JP4103115B2 - Combustion air blowing method for combustion melting furnace and combustion melting furnace - Google Patents

Description

  The present invention relates to a combustion air blowing method for a combustion melting furnace and a combustion melting furnace, and more specifically, combustion melting in which combustion gas in the furnace is swirled to collect molten slag on a wall surface and flow down. The present invention relates to a method for blowing air for combustion in a furnace.

  2. Description of the Related Art As a waste treatment method for treating waste such as municipal waste, a method for thermally recovering waste by pyrolyzing the waste and burning pyrolysis gas is known. In addition, fine incombustibles such as ash accompanying the pyrolysis gas are separated from the combustion exhaust gas by melting it with the combustion heat of pyrolysis gas and pyrolysis carbon generated by pyrolysis to form molten slag. It is known to collect (Patent Document 1).

  In particular, in order to promote the mixing of pyrolysis gas or pyrolysis carbon and combustion air, and to improve the collection rate of molten slag, the swirl flow is applied to the combustion air blown from the furnace wall and mixing is attempted. The fine combustion ash and molten slag are attached to the furnace wall by centrifugal force and collected. Furthermore, in order to increase the residence time in the furnace and promote melting and adhesion, it has been proposed to provide the air blowing nozzle inclined upward. On the other hand, Patent Document 2 proposes to provide an air blowing nozzle of a melting furnace horizontally or downward.

Japanese Patent Laid-Open No. 11-14024 JP-A-9-210336

  However, in Patent Documents 1 and 2, no consideration is given to a decrease in the air concentration in the center of the combustion melting furnace due to the swirling flow. That is, normally, the combustion air is pressurized into ambient temperature ambient air by a blower and blown into the furnace from an air blowing nozzle. Therefore, since the combustion air blown in and swirled has a higher specific gravity at a lower temperature than the combustion gas in the furnace, it is biased toward the furnace wall side by the centrifugal force of the swirling flow, and the air concentration in the furnace center portion becomes lower. The present inventors have found a phenomenon in which combustion gas containing a large amount of combustion components blows through the center of the furnace and hinders complete combustion.

  An object of the present invention is to realize a combustion air blowing method suitable for collecting molten slag on a wall surface by swirling flow while ensuring combustion in the center of a combustion melting furnace.

  In order to solve the above problems, the present invention introduces at least one combustion product of pyrolysis gas and pyrolysis carbon from the top of a combustion melting furnace and supplies the amount of air necessary for combustion of the combustion product to the combustion melting furnace. In a combustion air blowing method for a combustion melting furnace for supplying the gas to a plurality of locations in the furnace height direction of the furnace, burning the combustion product and converting incombustibles contained in the combustion product into molten slag, The first air flow blown toward the tangential direction of the imaginary circle centered at the center and the second air flow blown toward the core from the furnace wall are mixed.

  That is, the present invention forms a swirling flow that generates a centrifugal force for collecting the molten slag on the wall surface by the first air flow, and the swirling flow formed by the first air flow (swirl flow) is the second. The purpose of the present invention is to promote the mixing of the combustion gas of the combustion product and the combustion air by increasing the air concentration in the core and maintain the combustion by stirring the air flow (center blowing flow). In other words, the swirl flow that generates centrifugal force that collects molten slag on the wall and the central blow flow that promotes mixing of combustion gas and combustion air are mixed to produce and collect molten slag. Simultaneously, the concentration of the combustion air in the furnace cross section is averaged.

  By the way, the air blown into the furnace from the upper part of the furnace is generally referred to as primary air, and the combustion zone into which the primary air is blown is a reducing atmosphere, and the incombustible substances contained in the burned material are melted into slag. The temperature has not been reached. Therefore, it is preferable to promote the stirring of the combustion product and the combustion air in order to promote combustion, rather than the centrifugal force that collects the molten slag on the wall surface.

  Therefore, as a specific aspect of the present invention, it is preferable to blow a central blowing flow as the second air flow into the upper portion of the combustion melting furnace.

  The air blown into the intermediate position of the furnace height is generally referred to as secondary air, and the tertiary air may be blown into the intermediate position of the furnace height closer to the furnace bottom than the secondary air. Since the combustion area where the secondary air is blown has reached a temperature at which the incombustible material is melted into slag, it is preferable to generate centrifugal force to collect the molten slag on the wall surface by swirling the blown air. . On the other hand, it is preferable that the combustion product and air are sufficiently mixed even in the secondary combustion region where the secondary air is blown. However, if the total amount of secondary air is swirled, the air concentration in the furnace center may be lowered by the centrifugal force of swirling flow, and combustion in the center may be hindered. The same applies to the tertiary combustion zone into which tertiary air is blown.

  Therefore, as a specific aspect of the present invention, for the secondary or tertiary air blown between the furnace top and the furnace bottom, the first air flow and the second air flow are mixed and blown. preferable. As a result, the mixing and stirring of the combustion product and air is promoted by the intersection of the second air flow and the swirling flow of the combustion gas, and the decrease in the air concentration in the furnace center is suppressed. Promoted. In this case, it is desirable to shift the height position of the main flow at the core position so that the main flows of the first air flow and the second air flow do not interfere in the furnace.

In addition, a combustion melting furnace that directly implements the combustion air blowing method of the present invention includes a combustion substance injection nozzle that is provided at the top of the furnace and into which at least one of pyrolysis gas and pyrolysis carbon is injected, and an upper part of the furnace. A plurality of primary air blowing nozzles provided, a plurality of secondary air blowing nozzles provided between the position of the primary air blowing nozzle and the bottom of the furnace , and the secondary air in a combustion melting furnace provided with a plural blow nozzles of tertiary air disposed between the position and the bottom portion of the furnace of the blowing nozzle, a plurality of blow nozzles of the primary air, the furnace of the same height distributed along the periphery, and is provided toward the core, a plurality of blow nozzles of the secondary air are arranged in two stages in the dispersed and Rodaka along the periphery furnace, the furnace center the first blow of the lower disposed toward the tangential direction of the virtual circle centered on It and a second blow nozzle of the upper disposed toward the nozzle and the core, a plurality of blow nozzles of the tertiary air is distributed along the furnace around the same height It is, and be configured with at least one second blowing nozzle provided towards the first blow nozzle and the core disposed toward the tangential direction of the virtual circle around the core it can.

According to this, the pyrolysis gas and pyrolysis carbon introduced from the combustion substance introduction nozzle are caused to flow into the primary air by the stirring flow generated by the collision of the central blowing flow blown from the plurality of blowing nozzles of the primary air. And mixing and stirring are promoted, and combustion can be promoted. Further, in the region where the secondary air is blown, mixing and stirring is further promoted by the central blowing flow blown from the upper second blowing nozzle, and the swirling flow blown from the lower first blowing nozzle Molten slag is collected on the wall. In addition, air blown from a plurality of blow nozzles provided toward the core of primary air, secondary air, and tertiary air collide with each other in the core, and is divided into an upward flow or a downward flow. The stirring effect with the combustion product or combustion gas is further improved.

Further, a plurality of blowing nozzles tertiary air is distributed along the circumference furnace and arranged in two stages in Rodaka direction, the upper of the second blow nozzle and the lower the first blow And a nozzle .

Further, the first blowing nozzles for the secondary air and the tertiary air can be provided downward. As a result, interference due to the intersection or collision between the first air flow (swirl flow) and the second air flow (center blowing flow) can be reduced, and a swirl flow having a desired strength can be formed.

  According to the combustion air blowing method or combustion melting furnace of the present invention, combustion at the center of the combustion melting furnace can be secured, and molten slag can be collected on the wall surface by swirling flow.

  Hereinafter, an embodiment of a combustion melting furnace that directly implements the method for blowing combustion air of the present invention will be described with reference to the drawings. In FIG. 1, the longitudinal cross-sectional view of one Embodiment of a combustion melting furnace is shown. As shown in the figure, the combustion melting furnace 1 is formed in a vertical cylindrical shape, and a main burner 3 for burning the pyrolysis gas 2 is provided at the top of the furnace. The main burner 3 is concentrically provided with an auxiliary burner 4 for burning auxiliary fuel. In addition, a pair of charging nozzles 6 for charging pyrolytic carbon 5 is provided on the furnace shoulder. The axes of the pair of injection nozzles are symmetrically arranged in the tangential direction of the virtual circle centered on the core, so that pyrolytic carbon is introduced into the furnace while forming a swirling flow. Yes. Further, the furnace bottom portion of the combustion melting furnace 1 is connected to the vertical flue 8 via the horizontal flue portion 7, and a molten slag discharge port 9 is provided at the bottom of the horizontal flue portion 7. The vertical flue 8 is connected to, for example, an air heater (not shown) and a waste heat boiler that recover the heat of the combustion exhaust gas.

  On the other hand, on the furnace wall of the combustion melting furnace 1, a primary air blowing nozzle 11 and a secondary air blowing nozzle 12 that blow combustion air into the furnace from the top in the furnace height direction to the bottom of the furnace, The tertiary air blowing nozzles 13 are provided in multiple stages at intervals in the furnace height direction. The blowing nozzles 11, 12, and 13 are each configured with a plurality of blowing nozzles arranged at equal intervals along the furnace periphery. The blowing nozzles 11, 12, and 13 are connected to the blower via flow control valves (not shown), respectively, and 1 is controlled by the combustion control device based on the input amount of pyrolysis gas and pyrolysis carbon and the combustion state. Control is performed so that the secondary to tertiary air amounts have a predetermined excess air ratio.

  Here, the plurality of primary air blowing nozzles 11 are provided so as to be distributed along the periphery of the furnace at the same height and toward the core. In addition, a plurality of secondary air injection nozzles 12 are distributed along the periphery of the furnace at the same height between the position of the primary air injection nozzle 11 and the bottom of the furnace, and a virtual center around the core. It is provided toward the tangential direction of the circle. Further, the plurality of tertiary air blowing nozzles 13 are distributed along the same height of the periphery of the furnace between the position of the secondary air blowing nozzle 12 and the bottom of the furnace, and the virtual center around the core. It is provided toward the tangential direction of the circle.

  Here, a plurality of (for example, six) blowing nozzles 12 are provided with a part (for example, three) directed in the tangential direction of a virtual circle centered on the core, and the remaining (for example, three) are disposed in the core. It can also be provided toward.

  The combustion operation of the combustion melting furnace configured as described above will be described focusing on the method of blowing combustion air. The auxiliary burner 4 burns auxiliary fuel such as kerosene to raise the temperature in the furnace. Thereafter, pyrolysis gas is introduced from the main burner 3, pyrolytic carbon is introduced from the injection nozzle 6, and combustion air is blown from each of the blowing nozzles 11, 12, 13 for combustion. At this time, since the pyrolytic carbon supplied from the injection nozzle 6 is supplied into the furnace while turning, it is mixed and stirred with the pyrolysis gas and the primary air injected from the injection nozzle 11 and combusts.

  In particular, as shown in FIG. 2, the flows of primary air blown from a plurality of blow nozzles 11 collide with each other, and an upward flow and a downward flow as shown by arrows are formed. Mixing of cracked carbon and primary air is promoted, and an effective reducing combustion zone is formed.

  When the combustion gas in the upper part of the furnace flows down and reaches the region of the blowing nozzle 12 into which the secondary air is blown, the blowing gas is blown from the blowing nozzle 12 provided in the tangential direction of the virtual circle centering on the core. Combustion gas is swirled by the swirling flow of the air that is introduced, and mixed with the secondary air to form a high-temperature combustion zone. As a result, the fine ash and incombustibles contained in the combustion gas are melted into slag, moved by the centrifugal force of the swirling flow, and collected on the furnace wall. The collected molten slag flows down along the furnace wall and is discharged to the outside from the molten slag discharge port 9 at the bottom of the furnace.

  By the way, since a swirl flow is formed in the secondary combustion zone, the secondary air having a high specific gravity is biased toward the furnace wall, the air concentration in the core decreases, and combustion in the center is hindered. However, when the combustion gas in the secondary combustion region flows down and reaches the region of the blowing nozzle 13 where the tertiary air is blown, the tertiary air is blown from the plurality of blowing nozzles 13 provided toward the core. The flow of tertiary air collides with each other to form an upward flow and a downward flow as indicated by arrows. Thereby, mixing of combustion gas and tertiary air is promoted, and combustion can be promoted to complete combustion.

  Here, as shown in FIG. 2, among the plurality of secondary air injection nozzles 12, some of the injection nozzles are provided toward the core, and the air flows collide with each other to form a stirring flow. Thus, the mixing and stirring effect can be improved. In this case, among the plurality of tertiary air blowing nozzles 13, some of the blowing nozzles are provided in the tangential direction of the virtual circle centered on the core to compensate for the reduction in the swirling flow in the secondary air region. It is preferable to make it.

  In these cases, among the secondary air and tertiary air blowing nozzles, the blowing nozzle provided toward the tangential direction of the virtual circle is preferably provided downward as shown in FIG. Thereby, it can avoid that a swirling flow interferes with the center blowing flow toward a core, and the function of each other's airflow is prevented.

  Next, specific examples of the arrangement of the combustion air blowing nozzles 11, 12, and 13 according to the features of the present invention will be described. In Table 1, the structure of the Example of this invention of the blowing nozzles 11, 12, and 13 and a comparative example is shown and contrasted.

実施例の吹込みノズル１１、１２、１３はそれぞれ６本であり、１次空気の吹込みノズル１１は、炉肩部の熱分解カーボンの投入口５と同じ位置に、炉心を中心とする仮想円の接線方向に向けた旋回流を形成するように配置されている。この点は、実施形態と相違する。２次空気の吹込みノズル１２は、図３（ａ）に示すように、炉壁１４の周囲に等間隔に分散させて、炉心を中心とする仮想円１５の接線方向に向けた旋回流を形成する３本の吹込みノズル１２ａと、炉心に向けた中心吹込み流を形成する３本の吹込みノズル１２ｂから構成されている。旋回流を形成する３本の吹込みノズル１２ａは、図示していないが、図２で説明したように、ノズルの向きを下向きにして設けられている。

In the embodiment, the number of blowing nozzles 11, 12, 13 is six, and the primary air blowing nozzles 11 are virtually located around the core at the same position as the pyrolytic carbon inlet 5 in the furnace shoulder. It arrange | positions so that the swirling flow toward the tangential direction of the circle may be formed. This point is different from the embodiment. As shown in FIG. 3 (a), the secondary air blowing nozzle 12 is distributed at equal intervals around the furnace wall 14 to generate a swirl flow directed in the tangential direction of the virtual circle 15 centering on the core. The three blow nozzles 12a to be formed and the three blow nozzles 12b to form a central blow flow toward the core are configured. Although not shown, the three blowing nozzles 12a forming the swirl flow are provided with the nozzles facing downward as described in FIG.

  Further, as shown in FIG. 3B, the tertiary air blowing nozzles 13 are distributed at equal intervals around the furnace wall 14 and swivel in the tangential direction of the virtual circle 15 centering on the core. It consists of six blowing nozzles 12 that form a flow.

  In addition, although the nozzle diameter of the blowing nozzle 13 of an Example used the thing of a smaller diameter than the other blowing nozzles 11 and 12, the nozzle diameter of these blowing nozzles 11, 12, and 13 is required for combustion. The air amount is set to be blown in a predetermined flow velocity range, and is not limited to the nozzle diameters in Table 1.

  According to the embodiment configured as described above, as described in FIG. 2, due to the stirring effect by the flow of primary air blown from the blow nozzle 11, the pyrolysis gas, pyrolysis carbon, and primary air are mixed. Mixing is promoted to form a reducing combustion zone. When the combustion gas reaches the region of the blowing nozzle 12 into which the secondary air is blown, the combustion gas and the air are stirred by the upper and lower stirring flows generated by the central blowing air flow of the blowing nozzle 12b. . Further, the combustion gas is swirled by the swirling flow of the blowing nozzle 12a and mixed with the secondary air to form a high-temperature combustion zone. At this time, since the swirling flow is blown downward, the central blowing air flow and the swirling flow do not interfere with each other. Therefore, the fine ash and incombustible substances contained in the combustion gas are melted into slag, and are attached and collected on the furnace wall under the centrifugal force of the swirling flow. Further, when the combustion gas reaches the region of the blowing nozzle 13 into which the tertiary air is blown, the swirling flow of the blowing nozzle 13 promotes the mixing of the combustion gas and the tertiary air, and the combustion is promoted to complete combustion. The At the same time, the swirl flow promotes the generation and collection of molten slag.

  As a result, according to the example, an excellent combustion state can be formed as shown in Table 1, and as shown in Table 2, the CO concentration at the combustion melting furnace outlet is extremely low (0 to 10 ppm). It can be seen that almost complete combustion is achieved. In addition, the O2 concentration at the outlet could be reduced to an average of 3.3%, and the unburned carbon contained in the fly ash discharged from the combustion melting furnace could be lowered to an extremely low concentration of 0.057 wt%.

また、表２のデータは、図１の垂直煙道８の線Ｘ−Ｘの断面に設定した複数の測定点における分布値および平均値である。

Further, the data in Table 2 are distribution values and average values at a plurality of measurement points set in the cross section of line XX of vertical flue 8 in FIG.

Comparative example

  In the comparative example, the number of blowing nozzles 11 is six, and the number of blowing nozzles 12 and 13 is three. The primary air blowing nozzle 11 is arranged so as to form a swirling flow at the road shoulder. As shown in FIG. 4 (a), the secondary air blowing nozzle 12 is distributed at equal intervals around the furnace wall 14 to generate a swirling flow directed in the tangential direction of the virtual circle 15 centering on the core. Three blow nozzles 12 to be formed are arranged. Although not shown, the three blowing nozzles 12 are provided in a substantially horizontal direction. Further, as shown in FIG. 4B, the tertiary air blowing nozzle 13 is also arranged in the same manner as the blowing nozzle 12.

  According to the comparative example configured as described above, the mixing effect of the pyrolysis gas, pyrolysis carbon, and primary air is caused by the stirring effect by the flow of the primary air blown from the blow nozzle 11 as in the embodiment. Combustion is promoted. When the combustion gas reaches the region of the blowing nozzle 12, the combustion gas is swirled by the swirling flow of the blowing nozzle 12 and mixed with the secondary air to form a high-temperature combustion zone. As a result, the fine ash and incombustible substances contained in the combustion gas are melted into slag, and are collected and collected on the furnace wall under the centrifugal force of the swirling flow. Further, when the combustion gas reaches the region of the blowing nozzle 13, the mixing of the combustion gas and the tertiary air is promoted by the swirling flow of the blowing nozzle 13 and burned, and the swirling flow generates and collects molten slag. Is promoted. However, in the comparative example, both the secondary air and the tertiary air are only swirl flows, and since the supply of air to the furnace center is insufficient, the air concentration in the furnace center decreases, and the combustion gas is blown out. It has occurred.

As a result, according to the comparative example, an almost good combustion state can be formed as shown in Table 1, but as shown in Table 2, the CO concentration at the combustion melting furnace outlet is 0 to 115 ppm, and the distribution is It becomes larger and an incomplete combustion state has occurred. The O2 concentration at the outlet is maintained at an average of 3.6%, but the concentration of unburned carbon contained in the fly ash discharged from the combustion melting furnace is 0.156 wt%, which is compared with the embodiment. It turns out that the combustion state is getting worse.
(Analysis by simulation)
About the said Example and a comparative example, the result simulated with the combustion analysis model which combined the Ray nozzle stress model and the secondary upwind difference method is shown in FIGS. FIG. 5 is a swirl velocity distribution in the furnace, FIG. 6 is a swirl velocity distribution in which the secondary air and tertiary air blowing portions are enlarged, FIG. 7 is a temperature distribution in the furnace, FIG. 8 is an oxygen concentration distribution in the furnace, FIG. 9 shows the CO concentration distribution in the furnace. In these figures, (a) shows the results of the examples and (b) shows the results of the comparative examples.
(Swivel speed distribution)
According to the embodiment, as shown in FIGS. 5 (a) and 6 (a), the flow of the secondary air toward the furnace center reaches the core, collides, and burns from the upstream primary combustion zone. Mixing with gas is often done. Thus, it can be seen that the combustion gas blow-through from the primary combustion zone is completely eliminated. The tertiary air is supplied in the swirl direction, does not reach the furnace center, and is stirred and mixed with the combustion gas as a swirl flow.

On the other hand, according to the comparative example, as shown in FIGS. 5B and 6B, the secondary air is only supplied in the swirling direction, and the swirling flow is strong and does not reach the furnace center. As a result, it can be seen that the combustion gas from the upstream primary combustion zone is not stirred and mixed with the secondary air, particularly in the core, and flows in the downstream as it is. Similarly, since tertiary air is also supplied only in the swirl direction, the swirl flow is strong and there is no air reaching the furnace center. As a result, the combustion gas has no mixing and stirring with the tertiary air, particularly in the core, and flows in the downstream as it is.
(Temperature distribution)
According to the embodiment, as shown in FIG. 7 (a), the combustion gas from the primary combustion zone is well mixed with the central blow-in flow of secondary air in the furnace center so that the oxygen required for combustion is obtained. Is supplied to promote combustion. As a result, it can be seen that the combustion gas temperature is remarkably increased at the center of the furnace in the secondary combustion zone.

On the other hand, according to the comparative example, as shown in FIG. 7B, since the secondary air does not reach the furnace center, the combustion air becomes insufficient in the center of the secondary combustion zone, and combustion is not performed. Not promoted. As a result, the gas temperature in the secondary combustion zone hardly increases.
(Oxygen concentration distribution)
According to the embodiment, as shown in FIG. 8 (a), oxygen is supplied over a wide range of the secondary combustion region by the combination of the central air flow and the swirl flow of the secondary air, The anoxic region is very narrow. At the outlet of the tertiary combustion zone, the oxygen concentration is almost uniform at about 3%.

On the other hand, according to the comparative example, as shown in FIG. 8B, both the secondary combustion region and the tertiary combustion region have a portion with a high oxygen concentration on the outer periphery side of the furnace, and the combustion air is supplied by the swirl flow. For this reason, air is unevenly distributed on the outer peripheral portion. As a result, the oxygen-free state in the furnace center is not improved, and the oxygen-free condition still exists in the furnace center even at the outlet of the tertiary combustion zone.
(CO concentration distribution)
According to the embodiment, as shown in FIG. 9 (a), oxygen is supplied over a wide range of the secondary combustion region by the combination of the central air flow and the swirl flow of the secondary air, and the combustion is promoted. As a result, the CO concentration that is unburned is reduced to a level that remains slightly in the center of the furnace in the secondary combustion region, and the CO concentration is substantially zero in the tertiary combustion region.

  On the other hand, according to the comparative example, as shown in FIG. 9 (b), since air deviation occurs on the outer periphery side of the furnace in both the secondary combustion area and the tertiary combustion area, air shortage at the furnace center portion is caused. Generated and combustion is not promoted. As a result, regions where the CO concentration is high remain in the center of the furnace in the secondary combustion region and the tertiary combustion region.

  As described above, according to the embodiment of the present invention, the swirl flow that is the first air flow blown from the reactor wall toward the tangential direction of the virtual circle centered on the reactor core, and the reactor wall toward the reactor core. Therefore, it is possible to prevent the low-temperature combustion air from being biased toward the furnace wall by the swirling flow, and to generate and collect molten slag. At the same time, the concentration of combustion air in the furnace cross section can be averaged. As a result, it is possible to prevent a phenomenon that the exhaust gas is blown through the core portion and discharged incompletely.

  Moreover, as shown in the Example, a remarkable effect is acquired compared with a comparative example by mixing a center blowing flow with secondary air.

  However, the present invention is not limited to the embodiment. In short, the combustion air is blown out through the core portion by mixing the swirling flow and the central blowing flow, and is discharged as incomplete combustion. The main purpose is to reduce the combustion gas.

  However, since the combustion zone by primary air often does not reach the temperature at which molten slag is generated, a strong swirling flow for collecting molten slag is not necessarily required. Therefore, it is sufficient to have an agitation effect to the extent that the pyrolytic carbon is swirled and charged, so that only the central blowing flow is sufficient.

  On the other hand, since the region where the secondary air is blown is an active combustion region and is in a state where molten slag is generated, it is necessary to mix the swirling flow and the central blowing flow. Moreover, the area | region which blows in tertiary air is an active combustion area like a secondary combustion area, and exists in the state in which molten slag is produced | generated. However, if the air is sufficiently mixed in the secondary combustion zone, it is preferable from the viewpoint of collecting molten slag that the swirl flow is blown as the main flow. In any case, the present invention only needs to disperse and blow the necessary amount of air into the swirling flow and the central blowing flow by combining the blowing flow of the secondary air and the tertiary air.

1 is a longitudinal sectional view of a combustion melting furnace to which a combustion air blowing method according to an embodiment of the present invention is applied. It is a figure explaining the combustion operation | movement by the combustion air blowing method of FIG. 1 embodiment. It is a figure explaining the arrangement configuration of the air blowing nozzle of the example of the present invention. It is a figure explaining the arrangement configuration of the air blowing nozzle of the comparative example of the present invention. It is a figure which shows the rotational speed distribution in the combustion melting furnace obtained by carrying out the simulation analysis of the combustion air blowing method of the Example and comparative example of this invention. It is a figure which expands the blowing part of the secondary air and tertiary air of FIG. 5, and shows turning speed distribution. It is a figure which shows the temperature distribution in the combustion melting furnace obtained by carrying out the simulation analysis of the combustion air blowing method of the Example and comparative example of this invention. It is a figure which shows the oxygen concentration distribution in the combustion melting furnace obtained by carrying out the simulation analysis of the combustion air blowing method of the Example and comparative example of this invention. It is a figure which shows CO concentration distribution in the combustion melting furnace obtained by carrying out the simulation analysis of the combustion air blowing method of the Example and comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion melting furnace 3 Main burner 4 Auxiliary burner 6 Injection nozzle 7 Horizontal flue part 8 Vertical flue 9 Molten slag discharge port 11 Blowing nozzle (primary air)
12, 12a, 12b Blowing nozzle (secondary air)
13 Blowing nozzle (tertiary air)
14 Furnace wall 15 Virtual circle

Claims (3)

A combustion substance injection nozzle provided at the top of the furnace and into which at least one of the pyrolysis gas and pyrolysis carbon combustion substance is introduced; a plurality of primary air injection nozzles provided at the upper part of the furnace; A plurality of secondary air blowing nozzles provided between the position of the blowing nozzle and the furnace bottom, and the tertiary air provided between the position of the blowing nozzle of the secondary air and the furnace bottom. In a combustion melting furnace provided with a plurality of blowing nozzles,
The plurality of primary air blowing nozzles are distributed along the periphery of the furnace at the same height and provided toward the core,
A plurality of blow nozzles of the secondary air are arranged in two stages in the dispersed and Rodaka along the periphery furnace, the lower disposed toward the tangential direction of the virtual circle around the furnace heart A first blowing nozzle and an upper second blowing nozzle provided toward the core,
A plurality of blow nozzles of the tertiary air is distributed along the furnace around the same height, and the first blow provided toward the tangential direction of the virtual circle around the core combustion melting furnace, characterized by comprising at least one second blowing nozzle provided towards the nozzle and the core. A plurality of blow nozzles of the tertiary air is arranged in two stages in the dispersed and Rodaka along the periphery furnace, the upper of the second blow nozzle and the lower the first blow The combustion melting furnace according to claim 1 , further comprising a nozzle . The combustion melting furnace according to claim 1 or 2, wherein the first blowing nozzle for the secondary air or the tertiary air is provided downward.

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