Efficient heating furnace core tube

Abstract

The invention discloses an efficient heating furnace core pipe which comprises a pipe body, a main air pipe and a plurality of branch air pipes. The pipe body is a hollow cylinder with two open ends; the main air pipe is arranged in the pipe body in a penetrating mode, the two ends of the main air pipe penetrate out of the ends of the pipe body, the length direction of the main air pipe is parallel to the axis of the pipe body, the branch air pipes are arranged on the main air pipe in the radial direction, and the branch air pipes are arranged in the length direction of the main air pipe at intervals. The branch air pipes are respectively communicated with the main air pipe, and air outlets are formed in the branch air pipes. Generally, only an air inlet is designed at the front end of a furnace tube of a rotary furnace, gas distribution in the furnace is uneven, and reaction efficiency is low, according to the design of a main air tube and branch air tubes, gas is input from the main air tube, the branch air tubes arranged at intervals in the length direction of the main air tube output gas in different areas of a tube body, and the problem that gas distribution in the furnace is uneven is solved; the reaction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rotary furnaces, and in particular to a furnace core tube for efficient heating. Background Art

[0002] As a key heating equipment in industrial production, the design and performance of the rotary kiln directly affect the heating quality and production efficiency of the materials. Traditional rotary kilns mainly supply air into the furnace through fixed air inlets on the side of the furnace body to achieve the heating process of the materials. This design met basic production needs in early industrial applications, but with the development of technology and the improvement of production standards, its design concept and function realization gradually exposed limitations.

[0003] Current industrial production has stricter requirements on the efficiency, uniformity and environmental protection of heating equipment. High-efficiency heating can significantly shorten the production cycle and improve production capacity; uniform heating ensures product quality and meets the needs of precision manufacturing; energy saving and environmental protection respond to the call for global sustainable development and reduce production costs. However, the existing rotary kiln air inlet system does not perform well in these aspects, and urgently needs technological innovation and improvement to meet the high standards of modern industry.

[0004] Specifically, there are several major problems with the existing rotary kiln air inlet system: first, the uneven air inlet leads to inconsistent heating of the materials in the furnace, affecting the quality of the final product; second, the reaction efficiency is low, due to the fixed position and design of the air inlet, which limits the full contact between the gas and the material; finally, the energy consumption is high, due to the insufficient reaction efficiency, resulting in energy waste and increased production costs. The existence of these problems limits the application potential of rotary kilns in modern industrial production, and urgently needs to be solved through technological innovation. Summary of the invention

[0005] In view of the above defects, the purpose of the present invention is to provide a furnace core tube with high efficiency heating to solve the problems of uneven gas distribution in the tube, uneven material heating, unstable product quality and low reaction efficiency in the prior art.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A furnace core tube for efficient heating, comprising a tube body, a main air duct and a plurality of branch air ducts;

[0008] The tube body is a hollow cylinder with openings at both ends;

[0009] The main air duct is arranged in the tube body, and both ends of the main air duct pass through the end portions of the tube body. The length direction of the main air duct is parallel to the axis of the tube body. The main air duct is provided with the branch air duct in the radial direction. Several branch air ducts are arranged at intervals along the length direction of the main air duct. The branch air ducts are respectively connected to the main air ducts, and the branch air ducts are provided with air outlets.

[0010] Specifically, it also includes: a front sealing cover and a rear sealing cover, the two ends of the tube body are respectively connected to the front sealing cover and the rear sealing cover; the front end of the main air duct is connected to the external fixed structure through the front end fixing point of the air duct, and the rear end of the main air duct is connected to the rear sealing cover through a movable sealing device.

[0011] Specifically, the movable sealing device includes an air duct sealing platform, a sealing outer ring and a sealing pressure ring. The air duct sealing platform is provided on the outer side of the main air duct, the sealing pressure ring is provided on the outer side of the air duct sealing platform, the rear sealing cover is provided with the sealing outer ring, and the sealing pressure ring is provided on the outer fixed sleeve of the air duct sealing platform. The sealing pressure ring partial structure is located between the air duct sealing platform and the sealing outer ring. The sealing outer ring and the sealing pressure ring are installed by bolts and elastic parts. The elastic part is sleeved on the screw rod of the bolt, one end of the elastic part is abutted against the nut of the bolt, and the other end of the elastic part is abutted against the sealing pressure ring. The screw end of the bolt passes through the sealing pressure ring and is threadedly connected to the sealing outer ring. The area surrounded by the sealing outer ring, the air duct sealing platform, the rear sealing cover and the sealing pressure ring is filled with sealing material.

[0012] Specifically, it also includes an air duct bracket, at least one of which is provided, and the air duct bracket is used to provide support for the middle part of the main air duct.

[0013] Specifically, the air duct support includes a supporting foot, and the supporting foot is provided with at least one, one end of the supporting foot is fixed to the inner wall of the tube body, and the other end of the supporting foot is supported and connected to the outer side of the main air duct.

[0014] Specifically, the air duct bracket also includes a sleeve ring assembly, and the other end of the supporting foot is connected to the main air duct through the sleeve ring assembly. The main air duct is inserted into the sleeve ring assembly, and a thickening ring is provided on the outer periphery of the main air duct. The position of the thickening ring matches the sleeve ring assembly, and the sleeve ring assembly and the thickening ring can be relatively movably arranged.

[0015] Specifically, the sleeve ring assembly includes a support ring and a wear-resistant ring which are sleeved in sequence from the outside to the inside, and the inner periphery of the wear-resistant ring is in contact with the outer periphery of the thickened ring.

[0016] Specifically, the front and rear ends of the main air duct are respectively connected to air supply devices.

[0017] Specifically, the branch air duct is distributed in the lower area of ​​the main air duct, the end of the branch air duct is located in the range close to the tube body, and at least one air outlet is arranged at the end of the branch air duct.

[0018] Specifically, a plurality of said branch air ducts are arranged at intervals in the circumferential direction of said main air duct;

[0019] The branch air ducts are distributed in the material rising area within the tube body, and the branch air ducts are distributed in the lower area of ​​the main air duct; the air outlet is an inclined cut, and the inclined cuts of several branch air ducts are located on the same side of the end of the branch air duct, and the inclined cuts face the material descending area of ​​the tube body.

[0020] The technical solution provided by the present invention may include the following beneficial effects:

[0021] 1. Through the design of the main air duct and the branch air duct, the gas is input from the main air duct, and the branch air ducts arranged at intervals along the length direction of the main air duct output the gas in different areas of the pipe body respectively, so as to solve the problem of uneven gas distribution in the furnace and improve the reaction efficiency.

[0022] 2. By adopting a movable sealing device, the main air duct can be expanded and contracted within the set range while maintaining the sealing state inside the duct without affecting the overall operation of the equipment, thereby solving the problem that the main air duct is easily damaged due to thermal expansion and elongation.

[0023] 3. By adopting a multi-layer ring design of the air duct bracket, dynamic surrounding support is provided for the middle part of the main air duct, solving the problem that the main air duct cannot maintain stable operation in the equipment due to its long length. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the furnace core tube in an embodiment of the present invention.

[0025] Figure 2 In the embodiment of the present invention Figure 1 A partial enlarged schematic diagram of point A in the middle

[0026] Figure 3 It is a structural schematic diagram of the air duct installed in the furnace core tube in an embodiment of the present invention.

[0027] Figure 4 It is a structural schematic diagram of the air duct support installed in the furnace core tube in an embodiment of the present invention.

[0028] Wherein: pipe body 1, main air duct 2, branch air duct 3, front sealing cover 4, rear sealing cover 5, front end fixing point of air duct 6, movable sealing device 7, air duct bracket 8, material 9, air outlet 10, material rising area 11, material falling area 12;

[0029] Duct sealing platform 71, sealing outer ring 72, sealing pressure ring 73, bolts 74, elastic member 75, sealing material 76;

[0030] Support foot 81 , support ring 82 , wear-resistant ring 83 and thickening ring 84 . DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of the features, and are used to distinguish and describe features, without distinction of order or importance.

[0033] In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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.

[0035] Combine the following Figures 1 to 4 , describes an efficient heating furnace core tube according to an embodiment of the present invention, comprising a tube body 1, a main air duct 2 and a plurality of branch air ducts 3;

[0036] The tube body 1 is a hollow cylinder with openings at both ends;

[0037] The main air duct 2 is passed through the tube body 1, and both ends of the main air duct 2 pass through the ends of the tube body 1. The length direction of the main air duct 2 is parallel to the axis of the tube body 1. The main air duct 2 is provided with the branch air duct 3 in the radial direction. Several branch air ducts 3 are arranged at intervals along the length direction of the main air duct 2. The branch air ducts 3 are respectively connected to the main air duct 2, and the branch air ducts 3 are provided with air outlets 10.

[0038] The rotary furnace is usually only designed with an air inlet at the front end of the furnace tube, resulting in uneven gas distribution in the furnace and low reaction efficiency. The present invention, through the design of the main air duct and the branch air duct, inputs gas from the main air duct 2, and outputs gas from different areas of the tube body through multiple branch air ducts 3 spaced apart along the length direction of the main air duct 2, thereby solving the problem of uneven gas distribution in the furnace and improving the reaction efficiency.

[0039] Preferably, the axis of the main air duct 2 overlaps with the axis of the tube body 1, ensuring that the installation of the main air duct 2 does not affect the rotation of the tube body 1 and is easy to install.

[0040] In another embodiment, it also includes: a front sealing cover 4 and a rear sealing cover 5, and the two ends of the tube body 1 are respectively connected to the front sealing cover 4 and the rear sealing cover 5; the front end of the main air duct 2 is connected to the external fixed structure through the front end fixing point 6 of the air duct, and the rear end of the main air duct 2 is connected to the rear sealing cover 5 through a movable sealing device 7.

[0041] With this structure, a sealed space is formed inside the furnace core tube. When the temperature of the main air duct 2 rises, it will become longer due to thermal expansion and contraction. By adopting a movable sealing device, the main air duct 2 can be expanded and contracted within a set range without affecting operation, thereby solving the problem that the main air duct 2 is easily damaged due to thermal expansion and contraction.

[0042] Specifically, Figure 2As shown, the movable sealing device 7 includes an air duct sealing platform 71, a sealing outer ring 72 and a sealing pressure ring 73. The air duct sealing platform 71 is sleeved on the outer side of the main air duct 2, and the sealing pressure ring 73 is sleeved on the outer side of the air duct sealing platform 71. The rear sealing cover 5 is provided with the sealing outer ring 72, and the sealing pressure ring 73 is fixedly sleeved on the outer side of the air duct sealing platform 71. The sealing pressure ring 73 is partially located between the air duct sealing platform 71 and the sealing outer ring 72. The sealing outer ring 72 and the sealing pressure ring 73 are installed by a bolt 74 and an elastic member 75 that are pressed together. The elastic member 75 is sleeved on the screw of the bolt 74. One end of the elastic member 75 is abutted against the nut of the bolt 74, and the other end of the elastic member 75 is abutted against the sealing pressure ring 73. The screw end of the bolt 74 passes through the sealing pressure ring 73 and is threadedly connected to the sealing outer ring 72. The area surrounded by the sealing outer ring 72, the air duct sealing platform 71, the rear sealing cover 5 and the sealing pressure ring 73 is filled with sealing material 76.

[0043] The use of the air duct sealing platform 71 can increase the local connection rigidity of the main air duct 2. The partial structure of the sealing pressure ring 73 is located between the air duct sealing platform 71 and the sealing outer ring 72, so as to realize the limited installation between the main air duct 2 and the rear sealing cover 5. The sealing outer ring 72 and the sealing pressure ring 73 are pressed by bolts 74 and elastic members 75. The setting of the elastic members 75 realizes the adaptability of the sealing pressure ring 73. When the main air duct 2 is heated and elongated, the sealing pressure ring 73 compresses the elastic member 75. At the same time, due to the limiting effect of the bolts 74 and the sealing outer ring 72, the elastic member 75 also restricts the sealing pressure ring 73, so that the main air duct 2 and the rear sealing cover 5 can maintain sealing within the telescopic range of the main air duct 2. The use of the sealing material 76 further increases the sealing performance. By using the movable sealing device 7, the problem of poor telescopic sealing of the main air duct 2 within the set range is solved.

[0044] In another embodiment, it further includes an air duct support 8 , at least one of which is provided, and the air duct support 8 is used to provide support for the middle portion of the main air duct 2 .

[0045] The duct support 8 provides support for the middle of the main duct 2, thereby solving the problem of the main duct 2 bending and deforming due to gravity, and improving the service life of the equipment. It should be noted that there are multiple duct supports 8, and the multiple duct supports 8 are arranged at intervals along the length direction of the main duct 2. The multiple duct supports 8 are arranged to provide stable support for the main duct 2, avoiding the phenomenon of the main duct 2 bending and deforming due to gravity, and ensuring that the main duct 2 is located on the central axis of the tube body 1. The specific number of duct supports 8 is determined by the size, material, weight, and length of the main duct 2.

[0046] Specifically, Figure 4As shown, the air duct bracket 8 includes a supporting foot 81, and the supporting foot 81 is provided with at least one, one end of the supporting foot 81 is fixed to the inner wall of the tube body 1, and the other end of the supporting foot 81 is supported and connected to the outer side of the main air duct 2.

[0047] With this structure, one end of the duct bracket 8 is fixed to the pipe body 1, and the other end of the duct bracket 8 is movably connected to the main air duct 2. When the equipment is running, the pipe body 1 rotates, driving the duct bracket 8 to rotate around the main air duct 2, thereby solving the problem that the middle part of the main air duct 2 cannot be supported when the pipe body 1 rotates.

[0048] Preferably, the air duct bracket 8 also includes a sleeve ring assembly, and the other end of the supporting foot 81 is connected to the main air duct 2 through the sleeve ring assembly, the main air duct 2 is inserted into the sleeve ring assembly, and a thickening ring 84 is provided on the outer periphery of the main air duct 2, and the position of the thickening ring 84 matches the sleeve ring assembly, and the sleeve ring assembly and the thickening ring 84 can be relatively movably arranged.

[0049] When the tube body 1 rotates, it drives the duct bracket 8 to rotate around the main air duct 2, and the sleeve ring assembly rotates along with the rotation of the duct bracket 8. By setting the sleeve ring assembly and the thickening ring 84, the stability of the relative rotation between the tube body 1 and the main air duct 2 is improved. The setting of the sleeve ring assembly can increase the service life of the duct bracket 8. The duct bracket 8 is divided into the supporting feet 81 and the sleeve ring assembly to realize the replacement of the local structure, making subsequent maintenance more convenient.

[0050] Specifically, the sleeve ring assembly includes a support ring 82 and a wear-resistant ring 83 which are sleeved in sequence from the outside to the inside, and the inner periphery of the wear-resistant ring 83 is in contact with the outer periphery of the thickened ring 84 .

[0051] When the duct bracket 8 rotates around the main air duct 2, the friction between the duct bracket 8 and the main air duct 2 can easily cause wear on the contact portion between the duct bracket 8 and the main air duct 2. By adding a support ring 82 and a wear-resistant ring 83 and adopting a multi-layer structure, the support ring 82 is connected to the support foot 81 to form a stable annular support surface. At the same time, a thickened ring 84 is added to surround and fix on the outer periphery of the main air duct 2 to increase the local rigidity of the main air duct 2 and protect the main air duct 2 from deformation due to local support force. The support ring 82 and the thickened ring 84 cooperate with each other through the sleeve of the wear-resistant ring 83 to reduce friction. At the same time, the wear-resistant ring 83 can be replaced separately as a wear-prone part, which solves the problem of inconvenient maintenance after equipment wear caused by friction and improves the overall service life of the equipment.

[0052] Preferably, the support ring 82 , the wear-resistant ring 83 or the thickened ring 84 is a circular ring composed of at least two arc sections. This structure solves the problem that the air duct bracket 8 is difficult to install and maintain due to the existence of the branch air duct 3 .

[0053] Preferably, there are at least three supporting legs 81, and the three supporting legs 81 are arranged at equal intervals on the outer periphery of the sleeve ring assembly. By arranging multiple supporting legs 81 at equal intervals, the stability of the air duct bracket 8 is improved. Preferably, the number of supporting legs 81 is 4, and the 4 supporting legs 81 are distributed on the outer periphery of the sleeve ring assembly in a cross structure.

[0054] In another embodiment, the front and rear ends of the main air duct 2 are respectively connected to air supply devices.

[0055] The two-end opening gas supply method is adopted, and both ends can be used as air inlets to input gas at the same time, which solves the problem of uneven distribution of gas at both ends of the furnace core tube and improves the reaction efficiency.

[0056] Specifically, the branch air duct 3 is distributed in the lower area of ​​the main air duct 2 , the end of the branch air duct 3 is located close to the tube body 1 , and at least one air outlet 10 is provided at the end of the branch air duct 3 .

[0057] With this structure, the air distribution pipe 3 can be directly inserted into the material 9, so that the air outlet 10 is inside the material 9, and the gas is used to stir the material 9, thereby solving the problem of insufficient contact between the gas and the material 9 and improving the reaction efficiency.

[0058] For further explanation, the area where the pipe body can drive the material to move upward when rotating is defined as the material ascending area 11 of the pipe body, and the area where the material freely falls when rotating is defined as the material descending area 12 of the pipe body.

[0059] In one embodiment, the branch air duct 3 can be distributed in the material descending area 12 in the tube body 1, but at this time the branch air duct 3 needs to be distributed in the upper area of ​​the main air duct 2. At this time, the air outlet 10 needs to be downward or set in a radial direction perpendicular to the tube body 1 to avoid the situation where the material 9 blocks the branch air duct 3.

[0060] Specifically, a plurality of said branch air ducts 3 are arranged at intervals in the circumferential direction of said main air duct 2;

[0061] The branch air ducts 3 are distributed in the material rising area 11 in the tube body 1, and the branch air ducts 3 are distributed in the lower area of ​​the main air duct 2; the air outlet 10 is an inclined cut, and the inclined cuts of several branch air ducts 3 are located on the same side of the end of the branch air duct 3, and the inclined cuts are facing the material falling area 12 of the tube body 1.

[0062] One type of branch air ducts 3 are arranged at intervals along the length direction of the main air duct 2, and another type of branch air ducts 3 are arranged at intervals along the circumference of the main air duct 2, which can make the gas distribution more uniform and improve the reaction efficiency.

[0063] In a more preferred embodiment, Figure 3As shown, the branch air duct 3 is distributed in the material rising area 11 in the tube body 1, and the branch air duct 3 is distributed in the lower area of ​​the main air duct 2, that is, during the operation of the equipment, the branch air duct 3 is inserted into the material, which allows the gas to have more sufficient contact with the material 9, improves the reaction efficiency, and effectively reduces energy consumption. In addition, the air outlet 10 is an inclined cut, and the inclined cut is toward the material descending area 12 of the tube body 1, which avoids the problem that the material 9 easily enters the inclined cut when it is turned over and mixed in the tube body 1, and blocks the branch air duct 3. At the same time, the airflow formed by these multiple branch air ducts 3 arranged at intervals in the circumferential direction is opposite to the rotation direction of the tube body 1, which is also helpful to improve the reaction efficiency.

[0064] Other structures and operations of a high-efficiency heating furnace core tube according to an embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0065] In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A furnace core tube for efficient heating, characterized in that: It includes a pipe body, a main air duct and several branch air ducts; The tube body is a hollow cylinder with openings at both ends; The main air duct is arranged in the tube body, and both ends of the main air duct pass through the end portions of the tube body. The length direction of the main air duct is parallel to the axis of the tube body. The main air duct is provided with the branch air duct in the radial direction. Several branch air ducts are arranged at intervals along the length direction of the main air duct. The branch air ducts are respectively connected to the main air ducts, and the branch air ducts are provided with air outlets.

2. A furnace core tube for efficient heating as claimed in claim 1, characterized in that: Also includes: A front sealing cover and a rear sealing cover, both ends of the tube body are connected to the front sealing cover and the rear sealing cover respectively; The front end of the main air duct is connected to the external fixed structure through the front end fixing point of the air duct, and the rear end of the main air duct is connected to the rear sealing cover through a movable sealing device.

3. A furnace core tube for efficient heating as claimed in claim 2, characterized in that: The movable sealing device includes an air duct sealing platform, a sealing outer ring and a sealing pressure ring. The air duct sealing platform is sleeved on the outer side of the main air duct, the sealing pressure ring is sleeved on the outer side of the air duct sealing platform, the rear sealing cover is provided with the sealing outer ring, and the sealing pressure ring is sleeved on the outer side of the air duct sealing platform. The sealing pressure ring partial structure is located between the air duct sealing platform and the sealing outer ring. The sealing outer ring and the sealing pressure ring are installed by bolts and elastic parts. The elastic part is sleeved on the screw rod of the bolt, one end of the elastic part is abutted against the nut of the bolt, and the other end of the elastic part is abutted against the sealing pressure ring. The screw end of the bolt passes through the sealing pressure ring and is threadedly connected to the sealing outer ring. The area surrounded by the sealing outer ring, the air duct sealing platform, the rear sealing cover and the sealing pressure ring is filled with sealing material.

4. A furnace core tube for efficient heating as claimed in claim 1, characterized in that: It also includes an air duct bracket, at least one of which is provided and is used to provide support for the middle part of the main air duct.

5. A furnace core tube for efficient heating as claimed in claim 4, characterized in that: The air duct bracket includes a supporting foot, and at least one supporting foot is provided. One end of the supporting foot is fixed to the inner wall of the tube body, and the other end of the supporting foot is supported and connected to the outer side of the main air duct.

6. A furnace core tube for efficient heating as claimed in claim 5, characterized in that: The air duct bracket also includes a sleeve ring assembly, and the other end of the supporting foot is connected to the main air duct through the sleeve ring assembly. The main air duct is inserted into the sleeve ring assembly, and a thickening ring is provided on the outer periphery of the main air duct. The position of the thickening ring matches the sleeve ring assembly, and the sleeve ring assembly and the thickening ring can be relatively movably arranged.

7. A furnace core tube for efficient heating as claimed in claim 6, characterized in that: The sleeve ring assembly comprises a support ring and a wear-resistant ring which are sleeved in sequence from the outside to the inside, and the inner periphery of the wear-resistant ring is in contact with the outer periphery of the thickened ring.

8. The high-efficiency heating furnace core tube according to claim 1, characterized in that: The front and rear ends of the main air duct are respectively connected with air supply devices.

9. A furnace core tube for efficient heating as claimed in claim 1, characterized in that: The branch air duct is distributed in the lower area of ​​the main air duct, the end of the branch air duct is located close to the pipe body, and at least one air outlet is arranged at the end of the branch air duct.

10. The high-efficiency heating furnace core tube according to claim 1, characterized in that: A plurality of said branch air ducts are arranged at intervals in the circumferential direction of said main air duct; The branch air ducts are distributed in the material rising area within the tube body, and the branch air ducts are distributed in the lower area of ​​the main air duct; the air outlet is an inclined cut, and the inclined cuts of several branch air ducts are located on the same side of the end of the branch air duct, and the inclined cuts face the material descending area of ​​the tube body.

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