WO2020070926A1

WO2020070926A1 - Stoker furnace

Info

Publication number: WO2020070926A1
Application number: PCT/JP2019/024517
Authority: WO
Inventors: 嘉正澤本; 匡之馬渡; 寺部　保典
Original assignee: 三菱重工環境・化学エンジニアリング株式会社
Priority date: 2018-10-05
Filing date: 2019-06-20
Publication date: 2020-04-09
Also published as: JP3219379U; CN209355255U

Abstract

This stoker furnace is supplied, from a feeder (4), with material (B) to be incinerated which is then transported sequentially through a drying stage (11), an incineration stage (12), and post-incineration stage (13), to respectively undergo drying, incineration, and a post-incineration process before being discharged. The drying stage (11), the burning stage (12), and the post-burning stage (13) are each equipped with a plurality of stationary fire grates (15) and a plurality of movable fire grates (16). The drying stage (11) is provided so as to be inclined with the downstream side (D1) in the transport direction facing downward. The incineration stage (12) is provided so as to be inclined with the downstream side (D1) in the transport direction facing upward. The post-burning stage (13) is provided substantially horizontally, or so as to be inclined with the downstream side (D1) in the transport direction facing downward.

Description

Stoker furnace

The present invention relates to a stoker furnace.
Priority is claimed on Japanese Utility Model Application No. 2018-003881 filed on October 5, 2018, the content of which is incorporated herein by reference.

スト As an incinerator for incinerating incinerated materials such as garbage, a stoker furnace that can efficiently incinerate a large amount of incinerated materials without sorting them is known. As a stoker furnace, there is known a stoker furnace in which a stoker is configured in a stepwise manner and provided with a drying stage, a combustion stage, and a post-combustion stage so as to perform drying, combustion, and post-combustion functions.

傾斜 In order to ensure that the incinerated material is burned, the inclination of the stoker is being studied. For example, as described in Patent Document 1 and Patent Document 2, the inclination angle of the stalker is such that the downstream side in the transport direction of the installation surface of all of the drying stage, the combustion stage, and the post-combustion stage faces downward. Something you are doing. Hereinafter, for example, when the downstream side of the installation surface of the drying stage in the transport direction is downward, the drying stage is simply referred to as downward (the same applies to the combustion stage and the post-combustion stage).

Further, as described in Patent Document 3, there is a type in which a drying stage is inclined downward and a combustion stage and a post-combustion stage are horizontally arranged. Further, as described in Patent Document 4, there is a type in which the drying stage and the combustion stage are inclined downward, and the installation surface of the post-combustion stage is inclined upward in the transport direction downstream. Further, there is one in which all steps are inclined upward as described in Patent Document 5. For example, when the downstream side in the transport direction of the installation surface of the combustion stage is upward, the combustion stage is simply referred to as upward (the same applies to the drying stage and the post-combustion stage).
Further, as described in Patent Document 6, there is a type in which the drying stage is inclined downward, and the drying stage and the combustion stage are inclined upward.

JP-A-6-265125 JP-A-59-86814 Japanese Utility Model Publication No. 6-84140 JP-B-57-12053 Japanese Utility Model Publication No. 57-127129 Japanese Patent No. 6397107

By the way, in the stoker furnaces of Patent Documents 1 to 5, incinerated materials of various properties (material, shape, moisture content) are charged. Regarding incinerated materials having a high water content (high moisture content), it was difficult to incinerate any of the stoker furnaces in the same manner as other incinerated materials.

That is, in the stoker furnaces described in Patent Literature 1, Patent Literature 2, Patent Literature 3, and Patent Literature 4, the drying stage is inclined downward and the combustion stage is inclined downward or horizontal. In addition, since the incinerated material having a slippery material or a shape that easily rolls is conveyed to the post-combustion stage earlier than other incinerated materials, there is a problem that the incinerated material is not fully incinerated and is discharged without burning.

In addition, in the stoker furnace described in Patent Document 5, since all of the drying stage, the combustion stage, and the post-combustion stage are inclined upward, the incinerated material having a slippery material or a shape that easily rolls or having a high moisture content. Since the incinerated material accumulates at the bottom of the step (fall wall) disposed between the feeder and the drying stage and becomes difficult to be transported to the combustion stage, the amount of the incinerated material is limited or the introduction is temporarily stopped. There is a problem that need may arise.
Then, the stoker furnace of patent document 6 which solves the subject concerned was developed. The stoker furnace of Patent Literature 6 is extremely excellent in that the incinerator can be continuously charged regardless of the properties of the incinerator and that the incinerator can be left without burning. However, there is a possibility that the operating cost can be further reduced depending on the properties and uniformity of the incinerated material.

The object of the present invention is to provide a stoker furnace similar to the stoker furnace described in Patent Document 6 but capable of reducing operating costs.

According to the present invention, the stoker furnace supplies the incineration material from the feeder, and includes a plurality of fixed grate and a plurality of moving grate in the drying stage, the combustion stage, and the post-combustion stage, and the incineration material is provided. In a stoker furnace that sequentially performs drying, combustion, and post-combustion while discharging, and discharges the incinerated material after the post-combustion from a discharge chute connected to the post-combustion stage, the drying stage includes the conveyance The combustion stage is connected to the drying stage, and the downstream side in the transport direction is inclined so as to be upward, and the post-combustion stage is connected to the drying stage. It is characterized by being connected to a stage and arranged so as to be substantially horizontal, or to be inclined so that the downstream side in the transport direction is downward.

According to such a configuration, the post-combustion stage having little influence on the combustion of the incineration material is set to be substantially horizontal or downward, so that the power for driving the moving grate is reduced as compared with the upward slope. And the operation cost can be reduced. Further, as in the stoker furnace of Patent Document 6, the drying stage is arranged downward and the combustion stage is arranged upward, so that depending on the properties and uniformity of the incinerated material, the same combustion as in the stoker furnace of Patent Document 6 is performed. Performance can be achieved.

According to the present invention, it is possible to provide a stoker furnace that is similar to the stoker furnace described in Patent Literature 6 and that can reduce operating costs.

It is a schematic structure figure of a stoker furnace of a first embodiment of the present invention. It is a figure explaining a stalker inclination angle of a stoker furnace of a first embodiment of the present invention. It is a side view explaining the shape of the grate of the stoker furnace of the first embodiment of the present invention. It is a figure explaining a stoker inclination angle of a stoker furnace of a second embodiment of the present invention. It is a figure explaining a stoker inclination angle of a stoker furnace of a third embodiment of the present invention.

(First embodiment)
Hereinafter, a stoker furnace according to a first embodiment of the present invention will be described in detail with reference to the drawings.
The stoker furnace of the present embodiment is a stoker furnace for burning incinerators such as refuse, and as shown in FIG. 1, a hopper 2 for temporarily storing incinerators B and an incinerator for burning the incinerators B. The furnace 3, a feeder 4 for supplying the incinerator B to the incinerator 3, and a stoker 5 (a grate 15 of a drying stage 11, a combustion stage 12, and a post-combustion stage 13) provided on the bottom side of the incinerator 3. 16) and a wind box 6 provided below the stoker 5.

The feeder 4 continuously extrudes the incinerated material B supplied onto the feed table 7 via the hopper 2 into the incinerator 3. The feeder 4 reciprocates on the feed table 7 with a predetermined stroke by the feeder driving device 8.
The wind box 6 supplies primary air from a blower (not shown) to each part of the stoker 5.
The incinerator 3 is provided above the stoker 5 and has a combustion chamber 9 composed of a primary combustion chamber and a secondary combustion chamber. The incinerator 3 has a secondary air supply nozzle 10 that supplies secondary air to the combustion chamber 9.

The stalker 5 is a combustion device in which grate 15 and 16 are arranged in a stepwise manner. The incineration material B burns on the stoker 5.
Hereinafter, the direction in which the incinerated material B is transported is referred to as a transport direction D. The incinerated material B is transported on the stoker 5 in the transport direction D. 1, 2 and 3, the right side is the downstream side D1 in the transport direction. The surface on which the

grate

15 or 16 is attached is referred to as an installation surface, and is installed on a horizontal plane with the upstream end (11b, 12b, 13b) of the drying stage 11, the combustion stage 12, or the post-combustion stage 13 as a center. The angle formed on the side in the transport direction D formed by the surface is referred to as a stalker inclination angle (installation angle). If the downstream side of the installation surface in the transport direction is upward from the horizontal plane, the stoker inclination angle is a positive value. .

The stoker 5 includes a drying stage 11 for drying the incinerated material B, a combustion stage 12 for incinerating the incinerated material B, and a complete incineration of unburned matter (post-combustion) from the upstream side in the conveying direction of the incinerated material B. )), And a post-combustion stage 13. The stoker 5 performs drying, combustion, and post-combustion in the drying stage 11, the combustion stage 12, and the post-combustion stage 13 while sequentially transporting the incinerated material B.

Each

step

11, 12, 13 has a plurality of fixed grate 15 and a plurality of moving grate 16.
The fixed grate 15 and the moving grate 16 are alternately arranged in the transport direction D. The moving grate 16 reciprocates in the transport direction D of the incinerated material B. The object B on the stoker 5 is transported and agitated by the reciprocating motion of the moving grate 16. That is, the lower part of the incinerated material B is moved and replaced with the upper part of the incinerated material B.

The drying stage 11 receives the incinerated material B pushed out by the feeder 4 and dropped into the incinerator 3, evaporates the moisture of the incinerated material B, and partially decomposes it. The combustion stage 12 ignites the incinerated material B dried in the drying stage 11 with the primary air supplied from the lower wind box 6, and burns volatiles and fixed carbon. The post-combustion stage 13 burns unburned components such as fixed carbon which have passed through without being burned in the combustion stage 12 until they become completely ash.
At the outlet of the post-combustion stage 13, a discharge chute 17 is provided. The ash is discharged from the incinerator 3 through the discharge chute 17.

The stoker furnace 1 has a front arch 31 extending from above the feeder 4 to at least above the drying stage 11, and a rear arch 32 extending from above the discharge chute 17 to at least above the post-combustion stage 13. I have. That is, the end 31 b of the downstream side D <b> 1 of the front arch 31 in the transport direction is located above the drying stage 11 or the combustion stage 12. Further, an end 32 a of the rear arch 32 on the upstream side in the transport direction is located above the combustion stage 12 or the post-combustion stage 13.
The front arch 31 and the rear arch 32 are connected to a furnace wall 33 of the incinerator 3. The furnace wall 33 has a square tubular shape and guides exhaust gas generated by combustion of the incineration material B. The furnace wall 33 has a front wall 34 and a rear wall 35 facing the transport direction D, and a pair of side walls 36 along the transport direction D. The distance between the front wall 34 and the rear wall 35 and the distance between the pair of side walls 36 are, for example, 3 m to 4 m. Note that the front wall 34 is disposed upstream of the rear wall 35 in the transport direction D.

The center line C of the square cylindrical furnace wall 33 is on the combustion stage 12. That is, a center line C passing through the center of the furnace wall 33 along the front wall 34, the rear wall 35, and the side wall 36 intersects with the combustion stage 12.
The secondary air supply nozzle 10 is disposed on the front wall 34 and the rear wall 35. The secondary air supply nozzle 10 is directed to inject secondary air from the front wall 34 and the rear wall 35 toward the center of the furnace wall 33.
In the present embodiment, the secondary air supply nozzle 10 is disposed on the front wall 34 and the rear wall 35, but may be disposed on the front arch 31 and the rear arch 32.

The front arch 31 and the rear arch 32 are portions that form the ceiling (upper wall) of the stoker 5. The upstream end 31 a of the front arch 31 in the transport direction is located above the feeder 4. The vertical space between the end 31a of the front arch 31 on the upstream side in the transport direction and the feeder 4 is about 1 m.
The front arch 31 is inclined such that an end 31b on the downstream side D1 in the transport direction is higher than an end 31a on the upstream side in the transport direction. That is, the front arch 31 is inclined so that the space in the stoker 5 becomes wider toward the downstream side D1 in the transport direction.

The vertical distance between the end 32b of the rear arch 32 on the downstream side D1 in the transport direction and the end of the post-combustion stage 13 on the downstream side D1 in the transport direction is about 1 m.
The end 32 b of the rear arch 32 on the downstream side D <b> 1 in the transport direction is located above the discharge chute 17. The rear arch 32 is inclined such that the end 32b on the downstream side D1 in the transport direction is lower than the end 32a on the upstream side in the transport direction. That is, the rear arch 32 is inclined so that the space in the stoker 5 becomes narrower toward the downstream side D1 in the transport direction.

Each of the drying stage 11, the combustion stage 12, and the post-combustion stage 13 has a drive mechanism 18 for driving the moving grate 16. That is, the drying stage 11, the combustion stage 12, and the post-combustion stage 13 each have a drive mechanism 18 for driving a plurality of moving grate 16 separately.

The drive mechanism 18 is attached to a beam 19 provided on the stalker 5. The drive mechanism 18 has a hydraulic cylinder 20 attached to the beam 19, an arm 21 operated by the hydraulic cylinder 20, and a beam 22 connected to a tip of the arm 21.
The beam 22 and the moving grate 16 are connected via a bracket 23.

According to the drive mechanism 18 of the present embodiment, the arm 21 operates by the expansion and contraction of the rod of the hydraulic cylinder 20. With the operation of the arm 21, the beam 22 configured to move along the installation surface 11a of the drying stage 11, the installation surface 12a of the combustion stage 12, and the installation surface 13a of the post-combustion stage 13 moves. Is driven by the moving grate 16 connected to the grate.

The drive mechanism 18 of the present embodiment uses the hydraulic cylinder 20, but is not limited to this, and may employ, for example, a hydraulic motor, an electric cylinder, a conductive linear motor, or the like. The form of the drive mechanism 18 is not limited to the above-described form, and may be any form as long as the movable grate 16 can be reciprocated. For example, the beam 22 and the hydraulic cylinder 20 may be directly connected and driven without disposing the arm 21.

In the stoker furnace 1 of the present embodiment, the driving speed of the moving grate 16 in the drying stage 11, the combustion stage 12, and the post-combustion stage 13 is set to the same speed or the drying stage 11, the combustion stage 12, and the post-combustion stage 13. Can be at different speeds at least in part.
For example, when the incineration object B required to be sufficiently burned in the combustion stage 12 is introduced, the driving speed of the moving grate 16 in the combustion stage 12 is reduced, and the incineration object on the combustion stage 12 is reduced. The transport speed of B can be reduced to allow sufficient combustion.

As shown in FIG. 2 and FIG. 3, the fixed grate 15 and the moving grate 16 are located downstream of the installation surfaces 11 a, 12 a, and 13 a of the drying stage 11, the combustion stage 12, and the post-combustion stage 13 in the transport direction. It is arranged so that the side faces upward.

A part of the moving grate 16 of the drying stage 11 is a grate 16P with projections (the others are normal grate described later). As shown in FIG. 2, of the length of the drying stage 11 in the transport direction, the moving grate 16 in the range R1 of 50% to 80% from the downstream side in the transport direction is a grate 16P with projections. By using the grate with projections 16P, the stirring power can be improved.
As shown in FIG. 3, the grate with projection 16 </ b> P has a plate-shaped grate main body 25 and a triangular protrusion 26 provided at the tip of the grate main body 25. The protrusion 26 protrudes upward from the upper surface of the grate main body 25. The shape of the projection 26 is not limited to this, and may be, for example, a trapezoidal shape or a round shape.
Here, the fixed grate 15 in FIG. 3 is a grate having no protrusion on the top surface of the tip, and this shape is called a normal grate.

In the present embodiment, only the moving grate 16 is a grate with projections 16P. However, the present invention is not limited to this, and both the moving grate 16 and the fixed grate 15 may be grate with projections.
Further, the range in which the grate with projections 16P is provided is not limited to the above-described range. For example, all grate in the drying stage 11 may be the grate with projections 16P.
Further, depending on the properties and type of the incinerated material B, all grate (fixed grate and moving grate) in the drying stage may be a normal grate.

Similar to the drying stage 11, a part of the moving grate 16 in the combustion stage 12 is a grate 16P with projections. Specifically, of the length of the combustion stage 12 in the transport direction, the moving grate 16 in the range R2 of 50% to 80% from the downstream side in the transport direction is the grate 16P with projections. The other moving grate 16 of the combustion stage 12 is a normal grate. Similarly to the drying stage, both the moving grate 16 and the fixed grate 15 may be grate with projections, or all grate (fixed grate and moving grate) depending on the property and type of the incinerated material B. May be a normal grate.
As for the grate of the post-combustion stage 13, the moving grate 16 and the fixed grate 15 are both shown as normal grate in FIG. May be adopted.

Next, the stoker inclination angles (installation angles) of the drying stage 11, the combustion stage 12, and the post-combustion stage 13 will be described.
The drying stage 11 and the combustion stage 12 are inclined such that their main surfaces face the main combustion part M. Here, the main combustion portion M is near the lower end of the square tubular furnace wall 33 (in other words, near the end 31b of the front arch 31 and the end 32a of the rear arch 32) due to the burning of the incineration material B. This is a portion generated near the center line C of the furnace wall 33 and above the incineration object B. Radiant heat H from the flame of the main combustion part M is emitted radially around the main combustion part M.

As shown in FIG. 2, the drying stage 11 of the stoker 5 of the present embodiment is arranged downward. That is, the installation surface 11a of the drying stage 11 is inclined so that the downstream side D1 in the transport direction becomes lower. Specifically, the stoker inclination angle θ1 of the drying stage 11 which is an angle between the horizontal plane centered on the upstream end 11b of the drying stage 11 and the transport direction side of the installation surface 11a is −15 ° (−15 °). The angle is between −25 ° (minus 25 °).
Thereby, the main surface (installation surface 11a) of the drying stage 11 faces the main combustion section M and receives the radiant heat H efficiently.

The combustion stage 12 of the stoker 5 of the present embodiment is arranged upward. That is, the installation surface 12a of the combustion stage 12 is inclined such that the downstream side D1 in the transport direction is higher. Specifically, the stoker inclination angle θ2 of the combustion stage 12 which is the angle between the horizontal plane centered on the upstream end 12b of the combustion stage 12 and the transport direction side of the installation surface 12a is from + 5 ° (+ 5 °). The angle is between + 15 ° (plus 15 degrees), preferably between + 8 ° (plus 5 degrees) and + 12 ° (plus 15 degrees).
Thereby, the main surface (installation surface 12a) of the combustion stage 12 faces the main combustion part M and receives the radiant heat H efficiently.

The post-combustion stage 13 of the stoker 5 of the present embodiment shown in FIGS. 1 and 2 is horizontally arranged. The post-combustion stage 13 is formed such that the installation surface 13a of the post-combustion stage 13 is parallel to the horizontal plane.
However, the post-combustion stage 13 does not have to be strictly horizontal, but is substantially horizontal and may be slightly inclined. For example, the stoker inclination angle of the post-combustion stage 13 may be an angle between + 2 ° (plus 2 degrees) and −2 ° (minus 2 degrees).

A step (fall wall) 27 is formed between the drying stage 11 and the combustion stage 12. The downstream end 11c of the drying stage 11 in the transport direction is formed to be vertically higher than the upstream end 12b of the combustion stage 12 in the transport direction.
There is no step (fall wall) between the combustion stage 12 and the post-combustion stage 13. That is, the combustion stage 12 and the post-combustion stage 13 are continuously connected. In other words, the combustion stage 12 and the post-combustion stage 13 are formed such that the downstream end 12c of the combustion stage 12 and the post-combustion stage 13 are at the same height.

According to the above embodiment, since the drying stage 11 is inclined downward, the incineration object B of any property can be transported to the combustion stage 12 without any delay, and the combustion stage 12 By being inclined upward, the incinerated material B is sufficiently burned and conveyed without easily sliding down or rolling down downstream of the combustion stage 12.

That is, in the case of the incinerated material B having a slippery material or a shape that easily rolls, the material is conveyed to the combustion stage 12 early by rolling on the drying stage 11, so that the drying stage 11 may not be sufficiently dried. However, since the combustion stage 12 is inclined upward, the incineration object B that has rolled down the drying stage 11 does not further roll down the combustion stage 12, and the combustion stage 12 always performs sufficient drying and incineration. Since the incinerated material B having a high moisture content is conveyed to the combustion stage 12 while being dried without staying in the drying stage 11, it is also necessarily sufficiently incinerated in the combustion stage 12.
Thereby, the incinerated material B can be continuously charged irrespective of the properties of the incinerated material B, and the unburned material of the incinerated material B can be eliminated.

Further, since the main surfaces of the drying stage 11 and the combustion stage 12 face the main combustion portion M, the radiant heat H of the main combustion portion M can be effectively received. Therefore, in the drying stage 11, the drying efficiency can be improved, and in the combustion stage 12, the combustion efficiency can be improved.

Further, by arranging the post-combustion stage 13 horizontally, the power for driving the moving grate can be reduced as compared with a configuration in which the post-combustion stage is inclined upward. Therefore, although it is a stoker furnace similar to the stoker furnace of Patent Document 6, the stoker furnace can reduce the operating cost.
In addition, since the post-combustion stage 13 is arranged horizontally, it is possible to prevent the incineration material B from excessively accumulating on the combustion stage 12.

In addition, since the center line C of the square tubular furnace wall 33 is on the combustion stage 12, the position of the main combustion section M is on the combustion stage 12, and the radiant heat H is efficiently supplied to at least the drying stage 11 and the combustion stage 12. You can guess.

(Second embodiment)
Hereinafter, a stoker furnace according to a second embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, differences from the above-described first embodiment will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 4, a step (fall wall) 28 is formed between the combustion stage 12 and the post-combustion stage 13 of the stoker 5 of the present embodiment.

According to the above embodiment, by dropping the incinerated material B that has passed through the combustion stage 12 at the step 28, the incinerated material B can be impacted and ashes can be promoted.

(Third embodiment)
Hereinafter, a stoker furnace according to a third embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, differences from the above-described first embodiment will be mainly described, and the description of the same parts will be omitted.
As shown in FIG. 5, the post-combustion stage 13 of the stoker 5 of the present embodiment is inclined so that the downstream side D1 in the transport direction is downward. For example, the stoker inclination angle of the post-combustion stage 13 may be an angle between 0 ° (horizontal, 0 °) and −10 ° (−10 °).

によって Depending on the properties of the incinerated material B, such a form can be adopted. Also in this configuration, similar to the stoker furnace of the first embodiment and the second embodiment, the stoker furnace is similar to the stoker furnace of Patent Document 6, but can reduce the operating cost.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments, and includes a design change or the like without departing from the gist of the present invention. .
In addition, in the said embodiment, although the front-end | tip of the

grate

15,16 is arrange | positioned so that it may face downstream direction D1 in a conveyance direction, it is not restricted to this, For example, the front-end | tip of the

grate

15,16 of the drying stage 11 May be arranged to face the upstream side in the transport direction.

According to the present invention, it is possible to provide a stoker furnace capable of reducing operating costs.

REFERENCE SIGNS LIST 1 stoker furnace 2 hopper 3 incinerator 4 feeder 5 stoker 6 wind box 7 feed table 8 feeder driving device 9 combustion chamber 10 secondary air supply nozzle 11 drying stage 11a drying stage installation surface 12 combustion stage 12a combustion stage installation surface 13 Post-combustion stage 13a Post-combustion stage installation surface 15 Fixed grate 16 Moving grate 16P Grate with projection 17 Discharge chute 18 Drive mechanism 19 Beam 20 Hydraulic cylinder 21 Arm 22 Beam 23 Bracket 25 Grate main body 26

Projection

27, 28 Step (Head wall)
31 Front arch 32 Rear arch 33 Furnace wall 34 Front wall 35 Rear wall 36 Side wall B Incineration object C Center line D Transport direction D1 Transport direction downstream H Radiant heat M Main combustion section θ1, θ2 Stalker inclination angle

Claims

The incineration material is supplied from the feeder, and the drying stage, the combustion stage, and the post-combustion stage having a plurality of fixed grate and a plurality of movable grate, while sequentially transporting the incineration material, drying, burning, respectively. And in the stoker furnace that performs post-combustion and discharges the incinerated material after the post-combustion from a discharge chute connected to the post-combustion stage,
The drying stage is arranged inclined such that the downstream side in the transport direction is downward,
The combustion stage is connected to the drying stage, is disposed so as to be inclined such that the downstream side in the transport direction is upward,
The stoker furnace, wherein the post-combustion stage is connected to the combustion stage and is disposed so as to be substantially horizontal, or is disposed so as to be inclined such that the downstream side in the transport direction is downward.
A front arch extending from above the feeder to above the drying stage or the combustion stage;
A rear arch extending from above the discharge chute to above the post-combustion stage or above the combustion stage;
A square cylindrical furnace wall connected to the front arch and the rear arch, and for guiding exhaust gas generated by combustion of the incineration material,
The stoker furnace according to claim 1, wherein a center line of the square tubular furnace wall is on the combustion stage.
The fixed grate and the movable grate are arranged so as to be inclined such that the downstream side in the transport direction is upward with respect to the installation surface of the drying stage, the combustion stage, and the post-combustion stage. The stoker furnace according to claim 1 or 2, wherein
The stoker furnace according to any one of claims 1 to 3, wherein the combustion stage and the post-combustion stage are continuously connected without any step.