Zinc extraction rotary kiln head capable of preventing refractory material from falling off and prolonging service life of barrel
By designing annular reinforcement ribs, axial reinforcement ribs and other structures at the kiln head of the zinc rotary kiln, the problems of refractory material falling off and shortened cylinder life were solved, and stable operation and efficient production of the kiln head were achieved.
Patent Information
- Application Number
- CN202510857513.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-09-05
AI Technical Summary
In the rotary kiln process for zinc recycling, high-temperature heat radiation from the kiln head causes refractory materials to fall off, affecting production continuity, increasing costs, and shortening the life of the kiln.
The structural design of annular reinforcement ribs, axial reinforcement ribs, conical jackets, guard plates, annular air cooling pipes and smoke baffles are adopted to enhance the structural strength and heat management of the kiln head shell, prevent the refractory material from falling off and extend the life of the shell.
It improves the stable operation capability of the kiln head, reduces the shedding of refractory materials, prolongs the life of the cylinder, improves the energy utilization efficiency and dust removal efficiency of the rotary kiln, and reduces maintenance costs.
Smart Images
Figure CN120593500A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of zinc-extracting rotary kilns, and in particular relates to a zinc-extracting rotary kiln head with refractory material anti-falling and cylinder life extension. Background Art
[0002] The core principle of the current rotary kiln process for zinc recovery is to thoroughly mix carbonaceous materials with zinc-containing materials such as bag ash, fine ash, and trough ash. The mixture is then roasted at high temperatures to volatilize the zinc in the dust and re-enrich it for recovery. The kiln head area, the core high-temperature calcination zone of the entire process, maintains an operating temperature of 1050±50°C year-round.
[0003] Traditional zinc kiln head drums typically utilize a straight-cylinder design. During long-term, high-temperature operation, the drum is inevitably subjected to intense heat radiation reaching 1000°C, which gradually causes plastic deformation. This deformation not only alters the drum's original shape but, more critically, significantly weakens the previously tight bond between the refractory material and the drum. As the rotary kiln rotates continuously, the bond between the refractory material and the drum gradually loosens during dynamic operation, forming gaps of varying sizes.
[0004] Thermal radiation penetrates deeply into the core of the refractory material through these newly created voids. The anchor hooks, the key support structure for the refractory material, bear the brunt of the intense thermal radiation at their roots, and over time, they may even break. Once the anchor hooks are damaged and fail, the refractory material loses its foundation for stability, inevitably leading to its fall from the kiln head.
[0005] If the refractory material falls off and is not promptly detected and addressed, the kiln head cylinder will be directly exposed to the harsh environment of high temperature and high corrosion, and its surface will rapidly oxidize. Under the continuous combined effects of multiple negative factors such as thermal stress, gravity, and oxidative corrosion, the degree of plastic deformation of the cylinder will rapidly intensify, eventually forming an irregular opening shape similar to the mouth of a bell, causing the cylinder to lose its basic functional properties. This process not only significantly shortens the expected service life of the kiln head cylinder, but also inevitably severely affects production continuity due to the complex and time-consuming operation of cylinder replacement, resulting in a significant increase in production costs and a number of adverse effects on the company's efficient and stable production. Summary of the Invention
[0006] The purpose of the present invention is to provide a zinc extraction rotary kiln head with refractory material anti-falling and cylinder life extension, so as to solve the problems existing in the prior art.
[0007] The technical solution adopted by the present invention to solve its technical problem is:
[0008] A zinc-extracting rotary kiln head with refractory material anti-slip and cylinder life extension comprises a cylinder, an outer cover, a middle cover and an inner cover are arranged on the outside of the cylinder, a necking is fixed at one end of the cylinder, annular reinforcement ribs are welded on the inner walls of the necking, the cylinder and the connection between the cylinder and the necking, a number of axial reinforcement ribs are welded between adjacent annular reinforcement ribs, a number of guard plates are fixed on the outer wall of the connection between the cylinder and the necking, a conical sheath is fixed on the outer wall of the necking, a number of anchor hooks are welded on the inner walls of the necking and the cylinder, an annular air-cooling pipe is arranged on the outside of the cylinder, a number of air outlet holes are opened on the annular air-cooling pipe, the air outlet direction of the air outlet holes is toward the cylinder, and casting material is cast on the inner walls of the cylinder and the necking.
[0009] Furthermore, the necking is welded and fixed to the cylinder, and there are 16 axial reinforcement ribs between adjacent annular reinforcement ribs. The 16 axial reinforcement ribs are distributed in an annular array with the axis of the cylinder as the axis.
[0010] Furthermore, the shape of the guard plate matches the outer wall contour of the cylinder and the necking, and the guard plate is welded and bolted to the outer wall of the cylinder and the necking. There are 16 guard plates, and the 16 guard plates are distributed in a circular array with the axis of the cylinder as the axis.
[0011] Furthermore, the tapered sleeve matches the outer wall profile of the necking, and the tapered sleeve is welded and bolted to the outer wall of the necking.
[0012] Furthermore, a smoke baffle is fixed on the bottom of the inner cover, and two smoke baffles are fixed on the outer wall of the cylinder.
[0013] Furthermore, the smoke baffle at the bottom of the inner cover is located above the cylinder and has a gap with the cylinder. The two smoke baffles on the outer wall of the cylinder are respectively located between the inner cover and the middle cover and outside the middle cover.
[0014] Furthermore, the anchor hook is Y-shaped as a whole, and the bottom end of the anchor hook has a horizontal bend.
[0015] Furthermore, the annular air cooling pipe is connected to an air intake valve.
[0016] The present invention has the following beneficial effects:
[0017] 1. This invention addresses the issue of decreased adhesion between the casting material and the barrel through innovative design of the kiln head barrel structure, including the installation of a kiln head constriction, the use of annular and axial reinforcement ribs, the construction of an annular air-cooling pipe, and a tapered sheath and protective plate. The coordinated effect of the axial and annular reinforcement ribs enhances the overall structural strength of the kiln head, preventing oxidative corrosion and deformation of the barrel and constriction, which are particularly prone to occur in extremely high-temperature operating environments, thereby ensuring the long-term stable operation of the kiln head.
[0018] 2. The necking design can also concentrate the heat in the kiln, so that the kiln always maintains a stable micro-positive pressure state (5Pa±2Pa) during operation, thereby effectively preventing the kiln mouth cylinder from deformation and damage due to concentrated thermal stress. It synergistically ensures the stable operation of the kiln head and the firm adhesion of the casting material from multiple aspects, which is conducive to minimizing the heat loss and exhaust gas overflow, and improving the energy efficiency and environmental performance of the rotary kiln.
[0019] 3. The smoke control system is constructed through the design of the smoke baffle, which can regulate the flow rate and direction of the smoke from the inner cover to the middle cover and then from the middle cover to the outer cover, forming a labyrinth seal for the smoke, thereby improving the dust removal efficiency of the rotary kiln, effectively reducing the emission of dust pollutants in the smoke, and reducing the negative impact on the environment. Moreover, by optimizing the smoke flow state, it further promotes the rational distribution and utilization of heat in the kiln, providing strong support for improving the overall performance of the rotary kiln.
[0020] 4. Forced air cooling of the cylinder through the annular air cooling pipe can effectively reduce the temperature of the outer side of the cylinder in a timely manner, ensuring that the cylinder always maintains good initial rigidity during high-temperature operation, thereby effectively suppressing the risk of excessive deformation of the cylinder caused by high temperature.
[0021] 5. Through synergistic effects from multiple aspects, it can reduce the shedding of refractory materials, extend the life of the cylinder, and thus improve the overall operating efficiency of the rotary kiln, reduce maintenance costs and production downtime, create significant economic and social benefits for the enterprise, and promote the development and progress of zinc rotary kiln technology in the metallurgical field. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 It is a structural schematic diagram of the present invention.
[0023] Figure 2 It is a structural schematic diagram of the cylinder and the necking part of the present invention.
[0024] Figure 3 It is a schematic diagram of the cross-sectional structure of the cylinder and the necked portion (without the anchor hook welded thereto) of the present invention.
[0025] Figure 4 This invention Figure 3 Enlarged structural diagram at point A in the middle.
[0026] Figure 5 It is a schematic diagram of the cross-sectional structure of the cylinder after pouring the pouring material of the present invention.
[0027] Figure 6 This invention Figure 5 Enlarged structural diagram at point B in the middle.
[0028] Figure 7 This is a heat analysis diagram of the kiln head in the prior art.
[0029] Figure 8 This is a heat analysis diagram of the kiln head of the present invention.
[0030] Among them: 1. Cylinder; 2. Narrowing; 3. Annular reinforcement ribs; 4. Axial reinforcement ribs; 5. Guard plate; 6. Conical sleeve; 7. Anchor hook; 8. Annular air cooling pipe; 9. Air outlet; 10. Casting material; 11. Smoke baffle; 12. Inner cover; 13. Outer cover; 14. Middle cover; 15. Inlet valve. DETAILED DESCRIPTION
[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0032] like Figure 1-8 As shown, a zinc extraction rotary kiln head with refractory material to prevent falling off and extend the life of the cylinder includes a cylinder 1 (a steel cylinder with a diameter of φ4580mm, made of Q345B and a wall thickness of 40mm). The outer cover 13, the middle cover 14, and the inner cover 12 are mounted on the outside of the cylinder 1. A gap of 100mm is always maintained between the inner cover and the cylinder 1. A smoke baffle 11 (height 300mm) is fixed to the bottom of the inner cover 12, and two smoke baffles 11 are fixed to the outer wall of the cylinder 1. The smoke baffle 11 at the bottom of the inner cover 12 is located above the cylinder 1 and has a gap between it and the cylinder 1. The two smoke baffles 11 on the outer wall of the cylinder 1 are respectively located between the inner cover 12 and the middle cover 14 and on the outside of the middle cover 14. By designing the smoke baffle 11, a flue gas control system is constructed, which can control the flow rate and direction of the flue gas from the inner cover to the middle cover and then from the middle cover to the outer cover, forming a labyrinth seal for the flue gas, thereby improving the dust removal efficiency of the rotary kiln, effectively reducing the emission of dust pollutants in the flue gas, and reducing the negative impact on the environment. Moreover, by optimizing the flue gas flow state, the rational distribution and utilization of heat in the kiln are further promoted, providing strong support for improving the overall performance of the rotary kiln.
[0033] A necking 2 is welded and fixed at one end of the cylinder 1 (the necking 2 is in the shape of a truncated cone, with a diameter reduced from φ4580mm to φ3900mm and a height of 300mm). Through structural mechanics calculations and simulation analysis, the necking 2 design improves the deformation resistance of the cylinder 1 by more than 22%.
[0034] Annular reinforcement ribs 3 (30mm thick, three in total) are welded to the inner walls of the necking 2, the cylinder 1, and the connection between the cylinder 1 and the necking 2. Several axial reinforcement ribs 4 (30mm thick, 16 axial reinforcement ribs 4 distributed in a circular array with the axis of the cylinder 1 as the axis) are welded between adjacent annular reinforcement ribs 3. This increases the deflection of the cylinder 1 when heated at high temperatures, enhances the overall thermal deformation resistance of the cylinder 1 and the necking 2, and improves the problem of easily reduced adhesion between the casting material 10 and the cylinder 1. The coordinated effect of the axial reinforcement ribs 4 and the annular reinforcement ribs 3 improves the overall structural strength of the kiln mouth, and can prevent the oxidation corrosion and deformation problems that are very likely to occur in the cylinder 1 and the necking 2 in extremely high-temperature operating environments, thereby ensuring the long-term stable operation of the kiln head. At the same time, this constriction 2 design can also concentrate heat in the kiln, allowing the kiln to always maintain a stable micro-positive pressure state (5Pa±2Pa) during operation, thereby effectively preventing the kiln mouth barrel 1 from deformation and damage due to concentrated thermal stress. It synergistically ensures the stable operation of the kiln head and the firm adhesion of the casting material 10 from multiple aspects, which is conducive to minimizing heat loss and exhaust gas overflow, and improving the energy efficiency and environmental performance of the rotary kiln. 16 guard plates 5 are fixed to the outer wall of the connection between the barrel 1 and the constriction 2. The shape of the guard plates 5 matches the outer wall contours of the barrel 1 and the constriction 2. The guard plates 5 are welded and bolted to the outer walls of the barrel 1 and the constriction 2. The 16 guard plates 5 are distributed in a circular array with the axis of the barrel 1 as the axis. A conical sheath 6 (20mm thick Cr25Ni20 stainless steel material) is welded and bolted to the outer wall of the constriction 2. The conical sheath 6 matches the outer wall contour of the constriction 2. The guard plate 5 and the conical sleeve 6 are first welded and then bolted together for secondary reinforcement, thereby providing double fixing protection.
[0035] Several anchor hooks 7 are welded to the inner wall of the constriction 2 and the cylinder 1. The anchor hooks 7 are Y-shaped as a whole (depending on the welding position of the anchor hooks 7, the length of the anchor hooks 7 is 175mm, 200mm, 250mm, 250mm, 300mm and 325mm). The distance between the anchor hooks 7 is 180-200mm. The bottom of the anchor hook 7 has a horizontal bend. Casting material 10 is poured on the inner wall of the cylinder 1 and the constriction 2. The pouring height is 380mm, which is 180mm higher than the refractory bricks of the prior art. This design can effectively increase the thickness of the material layer in the kiln by 100mm, significantly prolong the reduction reaction time of the material in the kiln, ensure that the material can be fully and evenly calcined in the kiln, thereby greatly reducing the probability of the black kiln phenomenon caused by insufficient reduction of the material.
[0036] An annular air-cooling pipe 8 (11 meters from the cylinder, with a diameter of φ219) is mounted on the outside of the cylinder 1. This pipe can be secured with a bracket (e.g., to the ground). Several air outlets 9 are provided on this pipe, which direct air toward the cylinder 1. An air inlet valve 15 is connected to this pipe. After connecting the air inlet valve 15 to the cold air duct and opening it, forced air cooling is applied to the cylinder 1 through the air outlets 9. This effectively reduces the temperature outside the cylinder 1, ensuring that the cylinder 1 maintains good initial rigidity during high-temperature operation, thereby effectively suppressing the risk of excessive deformation of the cylinder 1 due to high temperatures.
[0037] Thermal analysis of the cylinder 1 of the present invention ( Figure 8 ) and the existing technology ( Figure 7 ), the red high-heat area is significantly reduced.
[0038] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the scope of protection of the present invention.
[0039] The technology, shape, and structure not described in detail in the present invention are all well-known technologies.
Claims
1. A zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension, comprising a cylinder, an outer cover, a middle cover, and an inner cover are arranged on the outside of the cylinder, characterized in that: A necking is fixed at one end of the cylinder, and annular reinforcement ribs are welded on the inner walls of the necking, the cylinder, and the connection between the cylinder and the necking. A number of axial reinforcement ribs are welded between adjacent annular reinforcement ribs. A number of guard plates are fixed on the outer wall of the connection between the cylinder and the necking, a conical sheath is fixed on the outer wall of the necking, and a number of anchor hooks are welded on the inner walls of the necking and the cylinder. An annular air-cooling pipe is mounted on the outside of the cylinder, and a number of air outlet holes are opened on the annular air-cooling pipe. The air outlet direction of the air outlet holes is toward the cylinder, and casting material is poured on the inner walls of the cylinder and the necking.
2. The zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: The necking is fixed to the cylinder by welding, and there are 16 axial reinforcement ribs between adjacent annular reinforcement ribs. The 16 axial reinforcement ribs are distributed in an annular array with the axis of the cylinder as the axis.
3. The zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: The shape of the guard plate matches the outer wall contour of the cylinder and the necking, and the guard plate is welded and bolted to the outer wall of the cylinder and the necking. There are 16 guard plates, and the 16 guard plates are distributed in a ring array with the axis of the cylinder as the axis.
4. The zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: The conical sleeve matches the outer wall profile of the necking, and the conical sleeve is welded and bolted to the outer wall of the necking.
5. The zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: A smoke baffle is fixed on the bottom of the inner cover body, and two smoke baffles are fixed on the outer wall of the cylinder.
6. The zinc extraction rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 5 is characterized in that: The smoke baffle at the bottom of the inner cover is located above the cylinder and has a gap with the cylinder. The two smoke baffles on the outer wall of the cylinder are respectively located between the inner cover and the middle cover and outside the middle cover.
7. The zinc-extracting rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: The anchor hook is Y-shaped as a whole, and the bottom end of the anchor hook has a horizontal bend.
8. The zinc-extracting rotary kiln head with refractory material anti-shedding and cylinder life extension according to claim 1 is characterized in that: The annular air cooling pipe is connected to an air intake valve.