GB159709A - Improvements in or relating to electrodes for oxidising nitrogen - Google Patents

Abstract

159,709. Loring, F. H. Dec. 31, 1919. Gases, treating with electric discharge. - A continuous - current arc is repeatedly drawn out by reciprocating electrodes in a magnetic field. This field may be produced by a series coil 5 around the lower electrode or an external extension thereof, or within or surrounding the arc chamber, which may be of cast iron so as to form part of the magnetic circuit except when the coil surrounds it in which case brass or manganese steel may be used. The electrodes may be of magnetic or non - magnetic material. The replaceable lower electrode 6 may be fitted on a conical support 3, also renewable and held by a tapered socket 2. Alternatively, when the upper electrode is hollow, the upper part of the lower electrode may be cupped. When the coil is inside the chamber, electric connection may be made by means of a supplementary tapered sleeve with mica insulation between tapering surfaces. Air may pass through the hollow movable upper electrode 10 to the arcs, the usual inlets 11, 12 being closed. In a modification, the upper electrode socket passes through an insulating partition, above which it is slotted to admit air from the holes 11, 12. To facilitate ejection of the upper electrode from its holder 19 in the arrangement shown, a split sleeve 18 covering apertures in the holder can be slid on to the lower part of the holder. Products are withdrawn by a pump. Mica insulation such as 17, where used, should have a free surface of not less than 15 mm. in order to prevent arcing due to deposition of metallic dust. A section of the casing is removable and is held by plunger catches 22. A window 27 of amber-coloured mica is provided. The products may be employed for bleaching flour. Specification 22101/05 is referred to. According to the Provisional Specification, the magnetic field may be produced by bringing near the electrodes the poles of the usual series inductance, or connecting these poles by bridge-pieces to the lower electrodes.