Method and device for deacidifying powder

Abstract

This application provides a method for deacidifying powder, comprising: moving the powder to be deacidified in the same direction as a first high-temperature gas flow in a conveying channel and directly contacting it for heat exchange, thereby preheating the powder to a target deacidification temperature within the conveying channel; the preheated powder then enters a deacidification space, into which a second high-temperature gas flow is introduced, causing the powder to undergo deacidification treatment under the action of the second high-temperature gas flow. This application completely separates the preheating process from the deacidification reaction process spatially, ensuring that the powder is preheated to the target deacidification temperature before entering the deacidification treatment space. This eliminates temperature fluctuations caused by the addition of cold material within the deacidification treatment space, significantly improving the stability of the deacidification temperature. This application also provides an apparatus for implementing the above-described powder deacidification method.

Description

Technical Field

[0001] This application relates to the field of deacidification technology, and to a method and apparatus for deacidifying powder. Background Technology

[0002] In the process of producing silica by the gas phase method, the raw material silicon tetrachloride will generate hydrogen chloride after hydrolysis, resulting in a certain amount of acid remaining in the finished silica. If the acid content is too high, it will directly affect the subsequent processing performance and product quality of silica. Therefore, it is necessary to deacidify the initial product.

[0003] The core mechanism of deacidification of silica involves two basic elements: first, temperature conditions, which require heating the silica powder to a high-temperature environment to desorb and release the adsorbed hydrogen chloride; and second, residence time, which requires maintaining the powder at the deacidification temperature for a sufficient time to ensure complete removal of hydrogen chloride. Furthermore, the deacidification effect also depends on the uniformity of the powder during the treatment process—if the powder is not heated uniformly, some parts may be completely deacidified while others retain residual hydrogen chloride, leading to unstable product quality.

[0004] Currently, the main types of silica deacidification devices known in the industry are as follows: A vertical static deacidification treatment container. Silica powder is loaded into the vertical container, and the powder is heated to the deacidification temperature by internal and external electric heating devices. This device has a simple structure, but its capacity is low, its electric heating energy consumption is high, and the static heating of the powder inside the container results in poor temperature uniformity.

[0005] Rotary kiln desulfurization unit. A rotary kiln is a rotating tubular furnace body. Silica powder enters from one end, is heated during the kiln's rotation, and moves towards the discharge end. This solution solves the problem of continuous production, but the equipment structure is complex, including a rotary sealing mechanism and a transmission device.

[0006] Fluidized bed deacidification unit. A fluidized bed uses hot air introduced from the bottom to fluidize the powder (in a suspended, boiling state) within the furnace, achieving sufficient contact and heat exchange between the powder and the hot airflow. However, silica powder has extremely low density and is easily carried away by the airflow, causing material loss. Simultaneously, directly feeding cold powder into a high-temperature fluidized bed leads to large temperature fluctuations in the bed, making it difficult to maintain a stable deacidification temperature, resulting in some powder being carried away before it can be deacidified.

[0007] The common drawback of the aforementioned existing technical solutions is that the deacidification device has dual functions of "heating" and "deacidification." After cold powder enters the deacidification furnace, it needs to be heated before reaching the deacidification temperature to begin the deacidification reaction. Continuous feeding of cold material causes the furnace temperature to fluctuate, making it difficult to maintain a stable deacidification temperature window; some powder has a short residence time in the furnace and is discharged before completing deacidification; temperature fluctuations result in inconsistent deacidification levels among different batches of powder. This "simultaneous feeding, heating, and deacidification" mode has low energy efficiency and makes it difficult to guarantee product quality.

[0008] Patent application CN102583396A discloses a deacidification device for the production of fumed silica. It designs a T-shaped connection deacidification device comprising a horizontal deacidification furnace and a vertical gas-solid separator. Utilizing the heat and steam generated by combustion of fuel gas, and aided by a densely perforated sieve plate and baffles, hydrogen chloride is separated from the surface of the fumed silica. The gas-solid separator separates the material from the gas, and an external insulation layer controls the temperature. Although this solution is essentially a fluidized bed deacidification device, the vertical gas-solid separator only separates impurities from the finished product, and thus cannot solve the problems existing in current deacidification devices. Summary of the Invention

[0009] The purpose of this application is to overcome the above-mentioned defects in existing powder deacidification methods and devices, and to provide a new powder deacidification method and device with stable deacidification temperature, uniform deacidification effect, and simple and reliable equipment structure.

[0010] To achieve the above-mentioned objective, this application provides a method for deacidifying powder, comprising: The powder to be deacidified flows in the same direction as the first high-temperature airflow in the conveying channel and directly contacts each other for heat exchange, so that the powder is preheated to the target deacidification temperature in the conveying channel. After being preheated, the powder enters the deacidification space, and a second high-temperature airflow is introduced into the deacidification space so that the powder undergoes deacidification treatment under the action of the second high-temperature airflow.

[0011] Furthermore, by setting the length of the conveying channel, the flow time of the powder within the conveying channel is sufficient to raise the powder temperature to the target deacidification temperature.

[0012] Furthermore, the second high-temperature airflow enters tangentially above the discharge area of ​​the deacidification treatment space, forming a rotating airflow field within the deacidification treatment space, causing the qualified powder to be suspended in the rotating airflow.

[0013] Compared with the traditional bottom uniform air distribution method, the rotating airflow generated by the tangential air intake drives the powder to tumble in three-dimensional space, which greatly increases the contact area and contact probability between the powder and the airflow, and significantly improves the mass and heat transfer efficiency. At the same time, the centrifugal force generated by the rotating airflow helps to classify the powder, with qualified fine powder suspended in the airflow and large particles being thrown to the outer wall and settling to the bottom.

[0014] Furthermore, the second high-temperature airflow is introduced tangentially through multiple nozzles distributed circumferentially along the deacidification treatment space, and the effective height of the rotating airflow field is limited to the space above the discharge area.

[0015] The second high-temperature airflow is uniformly introduced into the deacidification treatment space from multiple tangential directions, ensuring a uniform and symmetrical rotating airflow field and eliminating dead zones. The effective height of the rotating airflow field is limited to above the discharge area, so that the rotating airflow only acts on the deacidification treatment area. After the airflow reaches below the discharge area, it naturally attenuates and stops rotating, allowing the powder to fall smoothly in the discharge area for continuous removal.

[0016] Furthermore, the first high-temperature gas flow and / or the second high-temperature gas flow are generated by the combustion of combustible gas and oxygen-containing gas.

[0017] On the other hand, to achieve the above-mentioned objective, this application also provides an apparatus for implementing the above-mentioned powder deacidification method, characterized in that it comprises: A preheating conveying channel, wherein the inlet end 11 of the preheating conveying channel is used to introduce a first high-temperature airflow, and the preheating conveying channel is also provided with a powder feeding port; The deacidification treatment container is a vertical container. The inlet of the deacidification treatment container is connected to the outlet of the preheating conveying channel. The top of the deacidification treatment container is provided with an airflow outlet. The side wall of the container is provided with several second high-temperature airflow inlets. The side wall of the container below the second high-temperature airflow inlets is provided with a discharge outlet. The bottom of the container is provided with a non-conforming material discharge outlet.

[0018] Furthermore, the diameter of the upper part of the deacidification treatment container is larger than the diameter of the upper and lower ends.

[0019] In other words, the deacidification treatment container has a wide-bellied structure. Within this container, lightweight powders such as silica are easily carried upwards by the second high-temperature airflow. The wide-bellied structure increases the cross-sectional area of ​​the upper part of the container, naturally reducing the airflow velocity. This allows the powder to achieve a longer suspension residence time in the expanded area, preventing fine powders from being directly carried out of the container by the airflow. Simultaneously, the wide-bellied structure provides a larger gas-solid separation space, which is beneficial for the efficient separation of airflow and powder.

[0020] Furthermore, the device is also equipped with a burner located at the inlet end of the preheating conveying channel, which is used to burn combustible gas and oxygen-containing gas to generate a high-temperature gas flow.

[0021] Furthermore, several second high-temperature gas inlets are distributed along the circumference of the container and the jet direction is tangent to the inner wall of the container.

[0022] Furthermore, the first high-temperature gas flow and the second high-temperature gas flow are generated by combustion in the same burner.

[0023] Compared with the prior art, this application has the following beneficial effects: 1. This application completely separates the preheating process from the deacidification reaction process in space. The powder has been preheated to the target deacidification temperature before entering the deacidification treatment space. There is no longer any temperature fluctuation caused by the addition of cold material in the deacidification treatment space, and the stability of the deacidification temperature is greatly improved.

[0024] 2. Since all powders undergo the same preheating process in the preheating conveying channel, that is, they are in the same direction and flow directly in contact for heat exchange. When they enter the deacidification treatment space, the temperature is consistent, which eliminates the problem of uneven deacidification caused by uneven residence time and temperature gradient in traditional processes. This results in high uniformity of deacidification effect and significantly improved product quality.

[0025] 3. Under the same conditions, changing the second high-temperature airflow inlet method to "tangential airflow" can improve the deacidification efficiency. The rotating airflow field causes the powder to tumble in three-dimensional space, increasing the contact area and contact probability between the powder and the airflow, thus improving the mass and heat transfer efficiency.

[0026] 4. The wide-bellied container structure prevents powder carryover and extends residence time. The wide-bellied structure increases the cross-sectional area of ​​the upper part of the container, naturally reducing airflow velocity and effectively preventing extremely light powders from being directly carried to the top and discharged. Simultaneously, the increased cross-sectional area increases the gas-solid separation space, improving separation efficiency. Large, non-compliant particles and agglomerates settle to the bottom of the container due to their weight and are periodically discharged through a valve. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the fumed silica deacidification device of this application; Figure 2 This is a schematic diagram of the second high-temperature airflow inlet of the deacidification treatment container in this application; Figure 3 This is a schematic diagram of the overall structure of another fumed silica deacidification device according to this application.

[0028] Explanation of reference numerals in the attached figures: 1. Preheating conveying channel; 11. Inlet end; 12. Powder feeding port; 13. Outlet end; 2. Deacidification treatment container; 21. Inlet; 22. Airflow outlet; 23. Second high-temperature airflow inlet; 24. Outlet; 25. Outlet for non-conforming materials; 3. Burner. Detailed Implementation

[0029] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0030] Existing deacidification technologies simultaneously heat and deacidify powder in a single processing unit. The continuous addition of powder at lower temperatures to the deacidification equipment causes temperature fluctuations within the unit, making it impossible to maintain the deacidification temperature stably within the optimal range, resulting in poor product quality consistency. Some powder is discharged before complete deacidification due to insufficient residence time, leading to incomplete deacidification and significant batch-to-batch product quality variations. Existing deacidification equipment (such as rotary kilns) has a complex structure, and the rotating seals have a high failure rate under high-temperature, high-acid conditions, resulting in high maintenance costs. Existing deacidification technologies are energy-intensive, especially those using indirect electric heating methods, which have low energy efficiency. To address these technical problems, this application provides a novel powder deacidification method and apparatus that offers stable deacidification temperature, uniform deacidification effect, low energy consumption, and a simple and reliable equipment structure. The purpose of this application is to overcome the aforementioned deficiencies of existing powder deacidification methods and apparatuses.

[0031] In the following specific embodiments, the powder is fumed silica. During the production of fumed silica, a large amount of hydrogen chloride and moisture are inevitably mixed in; deacidification is a post-processing step for fumed silica. This application addresses the characteristics of fumed silica powder—extremely low density, easy dispersion, and a deacidification temperature of approximately 500-550℃—by providing a powder deacidification method, including: The powder to be deacidified flows in the same direction as the first high-temperature airflow in the conveying channel and directly contacts each other for heat exchange, so that the powder is preheated to the target deacidification temperature in the conveying channel. After being preheated, the powder enters the deacidification space, and a second high-temperature airflow is introduced into the deacidification space so that the powder undergoes deacidification treatment under the action of the second high-temperature airflow.

[0032] During implementation, the temperature of the first high-temperature gas flow is controlled at 600~800℃, and the target deacidification temperature is 450~600℃. When the temperature of the first high-temperature gas flow is below 600℃, the powder is unlikely to reach an effective deacidification temperature after heat exchange through the pipeline; when it is above 800℃, the powder inside the pipeline may undergo localized sintering. The target deacidification temperature of 450~600℃ can effectively desorb hydrogen chloride from the powder material.

[0033] In this application, the temperature of the second high-temperature gas flow is 450~600℃. When the temperature of the second high-temperature gas flow is below 450℃, it is insufficient to maintain the powder within the deacidification temperature window to complete deacidification; when it is above 600℃, although the deacidification effect is improved, the marginal benefit of increased energy consumption diminishes.

[0034] The first and / or second high-temperature gas streams are generated by the combustion of combustible gas and oxygen-containing gas. The temperature of the high-temperature gas streams is controlled by adjusting the flow rate of the combustible gas and / or the ratio of the oxygen-containing gas. By adjusting the stoichiometric ratio of the combustible gas and the oxygen-containing gas, the temperature of the combustion products can be controlled without the need for additional temperature control devices, making the control method simple and reliable. The combustible gas can be hydrogen, natural gas (mainly composed of methane), etc. Preferably, hydrogen is used as the combustible gas. Hydrogen combustion only produces water vapor, and the combustion products are clean, without introducing additional impurity elements into the powder. The high flame temperature of hydrogen combustion, when mixed with oxygen-containing gas, can produce a controllable high-temperature gas stream. In addition, in the production process of precipitated silica, byproduct hydrogen is generated. Utilizing byproduct hydrogen for deacidification preheating can significantly reduce operating costs and achieve internal energy recycling. Natural gas can also be used as the combustible gas, producing water and carbon dioxide after combustion. Ordinary air or compressed air can be used as the oxygen-containing gas.

[0035] In this application, the length of the conveying channel is set such that the flow time of the powder within the conveying channel is sufficient to raise the powder temperature to the target deacidification temperature. For example, based on production volume calculations, in one embodiment, the length of the preheating conveying channel 1 is 3~12m, and this length range is considered based on preheating time and common processing scale.

[0036] In this application, the second high-temperature airflow is introduced tangentially above the discharge area of ​​the deacidification treatment space, forming a rotating airflow field within the deacidification treatment space, causing the qualified powder to be suspended in the rotating airflow. Furthermore, the second high-temperature airflow is introduced tangentially through multiple nozzles distributed circumferentially along the deacidification treatment space, and the effective height of the rotating airflow field is limited to the space above the discharge area.

[0037] To implement the above methods, please refer to Figure 1 The apparatus for the powder deacidification method provided in this application, as illustrated, includes: The preheating conveying channel 1 has an inlet end 11 for introducing a first high-temperature airflow, and the preheating conveying channel 1 is also provided with a powder feeding port 12; the powder and the high-temperature airflow flow in the same direction in the preheating conveying channel 1 and the powder is preheated to the target deacidification temperature through direct contact heat exchange. The deacidification treatment container 2 is a vertical container. The inlet 21 of the deacidification treatment container 2 is connected to the outlet 13 of the preheating conveying channel 1. The top of the deacidification treatment container 2 is provided with an airflow outlet 22. The side wall of the container is provided with several second high-temperature airflow inlets 23. The side wall of the container below the second high-temperature airflow inlets 23 is provided with a discharge outlet 24. The bottom of the container is provided with a non-conforming material discharge outlet 25.

[0038] Furthermore, the device is also equipped with a burner located at the inlet end 11 of the preheating conveying channel 1. The burner includes a combustible gas inlet and an oxygen-containing gas inlet for combustion, and is used to burn the combustible gas and the oxygen-containing gas for combustion to generate a high-temperature gas flow. In this application, the upper diameter of the deacidification treatment container 2 is larger than the diameters of its upper and lower ends, forming a large-bellied vertical structure. Lightweight powders such as silica are easily carried upwards by the second high-temperature airflow. The large-bellied structure increases the cross-sectional area of ​​the upper part of the container, naturally reducing the airflow velocity. This allows the powder to have a longer suspension residence time in the expanded area, avoiding the problem of fine powder being directly carried out of the container by the airflow. Simultaneously, the large-bellied structure provides a larger gas-solid separation space, which is beneficial for the efficient separation of airflow and powder.

[0039] In this application, a plurality of second high-temperature gas inlets 23 are distributed along the circumference of the container and the spray direction is tangent to the inner wall of the container.

[0040] Figure 3 The diagram also illustrates the overall structure of another gas phase silica deacidification device of this application, in which the first high-temperature gas flow and the second high-temperature gas flow are generated by combustion in the same burner.

[0041] The present application is illustrated below through specific embodiments and comparative examples.

[0042] In the following examples and comparative examples, the natural gas used had a CH4 content ≥95%, and the hydrogen used had an H2 content ≥99.9%. The oxygen-containing gas used in the following examples and comparative examples was air.

[0043] The conveying channel 1 is a heat-resistant steel circular sealed pipe with an inner diameter of DN200. The deacidification treatment container 2 is a large-bellied vertical tank with a round cover at the top, which is 0.4m high; the upper middle part has a diameter of 2.5m and a height of 3m; the lower middle part is a conical cavity with a height of 2m, and the diameter of the unqualified material discharge port 25 at the bottom is 0.15m.

[0044] In Examples 1-4 and Comparative Examples 1-2 below, the feed temperature of the silica powder to be deacidified was 155±5℃, the initial pH value of the silica powder to be deacidified was 3.1, the initial moisture content was 9.0~10.0wt%, the average particle size of the powder was 15~25μm, and the loose packing density was 120~180kg / m³.

[0045] Example 1 Air at 500 Nm 3 The flow rate is fed into the burner 3 at a rate of / h and mixed with hydrogen for combustion. The hydrogen flow rate is adjusted to stabilize the combustion temperature at 700±10℃. The high-temperature gas flow generated by combustion enters the conveying channel 1 from the inlet end 11 of the preheating conveying channel as the first high-temperature gas flow. Air at 700 Nm 3 The gas is fed into the burner 3 at a flow rate of / h and mixed with natural gas for combustion. The natural gas flow rate is adjusted to stabilize the combustion temperature at 520±10℃. The high-temperature gas flow generated by combustion is used as the second high-temperature gas flow. The second high-temperature gas flow is introduced into the area above the outlet 24 of the deacidification treatment container through 4 tangential nozzles. The fumed silica powder to be deacidified enters the conveying channel 1 through the powder feeding port 12. Within the conveying channel, it flows in the same direction as the high-temperature airflow, preheating through direct contact heat exchange. After being conveyed through a 6m pipeline, the powder temperature rises to approximately 520℃, reaching the target deacidification temperature.

[0046] The preheated powder is carried by the airflow through the inlet 21 of the deacidification treatment container into the deacidification treatment container 2. Inside the deacidification treatment container 2, under the action of the second high-temperature airflow, the powder continues to undergo deacidification in a suspended state, causing water vapor and HCl to volatilize from the fumed silica and exit from the airflow outlet 22, entering the tail gas treatment system. Fine powder that has passed deacidification is continuously extracted and output from the side outlet 24, while large particles and agglomerates are discharged from the bottom unqualified material outlet 25. See Table 1 for details.

[0047] Examples 2 to 4: The control process is the same as in Example 1, except that the control parameters are different, as detailed in Table 1.

[0048] Comparative Example 1: Scheme of preheating the pipeline but without a second high-temperature airflow Based on Example 1, the second high-temperature airflow is eliminated (i.e., no auxiliary airflow is introduced into the deacidification treatment container 2), and deacidification is carried out solely by the heat carried by the powder itself and the residual heat of the high-temperature airflow from the preheating pipe.

[0049] Comparative Example 2: A scheme involving deacidification without pipe preheating, but only within the deacidification treatment container 2. The preheating conveying channel 1 and burner 3 are cancelled, and the powder to be deacidified is directly put into the deacidification treatment container 2. At the same time, 520℃ tangential hot air is introduced into the deacidification treatment container 2 for deacidification (i.e. the traditional single-equipment heating + deacidification mode, but using tangential air intake).

[0050] Table 1. Deacidification control parameters for each example and comparative example.

[0051] The pH, moisture content, and deacidification consistency of the fumed silica obtained after deacidification in the above embodiments and comparative examples were tested using the following methods: pH value: Refer to Appendix E - Determination of pH value of suspension in GB / T20020-2025 "Fused Silica"; Moisture content: Refer to GB / T 6284-2006 "General Method for Determination of Moisture in Chemical Products - Loss on Drying Method".

[0052] Deacidification consistency: During the deacidification process of a batch, the pH value of the deacidified fumed silica was taken every 20 minutes, and the pH value of 24 samples was continuously measured. The coefficient of variation of the pH value of the 24 samples was calculated.

[0053] The test results are shown in Table 2.

[0054] Table 2. Deacidification effect of each embodiment and comparative example

[0055] As can be seen from the above embodiments and comparative examples, the solution of this application can not only improve the deacidification efficiency, but also ensure high consistency of pH value of the product after deacidification.

[0056] A comparison of Examples 1 and 2 shows that the product obtained by using hydrogen as a combustible heating gas has a lower moisture content.

[0057] A comparison of Examples 1 and 3 shows that changing the second high-temperature airflow inlet method to "tangential airflow" can improve the deacidification efficiency. The rotating airflow field causes the powder to tumble in three-dimensional space, increasing the contact area and contact probability between the powder and the airflow, thereby improving the mass and heat transfer efficiency and helping to improve the deacidification efficiency.

[0058] A comparison of Examples 1 and 4 shows that a conveying channel 1 that is too short is not conducive to the preheating of the deacidified powder.

[0059] A comparison of Example 1 and Comparative Example 1 shows that heating the powder with only the first high-temperature airflow is insufficient to completely deacidify the powder.

[0060] A comparison of Example 1 and Comparative Example 2 shows that using only the second gas flow for deacidification results in poor consistency of the pH value of the product.

[0061] In addition, the inventors designed the deacidification treatment container 2 as a cylindrical vertical tank with a diameter of 2.5m and a height of 5m. However, due to the short residence time of the powder in the cylindrical vertical tank, the pH value after deacidification was 4.0 with a coefficient of variation of 2.31%, resulting in unqualified deacidification.

[0062] The inventors also used the deacidification device of this application to remove hydrochloric acid from Al2O3 powder, which can also achieve a high efficiency and good consistency in deacidification.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for deacidifying a powder, characterized by, include: The powder to be deacidified flows in the same direction as the first high-temperature airflow in the conveying channel and directly contacts each other for heat exchange, so that the powder is preheated to the target deacidification temperature in the conveying channel. After being preheated, the powder enters the deacidification space, and a second high-temperature airflow is introduced into the deacidification space so that the powder undergoes deacidification treatment under the action of the second high-temperature airflow.

2. The powder deacidification method according to claim 1, characterized by, By setting the length of the conveying channel, the flow time of the powder within the conveying channel is sufficient to raise the powder temperature to the target deacidification temperature.

3. The powder deacidification method according to claim 1, characterized by, The second high-temperature airflow enters tangentially above the discharge area of ​​the deacidification treatment space, forming a rotating airflow field within the deacidification treatment space, causing the qualified powder to be suspended in the rotating airflow.

4. The powder deacidification method according to claim 3, characterized by, The second high-temperature airflow is introduced tangentially through multiple nozzles distributed circumferentially along the deacidification treatment space, and the effective height of the rotating airflow field is limited to the space above the discharge area.

5. The powder deacidification method according to claim 1, characterized by, The first high-temperature gas flow and / or the second high-temperature gas flow are generated by the combustion of combustible gas and oxygen-containing gas.

6. An apparatus for carrying out the powder deacidification method according to any one of claims 1 to 5, characterized by include: The preheating conveying channel (1) is used to introduce a first high-temperature airflow at its inlet end (11), and the preheating conveying channel is also provided with a powder feeding port (12). The deacidification treatment container (2) is a vertical container. The inlet (21) of the deacidification treatment container is connected to the outlet (13) of the preheating conveying channel. The top of the deacidification treatment container is provided with an airflow outlet (22). The side wall of the container is provided with several second high-temperature airflow inlets (23). The side wall of the container below the second high-temperature airflow inlets is provided with a discharge outlet (24). The bottom of the container is provided with a non-conforming material discharge outlet (25).

7. The apparatus of claim 6, wherein, The diameter of the upper part of the deacidification treatment container is larger than the diameter of the upper and lower ends.

8. The apparatus of claim 6, wherein, The device is also equipped with a burner (3), which is located at the inlet end (11) of the preheating conveying channel and is used to burn combustible gas and oxygen-containing gas to generate a high-temperature gas flow.

9. The apparatus of claim 6, wherein, Several second high-temperature gas inlets are distributed along the circumference of the container and the spray direction is tangent to the inner wall of the container.

10. The apparatus of claim 6, wherein, The first high-temperature gas flow and the second high-temperature gas flow are generated by combustion in the same burner.

Images