WO2009033356A1 - Controlled cooling system for aluminum electrolytic cell - Google Patents

Abstract

A cooling system, especially a controlled cooling system for aluminium electrolytic cell is disclosed. The controlled cooling system of the present invention for aluminium electrolytic cell is carried into execution by the following technical means: a lateral exhausting tube is provided in the compartment located at the side of the electrolytic cell, the lateral exhausting tube supplies to the arterial vent-pipe, the arterial vent-pipe supplies to the main vent-pipe, and the main vent-pipe is connected to the exhaust fan. The system of the present invention has the simple structure and lower cost, which is easy to be reassembled, supervised and repaired. Some cooling plates are welded on the sides of the cell, and some exhausting tubes with special structure are also provided there. Thus the pipe orifice is near to the high temperature zone at the sides of the cell. By exhausting or blowing air via a tube, the high-temperature air layer near the high-temperature sidewall of the cell is destroyed and transferred, the air flow near the sidewall is enhanced, and the heat exchange by convection is improved, thus the aim to cool the cell is obtained.

Description

 Forced cooling system for aluminum electrolysis cell

 The present invention relates to a cooling system, and more particularly to a forced cooling system for an aluminum electrolytic cell. Background technique

 In the process of electrolytically producing aluminum by the Hall-Erute method, the temperature of the aluminum liquid and the electrolyte melt is stabilized at about 950 ° C by the Joule effect, and the heat is dissipated through the inner liner and the cover layer, thereby causing the entire electrolysis. The tank is in thermal equilibrium.

 With the continuous increase of the intensified current of the aluminum electrolysis cell, the heat dissipation per unit area of the cathode case is also increased under the premise of maintaining the original process conditions and the production system, which will inevitably lead to the thickness of the groove. The thinning, the rise in the temperature of the shell and the deformation of the outer steel plate affect the current efficiency of the electrolytic cell, the energy consumption per ton of aluminum, the stability and the life of the tank. Therefore, in the design process of large aluminum electrolysis cells, effective heat dissipation measures must be taken to improve the heat dissipation capacity of the electrolytic cell and maintain the thermal stability of the electrolytic cell.

 The former Soviet invention patents Nos. SU 605 865 and SU 663 760 disclose the installation of a cooling system that can be controlled outside the electrolysis cell. The side of the trough of such an electrolysis cell comprises a closed cavity, a variable heat shield and a blower, wherein the blower is equipped under the electrolysis cell and is controlled by an adjustable valve. The cooling air discharged from the blower is supplied by a blower or a compressor. But these devices require a huge and cumbersome infrastructure.

 European Patent Application No. EP 0 047 227 proposes to thicken the insulation layer in the electrolytic cell and to equip the heat pipe with a heat exchanger. The heat pipe passes through the shell and the insulation layer and is then inserted into the carbonized portion, such as the edge plate. This solution is more complicated and expensive to install, requiring major changes to the cell.

 In order to assist in the formation of a solidified electrolytic melt slope, U.S. Patent No. 4,087,345, the disclosure of which is incorporated herein incorporated by reference in its entirety in the entire entire entire entire entire entire entire entire portion side. However, these static devices are not suitable for precise control of heat flux.

In order to control the formation of the solidified electrolytic melt slope and to recover the heat extracted from the edge of the groove, US Pat. No. 4,608,135 proposes to install a pipe between the edge plate and the inner insulating layer of the tank body, and a gas collecting device is provided therein. And the air inlet hole is arranged at the side of the groove. Gas collecting device from Air is drawn around the edge of the groove and transported by the pipe along the edge plate. Although this equipment can effectively cool the side of the tank, it needs to make large changes to the electrolytic tank, and the electrolytic tank cannot be operated alone.

 On June 26, 2001, a patent US 6,251,237 B1 (corresponding to FR 2 777 574) filed by Pechiney, discloses an unsealed cooling device for cooling an electrolytic cell by blasting around a casing. However, this method blows a large amount of heat into the electrolysis plant, causing the temperature around the tank to rise, which deteriorates the operating environment in the electrolysis plant.

 On September 7th, 2005, another method of cooling was proposed by the patent CN 1665963 A (corresponding to US 200601 18410A1 on June 8, 2006). The outer tank of the electrolytic cell corresponding to the melt zone is sealed and two inlets are opened, one nozzle blowing air and the other being a coolant such as distilled water. The coolant is atomized to form a convective heat transfer with the surface of the tank, which is cooled by the vaporization latent heat storage tank, and finally carried away by forced air flow. At the same time, the patent has also developed a complete cycle cooling system for the condensation of the coolant. The closed system has a high cooling efficiency, but the electrolytic cell is too dependent on the system and cannot be stopped once it is operated; and the cooling system has a complicated structure, and additional equipment such as a condenser and an atomizing device are added, Operating costs.

 In view of the heat dissipation problem of the side of the aluminum electrolytic cell, the above solutions have certain defects. Therefore, the Applicant intends to propose a simple and low cost device. Summary of the invention

 In order to solve the above technical problems, the present invention provides a forced cooling system for an aluminum electrolytic cell, which aims to fully cool the operating environment in the electrolytic plant and to cool the tank casing without changing the internal structure of the electrolytic cell.

 The invention is realized as follows: The forced cooling system of the aluminum electrolytic cell has a suction end pipe in the compartment on the side of the aluminum electrolytic cell, the exhaust end pipe is connected with the ventilation main pipe, and the ventilation main pipe is connected to the ventilation main pipe. The ventilation main is connected to the exhaust fan.

 The exhaust fan can be replaced by a blower.

 A heat sink is disposed above and below the suction end pipe.

 The suction end pipe comprises a suction end pipe, a suction end pipe, a suction end main branch pipe and a suction end side branch pipe.

The pumping end cross tube, the pumping end main branch pipe and the pumping end side branch pipe are respectively upper and lower Features a heat sink.

 The pumping end main branch pipe and the pumping end side branch pipe are disposed between the pumping end main pipe and the pumping end cross pipe.

 The pumping end cross tube is of an up and down adjustable structure.

 The pumping end pipe comprises a pumping end main pipe, a pumping end main branch pipe and a pumping end side branch pipe, and a heat sink is respectively arranged at the upper and lower sides of the pumping end main branch pipe and the pumping end side branch pipe.

 The suction side branch pipe is a straight pipe or a curved pipe with an inclination of 90-170 degrees.

 The suction end side branch pipe is inclined from the suction end pipe and is bilaterally symmetrical, and is chamfered at the pipe turning and joint.

 The number of the suction side branch pipes is 1 - 16 .

 The suction end horizontal pipe, the suction end main branch pipe and the suction end side branch pipe inlet have an outer expansion shape.

 The distance between the heat sink and the horizontal end of the suction end, the main branch of the suction end and the side branch of the suction end is 20 mm-200 mm.

 The distance between the heat sink and the ventilating trunk is 40mm-300mm.

 The inlet of the suction end tube is aligned with the interface between the aluminum liquid and the electrolyte.

 The distance between the suction end pipe and the groove wall is 20 - 50 mm.

 The regulating valve is installed at the suction end pipe.

 The ventilation main pipe is a variable diameter pipe or a straight pipe.

 The variable diameter pipe is a tapered pipe.

 The vented trunk passes through the opening of the cradle.

The advantages and effects of the invention are as follows: The system has the advantages of simple structure, low cost, convenient disassembly, management and maintenance; welding a certain number of fins on the side of the trough, and then installing a special shape of the exhaust duct to make the nozzle close to the side wall of the electrolyzer In the high temperature area, the high temperature air layer near the high temperature wall of the tank shell is destroyed and transferred by means of pipe pumping or blowing, which enhances the air flow near the wall surface and strengthens the convective heat transfer, thereby achieving the purpose of cooling the electrolytic tank. It can be switched between pumping or blowing according to different situations, and has strong flexibility; it can effectively improve the working environment beside the aluminum electrolysis tank, and is suitable for daily operation of electrolysis workers. It can effectively cool the high temperature area on the side of the electrolytic cell, and form a regular furnace in the tank, which is beneficial to production. DRAWINGS BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of the present invention provided on an electrolytic cell.

 Figure 2 is a cross-sectional view showing a suction end pipe of Embodiment 1 of the present invention.

 Figure 3 is a cross-sectional view showing a suction end pipe of Embodiment 2 of the present invention.

 Figure 4 is a schematic illustration of a single tank cooling system of the present invention.

 Figure 5 is a schematic illustration of a multi-slot cooling system of the present invention.

 In the figure, 1, aluminum electrolysis cell; 2, exhaust end pipe; 3, ventilation main pipe; 4, ventilation main; 5, air extractor; 6, cradle; 7, heat sink; 8, groove wall; 10; electrolyte; 1 1, valve; 21, pumping end horizontal pipe; 22, pumping end main branch pipe; 23, pumping end side branch pipe; 24, pumping end pipe; 25, regulating valve. detailed description

 The embodiments of the present invention are further described below in conjunction with the accompanying drawings. However, the scope of protection of the present invention is not limited by the embodiments.

 Example 1

Referring to the drawings, the forced cooling system of the aluminum electrolytic cell of the present invention is provided with a suction end pipe 2 in the compartment on the side of the aluminum electrolytic cell 1, and the inlet of the suction end pipe 2 is aligned with the interface of the aluminum liquid 9 and the electrolyte 10. The exhaust end pipe 2 is connected to the ventilation main pipe 3, the ventilation main pipe 3 is connected to the ventilation main pipe 4, the ventilation main pipe 4 is connected with the exhaust fan 5, and the air volume control is performed by adjusting the wide door 1 1 at the suction end pipe 2 The upper and lower sides are provided with a heat sink 7, and the suction end pipe 2 includes a suction end pipe 24, a suction end horizontal pipe 21, a suction end main branch pipe 22, a suction end side branch pipe 23, and an air volume regulating valve 25, The fins 21, the pumping end main branch 22 and the pumping end side branch 23 are respectively provided with fins, and the spacing between the fins should not be too narrow. The heat radiation exchange coefficient should be minimized and aligned separately. The axis of the gas end main branch pipe 22 and the suction end side branch pipe 23, in order to achieve the day of uniform cooling of the tank wall 8, the suction end main branch pipe 22 and the suction end side branch pipe 23 are provided at the suction end pipe 24 and Between the suction end of the horizontal pipe 21, the suction end horizontal pipe 21 is an up-and-down adjustable structure, and the suction inlet can always be located in the range of interface variation. Inside, in order to achieve better heat dissipation. The suction end side branch pipe 23 is a straight pipe, and is inclined from the suction end pipe 24 to be bilaterally symmetrical, and is chamfered at the pipe turning and joint to smooth it; the suction end pipe 21, the suction end main branch pipe 22, and the pumping end The inlet of the end side branch pipe 23 has an outer expansion shape, and the distance between the heat sink 7 and the suction end horizontal pipe 2 1 , the suction end main branch pipe 22 and the suction end side branch pipe 23 is 20 mm - 200 mm to prevent thermal expansion due to the steel plate. When pressed against each other, the fins 7 are longitudinally welded to the groove wall 8, not to the suction end. The airflow in the inlet section of the tube 21 is hindered, and the heat sink 7 should not be too long, so that the distance between the top end of the heat sink 7 and the ventilation main pipe 3 is kept at 40 mm-300.

 In the range of mm, the distance between the suction end pipe 2 and the groove wall 8 is 20 mm to 50 mm. The ventilating main pipe 3 is a variable diameter pipe or a straight pipe, and the variable diameter pipe is a conical pipe. The vented trunk 3 passes through the opening of the cradle 6. A negative pressure is formed in the ventilation main pipe 21 by the exhaust fan 5, so that the high-temperature air near the high temperature region of the side wall of the electrolytic cell is sucked into the suction end main branch pipe 22 and the suction end side branch pipe 23 through the suction end cross pipe 21, and then It flows into the vent main 3 and then exits the electrolysis plant.

 Example 1

 The suction end pipe 2 in the embodiment 1 includes a suction end pipe 24, a suction end main branch pipe 22, and a suction end side branch pipe 23, and the suction end side branch pipe is a bent pipe having an inclination angle of 90 to 170 degrees. According to the actual situation, the angle and the number of the suction end side branch pipes 23 can be appropriately adjusted according to the number of the heat sinks and the welding position, and the number of the exhaust end side branch pipes is 1 - 16. Other the same embodiment 1

 In different climatic conditions, the exhaust fan 5 can be replaced with a blower to provide air cooling to the aluminum electrolysis cell on the existing pipe system.

Claims

Rights request 1. A forced cooling system for an aluminum electrolytic cell, characterized in that a suction end pipe is arranged in a compartment on the side of the aluminum electrolytic cell, the suction end pipe is connected with the ventilation main pipe, and the ventilation main pipe is connected to the ventilation main pipe, and the ventilation is provided. The supervisor is connected to the blower or blower.  2. A forced cooling system for an aluminum electrolytic cell according to claim 1, wherein said exhaust fan can be replaced by a blower.  3. The forced cooling system of an aluminum electrolytic cell according to claim 1, wherein the suction end pipe is provided with fins above and below.  4. The forced cooling system of an aluminum electrolytic cell according to claim 1 or 3, wherein the suction end pipe comprises a suction end pipe, a suction end horizontal pipe, a suction end main branch pipe, and a pumping end. End side branch pipe and regulating valve.  The forced cooling system for an aluminum electrolytic cell according to claim 4, wherein the suction end horizontal pipe, the suction end main branch pipe, and the suction end side branch pipe are respectively provided with fins.  6. The forced cooling system of an aluminum electrolytic cell according to claim 4, wherein the suction end main branch pipe and the suction end side branch pipe are disposed between the suction end main pipe and the suction end horizontal pipe. .  7. The forced cooling system of an aluminum electrolytic cell according to claim 6, wherein the suction end cross tube is of an up and down adjustable structure.  8. The forced cooling system of an aluminum electrolytic cell according to claim 4, wherein the suction side branch pipe is a straight pipe or a bent pipe having an inclination of 90 to 170 degrees.  9. The forced cooling system of an aluminum electrolytic cell according to claim 4, wherein the suction side branch pipe is inclined from the suction end pipe to be bilaterally symmetrical, and is chamfered at the pipe transition and the joint.  10. The forced cooling system of an aluminum electrolytic cell according to claim 4, wherein the number of the suction side branch pipes is 1 - 16.  A forced cooling system for an aluminum electrolytic cell according to claim 4, wherein said suction end horizontal pipe, the suction end main branch pipe, and the suction end side branch pipe inlet are in an expanded shape. 12. The forced cooling system of an aluminum electrolytic cell according to claim 4, wherein the air volume adjusting valve is disposed on the suction end pipe. 13. The forced cooling system of an aluminum electrolytic cell according to claim 5, wherein the distance between the heat sink and the suction end horizontal pipe, the suction end main branch pipe, and the suction end side branch pipe is 20-200 mm.  14. The forced cooling system of an aluminum electrolytic cell according to claim 5, wherein the heat sink has a distance of 40 to 300 mm from the vent main.  15. The forced cooling system of an aluminum electrolytic cell according to claim 1, wherein the inlet of the suction end pipe is aligned with the interface of the aluminum liquid and the electrolyte.  16. The forced cooling system of an aluminum electrolytic cell according to claim 15, wherein the distance between the suction end pipe and the groove wall is 20 to 50 mm.  17. The forced cooling system of an aluminum electrolytic cell according to claim 1, wherein the vented main pipe is a variable diameter pipe or a straight pipe.  18. The forced cooling system of an aluminum electrolytic cell according to claim 17, wherein said variable diameter pipe is a tapered pipe.  19. A forced cooling system for an aluminum electrolytic cell according to claim 18, wherein said vented main pipe passes through an opening of the cradle.