SU754500A1 - Switching apparatus - Google Patents

Description

The invention relates to electrical apparatuses, particularly for electrical devices, inverter-rectifier-converter equipment, and can be used for inverting or straightening special conditions exploitation ⁵ tion, e.g. in the presence of large magnitude converted currents or high ambient temperature, and also if necessary have a low frequency invert.

It can be implemented when creating industrial power plants of high power instead of common large-sized mercury-inverter converters, when creating autonomous inverter systems of a reduced frequency (less than 50 Hz) necessary to power induction mixers of metal melts and other conductive media in metallurgical chemical industry in particular

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cases of creating control systems with current type conversion, as well as in some other cases, for example, as a flow meter or electric meter for the number of

drawable piston doses of electrically conductive fluid, etc.

A switching device is known that contains an annular closed vessel made of electrically insulating material that is partially filled with an electrically conductive liquid, with contacts embedded in the walls of the vessel, and current-carrying buses arranged along the closed vessel and providing an electrically conducting liquid with an alternating magnetic field and opening and closing of the electrodes. The latter allows the conversion of direct current into pulsating (inverting) or vice versa (rectification) [1].

However, the device is difficult to constructive implementation and not reliably reliable in operation.

Closest to the present invention is a contact device containing a channel with built-in electrodes, switched with liquid metal and a drive. The drive is made in the form of two end-type induction systems, creating a rotating magnetic field in which the specified channel is placed [2].

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However, the device is also not sufficiently reliable in operation.

The aim of the invention is to improve the reliability of the device.

This goal is achieved by the fact that the known device containing a channel with built-in electrodes, switched with liquid metal and a drive, is equipped with a shaper of piston flow, installed between the drive and the channel.

The drawing schematically shows the proposed device.

The switching device contains at least one linear channel 1 (two channels are shown in the drawing) to which electrodes are connected, made in the form of current-carrying buses 2, which are separated by electrically insulating sections 3. The piston driver 4 is located at the exit to the channel (channels) flow. The rotating rotor 5 with shaped shaper openings can be driven by analogy with a turbine under the pressure of gas, vapor or liquid, coming through nozzles 6 and 7, one of which serves to supply a contacting electrically conductive liquid, or from a driving motor (the drawing shows an electric motor shaft 8 passing into the driver using seals), or from the inductor of the rotating field, covering the body of the driver of the piston flow (in the drawing, the inductor is not shown).

The switching device operates as follows.

The rotating rotor 5 of the piston flow former is alternately supplying portions of electrically conductive liquid and gas (steam or other non-conducting, immiscible with the first, liquid) flowing under pressure through nozzles 6 and 7. In this (each) channel a moving, for example, gas-liquid, piston flow. The repetition rate of the pistons is determined by the speed of rotation of the rotor and the number of its shaped holes. Moving through the channel, the piston flow provides alternate closure and opening of the adjacent electrodes, the number of which is determined by the needs of the conversion circuit. If a direct current voltage is applied to the electrodes, a harmonic interruption of the electrical circuit is performed, ensuring the inversion of electricity. With a consistent movement of the pistons with the frequency of alternating current oscillation, it can be straightened. Piston flow after passing the channel (s) can be thrown into the surrounding space, if the work is done

open loop. If desired, the spent piston flow may be subject to subsequent separation (or condensation) with the return of components to the pipes 6 and 7 (the work is carried out in a closed loop).

The short residence time of the piston in the channel, the limited length of the channel, and especially its linearity, ensure that the structure of the liquid piston remains as it was formed when the piston entered the channel of the switching device, which significantly increases the reliability of operation. An increase in the frequency of electric power conversion can be achieved not only by increasing the speed of rotation of the rotor and the number of its shaped holes, but also by increasing the number of electrodes, as well as the number of channels. In this case, several switching sections of the device are connected in series to each electrical circuit.

The proposed switching device can be used to invert relatively low voltage electric power with a large amount of currents, in some cases reaching values from a few to several tens of kiloamperes and representing a significant problem when using conventional equipment.

The device is unpretentious to elevated ambient temperatures, since the use of semiconductor conversion systems is limited to a temperature of the order of 100 ° C. The dimensions of the device are small, since the current density achieved in electrically conductive liquid media, in which liquid metal can be considered, is on the order of several tens of amperes per millimeter squared (10–50 A / mm ² ), while the permissible current density in the known thermomission electronic devices by one — three orders of magnitude less.

Claims (1)

Claim A switching device containing a channel with embedded electrodes switched by liquid metal and a drive, characterized in that, in order to increase reliability, the device is equipped with a piston flow driver installed between the drive and the channel.