SU955535A1 - Method of determining conductivity between electrode and three-phase three-electrode ore-smelting furnace bottom - Google Patents

Description

The invention relates to electrothermics and can be applied in determining the electrical parameters of a bath of a three-phase three-electrode ore-thermal furnace.

A known 'method for determining the electrical parameters of a bath of an ore-thermal furnace, in which the interelectrode voltages are regulated so that one of the voltages of the hearth electrode remains unchanged, and the conductivity of the interelectrode spaces of the bath G1] are calculated from changes in electrode currents.

The disadvantage of the known method is due to the fact that, although for a short time, the normal operation of the furnace is violated.

A method is also known that is suitable for continuous monitoring and does not interfere with the normal operation of the furnace. In this method, a measuring frequency is used that is different from the frequency supplying the furnace. The voltage of the measuring frequency is regulated so that the potentials of all the electrodes relative to the bottom are the same in amplitude and phase AND. .

However, at the same time, one of the voltages can not be regulated and customized.

under it, two others, which in the general case leads to the need to adjust .. four parameters, i.e. two

- amplitudes and two phases.

³ Closest to the proposed is a method for determining the conductivity between the electrode and the bottom of a three-phase three-electrode ore-thermal furnace, in which an adjustable power source of a measuring frequency different from the operating frequency of the furnace is connected in series with each electrode, the EMF of the sources is changed until the specified values and phases of the potentials of the measuring frequency are established on the electrodes, measure the current of the electrode of one of the phases and its voltage relative to the hearth at the measuring frequency and determined by the measured parameters the indicated conductivity I.

The disadvantage of this method is that during setup requires a change in four parameters of the quantities and phases of the two electrodes.

The purpose of the invention is to simplify the process of determining conductivity.

To achieve this goal, potential differences are established that measure the frequencies between all pairs of ³ θ mi electrodes in phase or counterphase, and the potential of the specified electrode relative to the bottom is different from the potentials of other electrodes in phase, the phase angle of the current of the specified electrode from its voltage is measured relative to the bottom and the angle of shift of 5 ha of phases of this current from voltage between any! two electrodes, and the conductivity is determined by the formula.

I e s i η B _________

U ^ · sinTft-l-β) ’where G is the electrode-conductivity. on the;

1 _e - current measuring frequency in the electrode; fifteen

U _5n ”voltage measuring frequency between the electrode and the bottom;

x is the phase angle between 1 _e and ^ ep> · _ τη β is the phase angle between 1 _e and the voltage between any pair of electrodes.

Na.Fig. 1 shows a power source of a measuring frequency; on. 2 diagram of the furnace circuits; in FIG. 3 - topographic * 5 graphical voltage diagram, combined with the vector diagram of the current of the first electrode. .

According to the method, it is proposed to input at least one of the EMF of a measuring frequency power supply · 30 directly into the branch of a short network supplying the electrode. A measuring frequency input device can be implemented using, for example, a transformer 35 made similarly to a current transformer, with the only difference being that the measuring frequency power supply is connected from the side of the winding with a large NUMBER OF CIRCUITS. The secondary circuit of such a transformer is a short circuit bus passing through the window of its core. The power source of the measuring frequency contains an ammeter A and a current circuit of the wattmeter W, the scales of which are graduated taking into account the transformation coefficient for currents reduced to the primary side, i.e. to the actual currents flowing in the furnace circuit, the transformer winding L _T with a large number of turns, a filter Φ _ή that transmits only currents of the measuring frequency and a filter Φ ₂ , which transmits only currents of the main frequency supplying the furnace, conventionally shown by 55 two-terminal devices, and the source measuring frequency supply with EMF e _{from (l} . Since at least one measuring frequency EMF introduced into the furnace circuit is generally necessary to regulate 60, a resistor Rp is provided in the input device.

Since the measurement of currents and voltages of the measuring frequency is performed using filters, then in Figs. 2 ^ 5, only | measuring frequency E. EMF, voltages and currents of the fundamental frequency are not shown. Short resistance network is represented as Z _Dfc, Ζθ _Β π Z _DC voltmeter - V5 are designed for measuring voltages between the electrodes and the electrodes and hearth. R ^, R _Ba ^and Rco denote the resistance of the bath under the electrodes, and R _Ab , R _Ac , R _{g (.} Between the electrodes, since they are practically active, Ig is the electrode current, Ugn “voltage electrode is the bottom, and .1 _eo is the fraction of the electrode current passing through the bath to the hearth with the corresponding indices A, B, and C. The ammeter and current circuit of the wattmeter are included in the primary circuit of the input device (Fig. 1) .However, in the diagram (Fig. 2) they are shown to facilitate the semantic side of things included directly in the short network of the first phase, as applied to the determination of the conductivity between Hereinafter, a further explanation is given: as sources of measuring frequency, a synchronous electric machine generator can be used, one phase of which is used with the winding beginning and end changed in comparison with the normal mode, so that, for example, the second phase is lagging behind the first, and the third - from the second to 1/6 of the period EMF e _Ivm create a three-phase EMF system of measuring frequency Ep _D , E _d0 , E _dc in the furnace circuit with the same phase rotation and phase shift as the EMF system e _MiM . For definiteness, in accordance with an example, we will consider the regulated EMF E _{P0 of the} second phase.

The method is as follows.

Example. We determine the conductivity of the furnace bath under the first electrode. Before the start of voltage regulation between the electrodes and the hearth (Fig. 3) are designated as _EPD) and _epB and _g .

Change R _p in the chain Ε _βΒ reduce and _EPV to a new value at _epy, so that the ends of the vectors U. ^, th _ep6 and _EP 0 lie on a straight ACO ABC triangle. In this case, the potential differences between the electrodes U _A6 , U _AC and U _Bc are in phase or out of phase with each other. In this case, the current of the first electrode CD can be decomposed into components only in two known directions AC and OA, but not in three, as in the case where the end of the vector and the _{EP are located} outside the direct AC.

The location of the vector Uj _n g on the straight line A'C can be achieved not only by changing the amplitude Ε _β0 , but also the phase, or both. The indicated arrangement of vectors can be fixed in various ways, for example, using a phase meter or voltmeters, and Y,. At this moment, the sum of the readings of the first two voltmeters is equal to the reading of the third V <+ V2 = V ·? .

When the end of the vector is located (J _3n g on the straight line AC, voltmeters .V4 and V _{5 are} taken. Based on these readings, a triangle is drawn.) Taking the readings of ammeter A and wattmeter W, we can indirectly determine the angle o, which is calculated by the formula = arccos - Tj --- ϊ-, '^ e -'eoA where Ρ - reading wattmeter W. Using the phase meter, the angle can be measured directly ού angle β can be determined from 4OMK since MK II SS β = <OAB -. oc.

Since AK = 1 _e oa » ^and OM = 1 _E A g, then by the sine theorem from A OMK _{t t} sinB

Choa ^x eA _S in (1t - os-β) conductivity of the first electrodin is found by the formula

Genus g of the desired '1 _ E 0A ^Gao "N _E pA hence for any electrode _E 1 sinB______

U _3n 'sin (' it -os-β) -.

The advantage of the proposed method is due to the ease of regulation, voltage measuring frequency, since regulation requires only one parameter. In addition, in some cases, when there is significant mutual conductivity between the electrodes, only two sources of measuring frequency can be dispensed with.

Claims (3)

The invention relates to electrothermal and can be applied in determining the electrical parameters of the bath three-phase three-electrode ore-smelting furnace. A known method for determining the electrical parameters of a bath of a ore-smelting furnace, in which the interelectrode voltages are controlled so that one of the voltages of the bottom electrode remains unchanged, and the conduction of the interelectrode spaces of the bath 1 is calculated from changes in electrode currents. although briefly, the normal operation of the furnace is disrupted. There is also known a method suitable for continuous control and non-disrupting the normal operation of the furnace. This method uses a measuring frequency that is different from the frequency that feeds the furnace. The voltage of the measuring frequency is adjusted so that the potentials of all the electrodes with respect to the bottom are the same in amplitude and phase 2. However, one of the voltages can not be adjusted and adjusted to two, which generally leads to the need to adjust four parameters, i.e. two amplitudes and two phases. The closest to the present invention is a method for determining the conductivity between the electrode and the bottom of a three-phase three-electrode ore-thermal furnace, in which successively each electrode switches off an adjustable power source of a measuring frequency different from the operating frequency of the furnace, the emf of the sources is changed to establish the specified values and phases of the potential potentials frequency on the electrodes, measure the electrode current of one of the phases and its voltage relative to the bottom of the measuring frequency and the measured parameters L 3 are the specified conductivity. The disadvantage of this method is that during tuning, a change of four parameters of the magnitudes and phases of the two electrodes is required. The purpose of the invention is to simplify the process of determining conductivity. To achieve this goal set the potential difference. the measuring frequency between all electrode pairs in phase or antiphase, and the potential of the electrode with respect to the bottom different from the potentials of other electrodes in phase, measure the phase angle of the current of the specified electrode from its voltage relative to the bottom and the phase angle This current is from a voltage between any 1 two electrodes, and the conductivity is determined by the formula. .sinB U3.sinT «-o6- (J) where G is the electrode-sounder conductivity; Ig current measuring frequency in the electrode; Ujj is the measuring frequency voltage between the electrode and the bottom; axis - phase angle between 1dI ep. B is the phase angle between Ig and the voltage between any pair of electrodes. On. 1 shows the power supply of the measuring frequency in FIG. 2 furnace circuit; in fig. 3 is a topographic voltage chart, compared with a vector current diagram of the first electrode. . According to the method, at least one - and - the emf of the power source of the measuring frequency is supplied directly to the branch of the short circuit that supplies the electrode. Measuring frequency input devices can be realized using For example, a transformer made similarly to a current transformer, the only difference being that the power supply of the measuring frequency is connected from the winding side with a large number of turns. The primary circuit of such a transformer is a bus of a short circuit passed through the window of its core. The power source of the measuring frequency contains an ammeter A and a current circuit of a wattmeter W, the scales of which are graduated taking into account the transformation ratio to currents reduced to the primary side, i.e. on the actual currents flowing in the furnace circuit, the winding of the transformer L with a large number of turns, filter F, which transmits only measuring frequency currents and filter F, which transmits only currents of the main frequency, supplying the furnace, conventionally depicted by two-poles, and power supply. frequency s, emf en-ji. Since at least one EMF of the measuring frequency introduced in the furnace chain needs to be generally controlled, a resistor Rp is provided in the input device. Since the measurement of currents and voltage of the measuring frequency is made using filters, figure 2 shows the power sources only (measuring frequencies E. The EMF voltage and voltage of the fundamental frequency are not shown. The resistance of the short circuit is represented as Z , ZrI Z Voltymeters .Vi - Vg are designed to measure voltages between electrodes and electrodes and bottom., 90 denote the resistance of the bath under the electrodes, and Kd Poison., Rg, .both the electrodes, since they are practically active, Ig is the current of the electrode, Ujn- electrode voltage is bottom, and Jjo is g l current of the electrode passing through the bottom bath with the corresponding indices A, B and C. The ammeter and wattmeter current circuit are included in the primary circuit of the input device (Fig. 1). However, in the diagram (Fig. 2) to facilitate the meaning of the matter shown are included directly in the short network of the first phase 1, as applied to the determination of conductivity between the electrode and the bottom of which further clarification is carried out. As sources of measuring frequency, you can use a synchronous electric machine generator, one phase of which is used lzuets with modified as compared to the normal mode, the start and end of winding, so that, for example, the second phase lagging It appears from the first and the third - on the second 1/6 period. EMF e „1, create a three-phase EMF system measuring the frequency Erd, Erd, E in the furnace circuit with the same alternation and phase shift as the system EMF. For definiteness, in accordance with the example, we will consider a regulated EMF Ep0 of the second phase. The method is as follows. Example. Determine the conductivity of the bath furnace under the first electrode. Prior to the adjustment of the voltage between the electrodes and the bottom of the fig. 3) are denoted by Csd, Ujj. By changing Rp in the E chain, a new value of UeBV is reduced so that the ends of the vectors Us), the PER lie on the same straight LAN of the ASO triangle. In this case, the differences between the potentials between the electrodes Odz, Odn, and Ug occur in phase or protinophase with each other. In this case, the current of the first electrode 1ed can be decomposed into components only in two known directions AC and OA, but not three, as in the case of the location of the end of the vector U3t (B outside the direct AC. Get the position of the vector Ujj, g to the direction My speaker can be not only a change in amplitude, but also a phase, or both. You can fix the specified location of the vectors in various ways, for example using a phase meter or V, V and V meters. At this point, the readings of the first two voltmeters are equal to the readings of the third V Vj When located The vector of the direct speaker is taking the readings of the V and Vj meters. From these readings, the triangle OABV-Sn is shown in the display of neither ammeter A and wattmeter W, but can indirectly determine the angle ot, which is calculated using the formula for arccos where F - wattmeter readings W. Using a phase meter, the angle σ can be measured directly. Angle (J can be determined from 4KM, because MK II AC ft ft OAV - base. Since AK IJQA- and OM TEA, t according to the sinus theorem from i OMK, sinft eA sin (1t - ob - (S)) The desired conductivity of the first elec - trope is found by the formula LEPA therefore, for any electrode 1e sinB U gnSinCft -oo-fj) -. The advantage of the proposed method is due to the ease of adjustment, the voltage measuring voltage, since the regulation requires only one parameter. In addition, in a number of cases when there is a significant mutual conduction between the electrodes, it is possible to do with only two sources of measuring frequency. The invention The method for determining the conductivity between the electrode and the bottom of a three-phase three-electrode ore-thermal furnace, in which an adjustable source of measuring frequency, different from the furnace frequency, is connected in series with each electrode, changes the emf of the sources before setting the specified values and phases of the measuring frequency potentials at electrodes, measure the electrode current of one of the phases and its voltage relative to the bottom of the measuring frequency, and from the measured parameters determine the specified conductivity, from In order to simplify the process of determining the conductivity when the phase emf is shifted by one sixth of the period, the potential differences of the measuring frequency between all pairs of electrodes are in phase or out of phase, and the potential of the specified electrode relative to the bottom is different from that of the other electrodes in phase , measure the phase angle of the current of the specified electrode from its voltage relative to the bottom and the phase angle of this current from the voltage between any two electrodes, and the conductivity is determined by the formula I sinR Ujn sinC-rt- -ab-B) where G is the conductivity between the electrode and the bottom; Ig current measuring frequency in the electrode; Ugji is the measuring frequency voltage between the electrode and the bottom; σc is the phase angle between ft; the phase angle between Ig and the voltage between any pair of electrodes. Sources of information taken into account in the examination 1. The author's certificate of the USSR. 436458, cl. H 05 B 7/144, 1972. 2. Authors certificate USSR 392424, cl. G 01 R 27/00, 1971. 3. Authorship of USSR USSR on the application # 2998716, cl. H 05 B 7/144, 1980. 9A Ujng Chzp Uyik Fig.Z