CN102312253A - Double-flue pipe gas-collecting pipeline system of aluminum electrolytic tank and control method - Google Patents

Abstract

The invention relates to a gas-collecting pipeline system with double smoke pipes in an aluminum electrolytic cell and a control method. Aluminum electrolytic cell double smoke pipe gas collection pipeline system, including aluminum electrolytic cell, anode and gas collection flue, the first smoke pipe communicates with the gas collection flue, the groove of the aluminum electrolytic cell communicates with the second smoke pipe, the first smoke pipe The pipe is connected to the first purification pipe, the second smoke pipe is connected to the second purification pipe, the first purification pipe and the second purification pipe are connected to the main purification pipe, the main purification pipe is connected to the reaction dust collector, the reaction dust collector is connected to the induced draft fan, and the induced draft fan is connected to the chimney . Advantages and effects: The two smoke pipes are provided with independent pipes to avoid mutual interference of the two airflows and destroy the existing air pressure balance in the purification pipe. The double flue pipe system can realize separate gas collection under normal tank condition and slotting operation, can effectively control the amount of smoke exhausted by a single tank, can improve the sealing efficiency of the electrolytic cell, reduce the fluoride emission in the electrolytic workshop, and realize Energy saving and emission reduction of purification system.

Description

Aluminum electrolytic cell double smoke pipe gas collection pipeline system and control method

technical field

The invention relates to a gas-collecting pipeline system, in particular to a system that can maintain a small amount of smoke exhaust in a closed state of the tank, and can rapidly increase the smoke exhaust volume of the electrolytic tank during the slotting operation, which can be obtained under different tank conditions. An aluminum electrolytic cell double-pipe gas-collecting pipeline system with better gas-collecting effect and economic indicators and a control method.

Background technique

During the aluminum electrolysis production process, the electrolytic cell emits a large amount of flue gas, and the fluoride contained in the flue gas is one of the main pollutants in the aluminum plant. These pollutants are emptied through the skylight of the electrolysis workshop and the chimney of the flue gas purification system, causing certain pollution to the local environment. The gas collection system of the electrolysis cell is the key to controlling the fluoride emission indicators of the electrolysis workshop and the purification system.

As shown in Figure 1, the existing aluminum electrolytic cell basically adopts a single smoke tube gas collection system, which can achieve better gas collection efficiency when the tank cover is sealed. However, during slotting operations, such as changing poles, tapping aluminum, and manually extinguishing the anode effect, etc., there is often insufficient smoke exhaust, and a large amount of flue gas leaks from the slotting, resulting in excessive fluorine emissions from the electrolysis workshop.

There are two traditional solutions: one is to maintain a relatively high smoke exhaust volume of the electrolyzer, which can meet the gas collection requirements even during slotting operation; The negative pressure at the outlet of the pipe can achieve the purpose of increasing the smoke exhaust volume. However, the increase of smoke exhaust will directly affect the processing capacity of the purification system, which will increase the investment and energy consumption proportionally; changing the opening of the smoke pipe control valve will destroy the air pressure balance of the existing purification pipeline and increase the internal pressure of the pipeline. The air flow disturbance and pipeline resistance loss are not conducive to the stable operation of the purification system.

Contents of the invention

In order to solve the above technical problems, the present invention provides an aluminum electrolytic cell double smoke pipe gas collection pipeline system and control method. To meet the demand for the maximum smoke exhaust volume of the electrolytic cell in special time periods, and achieve the effect of energy saving and emission reduction.

In order to achieve the above-mentioned purpose, the aluminum electrolytic cell double-smoke pipe gas-collecting pipeline system of the present invention comprises an aluminum electrolytic cell, an anode and a gas-collecting flue, the first smoke pipe communicates with the gas-collecting flue, and the second smoke pipe communicates with the groove of the aluminum electrolytic cell. The chamber is connected, the first smoke pipe is connected to the first purification pipe, the second smoke pipe is connected to the second purification pipe, the first purification pipe and the second purification pipe are connected to the main purification pipe, the main purification pipe is connected to the reaction dust collector, and the reaction dust collector is connected to the induced draft fan , the induced draft fan is connected with the chimney.

The first smoke pipe is provided with a first control valve.

The second smoke pipe is provided with a second control valve.

Aluminum electrolytic cell double smoke pipe gas collection pipeline system, including aluminum electrolytic cell, anode and gas collection flue, the first smoke pipe communicates with the gas collection flue, and a tank cover plate is arranged at the end of the aluminum electrolytic cell, the aluminum electrolytic cell The groove of the tank is connected with the second smoke pipe, the first smoke pipe is connected with the first purification pipe, the second smoke pipe is connected with the second purification pipe, the first purification pipe is connected with the main purification pipe, the second purification pipe is connected with the purification equipment through the pipeline, and the purification equipment And the purification main pipe is connected with the reaction dust remover, the reaction dust remover is connected with the induced draft fan, and the induced draft fan is connected with the chimney.

The control method of the aluminum electrolytic cell double smoke pipe gas collection pipeline system is characterized in that when the aluminum electrolytic cell is in normal operation, the chamber of the aluminum electrolytic cell is sealed, the first control valve is opened, and the first smoke pipe passes through the gas collecting smoke. before the abnormal operation of the aluminum electrolytic cell, keep the existing opening of the first control valve unchanged, open the second control valve, and add negative pressure at the opening of the second flue pipe , run the second flue gas collection system; after completing the operation and sealing the tank chamber, close the second control valve.

The abnormal operation of the aluminum electrolytic cell refers to the slotting operation, and the slotting operation refers to the operation of aluminum, pole change or slag removal.

The negative pressure added at the opening of the second smoke pipe in the groove ranges from 0 to -1000Pa.

The operation of the second flue gas collection system refers to the purification of the second pipe, the purification equipment, the connection of the reaction dust collector, the connection of the induced draft fan and the operation of the chimney.

The technical difficulty of the present invention lies in how to arrange the second smoke pipe on the electrolytic cell, and maintain a high negative pressure at its outlet to ensure the gas collection effect.

The advantage of the present invention is that a second smoke pipe is added to the electrolytic tank, and the maximum smoke exhaust volume of a single tank can be doubled compared with that of the traditional tank. The two smoke pipes are provided with independent pipes to avoid mutual interference of the two airflows and destroy the existing air pressure balance in the purification pipe. The double flue pipe system can realize separate gas collection under normal tank condition and slotting operation, can effectively control the amount of smoke exhausted by a single tank, can improve the sealing efficiency of the electrolytic cell, reduce the fluoride emission in the electrolytic workshop, and realize Energy saving and emission reduction of purification system.

Description of drawings

Figure 1 is a schematic diagram of a single-pipe gas-collecting flue of a traditional aluminum electrolytic cell.

Fig. 2 shows the structure diagram of the present invention.

FIG. 3 is a schematic diagram of the external piping system of the double smoke pipes in Embodiment 1.

Fig. 4 is a schematic diagram of the external piping system of the double smoke pipe in embodiment 2.

In the figure: 1. Aluminum electrolytic cell; 2. Anode; 3. Gathering flue; 4. Tank cover; 5. Slot; 6. First smoke pipe; 7. First control valve; 8. Second Smoke pipe; 9. Second control valve; 10. Purification first pipeline; 11. Purification second pipeline; 12. Purification main pipe; 13. Reaction dust collector; 14. Purification equipment;

Detailed ways

This patent will be described below in conjunction with examples, but the protection scope of this patent is not limited by the examples.

In the present invention, two independent smoke pipes are arranged on the electrolytic cell, and one smoke pipe is opened to collect gas when the electrolytic cell is in normal operation, and the minimum amount of smoke exhaust is maintained in the closed state of the tank chamber; the two smoke pipes are opened when the slotting operation is performed Gas collection, in the open state of the tank, to maintain the maximum amount of smoke exhaust, to prevent the smoke from overflowing the tank.

Example 1

As shown in Figures 2 and 3, the aluminum electrolytic cell double smoke pipe gas collection pipeline system of the present invention includes an aluminum electrolytic cell 1, an anode 2 and a gas collection flue 3, and the entire tank chamber and the tank cover plate 4 form a closed gas collection smoke box , two independent smoke pipes are set on the aluminum electrolytic cell 1, the first smoke pipe 6 communicates with the gas-collecting flue 3, and is responsible for the dust collection of the electrolytic cell under normal conditions; 8 is connected, the first smoke pipe 6 is connected with the first purification pipeline 10, in order to avoid the mutual interference of the soot airflow collected by the two smoke pipes, the second smoke pipe 8 is connected with the second purification pipeline 11, and the first purification pipeline 10 and the second purification pipeline 11 are connected with each other. The purification main pipe 12 is connected, the purification main pipe 12 is connected with the reaction dust remover 13, the reaction dust remover 13 is connected with the induced draft fan 15, and the induced draft fan 15 is connected with the chimney 16; the first smoke pipe 6 is provided with a first control valve 7 for adjusting the gas collection volume , the second smoke pipe 8 is provided with a second control valve 9 to adjust the amount of gas collection, the first control valve 7 and the second control valve 9 are both linked with the tank control box, so as to realize the switching of different smoke exhaust modes under different tank operating conditions .

When the aluminum electrolytic cell 1 is in normal operation, the chamber of the aluminum electrolytic cell 1 is sealed, the first control valve 7 is opened, and the first smoke pipe 6 collects gas in the chamber through the gas collecting flue 3; Before operation, the opening of the tank cover can be regarded as the air inlet of the smoke box, keep the existing opening of the first control valve 7 unchanged, open the second control valve 9, and pass through the second smoke pipe 8 at the opening of the tank. Add negative pressure to increase the negative pressure in the slot to prevent fluoride and flue gas from overflowing at the slot. Open the second control valve 9 before the slot operation, and run the second smoke pipe gas collection system; after the operation is completed And after sealing the groove, close the second control valve 9 again. The abnormal operation of the aluminum electrolytic cell 1 refers to the slotting operation, and the slotting operation refers to operations such as aluminum, pole changing or slag removal.

The additional negative pressure at the opening of the groove through the second smoke pipe 8 can reach 0-1000Pa, preferably -400--800Pa.

The operation of the second flue gas collection system refers to the purification of the second pipe, the purification equipment, the connection of the reaction dust collector, the connection of the induced draft fan and the work of the chimney.

The flue gas collected by the first purification pipeline 10 and the second purification pipeline 11 is merged in the main purification pipe 12, and the two airflows are connected in series and then enter the reaction dust collector 13, the induced draft fan 15, and finally are emptied through the chimney 16.

Example 2

As shown in Figures 2 and 4, the purification two pipelines 11 in the embodiment 1 are connected with the purification equipment 14 by the pipeline, and the purification equipment 14 is connected with the reaction dust collector 13, and the reaction dust collector 13 is connected with the induced draft fan 15, and the induced draft fan 15 is connected with the chimney 16 Connection, other are identical with embodiment 1.

The purification pipeline system of the two smoke pipes on the aluminum electrolytic cell 1 adopts a parallel structure. The first flue pipe 6 is connected with the first purification pipe 10, and the collected flue gas is merged in the main purification pipe 12, and then enters the reaction dust collector 13, the induced draft fan 15 in turn, and finally is emptied through the chimney 16. Outside the electrolysis workshop, the second flue pipe 8 is provided with a separate purification second pipeline 11, and the purification second pipeline 11 is collected into the purification equipment 14, then passed through the induced draft fan 15, and finally emptied through the chimney 16. The main function of the purification equipment 14 is to purify the flue gas from the second flue pipe 8, including removing fluoride and dust.

Claims (8)

1. the two smoke pipe gas collection pipe systems of aluminium cell comprise aluminium cell, anode and gas collection flue, and first smoke pipe is communicated with the gas collection flue; Second smoke pipe is communicated with the groove thorax of aluminium cell, first smoke pipe and purification one pipe connection, second smoke pipe and purification two pipe connection; Purify a pipeline and purify two pipelines and purify total pipe coupling; Purify house steward and be connected with the reaction fly-ash separator, the reaction fly-ash separator is connected with induced draft fan, and induced draft fan is connected with chimney.

2. the two smoke pipe gas collection pipe systems of aluminium cell according to claim 1 is characterized in that described first smoke pipe is provided with first valve.

3. the two smoke pipe gas collection pipe systems of aluminium cell according to claim 1 is characterized in that described second smoke pipe is provided with second valve.

4. the two smoke pipe gas collection pipe systems of aluminium cell comprise aluminium cell, anode and gas collection flue, and first smoke pipe is communicated with the gas collection flue; End at aluminium cell is provided with cell cover plate, and the groove thorax of aluminium cell is communicated with second smoke pipe, first smoke pipe and purification one pipe connection; Second smoke pipe and purification two pipe connection; Purify a pipeline and purify total pipe coupling, purify two pipelines and be connected with treating plant through pipeline, treating plant is connected with the reaction fly-ash separator with the purification house steward; The reaction fly-ash separator is connected with induced draft fan, and induced draft fan is connected with chimney.

5. the control method of the two smoke pipe gas collection pipe systems of aluminium cell according to claim 1 and 2; It is characterized in that described aluminium cell is when normal operation; The groove thorax of aluminium cell is airtight, and first valve is opened, and first smoke pipe is through gas collection flue gas collection in the groove thorax; Aluminium cell keeps the existing aperture of first valve constant before abnormal running, opens second valve, and opens wide the additional negative pressure in place at the groove thorax of second smoke pipe, moves the second smoke pipe natural gas gathering system; Behind complete operation and closed cell thorax, close second valve again.

6. the control method of the two smoke pipe gas collection pipe systems of aluminium cell according to claim 5 is characterized in that the abnormal running of described aluminium cell is meant the fluting operation, and the fluting operation is to point out aluminium, change poles or drag for slag operation.

7. the control method of the two smoke pipe gas collection pipe systems of aluminium cell according to claim 5, it is characterized in that described second smoke pipe the groove thorax open wide the additional negative pressure in place be 0～-1000Pa.

8. the control method of the two smoke pipe gas collection pipe systems of aluminium cell according to claim 5 is characterized in that the described operation second smoke pipe natural gas gathering system is meant two pipelines, treating plant, the connection of reaction fly-ash separator, induced draft fan connection and the chimney work of purifying.

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