US1133628A - Galvanizing wire, hoops, sheets, and the like. - Google Patents

Description

' HuH. FIELD, M. HUWARTH & E. A. ATKINS.

GALVANIZINGWIRE, HOOPS, SHEETS, AND THE LIKE.

APPLICATION FILED FEB. 11, 1913. 1,133,628. I Patented Mar. 30, 1915.

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/ 4.1% 04% Ml JAG/WM W/ TN 66 a HENRY HATTEN FIELD, OF GRAPPENHALL, MARK HOWARTH, 0F LATCHFORD, AND EVAN ARTHUR ATKINS, 0F LIVERPOOL, ENGLAND.

GALVANIZING WIRE, HOOPS, SHEETS, AND THE LIKE.

Specification of Letters Patent.

- Patented Mar. 30, 1915.

Application filed February 11, 1913. Serial No. 747,719.

To all whom it may concern: v

Be it known that we, HENRY HATTEN FIELD, MARK HOWARTH, and EVAN ARTHUR ATKINS, subjects of the King of England, residing at Grappenhall, in the county of Chester, England; Latchford, in the county of Chester, England, and Liverpool, in the county of Lancaster, England, respectively, have invented newand 'useful Improvements in or Connected With Galvanizing Wire, Hoops, Sheets, and the like, of which the following is a specification.

This invention has reference to the covering or coating of iron and steel-Wire, bands, strips, sheets, and other forms of articles, with zinc, by what is known as the galvanizing process; and it has primarily for its object to provide improvements in connection with the process of hot galvanizing, by which the quantity of dross and oxid formed in the process is reduced or eliminated, at the same time this effect is accomplished with very little expense.

In galvanizing iron and steel wire, (or other articles) by the ordinary hot process, it is customary for the wire or metal previous to entering the molten metal, to pass composed into its constituent elements, ironand chlorin; the iron combining with the zinc forming dross which falls to the bottom of the bath; the chlorin, at the same time combining with the zinc forming zinc chlorid. The zinc chlorid formed by these reactions, we find, is the flux that actively assists the wire or other iron or steel article to galvanize, by obviating the formation of iron oxid or decomposing any iron oxid that may be on the surface of the article; the zinc chlorid combining with the oxygen, forming oxy-zinc chlorid; the iron being liberated unites With zinc again orming dross. Some of the Water of solution which is carried by the article into the bath, is also decomposed by the molten metal, thus freezing oxygen and forming oxid of zinc. Upon these reactions, the invention hereunder is based and applied to the ends and effects The solution of iron chlorid hereinafter described. This latter chemical reaction also takes place in the ordinary process of sheet galvanizing, in which-it is customary to employ ammonium chlorid as a flux; zinc chlorid being here again the real reducing agent. In the same Way, other fluxes are used in the galvanizing process to effect the same purposes. In the cases of the use of all these fluxes, the chemical reaction taking place, causes the liberation of iron, chlorin, and oxygen, which instantly combine with the molten metal, forming dross, oxid, et cetera, in the manner described. In and by the present process, the employment of fluxes is rendered more easy.

In the present process, the prevention of the formation of dross is effected by, prior to the iron or steel article being subjected to the action of the molten metal, removing the chlorid and oxid of iron from its surface, and also preventing any oxid forming on it after its removal, and before it reaches the molten metal; and this is effected by an electrolytic action upon it in a bath or vessel containing a suitable electrolyte, such as hereinafter specified, through which the iron or steel article is passed prior to passing into the molten zinc metal, which has the combined effect of removing the oxicl from the iron or steel article as stated, and also of depositing. a protective covering on it, so that the formation of oxid on it, after it leaves this electrolytic treatment, and before it enters the molten metal, is prevented. By this treatment or process, when the iron or steel Wire or other article, enters the bath of moltenzinc metal, it carries no free iron compounds in solution, or iron oxid on its surface, and therefore,' the chemical action due to these, when brought into contact with the molten zinc metal, is obviated; and in this way the process avoids any exchange of iron compounds with the zinc metal, and so in this manner, the primary object of the invention is accomplished, namely, the saving of waste or loss in the form of dross, oxid, and the like, as no reducing action, resulting in the liberation of free iron takes place; While also, and .due to the same causes, little or no free oxygen is liberated; In addition to the above advantages, others, in respect to the mechanical characteristics connected with the carrying out of the process of hot galvanizing, are rendered possible by the non-production-=, of dross in the process; as for instance, the substitution of bottom or internal heating for side heating,

which is much more effective and economical than the latter method. The life of the bath or pot containing the molten metal, will also be considerably increased; and on account of the prevention of the chemical reactions which take place on the surface of the molten zinc, there will be a considerable reduction in the volume of fumes that pass off into the atmosphere.

The wire or metal to be treated will be pickled, as-usual; and after pickling, may

' be washed, immediately before it is moved into the electrolytic apparatus, so that on I entering this apparatus and being subjected to the electrolytic action, itwill have upon its surface, either the pickling liquid, or water. --i

The covering of zinc, electrol tically deposited upon 1 the wire or artic e, need be only a very'thin film, and it is obtained-by passing it throughfi'a vessel containing a suitable electrolyte, as above described, dis- 2 5'Jposed in the front of the bath of molten zinc metal; and from its passage through! thiselectrolyte, the wire or other articlereceivesa metallic coat of zinc, by the ordinary electrolytic process or action. 1

y used as the electrolyte, but that preferred is one in which either zinc chlorid, or stannous chlorid, is the base.

'Byjthe wire or metal passing through the acid batl' immediately before entering the electrolyticbath, it would be coated with a sdlution'of iron chlorid, and this iron chlorid is immediately decomposed by electrolytic action and'by interchange with the elements "in the electrolytic bath forms zinc chlorid and free. iron as iron hydrate, and it is covered' with a thin coating'or film of zinc, and I protected.

An arrangement of plant for galvanizing i if wire strip, or other continuousi form of' metal, is illustrated diagrammaticallyin the accompanying drawing.

suitable metallic solution may .be

In the drawing ais the wire or other continuous kind of metal; 6 is the acid bath through which the metal is first passed; 0 is the electrolytic cell, containing the zinc chlorid base, 0 being the anode and d the galvanizing bath containing the molten zinc orfspelter. 7

What we claim is 1. In galvanizing steel or iron wire, strips, bands, sheets and the like, the process consisting of converting oxid of iron on its surface, to chlorid of'iron, by subjecting it to the action of dilute hydrochloric acid; then removing the chlorid of iron so formedby subjecting its surface to an electrolytic action, by passing it through an electrolytic bath of chlorid of 'zinc, and also simultaneously thereby coating its surface with a thin coating of zinc, by electrolytic deposition; and finally immersing this iron chlorid free and zinc coated iron or steel articlefin molten zinc; substantially as described.

2. In galvanizing steel or iron wire strips,

bands, sheets and the like, the recess consisting of convertingthe oXid 0 iron on its surface to' chlorid of'iron by subjectingit to the actionof dilute. hydrochloric acid;

then removing the chlorid of iron soformed',

by subjecting its surface to an electrolytic action, by passing it through an electrolytic bath of chlorid of zinc,.the anode of which is a plate or body of zinc, and the article-to be coated is the cathode, and also simultaneously thereby coating its surface with a thin covering: of zinc by electrolytic deposition;

and finallyimmersingthis iron chlorid free I i SIDNEY Flam.

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