RU2624559C1 - Device for gases collecting and removing from aluminium electrolyser - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: device for collecting and evacuating anode gases from under the shelter of an electrolyser with burned anodes through gas-collecting windows through the gas channels of the beam-collector contains a flow-guiding structure. The flow-directing structure is fixed to the flange of the beam-collector and consists of the main longitudinal, additional longitudinal and transverse plates installed on the flange of the beam-collector, dividing the zone of depressurization under the flange of the beam-collector into at least three channels for the removal and evacuation of anode gases.

EFFECT: increasing the effectiveness of the system for removing the gases of the cell when the cell is not hermetically sealed.

4 cl, 5 dwg

Description

FIELD OF THE INVENTION

The invention relates to non-ferrous metallurgy, in particular to the production of aluminum in electrolyzers with prebaked anodes, and can be used to capture emissions during technological operations associated with depressurization of shelters.

State of the art

A device for automatically controlling the extraction of electrolysis baths for aluminum production, mainly when sucking gas from each electrolyzer using at least one suction channel, containing a common suction system for all channels, in addition, the device is equipped with means for measuring the temperature of the exhaust gases and changing them flow rate (dampers made with the possibility of rotation around an axis perpendicular to the axis of the channel) installed in each of the channels by the control unit, containing their temperature setting elements and comparison elements (SU Patent No. 1473718, IPC S25S 3/20, publ. 02.01.1986).

The disadvantages of the known device are that when depressurization of the electrolyzer’s shelter, cold air drops down towards the crust, as a result of which there may be a delay in turning on more intensive gas removal and the need for additional means of evacuating the gases and controlling the gas extraction modes. In addition, part of the gas, moving along the periphery of the shelter, will be knocked out through the gaps between the anode rods and the flange.

Closest to the claimed invention in technical essence, is a device for collecting and evacuating anode gases from under the shelter of an electrolytic cell with calcined anodes according to patent RU 2468127, IPC С25С 3/22, publ. 11/27/2012, taken as a prototype, which is aimed at increasing the efficiency of collecting electrolysis gases during depressurization of the electrolyzer. The device comprises a flow directing structure located in the center between the suction windows of the parallel exhaust ducts of the collector beam, made in the form of an inner wall passing from the lower shelf of the collector beam towards the melt, the inner wall relative to the lower shelf of the collector beam is installed with a gap, the ratio of the value of which to the width of the suction window of the exhaust channel of the beam-collector corresponds to the condition: b: B = 1: (0.1 ÷ 0.7), where b is the gap between the upper edge of the inner wall and the lower th shelf of the collector beam, B is the width of the suction window of the gas outlet channel of the collector beam. The removal of gases in the area of the gas collection windows is carried out due to the vacuum created by the gas collection windows of two parallel exhaust channels.

The disadvantage of the prototype device is that during depressurization of the electrolyzer, the air flow drawn in under the shelter moves the electrolysis gases along the electrolyzer and creates stagnant regions with an increased concentration of electrolysis gases under the lower flange of the collector beam. In these areas, gases are driven into the working area of the electrolysis body through the gaps between the anode rods and the flange, as well as through the gaps between the shelter shields. Knocking out occurs because the design of the lower flange and the installed dividing inner wall do not allow to isolate stagnant zones with a high concentration of electrolysis gases from the location of the structural clearances of the electrolyzer shelter.

Disclosure of invention

The basis of the invention is the task of increasing the efficiency of the gas removal system of the cell during depressurization of the shelter of the cell.

The technical result of the claimed invention is to ensure the direction of most of the gas flows into the zone of removal of electrolysis gases while localizing the remaining part of the stream under the flange of the collector beam without access to the clearance gaps.

The achievement of the above technical result is ensured by the fact that in the device for collecting and evacuating the anode gases from under the shelter of the electrolytic cell with calcined anodes through the gas collection windows by means of the gas outlet channels of the collector beam containing the flow guiding structure, in accordance with the claimed technical solution, the flow guiding structure is fixed to the flange of the collector beam and consists of the main longitudinal, additional longitudinal and transverse plates mounted on the flange of the collector beam, p dividing the depressurization zone under the flange of the collector beam into at least three channels for the removal and evacuation of anode gases.

The main longitudinal plates and gas collection windows form a gas removal channel, the main longitudinal plates and transverse plates form a vortex flow splitting channel, and additional longitudinal plates and transverse plates form a gas isolation channel.

The above particular embodiments of the invention are not the only ones possible. Various modifications and improvements are allowed without departing from the scope of the invention defined by the first claim.

Brief Description of the Drawings

The invention is illustrated by the following drawings:

in FIG. 1 shows a device for removing gases,

in FIG. 2 shows the direction of gas flows in the depressurization zone (cross section in the depressurization zone),

in FIG. 3 - section of the device in the installation area of the anode rod,

in FIG. 4 is a three-dimensional cross section of the device,

in FIG. 5 is a three-dimensional cross-section of the device in the installation area of the anode rod (view inside the cell).

The implementation of the invention

The device for collecting and removing gases consists of a collector beam 1, two gas exhaust channels 2 connected to the body gas removal system, as well as gas collection windows 3 and a flow guide structure fixed rigidly to the flange 4 of the collector beam 1. The flow guiding structure contains the main longitudinal plates 5, directed along the electrolyzer, mounted on the flange 4 of the collector beam 1 between the gas collection windows 3 and openings 6 for the anode rods 7, transverse plates 8, mounted on the flange 4 of the collector beam 1 on the perpend icular to the main longitudinal plates 5 sides of the aperture 6 for the anode rods 7, and additional longitudinal plates 9, forming with the transverse plates 8 a U-shaped plate with the possibility of overlapping the gap between the anode rod 7 and the flange 4.

The main longitudinal plates 5, directed along the electrolyzer, and the gas collection windows 3, through which gas enters the gas exhaust channels 2, form a gas removal channel 10. The main longitudinal plates 5 and transverse plates 8 form a vortex flow splitting channel 11. Additional longitudinal plates 9 and transverse the plates 8 form a channel for isolating gases 12, overlapping the gaps between the anode rods 7 and the flange 4. The plates 5 and 8 are simultaneously stiffening elements of the flange.

The device operates as follows. When performing operations on the electrolyzer associated with partial depressurization of the electrolyzer, air is drawn in under the cover, which mixes with the anode gases, forming vertical and horizontal vortex flows moving upward under the flange 4 of the collector beam 1. Main longitudinal plates 5 and transverse plates 8 of the guiding device break up the rising flows of anode gases into parts. Most of the gases under the action of the vacuum created by the gas collection windows 3 of two parallel exhaust pipes 2, is drawn into the gas removal channel 10 and then through the gas collection windows 3 enters the exhaust pipes 2, then to the gas purification. The remaining part of the anode gases is localized in the channel for splitting the vortex flows 11. The gaps between the anode rods 7 and the flange 4 are insulated in the gas isolation channels 12 formed by additional longitudinal plates 9 and transverse plates 8, to prevent gas being knocked out into the housing.

As a result of the use of the flow-guiding structure, most of the gases released under the shelter of the electrolyzer are directed to gas treatment, the remaining part is isolated from the structural clearances of the shelter. Thus, the efficiency of removal of the anode gases of a partially depressurized electrolyzer during technological operations is increased. The plates directing the flow of anode gases are simultaneously stiffeners, which increases the strength and reliability of the lower flange sheet of the collector beam.

Claims (4)

1. A device for collecting and evacuating the anode gases from under the shelter of the electrolytic cell with calcined anodes through the gas collection windows by means of the exhaust channels of the collector beam, comprising a flow guiding structure, characterized in that the flow guiding structure is fixed to the collector beam flange and is configured as installed on the flange of the collector beam of the main longitudinal, additional longitudinal and transverse plates dividing the depressurization zone under the flange of the collector beam, at least three channels niya and evacuation of anode gases. 2. The device according to claim 1, characterized in that the main longitudinal plates and gas collection windows form a gas removal channel. 3. The device according to claim 1, characterized in that the main longitudinal plates and transverse plates form a channel for splitting the vortex flows. 4. The device according to claim 1, characterized in that the additional longitudinal plates and transverse plates are installed with the formation of a channel for isolating gases.

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