A wastewater treatment device and a cathode material production system

Abstract

This utility model discloses a wastewater treatment device and a positive electrode material production system, relating to the field of wastewater treatment technology. Fresh steam transported by a first external steam pipeline heats air in an end heater and then supplies heat to the end drying section. Compressed steam output from a steam compressor heats air in an intermediate heater and then supplies heat to the intermediate drying section. The intermediate heater can also utilize both compressed steam and fresh steam for heating, which can significantly reduce steam consumption, improve energy utilization, and reduce process energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and more specifically, to a wastewater treatment device and a positive electrode material production system. Background Technology

[0002] In the preparation process of cathode materials, the preparation process of the precursor is a crucial component, and the quality of the precursor directly affects the performance of the cathode material. Generally, ternary cathode materials are formed by calcining a mixture of secondary spherical particles (formed from the agglomeration of fine nickel-cobalt-manganese hydroxide grains) and lithium hydroxide. Currently, the main method for producing ternary precursors is the co-precipitation method (divided into continuous and batch methods). This involves preparing a salt solution of nickel, cobalt, manganese, or aluminum salts in a specific ratio, forming a nickel-cobalt-manganese / aluminum hydroxide precipitate in the presence of an alkaline solution and a complexing agent. The precipitate is then obtained through steps such as centrifugation, washing, drying, mixing, and demagnetization.

[0003] Wastewater generated during precursor preparation is treated in an MVR system. After concentration, the wastewater is centrifuged to produce salt, which is then dried in a fluidized bed. During operation, steam is introduced from the bottom of the fluidized bed through a gas distributor, creating an upward airflow that fluidizes the solid particles in the fluidizing medium. Within the fluidized bed, the solid particles are agitated and mixed by the airflow, forming a uniform particle suspension. As the gas velocity gradually increases, the solid particles begin to exhibit liquid-like flow properties. At this point, the friction and resistance between the solid particles are low, allowing for the formation of a uniform fluidized bed.

[0004] Currently, the steam used in fluidized beds is fresh steam. The steam enters the cylinder (inlet) and middle section of the bed from the bottom via a blower and gas distributor. At the tail end of the bed, atmospheric air enters from the bottom via a blower to ensure the fluidity of the material within the bed. The purpose of introducing steam into the fluidized bed is to dry the material centrifuged from the centrifuge. Currently, because fresh steam is used, taking a 6T / h unit as an example, approximately 1 ton of steam is consumed per hour. This waste occurs because a large amount of fresh steam is introduced for drying at both the inlet and middle sections.

[0005] Furthermore, because the MVR system has its own steam compressor, the fluidized bed continuously uses fresh steam, resulting in energy waste due to insufficient energy utilization. Since fresh steam pressure is above 0.6 MPa, while the steam compressor outlet pressure is approximately 0.15 MPa, directly replacing fresh steam with compressed steam would result in insufficient steam pressure, leading to substandard product water content. Current technology introduces fresh steam at the fluidized bed inlet and middle, which results in incomplete reaction between the steam and material at the inlet, and continued steam supply in the middle, leading to steam waste.

[0006] Therefore, there is an urgent need to optimize the heat source used in wastewater treatment systems in order to reduce the amount of steam used in wastewater treatment.

[0007] In view of this, this utility model is proposed. Utility Model Content

[0008] The purpose of this invention is to provide a wastewater treatment device and a positive electrode material production system, which aims to significantly reduce the steam energy consumption in the treatment process.

[0009] This utility model is implemented as follows:

[0010] In the first aspect, this utility model provides a wastewater treatment device for treating wastewater generated during the preparation of positive electrode materials, including a steam compressor, an evaporator and a fluidized drying assembly. The output end of the steam compressor is connected to the evaporator, and the outlet of the steam compressor is connected to the compressed gas delivery pipeline. The fluidized drying assembly is used to dry the solid materials separated after evaporation and concentration.

[0011] The fluidized bed drying assembly includes an end drying section, an intermediate drying section, an end heater, and an intermediate heater. The end drying section is provided with a material inlet, and the inlet of the intermediate drying section is connected to the outlet of the end drying section. A first external steam pipeline is connected to the inlet of the end heater, and the outlet of the end heater is connected to the end drying section.

[0012] The compressed gas delivery pipeline and the second external steam pipeline are both connected to the inlet of the intermediate heater, and the outlet of the intermediate heater is connected to the intermediate drying section.

[0013] In an optional embodiment, the fluidized bed drying assembly further includes an end blower and an intermediate blower, the end blower being connected to an end heater and the intermediate blower being connected to an intermediate heater.

[0014] In an optional implementation, the compressed gas delivery line is connected to a second external steam line.

[0015] In an optional embodiment, a first shut-off valve is provided on the connecting pipe between the second external steam pipe and the intermediate heater.

[0016] In an optional embodiment, a second shut-off valve and a check valve are provided on the compressed gas delivery pipeline.

[0017] In an optional embodiment, the check valve is installed between the second shut-off valve and the intermediate heater.

[0018] In an optional implementation, a three-way valve is provided at the connection between the compressed gas delivery pipeline and the second external steam pipeline.

[0019] In an optional embodiment, the fluidized drying assembly further includes a cooling section connected to the end of the intermediate drying section away from the end drying section, so that the material passes through the end drying section, the intermediate drying section and the cooling section in sequence.

[0020] In an optional implementation, a separator is also included, which is connected to the inlet of the steam compressor.

[0021] Secondly, this utility model provides a cathode material production system, including a wastewater treatment device according to any of the foregoing embodiments.

[0022] The present invention has the following beneficial effects: the fresh steam transported by the first external steam pipeline heats the air in the end heater and then heats the end drying section; the compressed steam output by the steam compressor heats the air in the intermediate heater and then heats the intermediate drying section; the intermediate heater can also use compressed steam and fresh steam for heating together, which can significantly reduce steam consumption, improve energy utilization, and reduce process energy consumption. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the wastewater treatment device provided by this utility model.

[0025] Explanation of main component symbols: 1-Material inlet; 2-End drying section; 3-End heater; 4-End blower; 5-Intermediate drying section; 6-Intermediate heater; 7-Intermediate blower; 8-Cooling section; 9-Cooling blower; 10-Packaging machine; 12-Steam compressor; 13-Separator; 14-Evaporator; 15-Second shut-off valve; 16-First shut-off valve; 17-Check valve; 18-First external steam pipeline; 19-Second external steam pipeline; 20-Compressed gas delivery pipeline. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and 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, and therefore should not be construed as a limitation of this utility model.

[0030] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0031] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0032] If fresh steam is used entirely for drying materials without effectively utilizing steam recompression technology to save energy and reduce consumption, the high energy consumption and price of fresh steam will negatively impact overall production costs. Steam recompression technology replaces most of the steam with electricity. The purpose of this invention is to modify the heat source of the fluidized bed dryer and utilize compressed steam from steam recompression technology to replace some of the fresh steam, thereby reducing steam energy consumption.

[0033] like Figure 1 As shown, this embodiment of the invention provides a wastewater treatment device for treating wastewater generated during the preparation of cathode materials. The device includes a steam compressor 12, an evaporator 14, and a fluidized bed drying assembly. The output end of the steam compressor 12 is connected to the evaporator 14, and the outlet compressed gas delivery pipeline 20 of the steam compressor 12 is also connected, outputting compressed steam. The steam output from the steam compressor 12 heats the evaporator 14, causing the wastewater to evaporate and concentrate. The concentrated material is then centrifuged to obtain solid material (mainly solid material), which enters the fluidized bed drying assembly for drying.

[0034] The fluidized bed drying assembly includes an end drying section 2, an intermediate drying section 5, and a cooling section 8 connected in sequence. The end drying section 2 is provided with a material inlet 1. The inlet of the intermediate drying section 5 is connected to the outlet of the end drying section 2, and the outlet of the intermediate drying section 5 is connected to the cooling section 8, so that the material passes through the end drying section 2, the intermediate drying section 5, and the cooling section 8 in sequence. After being dried in two stages by the end drying section 2 and the intermediate drying section 5, the material enters the cooling section 8 for cooling.

[0035] Specifically, the end drying section 2 and the middle drying section 5 are two drying chambers. The end drying section 2 can be a cylindrical drying chamber, and the middle drying section 5 can be a straight drying chamber.

[0036] The fluidized bed dryer also includes an end heater 3 and an intermediate heater 6. A first external steam line 18 is connected to the inlet of the end heater 3, and the outlet of the end heater 3 is connected to the end drying section 2. Fresh steam from the first external steam line 18 enters the end heater 3 to heat the air before entering the end drying section 2. Similarly, a second external steam line 19 and a compressed air delivery line 20 are both connected to the inlet of the intermediate heater 6, and the outlet of the intermediate heater 6 is connected to the intermediate drying section 5. Steam output from the second external steam line 19 and the compressed air delivery line 20 enters the intermediate heater 6 to heat the air before entering the intermediate drying section 5.

[0037] The first external steam line 18 can provide fresh steam at a pressure above 0.6 MPa, which can remove most of the moisture from the material after drying in the end drying section 2. The intermediate drying section 5 can use compressed gas output from the compressed gas delivery line 20 to provide heat for further drying of the material. When the amount of compressed gas is insufficient, the compressed gas delivery line 20 and the second external steam line 19 can be opened simultaneously to provide a heat source for the intermediate drying section 5, enabling the device to adapt to different production capacities.

[0038] It should be noted that in a fluidized bed, solid particles are agitated and mixed by the airflow, forming a uniform particle suspension. As the gas velocity gradually increases, the solid particles in the fluidized bed begin to exhibit liquid-like flow properties. At this point, the friction and resistance between the solid particles are relatively small, allowing a uniform fluidized bed to form within the bed. Using only fresh steam for heating would result in significant waste, while using only compressed steam would result in insufficient pressure. Therefore, a combination of fresh and compressed steam is employed.

[0039] Furthermore, the fluidized bed drying assembly also includes an end blower 4 and an intermediate blower 7. The end blower 4 is connected to the end heater 3, and the intermediate blower 7 is connected to the intermediate heater 6. The end blower 4 blows the air heated by the end heater 3 into the end drying section 2 to perform fluidized bed drying on the material, and the intermediate blower 7 blows the air heated by the intermediate heater 6 into the intermediate drying section 5 to continue the fluidized bed drying on the material.

[0040] In some embodiments, the second external steam pipeline 19 and the compressed gas delivery pipeline 20 can be independently controlled, and both are connected to the intermediate heater 6. Switch valves are respectively installed on the second external steam pipeline 19 and the compressed gas delivery pipeline 20 to control the opening and closing of the pipelines and regulate the flow.

[0041] In another embodiment, such as Figure 1 As shown, the compressed gas delivery pipeline 20 is connected to the second external steam pipeline 19, and then connected to the intermediate heater 6 via a shared pipeline. To better regulate the compressed gas delivery pipeline 20 and the second external steam pipeline 19, a first shut-off valve 16 is installed on the connecting pipeline between the second external steam pipeline 19 and the intermediate heater 6. A second shut-off valve 15 and a check valve 17 are installed on the compressed gas delivery pipeline 20, with the check valve 17 installed between the second shut-off valve 15 and the intermediate heater 6. Through the first shut-off valve 16, the second shut-off valve 15, and the check valve 17, the independent heat supply of the two pipelines is better controlled, preventing steam from the second external steam pipeline 19 from entering the compressed gas delivery pipeline 20.

[0042] Specifically, the first shut-off valve 16, the second shut-off valve 15, and the check valve 17 are all existing valve structures. The shut-off valve controls the flow of the medium in the pipeline by cutting off or regulating the flow rate, and controls the opening and closing or the flow rate of the medium in the pipeline by raising and lowering the valve disc; the check valve can prevent the backflow of the fluid and automatically open and closes by relying on the pressure of the medium itself, without the need for manual or external operation.

[0043] In some embodiments, the compressed gas delivery pipeline 20 and the second external steam pipeline 19 are connected, and a three-way valve (not shown) is provided at the connection. The three-way valve makes it easier to adjust the opening and closing of the compressed gas delivery pipeline 20 and the second external steam pipeline 19. Under normal circumstances, the second external steam pipeline 19 is closed and the compressed gas delivery pipeline 20 is opened. When the compressed gas delivery pipeline 20 is not providing enough heat, the second external steam pipeline 19 is opened again.

[0044] Furthermore, the cooling section 8 in the fluidized bed drying assembly is connected to the end of the intermediate drying section 5 away from the end drying section 2. The material is cooled by blowing in ambient temperature air through the cooling blower 9, and the cooled material enters the packaging machine 10.

[0045] In some embodiments, the wastewater treatment apparatus further includes a separator 13 connected to the inlet of the steam compressor 12. The separator 13 is used to efficiently separate steam from liquid (or solid), ensuring the purity of the steam and avoiding the entrainment of droplets or particles, thereby protecting downstream equipment (such as the compressor) and improving process efficiency.

[0046] It should be noted that compared to the use of fresh steam in both the end drying section 2 and the intermediate drying section 5, the energy consumption of the wastewater treatment device provided in this embodiment is significantly reduced. Taking a fluidized bed device with a processing capacity of 6T / h as an example, the steam consumption is approximately 1 ton per hour. If a large amount of fresh steam is introduced at both the inlet and the middle section for drying, the steam at the inlet will not fully react with the material before introducing fresh steam in the middle section, resulting in some waste. Therefore, the middle section (i.e., the intermediate drying section) is replaced with compressed steam for heating, thereby saving steam consumption.

[0047] The operation flow of the wastewater treatment device provided in this embodiment of the utility model is as follows: During operation, the material after centrifugal dehydration enters the end drying section 2 through the material inlet 1. The end drying section 2 uses the end blower 4 to blow in air heated by the end heater 3 to fluidize and dry the material. The heat source of the end heater 3 comes from the fresh steam output from the first external steam pipeline 18. Then, under the action of hot air, it flows into the intermediate drying section 5. The intermediate drying section 5 uses the intermediate blower 7 to blow in air heated by the intermediate heater 6 to continue fluidizing and drying the material. The heat source of the intermediate heater 6 is cut off by the valve on the second external steam pipeline 19, and the fresh steam is switched to secondary steam delivered from the compressed air delivery pipeline 20. This secondary steam comes from the separator 13 and is compressed steam that is recompressed and heated by the steam compressor 12 and used in the evaporator 14. After being dried by the two stages of hot air in the end drying section 2 and the intermediate drying section 5, the material flows into the cooling section 8, where the cooling blower 9 blows in room temperature air to cool the material. The cooled material then enters the packaging machine 10 for packaging. By switching the heat source of the intermediate heater 6, the use of fresh steam is reduced, thereby reducing steam energy consumption.

[0048] This utility model embodiment also provides a cathode material production system, including the wastewater treatment device provided in this utility model embodiment, and may also include precursor synthesis equipment, sintering equipment, etc., forming a complete cathode material production system.

[0049] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A wastewater treatment device for treating wastewater generated during the preparation of cathode materials, characterized in that, It includes a steam compressor, an evaporator, and a fluidized bed dryer. The output of the steam compressor is connected to the evaporator, and the outlet of the steam compressor is connected to a compressed gas delivery pipeline. The fluidized bed dryer is used to dry the solid material separated after evaporation and concentration. The fluidized bed drying assembly includes an end drying section, an intermediate drying section, an end heater, and an intermediate heater. The end drying section is provided with a material inlet, and the inlet of the intermediate drying section is connected to the outlet of the end drying section. A first external steam pipeline is connected to the inlet of the end heater, and the outlet of the end heater is connected to the end drying section. The compressed gas delivery pipeline and the second external steam pipeline are both connected to the inlet of the intermediate heater, and the outlet of the intermediate heater is connected to the intermediate drying section.

2. The wastewater treatment device according to claim 1, characterized in that, The fluidized bed drying assembly further includes an end blower and an intermediate blower, wherein the end blower is connected to the end heater and the intermediate blower is connected to the intermediate heater.

3. The wastewater treatment device according to claim 1, characterized in that, The compressed gas delivery pipeline is connected to the second external steam pipeline.

4. The wastewater treatment device according to claim 3, characterized in that, A first shut-off valve is provided on the connecting pipe between the second external steam pipeline and the intermediate heater.

5. The wastewater treatment device according to claim 3, characterized in that, The compressed gas delivery pipeline is equipped with a second shut-off valve and a check valve.

6. The wastewater treatment apparatus according to claim 5, characterized in that, The check valve is installed between the second shut-off valve and the intermediate heater.

7. The wastewater treatment device according to claim 2, characterized in that, A three-way valve is installed at the connection between the compressed gas delivery pipeline and the second external steam pipeline.

8. The wastewater treatment device according to claim 1, characterized in that, The fluidized drying assembly further includes a cooling section, which is connected to the end of the intermediate drying section away from the end drying section, so that the material passes through the end drying section, the intermediate drying section and the cooling section in sequence.

9. The wastewater treatment device according to claim 1, characterized in that, It also includes a separator that is connected to the inlet of the steam compressor.

10. A cathode material production system, characterized in that, The wastewater treatment apparatus includes any one of claims 1-9.

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