Device for separating high-temperature titanium dioxide and chlorine at outlet of oxidizing furnace

Abstract

The invention relates to the technical field of chlorination process titanium dioxide, and discloses a device for separating high-temperature titanium dioxide and chlorine at an outlet of an oxidizing furnace. The graded dust collection module comprises a primary separation module and a secondary separation module which are arranged in series, the primary separation module is communicated with an outlet of the water bath cooling module and is used for carrying out primary coarse separation on the cooled mixture, and the secondary separation module is used for carrying out secondary fine separation on the mixture subjected to primary separation; a tail gas conveying pipeline is arranged at the top of the secondary separation module as a gas outlet; and the pulping module is used for receiving the titanium dioxide collected by the primary separation module and the secondary separation module and preparing the titanium dioxide into slurry. According to the invention, through a graded dust collection mode, a large amount of TiO2 is collected in the first-stage separation device and then enters the second-stage separation device for gas-solid fine separation, so that the yield of titanium dioxide can be effectively increased, and the method has a very good application prospect in the chlorination process titanium dioxide industry.

Description

Technical Field

[0001] The invention relates to the technical field of titanium dioxide powder produced by chloride process, and in particular to a device for separating high-temperature titanium dioxide powder and chlorine gas at an oxidation furnace outlet. Background Art

[0002] Chloride-process titanium dioxide is produced by reacting oxygen with titanium tetrachloride at high temperatures, generating titanium dioxide and chlorine. Because this reaction is exothermic, the temperature of the mixed material at the oxidation furnace outlet can reach approximately 1700°C to 1800°C. To separate the reaction products, TiO2, from Cl2, most existing devices use a single bag filter for gas-solid separation. However, since Cl2 remains highly oxidizing at temperatures between 150°C and 250°C, and chloride-process titanium dioxide is primarily rutile with a hardness of approximately 6.5, this can gradually cause wear and perforation of the bag filter bags, leading to excessive bag loads, significantly shortened lifespans, and frequent replacements. This results in a decrease in TiO2 yield, increasing production costs and impacting production continuity. In addition, the temperature of the material at the outlet of the oxidation furnace is extremely high, and direct cooling can easily lead to serious scaling of the pipeline, affecting the heat exchange efficiency and even clogging the pipeline; and if the cooling is improper, the subsequent bag filter inlet temperature will fluctuate too much. Too high a temperature will burn the filter bag, and too low a temperature will cause the residual titanium tetrachloride to liquefy, causing internal compaction of the equipment, seriously affecting the long-term stable operation of the system.

[0003] Therefore, there is a need in the prior art for improving the device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace. Summary of the Invention

[0004] In view of this, the purpose of the embodiment of the present invention is to propose a device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace. Through the method of graded dust collection, a large amount of TiO2 is collected in the first-stage separation device and then enters the secondary separation for gas-solid separation. It can effectively improve the yield of titanium dioxide and has good application prospects in the chloride method titanium dioxide industry.

[0005] Based on the above objectives, an embodiment of the present invention provides a device for separating high-temperature titanium dioxide and chlorine at an oxidation furnace outlet, comprising: Water bath cooling module; The graded dust collection module includes a primary separation module and a secondary separation module arranged in series. The primary separation module is connected to the outlet of the water bath cooling module and performs a primary rough separation on the cooled mixture. The secondary separation module performs a secondary fine separation on the mixture after the primary separation. An exhaust gas conveying pipeline is provided on the top of the secondary separation module as a gas outlet. The beating module is used to receive the titanium dioxide collected from the primary separation module and the secondary separation module and prepare it into slurry. A pressure difference control system is provided between the beating module and the exhaust gas conveying pipeline.

[0006] In some embodiments, the primary separation module is a cyclone dust collector or a sedimentation separation bin, and the secondary separation module is a bag filter or a cartridge dust collector.

[0007] In some embodiments, the bottom of the primary separation module is a first discharge port, and a first material seal control mechanism is provided at the first discharge port. The first material seal control mechanism includes a first material level meter, a first material level controller and a first rotary valve. The first rotary valve is interlocked with the first material level meter through frequency conversion regulation to control the material position in the primary separation module.

[0008] In some embodiments, the first material seal controller controls the material level in the primary separation module within a range of 20% to 80%.

[0009] In some embodiments, a screw conveyor and a second rotary valve are further provided downstream of the first rotary valve, and the operating frequency of the second rotary valve is linked in real time with the frequency of the first rotary valve to prevent material accumulation.

[0010] In some embodiments, the bottom of the secondary separation module is a second discharge port, and a second material sealing control mechanism including a second material level meter, a second material level controller and at least one rotary valve is provided at the second discharge port.

[0011] In some embodiments, circulating cooling water is passed through the water bath cooling module to submerge the high-temperature material pipeline passing therethrough.

[0012] In some embodiments, a descaling agent adding device is further provided in the water bath cooling module for adding an inert non-metallic particle descaling agent into the pipeline before the material enters the water bath cooling module.

[0013] In some embodiments, a temperature detection device is further provided between the primary separation module and the secondary separation module.

[0014] In some embodiments, the pressure difference control system includes: a first pressure gauge is provided at the tail gas delivery pipeline, and a second pressure gauge and a nitrogen inlet are provided at the pulping tank.

[0015] The present invention has at least the following beneficial technical effects: (1) By adopting a series-type graded dust collection module with a primary coarse separation and a secondary fine separation, the titanium dioxide particles are captured in a step-by-step and efficient manner. The primary separation module can collect 80%-90% of the coarse particle products, while the secondary separation module can almost completely capture the fine particles, which greatly improves the overall yield of titanium dioxide and reduces product loss. (2) Greatly extend the life of core equipment and reduce maintenance costs: The graded dust collection design fundamentally reduces the dust handling load and particle concentration of the secondary separation module, avoiding the direct erosion and wear of high-concentration, high-velocity coarse dust particles on the precision filter elements, thereby significantly extending their service life; (3) The modular integrated design enables smooth connection of the cooling, separation and beating processes. The primary separation module unloads most of the load first, ensuring the stable operation of the secondary separation module under optimal working conditions. It effectively prevents production interruptions caused by equipment blockage, filter bag damage or frequent start-stop, and ensures that the device can operate stably and continuously for a long period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of an embodiment of a device for separating high-temperature titanium dioxide and chlorine at an oxidation furnace outlet provided by the present invention; Description of reference numerals: 100. Water cooling module; 110. Overflow pool; 200, graded dust collection module; 210, primary separation module; 211, first discharge port; 212, first material level meter; 213, first material level controller; 214, first rotary valve; 215, screw conveyor; 216, second rotary valve; 220, secondary separation module; 221, second discharge port; 222, third rotary valve; 223, second material level meter; 224, second material level controller; 225, fourth rotary valve; 226, first pressure gauge; 227, second pressure gauge; 228, differential pressure controller; 229, exhaust gas conveying pipeline; 300. Beating module. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention pertains; the terms used in the specification herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention; for example, the directions or positions indicated by the terms "length", "width", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are for ease of description only and should not be construed as limiting the present technical solution.

[0020] The terms "including," "having," and any variations thereof in the present specification, claims, and accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the present specification, claims, and accompanying drawings are used to distinguish between different items, not to describe a particular order. "Multiple" means two or more, unless otherwise expressly specified.

[0021] In the specification and claims of the present invention and the above-mentioned description of the drawings, when an element is referred to as being “fixed to,” “mounted on,” “disposed on,” or “connected to” another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as being “connected to” another element, it may be directly or indirectly connected to the other element.

[0022] Furthermore, references herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] The present invention proposes a device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace. Figure 1 Shown, including: Water bath cooling module 100; The graded dust collection module 200 includes a primary separation module 210 and a secondary separation module 220 arranged in series. The primary separation module 210 is connected to the outlet of the water bath cooling module 100 and performs a primary rough separation on the cooled mixture. The secondary separation module 220 performs a secondary fine separation on the mixture after the primary separation. An exhaust gas conveying pipeline 229 is provided on the top of the secondary separation module 220 as a gas outlet. The beating module 300 is used to receive the titanium dioxide collected from the primary separation module 210 and the secondary separation module 220 and prepare it into slurry. A pressure difference control system is provided between the beating module and the exhaust gas conveying pipeline.

[0024] Furthermore, the primary separation module 210 is a cyclone dust collector or a sedimentation separation chamber, preferably a cyclone dust collector, and the secondary separation module 220 is a bag filter or a cartridge dust collector, preferably a bag filter. Those skilled in the art will understand that the primary separation module is not limited to a cyclone dust collector, and any gas-solid separation equipment that can achieve a similar coarse separation effect, such as a multi-tube cyclone, a gravity settling chamber, etc., falls within the scope of protection of the present invention. Similarly, the secondary separation module is not limited to a bag filter, and any high-efficiency dust removal equipment based on the principle of filtration, such as a cartridge dust collector, a sintered plate dust collector, etc., can be used instead.

[0025] Furthermore, the bottom of the primary separation module 210 is a first discharge port 211, where a first material seal control mechanism is located. This mechanism includes a first material level meter 212, a first material level controller 213, and a first rotary valve 214. The first rotary valve 214 is interlocked with the first material level meter 212 via frequency conversion regulation by the first material level controller 213 to control the material position within the primary separation module 210. In some embodiments, the first material seal controller 213 controls the material level within the primary separation module 210 within a range of 20% to 80%. The interlocking control of the material level meter and the rotary valve forms a material seal, preventing chlorine-containing gas from escaping into the pulping module.

[0026] Furthermore, a screw conveyor 215 and a second rotary valve 216 are further provided downstream of the first rotary valve 214. The operating frequency of the second rotary valve 216 is linked in real time with the frequency of the first rotary valve 214 to prevent material accumulation. The frequency of the screw conveyor and rotary valve 2 is adjusted in real time based on the operating frequency of the rotary valve 1, ensuring that their conveying capacity exceeds the material discharge capacity of the rotary valve 1, preventing material accumulation from causing equipment jams.

[0027] Furthermore, the bottom of the secondary separation module 220 is a second discharge port 221. A second material seal control mechanism, including a second material level gauge 223 and at least one rotary valve, is located at this second discharge port. Adjusting the frequency of the rotary valve prevents material accumulation from causing equipment stalls. The interlocking control of the material level gauge and the rotary valve forms a material seal, preventing chlorine-containing gas from escaping into the pulping module.

[0028] Furthermore, circulating cooling water is passed through the water bath cooling module 100 to submerge the high-temperature material pipeline passing therethrough.

[0029] Furthermore, a descaling agent adding device is also provided in the water bath cooling module 100, which is not shown in the figure and is used to add an inert non-metallic particle descaling agent into the pipeline before the material enters the water bath cooling module 100. Furthermore, a temperature detection device is also provided between the primary separation module 210 and the secondary separation module 220. Since high-temperature titanium dioxide easily adheres to the inside of the pipeline to form a scale layer, thereby affecting the heat exchange efficiency, a descaling agent that does not participate in the reaction needs to be added before the material enters the cooling water pool for descaling. Inert non-metallic particles such as rock salt, quartz sand, and zirconium beads can be selected as descaling agents. After the descaling agent enters the system, it scrapes against the pipe wall in the pipeline through the airflow to descaling. The amount of descaling agent added is linked to the cyclone outlet thermometer to control the cyclone outlet temperature within the range of 150~250℃, preventing the bag filter from burning due to excessive temperature or gas liquefaction due to excessive temperature, causing the material in the bag filter to become compacted.

[0030] Furthermore, the pressure differential control system specifically includes: a first pressure gauge 226 provided at the exhaust gas delivery pipeline 229, and a second pressure gauge 227 and a nitrogen inlet provided at the beating tank. The beating module, also known as the beating tank, is primarily used to mix the titanium dioxide collected by the graded dust collection module 200 with desalted water into a slurry for delivery to subsequent processes. During the beating process, the nitrogen entering the beating tank must be adjusted so that the pressure on the first pressure gauge 226 is 10-20 kPa higher than that on the second pressure gauge 227. This control is primarily used to ensure that the graded dust collection module 200 can discharge materials, and if a material seal is not effectively formed during the discharge process, excessive chlorine-containing gas will escape into the beating tank.

[0031] The present invention will be further explained below with reference to specific embodiments.

[0032] like Figure 1 The figure shows a device for separating high-temperature titanium dioxide and chlorine gas at the outlet of an oxidation furnace, comprising: Water bath cooling module 100; The graded dust collection module 200 includes a primary separation module 210 and a secondary separation module 220 arranged in series, wherein the primary separation module 210 is a cyclone dust collector and the secondary separation module 220 is a bag filter. The cyclone dust collector 210 is connected to the outlet of the water bath cooling module 100 and performs a primary coarse separation on the cooled mixture. The bag filter 220 performs a secondary fine separation on the mixture after the primary separation. An exhaust gas conveying pipeline 229 is provided on the top of the bag filter 220 as a gas outlet. The beating module 300 is used to receive the titanium dioxide collected from the cyclone dust collector 210 and the bag filter 220 and prepare it into slurry.

[0033] The water bath cooling module 100 is provided with circulating cooling water for flooding the high temperature material pipes passing therethrough. Figure 1As shown, a circulating water pipe is connected to the top of the water bath cooling module 100. The circulating water comes from the circulating water station. The cooling water outlet is connected to the overflow tank 110, where it is cooled and then recycled by the motor. Because high-temperature titanium dioxide easily adheres to the inside of the pipe to form a scale layer, thereby affecting heat exchange efficiency, a non-reactive descaling agent is added before the material enters the cooling water tank for descaling. Rock salt is selected as the descaling agent. After the descaling agent enters the system, it scrapes against the pipe wall through the airflow in the pipeline to remove scale. The amount of descaling agent added is linked to the cyclone outlet thermometer to control the cyclone outlet temperature within the range of 150-250°C.

[0034] At the bottom of the cyclone dust collector 210 is a first discharge port 211, where a first material seal control mechanism is located. This mechanism includes a first material level meter 212, a first material level controller 213, and a first rotary valve 214. The first rotary valve 214, through frequency conversion regulation by the first material level controller 213, interlocks with the first material level meter 212 to control the material position within the cyclone dust collector 210. Specifically, the first material seal control mechanism controls the material level within the cyclone dust collector 210 at 50%. Further downstream of the first rotary valve 214 are a screw conveyor 215 and a second rotary valve 216. The operating frequencies of the screw conveyor 215 and the second rotary valve 216 are linked in real time to the frequency of the first rotary valve 214, ensuring that their conveying capacity exceeds the discharge capacity of the first rotary valve 214, thus preventing material accumulation from causing equipment jams.

[0035] The bag filter 220 discharge is composed of two rotary valves. The third rotary valve 222 is interlocked with the second material level meter 223 through frequency conversion to achieve a material sealing level of 50% in the cyclone dust collector. The fourth rotary valve 225 is adjusted in real time according to the operating frequency of the third rotary valve 222 to ensure that its conveying capacity is greater than the discharge volume of the third rotary valve 222 to prevent material accumulation from causing equipment jamming.

[0036] A first pressure gauge 226 is installed at the exhaust gas delivery line 229, and a second pressure gauge 227 and a nitrogen inlet are installed at the beating tank. The beating module, also known as the beating tank, is primarily used to mix the titanium dioxide collected by the graded dust collection module 200 with desalted water to form a slurry for subsequent use in subsequent processes. During the beating process, a differential pressure controller 228 regulates the nitrogen entering the beating tank, ensuring that the pressure on the first pressure gauge 226 is 15 kPa higher than that on the second pressure gauge 227.

[0037] The specific method of using this device includes the following steps: (1) Add desalted water into the pulping tank 300 and control its liquid level within the range of 60% to 80%.

[0038] (2) Circulating cooling water is introduced into the water bath cooling module 100 so that the liquid level completely submerges the high-temperature material pipeline. After the circulating water in the water bath cooling module 100 overflows into the overflow pool 110, it is pumped to the circulating water station through a delivery pump to form a complete circulating cooling water system.

[0039] (3) After the high-temperature material at the outlet of the oxidation furnace is transported to the water bath cooling module 100 through a pipeline for heat exchange cooling, a fixed amount of inert non-metallic particle descaling agent is added to the pipeline through the descaling agent adding device. By adjusting the amount of descaling agent added, the temperature detection device set at the outlet of the cyclone dust collector 210 is maintained at a temperature within the range of 150~250℃. At the same time, nitrogen is introduced into the beating tank 300 through the nitrogen inlet port, and the nitrogen flow rate is adjusted so that the reading of the second pressure gauge 227 is 10~20kPa higher than the reading of the first pressure gauge 226.

[0040] (4) When the first material level meter 212 at the bottom of the cyclone dust collector 210 detects that the material level has risen to above 80%, the second rotary valve 216, the screw conveyor 215, and the first rotary valve 214 are sequentially activated to start the material discharge operation. Subsequently, the first material level meter 212, the first rotary valve 214, the screw conveyor 215, and the second rotary valve 216 are connected to form a chain control loop through the first material level controller 213 to achieve automatic material level control and stabilize the material level within the range of 20% to 80%.

[0041] (5) When the second material level meter 223 at the bottom of the bag filter 220 detects that the material level has risen to above 80%, the fourth rotary valve 225 and the third rotary valve 222 are activated in sequence to start the material discharge operation. Subsequently, the second material level meter 223, the third rotary valve 222, and the fourth rotary valve 225 are connected to form a chain control loop through the second material level controller 224 to achieve automatic material level control and stabilize the material level within the range of 20% to 80%.

[0042] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope of the embodiments disclosed in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless expressly limited to the singular.

[0043] It should be understood that, as used herein, the singular forms "a" and "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" is intended to include any and all possible combinations of one or more of the associated listed items.

[0044] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0045] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to limit the scope of the disclosure of the present invention (including the claims) to these examples. Within the spirit of the present invention, the technical features of the above embodiments or different embodiments may be combined, and many other variations exist in different aspects of the above embodiments, which are not provided in detail for the sake of clarity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace, characterized in that: include: Water bath cooling module; A graded dust collection module, comprising a primary separation module and a secondary separation module arranged in series, wherein the primary separation module is connected to the outlet of the water bath cooling module and performs a primary rough separation on the cooled mixture, and the secondary separation module performs a secondary fine separation on the mixture after the primary separation, and an exhaust gas conveying pipeline is provided on the top of the secondary separation module as a gas outlet; A beating module is used to receive the titanium dioxide collected from the primary separation module and the secondary separation module and prepare it into slurry. A pressure difference control system is provided between the beating module and the tail gas conveying pipeline.

2. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: The primary separation module is a cyclone dust collector or a sedimentation separation bin, and the secondary separation module is a bag filter or a cartridge dust collector.

3. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: The bottom of the primary separation module is a first discharge port, and a first material sealing control mechanism is provided at the first discharge port. The first material sealing control mechanism includes a first material level meter, a first material level controller, and a first rotary valve. The first rotary valve is interlocked with the first material level meter through frequency conversion regulation to control the material position in the primary separation module.

4. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 3, characterized in that: The first material level controller controls the material level in the primary separation module within a range of 20% to 80%.

5. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 3, characterized in that: A screw conveyor and a second rotary valve are further provided downstream of the first rotary valve. The operating frequency of the second rotary valve is linked in real time with the frequency of the first rotary valve to prevent material accumulation.

6. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: The bottom of the secondary separation module is a second discharge port, and a second material sealing control mechanism is provided at the second discharge port, including a second material level meter, a second material level controller and at least one rotary valve.

7. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: The water bath cooling module is filled with circulating cooling water for submerging the high-temperature material pipeline passing therethrough.

8. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: The water bath cooling module is also provided with a descaling agent adding device for adding an inert non-metallic particle descaling agent into the pipeline before the material enters the water bath cooling module.

9. The device for separating high-temperature titanium dioxide and chlorine at the outlet of an oxidation furnace according to claim 1, characterized in that: A temperature detection device is also provided between the primary separation module and the secondary separation module.

10. The device for separating high-temperature titanium dioxide and chlorine at the oxidation furnace outlet according to claim 1, characterized in that: The pressure difference control system includes: a first pressure gauge is provided at the tail gas delivery pipeline, and a second pressure gauge and a nitrogen input port are provided at the beating tank.

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