JP2001349527A - Rotary melting furnace with pre-combustor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary melting furnace with a pre-combustor capable of surely melting and slagging even a large amount of ashes charged into the furnace. SOLUTION: An ash charging opening 44 having water-cooled structure of jackets 43 and 53 arranged around the middle periphery of a pre-combustor 1 and a circulating flow of tertiary air conveying ashes is formed in an annular chamber 45 to uniformly charge the ashes into the pre-combustor 1 through the opening 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for introducing ash into a pre-combustor of a swirling melting furnace with a pre-combustor, and more particularly to a technique for melting ash by a swirling melting furnace using solid and liquid fuels. About the field.

[0002]

2. Description of the Related Art A swirling melting furnace using a solid or liquid fuel is a relatively small furnace having a very large heat load per unit volume and a very high temperature inside the furnace. It can be used for the purpose of dissolving and slag-forming. In a swirling melting furnace, during the process of heating the furnace by burning fuel, unburned and ash components of solid fuel such as pulverized coal that could not be burned by the burner are melted in a high-temperature atmosphere in the furnace and swirled in the furnace. The stream is pressed against the furnace wall by the centrifugal force to form a coating layer of molten slag on the furnace wall.

When a combustion ash is supplied from the outside in a state where a molten slag coating layer is formed on the furnace wall, the remaining volatile components are volatilized by the high temperature atmosphere in the furnace or the heat of the coating layer on the furnace wall and burnt. The ash of the remaining components is melted and pressed against the furnace wall by the swirling force, and melts into the coating layer. The molten slag excessively deposited on the coating layer is conveyed while being pressed against the furnace wall by swirling force, and is discharged from the slag discharge port to the outside of the furnace. Since the swirling melting furnace has a very high heat load, when pulverized coal is used as fuel, it depends on the melting temperature of the ash, but about 3 times the weight of coal ash and about 5 times the weight of the input coal. It is possible to melt trash ash.

[0004] In a rotary melting furnace provided with a pre-combustor, FIG.
As shown in the figure, there is provided a pre-combustor having an axis in the tangential direction of the swirling body of the revolving melting furnace, and an oil burner for raising the temperature of ignition and a pulverized coal burner formed on the outer periphery of the pre-combustor at the top center. However, a pilot burner is provided next to these burners, and an ash charging nozzle is also provided near the pulverized coal burner. In a swirling melting furnace with a pre-combustor, fuel is supplied to the pre-combustor and burned, and combustion gas is blown in a tangential direction of the main-body swirling melting furnace to form a swirling flow. To form a molten slag coating layer, which is extruded to a slag discharge port and taken out as molten slag.

In the conventional swirling melting furnace shown in FIG. 3, since the ash injection nozzle is provided behind the flame region of the burner formed in the pre-combustor, no special consideration is required for the cooling measures of the nozzle itself. . However, when an ash injection nozzle is provided at the top of the pre-combustor, there is no problem during the injection of a small amount of ash. As a result, ash is deposited on the inner wall of the opposing position of the injection nozzle due to insufficiency of the melting capacity due to the instability of combustion due to the flammability of the burner. In case of misfire, it may cause a misfire. In such a state, since the furnace temperature decreases, it becomes difficult to melt the input ash.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a swirling melting furnace with a pre-combustor capable of reliably forming molten slag even when a large amount of ash is charged.

[0007]

In order to solve the above-mentioned problems, an ash charging portion structure of a swirling melting furnace with a pre-combustor according to the present invention has an ash charging portion opening of a water-cooled jacket structure at an intermediate position of a pre-combustor body. It is characterized by being provided. At the intermediate position of the pre-combustor, the flame grows sufficiently and is stabilized, so even if a small amount of ash is thrown in, the flame holding of the burner flame is not impaired, and stable combustion and ash melting can be maintained. . Although the wall of the intermediate portion of the pre-combustor body is hot due to the burner flame, the periphery of the ash inlet is protected by a water-cooled jacket, so that the inlet is not melted and closed. In the swirling melting furnace having the ash charging section structure of the present invention, since the ash supplied from the outside is charged into the high-temperature portion of the burner flame, a phenomenon that unmelted ash adheres to the wall of the pre-combustor occurs. Absent.

In addition, an annular chamber is provided around the periphery of the pre-combustor body, and a slit-shaped hole is provided at the bottom of the annular chamber, and is connected to a slit-shaped ash inlet opening formed around the pre-combustor. It can be. When such a structure is used, ash and air are introduced into the annular chamber to generate a swirling flow, which is introduced into the pre-combustor through a slit-shaped opening extending over substantially the entire circumference of the pre-combustor. Therefore, since the ash charged into the pre-combustor is diluted and relatively uniformly charged into the pre-combustor, even when a large amount of ash is charged into the chamber, the ash becomes sufficiently high temperature to form molten slag. It falls into the swirling melting furnace and is discharged. In addition, no deposit is generated on the container wall since the material is not put in a lump state.

Further, it is preferable that the pre-combustor is composed of three members: an upper burner portion, a pre-combustor body portion, and a lower portion of the pre-combustor. At this time, by forming the ash input part at the abutting position of the pre-combustor body and the lower part of the pre-combustor,
A pre-combustor provided with an ash inlet at an intermediate position can be manufactured very easily. In particular, when using a water-cooled jacket on the pre-combustor body and the lower part of the pre-combustor, form an annular slit by folding the end of the jacket into the pre-combustor and use this as a slit for ash injection. Can be. In addition, the configuration in which the distal end of the water-cooled jacket is folded into the vessel can prevent the pre-combustor from falling off the lining refractory heat insulating material. When the three members are connected to each other with a connection mechanism that is easily detachable, for example, a bolt or the like, disassembly and assembly are easy, which is beneficial for maintenance. Further, the water cooling jackets may be connected by an external pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of a swirling melting furnace with a pre-combustor of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. The swirling melting furnace of the present embodiment,
It comprises a main body swirler 1 and a pre-combustor 2, and is arranged so that the center axis of the pre-combustor 2 is perpendicular to the center axis at a position shifted from the center of the main body swirler 1.

The pre-combustor 2 is configured to be divided into three parts: a burner section 3, a pre-combustor body 4, and a lower pre-combustor section 5. An oil burner 32 and a pulverized coal burner 33 are provided at the center of the burner section 3 located at the top of the pre-combustor 2, and a pilot burner 34 is provided beside it. When the pilot burner 34 is ignited and liquid fuel is supplied to the oil burner 32, the fuel is ignited and burns in the pre-combustor 2 to raise the temperature in the furnace. The pulverized coal burner 33 is configured to surround the oil burner 32, and when primary air and pulverized coal are supplied to the pulverized coal burner 33 when the inside of the furnace has reached a certain high temperature, the pulverized coal fuel burns the oil burner 32. Ignites. After that, the flame of the oil burner 32 is extinguished and retreated, but the pulverized coal fuel supplied from the pulverized coal burner 33 maintains combustion by its own flame and the hot furnace wall and maintains the flame. In addition, secondary air is ejected from a gap 35 provided with inclined blades provided on the outer periphery of the pulverized coal burner 33 to form a swirling flow to assist combustion in the furnace.

Further, a pre-combustor body 4 and a pre-combustor lower portion 5
A slit-shaped opening 44 is provided at the joining position of the ring and surrounds the periphery thereof in a ring shape, and is connected to an annular tertiary air supply chamber 45. The tertiary air chamber 45 is provided with one or an appropriate number of supply nozzles 46 for supplying tertiary air from a tangential direction. Air is supplied from the supply nozzle 46 to the tertiary air supply chamber 45.
When air is blown into the annular chamber, an airflow swirling in the annular chamber is generated, so that the tertiary air can flow into the pre-combustor 2 uniformly over the entire circumference of the slit-shaped opening 44. The combustion state in the pre-combustor 2 is optimally controlled by the tertiary air.

The lower part 5 of the pre-combustor becomes narrower as it goes down, and is finally narrowed down to the size of the opening 55 and connected to the opening 11 provided on the upper body side of the body 1. The hot air generated in the pre-combustor body 4 flows into the main body turning body 1 through the opening 55 of the lower part 5 of the pre-combustor. Since the center axis of the pre-combustor 2 is shifted from the center of the main body swirler 1,
The inflowing heat flow forms a swirling flow in the main body swirling drum 1, and the ash generated in the furnace flows down while being pressed against the furnace wall by centrifugal force. The ash pressed against the furnace wall melts into the molten slag coating layer, is gradually conveyed, and is discharged from a slag discharge port (not shown).

The inner surfaces of the burner section 3, the pre-combustor body 4, and the pre-combustor lower section 5 are provided with refractory heat insulating materials 31, 41, 51, respectively. Further, water cooling jackets 42 and 52 are provided on the outer wall of the pre-combustor body 4 and the lower part 5, and both are connected by an external cooling water pipe so that cooling water flows in series. Since the burner section 3 does not receive the heat of the flame strongly, there is no need to provide a water cooling jacket. The lower end 43 of the water-cooling jacket 42 of the pre-combustor body 4 is bent inward of the pre-combustor 2 to prevent the lining refractory and heat insulating material 41 from falling off and to form a slit-shaped opening of the tertiary air supply chamber 45. The upper structure of the part 44 is formed. The upper end 53 of the water cooling jacket 52 in the lower part 5 of the pre-combustor is also bent inside the pre-combustor 2 to form the lower structure of the slit-shaped opening 44 of the tertiary air supply chamber 45. The lower end portion 54 of the water-cooled jacket 52 in the lower part 5 of the pre-combustor is also bent toward the center of the pre-combustor 2 to prevent the lining refractory insulation 51 from falling off.

The tertiary air supply chamber 45 also serves as an ash charging section, and together with the tertiary air, coal ash generated in another boiler or the like and refuse combustion ash generated in a refuse disposal plant are supplied. These ashes, especially the ash collected by dust collectors, are extremely fine and float in the air, so that they are unlikely to settle. The ash is distributed almost uniformly in the swirling flow in the tertiary air supply chamber 45, and It is evenly supplied from the slit-shaped opening 44 into the pre-combustor 2.

The ash supply structure of the present embodiment has a sufficiently high temperature and a sufficiently grown structure that maintains a solid shape at a higher temperature as compared with the case where ash is supplied at once from the top of the burner section 3 where the flame has not developed. A large amount of ash can be introduced without greatly affecting the flame holding of the pulverized coal burner because the fuel is dispersed and supplied little by little at the position of the flame. Also,
Since a large amount of ash is not put into the furnace at a time, no ash is deposited on the inner wall of the pre-combustor 2. The slit-shaped opening 44 for supplying ash is provided near the center of the pre-combustor 2 having an extremely high flame temperature, but is surrounded by a water-cooling jacket and is water-cooled, so that damage due to heat can be prevented. In addition, even if the ash may melt at the position of the opening due to high temperature, it is hardened and easily peeled because it is cooled, so that it hardly grows and closes the opening, and operation is easy. is there.

In the description of this embodiment, the tertiary air supply nozzle 46 is provided in the tangential direction of the tertiary air supply chamber 45. However, especially when handling light ash, it floats in the air and hardly sediments. For example, even when the ash is provided vertically on the wall of the tertiary air supply chamber 45, the distribution of the ash is sufficiently uniform. Further, the opening 44 provided in the tertiary air supply chamber 45 is formed in a slit shape over the entire circumference of the pre-combustor 2, but may be divided into a plurality of slits. It may be supplied. In any of the methods, by supplying ash to the body of the pre-combustor, the amount of molten slag that can be converted to slag is increased and the melting efficiency is significantly improved as compared with the case where ash is supplied from a nozzle provided at the top.

[0018]

As described above, the pre-combustor attached to the swirling melting furnace of the present invention has a stable durability, and the structure of the ash input portion has a stable durability and a large amount of ash can be input. Since it is possible, the use of the swirling melting furnace of the present invention makes it possible to economically and efficiently treat boiler ash and waste ash.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a swirling melting furnace with a pre-combustor of the present invention.

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

FIG. 3 is a sectional view of a conventional swirling melting furnace with a pre-combustor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body revolving body 2 Precombustor 3 Burner part 4 Precombustor body 5 Precombustor lower part 11 Opening 31, 41, 51 Lining refractory heat insulating material 32 Oil burner 32 33 Pulverized coal burner 34 Pilot burner 35 Secondary air ejection Gaps for water 42,52 water cooling jacket 43 lower end of water cooling jacket 44 slit-shaped opening 45 tertiary air supply chamber 46 tertiary air supply nozzle 53 upper end of water cooling jacket 54 lower end of water cooling jacket 55 opening

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Isao Ichikawa 2-1-1, Minamisuna, Koto-ku, Tokyo Inside Kawasaki Heavy Industries, Ltd. Tokyo Design Office F-term (reference) 3K061 LA02 LA08 NB03 4D004 AA36 CA29 CA32 CB02 CB31 CB34 CB42 DA02 DA06

Claims (4)

[Claims] An ash inlet opening surrounded by a water-cooling jacket is provided substantially at the center of a body of a precombustor having a center axis in a tangential direction of a main body of a swirling melting furnace. Rotating melting furnace with vessel. 2. The ash input section is an annular chamber surrounding the pre-combustor body, and the ash input section opening is a slit extending over substantially the entire circumference of the pre-combustor. 2. A swirling melting furnace with a pre-combustor according to claim 1, wherein the ash is swirled in the annular chamber together with the air so that the ash leaks substantially uniformly from the slit into the pre-combustor together with air. . 3. The pre-combustor comprises an upper burner, a pre-combustor body, and a lower part of the pre-combustor, and a water-cooling jacket is provided on the outer periphery of the pre-combustor body and the lower part of the pre-combustor. 3. The swirling melting furnace with a pre-combustor according to claim 2, wherein a slit sandwiched by a water cooling jacket is formed between the pre-combustor body and a lower portion of the pre-combustor. 4. The water-cooling jacket of the pre-combustor body is formed by bending a lower part into a furnace to prevent falling off of the refractory and heat-insulating material of the pre-combustor body and form an upper water-cooling jacket at the ash inlet opening. 4. The swirling melting furnace with a pre-combustor according to claim 3, wherein an upper portion of a water-cooling jacket below the pre-combustor is extended into the furnace to form a lower water-cooling jacket at an opening of the ash charging section.