SPEED DETERMINATION OF AUTO-ELECTRO-MAGNETIC ROTATION (AEMR) OF DC ARC IN 'PLASMALAB' FFP-PLASMA REACTOR

摘要

The new "PLASMALAB" FFP-reactor consists of plasma torch with hollow cathode (or common graphite hollow cathode), coaxially mounted over a vertical cylindrical reactor-anode. The original technical solution for series connection of an inductor, coaxially mounted on the tube reactor-anode in the anode electric chain, allows arc rotation which is generated by the arc own current (Auto-Electro-Magnetic Rotation - AEMR). The designed and manufactured experimental stand makes possible the test of a graphite model of a new "PLASMALAB" FFP-plasma reactor. Experiments involving a common hollow graphite cathode (without plasma torch with water cooled nozzle) are performed on that stand. The advantage of this variant is that it is not necessary to blow plasma gas, which additionally cools the reactor space. In principle, this is one of the new solutions in the "PLASMALAB" reactor design. The main aim of this actual work is to develop an original scheme for measurement of speed rotation of DC arc, burning in an axial magnetic field. Rotation speeds of the arc spots (cathode and anode) under Auto-Electro-Magnetic Rotation are found, as functions of arc current and magnetic-field power. The results found employing the graphite model (new "PLASMALAB" FFP-plasma reactor) show that the rotation speed of the cathode spot is by an order lower than that of the anode spot. The maximal average rotation speed of the cathode spot found is about 800 min~(-1) at arc current 250 A and a distance between cathode front and inductor end - DELTA velence 50 mm. Under the same conditions, the maximal average rotation speed of the anode spot is over 10 000 min~(-1).