System and method for recycling waste batteries

Abstract

This invention belongs to the field of waste battery recycling technology, specifically relating to a waste battery recycling system and control method. The waste battery recycling system includes: a low-temperature drying furnace, an anaerobic pyrolysis furnace bed, a high-temperature flue gas heater, a cooling furnace, a hot air furnace, a high-temperature flue gas distributor, and a flue gas heat exchanger. A portion of the high-temperature flue gas generated by the hot air furnace is sent to the high-temperature flue gas heater to heat the anaerobic pyrolysis furnace bed. The high-temperature pyrolysis gas generated by the anaerobic pyrolysis furnace bed is sent to the low-temperature drying furnace to heat the material, and the low-temperature pyrolysis gas generated in the low-temperature drying furnace is sent to the hot air furnace for combustion. This invention utilizes the combined operation of four furnaces—the low-temperature drying furnace, the anaerobic pyrolysis furnace bed, the cooling furnace, and the hot air furnace—to heat the material itself using the chemical energy released from the combustion of high-calorific-value organic matter contained in waste batteries, replacing electric heating and achieving efficient energy recycling. Simultaneously, the hot air furnace can fully combust the waste gas, completely incinerating dioxins, thus solving the problems of high energy consumption and high pollution in the waste battery recycling field.

Description

[0001] This case is a divisional application. The parent application of this divisional application is the invention patent application filed on November 30, 2023, with application number 202311616464.0 and titled "Waste Battery Recycling System and Control Method". Technical Field

[0002] This invention belongs to the field of waste battery recycling technology, specifically relating to a waste battery recycling system and control method. Background Technology

[0003] Rechargeable batteries, due to their high energy density, light weight, and long lifespan, are widely used in communication tools such as mobile phones, laptops, and digital cameras, as well as digital electronic products, power tools, and electric vehicles. The increasing demand for rechargeable batteries will exacerbate the supply-demand imbalance of raw materials such as cobalt, nickel, and lithium needed for their production. On the other hand, waste rechargeable batteries contain high levels of valuable metals like cobalt, nickel, and manganese, as well as numerous toxic and harmful compounds. If large quantities of waste rechargeable batteries are not safely disposed of and utilized, it will lead to resource waste and serious environmental pollution. Therefore, the safe disposal and recycling of waste rechargeable batteries is not only an indispensable part of the battery industry but also a key measure to resolve the supply-demand imbalance of raw materials for battery production and reduce production costs.

[0004] However, traditional waste battery recycling processes have many drawbacks: (1) In traditional recycling processes, electric heating furnaces use resistance wire heating, which has a high power consumption. In order to achieve the required operating temperature, the resistance wires are continuously heated, resulting in a large power consumption and extremely high operating costs; (2) Traditional battery recycling systems use pure electric heating, and the heat energy in the pyrolysis gas volatilized from the pyrolysis of battery materials is not utilized, resulting in a great waste; (3) Traditional battery recycling electric heating furnace systems directly send the pyrolysis gas volatilized from the pyrolysis of battery materials into the tail gas treatment device, without complete incineration, resulting in the generation of a large amount of dioxins. Therefore, traditional waste battery recycling processes have high power consumption, high operating costs, low heat energy utilization, and incomplete dioxin treatment. Summary of the Invention

[0005] The purpose of this invention is to provide a waste battery recycling system and control method.

[0006] This application provides a waste battery recycling system, including:

[0007] Low-temperature drying furnace, anaerobic pyrolysis furnace bed, high-temperature flue gas heater, cooling furnace, hot blast stove, high-temperature flue gas distributor, flue gas heat exchanger; among which

[0008] Battery waste is sequentially passed through a low-temperature drying furnace, an oxygen-free pyrolysis furnace bed, and a cooling furnace;

[0009] The high-temperature flue gas generated by the hot blast stove passes through a high-temperature flue gas distributor. Part of it is sent to a high-temperature flue gas heater to heat the oxygen-free pyrolysis furnace bed, and the other part is sent directly to a flue gas heat exchanger and then enters the flue gas treatment equipment.

[0010] The high-temperature pyrolysis gas generated by the anaerobic pyrolysis furnace bed is sent into the low-temperature drying furnace to heat the material.

[0011] The low-temperature pyrolysis gas generated in the low-temperature drying furnace is sent into the hot air furnace for combustion.

[0012] The cooling air discharged from the cooling furnace is heated by the flue gas heat exchanger and then discharged into the hot blast furnace as combustion air.

[0013] In one embodiment of this application, the hot air furnace is heated by a burner during the start-up phase.

[0014] In one embodiment of this application, the waste battery recycling system further includes a battery crushing system;

[0015] The waste gas generated by the battery crushing system is sent to a hot blast furnace for combustion.

[0016] In one embodiment of this application, the waste battery recycling system further includes a nitrogen delivery system for delivering nitrogen to the battery crushing system, the low-temperature drying furnace, and the anaerobic pyrolysis furnace bed.

[0017] In one embodiment of this application, the cooling furnace includes:

[0018] A rotating drum, with a material inlet at one end and a material outlet at the other end;

[0019] The screw conveyor mechanism is installed at the material inlet of the rotating drum and is used to input the material output from the anaerobic pyrolysis furnace bed into the rotating drum;

[0020] The waste battery recycling system also includes a cold air system and a circulating cooling water system;

[0021] The cold air system is used to deliver cold air into the rotating drum to exchange heat with the material and form the cooling air.

[0022] The circulating cooling water system is used to cool the rotating drum.

[0023] Accordingly, this application provides a control method for the waste battery recycling system as described above, comprising:

[0024] Control the intake air volume of the combustion air and the heat supply of the burner to keep the temperature inside the hot air furnace between 850℃ and 1100℃.

[0025] Controlling the amount of flue gas fed into the high-temperature flue gas heater by the high-temperature flue gas distributor will keep the temperature inside the anaerobic pyrolysis furnace bed between 450℃ and 550℃.

[0026] By controlling the residence time of materials in the anaerobic pyrolysis furnace and the amount of nitrogen filling, the temperature of the high-temperature pyrolysis gas output from the anaerobic pyrolysis furnace is controlled at 300℃~400℃.

[0027] The temperature inside the low-temperature drying furnace is controlled at 100℃~250℃ by controlling the amount of nitrogen filling and the amount of high-temperature pyrolysis gas entering the furnace.

[0028] In one embodiment of this application, the method for controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace includes: controlling the production of high-temperature pyrolysis gas by controlling the amount of nitrogen filling in the oxygen-free pyrolysis furnace bed, thereby controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace.

[0029] In one embodiment of this application, the method for controlling the intake air volume of the combustion air and the heat supply of the burner to control the temperature inside the hot air furnace at 850°C to 1100°C includes:

[0030] When the amount of low-temperature pyrolysis gas fed into the hot blast furnace is lower than the preset value, the temperature inside the hot blast furnace is increased by increasing the temperature of the combustion air first.

[0031] When the combustion air temperature reaches the preset temperature value, the temperature inside the hot air furnace is increased by increasing the heat supply of the burner.

[0032] In one embodiment of this application, the method for increasing the combustion air temperature includes increasing the amount of high-temperature flue gas directly fed into the flue gas heat exchanger from the high-temperature flue gas distributor.

[0033] In one embodiment of this application, the method for increasing the temperature of the combustion air includes:

[0034] Reduce the amount of cold water supplied by the circulating cooling water system to the cooling furnace in order to increase the temperature of the cold air supplied by the cold air system to the rotating drum of the cooling furnace.

[0035] The beneficial effects of this invention are:

[0036] The waste battery recycling system and control method of this application utilizes four furnaces in combination: a low-temperature drying furnace, an anaerobic pyrolysis furnace, a cooling furnace, and a hot air furnace. It uses the chemical energy of high-calorific-value organic materials such as separator plastics and electrolytes contained in waste batteries to generate heat through combustion, thereby heating the materials themselves. This achieves efficient energy recycling, saves electricity consumption, and reduces operating costs. At the same time, the addition of a hot air furnace ensures complete combustion of exhaust gas and thorough incineration of dioxins, solving the technical problems of high energy consumption and high pollution in the field of waste battery recycling.

[0037] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a preferred embodiment of a waste battery recycling system of the present invention;

[0041] Figure 2 This is a schematic diagram of a cooling furnace according to a preferred embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] This application provides a waste battery recycling system and control method, which are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments of this application. Furthermore, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.

[0044] Please see Figure 1 The first aspect of the present invention provides a waste battery recycling system, comprising: a low-temperature drying furnace, an anaerobic pyrolysis furnace bed, a high-temperature flue gas heater, a cooling furnace, a hot air furnace, a high-temperature flue gas distributor, and a flue gas heat exchanger, wherein waste battery materials pass sequentially through the low-temperature drying furnace, the anaerobic pyrolysis furnace bed, and the cooling furnace.

[0045] As an optional connection method between equipment, the flue gas duct of the anaerobic pyrolysis furnace bed is connected to the low-temperature drying furnace, the flue gas duct of the low-temperature drying furnace is connected to the hot air furnace, the flue gas duct of the hot air furnace is connected to the high-temperature flue gas distributor, the flue gas duct of the high-temperature flue gas distributor is connected to the flue gas heat exchanger and the high-temperature flue gas heater, and the flue gas duct of the flue gas heat exchanger is connected to the flue gas treatment equipment.

[0046] Specifically, the low-temperature drying furnace can dry battery waste at a temperature of 100℃~250℃, causing low-boiling-point organic solvents to evaporate, thereby generating low-temperature pyrolysis gas. The low-temperature pyrolysis gas contains a large amount of organic waste gas and dioxins, which can be sent to the hot air furnace for combustion treatment to become high-temperature flue gas. The function of the low-temperature drying furnace is to pre-treat battery materials, which can reduce the material residence time in the anaerobic pyrolysis furnace bed.

[0047] A high-temperature flue gas heater can be installed at the bottom of an anaerobic pyrolysis furnace bed to heat the furnace bed. The anaerobic pyrolysis furnace bed can perform anaerobic carbonization of battery waste at a temperature of 450℃~550℃. The separator, plastic and other components of the waste battery are carbonized in an anaerobic environment to generate high-temperature pyrolysis gas. The high-temperature pyrolysis gas generated by pyrolysis and carbonization in the anaerobic pyrolysis furnace bed contains less than 1% oxygen and can be directly introduced into a low-temperature drying furnace to dry the materials.

[0048] The cooling furnace can use air cooling and / or water cooling to cool the battery waste to no more than 100°C. The cooling air generated by the air cooling furnace can be heated by the flue gas heat exchanger and then sent into the hot air furnace as combustion air.

[0049] The hot blast furnace can burn low-temperature pyrolysis gas. Part of the high-temperature flue gas generated by combustion is sent to the high-temperature flue gas heater to heat the oxygen-free pyrolysis furnace bed and then sent to the flue gas heat exchanger. The other part of the flue gas is sent directly to the flue gas heat exchanger. The flue gas heat exchanger can preheat the combustion air with the flue gas. After passing through the flue gas heat exchanger, the flue gas is discharged into the flue gas treatment equipment and discharged after treatment to meet the standards.

[0050] In this embodiment, optionally, during the system startup phase, the hot blast furnace can be heated by a burner, for example, by natural gas to 850°C to 1100°C, to generate high-temperature flue gas which is then introduced into a high-temperature flue gas heater to heat the anaerobic pyrolysis furnace bed. As the battery waste is stably transported, the low-temperature drying furnace and the anaerobic pyrolysis furnace bed can generate sufficient pyrolysis gas to supply the hot blast furnace for combustion, and the burner can be gradually shut off to achieve its own thermal cycle. Of course, when the pyrolysis gas supply is insufficient, the burner can be turned on to maintain the flue gas temperature.

[0051] In this embodiment, optionally, the waste battery recycling system also includes a battery crushing system for crushing waste batteries; since crushing waste batteries will generate waste gas, preferably, in this embodiment, the waste gas can also be sent to a hot air furnace for combustion, which can completely incinerate organic waste gas and dioxins while using its calorific value to produce high-temperature flue gas.

[0052] In this embodiment, optionally, the waste battery recycling system further includes a nitrogen delivery system for supplying nitrogen to the battery crushing system, the low-temperature drying furnace, and the anaerobic pyrolysis furnace. By purging the battery crushing system, the low-temperature drying furnace, and the anaerobic pyrolysis furnace with nitrogen to displace oxygen within the system, spontaneous combustion, explosion, or other incidents can be prevented during system operation.

[0053] In this embodiment, optionally, the waste battery recycling system further includes a cold air system and a circulating cooling water system; the cold air system is used to deliver cold air into the cooling furnace; the circulating cooling water system is used to exchange heat with the cooling furnace.

[0054] See Figure 2 As shown, the cooling furnace includes: a rotating cylinder 1, one end of which is a material inlet and the other end is a material outlet; and a screw conveyor 2, which is installed at the material inlet of the rotating cylinder 1 and is used to input the material output from the anaerobic pyrolysis furnace bed into the rotating cylinder 1.

[0055] In one specific embodiment, the rotating drum 1 can be multi-segmented, including a first segment 11 and a second segment 12; the cold air system can input cold air into the rotating drum 1 from the material inlet end of the rotating drum 1, exchange heat with the material in the first segment 11, and then discharge it from the exhaust port of the first segment 11 as combustion air; the circulating cooling water system can include a cold water pipe 3 and a hot water pipe 4, and each segment of the rotating drum 1 can be equipped with a cold water pipe 3 and a hot water pipe 4; the cold water pipe 3 can be set above the rotating drum 1 and extend along the length direction of the rotating drum 1, and the cold water pipe 3 can be provided with spray holes to spray and cool the rotating drum 1, and the hot water pipe 4 can be located below the rotating drum 1 for collecting spray water.

[0056] In this embodiment, optionally, the cooling furnace can mainly use water cooling for temperature reduction, with segmented water cooling and air cooling as an auxiliary method. The ratio of heat absorbed by water cooling to heat absorbed by air cooling can be 9:1. When it is necessary to increase the exhaust temperature of the cooling air, the water cooling in the first section 11 of the rotating drum 1 can be reduced or even stopped, so that the cooling air in the first section 11 of the rotating drum 1 can directly contact the high-temperature material, thereby reducing the heat absorbed by water cooling and increasing the heat absorbed by the cooling air. For example, increasing the ratio of heat absorbed by water cooling to heat absorbed by air cooling from 9:1 to 7:3 or even 5:5 can increase the exhaust temperature of the cooling air by 30°C to 50°C, thereby increasing the temperature of the combustion air.

[0057] Cooling water and materials do not come into contact. The circulating cooling water circulates outside the stainless steel cylinder, while the battery materials are propelled inside by a rotary conveyor. Cooling air is directly introduced into the cylinder to directly cool the materials.

[0058] In this embodiment, the flue gas treatment equipment may include, but is not limited to, environmental protection equipment such as dry desulfurization towers, bag filters, wet desulfurization towers, and activated carbon adsorption equipment; the flue gas treatment equipment may adopt existing technologies, which will not be elaborated here.

[0059] The negative pressure in the entire system is controlled by the induced draft fan installed in the flue gas treatment equipment. The induced draft fan is frequency-controlled. Each furnace body is connected by a flue. The flue is equipped with dampers, which can control the flue gas volume and negative pressure in the furnace in real time. The flue can be insulated.

[0060] Thermocouples can be installed in sections inside the low-temperature drying furnace to monitor the furnace temperature. Thermocouples and oxygen content detectors can be installed in the outlet flue to monitor the oxygen content of the low-temperature hot gas in real time. The thermometers and oxygen content detectors can be installed in the outlet flue of the pyrolysis gas in the anaerobic pyrolysis furnace bed to monitor the temperature and oxygen content of the high-temperature pyrolysis gas in real time. Thermocouples can be installed at the inlet and outlet of the hot blast furnace to monitor the temperature inside the hot blast furnace.

[0061] Based on the above embodiments, a second aspect of the present invention provides a control method for a waste battery recycling system, comprising:

[0062] (1) Control the intake air volume of the combustion air and the heat supply of the burner to keep the temperature inside the hot air furnace at 850℃~1100℃;

[0063] (2) Control the amount of flue gas fed into the high-temperature flue gas heater by the high-temperature flue gas distributor to control the temperature in the anaerobic pyrolysis furnace bed at 450℃~550℃.

[0064] (3) Control the residence time of materials in the anaerobic pyrolysis furnace and the amount of nitrogen filling to control the temperature of the high-temperature pyrolysis gas output from the anaerobic pyrolysis furnace to 300℃~400℃.

[0065] (4) Control the amount of nitrogen filling in the low-temperature drying furnace and the amount of high-temperature pyrolysis gas entering the furnace to control the temperature in the low-temperature drying furnace between 100℃ and 250℃.

[0066] Optionally, in step (1), specifically, the burner can be a natural gas burner, and the temperature inside the hot air furnace can be adjusted by adjusting the supply of natural gas.

[0067] In addition, the method for controlling the intake air volume of the combustion air and the heat supply of the burner to control the temperature inside the hot air furnace at 850℃~1100℃ may include: when the amount of low-temperature pyrolysis gas fed into the hot air furnace is lower than a preset value, the temperature inside the hot air furnace is increased by increasing the temperature of the combustion air first; when the temperature of the combustion air reaches the preset temperature value, the temperature inside the hot air furnace is increased by increasing the heat supply of the burner.

[0068] Specifically, the priority is to increase the temperature inside the hot blast furnace by raising the temperature of the combustion air, which can save on natural gas usage. However, the increase in combustion air temperature is limited. When it cannot be increased further, the temperature inside the hot blast furnace can be increased by adjusting the natural gas supply to the burner.

[0069] One possible way to increase the temperature of the combustion air is to increase the amount of high-temperature flue gas directly fed into the flue gas heat exchanger from the high-temperature flue gas distributor. Specifically, when the amount of high-temperature flue gas directly fed into the flue gas heat exchanger from the high-temperature flue gas distributor is increased, the amount of heat exchanged with the combustion air increases, and the temperature of the combustion air after heat exchange can be increased.

[0070] As another option to increase the temperature of the combustion air, the amount of cold water supplied by the circulating cooling water system to the cooling furnace can be reduced, thereby increasing the temperature of the cold air supplied by the cold air system to the rotating drum of the cooling furnace.

[0071] For example, see Figure 2 As shown, the material temperature in the first section 11 of the rotating drum 1 is relatively high. Closing the spray nozzles in the first section 11 reduces the amount of cooling water, allowing the hottest material in this section to exchange heat with the cold air, thus increasing the temperature of the exhaust cooling air and consequently the temperature of the combustion air. In other words, reducing the heat absorbed by the circulating cooling water system and increasing the heat absorbed by the cooling air raises the temperature of the combustion air. For example, adjusting the ratio of heat absorbed by water cooling to heat absorbed by air cooling from 9:1 to 7:3 or even 5:5 can increase the exhaust temperature of the cooling air by 30°C to 50°C, thereby increasing the temperature of the combustion air.

[0072] In step (2), specifically, when controlling the temperature inside the anaerobic pyrolysis furnace bed, if the temperature of the anaerobic pyrolysis furnace bed is high, the high-temperature flue gas distributor is controlled to reduce the amount of flue gas entering the high-temperature flue gas heater, and vice versa.

[0073] In addition, the oxygen-free pyrolysis furnace bed is protected by nitrogen purging, and the oxygen content is controlled below 1%. The pyrolysis gas outlet flue of the oxygen-free pyrolysis furnace bed is equipped with thermometers and oxygen content detectors to monitor the temperature and oxygen content of the high-temperature pyrolysis gas in real time. The high-temperature pyrolysis gas produced by pyrolysis and carbonization in the oxygen-free pyrolysis furnace bed has an oxygen content of less than 1% and can be directly introduced into the low-temperature drying furnace to dry materials.

[0074] In step (3), for example, the longer the material stays in the anaerobic pyrolysis furnace, the less pyrolysis gas is produced, and the closer the pyrolysis gas temperature is to the furnace temperature. When the high-temperature pyrolysis gas temperature is too high, the temperature can be lowered by appropriately increasing the feed rate. When the feed rate reaches the speed limit, the amount of nitrogen introduced into the anaerobic pyrolysis furnace can be increased to lower the high-temperature pyrolysis gas temperature; and vice versa.

[0075] In step (4), further, the method for controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace includes: controlling the production of high-temperature pyrolysis gas by controlling the amount of nitrogen filling in the oxygen-free pyrolysis furnace bed, thereby controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace.

[0076] For example, if the temperature inside the low-temperature drying furnace is too high, nitrogen can be added to the furnace to lower the temperature, while simultaneously reducing the amount of nitrogen filling the anaerobic pyrolysis furnace bed. This reduces the total amount of high-temperature pyrolysis gas, decreases the heat entering the low-temperature drying furnace, and lowers the furnace temperature. Conversely, if the temperature inside the low-temperature drying furnace is too low, the amount of nitrogen added can be reduced, while simultaneously increasing the amount of nitrogen filling the anaerobic pyrolysis furnace bed. This increases the amount of high-temperature pyrolysis gas, increases the heat entering the furnace, and raises the furnace temperature.

[0077] In summary, the waste battery recycling system and control method of this application have the following advantages:

[0078] (1) By combining four furnaces, namely a low-temperature drying furnace, an oxygen-free pyrolysis furnace, a cooling furnace, and a hot air furnace, the chemical energy of high-calorific-value organic matter such as separator plastic and electrolyte contained in waste batteries is used to burn heat to heat the material itself, replacing the traditional electric heating method. This achieves efficient energy recycling, saves electricity consumption, and reduces operating costs. At the same time, the hot air furnace can fully burn the waste gas and completely incinerate dioxins, solving the technical problems of high energy consumption and high pollution in the field of waste battery recycling.

[0079] (2) The cooling furnace cools down by combining water cooling and air cooling, which allows for easy adjustment of the ratio of heat absorbed by water cooling and heat absorbed by air cooling, thereby flexibly controlling the temperature of the combustion air.

[0080] (3) The control method of the waste battery recycling system is flexible, does not require additional power, and adopts the self-adjustment mode within the system first during the adjustment process to avoid energy waste.

[0081] All the devices (parts whose specific structures are not specified) selected in this application are general standard parts or parts known to those skilled in the art. Their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0082] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0083] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0084] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A control method for a waste battery recycling system, characterized in that, The waste battery recycling system includes: a low-temperature drying furnace, an anaerobic pyrolysis furnace bed, a high-temperature flue gas heater, a cooling furnace, a hot air furnace, a high-temperature flue gas distributor, a flue gas heat exchanger, and a nitrogen delivery system; wherein... The hot air furnace is heated by a burner during the start-up phase; The nitrogen delivery system is used to deliver nitrogen to the low-temperature drying furnace and the oxygen-free pyrolysis furnace bed. Battery waste is sequentially passed through a low-temperature drying furnace, an oxygen-free pyrolysis furnace bed, and a cooling furnace; The high-temperature flue gas generated by the hot blast stove passes through a high-temperature flue gas distributor. Part of it is sent to a high-temperature flue gas heater to heat the oxygen-free pyrolysis furnace bed, and the other part is sent directly to a flue gas heat exchanger and then enters the flue gas treatment equipment. The high-temperature pyrolysis gas generated by the anaerobic pyrolysis furnace bed is sent into the low-temperature drying furnace to heat the material. The low-temperature pyrolysis gas generated in the low-temperature drying furnace is sent into the hot air furnace for combustion. The cooling air discharged from the cooling furnace is heated by the flue gas heat exchanger and then discharged into the hot air furnace as combustion air. The control method includes: Control the intake air volume of the combustion air and the heat supply of the burner to keep the temperature inside the hot air furnace between 850℃ and 1100℃. Controlling the amount of flue gas fed into the high-temperature flue gas heater by the high-temperature flue gas distributor will keep the temperature inside the anaerobic pyrolysis furnace bed between 450℃ and 550℃. By controlling the residence time of materials in the anaerobic pyrolysis furnace and the amount of nitrogen filling, the temperature of the high-temperature pyrolysis gas output from the anaerobic pyrolysis furnace is controlled at 300℃~400℃. The temperature inside the low-temperature drying furnace is controlled at 100℃~250℃ by controlling the amount of nitrogen filling and the amount of high-temperature pyrolysis gas entering the furnace.

2. The control method for the waste battery recycling system according to claim 1, characterized in that, The method for controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace includes: controlling the output of high-temperature pyrolysis gas by controlling the amount of nitrogen filling in the oxygen-free pyrolysis furnace bed, thereby controlling the intake of high-temperature pyrolysis gas in the low-temperature drying furnace.

3. The control method for the waste battery recycling system according to claim 1, characterized in that, The method for controlling the intake air volume of the combustion air and the heat supply of the burner to control the temperature inside the hot air furnace at 850℃~1100℃ includes: When the amount of low-temperature pyrolysis gas fed into the hot blast furnace is lower than the preset value, the temperature inside the hot blast furnace is increased by increasing the temperature of the combustion air first. When the combustion air temperature reaches the preset temperature value, the temperature inside the hot air furnace is increased by increasing the heat supply of the burner.

4. The control method for the waste battery recycling system according to claim 3, characterized in that, The method for increasing the temperature of the combustion air includes increasing the amount of high-temperature flue gas directly fed into the flue gas heat exchanger from the high-temperature flue gas distributor.

5. The control method for the waste battery recycling system according to claim 3, characterized in that, The cooling furnace includes: A rotating drum, with a material inlet at one end and a material outlet at the other end; The screw conveyor mechanism is installed at the material inlet of the rotating drum and is used to input the material output from the anaerobic pyrolysis furnace bed into the rotating drum; The waste battery recycling system also includes a cold air system and a circulating cooling water system; The cold air system is used to deliver cold air into the rotating drum to exchange heat with the material and form the cooling air. The circulating cooling water system is used to cool the rotating drum; The method for increasing the temperature of the combustion air includes: Reduce the amount of cold water supplied by the circulating cooling water system to the cooling furnace in order to increase the temperature of the cold air supplied by the cold air system to the rotating drum of the cooling furnace.

6. The control method for the waste battery recycling system according to claim 1, characterized in that, The waste battery recycling system also includes a battery crushing system; The waste gas generated by the battery crushing system is sent to a hot blast furnace for combustion.

7. The control method for the waste battery recycling system according to claim 6, characterized in that, The nitrogen delivery system is also used to deliver nitrogen to the battery crushing system.

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