RU2059019C1 - Apparatus for raw material feeding of aluminum electrolyzer in two storey housings - Google Patents

Abstract

FIELD: apparatuses for row material feeding of aluminum electrolyzer in two storey housings. SUBSTANCE: electrolyzer feeding distribution system has additional bunker 2 mounted near electrolyzer base and linked with upper bunker 1 direct canals 3 and reverse canals 4 of airlift. In the case lower additional bunker 2 is made in the form of cyclone with tangential inlet of branch pipe to feed alumina from transportation means and from reverse canal of centralized distribution of alumina. Upper part of outlet branch pipe 18 has hole to release air. Bunker 2 has filter 19 to purify air. Upper end of direct canal 3 of airlift has diffuser 5 mounted vertically downward in inclined airchute of upper bunker 2. Lower part of bunker 8 has horizontal rack in projection of canal 7, connecting measuring out in doses bunker 8 with airchute 6. Airchute 6 has filters 9 to purify outgoing air and in the case filtering surface of every each filter is bigger than previous one along path of alumina motion in airchute. EFFECT: increased productivity. 7 cl, 4 dwg

Description

 The invention relates to the electrolytic production of aluminum and can be used on electrolyzers with a top current lead and self-baking anodes for feeding them alumina and other similar materials.

 A known electrolyzer for producing aluminum (AS USSR N 1560636, class C 25 C 3/14, 1988), containing an anode device with a gas collection bell, a device for supplying raw materials connected to an alumina distribution system, a punch with a rod placed in the pipe and a drive and a dispenser in the form of a glass with windows, mounted coaxially to the stem of the punch, in which, to increase reliability and reduce environmental pollution, the pipe in its lower part is connected to the cavity of the gas collection bell, and the windows in the glass of the dispenser are made in two rows, and the glass installed in the pipe with the ability to move, and the upper part of the rod is made in the form of a piston placed in a glass.

 The disadvantages of the known design include the following: the complexity of the design of the feeding device, combining both the dispenser and the punch; significant energy consumption during the operation of these devices associated with punching the electrolyte crust in the alumina feed zone; insignificant service life of the device due to abrasive wear of structural elements, as well as the impact of aggressive melt on the working bodies.

 A known electrolyzer for producing aluminum, adopted as a prototype (ed. St. N 1712467, class C 25 C 3/06, 1990), including an anode casing, bell gas collector, devices for feeding alumina to the bell-shaped space, connected to a raw material distribution system, working bodies for introducing alumina into the electrolyte, connected to drives for mixing them. The cell is equipped with a lower beam [-shaped, covering it on two longitudinal and one end sides, the ends of which above the gas collection bell are pivotally mounted on the periphery of the longitudinal sides of the anode casing, and its middle part is connected to the vertical displacement drive located at the top of the anode casing by two upper beams installed along the respective longitudinal sides of the cell above the lower beam, one end of each upper beam is pivotally mounted on the anode casing from the side of the drive a, and the middle part of each upper beam is pivotally connected to the lower beam with the possibility of their movement relative to each other, and the working bodies are installed in the podkolokolnom space and are fixed on the lower and upper beams, while one part of the working bodies located after the hinge is fixed on the upper beam.

 The disadvantages of the known design include the following: the hopper mounted on the electrolyzer has too large dimensions, which complicates the processing of the anode, for example, rearranging the pins, filling the anode mass, etc. on the other hand, reducing the dimensions of the hopper increases the complexity of maintenance associated with the need its constant replenishment with alumina especially floor-standing machines.

 The aim of the invention is to reduce the complexity and improve ease of maintenance of the cell.

 The goal is achieved by the fact that in the electrolyzer containing a system for distributing alumina into the podkolokolnoy space connected to the system of distribution of alumina, made in the form of a hopper with aerogloves, and the working bodies for introducing alumina into the electrolyte, the distribution system of alumina is equipped with an additional lower hopper installed at the base the electrolyzer and the direct and reverse airlift channels connected to the upper hopper; the lower hopper is made in the form of a cyclone with a tangential entry of pipes for entering alumina from vehicles and from the return channel from the airlift; the cyclone is equipped with a filter for air outlet; the upper end of the direct airlift channel is equipped with a diffuser mounted vertically down in the upper hopper.

 The installation of an additional hopper at the base of the electrolyzer at a zero mark allows it to be of a sufficiently large size, providing, for example, a daily supply of raw materials for each electrolyzer, or even one hopper for two adjacent electrolysers. This reduces the frequency of loading the hopper especially floor-standing machines and reduces the complexity of the maintenance of the cell.

 In the known design, the large dimensions of the hopper make it difficult to process the anode, and the small dimensions increase the complexity of servicing the cell.

 The small dimensions of the upper hopper mounted on the electrolyzer, allow you to set the aerogloo obliquely to the horizon at an angle close to the angle of repose of alumina, and to increase the reliability of the distribution system of alumina, which does not require high pressure in aeroguites.

 A device for the automatic loading of aluminum electrolyzers is known (USSR patent N 1063293 A, class C 25 C 3/14, 1979). A similar feature of the proposed and known devices is the presence of a main (pressure) hopper installed outside the electrolytic cell operating zone, and an intermediate one mounted on the electrolyzer, as well as the fact that in both cases the two hoppers are connected by pneumatic drives.

 The difference between the proposed design and the known one is that, in addition to the direct pipeline (channel), there is also a reverse one, which ensures the return of excess alumina from the upper (intermediate) hopper to the lower (main pressure) one, i.e. it forms an airlift. This embodiment requires some small increase in energy for the transportation of alumina, but it increases the reliability of the pneumatic conveying system, since in this case, the upper hopper, despite its small size, is always filled with alumina. In addition, this embodiment does not require monitoring the level of alumina in the upper hopper during operation.

 The known design does not have a return pipe (channel), so it requires the installation of a large intermediate hopper, as well as careful adjustment of the pneumatic transport system.

 In FIG. 1 shows a diagram of alumina transport; figure 2 and 3 of the loading scheme of alumina in the upper hopper; figure 4 is a diagram of the supply of alumina from the aeroflot into the metering hoppers (the lower part of the metering hopper is rotated).

 The device contains two systems: a system for distributing raw materials (alumina) and a system for supplying alumina to the bell-shaped space. The raw material distribution system comprises an upper hopper 1 mounted on the electrolyzer and connected to the lower additional hopper 2 by direct 3 and return 4 channels of the airlift. The upper end of the direct channel 3 of the airlift is equipped with a diffuser 5, mounted vertically downward in the upper hopper 1. The upper hopper 1 is much smaller than the lower hopper 2.

 The raw material distribution system is connected to the alumina supply system to the pod-bell space by an aeroglove 6, the upper end of which is connected to the lower part of the hopper 1. Mounted on the electrolyzer at an angle close to the angle of repose of the alumina, the aerogelut 6 is connected by channels 7 to the hoppers 8 of the dosing unit for feeding alumina into electrolyzer.

 The aero chute 6 is equipped with several filters 9 for air outlet, and the filtering surface of each subsequent filter is larger than the previous one in the course of moving alumina in the aero chute 6. The aero chute 6 is provided with a pipe 10 with openings 11 for supplying compressed air to the aerial chute.

 The lower hopper 2 has nozzles 12, 13 from vehicles, for example from a floor machine and a channel for centralized distribution of alumina (TsRG).

 The nozzles 12, 13 have a tangential entry into the hopper (cyclone) 2.

 In the lower part of the hopper 2 there is a metering device made in the form of a box 14 and a wind tunnel 15 with openings 16 for air passage. Box 14 through channel 17 is connected to channel 3 of the elevator. The lower hopper (cyclone) 2 has an exhaust pipe 18 for air outlet with a filter 19 and openings 20. The pipe from the channel 4 is tangentially connected to the pipe 18.

 To reduce the pressure of the alumina-air mixture from the aeroflot 6 on the dosing unit, there is a horizontal shelf 21 in the projection of the channel 7 connecting the dosing hopper 8 with the aeroflot 6 at the bottom of the hopper 8. At the top of the hopper 8, at a distance exceeding the angle of repose 22 of the alumina, filter 23 is installed for air outlet.

 The metering unit in the lower part of the hopper 8 has an aerotube 24 with openings 25 for air outlet, an inclined shelf 26 and an opening 27 for the passage of the alumina-air mixture through the channel 28 into the poplite space of the cell.

 The mechanism for introducing alumina into the electrolyte contains a lower beam 29 [-shaped, one end of which is secured by hinges 30 to the anode casing 31, and the other end is connected to a vertical displacement drive 32 installed in the end part of the anode casing. Above the lower beam, on each longitudinal side of the electrolyzer, there is an upper beam 33, which is fixed at one end by the hinge 34 to the anode casing 31 and its middle part is connected to the lower beam 29 by the hinge 35. Workers are fixed on the lower and upper beams bodies 36 associated with the alumina feed system in the popliteal space.

 The proposed device operates as follows.

 The channels 3 of the elevator supply air from a compressed air network. At the same time, air is fed into the aeration tube 15. The air leaving the aeration tube 15 through the openings 16 creates a boiling layer of alumina in the box 14 and flows through the channel 17 into the airlift channel 3 in an amount proportional to the volume of air supplied to the aeration tube 15.

 Alumina enters the hopper 1 through the channels 3 of the airlift through a diffuser 5, which helps to suppress the speed of movement of alumina. From here, the alumina enters the aerogloader 6, through which by gravity, as well as under the action of compressed air introduced into it through the pipe 10 and the holes 11, it moves towards the dosing unit. Then through the channels 7 it enters the metering hoppers 8. Here the air exits through the filter 23, and the alumina is lowered to the bottom of the hopper 8. Then, under the action of compressed air leaving the aeration tube 24 through the openings 25, the alumina through the openings 27 and the channel 28 enters the poplite space.

 By changing the pressure in the airlift channel 3, the amount of alumina entering the hopper 1 is controlled in such a way that it is equal to the amount of alumina leaving it in the aeration channel 6 or is slightly larger to increase reliability. In the latter case, the alumina gradually fills the hopper 1, and the excess alumina returns through the return channel 4 to the hopper (cyclone) 2. This embodiment makes it possible to install a small hopper on the electrolyzer and at the same time have a guaranteed supply of alumina in it without resorting to control his level.

 The air supply to the pipeline 10 and its outlet into the aero chute 6 through openings 11 located along the entire length of the aero tube create a boiling layer of alumina in the aero chute. The presence of sequentially installed filters 9 with a gradually increasing filter surface as you move away from the hopper 1 contribute to the dense filling of the air duct and uniform filling of the metering hoppers with alumina connected in series to the air duct. Alumina flows down the aeration channel mainly by gravity at a small (1-2 atm) pressure necessary for the formation of a fluidized bed.

 The presence of a horizontal shelf 21 helps to reduce the pressure of the alumina-air mixture from the aerogut on the dosing unit in the lower part of the hopper 8 and at the same time does not prevent the movement of alumina by gravity from the channel 7 to the hopper 8.

 The presence of a filter 23 on the hopper 8 eliminates the creation of excess pressure in the upper part of the metering hopper and the effect of this pressure on the fluidized bed of alumina in the lower part of the hopper 8, which occurs when air is supplied to the aeration tube 24 to move the alumina through the hole 27 and the channel 28 into the poplite space.

 The hopper (cyclone) 2 is periodically filled with alumina using a floor-standing machine or central heating system through nozzles 12, 13. In this case, the air displaced by alumina exits through openings 20 and filter 19, so it does not interfere with the full filling of hopper 2. At the same time, nozzle 18 is not filled this alumina and thus in the hopper 2 there is a container for receiving small portions of alumina through the return channel 4, and since the container is hollow and the hole in the pipe 18 is located above the box 14, it is never overfilled during operation of the airlift.

 The filters are cleaned by blowing them with compressed air from the outside, reducing at this moment the volume of air supply to the airlift and aerial chute.

 Immersion of the crust of the electrolyte is as follows. The drive 32 moves the [-shaped beam 29 down, and with it the working bodies 36. When the beam 29 moves down, the beam 33 moves through the hinge 35. Thus, both beams synchronously, and with them the working bodies 36 simultaneously act on the crust along the entire length, immersing it in the melt without destruction. After forcing the crust, the working bodies 36 are removed from under the gas collection bell, covering with their bases the holes in the anode casing girdle.

 Thus, this proposal reduces the complexity and improves the ease of maintenance and reliability of the feed system of the electrolyzer.

Claims (7)

 1. DEVICE FOR FEEDING WITH RAW MATERIALS OF AN ALUMINUM ELECTROLYZER IN TWO-STOREY HOUSES, containing a system for supplying alumina to the popliteal space connected to a raw material distribution system made in the form of a hopper with aeroguns, and a raw material input mechanism into the electrolyte, characterized in that it has an additional raw material distribution system a lower hopper installed at the base of the electrolyzer and connected to the upper hopper by the direct and return channels of the airlift.  2. The device according to p. 1, characterized in that the lower hopper is made in the form of a cyclone with a tangential entry of pipes for entering alumina from vehicles and from the return channel of the airlift.  3. The device according to p. 2, characterized in that in the upper part of the exhaust pipe holes are made for air outlet.  4. The device according to p. 2, characterized in that the cyclone has a filter for air outlet.  5. The device according to p. 1, characterized in that the upper end of the direct channel of the airlift is equipped with a diffuser mounted vertically downward in the upper hopper of the inclined aerofoil.  6. The device according to p. 1, characterized in that in the lower part of the hopper there is a horizontal shelf in the projection of the channel connecting the metering hopper to the air duct.  7. The device according to paragraphs. 1 and 5, characterized in that the aeration channel has filters for air outlet, and the filtering surface of each subsequent filter is larger than the previous one in the direction of movement of alumina in the aeration channel.

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