CN219260227U

CN219260227U - Electrolysis trough flue gas collecting system

Info

Publication number: CN219260227U
Application number: CN202320068222.1U
Authority: CN
Inventors: 袁永健; 刘迅; 张海龙; 陈丽新; 卢剑; 邓七一; 黎衡慧; 耿波; 柏庄; 谢照亮
Original assignee: GUIYANG ALUMINUM MAGNESIUM DESIGN & RESEARCH INSTITUTE CO LTD
Current assignee: GUIYANG ALUMINUM MAGNESIUM DESIGN & RESEARCH INSTITUTE CO LTD
Priority date: 2023-01-10
Filing date: 2023-01-10
Publication date: 2023-06-27
Anticipated expiration: 2033-01-10

Abstract

The utility model discloses a flue gas collecting system of an electrolytic tank, which comprises the electrolytic tank, wherein a fire hole side exhaust hood and an upper exhaust hood are respectively arranged above the fire hole position of the electrolytic tank, the fire hole side exhaust hood is connected with a fire hole exhaust pipe through a smoke exhaust branch pipe, and the upper exhaust hood is connected with a negative pressure exhaust pipe. According to the utility model, the flue gas containing high-concentration pollutants and the flue gas containing low-concentration pollutants overflowed from the fire hole of the electrolytic tank are respectively collected and then treated in a grading way by adopting two independent flue gas pipe networks, so that the scale and the running cost of the flue gas purifying treatment system are obviously reduced. Meanwhile, the side fume exhaust hood arranged on the periphery of the fire hole can avoid the damage to the fume exhaust hood caused by high temperature caused by the arrangement of the fume exhaust hood on the upper part of the fire hole in the traditional technology, and the service life of the fume exhaust hood is ensured. In addition, the side fume exhaust cover arranged around the fire hole can rotate, and when the anode is replaced, the fume exhaust cover can rotate from the side of the fire hole to a position which does not hinder the process operation.

Description

Electrolysis trough flue gas collecting system

Technical Field

The utility model relates to an electrolytic cell flue gas collection system, and belongs to the technical field of collection and treatment of flue gas pollutants of an aluminum electrolytic cell.

Background

In the production process of aluminum electrolysis cell using carbon anode, the amount of gas generated by electrochemical reaction is small (main component CO ₂ The yield is 3/4, which is converted into 622.2Nm ³ /t.Al, the volume of the main contaminant HF gas is smaller). In order to ensure the smoke collecting efficiency of the electrolytic cell, a certain negative pressure is required to be maintained in the cell cover, so that a large amount of ambient air enters the cell cover, and the ambient air and smoke (containing pollutants) generated by the electrolytic reaction enter the electrolytic smoke purifying system for treatment. In actual engineering, the exhaust gas amount of the electrolytic tank is generally 65,000Nm according to different tank types ³ above/t.Al, the proportion of pollutants is very low, which also determines the characteristics of the flue gas of the electrolytic cell of the traditional technology that the production is large, and the concentration of pollutants is low, such as: fluoride concentration 200mg/Nm ³ The method comprises the steps of carrying out a first treatment on the surface of the Using anodes with 2% sulfur content, SO ₂ About 200mg/Nm ³ . This also results in a back-end electrolytic flue gas treatment system that is bulky and costlyAnd the operation cost is high.

In the prior art, the Chinese patent application with publication number of CN102776531A and the utility model name of 'aluminium electrolysis cell fire hole gas collecting device' refers to a fire hole gas collecting device, and the fire hole gas collecting device only collects harmful flue gas overflowed from a fire hole through the fire hole gas collecting device, so that the flue gas treatment capacity of a purification system is reduced. In the actual operation process, if the method is adopted, the sealing mode of the electrolytic tank is not changed, and the negative pressure in the electrolytic tank cover cannot be ensured, so that the pollutants in the electrolytic tank overflow. Meanwhile, under the condition of slotting, the purpose of controlling the diffusion of pollutants cannot be met by reducing the smoke quantity; and the exhaust hood for collecting gas of the fire hole is arranged at the upper part of the charging point of the electrolytic tank, so that the operations of crust breaking, charging and the like of the electrolytic tank are influenced, and the implementation difficulty is high.

Disclosure of Invention

The utility model aims to provide an electrolytic cell flue gas collecting system which is used for respectively collecting flue gas containing high-concentration pollutants and low-concentration pollutants and creating conditions for realizing graded purification treatment of the flue gas of a rear-end electrolytic cell.

The technical scheme of the utility model is as follows: the utility model provides an electrolysis trough flue gas collecting system, includes the electrolysis trough, installs the fire hole lateral part fume hood and upper portion fume hood respectively in the fire hole position top of electrolysis trough, fire hole lateral part fume hood passes through the fume extraction branch pipe and is connected with the fire hole fume exhaust pipe, upper portion fume hood is connected with the negative pressure fume exhaust pipe.

Further, the upper end of the fire hole side fume exhaust hood is rotationally connected with the fume exhaust branch pipe through a rotating shaft.

Further, the lower end of the fire hole side fume exhaust hood is fixedly connected with a lower branch pipe, and a slit fume exhaust port is formed in the bottom of the lower branch pipe.

By adopting the technical scheme, the utility model has the advantages that: according to the utility model, the flue gas containing high-concentration pollutants and the flue gas containing low-concentration pollutants overflowed from the fire hole of the electrolytic tank are respectively collected and then treated in a grading way by adopting two independent flue gas pipe networks, so that the scale and the running cost of the flue gas purifying treatment system are obviously reduced. Meanwhile, the side fume exhaust hood arranged on the periphery of the fire hole can avoid the damage to the fume exhaust hood caused by high temperature caused by the arrangement of the fume exhaust hood on the upper part of the fire hole in the traditional technology, and the service life of the fume exhaust hood is ensured. In addition, the side fume exhaust cover arranged around the fire hole can rotate, and when the anode is replaced, the fume exhaust cover can rotate from the side of the fire hole to a position which does not hinder the process operation.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

fig. 2 is a partial enlarged view of fig. 1.

Reference numerals: the device comprises a 1-fire hole side smoke exhaust hood, a 2-smoke exhaust branch pipe, a 3-fire hole smoke exhaust pipe, a 4-upper smoke exhaust hood, a 5-negative pressure smoke exhaust pipe, a 6-lower branch pipe, a 7-slit smoke exhaust port, an 8-rotating shaft and a 9-electrolytic cell.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, the present utility model will be further described in detail with reference to the accompanying drawings and examples.

As shown in fig. 1, an electrolytic tank smoke collection system comprises an electrolytic tank 9, wherein a fire hole side smoke exhaust hood 1 and an upper smoke exhaust hood 4 are respectively arranged above the fire hole position of the electrolytic tank 9, the fire hole side smoke exhaust hood 1 is connected with a fire hole smoke exhaust pipe 3 through a smoke exhaust branch pipe 2, and the upper smoke exhaust hood 4 is connected with a negative pressure smoke exhaust pipe 5. The upper end of the fire hole side fume exhaust hood 1 is rotationally connected with the fume exhaust branch pipe 2 through a rotating shaft 8. The exhaust volume of the upper exhaust hood 4 is larger than the exhaust volume of the fire hole side exhaust hood 1.

Firstly, a fire hole side fume exhaust hood 1 is arranged at the fire hole position of an electrolytic tank 9 and is used for collecting fume containing high-concentration pollutants overflowed from the fire hole, the fume is collected to a fire hole fume exhaust pipe 3 through a fume exhaust branch pipe 2 and then is exhausted out of the electrolytic tank 9, meanwhile, an upper fume exhaust hood 4 is arranged at the upper part of the electrolytic tank 9 and is used for collecting fume containing low-concentration pollutants overflowed from the fire hole, and the fume of the upper fume exhaust hood 4 is collected to a negative pressure fume exhaust pipe 5 and then is exhausted out of the electrolytic tank 9, so that the aim of regional fume collection in the tank shell of the electrolytic tank 9 can be realized through the fire hole side fume exhaust hood 1 and the upper fume exhaust hood 4. The fire hole side fume exhaust cover 1 is closely attached to the fire hole position of the electrolytic bath 9, and the position of the upper fume exhaust cover 4 is higher than that of the fire hole side fume exhaust cover 1.

In the actual production process, most of pollutants generated by the aluminum electrolysis cell are discharged out of the electrolysis cell 9 from the fire hole smoke exhaust pipe 3, so that the smoke amount required to be treated in an important way is only one tenth to one fifth of that of the prior art; in order to ensure the negative pressure of the tank, the part of low-concentration smoke extracted from the negative pressure smoke exhaust pipe 5 is only required to be treated in a low-cost treatment mode or even is not required to be treated. By the regional flue gas collection mode, the flue gas quantity to be treated is obviously reduced, the volume and the scale of a later-stage flue gas treatment system are obviously reduced, and the corresponding system investment, occupied area and operation energy consumption are greatly reduced. Meanwhile, as the temperature of the flue gas extracted by the fire hole smoke exhaust pipe 3 is high, the temperature can reach more than 400 ℃, compared with the 150 ℃ smoke exhaust temperature of the electrolytic tank in the prior art, the value of the flue gas waste heat utilization of the fire hole smoke exhaust pipe 3 is obviously improved.

Embodiments of the utility model:

as shown in fig. 1, a certain number of crust breaking and charging positions are arranged between anodes of the electrolytic tank 9 according to the tank type of the electrolytic tank 9, and most of gaseous pollutants overflow from fire holes formed at the positions. The upper part of the fire hole is directly baked at high temperature by the molten electrolyte, so that the fire hole side fume hood 1 is arranged at the fire hole position and is used for collecting the fume containing high-concentration pollutants overflowed from the fire hole position. The smoke collected by the smoke exhaust hood 1 at the side of the fire hole arranged at the position of each fire hole is collected to the smoke exhaust pipe 3 of the fire hole through the smoke exhaust branch pipe 2 and discharged out of the electrolytic bath 9, and is treated by a purification system at the rear end. Because the flue gas amount of the fire hole is small, the back end flue gas purification treatment system is small in size, low in investment and low in operation cost.

In order to prevent a small amount of pollutants overflowed from the positions of the fire eyes and the like from polluting the workshop environment, the upper part of the electrolytic bath is also provided with an upper smoke exhaust hood 4, the smoke exhaust and air quantity of the upper smoke exhaust hood 4 is larger than that of the smoke exhaust hood 1 at the side part of the fire eyes, and the negative pressure in the bath hood can be effectively maintained, so that the pollutants are prevented from overflowing, and the smoke exhaust of each upper smoke exhaust hood 4 is converged to the negative pressure smoke exhaust pipe 5 and then discharged out of the electrolytic bath. Because the pollutant content in the negative pressure smoke exhaust pipe 5 is low, the pollutant can be treated or even not treated in a low-cost mode, so that the investment and the operation cost of the rear-end smoke purification treatment system are further reduced.

Because of the requirements of crust breaking and charging operations of the electrolytic bath, crust breaking steel bars extend into the fire holes from top to bottom at the upper parts of the fire holes, and the smoke exhaust hood 1 at the side parts of the fire holes can avoid the influence on the crust breaking operation of the crust breaking steel bars.

Referring to fig. 2, during the replacement of the anode, for example: the anodes 1# and 2# need to be replaced, and if the side fume exhaust hood 1 adopts a fixed mode, the process operation is hindered. So the fire hole side fume exhaust cover 1 and the lower branch pipe 6 are connected in a rotating way by adopting the rotatable rotating shaft 8, and in the anode replacement process, the fire hole side fume exhaust cover 1 and the lower part of the lower branch pipe 6 can rotate to a horizontal position around the rotating shaft 8, thereby avoiding interference with the pole change operation.

The lower part of the fire hole side fume exhaust cover 1 is provided with a strip seam fume exhaust port 7 for fume exhaust. Meanwhile, when the lower part of the side fume exhaust hood 1 can rotate to a horizontal position around the rotating shaft 8, dust such as alumina settled at the bottom of the fire hole side fume exhaust hood 1 can flow out from the slit fume exhaust port 7, so that the side fume exhaust hood 1 is prevented from being blocked.

Claims

1. An electrolysis cell flue gas collection system comprises an electrolysis cell (9), and is characterized in that: the fire hole side exhaust hood (1) and the upper exhaust hood (4) are respectively arranged above the fire hole position of the electrolytic tank (9), the fire hole side exhaust hood (1) is connected with the fire hole exhaust pipe (3) through the exhaust branch pipe (2), and the upper exhaust hood (4) is connected with the negative pressure exhaust pipe (5).

2. The electrolyzer stack gas collection system of claim 1, wherein: the upper end of the fire hole side fume exhaust hood (1) is rotationally connected with the fume exhaust branch pipe (2) through a rotating shaft (8).

3. The electrolyzer stack gas collection system of claim 1, wherein: the lower end of the fire hole side fume exhaust hood (1) is fixedly connected with a lower branch pipe (6), and a slit fume exhaust port (7) is formed in the bottom of the lower branch pipe (6).