CS255762B1 - Device for the continuous regulation of heating capacity - Google Patents

Abstract

The device for continuous regulation of the heating output is designed for optimal control of the electric heating of the liner of the vacuum vessel, which is a part of the vacuum equipment for extra-steel processing of steel. The heating element for heating is a graphite heating rod. Infinitely varied heating performance of the graphite heating rod is achieved by controlling the heating voltage by means of a variable adjustable reactance reactor, included in the secondary circuit of the heating transformer and with a stepwise adjustable secondary voltage. A controlled change in the reactor reactance changes the impedance of the electrical supply section from the heating transformer to the graphite heating rod, thereby altering the voltage drop across the section, thereby achieving a controlled change in the heating voltage and heating power of the heating rod within each of the two subsequent heating control stages. of the transformer, and hence the continuous control of the heating output in the control range of the heating transformer.

Description

255 762

The invention solves the continuous regulation of the heating power of the graphite heating rod, which serves for heating of the ceramic lining of the vacuum vessel, which is a part of the vacuum equipment for out-of-steel treatment of steel.

The hitherto known methods of heating power control utilize a connected step-by-step control of the heating power. In the case of the stepwise control of the secondary voltage of a single-phase heating transformer, it is not possible to achieve an optimum course of control of the heating output of the graphite topif bar as a function of the lining temperature of the vacuum vessel and to change the impedance of the graphite heating rod with time due to the reduction of the heating rod cross-section due to its firing. In the case of the use of a three-phase heating transformer and a controlled rectifier for continuous regulation of the heating output, greater demands are placed on the building space, the investment costs for this device are disproportionately increased and the power factor resulting from the controlled rectifier is significantly deteriorated principle of the controlled rectifier function.

The above-mentioned disadvantages are eliminated by the device for continuous regulating power according to the invention, the principle of which is that the variable adjustable induction reactive reactor is connected in the secondary circuit in series b by a single-phase winding of 2 - 2S5 762 heating, with a transformer with a step-adjustable secondary voltage in series with the electric supply line and a graphite-hung rod, held in copper contacts by graphite contacts. By controlling the reactance change, a continuous change in the heating voltage on the graphite heating rod is achieved between every two subsequent control stages of the nominal secondary voltage and hence the heating power control over the entire control range of the heating transformer. Another advantage is that the reactor can be designed both in design and manufacture with small dimensions, that it can be installed in both newly designed and existing objects of vacuum equipment, that there is no significant deterioration of the power factor in the regulation and that the utilization of the heating rods increases due to continuous regulation. consumption.

In the exemplary embodiment, the continuous heating power control apparatus of the present invention is illustrated in the accompanying drawings, wherein FIG. 1 shows a vacuum apparatus for the non-furnace treatment of a steel with a typical arrangement of a liner for heating a liner using a reactive reactor and FIG. this device is shown in a half-sectional view.

The apparatus for continuously adjusting the heating output according to FIGS. 1 and 2 is formed by a reactor 2 and a variable reactance set by the actuator Jg ' which is connected in a secondary circuit of a single-phase heating transformer 1 with a stepwise adjustable secondary voltage in series with an electrical supply line 2 ' The copper contacts are part of the movable brackets 8 which allow the assembly and replacement of the graphite heating rod 6 and the graphite contacts 6 on the work surface 11. Controlled change of reactor reactance 2 results in a controlled change

the impedance included in the section from the output of the heating transformer 11 to the copper contacts 2fa and thereby the controlled change in voltage drop across the section, thereby achieving a controlled change in the heating voltage on the graphite heating rod 5 within each of the following two regulating

Claims (2)

2SS 762 degrees of the heating transformer 1, and thereby a controlled continuous change in the heating power of the graphite heating rod 6, heating the ceramic lining 10 of the vacuum vessel 12 »The apparatus for continuously adjusting the heating output allows to optimally control the course of the heating output and thereby shorten the heating time of the lining of the vacuum vessel. the initial prescribed temperature, thereby increasing the use time of the vacuum device, and reducing the consumption of graphite heating rods to maintain the prescribed lining temperature. SUMMARY OF THE INVENTION An apparatus for continuously controlling the heating power, characterized in that the variable inductive reactive reactor (2) is connected in a secondary circuit in series with a single-phase heating transformer (1) with a stepwise adjustable secondary voltage in series with an electrical supply line (3.4) and a graphite heating rod (5) mounted in the copper contacts (7) by the graphite contacts (6). 2 drawings