JP2000274650A - Device and method for suppressing dioxin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for suppressing dioxin by which the generation of dioxin and its precursor can be suppressed, dioxin can be removed easily, and the generation of thermal NOx can be prevented. SOLUTION: A device for suppressing dioxin is provided with an ash melting furnace 2 which melts thrown-in ash in a combustion chamber 17 and drops the melted ash from a dropping port 18, at least a pair of heat storage bodies 3 and 4 which are connected to the combustion chamber 17, can quench a high- temperature exhaust gas, and can supply preheated air to the chamber 1, and a heating nozzle 7 which is positioned near the heat storage body on the combustion chamber 17 side and can cause high-temperature incineration in the chamber 17. The device is also provided with valves 8, 9, 10, and 11 which are arranged on the side of the heat accumulating bodies 3 and 4 opposite to the combustion chamber 17 and can alternately switch intake and exhaust through the combustion chamber 17 and heat accumulating bodies 3 and 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for suppressing dioxins generated in waste incineration facilities and the like.

[0002]

2. Description of the Related Art To suppress dioxin, which occurs at an incineration temperature of around 600 ° C. when incinerating industrial waste in an incinerator or a waste incinerator, the incineration temperature must be 800 ° C. or more and the residence time It is said that it is necessary to hold for 1 to 2 seconds or more. Further, it is considered that complete combustion is indispensable for the incineration conditions in order to easily decompose organic substances, dioxins and precursors, and it is said that it is desirable to maintain a combustion temperature of 850 ° C. or more for this purpose. In addition, in a reducing atmosphere, that is, in a low oxygen atmosphere, there is a report that dioxin generated by advancing a dechlorination reaction can be removed by a substitution phenomenon in which chlorine contained in dioxins reacts with hydrogen to generate hydrochloric acid. .

[0003]

In order to maintain the combustion temperature in a high temperature state required for suppressing the generation of dioxin, when the fuel is set to 1, air is reduced to, for example, 1.1.
It must be burned with a high air ratio.
However, under these combustion conditions, there is a problem in that when combustion air is excessively supplied, the combustion temperature becomes too high and reacts at once to generate thermal NOx. On the other hand, in order to suppress the generation of thermal NOx, for example, 0.
When the combustion is performed at a low air ratio of 9 or less, that is, in a reducing atmosphere or a low-oxygen atmosphere, the combustion temperature is reduced, and the combustion temperature required to suppress the generation of dioxin is reversed. There was also a problem that was not obtained.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a dioxin control apparatus and method which can suppress the generation of dioxins and precursors, can easily remove dioxins, and can prevent the generation of thermal NOx. .

[0005]

According to the present invention, there is provided an ash melting furnace in which ash to be charged is melted in a combustion chamber and dropped from an ash dropping port, and a high-temperature exhaust gas capable of being rapidly cooled by being connected to the combustion chamber. At least a pair of regenerators capable of supplying preheat to the combustion chamber, a heating nozzle arranged near the regenerator on the combustion chamber side and capable of high-temperature combustion in the combustion chamber, and a combustion chamber disposed on the anti-combustion chamber side of the regenerator and the heat storage A valve capable of alternately switching between intake and exhaust via a body.

According to the present invention, there is also provided an ash melting furnace in which ash is melted in a combustion chamber and dropped from an ash dropping port, and is connected to the combustion chamber so that high-temperature exhaust gas can be rapidly cooled and preheated into the combustion chamber. At least one pair of regenerators that can be supplied, a heating nozzle that is arranged near the regenerator on the combustion chamber side and that can heat the combustion chamber at a high temperature, and is suctioned through the combustion chamber and the regenerator that is arranged on the anti-combustion chamber side of the regenerator. And a valve capable of alternately switching between exhaust and exhaust air, and preheats ash introduced into the combustion chamber maintained in a low oxygen atmosphere state through one of the heat accumulators and heats the air sucked in by a heating nozzle at a high temperature. The high-temperature exhaust gas that is melted and generated in the combustion chamber at the same time is exhausted while rapidly cooling and recovering the sensible heat through the remaining heat accumulator, and the intake air and exhaust gas passing through this heat accumulator are subjected to high-temperature combustion and low oxygen atmosphere. By alternately switching with To suppress the generation of oxine, dioxin suppression wherein the is provided.

According to the apparatus and method of the present invention, the ash introduced into the combustion chamber of the ash melting furnace in a low-oxygen atmosphere having an air ratio of 0.9 or less is sent from an intake blower and a predetermined valve. In the heat exchanger connected to the combustion chamber on the intake side, the air that has passed through the preheatable regenerator is burned at once by the heating nozzle and burned at a high temperature of about 1300 ° C. to be completely melted. About 130 generated simultaneously in the combustion chamber
Exhaust gas in a high temperature state of 0 ° C. is heat-exchanged, that is, rapidly cooled at a stretch while passing through the heat storage body on the other exhaust side in a heat exchanger connected to the combustion chamber, and cooled to a temperature of 300 ° C. to 200 ° C. The gas passes through a predetermined valve and is exhausted from the exhaust blower. The pair of heat storage bodies can be switched between intake and exhaust alternately in a short cycle, for example, at a high cycle of 30 seconds. In this way, the combustion chamber can burn at a stretch to a high temperature of about 1300 ° C.
As it can be rapidly cooled from 300 ℃ to 300 ℃ to 200 ℃ at a stretch,
Generation of dioxins and precursors can be suppressed. In addition, even if dioxin was generated, the air ratio was set to a low oxygen atmosphere of 0.9 or less, so the chlorine contained in the dioxins reacted with hydrogen to generate hydrochloric acid, and the dechlorination reaction proceeded. Thus, dioxin can be easily removed. Further, generation of thermal NOx can be prevented.

[0008] According to a preferred embodiment of the present invention, the heat storage body has a honeycomb shape and is arranged at predetermined intervals, and a ceramic particle such as alumina filled between the head plates. Consists of According to this configuration, alumina ceramic particles which are filled between the head plates of the heat storage body serving as the cooling body in the heat exchanger and can be rapidly cooled by contact with the gas in a high temperature state are arranged. Therefore, the high-temperature exhaust gas burned at about 1300 ° C. is brought into contact with ceramic particles of alumina constituting the cooling body, and can be rapidly cooled to 300 ° C. to 200 ° C. in a passing process. Further, the surface shape of the ceramic particles is, for example, a spherical shape or a so-called tetrapot shape having protrusions in four directions, so that the surface area in contact with high-temperature exhaust gas can be increased, and the cooling effect can be further improved. Further, in the process of cooling the exhaust gas, sensible heat can be easily collected in the ceramic. The sensible heat collected and stored in the ceramic can preheat the air sent into the combustion chamber before high-temperature combustion by the heating nozzle of the regenerator in charge of the intake side, thereby improving the combustion efficiency and reducing the generation of dioxin. Can be suppressed.
Further, since the head plate is formed in a honeycomb shape, air and high-temperature exhaust gas can easily flow in the flux direction.

Further, according to a second embodiment of the present invention,
A waste incinerator having an exhaust port and an air intake port across the combustion chamber; and at least one pair of alumina connected to the exhaust port and the air intake port, respectively, capable of rapidly cooling high-temperature exhaust gas and supplying preheating to the combustion chamber. A dioxin, comprising: a heat storage body made of ceramic particles such as ceramics; and a valve disposed on the inlet side or the outlet side of the heat storage body and capable of alternately switching intake and exhaust with respect to a combustion chamber. A suppression device is provided.

According to the above-described apparatus of the present invention, the waste incinerator is, for example, a fluidized-bed furnace, and is connected to the exhaust port and the air intake port formed with the combustion chamber interposed therebetween through valves. Since the heat storage element forming the heat exchanger made of ceramic particles such as alumina forming the same pair of cooling elements as in the first embodiment is arranged, air is taken in through the predetermined valve and the heat storage element. Alumina and other ceramics that can be sent from the mouth and quickly burn sludge and other waste at a high temperature of about 1300 ° C in a combustion chamber at a stretch, and at the same time, heat the high-temperature exhaust gas of about 1300 ° C generated by the high-temperature combustion as a heat storage material on the cooling side , And can be evacuated while being rapidly cooled to 300 to 200 ° C. at once. Thus, high temperature combustion of about 1300 ° C and 300
Since rapid cooling can be performed at once in a short time and alternately in a short period of time, the generation of dioxins and precursors can be easily suppressed. Further, since the air sent to the combustion chamber can be preheated by the sensible heat stored in the ceramic, the generation of dioxin can be more easily suppressed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to the drawings. FIG. 1 is an overall configuration diagram showing a first embodiment of the dioxin suppression device of the present invention.
FIG. 2 is a view taken along the line AA in FIG. As shown in FIGS. 1 and 2, the dioxin suppression device 1 of the present invention includes an ash melting furnace 2, heat storage bodies 3 to 6, a heating nozzle 7, and valves 8 to 11.
, An intake blower 12, an exhaust blower 13, a gas dust 14, and a gas dust 15.

In FIG. 1 and FIG. 2, for example, in a state where combustion is performed at a low air ratio of 0.9 or less, that is, in a reducing atmosphere or a low oxygen atmosphere, the ash melting furnace 2 Is burned at a high temperature in a substantially circular combustion chamber 17 and melted.
As shown in FIG. In addition, heat storage units 3 to 6 which are heat exchangers capable of rapidly cooling high-temperature exhaust gas and supplying preheating to the combustion chamber and serving as a cooling body are connected to the combustion chamber 17.

As shown in FIG. 2, the heat accumulators 3 to 6 are connected to the combustion chamber 17 at positions that are approximately four equally spaced from the center of the combustion chamber 17 of the ash melting furnace 2. It is assumed that the heat storage bodies 3 and 4 located opposite to each other across the center point of the combustion chamber 17 are used as a pair, and the heat storage bodies 5 and 6 are used as another pair. In the present embodiment, a description will be given using the heat storage bodies 3 and 4 as a pair. The pair of regenerators 3 and 4 can be alternately switched between intake and exhaust in a short cycle, for example, at a high cycle of 30 seconds.

As shown in FIG. 1, the heat accumulators 3 and 4 are provided with cooling chambers 21 and 22, respectively, into which cooling bodies 20 are filled. The cooling chambers 21 and 22 are respectively provided with the valves 8 and 1.
Inlet blower 1 for supplying air into combustion chamber 17 through
2 are connected. Further, the heat storage body 3 includes a cooling chamber 21.
A gas duct 14 connected to the exhaust blower 13 via the valve 9 is arranged between the valve and the valve 8. On the other hand, a gas duct 15 connected to the exhaust blower 13 via the valve 10 is disposed between the cooling chamber 22 and the valve 11 in the heat storage body 4.

In the vicinity of the regenerators 3 and 4 on the combustion chamber 17 side, the fuel can be switched from a fuel supply device (not shown) into the combustion chamber 17 at a high temperature of about 1300.degree.
A heating nozzle 7 is provided which is capable of burning air sent from the intake valve 2 through a valve on the intake side and a heat storage element.

Further, the heat storage bodies 3 and 4 are respectively provided in the cooling chamber 2
1, two head plates 25 having a honeycomb shape and arranged at a predetermined interval;
And ceramic 26 particles such as alumina filled between them. With this configuration, alumina ceramic particles that are filled between the head plates of the heat storage body that forms the cooling body in the heat exchanger and that can be rapidly cooled by contacting a substance in a high-temperature state are arranged. Accordingly, the high-temperature exhaust gas burned at about 1300 ° C. is brought into contact with ceramic granules made of alumina constituting the cooling body, and is passed from 300 ° C. to 20 ° C.
It can be rapidly cooled to 0 ° C.

The surface shape of ceramic particles such as alumina is, for example, spherical or has a so-called tetrapot shape having projections in four directions. With such a shape, the surface area in contact with high-temperature exhaust gas of about 1300 ° C. can be increased, and the cooling effect of dropping at a stretch from 300 ° C. to 200 ° C. is further improved. Further, in the process of cooling the exhaust gas, sensible heat can be easily collected in the ceramic. On the other hand, the sensible heat collected and stored in the ceramic is
The air sent into the combustion chamber 17 can be preheated before the high-temperature combustion is performed by the heating nozzle 7 of the regenerator that is in charge of the intake side, thereby improving the combustion efficiency and suppressing the generation of dioxin. Furthermore, since the head plate has a honeycomb shape,
Air and high-temperature exhaust gas can easily flow in the flux direction.

With such a configuration, the ash introduced into the combustion chamber 17 of the ash melting furnace 2 is supplied to the heat exchanger connected to the combustion chamber 17 on the intake side sent from the intake blower 12 and a predetermined valve. The air that has passed through the preheatable regenerator is burned at once by the heating nozzle 7 and burned at a high temperature of about 1300 ° C. to be completely melted. At the same time, the exhaust gas having a high temperature of about 1300 ° C. generated in the combustion chamber 17 is heat-exchanged, that is, rapidly cooled by a heat exchanger connected to the combustion chamber 17 while passing through the heat storage body on the other exhaust side. The gas is cooled to a temperature of 200 ° C. to 200 ° C., passes through a predetermined valve, and is exhausted from the exhaust blower 13. In this way, combustion can be performed at a stretch in the combustion chamber 17 at a high temperature of about 1300 ° C., and a high-temperature exhaust gas of about 1300 ° C.
Since it can be quenched at a dash at a temperature, generation of dioxins and precursors can be suppressed. In addition, even if dioxin is generated, the air ratio is set to a low oxygen atmosphere of 0.9 or less,
By the substitution phenomenon in which chlorine contained in dioxins reacts with hydrogen to generate hydrochloric acid, the dechlorination reaction proceeds, and dioxins can be easily removed. Furthermore, thermal NOx
Can also be prevented from being generated.

Next, the dioxin control method of the present invention will be described using the dioxin apparatus 1 shown in FIG. In a low oxygen atmosphere with a low air ratio of 0.9 or less,
(1) First, fuel is fed into the combustion chamber 17 of the ash melting furnace 2 through the heating nozzle 7 while driving the intake blower 12 and the exhaust blower 13 while introducing ash from the ash inlet 16 as shown by an arrow H. (2) Next, the valves 8 and 10 are opened and the valves 9 and 1 are opened.
1 is closed and air is sent from the intake blower 12 into the combustion chamber 17 via the valve 8 and the heat storage unit 3 to ignite the fuel-air mixture gas by the heating nozzle 7.
The ash is melted by burning at a high temperature of 300 ° C. and dropped from the ash dropping port 18 as shown by an arrow H 1. (3) At the same time, the high temperature exhaust gas of about 1300 ° C. generated in the combustion chamber 17 is sent into the heat storage body 4. The exhaust gas is rapidly cooled to 300 ° C. to 200 ° C. at a stretch while the sensible heat is recovered in the ceramic by being brought into contact with a cooling body made of ceramic such as alumina, and exhausted from the exhaust blower 13 through the valve 11 and the gas duct 15 ( 4) Next, the valves 9 and 11 are opened and the valves 8 and 10 are closed, air is sent from the intake blower 12 into the combustion chamber 17 via the valve 11 and the heat storage unit 4, and the fuel-air mixture gas is ignited by the heating nozzle 7. Then, the inside of the combustion chamber 17 is burned at once at a high temperature of about 1300 ° C. (5) Simultaneously, the high-temperature exhaust gas of about 1300 ° C. generated in the combustion chamber 17 is sent into the regenerator 3 and cooled by a ceramic material such as alumina. Is contacted with body through while recovering sensible heat in the ceramic is rapidly cooled at once 300 ° C. to 200 ° C. The exhaust valve 9 and the duct 14 exhaust blower 1
The exhaust gas is exhausted from the heat storage unit 3, while the sensible heat collected and stored in the ceramic such as alumina is sent into the combustion chamber 17 in the heat storage unit 4 to be preheated. (6) As described above, the pair of heat storage units 3 And 4 are alternately switched between intake and exhaust in a short cycle, for example, at a high cycle of 30 seconds. Therefore,
Combustion and heat storage at a high temperature of about 1300 ° C. allow rapid cooling to 300 ° C. to 200 ° C., so that generation of dioxins and precursors can be suppressed. In addition, even if dioxin is generated, the deoxygenation reaction proceeds due to the low oxygen atmosphere, so that dioxin can be easily removed. Further, generation of thermal NOx can be prevented.

FIG. 3 is an overall configuration diagram showing a second embodiment of the dioxin suppression device according to the present invention. The dioxin suppression device 31 of the present invention includes a waste incinerator 32, heat storage bodies 33 and 34, valves 35 to 38, and gas dust 39.
And 40.

In the waste incinerator 32, waste such as sludge introduced in a fluidized-bed furnace type is fed into a sand layer disposed in a combustion chamber 45, and is burned by a fluidized fluidized bed 46. An exhaust port 47 is provided on the upper side with the substantially circular combustion chamber 45 interposed therebetween, and an air intake port 48 is provided on the lower side. Further, a pair of gas dust 40 and gas dust 39 are connected to the exhaust port 47 and the air intake port 48.

As shown in FIG. 3, the gas dust 39 connected to the air intake port 48 is branched at the intermediate portion, and the heat storage bodies 33 and 34 and the valve 35 which form a cooling body in the heat exchanger on the air intake port 48 side. And 37 are connected to an intake blower (not shown).

Further, the gas dust 39 connected to the exhaust port 47 is branched at the intermediate portion and shown in the drawing via heat storage elements 33 and 34 and valves 36 and 38 which form a cooling body in a heat exchanger on the side opposite to the exhaust port 47. Not connected to an exhaust blower.

Further, the heat storage bodies 33 and 34 are respectively provided in the cooling chambers 50 and 51 with two head plates 52 having a honeycomb shape and arranged at a predetermined interval, and a head plate 5.
And ceramic 53 particles such as alumina filled between the two. According to this configuration, alumina ceramic particles which are filled between the head plates of the heat storage body serving as the cooling body in the heat exchanger and can be rapidly cooled by contact with the gas in a high temperature state are arranged. Therefore, the high-temperature exhaust gas burned at about 1300 ° C. is brought into contact with the alumina ceramic particles constituting the cooling body, and is passed from 300 ° C. to 2 ° C.
It can be rapidly cooled to 00 ° C.

The surface shape of the ceramic particles such as alumina is, for example, spherical or has a so-called tetrapot shape having projections in four directions. With such a shape, the surface area in contact with high-temperature exhaust gas of about 1300 ° C. can be increased as in the first embodiment described above.
The cooling effect of dropping at a stretch from ℃ to 200 ℃ is further improved.

Next, a dioxin control method using the dioxin control apparatus of the present invention will be described with reference to FIG. In the waste incinerator 32 of the dioxin control device 31 of the present invention, (1) first open the valves 37 and 36 and close the valves 38 and 35, and supply air from the intake blower (not shown) as indicated by an arrow K to the intake side. Valve 37, heat storage 34 and air intake 4
8 into the combustion chamber 45 and further into the combustion chamber 4
Air is also blown into the sand layer in the fluidized bed 5 to fluidize it.
(2) At the same time, fuel is fed from a fuel supply device (not shown) and ignited to raise the temperature of the fluidized bed 46 in the combustion chamber 45 to a high temperature of about 1300 ° C. 45 and is burned in the fluidized bed 46 at a high temperature of about 1300 ° C.
The high-temperature exhaust gas of about 1300 ° C. generated in Step 5 is sent into the exhaust port 47 and the heat storage body 33 as shown by the arrow S, and is brought into contact with a cooling body made of ceramics such as alumina to recover the sensible heat into the ceramics. 300 ° C to 2 at a stretch
The gas is rapidly cooled to 00 ° C. and exhausted from an exhaust blower (not shown) through a valve 36. (4) Next, the valves 38 and 35 are opened and the valves 37 and 36 are closed to allow air from an intake blower (not shown) to flow into the valve 35 and the heat storage element. The waste is sent into the combustion chamber 45 via the combustion chamber 33 to burn the waste at a high temperature of about 1300 ° C. in the fluidized bed 46, and at the same time, is sent into the heat storage element 34 of the high-temperature exhaust gas of about 1300 ° C. generated in the combustion chamber 45. The exhaust gas is rapidly cooled to 300 ° C. to 200 ° C. at once at a time while being brought into contact with a cooling body made of ceramic such as alumina to recover sensible heat into the ceramic, and exhausted from an exhaust blower (not shown) through a valve 38. Inside, the air sent into the combustion chamber 45 is preheated by the sensible heat collected and stored in a ceramic such as alumina. (5) As described above, the pair of regenerators 3 and 4 are alternately switched between intake and exhaust in a short cycle, for example, at a high cycle of 30 seconds. Therefore, about 130
300 ℃ with a heat storage body that forms a combustion and cooling body at a high temperature of 0 ℃
Since it can be rapidly cooled to a temperature of at most 200 ° C., the generation of dioxins and precursors can be easily suppressed. Further, since the air sent to the combustion chamber can be preheated by the sensible heat stored in the ceramic, the generation of dioxin can be more easily suppressed.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously changed without departing from the gist of the present invention.

[0028]

As described above, the dioxin control apparatus and method of the present invention can suppress the generation of dioxins and precursors, can easily remove dioxins, and can prevent the generation of thermal NOx. , Etc. have excellent effects.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a first embodiment of a dioxin suppression device of the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is an overall configuration diagram showing a second embodiment of the dioxin suppression device of the present invention.

[Explanation of symbols]

 1, 31 Dioxin suppression device 2 Ash melting furnace 3-6, 33, 34 Heat storage unit 7 Heating nozzle 8-11, 35-38 Valve 12 Intake blower 13 Exhaust blower 14, 15, 39, 40 Gas dust 16 Ash inlet 17, 45 Combustion chamber 18 Ash dropper 20 Cooling body 21, 22 Cooling chamber 25, 52 Head plate 26, 53 Ceramic 32 Waste incinerator 46 Fluidized bed 47 Exhaust port 48 Air intake port 50, 51 Cooling chamber H, H1, K, S arrow

Continuing on the front page (72) Inventor Kazumi Mori 1st Shinnakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima-Harima Heavy Industries, Ltd. Yokohama Engineering Center F-term (reference) 3K023 QA06 QB02 QB10 QB14 QC05 SA00 3K061 NB01 NB09 4D004 AA36 AA46 CA28 CA29 CB02 CB31

Claims (5)

[Claims] At least one pair of an ash melting furnace for melting ash to be supplied in a combustion chamber and dropping it from an ash dropping port, and connected to the combustion chamber for rapidly cooling high-temperature exhaust gas and supplying preheating to the combustion chamber. A heat storage element, a heating nozzle arranged near the heat storage element on the combustion chamber side and capable of burning the combustion chamber at high temperature, and an intake air and an exhaust gas alternately arranged via the combustion chamber and the heat storage element disposed on the anti-combustion chamber side of the heat storage element. And a switchable valve. 2. The heat storage element comprises a head plate having a honeycomb shape and arranged at predetermined intervals, and ceramic particles such as alumina filled between the head plates. Item 7. A dioxin control device according to Item 1. 3. An ash melting furnace for melting the ash to be charged in a combustion chamber and dropping it from an ash dropping port, and at least one pair connected to the combustion chamber for rapidly cooling high-temperature exhaust gas and supplying preheating to the combustion chamber. A heat storage element, a heating nozzle disposed near the heat storage element on the combustion chamber side and capable of heating the combustion chamber at a high temperature, and an intake air and an exhaust gas alternately disposed through the combustion chamber and the heat storage element disposed on the anti-combustion chamber side of the heat storage element. And a valve that can be switched to a gas, and the ash injected into the combustion chamber maintained in a low-oxygen atmosphere state is preheated via one of the heat accumulators and the air sucked into the combustion chamber is heated at a high temperature by a heating nozzle and melted. At the same time, the high-temperature exhaust gas generated in the combustion chamber is exhausted while rapidly cooling and recovering the sensible heat through the remaining regenerator, and the intake and exhaust through the regenerator are alternately switched between high-temperature combustion and low-oxygen atmosphere. The generation of dioxin Braking is allowed, dioxin suppression wherein the. 4. The heat storage body comprises a head plate having a honeycomb shape and arranged at predetermined intervals, and ceramic particles such as alumina filled between the head plates. Item 3. A method for controlling dioxin according to Item 3. 5. A waste incinerator having an exhaust port and an air intake port across a combustion chamber, and being connected to each of the exhaust port and the air intake port, capable of rapidly cooling high-temperature exhaust gas and supplying preheat to the combustion chamber. A heat storage body made of at least a pair of ceramic particles such as alumina, and a valve arranged on the inlet side or the outlet side of the heat storage body and capable of alternately switching between intake and exhaust with respect to the combustion chamber. A dioxin control device characterized by the following.