Control method of level of top surface of slaggy phase and boundary of slaggy and metallic phase of melt in lift tube tank of iron-and-steel furnace by vanukov or romelt

FIELD: metallurgy.

SUBSTANCE: invention relates to non-ferrous metallurgy field. According to method it is implemented voltage feeding to electroconductive refractory rods, used for slag heating and setting adjusting of current value. It is displaced rod and implemented continuous measurement and comparison of current value through rod with setting. At equality of measured value of current to setting value it is fixed top surface of slaggy or metallic phase of melt in tank of iron-and-steel furnace. In the capacity of electroconductive refractory rod it is used graphitic rod or electrode, used for electroarc heating of melt in tank of iron-and-steel furnace. After achievement of equality of current setting to corresponding measured current values it is checked equality to zero of the first current derivative.

EFFECT: increasing of accuracy and reliability of control.

3 cl, 1 dwg

The method of control of level and interface of the slag or metal melt phase is intended primarily for use in the metallurgical industry, for example to control the level of the slag and metal phases in liquid bath furnaces type Vanyukov or remelt, and can find its application in various areas of the control level and/or topic different phases.

Currently, the level of molten metallurgical slag and metal baths furnaces type Vanyukov or remelt determine short-term immersion in them refractory rods (scrap, refractory rods, etc. Separate descriptions of such trivial method not found!). Because the mechanical resistance of the molten materials to the movement of the drop rod is almost the same, the accuracy of control, however, remains at a low level, which does not guarantee the loss of the metal phase from the slag or the last release with metal. In addition, the traditional way unsafe, accompanied by replacement of the control rod after each measurement and allows you to get continuous information about the level and the interface of the slag and molten metal in the furnace bath.

The known method of control of level and interface solutions in containers that are carried out by differentiation of the temperature of the phase sostavlyayushchikh metals and molten salts [Thermodifferential level switch liquid media model .S5100.]. This is a known technical solution is the closest analogue functionality of the proposed method.

The disadvantages of this analogue: when there is only a difference of temperatures in a controlled environment (in the steel tub not!); the sensor must be constantly in a production environment (in the bath metallurgical furnace environment is aggressive, so the sensor is destroyed in a matter of minutes); operating temperature range does not exceed 600°C (in the metallurgical furnace 1300-1900°C).

Also known for the level controller is a universal CIRCUIT, produced by the group of companies "URALSIB". The principle of control conductivity of liquid media whose value is set experimentally and are defined as settings - equivalents controlled levels or phases. The method implemented in this computer transmitter, is the prototype of the proposed method.

Cons: narrow range level control partition or different liquids with different specific conductivity; the sensing element may not be in a hostile environment and a high temperature of 1,300÷1900°C; method implemented in the prototype, does not provide for the selective separation of the measurement range of the level of the slag phase and the metal phase of the melt in the bath, i.e. cannot perform the function the selective control of changes in the level of slag and metal in the melt bath metallurgical furnaces. The prototype also not able to automatically find the origin of the slag level and especially the boundary between the slag and metal phases, since these controlled parameters of the metallurgical process of changing the height of the bath of the furnace in the function of actual performance and the degree of recovery of the metals in the furnace bath.

The problems solved by the invention, improving the reliability and accuracy of control of the level of the slag layer and the interface or contact between the slag and metal layers in the tub metallurgical furnace at steady-state bias level of the layer of slag and the specified boundary of the contact layer of the slag with the metal layer of the melt in the bath metallurgical furnace; improving the reliability and durability of the sensing element for the implementation of the proposed method to the longevity of technological elements metallurgical furnace, the opportunity to receive information on the controlled parameters remotely (without approximation staff to melt and environmentally safe conditions) with subsequent transfer of this information on computers and automated management tools without the participation of the subject.

The technical result is achieved due to the fact that in the method of controlling the level of the upper surface of the slag phase or the interface of the slag and Metallichesky phase of the melt in the bath siphon metallurgical Vanyukov furnace or remelt carry out the supply voltage to electrically conductive flame-resistant rod or rods, used to heat the slag, and setting the setpoint current value. Carry out the movement of the rod or rods with simultaneous and continuous measurement and comparison of the magnitude of the current through the rod or rods with setpoint and in case of equality of the measured current value to the setpoint value are fixing the upper surface of the slag or the boundary between the slag and metal phases of the melt in the bath metallurgical furnaces.

In addition, increasing the service life of the elements that implement the proposed method to the service life of items of technological equipment and technical simplify the implementation of this method, as a core use of a graphite rod or electrode for electric arc heating of the melt, and to achieve high precision control in the proposed method further measure the first derivative of the current through the rod.

Implementation and operation of the proposed method is illustrated by a functional diagram of a metallurgical furnace (Vanyukov, romelt etc), represented in the drawing. A description of an example method of implementation is given for the case of level control partition boundaries of the slag and metal phases in the tub siphon furnace. In the drawing are given the following designations: 1 - reaction zone of the furnace; 2 - siphon with a grounded enclosure with holes to release the slag phase 2 "and" and Metallichesky phase 2 "b"; 3 - conductive rod is moved vertically actuating mechanism 4 (2-rod control system is not given here) and connected to the transformer 5 with the measurement (current and napryajennymi windings) and other auxiliary elements, which, in turn, through a computer connected to the operator's monitor (not shown here).

From the reaction zone 1 bath Vanyukov furnace or remelt the slag and the metal component derived metallurgical melt enters the siphon 2. As the filling of the siphon 2 metal component (phase) accumulates in the lower zone of the bath siphon 2 and is available (continuously or intermittently) through the opening 2 b, and a slag phase accumulates above the layer of the metal phase and is also available through the hole 2 "and". For efficient operation of the furnace it is necessary to maintain the specified level of slag and metal, and more importantly the level of the zone boundaries of their division. For this purpose, the rod (electrode or more than two electrodes) serves stabilized voltage, providing an arc between the stud and the slag, and as you move down between the rod and the metal melt phase.

As necessary, the operator or by the computer program on the rod 3 applies a voltage, and the actuator 4, when the signal command from the operator or the of ontroller movement of the rod 3, the latter enters into contact with the upper surface of the slag phase in the trap 2. Between the lower end of the rod 3 and the slag occurs the arc current. As in the mode of adjustment of the measuring system as set point set the experimental value current slag when it is reached, the movement of the rod stop and fix the position of the rod at the time of occurrence of such equality, i.e. fixed to the upper level of the slag (m, cm, mm etc). Next, give the command on further movement of the rod 3 down with reference to the same dimensions.

To control the level of the boundary between slag and metal in the bath rod 3 with the same actuator 4 is moved further down to achieve the conditions of equality of current through the metal current value of the current through the rod.

After this movement of the rod 3 stop and fix the amount of its movement in the respective dimensions. Knowing a priori information (origin of movement and the geometric dimensions - height bath siphon 2), define the boundary of the slag and the metal layer of the melt in the bath Vanyukov furnace or Romelt.

Operating experience from Vanyukov furnaces, Romella and other metallurgical furnaces it is known that the melting and recovering of metallurgical raw materials, particularly those containing tugoplavok the e materials as titanomagnetites or molten lining materials, there are significant problems with the release of melt from the bath of the furnace high-viscosity slag, which leads to malfunction of the furnace or a major incident. In addition, to reduce the amount of mechanical removal of valuable metals from slag, the temperature of the slag at the interface with the metal phase must be raised to the maximum possible reduction in the viscosity of the slag. In this regard, as the rod 3 to effectively use one or more electrodes, the ends of which are located at the interface between the slag and metal. This can be achieved if after reaching the core metal level of the voltage applied to the rod 3, increase of requirements to ensure the required temperature to achieve the desired viscosity of the slag.

Thus, the set of distinctive features of the proposed technical solutions (method) provides the achievement of the previously mentioned technical and other positive effects.

1. The method of controlling the level of the upper surface of the slag phase and the boundary between the slag and metal phases of the melt in the bath siphon metallurgical Vanyukov furnace or remelt comprising applying voltage to the conductive flame-resistant rod or rods used to heat the slag, the setpoint reference current value, the movement of the rod or rods with simultaneous nepreryvnym measurement and comparison of the magnitude of the current through the rod or rods with setpoint, in this case the equality of the measured current value to the setpoint value, record the level of the upper surface of the slag phase or the interface of the slag and metal phases of the melt in the bath siphon metallurgical furnaces.

2. The method according to claim 1, characterized in that electrically conductive flame-resistant core use a graphite rod or electrode used for electrical heating of the melt in the bath metallurgical furnaces.

3. The method according to claim 1, characterized in that to confirm the location of the top surface of the slag phase or the interface of the slag and metal phases of the melt after achieving equality setpoint current with the corresponding measured values of the current test equality to zero of the first derivative of the current.