Non-deformable industrial furnace double-chamber front flue gas conveying duct

Abstract

The industrial electric furnace two-burner front flue gas conveying pipeline not prone to deformation of the utility model, including first, second pipe joint welded together in parallel, the part of first pipe joint close to the weld area is welded with first axial reinforcing rib and first circumferential reinforcing ring, the part of second pipe joint away from the weld area is welded with second axial reinforcing rib and second circumferential reinforcing ring, first axial reinforcing rib axially extends through the weld area and extends to second pipe joint and is welded in second pipe joint, axial gap is left between first, second axial reinforcing rib. Axial reinforcing rib and circumferential reinforcing ring respectively strengthen and strengthen circumferentially to pipe joint itself, and pipe joint is not prone to deformation. First axial reinforcing rib can strengthen the weld area. The axial extension of the first axial reinforcing rib is not subjected to circumferential constraint, avoiding forming "rigid lock" on both sides of the weld area, thereby effectively preventing thermal stress concentration to the weld area.

Description

Technical Field

[0001] This utility model relates to the field of flue gas conveying pipeline technology, specifically to a flue gas conveying pipeline in front of the secondary combustion chamber of an industrial electric furnace that is not easily deformed. Background Technology

[0002] Industrial electric furnaces (such as quantum electric furnaces and other high-temperature smelting equipment) consist of a furnace body and a secondary combustion chamber. A high-temperature flue gas conveying pipe made of stainless steel (i.e., the flue gas conveying pipe before the secondary combustion chamber) is installed between the furnace body and the secondary combustion chamber. During production in an industrial electric furnace, materials are heated and smelted at high temperatures within the furnace body, generating a large amount of high-temperature flue gas. This flue gas may carry unburned combustible components and harmful substances, which are typically sent into the secondary combustion chamber for combustion via the flue gas conveying pipe before the secondary combustion chamber. Due to the high temperature of the flue gas, typically exceeding 700°C, the pipe walls may become red-hot during operation; therefore, this pipe is also known in the industry as the "red pipe." Under these high-temperature conditions, the stainless steel pipe body of the flue gas conveying pipe before the secondary combustion chamber softens and is highly susceptible to deformation. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a flue gas conveying pipe in front of the secondary combustion chamber of an industrial electric furnace that is not easily deformed.

[0004] To solve the above-mentioned technical problems, the present invention provides a non-deformable flue gas conveying pipe for the secondary combustion chamber of an industrial electric furnace, comprising a first pipe section and a second pipe section welded together in parallel. The first pipe section is welded with a first axial reinforcing rib and a first circumferential reinforcing ring at the part near the weld seam, and the second pipe section is welded with a second axial reinforcing rib and a second circumferential reinforcing ring at the part away from the weld seam. The first axial reinforcing rib extends axially through the weld seam to the second pipe section and is welded to the second pipe section. An axial gap is left between the first and second axial reinforcing ribs.

[0005] Furthermore, the first and second pipe sections together form the first pipe segment; it also includes the second pipe segment, with the front end of the first pipe segment connected to the rear end of the second pipe segment via a flange.

[0006] Furthermore, an expansion joint is provided between the front end of the first pipe section and the rear end of the second pipe section, and a rearward first support frame and a forward second support frame are provided. The front end of the first pipe section is supported on the first support frame and connected to the rear end of the expansion joint through a flange. The rear end of the second pipe section is supported on the second support frame and connected to the front end of the expansion joint through a flange.

[0007] Furthermore, the first pipe section is positioned rearward while the second pipe section is positioned in front. The front section of the second pipe section serves as the front end of the first pipe section, is supported on the first support frame, and has a flange connection to connect to the rear end of the expansion joint.

[0008] Furthermore, the second axial reinforcing rib is located at the front section of the second pipe section and is not connected to the flange connection. There are multiple second axial reinforcing ribs arranged in parallel circumferentially. The second circumferential reinforcing ring connects the multiple second axial reinforcing ribs together. The lower second axial reinforcing rib is left open near the flange connection, and the first support is installed in the open space.

[0009] Furthermore, a third support frame is provided to support the second pipe section, and the third support frame is located between the first axial stiffener and the second axial stiffener.

[0010] Furthermore, the first axial stiffener has multiple circumferentially parallel stiffeners, and the first circumferentially reinforcing ring connects the multiple first axial stiffeners together. The second axial stiffener has multiple circumferentially parallel stiffeners, and the second circumferentially reinforcing ring connects the multiple second axial stiffeners together. The lower first and second axial stiffeners are left open near the gap, and the third support frame supports them at the open space.

[0011] Axial stiffeners and circumferential reinforcing rings respectively strengthen the pipe section axially and circumferentially, effectively improving its strength and making it less prone to deformation. Since the first axial stiffener extends axially through the weld area to the second pipe section and is welded there, it strengthens not only the first pipe section itself but also the weld area. A gap exists between the first and second axial stiffeners, and the first circumferential reinforcing ring is welded to the first pipe section. This means that the flue gas conveying pipe before the secondary combustion chamber of this invention does not apply circumferential constraints to the axially extended section of the first axial stiffener, avoiding a "rigid lock" on both sides of the weld area and effectively preventing thermal stress concentration in the weld area. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a flue gas conveying pipeline.

[0013] Figure 2 This is a schematic diagram of the horizontal section, the first expansion joint, and the bend section of the flue gas conveying pipeline. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to specific embodiments.

[0015] See Figure 1 The flue gas conveying pipeline in front of the secondary combustion chamber of the industrial electric furnace (hereinafter referred to as the flue gas conveying pipeline) includes multiple pipe sections, namely: inlet section 1, horizontal section 2, bend section 3 and outlet section 5.

[0016] See Figure 1The front end 102 of the inlet section 1 is connected to the flue gas outlet of the furnace body 1, and the rear end 101 is connected to the front end 202 of the horizontal section 2 via a flange. The horizontal section 2 includes front and rear pipe sections 21 and 22 arranged side by side. The front and rear pipe sections 21 and 22 are welded together to form a first weld area 911. The first weld area 911 is reinforced by multiple circumferentially arranged first reinforcing plates 921. A first expansion joint 61 is provided between the rear end 201 of the horizontal section 2 and the front end 302 of the bend section 3. The rear end 201 of the horizontal section 2 is connected to the front end 612 of the first expansion joint 61 via a flange, and the rear end 611 of the first expansion joint 61 is connected to the front end 302 of the bend section 3 via a flange. The first expansion joint 61 is existing technology and is used to absorb (or compensate for) the axial expansion and contraction in the front and rear directions caused by thermal expansion of the flue gas conveying pipeline.

[0017] See Figure 1 and Figure 2The front part 37 of the turning section 3 is in the front-to-back direction, the middle part 38 bends to the right, and the rear part 39 is in the left-to-right direction. The front part 37 of the turning section 3 includes four pipe sections arranged from front to back: intake pipe section 31, front guide pipe section 32, rear guide pipe section 33, and exhaust pipe section 34. The rear end 311 of the intake pipe section 31 is welded to the front end 322 of the front guide pipe section 32 to form the second weld area 912. The rear end 321 of the front guide pipe section 32 is welded to the front end 332 of the rear guide pipe section 33 to form the third weld area 913. The rear end 331 of the rear guide pipe section 33 is welded to the front end 342 of the exhaust pipe section 34 to form the fourth weld area 914. The rear end 341 of the exhaust pipe section 34 is welded to the middle part 38 of the turning section 3. The front section 323 of the pilot air pipe section 32 is close to the second weld area 912, and is welded with multiple circumferentially parallel first axial reinforcing ribs 711, and also with a first circumferential reinforcing ring 721, which connects the multiple first axial reinforcing ribs 711 together. The front section 314 of the intake pipe section 31 is away from the second weld area 912, and is welded with multiple circumferentially parallel second axial reinforcing ribs 712, and also with a second circumferential reinforcing ring 722, which connects the multiple second axial reinforcing ribs 712 together. The first axial reinforcing ribs 711 extend forward axially through the second weld area 912 to the rear section 313 of the intake pipe section 31 and are welded thereto. An axial gap 73 is left between the first and second axial reinforcing ribs 711 and 712. Axial stiffeners 711 and 712 and circumferential stiffeners 721 and 722 respectively reinforce the pipe sections 31 and 32 axially and circumferentially, effectively improving the strength of the pipe sections 31 and 32 and making them less prone to deformation. Since the first axial stiffener 711 extends axially through the second weld area 912 to the rear section 313 of the intake pipe section 31 and is welded to it, the first axial stiffener 711 not only strengthens the front guide pipe section 32 itself, but also strengthens the second weld area 912. A gap 73 is left between the first axial reinforcing rib 711 and the second axial reinforcing rib 712, and the first circumferential reinforcing ring 721 is welded to the front guide gas pipe section 32. That is to say, the flue gas conveying pipe of this utility model does not apply circumferential constraint to the axial extension section 7110 of the first axial reinforcing rib 711, so as to avoid forming "rigid lock" on both sides of the second weld area 912, thereby effectively preventing thermal stress from concentrating in the second weld area 912.

[0018] See Figure 1 and Figure 2The front section 314 of the intake pipe section 31 serves as the front end 302 of the bend section 3, and it is provided with a flange connection 3141 connecting to the rear end 611 of the first expansion joint 61. Multiple second axial reinforcing ribs 712 are not connected to the flange connection 3141, with the lower three second axial reinforcing ribs 712 having an open section at their front, forming a first open space 307. The flue gas conveying pipe 20 is provided with first and second support frames 81 and 82. The second support frame 82 is located in front of the first support frame 81 and below the rear end 201 of the horizontal section 2, supporting the rear end 201 of the horizontal section 2. The first support frame 81 is located at the first open space 307, supporting the front section 314 of the intake pipe section 31. When replacing the first expansion joint 61, the front section 314 of the intake pipe section 31 and the rear end 201 of the horizontal section 2 are independently supported by the first and second support frames 81 and 82 respectively, and will not sag due to the removal of the first expansion joint 61.

[0019] See Figure 1 and Figure 2 The first axial reinforcing rib 711, the first circumferential reinforcing ring 721, the second axial reinforcing rib 712, and the second circumferential reinforcing ring 722 together form the first reinforcing structure 701. The flue gas conveying pipe 20 is provided with a second reinforcing structure 702 on the rear section 324 of the front guide pipe section 32 and the rear guide pipe section 33. The second reinforcing structure 702 is roughly the same as the first reinforcing structure 701, except that: (1) the directions are opposite; (2) the first gap 307 of the first reinforcing structure 701 is formed by the front gap of the three lower second axial reinforcing ribs 712, and the second reinforcing structure 702 is changed to the rear of the three lower first axial reinforcing ribs 711 and the front of the three lower second axial reinforcing ribs 712 being left open, together forming the second gap 308. This flue gas conveying pipeline is equipped with a third support frame 83, which is located at the second open space 308, behind the first support frame 81, between the first axial reinforcing rib 711 and the second axial reinforcing rib 712 of the second reinforcing structure 702, and supports the rear gas guide pipe section 33. The support force exerted by the third support frame 83 between the first axial reinforcing rib 711 and the second axial reinforcing rib 712 will generate structural stress inside the rear gas guide pipe section 33. This stress is transmitted through the pipe wall to the first axial reinforcing rib 711 and the second axial reinforcing rib 712, and is borne by both of them, thus achieving effective stress dispersion.

[0020] See Figure 2 Multiple second reinforcing plates 922 arranged circumferentially in parallel are welded to the fourth weld area 914 to reinforce the fourth weld area 914.

[0021] See Figure 1A second expansion joint, a compound expansion joint 62, is provided between the right end 301 of the bend section 3 and the left end 502 of the outlet section 5. The right end 301 of the bend section 3 is connected to the left end 622 of the compound expansion joint 62 via a flange, and the right end 621 of the compound expansion joint 62 is connected to the left end 502 of the outlet section 5 via a flange. The right end 501 of the outlet section 5 is used to connect to the flue gas inlet of the secondary combustion chamber. The flue gas conveying pipeline 20 is provided with two supports 99, which respectively support and connect the right end 301 of the bend section 3 and the left end 502 of the outlet section 5. The compound expansion joint 62 is existing technology and is used to absorb (or compensate for) the axial expansion and contraction in the left and right directions of the flue gas conveying pipeline caused by thermal expansion.

[0022] The above description is merely an embodiment of the present invention and does not limit the scope of patent protection. Any non-substantial changes or substitutions made by those skilled in the art based on the present invention will still fall within the scope of patent protection.

Claims

1. A flue gas conveying pipe for the secondary combustion chamber of an industrial electric furnace that is not easily deformed, comprising first and second pipe sections welded together in parallel, characterized in that: The first pipe section is welded with a first axial reinforcing rib and a first circumferential reinforcing ring near the weld area. The second pipe section is welded with a second axial reinforcing rib and a second circumferential reinforcing ring away from the weld area. The first axial reinforcing rib extends axially through the weld area to the second pipe section and is welded to the second pipe section. An axial gap is left between the first and second axial reinforcing ribs.

2. The two-plenum front flue duct of claim 1, wherein: The first and second pipe sections together form the first pipe segment; it also includes the second pipe segment, with the front end of the first pipe segment connected to the rear end of the second pipe segment via a flange.

3. The two-plenum front flue duct of claim 2, wherein: An expansion joint is provided between the front end of the first pipe section and the rear end of the second pipe section. A first support frame is provided at the rear and a second support frame is provided at the front. The front end of the first pipe section is supported on the first support frame and connected to the rear end of the expansion joint through a flange. The rear end of the second pipe section is supported on the second support frame and connected to the front end of the expansion joint through a flange.

4. The two-plenum front flue duct of claim 3, wherein: The first pipe section is positioned at the rear, while the second pipe section is positioned at the front. The front section of the second pipe section serves as the front end of the first pipe section, is supported on the first support frame, and has a flange connection to connect to the rear end of the expansion joint.

5. The two-plenum front flue duct of claim 4, wherein: The second axial stiffener is located at the front section of the second pipe section and is not connected to the flange connection. There are multiple second axial stiffeners arranged in parallel circumferentially. The second circumferential stiffener ring connects the multiple second axial stiffeners together. The lower second axial stiffener is left open near the flange connection, and the first support is installed in the open space.

6. The two-plenum front flue duct of claim 1, wherein: The second pipe section is supported by a third support frame, which is located between the first axial stiffener and the second axial stiffener.

7. The two-plenum front flue duct of claim 6, wherein: The first axial stiffener has multiple circumferentially parallel stiffeners, and the first circumferentially reinforcing ring connects the multiple first axial stiffeners together. The second axial stiffener has multiple circumferentially parallel stiffeners, and the second circumferentially reinforcing ring connects the multiple second axial stiffeners together. The lower first and second axial stiffeners are left open near the gap, and the third support frame supports them at the open space.

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