JP7270193B2 - Gasification melting system - Google Patents

Description

In the present invention, unreacted gas generated by partial combustion of solid materials to be treated, including incombustibles such as municipal waste and industrial waste, is led to a melting furnace and burned at a high temperature to remove ash at a high temperature. The present invention relates to a gasification melting system that melts and discharges as molten slag and its operating method.

When incinerating solid materials to be treated, including incombustible materials such as municipal waste and industrial waste, they are usually completely incinerated in an incinerator with a sufficient amount of air necessary for combustion. The generated combustion gas is led to equipment such as a boiler, and thermal energy is recovered. Furthermore, after the ash contained in the combustion gas, whose temperature has been sufficiently lowered, is collected as dust by a dust collector such as a bag filter, the combustion gas is discharged into the atmosphere from a chimney.

In order to prevent the elution of heavy metals, the collected soot and dust must be treated with chemicals and landfilled in a dedicated disposal site. However, it is becoming increasingly difficult to locate a landfill disposal site, and it is necessary to reduce the amount of soot and dust in order to prolong its life. Therefore, a system has been devised to detoxify the dust by melting it into molten slag at a high temperature in an electric melting furnace and to reuse it. However, it was necessary to set up a melting facility separate from the incineration plant, and it was wasteful in terms of energy and cost because it was melted by electricity.

Therefore, the gasification melting equipment was invented. This facility is equipped with a gasification furnace for generating unreacted gas by thermal decomposition by partial combustion, and a melting furnace for burning the unreacted gas at high temperature. Solid objects to be treated, including incombustibles such as municipal waste and industrial waste, are partially burned in the gasification furnace, and unreacted gas (produced gas) generated therein is led to the melting furnace and heated to 1300 to 1500°C. burn at high temperature. Furthermore, the high temperature melts the ash and discharges it as molten slag.

If the gasification furnace is a fluidized bed furnace, even irregular combustibles can be stably treated, and it is most suitable for separating and discharging metals such as iron. As mentioned above, in normal incineration equipment, it is necessary to use a separately installed electric melting furnace to turn fly ash into slag, but in gasification and melting equipment, it is Since it can be made into slag inside the melting furnace, it is efficient because it does not use electric power and does not require a separate melting furnace.

2009-281694 publication 2010-236733 publication

However, in this type of gasification and melting equipment, clumps of clinker and dust tend to form on the upper inner wall of the primary combustion chamber of the melting furnace. If this clump of clinker or dust grows and becomes large, the gas flow in the melting furnace will be obstructed and the combustion reaction will become insufficient. It will be clogged, and adverse effects such as insufficient combustion and a drop in temperature will occur. Furthermore, when the clinker and dust lumps grow, the upper part of the primary combustion chamber of the melting furnace becomes clogged, which causes serious problems such as the inability to operate.

Therefore, the present invention prevents the formation of clinker and dust clumps adhering to the inner side wall in the primary combustion chamber of the melting furnace, promotes stable slag formation, and uniform and stable slag formation in the upper part of the primary combustion chamber of the melting furnace. A gasification melting system is provided that can enable high temperature combustion.

In one aspect, a gasification furnace for thermally decomposing an object to be treated including waste to generate a product gas, and a gasification furnace for burning the product gas and converting ash contained in the product gas into molten slag at a high temperature a melting furnace; and a product gas duct for introducing the product gas from the gasification furnace to the melting furnace, the product gas duct having a combustion air inlet to which a combustion air line is connected. A mixed gas of the product gas and combustion air emitted from the gasification furnace is formed in the product gas duct, and the product gas duct is eccentrically connected to the melting furnace. , the product gas duct is arranged to extend along a tangential line of the cylindrical side wall of the melting furnace, and the combustion gas generated by combustion of the mixed gas flows along the inner wall of the primary combustion chamber of the melting furnace; The melting furnace is configured to form a swirl flow, and the melting furnace has a swirl air inlet into which swirl air is introduced to promote combustion of the swirl flow and the mixed gas in the primary combustion chamber. and wherein a flow rate of said combustion air to said product gas duct is set to exceed a flow rate of said swirl air to said primary combustion chamber.

In one aspect, the combustion air inlet to which the combustion air line is connected is a plurality of combustion air inlets arranged at different positions.
In one aspect, the plurality of combustion air inlets include a first combustion air inlet connected to a first combustion air line for supplying air at room temperature and a first combustion air inlet for supplying air at a temperature higher than room temperature. a second combustion air inlet connected to a second combustion air line for
In one aspect, the plurality of combustion air inlets further includes a third combustion air inlet connected to a third combustion air line for supplying secondary air.
In one aspect, the position of the combustion air inlet is between the gasification furnace and the melting furnace, and the distance from the combustion air inlet to the melting furnace is The distance is such that the gas and the product gas are agitated in the duct and become a uniformly mixed gas mixture of the combustion air and the product gas upon entering the melting furnace.
In one aspect, the distance from the combustion air inlet to the melting furnace is in the range of 3000mm to 6000mm.

In one aspect, the swirl air inlet includes an upper swirl air inlet and a lower swirl air inlet, wherein the upper swirl air inlet is connected to the product gas duct. It is located at the same height as the center of the mixed gas inlet of the furnace or 600 mm to 900 mm below the upper end of the mixed gas inlet, and the lower swirl air inlet is positioned at the mixed gas inlet. It is arranged at the same height as the lower end or 600 mm to 900 mm below the swirling air inlet of the upper stage.
In one aspect, the lower stage swirl air introduction port is located downstream of the upper stage swirl air introduction port in the swirl direction of the combustion gas in the primary combustion chamber.
In one aspect, the air injection direction of the swirling air inlet is off-center of the primary combustion chamber and offset relative to the radial direction of the primary combustion chamber to aid in the swirling flow. .
In one aspect, the swirl air inlet is oriented horizontally or obliquely downward with respect to the horizontal direction.
In one aspect, the gasification and melting system further includes an oxygen gas supply line for enriching the swirl air introduced into the primary combustion chamber from the swirl air inlet port with oxygen gas.

In one embodiment, a product gas is generated by pyrolyzing a material to be treated, including waste, in a gasification furnace, and a product gas duct for introducing the product gas from the gasification furnace into a melting furnace is provided for combustion. introducing air from a combustion air inlet to form a mixed gas in which the generated gas and the combustion air are uniformly mixed in the generated gas duct; introducing the mixed gas into the melting furnace; While the mixed gas is combusted in the primary combustion chamber of the melting furnace to form a swirling flow of the combustion gas, swirl air is introduced into the primary combustion chamber for promoting the swirling flow and combustion of the mixed gas. and wherein the ash contained in the mixed gas is turned into molten slag at a high temperature, and the flow rate of the combustion air to the product gas duct exceeds the flow rate of the swirl air to the primary combustion chamber. is provided.

In one aspect, the combustion air comprises air that has passed through a precipitator.
In one aspect, the air that has passed through the dust collector contains air at 300°C to 400°C.
In one aspect, the position of the combustion air inlet is between the gasification furnace and the melting furnace, and the distance from the combustion air inlet to the melting furnace is It is the distance at which the gas and the generated gas are agitated in the duct and become a mixed gas in which the combustion air and the generated gas are uniformly mixed at the time of entering the melting furnace.
In one aspect, the distance from the combustion air inlet to the melting furnace is in the range of 3000mm to 6000mm.
In one aspect, the combustion air inlet is a plurality of combustion air inlets.
In one aspect, the swirling air introduced into the primary combustion chamber is enriched with oxygen gas.

According to the present invention, the following effects are obtained.
First, before entering the melting furnace, the generated gas and combustion air are sufficiently stirred and mixed inside the generated gas duct and homogenized, so that the mixed gas enters the primary combustion chamber of the melting furnace and burns at the same time. Since it can be started, stable high-temperature combustion is performed in the upper part of the primary combustion chamber of the melting furnace. As a result, there is no clinker formation or dust adhesion on the inner wall of the melting furnace, and a stable molten slag flow is formed. Operation can be continued.
In addition, by properly arranging the swirling air inlet in the primary combustion chamber of the melting furnace, a swirling flow of the combustion gas is properly formed inside the melting furnace. Higher temperature combustion is possible by enriching oxygen gas.

In addition, the use of high-temperature dust-collected air near 400°C generated from the cooling device and dust-collecting device of the high-temperature equipment in the gasification and melting plant site as the combustion air to be fed into the generated gas duct contributes to the improvement of the energy efficiency of the gasification and melting plant. It is a contribution.
In addition, low-temperature and high-temperature dust-collected air contains dust, which is turned into slag in the melting furnace by being fed into the gasification and melting equipment, and finally captured by the bag filter in the latter stage of the melting furnace. Since the dust is collected, there is an effect that a simple dust collector such as a cyclone that protects the blower can be used in each dust collector.

FIG. 2 is a diagram showing a configuration example of a supply system for combustion air and swirling air in the gasification and melting equipment according to the present invention; FIG. 2 is a horizontal cross-section of the melting furnace in FIG. 1, showing an embodiment of the arrangement of a mixed gas inlet and an upper swirling air inlet of the melting furnace; FIG. 2 is a horizontal cross-section of the melting furnace in FIG. 1, showing an embodiment of the arrangement of a mixed gas inlet and a swirling air inlet in the lower stage of the melting furnace; FIG. 10 is a diagram showing another embodiment of the arrangement of the mixed gas inlet and upper swirling air inlet of the melting furnace; FIG. 10 is a diagram showing another embodiment of the arrangement of the mixed gas inlet and the swirling air inlet in the lower stage of the melting furnace;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each explanatory diagram, the same reference numerals are given to the same or corresponding members, and overlapping descriptions are omitted. FIG. 1 is a schematic diagram illustrating one embodiment of a gasification melting system 10 . Gasification and melting system 10 may be applied, for example, to a gasification and melting power plant.

As shown in FIG. 1, the gasification and melting system 10 includes a gasification furnace 20 that thermally decomposes a material to be processed, including waste such as municipal waste and industrial waste, by partial combustion to generate a generated gas; A melting furnace 40 for burning gas and converting ash contained in the generated gas into molten slag at a high temperature, and a generated gas duct 30 for introducing the generated gas from the gasification furnace 20 to the melting furnace 40. Prepare.

The gasification and melting system 10 further includes a supply device 22 for supplying the material to be processed to the gasification furnace 20, a combustion air line 33 for supplying combustion air into the product gas duct 30, and a melting furnace 40. A swirl air line 45 is provided for forming a swirl flow inside. Although not shown, heat recovery equipment such as a boiler that recovers heat from the combustion gas F discharged from the melting furnace 40, dust collection equipment that collects and removes dust in the combustion gas F, an induced draft fan that draws in the combustion gas F, combustion A chimney or the like for releasing the gas F into the atmosphere is installed at the rear stage of the melting furnace 40 .

In this embodiment, the gasification furnace 20 comprises a fluidized bed furnace. Fluidizing air as primary combustion air is supplied below the fluidized bed 20a in the gasification furnace 20 to fluidize the fluidized medium forming the fluidized bed 20a. A material to be treated (for example, industrial waste) that serves as fuel is fed into the gasification furnace 20 by the supply device 22 . The flow rate of the fluidizing air as the primary combustion air is set lower than the flow rate of the air required for burning the material to be treated. For example, the flow rate of fluidizing air is about 30% of the flow rate of air required to completely burn the material to be treated. Therefore, the material to be treated is thermally decomposed by partial combustion in the gasification furnace 20 to generate a product gas D1, which is an unreacted gas. Incombustibles contained in the material to be treated are discharged out of the gasification furnace 20 together with part of the fluid medium. In this embodiment, the gasification furnace 20 is a fluidized bed furnace, but the gasification furnace 20 is not limited to a fluidized bed furnace as long as it generates the product gas D1. For example, gasifier 20 may be a kiln-type gasifier.

The product gas D1 drawn out from the gasification furnace 20 is supplied to the melting furnace 40 through the product gas duct 30 . The melting furnace 40 includes a primary combustion chamber 41 connected to a product gas duct 30 , a secondary combustion chamber 42 located downstream of the primary combustion chamber 41 , and a tertiary combustion chamber 42 located downstream of the secondary combustion chamber 42 . It has a combustion chamber 43 . The secondary combustion chamber 42 is inclined downward, and slag is discharged from the bottom. The shape of the secondary combustion chamber 42 is not particularly limited, and may be linear or arc-shaped, for example.

The generated gas D1 coming out of the gasification furnace 20 hardly contains oxygen. Most of the combustion air required for combusting the product gas D1 is supplied from the combustion air line 33 into the product gas duct 30 . In this embodiment, the combustion air includes air sent from a precipitator and/or a blower, as described below.

In this embodiment, the combustion air line 33 includes three combustion air lines 33-1, 33-2, 33-3. The product gas duct 30 has three combustion air inlets 30-1, 30-2, 30-3 respectively connected to these three combustion air lines 33-1, 33-2, 33-3. there is Therefore, the combustion air flowing through these three combustion air lines 33-1, 33-2, 33-3 is generated through the three combustion air inlets 30-1, 30-2, 30-3. It is supplied inside the gas duct 30 .

The first combustion air line 33-1 is connected to the first dust collector 34, and the air passing through the first dust collector 34 passes through the first combustion air line 33-1 as combustion air. It is fed into the product gas duct 30 . The first dust collector 34 is a room temperature dust collector for removing dust from the air in the plant site where the gasification melting system 10 is installed. Therefore, the combustion air sent from the first dust collector 34 to the first combustion air line 33-1 is room temperature air.

The second combustion air line 33-2 is connected to the second dust collector 35, and the air passing through the second dust collector 35 passes through the second combustion air line 33-2 as combustion air. It is fed into the product gas duct 30 . The second dust collector 35 is a hot dust collector within the gasification and melting plant site. In one embodiment, although not shown, the second dust collector 35 is connected to a classifier for classifying the incombustibles discharged from the gasification furnace 20 and a system for circulating the fluidized medium screened there. It is a high temperature dust collector. Since high-temperature incombustibles and fluid medium are introduced into the classifier, the air passing through the second dust collector 35 is high-temperature air. In one example, the combustion air sent from the second dust collector 35 to the second combustion air line 33-2 is air at 300° C. to 400° C., and the room temperature air flowing through the first combustion air line 33-1 is It has a higher temperature than the combustion air.

The third combustion air line 33-3 is connected to a blower 36 installed inside or outside the plant site. Combustion air sent from the blower 36 to the third combustion air line 33-3 is so-called secondary air, which is at room temperature, outside air temperature, or raised in temperature using a heat exchanger. The third combustion air line 33-3 is provided with an air control valve 31, and the flow rate of the combustion air line 33 flowing through the first combustion air line 33-1 and the second combustion air line 33-2 is , the air control valve 31 is opened when there is not enough to burn the product gas D1.

In the embodiment shown in FIG. 1, the three combustion air inlets 30-1, 30-2, 30-3 are arranged along the direction of flow of the product gas D1 for the first combustion air for the low temperature combustion air. Air inlet 30-1, second combustion air inlet 30-2 for hot combustion air, and third combustion air inlet 30-3 for secondary air. . However, the present invention is not limited to this order, and the order may be changed.

The reason why the combustion air is introduced into the product gas duct 30 is to uniformly mix the air and the product gas D1 before the product gas D1 enters the melting furnace 40 to make the temperature and oxygen concentration uniform. Even if air is introduced into the product gas duct 30, the product gas D1 does not burn immediately, and the introduced combustion air and product gas D1 are mixed to form a mixed gas D2. When the mixed gas D2, in which the air is evenly dispersed and the temperature and oxygen concentration are uniform, enters the melting furnace 40, the mixed gas D2 can be immediately ignited and evenly combusted. That is, the mixed gas D2 can be stably burned at a high temperature in the upper portion of the primary combustion chamber 41 only after being uniformly mixed with the combustion air in the product gas duct 30 . Therefore, the distance L from the mixed gas introduction port 40-1 of the melting furnace 40 to the combustion air introduction ports 30-1, 30-2, 30-3 is necessary and enough distance.

From this point of view, the positions of the combustion air inlets 30-1, 30-2, and 30-3 to the product gas duct 30 are set between the gasification furnace 20 and the melting furnace . That is, the combustion air supplied is sufficiently stirred and mixed with the generated gas D1, and the mixture gas D2 in which the combustion air and the generated gas D1 are uniformly mixed is obtained by the melting furnace 40 at the time of entering the melting furnace 40. A long distance L is secured. The distance L is set within the range of 3000 mm to 6000 mm, preferably within the range of 4000 mm to 5000 mm.

A first combustion air inlet 30-1 for low temperature combustion air, a second combustion air inlet 30-2 for high temperature combustion air, and a third combustion air for secondary air. The position of the introduction port 30-3 may be any of the ceiling surface, both side surfaces, or the bottom surface of the product gas duct 30, and may be determined based on the shape of the product gas duct 30. In this embodiment, the product gas duct 30 has a curved portion 30A for changing the flow direction of the product gas D1. More specifically, the product gas duct 30 is configured to arc upwardly from the gasification furnace 20 and connect horizontally to the melting furnace 40 . The three combustion air inlets 30-1, 30-2, 30-3 are located in the curved portion 30A and are located on the ceiling surface or both side surfaces of the product gas duct 30. As shown in FIG. Furthermore, these three combustion air inlets 30-1, 30-2, 30-3 face the primary combustion chamber 41 of the melting furnace 40. As shown in FIG. Combustion air is thus injected into the product gas duct 30 towards the primary combustion chamber 41 of the melting furnace 40 .

In normal operation, the air control valve 31 is closed and no secondary air is used. That is, in normal operation, low-temperature combustion air supplied from the first combustion air inlet 30-1 and high-temperature combustion air supplied from the second combustion air inlet 30-2 are used. When the amount of oxygen required for combustion becomes insufficient due to fluctuations in the flow rates of the low-temperature combustion air and the high-temperature combustion air, or when the amount of oxygen required for combustion is insufficient, the air control valve 31 is opened and the third combustion air inlets 30-3 to 2 are introduced. Next air can be appropriately introduced. As a result, a constant amount of oxygen required for combustion is supplied to maintain a high temperature in the primary combustion chamber 41 of the melting furnace 40, smooth slag flow, and stable operation.

As noted above, at least two combustion air inlets 30-1, 30-2 are used during operation. By introducing the combustion air from a plurality of combustion air inlets 30-1 and 30-2 arranged at different positions, the combustion air is more quickly and uniformly mixed with the generated gas D1. It's for.

Although one each of the first combustion air inlet 30-1, the second combustion air inlet 30-2, and the third combustion air inlet 30-3 is provided in FIG. However, in practice, a plurality of them may be used as appropriate according to the shape of the product gas duct 30 or the like. For example, although not shown, the combustion air line 33- 1, 33-2, and 33-3 are interconnected and switched by an air valve, it is possible to share the combustion air inlets 30-1, 30-2, and 30-3.

The swirling air line 45 is connected to the primary combustion chamber 41 of the melting furnace 40, and the secondary air line 46 is connected to the secondary air inlet 43- provided in the tertiary combustion chamber 43 of the melting furnace 40. 1. The flow rate of combustion air introduced into the product gas duct 30 is set to exceed the flow rate of swirl air introduced into the primary combustion chamber 41 of the melting furnace 40 . By doing so, the mixed gas D2 starts burning as soon as it enters the primary combustion chamber 41, and stable high-temperature combustion is possible in the upper portion of the primary combustion chamber 41. FIG. The secondary air supplied into the tertiary combustion chamber 43 of the melting furnace 40 is supplied in an amount necessary for reducing the CO concentration and cooling the combustion gas F.

In this embodiment, the swirl air line 45 includes an upper swirl air line 45-1 and a lower swirl air line 45-2. The primary combustion chamber 41 of the melting furnace 40 is provided with swirling air inlets 41-1 and 41-2 in a plurality of stages along the flow of the combustion gas F in the vertical direction. The upper swirl air inlet 41-1 and the lower swirl air inlet 41-2 are connected to an upper swirl air line 45-1 and a lower swirl air line 45-2, respectively. The upper stage swirl air line 45-1 and the lower stage swirl air line 45-2 may be two independent lines, or may be two lines branched from a common line.

The swirling air introduced from the swirling air inlets 41-1 and 41-2 not only promotes the swirling flow of the combustion gas F formed in the primary combustion chamber 41, but is also required for combustion of the mixed gas D2. It also contributes to the supply of sufficient oxygen. In this embodiment, two stages of swirling air inlets 41-1 and 41-2 are provided. From the viewpoint of promoting the swirling flow of the combustion gas F, it is conceivable to provide three or more stages of swirling air inlets. There is a possibility that the temperature may be lowered, or lumps such as clinker may be formed, thereby deteriorating the combustion state. From this point of view, in this embodiment, two stages of swirling air introduction ports 41-1 and 41-2 are provided.

The swirling air is, in one example, air at room temperature, but may be air at a temperature higher than room temperature. For example, the swirl air may be secondary air delivered from the blower 36 described above. The upper swirling air inlet 41-1 is positioned at the same height as the center of the mixed gas inlet 40-1, or 600 mm to 900 mm, preferably 700 mm to 800 mm below the upper end of the mixed gas inlet 40-1. are doing. The lower swirling air inlet 41-2 is positioned at the same height as the lower end of the mixed gas inlet 40-1, or 600 mm to 900 mm, preferably 700 mm to 800 mm below the upper swirling air inlet 41-1. are doing.

2 is a horizontal cross-sectional view of the mixed gas inlet 40-1 and the upper swirl air inlet 41-1 of the melting furnace 40, and FIG. 3 is the mixed gas inlet 40 of the melting furnace 40. -1 and a horizontal cross-sectional view of the lower swirling air inlet 41-2 as viewed from above. As shown in FIGS. 2 and 3, the product gas duct 30 is eccentrically connected to the melting furnace 40 . Since the product gas duct 30 is arranged to extend along the tangential line of the cylindrical side wall of the melting furnace 40, the mixed gas D2 introduced from the product gas duct 30 through the mixed gas introduction port 40-1 is It flows along the inner wall of the secondary combustion chamber 41 and forms a swirling flow of the combustion gas F within the primary combustion chamber 41 of the melting furnace 40 .

As shown in FIG. 2, a plurality of swirling air inlets 41-1 arranged in the primary combustion chamber 41 of the melting furnace 40 are arranged on the cylindrical side wall of the primary combustion chamber 41 in the horizontal plane. The air injection direction of each of the swirling air inlets 41-1 is offset from the center O of the primary combustion chamber 41, and is directed against the radial direction of the primary combustion chamber 41 so as to assist the swirling flow of the combustion gas F. is shifted downstream in the swirling direction of the combustion gas F. Further, each of the swirling air inlets 41-1 faces horizontally or obliquely downwards with respect to the horizontal direction.

Defining the phase angles 0°, 90°, 180°, 270° clockwise around the center O of the primary combustion chamber 41 of the melting furnace 40 when the melting furnace 40 is viewed from above, the product gas ducts 30 and the mixed gas introduction port 40-1 are within the range of 0° to 90°. Since the mixed gas introduction port 40-1 is oriented along the tangential direction of the primary combustion chamber 41 of the melting furnace 40 and deviated from the radial direction of the primary combustion chamber 41, the mixed gas D2 is 1 A swirling flow is formed in the secondary combustion chamber 41 .

The upper swirl air inlet 41-1 is positioned at 60° to 210°, more specifically 90° to 180°, at which the combustion gas F starts to swirl in the primary combustion chamber 41 of the melting furnace 40. are placed in the range of In the example shown in FIG. 2, three swirling air inlets 41-1 are provided, but the number is not particularly limited as long as the swirling flow of the combustion gas F in the primary combustion chamber 41 can be promoted. For example, the number of swirling air inlets 41-1 is appropriately adjusted depending on the diameter of the primary combustion chamber 41 and the diameter of the swirling air inlets 41-1.

As shown in FIG. 3, a plurality of swirling air inlets 41-2 arranged in the primary combustion chamber 41 of the melting furnace 40 are also arranged on the cylindrical side wall of the primary combustion chamber 41 in the horizontal plane. The air injection direction of each of the swirling air inlets 41-2 is offset from the center O of the primary combustion chamber 41, and is directed with respect to the radial direction of the primary combustion chamber 41 so as to assist the swirling flow of the combustion gas F. is shifted downstream in the swirling direction of the combustion gas F. Further, each of the swirling air inlets 41-2 is oriented horizontally or obliquely downward with respect to the horizontal direction.

The lower swirling air inlet 41-2 is located at a different position in the circumferential direction of the primary combustion chamber 41 from the upper swirling air inlet 41-1. More specifically, the lower swirling air inlet 41-2 is located downstream of the upper swirling air inlet 41-1 in the swirling direction of the combustion gas F in the primary combustion chamber 41. there is For example, the upper stage swirling air inlet 41-1 is in the range of 60° to 210°, while the lower stage swirling air inlet 41-2 is in the range of 210° to 330°. In this embodiment, the swirling air inlet port 41-2 in the lower stage is arranged in a range of 225° to 315°, which is 135° out of phase with the positional range of the swirling air inlet port 41-1 in the upper stage. . In the example shown in FIG. 3, three swirling air inlets 41-2 are provided, but the number is not particularly limited as long as the swirling flow of the combustion gas F in the primary combustion chamber 41 can be promoted. For example, the number of swirl air inlets 41-2 is appropriately adjusted depending on the diameter of the primary combustion chamber 41 and the diameter of the swirl air inlets 41-2.

In the embodiment shown in FIGS. 2 and 3, the swirling direction of the combustion gas F when viewed from above the primary combustion chamber 41 is clockwise, and the positions of the product gas duct 30 and the mixed gas inlet 40-1 are 0° to 90°, but in one embodiment, as shown in FIGS. good. In this case, the swirling direction of the combustion gas F is counterclockwise. The differences and their relationship to each other are the same as in the embodiment described with reference to FIGS.

According to the embodiment described with reference to FIGS. 2 to 5, in the melting furnace 40, combustion is performed at 1300° C. to 1500° C. in the primary combustion chamber 41 and the secondary combustion chamber 42, and the combustion gas is The dust contained in F is melted and discharged as slag.

As shown in FIG. 1, the oxygen gas supply line 48 may be connected to the upper stage swirl air line 45-1 and the lower stage swirl air line 45-2. In one embodiment, the oxygen gas supply line 48 may be connected to either the upper stage swirl air line 45-1 or the lower stage swirl air line 45-2. By enriching the swirl air introduced into the primary combustion chamber 41 of the melting furnace 40 from at least one of the swirl air inlets 41-1 and 41-2, It is possible to increase the temperature inside the primary combustion chamber 41 to improve the slag formation rate and to allow the slag to flow smoothly.

The combustion gas F then enters the tertiary combustion chamber 43, where secondary air introduced from the secondary air inlet 43-1 reduces the concentration of carbon monoxide (CO) and cools the combustion gas F. , is discharged from the melting furnace 40 . The exhausted combustion gas F passes through a heat recovery facility such as a boiler (not shown) to lower the gas temperature, and after dust is removed by a dust collector, it is released into the atmosphere through a chimney.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in its broadest scope in accordance with the technical spirit defined by the claims.

10 Gasification and melting system 20 Gasification furnace 20a Fluidized bed 30 Product gas duct 30A Curved portion 30-1 First combustion air inlet 30-2 Second combustion air inlet 30-3 Third combustion air inlet 31 Air Control valve 33-1 First combustion air line 33-2 Second combustion air line 33-3 Third combustion air line 34 First dust collector 35 Second dust collector 36 Blower 40 Melting furnace 40-1 Mixing Gas inlet 41 Primary combustion chamber 41-1 Upper swirl air inlet 41-2 Lower swirl air inlet 42 Secondary combustion chamber 43 Tertiary combustion chamber 43-1 Secondary air inlet 45 Swirl air line 45 -1 upper stage swirl air line 45-2 lower stage swirl air line 46 secondary air line 48 oxygen gas supply line D1 generated gas D2 mixed gas F combustion gas L mixed gas introduced into the melting furnace from the combustion air inlet of the generated gas duct distance to mouth

Claims (2)

a gasification furnace for thermally decomposing an object to be treated including waste to generate a product gas;
a melting furnace for burning the generated gas and converting ash contained in the generated gas into molten slag at a high temperature;
a product gas duct for introducing the product gas from the gasification furnace to the melting furnace;
The product gas duct has a portion extending upward from the gasification furnace, a curved portion for changing the flow direction of the product gas, and a portion extending horizontally from the curved portion to the melting furnace,
The product gas duct has a plurality of combustion air inlets to which combustion air lines are connected, and the product gas emitted from the gasification furnace and the gas supplied from the plurality of combustion air inlets configured such that a mixed gas with combustion air is formed in the product gas duct;
The plurality of combustion air inlets are located in the curved portion of the product gas duct, are arranged at different heights, and are arranged to eject the combustion air horizontally into the product gas duct. ,
The distance from the plurality of combustion air inlets to the melting furnace is such that the combustion air is stirred with the product gas in the product gas duct, and the combustion air and the product gas are mixed at the time of entering the melting furnace. is within the range of 3000 mm to 6000 mm so that the mixed gas is uniformly mixed and ignites immediately when the mixed gas enters the primary combustion chamber of the melting furnace,
The melting furnace has a plurality of upper stage swirling air inlets and a plurality of lower stage swirling air inlets into which swirling air is introduced for promoting combustion of the mixed gas in the primary combustion chamber. cage,
Defining the phase angles 0°, 90°, 180°, 270° clockwise around the center of the primary combustion chamber of the melting furnace when viewed from above the vertically extending melting furnace, the position of the product gas duct is within 0° to 90° and the product gas duct extends along a tangent to the cylindrical sidewall of the melting furnace;
The plurality of upper-stage swirling air inlets are at the same height as the center of the mixed gas inlet of the melting furnace connected to the product gas duct, and have a phase angle within the range of 90° to 180°,
The plurality of lower stage swirling air inlets are arranged at the same height as the lower end of the mixed gas inlet or 600 mm to 900 mm below the upper stage swirling air inlet, and A gasification and melting system positioned in a phase angle range of 225° to 315°, 135° out of phase with the air inlet position range . The plurality of combustion air inlets include a first combustion air inlet for introducing room temperature air, and a second combustion air inlet arranged above the first combustion air inlet for introducing air at 300 to 400 ° C. 2. The gasification and melting system of claim 1, including a combustion air inlet and a third combustion air inlet located above said second combustion air inlet for inputting room temperature air.

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