An apparatus for recycling residual energy of spent anodes during the electrolytic aluminum process

Abstract

The present invention discloses a device for recycling the residual energy of spent anodes during the electrolytic aluminum process, comprising: a new anode heating chamber including a plurality of new anode heating positions, one of which is position A and one is position B. Position A serves as the starting end of the new anode heating chamber, and position B serves as the ending end of the new anode heating chamber. The new anode moves from position A to position B; a spent anode oxidation chamber including a plurality of spent anode oxidation positions, one of which is position C and one is position D. Position C serves as the starting end of the spent anode oxidation chamber, and the spent anode moves from position C to position D; the starting end of the spent anode oxidation chamber is connected to the ending end of the new anode heating chamber through a circulation channel; a circulation fan for sucking the flue gas from position A and sending it to position D; and a blower arranged at position D. By releasing the residual energy of the spent anode, the present invention can heat the new anode to above 850 °C, thereby reducing the power consumption caused by the low-temperature anode absorbing heat during the electrolytic aluminum process.

Description

Technical Field

[0001] The present invention relates to the field of heat recovery and utilization, and particularly to a device for recovering residual energy of residual anodes during the electrolytic aluminum process. Background Art

[0002] The electrolytic aluminum process consumes a large amount of electrical energy. At the same time, due to the low energy utilization rate during the electrolytic aluminum process, the production of electrolytic aluminum is a high-energy-consuming industry. The energy utilization rate in the electrolytic aluminum production process is less than 50%, and more than half of the input energy is lost as waste heat in various forms. Among these waste heats, the flue gas waste heat and the sidewall waste heat account for a relatively large amount. However, due to the high temperature of the residual anodes, they also carry away about 4% of the waste heat, and the grade of the waste heat is relatively high.

[0003] If the waste heat of the residual anodes is recovered, not only can heat waste be reduced, but also the power consumption per ton of aluminum can be reduced. In fact, in addition to waste heat, the residual anodes also have a large amount of chemical energy. Oxidizing the anodes in a closed space releases heat, which is used to heat the new anodes, thereby reducing the heat absorption required when the new anodes are first placed in the electrolytic cell. At the same time, the high-temperature flue gas after waste heat recovery can enter the upper part of the electrolytic cell to further recover waste heat. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a device for recovering residual energy of residual anodes during the electrolytic aluminum process to recover the waste heat of the residual anodes.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A device for recovering residual energy of residual anodes during the electrolytic aluminum process, comprising:

[0007] A new anode heating chamber, including several new anode heating positions, one of which is position A and one is position B. Position A serves as the starting end of the new anode heating chamber, and position B serves as the ending end of the new anode heating chamber. The new anodes move from position A to position B;

[0008] A residual anode oxidation chamber, including several residual anode oxidation positions, one of which is position C and one is position D. Position C serves as the starting end of the residual anode oxidation chamber, and the residual anodes move from position C to position D; The starting end of the residual anode oxidation chamber is connected to the ending end of the new anode heating chamber through a circulation channel;

[0009] A circulation fan, used to suck the flue gas from position A and send it to position D to absorb the waste heat of the flue gas. The circulation fan needs to be high-temperature resistant and plays a role in heat equalization;

[0010] A blower, arranged at position D, provides a small amount of air to provide the necessary oxygen for the oxidation of the residual anodes and supply heat released by the oxidation of the residual anodes.

[0011] Furthermore, the residual anode energy recovery device in the aluminum electrolysis process further includes:

[0012] A waste heat recovery device, which is connected to the beginning of the new electrode heating chamber through a pipeline.

[0013] Furthermore, the residual anode energy recovery device in the aluminum electrolysis process further includes a new electrode cover plate. The overall shape of the new electrode cover plate is a "hui" character. The two sides are placed on the enclosure structure, and the hole in the middle is sleeved on the electrode rod and moves with the new electrode in the heating chamber.

[0014] Furthermore, the waste heat recovery device is used to heat alumina powder, and this part of heat is brought back to the electrolytic cell through the alumina powder. Subsequently, a heat exchanger can be further arranged to heat hot water or produce steam.

[0015] Furthermore, at least two to three residual anodes are placed in the residual anode oxidation chamber as heat sources to ensure the continuity of the production process and the heating process.

[0016] Furthermore, heat insulation layers are provided around the new electrode heating chamber and the residual anode oxidation chamber. On the one hand, it ensures the high-temperature environment in the heating chamber and the heating quality. On the other hand, it reduces the impact of the high-temperature environment on the workshop.

[0017] Furthermore, the residual anode energy recovery device in the aluminum electrolysis process further includes a track, which is used to move the residual anode one grid towards the D position, adopting the moving and sealing methods of a car-bottom furnace or a shuttle kiln to ensure that the electrode can move in a stepping manner therein.

[0018] Furthermore, in the A position, there is also a smoke exhaust channel leading to the electrolytic cell smoke exhaust system.

[0019] Furthermore, in the A position, B position, C position, and D position, a cover plate opening and assembly system is equipped; after removing the cover plate, putting in the electrode, using a crane to transfer the new electrode into the heating chamber, and then covering the cover plate; at the same time, after heating, removing the cover plate, and then using a crane to take out the heated electrode for slot installation, and the process is electrically controlled.

[0020] Furthermore, an observation hole is provided at the D position.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The present invention can heat a new anode to a temperature above 850°C by releasing the remaining energy of the spent anode, thereby reducing the power consumption caused by the low-temperature anode absorbing heat during the electrolytic aluminum process. The present invention can utilize the waste heat carried by the spent anode to heat the new anode. By introducing appropriate air to oxidize the spent anode and release heat, the new anode can be heated to a higher temperature, or more new anodes can be heated. By removing the covering material on the spent anode, fluoride emissions can be reduced. At the same time, the present invention can also heat the alumina raw material, and the effect can also well reduce the power consumption per ton of aluminum.

[0023] The present invention recovers the waste heat of the spent anode, which can not only reduce heat waste but also reduce the power consumption per ton of aluminum. In fact, in addition to waste heat, the spent anode also has a large amount of chemical energy. Oxidizing the anode in a closed space to release heat for heating the new anode, thereby reducing the heat absorption required when the new anode is first placed in the electrolytic cell. At the same time, the high-temperature flue gas after waste heat recovery can enter the upper part of the electrolytic cell to further recover waste heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the composition of the device for recovering and utilizing the remaining energy of the spent anode during the electrolytic aluminum process provided by an embodiment of the present invention;

[0025] In the figure: 1. New electrode heating chamber; 2. Spent electrode oxidation chamber; 3. Circulation fan; 4. Blower; 5. Circulation channel; 6. Waste heat recovery device; 7. New electrode cover plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] Embodiment:

[0027] The technical solution of the present invention will be further described below with reference to the drawings and embodiments.

[0028] Refer to Figure 1 As shown, the device for recovering and utilizing the remaining energy of the spent anode during the electrolytic aluminum process provided by this embodiment mainly includes a new electrode heating chamber 1, a spent electrode oxidation chamber 2, a circulation fan 3, and a blower 4.

[0029] Among them, the new electrode heating chamber 1 includes several new electrode heating positions. In this embodiment, it specifically includes eight new electrode heating positions, one of which is position A and one is position B. Position A is the starting end of the new electrode heating chamber, and position B is the ending end of the new electrode heating chamber. The new electrode moves from position A to position B.

[0030] The spent anode oxidation chamber 2 also includes eight spent anode oxidation positions, one of which is position C and one is position D. Position C is the starting end of the spent anode oxidation chamber. The spent anodes regularly move from position C to position D in the spent anode oxidation chamber. In the spent anode oxidation chamber 2, on the one hand, the waste heat of the spent anodes can be recovered, and on the other hand, the chemical energy of the spent anodes can be continuously released through oxidation to heat the flue gas and heat the new anodes. The starting end of the spent anode oxidation chamber 2 is connected to the end of the new anode heating chamber 1 through the circulation channel 5. The circulation fan 3 is used to suck the flue gas from position A and send it to position D, mainly to fully absorb the waste heat of the flue gas. The circulation fan needs to be heat-resistant and plays a role in heat equalization. Since there is a lack of oxygen in the circulating flue gas, it only plays a circulating role. The circulation fan 3 sends the high-temperature flue gas heated by the new anodes at position A to the rear of position D, and then after passing through each spent anode, it enters the circulation channel. When the temperature reaches the highest, it reaches position B, so that the new anodes can be preheated to the highest at position B. The new anodes are lifted into from position A, move in the opposite direction to the flue gas flow, fully recover the heat, and are lifted out from position B and then put into the electrolytic cell. The spent anodes are lifted into from position C, and the high-temperature waste heat enters the new anode heating chamber 1 along the air duct.

[0031] The blower 4 is arranged at position D to supply a small amount of air for the oxidation heat release of the spent anodes. By blowing a certain amount of air through the blower 4, the necessary oxygen is provided for the oxidation of the spent anodes to release more heat, further ensuring the heating of the new anodes. The new anodes can be heated to above 850 °C, thus reducing the power consumption caused by the low-temperature anodes absorbing heat during the electrolytic aluminum process. An observation hole is arranged at position D. After the oxidation of the spent anodes at position D is completed, the anode rod is lifted out, and at the same time, the spent anodes are moved one grid towards position D through the track. The moving and sealing methods of a car-bottom furnace or a shuttle kiln are adopted to ensure that the electrodes can move in a stepping manner therein.

[0032] Thus, it can be seen that this device can heat the new anodes to above 850 °C by releasing the remaining energy of the spent anodes, thus reducing the power consumption caused by the low-temperature anodes absorbing heat during the electrolytic aluminum process. The present invention can use the waste heat carried by the spent anodes to heat the new anodes. By adding appropriate air and oxidizing the spent anodes to release heat, the new anodes can be heated to a higher temperature and more new anodes can also be heated. By removing the covering material on the spent anodes, the fluoride emissions can be reduced.

[0033] As a preferred embodiment of the above-mentioned residual energy recovery device of the residual anode in the electrolytic aluminum process, the device also includes a waste heat recovery device 6, which is connected to the beginning of the new anode heating chamber 1 through a pipeline. Because there is a blower 4 at the D position to continuously send air to oxidize the residual anode, high-temperature flue gas is continuously released after the waste heat recovery device 6. By using this part of the waste heat to heat the alumina, this part of the heat is brought back to the electrolytic cell through the alumina powder, thereby reducing the original need to use electricity to heat this part of the alumina powder to above 900°C, thereby significantly reducing the power consumption per ton of aluminum. After recovering this part of the waste heat, the flue gas enters the electrolytic cell exhaust system for unified treatment. In addition, the waste heat recovery device 6 can be further arranged with a heat exchanger for heating hot water or producing steam.

[0034] As another preferred embodiment of the above-mentioned residual anode residual energy recovery and utilization device in the electrolytic aluminum process, the device also includes a new electrode cover plate 7. The new electrode cover plate 7 is independent and looks like a Chinese character "回". Both sides are placed on the enclosure structure. The middle hole is mounted on the electrode rod and has sealing measures. It moves with the new electrode in the heating chamber. It can not only ensure the sealing effect of the system, but also expose the anode guide rod outside the system, making the system more compact. After each new electrode is hoisted in, the new anode cover plate is covered. At position A, there is also a smoke exhaust channel leading to the electrolytic cell smoke exhaust system, which helps to simplify the flue gas treatment system and ensure the flue gas treatment effect. Move with the new electrode in the heating chamber. At position B, after the heating process is completed, the new electrode cover plate is first removed, and then the new electrode is hoisted into the electrolysis for use.

[0035] In addition, positions A, B, C, and D are equipped with cover opening and assembly systems. Remove the cover, put in the electrode, use the overhead crane to transfer the new electrode to the heating chamber, and then cover the cover. At the same time, after heating, remove the cover, and use the overhead crane to take out the heated electrode for slot loading. The process is electrically controlled. A transmission mechanism is set under the new electrode. The transmission power is electric energy, which is driven by a motor. The specific structure is the same as that of a car-bottom furnace or a trolley furnace. The temperature at the bottom is relatively low, and a heat insulation layer is arranged on the trolley, and the new electrode is placed on the insulation layer.

[0036] In a specific embodiment, heat-insulating layers are provided around the new electrode heating chamber 1 and the spent electrode oxidation chamber 2. On the one hand, it ensures the high-temperature environment in the heating chamber and the heating quality. On the other hand, it reduces the impact of the high-temperature environment on the workshop. At least two to three spent electrodes are placed in the spent electrode oxidation chamber 2 as heat sources to ensure the continuity of the production process and the heating process. In this way, not only the waste heat of the spent electrodes can be recovered, but also the residual energy of the spent electrodes can be further recovered. By appropriately blowing air, the spent electrodes are oxidized to release heat. If there are not enough spent electrodes, biomass materials can be appropriately considered for heating, and there is no additional carbon emission during the process. Finally, the flue gas of the system enters the large exhaust system, and the exhaust volume of the exhaust system is controlled to ensure zero pressure in the system. The sealing and heat insulation of the upper parts of the new electrode heating chamber and the spent electrode oxidation chamber should always be well done. The circulation fan 3 is a high-temperature fan, and neither the air volume nor the air pressure needs to be too high, as long as it can form a circulation in the heating chamber and the oxidation chamber. Since it is a high-temperature fan, the fan shaft and blades need to be made of high-temperature-resistant materials, and the electrodes are connected in a D type.

[0037] The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose is to enable those ordinary skilled in the art to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the essence of the content of the present invention should be covered within the protection scope of the present invention.

Claims

1. An apparatus for recycling residual energy of spent anodes in the electrolytic aluminum process, characterized in that, Comprising: A new anode heating chamber, including several new anode heating positions, one of which is position A and one is position B. Position A serves as the starting end of the new anode heating chamber, and position B serves as the ending end of the new anode heating chamber. The new anode moves from position A to position B. A spent anode oxidation chamber, including several spent anode oxidation positions, one of which is position C and one is position D. Position C serves as the starting end of the spent anode oxidation chamber, and the spent anode moves from position C to position D. The starting end of the spent anode oxidation chamber is connected to the ending end of the new anode heating chamber through a circulation channel. A circulation fan, used to suck the flue gas from position A and send it to position D to absorb the waste heat of the flue gas. A blower, arranged at position D, to provide the necessary oxygen for the oxidation of the spent anode. It further includes a track, used to move the spent anode one grid towards position D, adopting the moving and sealing methods of a car-bottom furnace or a shuttle kiln to ensure that the electrode moves in a stepping manner therein.

2. The device for recycling residual anode energy in the electrolytic aluminum process according to claim 1, wherein It further comprises: A waste heat recovery device, connected to the starting end of the new anode heating chamber through a pipeline.

3. The device for recycling the residual energy of the spent anode in the electrolytic aluminum process according to claim 1 or 2, wherein It further includes a new anode cover plate. The whole new anode cover plate is in the shape of a "return" character. The two sides are placed on the enclosure structure, and the hole in the middle is sleeved on the electrode rod and moves with the new anode in the heating chamber.

4. The residual anode energy recovery and utilization device in the electrolytic aluminum process according to claim 2, characterized in that, The waste heat recovery device is used to heat the alumina powder, and this part of the heat is brought back to the electrolytic cell through the alumina powder.

5. The device for recycling the residual energy of the spent anode in the electrolytic aluminum process according to claim 1, wherein, At least two spent anodes are placed in the spent anode oxidation chamber as heat sources.

6. The device for recycling residual anode energy in the electrolytic aluminum process according to claim 1, characterized in that, Heat insulation layers are provided around the new anode heating chamber and the spent anode oxidation chamber.

7. The residual anode energy recovery and utilization device in the electrolytic aluminum process according to claim 1, characterized in that , In position A, there is also a smoke exhaust channel leading to the electrolytic cell smoke exhaust system.

8. The device for recycling residual energy of spent anodes in the electrolytic aluminum process according to claim 1, characterized in that , Cover opening and assembly systems are equipped at positions A, B, C, and D. Remove the cover plate, put in the electrode, use the overhead crane to transfer the new anode into the heating chamber, and then cover the cover plate. At the same time, after heating, remove the cover plate, and then use the overhead crane to take out the heated electrode for slot installation, and the process is electrically controlled.

9. The device for recycling the residual energy of the spent anode in the electrolytic aluminum process according to claim 1, wherein An observation hole is arranged at position D.

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