Secondary air nozzle, secondary air system and garbage incinerator

Abstract

The present invention discloses a secondary air nozzle, a secondary air system and a waste incinerator. According to the secondary air nozzle, the secondary air system and the waste incinerator provided by the present invention, the secondary air nozzle adopts a sleeve design, the airflow ejected from the first air duct and the airflow ejected from the second air duct have different directions, by making the airflow ejected from the first air duct as the secondary air, and the airflow ejected from the second air duct of the secondary air nozzle as the wall-adhering wind, the wall-adhering wind can form a layer of wind curtain on the inner wall of the furnace of the waste incinerator, and the high-temperature molten ash particles in the flue gas are effectively cooled before contacting the inner wall of the furnace, effectively blocking the ash particles in the flue gas from staying and agglomerating on the wall surface, slowing down the occurrence of coking, and extending the operation cycle of the waste incinerator.

Description

Technical Field

[0001] The present invention relates to the field of waste incineration treatment, and in particular to a secondary air nozzle, a secondary air system and a waste incinerator. Background Art

[0002] With the progress of urbanization and the improvement of people's living standards, the amount of garbage generated has increased year by year. Waste incineration has the advantages of high treatment efficiency, small footprint, relatively small impact on the environment, etc. It can better meet the requirements of domestic waste treatment for reduction and harmlessness, and use the heat energy generated by incineration to realize the resource utilization of garbage. It has been widely used and promoted in recent years.

[0003] The existing garbage incinerator injects secondary air at the front and rear arches of the throat to supplement the oxygen required for secondary combustion, and forms sufficient disturbance in the combustion chamber, prolongs the residence time of the flue gas, promotes the complete combustion of the fuel, embodies the "3T+E" principle, improves thermal efficiency, and effectively controls the generation of dioxins. However, existing operating experience shows that although this arrangement has strengthened the disturbance of the flow field to a certain extent and prolonged the residence time of the flue gas, the traditional secondary air nozzle directly injects secondary air into the furnace, resulting in a large amount of ash particles in the flue gas being transported to the opposite side of the furnace arch or agglomerated in the furnace arch on this side due to the entrainment of the secondary air, creating good conditions for coking. In severe cases, the throat is blocked and the furnace is forced to stop.

[0004] Therefore, it is necessary to propose a secondary air nozzle, a secondary air system and a garbage incinerator to solve the above problems. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] The present invention provides a secondary air nozzle, comprising:

[0007] an inner tube, wherein the inner tube forms a first air duct;

[0008] An outer tube, the outer tube is sleeved outside the inner tube and arranged in parallel with the inner tube, and a second air duct is formed between the inner tube and the outer tube;

[0009] The end plate is arranged at the end of the secondary air nozzle so that the direction of the airflow ejected from the first air duct is different from that of the airflow ejected from the second air duct.

[0010] Further, the end plate does not change the airflow direction of the first air duct, and the end plate changes the airflow direction of the second air duct.

[0011] Furthermore, the end plate is in a circular ring shape, the opening of the end plate is consistent with the inner tube, and the outer edge of the end plate exceeds the side wall of the outer tube.

[0012] Furthermore, an extension direction of the end plate intersects or is perpendicular to an extension direction of the inner tube.

[0013] Furthermore, the inner tube and the outer tube are fixedly connected via a rib plate.

[0014] Furthermore, the inner tube, the outer tube and the end plate are all made of corrosion-resistant and high-temperature-resistant metal.

[0015] The present invention also provides a secondary air system, comprising the secondary air nozzle as described above, wherein the airflow ejected from the first air duct of the secondary air nozzle is secondary air, and the airflow ejected from the second air duct of the secondary air nozzle is wall-attached air.

[0016] Furthermore, the secondary air system further comprises:

[0017] The first air supply unit is arranged on the upper part of the front arch of the furnace of the garbage incinerator, and includes a front arch secondary air header and a plurality of the secondary air nozzles;

[0018] The second air supply unit is arranged on the upper part of the rear arch of the furnace of the waste incinerator, and includes a secondary air header on the rear arch and a plurality of the secondary air nozzles;

[0019] A third air supply unit is arranged at the lower part of the rear arch of the furnace of the waste incinerator, including a secondary air header under the rear arch and a plurality of the secondary air nozzles;

[0020] The first air supply unit and the second air supply unit provide upper-layer secondary air, and the third air supply unit provides lower-layer secondary air.

[0021] Furthermore, the secondary air nozzle of the first air supply unit and the secondary air nozzle of the second air supply unit are arranged in a staggered manner.

[0022] Furthermore, the secondary air nozzle of the first air supply unit, the secondary air nozzle of the second air supply unit and the secondary air nozzle of the third air supply unit all spray secondary air obliquely downward, and the angle between the secondary air and the vertical direction ranges from 60° to 80°.

[0023] Furthermore, the end plate of the secondary air nozzle of the first air supply unit is parallel to the upper part of the front arch of the furnace of the waste incinerator, the end plate of the secondary air nozzle of the second air supply unit is parallel to the upper part of the rear arch of the furnace of the waste incinerator, and the end plate of the secondary air nozzle of the third air supply unit is parallel to the lower part of the rear arch of the furnace of the waste incinerator.

[0024] Furthermore, the angle between the upper part of the front arch of the furnace of the waste incinerator and the vertical direction ranges from 6° to 10°, the angle between the upper part of the rear arch of the furnace of the waste incinerator and the vertical direction ranges from 10° to 14°, the angle between the lower part of the front arch of the furnace of the waste incinerator and the vertical direction ranges from -24° to -28°, and the angle between the lower part of the rear arch of the furnace of the waste incinerator and the vertical direction ranges from -1° to -3°.

[0025] Furthermore, the secondary air system also includes: a fan, a main pipe connected to the fan, and a plurality of branch pipes connected to the main pipe, wherein the plurality of branch pipes are respectively connected to the first air supply unit, the second air supply unit or the third air supply unit.

[0026] Furthermore, a valve is provided on the branch pipe.

[0027] The present invention also provides a garbage incinerator, comprising the secondary air system as described above.

[0028] According to the secondary air nozzle, secondary air system and waste incinerator provided by the present invention, the secondary air nozzle adopts a sleeve design, and the direction of the airflow ejected from the first air duct is different from the direction of the airflow ejected from the second air duct. By making the airflow ejected from the first air duct as the secondary air, the airflow ejected from the second air duct of the secondary air nozzle is used as the wall wind. The wall wind can form a layer of wind curtain on the inner wall of the furnace of the waste incinerator. The high-temperature molten ash particles in the flue gas are effectively cooled before they contact the inner wall of the furnace, which effectively prevents the ash particles in the flue gas from staying and gathering on the wall surface, slows down the occurrence of coking, and extends the operation cycle of the waste incinerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following drawings of the present invention are used to understand the present invention as part of the present invention. The embodiments of the present invention are shown in the drawings and the description thereof is used to explain the principle of the present invention.

[0030] In the attached figure:

[0031] Figure 1A is a schematic structural diagram of a secondary air nozzle according to an embodiment of the present invention;

[0032] Figure 1B is a front view of a secondary air nozzle according to an embodiment of the present invention;

[0033] Figure 1C is a right side view of a secondary air nozzle according to an embodiment of the present invention;

[0034] Figure 2A A schematic diagram of a waste incinerator and a secondary air system according to an embodiment of the present invention;

[0035] Figure 2Bis a partial schematic diagram of a secondary air system according to an embodiment of the present invention;

[0036] Figure 2C A schematic diagram of the arrangement of a first air supply unit and a second air supply unit of a secondary air system according to an embodiment of the present invention;

[0037] Figure 2D Schematic diagram of the arrangement of the third air supply unit of the secondary air system according to an embodiment of the present invention.

[0038] Reference numerals

[0039] 100. Secondary air nozzle 101. External pipe

[0040] 102. Inner tube 103. Rib plate

[0041] 104, end plate 105, first air duct

[0042] 106. Second Air Duct

[0043] 201, first air supply unit 202, second air supply unit

[0044] 203. Third air supply unit 204. Fan

[0045] 205, main pipe 206, branch pipe

[0046] 207. Valve

[0047] 300. Waste incinerator furnace DETAILED DESCRIPTION

[0048] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0049] In order to fully understand the present invention, a detailed description will be provided in the following description to illustrate the secondary air nozzle, secondary air system and waste incinerator of the present invention. Obviously, the implementation of the present invention is not limited to the specific details familiar to those skilled in the art of waste incineration treatment. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0050] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of the features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0051] Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of layers and regions is exaggerated, and the same reference numerals are used to represent the same elements, and thus their description will be omitted.

[0052] Aiming at the problem that a large amount of ash particles in the flue gas are coked on the inner wall of the furnace by directly injecting secondary air into the furnace of the waste incinerator by the conventional secondary air nozzle, the present invention provides a secondary air nozzle such as Figures 1A-1C As shown, including:

[0053] An inner tube 102, wherein the inner tube 102 constitutes a first air duct 105;

[0054] An outer tube 101, wherein the outer tube 101 is sleeved outside the inner tube 102 and arranged in parallel with the inner tube 102, and a second air duct 106 is formed between the inner tube 102 and the outer tube 101;

[0055] The end plate 104 is disposed at the end of the secondary air nozzle 100 so that the directions of the airflow ejected from the first air duct 105 and the airflow ejected from the second air duct 106 are different.

[0056] like Figure 1A and Figure 1BAs shown, the end plate 104 is located at the end of the secondary air nozzle 100, i.e., the outlet end of the airflow in the first air duct 105 and the second air duct 106. The end plate 104 is in a circular shape, and the opening in the middle of the circular ring is consistent with the inner tube 102. It does not block the outlet of the first air duct 105, and thus does not change the direction of the airflow in the first air duct 105, but it blocks the outlet of the second air duct 106, and there is a gap between the end plate 104 and the outer tube 101, so the direction of at least part of the airflow in the second air duct 106 can be changed. Furthermore, the outer edge of the end plate 104 exceeds the side wall of the outer tube 101, and therefore, the end plate 104 changes the direction of the overall airflow in the second air duct 106, so that the direction of the airflow ejected from the first air duct 105 is different from that of the airflow ejected from the second air duct 106.

[0057] Exemplarily, the extension direction of the end plate 104 intersects or is perpendicular to the extension direction of the inner tube 102. In the embodiment of the present invention, the extension direction of the inner tube 102 is a first direction, and the airflow ejected from the first air duct 105 advances in the first direction, and the extension direction of the end plate 104 is a second direction, and the airflow ejected from the second air duct 106 is blocked by the end plate 104 when advancing in the first direction, and changes the advancing direction and is ejected in the second direction.

[0058] In the embodiment of the present invention, the inner tube 102 and the outer tube 101 are fixedly connected by the rib plate 103, and the end plate 104 is also fixed to the end of the secondary air nozzle 100 by the rib plate 103. It should be noted that the above method is only exemplary, and any fixing method that can achieve the relative position fixation between the inner tube 102, the outer tube 101 and the end plate 104 and does not affect the air outlet of the first air duct 105 and the second air duct 106 can be applied to the present invention.

[0059] Exemplarily, the secondary air nozzle 100 is made entirely of corrosion-resistant and high-temperature resistant metal, that is, the inner tube 102, the outer tube 101, the end plate 104 and the rib plate 103 are all made of corrosion-resistant and high-temperature resistant metal to be suitable for high-temperature corrosion environments such as waste incinerators.

[0060] The present invention further provides a secondary air system, comprising the secondary air nozzle 100 as described above, wherein the airflow ejected from the first air duct 105 of the secondary air nozzle 100 is secondary air, and the airflow ejected from the second air duct 106 of the secondary air nozzle 100 is wall-attached air. Figure 2B shown.

[0061] The secondary air nozzle 100 adopts a sleeve design as a whole, and has two independent air ducts 105 and 106 that do not interfere with each other. The first air duct 105 plays the role of traditional secondary air, increases the turbulence of the furnace, provides sufficient oxygen, fully mixes the unburned components in the flue gas with oxygen, prolongs the residence time of the flue gas, and ensures the complete combustion of the fuel; the second air duct 106 flows through the wall-adhering wind, and after the wall-adhering wind moves to the front end plate 104 of the secondary air nozzle, it flows out from the gap between the end plate 104 and the outer tube 101. The end faces of the end plate 104 and the inner tube 102 are parallel to the inner wall of the furnace, the end face of the outer tube 101 is flush with the inner wall of the furnace, and the middle opening of the end plate 104 fits with the inner tube 102, so that the secondary air flows out from there, and the wall-adhering wind flows out through the gap between the end plate 104 and the outer tube 101. The outer edge of the end plate 104 exceeds the outer tube 101, which is conducive to good guidance of the wall-adhering wind, so that the wall-adhering wind flows evenly along the inner wall of the furnace. Since high-speed cold air flows through both the inner and outer tubes, a good cooling effect is exerted on the nozzle, thereby preventing the high temperature in the furnace from damaging the secondary air nozzle 100 .

[0062] like Figure 2A As shown, the secondary air system also includes:

[0063] The first air supply unit 201 is arranged at the upper part of the front arch of the furnace 300 of the garbage incinerator, and includes a front arch secondary air header and a plurality of the secondary air nozzles 100;

[0064] The second air supply unit 202 is arranged on the upper part of the rear arch of the furnace 300 of the waste incinerator, and includes a secondary air header on the rear arch and a plurality of the secondary air nozzles 100;

[0065] The third air supply unit 203 is arranged at the lower part of the rear arch of the furnace 300 of the waste incinerator, and includes a secondary air header under the rear arch and a plurality of the secondary air nozzles 100;

[0066] The first air supply unit 201 and the second air supply unit 202 provide upper-layer secondary air, and the third air supply unit 203 provides lower-layer secondary air.

[0067] For example, Figure 2A and 2B As shown, the waste incinerator furnace 300 includes a front arch upper part, a rear arch upper part, a front arch lower part and a rear arch lower part. The angle between the front arch upper part of the waste incinerator furnace 300 and the vertical direction is in the range of 6° to 10°, preferably 8°; the angle between the rear arch upper part of the waste incinerator furnace 300 and the vertical direction is in the range of 10° to 14°, preferably 12°; the angle between the front arch lower part of the waste incinerator furnace 300 and the vertical direction is in the range of -24° to -28°, preferably -26°; the angle between the rear arch lower part of the waste incinerator furnace 300 and the vertical direction is in the range of -1° to -3°, preferably -1°.

[0068] The front and rear arches of the 300 furnace of the garbage incinerator adopt a two-stage small-angle furnace arch design, which is conducive to the ash particles sliding down the wall surface and avoids the accumulation of ash particles in the flue gas on the furnace arch wall due to a large inclination angle. At the same time, it ensures that the furnace volume heat load is within a reasonable range and avoids excessive furnace temperature causing ash particles to melt and stick together to cause coking.

[0069] For example, Figure 2A and 2B As shown, the secondary air nozzle 100 of the first air supply unit 201, the secondary air nozzle 100 of the second air supply unit 202 and the secondary air nozzle 100 of the third air supply unit 203 all spray secondary air obliquely downward, and the angle between the secondary air and the vertical direction ranges from 60° to 80°, preferably 70°.

[0070] By using the airflow ejected from the first air duct as secondary air, the oxygen required for secondary combustion is supplemented, sufficient disturbance is formed in the combustion chamber, the residence time of flue gas is prolonged, and the complete combustion of fuel is promoted, thus embodying the "3T+E" principle, improving thermal efficiency, and effectively controlling the generation of dioxins.

[0071] For example, Figure 2B As shown, the end plate of the secondary air nozzle of the first air supply unit 201 is parallel to the upper part of the front arch of the waste incinerator furnace 300 to form wall-adhering wind at the upper part of the front arch; the end plate of the secondary air nozzle of the second air supply unit 202 is parallel to the upper part of the rear arch of the waste incinerator furnace 300 to form wall-adhering wind at the upper part of the rear arch; the end plate of the secondary air nozzle of the third air supply unit 203 is parallel to the lower part of the rear arch of the waste incinerator furnace 300 to form wall-adhering wind at the lower part of the rear arch.

[0072] By making the airflow ejected from the second air duct serve as wall-adhering wind, a layer of wind curtain is formed on the inner wall of the furnace of the waste incinerator while injecting secondary air into the furnace. The high-temperature molten ash particles in the flue gas are effectively cooled before they contact the inner wall of the furnace, effectively preventing the ash particles in the flue gas from staying and gathering on the wall surface, slowing down the occurrence of coking, and extending the operation cycle of the waste incinerator.

[0073] Exemplarily, the first air supply unit 201 and the second air supply unit 202 provide upper-layer secondary air, and the third air supply unit 203 provides lower-layer secondary air.

[0074] Exemplarily, the secondary air nozzles 100 of the first air supply unit 201 and the secondary air nozzles 100 of the second air supply unit 202 are arranged in a staggered manner.

[0075] In one embodiment, the secondary air is arranged in two layers, referring to Figure 2CThe first air supply unit 201 and the second air supply unit 202 provide upper secondary air. The upper secondary air nozzles are of two sizes, coarse and fine. The secondary air nozzles 100 of the first air supply unit 201 and the secondary air nozzles 100 of the second air supply unit 202 are arranged in a staggered manner, with 9 in front and 8 in the back, to better mix the smoke disturbance. Figure 2D The third air supply unit 203 provides secondary air for the lower layer, and adopts a single specification nozzle, 7 in number, so that the center of the flame tends to the center of the furnace, the temperature of the furnace is more uniform, and the drying effect of the garbage in the drying section is guaranteed.

[0076] Through the staggered counter-arrangement of the upper secondary air, the high-speed secondary air flowing out of the first air duct 105 causes strong disturbance in the furnace, promotes the complete combustion of the fuel, and reduces the generation of pollutants. At the same time, after the high-speed airflow of the second air duct 106 is guided by the end plate 104, a dense wind curtain is formed on the inner wall of the furnace. On the one hand, it has a good cooling effect on the wall of the furnace castable to prevent the castable from being damaged by high temperature. On the other hand, the high-temperature ash particles in the flue gas are cooled and hardened before contacting the furnace wall, and no longer have adhesion characteristics. The particles reaching the wall are also easily removed by the wall wind, which greatly reduces the aggregation and adhesion of high-temperature ash particles on the wall and effectively reduces the generation of coke. At the same time, due to the reduction in the temperature of the inner wall of the furnace, the heat dissipation of the front and rear arches is effectively reduced, and the overall efficiency of the waste incinerator is improved.

[0077] In one embodiment, Figure 2A As shown, the secondary air system further includes: a fan 204, a main pipe 205 connected to the fan 204, and a plurality of branch pipes 206 connected to the main pipe 205, wherein the plurality of branch pipes 206 are respectively connected to the first air supply unit 201, the second air supply unit 202, and the third air supply unit 203. Furthermore, a valve 207 is provided on each branch pipe 206.

[0078] It should be noted that the above methods are merely exemplary, and any method that can achieve air supply to the first air supply unit 201, the second air supply unit 202, and the third air supply unit 203 is applicable to the present invention.

[0079] The present invention also provides a waste incinerator, which comprises the secondary air system as described above.

[0080] According to the secondary air nozzle, secondary air system and waste incinerator provided by the present invention, the secondary air nozzle adopts a sleeve design, and the direction of the airflow ejected from the first air duct is different from the direction of the airflow ejected from the second air duct. By making the airflow ejected from the first air duct as the secondary air, the airflow ejected from the second air duct of the secondary air nozzle is used as the wall wind. The wall wind can form a layer of wind curtain on the inner wall of the furnace of the waste incinerator. The high-temperature molten ash particles in the flue gas are effectively cooled before they contact the inner wall of the furnace, which effectively prevents the ash particles in the flue gas from staying and gathering on the wall surface, slows down the occurrence of coking, and extends the operation cycle of the waste incinerator.

[0081] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A secondary air nozzle, characterized in that: include: an inner tube, wherein the inner tube forms a first air duct; An outer tube, the outer tube is sleeved outside the inner tube and arranged in parallel with the inner tube, a second air duct is formed between the inner tube and the outer tube, and the inner tube and the outer tube are fixedly connected by a rib plate; An end plate is arranged at the end of the secondary air nozzle so that the directions of the airflow ejected from the first air duct and the airflow ejected from the second air duct are different; the end plate is in a circular ring shape, the opening of the end plate is consistent with the inner tube, the outer edge of the end plate exceeds the side wall of the outer tube, the extension direction of the end plate intersects or is perpendicular to the extension direction of the inner tube, the end plate blocks the outlet of the second air duct, and there is a gap between the end plate and the outer tube.

2. The secondary air nozzle according to claim 1, characterized in that: The end plate does not change the airflow direction of the first air duct, and the end plate changes the airflow direction of the second air duct.

3. The secondary air nozzle according to claim 1, characterized in that: The inner tube, the outer tube and the end plate are all made of corrosion-resistant and high-temperature-resistant metal.

4. A secondary air system, characterized in that: It comprises the secondary air nozzle according to any one of claims 1 to 3, wherein the airflow ejected from the first air duct of the secondary air nozzle is secondary air, and the airflow ejected from the second air duct of the secondary air nozzle is wall-adhering wind.

5. The secondary air system according to claim 4, characterized in that: Also includes: The first air supply unit is arranged on the upper part of the front arch of the furnace of the garbage incinerator, and includes a front arch secondary air header and a plurality of the secondary air nozzles; The second air supply unit is arranged on the upper part of the rear arch of the furnace of the waste incinerator, and includes a secondary air header on the rear arch and a plurality of the secondary air nozzles; A third air supply unit is arranged at the lower part of the rear arch of the furnace of the waste incinerator, including a secondary air header under the rear arch and a plurality of the secondary air nozzles; The first air supply unit and the second air supply unit provide upper-layer secondary air, and the third air supply unit provides lower-layer secondary air.

6. The secondary air system according to claim 5, characterized in that: The secondary air nozzle of the first air supply unit and the secondary air nozzle of the second air supply unit are arranged in a staggered manner.

7. The secondary air system according to claim 5, characterized in that: The secondary air nozzle of the first air supply unit, the secondary air nozzle of the second air supply unit and the secondary air nozzle of the third air supply unit all spray secondary air obliquely downward, and the angle between the secondary air and the vertical direction ranges from 60° to 80°.

8. The secondary air system according to claim 7, characterized in that: The end plate of the secondary air nozzle of the first air supply unit is parallel to the upper part of the front arch of the furnace of the waste incinerator, the end plate of the secondary air nozzle of the second air supply unit is parallel to the upper part of the rear arch of the furnace of the waste incinerator, and the end plate of the secondary air nozzle of the third air supply unit is parallel to the lower part of the rear arch of the furnace of the waste incinerator.

9. The secondary air system according to claim 8, characterized in that: The angle between the upper part of the front arch of the furnace of the waste incinerator and the vertical direction ranges from 6° to 10°, the angle between the upper part of the rear arch of the furnace of the waste incinerator and the vertical direction ranges from 10° to 14°, the angle between the lower part of the front arch of the furnace of the waste incinerator and the vertical direction ranges from -24° to -28°, and the angle between the lower part of the rear arch of the furnace of the waste incinerator and the vertical direction ranges from -1° to -3°.

10. The secondary air system according to claim 5, characterized in that: Also includes: A fan, a main pipe connected to the fan, and a plurality of branch pipes connected to the main pipe, wherein the plurality of branch pipes are respectively connected to the first air supply unit, the second air supply unit or the third air supply unit.

11. The secondary air system according to claim 10, characterized in that: The branch pipe is provided with a valve.

12. A garbage incinerator, characterized in that: Comprising the secondary air system described in any one of claims 4-11.

Images