阅读说明：本技术 焚烧炉 (Incinerator ) 是由 重政祥子 古林通孝 于 2020-03-10 设计创作，主要内容包括：一种焚烧炉,具备：一次燃烧室(12),其从前侧朝向后侧依次具有干燥段(24)、燃烧段(25)、后燃烧段(26)；以及二次燃烧室(13),其与一次燃烧室(12)的出口侧连接设置。一次燃烧室(12)在后侧的顶壁(23)和/或后壁(22)上具有一次燃烧室用后部供给喷嘴(40)。二次燃烧室(13)具有前部供给喷嘴(44)。一次燃烧室用后部供给喷嘴(40)利用从该喷嘴(40)供给的气流将在燃烧段(25)中产生的未燃气体引到后壁(22)侧。前部供给喷嘴(44)利用从该喷嘴(44)供给的气流将在干燥段(24)中产生的未燃气体引到前侧,并流入二次燃烧室(13)。(An incinerator is provided with: a primary combustion chamber (12) having a drying section (24), a combustion section (25), and a post-combustion section (26) in this order from the front side toward the rear side; and a secondary combustion chamber (13) connected to the outlet side of the primary combustion chamber (12). The primary combustion chamber (12) has a rear supply nozzle (40) for the primary combustion chamber on the rear ceiling wall (23) and/or the rear wall (22). The secondary combustion chamber (13) has a front supply nozzle (44). A rear supply nozzle (40) for a primary combustion chamber guides unburned gas generated in a combustion section (25) to the rear wall (22) side by means of a gas flow supplied from the nozzle (40). The front supply nozzle (44) guides unburned gas generated in the drying section (24) to the front side by a gas flow supplied from the nozzle (44) and flows into the secondary combustion chamber (13).)

1. An incinerator, comprising:

a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and

a secondary combustion chamber connected to an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle,

the primary combustion chamber has a rear supply nozzle for the primary combustion chamber for supplying any one of air, EGR gas, and a mixed gas of air and EGR gas toward the front side, on at least one of a ceiling wall and a rear wall on the rear side,

in the secondary combustion chamber there is a front supply nozzle which supplies the air flow towards the rear side,

the rear supply nozzle for the primary combustion chamber guides the unburned gas generated in the combustion section to the rear wall side by the gas flow supplied from the rear supply nozzle for the primary combustion chamber,

the front supply nozzle introduces unburned gas generated in the drying section to the front side by the gas flow supplied from the front supply nozzle, and flows into the secondary combustion chamber.

2. An incinerator according to claim 1,

the secondary combustion gas supply nozzle that supplies the airflow toward the rear side also serves as the front supply nozzle.

3. An incinerator according to claim 1,

the plurality of secondary combustion gas supply nozzles are provided in a plurality of stages in the vertical direction, and the secondary combustion gas supply nozzle that supplies the airflow toward the rear side of the lowermost stage also serves as the front portion supply nozzle.

4. An incinerator according to claim 3,

the other secondary combustion gas supply nozzles, except for the lowest secondary combustion gas supply nozzle, perform an adjustment function of adjusting the supply amount of the secondary air.

5. An incinerator according to any one of claims 1 to 4,

the front supply nozzles are staggered from the rear supply nozzles for the primary combustion chamber to avoid interference between the supply gas from the front supply nozzles and the supply gas from the rear supply nozzles for the primary combustion chamber.

6. An incinerator according to any one of claims 1 to 5,

the primary combustion chamber is provided with: a feeding hopper, a front width part connected with the feeding hopper, a front top wall connected with the front width part,

the rear part of the top wall of the primary combustion chamber on the front side is connected with the secondary combustion chamber,

the front feed nozzle sprays the air flow in a horizontal direction or downward than the horizontal direction,

the top wall of the front side is inclined upward at an angle exceeding 0 degrees and 60 degrees or less with respect to the horizontal direction as going from the front side toward the rear side.

7. An incinerator according to any one of claims 1 to 6,

the drying section, the combustion section and the post-combustion section are respectively provided with a fire grate, and the fire grate is at least downwards inclined from the drying section to the combustion section.

8. An incinerator according to any one of claims 1 to 7,

the primary combustion chamber supplies air to at least the primary combustion chamber with the rear supply nozzle,

the incinerator is provided with a control device for controlling the supply amount of gas from the rear supply nozzle for the primary combustion chamber to the primary combustion chamber, thereby adjusting the oxygen concentration in the primary combustion chamber.

9. An incinerator according to claim 8,

a plurality of rear supply nozzles for the primary combustion chamber are provided in the upper and lower stages,

in the plurality of rear supply nozzles for the primary combustion chamber, the oxygen concentration in the primary combustion chamber is adjusted by fixing the gas supply amount in a part of the rear supply nozzles for the primary combustion chamber and controlling the gas supply amount in the other rear supply nozzles for the primary combustion chamber.

10. An incinerator according to any one of claims 1 to 9,

the secondary combustion chamber has a front wall for providing the front supply nozzle, and the front wall is located at a position closer to the rear side than the rear end of the drying section.

11. An operation method of an incinerator, the method operating the incinerator, the incinerator comprising:

a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and

a secondary combustion chamber provided in connection with an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, the method being characterized in that,

a rear supply nozzle for a primary combustion chamber provided on at least one of a ceiling wall and a rear wall on the rear side of the primary combustion chamber and configured to supply any one of primary air, EGR gas, and a mixture gas of the primary air and the EGR gas toward the front side, and to introduce unburned gas generated in a combustion zone to the rear wall side using the rear supply nozzle for a primary combustion chamber,

a front supply nozzle provided in the secondary combustion chamber and supplying a gas flow toward the rear side is used, and at least unburned gas generated in the drying section is introduced to the front side by the gas flow supplied from the front supply nozzle and flows into the secondary combustion chamber.

12. An incinerator, comprising:

a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and

a secondary combustion chamber connected to an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle,

the primary combustion chamber has a rear supply nozzle for the primary combustion chamber for supplying any one of primary air, EGR gas, and a mixture gas of the primary air and the EGR gas toward the front side, on at least one of a ceiling wall and a rear wall on the rear side,

in the secondary combustion chamber there is a front supply nozzle which supplies the air flow towards the rear side,

the primary combustion chamber is provided with: a loading hopper for the combustion object, a front width part connected from the loading hopper, a front side top wall connected from the front width part,

the rear part of the top wall of the primary combustion chamber on the front side is connected with the secondary combustion chamber,

the top wall of the front side is inclined upward at an angle exceeding 0 degree and 60 degrees or less with respect to the horizontal direction as going from the front side toward the rear side,

the drying section, the combustion section and the post-combustion section are respectively provided with a fire grate, and the fire grate is at least downwards inclined from the drying section to the combustion section.

Technical Field

The present invention relates to an incinerator.

Background

JPH05-113208A discloses the following: in the incinerator, an appropriate amount of secondary air is supplied to the secondary combustion chamber, and EGR Gas (Exhaust Gas Recirculation) Gas) is supplied from the top of the rear side of the primary combustion chamber. Thus, the minimum amount of oxygen necessary for combustion of the unburned gas in the secondary combustion chamber is ensured by the secondary air, and the secondary air and the unburned gas are sufficiently stirred by the stirring gas flow generated by supplying the EGR gas. This is illustrated in paragraph 0015 of JPH05-113208A, which is capable of maintaining a high combustion gas temperature and suppressing the generation of carbon monoxide (CO) and dioxins.

JPH07-158827A discloses the following: in the incinerator, a nozzle for supplying air for secondary combustion is provided at the rear top of the primary combustion chamber, and air for secondary combustion is supplied from the nozzle toward the inside of the combustion flame of the waste or the vicinity of the front end thereof. Paragraph 0013 of JPH07-158827A describes: the supplied secondary combustion air directly contacts the high-temperature flame, and the oxygen concentration in the inner direction of the flame and in the vicinity of the outer periphery of the flame increases, so that a large amount of unburned soot medium, unburned gas such as CO, and the like existing in the vicinity of the outer periphery of the flame burns vigorously. And illustrates the results: the total amount of unburned soot medium and CO transferred into the secondary combustion chamber is reduced, so that the generation of soot is prevented, and the CO concentration in the exhaust gas is reduced.

However, in the technique described in JPH05-113208A, JPH07-158827a, although a large amount of unburned soot medium, unburned gas such as CO, and the like are burned vigorously in the primary combustion chamber, a space between the post-combustion bank (rear side) in the primary combustion chamber and the ceiling wall of the combustion chamber in which the post-combustion bank is provided is not sufficiently utilized. Therefore, the following techniques are availableThe problems of the operation are as follows: the concentration of unburned gas in the primary combustion chamber or the secondary combustion chamber is locally increased, and thus Nitrogen Oxide (NO) is generated_x)。

To solve this technical problem, JP2014-167353a discloses: the recirculated exhaust gas from the front side is supplied toward the rear from the ceiling wall of the front side in the primary combustion chamber of the incinerator, and the recirculated exhaust gas from the rear side is supplied toward the front from the rear wall or the rear ceiling wall in the primary combustion chamber. With this configuration, it is possible to greatly reduce NO by dividing the case where the combustion position in the primary combustion chamber is before the reference range, the case where the combustion position in the primary combustion chamber is after the reference range, and the case where the combustion position in the primary combustion chamber is within the reference range, and changing the distribution ratio of the recirculated exhaust gas from the front side to the recirculated exhaust gas from the rear side in accordance with each case_xAnd (4) concentration.

Disclosure of Invention

Technical problem to be solved

The object of the present invention is to further improve the technology described in JP2014-167353a to obtain an incinerator capable of significantly reducing NO by supplying recirculated exhaust gas from the front side toward the rear from the front top wall in the primary combustion chamber of the incinerator and supplying recirculated exhaust gas from the rear side toward the front from the rear wall or the rear top wall in the primary combustion chamber_xCompared with the concentration technique, the same NO can be expressed by a simpler structure_xThe effect is reduced.

(II) technical scheme

In order to achieve the above object, an incinerator according to the present invention includes: a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and a secondary combustion chamber which is connected to an outlet side of the primary combustion chamber and has a secondary combustion gas supply nozzle, wherein the primary combustion chamber has a rear supply nozzle for the primary combustion chamber which supplies any one of air, EGR gas, and a mixed gas of air and EGR gas to a front side of at least one of a ceiling wall and a rear wall of the rear side, the secondary combustion chamber has a front supply nozzle which supplies an airflow to the rear side, the rear supply nozzle for the primary combustion chamber guides an unburned gas generated in a combustion stage to the rear wall side by the airflow supplied from the rear supply nozzle for the primary combustion chamber, and the front supply nozzle guides the unburned gas generated in a drying stage to the front side by the airflow supplied from the front supply nozzle and flows into the secondary combustion chamber.

According to the present invention, in the above-described incinerator, it is preferable that the secondary combustion gas supply nozzle for supplying the gas flow to the rear side also serves as the front supply nozzle.

According to the present invention, in the above-described incinerator, it is preferable that the plurality of secondary combustion gas supply nozzles be provided in a plurality of stages in the vertical direction, and the secondary combustion gas supply nozzle that supplies the airflow toward the rear side of the lowermost stage be used also as the front supply nozzle.

According to the present invention, in the above-described incinerator, it is preferable that the other secondary combustion gas supply nozzle except the lowest secondary combustion gas supply nozzle performs a function of adjusting the supply amount of the secondary air.

According to the present invention, it is preferable that the front supply nozzle and the rear supply nozzle for the primary combustion chamber are arranged alternately so as to avoid interference between the supply gas from the front supply nozzle and the supply gas from the rear supply nozzle for the primary combustion chamber.

According to the present invention, in the above-described incinerator, the primary combustion chamber preferably includes: the primary combustion chamber is connected to the secondary combustion chamber at a rear portion of the front ceiling wall, the front supply nozzle injects an air flow in a horizontal direction or downward than the horizontal direction, and the front ceiling wall is inclined upward at an angle exceeding 0 degree and 60 degrees or less with respect to the horizontal direction as going from the front side to the rear side.

According to the present invention, in the above-described incinerator, the drying section, the combustion section, and the post-combustion section preferably have grates, respectively, which are inclined downward at least from the drying section toward the combustion section.

According to the present invention, in the above-described incinerator, it is preferable that the rear supply nozzle for the primary combustion chamber supplies air to at least the primary combustion chamber, and the incinerator is provided with a control device for controlling the supply amount of gas from the rear supply nozzle for the primary combustion chamber to the primary combustion chamber, thereby adjusting the oxygen concentration in the primary combustion chamber.

According to the present invention, in the above-described incinerator, it is preferable that the plurality of primary combustion chamber rear supply nozzles are provided in a plurality of stages in the vertical direction, and the oxygen concentration in the primary combustion chamber is adjusted by fixing the gas supply amount in some of the primary combustion chamber rear supply nozzles and controlling the gas supply amount in the other primary combustion chamber rear supply nozzles.

According to the present invention, in the above-described incinerator, the secondary combustion chamber preferably has a front wall for installing the front feed nozzle, the front wall being located rearward relative to the rear end of the drying section.

An incinerator operating method according to the present invention is an incinerator operating method, the incinerator including: a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and a secondary combustion chamber provided in connection with an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, characterized in that a rear supply nozzle for the primary combustion chamber is provided on at least one of a rear ceiling wall and a rear wall of the primary combustion chamber, and supplies any one of primary air, EGR gas, and a mixed gas of the primary air and the EGR gas toward a front side, unburned gas generated in a combustion stage is introduced to the rear wall side using the rear supply nozzle for the primary combustion chamber, and at least unburned gas generated in a drying stage is introduced to the front side using a gas flow supplied from the front supply nozzle and flows into the secondary combustion chamber using a front supply nozzle provided in the secondary combustion chamber and supplying a gas flow toward the rear side.

Another incinerator of the present invention comprises: a primary combustion chamber having a drying section, a combustion section, and a post-combustion section in this order from a front side toward a rear side, and having a top wall and a rear wall of the rear side; and a secondary combustion chamber provided in connection with an outlet side of the primary combustion chamber and having a secondary combustion gas supply nozzle, wherein the primary combustion chamber has a primary combustion chamber rear supply nozzle provided on at least one of a rear top wall and a rear wall thereof, and configured to supply any one of primary air, EGR gas, and a mixed gas of the primary air and the EGR gas to a front side, and the secondary combustion chamber has a front supply nozzle configured to supply an airflow to a rear side, and the primary combustion chamber includes: a feeding hopper for the material to be burned, a front width part connected from the feeding hopper, a front side top wall connected from the front width part, a primary combustion chamber connected with a secondary combustion chamber at the rear part of the front side top wall,

the top wall of the front side is inclined upward at an angle exceeding 0 degree and 60 degrees or less with respect to the horizontal direction as going from the front side toward the rear side,

the drying section, the combustion section and the post-combustion section are respectively provided with a fire grate, and the fire grate is at least downwards inclined from the drying section to the combustion section.

(III) advantageous effects

According to the present invention, the front supply nozzle can introduce the unburned gas generated in the drying section to the front side and flow into the secondary combustion chamber by the airflow supplied from the front supply nozzle, and therefore can contribute to achieving the same hot NO as in the prior art in which the recirculated exhaust gas is supplied from the ceiling wall of the front side in the primary combustion chamber of the incinerator_xThe effect is reduced.

Drawings

FIG. 1 is a front view showing the structure of an incinerator according to an embodiment of the present invention.

Fig. 2 is an enlarged cross-sectional view in plan view of a main part of the incinerator.

Fig. 3 is an enlarged cross-sectional view in plan view of the secondary combustion chamber in the incinerator.

Detailed Description

The incinerator shown in fig. 1 includes: a garbage supply part 11, a primary combustion chamber 12, a secondary combustion chamber 13, and an exhaust path 14. In the primary combustion chamber 12 and the secondary combustion chamber 13, combustion of the garbage and combustion of unburned gas containing carbon and hydrogen as main components generated from the garbage are performed. An exhaust gas outlet 15 is provided at an upper portion of the primary combustion chamber 12, and the primary combustion chamber 12 and the secondary combustion chamber 13 are communicated with each other through the outlet 15. The garbage supply unit 11 includes: a feeding hopper 16 for receiving garbage, a crane 18 for feeding garbage 17 from a garbage pit outside the figure into the feeding hopper 16, and a pusher 19 as a garbage feeding device for feeding the garbage from the bottom of the feeding hopper 16 into the primary combustion chamber 12.

In the illustrated incinerator, the primary combustion chamber 12 is constructed from a plurality of wall sections. Specifically, if the side on which the input hopper 16 is provided is defined as the front side and the side away from the input hopper 16 is defined as the rear side, the primary combustion chamber 12 includes: a front side width portion 20 connected from the input hopper, a front side ceiling wall 21 inclined so as to gradually rise from an upper end of the front side width portion 20 toward the rear side, a vertically rear wall 22 provided on the other side, i.e., the rear side, and a rear side ceiling wall 23 inclined so as to gradually rise from an upper end of the rear wall 22 toward the front side. An outlet 15 for exhaust gas from the primary combustion chamber 12 is provided between the rear portion of the front side ceiling wall 21 and the front portion of the rear side ceiling wall 23.

In the present invention, no nozzle for supplying gas into the primary combustion chamber 12 is provided in the front ceiling wall 21. The reason is that: since the total gas supply amount (also referred to as "flow rate") that can be supplied into the waste incinerator is determined to be an appropriate amount so that the oxygen concentration of the exhaust gas and the temperature in the incinerator become appropriate values, the gas supply amount that can be supplied by other nozzles (particularly, the after-mentioned secondary combustion gas supply nozzle 44 and the primary combustion chamber rear supply nozzle 40) provided in the waste incinerator can be increased without providing a nozzle for supplying gas into the primary combustion chamber 12 in the front ceiling wall 21. In addition, the method also has the advantages of reducing initial cost, saving space and the like.

The front ceiling wall 21 is preferably inclined at an angle of, for example, 15 degrees or more and 40 degrees or less, more preferably 15 degrees or more and 30 degrees or less, with respect to the horizontal direction, so that no nozzle is provided in the ceiling wall 21 of the drying stage 24 and unburned gas generated in the drying stage 24 is likely to flow to the front side portion of the primary combustion chamber 12. The length of the front ceiling wall 21 is preferably 1m to 5m, more preferably 2m to 4 m.

As for the rear side ceiling wall 23, in the primary combustion chamber 12, as indicated by reference numeral 64 in fig. 1, in order to introduce the unburned gas generated by combustion in the combustion stages 25 and 26 and heading toward the secondary combustion chamber 13 to the rear wall 22 side of the primary combustion chamber 12, the inclination angle of the ceiling wall 23 with respect to the horizontal direction is preferably 15 degrees or more and 60 degrees or less, more preferably 15 degrees or more and 35 degrees or less. The length of the rear ceiling wall 23 is preferably 2m to 8m, and more preferably 4m to 7 m.

The primary combustion chamber 12 has a drying section 24, a combustion section 25, and a post-combustion section 26 in this order from the front side to the rear side after the pusher 19. A drying grate 27 is provided at the bottom of the drying section 24, a combustion grate 28 is provided at the bottom of the combustion section 25, and an after-combustion grate 29 is provided at the bottom of the after-combustion section 26 (hereinafter, the drying grate 27, the combustion grate 28, and the after-combustion grate 29 may be simply referred to as "grates", respectively). In the illustrated incinerator, the drying grate 27 and the combustion grate 28 of the grates 27, 28, 29 are arranged to be inclined downward from the front side toward the rear side, i.e., in a direction from the drying section 24 toward the combustion section 25. In the illustrated incinerator, the post-combustion grate 29 is disposed in a horizontal direction. An ash discharge port 30 for discharging ash generated by burning the refuse 17 is provided on the rear side of the post-combustion stage 26. In the case where the drying grate 27, the combustion grate 28, and the post-combustion grate 29 are inclined, the inclination angle is preferably 0 degrees to 20 degrees with respect to the horizontal direction, and more preferably 10 degrees to 20 degrees, in order to facilitate the transport of the waste 17 to the rear side in the primary combustion chamber 12.

The primary air supply path 31 is a pipe for supplying primary air (combustion air, hereinafter, the combustion air may be simply referred to as "air") to the primary combustion chamber 12. The primary air supply path 31 is branched in correspondence with the grates 27, 28, 29, and is connected to air boxes 32, 33, 34 provided below the grates 27, 28, 29, respectively. The primary air from the primary air supply path 31 is supplied to the interior of the primary combustion chamber 12 through the respective grates by a blower (fan).

The primary combustion chamber 12 is provided with a primary combustion chamber rear supply nozzle 40. The rear supply nozzle 40 for the primary combustion chamber is provided on at least one of the ceiling wall 23 and the rear wall 22 on the rear side. And a plurality of the primary combustion chambers 12 are provided in parallel with a predetermined interval in the width direction thereof in accordance with the size of the incinerator.

The rear supply nozzle 40 for the primary combustion chamber is preferably provided in a plurality of stages in the vertical direction and in the same row in the width direction. In addition, when the plurality of rear supply nozzles 40 for the primary combustion chamber are provided in a plurality of stages in the vertical direction, it is preferable to control the gas supply amount of the rear supply gas for the primary combustion chamber by fixing the gas supply amount in some of the rear supply nozzles 40 for the primary combustion chamber and controlling the gas supply amount in the other rear supply nozzles 40 for the primary combustion chamber. In this way, by utilizing a sufficient flow rate of gas supplied from the rear supply nozzle 40 for the primary combustion chamber, in which the gas supply amount is fixed, the exhaust gas and the unburned gas generated particularly in the combustion stage 25 flow into the upper space 65 in the primary combustion chamber 12 in the post-combustion stage 26, and the flow in the primary combustion chamber denoted by reference numeral 64 in fig. 1 can be stably maintained. As a result, the space 65 between the post-combustion grate 29 in the primary combustion chamber 12 and the top wall 23 of the portion of the primary combustion chamber 12 where the post-combustion grate 29 is provided is sufficiently utilized to perform combustion of the unburned gas. For example, the supply amount of the rear supply nozzle 40 for a primary combustion chamber, which has a fixed gas supply amount, varies depending on the nozzle diameter, and the flow rate is preferably 35m/s to 70 m/s.

It is preferable that the supply amount of the oxygen-containing gas can be controlled as described above for the other rear supply nozzle 40 for the primary combustion chamber, except for the above-described part. The rear supply nozzle 40 for the primary combustion chamber, which is controlled by the amount of the oxygen-containing gas to be supplied, can adjust the oxygen concentration in the primary combustion chamber 12, and efficiently combust unburned gas at an appropriate oxygen concentration in the space 65 of the primary combustion chamber 12 where the post-combustion grate 29 is provided. By efficiently combusting the unburned gas at an appropriate oxygen concentration in the space 65 of the primary combustion chamber 12, it is also possible to suppress the generation of CO and dioxins due to incomplete combustion.

In this case, it is particularly preferable to control the supply amount of the rear supply nozzle 40 for the primary combustion chamber other than the lowermost stage while fixing the supply amount of the rear supply nozzle 40 for the primary combustion chamber of the lowermost stage. By fixing the supply amount of the rear supply nozzle 40 for the lowermost primary combustion chamber, it is possible to make the exhaust gas and the unburned gas generated particularly in the combustion stage 25 flow into the upper space 65 of the primary combustion chamber 12 in the post-combustion stage 26, and to sufficiently and effectively utilize the upper space 65 of the post-combustion flue gas 29 in the combustion chamber 12 to perform combustion of the unburned gas.

In the example of fig. 1, the rear supply nozzle 40 for the primary combustion chamber is provided in two stages in the upper and lower direction on the rear ceiling wall 23. As shown in fig. 2, two rear supply nozzles 40 for the primary combustion chamber are provided in parallel in the width direction of the primary combustion chamber 12. Specifically, 40a is two nozzles on the upper stage side, and 40b is two nozzles on the lower stage side, and they are arranged in the same row in the width direction with a predetermined interval therebetween. In the illustrated example, the upper and lower two-stage nozzles 40a and 40b are provided in a portion on the rear end side of the rear ceiling wall 23 (the ceiling wall 23 in the rear combustion stage 26). In addition, in the right part of fig. 2, a part of the primary combustion chamber 12 on the lower stage side where the rear supply nozzle 40b for the primary combustion chamber is provided is shown in cross section, and in the left part of fig. 2, a part of the secondary combustion chamber 13 where a front supply nozzle 44 described later is provided is shown in cross section. In order to avoid interference with the air flow of the front supply nozzle 44, it is preferable to arrange the rear supply nozzle 40 for the primary combustion chamber and the front supply nozzle 44 in a staggered (zigzag) manner as shown in the drawing. In fig. 2, the one-dot chain line 38 indicates a central position in the combustion chambers 12 and 13.

Alternatively, instead of the configuration of fig. 2, the number of the primary combustion chamber rear supply nozzles 40 may be arbitrarily changed according to, for example, the size of the primary combustion chamber 12 in the width direction. For example, when the dimension of the primary combustion chamber 12 in the width direction is large, three nozzles 40a on the upper stage side and three nozzles 40b on the lower stage side may be provided in parallel in the width direction of the primary combustion chamber 12. In this case, the size of the secondary combustion chamber 13 also becomes large accordingly, and accordingly, three front supply nozzles 44 may be provided in parallel in the width direction of the secondary combustion chamber 13. In this case, the air flow of the primary combustion chamber rear supply nozzle 40 and the air flow of the front supply nozzle 44 may be configured to collide with each other, differently from the above.

Further, depending on the shape of the furnace, at least one of the rear supply nozzle 40 and the front supply nozzle 44 for the primary combustion chamber may be preferably disposed at the central position 38, instead of the configuration of fig. 2.

The gas supply path 41 is a pipe for supplying one of air, EGR gas, and a mixed gas of air and EGR gas, which is a rear supply gas, to the rear supply nozzle 40 for the primary combustion chamber. Then, the rear supply gas is supplied from the gas supply path 41 to the primary combustion chamber 12 through the primary combustion chamber rear supply nozzle 40 by a blower (fan), not shown. In this way, the exhaust gas and the unburned gas generated particularly in the combustion stage 25 can be made to flow into (swirl around) the upper space 65 of the primary combustion chamber 12 in the post-combustion stage 26, and the unburned gas can be burned in the space 65 between the post-combustion bank 29 in the primary combustion chamber 12 and the ceiling wall 23 of the primary combustion chamber 12 in which the post-combustion bank 29 is provided.

The secondary combustion chamber 13 is connected to the outlet 15 of the primary combustion chamber 12 as described above and is disposed upward. The secondary combustion chamber 13 is rectangular in cross section, 42 is a front wall of the secondary combustion chamber 13, and 43 is a rear wall of the secondary combustion chamber 13. The front top wall 21 is connected to the front wall 42 at the front intersection 63A. The rear ceiling wall 23 is connected to the rear wall 43 at the rear intersection 63B. The front intersection 63A and the rear intersection 63B are preferably at the same height. In the front-side intersecting portion 63A, the rear end of the front-side ceiling wall 21 and the lower end of the front wall 42 are preferably connected to each other so as to form an arc-shaped cross section. The height of the intersection 63A from the grates 27, 28 to the front side is preferably 1.0m to 5.0m, and more preferably 2.0m to 4.0 m.

As shown in fig. 1 and 3, a secondary combustion gas supply nozzle 44 for supplying a secondary combustion gas to the secondary combustion chamber 13 is provided on the front wall 42 and the rear wall 43 of the secondary combustion chamber 13. The secondary combustion gas supply nozzle 44 is provided in a plurality of stages in the vertical direction, and a plurality of secondary combustion gas supply nozzles are provided in each stage in parallel in the width direction at predetermined intervals corresponding to the size of the incinerator. In the incinerator shown in fig. 1, the secondary combustion gas supply nozzles 44 of the front wall 42 are provided in two stages, upper and lower. 44a is a nozzle on the upper stage side, and 44b is a nozzle on the lower stage side. As shown in fig. 3, in each stage, the secondary combustion gas supply nozzles 44 are arranged in a staggered (zigzag) manner on the front wall 42 and the rear wall 43 in order to avoid interference with each other.

Fig. 3 shows an example of the arrangement of the secondary combustion gas supply nozzles 44 on the front wall 42 and the rear wall 43 of the secondary combustion chamber 13 in the case where two rear supply nozzles 40 for the primary combustion chamber are provided in the width direction of the primary combustion chamber 12 as shown in fig. 2. As shown in the drawing, two secondary combustion gas supply nozzles 44 are provided in the front wall 42, and three secondary combustion gas supply nozzles 44 are provided in the rear wall 43.

In contrast, for example, in the case where three rear supply nozzles 40 for the primary combustion chamber are provided in parallel in the width direction of the primary combustion chamber 12 in accordance with the increase in the width direction dimension of the primary combustion chamber 12 as described above, the size of the secondary combustion chamber 13 also increases in accordance with the increase in the width direction dimension, and therefore, for example, four secondary combustion gas supply nozzles 44 for the rear wall 43 of the secondary combustion chamber 13 may be provided in parallel in the width direction of the secondary combustion chamber 13. The number of the secondary combustion gas supply nozzles 44 is not limited to the above example, and may be arbitrarily set according to the size of the furnace, that is, the size of the secondary combustion chamber 13.

The secondary combustion gas supplied from the secondary combustion gas supply nozzle 44 is used to promote combustion of the unburned gas after the part 61 of the unburned gas from the drying zone 24 and the part 64 of the unburned gas introduced from the combustion zone 25 to the rear wall 22 side of the primary combustion chamber 12 merge together. The secondary combustion gas is any one of secondary air (combustion air), EGR gas, and a mixed gas of secondary air and EGR gas.

The position of the front wall 42 of the secondary combustion chamber 13 is preferably closer to the rear wall 22 of the primary combustion chamber 12 than the rear end of the drying section 24. The reason is to easily perform the following control: the unburned gas generated in the drying zone 24 is introduced to the front wall 42 side by a gas flow supplied from a front supply nozzle 44 described later, and the unburned gas generated in the drying zone 24 and the combustion zone 25 is introduced to the rear wall 22 side by a gas flow supplied from a rear supply nozzle 40 for a primary combustion chamber.

A front supply nozzle 44 is provided in the front wall 42 of the secondary combustion chamber 13. The front supply nozzle 44 is provided at a position near the lower end of the front wall 42 of the secondary combustion chamber 13. Specifically, the distance is preferably 0mm to 2000mm, more preferably 300mm to 800mm, from the lower end of the front wall 42. When the front supply nozzle is provided in a plurality of stages, the first stage is preferably disposed at a distance of 0mm to 1000mm, more preferably 500mm to 800mm from the lower end. The second section is preferably disposed at a distance of 300mm to 2000mm, more preferably 500mm to 800mm from the lower end. As described above, a plurality of secondary combustion chambers 13 are provided in parallel in the width direction of the front wall 42, corresponding to the size of the incinerator.

Preferably, the front feed nozzles 44 spray in a horizontal direction or spray downwardly from a horizontal direction. Specifically, the front supply nozzle 44 preferably injects the gas at an angle of 0 degrees or more and 30 degrees or less from the horizontal direction. The gas supply amount is controlled so that the flow velocity in the front supply nozzle 44 is 20m/s to 60 m/s.

In the incinerator of fig. 1, an example is shown in which a secondary combustion gas supply nozzle 44 provided at a position near the lower end of the front wall 42 of the secondary combustion chamber 13 and supplying a gas flow toward the rear side is used as the front supply nozzle 44 as well. That is, a secondary combustion gas supply nozzle 44 serving also as a front supply nozzle is provided in a position near the lower end of the front wall 42 of the secondary combustion chamber 13 near the outlet 15, which is a communication port with the primary combustion chamber 12. In the incinerator shown in fig. 1, the secondary combustion gas supply nozzle 44 is also provided so as to face the secondary combustion gas supply nozzle 44 also serving as a front supply nozzle in the vicinity of the lower end of the rear wall 43 of the secondary combustion chamber 13, and to stir the unburned gas in the secondary combustion chamber 13.

In the incinerator shown in fig. 1, a bag filter 45, an induction fan 46, and a chimney 47 are provided on the downstream side of the exhaust passage 14 connected to the secondary combustion chamber 13. In addition, a cooling tower, an economizer, and the like may be appropriately provided.

A boiler 48 using exhaust gas as a heat source is provided in the exhaust gas passage 14. The flow meter 49 is used to measure the flow of steam from the boiler 48. Further, the exhaust passage 14 is provided with an oxygen concentration sensor 51 for detecting the oxygen concentration of the exhaust gas passing through the passage 14. The oxygen concentration meter 52 receives a signal from the oxygen concentration sensor 51 to calculate the oxygen concentration. One or more exhaust gas sensors 53 are provided in the stack 47 and other exhaust path portions. The exhaust gas sensor 53 is connected to NO_xMetering and SO_xAn exhaust gas meter 55 such as a meter, a CO meter, and an oxygen concentration meter.

In fig. 1, 54 is a control device for controlling the combustion state of the illustrated incinerator. A flow meter and a damper are provided in each of the branch paths of the primary air supply path 31, the gas supply path to the secondary combustion gas supply nozzle 44, and the gas supply path 41 to the primary combustion chamber rear supply nozzle 40, the detailed description of which is omitted. The controller 54 controls the dampers to have a desired opening degree after receiving signals from the respective flowmeters.

In such a configuration, the combustion of the refuse 17 and the combustion of the unburned gas containing carbon and hydrogen generated from the refuse 17 as main components are performed in the primary combustion chamber 12 and the secondary combustion chamber 13. In particular, in the secondary combustion chamber 13, the unburned gas generated in the primary combustion chamber 12 is burned with a gas containing oxygen from the secondary combustion gas supply nozzle 44. Specifically, the refuse 17 fed from the input hopper 16 to the primary combustion chamber 12 by the pusher 19 is dried in the drying section 24, fed to the combustion section 25 as the next refuse is fed to the drying section 24, combusted in the combustion section 25, and then similarly fed to the post-combustion section 26 to be post-combusted. As a result, the generated incineration ash is discharged from the discharge port 30 to the outside of the furnace. Since the drying grate 27 and the combustion grate 28 are inclined downward toward the rear side, the garbage can be easily transferred toward the rear side.

The gas is injected from a secondary combustion gas supply nozzle 44 serving also as a front supply nozzle provided on the front wall 42 of the secondary combustion chamber 13 toward the rear wall 43 of the secondary combustion chamber 13. Then, by this jet flow, a part 61 of the unburned gas generated in the drying section 24 is not guided to the rear wall 22 side by the airflow supplied from the primary combustion chamber rear supply nozzle 40. Therefore, in a state where the flow of the part 61 of the unburned gas from the drying zone 24 can be stably maintained, the part 61 of the unburned gas can be made to flow into the secondary combustion chamber 13.

In the incinerator shown in fig. 1, preferably, the secondary combustion gas supply nozzle 44 has a two-stage structure of the upper-stage nozzle 44a and the lower-stage nozzle 44b as described above, so that, for example, the flow rate from the lower-stage nozzle 44b is fixed (fixed), and the flow rate from the upper-stage nozzle 44a is adjusted to control the entire flow rate of the secondary combustion gas supply nozzle 44. That is, the lower nozzle 44b is used for the purpose of flowing a part 61 of the unburned gas generated in the drying zone 24 to the upper space 62 as the front supply nozzle as described above and securing the flow velocity and flow rate necessary for combustion in the primary combustion chamber 12. In contrast, the upper nozzle 44a can be used to adjust the oxygen concentration in the secondary combustion chamber 13.

For example, when the quality or quantity of the refuse 17 to be incinerated changes, the gas supply amount to the upper nozzle 44a is adjusted. The adjustment of the gas supply amount can be performed by a control type damper or a manual damper, not shown, provided in a gas supply path to the secondary combustion gas supply nozzle 44.

By operating the secondary combustion gas supply nozzle 44 that also serves as the front supply nozzle as described above, a part 61 of the unburned gas generated in the drying stage 24 can be made to flow into the upper space 62 in the drying stage 24 by the gas flow supplied from the front supply nozzle.

The operation of the rear supply nozzle 40 for the primary combustion chamber will be described below. By injecting the air flow from the rear supply nozzle 40 for the primary combustion chamber toward the front width portion 20 side in the horizontal direction or upward in the horizontal direction in accordance with the inclination of the top wall 23 on the rear side, the unburned gas generated by combustion in the drying stage 24, the combustion stage 25, and the rear combustion stage 26 and heading toward the secondary combustion chamber 13 in the primary combustion chamber 12 can be introduced to the rear wall 22 side of the primary combustion chamber 12 as indicated by reference numeral 64 in fig. 1. This makes it possible to flow (swirl) the exhaust gas and the unburned gas generated in the combustion stage 25 into the upper space 65 of the primary combustion chamber 12 in the post-combustion stage 26, and to stir them. Therefore, the concentration of the unburned gas in the primary combustion chamber 12 does not become locally too high. Further, the unburned gas can be combusted for a certain period of time in the upper space 65 of the post-combustion stage 26, and the amount of the unburned gas to be fed to the secondary combustion chamber 13 can be reduced or appropriately controlled.

The amount of gas supplied to the rear supply nozzle 40 for the primary combustion chamber is preferably determined on a case-by-case basis based on the combustion position on each grate 27, 28, 29. For example, when the combustion position is forward, it is preferable to increase the gas supply amount of the primary combustion chamber rear supply nozzle 40. When the combustion position is further rearward, the gas supply amount of the primary combustion chamber rear supply nozzle 40 may be controlled to be decreased. In the case where the combustion position is later, the same control as in the case where the combustion position is within the reference range can be performed. It is preferable that the combustion position is determined based on the combustion start position and/or the burnout position on each grate 27, 28, 29, and confirmed by an infrared camera or an industrial camera, not shown.

In the incinerator shown in fig. 1, the primary combustion chamber rear supply nozzle 40 has a two-stage structure of the upper-stage primary combustion chamber rear supply nozzle 40a and the lower-stage primary combustion chamber rear supply nozzle 40b as described above. In this case, it is preferable that the lower rear supply nozzle 40b for the primary combustion chamber be used to ensure the flow velocity, and the upper rear supply nozzle 40a for the primary combustion chamber be used to assist in ensuring the required flow rate. The reason is that: if the gas is excessively injected at an ultra high speed from one rear supply nozzle 40 for the primary combustion chamber, the flow is disturbed beyond the maximum amount of gas that can be injected from the nozzle diameter of the rear supply nozzle 40 for the primary combustion chamber, and the desired entrainment effect cannot be exhibited, and the gas inside the primary combustion chamber 12 cannot be stirred well. Further, by using the rear supply nozzle 40b for the primary combustion chamber on the lower stage side for ensuring the flow velocity for exerting the required drawing effect, the exhaust gas containing the unburned gas can be drawn to the rear of the primary combustion chamber 12 and can be burned further rearward than the space 65, as compared with the case where the rear supply nozzle 40a for the primary combustion chamber on the upper stage side for ensuring the flow velocity.

The exhaust gas containing unburned gas is easily led rearward of the primary combustion chamber 12 by the angle of inclination of the gas flow from the rear supply nozzle 40 for the primary combustion chamber being as upward as possible. However, if the height is too high, the damping is generated by friction with the top wall 23, and the required function cannot be performed. In order to introduce the exhaust gas containing unburned gas to the rear side without significant attenuation, the inclination angle of the gas flow from the primary combustion chamber rear supply nozzle 40 is preferably within minus 35 degrees from the inclination angle of the ceiling wall 23, and more preferably within minus 20 degrees from the inclination angle of the ceiling wall 23. The lower limit of the inclination angle of the air flow from the rear supply nozzle 40 for the primary combustion chamber is preferably 0 degree, i.e., the horizontal direction, in consideration of the direct influence of the air flow on the flame region on each grate 27, 28, 29.

As described above, according to the present invention, by injecting gas from the secondary combustion gas supply nozzle 44 provided on the front wall 42 of the secondary combustion chamber 13 toward the rear wall 43 of the secondary combustion chamber 13, a part 61 of the unburned gas generated in the drying section 24 is guided to the front side. That is, the same operational effects as those obtained by providing the supply device can be obtained without providing the supply device, and the same apparent NO can be obtained_xReducing effect of whereinThe supply device does not introduce a part 61 of the unburned gas to the rear wall side by the flow of the air supplied from the rear supply nozzle 40 for the primary combustion chamber, but allows the unburned gas to flow into the upper space 62 of the arm drying grate 27, and supplies recirculated exhaust gas or the like from the front ceiling wall 21 of the primary combustion chamber 12 toward the rear.

Further, according to the present invention, the following advantages can also be obtained. That is, in the primary combustion chamber 12, compared with JP2014-167353a, since the drying grate 27 and the combustion grate 28 are close to the front supply nozzle (the secondary combustion gas supply nozzle 44 also serving as the front supply nozzle) and the stirring effect by the gas supply nozzle provided in the ceiling of the drying stage in the known art is performed by the gas flow from the front supply nozzle (the secondary combustion gas supply nozzle 44 also serving as the front supply nozzle), and particularly, since the inclination angle of the ceiling wall 21 in the drying stage 24 is set to 60 degrees or less, preferably 30 degrees or less, more preferably 15 to 25 degrees after the primary combustion chamber 12 is made to be of the inclined type, it is easy to cause a part of the combustion exhaust gas to flow along the front side portion of the primary combustion chamber 12 without providing a nozzle in the ceiling wall 21 of the drying stage 24, the same NO as in the case where the nozzle is provided in the ceiling wall 21 on the front side can be obtained as in JP2014-167353A_xThe effect is reduced. By thus reducing the number of nozzles provided in the primary combustion chamber 12 without providing nozzles in the front ceiling wall 21, the total flow rate limit that can be supplied by other nozzles provided in the primary combustion chamber 12 is relaxed. That is, the amount of gas that can be supplied from other nozzles (particularly, the after-mentioned secondary combustion gas supply nozzle 44 and the after-mentioned primary combustion chamber supply nozzle 40) provided in the waste incinerator can be increased. Therefore, the flow rate of the other nozzles provided in the primary combustion chamber 12 can be increased to increase the flow velocity, and thus the exhaust gas can be easily stirred.

In the above description, the example in which the secondary combustion gas supply nozzle 44 is used as the front supply nozzle has been described, but the secondary combustion gas supply nozzle may not be used as the front supply nozzle.

In addition, due to the particularly upper space 65 ratio in the post-combustion section 26Since the upper space 62 is large, the unburned gas and the like can be prevented from remaining for a long retention time, and the unburned gas is locally accumulated, and the unburned gas can be gradually burned from the space 65 in the upper portion. As a result, since the amount of unburned gas flowing into the secondary combustion chamber 13 through the space 65 is reduced, the combustion temperature does not locally increase even in the secondary combustion chamber 13, and it is possible to make NO generation difficult_xThe multi-stage combustion of (2).

Further, the unburned gas generated in the combustion zone 25 and the like is introduced to the rear wall 22 side by the gas flow supplied from the rear supply nozzle 40 for the primary combustion chamber, while the unburned gas generated in the drying zone 24 is introduced to the front side by the gas flow supplied from the front supply nozzle. That is, the unburned gas generated in the drying section 24 is not guided to the rear wall 22 side by the gas flow supplied from the rear supply nozzle 40 for the primary combustion chamber, but flows into the secondary combustion chamber 13. Further, since both the unburned gases are merged in the secondary combustion chamber 13, the unburned gases can be adjusted in the secondary combustion chamber 13, and therefore the combustion temperature does not locally rise, and NO is less likely to be generated_x。

Further, since sufficient combustion can be performed in the primary combustion chamber 12, it is possible to minimize the supply amount of oxygen (secondary air) from the secondary combustion gas supply nozzle 44 in the secondary combustion chamber 13, and to ensure sufficient stirring of the unburned gas and the secondary air. Therefore, the supply amount of oxygen can be minimized, and the generation of NO can be suppressed_xAnd also can inhibit the generation of CO and dioxins.

Further, even in the space 65 of the primary combustion chamber 12, the appropriate oxygen concentration can be maintained by supplying air from the rear supply nozzle 40 for the primary combustion chamber. Therefore, the unstable combustion can be suppressed to generate CO and dioxins.

On the other hand, there is a problem that combustion is unstable due to a low air ratio with a low oxygen concentration. Specifically, if unburned gas is burned at a low air ratio, there are problems that the combustion is unstable, CO is increased, and the flame temperature is locally increasedUp to NO_xThe amount of soot produced increases dramatically, and the amount of pollutants in the exhaust gas increases. In the waste incineration furnace, the amount of air supplied into the primary combustion chamber through the furnace is controlled to be increased or decreased according to the amount of steam generated in the boiler or the like. In such control, when the waste quality of the waste charged into the primary combustion chamber 12 is improved (for example, the amount of heat generated per unit weight is high) and the amount of steam generated in the boiler 48 is increased, the amount of air supplied through the grates 27, 28, 29 is reduced, and therefore the concentration of unburned gas in the exhaust gas flowing from the primary combustion chamber 12 into the secondary combustion chamber 13 is increased. In this case, the unburned gas that has reached the secondary combustion chamber 13 is burned at once by the air injected from the nozzle 44 disposed in the secondary combustion chamber 13, and a high-temperature region is formed in the vicinity of the nozzle 44. As a result, NO in the exhaust gas discharged from the secondary combustion chamber 13 is generated_xThe concentration rises.

A method of controlling the supply amount of the primary combustion chamber rear supply gas in the case where at least one of air, EGR gas, and a mixed gas of air and EGR gas is supplied from the primary combustion chamber rear supply nozzle 40 to solve the above-described problem will be described.

First, control of the supply amount of the secondary air for combustion from the secondary combustion gas supply nozzle 44 will be described. The supply amount of the secondary air for combustion from the secondary combustion gas supply nozzle 44 is controlled by the control device 54 based on the measurement result of the oxygen concentration meter 52. Specifically, the supply amount of the secondary air for combustion is controlled so that the oxygen concentration measured by the oxygen concentration meter 52 is 3 to 5%. By reducing the supply amount of the secondary air, the amount of exhaust gas from the incinerator can be reduced.

The control of the amount of primary air supplied through each grate 27, 28, 29 will be described. The control device 54 controls the supply amount of the primary air so that the steam amount from the boiler 48 approaches the target steam amount. For example, when the steam amount from the boiler 48 is larger than the target steam amount, the command value of the garbage feeding speed by the pusher 19 is decreased from the current value. When the drying grate 27, the combustion grate 28, and the post-combustion grate 29 are configured to be movable in the front-rear direction and to sequentially convey the garbage to the rear side, the feeding speed is controlled to be slow. Then, the command value for the primary air supply amount is decreased from the current value.

The control of the supply amount of air from the primary combustion chamber rear supply nozzle 40 will be described. The supply amount of air from the primary combustion chamber rear supply nozzle 40 is an amount necessary for burning the unburned gas generated inside the primary combustion chamber 12. Specifically, the supply amount of air from the rear supply nozzle 40 for the primary combustion chamber is controlled by the control device 54 in accordance with the oxygen concentration measured by the oxygen concentration meter 52 so that the air ratio in the interior of the primary combustion chamber 12 (hereinafter referred to as "primary combustion chamber air ratio") is a predetermined value (for example, 0.7 to 1.2, preferably 0.95 to 1.10).

The primary combustion chamber air ratio is calculated by the following equation (1).

Air ratio of primary combustion chamber [ - ]

Here, the under-grate air ratio [ - ] + after-combustion roof air ratio [ - ] · (1), which is defined in the following formula (2). The afterburner plate air ratio is defined in the following formula (3).

[ equation 1]

[ equation 2]

In the above-described equation (3), the post-roof plate air flow rate is a flow rate of air included in the gas injected from the rear supply nozzle 40 for the primary combustion chamber. In the above-described equations (2) and (3), the total intake air amount is the sum of the grate-down air flow rate, the primary combustion chamber rear supply gas flow rate of the rear roof, and the secondary air flow rate in the secondary combustion chamber 13.

In the post-combustion stage 26 of the primary combustion chamber 12, i.e., in the upper space 65 of the grate 29 for post-combustion, it is preferable to control the internal oxygen concentration of the primary combustion chamber 12 when burning unburned gas. By controlling the oxygen concentration inside the primary combustion chamber 12, the following technical problems can be improved: unstable combustion, increased CO production, locally increased flame temperature and NO_xThe amount of coal produced increases dramatically, and the amount of pollutants in the exhaust gas increases.

(other modes for carrying out the invention)

Fig. 1 illustrates a configuration in which the rear supply nozzle 40 for the primary combustion chamber is provided on the ceiling wall 23 on the rear side, but it may be provided on the rear wall 22.

In the case where the incinerator is large, and the air flow rate and/or the EGR gas flow rate are insufficient, the flow rate supplied from the nozzle is decreased. In this case, it is desirable to provide a throttle valve or the like in the outlet 15 of the primary combustion chamber 12 (inlet of the secondary combustion chamber 13) which is a flow path, and to increase the flow rate of the combustion exhaust gas by the ejector effect of the throttle valve to realize a necessary flow rate.

In the incinerator shown in fig. 1, the secondary combustion gas supply nozzle 44 is provided on both the front wall 42 and the rear wall 43 in the secondary combustion chamber 13. In this case, in order to avoid interference between the air flow from the secondary combustion gas supply nozzle 44 provided on the front wall 42 and the air flow from the secondary combustion gas supply nozzle 44 provided on the rear wall 43, it is preferable to arrange these secondary combustion gas supply nozzles 44 in a staggered (zigzag) manner in a plan view. That is, the secondary combustion gas supply nozzle 44 provided on the front wall 42 and the secondary combustion gas supply nozzle 44 provided on the rear wall 43 are preferably provided at separate positions along a direction perpendicular to the paper surface in fig. 1.

In the incinerator, the same operation as the operation of supplying recirculated exhaust gas or the like to the rear side from the supply device of the ceiling wall 21 provided on the front side of the primary combustion chamber 12 is performed by the gas injected in the horizontal direction from the secondary combustion gas supply nozzle 44 provided on the front wall 42 of the secondary combustion chamber 13 toward the rear wall 43 of the secondary combustion chamber 13, and in order to enable this operation, the installation position of the secondary combustion gas supply nozzle 44, particularly the shape of the space formed by the front side ceiling wall 21 of the primary combustion chamber 12, other structures in the primary combustion chamber 12, and the like can be appropriately set.