CN111465132B - Method for calculating resistivity and maximum discharge of baked electrode paste with self-baked electrode - Google Patents

Abstract

Method for calculating resistivity and maximum discharge of baked electrode paste with self-baked electrodeThe electrode shell and the self-baking electrode in the electrode shell are in parallel circuit, and the resistivity rho of the self-baking electrode paste is established_Pole(s)The maximum amount of the feed per day H_Day(s)The functional relationship between the two is derived to calculate the limiting resistivity rho_Pole(s)To obtain the ultimate resistivity ρ_Pole(s)Maximum daily payout under the conditions H_RimTo determine the maximum downward discharge H of the self-baking electrode_RimAnd its self-baking electrode resistivity rho_Pole(s)Due to the self-baking electrode resistivity ρ_Pole(s)Can be measured in a laboratory when p is_Pole(s)After the determination, the daily maximum downward discharge H of the self-baking electrode can be measured and calculated_RimEnsuring the maximum daily discharge H of the self-baking electrode_RimThe method is more scientific and accurate, further provides scientific measuring and calculating basis for selecting the matched self-baking electrode paste production scheme for the submerged arc furnace, effectively improves the production efficiency and the quality of the self-baking electrode, and obviously reduces the potential safety hazard of the self-baking electrode.

Description

Method for calculating resistivity and maximum discharge of baked electrode paste with self-baked electrode

Technical Field

The invention relates to the technical field of self-baking electrodes, in particular to a method for calculating the resistivity and the maximum discharge amount of electrode paste of a self-baking electrode baking belt.

Background

The maximum discharging amount of the self-baking electrode is related to the heat quantity obtained by the electrode, the heat quantity source of the self-baking electrode is mainly conductive heat, radiant heat and resistance heat of current passing through the electrode from a hearth, the radiant heat and the conductive heat are not negligible for a closed furnace for normally discharging the electrode, so that the baking capacity of the self-baking electrode is simplified to be determined by the resistance heat, the maximum discharging amount of the self-baking electrode is related to the current passing through the self-baking electrode and the resistivity of the self-baking electrode, but when the current is constant, the relationship between the maximum discharging amount of the self-baking electrode and the resistivity of the self-baking electrode is difficult to determine, great inconvenience is brought to the efficient and safe production of the self-baking electrode, and the production is seriously influenced.

Disclosure of Invention

In view of the above, it is necessary to provide a method for calculating the resistivity and the maximum amount of discharge of the baked electrode paste.

A method for calculating the electrode paste resistivity and the maximum downward discharge amount of a baked electrode baked belt comprises the following steps of (1) using the baked electrodes in an electrode shell and an electrode shell as parallel circuits, wherein the baked electrodes are columnar baked belts, and the daily maximum downward discharge amount of the baked electrodes is calculated according to the following method:

s1, self-baking electrode baking heat Q_Pole(s)，Q_Pole(s)＝0.24I_Pole(s) ²R_Pole(s)t, (formula 1),

in the formula: q_Pole(s)Resistance heat generated by the self-baking electrode baking zone is cal;

I_pole(s)Is the current through the self-baking electrode carbon material and has the unit of A;

R_pole(s)The resistance of the self-baking electrode carbon material is in omega;

t is time in units of S;

s2, electrode shell resistance R_Shell，R_Shell＝ρ_ShellL/S_Shell＝1.35×10^-5Ω, (formula 2);

in the formula: r_ShellIs the resistance of the electrode shell in Ω;

ρ_shellIs the resistivity of the electrode shell, is constant, p_Shell＝1.333Ω·mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_shellThe sectional area of the motor casing steel plate containing the rib pieces is 24720mm²；

S3，R_Pole(s)＝ρ_Pole(s)L/S_Pole(s)＝1.33×10^-7ρ_Pole(s)(formula 3);

in the formula, R_Pole(s)The resistance of the self-baking electrode carbon material is in omega;

ρ_pole(s)For self-baking electrode baking, the resistivity of the electrode paste at the baking temperature is given in units of omega mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_pole(s)The sectional area of the self-baking electrode paste is 1886000mm²；

S4，I_{General assembly}＝I_Pole(s)+I_Shell(formula 4) wherein I_Pole(s)Is the current passing through the carbon material of the self-baking electrode

Is A;

I_pole(s)/I_Shell＝R_Shell/R_Pole(s)＝ρ_ShellL S_Pole(s)/(ρ_Pole(s)LS_Shell)≈102/ρ_Pole(s)(formula 5);

calculating I by the formulas 4 and 5_Pole(s)，I_Pole(s)＝102I_{General assembly}/(102+ρ_Pole(s))＝1.17×10⁷/(102+ρ_Pole(s)) (formula 6);

in the formula I_{General assembly}The total current of the electrode and the electrode shell is 115000A according to the actual production condition;

s5: resistance heat Q generated by self-baking electrode baking belt every day_{Solar pole}，Q_{Solar pole}＝0.24I_Pole(s) ²R_Pole(s)t＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²(formula 7);

wherein t is the daily time and is a constant of 60X 24S;

self-baking electrode dailyThe total heat generated is Q_{General assembly}，Q_{General assembly}＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²+ K, (formula 8);

wherein K is Q_{Conveying appliance}+Q_Spoke+Q_ShellIs a constant;

s6: daily discharge H of self-baking electrode_Day(s)，H_Day(s)＝Q_{General assembly}/(a×d×S_Pole(s))＝1.34×10⁵ρ_Pole(s)/(102+ρ_Pole(s))²+3.53×10^-7K, (formula 9);

in the formula, a is the heat quantity required by roasting each kilogram of self-roasting electrode paste, and the value is 1000 kilocalories/kg;

d is the density of the self-baking electrode and is 1500Kg/m³；

S7: daily maximum downward discharge H of self-baking electrode_RimCalculating the extreme value of the derivative of equation 9 to obtain rho_{Polar lim}＝102Ω·mm²M, and will be_{Polar lim}＝102Ω·mm²Substituting m into formula 9 to obtain the maximum discharge H_Rim＝328.4mm。

Preferably, a daily safe lower discharge amount H is also set_SecureThe daily discharge amount H of the self-baking electrode_Day(s)Between H_SecureAnd H_RimIn the meantime.

The specific technical parameters of the submerged arc furnace are set, and the resistivity rho of the self-baking electrode paste is established_Pole(s)The maximum amount of the feed per day H_Day(s)The functional relationship between the two is derived to calculate the limiting resistivity rho_Pole(s)To obtain the ultimate resistivity ρ_Pole(s)Maximum daily payout under the conditions H_RimTo determine the maximum downward discharge H of the self-baking electrode_RimAnd its self-baking electrode resistivity rho_Pole(s)Due to the self-baking electrode resistivity ρ_Pole(s)Can be measured in a laboratory when p is_Pole(s)After the determination, the daily maximum downward discharge H of the self-baking electrode can be measured and calculated_RimEnsuring the maximum daily discharge H of the self-baking electrode_RimMore scientific and accurate, and further provides a self-baking electrode paste production scheme for selecting and matching the submerged arc furnaceScientific measuring and calculating basis, effectively improves the production efficiency and the quality of the self-baking electrode, and obviously reduces the potential safety hazard.

Drawings

Fig. 1 is a schematic diagram of a parallel circuit of an electrode shell and a self-baking electrode.

FIG. 2 is the self-baking electrode resistivity ρ_Pole(s)And daily dosage H_Day(s)A graph of the relationship (c).

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Referring to fig. 1, the present invention provides a method for calculating the resistivity and maximum run-down of an electrode paste in a self-baking electrode baking belt, wherein the electrode shell and a self-baking electrode in the electrode shell are in a parallel circuit, the self-baking electrode is a columnar baking belt, the height of the self-baking electrode is about 1/4 of the length of a copper tile, and the maximum run-down of the self-baking electrode per day is calculated according to the following method:

s1, self-baking electrode baking heat Q_Pole(s)，Q_Pole(s)＝0.24I_Pole(s) ²R_Pole(s)t, (formula 1);

in the formula: q_Pole(s)Resistance heat generated by the self-baking electrode baking zone is cal;

I_pole(s)Is the current through the self-baking electrode carbon material and has the unit of A;

R_pole(s)The resistance of the self-baking electrode carbon material is in omega;

t is time in units of S;

s2, electrode shell resistance R_Shell，R_Shell＝ρ_ShellL/S_Shell(formula 2);

in the formula: r_ShellIs the resistance of the electrode shell in Ω;

ρ_shellIs the resistivity of the electrode shell, is constant, p_Shell＝1.333Ω·mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_shellThe sectional area of the motor casing steel plate containing the rib pieces is 24720mm²；

Through S2, the electrode shell resistance R is calculated_Shell，R_Shell＝ρ_ShellL/S_Shell＝1.33×0.25/24720＝1.35×10^-5Ω。

Specifically, when the ratio of the cross sectional area of the electrode shell (including the fins) to the cross sectional area of the self-baking electrode is 1: 75 and the temperature is 750 ℃, the electrode carbon material and the metal have the same conductivity, and the resistivity rho of the electrode shell is measured at the time_Shell＝1.333Ω·mm²/m；

S3，R_Pole(s)＝ρ_Pole(s)L/S_Pole(s)(formula 3);

in the formula, R_Pole(s)The resistance of the self-baking electrode carbon material is in omega;

ρ_pole(s)For self-baking electrode baking, the resistivity of the electrode paste at the baking temperature is given in units of omega mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_pole(s)The sectional area of the self-baking electrode paste is 1886000mm²；

From S3, the self-baking electrode resistance R was calculated_Pole(s)，R_Pole(s)＝ρ_Pole(s)L/S_Pole(s)＝0.25×ρ_Pole(s)/1886000＝1.33×10^-7ρ_Pole(s)；

S4，I_{General assembly}＝I_Pole(s)+I_Shell(formula 4) wherein I_Pole(s)Is the current passing through the carbon material of the self-baking electrode

Is A;

I_pole(s)/I_Shell＝R_Shell/R_Pole(s)＝ρ_ShellL S_Pole(s)/(ρ_Pole(s)LS_Shell) (formula 5);

by equation 5, calculate I_Pole(s)/I_Shell＝R_Shell/R_Pole(s)＝ρ_ShellL S_Pole(s)/(ρ_Pole(s)LS_Shell)＝1.333×1886000/ρ_Pole(s)×24720≈102/ρ_Pole(s)；

Calculating I by the formulas 4 and 5_Pole(s)，I_Pole(s)＝102I_{General assembly}/(102+ρ_Pole(s)) (formula 6);

in the formula I_{General assembly}The total current of the electrode and the electrode shell is 115000A according to the actual production condition;

by the formula 6, I is calculated_Pole(s)，I_Pole(s)＝102I_{General assembly}/(102+ρ_Pole(s))＝1.17×10⁷/(102+ρ_Pole(s))；

S5: resistance heat Q generated by self-baking electrode baking belt every day_{Solar pole}，Q_{Solar pole}＝0.24I_Pole(s) ²R_Pole(s)t, (formula 7);

wherein t is the daily time and is a constant of 60X 24S;

by equation 7, Q is calculated_{Solar pole}，Q_{Solar pole}＝0.24I_Pole(s) ²R_Pole(s)t＝0.24×(102I_{General assembly})²/(102+ρ_Pole(s))²×1.33×10^-7×ρ_Pole(s)×60×60×24＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²；

The total daily heat generated by the self-baking electrode is Q_{General assembly}，Q_{General assembly}＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²+ K, (formula 8);

specifically, the self-baking electrode actually has the conduction heat Q of the furnace body during the baking process_{Conveying appliance}Radiant heat Q of furnace body_SpokeResistance heat Q of electrode shell_ShellAnd the three heat quantities Q_{Conveying appliance}、Q_Spoke、Q_ShellThe total sum of the heat absorption coefficient and the heat absorption coefficient is stable in the normal operation state of the submerged arc furnace and is approximately a constant K, and the total heat absorption formula of the self-baking electrode is as follows: q_{General assembly}＝Q_{Solar pole}+Q_{Conveying appliance}+Q_Spoke+Q_Shell＝Q_{Solar pole}+K＝0.24I_Pole(s) ²R_Pole(s)t+K＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²+k；

S6: daily discharge H of self-baking electrode_Day(s)，H_Day(s)＝Q_{General assembly}/(a×d×S_Pole(s)) (formula 9);

in the formula, a is the heat quantity required by roasting each kilogram of self-roasting electrode paste, and the value is 1000 kilocalories/kg;

d is the density of the self-baking electrode and is 1500Kg/m³；

By equation 9, calculate H_Day(s)＝Q_{General assembly}/(a×d×S_Pole(s))＝{3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²+k}/1000×1500×1.886×10⁶×10^-6＝1.34×10⁵ρ_Pole(s)/(102+ρ_Pole(s))²+3.53×10^-7K；

S7: daily maximum downward discharge H of self-baking electrode_RimCalculating the extreme value of the derivative of equation 9 to obtain rho_{Polar lim}＝102Ω·mm²M, and will be_{Polar lim}＝102Ω·mm²Substituting m into formula 9 to obtain the maximum discharge H_Rim＝328.4mm。

Specifically, the daily discharge H of the self-baking electrode_Day(s)Resistivity rho of electrode paste in a baked state for self-baking_Pole(s)The derivative of equation 9 is used to calculate an extremum value, which can be used to calculate ρ_lim。

△＝[1.34×10⁵×(102+ρ_Pole(s))²-2×(102+ρ_Pole(s))×1.34×10⁵ρ_Pole(s)]/(102+ρ_Pole(s))⁴That is, when Δ is equal to 0, ρ is calculated_Pole(s)Value can be obtained as H_{Day am}Maximum value

1.34×10⁵×(102+ρ_Pole(s))²-2×(102+ρ_Pole(s))×1.34×10⁵ρ_Pole(s)＝0；

(102+ρ_Pole(s))×(102-ρ_Pole(s))＝0；

Solved to get rho_lim＝102Ω·mm²/m；

Will rho_lim＝102Ω·mm²Substituting/m into formula 9, theObtaining the lower limit discharge quantity H_Rim＝328.4mm。

Further, a daily safe release amount H is also arranged_SecureThe daily discharge amount H of the self-baking electrode_Day(s)Between H_SecureAnd H_RimIn the meantime.

In detail, referring to the table I, after the technical parameters of the submerged arc furnace are determined, the submerged arc furnace has a maximum discharge H related to the parameters_RimMeanwhile, the submerged arc furnace also has a daily safe discharge H_SecureSaid H is_SecureTo take into account p_Pole(s)Fluctuation of (p)_Pole(s)The size of the fluctuation is related to the quality of the self-baking electrode paste, and the daily safety discharge H is usually preset according to specific industrial and mining conditions and tests_SecureThe downward discharge amount is the minimum downward discharge amount per day of the self-baking electrode of the ore furnace, so the downward discharge amount per day of the self-baking electrode meets the following relation: h_Secure＜H_Day(s)＜H_Rim。

TABLE 40500KVA submerged arc furnace parameters

Referring to FIG. 2, specifically, firing resistance ρ of the self-baking electrode paste_Pole(s)Closer to p_limMaximum lower discharge H_Day(s)The larger, when ρ is_Pole(s)>ρ_limIn this case, the higher the resistivity of the electrode paste, the lower the resistance heat generated from the electrode, and the maximum lowering amount H_Day(s)The smaller the size; when rho_Pole(s)<ρ_limIn this case, the higher the resistivity of the electrode paste, the higher the resistance heat generated from the electrode, and the maximum lowering amount H_Day(s)The larger.

Specifically, formula 3 and formula 5 are substituted into formula 1, Q_Pole(s)＝0.24I_Pole(s) ²R_Pole(s)t＝28.69I_{General assembly} ²ρ_Pole(s)/(102+ρ_Pole(s))²Formula 10, bringing formula 10 into formula 9, H_Day(s)＝Q_{General assembly}/(a×d×S_Pole(s))＝10.14×10^-6I_{General assembly} ²ρ_Pole(s)/(102+ρ_Pole(s))²Equation 11, as can be seen from equation 11, when ρ_Pole(s)A timing of H_Day(s)And a secondary current I_{General assembly}Is proportional to the square of.

Specifically, a plurality of ribs are further arranged in the electrode shell.

The modules or units in the device of the embodiment of the invention can be combined, divided and deleted according to actual needs.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (2)

1. A method for calculating the resistivity and the maximum discharge of a self-baking electrode baked belt electrode paste is characterized by comprising the following steps of: the electrode shell and the self-baking electrode in the electrode shell are in a parallel circuit, the self-baking electrode is a columnar baking belt, and the daily maximum downward discharge amount of the self-baking electrode is calculated according to the following method:

s1, self-baking electrode baking heat Q_Pole(s)，Q_Pole(s)＝0.24I_Pole(s) ²R_Pole(s)t, (formula 1),

in the formula: q_Pole(s)Resistance heat generated by the self-baking electrode baking zone is cal;

I_pole(s)Is the current through the self-baking electrode carbon material and has the unit of A;

R_pole(s)The resistance of the self-baking electrode carbon material is in omega;

t is time in units of S;

s2, electrode shell resistance R_Shell，R_Shell＝ρ_ShellL/S_Shell＝1.35×10^-5Ω, (formula 2);

in the formula: r_ShellIs the resistance of the electrode shell inΩ；

ρ_ShellIs the resistivity of the electrode shell, is constant, p_Shell＝1.333Ω·mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_shellThe sectional area of the motor casing steel plate containing the rib pieces is 24720mm²；

S3，R_Pole(s)＝ρ_Pole(s)L/S_Pole(s)＝1.33×10^-7ρ_Pole(s)(formula 3);

in the formula, R_Pole(s)The resistance of the self-baking electrode carbon material is in omega;

ρ_pole(s)For self-baking electrode baking, the resistivity of the electrode paste at the baking temperature is given in units of omega mm²/m；

L is the length of the baking belt of the self-baking electrode, and the value is 0.25m when corresponding to 1 meter of copper tile;

S_pole(s)The sectional area of the self-baking electrode paste is 1886000mm²；

S4，I_{General assembly}＝I_Pole(s)+I_Shell(formula 4) wherein I_Pole(s)Is the current through the self-baking electrode carbon material and has the unit of A;

I_pole(s)/I_Shell＝R_Shell/R_Pole(s)＝ρ_ShellL S_Pole(s)/(ρ_Pole(s)LS_Shell)≈102/ρ_Pole(s)(formula 5);

calculating I by the formulas 4 and 5_Pole(s)，I_Pole(s)＝102I_{General assembly}/(102+ρ_Pole(s))＝1.17×10⁷/(102+ρ_Pole(s)) (formula 6);

in the formula I_{General assembly}The total current of the electrode and the electrode shell is 115000A according to the actual production condition;

s5: resistance heat Q generated by self-baking electrode baking belt every day_{Solar pole}，Q_{Solar pole}＝0.24I_Pole(s) ²R_Pole(s)t＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²(formula 7);

wherein t is the daily time and is a constant of 60X 24S;

the total daily heat generated by the self-baking electrode is Q_{General assembly}，Q_{General assembly}＝3.78×10¹¹ρ_Pole(s)/(102+ρ_Pole(s))²+ K, (formula 8);

wherein K is Q_{Conveying appliance}+Q_Spoke+Q_ShellIs a constant;

s6: daily discharge H of self-baking electrode_Day(s)，H_Day(s)＝Q_{General assembly}/(a×d×S_Pole(s))＝1.34×10⁵ρ_Pole(s)/(102+ρ_Pole(s))²+3.53×10^{- 7}K, (formula 9);

in the formula, a is the heat quantity required by roasting each kilogram of self-roasting electrode paste, and the value is 1000 kilocalories/kg;

d is the density of the self-baking electrode and is 1500Kg/m³；

S7: daily maximum downward discharge H of self-baking electrode_RimCalculating the extreme value of the derivative of equation 9 to obtain rho_{Polar lim}＝102Ω·mm²M, and will be_{Polar lim}＝102Ω·mm²Substituting m into formula 9 to obtain the maximum discharge H_Rim＝328.4mm。

2. The method for calculating the resistivity and the maximum lowering amount of a self-baking electrode baked strip paste according to claim 1, wherein a daily safety lowering amount H is further provided_SecureThe daily discharge amount H of the self-baking electrode_Day(s)Between H_SecureAnd H_RimIn the meantime.

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