Waste heat recovery device for electrolytic aluminum electrolytic bath

Abstract

The invention relates to a heat exchanger, and particularly discloses an electrolytic aluminum electrolytic bath waste heat recovery device which comprises a tank body, a plurality of heat conduction plates vertically arranged on the side wall of the tank body, a heat exchanger in sliding connection with the heat conduction plates and a supporting device used for supporting the heat exchanger. The heat exchanger comprises a heat exchange plate close to the heat conduction plate, a plurality of heat conduction strips arranged on the side, close to the heat conduction plate, of the heat exchange plate, a supporting plate arranged on the side, away from the heat conduction plate, of the heat exchange plate, a circulating water device and a sealing strip. Heat conduction gaps are formed between the adjacent heat conduction plates, one heat conduction strip is clamped in one heat conduction gap, and the sealing strips are used for connecting the side edges of the heat exchange plates and the side edges of the supporting plates. A heat exchange cavity is defined by the heat exchange plate, the supporting plate and the sealing strip, and the circulating water device communicates with the heat exchange cavity. According to the waste heat recovery device for the electrolytic aluminum electrolysis bath, the heat exchange efficiency can be effectively adjusted according to the electrolysis process.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and in particular to a waste heat recovery device for an aluminum electrolytic cell. Background Art

[0002] Electrolytic aluminum is aluminum obtained by electrolysis. Modern electrolytic aluminum industry production adopts cryolite-alumina molten salt electrolysis. Molten cryolite is the solvent, alumina is the solute, carbonite is the anode, and aluminum liquid is the cathode. After a strong direct current is passed through, an electrochemical reaction is carried out at the two electrodes in the electrolytic cell at 950℃-970℃, that is, electrolysis.

[0003] A large amount of heat is generated in the process of electrolysis of aluminum, and most of this heat is dissipated into the air through the electrolytic cell, resulting in a waste of energy. Therefore, some electrolytic cells are also equipped with waste heat recovery, that is, a corresponding heat exchanger is arranged on the side wall of the electrolytic cell to achieve the purpose of waste heat recovery. However, the heat dissipated by the electrolytic cell in the early stage of electrolysis is very large, and a higher waste heat recovery efficiency is required at this time. However, the medium in the heat exchanger is usually difficult to withstand the high temperature, and in the later stage of electrolysis, the electrolytic cell needs to be insulated. Therefore, the heat exchange efficiency needs to be significantly reduced at this time, and it is difficult for conventional heat exchangers to make real-time adjustments according to the above situation. Summary of the invention

[0004] The object of the present invention is to provide a waste heat recovery device for an aluminum electrolytic cell, which can effectively adjust the heat exchange efficiency according to the electrolysis process.

[0005] The present invention is achieved through the following technical solutions: the waste heat recovery device of the electrolytic aluminum electrolytic cell of the present invention comprises a cell body, a plurality of heat-conducting plates vertically arranged on the side walls of the cell body, a heat exchanger slidably connected to the heat-conducting plates, and a supporting device for supporting the heat exchanger; the heat exchanger comprises a heat-exchange plate arranged close to the heat-conducting plate, a plurality of heat-conducting strips arranged on the side of the heat-exchange plate close to the heat-conducting plate, a supporting plate arranged on the side of the heat-exchange plate away from the heat-conducting plate, a circulating water device, and a sealing strip; a heat-conducting gap is arranged between adjacent heat-conducting plates, one heat-conducting strip is stuck in one of the heat-conducting gaps, and the sealing strip is used to connect the side of the heat-exchange plate and the side of the support plate; the heat-exchange plate, the support plate and the sealing strip enclose a heat-exchange cavity, and the circulating water device is connected to the heat-exchange cavity.

[0006] Furthermore, two sides of the heat-conducting strip are respectively in contact with the heat-conducting plates adjacent thereto.

[0007] Furthermore, the angle between the heat conducting plate and the outer wall of the tank body is 45-60 degrees.

[0008] Furthermore, the heat conducting strip is a hollow structure, and the interior of the heat conducting strip is connected to the heat exchange cavity.

[0009] Furthermore, the sealing strip is made of elastic high-temperature resistant rubber material.

[0010] Furthermore, the support plate is fixedly connected to the trough body via a support device.

[0011] Furthermore, the circulating water device includes a water inlet pipe connected to the lower end of the heat exchange chamber, a water pump connected to the water inlet pipe, and a drain pipe connected to the upper end of the heat exchange chamber.

[0012] Furthermore, a pressure valve is provided on the drain pipe.

[0013] Furthermore, a plurality of V-shaped spring sheets are provided in the heat exchange cavity, one end of the spring sheet is fixedly connected to the inner wall of the heat exchange plate, and the other end of the spring sheet is fixedly connected to the inner wall of the support plate.

[0014] Furthermore, the supporting device includes a plurality of vertically arranged support rods and a plurality of connecting blocks arranged on the sides of the support rods; the plurality of support rods are distributed along the length direction of the trough body, both ends of the support rods are fixedly connected to the outer wall of the trough body, and the connecting blocks are connected to the outer wall of the support plate.

[0015] The technical solution of the present invention has at least the following advantages and beneficial effects: the waste heat recovery device of the electrolytic aluminum electrolytic cell of the present invention, when in use, the circulating water device sends low-temperature water into the heat exchange chamber, and the water is discharged after being heated in the heat exchange chamber, so as to achieve the effect of heat reuse. During the electrolysis of the cell body, a large amount of heat is transferred to the heat conduction plate on the outer wall of the cell body, and then transferred to the heat conduction bar through the heat conduction plate, and then transferred to the heat conduction plate through the heat conduction bar, and finally transferred to the inner wall of the heat exchange chamber, so as to achieve the effect of heating the water in the heat exchange chamber. Since the heat-conducting strip and the heat-conducting plate are not completely fixedly connected, the position of the heat-conducting strip can be moved in the horizontal direction, and then the contact area between the heat-conducting strip and the heat-conducting plate can be adjusted to adjust the heat transfer efficiency, and finally the purpose of heat exchange efficiency can be achieved. In this way, the heat recovery efficiency can be adjusted in real time for different stages of the electrolysis process. For example, during electrolysis, a large amount of heat will be generated instantly. At this time, the heat-conducting strip can be moved close to the tank body to increase the contact area between the heat-conducting strip and the heat-conducting plate, and the heat exchange efficiency can be improved (the heat-conducting strip and the heat-exchange plate can also be protected by reducing the heat exchange efficiency). It can also better reduce the temperature of the tank body to avoid excessive temperature. In the later stage, when heat preservation is needed to prevent the electrolyte from solidifying during the discharge process, the heat-conducting strip can be moved away from the tank body, reducing the contact area between the heat-conducting strip and the heat-conducting plate, and reducing the rate of heat loss in the tank body. Therefore, the device can better adjust the heat exchange rate in real time according to the needs of the tank body and the electrolysis process, and can better protect the tank body while making full use of electrolysis preheating, and does not affect the original production of electrolytic aluminum. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a waste heat recovery device for an aluminum electrolytic cell provided in an embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the structure inside the waste heat recovery device for an electrolytic aluminum cell provided in an embodiment of the present invention;

[0018] Figure 3 A schematic diagram of the structure of a heat conducting plate provided in an embodiment of the present invention;

[0019] Figure 4 A schematic structural diagram of a heat-conducting strip portion provided in an embodiment of the present invention;

[0020] Figure 5 for Figure 2 Enlarged view of part A.

[0021] Icons: 11- trough body, 12- support rod, 13- connection block, 14- heat conduction plate, 21- support plate, 22- heat exchange plate, 23- heat conduction strip, 24- sealing strip, 25- heat exchange chamber, 26- spring clip, 31- water inlet pipe, 32- drain pipe, 33- pressure valve. DETAILED DESCRIPTION

[0022] Example

[0023] The following is further described in conjunction with specific embodiments. Figure 1 -Attached Figure 5 As shown, the waste heat recovery device of the electrolytic aluminum electrolytic cell of this embodiment includes a cell body 11, a plurality of heat conducting plates 14 vertically arranged on the side walls of the cell body 11, a heat exchanger slidably connected to the heat conducting plates 14, and a supporting device for supporting the heat exchanger; the heat exchanger includes a heat exchange plate 22 arranged near the heat conducting plate 14, a plurality of heat conducting strips 23 arranged on the side of the heat exchange plate 22 close to the heat conducting plate 14, a supporting plate 21 arranged on the side of the heat exchange plate 22 away from the heat conducting plate 14, a circulating water device, and a sealing strip 24; a heat conducting gap is provided between adjacent heat conducting plates 14, one heat conducting strip 23 is stuck in one of the heat conducting gaps, and the sealing strip 24 is used to connect the side of the heat exchange plate 22 and the side of the support plate 21; the heat exchange plate 22, the support plate 21 and the sealing strip 24 enclose a heat exchange cavity 25, and the circulating water device is connected to the heat exchange cavity 25. Specifically, when in use, the circulating water device delivers low-temperature water into the heat exchange chamber 25, and the water is discharged after being heated in the heat exchange chamber 25, so as to achieve the effect of heat recycling. During the electrolysis process of the tank body 11, a large amount of heat is transferred to the heat conducting plate 14 on the outer wall of the tank body 11, and then transferred to the heat conducting strip 23 through the heat conducting plate 14, and then transferred to the heat conducting plate 14 through the heat conducting strip 23, and finally transferred to the inner wall of the heat exchange chamber 25, so as to achieve the effect of heating the water in the heat exchange chamber 25. Since the heat conducting strip 23 and the heat conducting plate 14 are not completely fixedly connected, the position of the heat conducting strip 23 can be moved in the horizontal direction, and then the contact area between the heat conducting strip 23 and the heat conducting plate 14 can be adjusted to adjust the heat transfer efficiency, and finally the purpose of heat exchange efficiency can be achieved. In this way, the heat recovery efficiency can be adjusted in real time for different stages of the electrolysis process. For example, during electrolysis, a large amount of heat will be generated instantly. At this time, the heat conducting strip 23 can be moved close to the tank body 11 to increase the contact area between the heat conducting strip 23 and the heat conducting plate 14, improve the heat exchange efficiency, and better reduce the temperature of the tank body 11 to avoid excessive temperature. In the later stage, when heat preservation is required to prevent the electrolyte from solidifying during the discharge process, the heat conducting strip 23 can be moved away from the tank body 11 to reduce the contact area between the heat conducting strip 23 and the heat conducting plate 14, and reduce the rate of heat loss in the tank body 11. Therefore, the device can better adjust the heat exchange rate in real time according to the needs of the tank body 11 and the electrolysis process, and can better protect the tank body 11 while making full use of the electrolysis preheating, and does not affect the original electrolytic aluminum production.

[0024] The two sides of the heat conducting strip 23 in this embodiment are respectively in contact with the adjacent heat conducting plate 14. Specifically, this can increase the contact area between the heat conducting strip 23 and the heat conducting plate 14 and improve the heat conduction efficiency.

[0025] In this embodiment, the angle between the heat conducting plate 14 and the outer wall of the tank body 11 is 45-60 degrees. Specifically, this can better increase the width of the heat conducting strip 23 and the heat conducting plate 14 within a limited width, thereby increasing the contact area and heat conduction efficiency of the two.

[0026] The heat conducting strip 23 in this embodiment is a hollow structure, and the interior of the heat conducting strip 23 is connected to the heat exchange chamber 25. Specifically, the heat exchange chamber 25 can accommodate more water, and the contact area between the water and the heat conducting strip 23 is larger, so the heating effect of the water is better.

[0027] The sealing strip 24 in this embodiment is made of elastic high temperature resistant rubber material. The support plate 21 is fixedly connected to the tank body 11 through a support device. Specifically, since the support plate 21 is fixed and the sealing strip 24 is made of elastic material (the sealing strip 24 is a ring-shaped structure), the heat exchange plate 22 is a movable structure. In this way, the gap between the support plate 21 and the heat exchange plate 22 can be adjusted by adjusting the amount of water in the heat exchange chamber 25, thereby adjusting the contact area and heat exchange efficiency between the heat conductive strip 23 and the heat conductive plate 14. By increasing the water storage amount in the heat exchange chamber 25, the heat exchange chamber 25 can be expanded, thereby pushing the heat exchange plate 22 and the heat conductive strip 23 to the side close to the heat conductive plate 14, thereby increasing the contact area and heat exchange efficiency between the heat conductive plate 14 and the heat conductive strip 23. Conversely, by reducing the water storage amount in the heat exchange chamber 25, the heat exchange plate 22 and the heat conductive strip 23 will move away from the heat conductive plate 14, thereby reducing the contact area and heat exchange efficiency between the heat conductive plate 14 and the heat conductive strip 23.

[0028] The circulating water device in this embodiment includes a water inlet pipe 31 connected to the lower end of the heat exchange chamber 25, a water pump connected to the water inlet pipe 31, and a drain pipe 32 connected to the upper end of the heat exchange chamber 25. A pressure valve 33 is provided on the drain pipe 32. Specifically, when it is necessary to increase the heat exchange efficiency, the water pressure of the water pump can be increased, and the drainage pressure of the pressure valve 33 can be increased, so that the water pressure and water storage capacity in the heat exchange chamber 25 can be increased, so that the heat exchange plate 22 is away from the support plate 21. When it is necessary to reduce the heat exchange efficiency, the drainage pressure of the pressure valve 33 can be reduced, and the water in the heat exchange chamber 25 can be discharged faster, so that the water capacity in the heat exchange chamber 25 can be reduced, so that the heat exchange plate 22 moves toward the support plate 21.

[0029] In the heat exchange cavity 25 of the present embodiment, a plurality of V-shaped spring pieces 26 are provided, one end of the spring piece 26 is fixedly connected to the inner wall of the heat exchange plate 22, and the other end is fixedly connected to the inner wall of the support plate 21. Specifically, the function of the spring piece 26 is that when the heat conductive strip 23 moves, the tension of the spring piece 26 on the heat exchange plate 22 and the heat conductive strip 23 is always perpendicular to the support plate 21, and since the heat conductive strip 23 and the heat conductive plate 14 are both inclined, under the action of the spring piece 26, the heat conductive strip 23 will be more inclined to be in close contact with the heat conductive plate 14 on one side thereof, so that the contact efficiency between the heat conductive plate 14 and the heat conductive strip 23 can be guaranteed as much as possible (since the heat conductive plate 14 and the heat conductive strip 23 are movable structures, there must be a gap between the two. If the heat conductive strip 23 cannot fully contact the heat conductive plates 14 on both sides, the heat exchange efficiency is difficult to guarantee). The second function of the spring 26 is to apply continuous pulling force to the heat exchange plate 22. When the drainage pressure of the pressure valve 33 is reduced, under the pulling force of the spring 26, the heat exchange plate 22 can approach the support plate 21 and squeeze out the water therein, wherein the spring 26 can be replaced by a spring.

[0030] The supporting device in this embodiment includes a plurality of vertically arranged support rods 12, and a plurality of connecting blocks 13 arranged on the sides of the support rods 12; the plurality of support rods 12 are distributed along the length direction of the trough body 11, and both ends of the support rods 12 are fixedly connected to the outer wall of the trough body 11, and the connecting blocks 13 are connected to the outer wall of the support plate 21.

[0031] In summary, in the waste heat recovery device for the electrolytic aluminum reduction cell of this embodiment, when in use, the circulating water device sends low-temperature water into the heat exchange chamber 25, and the water is discharged after being heated in the heat exchange chamber 25, so as to achieve the effect of heat recycling. During the electrolysis process of the cell body 11, a large amount of heat is transferred to the heat conduction plate 14 on the outer wall of the cell body 11, and is transferred to the heat conduction bar 23 through the heat conduction plate 14, and is transferred to the heat conduction plate 14 through the heat conduction bar 23, and finally transferred to the inner wall of the heat exchange chamber 25, so as to achieve the effect of heating the water in the heat exchange chamber 25. Since the heat conducting strip 23 and the heat conducting plate 14 are not completely fixedly connected, the position of the heat conducting strip 23 can be moved in the horizontal direction, and then the contact area between the heat conducting strip 23 and the heat conducting plate 14 can be adjusted to adjust the heat transfer efficiency, and finally the purpose of heat exchange efficiency can be achieved. In this way, the heat recovery efficiency can be adjusted in real time for different stages of the electrolysis process. For example, during electrolysis, a large amount of heat will be generated instantly. At this time, the heat conducting strip 23 can be moved close to the tank body 11 to increase the contact area between the heat conducting strip 23 and the heat conducting plate 14, improve the heat exchange efficiency, and better reduce the temperature of the tank body 11 to avoid excessive temperature. In the later stage, when heat preservation is required to prevent the electrolyte from solidifying during the discharge process, the heat conducting strip 23 can be moved away from the tank body 11 to reduce the contact area between the heat conducting strip 23 and the heat conducting plate 14, and reduce the rate of heat loss in the tank body 11. Therefore, the device can better adjust the heat exchange rate in real time according to the needs of the tank body 11 and the electrolysis process, and can better protect the tank body 11 while making full use of the electrolysis preheating, and does not affect the original electrolytic aluminum production. The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waste heat recovery device for an aluminum electrolytic cell, characterized in that: It comprises a tank body (11), a plurality of heat conducting plates (14) vertically arranged on the side walls of the tank body (11), a heat exchanger slidably connected to the heat conducting plates (14), and a supporting device for supporting the heat exchanger; The heat exchanger comprises a heat exchange plate (22) arranged close to the heat conduction plate (14), a plurality of heat conduction strips (23) arranged on a side of the heat exchange plate (22) close to the heat conduction plate (14), a support plate (21) arranged on a side of the heat exchange plate (22) away from the heat conduction plate (14), a circulating water device, and a sealing strip (24); A heat conduction gap is provided between adjacent heat conduction plates (14), one heat conduction strip (23) is inserted into one of the heat conduction gaps, and the sealing strip (24) is used to connect the side edge of the heat exchange plate (22) and the side edge of the support plate (21); The heat exchange plate (22), the support plate (21) and the sealing strip (24) enclose a heat exchange cavity (25), and the circulating water device is in communication with the heat exchange cavity (25).

2. The waste heat recovery device for aluminum electrolysis cell according to claim 1, characterized in that: Both sides of the heat-conducting strip (23) are in contact with the heat-conducting plates (14) adjacent thereto respectively.

3. The waste heat recovery device for aluminum electrolysis cell according to claim 1, characterized in that: The included angle between the heat conducting plate (14) and the outer wall of the tank body (11) is 45-60 degrees.

4. The waste heat recovery device for aluminum electrolysis cell according to claim 3 is characterized in that: The heat conducting strip (23) is a hollow structure, and the interior of the heat conducting strip (23) is connected to the heat exchange cavity (25).

5. The waste heat recovery device for aluminum electrolysis cell according to claim 1, characterized in that: The sealing strip (24) is made of elastic high-temperature resistant rubber material.

6. The waste heat recovery device for aluminum electrolysis cell according to claim 5, characterized in that: The support plate (21) is fixedly connected to the tank body (11) via a support device.

7. The waste heat recovery device for aluminum electrolysis cell according to claim 6, characterized in that: The circulating water device comprises a water inlet pipe (31) communicating with the lower end of the heat exchange chamber (25), a water pump connected to the water inlet pipe (31), and a drain pipe (32) communicating with the upper end of the heat exchange chamber (25).

8. The waste heat recovery device for aluminum electrolysis cell according to claim 7, characterized in that: The drainage pipe (32) is provided with a pressure valve (33).

9. The waste heat recovery device for aluminum electrolysis cell according to claim 8, characterized in that: A plurality of V-shaped spring sheets (26) are arranged in the heat exchange cavity (25); one end of the spring sheet (26) is fixedly connected to the inner wall of the heat exchange plate (22), and the other end is fixedly connected to the inner wall of the support plate (21).

10. The waste heat recovery device for aluminum electrolysis cell according to claim 6, characterized in that: The supporting device comprises a plurality of vertically arranged supporting rods (12), and a plurality of connecting blocks (13) arranged on the sides of the supporting rods (12); The plurality of support rods (12) are distributed along the length direction of the trough body (11); both ends of the support rods (12) are fixedly connected to the outer wall of the trough body (11); and the connection block (13) is connected to the outer wall of the support plate (21).

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