incineration residues are collected as incineration fly ash by an exhaust gas treatment facility.

[0003] By the way, incinerated fly ash discharged from a stoker type incinerator or a fluidized bed type incinerator and collected by an exhaust gas treatment facility contains a large amount of volatile components such as heavy metals having low boiling point and dioxins. Not only that, but also in the case of performing a dry treatment in which slaked lime Ca (OH) ₂ is blown in an exhaust gas treatment facility as a treatment for an acidic gas such as HCl or SOx contained in the exhaust gas, a high basicity (CaO / SiO ₂ ) and a high melting point substance.

[0004] In recent years, in order to reduce the volume, detoxify, and stabilize incinerated ash and incinerated fly ash, attention has been paid to the melting and solidification of incinerated ash and incinerated fly ash. In particular,
Incinerated fly ash has a higher concentration of dioxins and a higher content of heavy metals than incinerated ash, and is strongly required to be melted and solidified.

For melting of incinerated ash and incinerated fly ash, a fuel combustion type melting furnace (for example, a surface melting furnace, a rotary melting furnace, a coke bed furnace) using a combustion heat of fossil fuel such as kerosene or natural gas as a heat source, And an electric melting furnace (for example, an arc melting furnace, a plasma arc furnace, and an electric resistance furnace) using electric energy as a heat source, all of which are practically used. Generally, in the case of an incineration facility having a power generation facility, an electric melting furnace is used.
In addition, a fuel combustion type melting furnace is used when there is no power generation equipment or when performing wide area processing.

A typical example of the fuel combustion type melting furnace is a surface melting furnace. That is, in the surface melting furnace, incineration ash or incineration fly ash is supplied from four directions into the furnace to form an inclined molten surface by incineration ash or incineration fly ash being supplied from four directions. It has a face-to-face structure that is supplied and forms an inclined melting surface, and incineration ash and incineration fly ash stored in a hopper around the melting furnace are pushed out into the furnace by an ash supply device and installed on the furnace ceiling. The surface of incinerated ash and incinerated fly ash extruded by the combustion heat of a burner using preheated air as a supporting gas is melted. This surface melting furnace
It has advantages such as being suitable for melting a material having a non-uniform particle size including a coarse material such as incineration ash, and having a simple structure and capable of using various fossil fuels.

[0007]

However, when the incinerated fly ash is solely melted in a fuel combustion type melting furnace such as a surface melting furnace, there are the following problems. Since incinerated fly ash blown with slaked lime Ca (OH) ₂ as an acid gas treatment has a high basicity and a high melting point, when the incinerated fly ash is melted in a fuel combustion type melting furnace,
A burner using ordinary air as a supporting gas has a low combustion temperature and is difficult to completely melt. Since incineration fly ash contains a large amount of volatile components such as heavy metals and is in the form of powder, there are many incineration fly ash taken out together with the exhaust gas without melting, and the dust concentration in the exhaust gas increases and the duct In addition, there is a problem that blockage of the slag may be caused, and that a slag conversion rate may be reduced. In a fuel combustion type melting furnace, preheated air is generally used to burn fossil fuel such as kerosene, but there is a problem that the amount of heat carried out of exhaust gas increases and the fuel ratio increases. The incineration fly ash receives the heat of combustion from the burner is the surface of the molten surface that is extruded into the furnace and formed at the angle of repose, and requires a large surface area to receive enough heat to melt .

The present invention has been made in view of the above problems, and an object of the present invention is to stably melt incinerated fly ash generated when waste is incinerated in an incinerator at a low fuel ratio. An object of the present invention is to provide a fly ash melting furnace which can be used.

[0009]

In order to achieve the above object, the invention of claim 1 of the present invention is directed to a vertical cylindrical refractory structure having a molten slag discharge port and an exhaust gas outlet at the lower end. A fly ash melting furnace equipped with a melting furnace main body and an oxygen burner provided on a ceiling wall of the melting furnace main body in a downward position, and supplies incinerated fly ash collected by an exhaust gas treatment facility of the incinerator to the oxygen burner. It is characterized in that the gas is transported by the generated oxygen, and the incinerated fly ash is blown into the high-temperature flame of the oxygen burner together with the oxygen to burn and melt.

According to a second aspect of the present invention, the oxygen burner has a structure in which oxygen as a supporting gas can be divided into primary oxygen and secondary oxygen and supplied to the furnace in two stages. Primary oxygen is blown into the high-temperature flame of the oxygen burner while swirling from the center of the oxygen burner together with the incineration fly ash, and secondary oxygen is swirled from the secondary oxygen nozzle formed in the melting furnace body. It is characterized in that it is configured to blow air into.

According to a third aspect of the present invention, there is provided a basin for storing molten slag at the bottom of a melting furnace main body, and the molten slag stored in the basin overflows from a slag port to discharge hot water. It is characterized in that the combustion exhaust gas generated in the furnace is discharged from an exhaust gas outlet formed in a direction opposite to the slag outlet.

According to a fourth aspect of the present invention, there is provided a secondary combustion tower having a secondary combustion chamber communicating with an exhaust gas outlet of a melting furnace main body and an oxygen injection nozzle for blowing oxygen for secondary combustion into the secondary combustion chamber. It is connected to the melting furnace main body, and the unburned gas in the combustion exhaust gas sent from the melting furnace main body into the secondary combustion chamber is completely burned by the secondary combustion oxygen in the secondary combustion chamber. is there.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an example of a facility for melting incineration fly ash A using a fly ash melting furnace 1 according to an embodiment of the present invention. In FIG. Furnace body 3, oxygen burner 4, oxygen fly ash supply mechanism 5, primary oxygen supply pipe 6, secondary oxygen supply pipe 6,
Is an oxygen supply pipe for secondary combustion, 8 is an oxygen supply source, 9 is a control valve, 10 is a flow meter, 11 is a secondary combustion tower, 12 is a secondary combustion chamber, 13 is an oxygen injection nozzle, and 14 is a temperature reduction. Tower, 15 is a slag cooling water tank, 16 is a water-sealed slag conveyor, 17 is an incineration fly ash supply device, 18 is a fly ash silo, 19 is a silo quantitative cut-out device, 20 is a fly ash supply conveyor, and 21 is fly ash measurement. , 22 is a weighing machine discharge device, 23 is a hopper, 24 is a hopper fixed amount cutout device, and 25 is a hopper level sensor.

The fly ash melting furnace 1 includes a vertical cylindrical melting furnace main body 2 having a refractory structure, an oxygen burner 3 provided in the melting furnace main body 2, and an oxygen burner 3 connected to the oxygen burner 3. And a secondary combustion tower 11 and the like connected to the melting furnace main body 2 and the like. The incineration fly ash A is supplied by oxygen as a supporting gas of the oxygen burner 3. Is transported to the oxygen burner 3 and is blown into the high-temperature flame of the oxygen burner 3 to burn and melt, and the flue gas G generated in the furnace is guided to the secondary combustion tower 11 so that the unburned The gas is completely burned by the secondary combustion oxygen D in the secondary combustion tower 11.

That is, as shown in FIG. 1, the melting furnace main body 2 has a side wall 2a and a ceiling wall 2b formed of a metal casing and a refractory such as a castable refractory or a refractory brick.
And a furnace bottom 2c in a vertical cylindrical shape, and a lower part of the side wall 2a has a slag outlet 2d for discharging molten slag H, an inclined trough 2e, and an exhaust gas outlet 2 for discharging combustion exhaust gas G.
f are formed respectively. The slag outlet 2d and the exhaust gas outlet 2f are formed in the lower part of the side wall 2a so as to face each other and in the opposite directions. In the bottom 2c of the melting furnace body 2 is formed a recessed pool 2g for storing the molten slag H, and the molten slag H stored in the pool 2g overflows from the slag port 2d. Hot water is to be taken out. Further, a molten slag dropping chute 26 having a refractory structure is connected to the slag port 2d of the melting furnace main body 2, and the molten slag H discharged from the slag port 2d and the gutter 2e passes through the molten slag falling chute 26. After that, it falls into the slag cooling water tank 15.

The oxygen burner 3 is provided at the center of the ceiling wall 2b of the melting furnace main body 2 in a downward posture, and converts oxygen, which is a supporting gas supplied by an oxygen fly ash supply mechanism 4 described later, into the furnace. The primary incineration fly ash A transported in gas by the primary oxygen B can be blown into the furnace together with the primary oxygen B while the primary oxygen B and the secondary oxygen C can be supplied in two stages. That is, the oxygen burner 3 injects the primary oxygen B into the high-temperature flame of the oxygen burner 3 while swirling the primary oxygen B together with the incineration fly ash A from the center of the oxygen burner 3, and the secondary oxygen C to the melting furnace main body 2. It is configured such that it can be blown into the furnace while swirling from the formed secondary oxygen nozzle 33.

Specifically, as shown in FIG. 2, the oxygen burner 3 is disposed at the center of the burner throat 27 and the burner throat 27 and the burner tile 28 formed at the center of the ceiling wall 2b of the melting furnace main body 2. , Fuel E into the furnace at the tip
(A liquid fuel such as kerosene or a gaseous fuel such as natural gas), a burner gun 29 provided with a nozzle 29a, a fuel supply pipe 30 connected to the burner gun 29, and a spray medium supply pipe 31 connected to the burner gun 29 (fuel (Not necessary if E is a gaseous fuel), a wind box 32 connected in communication with the burner throat 27 and supplying primary oxygen B and incineration fly ash A to the burner throat 27, and a ceiling wall 2b (or a side wall 2a). And a plurality of secondary oxygen nozzles 33 for blowing secondary oxygen C into the furnace. Primary oxygen B and secondary oxygen C are blown into the furnace from the burner throat 27 and the secondary oxygen nozzle 33. Meanwhile, fuel E is blown into the furnace from the burner gun 29, and is ignited and burned by an igniter (not shown) such as a pilot burner. And to be able to form a hot flame. In the wind box 32 of the oxygen burner 3,
The primary oxygen supply pipe 5 of the oxygen fly ash supply mechanism 4 described later is connected in a tangential direction, and the primary oxygen B and the incinerated fly ash A supplied into the wind box 32 are swirled from the burner throat 27 into the furnace. It is to be blown. Further, the secondary oxygen nozzles 33 of the oxygen burner 3 are provided at several places on the ceiling wall 2b of the melting furnace main body 2 so that the secondary oxygen C blown into the furnace turns in the same direction as the primary oxygen B. The secondary oxygen C can be blown into the furnace to form a swirling flow in the furnace. The secondary oxygen nozzle 33 is connected to a secondary oxygen supply pipe 6 of the oxygen fly ash supply mechanism 4 described later.

According to the oxygen burner 3, the primary oxygen B and the incinerated fly ash A supplied from the primary oxygen supply pipe 5 into the wind box 32 are swirled in the wind box 32, and swirled. The gas is blown from the burner throat 27 into the high-temperature flame of the oxygen burner 3. The secondary oxygen C is supplied from the secondary combustion oxygen supply pipe 7 to the secondary oxygen nozzle 33, and the secondary oxygen C is supplied from the secondary oxygen nozzle 33 to a swirl in the same direction as the primary oxygen B. It is blown into the furnace.

In the oxygen burner 3, the fuel E
When liquid fuel is used, steam, oxygen, and compressed air can be used as the spray medium F. However, since the amount of generated NOx increases in the order of steam <oxygen <compressed air, N
Considering the suppression of Ox, the use of steam as the spray medium F is desired.

The oxygen fly ash supply mechanism 4 includes an oxygen burner 3
The primary oxygen B and the secondary oxygen C are supplied to the oxygen burner 3 and the incineration fly ash A is supplied to the oxygen burner 3 by gas transportation. As shown in FIG. Connected and wind box 32
Primary oxygen supply pipe 5 for supplying primary oxygen B and incineration fly ash A to the secondary oxygen supply pipe 6 connected to the secondary oxygen nozzle 33, and connection to the primary oxygen supply pipe 5 and the secondary oxygen supply pipe 6 And a control valve 9 and a flow meter 10 provided in the primary oxygen supply pipe 5 and the secondary oxygen supply pipe 6, respectively.

The secondary combustion tower 11, as shown in FIG.
It has a vertical cylindrical refractory structure having a secondary combustion chamber 12 therein, and is connected to an exhaust gas outlet 2 f of the melting furnace main body 2 in a communicating manner. The secondary combustion tower 11, when the oxygen injection amount of the oxygen burner 3 is made smaller than the oxygen amount required for combustion of the fuel E and the inside of the furnace is set to a reducing atmosphere, the unburned It completely burns the gas. In this case, the inside of the furnace can be set to a reducing atmosphere, and the NOx of the combustion exhaust gas G can be reduced. Also, the secondary combustion tower 11
Upstream position (lower position of secondary combustion tower 11 shown in FIG. 1)
Is provided with an oxygen blowing nozzle 13 for blowing oxygen D for secondary combustion into the secondary combustion chamber 12. The oxygen blowing nozzle 13 blows oxygen D for secondary combustion in the tangential direction along the inner peripheral surface of the secondary combustion chamber 12 to
A swirling flow can be formed in the inside 2 and is connected to an oxygen supply source 8 via a secondary combustion oxygen supply pipe 7.

The incineration fly ash supply device 17 includes a fly ash silo 18 for storing incineration fly ash A collected in an exhaust gas treatment facility of a stoker type incinerator or a fluidized bed incinerator, and a fly ash silo 18. A silo quantitative cut-out device 19 that cuts out incinerated fly ash A, a fly ash supply conveyor 20 that conveys the cut out incinerated fly ash A, a fly ash meter 21 that measures the incinerated fly ash A,
A weighing machine discharging device 22 for discharging the incinerated fly ash A in the fly ash measuring device 21, a hopper 23 for storing the incinerated fly ash A discharged from the weighing machine discharging device 22, and an incinerated fly ash A in the hopper 23
24, a hopper level sensor 25 for detecting the amount of incinerated fly ash A stored in the hopper 23, and a silo quantitative cutting device 1
9, a control device (not shown) for controlling the fly ash supply conveyor 20, the weighing machine discharge device 22, and the like.
A hopper quantitative cutout device 24 for incinerated fly ash A in the hopper 23
Thus, the primary oxygen supply pipe 5 is cut out by a predetermined amount and supplied into the primary oxygen supply pipe 5. The incinerated fly ash A cut into the primary oxygen supply pipe 5 is gas-transported by the primary oxygen B supplied from the oxygen supply source 8 and supplied to the oxygen burner 3 together with the primary oxygen B. The incineration fly ash supply device 17 is driven and controlled by a control device (not shown) such that the incineration fly ash A is supplied into the hopper 23 as needed and the level of the incineration fly ash A in the hopper 23 becomes constant. I have. That is, the control device detects the incineration fly ash A in the hopper 23 from the hopper level sensor 25.
Receives a signal indicating that the level of the silo has decreased, the fly ash meter 21 detects the set weight until the silo quantitative cutout device 1 is detected.
9 and the fly ash supply conveyor 20 are operated, and then, when the fly ash measuring machine 21 detects the set weight, the silo quantitative cut-out device 19 and the fly ash supply conveyor 20 are sequentially stopped, and then the weighing machine discharge device 22 is turned off. Driving incineration fly ash A in hopper 2
3.

Next, the case where the incineration fly ash A collected in the exhaust gas treatment equipment of the incinerator is melted using the melting processing equipment provided with the above-mentioned fly ash melting furnace 1 will be described. When melting the incineration fly ash A, the oxygen burner 3 and the like are activated in advance to preheat the furnace temperature of the melting furnace body 2 to a predetermined temperature (a temperature at which the incineration fly ash A can be melted).

When the temperature in the furnace of the melting furnace body 2 reaches a predetermined temperature, the incinerated fly ash A is supplied to the oxygen burner 3 together with the primary oxygen B by the incinerated fly ash supply device 17 and the oxygen fly ash supply mechanism 4. . That is, the incinerated fly ash A charged into the fly ash silo 18 is supplied to the silo quantitative cut-out device 19, the fly ash supply conveyor 20, the fly ash measuring machine 21, the measuring machine discharging device 22, the hopper 2
The primary oxygen supply pipe 5 is supplied to the primary oxygen supply pipe 5 sequentially through the primary oxygen supply pipe 3 and the hopper fixed amount cutout device 24, is gas-transported by the primary oxygen B flowing in the primary oxygen supply pipe 5, and is supplied into the wind box 32 together with the primary oxygen B.

The primary oxygen B and the incinerated fly ash A supplied into the wind box 32 are swirled and blown into the furnace from the burner throat 27, and are burned and melted in the high-temperature flame of the oxygen burner 3 to form molten slag. H. At this time,
Since the oxygen burner 3 uses oxygen as a combustion supporting gas,
A higher temperature flame is obtained as compared to a burner using air as a supporting gas. As a result, even incinerated fly ash A having a high melting point can be reliably burned and melted alone. In addition, since the incinerated fly ash A is transported by gas to the high-temperature flame by the primary oxygen B which is a supporting gas, the surface area of each fly ash particle can be fully utilized as a heat receiving surface, and the incinerated fly ash can be used. A can be efficiently melted.

The molten slag H adheres to the inner surface of the side wall 2a of the melting furnace main body 2 by the swirling flow of the combustion exhaust gas G generated by the primary oxygen B and the secondary oxygen C which are blown while being swirled into the furnace, and is attached to the furnace bottom 2c side. Flow to At this time, a coating layer of the molten slag H is formed on the inner surface of the side wall 2a by the molten slag H attached to the inner surface of the side wall 2a of the melting furnace main body 2. Thereby, the surface of the refractory forming the side wall 2 a can be protected from the high-temperature flame of the oxygen burner 3.

The molten slag H flowing to the furnace bottom 2c side
Is temporarily stored in a hot water pool 2g formed in the furnace bottom 2c, and then overflows sequentially from the slag outlet 2d to form a gutter 2
e, and falls into the slag cooling water tank 15 thereunder,
The slag is rapidly cooled and solidified by the cooling water to form granular granulated slag, which is carried out by the water-seal slag conveyor 16. At this time, the pool 2g formed in the furnace bottom 2c of the melting furnace body 2
Because the molten slag H is temporarily stored in
The surface of the refractory forming the furnace bottom 2c can be protected from the high-temperature flame of the oxygen burner 3. Further, since the molten slag H is stored in the pool 2g of the furnace bottom 2c, the residence time of the molten slag H in the furnace is prolonged, and the content of heavy metals in the molten slag H is reduced. Then, the unmelted material in the combustion exhaust gas G falls to the pool 2g and is completely melted.

On the other hand, high-temperature flue gas G generated in the furnace
Is sent into the secondary combustion chamber 12 through the exhaust gas outlet 2 f, where the oxygen is injected from the oxygen injection nozzle 13 to the secondary combustion chamber 12.
Secondary combustion chamber 1 by secondary combustion oxygen D blown into the
The secondary combustion is performed in 2. At this time, oxygen D for secondary combustion is blown from the oxygen injection nozzle 13 along the inner peripheral surface of the secondary combustion chamber 12 in a tangential direction to form a swirling flow in the secondary combustion chamber 12. Therefore, the unburned gas contained in the exhaust gas G is stirred and burned in the secondary combustion chamber 12 with a sufficient residence time and temperature. As a result, the unburned gas in the exhaust gas G discharged from the melting furnace body 2 is completely burned.

The exhaust gas G after the secondary combustion in the secondary combustion chamber 12 is continuously sent to the temperature reducing tower 14, where the temperature of the exhaust gas G is reduced by injection of a cooling medium I such as cooling water or compressed air. After passing through an exhaust gas treatment facility (not shown) such as a dust collector and a catalytic denitration tower, the gas becomes a clean gas and is released into the atmosphere from a chimney (not shown).

[0030]

As described above, the fly ash melting furnace of the present invention is provided with an oxygen burner for producing a high-temperature flame in the melting furnace body,
The incineration fly ash is gas-transported by oxygen, which is the supporting gas of the oxygen burner, and the incineration fly ash is blown into the high-temperature flame of the oxygen burner together with the oxygen to be burned and melted. The ash can be melted by itself, and the surface area of the individual fly ash particles can be fully utilized as a heat receiving surface by gas transporting the incinerated fly ash into a high-temperature flame by oxygen as a supporting gas. The incineration fly ash can be efficiently melted, and the furnace itself can be made compact. Since the fly ash melting furnace uses an oxygen burner, the amount of exhaust gas can be reduced. As a result, the amount of heat taken out of the exhaust gas can be reduced, the fuel ratio can be reduced, and the exhaust gas processing equipment after the melting furnace can be reduced, so that the installation space and equipment cost can be reduced. In the fly ash melting furnace of the present invention, oxygen, which is a supporting gas of the oxygen burner, is divided into primary oxygen and secondary oxygen into the furnace and supplied in two stages. The molten slag adheres to the inner surface of the side wall of the melting furnace body and flows to the bottom of the furnace due to the swirling flow of the combustion exhaust gas generated by the primary oxygen and secondary oxygen that are blown while swirling into the furnace. Go. As a result, the surface of the refractory forming the side wall can be protected from the high-temperature flame of the oxygen burner by the molten slag attached to the inner surface of the side wall of the melting furnace main body. Furthermore, the fly ash melting furnace of the present invention is provided with a pool in which the molten slag is stored at the furnace bottom of the melting furnace main body, and the molten slag stored in the pool is overflowed from the slag port to discharge hot water. Therefore, the surface of the refractory forming the furnace bottom can be protected from the high-temperature flame of the oxygen burner by the molten slag temporarily stored in the pool. Of course, the residence time of the molten slag in the furnace is prolonged to reduce the content of heavy metals in the molten slag, and the unmelted material in the combustion exhaust gas falls into the pool and is completely melted. . In addition, the fly ash melting furnace of the present invention connects a secondary combustion chamber having a secondary combustion chamber and an oxygen injection nozzle to the melting furnace main body, so that the flue gas discharged from the melting furnace main body into the secondary combustion chamber can be used. Of the unburned gas in the secondary combustion chamber in the secondary combustion with oxygen for secondary combustion,
The unburned gas in the combustion exhaust gas can be completely burned, and the oxygen in the oxygen burner can be reduced to make the inside of the furnace a reducing atmosphere, so that the NOx of the combustion exhaust gas can be reduced. Naturally, the content of heavy metals in the molten slag can be reduced by melting the incinerated fly ash in a high-temperature flame and in a reducing atmosphere.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of a melting processing facility using a fly ash melting furnace according to an embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view of an oxygen burner used in a fly ash melting furnace.

[Brief description of reference numerals]

1 is a fly ash melting furnace, 2 is a melting furnace body, 2b is a ceiling wall, 2c
Is a furnace bottom, 2d is a slag outlet, 2f is an exhaust gas outlet, 2g is a pool, 3 is an oxygen burner, 11 is a secondary combustion tower, 12 is a secondary combustion chamber, 13 is an oxygen injection nozzle, and 33 is a secondary burner. Primary oxygen nozzle, A is incineration fly ash, B is primary oxygen, C is secondary oxygen, D
Is oxygen for secondary combustion, G is combustion exhaust gas, and H is molten slag.

Continued on the front page (72) Inventor Shizuo Kataoka 2-33, Kinrakuji-cho, Amagasaki-shi, Hyogo F-term in Takuma Co., Ltd. (Reference) 3K061 NB03 NB13 NB15 NB24 NB27 3K070 DA07 DA37 4D004 AA37 AB03 AB07 AC04 CA29 CA30 CB02 CB34 CB42

Claims (4)

[Claims] A vertical cylindrical melting furnace body having a refractory structure having a molten slag discharge port and an exhaust gas outlet at a lower end;
A fly ash melting furnace having an oxygen burner provided in a downward position on a ceiling wall of a melting furnace body, wherein incinerated fly ash collected in an exhaust gas treatment facility of an incinerator is gasified by oxygen supplied to the oxygen burner. A fly ash melting furnace which is transported and blows the incinerated fly ash together with oxygen into a high-temperature flame of an oxygen burner to be burned and melted. 2. An oxygen burner has a structure in which oxygen, which is a supporting gas, can be divided into primary oxygen and secondary oxygen and supplied to the furnace in two stages. While being swirled together from the center of the oxygen burner, it can be blown into the high-temperature flame of the oxygen burner, and secondary oxygen can be blown into the furnace while swirling from the secondary oxygen nozzle formed in the melting furnace body. The fly ash melting furnace according to claim 1, wherein: 3. A basin for storing molten slag is provided at the bottom of the main body of the smelting furnace. The slag accumulated in the basin overflows from a slag port to discharge hot water, and the combustion exhaust gas generated in the furnace is discharged. The fly ash melting furnace according to claim 1 or 2, wherein the fly ash is discharged from an exhaust gas outlet formed in a direction opposite to the slag outlet. 4. A secondary combustion chamber communicating with an exhaust gas outlet of the melting furnace main body and a secondary combustion tower having an oxygen injection nozzle for blowing oxygen for secondary combustion into the secondary combustion chamber are connected to the melting furnace main body. An unburned gas in the combustion exhaust gas sent from the furnace body into the secondary combustion chamber is completely burned by the oxygen for secondary combustion in the secondary combustion chamber. Or the fly ash melting furnace according to claim 3.