An apparatus for hydrolyzing secondary aluminum dross

Abstract

The utility model provides a kind of secondary aluminium ash hydrolysis's device, belong to the technical field of aluminium ash processing equipment, including hydrolysis reaction mechanism, the hydrolysis reaction mechanism includes fluidized bed reactor, solid collector, dilute ammonia water collector and brine collector, the fluidized bed reactor is connected with aluminium ash grinding pulping device, heat exchanger and rotary separator respectively by pipeline, the rotary separator is connected with pre-heat exchanger by pipeline, by the utility model, realized using hydrolysis generated reaction liquid waste heat and high-temperature steam, twice preheating water supply, form heat closed loop recovery, significantly improve energy utilization, reduce external energy consumption demand, and with fluidized bed reactor combination baffle structure, so that fluidized state under gas-liquid-solid sufficient contact and baffle extension reaction path, the collaborative design of structure and process, build up efficient environmental protection secondary aluminium ash hydrolysis system, reach continuous efficient conversion, substantially improve aluminium nitride hydrolysis efficiency.

Description

Technical Field

[0001] This utility model mainly relates to the technical field of aluminum ash treatment equipment, specifically a device for secondary aluminum ash hydrolysis. Background Technology

[0002] Aluminum ash is a mixture of slag generated during the smelting, casting, and processing of aluminum and aluminum alloys, produced by the reaction of molten aluminum with air and flux, as well as refractory material debris from furnace walls, crucibles, and other materials. Secondary aluminum ash is produced during the smelting of recycled aluminum (waste aluminum recycling), and its composition is more complex, containing aluminum nitride (AlN), fluorides, etc. Secondary aluminum ash hydrolysis utilizes the chemical reaction between aluminum nitride, metallic aluminum, etc. in aluminum ash and water. This is an exothermic reaction that produces stable substances (such as Al(OH)3). The recyclable substances (such as ammonia, aluminum, and salts) are then extracted and reused, achieving a process of harmless treatment and resource recovery.

[0003] In existing secondary aluminum ash hydrolysis devices, such as the application with application number 202021472068.7, a stirring device is installed in the main reactor, a packing port is opened at the top of the main reactor, and a slurry discharge pipe connected to a circulating pump is opened at the bottom of the main reactor. The other end of the circulating pump is connected to the inner cavity of the main reactor through the slurry circulation pipe. The main reactor is fitted with a hollow jacket with a circulating water outlet. A hollow shell is fitted over the heat exchanger with a circulating water inlet. A water supply pipe is connected between the jacket of the main reactor and the shell of the heat exchanger. An ammonia outlet connected to the inner cavity of the heat exchanger is installed on the heat exchanger. An ammonia supply pipe is connected between the heat exchanger and the main reactor. A flow guide is fixedly installed at the position opposite to the outlet of the slurry circulation pipe in the inner cavity of the main reactor. This device solves the problems of incomplete AlN hydrolysis in aluminum ash, lack of dust prevention during aluminum ash feeding, and low thermal efficiency of water-ammonia separation in existing aluminum ash hydrolysis and recovery devices. It can achieve one-time feeding and control the reaction time, and the secondary aluminum ash reaction is complete.

[0004] However, there are still some drawbacks. The reaction device is intermittently fed, which cannot achieve continuous production. At the same time, due to its intermittent production, it cannot make full use of the large amount of heat energy generated by hydrolysis, thus failing to preheat the materials sufficiently, resulting in heat loss in the system. Furthermore, since different batches of raw materials enter the reactor intermittently, the stability of the hydrolysis products cannot be guaranteed, which can easily have an adverse effect on subsequent continuous production. Utility Model Content

[0005] This utility model provides a solution that is significantly different from existing technologies, addressing the problem that existing solutions are too simplistic. Specifically, this utility model provides a device for secondary aluminum ash hydrolysis, which solves the problem mentioned in the background that existing secondary aluminum ash hydrolysis devices cannot fully utilize the large amount of heat energy generated by hydrolysis, cannot adequately preheat the material, resulting in heat loss within the system and low energy utilization.

[0006] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0007] A device for secondary aluminum ash hydrolysis includes a hydrolysis reaction mechanism comprising a fluidized bed reactor, a solid collector, a dilute ammonia water collector, and a brine collector, all connected by pipelines. The fluidized bed reactor is connected via pipelines to an aluminum ash grinding and slurry preparation device, a heat exchanger, and a rotary separator. The rotary separator is connected via pipelines to a preheat exchanger. The shell-side inlet of the preheat exchanger is equipped with a water supply pipe, and the shell-side outlet of the preheat exchanger is connected to the tube-side inlet of the heat exchanger. The tube-side outlet of the heat exchanger is connected via pipelines to the pipeline between the aluminum ash grinding and slurry preparation device and the fluidized bed reactor.

[0008] Furthermore, the shell-side air inlet of the heat exchanger and the air outlet of the fluidized bed reactor are connected by a pipeline.

[0009] Furthermore, the inner wall of the fluidized bed reactor shell is provided with multiple baffles on both sides, and the baffles on each side are distributed alternately at equal intervals.

[0010] Furthermore, a vent valve is provided at the top of the shell of the fluidized bed reactor.

[0011] Furthermore, the shell-side outlet of the heat exchanger and the dilute ammonia water collector are connected by a pipeline.

[0012] Furthermore, the tube-side inlet of the preheat exchanger is connected to the outlet of the rotary separator via a pipe, and the tube-side outlet of the preheat exchanger is connected to the brine collector.

[0013] Furthermore, the solid discharge port of the rotary separator is connected to the solid collector via a pipe.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] This invention achieves a synergistic design of structure and process by incorporating an aluminum ash grinding and slurry preparation device, a fluidized bed reactor, a rotary separator, a heat exchanger, a preheat exchanger, a solid collector, a dilute ammonia water collector, a brine collector, and a water supply pipe. This results in a highly efficient and environmentally friendly secondary aluminum ash hydrolysis system. On the one hand, by combining a fluidized bed reactor with a baffle structure, the system achieves continuous and efficient conversion of secondary aluminum ash hydrolysis through full contact between gas, solid, and liquid in a fluidized state and by extending the reaction path through baffles. This significantly improves the efficiency of aluminum nitride hydrolysis.

[0016] On the other hand, the innovative two-stage heat exchanger allows the waste heat from the hydrolysis reaction liquid and the high-temperature steam to be used twice for preheating and replenishing water, forming a closed-loop heat recovery system. This significantly improves energy utilization and reduces external energy consumption. At the same time, it facilitates precise control of parameters such as reaction temperature and time, promoting the stable generation of hydrolysis products (such as aluminum hydroxide and dilute ammonia) and avoiding side reactions. This lays the foundation for subsequent resource utilization processes such as preparing water purification agents from aluminum ash products, recovering metallic aluminum, and reusing ammonia. It truly achieves the harmlessness, energy saving, and high value of secondary aluminum ash treatment.

[0017] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure and process of this utility model;

[0019] Figure 2 This is a schematic diagram showing the flow direction of the water supply pipe connection in this utility model.

[0020] In the diagram: 1. Aluminum ash grinding and pulping device; 2. Fluidized bed reactor; 3. Rotary separator; 4. Heat exchanger; 5. Preheat exchanger; 6. Solid collector; 7. Dilute ammonia water collector; 8. Brine collector; 9. Vent valve; 10. Baffle plate; 11. Water supply pipe. Detailed Implementation

[0021] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the utility model more thorough and comprehensive.

[0022] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Please refer to the appendix carefully. Figure 1-2 A device for secondary aluminum ash hydrolysis includes a hydrolysis reaction mechanism comprising a fluidized bed reactor 2, a solid collector 6, a dilute ammonia water collector 7, and a brine collector 8, all connected by pipelines. The fluidized bed reactor 2 is connected via pipelines to an aluminum ash grinding and slurry preparation device 1, a heat exchanger 4, and a rotary separator 3. The rotary separator 3 is connected via pipelines to a preheater 5. The shell-side inlet of the preheater 5 is equipped with a water supply pipe 11, and the shell-side outlet of the preheater 5 is connected to the tube-side inlet of the heat exchanger 4. The tube-side outlet of the heat exchanger 4 is connected via a pipeline between the aluminum ash grinding and slurry preparation device 1 and the fluidized bed reactor 2.

[0025] This device constructs a highly efficient and environmentally friendly secondary aluminum ash hydrolysis system through the coordinated design of structure and process: On the one hand, by combining a fluidized bed reactor 2 with a baffle plate 10 structure, the reaction path is extended through full contact between gas, solid and liquid in the fluidized state, thereby achieving continuous and efficient conversion of secondary aluminum ash hydrolysis and significantly improving the hydrolysis efficiency of aluminum nitride (AlN). On the other hand, a two-stage heat exchanger 4 is innovatively set up to use the high-temperature steam and waste heat of the reaction liquid generated by hydrolysis for preheating and replenishing water, forming a closed-loop heat recovery, significantly improving energy utilization and reducing external energy consumption requirements.

[0026] Heat exchanger 4: Utilizes waste heat from the gas phase (high temperature ammonia and water vapor) to preheat water for subsequent pulping or system water use, thus achieving energy recovery.

[0027] Preheater 5: Utilizes the residual heat of the separated liquid (temperature higher than that of the makeup water) to preheat the water flow in the makeup water pipe 11 a second time, thus recovering energy.

[0028] The specific operation is as follows: First, the secondary aluminum ash enters the aluminum ash grinding and pulping device 1, and after grinding and refining, water is added to make slurry. To prevent the slurry from settling and agglomerating, the pulping time must be strictly controlled. The prepared slurry is transported to the bottom of the fluidized bed reactor 2, and after being fully mixed with the makeup water, it enters the inner cavity of the reactor. In the fluidized bed reactor 2, the slurry and steam are in fluidized contact, which promotes the hydrolysis of components such as aluminum nitride in the aluminum ash. The liquid after the reaction overflows from the inner cavity to the annular gap between the outer wall of the fluidized bed and the inner cavity. The 10-baffle design enhances the turbulence of the liquid, prolongs the residence time, and further improves the hydrolysis reaction efficiency.

[0029] The water vapor and ammonia generated during the reaction are introduced into the heat exchanger 4 through the top pipe of the fluidized bed reactor 2. The steam flows in the shell side of the heat exchanger 4 to preheat the makeup water in the tube side. After heat recovery, it condenses to form dilute ammonia water, which is stored in the dilute ammonia water collector 7. The fully reacted reaction liquid is discharged from the bottom valve of the fluidized bed reactor 2 and enters the rotary separator 3 for solid-liquid separation. The separated solid residue is collected in the solid collector 6, while the separated brine is preheated in the tube side of the preheater 5 to preheat the makeup water in the shell side. After secondary heat recovery, it becomes cold brine and enters the brine collector 8. The entire process achieves high efficiency and maximizes resource utilization in the hydrolysis treatment of aluminum ash through the coordinated operation of various devices.

[0030] Please refer to the appendix carefully. Figure 1 The shell-side inlet of the heat exchanger 4 and the outlet of the fluidized bed reactor 2 are connected by a pipe. The heat from ammonia and water vapor is used to heat the makeup water, while simultaneously the ammonia and water vapor exchange heat to cool it down. Multiple baffles 10 are installed on both sides of the inner wall of the fluidized bed reactor 2 shell, with the baffles 10 evenly spaced and alternating. This ensures sufficient contact between the gas, solid, and liquid in the fluidized state and extends the reaction path, achieving continuous and efficient conversion of secondary aluminum ash hydrolysis and significantly improving the aluminum nitride hydrolysis efficiency. A vent valve 9 is installed at the top of the fluidized bed reactor 2 shell. This vent valve 9 allows for automatic or manual venting when the pressure in the fluidized bed reactor 2 or the system abnormally increases (such as steam accumulation or blockage), releasing excess gas and ensuring... The device is safe. The shell-side outlet of the heat exchanger 4 and the dilute ammonia water collector 7 are connected by a pipeline. The dilute ammonia water collector 7 collects and stores the dilute ammonia water generated during the hydrolysis reaction and provides a buffer space for subsequent ammonia water recycling or treatment. The tube-side inlet of the preheat exchanger 5 is connected to the outlet of the rotary separator 3 by a pipeline, and the tube-side outlet of the preheat exchanger 5 is connected to the brine collector 8 for heat exchange and cooling of the brine. The solid outlet of the rotary separator 3 is connected to the solid collector 6 by a pipeline. The solid collector 6 collects and temporarily stores the solid residue after the hydrolysis reaction and solid-liquid separation, and provides a buffer and transfer space for the subsequent harmless treatment or resource utilization of the residue.

[0031] The present invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. An apparatus for secondary aluminum ash hydrolysis, comprising a hydrolysis reaction mechanism, said hydrolysis reaction mechanism comprising a fluidized bed reactor (2), a solid collector (6), a dilute ammonia water collector (7), and a brine collector (8), connected by pipelines, characterized in that, The fluidized bed reactor (2) is connected to an aluminum ash grinding and slurry preparation device (1), a heat exchanger (4) and a rotary separator (3) via pipes. The rotary separator (3) is connected to a preheat exchanger (5) via pipes. The shell-side inlet of the preheat exchanger (5) is equipped with a water supply pipe (11). The shell-side outlet of the preheat exchanger (5) is connected to the tube-side inlet of the heat exchanger (4). The tube-side outlet of the heat exchanger (4) is connected to the pipeline between the aluminum ash grinding and slurry preparation device (1) and the fluidized bed reactor (2) via pipes.

2. The apparatus for secondary aluminum ash hydrolysis according to claim 1, characterized in that, The shell-side inlet of the heat exchanger (4) and the outlet of the fluidized bed reactor (2) are connected by a pipe.

3. The apparatus for secondary aluminum ash hydrolysis according to claim 2, characterized in that, The fluidized bed reactor (2) has multiple baffles (10) on both sides of the inner wall of the shell, and the baffles (10) on each side are distributed alternately at equal intervals.

4. The apparatus for secondary aluminum ash hydrolysis according to claim 3, characterized in that, The fluidized bed reactor (2) is equipped with a vent valve (9) at the top of its shell.

5. The apparatus for secondary aluminum ash hydrolysis according to claim 2, characterized in that, The shell-side outlet of the heat exchanger (4) and the dilute ammonia water collector (7) are connected by a pipe.

6. The apparatus for secondary aluminum ash hydrolysis according to claim 1, characterized in that, The tube inlet of the preheater (5) is connected to the outlet of the rotary separator (3) by a pipe, and the tube outlet of the preheater (5) is connected to the brine collector (8).

7. The apparatus for secondary aluminum ash hydrolysis according to claim 6, characterized in that, The solid discharge port of the rotary separator (3) is connected to the solid collector (6) via a pipe.

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