Microwave continuous regeneration system for saturated adsorption of waste activated carbon

Abstract

The invention discloses a microwave continuous regeneration system for saturated adsorption waste activated carbon, and relates to the technical field of activated carbon regeneration. The device comprises a cleaning pool, a filter press, a material drying box, a microwave pyrolysis regeneration furnace and a cooling channel which are arranged in sequence, the cleaning pool is used for cleaning the activated carbon; the filter press is used for filter-pressing and dewatering the cleaned activated carbon; the material drying box is used for drying the filter-pressed and dehydrated activated carbon; the material drying box is connected with the microwave pyrolysis regeneration furnace through a material conveying device; and the microwave pyrolysis regeneration furnace is connected with the cooling channel through a discharging pipeline. According to the system, efficient and continuous regeneration of different types of activated carbon can be achieved, meanwhile, the tail gas circulating system is used for conducting waste heat utilization on tail gas with waste heat, and the energy utilization efficiency in the activated carbon regeneration process is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of activated carbon regeneration, and more particularly to a microwave continuous regeneration system for saturated adsorption waste activated carbon. Background Art

[0002] As a common adsorbent material, activated carbon has excellent adsorption properties due to its high porosity and large specific surface area, and is widely used in various water or gas adsorption purification processes. When activated carbon reaches adsorption saturation during the purification of water or gas, it will no longer have adsorption capacity. Because activated carbon that has reached adsorption saturation contains a large amount of substances that are harmful to the environment and human body, it cannot be directly discarded and requires secondary treatment. Common methods for treating saturated activated carbon are landfill or incineration, which is bound to cause a large amount of energy loss and waste of resources. Therefore, the regeneration and recycling of adsorption saturated activated carbon through a regeneration process will be beneficial to environmental protection and efficient utilization of resources, bringing higher economic benefits.

[0003] The most common activated carbon regeneration process in industrial applications is thermal regeneration. This method is characterized by high efficiency and good regeneration stability, making it the most widely used and mature method. However, when saturated activated carbon is directly regenerated using the thermal regeneration method, the regenerated activated carbon generally suffers from decreased adsorption capacity and poor adsorption efficiency. This is mainly due to the destruction of the carbon structure under high temperature conditions, resulting in reduced activity, and the adsorbed substances blocking the internal pores of the activated carbon, which cannot be completely removed. A simple thermal regeneration method cannot effectively restore the pores. At the same time, during the thermal regeneration process, high temperatures will cause the adsorbed substances to decompose and release a large amount of harmful waste gas, requiring additional tail gas collection equipment for waste treatment. Therefore, the development of a convenient and efficient activated carbon regeneration process is of great scientific significance and practical value. Summary of the Invention

[0004] In view of this, the present invention provides a microwave continuous regeneration system for saturated adsorption waste activated carbon, which can realize efficient and continuous regeneration of different types of activated carbon, and at the same time utilize the exhaust gas circulation system to utilize the waste heat of the exhaust gas with waste heat, thereby improving the energy utilization efficiency during the activated carbon regeneration process.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A microwave continuous regeneration system for saturated adsorption waste activated carbon, comprising a bubble cleaning tank, a filter press, a material drying box, a microwave pyrolysis regeneration furnace and a cooling channel arranged in sequence;

[0007] The bubble cleaning tank is used to pre-treat and remove most of the organic matter and salt adsorbed on the surface of the activated carbon. The large pieces of activated carbon agglomerated by the salt and organic matter are broken up by the impact of a high-pressure air pump. The organic matter and salt on the surface of the activated carbon particles are removed by water flow, bubble impact and acidic / alkaline cleaning solution. The adsorption capacity of the activated carbon pre-treated in the bubble cleaning tank can be restored by 20% to 30%.

[0008] The filter press removes excess water from the pre-treated activated carbon, separating the washed organic matter and salt from the activated carbon, thereby preventing the organic matter and salt from being re-adsorbed back onto the surface of the activated carbon as the water content decreases during the subsequent drying process.

[0009] The material drying box is used to dry the activated carbon dehydrated by filter pressing. Due to the large temperature difference between different areas of the microwave equipment itself, water vapor is easily condensed and then absorbed to form abnormal hot spots, causing equipment damage and other problems. The moisture content of the activated carbon itself needs to be reduced as much as possible. The moisture content after drying should not exceed 10%;

[0010] The material conveying device mainly transports the dried activated carbon to the microwave pyrolysis regeneration furnace quickly by means of transportation and lifting, so as to prevent the dried activated carbon from re-adsorbing water from the surrounding environment during the cooling process;

[0011] The microwave pyrolysis regeneration furnace utilizes microwave pyrolysis of organic matter and the self-heating properties of activated carbon to efficiently remove organic matter adsorbed in the pores of activated carbon, greatly improving the regeneration efficiency of activated carbon.

[0012] The cooling channel is connected to the microwave pyrolysis regeneration furnace to achieve rapid cooling of the activated carbon after it is discharged from the furnace body, thereby preventing the regenerated activated carbon from spontaneously combusting due to contact with oxygen due to excessively high temperature.

[0013] Optionally, it further comprises a separation tank, a wastewater storage tank and an exhaust gas catalytic decomposition box, wherein the separation tank is connected to a material drying box, and the material drying box is connected to an exhaust port of the microwave pyrolysis regeneration furnace;

[0014] The wastewater storage tank is used to store wastewater produced or separated by the cleaning tank, filter press, and separation tank;

[0015] The exhaust gas catalytic decomposition box is used to absorb the exhaust gas generated by the separation tank.

[0016] Optionally, the cleaning tank includes a cleaning tank body, a high-pressure air pump and a barrier grid;

[0017] The bubble cleaning tank is filled with acidic / alkaline cleaning liquid, and a high-pressure air pump is provided at the bottom of the cleaning tank; a barrier grid is provided inside the cleaning tank on one side adjacent to the drain outlet. The high-speed water flow and bubbles generated by the high-pressure air pump can quickly disperse or crush the organic matter or agglomerated salts attached to the surface of the activated carbon, perform preliminary treatment on the adsorbed substances on the activated carbon, and reduce the pressure of subsequent processes. In addition to intercepting the activated carbon to achieve the circulation of the cleaning liquid during the cleaning process, the barrier grid, based on the loose and porous nature of the activated carbon itself and its low specific gravity, realizes the preliminary screening of activated carbon of different particle sizes through the different water absorption properties of activated carbon of different particle sizes, thereby avoiding the agglomeration and aggregation of activated carbon of different particle sizes in the subsequent filtration and drying steps, which affects the regeneration effect.

[0018] Optionally, the material drying box includes a drying box body, in which a heat source generator and a conveying device are arranged; the heat source generator is arranged above the conveying device; during the drying process, the drying box mainly uses the heat source generator and the waste heat of the flue gas generated during the regeneration process to dry the activated carbon completed by filter pressing; the heat source generator is arranged above the side to achieve efficient and uniform energy transfer to the activated carbon on the conveyor belt, and at the same time, further optimizes the equipment layout in the drying box by arranging an induced draft duct above and a heat source generator above, which can effectively avoid the problems of low heat conduction efficiency, equipment failure, etc. caused by the condensation of volatile organic compounds around the heat source generator during the drying process.

[0019] Optionally, the microwave pyrolysis regeneration furnace includes a cylindrical furnace body, a screw feeder is provided on one side of the cylindrical furnace body, a discharge pipe is provided on the other side, and a collecting hopper is provided on the top of the screw feeder; a feeding auger is provided in the cylindrical furnace body; an exhaust air duct is provided on the discharge pipe, and the exhaust air duct is connected to the material drying box.

[0020] Optionally, the outer wall of the cylindrical furnace body is provided with multiple groups of magnetrons, and the magnetrons are used to control the temperature of the cylindrical furnace body. The arrangement of the magnetrons is optimized as follows: multiple rows of magnetrons are evenly arranged around the furnace body in an asymmetrical form, totaling 3 to 7 rows (the number of rows is odd to ensure that all magnetrons are asymmetrically arranged); each row of magnetrons is optimized to be installed in the order from the feed port to the discharge port in the form of "front sparse-middle dense-back sparse" arrangement: "front sparse" is to ensure that the regeneration furnace quickly removes any moisture or volatile organic matter that may exist in the material after feeding, while reducing the risk of combustion of the activated carbon during rapid heating; "middle dense" is to increase the microwave power to quickly raise the temperature to the process requirement temperature; "back sparse" is to reduce the arrangement of magnetrons in the rear insulation zone to reduce energy consumption, and to avoid the high microwave power causing the temperature to continue to rise beyond the regeneration requirement, resulting in excessive carbon loss during the activated carbon regeneration process.

[0021] Optionally, the material drying box is a box-type structure with left and right openings, with slightly positive pressure air curtains set at both ends of the inlet and outlet, and an induced draft fan set at the upper end of the box to extract the exhaust gas and maintain a slightly negative pressure state inside the box.

[0022] It can be seen from the above technical solution that, compared with the prior art, the present invention provides a microwave continuous regeneration system for saturated adsorption waste activated carbon, which has the following beneficial effects:

[0023] (1) The main purpose of the present invention is to achieve efficient and continuous regeneration of saturated adsorption waste activated carbon by this system, while utilizing the exhaust gas circulation system to utilize the waste heat of the exhaust gas, thereby improving the energy utilization efficiency during the activated carbon regeneration process. At the same time, the microwave regeneration method can use green electricity, which is green and low-carbon. This solves the problems of low regeneration efficiency and high carbon emissions of traditional thermal regeneration methods.

[0024] (2) Compared with the existing microwave regeneration device, the activated carbon regeneration system provided by the present invention integrates processes with different functions, which can realize the industrial operation of activated carbon cleaning, drying, continuous regeneration, and three wastes treatment during the regeneration process. The performance of the regenerated activated carbon can reach more than 95% of the performance of the new activated carbon. The regeneration system has a stable and excellent regeneration effect on activated carbons of different types and different particle sizes. The regeneration effect is stable, the particle size ratio remains unchanged before and after regeneration, the mechanical properties of the regenerated activated carbon are stable, and basically no wear occurs. The regenerated activated carbon product has stable cyclic regeneration performance, and the number of cycles can reach about 3 to 5 times.

[0025] (3) The present invention can effectively recover a portion of the activated carbon material particles extracted with the waste gas through the separation tank and the tail gas collection system, thereby reducing the material loss during the regeneration process. At the same time, since the waste gas itself has a high organic matter content and complex composition, the waste heat utilization + centralized collection and treatment method is adopted to reduce the complexity of the system.

[0026] (4) This equipment can not only be used for the pyrolysis and regeneration of activated carbon materials, but also can be used for other material processing systems due to the pyrolysis and regeneration furnace itself being a high-temperature roasting furnace, including but not limited to material sintering, modification and other waste treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 A schematic diagram of a microwave continuous regeneration system for saturated adsorption waste activated carbon provided by the present invention;

[0029] Figure 2 It is an enlarged schematic diagram of the bubble cleaning pool;

[0030] Figure 3 It is an enlarged schematic diagram of the drying oven;

[0031] Figure 4 It is an enlarged schematic diagram of the microwave pyrolysis regeneration furnace;

[0032] Among them, 1 is a bubble cleaning tank; 2 is a filter press; 3 is a material drying box; 4 is a material conveying device; 5 is a microwave pyrolysis regeneration furnace; 6 is a nitrogen generator; 7 is a cooling channel; 8 is a separation tank; 9 is a waste gas catalytic decomposition box; 10 is a wastewater storage tank; 1-1 is a bubble cleaning tank body; 1-2 is a barrier grid; 1-3 is a high-pressure air pump; 1-4 is a drain outlet; 3-1 is a drying box body; 3-2 is a heat source generator; 3-3 is a conveying device; 5-1 is a collecting hopper; 5-2 is a screw feeder; 5-3 is a cylindrical furnace body; 5-4 is a feeding auger; 5-5 is a magnetron group; 5-6 is a discharge pipe; 5-7 is an exhaust air duct. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0034] Example 1

[0035] like Figure 1 As shown, in this embodiment, a microwave continuous regeneration system for saturated adsorption waste activated carbon is disclosed. The saturated adsorption waste activated carbon becomes a regenerated activated carbon product after undergoing processes including cleaning, drying, pyrolysis regeneration, and cooling. The adsorption performance of the activated carbon obtained by regeneration is restored to more than 95% of the new activated carbon, and can reach 99% to 100% under some process conditions. The regeneration system proposed in the present invention has a stable and excellent regeneration effect on activated carbons of different types and different particle sizes. The regeneration effect is stable, the particle size specific gravity remains unchanged before and after regeneration, the mechanical properties of the regenerated activated carbon are stable, and basically no wear occurs. The regenerated activated carbon product has stable cyclic regeneration performance, and the number of cycles can reach about 3 to 5 times. The system includes a cleaning tank 1, a filter press 2, a material drying box 3, a microwave pyrolysis regeneration furnace and a cooling channel 7 arranged in sequence;

[0036] The cleaning tank 1 is used to clean the activated carbon;

[0037] The filter press is used to filter and dehydrate the cleaned activated carbon;

[0038] The material drying box 3 is used to dry the activated carbon dehydrated by filter pressing;

[0039] The material drying box 3 is connected to the microwave pyrolysis regeneration furnace 5 through the material conveying device 4;

[0040] The microwave pyrolysis regeneration furnace 5 is connected to the cooling channel 7 through the discharge pipe 5-6.

[0041] Further, such as Figure 2 As shown, the bubble cleaning pool includes a bubble cleaning pool body 1-1, a high-pressure air pump 1-3 and a barrier grille 1-2; the cleaning pool body is filled with cleaning liquid, and a high-pressure air pump 1-3 is arranged at the bottom of the cleaning pool body; a barrier grille 1-2 is arranged inside the cleaning pool body on one side adjacent to the drain outlet 1-4.

[0042] Further, such as Figure 3 As shown, the material drying box 3 includes a drying box body 3-1, and a heat source generator 3-2 and a conveying device 3-3 are arranged in the drying box body 3-1; the heat source generator 3-2 is arranged above the conveying device 3-3.

[0043] Further, such as Figure 4 As shown, the microwave pyrolysis regeneration furnace 5 includes a cylindrical furnace body 5-3, a screw feeder 5-2 is provided on one side of the cylindrical furnace body 5-3, and a discharge pipe 5-6 is provided on the other side, and a collecting hopper 5-1 is provided on the top of the screw feeder; a feeding auger 5-4 is provided in the cylindrical furnace body; an exhaust air duct 5-7 is provided on the discharge pipe, and the exhaust air duct 5-7 is connected to the material drying box 3.

[0044] The continuous microwave regeneration system based on the above-mentioned saturated adsorption waste activated carbon microwave continuous regeneration system is as follows:

[0045] The activated carbon used is saturated adsorption waste activated carbon obtained from treating wastewater containing organic extractants. Its primary adsorbents are inorganic metal salts and organic oils. Its particle size ranges from 5 to 150 mesh, and its adsorption capacity is 45.58 mg / g. The saturated adsorption waste activated carbon is placed proportionally into a bubble cleaning tank 1 filled with alkaline solution. High-pressure air pumps 1-3 are then turned on to introduce air bubbles into the cleaning tank 1 for 0.5 to 3 hours, with one to three water changes during the cleaning process. After cleaning, the activated carbon is salvaged and set aside for later use.

[0046] Since activated carbon itself has rich pores, small specific gravity, small particle size and strong water storage performance, the cleaned waste activated carbon is sent to the filter press 2 for filtration to discharge most of the water in the waste activated carbon. The moisture content of the obtained waste activated carbon is about 28-40%.

[0047] The spent activated carbon after filtration is continuously fed into a drying oven (3) at a rate of approximately 30 kg / h. The oven temperature is set at 100-200°C, and at least one temperature sensor is installed on both the oven body and conveyor 3-3. The activated carbon is continuously transported along conveyor 3-3 to the outlet, where it is dried to a moisture content below 10%. The mass of the discharged material decreases by approximately 20-30%. After drying and cleaning, the activated carbon's iodine adsorption value returns to 148.58 mg / g.

[0048] The dried spent activated carbon is conveyed via material conveyor 4 to the collection hopper 5-1 of the microwave pyrolysis regeneration furnace 5. The conveying speed and volume are determined by the processing capacity of the microwave pyrolysis regeneration furnace 5. A constant layer of material, approximately 12 to 25 cm, is maintained in the collection hopper 5-1. This prevents exhaust gases from escaping from the feed port of the microwave pyrolysis regeneration furnace 5 and effectively shields the microwaves, preventing significant microwave leakage at the inlet.

[0049] The waste activated carbon in the collecting hopper 5-1 is fed into the microwave pyrolysis regeneration furnace 5 through the screw feeder 5-2. The screw feeder 5-2 can control the feeding speed by changing the motor frequency. In this practical example, the feeding amount is 15 to 20 kg / h.

[0050] The waste activated carbon material fed into the microwave pyrolysis regeneration furnace 5 through the feed port is transported by the feed auger 5-4 through the low-temperature heating zone, high-temperature heating zone, and constant-temperature regeneration zone. The cylindrical furnace body 5-3, serving as the main body of the microwave pyrolysis regeneration furnace 5, is approximately 4.5 to 8 meters long. The low-temperature heating zone, high-temperature heating zone, and constant-temperature regeneration zone are set to different lengths based on actual process requirements. Temperature sensors are installed in each temperature zone, the screw feed port, the discharge pipe 5-6, and the exhaust air duct 5-6. The temperature of each section is monitored in real time to prevent temperature anomalies. Each section is equipped with at least one temperature sensor. The cylindrical furnace body 5-3 is equipped with an insulation structure.

[0051] The temperature of the low-temperature heating zone is controlled at 300-650°C, the temperature of the high-temperature heating zone is controlled at 500-800°C, and the temperature of the high-temperature regeneration zone A3 is controlled at 500-850°C. The relative pressure in the cylindrical furnace during the pyrolysis and regeneration process is controlled at a slightly positive pressure range of approximately 5kPa-20kPa to prevent the ingress of outside air.

[0052] During the operation of the microwave pyrolysis regeneration furnace 5, the temperature of different sections is controlled by the magnetron group 5-5. In the low temperature heating zone, the magnetron group 5-5 maintains low power and continuous operation to ensure that the activated carbon generates heat by itself to form a temperature gradient. The residence time of the activated carbon in this temperature zone is 5 to 20 minutes.

[0053] In the high temperature heating zone, the magnetron maintains high power and operates intermittently, controlling the high temperature heating zone at 500-800°C with a residence time of 5-20 minutes;

[0054] In the high-temperature constant temperature zone, the magnetron maintains normal power and intermittent operation, and the temperature of the high-temperature constant temperature zone is controlled at 500-850°C. The actual temperature is adjusted according to the actual process requirements. The temperature control error is about ±10°C, and the activated carbon stays in this temperature zone for 10-30 minutes.

[0055] After high-temperature regeneration, the regenerated activated carbon product is discharged through discharge pipe 5-6. A cooling water circulation pipe is wrapped around the outside of the pipe to prevent accidental burns. This also cools the regenerated high-temperature activated carbon product, starting from discharge pipe 5-6. The temperature of the regenerated activated carbon product in discharge pipe 5-6 is approximately 500-750°C.

[0056] The regenerated activated carbon product is sent to the cooling channel 7 through the discharge pipe 5-6, and is cooled to below 100°C by water cooling to prevent the activated carbon product from being oxidized when in contact with air under high temperature conditions.

[0057] The temperature of the regenerated waste gas obtained by microwave pyrolysis is about 80-150°C after passing through the induced draft fan. The pyrolysis regenerated waste gas is introduced into the 3 drying oven to provide waste heat, and the waste gas is drawn into the separation tank 8 through the induced draft fan of the 3 drying oven to completely separate the dried moisture, soot and waste gas.

[0058] The exhaust gas is sent to the 9 waste catalytic decomposition box to treat the complex exhaust gas and discharge it after meeting the standards.

[0059] The wastewater generated during the operation of the system is collected and poured into the wastewater storage tank 10 for collection and storage, and then sent to a special wastewater treatment plant for treatment and discharged after meeting the standards.

[0060] Saturated adsorption spent activated carbon was regenerated under optimal process conditions, resulting in an average iodine adsorption value of 880.07 mg / g for the regenerated activated carbon product. The highest iodine adsorption value achieved during continuous operation was 1056.35 mg / g. The particle size ratio of the regenerated activated carbon product remained essentially unchanged from that of the unregenerated activated carbon, and mechanical properties were 99.2%. Mechanical wear was virtually non-existent. These data demonstrate the excellent regeneration of saturated adsorption spent activated carbon by this system, resulting in a high-quality regenerated activated carbon product with no significant wear.

[0061] After multiple cycles of treatment, the performance of the activated carbon regeneration product remained basically unchanged during 2 to 5 adsorption-regeneration cycles, indicating that the regenerated activated carbon product has excellent cyclic performance.

[0062] Example 2

[0063] This embodiment discloses a continuous regeneration system for saturated adsorption waste activated carbon, which can achieve continuous operation at the industrial application level. It combines the traditional thermal regeneration and microwave regeneration activated carbon regeneration processes, designs a regeneration process, and improves the energy utilization efficiency in the regeneration system. Compared with the existing microwave regeneration device, the activated carbon regeneration system provided by the present invention integrates processes with different functions, and can achieve industrial operation of activated carbon cleaning, drying, continuous regeneration, and treatment of three wastes during the regeneration process. The performance of the regenerated activated carbon can reach more than 95% of the performance of the new activated carbon, and the performance of the regenerated activated carbon remains stable after multiple cycles of regeneration.

[0064] The present invention proposes a continuous regeneration system and method for saturated adsorption waste activated carbon. The regeneration system includes a bubble cleaning tank 1, a filter press 2, a material drying oven 3, a material conveying device 4, a microwave pyrolysis regeneration furnace 5, a nitrogen generator 6, a cooling channel 7, a separation tank 8, an exhaust gas catalytic decomposition tank 9, and a wastewater storage tank 10. The microwave drying oven includes a microwave generator and a material conveyor belt; the microwave pyrolysis regeneration furnace 5 comprises a collection hopper 5-1, a feed pipe, a furnace cavity, a magnetron assembly 5-5, a feed auger 5-4, and a discharge pipe 5-6.

[0065] The bubble cleaning tank 1 is mainly used to efficiently clean the saturated adsorption waste activated carbon to remove organic matter and salts attached to the surface of the activated carbon, thereby achieving the purpose of preliminary regeneration and reducing the pressure of subsequent regeneration processes.

[0066] The cleaning solutions used in the above cleaning process include, but are not limited to, pure water, dilute hydrochloric acid solution, dilute sulfuric acid solution or other salt-containing solutions. The cleaning solution is selected according to the type of substance adsorbed by the waste activated carbon.

[0067] The cleaning method used in the above cleaning process is bubble cleaning, and high-pressure air pumps 1-3 installed at the bottom and sides of the bubble cleaning pool 1 compress air and blow it into the cleaning pool 1 to provide a large number of tiny bubbles required for cleaning.

[0068] The filter press 2 applies a certain pressure to the material to cause the liquid to seep out, wherein the support frame is composed of cast iron structural parts, and the filter press device is composed of stacked stainless steel filter plates.

[0069] The material drying box 3 is a box-shaped structure with left and right openings. In order to ensure that the exhaust gas generated during the drying process is completely collected and not leaked, a slightly positive pressure air curtain is set at both ends of the inlet and outlet, and an induced draft fan is set at the upper end of the box to extract the exhaust gas and maintain a slightly negative pressure state inside the box.

[0070] The material drying box 3 dries the material to ensure that the moisture content of the material subsequently entering the pyrolysis regeneration furnace is less than 10%. When the moisture content of the material is less than 10%, the performance of the regenerated material is excellent after microwave pyrolysis regeneration, and the performance remains stable during the continuous regeneration process. When the material is dried in the material drying box 3, some volatile organic matter adsorbed by the saturated adsorption waste activated carbon will volatilize as the temperature rises. As the organic matter volatilizes, the material recovers a certain performance, which can improve the efficiency of the subsequent microwave pyrolysis regeneration process, increase the complexity of the exhaust gas components generated during the drying process, and increase the difficulty of processing. Therefore, the tail gas generated in the drying stage and the pyrolysis regeneration stage is collected and processed in a centralized manner to reduce the complexity of the regeneration system and improve the operating efficiency of the regeneration system.

[0071] The upper end of the inner box body of the above-mentioned material drying box 3 is provided with devices including but not limited to: a microwave generator, a hot air blower and a resistor to provide heat energy, so as to dry the activated carbon. The storage and movement of the activated carbon in the material drying box 3 are provided by containers including but not limited to: trays, saggers or conveyor belts installed on the conveying device 3-3.

[0072] The material conveying device 4 is mainly used to carry and transport the dried material into the microwave pyrolysis regeneration furnace, and its types include but are not limited to: plate chain conveyor, belt conveyor, rolling conveyor, screw conveyor and vertical conveyor.

[0073] The material of the material conveying device 4 includes but is not limited to: rubber and fiber, metal composite products, plastic and fabric composite products, etc.

[0074] The microwave pyrolysis regeneration furnace 5 is horizontally arranged and includes a material collection hopper, a screw feeder 5-2, a cylindrical furnace body 5-3, a feeding auger 5-4, a magnetron assembly 5-5, and a discharge pipe 5-6. The microwave pyrolysis regeneration furnace 5 and its connected equipment are controlled by an integrated control system.

[0075] Collection hopper 5-1: The microwave pyrolysis regeneration furnace 5 collects the materials through the collection hopper 5-1. At the same time, the material itself accumulates in the collection hopper 5-1 to form a material layer of a certain thickness, which can effectively isolate the atmosphere inside and outside the furnace cavity from flowing, and helps to maintain the stability of the protective atmosphere during the regeneration process.

[0076] Screw feeder 5-2: Installed below the feed hopper 5-1 and connected to the furnace body via a feed pipe, screw feeder 5-2 delivers material from the feed hopper 5-1 into the furnace body for regeneration. An air inlet is installed on the feed pipe. Nitrogen is introduced during the screw feed to fully mix the material with the protective nitrogen gas, reducing the probability of material contact with air during the regeneration process and improving regeneration efficiency.

[0077] Cylindrical furnace body 5-3: The cylindrical furnace body 5-3 is the main body of the microwave regeneration furnace. A feed port is provided at one end of the furnace body to be connected to the feed pipe, and a regenerated product discharge port is provided at the other end to be connected to the discharge pipe 5-6. A waste gas outlet and an induced draft system are provided at the discharge port to promptly extract the waste gas generated during the intracranial regeneration process and send it to subsequent work sections for utilization and treatment.

[0078] The above-mentioned cylindrical furnace body 5-3 is composed of a stainless steel shell, a microwave shielding layer, an insulation layer, and a furnace cavity. The cylindrical furnace body shell is made of stainless steel including but not limited to 316, 310S, etc., and the choice of shell material is determined by the actual needs of industrial applications. The microwave shielding layer is composed of a shell with high microwave absorption performance such as a carbon shell, which is mainly used to isolate microwaves as soon as microwave leakage occurs, and is set thicker at the inlet and outlet. The insulation layer is composed of insulation fiber or special microporous material. The furnace cavity is composed of microwave transparent materials such as alumina, special silica and other materials. A feed port is opened for the magnetron on the cylindrical furnace body 5-3, and the magnetrons are arranged in a regular pattern, while avoiding microwave interference caused by improper arrangement of the feed port.

[0079] The exhaust gas extracted from the above-mentioned cylindrical furnace body 5-3 still contains residual heat and complex components. After being discharged by the induced draft fan, it enters the drying box again for residual heat utilization. The induced draft fan in the drying box is used to extract the regenerated exhaust gas that has completed residual heat utilization and the exhaust gas generated during the drying process and send them to the back-end for treatment.

[0080] In some embodiments, a filter element is provided at the regeneration exhaust gas outlet to prevent the exhaust gas from carrying the activated carbon after activation and regeneration out of the microwave regeneration device.

[0081] The cylindrical furnace body 5-3 is divided into a low-temperature heating zone, a high-temperature heating zone, and a constant-temperature regeneration zone based on the arrangement of the magnetron group 5-5, the feed position, the discharge position, and the auger installation, thereby ensuring the regeneration efficiency of the activated carbon material. The temperature zones are divided according to the actual length of the furnace body and the actual temperature required during the regeneration process.

[0082] The different temperature zones are functionally divided as follows: The low-temperature heating zone maintains low-power, uninterrupted microwave irradiation to ensure that the saturated adsorbed spent activated carbon entering the furnace absorbs the microwaves and converts them into heat, creating a temperature gradient conducive to adsorbate desorption. The high-temperature regeneration zone uses high-power microwave irradiation or preheating to accelerate the heating rate of the activated carbon material, bringing it to the regeneration temperature as quickly as possible. The constant-temperature regeneration zone maintains a stable temperature for the material and the furnace environment, allowing the material to be regenerated. After regeneration, the activated carbon material is conveyed to the discharge port via an auger.

[0083] Furthermore, the length of the low temperature heating zone is 10% to 30% of the total length of the cylindrical furnace body 5-3.

[0084] Furthermore, the length of the high temperature rising zone is 20% to 40% of the total length of the cylindrical shell.

[0085] Furthermore, the length of the constant temperature regeneration zone is 20% to 40% of the total length of the cylindrical shell.

[0086] Feeding auger 5-4: Feeding auger 5-4 is used to drive the materials entering the furnace to move forward in the furnace, ensuring that the saturated adsorption waste activated carbon materials pass through various temperature zones under the drive of the auger, so as to ensure the activation and regeneration effect of the materials.

[0087] The feed auger 5-4 is installed axially within the cylindrical furnace body 5-3, contacting the shell and bottom of the cylinder while avoiding friction. The auger's shaft is connected to the screw feeder 5-2 at the inlet, and the auger is partially extended at the outlet to more conveniently feed the material out of the furnace.

[0088] The feeding auger 5-4 is made of hard non-metallic material to prevent the recycled product from being contaminated by corrosion or wear.

[0089] Magnetron Group 5-5: Magnetrons are installed on the wall of the cylindrical furnace body 5-3 as microwave generators. Magnetron groups 5-5 are organized into different groups based on the temperature zones and are controlled by an integrated electronic control system. The magnetron groups 5-5 are arranged on the cylindrical furnace body 5-3 according to specific requirements. The arrangement of the magnetron groups 5-5 should be done to avoid microwave interference.

[0090] Discharge pipe 5-6: responsible for transporting the regenerated materials to the next process.

[0091] The nitrogen generator 6 produces nitrogen and inputs it into the microwave pyrolysis regeneration furnace 5 to provide a protective atmosphere. The nitrogen generator 6 is connected to the regeneration furnace through an air supply pipe and an air inlet valve at the feed inlet or discharge port and feeds the nitrogen into the regeneration furnace cavity through the air inlet valve.

[0092] The cooling channel 7 quickly cools the regenerated product to room temperature to prevent it from coming into contact with air at a high temperature and causing oxidation loss.

[0093] The cooling channel 7 can adopt belt conveying and spiral conveying according to different needs, and adopt water cooling to reduce the temperature.

[0094] The separation tank 8 adopts a water bath cooling method to pass the high-temperature waste smoke mixture into the separation tank 8 placed in the water medium condenser. Due to the effect of the water medium condenser, the waste water and the smoke are effectively separated according to the differences in boiling point, density and other factors in the mixture.

[0095] The exhaust gas catalytic decomposition box 9 is mainly used for adsorbing, filtering and purifying the organic exhaust gas generated during the operation of the regeneration system. The processes and methods adopted include but are not limited to: organic exhaust gas activated carbon adsorption treatment method, catalytic combustion method, catalytic oxidation method, acid-base neutralization method and plasma method.

[0096] The wastewater storage tank 10 is used to store wastewater produced or separated by equipment such as the cleaning tank 1, the filter press 2, and the separation tank 8, so as to facilitate the transportation of the wastewater to the wastewater treatment plant for treatment.

[0097] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0098] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A microwave continuous regeneration system for saturated adsorption waste activated carbon, characterized in that: It includes a bubble cleaning tank, a filter press, a material drying box, a microwave pyrolysis regeneration furnace and a cooling channel which are arranged in sequence; The bubble cleaning tank is used to pre-treat and remove most of the organic matter and salt adsorbed on the surface of the activated carbon. The large activated carbon agglomerated by the salt and organic matter is broken up by the impact of a high-pressure air pump. The organic matter and salt on the surface of the activated carbon particles are removed by water flow, bubble impact and acidic / alkaline cleaning solution. The adsorption capacity of the activated carbon pre-treated in the bubble cleaning tank is restored by 20% to 30%. The filter press removes excess water from the pre-treated activated carbon, separates the washed organic matter and salts from the activated carbon, and re-adsorbs the organic matter and salts back onto the surface of the activated carbon; The material drying box is used to dry the activated carbon dehydrated by filter pressing; The material conveying device mainly transports and elevates the dried activated carbon to the microwave pyrolysis regeneration furnace quickly; The microwave pyrolysis regeneration furnace utilizes microwave pyrolysis of organic matter and the self-heating property of activated carbon to remove organic matter adsorbed in the pores of activated carbon, greatly improving the regeneration efficiency of activated carbon. The cooling channel is connected to the microwave pyrolysis regeneration furnace.

2. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 1, characterized in that: It also includes a separation tank, a wastewater storage tank and an exhaust gas catalytic decomposition box, the separation tank is connected to the material drying box, and the material drying box is connected to the exhaust port of the microwave pyrolysis regeneration furnace; The wastewater storage tank is used to store wastewater produced or separated by the bubble cleaning tank, filter press, and separation tank; The exhaust gas catalytic decomposition box is used to absorb the organic exhaust gas generated by the pyrolysis and regeneration of materials during the operation of the system to achieve standard exhaust gas.

3. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 1, characterized in that: The bubble cleaning pool includes a cleaning pool body, a high-pressure air pump and a barrier grid; The bubble cleaning tank body is filled with acidic / alkaline cleaning liquid, and a high-pressure air pump is arranged at the bottom of the cleaning tank body; a barrier grid is arranged inside the bubble cleaning tank body on one side adjacent to the drain outlet.

4. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 1, characterized in that: The material drying box includes a drying box body, in which a heat source generator and a conveying device are arranged; the heat source generator is arranged above the conveying device.

5. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 1, characterized in that: The microwave pyrolysis regeneration furnace includes a cylindrical furnace body, a screw feeder is provided on one side of the cylindrical furnace body, a discharge pipe is provided on the other side, and a collecting hopper is provided on the top of the screw feeder; a feeding auger is provided in the cylindrical furnace body; an exhaust air duct is provided on the discharge pipe, and the exhaust air duct is connected to the material drying box.

6. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 5, characterized in that: The outer wall of the cylindrical furnace body is provided with a plurality of magnetron groups, and the magnetron groups are used to control the temperature of the cylindrical furnace body.

7. The microwave continuous regeneration system for saturated adsorption waste activated carbon according to claim 4, characterized in that: The material drying box is a box-shaped structure with left and right openings. Micro-positive pressure air curtains are set at both ends of the inlet and outlet. An induced draft fan is set at the upper end of the box to extract the exhaust gas and maintain a micro-negative pressure state inside the box.

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