WO2003087669A1

WO2003087669A1 - Fusion furnace, gasification fusion furnace, and method of processing waste

Info

Publication number: WO2003087669A1
Application number: PCT/JP2003/004568
Authority: WO
Inventors: Nobuya Azuma; Shigeru Kosugi; Takashi Nakajima; Tetsuya Ando; Toshio Kojima
Original assignee: Ebara Corporation
Priority date: 2002-04-12
Filing date: 2003-04-10
Publication date: 2003-10-23
Also published as: JPWO2003087669A1; KR20040095194A; US20040237861A1; AU2003236057A1; CA2456335A1; EP1496310A1

Abstract

A fusion furnace (10) and a gasification fusion furnace, the fusion furnace comprising combustion chambers (11, 12, 13) for melting ash and a slag falling port (17) for discharging molten slag (20) produced by melting the ash, wherein the slag falling port (17) is formed of a replaceable refractory material, and the peripheral end part of the slag falling port (17) is formed higher on the upstream side of a gas flow than on the downstream side; the gasification fusion furnace comprising a fluidized gasification furnace and primary, secondary, and tertiary combustion chambers (11, 12, 13), wherein a slag falling port part block is formed on the lowest part of the secondary combustion chamber.

Description

Melting furnace, gasification melting furnace and waste treatment method

The present invention introduces a product gas containing ash and unburned carbon from a gasifier, etc.

The present invention relates to a melting furnace and a gasification and melting system, which burn at a high temperature and melt the ash to form a molten slag.

Background art

It is desired to incinerate and reduce waste such as municipal solid waste, industrial waste, medical waste, shredder dust and old tires, and to make effective use of the incineration heat. Since waste incineration ash usually contains harmful heavy metals, it is necessary to take measures to solidify heavy metal components in order to treat incineration ash by landfill. In addition, the scale down of the entire equipment is required. As equipment that can cope with such issues, it is possible to recover various metals, melt ash to form molten slag, recover this molten slag, and recover energy such as heat and power. In recent years, attention has been focused on gasification and melting furnaces (gasification and melting systems), which are not simply incineration treatments, but rather a combination of pyrolysis gasification and high-temperature combustion, and which enable material recycling.

Figure 1 is a schematic diagram showing a conventional gasification and melting system that is a combination of a fluidized bed gasification furnace and a swirling melting furnace. As shown in FIG. 1, the gasification and melting system includes a fluidized bed gasification furnace 1 and a swirling melting furnace 10. In the gasification and melting system shown in Fig. 1, the waste is collected in the fluidized bed 2 of the fluidized bed gasifier 1 The gas is then gasified in the gasifier 1 to generate unburned gas containing unburned carbon and ash at a temperature of about 500 ° C to 600 ° C. 10 and the high temperature combustion at a low air ratio (approximately 1.3 to 1.5) with the secondary air introduced into the melting furnace 10, and the inside of the swirling melting furnace 10 is heated to the melting point of ash or higher (130 0 ° C or higher, preferably about 135 ° C). At this high temperature, the ash is collected on the furnace wall to generate a molten slag flow. The molten slag falls out of the furnace from the slag outlet 17 and is brought into contact with the slag cooling water to form granulated slag.

Further, high-temperature combustion gas generated by converting ash into molten slag is introduced into a waste heat boiler, a heat exchanger, and the like, and thermal energy is recovered. In such a gasification and melting system, the structure of the melting furnace affects the molten state of the ash and the smooth operation and maintenance. It has been considered an important point.

FIG. 2 is a diagram showing a configuration example of this type of conventional melting furnace. In FIG. 2, reference numeral 10 denotes a melting furnace, and the melting furnace 10 includes a primary combustion chamber 11, a secondary combustion chamber 12, and a tertiary combustion chamber 13. The passage through which the combustion gas 16 in the furnace passes is formed in a substantially V-shape, and a slag drop 17 is formed at the bottom of the V-shape.

The generated gas 14 containing unburned carbon or ash gasified in the gasifier 1 (see Fig. 1) or the gas mixed with the combustion gas together with the generated gas 14 is the primary combustion chamber of the melting furnace 10. The combustion air 15 introduced into the upper part of 11 in the tangential direction of the inner wall of the furnace wall, and also introduced into the primary combustion chamber 11 in the tangential direction of the inner surface of the furnace wall, burns while forming a swirling flow. It moves to the secondary combustion chamber 12 and performs high-temperature combustion (1200 ° C to 140 ° C, preferably temperature of 135 ° C), and further passes through the tertiary combustion chamber 13 to generate exhaust gas 16 and the like. To a waste heat boiler (not shown) Will be issued. In FIG. 2, reference numerals 18 and 19 denote a temperature-raising and combustion-supporting wrench, respectively. Also, in the above example, an example in which both the generated gas 14 and the combustion air 15 are introduced in the tangential direction of the inner wall of the furnace wall has been described, but either the generated gas 14 or the combustion air 15 In some cases, a swirl flow is formed by introducing the swirl flow in the tangential direction of the inner surface, and the other is blown into the swirl flow to perform mixed combustion.

As described above, the product gas 14 containing unburned carbon and ash introduced into the upper part of the primary combustion chamber 11 and the combustion air 15 mix and burn while forming a swirling flow, and the secondary combustion chamber 1 2 Then, it moves to the third combustion chamber 13. The ash is collected on the furnace wall by this swirling flow, is melted at a high temperature to form molten slag 20, flows through the furnace bottom, and falls from the slag drop 17 through the slag chute 30 to the outside of the furnace. The dropped molten slag 20 comes into contact with slag cooling water (not shown) and becomes granulated slag, which is collected.

FIG. 3 is a diagram showing an example of the vicinity of the slag outlet of the melting furnace. As shown in FIG. 3, in the melting furnace 10 having the above-described configuration, the molten slag 20 flowing down from the furnace wall of the melting furnace 10 gathers at the furnace bottom and travels along the inner wall surface 17 a of the slag outlet 17. Fall. As a result, the inner wall 17a of the slag drop 17 is intensively exposed to the high-temperature molten slag 20 and is severely melted. If the melt proceeds, the inner wall of the slag drop 17 is replaced. There is a need. Further, the slag outlet 17 is located in the high-temperature secondary combustion chamber 12 and the tertiary combustion chamber 13 and the low-temperature slag chute 30 (below the slag cooling water, (30 is low temperature), which is a more severe condition for refractory materials due to a temperature gradient, and is easily damaged. However, since the inner wall of the slag drop 17 is integrated with the inner wall of the melting furnace 10, there is a problem that the replacement operation is not easy. As a countermeasure against this melting and thermal damage, it is conceivable that the inner wall of the slag opening 17 is made of a refractory material that is particularly resistant to erosion and high heat. Because it is formed integrally with the inner wall, it was difficult to construct only the inner wall of the slag opening 17 with a refractory material resistant to erosion and high heat. In addition, since refractory materials resistant to erosion and high heat are expensive, it is uneconomical to construct the entire inner wall of the melting furnace 10 with the refractory materials resistant to erosion and high heat.

In some cases, a water pipe is provided on the inner wall of the slag outlet 17 in order to reduce the amount of erosion.However, the inner wall 17a is supercooled, and the molten slag 20 adheres. There is also a problem that it grows into such massive slag 21 and, in the worst case, blocks the slug drop 17. In this case, there is also a problem that the refractory material does not exhibit its original strength unless it is dried and fired, and if it is supercooled by a water pipe, the refractory material is damaged and becomes weak due to insufficient strength.

On the other hand, FIG. 4 is a second view showing the vicinity of the slag outlet of the melting furnace 10. As shown in FIG. 4, the height of the peripheral edge of the slug Ochiguchi 1 7 upstream of the combustion gas 1 6 height 1 ^ and downstream height h ₂ is the same height (1 ^ = 11, That is, the height of the peripheral end of the slug drop 17 is the same level, and the upper surface 17 b of the outer peripheral part of the slug drop 17 is a slope that descends toward the slug drop 17. As a result, the combustion gas 16 flowing along the upstream side of the upper surface 17 b of the outer peripheral portion of the slag drop 17 collides with the inner wall 17 a of the slag drop 17 and the slag drop 1 ロThere is a problem that the turbulent flow may adversely affect the molten slag discharged from the slag outlet 17.

One of the accompanying problems is that molten slag 20 adheres to the inner wall 17a of the slag outlet 17 and solidifies and grows into massive slag 21 (see Fig. 3). Problems with blockage of 17 and combustion gas containing harmful components There was a problem that slag 16 could be discharged outside the furnace through the slag outlet 17 and contaminate the slag cooling water. Disclosure of the invention

The present invention has been made in view of the above points, and eliminates the above-mentioned problems. When the wall of the slag outlet of the melting furnace is melted, the replacement thereof is easy, and the melt is hardly damaged and damaged. It is an object of the present invention to provide a melting furnace and a gasification and melting system that can prevent molten slag from adhering and solidifying at a slag drop due to supercooling of a slag dropping portion.

It is another object of the present invention to provide a melting furnace and a gasification melting system which do not generate a turbulent gas flow at a slag outlet of the melting furnace and do not affect the molten slag discharge state.

It is another object of the present invention to provide a melting furnace and a gasification melting system capable of detecting the state of adhesion and solidification of molten slag at a slag outlet to prevent or release blockage of the slag outlet.

In order to solve the above problems, one embodiment of the melting furnace of the present invention includes a combustion chamber that burns ash-containing combustible gas to melt the ash, and a slag drop that discharges molten slag generated by melting the ash. In a melting furnace having a mouth, the slag outlet is made of a replaceable refractory material.

As described above, by making the slag dropper a slag dropout block made of replaceable refractory material separate from the furnace wall, the slag dropout block is resistant to melting damage and high heat. Using a refractory material, it is manufactured in a factory or the like through a predetermined manufacturing process (for example, a forming process and a drying process) before being transported to the site where the melting furnace is installed, where the melted slag is dropped. It becomes easy to replace with a block. In addition, the slag opening block is damaged. For example, by using a high chromium-based refractory material, it is possible to prevent the slag wall from being damaged or damaged. In addition, by making the slag outlet block around the slag outlet, it is not necessary to cool the refractory material with a water pipe as in the past, or it can be improved with a small amount of cooling. Adhesion and solidification can be prevented.

According to one aspect of the present invention, the slag outlet is a block having an opening formed in the center, and at least one slag flow that reaches the slag outlet from the outer periphery of the upstream side of the combustion gas flow on the upper surface of the block. A feature is that a groove is formed. As described above, a slag flow-down groove reaching the slag discharge from the upstream outer periphery of the combustion gas passage was formed on the block upper surface of the slag discharge block, and the molten slag flowing down the inner wall surface of the melting furnace formed the slag flow-down groove. As the molten slag flows into the slag dropper, the discharge position of the molten slag is limited. In addition, since the molten slag flows intensively, even if the facility is small and the operating state is small, the molten slag is difficult to cool down and adheres and solidifies on the surface of the slag outlet block. Can be prevented as much as possible.

According to one aspect of the present invention, the slag outlet block is an inclined surface whose upper surface is lowered toward the slag outlet, and the upper end of the outer periphery of the slag outlet is higher in the upstream side of the combustion gas flow and downstream. _C As described above, the upper surface of the slag opening block is an inclined surface that descends toward the slag opening, and the upper end of the outer periphery of the slag opening is the combustion gas. Since the upstream side of the flow is formed high and the downstream side is formed low, the combustion gas flowing into the upstream upper surface of the slag drop block passes through the upper part of the slag drop and then flows along the downstream upper surface. As it proceeds, it does not collide with the inner surface of the slag opening, so that the combustion gas flowing into the slag opening can be suppressed as much as possible. In addition, the gas flow near the slag mouth is smoothed and discharged. The drop of the molten slag discharged does not cause blurring. (If the blurring is large, the molten slag adheres to the inner surface of the slag chute instead of the granulated surface.)

According to one aspect of the present invention, the slag opening block is characterized in that its upper surface is an inclined surface descending toward the outer periphery.

Since the slag opening block has an inclined surface whose upper surface descends toward the outer periphery, the combustion gas flowing into the upper surface on the upstream side of the slag opening block becomes a flow that rises toward the slag opening. As a result, the combustion gas flowing into the slag outlet can be minimized. Furthermore, since the upper surface is an inclined surface that descends toward the outer periphery, all the molten slag attached to the upper surface is collected on the outer periphery, and the molten slag flowing down the inner wall surface of the melting furnace is collected on the outer peripheral portion of the slag outlet block. Since the molten slag flows into the slag outlet through the slag flow-down groove, it is possible to prevent the molten slag from adhering and solidifying to the surface of the slag outlet block.

According to one aspect of the present invention, the slag exit block is composed of a plurality of blocks.

As described above, since the slag opening block is composed of a plurality of blocks, the production and transport of the slag opening block can be facilitated. Also, even in the case of damage, the replacement is easy because only the damaged block needs to be replaced.

The gasification and melting system according to the present invention includes: a gasification furnace that gasifies waste to generate a combustible gas containing ash and unburned carbon; and combustible gas containing the ash and unburned carbon at a high temperature. A gasification melting system including a melting furnace for melting the melt, wherein the melting furnace is used as the melting furnace.

As described above, by using the above-mentioned melting furnace for the melting furnace of the gasification and melting system, the gas having the above-mentioned characteristics possessed by the melting furnace and having high operating efficiency can be obtained. A chemical melting system can be constructed.

Further, in order to solve the above-mentioned problems, another embodiment of the melting furnace of the present invention includes a combustion chamber for burning a combustible gas containing ash to melt the ash, and a slag produced by melting the ash. In a melting furnace equipped with a slag dropper to be discharged, the height of the peripheral end of the slag drop is higher on the upstream side of the combustion gas flow and lower on the downstream side.

As described above, the height of the peripheral end of the slag drop is higher on the upstream side of the combustion gas flow and lower on the downstream side, so that the combustion gas flowing along the upper surface on the upstream side of the outer periphery of the slag drop is Since it passes over the slag opening and reaches the upper surface on the downstream side, the flue gas flows smoothly without hitting the downstream peripheral end surface of the slag opening and generating turbulence as in the past. Does not adversely affect the molten slag discharge status. Further, since the combustion gas passes over the slag drop and can be redirected by the upper surface on the downstream side, the combustion gas flowing into the slag drop can be suppressed as much as possible.

According to one aspect of the present invention, the upper surface of the outer peripheral portion of the slag drop is a slope rising toward the slag drop, and the molten slag reaching the slag drop on the upstream slope of the combustion gas flow. It is characterized in that at least one slag flow-down groove is formed in which slag flows down.

As described above, the upper surface of the outer peripheral portion of the slag drop is a slope that rises toward the slag drop, and the combustion gas flowing along the upstream slope reaches the slope on the downstream side By setting the height of the peripheral end of the slag drop and the inclination angle of the upstream slope as described above, the combustion gas flowing along the upper surface on the upstream side of the outer peripheral portion of the slag drop is discharged. The slag flows over the slag opening without turbulence by colliding with the surrounding side surface downstream of the slag, and reaches the upper surface on the downstream side without fail. Does not adversely affect

In addition, since the outer periphery of the slag outlet is an inclined surface whose upper surface rises toward the outlet, the combustion gas flowing into the upstream of the upper surface of the outer peripheral portion of the slag rises toward the slag outlet. As a result, the combustion gas flowing into the slag outlet can be suppressed as much as possible.

In addition, a slag flow-down groove was formed on the upper surface of the outer peripheral portion of the slag outlet where the molten slag reaching the slag outlet from the upstream inclined surface of the combustion gas passage was formed, so that the molten slag flowing down the inner wall surface of the melting furnace was formed. Since the molten slag flows into the slag outlet through the slag flow-down ditch, the discharge position of the molten slag is limited. In addition, since the molten slag flows intensively through the slag flow channel, cooling of the molten slag is difficult to occur even in a facility with a small amount of slag and in operation, and the molten slag is located around the slag outlet. Adhesion and solidification on the surface of the part can be prevented as much as possible.

In one embodiment of the waste treatment method of the present invention, waste is gasified in a fluidized-bed furnace, a combustible gas containing ash is generated, and the combustible gas is burned to convert ash into molten slag in a melting furnace. The melting furnace includes a primary combustion chamber, a secondary combustion chamber, and a tertiary combustion chamber, and collects the molten slag on a wall surface of the primary combustion chamber and transfers the molten slag to the secondary combustion chamber. The slag drop-down block located at the lowest part of the secondary combustion chamber has a slag flow-down groove only on the primary combustion chamber side, and melts the slag on the wall surface of the secondary combustion chamber. The molten slag is discharged from the slag flow-down groove by flowing down to the slag flow-down groove, and the molten slag is collected on the wall surface of the tertiary combustion chamber from the combustion gas led to the tertiary combustion chamber. Flow down to the block and discharged from the slag flow-down groove. Passed down into granulated trough the discharged molten slag from, characterized in that cooling. According to the present invention, since the slag flow-down groove is provided only on the primary combustion chamber side as described above, the molten slag is concentrated in the slag flow-down groove, and a part of the combustion gas flows through the slag flow-down groove. By flowing, the cooling of the molten slag can be prevented.

In another aspect of the waste treatment method of the present invention, waste is gasified in a fluidized bed furnace to generate a combustible gas containing ash, and the combustible gas is burned to melt ash in a melting furnace. A method for treating waste to be converted into a waste gas, wherein the melting furnace includes a primary combustion chamber, a secondary combustion chamber, and a tertiary combustion chamber, wherein the molten slag is collected on a wall surface of the primary combustion chamber and the secondary slag is collected. The slag dropper block disposed at the lowest part of the secondary combustion chamber has a slag flow-down groove on the primary combustion chamber side, and melts slag on the wall surface of the secondary combustion chamber. The molten slag is discharged from the slag flow-down groove by flowing down into the slag flow-down groove, and the molten slag is collected on the wall surface of the tertiary combustion chamber from the combustion gas led to the tertiary combustion chamber. Slag flowing down to the block and discharged from the slag flow-down groove-slag flow-down The molten slag discharged from the furnace is cooled and solidified, and together with the water vapor generated by the cooling and solidification, the combustion gas is sucked from the slag outlet of the secondary combustion chamber to form a mixed gas, and the mixed gas is introduced into the tertiary combustion chamber It is characterized by doing.

According to the present invention, by sucking the combustion gas from the slag outlet together with the steam generated by the slag cooling and solidification as described above, the cooling of the slag dropper portion by the steam is prevented, and the combustion gas is combined. By suction, the slag drop and its surroundings can be kept at a high temperature.

In one embodiment of the waste treatment method of the present invention, waste is gasified in a fluidized-bed furnace, a combustible gas containing ash is generated, and the combustible gas is burned to convert ash into molten slag in a melting furnace. Waste treatment method, wherein the melting furnace is a primary combustion A secondary combustion chamber and a tertiary combustion chamber, wherein the molten slag is collected on a wall surface of the primary combustion chamber and flows down to the secondary combustion chamber, and is disposed at a lowest part of the secondary combustion chamber. The slag drop block has a slag flow-down groove on the side of the primary combustion chamber, and causes the molten slag on the wall of the secondary combustion chamber to flow down to the slag flow-down groove so that the molten slag flows from the slag flow-down groove. Discharging, collecting molten slag on the wall surface of the tertiary combustion chamber from the combustion gas guided to the tertiary combustion chamber, flowing down to the slag drop block, and discharging from the slag flow-down groove; The molten slag discharged from the downflow groove is cooled in a slag chute, a pressure difference between the secondary combustion chamber and the inside of the slag shot is detected, and when the pressure difference exceeds a predetermined value, the secondary combustion is performed. Secondary combustion chamber installed in the chamber The slag is heated around the opening of the slag.

According to the present invention, as described above, the pressure difference between the secondary combustion chamber and the inside of the slag shot is detected, and when the pressure value becomes equal to or higher than a predetermined value, the slag outlet is formed by slag adhesion and solidification. It is predicted that there is a tendency of blockage, and the slag drop and its surroundings can be heated by the secondary combustion chamber burner to prevent slag blockage.

The waste treatment apparatus according to the present invention is characterized in that the waste is gasified in a fluidized bed furnace to generate a combustible gas containing ash, and the combustible gas is burned in a melting furnace to convert the ash into molten slag. A waste treatment apparatus for cooling a waste gas, wherein the melting furnace is disposed at a lowest part of the primary combustion chamber, a secondary combustion chamber, a tertiary combustion chamber, and the secondary combustion chamber, and is disposed on a primary combustion chamber side. A slag outlet block having a slag flow-down groove, wherein the molten slag is collected on a wall surface of the primary combustion chamber and allowed to flow down to the secondary combustion chamber, and the molten slag is collected on a wall surface of the secondary combustion chamber. The molten slag is caused to flow down into the slag flow-down groove and discharged from the slag flow-down groove, The molten slag is collected on the wall surface of the tertiary combustion chamber from the combustion gas guided to the tertiary combustion chamber, flows down to the slag outlet block, and is discharged from the slag flow-down groove, A slag chute for cooling the molten slag discharged from the slag flow-down groove is provided below the block, and a pressure detector for detecting a pressure difference between the secondary combustion chamber and the inside of the slag chute is provided. A pressure detector detects a pressure difference between the secondary combustion chamber and the slag chute, and when the pressure difference becomes a predetermined value or more, a secondary combustion chamber burner provided in the secondary combustion chamber. Is activated to heat the periphery of the slag dropping portion.

According to the present invention, as described above, the pressure difference between the secondary combustion chamber and the inside of the slag shot is detected, and when the pressure value becomes equal to or higher than a predetermined value, the slag outlet is formed by slag adhesion and solidification. It is predicted that the slag is likely to be blocked, and the slag outlet and its surroundings can be heated by the burner of the secondary combustion chamber to prevent slag blockage. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram showing a conventional gasification and melting system.

FIG. 2 is a diagram showing a configuration example of a conventional melting furnace.

FIG. 3 is a diagram showing an example of the vicinity of the slag outlet of the melting furnace.

FIG. 4 is a diagram showing another example near the slag drop of the melting furnace.

FIG. 5 is a view showing the vicinity of the slag outlet of the melting furnace according to the present invention. In FIGS. Figure 6 A through Figure 6 C is illustrating the structure of the slag Ochiguchi unit block, FIG. 6 A is a side sectional view (FIG. 6 VI _A of B - VI _A line cross-sectional view), FIG. 6 B is a plan view, FIG. 6 C is a side sectional view (VI _C in FIG. 6 B - VI _C line cross-sectional view) is.

FIG. 7 is a view showing an example of a slag drop block of a melting furnace according to the present invention. is there.

FIG. 8 is a view showing the vicinity of the slag outlet of the melting furnace according to the present invention.

Figure 9 A is a side sectional view of the slug落Ro portion proc shown in FIG. 8 (IX _A one IX _A line cross section of FIG. 9 B), FIG. 9 B is a plan view of a slug Ochiguchi portion proc shown in FIG.

FIG. 10 is a view showing another embodiment showing the vicinity of the slag outlet of the melting furnace according to the present invention.

FIG. 11 is an enlarged view of a main part of FIG.

FIG. 12 is a view showing another embodiment showing the vicinity of the slag dropping portion of the melting furnace according to the present invention.

FIG. 13A is a side sectional view of a slag drop, and FIG. 13B is a plan view.

FIG. 14 is a view showing a melting furnace of another embodiment according to the present invention.

FIG. 15A to FIG. 15C are views showing the block of the slag dropper.

5 A is a perspective view of a slug落Ro portion, FIG. 1 5 B is XV _B of FIG 1 5 A - XV _B line cross-sectional view, FIG. 1 5 C is XV _C in FIG. 1 5 A - is a XV _C line cross-sectional view .

FIG. 16 is an enlarged view of a main part of FIG.

FIGS. 17A and 17B are cross-sectional views showing the flow of molten slag passing through the slag outlet.

FIG. 18 is a view showing a melting furnace according to another embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 5 is a view showing the vicinity of the slag outlet of the melting furnace according to the present invention. As shown in FIG. 5, a slag outlet block 22 is provided at the bottom of the melting furnace 10 between the secondary combustion chamber 12 and the tertiary combustion chamber 13. Note that reference numeral 23 is This is a water pipe provided at the lower part of the block.

In FIGS. Figure 6 A through Figure 6 C is illustrating the structure of the slag Ochiguchi unit block 2 2, FIG. 6 A is a side sectional view (FIG. 6 VI _A of B - VI _A cross-sectional view), FIG. 6 B is a plan view, Figure 6 C is a side sectional view (FIG. 6 VI _{_C} _ VI _C sectional view of B). The slag outlet block 2 2 is made of a refractory material that is resistant to erosion and high heat (for example, a high chromium type refractory material (chrome material with a chrome of 60% or more)). Are formed. The upper surface 22 a of the slag drop block 22 is an inclined surface descending toward the central slag drop 17, and the inner peripheral surface 2 2 c that is the inner surface of the slag drop 17 is vertical Formed on the surface.

The height 1 ^ on the upstream side (arrow C side) of the flow of combustion gas 16 on the inner peripheral surface 2 2 c of the slag outlet block 22 serving as the inner surface of the slag outlet 17 is the downstream side (arrows). higher than the height h ₂ of the D side) (! ^> has 11. Further, the upstream side periphery of the upper surface 2 2 a slug Ochiguchi unit block 2 second combustion gas 1 6 flows crow lag Ochiguchi 1 A slag flow-down groove 2 2 d is formed to reach 7. The slag flow-down groove 2 2 d has a wide outer peripheral side, a narrow slag outlet 17 side, and a substantially arc-shaped bottom. .

When the slag drop block 22 of the above configuration is installed in the opening provided at the bottom between the secondary combustion chamber 12 and the tertiary combustion chamber 13, the slag dropper block 2 2 moves from the secondary combustion chamber 12 to the tertiary combustion chamber 1. The combustion gas 16 flowing to 3 flows into the upper surface 2 a of the slag drop block 22 from the upstream side (arrow C side), and passes through the upper part of the slag drop 17 to the downstream side (arrow D side). As shown above, the height 1 ^ on the upstream side of the upper end of the inner peripheral surface 2 2c is higher than the height h ₂ on the downstream side (hi> h ₂ ), as shown in Fig. 6A. As described above, the angle of inclination of the upper surface 22a on the upstream side is set so that the combustion gas 16 passing through the upper part of the slag drop 17 does not collide with the inner peripheral surface 22c. Gas 16 is the upper surface on the downstream side 2 2 a Flows into the tertiary combustion chamber 13, and the combustion gas 16 does not flow into the slag tank 17.

Also, since the slag drop block 22 is a separate part from the furnace wall of the melting furnace, it is not supercooled by the water pipe 23, and there is no adhesion and solidification of the molten slag 20 due to supercooling. Become. The upper surface 22a of the slag outlet block 22 has a slag flow-down groove 2d reaching the slag outlet 17 from the outer periphery on the upstream side, so that it flows down the inner wall surface of the melting furnace 10. Since the molten slag 20 is collected in the slag flow ditch 2 2 d and flows into the slag drop 1 Ί, it is possible to prevent the molten slag 20 from adhering and solidifying to the surface of the slag drop block 22. it can. The number of the slag flow-down grooves 22 d may be one or more.

In addition, the length of the inner peripheral surface 22 c of the slag outlet block 22 serving as the inner surface of the slag outlet 17 is preferably shorter from the viewpoint of preventing adhesion and solidification of the molten slag 20 as much as possible. For example, as shown in FIG. 7, the height dimension h of the slag opening portion block 22 may be shortened.

FIG. 8 is a view showing the vicinity of the slag outlet of the melting furnace according to the present invention. Figure 9 A is a side sectional view of the slug Ochiguchi portion Proc (Figure 9 IX _A of B - IX _A cross-sectional view), Fig. 9 B is a plan view of a slug落Ro portion proc 2 2 shown in FIG. As shown in FIG. 9A and FIG. 9B, a slag dropper block 22 having an inclined surface whose upper surface 22a descends toward the outer periphery is used. A slag flow-down groove 2 d reaching the slag port 17 from the outer periphery of the combustion gas passage on the upper surface 22 a on the upstream side is formed.

As described above, since the slag outlet block 22 is formed as an inclined surface whose upper surface 22a descends toward the outer periphery, all the molten slag adhered to the upper surface 22a is collected on the outer periphery, and the melting furnace 10 Secondary combustion chamber 12 and tertiary combustion Along with the molten slag 20 flowing down the inner wall surface of the firing chamber 13, it flows into the joint between the inner wall surface and the outer periphery of the slag outlet block 22, and further passes through the slag lowering groove 22 d to the slag outlet 1 Ί Since the molten slag 20 falls and falls, it is possible to prevent the molten slag 20 from adhering to and solidifying on the surface of the slag dropping block 22 as much as possible. Here, the number of the slag flow-down grooves 2 2 d may be one or more.

In addition, the combustion gas 16 flowing into the upper surface 22 a on the upstream side of the slag drop block 22 will flow ascending toward the slag drop 17 (see FIG. 9A). Since the gas flows over the slug drop 17, the combustion gas 16 flowing into the slug drop 17 can be suppressed as much as possible. In addition, since the upper surface is an inclined surface that descends toward the outer periphery, all the molten slag attached to the upper surface is collected on the outer periphery, and the molten slag flowing down the inner wall surface of the melting furnace is collected on the outer periphery of the slag outlet block. Since the slag flows into the slag opening 17 through the slag flow-down groove 2 d, it is possible to prevent molten slag from adhering and solidifying to the surface of the slag opening block.

In addition, as described above, the slag opening block 22 is manufactured as a precast block through a molding step and a drying step in advance using a refractory material at a factory. This makes it possible to use refractory materials that are resistant to melting and resistant to high heat (for example, high chromium (60% or more chromium)). In addition, if the slag opening portion block 22 is divided into a plurality of blocks and is manufactured through the above-described forming step and drying step, manufacturing, transportation, and replacement of only the damaged portion become easy. In the above example, the slag outlet block 22 has a circular shape, but may have an elliptical shape, a square shape, or the like so as to conform to the structure of the melting furnace 10.

FIG. 10 is a diagram showing another embodiment showing the vicinity of the slag dropping part of the melting furnace according to the present invention. As shown in Fig. 10, the secondary combustion chamber 1 2 of the melting furnace 10 A slag outlet 17 is provided at the bottom between the slag and the tertiary combustion chamber 13. The upper surface 17 b of the outer peripheral part of the slag drop 17 is a slope that descends toward the slag drop 17, and the height of the peripheral end of the slag drop 17 is the flow of the combustion gas 16. high summer and are (! ^. Figure 1 1 of the upstream side height than the height h ₂ of the downstream side of a main part enlarged view of FIG. 1 0. as shown in FIG. 1 1, the slag drop port 1 The combustion gas 16 flowing along the upstream side of the upper surface 17 b of the outer peripheral portion of the upper slag 17 passes through the upper portion of the slag drop 17 and reaches the upper surface 17 b of the downstream side so as to reach the upper surface 17 b of the downstream side. Set the inclination angle _{α of} b and the height of the slag drop 17 on the upstream side of the peripheral end. The height h ₂ on the downstream side is set.

As described above, setting the upstream upper surface 1 7 b inclination monument and slag Ochiguchi 1 7 height h ₂ of the downstream side have a height h of the peripheral edge the upstream side of the outer peripheral portion of the slag Ochiguchi 1 7 As a result, the combustion gas 16 flowing along the upper surface 17 b on the upstream side of the outer periphery of the slag drop 17 generates turbulence near the slag drop 17 as shown in Fig. 11. Without flowing, a smooth flow passes through the upper part of the slag outlet 17. Therefore, there is no adverse effect on the discharge state of the molten slag 20 flowing into the slag outlet 17. Further, the combustion gas 16 discharged outside the furnace through the slag outlet 17 can be suppressed.

FIG. 12 is a view showing the vicinity of the slag outlet of the melting furnace according to the present invention. FIG. 13A is a side sectional view of the slag drop shown in FIG. 12, and FIG. 13B is a plan view of the slag drop shown in FIG. Here, as shown in FIGS. 13A and 13B, the upper surface 17b of the outer peripheral portion of the slag drop 17 is formed as an inclined surface that rises toward the slag drop 17. Further, a slag flow-down groove 17 d reaching the slag drop 17 from the outer periphery on the upstream side of the combustion gas passage is formed on the outer peripheral portion upper surface 17 b.

As described above, the upper surface 17b of the outer peripheral portion of the slag outlet 17 As a result, the combustion gas 16 flowing into the upper surface on the upstream side of the slag outlet 17 rises toward the slag outlet 17 as shown in Fig. 13A. The flow proceeds and flows above the slag drop 17, so that the combustion gas 16 flowing into the slag drop 17 can be suppressed as much as possible. Also, since the upper surface 17b of the outer peripheral portion is an inclined surface that rises toward the slag outlet 17, all the molten slag 20 attached to the upper surface is collected on the outer periphery, and the inner wall surface of the melting furnace is removed. The molten slag that has flowed down is collected at the outer peripheral portion of the slag opening 17 and the molten slag can be prevented from adhering and solidifying on the outer peripheral surface of the slag opening 17 as much as possible.

Further, when the gasification and melting system according to the present invention, which is provided with the gasification furnace for gasifying waste and generating a product gas containing ash and unburned carbon and the melting furnace having the above configuration, the gasification furnace is used. For example, an internal circulation type fluidized bed gasification furnace, an external circulation type fluidized bed gasification furnace, a kiln furnace or the like can be used.

In addition, as described in the example of the swirling melting furnace, the present invention is characterized in that one of the features of the present invention is to add a height and / or an inclination angle to a slag outlet in order to prevent blockage at a slag discharge part of the melting furnace. In the meantime, the embodiment of the present invention is not limited to the rotary melting furnace, and any melting furnace can be selected.

FIG. 14 is a view showing a melting furnace of another embodiment according to the present invention. The slag outlet block 32 arranged at the lowest part of the secondary combustion chamber has a slag flow-down groove 32 d only on the primary combustion chamber 11 side. Figure 1 5 A to FIG. 1 5 C is a diagram showing a slag Ochiguchi unit Proc, FIG 1 5 A is a perspective view of a slug Ochiguchi portion, FIG. 1 5 B Figure 1 5 A of XV _B - XV _B line sectional view, FIG. 1 5 C is a XV _c one XV _C line sectional view of FIG. 1 5 a. As shown in FIGS. 15A to 15C, the slag outlet block 32 is a slag flow-down groove 3 2 d facing the primary combustion chamber 11 side. And is disposed at the bottom of the secondary combustion chamber 12 at the end of the primary combustion chamber 11.

With this arrangement, as shown in Fig. 15A, the molten slag 20, which has flowed down the inner wall of the melting furnace 10, gathers around the slag drop block 32, and the slag flow-down groove 3 Emitted from 2d. Concentration of slag discharge in the slag flow ditch 3 2d prevents molten slag from cooling. Also, by disposing the slag flow-down groove 32 d on the upstream side of the combustion gas 16 (primary combustion chamber), a part of the combustion gas 16 flows into the slag flow-down groove 32 d. Can be kept at a high temperature.

FIG. 16 is a diagram for explaining the present embodiment in more detail. FIGS. 17A and 17B are cross-sectional views showing a state in which the molten slag flows through the slag opening. As shown in Fig. 14 and Fig. 16, a pipe 40 is provided to connect the slag chute 30 and the tertiary combustion chamber 13 and the dust collector 41 and the fan 42 are connected. It is provided in the pipe 40. The slag shoot 30 constitutes a granulated trough, and the molten slag 20 discharged from the slag outlet is cooled by slag cooling water to form granulated slag. In FIGS. 14 and 16, the steam generated by slag cooling and solidification from the slag chute 30 using the fan 42 and the combustion gas 16 from the slag outlet 17 are sucked into the mixed gas using the fan 42, and this mixed gas is used. Is sent to the tertiary combustion chamber 13. With this configuration, the molten slag is smoothly discharged to the slag chute 30 and the water tank 43 through the slag outlet 17 as shown in FIGS. 16 and 17A.

The supply position of the mixed gas sucked from the slag and supplied to the melting furnace 10 is not limited to the tertiary combustion chamber 13. That is, the piping 40 is a duct connecting the gasification furnace and the melting furnace, a primary combustion chamber, and a secondary fuel. At least one of the firing chamber, tertiary combustion chamber, and flue in front of the waste heat boiler can be connected to the slag shoot (not shown). In this case, a dust collector 41 and a fan 42 are provided in the pipe 40, and a heating device can be further provided. With this configuration, as shown in Fig. 16 and Fig. 17A, blockage of the slag outlet 17 can be prevented, and molten slag passes through the slag outlet 17 and the slag shot 30 and water It can be smoothly discharged to the tank 43. With this configuration, even if the mixed gas contains unburned carbon or the like, the combustion process can be performed, so that the mixed gas can be suitably processed. When a heating device is installed in the pipe 40, the heating device is used to reduce the temperature of the mixed gas by about 2 so that the supply of the mixed gas to the melting furnace does not cause a significant temperature drop in the melting furnace. The temperature is preferably at least 100 ° C, more preferably at least 300 ° C.

Even in the above configuration, if the system is operated for a long time, even if the molten slag is prevented from being cooled down rapidly and partially, as shown in Fig. 14, the block at the slag opening section will not There is a risk that molten slag adheres and solidifies near the slag opening such as 2 and grows into massive slag 21 to close the slag drop (see Fig. 17B). If the slag opening is blocked in this way, molten slag will not be discharged from the slag opening. In addition, if the system is operated for a long time, even if the slag discharge function does not stop completely, the slag drop may become obstructed due to slag adhesion and solidification. The slag opening must not be obstructed. The reason is that when the area of the opening of the slag opening is reduced, the slag opening is rapidly blocked by the following vicious cycle. In other words, the vicious cycle means that when the opening area of the slag outlet decreases, the ventilation resistance (pressure loss) of the combustion gas 16 passing therethrough increases, and the suction This is a phenomenon in which the amount of combustion gas generated decreases, making it difficult to maintain the molten slag at high temperatures, and further reducing the opening area of the slag outlet. Therefore, it is necessary to avoid that the slag outlet is becoming obstructive. Therefore, it is extremely important to proactively prevent the above problems from occurring in order to secure the slag discharge function of discharging molten slag from the slag outlet.

In order to achieve this purpose, in the present embodiment shown in FIG. 18, the pressure difference between the inside of the slag shout 30 and the inside of the secondary combustion chamber 12 was further measured by the pressure detector 45, and the pressure difference became larger than the predetermined pressure difference. In this case, it is determined that the slag outlet is obstructed, and the secondary combustion chamber parner 46 heats the slag outlet and its surroundings. For example, a signal measured by the pressure detector 45 is sent to a control device (not shown) via the first signal transmission means. After the controller determines whether or not the pressure difference is equal to or greater than the predetermined pressure difference, if the pressure difference is equal to or greater than the predetermined pressure difference, the controller transmits a second signal from the controller to start the secondary combustion chamber parner 46. It is configured to be sent to the secondary combustion chamber parner 46 through the means. With such a configuration, it is possible to positively prevent the slag from dropping in and around the slag.

As described above, according to the present invention, the following excellent effects can be expected.

(1) The slag outlet block is replaced with a slag drop block that can be replaced separately from the furnace wall, so that the slag outlet block is made in advance using a refractory material that is resistant to melting and high heat. Manufactured through a specified manufacturing process (eg, molding process, drying process) at a factory, etc., then transported to the site where the melting furnace is installed, and replaced with a damaged and damaged slag drop block It becomes easier. In addition, the slag opening block is melted and damaged. By using a refractory material, it is possible to suppress erosion and breakage of the slag wall. In addition, by making the slag outlet block around the slag outlet, the supercooling by the water pipe as in the conventional case is eliminated, and the adhesion and solidification of the molten slag can be prevented.

(2) Since a slag flow-down groove is formed on the block upper surface of the slag drop-down block from the outer periphery of the upstream side of the combustion gas passage to the slag drop opening, the molten slag flowing down the inner wall surface of the melting furnace forms the slag flow-down groove. As the molten slag flows through the slag outlet, the discharge position of the molten slag is limited. In addition, since the molten slag flows intensively, cooling of the molten slag is difficult to occur even in a facility with a small amount of slag and in an operating state, and it is attached to the surface of the slag outlet block. Solidification can be prevented as much as possible.

(3) The upper surface of the slag drop block has a slope that descends toward the slag drop, and the upper end of the outer periphery of the slag drop is formed so that the upstream side of the combustion gas flow is high and the downstream side is low. The combustion gas flowing into the upper surface on the upstream side of the slag outlet block passes through the upper portion of the slag outlet and then flows along the upper surface on the downstream side to collide with the inner surface of the slag outlet. As a result, combustion gas flowing into the slag outlet can be minimized. In addition, the gas flow near the slag outlet is smoothed, and the melted slag discharged does not fall off.

(4) Since the upper surface of the slag drop block is a slope that descends toward the outer circumference, the combustion gas flowing into the upper surface on the upstream side of the slag drop block rises toward the slag drop. As a result, the combustion gas flowing into the slag mouth can be suppressed as much as possible. Furthermore, since the upper surface is an inclined surface descending toward the outer periphery, all the molten slag attached to the upper surface is collected on the outer periphery, and the molten slag flowing down the inner wall surface of the melting furnace is slag. Since the slag collects on the outer peripheral portion of the drop block and flows into the slag drop through the slag flow-down groove, it is possible to prevent the molten slag from adhering and solidifying on the surface of the slag drop block.

(5) Since the slag exit block is composed of a plurality of blocks, the production and transportation of the slag exit block become easy. In addition, even in the case of damage, replacement is easy because only the damaged block needs to be replaced.

(6) By using any one of the above-mentioned melting furnaces as the melting furnace of the gasification and melting system, a melting furnace of the gasification and melting system exhibiting the above-mentioned characteristics of the melting furnace can be constructed.

(7) As the height of the peripheral end of the slag drop is higher on the upstream side of the combustion gas flow and lower on the downstream side, the combustion gas flowing along the upper surface on the upstream side of the outer periphery of the slag drop is reduced. Since it passes over the slag opening and reaches the upper surface on the downstream side, the flue gas flows smoothly without turbulence, colliding with the downstream peripheral side surface of the slag opening, as in the past. It does not adversely affect the slag emission status.

(8) Since the direction of the combustion gas is changed by the upper surface on the downstream side through the upper part of the slag drop, the amount of the combustion gas flowing into the slag drop can be minimized.

(9) The upper surface of the outer periphery of the slag drop is a slope that rises toward the slag drop, so that the combustion gas flowing along the upstream slope reaches the slope on the downstream side. By setting the height of the peripheral end of the slag drop and the inclination angle of the upstream slope, the combustion gas flowing along the upper surface on the upstream side of the outer peripheral portion of the slag drop is downstream of the slag drop. Passes above the slag drop without turbulence by colliding with the surrounding side surface, and securely on the upper surface on the downstream side , The flow is smooth and does not adversely affect the molten slag discharge status.

(10) Since the outer periphery of the slag outlet is an inclined surface whose upper surface rises toward the slag outlet, the combustion gas flowing into the upstream side of the outer peripheral upper surface of the slag outlet is the slag outlet. Therefore, the combustion gas flowing into the slag mouth can be suppressed as much as possible.

(1 1) A slag flow-down groove is formed on the upper surface of the outer peripheral part of the slag outlet where the molten slag that reaches the slag outlet from the upstream slope of the combustion gas passage flows down, so the molten slag flowing down the inner wall surface of the melting furnace Flows into the slag outlet through the slag flow-down groove, so that the discharge position of the molten slag is limited.

(1 2) Since the molten slag flows intensively through the slag flow-down gutter, cooling of the molten slag becomes difficult even in a facility with a small amount of slag and in operation, and the molten slag is dropped. Adhesion and solidification on the outer peripheral surface of the mouth can be prevented as much as possible.

(13) Since the slag outlet block has a slag flow-down groove only on the primary combustion chamber side, the molten slag is concentrated in the slag flow-down groove, and a part of the combustion gas flows into the slag flow-down groove. The cooling of the molten slag can be prevented by flowing water.

(14) By suctioning the combustion gas from the slag outlet together with the steam generated by cooling and solidifying the slag, the cooling of the slag outlet by the steam is prevented, and the combustion gas is sucked together. This keeps the slag outlet and its surroundings at a high temperature.

(15) When the pressure difference between the secondary combustion chamber and the inside of the slag is detected, and when the pressure value exceeds a predetermined value, the slag outlet tends to close due to slag adhesion and solidification. It is predicted that there is Can be heated to prevent slag blockage. Industrial applicability

INDUSTRIAL APPLICABILITY The present invention can be suitably used in a melting furnace and a gasification melting system, in which a generated gas containing ash and unburned carbon from a gasification furnace or the like is introduced and burnt at a high temperature, and the ash is melted into molten slag. It is.

Claims

The scope of the claims

1. a combustion chamber for combustible gas containing ash to melt the ash;

A slag outlet for discharging the molten slag generated by melting the ash,

A melting furnace, wherein the slag drop is made of a replaceable refractory material.

2. The melting furnace according to claim 1,

The slag dropper is a block having an opening formed in the center, and at least one slag flow-down groove is formed on the upper surface of the block from the upstream outer periphery of the combustion gas flow to the slag dropout. Melting furnace.

3. The melting furnace according to claim 2,

The slag outlet block has an inclined surface whose upper surface is lowered toward the slag outlet, and the upper end of the outer periphery of the slag outlet is formed so that the upstream side of the combustion gas flow is high and the downstream side is low. A melting furnace.

4. The melting furnace according to claim 2,

The melting furnace, wherein the slag outlet block has an inclined surface whose upper surface is lowered toward the outer periphery.

5. The melting furnace according to any one of claims 1 to 4,

The slag drop block is composed of a plurality of blocks.

6. A gasifier for gasifying waste to produce combustible gases including ash and unburned carbon;

A gasification and melting system comprising: a melting furnace for burning the ash and a combustible gas containing unburned carbon at a high temperature; and melting the ash.

A gasification and melting system, wherein the melting furnace according to any one of claims 1 to 5 is used as the melting furnace.

7. A combustion chamber for combustible gas containing ash to melt the ash;

A slag outlet for discharging the molten slag generated by melting the ash,

A melting furnace wherein the height of the peripheral end of the slag outlet is higher on the upstream side of the combustion gas flow and lower on the downstream side.

8. The melting furnace according to claim 7,

The upper surface of the outer peripheral part of the slag drop is a slope that rises toward the slag drop, and at least one molten slag that reaches the slag drop flows down the slope on the upstream side of the combustion gas flow. Melting furnace characterized by forming a slag flow-down groove.

9. A waste treatment method in which waste is gasified in a fluidized-bed furnace to generate ash-containing combustible gas, and the combustible gas is burned to convert ash into molten slag in a melting furnace.

The melting furnace includes a primary combustion chamber, a secondary combustion chamber, and a tertiary combustion chamber, The molten slag is collected on the wall of the primary combustion chamber and allowed to flow down to the secondary combustion chamber,

The slag drop block located at the lowest part of the secondary combustion chamber has a slag flow-down groove only on the primary combustion chamber side, and the molten slag on the wall surface of the secondary combustion chamber is transferred to the slag flow-down groove. And the molten slag is discharged from the slag flow-down groove,

The molten slag is collected on the wall surface of the tertiary combustion chamber from the combustion gas guided to the tertiary combustion chamber, flows down to the slag outlet block, and is discharged from the slag flow-down groove,

A method for treating waste, wherein the molten slag discharged from the slag flow-down groove is caused to flow down to a granulation trough and cooled.

10. A method for treating waste in which a waste is gasified in a fluidized bed furnace to generate a combustible gas containing ash, and the combustible gas is burned to convert ash into molten slag in a melting furnace.

The melting furnace includes a primary combustion chamber, a secondary combustion chamber, and a tertiary combustion chamber. The molten slag is collected on a wall surface of the primary combustion chamber and allowed to flow down to the secondary combustion chamber.

The slag dropper block disposed at the lowest part of the secondary combustion chamber has a slag flow-down groove on the primary combustion chamber side, and flows molten slag on the wall surface of the secondary combustion chamber into the slag flow-down groove. To discharge the molten slag from the slag flow-down groove,

The molten slag is collected on the wall of the tertiary combustion chamber from the combustion gas led to the tertiary combustion chamber, flows down to the slag outlet block, and is discharged from the slag flow-down groove, The molten slag discharged from the slag flow-down groove is cooled and solidified, and together with the water vapor generated by the cooling and solidification, a combustion gas is sucked from a slag outlet of the secondary combustion chamber to form a mixed gas. A waste disposal method characterized by being introduced into a tertiary combustion chamber.

1 1. A method for treating waste in which a waste is gasified in a fluidized bed furnace to generate a combustible gas containing ash, and the combustible gas is burned to convert ash into molten slag in a melting furnace.

The slag outlet block located at the lowest part of the secondary combustion chamber has a slag flow-down groove on the primary combustion chamber side, and the molten slag on the wall surface of the secondary combustion chamber flows down to the slag flow-down groove. To discharge the molten slag from the slag flow-down groove,

From the combustion gas guided to the tertiary combustion chamber, molten slag is collected on the wall surface of the tertiary combustion chamber, flows down to the slag outlet block, and is discharged from the slag flow-down groove,

The molten slag discharged from the slag flow down groove is cooled in a slag chute,

A pressure difference between the secondary combustion chamber and the inside of the slag chute is detected, and when the pressure difference becomes equal to or more than a predetermined value, a secondary combustion chamber parner provided in the secondary combustion chamber is activated. And heating the periphery of the slag dropping portion by heating.

1 2. Gasification of waste in a fluidized-bed furnace to generate combustible gas containing ash, burning of the combustible gas in a melting furnace to convert the ash into molten slag, and cooling the molten slag to treat waste A device,

The melting furnace includes a primary combustion chamber, a secondary combustion chamber, a tertiary combustion chamber, and a slag outlet block disposed at the lowest part of the secondary combustion chamber and having a slag flow-down groove on the primary combustion chamber side. With

The molten slag is collected on the wall surface of the primary combustion chamber and flows down to the secondary combustion chamber. The molten slag on the wall surface of the secondary combustion chamber flows down to the slag flow-down groove and the slag flow-down groove. The molten slag is collected on the wall surface of the tertiary combustion chamber from the combustion gas led to the tertiary combustion chamber, flows down to the slag dropper block, and is discharged from the slag flow-down groove,

A slag shot for cooling the molten slag discharged from the slag flow-down groove is provided below the slag dropper block, and a pressure detector for detecting a pressure difference between the secondary combustion chamber and the slag shot is provided. The pressure detector detects a pressure difference between the secondary combustion chamber and the inside of the slag shot, and when the pressure difference exceeds a predetermined value, a secondary combustion chamber provided in the secondary combustion chamber is provided. A waste treatment apparatus wherein a room parner is activated to heat the area around the slag dropping portion.