US1191526A - Process of coating wire with metal. - Google Patents

Description

G. L. MEAKERL I PROCESS OF COATING WIRE WITH METAL.

APPLICATION'HLED JUNE 27)!913.

Patented July 18, 191

GUY L. MEAKER, OF JOLIET, ILLINOIS.

'Paocnss or COATING WIRE WITH METAL.

I Specification of Letters Patent. Patented, July 1916.

Application filed June 27, 1913. Serial No. 776,151.

To all whom it may concern:

Be it known that I, GUY L. MEAKER, a citizen of the United States, residing at Joliet, in the county of Will and State'of Illinois, have invented a new and useful 'Process of. Coating Wire with Metal, of which the following is a specification.

My process is especially intended and adapted for-coating iron or steel wire with zinc or spelter commonly known as galvanizing, though as will appear from the following specification it is in some of its features applicable to other coating. processes. In the following specification I have specifically described the process with reference to its employment for galvanizing wire but it is'to be understood that the specific description is for the purpose of exemplification only and that the scope of the invention is to be determined from the following claims, in which I have endeavored to distinguish it from the prior art so far as known to me without, however, relinquishing or abandoning any part thereof.

Coating metal'with metal and more specifically galvanizing is ordinarily accomplished by either of two processes, the first electrochemical in its nature, the metal being de-' posited from a solution, and the second, which is the more generally employed so far as galvanizing is concerned, the so-called hot process in which the metal to be coated is submitted to a bath of hot coating metal. My invention relates more particularly to this latter process and to its applicatlon for coating or galvanizing iron or steel wire.

The steps involved in galvanizing wire consist of annealing, cooling, cleaning or pickling, usually in hydrochloric acid, washing, fluxing and passing the wire through the molten spelter or zinc to accomplish the coating. Ordinarily the steps of the process occur in the order in which they have just been recited. So far as the ultimate result of the treatment is concerned, the order of the annealing step of the process is unimportant so long as it precedes the galvanizing step, but it has heretofore been performed prior to'fluxing the wire upon the theory that the heat of annealing v would dissipate the flux which is ordinarily either ferrous or zinc chlorid. Obviously, however, with the annealing step,-the,first in the process, and the galvanizing step, the last,

and with ,the intermediate steps consisting of immersing the wire in aqueous baths for pickling, washing and fluxing, theheat used in annealing the wire is dissipated before the last step is reached In order to secure the best results however the wire must be hot when it enters the galvanizing bath in order to open its pores that it may properly receive the coating or spelter and such a close unlon be "formed between the wire or steel and the zinc that the coating will not flake or peel ofl'. It has been customary therefore after the pickling, washing and fluxing operations toreheat the wire prior to its entry into the spelter tank. Thisreheating as well as the preceding steps following the cleaning of the wire under ordinary practicefurnish opportunity for reoxidation of the wire and consequent interference with perfect galvanization.

The objects of my invention are to overcome the objections and difliculties above pointed out and to provide aprocess in which a single heating of the wire is suflicient for both annealing and galvanizing and no opportunity is presented for oxidization of the wire after the annealing operation.

With these objects in view my process contemplates the reversal of the relative positions of the steps of annealing and fluxing as usually carried out and the use of but one heating agency for the annealing and coating operations.

In my process the green wire or wire as it comes from the drawing operation'is cleaned to remove any oxidation products or scale formed in the drawing operation by pickling and'washing and is then fluxed, all these operations .as well as the drying of the wirebeing performed before the annealing operation. The latter immediately precedes the coating with metal and 1s so performed with relation to that step that no opportunity is afforded for the acquisition of oxids or scales by the wire. The wire is boiling point above the annealing temperature and is also stable thereat.

In the accompanying drawings, I have illustrated apparatus for carrying my proc ess into efiect but such apparatus is not a part of the present invention, which may be carried out in other forms of apparatus, but

forms the subject matter of another application. Serial No. 776,150 filed by me omthe spelter tank. From the flue 13 the products I same day herewith.

ill

lln'said drawing, Figure I is a diagram-' matic view of a complete apparatus for carrying out my process; Fig. 2 a "vertical longitudinal section of that portion of the apparatus in which the steps of annealing and galvanizing are. carried out; and Fig. 3 a cross sectional detail.

Referring first to Fig. 1, it will be seen that the apparatus there shown is adapted for the n simultaneous treatment of four strands of wire though obviously if desired the construction could be modified for the treatment of a greater or less number of strands. Four wire reels are shown at A the wire from which passes over a guide B into and through a hood C and through a pickling bath'D of dilute hydrochloric or other suitable acid, a washing tank E which may contain water and a fluxing tank F containing a suitable flux. As heretofore stated the flux which I preferably employ must. be unafi'ected by the annealing temperature of 1300" F. and with this in view I have chosen zinc chlorid which has aboiling point of approximately 1436 F. and is stable at that temperature as suitable for the-practice of my process though as above stated other. fluxes capable of resisting the annealing.

temperature employed may. be substituted therefor. vThe wire coming from the reels is led through the baths in the order stated around aroller or stationary guide G whence it is carried back beneath the hood to be wholly or partially dried by the heat arising from heated baths E, F. From the hood C the wires are carried to a furnace H provided with suitable heating means as with that to be presently described and contain:

ing one or more longitudinal tubes I through which the wires are passed to be heated on their way to the galvanizing bath K. From the latter the wires are ledaway to be cooled and reeled up ready for use.

ing to Fig. 2, the furnace construction by which the annealing tubes and spelter bath are heated comprises a fire box 3 having the grate bars 4: and supplied with air through an air flue 5. The latter receives its supply of air from an intake due 6 having a perforated cover 6' arranged intermediate the heating chamber 7 and that portion of the furnace which surrounds and heats the spelter bath K. Flue 6 co cates with a'pair of side dues 9 arranged on .opposite sides of the downcomer due 10 for mentioned, thence through the 'downtake an uptake flue 13 arranged beneath the pass along the horizontal flue 14 beneath thespelter tank and provided with suitable bafies 15- from which they pass into the downtake 16 and so to the chimney at 17. At 18 I have shown a supplemental fire box beneath the spelter tank and communicating with the fiue 13 by a passage 19. Ordinarily this supplemental fire box is employed only in starting the furnace. Above the flue l4 and forming the top wall thereof is a spelter tank K with the interior of which communicate one or more annealing tubes 1 the main bodies of which are contained in the heating chamber 7 where they are raised to an annealing temperature. At the entering end the tube or tubes are upwardly inclined as at 20 to tacilitate the entrance of the wires to he annealed and at the other end they extend across and are cooled by the flue 6. Beyond said due they abut against the vertical wall of the spelter tank to which they are connected by reducing bushings 22 having flanges on the inside of said tank and extending a little way into the ends of the tubes. Each tube is preferably provided with partitions 21 see Fig. 3 so that it. may be employed for the heating of a set of wires simultaneously without their ,in any wise interference with each other. Within the tributes itself through the annealing tubes 20 within which it surrounds the wires in the various compartments and rises, at the intake end of said tubes to a level intermediate the levels of the lead and spelter respectively in the coating tank. The lead within the tubes is heated to an annealing temperature and evenly heats the wires to the same temperature.

The steps of the process have already been described but may be recapitulated as follows: The wire or wires from the reels A.

pass successively through the pickling, Washing and flum'ng tanks around the roll G and again under the hood C where they are dried by the currents of hot air rising from and around the baths. From the hood 0 the wire passesthrough the tubes 20 in which the several strands are received and heated to an annealing temperature. lhence the wires emergeinto the lead bath 27 and pass upwardly into the spelter bath- 26 through which they are guided in a horizontal course by the guide rods 24, 25 finally emerging in an annealed and coated condition at the end of the tank. Obviously a number of tubes may be used depending upon the numberof separate strands of Wire to be treated.

The heated gases and products of combustion from the fire box 3 first come in contact with the tubes I Whichare highly heated thereby, and then pass to the tank K which they also heat but to. a lesser degree. The wires are therefore heated to an annealing temperature in the tubes I and after being cooled somewhat in that portion of the tubes which traverse flue 6 enter the spelter at temperature which is considerably higher than the temperature of the coating metal,

this being a condition which is necessary for the best results in coating with metal. The continual passing of the highly heated wires from the annealing tubes into the spelter bath also assists in maintaining the temperature of the latter. The lead of the annealing bath has no tendency to coat or alloy with.

the iron or other metal of the wires notwithstanding the presence of the flux thereon nor does it materially affect the coating of the flux which is retained by the wires at the time they enter the spelter bath and assists in securing a firm union between the metal of the wire and the coating metal. From the time; that the wire enters the annealing tubes until it, leaves the spelter bath it is at no time exposed to oxidation and but one heating is required which serves not only for the annealing but also for the coating operation, thus saving materially in the fuel cost. By using as the flux a material stable and non-volatile atthetemperature used for annealing the latter step in no way interferes with the fiugr. The lead employed being practically covered or inclosed, in part by spelter and in part by the annealing tubes, the danger from poisonous fumes therefrom is negligible. Also the life of the spelter pan is increased by reason of the fact that it is in the main protected by the lead from the direct action of the spelter especlally at the bottom where the heat is the greatest.

I claim: '1. A process of coating with metal con- 7 sisting in forming a bath of non-adherent material and a bath of coating metal in contact with each other, raising the bath of nonadherent material to an annealing temperature and passing the article to be coated suceessively through the non-adherent material A process of coating Wire with metal ch consists 1n forming a bath of nonatiiherent material and a bath of coating metal in contact with each other, raising the bath of non-adherent metal to an annealing temperature and passing the wire successively through the non-adherent -materialand through the bath of sp 1t 4. A process of coating'with metalconsisting in supporting a bath of coating metal upon a bath of heavier non-adherent metal, heating the latter to an annealing temperature and passing the article to be coated first through the bath of non-adherent metal and then through the bath of coating metal.

5. A'process of coating with metal consisting in maintaining a bath of non-adherent metal at an annealing temperature, malntaming a bath of coating metal at amaterially lower temperature in contact therewlth and passing an article to be coated through the annealing bath, the surfaces of contact between the annealing and coating bath and through the latter bath.

6. A process of annealing and coating wire, consisting in maintaining a bath of non-adherent metal at an annealing temperature, maintaining a bath of coating metal in contact therewith at a non-annealing temperature and passing the wire T .through the annealing bath, the surfaces ofcontact of the baths and the coating bath.

7. The process of coating with metal consisting in maintaining a bath of non-adherent metal at an annealing temperature,

maintaining a bath of coating metal in con-' tact with the first said bath at a temperature below an annealing temperature, fluxing the article to be coated and passing it first through the annealing bath, then through the surfaces of contact between the annealing and coating bath and then through the latter said bath.

i 8. The process of coating with metal consisting in. maintaining a bath of non-adherent metal at an annealing temperature, maintaining a bath of coating metal in contact with the first said bathat'a temperature below an annealing temperature, fluxing the' wire to be coated and passing it first through i the annealing bath, then through the surfaces of contact between the annealing and coating bath and then through the latter 1 said bath.

9. '"A'process of coating wlth'metal consisting in maintaining an annealing and a coating bath in contact with each other, maitaining a portion of said anneallng bath at an annealing temperature and the remaiader of said bath at lower temperatures, maintaining the coating bath at a temperature below that of the annealing bath and passing the articleto be coated first through the annealing bath, then through the surfaces of contact between the annealing and the coating baths and then through the lat ter said bath.

10. A process of coating with metal consisting in maintaining an annealing and a coating bath in contact with each other, maintaining 'a portion of said annealing bath at an annealing temperature and the remainder of said bath at lower temperatures, maintaining the coating bath at a temperature below that of the annealing bath and passing the wire to be coated first through the annealing bath, then through the surfaces of contact. between the annealing and the coating v baths and then through the lattersaid bath.

11. A process for coating wire with metal consisting in maintaining an annealing bath and a coating bath in contact with each other, heating the portion of the annealing bath more remote from the coating bath to an annealing temperature, reducing the Witnesses manage temperature of the annealing bath adjacent the coating bath, maintaining the coatlng at a lower temperature than the annealing bath and passing the wire successively.

an annealing temperature and another portion at amaterially lower temperature, sup porting a bath of .coating metal upon the cooler portion of the annealing bath, heating the coating bath in contact with the cooler v portion of the annealing bath and passing the Wire successively through the annealing bath, the-surfaces of contact of the annealing bath and the coating bath, and through the coating bath. 1,

- A GUY L. MEAKER.

Envm T. Gms'r, JOHN H. GARNSEY.

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