Device for avoiding back flushing and carrying of aluminum electrolysis conveyed materials

Abstract

The utility model discloses a device for avoiding back flushing and carrying of aluminum electrolysis conveyed materials, which comprises a material box, an exhaust pipe and a feeding pipe are vertically arranged on the material box, and the lower end of the exhaust pipe and the lower end of the feeding pipe both extend into an inner cavity of the material box; the exhaust pipe comprises an inner pipe and an outer pipe which are arranged in a sleeved mode, and a damping strip is arranged between the inner pipe and the outer pipe to form a spiral rising structure. By means of the feeding pipe and the exhaust pipe extending into the material box and the damping strip arranged between the inner pipe and the outer pipe, the problem that a large amount of aluminum oxide and gas are exhausted from the exhaust pipe in the aluminum oxide ultra-concentrated phase conveying process of the electrolytic cell, and consequently a large amount of aluminum oxide is stored in the shell area is effectively solved; and the problems of furnace wall melting, rapid anode explosion, pole separation, reduction of primary aluminum quality, poor current efficiency and the like caused by too thick insulating layer of the electrolytic cell are solved, the safety risk that the operator scalds the aluminum oxide on the shell surface during transportation is avoided, and the device is economical and practical.

Description

Technical Field

[0001] The utility model relates to the field of aluminum electrolysis production equipment, in particular to a device for preventing aluminum electrolysis material feeding from back-blowing. Background Art

[0002] Energy conservation and consumption reduction during electrolytic aluminum production have always been a key focus and challenge in production management, impacting the economic benefits of enterprises and serving as a means to enhance their viability and competitiveness. The current conveying method used in domestic electrolytic cell designs utilizes the fluidization properties of alumina particles for super-dense phase conveying. Super-dense phase conveying equipment includes a chute, air supply pipes, a variable-frequency centrifugal fan, and a control system. The chute consists of a material flow layer, a permeable fabric layer, an air chamber layer, and a balancing column. The principle is that air, pressurized by a variable-frequency centrifugal fan, flows through the air supply pipes to the chute's air chamber, then through the permeable fabric to the material flow layer, filling the gaps in the powdered material layer. When the airflow reaches a certain velocity, the original equilibrium between the powder particles is disrupted, resulting in an increase in volume and a decrease in density. The internal friction between the particles and the friction angle with the chute wall approach zero, thus fluidizing the powdered material. This characteristic of the powdered material is exploited, and combined with valves in the chute air supply pipes, the pressure in each chute section is adjusted to create a pressure differential. The balancing column at the top removes excess air, allowing the material to flow from the higher pressure section to the lower pressure section.

[0003] However, due to significant variations in the design, fabrication, installation, process, materials, and operational factors of super-dense phase conveying equipment, a large amount of alumina and gas is discharged from the exhaust pipe of the material box during the super-dense phase conveying of alumina in the electrolytic cell. This results in a large amount of alumina remaining on the electrolytic cell shell, requiring manual cleaning, which significantly increases the intensity and workload. Furthermore, the high temperature of the electrolytic cell shell creates a safety hazard of burns during the cleaning process. Furthermore, the large amount of discharged alumina can easily cause the alumina insulation layer on the electrolytic cell shell to become too thick, placing it in a hot zone. This can lead to problems such as melting of the furnace side, rapid anode explosion, and depolarization, affecting the quality of the raw aluminum, reducing current efficiency, and even causing cell failure. Utility Model Content

[0004] The utility model provides a device for preventing back-blowing of materials during aluminum electrolysis feeding, with the purpose of solving the problem that during the aluminum electrolysis feeding process, alumina in the material box is discharged to the shell surface of the electrolytic cell along with pressurized gas, resulting in a large amount of material piles that need to be manually cleaned, and the cleaning process has great safety hazards and low work efficiency.

[0005] To achieve its purpose, the utility model adopts the following technical solutions:

[0006] A device for preventing back-blowing of aluminum electrolysis feed, comprising a material box, on which an exhaust pipe and a feed pipe are vertically provided, wherein the lower ends of the exhaust pipe and the feed pipe extend into the inner cavity of the material box; the exhaust pipe comprises an inner pipe and an outer pipe which are sleeved, and a damping strip is provided between the inner pipe and the outer pipe.

[0007] Furthermore, the length of the pipe extending from the lower ends of the exhaust pipe and the feed pipe into the inner cavity of the material box is H1, and H1=100~1500mm.

[0008] Furthermore, the outlet of the inner tube is lower than the outlet of the outer tube, and the height difference H2 is 10-15 mm.

[0009] Furthermore, the damping strip is spirally wound between the inner tube and the outer tube, and a plurality of openings are equidistantly provided on the damping strip.

[0010] Furthermore, the length of the opening of the spiral damping strip is 1 / 4 of the arc length of the inner diameter of the outer tube.

[0011] Furthermore, the spacing between the openings of adjacent spiral damping strips is 1 / 4 of the arc length of the inner diameter of the outer tube, and they are disconnected at intervals of 1 / 4 of the arc length, so that the damping strip as a whole is in a spiral ascending shape.

[0012] Furthermore, the horizontal inclination angle of the damping strip is α, α=30-45°.

[0013] Furthermore, the thickness of the damping strip is 1 to 2 mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. The device for avoiding back-blowing of aluminum electrolysis feeding provided by the utility model effectively solves the problem that a large amount of alumina and gas are discharged from the exhaust pipe of the material box during the super-dense phase transportation of alumina in the electrolytic cell, resulting in a large amount of alumina on the shell area. It also solves the problems of workers pulling alumina due to the excessive thickness of the insulation layer of the electrolytic cell, such as melting of the furnace wall, rapid explosion of the anode, depolarization, reduced quality of raw aluminum, and poor current efficiency. It avoids the safety risk of workers being burned by hot alumina when pulling the shell surface, and has good economic practicality, simple structure, low modification cost, and flexible operation.

[0016] 2. The device provided by the present invention is used to avoid the back-blowing of aluminum electrolysis feeding. The exhaust pipe is arranged into a set of inner and outer pipes, so that the outlet of the inner pipe is lower than the outlet of the outer pipe, ensuring that the material discharged from the exhaust pipe can fall between the inner and outer pipes and is not discharged outside. At the same time, a section of inclined and discontinuous damping strip is serpentine-wound between the inner and outer pipes, so that the aluminum oxide with smaller particles rises from the exhaust pipe under the action of pressurized gas. After encountering the damping plate, the gas pressure decreases with the increase of height and the number of damping plates, so that the aluminum oxide impurities fall into the material box under the action of gravity. In addition, the damping strip is provided with multiple openings. The material falling into the outer pipe through the inner pipe does not accumulate on the damping strip, but falls into the material box through the opening and continues to be used, thereby saving material resources and reducing production and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 for Figure 1 A top view of

[0019] Figure 3 for Figure 1 Schematic diagram of the structure of the intermediate material box and exhaust pipe;

[0020] Figure 4 for Figure 3 A magnified view of the internal structure at center A;

[0021] Figure 5 for Figure 4 Cross-sectional view at the middle BB;

[0022] In the figure: 1- material box; 2- exhaust pipe; 3- feed pipe; 4- inner pipe; 5- outer pipe; 6- damping strip. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] like Figure 1-5 As shown, the present invention is a device for preventing back-blowing of aluminum electrolysis feed, comprising a feed box 1, on which an exhaust pipe 2 and a feed pipe 3 are vertically inserted, and the lower ends of the exhaust pipe 2 and the feed pipe 3 extend into the inner cavity of the feed box 1. The extended pipe length H1 = 100 mm is determined according to the size of the feed box volume. The exhaust pipe 2 includes an inner tube 4 and an outer tube 5, and the outlet of the inner tube 4 is 10 mm lower than the outlet of the outer tube 5. A damping strip 6 with a thickness of 1 mm is spirally wound between the inner tube 4 and the outer tube 5. The damping strip 6 is provided with multiple openings at equal intervals. Specifically, the length of the opening of the spiral damping strip 6 is 1 / 4 of the arc length of the inner diameter of the outer tube 5. The spacing between the openings of adjacent spiral damping strips 6 is also 1 / 4 of the arc length of the inner diameter of the outer tube 5, and they are disconnected at intervals of 1 / 4 of the arc length. The entire damping strip 6 forms a spiral ascending structure, and the horizontal inclination angle of the damping strip 6 is α = 30°.

[0025] Before feeding aluminum electrolysis, adjust the operating parameters according to the electrolytic cell manual, adjust the super-dense phase conveying process parameters, adjust the centrifugal fan frequency to 25-28Hz, and gradually adjust the fan pressure from 5800Pa to 4900Pa and the flow rate from 7200m 3 / min adjusted to 4200m 3 / min. Next, adjust the opening of each valve at the fluorine-carrying bin discharge port to ensure that the amount of fluorine-carrying alumina flowing into the chute reaches 2 / 3 of the chute's sight glass. This ensures space for gas and material fluidization, and that the material does not occupy the space in the balance column bags, allowing excess gas to be discharged from the bags and increasing the material flow rate to 1.5m / s. Next, adjust the opening of the valves in the air supply line to ensure that the pressure corresponding to the opening of each chute section decreases sequentially, creating a decreasing pressure differential between each chute section and ensuring efficient material flow within the chute.

[0026] When using this device for feeding, alumina material is fed into bin 1 via feed pipe 3. A large amount of alumina sinks to the bottom of bin 1, while some smaller alumina particles (less than 45 μm) rise with the pressurized gas and are discharged from exhaust pipe 2. Because exhaust pipe 2 comprises a nested inner and outer tubes 4 and 5, with the outlet of inner tube 4 lower than that of outer tube 5, material discharged from exhaust pipe 2 falls between the inner and outer tubes 4 and 5, preventing it from being discharged externally. Simultaneously, an inclined, discontinuous damping strip 6 is wound in a serpentine pattern between the inner and outer tubes 4 and 5. This allows the smaller alumina particles to rise from exhaust pipe 2 under the influence of the pressurized gas. Upon encountering damping plates 6, the gas pressure decreases with increasing height and the number of damping plates 6, allowing the alumina impurities to fall by gravity into bin 1. In addition, the damping strip 6 is provided with a plurality of openings, so that the material falling into the outer tube 5 through the inner tube 4 does not accumulate on the damping strip 6, preventing the resistance of the exhaust pipe 2 from increasing. Instead, the material falls into the material box 1 through the opening and continues to be used, saving material resources and reducing production and maintenance costs.

Claims

1. A device for preventing back-blowing of aluminum electrolysis feed, comprising a feed box (1), wherein an exhaust pipe (2) and a feed pipe (3) are vertically provided on the feed box (1), characterized in that: The lower ends of the exhaust pipe (2) and the feed pipe (3) extend into the inner cavity of the material box (1); the exhaust pipe (2) comprises a sleeved inner pipe (4) and an outer pipe (5), and a damping strip (6) is provided between the inner pipe (4) and the outer pipe (5).

2. The device for preventing back-blowing of aluminum electrolysis feed according to claim 1, characterized in that: The length of the pipes extending from the lower ends of the exhaust pipe (2) and the feed pipe (3) into the inner cavity of the material box (1) is H1, where H1 = 100 to 1500 mm.

3. The device for preventing back-blowing of aluminum electrolysis feed according to claim 2, characterized in that: The outlet of the inner tube (4) is lower than the outlet of the outer tube (5), and the height difference H2 is 10-15 mm.

4. The device for preventing back-blowing of aluminum electrolysis feed according to claim 2, characterized in that: The damping strip (6) is spirally wound between the inner tube (4) and the outer tube (5), and a plurality of openings are equidistantly provided on the damping strip (6).

5. The device for preventing back-blowing of aluminum electrolysis feed according to claim 4, characterized in that: The length of the opening of the spiral damping strip (6) is 1 / 4 of the arc length of the inner diameter of the outer tube (5).

6. The device for preventing back-blowing of aluminum electrolysis feed according to claim 5, characterized in that: The spacing between the openings of adjacent spiral damping strips (6) is 1 / 4 of the arc length of the inner diameter of the outer tube (5), and they are disconnected at intervals of 1 / 4 of the arc length, and the damping strips (6) are formed into a spiral rising shape as a whole.

7. A device for preventing back-blowing of aluminum electrolysis feed according to any one of claims 1 to 6, characterized in that: The horizontal inclination angle of the damping strip (6) is α, α=30-45°.

8. A device for preventing back-blowing of aluminum electrolysis feed according to any one of claims 1 to 6, characterized in that: The thickness of the damping strip (6) is 1 to 2 mm.

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