AN IMPROVED PROCESS AND APPARATUS FOR COMPRESSING OR CONDENSING INGOTS DURING THE CASTING OF THE SAME
Year: 1877

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents; Southampton Buildings, London, for the Invention of
"AN IMPROVED PROCESS AND APPARATUS FOR COMPRESSING OR CONDENSING
INGOTS DURING THE CASTING OF THE SAME." A communication from abroad
by David McCandless, of Pittsburgh, Pennsylvania, United States of America,
Steel Manufacturer.
Sealed the 15th May 1877, and dated the 10th January 1877.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 10th January 1877.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS AND APPARATUS FOR
COMPRESSING OR CONDENSING INGOTS DURING THE CASTING OF THE SAME." A
communication from abroad by David McCandless, of Pittsburgh, Pennsylvania,
United States of America, Steel Manufacturer.
This Invention relates to a process of compressing ingots while casting them, and
to apparatus therefor, and consists in admitting a direct steam pressure upon the
surface of the molten metal in the flask, and also in allowing the steam to superheat
after all vents have been closed, and also consists in the apparatus, as herein-after
fully described.
The said Invention has reference particularly to the casting of "Bessemer ingots,"
though it may be applied to foundry purposes generally. It is well known that by
reason of the process of conversion used in the "Bessemer float" the resulting metal
is badly honeycombed and extremely heterogeneous, consequently it requires con-
siderable reworking to render it solid and homogeneous. This irregularity of the
ingot makes it difficult, almost impossible, to produce a constant and invariable quality
of finished material, no matter with how great precision and chemical accuracy the
conversion is accomplished, because no two ingots will be honeycombed in the same
manner or degree, and as there can be no positive determination of the interior, so
there can
be no accurate standard of comparison between one ingot and another as
to the amount of rolling or hammering necessary to bring them to the same degree
of fineness and homogeneity. This defect is one which steel producers have long.
11

page_text: contended against, but with how much success the state of the art shows; I propose
then a process by means of which the ingots will be cast solid throughout, so that
when rolled or hammered to the same degree all the products shall be of a definite,
thus making
uniform, and determinate quality, which can be constantly maintained;
the product in every respect more reliable and marketable, enhancing its value to
the consumer, and enriching the producer.
The accompanying Drawing illustrates the application of my Invention to a single
"Bessemer" flask.
Figure 1 is a perspective elevation; Figure 2 is a vertical section; and Figure 3
is a plan of the same.
The flask A is of the usual form having the vertical sprue B leading the metal
down to the ingot and into the bottom of the flask, whence it fills the flask by the
law of equilibrium. The mere shape of the flask or style of ingate or sprue is not
of the essence of my Invention, as I have merely adopted this form as being in
general use and suitable to the purpose of my Invention. The flask A is topped by
a strong cover C tightly clamped down, and which has a vent hole a for the escape
of air and gases from the flowing metal. This vent has a removable plug b fitted
to it. Coming from the boiler or other source is a steam pipe D which passes
through the cover C and delivers inside the flask at or about the top. The pipe D
which delivers the steam is fitted with a stop-cock d which may be at any point,
but preferably near the flask. It may also be desirable to have a flexion joint on
the pipe D to facilitate the removal of parts when necessary. On the shaft of the
sprue B are two pivot lugs e, c, which constitute a bearing for the bail or arch f;
the latter is provided with an adjusting screw g which bears down upon the cover h
of the sprue and binds it tightly in place.
The operation of my Invention is as follows:-Everything being in readiness for
pouring, the sprue uncovered, the vent a open, and the cock d shut, the ladle is
swung over the sprue, and the metal allowed to flow in till the flask is almost
full; then the usual sand or loam is shovelled into the top of the sprue B, its cover h
applied, and the screw g tightened down. After this the plug b is driven into the
bent, then the cock d is opened to give access of steam, and when the steam has
filled the space at the top of the molten metal the said cock is again closed; this
occupies but an instant's time. There is to begin with an initial pressure down-
wardly upon the still fluid ingot equal to the pressure in the boiler. Ordinarily
this is about seventy-five pounds to the square inch, which would give upon an
ingot twelve inches square at the top nearly eleven thousand pounds pressure; but
the vividly intense heat of such a molten mass of incandescent metal will instan-
taneously effect the superheating of the steam above it, and with lightning speed
send the pressure up to an enormous degree. The result is that the ingot is com-
pressed into perfectly solid and homogeneous mass of metal, which when cut in
sections exhibits a smooth and even structure throughout. Such being the case it
necessarily follows that such an ingot requires little or no reworking beyond the
usual reduction to form and gauge. Hence since all the ingots produced by this
process are of the same degree of perfect solidity and homogeneity, all products of
similar dimensions will have almost exactly the same tensile strength, a result it is
believed never before accomplished in the history of the art.
Instead of a single flask the usual group of flasks may be used with the same results.
The steam having direct contact with the liquid metal affords an elastic medium
into which the pent-up gases of the metal can find an entrance, a result which
cannot be accomplished by any such device as a plunger or piston, since they afford
no exit for these gases.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. The process of compressing or condensing ingots during the casting of the
same, which process consists in submitting the surface of the otherwise confined
molten metal to the direct pressure of "live" steam, as above set forth.

page_text: Second. In the process of compressing ingots while casting them, the method of
utilizing the expansive force of steam consisting in first admitting "live" steam to the
surface of the otherwise confined metal, then closing the steam inlet and allowing
the steam to superheat, as above set forth, and for the purpose specified.
Third. In an apparatus for compressing ingots while casting then, the sprue
provided with an adjustable cover, and the steam supply pipe having a cock in
combination with the flask or group of flasks having an outlet or outlets for the
air, and so constructed that the same may be opened and closed at will, as above
set forth, and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set
my hand and seal, this Tenth day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.
W. ROBT. LAKE. (L.S.)