An internal heat exchange device for an electrolytic cell

Abstract

The utility model relates to aluminum electrolysis technical field, especially a kind of internal heat exchange device of electrolytic cell, including main blowing pipe, several branch pipes and air supply component, main blowing pipe is set in the upper portion position of tank, air supply component and main blowing pipe are connected, main blowing pipe is inserted into electrolytic cell and is covered with material and tank shell between the buffer cavity is provided, several branch pipes are evenly distributed in the side of main blowing pipe, for evenly blowing hot air into buffer cavity.In the utility model, by sending temperature controllable hot air (temperature is lower than tank but higher than environment) to the high-temperature cavity between the covering material and tank shell inside electrolytic cell, a mild "temperature buffer zone" is established between high-temperature area in tank and environment, actively guide heat gentle release, so that the cooling of each part of tank body is realized synchronously, evenly, slowly, fundamentally avoid the thermal stress overproof and lining structure damage caused by excessively large cooling gradient.

Description

Technical Field

[0001] This utility model relates to the field of aluminum electrolysis technology, and in particular to a heat exchange device inside an electrolytic cell. Background Technology

[0002] After the aluminum electrolytic cell is shut down, its internal refractory materials, cathode carbon blocks, and steel tank shell undergo a natural cooling process from a high temperature. If this cooling process is not controlled, it can lead to excessively rapid temperature drop, generating enormous thermal stress in the electrolytic cell lining and steel structure—a phenomenon known as thermal shock. This thermal shock is one of the main causes of cracks in the electrolytic cell lining, spalling of the refractory material, damage to the cathode carbon blocks, and irreversible deformation of the tank shell.

[0003] Damage to the lining and tank structure can severely weaken the structural integrity and stability of an electrolytic cell. For electrolytic cells requiring a second start-up, such damage will directly lead to a deterioration in post-startup operation, reduced current efficiency, and shortened lifespan. For electrolytic cells undergoing major overhaul, severe thermal shock damage will significantly increase the cost and difficulty of the overhaul.

[0004] Currently, in terms of thermal shock resistance, existing technologies mostly focus on passively improving the structural design and material selection of the electrolytic cell itself, such as using refractory materials with better thermal shock resistance or optimizing the reinforcement structure of the cell shell. However, these methods are preventative measures, costly, and cannot solve the problem of active cooling management under the specific operating condition of cell shutdown. Utility Model Content

[0005] In view of the technical problems existing in the background art, the utility model provides a carbon block repair device on the side of an electrolytic cell to solve the above-mentioned problems.

[0006] To achieve the above objectives, the technical solution provided by this utility model is as follows: An internal heat exchange device for an electrolytic cell includes a main air duct, several branch pipes, and an air supply assembly. The main air duct is located at the upper part of the cell, and the air supply assembly is connected to the main air duct. The main air duct extends through the upper part of the cell into the electrolytic cell. A buffer cavity is provided between the covering material and the cell shell. Several branch pipes are evenly distributed on one side of the main air duct to blow hot air evenly into the buffer cavity.

[0007] Preferably, the branch pipe adopts a segmented structure design, which includes an end pipe and a throat pipe. The end pipe is respectively located on both sides of the throat pipe, and the diameter of the end pipe is larger than the diameter of the throat pipe.

[0008] Preferably, a number of through negative pressure holes are provided at the position of the throat tube, the negative pressure holes are connected to the throat tube, and the negative pressure holes and the throat tube are arranged perpendicular to each other in the axial direction.

[0009] Preferably, a filter element is provided on the outside of the branch pipe. The filter element includes an annular convex plate and a filter cover. The annular convex plate is disposed outside the negative pressure hole, and the filter cover is detachably connected to one end of the annular convex plate.

[0010] Preferably, the air supply assembly includes a long-shaft fan, a heating plate, and a deflector. The air supply assembly is installed on a truck. The front end of the deflector is provided with a diversion port, and one end of the main air pipe is connected to the diversion port.

[0011] Preferably, the air supply unit is connected to the truck via a bracket.

[0012] Preferably, the heating plate is in the form of a box and is located at the front end of the fan blades of the long-shaft fan.

[0013] Preferably, the drainage shroud is located on one side of the heating plate and has a conical structure.

[0014] This utility model has the following advantages and beneficial effects: Achieving controllable cooling and effectively preventing thermal shock: By blowing temperature-controlled hot air (temperature lower than inside the tank but higher than the environment) into the high-temperature cavity between the covering material and the tank shell inside the electrolytic cell, a mild "temperature buffer zone" is established between the high-temperature area inside the tank and the environment. This actively guides the gradual release of heat, enabling synchronous, uniform, and slow cooling of all parts of the tank. This fundamentally avoids excessive thermal stress and damage to the inner lining structure caused by excessive cooling gradient. Attached Figure Description

[0015] Figure 1 This is a schematic diagram showing the installation position of an internal heat exchange device for an electrolytic cell according to the present invention. Figure 2 This is a schematic diagram of the main air pipe and branch pipe of the heat exchange device inside an electrolytic cell proposed in this utility model; Figure 3 This is a cross-sectional view of the main air pipe and branch pipe of the heat exchange device inside an electrolytic cell proposed in this utility model. Figure 4 for Figure 3 A magnified view of a portion of the image; Figure 5 This is a schematic diagram of the air supply component structure of an internal heat exchange device for an electrolytic cell proposed in this utility model; Figure 6 This is a cross-sectional view of the air supply component of an internal heat exchange device for an electrolytic cell proposed in this utility model.

[0016] Reference numerals: 1-Tank shell, 11-Covering material, 2-Main air duct, 3-Branch pipe, 31-End pipe, 32-Throat pipe, 321-Negative pressure hole, 322-Annular convex plate, 323-Filter cover, 4-Air supply assembly, 41-Long shaft fan, 42-Heating plate, 43-Drainage cover, 44-Diverter port, 45-Bracket, 5-Truck. Detailed Implementation

[0017] 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 some embodiments of this utility model, but not all embodiments.

[0018] 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.

[0019] Example like Figures 1-6 As shown, a heat exchange device inside an electrolytic cell has the core function of actively, uniformly, and controllably managing heat exchange in key areas inside the electrolytic cell after shutdown, in order to guide the cell to cool down smoothly. The device includes a main air duct 2, several branch pipes 3, and an air supply assembly 4.

[0020] like Figures 1-4 As shown, multiple main air ducts 2 and branch ducts 3 are installed inside the electrolytic cell. The main air duct 2, as the core trunk line of the system, is typically made of high-temperature resistant alloy steel or stainless steel, possessing sufficient strength and heat resistance to withstand the high-temperature radiation environment near the electrolytic cell inlet. Its diameter is designed according to the required total air volume, and one end is connected to the output end of the air supply assembly 4 via a high-temperature resistant flexible connecting pipe or flange. During installation, the main air duct 2 passes through a pre-reserved dedicated interface at the top of the electrolytic cell, allowing its main body to extend into the cell's interior space.

[0021] Several branch pipes 3 are welded at a vertical angle or connected to one side of the main air pipe 2 through quick connectors, arranged in a comb shape. The branch pipes 3 are connected to the main air pipe 2, and the air outlet of the branch pipes 3 is suspended above the covering material 11 and in the buffer cavity formed by the side wall of the tank shell 1.

[0022] Branch pipe 3 comprises end pipe 31 and throat pipe 32, and its structure adopts a three-section combination structure of "end pipe 31-throat pipe 32-end pipe 31". The end pipes 31 at both ends have the same diameter and are conical in shape, while the throat pipe 32, located in the middle, has a significantly smaller diameter than the end pipes 31 and is cylindrical in shape. When airflow flows from end pipe 31 into throat pipe 32, the sudden reduction in flow cross-sectional area leads to a sharp increase in flow velocity, and the static pressure at this point will decrease significantly, thus forming a local negative pressure zone on the pipe wall of throat pipe 32. On the pipe wall of this negative pressure zone, several through negative pressure holes 321 are uniformly opened circumferentially. These negative pressure holes 321 are the key structure for realizing "secondary air induction", which can guide the airflow in the buffer cavity into branch pipe 3 and increase the turbulence of the airflow inside the electrolytic cell.

[0023] Considering that alkaline dust, volatile fluorides and other particulate matter often exist in the cavity inside the electrolytic cell, in order to prevent these impurities from being sucked into the pipe through the negative pressure hole 321 and causing blockage or corrosion, this device is specially equipped with a filter on the outside of the throat section of the branch pipe.

[0024] The filter element consists of two parts: an annular convex plate 322 and a filter cover 323. The annular convex plate 322 serves as a fixed mounting base, securely connected to the outer wall of the branch pipe by welding, and completely covers the area where the negative pressure hole 321 of the throat section is located. The filter cover 323 is a detachable cover, preferably made of high-temperature and corrosion-resistant stainless steel wire mesh sintered plate or woven mesh, with sufficient porosity to ensure smooth airflow while effectively intercepting solid particles larger than micrometers. The filter cover 323 is sealed and fixed to the annular convex plate 322 by a threaded connection. This detachable design allows operators to easily remove the filter cover 323 for cleaning or replacement when it accumulates dust due to long-term use, ensuring the long-term operational efficiency and reliability of the device.

[0025] To achieve high flexibility and versatility of the device and avoid the need to install expensive equipment in each electrolytic cell, the air supply assembly 4 is integrated into a standard truck 5, forming a mobile heat exchange station.

[0026] like Figures 5-6As shown, the air supply assembly 4 is the power and thermal core of the device, mainly including a long-shaft fan 41, a heating plate 42, and a draft hood 43. The long-shaft fan 41 provides a stable airflow with sufficient pressure and volume. For example, a long-shaft fan 41 of model KL-90 can be used. The heating plate 42 is usually a resistance heater, arranged on the air outlet duct of the long-shaft fan 41. Its power is precisely adjusted by an external temperature control system to heat the intake ambient air to a preset target temperature. This target temperature is a core control parameter, and its set value must be higher than the ambient temperature but significantly lower than the current temperature inside the electrolytic cell. For example, when the ambient temperature is 25°C and the temperature inside the cell is 800°C, the target temperature can be set between 150-300°C to establish a gentle heat transfer gradient between the high temperature inside the cell and the low temperature inside the environment. The air intake hood 43 is connected to one end of the heating plate 42. Its structure is designed as a tapered cone with a diversion port 44 at the front end for quick connection with multiple main air pipes 2. The entire air supply assembly 4 is mounted on the cargo deck of the truck 5 by a sturdy metal bracket 45, ensuring stability during transportation and operation, while preventing the temperature of the heating plate 42 from being directly transferred to the deck.

[0027] Working Principle: When one of the electrolytic cells in the series is shut down, a truck 5 carrying a mobile air supply assembly 4 approaches the electrolytic cell. The operator reliably connects the inlet of the main air duct 2 to the branch pipe port 44 of the air supply assembly 4's duct cover 43. After the system is started, the long-shaft fan 41 begins to work, drawing in ambient air. The ambient air flows through the heating plate 42, which is in operation, and is heated to a preset precise temperature, forming primary hot air. The primary hot air is distributed through the main air duct 2 and enters each branch pipe 3. Inside the branch pipe 3, the primary hot air first flows through the inlet end pipe 31 and then enters the throat pipe 32. In the throat pipe 32 section, due to the Venturi effect, the high-speed airflow generates a strong suction at the negative pressure hole 321. This suction, through the external filter cover 323, draws a portion of the high-temperature secondary air from the electrolytic cell cavity into the throat pipe 32. Primary hot air (from air supply component 4, temperature controllable) and secondary hot air (from the cavity inside the tank, higher temperature) are thoroughly mixed and exchange heat in the throat pipe 32 and the outlet pipe 31. This process achieves two key objectives: first, to further homogenize the outlet air temperature and avoid local overcooling; and second, to promote the micro-circulation of the gas within the cavity inside the tank, thereby enhancing the overall temperature uniformity.

[0028] The final airflow, after mixing and conditioning, is blown out from the end of the branch pipe 3, acting directly and evenly on the entire cavity above the covering material 11. This precisely temperature-controlled mixed airflow continuously and gently absorbs heat from the tank and carries the heat out of the tank through its own flow (or dissipates heat through convection), thereby reducing the temperature inside the electrolytic cell at a predictable and gradual rate. By monitoring the temperature changes inside the tank in real time and adjusting the outlet air temperature and airflow of the air supply component 4 accordingly, closed-loop precise control of the entire cooling process can be achieved. This ensures that the electrolytic cell safely and smoothly passes through the temperature range with the highest risk of thermal shock due to excessively rapid cooling, ultimately achieving the fundamental goal of protecting the integrity of the lining and structure.

[0029] The above content is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat exchange device for an internal electrolytic cell, characterized in that, It includes a main air duct, several branch pipes, and an air supply assembly. The main air duct is located at the upper part of the tank. The air supply assembly is connected to the main air duct. The main air duct extends through the upper part of the tank and into the electrolytic cell. A buffer cavity is provided between the covering material and the tank shell. Several branch pipes are evenly distributed on one side of the main air duct and are used to blow hot air into the buffer cavity.

2. The heat exchange device inside an electrolytic cell according to claim 1, characterized in that, The branch pipe adopts a segmented structure design, which includes an end pipe and a throat pipe. The end pipe is respectively located on both sides of the throat pipe, and the diameter of the end pipe is larger than the diameter of the throat pipe.

3. The heat exchange device inside an electrolytic cell according to claim 2, characterized in that, Several through negative pressure holes are provided at the location of the throat tube. The negative pressure holes are connected to the throat tube and are arranged perpendicular to each other in the axial direction.

4. The heat exchange device inside an electrolytic cell according to claim 3, characterized in that, A filter element is provided on the outside of the branch pipe. The filter element includes an annular convex plate and a filter cover. The annular convex plate is located outside the negative pressure hole, and the filter cover is detachably connected to one end of the annular convex plate.

5. The heat exchange device inside an electrolytic cell according to claim 1, characterized in that, The air supply assembly includes a long-shaft fan, a heating plate, and a deflector. The air supply assembly is installed on a truck. A diversion port is provided at the front end of the deflector, and one end of the main air pipe is connected to the diversion port.

6. The heat exchange device inside an electrolytic cell according to claim 5, characterized in that, The air supply assembly is connected to the truck via a bracket.

7. The heat exchange device inside an electrolytic cell according to claim 5, characterized in that, The heating plate, in a box-shaped structure, is positioned at the front end of the fan blades of the long-shaft fan.

8. The heat exchange device inside an electrolytic cell according to claim 5, characterized in that, The drainage hood is located on one side of the heating plate and has a conical structure.

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