SU538848A1 - Device for initiating arc in plasma torches - Google Patents

Description

one

The invention relates to electrical engineering, in particular to plasmatrons with water arc stabilization, used for cutting and surface treatment of metals.

At present, the ignition of the arc in plasmatrons with water stabilization of the arc is carried out using wire fuses. The fuses from the wire are inconvenient for use: before each start it is necessary to sharpen the electrode, drill a hole in its end, insert a piece of metal wire into the fuse and then only, insert the electrode into the head, start by touching the fuse to the workpiece. Starting with fuses is unreliable, since the ignition of the arc during the combustion of the igniter may not occur and then all the starting operations must be repeated.

Arrangements are known for initiating arcs in gas-stabilized plasmatrons operating using high-frequency oscillators.

A device for initiating an arc in plasmatrons, containing an oscillator connected in parallel to a source, electromagnetic valves, a current relay in a cathode circuit, a product whose contacts are included in the supply circuit of electromagnetic valves, is known. However, such a device cannot be used to start up plasmatrons with water and arc stabilization due to the absence of starting-regulating elements in the plasma-forming water supply system, as a result of which the plasmatron may fail during the transition from the duty mode to the operating mode.

In order to increase the reliability of the excitation of an arc in plasmatrons with water stabilization of the latter in the proposed device, one solenoid valve is installed in

the supply line and the other in the supply line, both of which are interconnected at the outlet of the valves. The scheme of the proposed device for initiating an arc in plasmatrons is shown in the drawing.

Electrode 1, placed in an annular diffuser 2, is attached to minus power supply 3, plus which via ballast

resistor 4 is attached to the diffuser and directly to the metal being cut 5.

Before starting, the water from the pipeline enters through the pipeline 6 to the stabilization

a part of the plasmatron with a nozzle 7. The water solenoid valve 8 is closed. The firing gas flows through the open gas solenoid valve 9 through the pipeline 10 into the meleda gap by a diffuser and an electrode. To start include

a high frequency oscillator 11 and an auxiliary arc is ignited between the diffuser and the electrode. This arc is blown out of the nozzle 7 by a stream of gas.

To ignite the main arc, touch the auxiliary arc flame tab to the metal being processed (as usual). The main arc is turned on, including the current relay 12, which turns off the solenoid valve 9, closes it, and the gas enters the gap between the electrode and the diffuser. At the same time, the valve 8 is torn off and the cooling water through the pipeline 13 begins to flow into the gap between the electrode and the diffuser, cooling them.

Claims (1)

Invention Formula A device for initiating an arc in plasmatrons, containing an oscillator connected in parallel to the source, solenoid valves, a current relay in a cathode circuit — a product whose contacts are included in the supply circuit of solenoid valves, characterized in that, in order to increase the reliability of arc excitation in plasmatrons from stabilization of the latter, one solenoid valve is installed in the pipeline, supply air, and the other - in the pipeline, supplying water, both The piping is interconnected at the outlet of the valves. Bosirjx water