Temperature control type gravity dust collector and dust-containing flue gas treatment method

Abstract

The invention relates to the technical field of flue gas treatment, in particular to a temperature control type gravity dust collector and a dust-containing flue gas treatment method. The temperature control type gravity dust collector comprises a gravity dust collector main body structure, the gravity dust collector main body structure comprises an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III which are connected in sequence; air ducts are arranged outside the gravity dust collector main body structure, specifically, the air ducts rising spirally are arranged outside the air inlet pipe I section, the ash collecting tank II section and the air outlet pipe III section, the lower ends of the air ducts are air inlets, and the upper ends of the air ducts are air outlets. The device can meet the regulation and control requirements of complex working conditions on the temperature of dust-containing flue gas, the temperature and the air speed of the air inlet can be regulated according to requirements, and the wall surface temperature of the gravity dust collector is controlled, so that the effects of cooling, heat preservation and heating of the dust-containing flue gas are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and in particular to a temperature-controlled gravity dust collector and a method for treating dust-containing flue gas. Background Art

[0002] At present, the main method for producing titanium tetrachloride is boiling chlorination, that is, mixing titanium raw materials rich in TiO2 with petroleum coke in a certain proportion, adding chlorine gas to carry out a closed chemical reaction in a chlorination furnace. The reaction temperature is generally greater than 900°C, and titanium tetrachloride is obtained after the reaction. However, due to the natural endowment of titanium-containing ores in my country, the natural raw ore is mainly vanadium-titanium magnetite, which has high calcium and magnesium content. The processing cost of preparing titanium raw materials with a mass content of TiO2 ≥90% and a mass content of CaO and MgO ≤1.5% required by the traditional boiling chlorination process is high, the process is long, and the difficulty is great. After years of intensive research, Panzhihua Iron and Steel has gradually formed a process route for the simultaneous preparation of titanium tetrachloride by treating titanium-containing blast furnace slag based on the "high-temperature carbonization-low-temperature chlorination" process.

[0003] The main component of the mixed gas coming out of the low-temperature chlorination furnace is TiCl4, and it also contains impurities such as FeCl3. In order to obtain relatively pure TiCl4, it is necessary to first remove impurities such as FeCl3 from the steam. The gravity dust collector has a simple structure and good corrosion resistance. Through reasonable structural design, it can have a certain cooling effect. It can condense high-boiling impurities such as FeCl3 in the steam and deposit them together with the entrained solid particles, thereby achieving a dust removal effect. Patent application document CN202310633004.2 discloses a cooling gravity dust collector and a high-temperature dust-containing gas treatment system and treatment method. The designed gravity dust collector is divided into a cylinder and an ash hopper, including an air inlet channel, an air outlet channel and a partition, and a cooling water flow channel is formed between the air inlet channel, the air outlet channel and the cylinder to cool the high-temperature dust-containing gas. Patent application document CN202221778612.X discloses a gravity dust collector used in the field of titanium tetrachloride production technology. The cylinder part is designed as a double-layer structure, and coolant is passed between the double-layer structure. At the same time, an impact device is set inside the cylinder to impact the inner wall of the cylinder, so that impurities bonded to the inner wall of the cylinder fall off. The above patents all have defects such as inability to accurately control temperature, inability to cool in sections, and inability to be used for heat preservation or temperature increase control of flue gas. In addition, the process requires that the dust-containing flue gas be cooled sometimes, kept warm or heated sometimes, or the three conditions are frequently switched, and control cannot be achieved. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a temperature-controlled gravity dust collector and a method for treating dust-containing flue gas, which can meet the requirements for controlling the temperature of dust-containing flue gas under complex working conditions.

[0005] The present invention provides a temperature-controlled gravity dust collector, comprising:

[0006] The main structure of the gravity dust collector; the main structure of the gravity dust collector comprises an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III which are connected in sequence;

[0007] An air duct is arranged outside the main structure of the gravity dust collector: spiral ascending air ducts are arranged outside the air inlet pipe section I, the ash collecting tank section II and the air outlet pipe section III, the lower end of the air duct is the air inlet, and the upper end of the air duct is the air outlet.

[0008] Preferably, the air inlet pipe section I is arranged vertically, with a smoke inlet arranged at the top and a smoke outlet arranged at the bottom;

[0009] The ash collecting tank section II is an inverted cone structure, with a dust removal ash outlet at the bottom and a smoke inlet and a smoke outlet at the top; the smoke inlet of the ash collecting tank section II is connected to the smoke outlet of the air inlet pipe section I;

[0010] The air outlet pipe section III is vertically arranged, with a smoke inlet at the bottom and a smoke outlet at the top; the smoke inlet of the air outlet pipe section III is connected to the smoke outlet of the ash collecting tank section II.

[0011] Preferably, the air inlet pipe section I is a cylindrical pipe or a rectangular pipe;

[0012] The air outlet pipe section III is a cylindrical pipe or a rectangular pipe.

[0013] The present invention also provides a method for treating dusty flue gas, comprising the following steps:

[0014] The dusty flue gas passes through the air inlet pipe section I, the dust collecting tank section II and the air outlet pipe section III of the temperature-controlled gravity dust collector in sequence to obtain the treated flue gas;

[0015] The temperature-controlled gravity dust collector is the temperature-controlled gravity dust collector described above.

[0016] Preferably, in the dust-containing flue gas, the mass content of TiCl4 is ≥90%, the mass content of FeCl3 is 7% to 9%, and the mass content of dust particles is 1% to 10%.

[0017] Preferably, the temperature of the dust-containing flue gas is 260-950°C.

[0018] Preferably, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to room temperature, and the wind speed is 8-10m / s; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to 150-220℃, and the wind speed is 5-6m / s; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to room temperature, and the wind speed is 6-8m / s.

[0019] Preferably, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0.

[0020] Preferably, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be 310-350°C, and the wind speed is 5-10m / s; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to be 310-350°C, and the wind speed is 5-10m / s; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be 310-350°C, and the wind speed is 5-10m / s.

[0021] Preferably, the inner wall temperature of the main structure of the gravity dust collector is controlled to be 220-380°C.

[0022] The present invention provides a temperature-controlled gravity dust collector, comprising: a gravity dust collector main structure; the gravity dust collector main structure comprises an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III connected in sequence; an air duct is arranged outside the gravity dust collector main structure: a spirally ascending air duct is arranged outside the air inlet pipe section I, the ash collecting tank section II and the air outlet pipe section III, the lower end of the air duct is an air inlet, and the upper end of the air duct is an air outlet. The present invention can adjust the temperature and wind speed of the air inlet as needed, control the wall temperature of the gravity dust collector, and thus achieve the effects of cooling, heat preservation and heating of dusty flue gas. Typically, when used to remove impurities such as FeCl3 in titanium tetrachloride vapor, the wall temperature of the gravity dust collector is controlled to be 220℃~300℃, and the dusty hot flue gas is sent into the temperature-controlled gravity dust collector from the inlet. The FeCl3 gas in the flue gas condenses and adheres to the surface of the dusty particles, and a small amount adheres to the inner wall surface of the gravity dust collector. The clean flue gas except FeCl3 is discharged from the air outlet. The present invention can meet the requirements for controlling the temperature of dusty flue gas under complex working conditions, and has the advantages of simple equipment, high efficiency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a temperature-controlled gravity dust collector provided for one embodiment of the present invention. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The present invention provides a temperature-controlled gravity dust collector, comprising:

[0026] The main structure of the gravity dust collector; the main structure of the gravity dust collector comprises an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III which are connected in sequence;

[0027] An air duct is arranged outside the main structure of the gravity dust collector: spiral ascending air ducts are arranged outside the air inlet pipe section I, the ash collecting tank section II and the air outlet pipe section III, the lower end of the air duct is the air inlet, and the upper end of the air duct is the air outlet.

[0028] Figure 1 A schematic diagram of the structure of a temperature-controlled gravity dust collector provided for an embodiment of the present invention. 1 is the air inlet section I, 1-1 is the air inlet of the air inlet section I, 1-2 is the air outlet of the air inlet section I, 2 is the ash collecting tank section II, 2-1 is the air inlet of the ash collecting tank section II, 2-2 is the air outlet of the ash collecting tank section II, 3 is the air outlet section III, 3-1 is the air inlet of the air outlet section III, and 3-2 is the air outlet of the air outlet section III.

[0029] The present invention has no special restrictions on the arrangement of the sequentially connected air inlet pipe section I, ash collecting tank section II and air outlet pipe section III, and the arrangement of the air inlet pipe section I, ash collecting tank section II and air outlet pipe section III well known to those skilled in the art can be adopted.

[0030] The air inlet pipe section I is arranged vertically, with a smoke inlet arranged at the top and a smoke outlet arranged at the bottom;

[0031] The ash collecting tank section II is an inverted cone structure, with a dust removal ash outlet at the bottom and a smoke inlet and a smoke outlet at the top; the smoke inlet of the ash collecting tank section II is connected to the smoke outlet of the air inlet pipe section I; the connection method can be welding or threaded connection;

[0032] The gas outlet pipe section III is vertically arranged, with a smoke inlet at the bottom and a smoke outlet at the top; the smoke inlet of the gas outlet pipe section III is connected to the smoke outlet of the ash collecting tank section II by welding or threaded connection.

[0033] In some embodiments of the present invention, the air inlet pipe section I 1 and the air outlet pipe section III 3 may be cylindrical pipes or rectangular pipes.

[0034] In some embodiments of the present invention, a spiral rising air duct of the air intake pipe is arranged outside the air intake pipe section I, the lower end of the spiral rising air duct of the air intake pipe is an air inlet, and the upper end of the spiral rising air duct of the air intake pipe is an air outlet.

[0035] In some embodiments of the present invention, a spiral rising air duct for the ash collecting tank is arranged outside the ash collecting tank section II, the lower end of the spiral rising air duct for the ash collecting tank is an air inlet, and the upper end of the spiral rising air duct for the ash collecting tank is an air outlet.

[0036] In some embodiments of the present invention, a spiral rising air duct of the air outlet pipe is arranged outside the air outlet pipe section III, the lower end of the spiral rising air duct of the air outlet pipe is an air inlet, and the upper end of the spiral rising air duct of the air outlet pipe is an air outlet.

[0037] In the present invention, the temperature and wind speed of the air inlet are adjusted as needed. The dusty hot flue gas is sent into the temperature-controlled gravity dust collector from the air inlet, and the FeCl3 gas in the flue gas condenses and adheres to the surface of the dusty particles, and a small amount adheres to the inner wall surface of the main structure of the gravity dust collector, and the clean flue gas with FeCl3 removed is discharged from the air outlet.

[0038] The present invention has no special limitation on the size of the air duct, as long as the required temperature control can be achieved.

[0039] The present invention also provides a method for treating dusty flue gas, comprising the following steps:

[0040] The dusty flue gas passes through the air inlet pipe section I, the dust collecting tank section II and the air outlet pipe section III of the temperature-controlled gravity dust collector in sequence to obtain the treated flue gas;

[0041] The temperature-controlled gravity dust collector is the temperature-controlled gravity dust collector described above.

[0042] In some embodiments of the present invention, the mass content of TiCl4 in the dusty flue gas is ≥90%, the mass content of FeCl3 is 7% to 9%, and the mass content of dust particles is 1% to 10%. The temperature of the dusty flue gas is 260 to 950°C, such as 330 to 400°C, 260 to 310°C.

[0043] In some embodiments of the present invention, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be room temperature, and the wind speed is 8 to 10 m / s; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to be 150 to 220°C, and the wind speed is 5 to 6 m / s; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be room temperature, and the wind speed is 6 to 8 m / s.

[0044] In some embodiments of the present invention, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be 330-400°C, and the wind speed is 0-3m / s, and is not 0.

[0045] In some embodiments of the present invention, the cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be 310-350°C, and the wind speed is 5-10m / s; the cold air temperature at the air inlet of section II of the ash collection tank is controlled to be 310-350°C, and the wind speed is 5-10m / s; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be 310-350°C, and the wind speed is 5-10m / s.

[0046] In some embodiments of the present invention, the temperature of the inner wall of the main structure of the gravity dust collector is controlled to be 220-380°C; for example, 220-300°C, 340-380°C, 310-350°C.

[0047] After the hot dust-containing flue gas is treated by the temperature-controlled gravity dust collector, the treated flue gas is cooled to room temperature, or the treated flue gas temperature is 330-400°C, 290-330°C.

[0048] The present invention realizes the temperature control function of the gravity dust collector by controlling the temperature and wind speed of the cooling air or the heating air at the air inlet, and has a simple structure and is convenient to control.

[0049] In the present invention, the temperature of the air inlet pipe section I, the ash collecting tank section II and the air outlet pipe section III of the temperature-controlled gravity dust collector are controlled in sections, which can realize the precise control of the wall temperature of the gravity dust collector to meet the different working conditions such as flue gas temperature cooling, heat preservation and heating.

[0050] When the temperature-controlled gravity dust collector is used to cool the flue gas, the wall temperature of the gravity dust collector is cleverly controlled to be higher than the boiling point of titanium tetrachloride and lower than the sublimation point of ferric chloride. The FeCl3 gas in the dusty flue gas condenses and adheres to the surface of the dusty flue gas and is discharged from the ash discharge port.

[0051] In order to further illustrate the present invention, the temperature-controlled gravity dust collector and the method for treating dust-containing flue gas provided by the present invention are described in detail below in combination with the embodiments, but it should not be understood as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] According to the working conditions, the temperature-controlled gravity dust collector is used to cool the dusty hot flue gas. Using slag produced by a certain unit with a mass concentration of 14% titanium carbide as raw material, the test was carried out on a fluidized bed reactor. The temperature of the dusty flue gas obtained at the top of the furnace after the reaction was 330-400°C. In the dusty flue gas, the mass content of TiCl4 is ≥90%, the mass content of FeCl3 is 7%-9%, and the mass content of dust particles is 1%-10%.

[0054] The dust-containing flue gas is sequentially passed through Figure 1 The temperature-controlled gravity dust collector shown has an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III to obtain treated flue gas.

[0055] The cold air temperature at the air inlet of section I of the air inlet pipe is controlled to be room temperature, and the wind speed is 8-10m / s; the cold air temperature at the air inlet of section II of the ash collecting tank is controlled to be 150-220℃, and the wind speed is 5-6m / s; the cold air temperature at the air inlet of section III of the air outlet pipe is controlled to be room temperature, and the wind speed is 6-8m / s. The inner wall temperature of the temperature-controlled gravity dust collector is adjusted to 220-300℃. After the dust-containing flue gas is cooled to room temperature through the temperature-controlled gravity dust collector, the removal rate of FeCl3 in the flue gas reaches more than 80%.

[0056] Example 2

[0057] According to the working conditions, the temperature-controlled gravity dust collector is used to keep the dusty hot flue gas warm. Using slag produced by a certain unit with a mass concentration of 14% titanium carbide as raw material, the experiment was carried out on a fluidized bed reactor. The temperature of the dusty flue gas obtained at the top of the furnace after the reaction was 330-400°C. In the dusty flue gas, the mass content of TiCl4 is ≥90%, the mass content of FeCl3 is 7%-9%, and the mass content of dust particles is 1%-10%.

[0058] The dust-containing flue gas is sequentially passed through Figure 1 The temperature-controlled gravity dust collector shown has an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III to obtain treated flue gas.

[0059] Control the cold air temperature at the air inlet of section I of the air inlet pipe to be 330-400℃, and the wind speed to be 0-3m / s, and not 0; the cold air temperature at the air inlet of section II of the ash collecting tank to be 330-400℃, and the wind speed to be 0-3m / s, and not 0; the cold air temperature at the air inlet of section III of the air outlet pipe to be 330-400℃, and the wind speed to be 0-3m / s, and not 0. Adjust the inner wall temperature of the temperature-controlled gravity dust collector to 340-380℃. After the dust-laden flue gas passes through the temperature-controlled gravity dust collector, the flue gas temperature is still 330-400℃, the chloride in the flue gas does not condense, the dust material collected in the ash discharge tank is not agglomerated, and the ash discharge channel is unobstructed.

[0060] Example 3

[0061] According to the working conditions, the temperature-controlled gravity dust collector is used to heat the dusty hot flue gas. Using slag produced by a certain unit with a mass concentration of 14% titanium carbide as raw material, the test was carried out on a fluidized bed reactor. The temperature of the dusty flue gas obtained on the top of the furnace after the reaction was 260-310°C. In the dusty flue gas, the mass content of TiCl4 is ≥90%, the mass content of FeCl3 is 7%-9%, and the mass content of dust particles is 1%-10%.

[0062] The dust-containing flue gas is sequentially passed through Figure 1 The temperature-controlled gravity dust collector shown has an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III to obtain treated flue gas.

[0063] Control the cold air temperature at the air inlet of section I of the air inlet pipe to be 310-350℃, and the wind speed to be 5-10m / s; the cold air temperature at the air inlet of section II of the ash collecting tank to be 310-350℃, and the wind speed to be 5-10m / s; the cold air temperature at the air inlet of section III of the air outlet pipe to be 310-350℃, and the wind speed to be 5-10m / s. Adjust the inner wall temperature of the temperature-controlled gravity dust collector to 310-350℃. After the dust-laden flue gas passes through the temperature-controlled gravity dust collector, the flue gas temperature is 290-330℃, reaching the predetermined temperature, the chloride in the flue gas does not condense, the dust material collected in the ash discharge tank is not agglomerated, and the ash discharge channel is unobstructed.

[0064] Comparative Example 1

[0065] A conventional gravity dust collector was used to carry out an experiment on a fluidized bed reactor using slag produced by a certain unit with a mass concentration of 14% titanium carbide as raw material. The temperature of the dusty flue gas obtained at the top of the furnace after the reaction was 260-310°C. In the dusty flue gas, the mass content of TiCl4 was ≥90%, the mass content of FeCl3 was 7%-9%, and the mass content of dust particles was 1%-10%.

[0066] In the early stage of production, the titanium tetrachloride in the flue gas condensed and liquefied in the gravity dust collector, causing the dust collected in the gravity dust collector to become seriously compacted, making it difficult to discharge the dust, and eventually leading to production shutdown.

[0067] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A temperature-controlled gravity dust collector, comprising: The main structure of the gravity dust collector; the main structure of the gravity dust collector comprises an air inlet pipe section I, an ash collecting tank section II and an air outlet pipe section III which are connected in sequence; An air duct is arranged outside the main structure of the gravity dust collector: spiral ascending air ducts are arranged outside the air inlet pipe section I, the ash collecting tank section II and the air outlet pipe section III, the lower end of the air duct is the air inlet, and the upper end of the air duct is the air outlet.

2. The temperature-controlled gravity dust collector according to claim 1, characterized in that: The air inlet pipe section I is arranged vertically, with a smoke inlet arranged at the top and a smoke outlet arranged at the bottom; The ash collecting tank section II is an inverted cone structure, with a dust removal ash outlet at the bottom and a smoke inlet and a smoke outlet at the top; the smoke inlet of the ash collecting tank section II is connected to the smoke outlet of the air inlet pipe section I; The air outlet pipe section III is vertically arranged, with a smoke inlet at the bottom and a smoke outlet at the top; the smoke inlet of the air outlet pipe section III is connected to the smoke outlet of the ash collecting tank section II.

3. The temperature-controlled gravity dust collector according to claim 1, characterized in that: The air intake pipe section I is a cylindrical pipe or a rectangular pipe; The air outlet pipe section III is a cylindrical pipe or a rectangular pipe.

4. A method for treating dusty flue gas, comprising the following steps: The dusty flue gas passes through the air inlet pipe section I, the dust collecting tank section II and the air outlet pipe section III of the temperature-controlled gravity dust collector in sequence to obtain the treated flue gas; The temperature-controlled gravity dust collector is the temperature-controlled gravity dust collector described in any one of claims 1 to 3.

5. The processing method according to claim 4, characterized in that: In the dust-laden flue gas, the mass content of TiCl4 is ≥90%, the mass content of FeCl3 is 7% to 9%, and the mass content of dust particles is 1% to 10%.

6. The processing method according to claim 4, characterized in that: The temperature of the dust-containing flue gas is 260-950°C.

7. The processing method according to claim 4, characterized in that: Control the cold air temperature at the air inlet of section I of the air inlet pipe to room temperature, and the wind speed to 8-10m / s; the cold air temperature at the air inlet of section II of the ash collection tank to 150-220℃, and the wind speed to 5-6m / s; the cold air temperature at the air inlet of section III of the air outlet pipe to room temperature, and the wind speed to 6-8m / s.

8. The processing method according to claim 4, characterized in that: Control the cold air temperature at the air inlet of section I of the air inlet pipe to be 330-400℃, and the wind speed to be 0-3m / s, and not 0; control the cold air temperature at the air inlet of section II of the ash collection tank to be 330-400℃, and the wind speed to be 0-3m / s, and not 0; control the cold air temperature at the air inlet of section III of the air outlet pipe to be 330-400℃, and the wind speed to be 0-3m / s, and not 0.

9. The processing method according to claim 4, characterized in that: Control the cold air temperature at the air inlet of section I of the air inlet pipe to 310~350℃, and the wind speed to 5~10m / s; control the cold air temperature at the air inlet of section II of the ash collection tank to 310~350℃, and the wind speed to 5~10m / s; control the cold air temperature at the air inlet of section III of the air outlet pipe to 310~350℃, and the wind speed to 5~10m / s.

10. The processing method according to claim 4, characterized in that: The inner wall temperature of the main structure of the gravity dust collector is controlled to be 220-380°C.

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