A method of welding the internal structure of an external combustion kiln

Abstract

The present application relates to a welding method of the internal structure of an external combustion kiln, and relates to the field of welding, which is used for welding a plurality of reinforcing ribs in a ring shape at intervals in a columnar kiln body, the length direction of the reinforcing ribs is the same as the length direction of the kiln body, the cross section of the reinforcing ribs is L-shaped, rectangular, I-shaped, triangular or T-shaped, the present application has the advantages that the reinforcing ribs can be stably and accurately welded with large length, the reinforcing ribs can stably support the structure of the kiln body, and can play a stirring role when calcining mineral materials.

Description

Technical Field

[0001] This invention relates to the field of rotary kiln technology, and more particularly to a welding method for the internal structure of an external combustion kiln. Background Technology

[0002] A rotary kiln, also known as a rotating calcining kiln, is a thermal processing device that performs high-temperature heat treatment on raw materials within a rotating cylinder. The raw materials, installed at an incline, are propelled from the high end (kiln tail) to the low end (kiln head) by gravity and the rotation of the cylinder. Fuel is fed into the cylinder from the low end for combustion, and the resulting flue gas flows upwards, causing the flue gas and raw materials to move in opposite directions. During this high-temperature flue gas flow, heat exchange occurs between the flue gas and the raw materials, achieving calcination. An externally combusted rotary kiln consists of an outer furnace connected to the rotary kiln, where burners are installed to heat the outer wall of the rotary kiln. Because multiple burners can be spaced along the length of the rotary kiln, externally combusted rotary kilns ensure uniform heating throughout the kiln, resulting in a very high degree of calcination of the raw materials.

[0003] Because conventional external combustion kilns have lower requirements for calcination efficiency, their length is relatively short, resulting in a shorter raw material flow distance and reduced calcination efficiency. Insufficient calcination often occurs. Extending the external combustion kiln, due to its excessive length and exposure to high temperatures, requires rotation, which can easily cause a "twisting" problem, leading to the scrapping of the entire external combustion kiln.

[0004] Therefore, to address the above shortcomings, a welding method for the internal structure of an external combustion kiln is needed. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The technical problem to be solved by this invention is to address the issue of low structural strength in extended rotary kilns.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, this invention provides a welding method for the internal structure of an external combustion kiln, comprising the following steps:

[0009] Ⅰ. Install a tail fixing frame on one side of the kiln body, and insert reinforcing ribs on the tail fixing frame according to the original design. The tail fixing frame is located at one end of the reinforcing rib.

[0010] II. A head fixing frame is installed at the other end of the reinforcing rib, and the head fixing frame abuts against the reinforcing rib to ensure that the arrangement of each reinforcing rib is the same as the original design;

[0011] Ⅲ. The kiln body is placed in the installation area by means of gantry crane hoisting. Then, the first and last fixing frames with the arranged reinforcing ribs are hoisted to one side of the kiln body by gantry crane. The first and last fixing frames are lowered until the track wheel at the bottom of the last fixing frame abuts the track. Then, the reinforcing ribs are pulled into the kiln body by gantry crane and the last fixing frame abuts the kiln body port.

[0012] IV. A support frame is placed in the middle of the kiln body. The support frame extends into the kiln body from the middle hole of the tail fixing frame. The support frame extends to abut the reinforcing rib against the inner wall of the kiln body.

[0013] V. Weld the reinforcing ribs. After welding, remove the head and tail fixing frames, and finally remove the support frame to complete the stable welding of the internal structure of the kiln.

[0014] As a further explanation of the present invention, preferably, the reinforcing ribs can also be a rhomboid mesh structure.

[0015] As a further explanation of the present invention, preferably, the tail fixing frame includes an abutment ring and a receiving ring. Both the abutment ring and the receiving ring are annular structures with inner diameters smaller than the inner diameter of the kiln body. The outer diameter of the abutment ring is larger than the outer diameter of the kiln body, and the outer diameter of the receiving ring is smaller than the inner diameter of the kiln body. An annular groove is formed on the outer wall of the receiving ring, and an annular plaster mold is cast in the annular groove. Reinforcing ribs are embedded in the plaster mold.

[0016] As a further explanation of the present invention, preferably, before welding the reinforcing ribs, the tail fixing frame is first placed flat on the ground, and a ring with the same inner diameter as the kiln body is formed around the outside of the annular groove using wooden boards. Then, the reinforcing ribs are placed in the space between the ring and the annular groove according to the design position. The prepared gypsum slurry is poured into the space between the ring and the annular groove, and the welding of the reinforcing ribs begins after the gypsum has solidified.

[0017] As a further explanation of the present invention, preferably, after the wooden board is used to form a ring, a mold with the same cross-sectional shape as the reinforcing rib but with a larger outer diameter can be placed in the space, and then plaster can be used for casting. After the plaster solidifies, the mold is removed, so that the solidified plaster forms a plaster mold. Finally, the reinforcing rib is embedded in the plaster mold and welded.

[0018] As a further explanation of the present invention, preferably, the head fixing frame is circular, and a positioning sleeve is provided on the outer arc surface of the head fixing frame. The positioning sleeve is made of plaster, and reinforcing ribs are embedded in the positioning sleeve.

[0019] As a further explanation of the present invention, preferably, the positioning sleeve covers the local reinforcing rib structure.

[0020] As a further explanation of the present invention, preferably, the support frame includes a main ring, threaded rods, a push plate and a limiting nut. The main ring is a circular ring with an outer diameter smaller than the inner diameter of the tail fixing frame. Several threaded rods are slidably connected to the outer wall of the main ring in a divergent manner. The push plate is an arc-shaped plate with an outer diameter equal to the inner diameter of the reinforcing rib distribution. The inner end face of the push plate is fixedly connected to the threaded rods. The limiting nut is threadedly connected to the outside of the threaded rods and abuts against the outer wall surface of the main ring.

[0021] By pushing the threaded rod out of the main ring, the push plate abuts against the reinforcing rib. The threaded rod continues to be pushed out until the reinforcing rib abuts against the inner wall of the kiln. Finally, the limit nut is screwed to abut against the outer wall of the main ring to fix the threaded rod, thereby enabling the reinforcing rib to abut against the inner wall of the kiln stably.

[0022] As a further explanation of the present invention, preferably, after the reinforcing ribs are welded, the positioning sleeve can be broken to remove the head estimation frame, and then the plaster mold can be cracked or broken by tapping the inner wall of the receiving ring before the tail fixing frame can be removed.

[0023] (III) Beneficial Effects

[0024] The above-described technical solution of the present invention has the following advantages:

[0025] This invention improves the structural strength of a rotary kiln by accurately and quickly welding long reinforcing ribs at designed locations within the kiln. This allows the extended rotary kiln to operate stably, ensuring a longer calcination time for the material. Furthermore, the reinforcing ribs can also stir the raw materials during rotation, resulting in more complete calcination and improved calcination efficiency. Attached Figure Description

[0026] Figure 1 This is a front view of the welding state of the present invention;

[0027] Figure 2 This is a rear view of the welding state of the present invention;

[0028] Figure 3 This is a structural diagram of the first fixing frame of the present invention;

[0029] Figure 4 yes Figure 3 Enlarged view of A in the middle;

[0030] Figure 5 This is a cross-sectional view of the present invention;

[0031] Figure 6 This is a structural diagram of the support frame of the present invention;

[0032] Figure 7 This is a structural diagram of the sheet-like reinforcing rib of the present invention;

[0033] Figure 8This is a structural diagram of the I-shaped reinforcing rib of the present invention;

[0034] Figure 9 This is a structural diagram of the V-shaped reinforcing rib of the present invention;

[0035] Figure 10 This is a structural diagram of the T-shaped reinforcing rib of the present invention;

[0036] Figure 11 This is a structural diagram of the mesh reinforcing ribs of the present invention.

[0037] In the diagram: 1. Kiln body; 11. Reinforcing rib; 2. Tail fixing frame; 21. Abutment ring; 22. Receiving ring; 23. Plaster mold; 24. Lifting ring; 25. Track wheel; 3. Head fixing frame; 31. Support rod; 32. Positioning sleeve; 33. Lifting column; 34. Steel wire; 4. Support frame; 41. Main ring; 42. Threaded rod; 43. Push plate; 44. Limit nut. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] An external combustion kiln internal structure, combined with Figure 3 , Figures 7-11 Several reinforcing ribs 11 are welded in a ring at intervals inside the columnar kiln body 1. The length direction of the reinforcing ribs 11 is the same as that of the kiln body 1, and the cross-section of the reinforcing ribs 11 is L-shaped, rectangular, I-shaped, triangular, or T-shaped. The reinforcing ribs 11 can also be a rhomboid mesh structure. By setting the above-mentioned reinforcing rib structure 11, the structural strength of the extended kiln body 1 can be improved, and the deformation rate of the kiln body 1 is almost zero under high-temperature calcination. Moreover, during the calcination process, the reinforcing ribs 11 can also stir the materials, allowing the bottom material to decompose at high temperature. Combined with the longer calcination time, the raw materials can react fully, avoiding waste.

[0040] Since the length of the reinforcing rib 11 is basically the same as the length of the extended kiln body 1, the traditional method of welding each rib individually is labor-intensive, and it is also difficult to ensure that the distribution of each reinforcing rib 11 is uniform. Therefore, this invention also provides a welding method for the internal structure of an external combustion kiln, which involves a welding mold, including a tail fixing frame 2, a head fixing frame 3, and a support frame 4.

[0041] Combination Figure 2 , Figure 5The tail support frame 2 includes an abutment ring 21 and a support ring 22. Both the abutment ring 21 and the support ring 22 are annular structures with inner diameters smaller than the inner diameter of the kiln body 1. If the kiln body 1 has a large diameter, steel abutment rings 21 and 22 can be used. If the diameter is small, epoxy resin abutment rings 21 and 22 can be used, which are low in cost and have high structural hardness and strength. They can be used to support the steel reinforcing ribs 11, and the annular design effectively reduces the weight of the tail support frame 2, facilitating hoisting and transportation. The outer diameter of the abutment ring 21 is larger than the outer diameter of the kiln body 1, and the outer diameter of the support ring 22 is smaller than the inner diameter of the kiln body 1. An annular groove is formed on the outer wall of the support ring 22, and an annular plaster mold 23 is cast in the annular groove. The outer diameter of the plaster mold 23 is larger than the outer diameter of the support ring 22, and one end of the reinforcing rib 11 can be embedded in the plaster mold 23. A lifting ring 24 is fixed to the top of the abutment ring 21 for easy hooking by the gantry crane. The bottom of the abutment ring 21 is rotatably connected to the track wheel 25. During welding, the cooperation of the track and the gantry crane prevents the tail fixing frame 2 from swaying, ensuring that the reinforcing rib 11 can smoothly enter the kiln body 1.

[0042] Combination Figure 3 , Figure 5 The head fixing frame 3 is a steel ring. A cross-shaped support rod 31 is fixed to the middle of the head fixing frame 3 to support the head fixing frame 3, which has a large outer diameter but a thin wall thickness, thereby improving the structural strength of the head fixing frame 3. A positioning sleeve 32 is provided on the outer arc surface of the head fixing frame 3. The positioning sleeve 32 is made of plaster, and the other end of the reinforcing rib 11 is embedded in the positioning sleeve 32. The positioning sleeve 32 covers part of the reinforcing rib 11 structure, which can fix the position of the reinforcing rib 11 by the hardness of the plaster and the tail fixing frame 2, and facilitates the disassembly and separation of the head fixing frame 3 and the reinforcing rib 11 later. A columnar hoisting column 33 is fixed to the middle of the support rod 31. The hoisting column 33 extends out of the head fixing frame 3, so that the steel rope of the gantry crane can be tied to the hoisting column 33 to hoist the head fixing frame 3.

[0043] Combination Figure 5 , Figure 6 The support frame 4 includes a main ring 41, threaded rods 42, a push plate 43, and a limiting nut 44. The main ring 41 is a circular ring with an outer diameter smaller than the inner diameter of the tail fixing frame 2. Several threaded rods 42 are slidably connected to the outer wall of the main ring 41 in a divergent manner. The push plate 43 is an arc-shaped plate with an outer diameter equal to the inner diameter of the reinforcing ribs 11. The inner end face of the push plate 43 is fixedly connected to the threaded rods 42. The limiting nut 44 is threaded to the outside of the threaded rods 42 and abuts against the outer wall of the main ring 41. The support frame 4 is designed to prevent the middle part of the reinforcing ribs 11 from bending downward under gravity and to ensure that the middle part of the reinforcing ribs 11 located at the top can also abut against the kiln body 1, facilitating subsequent welding and installation.

[0044] The welding method for stiffener 11 includes the following steps:

[0045] Ⅰ. A tail fixing frame 2 is installed on one side of the kiln body 1. Reinforcing ribs 11 are inserted into the tail fixing frame 2 according to the original design. The tail fixing frame 2 is located at one end of the reinforcing rib 11.

[0046] II. A head fixing frame 3 is installed at the other end of the reinforcing rib 11, and the head fixing frame 3 abuts against the reinforcing rib 11 so that the arrangement of each reinforcing rib 11 is the same as the original design;

[0047] Ⅲ. The kiln body 1 is placed in the installation area by means of gantry crane hoisting. Then, the head fixing frame 3 and the tail fixing frame 2 with the arranged reinforcing ribs 11 are hoisted to one side of the kiln body 1 by gantry crane. The head fixing frame 3 and the tail fixing frame 2 are lowered until the track wheel 25 at the bottom of the tail fixing frame 2 abuts against the track. Then, the steel wire on the gantry crane is tied to the hoisting column 33. The tail fixing frame 2 is pushed to pull the reinforcing ribs 11 into the kiln body 1 and make the tail fixing frame 2 abut against the end of the kiln body 1.

[0048] IV. A support frame 4 is placed in the middle of the kiln body 1. The support frame 4 extends into the kiln body 1 through the hole in the middle of the tail fixing frame 2. Then, the threaded rod 42 is pushed out from the main ring 41 so that the push plate 43 abuts against the reinforcing rib 11. The threaded rod 42 continues to be pushed out until the reinforcing rib 11 abuts against the inner wall of the kiln body 1. Finally, the limiting nut 44 is screwed to abut against the outer wall of the main ring 41 to fix the threaded rod 42, thereby enabling the reinforcing rib 11 to abut against the inner wall of the kiln body 1 stably. The reinforcing rib 11 is abutted against the inner wall of the kiln body 1 by the extension of the support frame 4.

[0049] V. Weld the reinforcing ribs 11. After welding, remove the head fixing frame 3 and the tail fixing frame 2. Finally, remove the support frame 4 to complete the stable welding of the internal structure of the kiln body 1.

[0050] Before welding the reinforcing ribs 11, the tail support frame 2 is placed flat on the ground. A ring with the same inner diameter as the kiln body 1 is formed around the outside of the annular groove using wooden boards. Then, the reinforcing ribs 11 are placed in the space between the ring and the annular groove according to the design position. The prepared gypsum slurry is poured into the space between the ring and the annular groove. After the gypsum solidifies, welding of the reinforcing ribs 11 begins. By adopting the above method, the tail support frame 2 can position and support reinforcing ribs 11 with different cross-sectional shapes, eliminating the need for manual support and welding of each rib individually, and eliminating the need to manufacture various molds to adapt to reinforcing ribs 1 with different cross-sections, greatly reducing labor and material costs.

[0051] Furthermore, to further reduce welding difficulty, after forming a ring with wooden boards, a mold with the same cross-sectional shape as the reinforcing rib 11 but a slightly larger outer diameter can be placed in the space. Plaster is then poured, and after the plaster solidifies, the mold is removed. The mold leaves a concave shape in the solidified plaster, forming a plaster mold 23. Finally, the reinforcing rib 11 is embedded in the concave shape of the plaster mold 23 for welding. This method eliminates the need to hoist and arrange the reinforcing rib 11, saving manpower. It also avoids the problem of the reinforcing rib 11 being too long and prone to swaying, which could lead to inaccurate positioning or ensure parallelism in the length direction of the reinforcing ribs.

[0052] The forming method of the positioning sleeve 32 on the first fixing frame 3 is the same as that of the plaster mold 23. Preferably, the mold is poured first, then removed, and then the reinforcing rib 11 is welded. Furthermore, when placing one end of the reinforcing rib 11 at the positioning sleeve 32, plaster should be poured into the concave mold of the positioning sleeve 32 to stably fix the reinforcing rib 11 in place. To prevent the reinforcing rib 11 from loosening, steel wire 34 needs to be tied to the reinforcing rib 11 around the positioning sleeve 32 to prevent the reinforcing rib 11 at the bottom of the positioning sleeve 32 from detaching from the positioning sleeve 32 under gravity during hoisting. Moreover, to further facilitate welding and disassembly, the length of the reinforcing rib 11 should be greater than the length of the kiln body 1. After welding, the excess portion can be cut off.

[0053] After the reinforcing rib 11 is welded, the positioning sleeve 32 can be broken to remove the head fixing frame 3. Then, the plaster mold can be cracked or broken by tapping the inner wall of the receiving ring 22, and the tail fixing frame 2 can be removed. The broken plaster can be used for road paving or factory construction to avoid waste. The tail fixing frame 2 and the head fixing frame 3 can be reused to save costs.

[0054] In summary, the welding molds and methods described above significantly reduce the workload and difficulty for welding workers. Furthermore, the number of workers required to weld one kiln body can be reduced from 15 people working in shifts to just 4. The welding time can also be shortened from over a month to nearly half a month, making it highly practical.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of welding the internal structure of an external combustion kiln, characterized by: Comprising the following steps, I. A tail fixed frame (2) is erected on one side of the kiln body (1), and the reinforcing ribs (11) are arranged according to the original design on the tail fixed frame (2), the cross section of the reinforcing rib (11) is L-shaped, rectangular, I-shaped, triangular or T-shaped, the length direction of the reinforcing rib (11) is the same as the length direction of the kiln body (1), and the tail fixed frame (2) is located at one end of the reinforcing rib (11); II. A head fixed frame (3) is erected at the other end of the reinforcing rib (11), and the head fixed frame (3) and the reinforcing rib (11) are in abutment to make the arrangement position of each reinforcing rib (11) the same as the original design; III. The kiln body (1) is placed in the installation area by the gantry crane lifting mode, the head fixed frame (3) and the tail fixed frame (2) with the arranged reinforcing rib (11) are lifted to one side of the kiln body (1) by the gantry crane, the head fixed frame (3) and the tail fixed frame (2) are lowered until the track wheel (25) at the bottom of the tail fixed frame (2) is in abutment with the track, then the reinforcing rib (11) is pulled into the kiln body (1) by the gantry crane, and the tail fixed frame (2) is in abutment with the port of the kiln body (1); IV. A support frame (4) is placed in the middle of the kiln body (1), the support frame (4) extends into the kiln body (1) from the middle hollow of the tail fixed frame (2), and the support frame (4) extends to abut the reinforcing rib (1) on the inner wall of the kiln body (1); V. The reinforcing rib (11) is welded, the head fixed frame (3) and the tail fixed frame (4) are removed after welding is completed, and finally the support frame (4) is removed, and the stable welding of the internal structure of the kiln body (1) is completed.

2. A method of welding the internal structure of an external combustion kiln according to claim 1, characterized in that: The tail fixed frame (2) comprises an abutment ring (21) and a receiving ring (22), both the abutment ring (21) and the receiving ring (22) are annular structures and have an inner diameter smaller than that of the kiln body (1), the outer diameter of the abutment ring (21) is greater than that of the kiln body (1), the outer diameter of the receiving ring (22) is smaller than that of the kiln body (1), an annular groove is formed in the outer wall surface of the receiving ring (22), a ring-shaped gypsum mold (23) is cast in the annular groove, and the reinforcing rib (11) is embedded in the gypsum mold (23).

3. A method of welding the internal structure of an external combustion kiln according to claim 2, characterized in that: Before welding the reinforcing rib (11), the tail fixed frame (2) is placed flat on the ground, a circular ring with the same inner diameter as the kiln body (1) is formed on the outer side of the annular groove by a wooden board, then the reinforcing rib (11) is placed in the space between the circular ring and the annular groove according to the design position, and the adjusted gypsum slurry is poured into the space between the circular ring and the annular groove.

4. A method of welding the internal structure of an external combustion kiln according to claim 3, characterized in that: After the circular ring is formed by the wooden board, a mold with the same cross-sectional shape as the reinforcing rib (11) but a larger outer diameter size can be placed in the space first, then gypsum is used for casting, and after the gypsum solidifies, the mold is removed, so that the solidified gypsum forms the gypsum mold (23).

5. A method of welding the internal structure of an external combustion kiln according to claim 4, characterized in that: The head fixed frame (3) is circular, and a positioning sleeve (32) is arranged on the outer arc surface of the head fixed frame (3), the positioning sleeve (32) is made of gypsum, and the reinforcing rib (11) is embedded in the positioning sleeve (32).

6. A method of welding an internal structure of an external combustion kiln according to claim 5, wherein: The positioning sleeve (32) covers part of the structure of the reinforcing rib (11).

7. A method of welding an internal structure of an external combustion kiln according to claim 6, wherein: The support frame (4) comprises a main ring (41), threaded rods (42), a push plate (43) and a limiting nut (44), the main ring (41) is a circular ring with an outer diameter smaller than the inner diameter of the tail fixed frame (2), a plurality of threaded rods (42) are slidingly connected on the outer wall of the main ring (41) in a diverging manner, the push plate (43) is a circular arc sheet, the outer diameter of the push plate (43) is equal to the inner diameter of the reinforcing rib (11), the inner end surface of the push plate (43) is fixedly connected with the threaded rod (42), and the limiting nut (44) is threadedly connected outside the threaded rod (42) and abuts against the outer wall surface of the main ring (41); The push plate (43) is abutted against the reinforcing rib (11) by pushing the threaded rod (42) out of the main ring (41), the threaded rod (42) is continuously pushed out until the reinforcing rib (11) abuts against the inner wall surface of the kiln body (1), and finally the limiting nut (44) is screwed to abut against the outer wall surface of the main ring (41), so that the threaded rod (42) is fixed, and then the reinforcing rib (11) can be stably abutted against the inner wall surface of the kiln body (1).

8. A method of welding an internal structure of an external combustion kiln according to claim 7, characterized in that: After the reinforcing rib (11) is welded, the positioning sleeve (32) is knocked off, the head fixed frame (3) is removed, the tail fixed frame (2) is removed after the gypsum mold (23) is cracked or broken by knocking the inner wall surface of the supporting ring (22).

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