Low-resistance ash bucket and denitration system

Abstract

The utility model relates to the field of environmental protection equipment, and provides a low-resistance ash bucket and a denitration system, the low-resistance ash bucket comprises an inlet section, a body section and an outlet section which are connected in sequence, the inlet section is used for introducing flue gas discharged from an outlet of a denitration reactor, and the outlet section is used for being connected with downstream equipment of the denitration system; the body section comprises a frustum section, a square-to-round transition section and an arc section which are sequentially connected, the bottom surface of the frustum section is connected with the inlet section, an ash falling opening is formed in the top surface of the frustum section and used for discharging ash falling from smoke, a first conical surface of the frustum section is connected with the arc section through the square-to-round transition section, the arc section is connected with the outlet section, and a second conical surface of the frustum section is connected with the outlet section. And the joints of the square-to-circle transition section, the arc section and the outlet section are in smooth transition. The flue gas can smoothly enter the square-to-round transition section from the frustum section and then smoothly enter the outlet section from the arc section, so that the local resistance to the flue gas is reduced, the total pressure drop of the whole denitration system is reduced, the safety and stability of the whole system are ensured, and the operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection equipment, in particular to a low-resistance ash hopper and a denitration system. Background Art

[0002] At present, the SCR denitrification technology is used to denitrify flue gas containing nitrogen oxides. It has many advantages such as high denitrification efficiency, small ammonia escape, simple operation and high safety, and is widely used in various fields such as cement environmental protection. Traditional cement kiln systems often do not take into account the future addition of other environmental protection equipment during the design stage, and the resistance margin is small. In order to denitrify the flue gas discharged from the cement kiln, most cement kiln systems have subsequently added a denitrification system, and the resistance margin of the cement kiln system itself is small. Therefore, it is very important to control the resistance of the denitrification system.

[0003] The resistance loss value of the denitrification system directly affects the selection of high-temperature fans and other equipment in the cement kiln system, and further affects the operating cost and safety stability of the entire cement kiln system. In the existing technology, the local resistance of the flue gas is relatively large, which leads to an increase in the total pressure drop of the denitrification system, thereby increasing the power consumption of the entire system and increasing the operating cost. Utility Model Content

[0004] The utility model provides a low-resistance ash hopper and a denitration system, which are used to solve the problem in the existing denitration system that the local resistance of the flue gas flow is large, which increases the total pressure drop of the whole system, thereby increasing the power energy consumption of the whole system and causing an increase in operating costs.

[0005] The utility model provides a low-resistance ash hopper, comprising: an inlet section, a main body section and an outlet section connected in sequence, the inlet section is used to pass the flue gas discharged from the outlet of the denitration reactor, the outlet section is used to connect with the downstream equipment of the denitration system, wherein the main body section comprises a frustum section, a square-to-circle transition section and an arc section connected in sequence, the bottom surface of the frustum section is connected to the inlet section, the top surface of the frustum section is provided with an ash outlet for discharging the ash falling from the flue gas, the first cone surface of the frustum section is connected to the arc section through the square-to-circle transition section, the arc section is connected to the outlet section, and the connection between the square-to-circle transition section, the arc section and the outlet section is smoothly transitioned.

[0006] According to a low-resistance ash hopper provided by the utility model, the orthographic projection of the top surface of the frustum segment on the bottom surface of the frustum segment is located on the bottom surface of the frustum segment.

[0007] According to a low-resistance ash hopper provided by the utility model, the cross section of the outlet section is circular, the arc section is a sector ring intercepted from a ring surface, and the angle between the two end surfaces of the arc section is 50° to 75°.

[0008] According to a low-resistance ash hopper provided by the utility model, the square-to-circular transition section has a trapezoidal structural surface connected to the first conical surface and a circular structural surface connected to the outlet section, and a square-to-circular transition surface is between the trapezoidal structural surface and the circular structural surface.

[0009] According to a low-resistance ash hopper provided by the utility model, the inlet section has a first side wall flush with the first conical surface, and the square-to-round transition surface is arranged at an obtuse angle to the end surface of the first side wall.

[0010] According to a low-resistance ash hopper provided by the utility model, the angle between the square-to-round transition surface and the end surface of the first side wall is 100° to 140°.

[0011] According to a low-resistance ash hopper provided by the utility model, the frustum section has a second conical surface, a third conical surface and a fourth conical surface connected in sequence with the first conical surface, and the angles formed by the second conical surface, the third conical surface and the fourth conical surface and the top surface of the frustum section are 50° to 75° respectively.

[0012] According to a low-resistance ash hopper provided by the utility model, the second conical surface, the third conical surface and the fourth conical surface respectively form equal angles with the top surface of the frustum segment.

[0013] According to a low-resistance ash hopper provided by the utility model, the top surface of the frustum section is hollowed out to form the ash outlet, and the side length of the top surface of the frustum section is 350 mm to 650 mm.

[0014] In the second aspect, the utility model provides a denitrification system, comprising a denitrification reactor, downstream equipment, an ash conveying device and a low-resistance ash hopper as described in any one of the above items, the outlet of the denitrification reactor is connected to the inlet section, the outlet section is connected to the inlet of the downstream equipment, and the ash conveying device is arranged at the ash dropping port for conveying ash falling from the flue gas.

[0015] The utility model provides a low-resistance ash hopper and a denitration system, wherein an inlet section, a body section and an outlet section are connected in sequence, the inlet section is used to pass the flue gas discharged from the outlet of the denitration reactor, and the outlet section is used to connect with the downstream equipment of the denitration system; the body section comprises a frustum section, a square-to-circle transition section and an arc section which are connected in sequence, the bottom surface of the frustum section is connected with the inlet section, when the flue gas hits the conical surface of the frustum section, the soot and other solid particles mixed in the flue gas slide along the conical surface into the top surface of the frustum section, the top surface of the frustum section is provided with an ash drop port, and the soot and other soot particles can be discharged; The first cone surface of the frustum section is connected with the arc section and the outlet section through the square-to-circle transition section. The connections between the square-to-circle transition section, the arc section and the outlet section are all smoothly transitioned. The flue gas can smoothly enter the square-to-circle transition section from the frustum section, and enter the arc section from the square-to-circle transition section flow field, and then enter the outlet section more smoothly, thereby reducing the local resistance loss of the flue gas. The pressure loss of the flue gas when flowing through the low-resistance ash hopper is small, thereby reducing the total pressure drop of the entire denitrification system, ensuring the safe and stable operation of the entire system and reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the low-resistance ash hopper provided by the utility model.

[0018] Figure 2 It is a front view of the low resistance ash hopper provided by the utility model.

[0019] Figure 3 It is a structural schematic diagram of the inlet section provided by the utility model.

[0020] Figure 4 It is a structural schematic diagram of the frustum section provided by the utility model.

[0021] Figure 5 It is a structural schematic diagram of the arc segment provided by the utility model.

[0022] Figure 6 It is a structural schematic diagram of the square-to-circular transition section provided by the utility model.

[0023] Reference numerals:

[0024] 1. Inlet section; 11. First side wall; 2. Cone section; 21. Bottom surface of the cone section; 22. Top surface of the cone section; 221. Ash outlet; 23. First cone surface; 24. Second cone surface; 25. Third cone surface; 26. Fourth cone surface; 3. Arc section; 4. Exit section; 5. Square to round transition section; 51. Trapezoidal structural surface; 52. Square to round transition surface; 53. Circular structural surface; 100. Ash conveying device. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] The term "first" or "second" in the specification and claims of the utility model may explicitly or implicitly include one or more of the features. In the description of the utility model, unless otherwise specified, "multiple" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the related objects are in an "or" relationship.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Combine the following Figure 1-Figure 6 , through specific embodiments and application scenarios, a low-resistance ash hopper and denitrification system provided by an embodiment of the utility model are described in detail.

[0030] like Figure 1 and Figure 2 As shown, the utility model provides a low resistance ash hopper, comprising: an inlet section 1, a body section and an outlet section 4 connected in sequence. The inlet section 1 is used to pass the flue gas discharged from the outlet of the denitration reactor, and the outlet section 4 is used to connect with the downstream equipment of the denitration system.

[0031] The main body section includes a frustum section 2, a square-to-round transition section 5 and an arc section 3 which are connected in sequence. The bottom surface 21 of the frustum section is connected to the inlet section 1, and the top surface 22 of the frustum section is provided with an ash outlet 221 for discharging smoke dust falling from the flue gas. The first cone surface 23 of the frustum section 2 is connected to the arc section 3 through the square-to-round transition section 5, and the arc section 3 is connected to the outlet section 4. The connection between the square-to-round transition section 5, the arc section 3 and the outlet section 4 is smoothly transitioned.

[0032] It is understandable that in industrial combustion systems such as cement kiln systems, denitrification systems or boilers, smoke and solid dust are generated after fuel combustion. Solid dust is often mixed in the smoke. In order to effectively clean and discharge these solid wastes, a low-resistance ash hopper is required. The low-resistance ash hopper can collect impurities such as ash or ash powder in the smoke to prevent them from being scattered in the atmosphere.

[0033] For example, in a cement kiln system with a denitration system, the flue gas containing nitrogen oxides generated during the combustion process of the cement kiln is discharged into the denitration reactor for denitration treatment. After denitration, the flue gas is discharged from the outlet of the denitration reactor. A low-resistance ash hopper is set between the denitration reactor and the downstream equipment to guide the flue gas into the downstream equipment for further treatment.

[0034] Specifically, Figure 1 As shown, the low resistance ash hopper provided by the utility model is arranged in the pipeline between the denitration reactor and the downstream equipment. Figure 3 As shown, the inlet section 1 is in the shape of a rectangular column and is used to introduce the flue gas discharged from the outlet of the denitration reactor. Figure 1 and Figure 2 The arrow indicates the direction of smoke entry.

[0035] The inlet section 1 is connected to one end of the body section, and the outlet section 4 is connected to the other end of the body section. The outlet section 4 is connected to the downstream equipment. The flue gas passes through the inlet section 1, the body section and the outlet section 4 in sequence, and then is discharged into the downstream equipment.

[0036] Among them, Figure 1 and Figure 2As shown, the main body section includes a frustum section 2, a square-to-circle transition section 5 and an arc section 3. Figure 4 As shown, the frustum section 2 is in the shape of a quadrangular frustum. Figure 1 As shown, the bottom surface 21 of the frustum section is connected to the inlet section 1. When the flue gas hits the conical surface of the frustum section 2, the soot and other solid dust mixed in the flue gas slide along the conical surface into the top surface 22 of the frustum section. The top surface 22 of the frustum section is provided with an ash outlet 221 for discharging soot and other solid waste.

[0037] Furthermore, if Figure 1 , Figure 2 , Figure 4 and Figure 6 As shown, the frustum section 2 has a first conical surface 23, the first conical surface 23 is trapezoidal, and the outlet section 4 is cylindrical. One end of the arc section 3 is connected to the outlet section 4, and the other end is connected to the conical surface 23 through a square-to-circle transition section 5. One end of the square-to-circle transition section 5 is a trapezoidal structural surface adapted to connect with the first conical surface, and the other end is a circular structural surface smoothly connected to one end of the arc section.

[0038] like Figure 1 , Figure 2 and Figure 5 As shown, the end of the arc segment 3 close to the outlet segment 4 is rounded and matches the shape of the outlet segment 4. The arc segment 3 and the outlet segment 4 have a smooth transition. Therefore, after the flue gas passes through the frustum segment 2, it can smoothly enter the outlet segment 4 from the square-to-circle transition segment 5 and the arc segment 3, thereby reducing the local resistance of the flue gas, thereby reducing the total pressure drop of the entire denitrification system, ensuring the safety and stability of the entire cement kiln system, and reducing the operating cost.

[0039] The utility model provides a low-resistance ash hopper, wherein an inlet section 1, a body section and an outlet section 4 are connected in sequence, the inlet section 1 is used to pass the flue gas discharged from the outlet of the denitration reactor, and the outlet section 4 is used to connect with the downstream equipment of the denitration system; the body section comprises a frustum section 2, a square-to-circle transition section 5 and an arc section 3 which are connected in sequence, the bottom surface 21 of the frustum section is connected with the inlet section 1, when the flue gas hits the conical surface of the frustum section 2, the solid dust such as smoke dust mixed in the flue gas slides along the conical surface into the top surface 22 of the frustum section, the top surface 22 of the frustum section is provided with an ash falling opening 221, which can discharge the smoke dust. Solid dust such as ash is discharged; the first cone surface 23 of the frustum section 2 is connected to the arc section 3 through the square-to-circle transition section 5, and the connection between the square-to-circle transition section 5, the arc section 3 and the outlet section 4 is smoothly transitioned. The flue gas can smoothly enter the square-to-circle transition section 5 and the arc section 3 from the frustum section 2, and smoothly enter the outlet section 4 from the arc section 3, thereby reducing the local resistance of the flue gas. The resistance loss when the flue gas flows through the low-resistance ash hopper is small, thereby reducing the total pressure drop of the entire denitrification system, ensuring the safe and stable operation of the entire system, and reducing the operating cost.

[0040] Specifically, in some embodiments, the orthographic projection of the top surface 22 of the frustum segment on the bottom surface 21 of the frustum segment is located on the bottom surface 21 of the frustum segment.

[0041] It can be understood that the orthographic projection of the top surface 22 of the frustum section is located on the bottom surface 21 of the frustum section, and the ash outlet 221 is arranged on the top surface 22 of the frustum section, which can reduce the distance that solid dust such as smoke flows in the low-resistance ash hopper. Solid waste such as smoke falls directly into the ash outlet 221 from the cone surface without turning, thereby reducing the flow resistance of the flue gas and ensuring that the flue gas can pass through the square-to-circular transition section 5, the arc section 3 and the outlet section 4 more smoothly.

[0042] Specifically, Figure 1 As shown, the cross section of the outlet section 4 is circular. The arc section 3 is a sector ring cut from a toroidal surface, and the angle between the two end faces of the arc section 3 is 50° to 75°.

[0043] It is understandable that if Figure 1 As shown, the outlet section 4 is cylindrical and its cross section is circular. The arc section 3 can be a sector ring cut from a ring surface. The angle between the two end faces of the arc section 3 is 50° to 75°, so that the flue gas can smoothly enter the outlet section 4 along the arc wall of the arc section 3, thereby reducing the local resistance of the flue gas and further reducing the total pressure drop of the entire denitrification system.

[0044] Furthermore, if Figure 2 and Figure 6 As shown, the square-to-circular transition section 5 has a trapezoidal structural surface 51 connected to the first conical surface 23 and a circular structural surface 53 connected to the outlet section 4, a square-to-circular transition surface 52 is between the trapezoidal structural surface 51 and the circular structural surface 53, and the circular structural surface 53 is adapted to the connecting surface of the arc section 3.

[0045] It is understandable that the square-to-round transition section 5 has a trapezoidal structural surface 51, a square-to-round transition surface 52 and a circular structural surface 53. The trapezoidal structural surface 51 and the circular structural surface 53 are arranged opposite to each other. The trapezoidal structural surface 51 and the square-to-round transition surface 52 are respectively connected to two adjacent side edges of the first conical surface 23. Among them, the circular structural surface 53 is smoothly transitionally connected to the connecting surface of the arc segment 3, thereby ensuring that the smoke can flow smoothly from the square-to-round transition section 5 to the arc segment 3.

[0046] In some embodiments, Figure 2 and Figure 3 As shown, the inlet section 1 has a first side wall 11 flush with the first conical surface 23. The first conical surface 23 is connected to and flush with the end surface of the first side wall 11, the trapezoidal structure surface 51 coincides with the first conical surface 23, and the square-to-round transition surface 52 and the first side wall 11 are set at an obtuse angle.

[0047] It is understandable that the first conical surface 23 is flush with the first side wall 11 of the inlet section 1, so that the smoke enters the frustum section 2 from the inlet section 1 in a straight direction. Further, the trapezoidal structural surface 51 is connected to the first conical surface 23, and since the first conical surface 23 is flush with the first side wall 11, a connection is formed between the end surface of the trapezoidal structural surface 51 and the first side wall 11.

[0048] like Figure 2 As shown, the trapezoidal structural surface 51 is connected to and flush with the end surface of the first side wall 11, and the square-to-circle transition surface 52 and the first side wall 11 are set at an obtuse angle, which can ensure that the smoke smoothly enters the square-to-circle transition section 5 from the frustum section 2, avoids the formation of a flow dead angle at the connection between the frustum section 2 and the square-to-circle transition section 5, thereby reducing the smoke resistance.

[0049] It can be understood that the angle between the trapezoidal structural surface 51 and the end surface of the first side wall 11 should not be set too large, otherwise it is difficult to guide the smoke to the square-to-round transition section 5.

[0050] Optionally, the included angle between the trapezoidal structural surface 51 and the end surface of the first side wall 11 is 100° to 140°.

[0051] Preferably, the angle between the trapezoidal structural surface 51 and the end surface of the first side wall 11 is 120°.

[0052] Furthermore, if Figure 4 As shown, the frustum segment 2 has a second conical surface 24, a third conical surface 25 and a fourth conical surface 26 connected in sequence to the first conical surface 23. The angles formed by the second conical surface 24, the third conical surface 25 and the fourth conical surface 26 and the top surface 22 of the frustum segment are 50° to 75°.

[0053] It is understandable that the first conical surface 23 is flush with the first side wall 11, the second conical surface 24, the third conical surface 25 and the fourth conical surface 26 are inclined toward the square-to-round transition section 5, and the angles formed by the second conical surface 24, the third conical surface 25 and the fourth conical surface 26 and the top surface 22 of the frustum section are set to 50° to 75°, ensuring that the three conical surfaces have a certain inclination to guide the flue gas into the square-to-round transition section 5. At the same time, solid dust such as dust in the flue gas can slide along the three conical surfaces to the ash drop port 221 in a concentrated manner.

[0054] Optionally, the second conical surface 24, the third conical surface 25 and the fourth conical surface 26 respectively form equal angles with the top surface 22 of the frustum segment to ensure the guiding effect of the three conical surfaces on smoke and ash.

[0055] It should be noted that the angles formed by the second conical surface 24, the third conical surface 25 and the fourth conical surface 26 and the top surface 22 of the frustum segment may not be equal. For example, the angle formed by the first conical surface 23 and the top surface 22 of the frustum segment is 60°, the angle formed by the third conical surface 25 and the top surface 22 of the frustum segment is 50°, and the angle formed by the fourth conical surface 26 and the top surface 22 of the frustum segment is 75°. The present invention does not make any specific limitation on this.

[0056] Specifically, the top surface 22 of the frustum section is hollowed out to form an ash drop opening 221. The side length of the top surface 22 of the frustum section is 350 mm to 650 mm.

[0057] The ash drop opening 221 is used to connect with the smoke conveying device 100. The user can reasonably select the size of the ash drop opening 221 according to the size of the aperture of the transport pipe of the smoke conveying device 100 and the falling speed of the smoke. It can be understood that when the dust falling speed is high, in order to prevent the accumulation of solid dust such as smoke in the low resistance ash hopper, the size of the ash drop opening 221 should be set larger. When the flow rate of the smoke is low, the size of the ash drop opening 221 should be set smaller to prevent a large amount of smoke from leaking from the ash drop opening 221.

[0058] Optionally, the top surface 22 of the frustum segment is square with a side length of 500 mm.

[0059] In the second aspect, the utility model also provides a denitration system, including a denitration reactor, downstream equipment, a smoke conveying device 100 and the low-resistance ash hopper as described above. The outlet of the denitration reactor is connected to the inlet section 1, the outlet section 4 is connected to the inlet of the downstream equipment, and the smoke conveying device 100 is arranged at the ash falling port 221 for conveying the smoke falling from the smoke.

[0060] It is understandable that the denitration system provided by the utility model, the denitration reactor is mainly used to treat nitrogen oxides generated during the combustion process. Nitrogen oxides are one of the air pollutants and are harmful to the environment and health. The denitration reactor uses chemical reactions to convert nitrogen oxides into harmless nitrogen and water vapor, thereby reducing pollution to the atmosphere. Common denitration technologies include selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR). Among them, SCR denitration usually uses a catalyst at high temperature, adding ammonia or urea as a reducing agent to convert nitrogen oxides into nitrogen and water. SNCR denitration directly injects ammonia or urea solution during the combustion process, and uses a non-catalytic reduction reaction at high temperature to convert nitrogen oxides into nitrogen and water.

[0061] In some embodiments, the denitrification system adopts a low-resistance ash hopper as described above, and the flue gas can pass smoothly through the low-resistance ash hopper and enter the downstream equipment, reducing the flow resistance of the flue gas and directly reducing the total pressure drop of the entire denitrification system to achieve low-resistance operation of the outlet flue of the denitrification system, thereby reducing the investment and operating costs of the denitrification system and improving the safety and stability of the operation of the entire cement kiln system.

[0062] Furthermore, the denitration system also includes a smoke dust conveying device 100. The smoke dust conveying device 100 is arranged at the ash outlet 221. The smoke enters the low-resistance ash hopper from the inlet section 1, and after flowing through the frustum section 2, turns and enters the square-to-circle transition section 5 and the arc section 3, and then flows out from the outlet section 4. Since the smoke dust in the smoke is in the frustum because its own inertia is greater than the smoke, most of it falls directly to the ash outlet 221. At this time, the smoke dust conveying device 100 can be used to transport the smoke dust to the outside, which is very convenient.

[0063] Since the denitrification system includes a low-resistance ash hopper, the specific structure of the low-resistance ash hopper refers to the above-mentioned embodiment, and the denitrification system of this embodiment includes all the technical solutions of the above-mentioned embodiments, and therefore has at least all the beneficial effects achieved by all the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A low resistance ash hopper, characterized in that: include: An inlet section, a main body section and an outlet section are connected in sequence, the inlet section is used to allow the flue gas discharged from the outlet of the denitration reactor to pass through, and the outlet section is used to connect with the downstream equipment of the denitration system, wherein the main body section includes a frustum section, a square-to-circle transition section and an arc section connected in sequence, the bottom surface of the frustum section is connected to the inlet section, the top surface of the frustum section is provided with an ash outlet for discharging the ash falling from the flue gas, the first cone surface of the frustum section is connected to the arc section through the square-to-circle transition section, the arc section is connected to the outlet section, and the connection between the square-to-circle transition section, the arc section and the outlet section is smoothly transitioned.

2. The low resistance ash hopper according to claim 1, characterized in that: The orthographic projection of the top surface of the frustum segment on the bottom surface of the frustum segment is located on the bottom surface of the frustum segment.

3. The low resistance ash hopper according to claim 1, characterized in that: The cross section of the outlet section is circular, the arc section is a sector ring intercepted from a ring surface, and the angle between the two end surfaces of the arc section is 50° to 75°.

4. The low resistance ash hopper according to claim 1, characterized in that: The square-to-circular transition section has a trapezoidal structural surface connected to the first conical surface and a circular structural surface connected to the outlet section, and a square-to-circular transition surface is between the trapezoidal structural surface and the circular structural surface.

5. The low resistance ash hopper according to claim 4, characterized in that: The inlet section has a first side wall flush with the first conical surface, and the square-to-round transition surface is arranged at an obtuse angle with the end surface of the first side wall.

6. The low resistance ash hopper according to claim 5, characterized in that: The included angle between the square-to-round transition surface and the end surface of the first side wall is 100° to 140°.

7. The low resistance ash hopper according to claim 1, characterized in that: The frustum segment has a second conical surface, a third conical surface and a fourth conical surface connected in sequence to the first conical surface, and the angles formed by the second conical surface, the third conical surface and the fourth conical surface and the top surface of the frustum segment are 50° to 75° respectively.

8. The low resistance ash hopper according to claim 7, characterized in that: The second conical surface, the third conical surface and the fourth conical surface respectively form equal angles with the top surface of the frustum segment.

9. The low resistance ash hopper according to claim 1, characterized in that: The top surface of the frustum section is hollowed out to form the ash dropout opening, and the side length of the top surface of the frustum section is 350 mm to 650 mm.

10. A denitration system, characterized in that: It comprises a denitration reactor, downstream equipment, an ash conveying device and a low-resistance ash hopper as described in any one of claims 1 to 9, the outlet of the denitration reactor is connected to the inlet section, the outlet section is connected to the inlet of the downstream equipment, and the ash conveying device is arranged at the ash dropping port for conveying ash dropped from the flue gas.

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