ã€China Aluminum Industry Network】 1. The role of furnaces The quality of electrolytic tanks depends entirely on the regulation of the furnace. The electrolyzers with uneven furnace bottoms and furnace bottoms are relatively poor in voltage stability. The aluminum mirrors in the tanks have large fluctuations in the mirror surface, which exacerbates the secondary reactions of aluminum and reduces the current efficiency. It is necessary to maintain normal operation. Maintaining higher voltages increases production costs. A better hearth can maintain the heat of the electrolyzer, reduce the heat loss of the electrolyzer, reduce the input of energy, thereby reducing the voltage, and can reduce the direction of the lateral horizontal current and reduce the current consumption. The production of the electrolyzer should be tight. Adjust the parameters around the changes in the furnace to ensure the stability of the indicators and the smooth operation of the electrolyzer. Flanged Carbon Steel Ball Valve Flanged Carbon Steel Ball Valve,Mild Steel Ball Valve,Carbon Steel Flanged Ball Valve,Carbon Steel Socket Weld Ball Valve Zhejiang Chenxiang import and export trade Co., Ltd , https://www.chenxiang-valve.com
2. How to form the primary crystal temperature characteristics of the furnace electrolyte indicates that when the temperature of the furnace lining is lower than the primary crystal temperature, the cryolite in the electrolyte will crystallize here to form side crusts, forming a furnace ledge. When the temperature of the lance is higher than the primary crystal temperature, the cryolite in the electrolyte hardly forms crusts on the sides, and under the action of the magnetic field, the side carbon blocks are continuously washed to cause the temperature of the cooling shell of the electrolytic cell shell. Gradually increase, jeopardizing safe production.
2.1 Adjusting the ratio of molecules When the ratio of electrolyte molecules is low in the same series of currents and voltages, the primary crystal temperature is low, the superheat becomes large, and the formed furnace is thin to facilitate heat dissipation and maintain the heat balance of the electrolytic cell. And when the molecular ratio is high, its primary crystal temperature is high, the superheat degree becomes smaller, and under the condition that the voltage generates no change in heat, the heat radiation of the thin furnace is obviously too large, which breaks the original heat balance of the electrolytic cell and the electrolyte The polymer material in the segregation continues to segregate to the grate, thereby forming a thicker grate, reducing the amount of heat, and re-establishing a new thermal balance. This molecular ratio, the primary crystal temperature, the superheat, the thickness of the grate, and the heat dissipation of the grate form a delicate thermal equilibrium relationship with the electrolyzer. From this point one conclusion can be drawn: The thickness of the electrolytic cell furnace grate has a certain relationship with the molecular ratio. In the same series of currents, when the same voltage and molecular ratio are low, the formed furnace is thin and the molecular ratio is high, the formed furnace is thick. However, too low molecular weight is thinner than the formed furnace roof, and it is easy to form side conduction, and the ability of dissolving alumina is reduced. Under the condition of constant volume and feeding, part of the material dissolves into the electrolyte, and a part of the material sinks into the bottom of the furnace and becomes dilute precipitate. After the hard crust is formed, the pressure drop at the bottom of the furnace is increased, more side currents are formed, and the electric efficiency is affected. Excessively high molecules are thicker than the formed furnace, which is both heat-insulated and insulated. Vertical currents are concentrated, the temperature at the bottom of the furnace is increased, the crust is melted, the pressure drop at the bottom of the furnace is reduced, and the electrical efficiency is improved.
2.2 Adjusting the tank voltage Under normal circumstances, a series of electrolytic tanks are connected in series. The current of each electrolytic tank is equal. The main parameter for controlling the hot income of the electrolytic tank is the voltage. According to the formula W=IVT, the higher the tank voltage is, the higher the thermal income is; the lower the tank voltage is, the lower the heat income is. In the case where the current and molecular ratio are basically stable, in order to form an ideal hearth, it is necessary to gradually reduce the cell voltage, reduce the heat income of the electrolytic cell, and promote the precipitation of high molecular substances in the electrolyte. Because the higher the temperature of the electrolytic cell, the higher the degree of superheat of the electrolyte, and the formation of the grate is when the temperature close to the primary crystal temperature of the electrolyte, will precipitate in the sidewall to form crystals, and gradually form the furnace. If the grate is too thick, it is easy to melt and stretch the legs and reduce the current efficiency. In this case, raise the voltage, increase the hot income, melt the thick grate, and increase the side. Heat dissipation, lower furnace bottom temperature, promote stretch development.
2.3 The effect of parameter adjustment on the polar distance In the series production of the electrolytic cell, except for the current all the electrolytic cell is the same, the remaining parameters, such as the cell voltage, molecular ratio, aluminum level, electrolyte level, effect coefficient, hearth pressure Drop, insulation materials, etc., due to human-induced operation reasons and mechanical volatilization, as well as computer control design errors and other factors, so that the troughs are different from each other, it requires production and operation management personnel to conduct a detailed comparative analysis of the parameters of each cell. Lowering the cell voltage can reduce the cell's heat gain, but reducing the cell voltage is at the expense of the pole pitch. The pole pitch is the distance from the bottom of the anode to the mirror of the aluminum liquid. It is both the center of the heat source of the electrolytic cell and the area where the electrochemical reaction is produced by electrolysis. On the surface, the heat income of the electrolytic cell is reduced, but after reducing the polar distance, the secondary reaction of the aluminum liquid layer of the electrolytic cell will increase, and the generated alumina will burn at a high temperature, releasing a large amount of energy, forming a hot trough . However, this is not the same as the newly started electrolytic cell. The new cell voltage is high and the polar distance is high. Although its cell temperature is high, the secondary reaction of aluminum liquid is less. So we want to reduce the voltage, but do not want to affect the pole pitch, a more effective way is to change the electrolyte composition, improve the conductivity of the electrolyte. At the time of aluminum production, we observed the drop of 3% in the large bus and the voltage dropped by 0.1V. It can be concluded that the polar distance is reduced by 1 , and the voltage is decreased by 0.03V; if the same voltage is tested, the molecular ratio is 2.2. The polar distance is measured as 41?, and the polar distance is measured as 45 when the molecular ratio is adjusted to 2.4. From this, it can be concluded that the polar distance is increased by 1? and the molecular ratio is increased by 0.05; according to our test results and daily measurement data , can make correct adjustments to the parameters to ensure the smooth operation of the electrolytic cell.
2.4 Influence of Aluminum Level and Insulation Material on the Formation of the Furnace The insulation and heat dissipation of the electrolytic tank is a contradictory and contradictory relationship. It requires both the side heat dissipation and the top insulation, and it also needs to form both insulating and insulating on the side. Furnace. According to data, each increase or decrease in insulation material on the pole is equivalent to the heat generated by the voltage of 60mV. In the case of a constant voltage, increasing the pole insulation material corresponds to an increase in the pole pitch of the electrolytic cell, which reduces the secondary reaction of aluminum. The same adjustment of aluminum level can also change the heat income of the electrolyzer, adjust the 1? Aluminum level affect the heat generated by the voltage of 70mV, and the higher the level of aluminum, the smaller the fluctuation of the aluminum liquid mirror in the tank, the more stable the flow, the precipitation of molten aluminum involved The reduced chance of secondary reactions has great benefits in reducing the bath temperature and electrolyte superheat, which are prerequisites for the formation of the furnace. By lowering the cell voltage, adjusting the composition of the electrolyte, reducing the heat income, raising the primary crystal temperature, reducing the superheat, promote the formation of the furnace. Correspondingly, the conductivity and the polar distance of the electrolyte are increased, and the secondary reaction of aluminum is reduced. With the thickening of the furnace, the furnace of the electrolytic cell is further structured, and the energy saving and consumption reduction achieves remarkable results.
3. Conclusion The operation of the electrolyzer is a dynamic and balanced relationship. Whether or not the production can be stabilized depends entirely on whether or not the parameters in the production operation are reasonably allocated. The long-reaching legs and the thin screed are formed in advance. As long as the parameters are adjusted properly, they will be fully completed in the later period. Can be rebuilt, in order to ensure good economic benefits, the following points should be made:
3.1 To measure multiple data, reduce the measurement error by averaging multiple data.
3.2 Perform a comparative analysis of various operating parameters and determine which parameters need to be adjusted based on the direction of the adjustment.
3.3 Avoid single adjustment of the influence of one parameter on other parameters. When adjusting one parameter, others should also make micro adjustments.
3.4 The reasonable combination of parameters and operation quality is the fundamental guarantee of electrolytic production.
Aluminum Electrolytic Slot Furnace Formation and Energy Conservation