Coating Iron or other Metal.
Year: 1885

page_text: Coating Iron or other Metal.
I, WILLIAM HENRI LUTHER, of 335 Argyle Street, Glasgow, in the county of
Lanark, Galvanized Iron Manufacturer, do hereby declare the nature of my
Invention for "IMPROVEMENTS IN VESSELS OR BATHS FOR GALVANIZING, TINNING,
OR COATING IRON OR OTHER METAL," to be as follows:-
--
This Invention relates to special improvements in the construction and shape of
vessels or baths for galvanizing or coating sheet-iron, wire-netting, or other extended
surfaces of iron or other metal, which will give advantages,-in economy of
material in construction, fuel in heating surfaces, and fluxes, whilst preventing or
lessening oxidising action of the molten metal,-
,-over vessels or baths hitherto in.
use for this purpose.
According to this Invention the vessel or bath is constructed or formed of oval
or round shape in transverse section, but which might be of deep rectangular or
other form with the angles well rounded; and of a length greater than the largest
sheet or article to be galvanized. In the top or upper part of the vessel, a long
narrow opening or slit is formed, or the sides of vessel contracted at top to form
this slit, as in the oval shape, through which the article or plate to be galvanized is
inserted, and somewhat longer than the largest sheet or article to be galvanized.
The edges of this slit would preferably be bent up funnel-ways in cross section for
the easier insertion of the plate and its carrying hooks or tongs, or this might be
done by an angle-iron rivetted outside along the edge of the slit, a rectangular or
other shaped hole being left at one or it might be at both ends of the slit for
removing the skim from the surface of the molten metal. This slit is for the
purpose of saving and preventing the escape of the volatile gasos arising from the
expensive salts or constituents used in the process within the bath, and to prevent
ingress of air and consequent oxidising re-action of the molten coating metal on the
surface of the plate or within the bath.
On the off side of the slit from which the plates are inserted, one, two, or more
guide bars are secured projecting down a considerable distance into the vessel to
guide the plates, while the hooks or bars carrying the plates guide then on the
entrance side of the slit, and so prevent the surface of the plate touching the slit
ΓΙ •
:

page_text: through which the plates are inserted or passed, while being moved up and down
to thoroughly galvanize their surfaces.
This improved bath is preferably made with dombed or rounded ends, and being
all smooth inside without projecting rivets or angles, is less liable to the corrosive
action of the chemicals employed, and is always cleaner and more durable in
consequence, besides containing less of the molten metal, and exposed surface of
same for the loss of heat.
Coating Iron or other Metal.
I, WILLIAM HENRI LUTHER, of 335 Argyle Street, Glasgow in the County of
Lanark, galvanized iron manufacturer, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, reference being had to
the accompanying drawings and the letters of reference marked thereon (that is
to say):
This Invention relates to special improvements in the construction and shape of
vessels or baths for galvanizing, or otherwise coating with metal, sheet iron, wire-
netting, or other extended surlaces of iron or other metal, which will give advantages,
in economy of material, in construction, in heating surface, in economy of fuel and
of fluxes employed in the working of the vessels or bathis, and also in security
against accidents, over vessels or baths hitherto in use for this purpose, and will
also prevent the oxidising action of the molten metal, or lesson such action from
what is usual in vessels or baths of the ordinary construction employed for the
purpose.
According to this invention, the vessel or bath is constructed or formed of such
shape, in transverse section, that the mouth or open top is much narrower across
than the lower part in which the greater portion of the coating material is contained.
The object of forming the mouth narrow is to expose as small a surface as possible
on the top of the flux which floats on the coating material, and thus prevent, as far
as possible, the escape of the volatile gases arising from the expensive salts or
constituents employed in the process of coating, and also prevent, as far as possible,
ingress of air and consequent oxidising re-action of the molten coating metal on the
surface of the sheet or article being coated or on the plates composing the structure
of the vessel or bath. The vessel or bath is of sufficient length to receive the
entire length of the longest sheet or article for which it is intended to be used.

page_text: A convenient form for the bath, in transverse section, 18 circular, or oval with the
major axis vertical, the mouth consisting of a narrow opening at the top for the
entire length of the bath. The edges of the plate on each side of the opening are,
preferably, turned up funnel-wise, or angle bars are riveted along the edges of the
opening, to form a trough in which the flux collects or floats, and to enable the
sheet or article which is to be coated and its carrying hooks or tongs being the more
easily inserted into the bath.
:
This invention will be clearly understood on reference to the accompanying
drawings, of which figure 1 is a transverse section through a circular galvanizing
bath (or other bath employed for coating iron or other metal) constructed according
to this invention, and shewing also a transverse section through the heating flues.
Figure 2 is a plan of figure 1, but with the standing plates and seating omitted.
Figures 3, 4 and 5 are transverse sections of galvanizing baths constructed according
to this invention, and are, respectively, a modified construction of circular bath,
and oval bath, and a rectangular bath with rounded top (or deep D-shape).
Referring to figures and 2, a a is the shell of the bath, bb is the narrow
opening forming the mouth, and is made as narrow (say 8 or 10 inches wide) as
will permit of the dross being readily removed, and enable a man to get inside the
bath for repairs. c c are the edges of the plate forming the bath turned up to form
a funnel or hopper. The ends d d are, preferably, domed and welded to the shell.
e e are angle-bars riveted to the outside of the edges cc at the top thereof, for the
purpose of preventing the flux getting between the bath and the seating and of
stiffening the edges, and for receiving the inner ends of the standing plates ff.
99 are flues from the ordinary coal furnace at one end of the bath. The end of the
bath nearest to the fire is protected with fire-brick in the usual manner, and the
flues g g join one another across the other end of the bath. The connection between
the flues and the chimney is of the description usual with baths heated by coal.
The normal level of the molten coating metal is shown by the broken line, figure 1,
and the flux of course floats above. hhh are guide bars hung on the edge of the
off-side of the mouth or funnel, and passing down a considerable distance into the
bath, to guide the sheets (or other articles) being coated, while the ordinary books
or tongs carrying the sheets guide them on the entrance side of the mouth or funnel,
and thus the surface of a sheet is prevented from touching the side of the mouth
or funnel as it is passed therethrough while being moved up and down to thoroughly
coat its surface. The guide bars h h h are curved backwards at their lower ends,
as shewn, to prevent the chance of being caught by hooks employed to carry the
sheets within the bath.
It is preferred, when the size of the bath conveniently admits thereof, to form
the shell in one plate, and in any case to weld parts together instead of riveting
them, though the angle bars are, of course, riveted on, but with rivets countersunk-
headed on the inside.
This improved vessel or bath having thus no internal rivet heads or angle bars,
is consequently smooth over its whole interior, and is therefore less liable to the
corrosive action of the chemicals employed, and is thus cleaner and more durable
than if riveted together. It may also be made of much thinner plate, and conse-
quently be lighter for a given strength, than baths of the usual construction, in
comparison with which, also, a greater heating surface is exposed in proportion to
the capacity of the bath, and economy of fuel effected. The capacity of the bath
is reduced below what is necessary in the ordinary construction of baths, and thus
a much less quantity of coating metal is required within the bath; and the surface
area of the molten metal being greatly reduced, a very considerably reduced quantity
of flux is needed within the bath, and the escape of heat aud of volatile gases from
the bath, and the ingress of air and consequent oxidising re-action, is reduced to a
minimum. The narrow mouth also reduces considerably the liability of an accident
by the attendant slipping into the bath.
The circular bath illustrated in transverse section by figure 3 differs from that
similarly illustrated by figure 1, in that angle bars o¹ c¹ are riveted to the boiler

page_text: shell to form the sides of the mouth or funnel, in lieu of turning up the edges of
the plate.
In figures 4 and 5 the sides of the mouth or funnel are formed similarly as in
figure 3, but in both cases they may be formed as shewn by figure 1, that is by
turning up the edges of the plate.
U
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim in respect of vessels or baths for galvanizing, tinning, or otherwise coating
with metal, sheet iron, wire-netting, or other extended surfaces of iron or other
metal, is
1. Such a vessel or bath having a mouth or open top considerably narrower across
than the diameter or width of the vessel or bath, substantially as described and
shewn, and for the purpose set forth.
2. Such a vessel or bath formed of a circular or oval shape in transverse section,
or of a rectangular shape with rounded top (deep D-shape), and having a narrow
open top or mouth, and with or without a funnel thereto formed either by turning
up the edges of the plates or by riveting angle bars along the edges of the opening,
substantially as described and shewn and for the purpose set forth.
Dated this Thirteenth day of November 1885.