A wall-climbing titanium reduction production process suitable for inverted U-shaped large reduction distillation furnace

Abstract

The present application relates to the technical field of reduction distillation furnace, in particular to a wall-climbing titanium reduction production process suitable for inverted U-shaped large reduction distillation furnace, without changing the original discharge frequency, fan and temperature control parameters, comprising S1 equipment pretreatment, S2 magnesium addition and liquid level correction, measuring the initial liquid level and calculating the first discharge amount by formula; S3 lifting and locking the reaction liquid level, segmented conveying titanium tetrachloride, differential pressure discharging magnesium chloride, controlling the liquid surface position, and eliminating local supercooling of the furnace wall by dynamic air distribution of double air inlets; S4 precise discharge, controlling the discharge time and weight deviation; S5 following the existing distillation discharge process after reduction is completed. The present application can stably control the wall-climbing titanium ratio within 4% by means of liquid level calibration, discharge optimization and double air inlet coordinated temperature control, improve the raw material utilization rate, reduce operation and maintenance and cleaning furnace costs, and the product can reach national standard 0A level or above, without hardware modification, and is convenient for existing production line popularization.

Description

Technical Field

[0001] This invention relates to the field of reducing distillation furnace technology, and more specifically, to a climbing titanium reduction production process suitable for a large inverted U-shaped reducing distillation furnace. Background Technology

[0002] The industrial production of sponge titanium commonly employs the Kroll magnesothermic reduction-vacuum distillation combined process. Large-scale 8-10t inverted U-shaped reduction distillation furnaces have been widely adopted in the domestic sponge titanium industry. However, traditional production methods utilize low-level liquid control, adapted for smaller furnaces, resulting in a large area of ​​low-temperature empty cylinder wall at the top of the furnace. This easily leads to the adhesion and crystallization of titanium vapor and liquid, forming "climbing titanium." In actual production, the proportion of climbing titanium has consistently remained at 10%-15%, resulting in titanium raw material loss, reduced raw material utilization, increased furnace cleaning time, and a tendency to cause localized overheating and deformation of the reactor cylinder wall, increasing equipment maintenance frequency. To address this issue, the invention patent with authorization announcement number CN113946167B... The patent discloses a solution for increasing the number of discharge cycles. However, this solution requires repeated pressurization and depressurization of the furnace, resulting in high argon consumption. Frequent discharge can also disrupt the temperature field and liquid phase distribution within the furnace, causing fluctuations in reaction conditions and affecting batch consistency. Furthermore, it increases equipment investment and labor costs, making the modification less economical. Other improvement solutions, such as continuous discharge, rely on high-precision online metering and complex control systems, leading to high modification costs, high instrument failure rates, and difficulty in large-scale production line implementation. Therefore, how to eliminate localized supercooling conditions on the reactor wall without adding new hardware or increasing the discharge frequency, and suppress the formation of climbing titanium from the source, has become a pressing technical challenge in this field. Summary of the Invention

[0003] The purpose of this invention is to provide a climbing titanium reduction production process suitable for a large inverted U-shaped reducing distillation furnace, in order to solve the problems mentioned in the background art, such as high argon consumption, frequent discharge which disturbs the temperature field and liquid phase distribution in the furnace, causing fluctuations in reaction conditions, affecting batch consistency of products, and also bringing about increased equipment investment and labor costs, resulting in poor economic efficiency of the modification and implementation.

[0004] To achieve the above objectives, this invention provides a process for reducing titanium production by climbing walls, applicable to a large inverted U-shaped reducing distillation furnace. The process includes an inverted U-shaped reducing distillation furnace producing 8-10 tons of sponge titanium. The furnace is equipped with a cooling fan, which has a first air inlet and a second air inlet arranged vertically along the reactor cylinder axis. Without changing the original discharge frequency, fan rated parameters, or system temperature control standards, the process includes the following steps: S1, Equipment pretreatment: After leak detection and overall machine inspection, the furnace body is heated and melted to remove residual deposits from the furnace wall; S2, Magnesium addition and initial liquid level correction: After melting, magnesium is added, controlling the magnesium feeding ratio. Once the furnace conditions stabilize, the initial liquid level is measured. The initial discharge volume is calculated based on the relevant liquid level formula; S3, Raising and locking the reaction liquid level: Titanium tetrachloride raw material is transported in stages, and magnesium chloride is discharged by relying on the pressure difference in the furnace, controlling the position of the melt liquid level in the furnace before and after discharge; The air volume of the first air inlet and the second air inlet is dynamically distributed and adjusted to regulate the temperature of the upper outer wall of the reactor and eliminate local supercooling of the furnace wall; S4, Precise discharge: Discharge operation is carried out according to the calculated discharge volume, and the deviation of discharge time and discharge weight is controlled; S5, Post-processing: After the titanium tetrachloride feeding and reduction discharge are completed, the existing mature process is used to complete the distillation, cooling, discharge and furnace cleaning; Through the above process, the proportion of titanium climbing the furnace wall is stably controlled within 4%.

[0005] This setup, through the entire process of equipment pretreatment, magnesium level correction, raising and locking the reaction liquid level, precise material discharge, and post-processing, eliminates the conditions for climbing titanium crystals to adhere from both spatial and temperature dimensions without altering the original equipment and basic process conditions. It controls the proportion of climbing titanium to within 4%, thus balancing product quality and production stability.

[0006] As a preferred embodiment of the present invention, the center distance between the first air inlet and the second air inlet is 600-800mm; in S1, the furnace is heated to 800-840℃ and kept at a constant temperature for 4-6 hours to melt residual condensed by-products and production residues on the inner wall of the furnace.

[0007] This setting matches the dimensions of the furnace's dual air inlet structure, and through high-temperature melting, it fully dissolves the by-products and attachments left on the furnace inner wall, eliminating the interference of residual impurities on the accuracy of liquid level measurement and the stability of the reduction reaction.

[0008] As a preferred embodiment of the present invention, in step S2, after melting, the temperature is lowered to 780-820℃ and magnesium is added in one go, with the magnesium addition time being 0.4-0.6 hours; high-purity argon gas with a purity ≥99.99% is introduced throughout the feeding process, and the furnace pressure is maintained at 1-5 kPa; the total amount of magnesium added is 38%-42% of the total mass of titanium tetrachloride added; after the magnesium is added, the material is kept at a constant temperature of 780-800℃ for 1-2 hours to mix the material, and then kept still for 0.5-1 hours to stabilize the temperature field, pressure field, and liquid phase distribution in the furnace; the initial liquid level is measured using a mechanical probe liquid level device; the formula for calculating the initial discharge volume is as follows. In the formula: This is the initial discharge volume; This refers to the amount of titanium tetrachloride added during the initial discharge. The standard liquid level is represented by k, where k is the liquid level coefficient. H is the measured distance from the feed pipe inlet to the center of the first air inlet; the liquid level coefficient k is coupled with the reactor inner diameter D and the total feed rate T of titanium tetrachloride per furnace: when D=1800mm-1900mm and T=32t-36t, k=4.2-4.7kg / mm; when D=1900mm-2000mm and T=36t-40t, k=4.7-5.2kg / mm; intermediate values ​​are linearly interpolated; when the feed rate of titanium tetrachloride per furnace is 32t-40t... Values ​​range from 700 to 1100 kg.

[0009] This setting strictly controls the magnesium addition process parameters to ensure sufficient magnesium thermal reduction reaction ratio, relies on static setting to ensure sufficient stability of furnace conditions, calculates the initial discharge amount using calibration formula, unifies the liquid level benchmark for each furnace, and eliminates the initial operating condition differences between different furnaces.

[0010] As a preferred embodiment of the present invention, the mechanical probe liquid level device is a stainless steel round tube with a total length of 5000mm, an outer diameter of 20-30mm, and a wall thickness of 2-3mm. Depth markings are set every 100mm along the tube body. Liquid level measurement: The probe is vertically inserted from the top feeding port until its upper end face is flush with the feeding port. After extraction, the length from the wetting mark at the lower end of the probe to the upper edge of the probe is measured. Repeat the measurement 2-3 times and take the average value. The measurement accuracy is ±5mm.

[0011] This setting provides a practical method for measuring liquid level. By taking the average of multiple measurements, it reduces human measurement errors, ensures the accuracy of the initial liquid level acquisition, and provides reliable basic data for subsequent discharge volume calculation.

[0012] As a preferred embodiment of the present invention, in S3, the titanium tetrachloride conveying pressure is 0.3-0.6MPa, and the segmented feeding flow rates are: 200-250kg / h for cumulative feeding of 0-8t; 450-500kg / h for cumulative feeding of 8-27t; and 280-320kg / h for cumulative feeding of 27t-40t. The discharge process conditions are: melt discharge temperature of 750-840℃, instantaneous furnace pressure of 40-90kPa, and discharge rate of 3000-4000kg / h. Before each discharge is started, the melt level is 0-200mm below the center of the second air inlet, and after the discharge is completed, the melt level rises to 100-300mm above the center of the first air inlet.

[0013] This setup employs segmented feeding to adapt to the exothermic characteristics of different stages of the reduction reaction, and matches reasonable discharge process parameters to lock the reaction liquid level in the constant temperature range of the cylinder corresponding to the dual air inlets. It utilizes liquid phase materials to cover the original low-temperature empty furnace wall, compressing the space for climbing titanium growth.

[0014] As a preferred embodiment of the present invention, the S3 air volume distribution benchmark is as follows: the first air inlet is allocated 60%-80% of the total air volume, and the second air inlet is allocated 20%-40% of the total air volume; 4-6 thermocouples are evenly distributed around the circumference of the upper outer wall of the reactor cylinder, and the average temperature measurement is taken as the air volume adjustment benchmark; if the average temperature of the outer wall is higher than 790℃, the air volume ratio of the second air inlet is increased by 10%-20%, and the air volume ratio of the first air inlet is reduced by the same amount; if the average temperature of the outer wall is lower than 760℃, the air supply of the second air inlet is reduced or shut off; the temperature of the upper outer wall of the reactor is stably maintained at 760-790℃.

[0015] This setup relies on a dual-outlet dynamic airflow distribution strategy to compensate and adjust the temperature of the upper part of the furnace body, eliminating large-scale local low-temperature zones in the upper part of the cylinder and disrupting the thermodynamic conditions for the adhesion of titanium crystals climbing the wall.

[0016] As a preferred embodiment of the present invention, in S4, the actual time consumption of a single discharge deviates from the planned time by ≤30 min, and the actual weight of magnesium chloride discharged in a single discharge deviates from the theoretical calculated value by ≤100 kg.

[0017] This setting strictly controls the deviation of the material discharge operation, avoids instantaneous large fluctuations in the liquid level in the furnace, and ensures that the material system and temperature field in the furnace remain stable after each round of material discharge, thus maintaining the steady-state operation of the reduction reaction.

[0018] As a preferred embodiment of the present invention, the reducing distillation furnace further includes a reactor shell, a cooling fan, an air volume regulating valve, a mechanical probe level device, a titanium tetrachloride feeding system, a discharge pipeline, and thermocouples; the cooling fan is provided with two air supply branches, which are respectively connected to a first air inlet and a second air inlet on the reactor shell; the first air inlet and the second air inlet are arranged vertically along the axial direction of the reactor shell; an air volume regulating valve is installed on each air supply branch; the mechanical probe level device is located at the top of the reactor shell at the feeding port position; multiple thermocouples are evenly distributed and fixed on the upper outer wall of the reactor shell along the circumference; the thermocouple signal output terminals are electrically connected to the control unit of the air volume regulating valve.

[0019] This setting constructs a furnace hardware architecture adapted to this process. It uses temperature signals collected by thermocouples to control the air volume regulating valve, thereby achieving automatic and dynamic adjustment of the air volume at both air outlets and ensuring the stable execution of the furnace wall temperature control strategy.

[0020] As a preferred embodiment of the present invention, the center-to-center distance between the first air inlet and the second air inlet is 600-800mm; the inner diameter of the reactor cylinder is 1800-2000mm, and the effective height of the reactor cylinder is ≥2800mm; the mechanical probe liquid level device is a stainless steel round tube with a total length of 5000mm, an outer diameter of 20-30mm, a wall thickness of 2-3mm, and pre-marked depth graduations every 100mm on the tube body.

[0021] This setting limits the reactor size and liquid level measurement device specifications to match an 8-10t inverted U-shaped large-scale reduction distillation furnace, ensuring that the process can be adapted to mainstream furnace equipment in use.

[0022] As a preferred embodiment of the present invention, the number of thermocouples is multiple, and the installation positions are respectively located on the inner wall and outer wall of the reactor cylinder.

[0023] This setting simultaneously collects the temperature of the inner and outer walls of the furnace, providing a more comprehensive feedback on the actual temperature of the furnace wall, reducing temperature deviation caused by measuring only the outer wall, and improving the accuracy of airflow regulation.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This process for reducing titanium content in a wall-climbing process applicable to a large inverted U-shaped reducing distillation furnace does not require hardware modifications to the existing reducing distillation furnace. It can be implemented without changing the original discharge frequency, fan rated parameters, and system temperature control standards. This avoids the problems of additional equipment investment and operator recruitment caused by the process of increasing the discharge frequency. It also eliminates the need for high-precision online metering instruments and complex control systems required for continuous discharge. It can be directly replicated and implemented on existing 8-10t inverted U-shaped reducing distillation production lines. The process has strong versatility and the modification cost is almost zero.

[0026] 2. In the process of reducing the amount of titanium climbing on the wall in a large-scale inverted U-shaped reducing distillation furnace, the reaction liquid level is raised to the constant temperature range of the dual tuyeres by calibrating the initial liquid level formula and optimizing the discharge parameters. Combined with the dynamic air distribution of the dual tuyeres to eliminate local supercooling of the furnace wall, the environment for the crystallization and adhesion of titanium climbing on the wall is destroyed from the perspective of spatial and thermodynamic conditions. The proportion of titanium climbing on the wall can be stably controlled within 4%, which is significantly lower than the 10%-15% proportion of titanium climbing on the wall in the traditional process. The raw material loss is significantly reduced, and the utilization rate of titanium raw materials is effectively improved. At the same time, the thickness of titanium climbing on the furnace wall is greatly reduced, and the time for manual furnace cleaning after discharge is significantly shortened, reducing the labor intensity on site.

[0027] 3. In the climbing titanium reduction production process applicable to the inverted U-shaped large-scale reducing distillation furnace, the original discharge frequency is retained, and frequent pressurization and depressurization operations are avoided, effectively reducing the consumption of argon protective gas. At the same time, it will not cause additional disturbance to the temperature field, pressure field, and liquid phase system inside the furnace. The reduction reaction can maintain steady-state operation, reduce the product impurity fluctuation problem caused by the fluctuation of operating conditions, improve the physicochemical properties of sponge titanium products and the batch consistency of products between different furnaces, and the product quality can reach a level better than the national standard 0A grade.

[0028] 4. In the titanium reduction production process applicable to the inverted U-shaped large-scale reducing distillation furnace, the amount of titanium adhering to the furnace wall decreases, avoiding local titanium buildup that causes heat dissipation obstruction and local overheating deformation of the cylinder wall, reducing reactor deformation failures and equipment overhaul frequency, extending the service life of the reducing distillation furnace, and reducing equipment maintenance and replacement costs; considering argon consumption, manual furnace cleaning, equipment operation and maintenance, and raw material loss, the overall operating cost of a single furnace is reduced, resulting in good industrial economic benefits. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the reactor cylinder in this invention;

[0030] Figure 2 This is a schematic diagram of the inverted U-shaped large-scale reducing distillation furnace in this invention;

[0031] Figure 3 This is a schematic diagram of the process of the present invention;

[0032] The meanings of the labels in the diagram are as follows:

[0033] 1. Cooling fan; 2. First air inlet; 3. Second air inlet; 4. Mechanical probe liquid level device; 5. Thermocouple; 6. Reactor shell; 7. Air volume regulating valve; 8. Titanium tetrachloride feeding system; 9. Discharge pipeline. Detailed Implementation

[0034] 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.

[0035] This invention provides a process for reducing titanium content by climbing the wall in a large inverted U-shaped reducing distillation furnace, such as... Figures 1-3 As shown, the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0036] Example 1

[0037] This invention provides a process for reducing titanium production by climbing walls in a large inverted U-shaped reducing distillation furnace. The inverted U-shaped reducing distillation furnace used in this process produces 8-10 tons of sponge titanium. The reducing distillation furnace is equipped with a cooling fan 1, which has a first air inlet 2 and a second air inlet 3 arranged vertically along the reactor cylinder axis. This process, without changing the original discharge frequency, fan rated parameters, or system temperature control standards, includes the following steps: S1, Equipment pretreatment: After leak detection and overall machine inspection, the furnace body is heated and melted to remove residual deposits on the furnace wall; S2, Magnesium addition and initial liquid level correction: After melting, magnesium is added, controlling the magnesium feeding ratio, and the initial liquid level is measured after the furnace conditions stabilize. S3. Initial liquid level: The initial discharge volume is obtained based on the relevant liquid level calculation formula; S4. Raise and lock the reaction liquid level: Titanium tetrachloride raw material is transported in stages, and magnesium chloride is discharged by relying on the pressure difference in the furnace, controlling the position of the melt liquid level in the furnace before and after discharge; The air volume of the first air inlet 2 and the second air inlet 3 is dynamically distributed and adjusted to regulate the temperature of the upper outer wall of the reactor and eliminate local supercooling of the furnace wall; S5. Precise discharge: Discharge operation is carried out according to the calculated discharge volume, and the deviation of discharge time and discharge weight is controlled; S6. Post-processing: After the titanium tetrachloride feeding and reduction discharge are completed, the existing mature process is used to complete the distillation, cooling, discharge and furnace cleaning; Through the above process, the proportion of titanium climbing the furnace wall is stably controlled within 4%.

[0038] In this embodiment, the center distance between the first air inlet 2 and the second air inlet 3 is 600-800 mm; in S1, the furnace temperature is raised to 800-840℃ and held at a constant temperature for 4-6 hours to melt the residual condensed by-products and production residues on the inner wall of the furnace. The residual condensed by-products and previous residues on the inner wall of the furnace are fully melted, and the molten impurities can be melted into the magnesium liquid system, eliminating the interference of residual impurities on the accuracy of liquid level measurement and the stability of the reduction reaction.

[0039] Specifically, in step S2, after melting, the temperature is lowered to 780-820℃ and magnesium is added in one go, with the magnesium addition time being 0.4-0.6 hours; high-purity argon gas with a purity ≥99.99% is introduced throughout the feeding process, and the furnace pressure is maintained at 1-5 kPa; the total amount of magnesium added is 38%-42% of the total mass of titanium tetrachloride added; after the magnesium is added, the material is kept at a constant temperature of 780-800℃ for 1-2 hours to mix it, and then kept still for 0.5-1 hours to stabilize the temperature field, pressure field, and liquid phase distribution in the furnace; the initial liquid level is measured using a mechanical probe liquid level device 4; the formula for calculating the initial discharge volume is as follows: In the formula: This is the initial discharge volume; This refers to the amount of titanium tetrachloride added during the initial discharge. The standard liquid level is represented by k, where k is the liquid level coefficient. H is the measured distance from the feed pipe inlet to the center of the first air inlet 2; the liquid level coefficient k is coupled with the reactor inner diameter D and the total feed rate T of titanium tetrachloride in a single furnace: when D=1800mm-1900mm and T=32t-36t, k=4.2-4.7kg / mm; when D=1900mm-2000mm and T=36t-40t, k=4.7-5.2kg / mm; intermediate values ​​are linearly interpolated; when the feed rate of titanium tetrachloride in a single furnace is 32t-40t, The value is 700-1100 kg. By limiting the magnesium addition process parameters, the magnesium thermal reduction reaction ratio is ensured to be sufficient. The furnace is allowed to settle sufficiently to stabilize the temperature and pressure fields. The initial discharge volume is calibrated using a calculation formula to unify the liquid level benchmark for each furnace and eliminate the differences in initial operating conditions between different furnaces.

[0040] Specifically, the mechanical probe leveling device 4 is a 5000mm long stainless steel round tube with an outer diameter of 20-30mm and a wall thickness of 2-3mm. Depth markings are set every 100mm along the tube. Level measurement: The probe is inserted vertically from the top feed port until its upper end is flush with the feed port. After extraction, the length from the lower wetting mark to the upper edge of the probe is measured. Repeat the measurement 2-3 times and take the average value, with a measurement accuracy of ±5mm. The mechanical probe liquid level device 4 is resistant to high temperature and magnesium liquid corrosion. Taking the average value of multiple measurements can reduce the measurement error caused by human operation, ensure the accuracy of the initial liquid level acquisition, and provide reliable basic data for the discharge volume calculation.

[0041] Furthermore, in S3, the titanium tetrachloride conveying pressure is 0.3-0.6MPa, and the segmented feeding flow rates are: 200-250kg / h for cumulative feeding of 0-8t; 450-500kg / h for cumulative feeding of 8-27t; and 280-320kg / h for cumulative feeding of 27t-40t. The discharge process conditions are: melt discharge temperature of 750-840℃, instantaneous furnace pressure of 40-90kPa, and discharge rate of 3000-4000kg / h. Before each discharge is started, the melt level is 0-200mm below the center of the second air inlet 3, and after the discharge is completed, the melt level rises to 100-300mm above the center of the first air inlet 2. The segmented feeding adapts to the exothermic characteristics of different stages of the reduction reaction, and the discharge is achieved by relying on the pressure difference inside the furnace without the need for additional equipment modifications; the reaction liquid level is raised and locked to the constant temperature range of the dual air outlets, and the liquid phase is used to cover the low-temperature empty furnace wall, compressing the space for climbing titanium growth.

[0042] Furthermore, the S3 airflow distribution criteria are as follows: the first air inlet 2 distributes 60%-80% of the total airflow, and the second air inlet 3 distributes 20%-40% of the total airflow; 4-6 thermocouples 5 are evenly distributed around the circumference of the upper outer wall of the reactor cylinder, and the average temperature measurement is used as the airflow adjustment criterion; if the average temperature of the outer wall is higher than 790℃, the airflow ratio of the second air inlet 3 is increased by 10%-20%, and the airflow ratio of the first air inlet 2 is decreased by the same amount; if the average temperature of the outer wall is lower than 760℃, the air supply of the second air inlet 3 is reduced or shut off; the temperature of the upper outer wall of the reactor is stably maintained at 760-790℃. By dynamically distributing the cooling airflow through the dual air inlets, temperature compensation is performed on the upper part of the furnace body, eliminating local low-temperature areas in the upper part of the cylinder and disrupting the thermodynamic conditions for the adhesion of climbing titanium crystals.

[0043] Furthermore, in S4, the actual time spent on a single discharge operation deviates from the planned time by ≤30 minutes, and the actual weight of magnesium chloride discharged in a single operation deviates from the theoretical calculated value by ≤100 kg. Strict control over the duration and weight deviation of the discharge operation is crucial to prevent sudden and significant fluctuations in the liquid level within the furnace, maintain the stability of the furnace temperature field and liquid phase system, and ensure the steady-state operation of the magnesothermic reduction reaction.

[0044] Furthermore, the reducing distillation furnace also includes a reactor body 6, a cooling fan 1, an airflow regulating valve 7, a mechanical probe level device 4, a titanium tetrachloride feeding system 8, a discharge pipe 9, and thermocouples 5. The cooling fan 1 has two air supply branches, which are respectively connected to the first air inlet 2 and the second air inlet 3 on the reactor body 6. The first air inlet 2 and the second air inlet 3 are arranged vertically along the axial direction of the reactor body 6. An airflow regulating valve 7 is installed on each air supply branch. The mechanical probe level device 4 is located at the top of the reactor body 6 at the feeding port. Multiple thermocouples 5 are evenly distributed and fixed to the upper outer wall of the reactor body 6. The signal output terminals of the thermocouples 5 are electrically connected to the control unit of the airflow regulating valve 7. The hardware architecture is adapted to the implementation conditions of this process. The thermocouples 5 collect temperature signals and feed them back to the airflow regulating valve 7 to realize automatic dynamic adjustment of the airflow at both air inlets, ensuring the stable execution of the furnace wall temperature control strategy.

[0045] Furthermore, the center-to-center distance between the first air inlet 2 and the second air inlet 3 is 600-800mm; the inner diameter of the reactor cylinder 6 is 1800-2000mm, and the effective height of the reactor cylinder 6 is ≥2800mm; the mechanical probe level device 4 is a stainless steel round tube with a total length of 5000mm, an outer diameter of 20-30mm, a wall thickness of 2-3mm, and pre-marked depth graduations every 100mm on the tube body. The equipment size matches the mainstream 8-10t inverted U-shaped reduction distillation furnace on the market, and the process can be directly implemented on existing production lines without large-scale hardware modifications.

[0046] Furthermore, multiple thermocouples 5 are used, installed on both the inner and outer walls of the reactor cylinder 6. Simultaneous temperature measurement of both the inner and outer walls provides a more comprehensive reflection of the actual furnace wall temperature, reducing errors from single temperature measurement points and improving the accuracy of airflow regulation.

[0047] Example 1: This example uses a U-shaped reduction distillation furnace producing 10t of sponge titanium. The reactor cylinder 6 has an inner diameter of 2000mm and an effective height of 3100mm. The center-to-center distance between the first air inlet 2 and the second air inlet 3 is 700mm. The single-furnace titanium tetrachloride feed rate is 38t. The measured distance H from the feed pipe to the center of the first air inlet 2 is 2350mm. Standard liquid level... =2150mm, liquid level coefficient k is taken as 5.2kg / mm, The value is 900 kg. S1 equipment pretreatment: the furnace body leak detection and the whole machine inspection are all qualified. The furnace temperature is raised to 820℃ and kept at a constant temperature for 5 hours. The residual condensed by-products and production residues on the inner wall of the melting reactor cylinder 6 are removed.

[0048] S2 Magnesium Addition and Initial Liquid Level Correction: The temperature was lowered to 800℃, and 99.995% high-purity argon gas was introduced. The furnace pressure was maintained at 3 kPa. Magnesium was added in one go over 0.5 hours, with a total of 15.2 tons of magnesium, accounting for 40% of the total titanium tetrachloride feed. After magnesium addition, the material was kept at 790℃ for 1.5 hours to mix it, and then allowed to stand for another 0.5 hours to allow the temperature, pressure, and liquid phase distribution within the furnace to stabilize. The initial liquid level was measured three times using a mechanical probe leveling device, with readings of 1848 mm, 1852 mm, and 1850 mm. The average value was taken. =1850mm; Substitute into the formula to calculate the initial discharge amount.

[0049] S3 raises and locks the reaction liquid level: Titanium tetrachloride feeding system 8 conveying pressure control 0.4-0.5MPa; cumulative feed 0-8t flow rate 220kg / h, cumulative feed 8-27t flow rate 480kg / h, cumulative feed 27-38t flow rate 300kg / h; relying on argon gas in the furnace to establish pressure difference, instantaneous furnace pressure during discharge 60-80kPa, melt discharge temperature 780-820℃, discharge rate 3500kg / h; melt level control before each discharge start-up. 100mm below the center of the second air inlet 3, after the discharge is completed, the liquid level rises to 200mm above the center of the first air inlet 2; the total air volume of the cooling fan 1 is 9600m³ / h, and under the reference working condition, the first air inlet 2 is allocated 70% of the total air volume, and the second air inlet 3 is allocated 30% of the total air volume; the thermocouple 5 simultaneously collects the temperature of the inner and outer walls of the reactor cylinder 6, takes the average value as the air adjustment reference, and dynamically adjusts the air volume regulating valve 7 to stably control the temperature of the upper outer wall of the reactor cylinder 6 at 760-790℃.

[0050] S4 Precision Discharge: When performing discharge operations, the actual discharge time and planned time deviation for a single discharge are controlled within 30 minutes, and the actual discharged weight of magnesium chloride deviates from the theoretical calculation value by less than 100 kg.

[0051] S5 Post-Processing: After the feeding and reduction of titanium tetrachloride are completed, the existing mature process is used to carry out distillation, cooling, discharge, and furnace cleaning. After completion of this embodiment, the measured proportion of climbing titanium is 3.6%, the average thickness of climbing titanium is 9mm, and the furnace cleaning time per furnace is 1.5h; the impurity index of the finished sponge titanium is Fe=0.012%, Cl=0.045%, N=0.004%, O=0.035%, C=0.009%, which is better than the national standard 0A grade sponge titanium index.

[0052] Example 2

[0053] This embodiment uses an inverted U-shaped reduction distillation furnace that produces 9 tons of sponge titanium. The reactor cylinder 6 has an inner diameter of 1900 mm and an effective height of 3000 mm. The center-to-center distance between the first air inlet 2 and the second air inlet 3 is 650 mm. The single-furnace titanium tetrachloride feed rate is 36 tons, and H=2320 mm. =2120mm, k=4.7kg / mm, The value is 820 kg. S1 equipment pretreatment: The furnace body leak detection point is qualified, the furnace temperature is raised to 810℃, and the constant temperature is maintained for 4.5 hours to melt the residual deposits on the inner wall of the furnace.

[0054] S2 Magnesium Addition Operation and Initial Liquid Level Correction: Cool down to 790℃, introduce 99.99% pure high-purity argon gas, maintain furnace pressure at 2kPa, add metallic magnesium in one go over 0.45h, magnesium feed amount is 14.04t, which is 39% of the total feed mass of titanium tetrachloride; after magnesium addition, keep at 785℃ for 1.2h to mix the material, and let stand for 0.8h to stabilize the working condition; mechanical probe liquid level device 4 is used to measure twice, and the average is taken to obtain the initial liquid level, which is then substituted into the formula to calculate the first discharge amount.

[0055] S3 raises and locks the reaction liquid level: Titanium tetrachloride delivery pressure 0.35-0.5MPa; cumulative feed flow rate 230kg / h for 0-8t, 460kg / h for 8-27t, and 290kg / h for 27-36t; instantaneous discharge furnace pressure 50-75kPa, melt discharge temperature 760-830℃, discharge rate 3300kg / h; before discharge, the liquid level is 120mm below the center of the second air inlet 3, and after discharge, the liquid level rises to 180mm above the center of the first air inlet 2; the reference air volume ratio is 65% allocated to the first air inlet 2 and 35% allocated to the second air inlet 3; thermocouple 5 collects the temperature of the inner and outer walls of the cylinder, and dynamically adjusts the two air volumes through the air volume regulating valve 7 to maintain the upper outer wall temperature at 760-790℃.

[0056] S4 precise material feeding strictly controls feeding time and feeding weight deviation.

[0057] S5 performs the existing distillation, cooling, discharge, and furnace cleaning process. In this embodiment, the measured titanium content on the wall is 3.7%, and the various impurity indicators of the product are better than the national standard 0A grade sponge titanium requirements.

[0058] Example 3

[0059] This embodiment uses an inverted U-shaped reduction distillation furnace that produces 8 tons of sponge titanium. The reactor cylinder 6 has an inner diameter of 1800 mm and an effective height of 2900 mm. The center-to-center distance between the first air inlet 2 and the second air inlet 3 is 750 mm. The single-furnace titanium tetrachloride feed rate is 34 tons, and H=2280 mm. =2080mm, k=4.2kg / mm, Mfirst value is 750kg. S1 equipment pretreatment: the furnace body leak detection point is qualified, the furnace temperature is raised to 830℃, and the constant temperature is maintained for 6h to melt the residual condensed by-products on the inner wall of the furnace.

[0060] S2 Magnesium Addition Operation and Initial Liquid Level Correction: Cool down to 810℃, introduce 99.99% high-purity argon gas, furnace pressure 4kPa, add metallic magnesium in one go over 0.6h, magnesium feed amount 12.92t, which is 38% of the total feed mass of titanium tetrachloride; after magnesium addition, keep at 795℃ for 2h to mix the material, and let stand for 1h to stabilize the furnace conditions; the initial liquid level is obtained by taking the average of multiple measurements with the mechanical probe liquid level device 4, and then used to calculate the first discharge amount in the formula.

[0061] S3 raises and locks the reaction liquid level: Titanium tetrachloride delivery pressure 0.4-0.6MPa; cumulative feed flow rate 240kg / h for 0-8t, 490kg / h for 8-27t, and 310kg / h for 27-34t; instantaneous discharge furnace pressure 55-85kPa, melt discharge temperature 770-840℃, discharge rate 3800kg / h; before discharge, the liquid level is 80mm below the center of the second air inlet 3, and after discharge, the liquid level rises to 250mm above the center of the first air inlet 2; the reference air volume ratio is 75% allocated to the first air inlet 2 and 25% allocated to the second air inlet 3; thermocouple 5 collects the temperature of the inner and outer walls of the cylinder, the air volume regulating valve 7 dynamically distributes the air, and the upper outer wall temperature is stable at 760-790℃.

[0062] S4 Precision Feeding controls feeding time and weight deviation.

[0063] S5 utilizes existing mature downstream processes to complete distillation, cooling, discharge, and furnace cleaning. In this embodiment, the measured titanium content climbing the wall was 3.8%, meeting the control target of ≤4% titanium content climbing the wall, and the raw material utilization rate was significantly improved.

[0064] Five furnace cycles were selected from the same production line for comparative analysis. Traditional low-level liquid control was used, but the liquid level calibration and dual-air outlet dynamic air distribution process of this invention were not adopted. The other raw materials and equipment conditions were kept the same as in Examples 1-3. The measured titanium climbing ratios were 12.1%, 13.5%, 11.8%, 14.2%, and 12.9%, respectively, with an average titanium climbing ratio of 12.9%. The maximum circumferential temperature difference on the upper part of the furnace wall was 45-50℃, indicating a significant local overcooling phenomenon.

[0065] This invention is applicable to 8-10t inverted U-shaped large-scale reducing distillation furnaces. No additional hardware modifications are required. Through liquid level calibration, discharge parameter optimization, and the synergistic effect of dynamic air distribution and temperature control at dual air outlets, the proportion of climbing titanium can be stably controlled within 4%, thereby improving raw material utilization, reducing furnace cleaning time, improving batch consistency of products, and reducing equipment operation and maintenance and overall production costs. It is suitable for large-scale promotion and use in the industry.

[0066] Finally, it should be noted that the electronic components in the cooling fan 1 and other components in this embodiment are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires. The specific connection method should refer to the working order between the electrical components in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for reducing titanium content by climbing walls in a large inverted U-shaped reducing distillation furnace, characterized in that: An inverted U-shaped reduction distillation furnace is used to produce 8-10t sponge titanium. The reduction distillation furnace is equipped with a cooling fan (1). The cooling fan (1) is provided with a first air inlet (2) and a second air inlet (3) arranged vertically along the axial direction of the reactor cylinder. The process includes the following steps without changing the original discharge frequency, fan rated parameters and system temperature control standards: S1. Equipment pretreatment: After the furnace body leak detection and the whole machine inspection are qualified, the furnace is heated and melted to remove the residual deposits on the inner wall of the furnace. S2. Magnesium Addition and Initial Liquid Level Correction: After melting is completed, magnesium addition is performed, and the magnesium feed ratio is controlled. After the furnace conditions stabilize, the initial liquid level is measured. The initial discharge volume is obtained based on the liquid level-related calculation formula; S3. Raise and lock the reaction liquid level: transport titanium tetrachloride raw material in sections, discharge magnesium chloride by relying on the pressure difference in the furnace, and control the position of the melt liquid level in the furnace before and after discharge; dynamically distribute and adjust the air volume of the first air inlet (2) and the second air inlet (3) to regulate the temperature of the upper outer wall of the reactor and eliminate local overcooling of the furnace wall. S4. Precise material feeding: Carry out material feeding operations according to the calculated material feeding amount, and control the deviation of material feeding time and material feeding weight. S5. Post-processing: After the titanium tetrachloride feed and reduction discharge are completed, the existing mature process is used to complete the distillation, cooling, discharge and furnace cleaning. The above process ensures that the proportion of titanium climbing the furnace wall is stably controlled within 4%.

2. The process for reducing titanium content in a wall-climbing process suitable for a large inverted U-shaped reducing distillation furnace according to claim 1, characterized in that: The center distance between the first air inlet (2) and the second air inlet (3) is 600-800mm; the furnace in S1 is heated to 800-840℃ and kept at a constant temperature for 4-6h. The inner wall of the melting furnace contains residual condensed by-products and production residues.

3. The process for reducing titanium content in a wall-climbing process suitable for a large inverted U-shaped reducing distillation furnace according to claim 1, characterized in that: In S2, after melting, the temperature is lowered to 780-820℃ and magnesium is added in one go, with a magnesium addition time of 0.4-0.6h; high-purity argon gas with a purity ≥99.99% is introduced throughout the feeding process, and the furnace pressure is maintained at 1-5kPa; the total amount of magnesium is 38%-42% of the total mass of titanium tetrachloride; after adding magnesium, the material is kept at a constant temperature of 780-800℃ for 1-2h to mix the material, and then kept at a constant temperature for 0.5-1h to stabilize the temperature field, pressure field and liquid phase distribution in the furnace; the initial liquid level is measured by a mechanical probe liquid level device (4). Initial discharge volume calculation formula: In the formula: This is the initial discharge volume; This refers to the amount of titanium tetrachloride added during the initial discharge. The standard liquid level is represented by k; k is the liquid level coefficient. Standard liquid level H is the measured distance from the feed pipe inlet to the center of the first air inlet (2); the liquid level coefficient k is coupled with the reactor inner diameter D and the total feed amount T of titanium tetrachloride per furnace: When D=1800mm-1900mm and T=32t-36t, k=4.2-4.7kg / mm; When D=1900mm-2000mm and T=36t-40t, k=4.7-5.2kg / mm; intermediate values ​​are obtained through linear interpolation; when the single furnace titanium tetrachloride feed rate is 32t-40t, Values ​​range from 700 to 1100 kg.

4. The titanium reduction production process for a wall-climbing furnace suitable for a large inverted U-shaped reducing distillation furnace according to claim 3, characterized in that: The mechanical probe level device (4) is a stainless steel round tube with a total length of 5000mm, an outer diameter of 20-30mm, and a wall thickness of 2-3mm. Depth markings are set every 100mm along the tube body. Level measurement: The probe is inserted vertically from the top feed port until the upper end of the probe is flush with the feed port. After being pulled out, the length from the wetting mark at the lower end of the probe to the upper edge of the probe is measured. Repeat the measurement 2-3 times and take the average value. The measurement accuracy is ±5mm.

5. The wall-climbing titanium reduction production process applicable to a large inverted U-shaped reducing distillation furnace according to claim 1, characterized in that: In S3, the titanium tetrachloride conveying pressure is 0.3-0.6 MPa, and the segmented feeding flow rates are: 200-250 kg / h for cumulative feeding of 0-8t; 450-500 kg / h for cumulative feeding of 8-27t; and 280-320 kg / h for cumulative feeding of 27t-40t. The discharge process conditions are: melt discharge temperature of 750-840℃, instantaneous furnace pressure at discharge of 40-90 kPa, and discharge rate of 3000-4000 kg / h. Before a single discharge is started, the melt level is 0-200mm below the center of the second air inlet (3). After the discharge is completed, the melt level rises to 100-300mm above the center of the first air inlet (2).

6. The process for reducing titanium content in a wall-climbing process suitable for a large inverted U-shaped reducing distillation furnace according to claim 1, characterized in that: The S3 air volume distribution benchmark is as follows: the first air inlet (2) distributes 60%-80% of the total air volume, and the second air inlet (3) distributes 20%-40% of the total air volume; 4-6 thermocouples (5) are evenly distributed around the circumference of the upper outer wall of the reactor cylinder, and the average temperature is taken as the air adjustment benchmark; if the average temperature of the outer wall is higher than 790℃, the air volume ratio of the second air inlet (3) is increased by 10%-20%, and the air volume ratio of the first air inlet (2) is reduced by the same amount; if the average temperature of the outer wall is lower than 760℃, the air supply of the second air inlet (3) is reduced or shut off; the temperature of the upper outer wall of the reactor is kept stable at 760-790℃.

7. The wall-climbing titanium reduction production process applicable to a large inverted U-shaped reducing distillation furnace according to claim 1, characterized in that: In S4, the actual time spent on a single discharge deviates from the planned time by ≤30 min, and the actual weight of magnesium chloride discharged in a single discharge deviates from the theoretical calculated value by ≤100 kg.

8. The wall-climbing titanium reduction production process applicable to an inverted U-shaped large-scale reducing distillation furnace according to any one of claims 1-7, characterized in that: The reducing distillation furnace also includes a reactor cylinder (6), a cooling fan (1), an air volume regulating valve (7), a mechanical probe liquid level device (4), a titanium tetrachloride feeding system (8), a discharge pipeline (9), and a thermocouple (5); The cooling fan (1) is provided with two air supply branches, which are respectively connected to the first air inlet (2) and the second air inlet (3) on the reactor body (6); the first air inlet (2) and the second air inlet (3) are arranged vertically along the axial direction of the reactor body (6); each air supply branch is equipped with an air volume regulating valve (7); the mechanical probe liquid level device (4) is located at the top of the reactor body (6) at the feeding port position; multiple thermocouples (5) are evenly distributed and fixed on the upper outer wall of the reactor body (6) along the circumference; the signal output terminal of the thermocouple (5) is electrically connected to the control unit of the air volume regulating valve (7).

9. The wall-climbing titanium reduction production process applicable to a large inverted U-shaped reducing distillation furnace according to claim 8, characterized in that: The center-to-center distance between the first air inlet (2) and the second air inlet (3) is 600-800mm; the inner diameter of the reactor cylinder (6) is 1800-2000mm, and the effective height of the reactor cylinder (6) is ≥2800mm; the mechanical probe liquid level device (4) is a stainless steel round tube with a total length of 5000mm, an outer diameter of 20-30mm, a wall thickness of 2-3mm, and pre-marked depth scales every 100mm on the tube body.

10. The wall-climbing titanium reduction production process applicable to a large inverted U-shaped reducing distillation furnace according to claim 8, characterized in that: The thermocouples (5) are multiple in number and are installed at the inner wall and outer wall of the reactor cylinder (6).

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