JPH1114024A - Combustion melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion melting furnace which achieves a higher recovery efficiency of melted flying ash therein. SOLUTION: In a combustion melting furnace, a pyrolytic gas G1 a combustible powder (d) and air F for combustion are supplied from an upper part of a vertical type cylindrical furnace body 11 to be burned, and combustion ash generated by the combustion is turned to a melted slag (g). The melted slag (g) is made to adhere to an inner wall 11a of the furnace and falls down to be discharged from a lower discharge port 19, while the air F for combustion is supplied from an air nozzle 17. The air nozzle 17 has an angle of inclination (5-50 deg., 40-80 deg.) upward and in the circumferential direction thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a combustion melting furnace, and more particularly to a combustion melting furnace used as a waste treatment device.

[0002]

2. Description of the Related Art Conventionally, as one of apparatuses for treating industrial waste including general waste such as municipal waste and combustible materials such as waste plastic, the waste is put into a pyrolysis reactor and heated in a low oxygen atmosphere. To generate a pyrolysis gas and a pyrolysis residue mainly composed of non-volatile components.Then, the pyrolysis residue is cooled and led to a separation device. It is separated into non-combustible components such as metal, pottery, gravel and concrete flakes, and crushes the flammable components.The crushed combustible components and pyrolysis gas are led to a combustion melting furnace, where the combustion and melting are performed. There is known a waste treatment apparatus in which combustion ash generated by burning in a furnace is melted to form molten slag, and the molten slag is discharged and solidified by cooling (for example, JP-A-1-49816).

[0003] The combustion melting furnace in this waste treatment apparatus usually has a vertical cylindrical furnace body 1 as shown in FIG.
Pyrolysis supplies pyrolysis gas G ₁ to the top of the gas nozzle 2
When it is inserted into the pyrolysis gas nozzle 2, a pre-combustion air nozzle 3 for injecting pre-combustion air F ₁ to mix with the pyrolysis gas G _1, flammability powder d such unburned carbon
And a primary air nozzle 6. The secondary air nozzle 7 is provided in the furnace body 1 at a predetermined interval above and below the primary air nozzle 6. , And a tertiary air nozzle 8. A slag discharge port 9 and a combustion gas G ₂
Exhaust gas passage 10 is provided. Then, the combustible powder d supplied from the powder nozzle 4 is burned in a high temperature range of about 1,300 ° C., and the combustion ash generated by this combustion is melted to become molten slag g, thereby forming an inner wall of the furnace body 1. 1a, flows down, is discharged from the lower discharge port 9, and is cooled and solidified by a cooling device (not shown).

[0004]

However, in the conventional combustion melting furnace, there is a problem that the recovery of the molten slag g is not sufficient. That is, from the powder nozzle 4 to the furnace body 1
The diameter of the combustible powder d supplied to the inside is about 1 mm. Therefore, the combustion ash and the molten slag g generated by burning the fine combustible powder d also temporarily include the combustion gas G _2.
It will float inside. For this purpose, it is considered that a swirling flow is applied to the primary air F ₂ , the secondary air F ₃ and the tertiary air F ₄ to adhere fine combustion ash and molten slag g to the furnace inner wall 1 a by centrifugal force. Ash and molten slag g
There the inability effectively turning, not generated sufficient centrifugal force is discharged from the exhaust gas passage 10 entrains become molten fly ash in the pyrolysis gas G _2. As a result, the recovery rate of the molten slag g is low.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems.
Pyrolysis gas, combustible powder and combustion air are supplied from the upper part of the vertical cylindrical furnace body and burned, and the combustion ash generated by the combustion is turned into molten slag, and the molten slag adheres to the furnace inner wall. The combustion and melting furnace is configured such that the air for combustion is supplied from an air nozzle and the air nozzle is arranged to have an inclination angle inclined upward and circumferentially. It is assumed that.

This air nozzle is composed of a primary air nozzle, a secondary air nozzle and a tertiary air nozzle which are arranged at predetermined intervals in the vertical direction. All of these primary, secondary and tertiary air nozzles are used. Or at least one of the air nozzles is arranged to have an inclination angle that is inclined upward and circumferentially. The angle of inclination is preferably in the range of 5 to 50 degrees in the upward direction and 40 to 80 degrees in the circumferential direction.

Further, it is preferable that the combustion air supplied from the air nozzle is accompanied by a combustible powder. According to the air combustion melting furnace configured as described above, the combustion air supplied from the air nozzle generates a swirling flow upward along the furnace inner wall. As a result, centrifugal force is applied to the fine combustion ash and the molten slag g, and the residence time is prolonged by the air flow from bottom to top. As a result, the combustion ash and the molten slag g adhere to the inner wall of the furnace and the recovery rate is reduced. Can be improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a combustion melting furnace according to the present invention will be described below with reference to FIGS. A pyrolysis gas nozzle 12 supplies the pyrolysis gas G ₁ at the top of the vertical cylindrical melting furnace 11, pre-combustion air F ₁ to mix is inserted into the pyrolysis gas nozzle 12 and the pyrolysis gases G ₁ Pre-combustion air nozzle 13 for ejecting fuel, powder nozzle 14 for ejecting combustible powder d such as unburned carbon, and ignition burner 1
5 and the primary air nozzle 16 for supplying primary air F _2, a secondary air nozzle 17 for supplying secondary air F _3, are further arranged and tertiary air nozzles 18 for supplying tertiary air F _4. And the lower part of the furnace body 11, a slag discharge port 19 and the exhaust gas passage 20 of the combustion gas G ₂ is provided.

The secondary air nozzle 17 will be described in detail.
As shown in FIGS. 2 and 3, this secondary air nozzle 1
7 are provided at predetermined intervals in the circumferential direction of the melting furnace (furnace body) 11 (six in the illustrated example), and each secondary air nozzle 17 is planarly arranged from the center line of the melting furnace 11. Has an inclination angle β ₁ (an angle formed by the center line of the secondary air nozzle 17 with respect to a tangent to the inner diameter of the melting furnace 11), and an upward inclination angle α ₁ (horizontal plane of the melting furnace 11). (Upward corner with respect to).

According to the knowledge of the present inventor, the inclination angle β _{1 in the} circumferential direction is preferably in the range of 40 to 80 degrees, and the inclination angle α _{1 in the} upward direction is preferably in the range of 5 to 50 degrees. preferable. By providing the secondary air nozzle 17 with the two inclination angles α ₁ and β ₁ with respect to the melting furnace 11 in this manner, as shown in FIG. _{In 2} , an upward swirling flow f ₁ along the inner wall 11 a of the furnace body 11 and a descending flow f _{2 at the} center are generated.

Accordingly, the combustion ash and the molten slag g entrained in the combustion gas G ₂ are thrown upward while being swirled by the centrifugal force, so that the descending force is reduced and the residence time is reduced. Since it can be held for a long time, it easily adheres to the inner wall 11a, and as a result, the recovery rate of the molten slag g can be improved. Although only the secondary air nozzle 17 has been described in the above embodiment, the primary air nozzle 16 and the tertiary air nozzle 18
Can have a similar structure, or the primary air nozzle 1
Only 6 or only the tertiary air nozzle 18 can have a circumferential and upward tilt angle.

[0012] Figure 5 is a further embodiment of the primary air nozzle 16, in this primary air nozzle 16 is connected a line L _3, the combustion component d sent from the line L ₃ is primary air F ₂ And supplied into the combustion and melting furnace 11. Of course, the combustible component d is the secondary air F ₃
Or tertiary can be fed by mixing air F _4. Further, if necessary, fly ash collected by a dust collecting device described later or combustion ash generated by other incineration can be mixed with the combustible component d.

FIG. 6 is a system diagram of a waste treatment apparatus equipped with a combustion melting furnace 11 according to the present invention. Reference numeral 21 denotes a thermal decomposition reactor comprising, for example, a horizontal rotary drum. The waste a is charged by the charging device 22. This is the pyrolysis reactor 21 heated air b which has been heated by air heater 23 is supplied from the line L ₁ inside 300 ° C. to 600 ° C., with typically is heated to about 450 ° C., not shown seal The inside thereof is maintained in a low oxygen atmosphere below the atmospheric pressure by the mechanism and the induction blower 24.

The waste a supplied into the pyrolysis reactor 21 is heated and pyrolyzed here, and the pyrolysis gas G
₁ and the pyrolysis residue c separated at the discharge device 25, the pyrolysis gases G ₁ are a combustion melting furnace 11 through a line L ₂
Is supplied to the thermal decomposition nozzle 12.

On the other hand, the pyrolysis residue c is cooled by a cooling device 26 and then separated by a separating device 27 into a combustible component d mainly composed of carbon and a non-combustible component e such as metal and rubble. The non-combustible component e is collected in the container 28. The combustible component d is ground to less fine example 1mm by a pulverizer 29, the pulverized combustible component d is supplied from the line L ₃ to the powder nozzles 14 of the combustion melting furnace, where the line L ₂ Pyrolysis gas G supplied
Combustion treatment is performed in a high temperature range of about 1,300 ° C. by the pre-combustion air F ₁ , the primary air F ₂ , the secondary air F ₃ and the tertiary air F ₄ supplied from the line L ₄ by ₁ and the forced blower 30. .

The combustion ash generated by this combustion and the ash contained in the combustible component d are melted and become molten slag g and adhere to the furnace inner wall 11a while rotating in the melting furnace 11,
The slag is discharged from the downflow slag discharge port 19 into the water tank 31 and solidified by cooling. Combustion gas G ₂ generated in the combustion melting furnace 11
, After being heat-recovered by the waste heat boiler 32 provided by the air heater 23 also to the exhaust gas line L ₅ in the exhaust gas channel 20, the dust collecting device 33, after the dust has been cleaned by the gas cleaning device 34, compared most become specific low-temperature exhaust gas G ₃ are released from the chimney 35 into the atmosphere, part of it is supplied to the cooling device 26 via line L ₆ by the circulating blower 36. Reference numeral 37 denotes a power generator driven by the steam S obtained by the waste heat boiler 32.

[0017]

As is apparent from the above description, according to the combustion melting furnace of the present invention, at least one of the primary air nozzle, the secondary air nozzle and the tertiary air nozzle is inclined upward at an angle α. ₁ and circumferential angle β ₁
By forming a swirl flow and an upward flow in the combustion gas G ₂ ,
The residence time of the molten fly ash can be kept long, and the molten fly ash can be easily attached to the furnace inner wall, and as a result, the slag recovery rate can be improved.

[Brief description of the drawings]

FIG. 1 is a side view in which a part of a combustion melting furnace according to the present invention is cut away.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG. 2;

FIG. 4 is an explanatory diagram of a combustion gas flow.

FIG. 5 is an explanatory view of another embodiment of the primary air nozzle.

FIG. 6 is a system diagram of a waste treatment apparatus equipped with a combustion melting furnace according to the present invention.

FIG. 7 is a partially broken side view of a conventional combustion melting furnace.

[Explanation of symbols]

1,11 Combustion melting furnace 2,12 Pyrolysis gas nozzle 3,13 Pre-combustion air nozzle 5,15 Ignition burner 6,16 Primary air nozzle 7,17 Secondary air nozzle 8,18 Tertiary air nozzle 9,19 Slag outlet 2,20 Exhaust gas passage 21 Pyrolysis reactor 22 Input device 23 Air heater 24 Induced blower 25 Discharge device 26 Cooling device 27 Separator 28 Container 29 Crusher 30,36 Push-in blower 31 Water tank 32 Waste heat boiler 33 Dust collector 34 Gas cleaning equipment 35 Chimney 37 Power generator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F23J 1/00 F23J 1/00 B

Claims (5)

[Claims] 1. A combustion furnace comprising a pyrolysis gas, a combustible powder, and combustion air supplied from an upper portion of a vertical cylindrical furnace body and burned, and combustion ash generated by the combustion is converted into a molten slag. The combustion air is supplied from an air nozzle, and the combustion air is supplied from an air nozzle, and the air nozzle is arranged so as to have an inclination angle inclined upward and circumferentially. Melting furnace. 2. The air nozzle comprises a primary air nozzle, a secondary air nozzle and a tertiary air nozzle arranged at predetermined intervals in a vertical direction, and at least one of the air nozzles is arranged in an upward direction and a circumferential direction. 2. The combustion melting furnace according to claim 1, wherein the furnace is arranged so as to have an inclined angle. 3. The air nozzle according to claim 1, wherein the inclination angle in the upward direction is 5 to 50 degrees and the inclination angle in the circumferential direction is 40 to 80 degrees. 4. The air nozzle according to claim 1, wherein the combustible powder is supplied together with combustion air. 5. The method according to claim 1, comprising unburned carbon and ash.
5. The flammable powder according to 4.