Fluidized boiling chlorination furnace temperature control system and control method
By using a fluidized bed chlorination furnace temperature control system, the bed and outlet gas temperatures are precisely controlled, solving the problems of poor fluidization effect and pipeline blockage caused by uncontrolled temperature, and achieving safe and efficient operation of the fluidized bed chlorination furnace.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LUOYANG SUNRUI WANJI TITANIUM CO LTD
- Filing Date
- 2023-06-25
- Publication Date
- 2026-05-19
AI Technical Summary
In existing technologies, the bed reaction temperature and outlet gas temperature of fluidized bed chlorination furnaces are not controlled, resulting in poor fluidization effect and blockage of furnace gas pipelines.
A fluidized bed chlorination furnace temperature control system is adopted, including a gas distributor and a furnace top spray tower. By controlling the flow rates of Cl2, O2, compressed air and N2, combined with temperature detection and spraying devices, the bed temperature is precisely controlled within the range of 950 to 1000℃ and the outlet gas temperature is controlled within the range of 580 to 630℃.
It achieves active and precise temperature control of bed temperature and furnace gas pipeline temperature, improves the fluidized bed chlorination reaction effect, avoids pipeline blockage, extends the chlorination furnace operation cycle, and ensures safe production.
Smart Images
Figure CN116768266B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fluidized bed chlorination furnaces for TiCl4 production, and more specifically, to a temperature control system and control method for a fluidized bed chlorination furnace used in the production of titanium tetrachloride using fluidized bed chlorination technology. Background Technology
[0002] In the TiCl4 production process, the main raw materials in the fluidized bed chlorination stage are titanium-rich materials and petroleum coke. These react with chlorine and other substances in a specific ratio within a fluidized bed chlorination furnace at 950–1000℃ to produce crude TiCl4. The reaction temperature within the chlorination furnace is a crucial process parameter reflecting the furnace condition and chlorination efficiency. Too low a temperature results in insufficient kinetics, leading to a slower chlorination reaction rate, incomplete chlorination of the titanium slag, and excessive chlorine content in the tail gas, severely impacting titanium tetrachloride production capacity and increasing tail gas emissions. When chlorinating high-calcium magnesium titanium slag, lower temperatures cause the bed material to easily agglomerate, worsening furnace conditions and further reducing the chlorination efficiency of the titanium slag. Higher temperatures are beneficial for increasing the reaction rate and chlorination rate, but the increased participation of carbon (C) in the reaction to form CO leads to increased heat absorption and carbon consumption, while also exacerbating corrosion of the furnace lining. Therefore, maintaining a stable furnace temperature within a certain range is fundamental for safe and stable production.
[0003] Meanwhile, fluidized bed chlorination furnaces use a top-discharge slag process, and the gas temperature at the furnace top is generally maintained at 750-900℃. At this temperature, CaCl2 (melting point 772℃, boiling point 1600℃), MgCl2 (melting point 708℃, boiling point 1412℃), MnCl2 (melting point 650℃, boiling point 1190℃), and FeCl2 (melting point 670℃, boiling point 1030℃) are all in a molten state. Due to the boundary layer effect in the pipeline, these molten impurities, along with unreacted C, TiO2, and other particles, accumulate in the furnace gas pipeline, which can easily lead to pipeline blockage, forcing a furnace shutdown for maintenance and disrupting production stability. Summary of the Invention
[0004] In view of this, the present invention aims to propose a fluidized bed chlorination furnace temperature control system and control method to solve the problems of poor bed fluidization effect and furnace gas pipeline adhesion and blockage caused by uncontrolled reaction temperature of fluidized bed and gas outlet temperature of chlorination furnace in the prior art.
[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:
[0006] A fluidized bed chlorination furnace temperature control system includes a fluidized bed chlorination furnace, a gas distributor, and a furnace top spray tower. The gas distributor is located at the bottom of the chlorination furnace, and the furnace top spray tower is located at the top of the chlorination furnace. The furnace top spray tower is connected to a dust collection system via a furnace gas pipeline. The gas distributor is connected to a mixed gas main pipeline, which is connected to a Cl2 pipeline, a compressed air pipeline, and an O2 pipeline. The gas distributor controls the distribution of Cl2, O2, and compressed air into the chlorination furnace. The temperature control system also includes a chlorination furnace bed temperature control system and a chlorination furnace top outlet gas pipeline temperature control system. The chlorination furnace bed temperature control system is located in the middle or near the middle of the chlorination furnace. The chlorination furnace bed temperature control system includes a first crude TiCl4 pipeline and a first N2 pipeline. The bed temperature is controlled within the range of 950-1000℃ through the gas distributor and the chlorination furnace bed temperature control system. The chlorination furnace top outlet gas pipeline temperature control system is located in the furnace top spray tower. The furnace top outlet gas pipeline temperature control system includes a branch of the first crude TiCl4 pipeline and a second N2 pipeline. The chlorination furnace outlet gas temperature control system is controlled within the range of 580-630℃ through the furnace top outlet gas pipeline temperature control system.
[0007] Furthermore, a Cl2 regulating valve is installed on the Cl2 pipeline, a compressed air regulating valve is installed on the compressed air pipeline, an O2 regulating valve is installed on the O2 pipeline, and an oxygen content detector is installed on the main mixed gas pipeline. The oxygen content detector is used to monitor the O2 content in the main mixed gas pipeline.
[0008] Furthermore, the first N2 pipeline and the first crude TiCl4 pipeline are connected to the chlorination furnace. A first nozzle is provided inside the connection between the first N2 pipeline and the first crude TiCl4 pipeline and the chlorination furnace. The first nozzle is used to control the channel for crude TiCl4 and N2 to enter the middle of the chlorination furnace. The chlorination furnace bed temperature control system forms a central spray device inside the chlorination furnace. The central spray device is located 500-1000 mm above the material in the chlorination furnace bed.
[0009] Furthermore, the first crude TiCl4 pipeline is divided into two paths that enter the interior of the furnace top spray tower. A second nozzle and a third nozzle are respectively installed at the ends of the two paths. The second nozzle is located below the third nozzle. The second nozzle and the crude TiCl4 gas flow in the same direction as the flow, while the third nozzle and the crude TiCl4 gas flow in the opposite direction.
[0010] Furthermore, a cooling device is installed on the furnace gas pipeline before the crude TiCl4 gas is discharged from the top of the furnace top spray tower and enters the dust collection system. The cooling device includes a high-pressure third N2 pipeline, a second crude TiCl4 pipeline, and a fourth nozzle. A fourth pressure sensor is also installed before the fourth nozzle to detect the spray pressure of the fourth nozzle.
[0011] Compared with existing technologies, the fluidized bed chlorination furnace temperature control system described in this invention has the following advantages:
[0012] It can effectively and precisely control the bed reaction temperature of the chlorination furnace at 950–1000℃, improving the fluidized bed chlorination reaction effect and solving the problems of low chlorine utilization rate and accelerated corrosion of the furnace lining caused by uncontrollable bed temperature. It controls the top outlet gas temperature of the chlorination furnace at 580–630℃ and the furnace gas temperature before the dust collection equipment at 180–220℃, solving the pipeline blockage problem caused by impurity phase change and pipeline boundary layer effect, extending the chlorination furnace operating cycle, and ensuring safe production. It achieves active and precise temperature control of the bed temperature and furnace gas pipeline temperature, improving the fluidized bed chlorination reaction effect, and achieving the goal of safe, efficient, continuous, and stable operation of the fluidized bed chlorination furnace.
[0013] This invention also provides a temperature control method for a fluidized bed chlorination furnace, using the aforementioned fluidized bed chlorination furnace temperature control system. The temperature control method includes a fluidized bed chlorination furnace temperature control method and a furnace top outlet gas pipeline temperature control method. The fluidized bed chlorination furnace temperature control method includes: when the bed temperature is below 950°C, supplying compressed air into the fluidized bed chlorination furnace to assist in temperature increase; when the bed temperature is above 1000°C, introducing crude TiCl4 liquid into the chlorination furnace through a first crude TiCl4 pipeline for flash evaporation to remove bed heat and reduce temperature.
[0014] Furthermore, when the bed temperature is below 950°C, O2 is supplied to the fluidized bed chlorination furnace through the O2 pipeline 103 via the gas distributor to increase the heating rate.
[0015] Furthermore, during the O2 introduction process, the O2 content in the main gas mixture pipeline 105 needs to be monitored to be between 18% and 30% using an oxygen content detector.
[0016] Furthermore, when the bed temperature exceeds 1000℃ and the spray pressure of the coarse TiCl4 pipeline exceeds the control range, the spray pressure can be assisted by adjusting the first N2 regulating valve on the first N2 pipeline.
[0017] Furthermore, the method for controlling the temperature of the furnace top outlet gas pipeline includes: controlling the pressure of the first crude TiCl4 pipeline 106 of the furnace top outlet gas pipeline temperature control system to stably control the outlet gas temperature of the chlorination furnace within the range of 580 to 630°C. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the temperature control system for the fluidized bed chlorination furnace according to an embodiment of the present invention.
[0019] Explanation of reference numerals in the attached figures:
[0020] 1. Fluidized bed chlorination furnace; 2. Bed thermocouple; 3. Gas distributor; 4. Cl2 regulating valve; 5. Compressed air regulating valve; 6. O2 regulating valve; 7. Furnace top spray tower; 8. Oxygen content detector; 9. First crude TiCl4 regulating valve; 17. Second crude TiCl4 regulating valve; 18. Third crude TiCl4 regulating valve; 23. Fourth crude TiCl4 regulating valve; 10. First N2 regulating valve; 16. Second N2 regulating valve; 19. Third N2 regulating valve; 22. Fourth N2 regulating valve; 11. First pressure sensor; 2. Second pressure sensor. Sensor 20, third pressure sensor 21, fourth pressure sensor 24; first nozzle 12, second nozzle 14, third nozzle 15, fourth nozzle 25; first thermocouple 13, second thermocouple 26; Cl2 pipeline 101, compressed air pipeline 102, O2 pipeline 103, furnace gas pipeline 104, mixed gas main pipeline 105; first N2 pipeline 107, second N2 pipeline 108, third N2 pipeline 109; first coarse TiCl4 pipeline 106, second coarse TiCl4 pipeline 110 Detailed Implementation
[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0022] like Figure 1As shown, a fluidized bed chlorination furnace temperature control system includes a fluidized bed chlorination furnace 1, a gas distributor 3, and a furnace top spray tower 7. The gas distributor 3 is located at the lower part of the fluidized bed chlorination furnace 1, and the furnace top spray tower 7 is located at the top of the fluidized bed chlorination furnace 1. The furnace top spray tower 7 is connected to a dust collection system via a furnace gas pipeline 104. The gas distributor 3 is connected to a mixed gas main pipeline 105, which is connected to a Cl2 pipeline 101, a compressed air pipeline 102, and an O2 pipeline 103, respectively. The gas distributor 3 controls the distribution of Cl2, O2, and compressed air into the fluidized bed chlorination furnace 1. A bed thermocouple 2 is also installed on the fluidized bed chlorination furnace 1 to detect the bed temperature. The control system described in this embodiment includes a chlorination furnace bed temperature control system and a chlorination furnace top outlet gas pipeline temperature control system. The chlorination furnace bed temperature control system is located in the middle or near the middle of the chlorination furnace 1. This system includes a first crude TiCl4 pipeline 106 and a first N2 pipeline 107. The bed temperature is controlled within a reasonable process requirement range of 950–1000°C via a gas distributor 3 and the chlorination furnace bed temperature control system. The chlorination furnace top outlet gas pipeline temperature control system is located inside the furnace top spray tower 7. This system is configured as a crude TiCl4 liquid spray device and includes a branch of the first crude TiCl4 pipeline 106 and a second N2 pipeline 108. The chlorination furnace outlet gas temperature is controlled within a range of 580–630°C via the furnace top outlet gas pipeline temperature control system.
[0023] Furthermore, a Cl2 regulating valve 4 is installed on the Cl2 pipeline 101, a compressed air regulating valve 5 is installed on the compressed air pipeline 102, and an O2 regulating valve 6 is installed on the O2 pipeline 103, controlling the flow rate of each intake through these regulating valves. Simultaneously, an oxygen content detector 8 is installed on the main mixed gas pipeline 105 to monitor the O2 content within the main mixed gas pipeline 105.
[0024] In the chlorination furnace bed temperature control system, the first N2 pipeline 107 and the first crude TiCl4 pipeline 106 are combined and connected to the chlorination furnace 1. A first nozzle 12 is installed inside the connection between the two pipelines and the chlorination furnace 1. The first nozzle 12 is used to control the channel through which crude TiCl4 and N2 enter the middle of the chlorination furnace 1. Furthermore, the chlorination furnace bed temperature control system forms a central spray device inside the chlorination furnace 1, which is located 500-1000 mm above the material on the chlorination furnace bed.
[0025] A first coarse TiCl4 regulating valve 9 is installed on the first coarse TiCl4 pipeline 106 to regulate the flow rate of coarse TiCl4. A first N2 regulating valve 10 is installed on the first N2 pipeline 107 to regulate the N2 flow rate on the first N2 pipeline 107. Furthermore, a first pressure sensor 11 is installed before the first nozzle 12 to detect the spray pressure of the first nozzle 12.
[0026] In the temperature control system of the gas outlet pipeline at the top of the chlorination furnace, the first crude TiCl4 pipeline 106 splits into two paths entering the furnace top spray tower 7. A second nozzle 14 and a third nozzle 15 are respectively installed at the ends of the two paths. The second nozzle 14 is located below the third nozzle 15, and the spray directions of the second nozzle 14 and the third nozzle 15 are opposite. The second nozzle 14 flows in the same direction as the crude TiCl4 gas, primarily cooling the crude TiCl4 gas. The third nozzle 15 flows in the opposite direction to the crude TiCl4 gas. Besides cooling the crude TiCl4 gas, its function is to allow large particles trapped in the gas to continue the chlorination reaction as they fall back into the furnace due to inertial collisions, interception, and agglomeration, reducing particle entrainment and increasing Ti yield. A second crude TiCl4 regulating valve 17 and a second pressure sensor 20 are installed before the second nozzle 14, and a third crude TiCl4 regulating valve 18 and a third pressure sensor 21 are installed before the third nozzle 15. The second N2 pipeline 108 is divided into two lines, which are connected to the front of the second nozzle 14 and the front of the third nozzle 15 respectively, to purge the two nozzles and adjust the spray pressure.
[0027] As part of an embodiment of the present invention, a cooling device is installed on the furnace gas pipeline 104 before the crude TiCl4 gas is discharged from the top of the furnace top spray tower 7 and enters the dust collection system. The cooling device includes a high-pressure third N2 pipeline 109, a second crude TiCl4 pipeline 110, and a fourth nozzle 25. A fourth pressure sensor 24 is installed before the fourth nozzle 25 to detect the spray pressure of the fourth nozzle 25. Furthermore, a second thermocouple 26 is installed on the furnace gas pipeline 104, located after the cooling device, to detect the temperature of the crude TiCl4 gas entering the dust collection system. A fourth N2 regulating valve 22 is installed on the third N2 pipeline 109, and a fourth crude TiCl4 regulating valve 23 is installed on the second crude TiCl4 pipeline 110.
[0028] It should be noted that the gas regulating valves in this embodiment are all pneumatic regulating valves. The pressure sensors, thermocouples, and other instruments, valves, and monitoring devices described in this embodiment are all centrally controlled by a DCS system, and the regulating valves are interlocked with the temperature, pressure, and flow parameters to be controlled, thus achieving automatic control.
[0029] The fluidized bed chlorination furnace temperature control system described in this invention can precisely control the bed reaction temperature of the fluidized bed chlorination furnace, thereby improving the fluidized bed chlorination reaction effect; avoid the bed temperature rise caused by the high heat release of materials during the fluidized bed chlorination reaction, slow down the high-temperature erosion corrosion of the fluidized bed chlorination furnace lining, and extend the service life of the fluidized bed chlorination furnace; precisely control the temperature of the fluidized bed chlorination furnace outlet gas pipeline, avoid phase change of impurities such as CaCl2, MgCl2, MnCl2, and FeCl2 in the furnace gas pipeline, solve the problem of furnace gas pipeline blockage, and improve the operational stability of the fluidized bed chlorination furnace.
[0030] During operation, Cl2 is introduced into the fluidized bed chlorination furnace 1 via pipeline 101 through the Cl2 regulating valve 4 and the bottom gas distributor 3. Cl2 reacts with titanium raw materials and petroleum coke to produce crude TiCl4. This process requires the bed temperature to be controlled within the reasonable process range of 950–1000℃ using bed thermocouples 2. The generated crude TiCl4 gas is then transported to subsequent dust removal, condensation, and refining systems via the furnace top spray tower 7 and furnace gas pipeline 104.
[0031] The present invention also provides a method for controlling the temperature of a chlorination furnace, using the aforementioned chlorination furnace temperature control system. The method includes a method for controlling the temperature of the fluidized bed in the fluidized bed chlorination furnace and a method for controlling the temperature of the gas outlet line at the furnace top.
[0032] The method for controlling the bed temperature in a fluidized bed chlorination furnace includes the following processes:
[0033] When the bed temperature is below 950℃, compressed air is supplied to the boiling chlorination furnace 1 to assist in raising the temperature; when the bed temperature is above 1000℃, based on the characteristics of heat absorption and heat transfer during liquid vaporization and evaporation, crude TiCl4 liquid is introduced into the chlorination furnace through the first crude TiCl4 pipeline 106 to flash evaporate and remove the bed heat in order to lower the temperature.
[0034] Specifically, when the bed temperature is below 950℃, compressed air is supplied to the fluidized bed chlorination furnace 1 through compressed air pipeline 102 to assist in temperature increase. A certain amount of compressed air is introduced into the furnace by adjusting the compressed air regulating valve 5 to maintain the bed temperature within the process requirement range of 950-1000℃. If a rapid temperature increase is required, O2 can be supplied to the fluidized bed chlorination furnace 1 through O2 pipeline 103 and gas distributor 2 to increase the heating rate and achieve rapid temperature rise. In this case, a certain amount of O2 is introduced into the furnace by adjusting the O2 regulating valve 6. It is particularly important to note that an oxygen content detector 8 is installed on the mixed gas main pipeline 105. During the O2 introduction process, the O2 content in the mixed gas main pipeline 105 must be monitored by the oxygen content detector 8 to ensure it is between 18% and 30%, preventing excessively high O2 concentrations that could lead to localized oxygen enrichment within the furnace and exacerbate erosion of metal pipes, castables, and furnace bricks.
[0035] If the bed temperature is higher than 1000℃, based on the characteristics of liquid vaporization and evaporation heat absorption and heat transfer, crude TiCl4 liquid is introduced into the fluidized bed chlorination furnace 1 through the first crude TiCl4 pipeline 106 for flash evaporation to remove the bed heat. At the same time, a first crude TiCl4 regulating valve 9 is installed on the first crude TiCl4 pipeline 106. By controlling the opening of the first crude TiCl4 regulating valve 9, the spray pressure of the first nozzle 12 is controlled to be maintained within the control range of 0.3 to 0.5 MPa (g), thereby ensuring the continuous introduction of crude TiCl4 and keeping the bed temperature stably controlled within the process requirement range of 950 to 1000℃.
[0036] Furthermore, if the spray pressure of the first nozzle 12 is not within the control range, the spray pressure can be adjusted by increasing or decreasing the first N2 regulating valve 10 on the first N2 pipeline 107. Since crude TiCl4 is continuously introduced, the first N2 regulating valve 10 can be fully closed if necessary.
[0037] It should be noted that the N2 pressure should be maintained at 0.6–0.8 MPa (g). After the crude TiCl4 is stopped flowing in (i.e., the first crude TiCl4 regulating valve 9 is closed), the N2 flow rate must be maintained at 4–8 m³ / g. 3 The purging rate is maintained at / h to keep the first nozzle 12 unobstructed. Furthermore, the central spray position of the fluidized bed chlorination furnace 1 is selected 500-1000mm above the material in the chlorination furnace bed to prevent the liquid from directly spraying into the bed and interfering with the fluidization state of the material. Also, after the crude TiCl4 liquid flashes, most of the particles carried within it will overflow from the top of the chlorination furnace along with the crude TiCl4 gas, without affecting the content distribution of the bed material.
[0038] The method for controlling the temperature of the gas outlet pipeline at the top of the fluidized bed chlorination furnace includes the following process:
[0039] A first thermocouple 13 is installed inside the furnace top spray tower 7 to detect the internal temperature. Specifically, the first thermocouple 13 extends into the middle of the furnace top spray tower 7 to ensure accurate measurement of the furnace gas temperature. The temperature detected by the first thermocouple 13 is 800–900°C. At this temperature, the impurities CaCl2 (melting point 772°C, boiling point 1600°C), MgCl2 (melting point 708°C, boiling point 1412°C), MnCl2 (melting point 650°C, boiling point 1190°C), and FeCl2 (melting point 670°C, boiling point 1030°C) carried in the crude TiCl4 gas are in a molten state and easily adhere to the wall and cause blockage. To reduce the phase change of impurities in the pipeline, the outlet temperature of the chlorination furnace needs to be controlled at 580–630°C, so that the above impurities are in solid form and blown out under the action of the crude TiCl4 gas, avoiding wall blockage. Therefore, the main method for controlling the temperature of the gas outlet pipeline at the top of the fluidized bed chlorination furnace is to install a top crude TiCl4 liquid spraying device on the straight section of the gas outlet pipeline to control the temperature of the crude TiCl4 gas at 580-630℃.
[0040] As part of an embodiment of the present invention, the process for controlling the temperature of the gas outlet pipeline at the top of the fluidized bed chlorination furnace is described in detail below:
[0041] By adjusting the second crude TiCl4 regulating valve 17 via the first crude TiCl4 pipeline 106 and controlling the spray pressure displayed by the second pressure sensor 20 within the range of 0.2–0.3 MPa(g), the continuous flow of crude TiCl4 is ensured, thereby stabilizing the outlet gas temperature of the chlorination furnace within the process requirement range of 580–630℃. If the spray pressure displayed by the second pressure sensor 20 is outside the control range, the spray pressure can be adjusted by increasing or decreasing the second N2 regulating valve 16 on the second N2 pipeline 108. Since crude TiCl4 is continuously supplied, the second N2 regulating valve 16 can be fully closed if necessary.
[0042] The control method for spraying crude TiCl4 liquid at the third nozzle 15 is consistent with the above. The temperature can be adjusted by controlling and adjusting the two sets of spraying devices corresponding to the second nozzle 14 and the third nozzle 15 respectively, so that the temperature at the top of the chlorination furnace cooling tower detected by the first thermocouple 13 can be stably controlled at 580-630℃.
[0043] It should be noted that the N2 pressure should be maintained at 0.6–0.8 MPa (g). When the crude TiCl4 flow stops (i.e., the second and third crude TiCl4 regulating valves 17 and 18 are closed), the N2 flow rate must be maintained at 4–8 m³ / g. 3 The purging rate of / h keeps the second nozzle 14 and the third nozzle 15 unobstructed.
[0044] Generally, after the crude TiCl4 gas overflows from the top of the chlorination furnace, it needs to be purified and dust removed by a dust collection system. The high gas temperature (>500℃) places higher demands on the material and performance of the dust collection equipment. Therefore, a spray cooling device is installed again in the furnace gas pipeline before the crude TiCl4 gas enters the dust collection equipment to cool the crude TiCl4 gas.
[0045] Furthermore, the spray control method of the cooling device remains consistent with the above, reducing the temperature of the crude TiCl4 gas to 180–220°C before it enters the dust collector. It should be noted that if the temperature is controlled too low, it can easily cause TiCl4 to thin and clog the equipment. Additionally, TiCl4 releases heat and expands rapidly upon contact with water, posing a safety hazard. If the temperature is controlled too high, high-boiling-point impurities and solid particles carried by the crude TiCl4 cannot be effectively removed and will enter the subsequent condensation and refining systems, easily causing scaling and blockage in equipment and pipelines, leading to fluctuations in product quality and decreased production stability. Therefore, through the coordinated control of the fourth crude TiCl4 regulating valve 23 and the fourth N2 regulating valve 22, combined with the chlorination furnace bed temperature control system and the chlorination furnace top outlet gas pipeline temperature control system, the temperature of the crude TiCl4 gas before entering the dust collector is precisely controlled within the range of 180–220°C.
[0046] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.
Claims
1. A fluidized bed chlorination furnace temperature control system, comprising a fluidized bed chlorination furnace (1), a gas distributor (3), and a furnace top spray tower (7), wherein the gas distributor (3) is disposed at the lower part of the fluidized bed chlorination furnace (1), the furnace top spray tower (7) is disposed at the top of the fluidized bed chlorination furnace (1), and the furnace top spray tower (7) is connected to a dust collection system via a furnace gas pipeline (104), characterized in that, The gas distributor (3) is connected to the mixed gas main pipeline (105), which is connected to the Cl2 pipeline (101), the compressed air pipeline (102), and the O2 pipeline (103). The gas distributor (3) controls the distribution of Cl2, O2, and compressed air into the fluidized bed chlorination furnace (1). The temperature control system also includes a chlorination furnace bed temperature control system and a chlorination furnace top outlet gas pipeline temperature control system. The chlorination furnace bed temperature control system is located in the middle or near the middle of the fluidized bed chlorination furnace (1). The chlorination furnace bed temperature control system includes a first crude TiCl4 pipeline (106) and a first N2 pipeline (103). 107), the bed temperature is controlled within the range of 950~1000℃ by the gas distributor (3) and the chlorination furnace bed temperature control system. The chlorination furnace top outlet gas pipeline temperature control system is set inside the furnace top spray tower (7). The furnace top outlet gas pipeline temperature control system includes a branch of the first crude TiCl4 pipeline (106) and the second N2 pipeline (108). The chlorination furnace outlet gas temperature is controlled within the range of 580~630℃ by the furnace top outlet gas pipeline temperature control system. The chlorination furnace bed temperature control system forms a central spray device inside the fluidized bed chlorination furnace (1). The central spray device is selected at a position 500~1000mm above the chlorination furnace bed material.
2. The temperature control system for the fluidized bed chlorination furnace according to claim 1, characterized in that, A Cl2 regulating valve (4) is installed on the Cl2 pipeline (101), a compressed air regulating valve (5) is installed on the compressed air pipeline (102), an O2 regulating valve (6) is installed on the O2 pipeline (103), and an oxygen content detector (8) is installed on the mixed gas main pipeline (105). The oxygen content detector (8) is used to monitor the O2 content in the mixed gas main pipeline (105).
3. The temperature control system for the fluidized bed chlorination furnace according to claim 1, characterized in that, The first N2 pipeline (107) and the first crude TiCl4 pipeline (106) are connected to the fluidized bed chlorination furnace (1). A first nozzle (12) is provided on the inner side of the connection between the first N2 pipeline (107) and the first crude TiCl4 pipeline (106) and the fluidized bed chlorination furnace (1). The first nozzle (12) is used to control the entry of crude TiCl4 and N2 into the middle channel of the fluidized bed chlorination furnace (1).
4. The temperature control system for the fluidized bed chlorination furnace according to claim 1, characterized in that, The first coarse TiCl4 pipeline (106) is divided into two paths and enters the furnace top spray tower (7). At the end of the two paths, a second nozzle (14) and a third nozzle (15) are respectively provided. The second nozzle (14) is located below the third nozzle (15). The second nozzle (14) and the coarse TiCl4 gas move in the same direction as the flow, while the third nozzle (15) and the coarse TiCl4 gas move in the opposite direction.
5. The temperature control system for the fluidized bed chlorination furnace according to claim 1, characterized in that, A cooling device is also installed on the furnace gas pipeline (104) before the crude TiCl4 gas is discharged from the top of the furnace top spray tower (7) and enters the dust collection system. The cooling device includes a high-pressure third N2 pipeline (109), a second crude TiCl4 pipeline (110) and a fourth nozzle (25). A fourth pressure sensor (24) is also installed before the fourth nozzle (25) to detect the spray pressure of the fourth nozzle (25).
6. A method for temperature control in a fluidized bed chlorination furnace, characterized in that, The fluidized bed chlorination furnace temperature control system according to any one of claims 1 to 5 includes a fluidized bed chlorination furnace temperature control method and a furnace top outlet gas pipeline temperature control method. The fluidized bed chlorination furnace temperature control method includes: when the bed temperature is below 950°C, supplying compressed air into the fluidized bed chlorination furnace to assist in temperature increase; when the bed temperature is above 1000°C, introducing crude TiCl4 liquid into the chlorination furnace through a first crude TiCl4 pipeline for flash evaporation to remove bed heat and reduce temperature.
7. The temperature control method for a fluidized bed chlorination furnace according to claim 6, characterized in that, When the bed temperature is below 950°C, O2 is supplied to the fluidized bed chlorination furnace through the O2 pipeline 103 via the gas distributor to increase the heating rate.
8. The temperature control method for a fluidized bed chlorination furnace according to claim 7, characterized in that, During the O2 introduction process, the O2 content in the main gas mixture pipeline 105 needs to be monitored to be between 18% and 30% using an oxygen content detector.
9. The temperature control method for a fluidized bed chlorination furnace according to claim 6, characterized in that, When the bed temperature is higher than 1000℃, and the spray pressure of the crude TiCl4 pipeline exceeds the control range, the spray pressure can be adjusted by increasing or decreasing the first N2 regulating valve on the first N2 pipeline.
10. The temperature control method for a fluidized bed chlorination furnace according to claim 6, characterized in that, The method for controlling the temperature of the furnace top outlet gas pipeline includes controlling the pressure of the first crude TiCl4 pipeline 106 of the furnace top outlet gas pipeline temperature control system to stably control the outlet gas temperature of the chlorination furnace within the range of 580~630℃.