An integrated structure of carbon rotary kiln air nozzle and lining and construction method

Abstract

The invention discloses an integrated structure of a carbon rotary kiln air nozzle and an inner lining and a construction method. The integrated structure consists of a kiln body, a kiln inner lining, an outer air duct, an inner air duct and an air nozzle, wherein the outer air duct is spirally distributed outside the kiln body, and the inner air duct is spirally embedded in the kiln inner lining corresponding to the outer air duct; with the outer air duct close to the kiln head direction as the base point, a hole is opened on the kiln body and welded to the air nozzle along the outer air duct, and after the air nozzle is inserted into the kiln body, it is double-sidedly welded to the kiln body, and the part higher than the kiln inner lining is cast after being connected by a PVC pipe sleeve support form; the air inlet of the air nozzle is on the same curved surface as the surface of the kiln inner lining; the air inlet is connected with the outer air duct and the inner air duct; the inner air duct and the kiln inner lining are cast into one piece at one time. After the air nozzle is improved, the service life is extended and the combustion-supporting effect in the kiln is good; the production stability of the rotary kiln is greatly improved, the operation rate of the rotary kiln is guaranteed; and the natural gas cost and the cost of the air nozzle mid-repair are saved.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal aluminum electrolysis, and in particular to an integrated structure of a carbon rotary kiln air nozzle and an inner lining and a construction method. Background Art

[0002] Since the carbon rotary kiln is in a state of continuous rotation during the production process, under high temperature and continuous operation, the bottom layer of lightweight insulation material of the rotary kiln lining is easy to loosen in long-term operation, and scatters from the construction joints of heavy castables and is washed out, resulting in the phenomenon of excessive temperature of the local kiln skin. The tuyere castable is at an external high temperature of 1300℃, internal ventilation and dynamic operation conditions, resulting in a large temperature difference between the inside and outside of the stainless steel tuyere barrel wall, and the castable is very easy to crack. Once cracks appear, small and red-hot carbon particles will enter the cracks, melt the castable and oxidize the tuyere anchors, causing the tuyere castable to fall off.

[0003] In view of the above situation, the applicant optimized and improved the original linear arrangement of the nozzle duct to a "Z" type duct arrangement, and the number of nozzles was optimized from 12 to 8 (4 for the secondary and tertiary air nozzles), and the PVC pipe was used for the mold, and the front end of the rotary kiln nozzle was cast in a rectangular boss shape. However, during the calcination process of the rectangular boss, as the rotary kiln rotates, the nozzle passes through the material, and part of the material accumulates on the front end surface. After the nozzle rotates to a height of more than 45°, the accumulated material falls downward. During the material falling process, it is completely exposed to the high-temperature calcination atmosphere, resulting in excessive calcination of the material and increased burn loss.

[0004] In this regard, according to the actual operation of the rotary kiln tuyere, the second and third rectangular end tuyere of the rotary kiln were improved again, and the rectangular boss cast on the front end of the tuyere was improved to a conical end casting shape. However, after the modification, the conical end casting shape will partially or completely fall off within 6 months of actual use. When the conical end casting shape partially falls off, the root of the tuyere and the air duct will turn red, and the rotary kiln needs to stop feeding, keep warm, and perform temporary blocking. When the conical end casting shape falls off completely, the kiln skin at the falling part will turn red, resulting in unplanned shutdown of the rotary kiln, resulting in a large amount of natural gas consumption, and affecting the output of calcined coke.

[0005] Therefore, in view of the above technical problems, it is very necessary to optimize and improve the rectangular end-face bulge-type tuyere of the rotary kiln's secondary and tertiary air according to the actual operating conditions of the rotary kiln tuyere. Summary of the invention

[0006] In order to solve the problem that the service life of the drum-type tuyere of the rotary kiln using the original construction process is short and has a great impact on the normal production of the rotary kiln, based on the principle of reducing the height and volume of the tuyere as much as possible and lengthening the annular length of the air duct, the present invention provides an integrated structure of a carbon rotary kiln tuyere and a liner and a construction method.

[0007] The present invention discloses an integrated structure of a carbon rotary kiln air nozzle and an inner lining, the integrated structure consists of a kiln body 1, a kiln inner lining 2, an outer air duct 31, an inner air duct 32 and an air nozzle 4, wherein the outer air duct 31 is spirally distributed outside the kiln body, and the inner air duct 32 is spirally embedded in the kiln inner lining 2 corresponding to the outer air duct 31; there are multiple air nozzles 4, with the outer air duct 31 close to the head direction of the kiln body 1 as the base point, and the air nozzles 4 are opened and welded on the kiln body 1 along the outer air duct 31, and the angles between the air nozzles 4 are 30°; after the air nozzle 4 is inserted into the kiln body 1, it is welded to the kiln body 1 on both sides, and the part higher than the kiln inner lining 2 is cast after being sleeved with a PVC pipe sleeve supporting formwork to form an air inlet of the air nozzle 4; the air inlet and the surface of the kiln inner lining 2 are on the same curved surface; the air inlet is connected with the outer air duct 31 and the inner air duct 32; the inner air duct 32 and the kiln inner lining 2 are cast into one piece at one time.

[0008] Furthermore, the inner air duct 32 is made of PVC tube.

[0009] Furthermore, the number of the air nozzles 4 is 8, with 4 each at the secondary and tertiary air positions of the rotary kiln. The longitudinal distance between the air nozzles 4 is 1200 mm, and the lateral distance is 680 mm.

[0010] Furthermore, the external air duct 31 is made of a Φ133×4mm seamless steel pipe with a curvature of R1820mm and a length of 6000mm, and is connected to the air inlet with a flange.

[0011] Furthermore, the tuyere 4 is inserted into the kiln body 1 by a Φ133×6mm seamless steel pipe, and the portion higher than the kiln body lining 2 is 300mm.

[0012] Furthermore, the PVC pipe sleeve formwork can also be replaced by wood or steel plate, and the inner wall of the PVC pipe sleeve formwork or the inner side of the wood or steel plate can be coated with oil or a release agent before pouring.

[0013] The above-mentioned construction method of the integrated structure of the carbon rotary kiln air nozzle and the lining includes the following steps:

[0014] Step 1, arrangement of external air duct and air nozzle: make a Φ133×4mm seamless steel pipe into an arc-shaped steel pipe with an arc of R1820mm and a length of 6000mm, and fix it spirally outside the kiln body 1; then take the external air duct 31 close to the head direction of the kiln body 1 as the base point, open holes and weld air nozzles 4 on the kiln body 1 along the external air duct 31, and the angle between the air nozzles 4 is 30°; insert the air nozzle 4 made of Φ133×6mm seamless steel pipe into the kiln body 1 and weld it to the kiln body 1 on both sides, the part higher than the inner lining 2 of the kiln body is 300mm, and cast the air inlet of the air nozzle 4 after the PVC pipe sleeve formwork is connected, so that the air inlet and the surface of the kiln body lining 2 are on the same curved surface; among them, the number of air nozzles 4 is 8, and the secondary and tertiary air positions of the rotary kiln are 4 each, and the longitudinal distance between the air nozzles 4 is 1200mm, and the lateral distance is 680mm;

[0015] Step 2, arrangement of inner air duct and casting of inner lining: the arrangement of inner air duct 32 is based on the standard of reducing the height and volume of the wind bag and lengthening the annular length of the air duct. The inner air duct 32 adopts PVC pipe. The inner air duct 32 is spirally embedded in the inner lining 2 of the kiln body corresponding to the outer air duct 31, and is cast into one piece with the inner lining 2 of the kiln body at one time, fully vibrated, and connected with the outer air duct 31 through the air inlet of the air nozzle 4;

[0016] Step 3: Check the sealing of the kiln lining and branch pipes: After completing the arrangement of the external air duct, air nozzle, internal air duct and the pouring of the inner lining, open the kiln and check the sealing of the joints until the requirements are met.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The service life of the tuyere is extended and the combustion-supporting effect in the kiln is good.

[0019] (2) After the improvement of the mechanism, the phenomenon of reddening of the kiln skin caused by large-scale shedding of castables at the bulging tuyere was eliminated, thus ensuring the safe operation coefficient of the rotary kiln shell.

[0020] (3) It eliminates the phenomenon of temporarily blocking the tuyere and emergency kiln shutdown due to the falling of cast material from the bulging tuyere, which greatly improves the production stability of the rotary kiln and ensures the operation rate of the rotary kiln.

[0021] (4) It eliminates the unplanned kiln shutdown caused by large-scale shedding of castables from the bulging tuyere, greatly reduces the adverse effects on the kiln lining, and is of great significance for extending the service life of the rotary kiln lining.

[0022] (5) The service life of the tuyere is extended from 1 year to 2 years, which enables the maintenance of the tuyere in sync with the rotary kiln lining. This reduces the maintenance of the tuyere by one time within 2 years, thus saving the cost of natural gas and the cost of maintenance of the tuyere. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the integrated structure of the rotary kiln tuyere and lining of the present invention;

[0024] Figure 2 It is a schematic diagram of the external branch pipe arrangement structure of the present invention.

[0025] In the figure: 1. kiln body; 2. kiln lining; 31. external air duct; 32. internal air duct; 4. air nozzle; Figure 1 The middle arrow indicates the kiln body rotation direction. Figure 2 The middle arrow indicates the direction of the kiln head. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] Please refer to the attached Figure 1 and attached Figure 2 The present invention provides an integrated structure of a carbon rotary kiln air nozzle and an inner lining, the integrated structure consists of a kiln body 1, a kiln inner lining 2, an outer air duct 31, an inner air duct 32 and an air nozzle 4, wherein the outer air duct 31 is spirally distributed outside the kiln body, and the inner air duct 32 is spirally embedded in the kiln inner lining 2 corresponding to the outer air duct 31; there are multiple air nozzles 4, with the outer air duct 31 close to the head direction of the kiln body 1 as the base point, and the air nozzles 4 are opened and welded on the kiln body 1 along the outer air duct 31, and the angles between the air nozzles 4 are 30°; after the air nozzle 4 is inserted into the kiln body 1, it is welded to the kiln body 1 on both sides, and the part higher than the kiln inner lining 2 is cast after being sleeved with a PVC pipe sleeve supporting formwork; the air inlet of the air nozzle 4 is on the same curved surface as the surface of the kiln inner lining 2; the air inlet is connected with the outer air duct 31 and the inner air duct 32; the inner air duct 32 and the kiln inner lining 2 are cast into one piece at one time.

[0029] Preferably, the inner air duct 32 is a PVC tube.

[0030] Preferably, the number of the air nozzles 4 is 8, with 4 each at the secondary and tertiary air positions of the rotary kiln, and the longitudinal distance between the air nozzles 4 is 1200 mm and the lateral distance is 680 mm.

[0031] Preferably, the external air duct 31 is made of a Φ133×4mm seamless steel pipe with a manufacturing curvature of R1820mm and a length of 6000mm, and is connected to the air inlet with a flange.

[0032] Preferably, the tuyere 4 is inserted into the kiln body 1 by a Φ133×6mm seamless steel pipe, and the portion higher than the kiln inner lining 2 is 300mm.

[0033] Preferably, the PVC pipe sleeve formwork can also be replaced by wood or steel plate, and the inner wall of the PVC pipe sleeve formwork or the inner side of the wood or steel plate is coated with oil or a release agent before pouring.

[0034] Due to the optimization and improvement of the secondary and tertiary air nozzles and air duct layout of the rotary kiln, the secondary and tertiary air nozzles of the rotary kiln are arranged in a spiral shape along the circumference of the rotary kiln instead of in a straight line along the axial direction of the rotary kiln. The improved air nozzles are arranged in a spiral shape, and the directions of the air nozzles and the airflow are different. Combining the influence of these two aspects, the disturbance of the airflow in the kiln by the combustion-supporting air is significantly enhanced, the mixing of the combustion-supporting air and the combustible components in the kiln is more rapid and sufficient, and the adjustment and change of the temperature in the kiln are more sensitive. The rotary kiln bulge-type air nozzle is improved to a non-bulge-type air nozzle, which is of great significance to the safe and stable operation of the rotary kiln and the extension of the life of the kiln lining, and eliminates the loss caused by the unplanned shutdown of the rotary kiln due to the falling of the air nozzle castable.

[0035] Example 2

[0036] A construction method for an integrated structure of a carbon rotary kiln air nozzle and an inner lining. Specifically comprising the following steps:

[0037] Step 1, arrangement of external air duct and air nozzle: make a Φ133×4mm seamless steel pipe into an arc-shaped steel pipe with an arc of R1820mm and a length of 6000mm, and fix it spirally outside the kiln body 1; then take the external air duct 31 close to the head direction of the kiln body 1 as the base point, open holes and weld air nozzles 4 on the kiln body 1 along the external air duct 31, and the angle between the air nozzles 4 is 30°; insert the air nozzle 4 made of Φ133×6mm seamless steel pipe into the kiln body 1 and weld it to the kiln body 1 on both sides, the part higher than the inner lining 2 of the kiln body is 300mm, and cast the air inlet of the air nozzle 4 after the PVC pipe sleeve formwork is connected, so that the air inlet and the surface of the kiln body lining 2 are on the same curved surface; among them, the number of air nozzles 4 is 8, and the secondary and tertiary air positions of the rotary kiln are 4 each, and the longitudinal distance between the air nozzles 4 is 1200mm, and the lateral distance is 680mm;

[0038] Step 2, arrangement of inner air duct and casting of inner lining: the arrangement of inner air duct 32 is based on the standard of reducing the height and volume of the wind bag and lengthening the annular length of the air duct. The inner air duct 32 adopts PVC pipe. The inner air duct 32 is spirally embedded in the inner lining 2 of the kiln body corresponding to the outer air duct 31, and is cast into one piece with the inner lining 2 of the kiln body at one time, fully vibrated, and connected with the outer air duct 31 through the air inlet of the air nozzle 4;

[0039] Step 3: Check the sealing of the kiln lining and branch pipes: After completing the arrangement of the external air duct, air nozzle, internal air duct and the pouring of the inner lining, open the kiln and check the sealing of the joints until the requirements are met.

[0040] Although 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 appended claims and their equivalents.

Claims

1. An integrated structure of a carbon rotary kiln air nozzle and an inner lining, the integrated structure comprising a kiln body (1), a kiln inner lining (2), an outer air duct (31), an inner air duct (32) and an air nozzle (4), characterized in that: The outer air duct (31) is spirally distributed outside the kiln body, and the inner air duct (32) is spirally embedded in the kiln body lining (2) corresponding to the outer air duct (31); there are a plurality of air nozzles (4), with the outer air duct (31) close to the head direction of the kiln body (1) as the base point, and the air nozzles (4) are opened and welded on the kiln body (1) along the outer air duct (31), and the angle between the air nozzles (4) is 30°; after the air nozzles (4) are inserted into the kiln body (1), they are welded to the kiln body (1) on both sides, and the part protruding from the kiln body lining (2) is cast after being sleeved with a PVC pipe sleeve support formwork to form an air inlet of the air nozzle (4); the air inlet is on the same curved surface as the surface of the kiln body lining (2); the air inlet is connected to the outer air duct (31) and the inner air duct (32); the inner air duct (32) and the kiln body lining (2) are cast into one piece at one time.

2. The integrated structure of the carbon rotary kiln tuyere and lining according to claim 1 is characterized in that: The inner air duct (32) is a PVC tube.

3. The integrated structure of the carbon rotary kiln tuyere and lining according to claim 1 is characterized in that: The external air duct (31) is made of a Φ133×4mm seamless steel pipe with a curvature of R1820mm and a length of 6000mm, and is connected to the air inlet with a flange.

4. The integrated structure of the carbon rotary kiln tuyere and lining according to claim 1 is characterized in that: The number of the air nozzles (4) is 8, with 4 each at the secondary and tertiary air positions of the rotary kiln; the longitudinal distance between the air nozzles (4) is 1200 mm, and the lateral distance between the air nozzles (4) is 680 mm.

5. The integrated structure of the carbon rotary kiln tuyere and lining according to claim 1 or 4, characterized in that: The tuyere (4) is inserted into the kiln body 1 using a Φ133×6mm seamless steel pipe, with the portion protruding from the kiln body lining (2) being 300mm.

6. The integrated structure of the carbon rotary kiln tuyere and lining according to claim 1 is characterized in that: The PVC pipe sleeve formwork can also be replaced by wood or steel plate. Before pouring, the inner wall of the PVC pipe sleeve formwork or the inner side of the wood or steel plate is coated with oil or a release agent.

7. A construction method for an integrated structure of a carbon rotary kiln air nozzle and an inner lining, characterized in that: The specific steps include: Step 1: Arrangement of the external air duct and air nozzle: a Φ133×4mm seamless steel pipe is made into an arc-shaped steel pipe with an arc of R1820mm and a length of 6000mm, and is spirally fixed to the outside of the kiln body (1); then, with the external air duct (31) close to the head direction of the kiln body (1) as the base point, holes are opened on the kiln body (1) along the external air duct (31) to weld air nozzles (4), and the angle between the air nozzles (4) is 30°; a Φ133×6mm seamless steel pipe is used to form a circular arc-shaped steel pipe with an arc of R1820mm and a length of 6000mm, and is spirally fixed to the outside of the kiln body (1); then, with the external air duct (31) close to the head direction of the kiln body (1) as the base point, air nozzles (4) are welded on the kiln body (1) along the external air duct (31), and the angle between the air nozzles (4) is 30°; After the air nozzle (4) of the pipe is inserted into the kiln body (1), it is double-sidedly welded to the kiln body (1), and the portion protruding from the kiln body lining (2) is 300 mm. The air inlet of the air nozzle (4) is formed by casting after being sleeved with a PVC pipe sleeve supporting formwork, so that the air inlet and the surface of the kiln body lining (2) are on the same curved surface; wherein, the number of the air nozzles (4) is 8, and the second and third air positions of the rotary kiln are 4 each, and the longitudinal distance between the air nozzles (4) is 1200 mm, and the lateral distance is 680 mm; Step 2: Arrangement of the inner air duct and casting of the inner lining: The arrangement of the inner air duct (32) is based on the standard of reducing the height and volume of the wind bag and lengthening the annular length of the air duct. The inner air duct (32) is made of PVC pipe. The inner air duct (32) is spirally embedded in the kiln body lining (2) corresponding to the outer air duct (31), and is cast into one piece with the kiln body lining (2) at one time, fully vibrated, and connected with the outer air duct (31) through the air inlet of the air nozzle (4); Step three, check the sealing of the kiln lining and branch pipes: after completing the arrangement of the external air duct, air nozzle, internal air duct and the pouring of the inner lining, open the kiln and check the sealing of the joints until the requirements are met.

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