Granular activated carbon preparation method based on vertical tube nest furnace and vertical tube nest furnace

Abstract

The invention discloses a granular activated carbon preparation method based on a vertical tube nest furnace and the vertical tube nest furnace. The defects that a horizontal rotary furnace is thick in wall, high in energy consumption, limited in temperature, low in material crushing yield and difficult to control in retention time are overcome. The method comprises the following steps: filling a vertical furnace tube with a to-be-regenerated material, and heating to a working temperature of 550-900 DEG C; by adjusting the opening and closing frequency control speed of the discharging control valve, the materials slowly fall down due to gravity and stay to exceed a threshold value to complete desorption; high-temperature waste gas is collected to the feeding bin through the exhaust pipe to preheat materials and then discharged. By utilizing the advantages that the vertical furnace tube is thin and has no stress in the length direction, the energy consumption is obviously reduced; meanwhile, the retention time precision is + / -2%, the desorption efficiency is improved, and the regeneration quality and the production efficiency of the granular activated carbon are comprehensively improved.

Description

Technical Field

[0001] This invention relates to a method for preparing granular activated carbon based on a vertical tube furnace and the vertical tube furnace itself, belonging to the field of advanced inorganic non-metallic materials technology. Background Technology

[0002] Existing horizontal rotary furnaces, such as the patent with classification number C01B32 and application number 202220903512.9, and graphitization furnaces with energy-saving waste heat recovery, have the following technical defects in the preparation of granular activated carbon: The biggest problem with horizontal rotary kilns is that the furnace walls need to be very thick to prevent deformation at high temperatures. However, thick walls require very high heating temperatures, resulting in a lot of wasted heat. Even with thick walls, there are still limitations on the high temperature of the furnace tubes, as excessively high temperatures can still cause deformation of the horizontal furnace tubes along their length. The material in a horizontal rotary kiln experiences repeated collisions and breakage with the furnace walls and other materials during its journey, leading to a low material yield. The residence time of materials in a horizontal rotary kiln depends on the furnace rotation speed, making it difficult to precisely match the desorption time of different contaminants, which can easily result in insufficient desorption or excessive energy consumption.

[0003] Therefore, existing technologies need further improvement and refinement. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention aims to provide a method for preparing granular activated carbon based on a vertical tube furnace and the vertical tube furnace itself.

[0005] According to an embodiment of the present invention, the first embodiment is provided as: a method for preparing granular activated carbon based on a vertical tube furnace, comprising the steps of: The granular activated carbon material to be regenerated is obtained from the feed hopper and filled into each vertically arranged furnace tube of the vertical tube furnace. The furnace tubes are heated to their operating temperature by an external heating source. The material descent speed is controlled by adjusting the opening and closing frequency of the discharge control valve at the bottom of the furnace tube, so that the material falls slowly under the action of gravity and stays in the furnace tube for a longer than the working time threshold. The granular activated carbon material undergoes regeneration treatment in each furnace tube at the working temperature and residence time to complete the desorption of organic pollutants. The high-temperature exhaust gas in the vertical furnace tube is collected through the exhaust pipe and sent to the feed hopper to preheat the granular activated carbon material to be regenerated. The exhaust gas is discharged after its temperature drops below the discharge temperature threshold.

[0006] Furthermore, the operating temperature is 550℃-600℃, the operating time threshold is 30min-60min, and the waste discharge temperature threshold is 70℃-90℃.

[0007] Furthermore, by controlling the opening and closing frequency of the discharge control valve, the material passes through the upper, middle and lower temperature zones of the furnace tube from top to bottom. The material is fully heated to the working temperature in the upper temperature zone, the material stays in the middle temperature zone for a period exceeding the working time threshold to complete the regeneration process, and the material is cooled in the lower temperature zone to allow the regenerated granular activated carbon material to be shaped.

[0008] Furthermore, the vertically arranged furnace tubes have different diameters from top to bottom to adjust the speed at which the material passes through the upper, middle, and lower temperature zones. The discharge control valve controls the material descent at the working opening and closing frequency. The furnace tube diameter in the upper temperature zone is smaller so that the material passes through the upper temperature zone slowly and can be fully heated to the working temperature. The furnace tube diameter in the middle temperature zone is larger so that the material passes through the middle temperature zone quickly and fully desorbs organic pollutants. The furnace tube diameter in the lower temperature zone is smaller so that the material passes through slowly and avoids excessive cooling that could cause the particles to crack.

[0009] Furthermore, the furnace tube length corresponding to the middle temperature zone is the longest to ensure the residence time of the granular activated carbon material in the middle temperature zone.

[0010] Furthermore, the real-time mid-section temperature of the mid-section temperature zone is obtained; The opening and closing frequency of the discharge control valve is adjusted based on the difference between the real-time mid-section temperature and the reference temperature to ensure that the desorption efficiency of each activated carbon particle is consistent.

[0011] According to an embodiment of the present invention, utilizing the granular activated carbon preparation method based on a vertical tube furnace in the first embodiment of the present invention, a second embodiment is provided as follows: A vertical tube furnace, comprising: Multiple vertically arranged furnace tubes, with a heating source installed on the outside of each furnace tube; Each furnace tube is connected to a feeding hopper at the top, and the feeding hopper is equipped with a feeding distribution device; Each furnace tube is equipped with a discharge control valve at the bottom. The discharge control valve controls the descent speed of the material by controlling the opening and closing frequency, so that the material falls slowly under the action of gravity and stays in the furnace tube for more than the working time threshold to complete the desorption of organic pollutants. Each furnace tube is equipped with an exhaust pipe, through which high-temperature exhaust gas is collected and sent to the feed hopper to preheat the granular activated carbon material to be regenerated.

[0012] Furthermore, the furnace tube has a three-stage structure, wherein the upper section has a smaller diameter to allow the material to pass through the upper temperature zone slowly, the middle section has a larger diameter to allow the material to pass through the middle temperature zone quickly and fully desorb organic pollutants, and the lower section has a smaller diameter to avoid excessive cooling that could cause the particulate matter to crack.

[0013] Furthermore, the exhaust pipe is arranged on the axis of the furnace tube, and multiple branch pipes are arranged around the exhaust pipe, which extend into the granular activated carbon material to collect the waste gas.

[0014] Furthermore, multiple branch pipes arranged on the exhaust pipe along the furnace tube axis extend downwards in a spiral pattern to guide the material on the axis to rotate and fall towards the tube wall as it falls.

[0015] Compared with the prior art, the beneficial effects of the independent claims of the technical solution provided in this application are as follows: First, the tubes of the vertical tube furnace are thinner, resulting in higher heat transfer efficiency, less heat transfer loss, and lower energy consumption. Higher temperatures can be used for material processing, and high-temperature exhaust gas can be used to preheat materials. Secondly, the high temperature of horizontal furnace tubes is limited by high-temperature deformation, and the operating temperature cannot meet the requirements for deep desorption. However, when vertical furnace tubes are installed vertically, there is no force along the length, and the operating temperature can be raised to 550-900℃, which can meet the requirements for deep desorption of organic pollutants such as benzene series compounds and polycyclic aromatic hydrocarbons. Third, the vertical furnace tube is filled with material and falls slowly under gravity control, which can significantly reduce the material breakage rate and improve the yield of granular activated carbon, thus avoiding raw material waste and reducing production costs. Fourth, this vertical tube furnace precisely controls the material descent speed by adjusting the opening and closing frequency of the discharge control valve, and the residence time control accuracy is within ±2%. It can also flexibly adjust the residence time according to the type of pollutant, thereby improving the desorption efficiency.

[0016] This invention, through the structural advantages and process optimization of vertical tube furnaces, comprehensively solves the core defects of horizontal rotary furnaces from four dimensions: energy consumption, temperature adaptability, material yield, and desorption efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] in: Figure 1 This is a schematic diagram of the overall structure of a vertical tube furnace in one embodiment; Figure 2 This is a schematic diagram of the layout of the heating source of a vertical tube furnace in one embodiment; Figure 3 This is a schematic diagram of the exhaust pipe structure in one embodiment; Figure 4This is a schematic diagram of the feed hopper structure in one embodiment; Figure 5 This is a schematic diagram of the discharge control valve in one embodiment; Figure 6 This is a schematic flowchart of a method for preparing granular activated carbon based on a vertical tube furnace in one embodiment.

[0019] Figure label: 10-Furnace tube; 11-Feed hopper; 12-Discharge control valve; 13-Heating source; 14-Exhaust pipe; 15-Feed distribution device. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] Example 1

[0022] This embodiment specifically relates to a method for preparing granular activated carbon based on a vertical tube furnace. Existing technologies often employ horizontal rotary furnaces for granular activated carbon preparation. This method has certain drawbacks. For example, the biggest problem with horizontal rotary furnaces is the need for very thick furnace walls to prevent deformation at high temperatures. However, thick walls require very high heating temperatures, resulting in significant heat waste. Even with thick walls, the high temperature of the furnace tubes 10 is still somewhat limited, as excessively high temperatures can still cause deformation of the horizontal furnace tubes 10 along their length. Furthermore, the material in the horizontal rotary furnace experiences repeated collisions and breakage with the furnace walls and other materials during its movement, leading to a low material yield. The material residence time in a horizontal rotary furnace depends on the furnace rotation speed, making it difficult to precisely match the desorption time for different pollutants, easily resulting in insufficient desorption or excessive energy consumption.

[0023] Furthermore, the vertical tube furnace is not simply a horizontal furnace placed vertically and with thinner tube walls. Its core innovation lies in the precise control of the material's falling speed by gravity through the opening and closing frequency of the discharge control valve, which solves the problem of traditional horizontal furnaces relying on rotational speed control.

[0024] This embodiment provides a method for preparing granular activated carbon based on a vertical tube furnace, such as... Figure 6 As shown, the steps include: S1: Obtain the granular activated carbon material to be regenerated from the feed hopper 11 and fill each vertically arranged furnace tube 10 of the vertical tube furnace with the material. S2: The furnace tube 10 is heated to the working temperature by the heating source 13 outside the furnace tube 10; S3: By adjusting the opening and closing frequency of the discharge control valve 12 at the bottom of the furnace tube 10, the descent speed of the material is controlled so that the material falls slowly under the action of gravity and stays in the furnace tube 10 for a longer time than the working time threshold. The granular activated carbon material undergoes regeneration treatment in each furnace tube 10 at the working temperature and residence time to complete the desorption of organic pollutants. S4: The high-temperature exhaust gas in the vertical furnace tube 10 is collected through the exhaust pipe 14 and sent to the feed hopper 11 to preheat the granular activated carbon material to be regenerated. The exhaust gas is discharged after its temperature drops below the discharge temperature threshold.

[0025] Through the above scheme, the vertical tube furnace tube 10 is thinner, with higher heat transfer efficiency, less heat transfer loss, and lower energy consumption. It can use higher temperatures for material processing and can also obtain high-temperature exhaust gas to preheat materials. The horizontal furnace tube 10 is limited by high-temperature deformation, and its operating temperature cannot meet the requirements for deep desorption. However, when the vertical furnace tube 10 is installed vertically, it is not subjected to force in the length direction, and the operating temperature can be raised to 550-900℃, which can meet the requirements for deep desorption of organic pollutants such as benzene series compounds and polycyclic aromatic hydrocarbons. The vertical tube furnace 10 is filled with material and descends slowly under gravity, significantly reducing material breakage and increasing the yield of granular activated carbon, thus avoiding raw material waste and reducing production costs. This vertical tube furnace precisely controls the material descent speed by adjusting the opening and closing frequency of the discharge control valve 12, achieving a residence time control accuracy within ±2%. The residence time can also be flexibly adjusted according to the type of contaminant, further improving desorption efficiency. This invention, through the structural advantages and process optimization of the vertical tube furnace, comprehensively solves the core defects of horizontal rotary kilns from four dimensions: energy consumption, temperature adaptability, material yield, and desorption efficiency.

[0026] Example 2

[0027] This embodiment elaborates on the method for preparing granular activated carbon based on a vertical tube furnace.

[0028] The granular activated carbon material to be regenerated is first stored, or partially stored, in the feed hopper 11, which is equipped with a feed distribution device 15, such as... Figure 4 As shown, the granular activated carbon material in the feed hopper 11 is evenly transported into the vertically arranged furnace tubes 10. After each furnace tube 10 is evenly filled with granular activated carbon material, the continuous high-temperature activation treatment of granular activated carbon begins. Traditional horizontal rotary furnaces are limited by deformation, making it difficult to maintain the ≥550℃ high temperature required for deep desorption. Excessive temperature can easily cause deformation of the furnace wall under the combined effects of high temperature and horizontal rotation. This solution, however, sets the furnace tube 10 vertically, eliminating the need to consider its deformation. Its maximum operating temperature can exceed 900℃ depending on the material processing technology, far surpassing the limitations of traditional heating equipment. The operating time threshold can also be further increased to 60 minutes. Simultaneously, the exhaust gas temperature is also higher, allowing for thorough preheating of the granular activated carbon material awaiting regeneration in the feed hopper 11. This results in a significantly higher temperature throughout the entire material preparation system of the vertical tube furnace compared to traditional solutions. This is something that technicians using traditional methods could not have imagined or achieved.

[0029] Specifically, in controlling the material descent speed, this embodiment creatively proposes to control the material descent speed by utilizing the opening and closing frequency of the discharge control valve 12 at the bottom of the furnace tube 10, such as... Figure 5 As shown, in addition to the conventional opening and closing function of discharging materials, the discharge control valve 12 unexpectedly plays a technical role in controlling the descent speed of materials in the furnace tube 10. Moreover, this control structure is simple to implement, and has outstanding advantages such as accurate control process and high control precision.

[0030] Furthermore, since the activation temperature of the material can be raised to a very high temperature range, this brings about the technical problem of excessively high temperature gradient of granular activated carbon material. This problem causes the material to stay in the high temperature zone for a longer time to ensure that the temperature can rise to the working temperature range. However, this process is difficult to monitor, which leads to conservative operation, thereby prolonging the heating time of the material and reducing the overall preparation efficiency.

[0031] To solve this technical problem, this embodiment specifically arranges at least three layers of electric heating sources 13 outside the vertically arranged furnace tube 10 to heat the upper, middle and lower temperature zones of the furnace tube 10. The material is fully heated to the working temperature in the upper temperature zone, the material stays in the middle temperature zone for a period of time exceeding the working time threshold to complete the regeneration process, and the material is cooled in the lower temperature zone to allow the regenerated granular activated carbon material to be shaped.

[0032] Furthermore, the furnace tubes 10 of various rotary kilns and tube furnaces are usually circular tubes of the same diameter. Therefore, when the material passes through the furnace tubes 10 of the tube furnace, the passage speed is the same in different parts. However, in the above implementation scheme, if circular tubes of the same diameter are used, the material will pass through the upper temperature zone too fast, resulting in insufficient heating of the material. The speed in the lower temperature zone is also too fast, which will also cause the material to cool down too quickly and cause the particles to crack. Therefore, it is necessary to slow down the speed in the middle temperature zone at the same time, which will reduce the overall activation efficiency.

[0033] To address this technical problem, this embodiment specifically uses different diameters for the vertically arranged furnace tubes 10 from top to bottom to adjust the speed at which the material passes through the upper, middle, and lower temperature zones. The discharge control valve 12 controls the descent of the material at the working opening and closing frequency. The furnace tubes 10 in the upper temperature zone have smaller diameters so that the material passes through the upper temperature zone slowly, allowing the material to be fully heated to the working temperature. The furnace tubes 10 in the middle temperature zone have larger diameters so that the material passes through the middle temperature zone quickly and fully desorbs organic pollutants. The furnace tubes 10 in the lower temperature zone have smaller diameters so that the material passes through slowly to avoid excessive cooling and cracking of particles.

[0034] Furthermore, the lengths of the furnace tubes 10 corresponding to the upper, middle, and lower temperature zones can be further adjusted to ensure that the furnace tube 10 corresponding to the middle temperature zone has the longest length, thereby maximizing the residence time of the granular activated carbon material in the middle temperature zone.

[0035] Furthermore, under high-temperature conditions, the existing conventional electric heating source 13 cannot guarantee a very precise and stable temperature range at a specific temperature value. There is usually a certain temperature range fluctuation, which leads to inconsistent desorption efficiency of granular activated carbon material passing through the terminal temperature zone. In particular, when the temperature range fluctuation is large, it will cause significant fluctuations in material quality.

[0036] To address this technical challenge, this embodiment specifically discloses a method for preparing granular activated carbon. By acquiring the real-time temperature of the intermediate temperature zone, and adjusting the opening and closing frequency of the discharge control valve 12 based on the difference between the real-time intermediate temperature and the reference temperature, the desorption efficiency of each granular activated carbon material is ensured to be consistent. This solution innovatively achieves adjustment of the material's speed through activation zones at different temperatures by adjusting the conventional mechanical structure of the discharge control valve 12, ultimately realizing uniform activation process control and demonstrating unexpected technical effects and significant substantive contributions.

[0037] Example 3

[0038] In certain scenarios involving the segmented desorption of pollutants, the existing overall heating mode in the middle temperature zone cannot adjust the temperature according to the different desorption states of materials at different locations, resulting in insufficient desorption of local materials. In particular, the organic residue of materials near the tail end may be close to or exceed the threshold due to insufficient temperature compared with the preset desorption effect.

[0039] To address this technical problem, this embodiment proposes a method for preparing granular activated carbon based on a vertical tube furnace. This method divides the middle temperature zone into at least two independent sub-temperature zones along the material falling direction. Each sub-temperature zone is equipped with an independent heating source 13, a temperature sensor, and an adjustable pipe diameter structure. The temperature of each sub-temperature zone, the exhaust gas temperature of the corresponding sub-temperature zone's exhaust pipe 14, and the material residence time are collected in real time. Based on the preset desorption curve, the heating power of each sub-temperature zone, the opening and closing frequency of the corresponding discharge control valve 12, and the pipe diameter of the sub-temperature zone are adjusted to control the temperature uniformity within the middle temperature zone within ±5℃, thereby minimizing the proportion of insufficient desorption of local materials.

[0040] Through this implementation scheme, the internal temperature difference of the middle temperature zone is reduced from ±15℃ to within ±5℃, and the proportion of insufficient local desorption is further reduced. For pollutants that are difficult to desorb, such as polycyclic aromatic hydrocarbons, the deep desorption rate can be effectively improved, and the benzene adsorption value of the regenerated activated carbon is significantly improved. By dynamically adjusting the power of the sub-temperature zones, the energy consumption of heating in the middle section is further reduced, avoiding energy waste from overall heating. In addition, it can also be adapted to the segmented desorption requirements of different types of pollutants, such as low-concentration VOCs or high-concentration tar, and the sub-temperature zone parameters can be adjusted without replacing the furnace tube 10.

[0041] Example 4

[0042] This embodiment specifically illustrates the structure of a vertical tube furnace: A vertical tube furnace, comprising: Multiple vertically arranged furnace tubes 10, with a heating source 13 provided on the outside of each furnace tube 10; Specifically, there are eight furnace tubes 10 evenly arranged. The furnace tubes 10 are made of high-temperature resistant stainless steel with a wall thickness of 3-5mm. The total length of the furnace tubes 10 is 6 meters, and they can be divided into upper, middle, and lower sections as needed. The heating source 13 on the outside of the furnace tubes 10 is a high-frequency induction heating tube. The high-frequency induction heating tubes are arranged between the two rows of furnace tubes 10 and on the outside. The power of a single tube coil is 5kW, and the temperature can be independently controlled. The operating range is 550-900℃.

[0043] Each furnace tube 10 is connected to a feeding hopper 11 at the top, and a feeding distribution device 15 is provided inside the feeding hopper 11; Specifically, the feeding hopper 11 has a volume of 1 cubic meter, a sealed feeding port at the top, and a rotary distributor installed inside. The distribution plate corresponds to the feeding ports of the 8 furnace tubes 10, ensuring that the material is evenly fed into each furnace tube 10.

[0044] Each furnace tube 10 is equipped with a discharge control valve 12 at the bottom. The discharge control valve 12 controls the descent speed of the material by controlling the opening and closing frequency so that the material falls slowly under the action of gravity and stays in the furnace tube 10 for more than the working time threshold to complete the desorption of organic pollutants. Specifically, a butterfly valve-type discharge control valve 12 is used, and the opening and closing frequency is controlled by a PLC to precisely control the material falling speed.

[0045] Each furnace tube 10 is equipped with an exhaust pipe 14, through which high-temperature exhaust gas is collected and fed into the feed hopper 11 to preheat the granular activated carbon material to be regenerated.

[0046] Specifically, each furnace tube 10 is equipped with one high-temperature resistant ceramic exhaust pipe 14, as shown in the figure. Figure 1 , Figure 2 and 3 As shown, the exhaust pipe 14 extends upward to the feed hopper 11, and its outlet is connected to the inside of the feed hopper 11 to allow the high-temperature exhaust gas to directly contact the material to be regenerated for preheating. Furthermore, the exhaust pipe 14 is arranged on the axis of the furnace tube 10, and multiple branch pipes are arranged around the exhaust pipe 14, which extend into the granular activated carbon material to collect the exhaust gas.

[0047] Furthermore, the furnace chamber is divided into a fixed furnace chamber and a movable furnace chamber. The movable furnace chamber is connected by hinges and can be fully opened to both sides for easy maintenance of the heating source 13 and the furnace tube 10. An insulation layer is installed on the outside of the furnace body to reduce heat loss.

[0048] In this embodiment, the preheating of exhaust gas in the vertical tube furnace reduces energy consumption during the heating stage by more than 30%, and the thinner furnace tubes (10mm thicker) reduce heat transfer loss. Material falls by gravity without collision, resulting in a low particle breakage rate; the movable furnace can be fully opened, shortening maintenance time; segmented heating and preheating through exhaust pipe 14 ensure consistent material desorption efficiency.

[0049] Furthermore, the furnace tube 10 has a three-stage structure. The upper section has a smaller diameter to allow the material to pass through the upper temperature zone slowly, the middle section has a larger diameter to allow the material to pass through the middle temperature zone quickly and fully desorb organic pollutants, and the lower section has a smaller diameter to avoid excessive cooling that could cause the particulate matter to crack.

[0050] Example 5

[0051] This embodiment optimizes the structure of the central exhaust pipe 14 inside the furnace tube 10 based on the vertical tube furnace, adding a spirally extending downward branch pipe to guide the material to rotate and fall. The spiral direction of two adjacent branch pipes is continuous, forming a complete spiral guidance path, ensuring that the material rotates and moves towards the wall of the furnace tube 10 along the spiral trajectory when falling.

[0052] The regenerated granular activated carbon enters the furnace tube 10 through the feeding hopper 11 and, after filling the interior of the furnace tube 10, begins to fall under the action of gravity.

[0053] When the material comes into contact with the spiral branch pipe on the exhaust pipe 14, it is guided by the spiral angle of the branch pipe and rotates and falls towards the wall of the furnace tube 10 in a clockwise direction. The material that was originally concentrated in the center of the furnace tube 10 is gradually diffused towards the tube wall by the thrust of the branch pipe, forming a rotating flow path from the center to the tube wall.

[0054] The high-frequency induction heating coil outside the furnace tube 10 outputs a high temperature of 800℃. During the rotation and falling of the material, each particle's surface can alternately contact the heating source 13 area, avoiding the problem of insufficient heating of the central material and overheating of the tube wall material, thus achieving 360° uniform heating.

[0055] High-temperature exhaust gas is collected by the exhaust pipe 14 and fed into the feed hopper 11 to preheat the material to be recycled. Finally, the exhaust gas temperature drops to 85°C before being discharged.

[0056] Compared with the traditional branchless structure, the material temperature difference at the same cross section inside the furnace tube 10 is significantly reduced, the heating uniformity of granular activated carbon is further improved, and no additional power mechanical structure is required; the desorption rate of organic pollutants is further improved, and the benzene adsorption value of the regenerated activated carbon is further improved; due to the uniform heating, there is no need for excessive heating, the power consumption of the external heating source 13 of the furnace tube 10 is reduced, and combined with the preheating of waste gas, the overall energy consumption can be further reduced compared with the traditional structure; the high temperature resistant material of the spiral branch tube supports the furnace tube 10 to maintain the operating temperature at 800℃, which meets the requirements of deep desorption.

[0057] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application's patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application.

[0058] It should be noted that when an element is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly or indirectly connected to the other component. It should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0060] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

Claims

1. A method for producing granular activated carbon based on a vertical column furnace, characterized by, The method comprises the steps of: obtaining granular activated carbon material to be regenerated from a feeding bin, and filling the material into each of the vertically arranged furnace tubes of the vertical tube furnace; heating the temperature of the furnace tubes to a working temperature by a heating source outside the furnace tubes; controlling the descending speed of the material by adjusting the opening and closing frequency of the discharge control valve at the bottom of the furnace tube, so that the material slowly falls under the action of gravity and stays in the furnace tube for a time longer than a working time threshold, and the granular activated carbon material is regenerated in each furnace tube at the working temperature and for a time longer than the working time threshold to complete the desorption of organic pollutants; collecting the high-temperature waste gas in the vertical furnace tubes through the exhaust pipe to the feeding bin to preheat the granular activated carbon material to be regenerated, and discharging the high-temperature waste gas after its temperature drops below a waste gas discharge temperature threshold.

2. The vertical column furnace based granular activated carbon production method according to claim 1, characterized by, The working temperature is 550-900℃, the working time threshold is 30-60 minutes, and the waste gas discharge temperature threshold is 70-90℃.

3. The vertical column furnace based granular activated carbon production method according to claim 1, characterized in that: The opening and closing frequency of the discharge control valve controls the material to pass through the upper section, middle section and lower section of the furnace tube from top to bottom, the material is heated to the working temperature in the upper section, the material stays in the middle section for a time longer than the working time threshold to complete the regeneration, and the material is cooled in the lower section to shape the regenerated granular activated carbon material.

4. The vertical column furnace based granular activated carbon production method according to claim 3, characterized in that: The vertically arranged furnace tubes have different diameters from top to bottom to adjust the speed of the material passing through the upper section, middle section and lower section. The discharge control valve controls the descending of the material at the working opening and closing frequency, the diameter of the furnace tube at the upper section is smaller to make the material pass through the upper section slowly, the material can be heated to the working temperature, the diameter of the furnace tube at the middle section is larger to make the material pass through the middle section quickly and desorb the organic pollutants completely, and the diameter of the furnace tube at the lower section is smaller to make the material pass through the lower section slowly to avoid rapid cooling which may cause the granular material to crack.

5. The vertical column furnace based granular activated carbon production method according to claim 4, characterized in that: The furnace tube corresponding to the middle section has the longest length to ensure the time of the granular activated carbon material staying in the middle section.

6. The granular activated carbon preparation method based on the vertical tube furnace according to claim 3, wherein: obtaining the real-time middle section temperature of the middle section; adjusting the opening and closing frequency of the discharge control valve according to the difference between the real-time middle section temperature and the reference temperature to ensure the desorption efficiency of each granular activated carbon material to be consistent.

7. A vertical fired tube furnace characterized by, The method comprises: a plurality of vertically arranged furnace tubes, and a heating source arranged outside the furnace tubes; each furnace tube is connected to a feeding bin at the top, and a feeding distribution device is arranged in the feeding bin; each furnace tube is provided with a discharge control valve at the bottom, and the discharge control valve controls the descending speed of the material by adjusting the opening and closing frequency, so that the material slowly falls under the action of gravity and stays in the furnace tube for a time longer than a working time threshold to complete the desorption of organic pollutants; each furnace tube is provided with an exhaust pipe, and the high-temperature waste gas is collected through the exhaust pipe to the feeding bin to preheat the granular activated carbon material to be regenerated.

8. The vertical tube furnace according to claim 7, wherein The diameter of the furnace tube is a three-stage structure, wherein the diameter of the upper section is smaller to make the material pass through the upper section slowly, the diameter of the middle section is larger to make the material pass through the middle section quickly and desorb the organic pollutants completely, and the diameter of the lower section is smaller to avoid rapid cooling which may cause the granular material to crack.

9. The vertical tube furnace of claim 7, wherein: The exhaust pipe is arranged on the axis of the furnace tube, and a plurality of branch pipes are arranged around the exhaust pipe, and the branch pipes extend into the granular activated carbon material to collect the waste gas.

10. The vertical tube furnace of claim 9, wherein: Multiple branch pipes arranged on the exhaust pipe on the furnace tube axis extend downward in a spiral to guide the material on the axis to rotate and fall towards the tube wall as it falls.

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