GB1465431A - Electrolytic treatment of elongate articles such as bars tubes or strips - Google Patents

Abstract

1465431 Electrolytically treating moving elongate article ELECTRICITY COUNCIL 9 Jan 1976 [13 Jan 1975] 1364/75 Heading C7B An elongate rigid article such as bar, tube or strip is electrolytically treated e.g. cleaned by passing the article e.g. steel bar 5 horizontally through a bath chamber 1 containing electrolyte and having entry and exit apertures 13 in opposite walls and at least a further aperture below providing communication to an electrolyte reservoir exposed to atmospheric pressure in an external tank 2 in which the electrolyte level is maintained at or below the level of apertures 13 e.g. by a weir 6, air being evacuated continuously from the upper part of chamber 1 e.g. via ducting 17 to reduce the pressure therein so that air is drawn into the chamber continuously through apertures 13 and electrolyte is drawn from the reservoir to maintain its level in the chamber above the level of apertures 13. Any overflow through apertures 13 runs down into the reservoir and over weir 6 into collecting region 7 and out via pipes 8; the electrolyte e.g. a solution of NaOH and KOH may be continuously recirculated e.g. by pump from a storage tank into chamber 1 through two spray pipes 3 which direct the electrolyte spray downwardly on to an anode (4), Fig. 1 (not shown) e.g. a Ni or steel plate of semicircular form. Treatment may be carried out in two separate cells in which the passing article is subjected to a submerged arc in each stage, the voltage in the first being higher e.g. 150 v than that e.g. 110 v in the second; the article leaving the first stage may be cooled by electrolyte spray. Specification 1399710 is referred to.