An atmosphere controllable rotary kiln device for vanadium-nitrogen alloy production

Abstract

The application discloses a kind of atmosphere controllable type rotary kiln device for vanadium-nitrogen alloy production, including kiln body component, heating unit, cooling unit and atmosphere control device.Kiln body component includes preheating kiln, high-temperature nitriding kiln and cooling kiln in turn communication;Double-stage air-locking discharge device is equipped on feeding end cover and discharging end cover, to prevent air infiltration.Ambience control device includes partitioned zone gas supply pipe, which is divided into preheating kiln gas supply chamber, high-temperature nitriding kiln gas supply chamber and cooling kiln gas supply chamber, respectively provided with gas outlet in each kiln section, through the action of first necking section and second necking section, micro-positive pressure is formed in preheating kiln and cooling kiln, high-pressure atmosphere is formed in high-temperature nitriding kiln.Each kiln section is respectively provided with exhaust pipe, tail gas is recycled after dust removal and ammonia removal.The application realizes independent control of temperature, atmosphere and pressure of each section of preheating, high-temperature nitriding and cooling, with reliable sealing, high nitrogen utilization rate, uniform and stable product nitrogen content, and is suitable for continuous production of vanadium-nitrogen alloy.

Description

Technical Field

[0001] This invention belongs to the technical field of vanadium-nitrogen alloy production equipment, specifically relating to an atmosphere-controlled rotary kiln device for vanadium-nitrogen alloy production. Background Technology

[0002] Vanadium-nitrogen alloys are important additives in steelmaking. Adding vanadium-nitrogen alloys to steel can refine grains, improve the strength, toughness, and weather resistance of the steel, while significantly reducing the amount of vanadium required, thus saving alloy costs. Currently, the industrial production of vanadium-nitrogen alloys mainly adopts the carbothermic reduction nitriding method. This method uses vanadium oxides such as vanadium pentoxide, vanadium trioxide, or ammonium vanadate as the vanadium source, and carbonaceous materials such as carbon powder and graphite powder as the reducing agent. The two are mixed, shaped into spheres or blocks, and then subjected to reduction and nitriding reactions in a high-temperature nitrogen atmosphere, ultimately producing vanadium-nitrogen alloy products with V₂N and VN as the main components.

[0003] The existing vanadium-nitrogen alloy production equipment mainly includes three types: pusher kiln, vacuum resistance furnace and ordinary rotary kiln.

[0004] Although pusher kilns can achieve zoned temperature control along the kiln length, the materials are placed in a static stacking manner in the pusher or sagger, resulting in poor solid-gas contact within the material layer and poor atmosphere uniformity. This leads to incomplete nitriding reaction, large fluctuations in the nitrogen content of the product, and pusher kilns operate intermittently or semi-continuously, resulting in low production efficiency.

[0005] Vacuum resistance furnaces carry out nitriding reactions under vacuum or slightly positive pressure atmospheres, resulting in better product quality. However, they are intermittent operations with long cycles of charging, vacuuming, heating, holding, and cooling, leading to high energy consumption and low output per furnace, making it difficult to meet the needs of large-scale continuous production.

[0006] Ordinary rotary kilns enable materials to tumble continuously within the kiln, offering advantages such as good heat and mass transfer conditions and continuous production capability. In recent years, they have been gradually introduced into the production of vanadium-nitrogen alloys. However, the following prominent technical problems still exist in practical applications: First, the ability to control the atmosphere in different zones is poor. Vanadium-nitrogen alloy production has different requirements for the furnace atmosphere in the preheating, high-temperature nitriding, and cooling sections: the preheating section needs to remove moisture and volatiles and maintain an inert or weakly reducing atmosphere; the high-temperature nitriding section requires a high-concentration nitrogen atmosphere to ensure the nitriding reaction proceeds fully; and the cooling section requires an inert atmosphere to prevent product oxidation. Existing conventional rotary kilns typically only supply gas from both ends of the kiln body, making it impossible to independently control the atmosphere composition, gas pressure, and flow rate along the kiln axis for the preheating, high-temperature nitriding, and cooling zones. This leads to crosstalk between the atmospheres in each functional zone, resulting in unstable nitrogen concentration in the high-temperature nitriding zone. Volatiles and residual air from the preheating zone can easily enter the high-temperature zone, affecting the nitriding reaction, and the product in the cooling zone is also prone to oxidation, severely impacting product quality stability.

[0007] Secondly, the temperature and atmosphere of each functional section are difficult to adjust independently. Ordinary rotary kilns typically have a monolithic cylindrical structure, sharing a single rotary drive system and heating system. This makes it impossible to set different rotational speeds, temperature, and atmosphere parameters for the three functional sections: preheating, high-temperature nitriding, and cooling, resulting in poor process adaptability. For example, the preheating time and high-temperature nitriding time of materials often require different kiln rotational speeds to match, but monolithic rotary kilns can only operate at a uniform speed, limiting the scope for process optimization.

[0008] Third, nitrogen consumption is high and utilization efficiency is low. Existing rotary kilns typically discharge exhaust gas directly after simple treatment, resulting in the non-recovery and significant waste of unreacted nitrogen, leading to high production costs. Furthermore, if ammonia is used as the reducing atmosphere source, the direct discharge of unreacted ammonia entrained in the exhaust gas will also cause environmental pollution.

[0009] Therefore, there is an urgent need to develop an atmosphere-controlled rotary kiln device that can achieve independent temperature control, independent pressure control, and independent atmosphere control in the preheating section, high-temperature nitriding section, and cooling section, with high nitrogen utilization rate, and can realize continuous and stable production of vanadium-nitrogen alloys. Summary of the Invention

[0010] In view of this, the present invention provides an atmosphere-controlled rotary kiln apparatus for the production of vanadium-nitrogen alloys to solve the above-mentioned problems.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: An atmosphere-controlled rotary kiln apparatus for the production of vanadium-nitrogen alloys, comprising: Kiln body components, heating unit, cooling unit, and atmosphere control device; The kiln assembly includes a preheating kiln, a high-temperature nitriding kiln, a cooling kiln, a drive unit, a feed end cover, and a discharge end cover. The feed end cover and the discharge end cover are both fixedly installed on the ground by support members. The preheating kiln, the high-temperature nitriding kiln, and the cooling kiln are connected in sequence. One end of the preheating kiln is rotatably and sealingly connected to the feed end cover, and the other end of the cooling kiln is rotatably and sealingly connected to the discharge end cover. The drive unit is connected to the preheating kiln, the high-temperature nitriding kiln, and the cooling kiln for driving each kiln body to rotate around its own axis. Both the infeed end cover and the discharge end cover are equipped with a dual-stage airlock unloading device, which is used for feeding and unloading respectively; The heating units are fixedly installed on the outer walls of the preheating kiln and the high-temperature nitriding kiln, respectively, for heating the preheating kiln and the high-temperature nitriding kiln; the cooling units are fixedly installed on the outer wall of the cooling kiln for cooling the cooling kiln. The atmosphere control device includes a zoned air supply pipe, one end of which is rotatably and sealed to the discharge end cover, and the other end passes through the feed end cover and is rotatably and sealed to the feed end cover; the zoned air supply pipe is fixedly connected to the inner wall of the preheating kiln via a connecting rod. The partitioned gas supply pipe is provided with a dividing plate along the axial direction, dividing the interior of the partitioned gas supply pipe into a preheating kiln gas supply chamber, a high-temperature nitriding kiln gas supply chamber, and a cooling kiln gas supply chamber; the preheating kiln gas supply chamber, the high-temperature nitriding kiln gas supply chamber, and the cooling kiln gas supply chamber are respectively provided with gas outlets in the preheating kiln, the high-temperature nitriding kiln, and the cooling kiln.

[0012] Furthermore, the kiln body assembly also includes a first necking section and a second necking section, both of which are fixedly installed on the ground by support members. One end of the preheating kiln is rotatably and sealed to the feed end cover, and the other end of the preheating kiln is rotatably and sealed to the first necking section. The high-temperature nitriding kiln is sealed and rotatably connected between the first and second necking sections; the preheating kiln, high-temperature nitriding kiln, cooling kiln, first necking section, second necking section and zoned gas supply pipe are coaxially arranged, and the axis is set at an angle to the horizontal direction for the downward transfer of materials. One end of the cooling kiln is rotatably and sealed to the second necking section, and the other end of the cooling kiln is rotatably and sealed to the discharge end cover. The drive device is provided in multiple ways, and the multiple drive devices are respectively connected to the preheating kiln, the high-temperature nitriding kiln and the cooling kiln to realize the different rotation requirements of each kiln body. The first and second necking sections are used to create independent micro-positive pressures in the preheating kiln and cooling kiln, and to create high pressures in the high-temperature nitriding kiln.

[0013] Furthermore, the atmosphere control device also includes a preheating kiln exhaust pipe, a high-temperature nitriding kiln exhaust pipe, and a cooling kiln exhaust pipe; The preheating kiln exhaust pipe is connected to one end of the first necking section near the preheating kiln. The exhaust pipe of the high-temperature nitriding kiln is connected to one end of the second necking section near the high-temperature nitriding kiln. The exhaust pipe of the cooling kiln is connected to the discharge end cover.

[0014] Furthermore, the atmosphere control device also includes a gas source and a rotary sealing joint, wherein the gas source is connected to the zoned gas supply pipe through the rotary sealing joint.

[0015] Furthermore, the diameter of the air outlet holes in the preheating kiln and cooling kiln is smaller than the diameter of the air outlet holes in the high-temperature nitriding kiln, so that a slight positive pressure is formed in the preheating kiln and cooling kiln, and a high pressure is formed in the high-temperature nitriding kiln.

[0016] Furthermore, the dual-stage airlock unloading device includes an upper-stage rotary valve, an intermediate buffer chamber, and a lower-stage rotary valve. The intermediate buffer chamber is located between the upper-stage rotary valve and the lower-stage rotary valve. Inert gas is introduced into the intermediate buffer chamber to maintain a slight positive pressure and prevent air from entering the kiln.

[0017] Furthermore, the outlet ends of the preheating kiln exhaust pipe, the high-temperature nitriding kiln exhaust pipe, and the cooling kiln exhaust pipe are all equipped with tail gas treatment devices. The tail gas treatment devices include dust collectors and ammonia removal devices. The dust collectors and ammonia removal devices are connected to each exhaust pipe outlet end, and are used to remove dust and ammonia from the gas discharged from each kiln before recycling.

[0018] Furthermore, the ammonia removal device of the tail gas treatment device on the exhaust pipe of the preheating kiln is connected to the intermediate buffer chamber of the double-stage airlock unloading device on the feed end cover, so as to maintain a slight positive pressure in the intermediate buffer chamber and prevent air from entering the kiln. The ammonia removal device of the tail gas treatment device on the exhaust pipe of the high-temperature nitriding kiln is connected to the pipeline between the gas source and the rotary sealing joint for the purpose of recovering nitrogen for reuse. The ammonia removal device of the tail gas treatment device on the exhaust pipe of the cooling kiln is connected to the intermediate buffer chamber of the double-stage airlock unloading device on the discharge end cover, which is used to maintain a slight positive pressure in the intermediate buffer chamber to prevent air from entering the kiln.

[0019] Furthermore, the inner wall of the high-temperature nitriding kiln is provided with lifting plates, which are arranged at intervals along the axial and circumferential directions of the kiln body.

[0020] Furthermore, the driving device includes a gear ring, a gear, and a motor. The gear ring is fixedly sleeved on the outer wall of the preheating kiln, the high-temperature nitriding kiln, or the cooling kiln. The gear is fixedly installed at the output end of the motor and meshes with the gear ring.

[0021] The beneficial effects of this invention are as follows: 1. This invention divides the kiln body into three independent kiln sections: a preheating kiln, a high-temperature nitriding kiln, and a cooling kiln. Each kiln section is supplied with gas independently via a partitioned gas supply pipe, and each section is equipped with its own exhaust pipe. Combined with the functions of the first and second necking sections, independent control of the atmosphere and pressure in the preheating, high-temperature nitriding, and cooling sections is achieved. Heating units are installed on the outer walls of the preheating and high-temperature nitriding kilns, and a cooling unit is installed on the outer wall of the cooling kiln, enabling independent temperature control in these sections. This eliminates crosstalk between the atmospheres of different zones, ensuring a stable high-pressure nitriding atmosphere within the high-temperature nitriding kiln and resulting in a uniform and stable nitrogen content in the product.

[0022] 2. Each kiln section is driven by an independent drive unit, and the speed can be adjusted separately according to process requirements, so as to achieve independent optimization and matching of preheating, nitriding and cooling residence time, and strong process adaptability.

[0023] 3. The tail gas from each kiln section is recycled after dust removal and ammonia removal. The nitrogen in the tail gas of the high-temperature nitriding kiln is returned to the gas supply pipeline for reuse. The tail gas of the preheating kiln and cooling kiln is used as the sealing gas of the buffer chamber, realizing the cascade utilization of nitrogen, significantly reducing nitrogen consumption, and saving energy and protecting the environment. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of an atmosphere-controlled rotary kiln device for the production of vanadium-nitrogen alloys. Figure 2 for Figure 1 Sectional view of AA; In the figure: 11-Preheating kiln, 12-High-temperature nitriding kiln, 13-Cooling kiln, 14-Drive unit, 141-Gear ring, 142-Gear, 143-Motor, 15-Feed end cover, 16-Discharge end cover, 17-First necking section, 18-Second necking section, 2-Heating unit, 3-Cooling unit, 41-Zoned air supply pipe, 42-Divider plate, 43-Preheating kiln air supply chamber, 44-High-temperature nitriding kiln air supply chamber, 45- 46-Air outlet, 47-Preheating kiln exhaust pipe, 48-High temperature nitriding kiln exhaust pipe, 49-Cooling kiln exhaust pipe, 410-Gas source, 411-Rotary sealing joint, 412-Tail gas treatment device, 413-Dust collector, 414-Ammonia removal device, 5-Double-stage airlock unloading device, 51-Upper-stage rotary valve, 52-Intermediate buffer silo, 53-Lower-stage rotary valve, 6-Lifting plate. Detailed Implementation

[0026] 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, and 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.

[0027] See attached document Figure 1-2As shown, an atmosphere-controlled rotary kiln device for the production of vanadium-nitrogen alloys according to the present invention includes a kiln body assembly, a heating unit 2, a cooling unit 3, and an atmosphere control device.

[0028] The kiln assembly includes a preheating kiln 11, a high-temperature nitriding kiln 12, a cooling kiln 13, a first necking section 17, a second necking section 18, multiple drive units 14, a feed end cover 15, and a discharge end cover 16. The feed end cover 15 and the discharge end cover 16, the first necking section 17, and the second necking section 18 are all fixedly installed on the ground by support members.

[0029] One end of the preheating kiln 11 is rotatably and sealed to the feed end cover 15, and the other end of the preheating kiln 11 is rotatably and sealed to the first constriction section 17. The high-temperature nitriding kiln 12 is rotatably and sealed between the first constriction section 17 and the second constriction section 18. One end of the cooling kiln 13 is rotatably and sealed to the second constriction section 18, and the other end of the cooling kiln 13 is rotatably and sealed to the discharge end cover 16. Thus, the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13 are connected in sequence, and the material, under the action of gravity, passes through the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13 in sequence along the inclined kiln body to complete the preheating, high-temperature nitriding reaction, and cooling process.

[0030] Multiple drive units 14 are respectively connected to the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13. Each drive unit 14 includes a gear ring 141, a gear 142, and a motor 143. The gear ring 141 is fixedly sleeved on the outer wall of the preheating kiln 11, the high-temperature nitriding kiln 12, or the cooling kiln 13. The gear 142 is fixedly installed at the output end of the motor 143, and the gear 142 meshes with the gear ring 141. The motor 143 drives the gear 142 to rotate, thereby causing the gear ring 141 and the kiln body to rotate around their own axis. Since the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13 are each driven by an independent drive unit 14, the different rotation requirements of each kiln can be met, and the rotation speed of each kiln section can be set according to the process requirements.

[0031] Both the feed end cover 15 and the discharge end cover 16 are equipped with a two-stage airlock unloading device 5. The two-stage airlock unloading device 5 includes an upper-stage rotary valve 51, an intermediate buffer chamber 52, and a lower-stage rotary valve 53. The two-stage airlock unloading device 5 on the feed end cover 15 is used to continuously or intermittently add material into the preheating kiln 11, while the two-stage airlock unloading device 5 on the discharge end cover 16 is used to unload the cooled vanadium-nitrogen alloy product. The intermediate buffer chamber 52 is circulated with inert gas that has undergone ammonia removal treatment to maintain a slight positive pressure, preventing air from entering the kiln when the upper-stage discharge valve is opened, thus ensuring the airtightness of the kiln atmosphere.

[0032] Heating units 2 are fixedly installed on the outer walls of preheating kiln 11 and high-temperature nitriding kiln 12, respectively. Heating units 2 use electric heating elements (such as silicon carbide rods or silicon molybdenum rods). The heating units 2 of preheating kiln 11 and high-temperature nitriding kiln 12 are independently temperature controlled, and the temperatures of preheating kiln 11 and high-temperature nitriding kiln 12 can be set separately according to process requirements.

[0033] The cooling unit 3 is fixedly installed on the outer wall of the cooling kiln 13 and adopts a water-cooled jacket or air-cooled jacket structure to indirectly cool the material inside the cooling kiln 13.

[0034] The atmosphere control device includes a zoned gas supply pipe 41, a preheating kiln exhaust pipe 47, a high-temperature nitriding kiln exhaust pipe 48, a cooling kiln exhaust pipe 49, a gas source 410, and a rotary sealing joint 411.

[0035] The zoned air supply pipe 41 is a tubular structure arranged along the axial direction of the kiln body. The preheating kiln 11, the high-temperature nitriding kiln 12, the cooling kiln 13, the first necking section 17, the second necking section 18, and the zoned air supply pipe 41 are arranged coaxially, and the axis forms an angle with the horizontal direction (2° to 5° in this embodiment), so that the material is automatically transferred from the feed end to the discharge end under the action of gravity. One end of the zoned air supply pipe 41 is sealed and rotatably connected to the discharge end cover 16, and the other end passes through the feed end cover 15 and is sealed and rotatably connected to the feed end cover 15. The zoned air supply pipe 41 is fixedly connected to the inner wall of the preheating kiln 11 through a connecting rod, and the entire zoned air supply pipe 41 rotates with the preheating kiln 11. The partitioned air supply pipe 41 is internally divided into three independent air supply chambers: a preheating kiln air supply chamber 43, a high-temperature nitriding kiln air supply chamber 44, and a cooling kiln air supply chamber 45, by a partition plate 42 arranged axially inside the pipe. Air outlets 46 are respectively provided on the pipe walls of the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13.

[0036] Gas source 410 is connected to partitioned gas supply pipe 41 via rotating sealing joint 411. Gas source 410 provides a mixture of high-purity nitrogen and ammonia, and the mixing ratio of the mixture can be adjusted according to process requirements. After entering partitioned gas supply pipe 41, the mixed gas enters preheating kiln gas supply chamber 43, high-temperature nitriding kiln gas supply chamber 44, and cooling kiln gas supply chamber 45 respectively, and is evenly sprayed into the corresponding kiln section through their respective outlet holes 46. By designing the size and number of outlet holes 46 in each gas supply chamber, different gas pressures can be achieved in preheating kiln 11, high-temperature nitriding kiln 12, and cooling kiln 13. In this embodiment, the outlet holes 46 of preheating kiln gas supply chamber 43 and cooling kiln gas supply chamber 45 have smaller diameters, creating a slight positive pressure in preheating kiln 11 and cooling kiln 13; the outlet holes 46 of high-temperature nitriding kiln gas supply chamber 44 have larger diameters, creating high pressure in high-temperature nitriding kiln 12. The first necking section 17 and the second necking section 18 are respectively located between the preheating kiln 11 and the high-temperature nitriding kiln 12, and between the high-temperature nitriding kiln 12 and the cooling kiln 13. The necking structure effectively reduces the cross-sectional area of ​​the airflow channel between adjacent kiln sections, further promoting the establishment and maintenance of the independent pressure environment of each kiln section.

[0037] The preheating kiln exhaust pipe 47 is connected to the end of the first constriction section 17 near the preheating kiln 11, and is used to discharge the gas inside the preheating kiln 11. The high-temperature nitriding kiln exhaust pipe 48 is connected to the end of the second constriction section 18 near the high-temperature nitriding kiln 12, and is used to discharge the gas inside the high-temperature nitriding kiln 12. The cooling kiln exhaust pipe 49 is connected to the discharge end cover 16, and is used to discharge the gas inside the cooling kiln 13. Each exhaust pipe is equipped with a tail gas treatment device 412 at its outlet end. The tail gas treatment device 412 includes a dust collector 413 and an ammonia removal device 414. The dust collector 413 is connected to the ammonia removal device 414 and then connected to the outlet end of each exhaust pipe. The gas discharged from each kiln section is treated by the dust collector 413 to remove entrained dust, and then by the ammonia removal device 414 to remove unreacted ammonia before being recycled.

[0038] The ammonia removal device 414 of the tail gas treatment device 412 on the preheating kiln exhaust pipe 47 is connected to the intermediate buffer chamber 52 of the double-stage airlock unloading device 5 on the feed end cover 15. The inert gas after ammonia removal is introduced into the intermediate buffer chamber 52 to maintain a slight positive pressure in the intermediate buffer chamber 52 and prevent air from entering the kiln through the feed end.

[0039] The ammonia removal device 414 of the tail gas treatment device 412 on the exhaust pipe 48 of the high-temperature nitriding kiln is connected to the pipeline between the gas source 410 and the rotary sealing joint 411. The recovered high-purity nitrogen is mixed with fresh mixed gas and then circulated into the kiln to realize the recycling of nitrogen.

[0040] The ammonia removal device 414 of the tail gas treatment device 412 on the exhaust pipe 49 of the cooling kiln is connected to the intermediate buffer chamber 52 of the double-stage airlock unloading device 5 on the discharge end cover 16. The inert gas after ammonia removal is introduced into the intermediate buffer chamber 52 at the discharge end, so that the intermediate buffer chamber 52 maintains a slight positive pressure and prevents air from entering the kiln through the discharge end.

[0041] The inner wall of the high-temperature nitriding kiln 12 is equipped with lifting plates 6, which are arranged at intervals along the axial and circumferential directions of the kiln body. When the high-temperature nitriding kiln 12 rotates, the lifting plates 6 continuously lift and scatter the material to form a uniform material curtain, enhance the contact between the material and nitrogen, and improve the nitriding reaction rate and uniformity.

[0042] The working process of the device of the present invention is as follows: Vanadium pentoxide powder is mixed evenly with carbonaceous reducing agent and binder in a certain proportion, and then formed into pellets or blocks by pressing. The material is continuously fed into the preheating kiln 11 through the double-stage airlock discharge device 5 on the feed end cover 15.

[0043] The gas source 410 provides a mixture of high-purity nitrogen and ammonia. The mixture enters the partitioned gas supply pipe 41 through the rotating sealing joint 411 and is injected into the preheating kiln 11, the high-temperature nitriding kiln 12, and the cooling kiln 13 through the respective gas outlets 46 of the preheating kiln gas supply chamber 43, the high-temperature nitriding kiln gas supply chamber 44, and the cooling kiln gas supply chamber 45.

[0044] Inside the preheating kiln 11, the heating unit 2 controls the kiln temperature at 600–1000°C. The material is preheated under a slightly positive pressure nitrogen atmosphere to remove moisture and volatiles. The preheated material then enters the high-temperature nitriding kiln 12 through the first constriction section 17.

[0045] Inside the high-temperature nitriding kiln 12, the heating unit 2 controls the kiln temperature at 1100–1500°C, and a mixture of high-purity nitrogen and ammonia is introduced. The material, under the scattering action of the lifting plates 6, comes into full contact with the nitrogen, undergoing a carbothermic reduction nitriding reaction to produce a vanadium-nitrogen alloy. The reaction exhaust gas is discharged through the high-temperature nitriding kiln exhaust pipe 48, and after dust removal by the dust collector 413 and ammonia removal by the ammonia removal device 414, the recovered nitrogen is returned to the pipeline between the gas source 410 and the rotary sealing joint 411 for recycling.

[0046] After the high-temperature nitriding reaction is completed, the vanadium-nitrogen alloy material enters the cooling kiln 13 through the second necking section 18. Under the indirect cooling effect of the cooling unit 3, it is cooled to below 150°C, while oxidation is prevented under a nitrogen protective atmosphere. The cooled vanadium-nitrogen alloy product is continuously discharged through the double-stage airlock unloading device 5 on the discharge end cover 16, thus obtaining the finished product.

[0047] In this embodiment, the rotation speed of the preheating kiln 11 is set to 1-3 r / min, the rotation speed of the high-temperature nitriding kiln 12 is set to 0.5-2 r / min, and the rotation speed of the cooling kiln 13 is set to 2-4 r / min. The rotation speed of each kiln section is adjusted independently according to the material residence time requirements.

[0048] The above descriptions are merely specific embodiments of the present invention, and common knowledge regarding the specific structures and characteristics of the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

[0049] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0050] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An atmosphere-controlled rotary kiln device for the production of vanadium-nitrogen alloys, characterized in that, include: Kiln body components, heating unit (2), cooling unit (3) and atmosphere control device; The kiln assembly includes a preheating kiln (11), a high-temperature nitriding kiln (12), a cooling kiln (13), a drive device (14), a feed end cover (15), and a discharge end cover (16). The feed end cover (15) and the discharge end cover (16) are both fixedly installed on the ground by support members. The preheating kiln (11), the high-temperature nitriding kiln (12), and the cooling kiln (13) are connected in sequence. One end of the preheating kiln (11) is sealed and rotatably connected to the feed end cover (15), and the other end of the cooling kiln (13) is sealed and rotatably connected to the discharge end cover (16). The drive device (14) is connected to the preheating kiln (11), the high-temperature nitriding kiln (12), and the cooling kiln (13) for driving each kiln body to rotate around its own axis. Both the feed end cover (15) and the discharge end cover (16) are equipped with a double-stage airlock unloading device (5), which is used for feeding and unloading respectively; The heating unit (2) is fixedly installed on the outer wall of the preheating kiln (11) and the high-temperature nitriding kiln (12) respectively, for heating the preheating kiln (11) and the high-temperature nitriding kiln (12); the cooling unit (3) is fixedly installed on the outer wall of the cooling kiln (13), for cooling the cooling kiln (13); The atmosphere control device includes a zoned air supply pipe (41), one end of which is sealed and rotatably connected to the discharge end cover (16), and the other end passes through the feed end cover (15) and is sealed and rotatably connected to the feed end cover (15); the zoned air supply pipe (41) is fixedly connected to the inner wall of the preheating kiln (11) through a connecting rod. The partitioned gas supply pipe (41) is provided with a partition plate (42) along the axial direction inside, which divides the interior of the partitioned gas supply pipe (41) into a preheating kiln gas supply chamber (43), a high-temperature nitriding kiln gas supply chamber (44), and a cooling kiln gas supply chamber (45); the preheating kiln gas supply chamber (43), the high-temperature nitriding kiln gas supply chamber (44), and the cooling kiln gas supply chamber (45) are respectively provided with gas outlets (46) in the preheating kiln (11), the high-temperature nitriding kiln (12), and the cooling kiln (13).

2. The atmosphere-controlled rotary kiln device for vanadium-nitrogen alloy production according to claim 1, characterized in that, The kiln body assembly also includes a first necking section (17) and a second necking section (18), both of which are fixedly installed on the ground by support members. One end of the preheating kiln (11) is sealed and rotatably connected to the feed end cover (15), and the other end of the preheating kiln (11) is sealed and rotatably connected to the first necking section (17); the high-temperature nitriding kiln (12) is sealed and rotatably connected between the first necking section (17) and the second necking section (18). One end of the cooling kiln (13) is sealed and rotatably connected to the second neck section (18), and the other end of the cooling kiln (13) is sealed and rotatably connected to the discharge end cover (16); the preheating kiln (11), the high-temperature nitriding kiln (12), the cooling kiln (13), the first neck section (17), the second neck section (18) and the partitioned air supply pipe (41) are coaxially arranged, and the axis is set at an angle to the horizontal direction for the downward transfer of materials; Multiple drive devices (14) are provided, and the multiple drive devices (14) are respectively connected to the preheating kiln (11), the high-temperature nitriding kiln (12) and the cooling kiln (13) to realize the different rotation requirements of each kiln body; The first necking section (17) and the second necking section (18) are used to create independent micro-positive pressure in the preheating kiln (11) and the cooling kiln (13), and to create high pressure in the high-temperature nitriding kiln (12).

3. The atmosphere-controlled rotary kiln device for vanadium-nitrogen alloy production according to claim 2, characterized in that, The atmosphere control device also includes a preheating kiln exhaust pipe (47), a high-temperature nitriding kiln exhaust pipe (48), and a cooling kiln exhaust pipe (49). The preheating kiln exhaust pipe (47) is connected to one end of the first constriction section (17) near the preheating kiln (11); The exhaust pipe (48) of the high-temperature nitriding kiln is connected to one end of the second neck section (18) near the high-temperature nitriding kiln (12); The cooling kiln exhaust pipe (49) is connected to the discharge end cover (16).

4. The atmosphere-controlled rotary kiln device for vanadium-nitrogen alloy production according to claim 3, characterized in that, The atmosphere control device also includes a gas source (410) and a rotary sealing joint (411), wherein the gas source (410) is connected to the zoned gas supply pipe (41) through the rotary sealing joint (411).

5. The atmosphere-controlled rotary kiln apparatus for vanadium-nitrogen alloy production according to claim 4, characterized in that, The diameter of the air outlet (46) in the preheating kiln (11) and cooling kiln (13) is smaller than the diameter of the air outlet (46) in the high-temperature nitriding kiln (12), so that a slight positive pressure is formed in the preheating kiln (11) and cooling kiln (13), and a high pressure is formed in the high-temperature nitriding kiln (12).

6. The atmosphere-controlled rotary kiln apparatus for the production of vanadium-nitrogen alloys according to claim 4, characterized in that, The dual-stage airlock unloading device (5) includes an upper-stage rotary valve (51), an intermediate buffer chamber (52), and a lower-stage rotary valve (53). The intermediate buffer chamber (52) is located between the upper-stage rotary valve (51) and the lower-stage rotary valve (53). Inert gas is introduced into the intermediate buffer chamber (52) to maintain a slight positive pressure and prevent air from entering the kiln.

7. The atmosphere-controlled rotary kiln apparatus for vanadium-nitrogen alloy production according to claim 6, characterized in that, The exhaust pipes of the preheating kiln (47), the high-temperature nitriding kiln (48), and the cooling kiln (49) are all equipped with tail gas treatment devices (412). The tail gas treatment devices (412) include a dust collector (413) and an ammonia removal device (414). The dust collector (413) is connected to the ammonia removal device (414) and then connected to the exhaust pipe outlets of each kiln. The dust collector (413) is connected to the ammonia removal device (414) and then to the exhaust pipe outlets of each kiln. The dust collector is used to remove dust and ammonia from the gas discharged from each kiln and then recover it.

8. The atmosphere-controlled rotary kiln apparatus for vanadium-nitrogen alloy production according to claim 7, characterized in that, The ammonia removal device (414) of the tail gas treatment device (412) on the preheating kiln exhaust pipe (47) is connected to the intermediate buffer chamber (52) of the double-stage airlock unloading device (5) on the feed end cover (15), so as to maintain a slight positive pressure in the intermediate buffer chamber (52) and prevent air from entering the kiln. The ammonia removal device (414) of the tail gas treatment device (412) on the exhaust pipe (48) of the high-temperature nitriding kiln is connected to the pipeline between the gas source (410) and the rotary sealing joint (411) for the purpose of recovering nitrogen for reuse. The ammonia removal device (414) of the tail gas treatment device (412) on the exhaust pipe (49) of the cooling kiln is connected to the intermediate buffer chamber (52) of the double-stage airlock unloading device (5) on the discharge end cover (16) to maintain a slight positive pressure in the intermediate buffer chamber (52) and prevent air from entering the kiln.

9. The atmosphere-controlled rotary kiln device for vanadium-nitrogen alloy production according to claim 1, characterized in that, The inner wall of the high-temperature nitriding kiln (12) is provided with lifting plates (6), which are arranged at intervals along the axial and circumferential directions of the kiln body.

10. The atmosphere-controlled rotary kiln apparatus for the production of vanadium-nitrogen alloys according to claim 1, characterized in that, The drive device (14) includes a gear ring (141), a gear (142) and a motor (143). The gear ring (141) is fixedly sleeved on the outer wall of the preheating kiln (11), the high-temperature nitriding kiln (12) or the cooling kiln (13). The gear (142) is fixedly installed at the output end of the motor (143). The gear (142) meshes with the gear ring (141).

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