IMPROVEMENTS IN MACHINERY AND APPARATUS USED IN THE MANUFACTURE OF STEEL AND IRON
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Francis Preston at the Office
of the Commissioners of Patents, with his Petition, on the 17th
January 1866.
I, FRANCIS PRESTON, of the Lancashire Steel Company, Limited, near
the City of Manchester, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN MACHINERY AND APPARATUS USED IN
THE MANUFACTURE OF STEEL AND IRON," to be as follows:-
The first part of my Invention consists in introducing a jet or jets of
steam near the top of the mouth of the converting vessel used in the
manufacture of steel and iron by the atmospheric process. The steam is
intended to produce a vacuum or partial vacuum within the convertor, so
as to reduce the top pressure on the molten metal when under the process
of conversion. The steam may be either conveyed through one of the
trunnions of the convertor and then carried upwards to the mouth thereof
through a pipe or pipes, and then through one or more apertures into the
inside of the convertor, or it may be carried separately and independently
at the outside to a position immediately above or near the mouth of the
convertor. Above the mouth of the convertor I also propose erecting a
separate and-stationary-mouth-piece or chimney so as to assist the draft, and
hence increase the vacuum still more; but the steam may be used either
with or without this separate mouth-piece or chimney. and the steam may
be either superheated or otherwise.

page_text: The second part of my improvements consists in the introduction of
atmospheric air into the ash-pits of reverberatory furnaces or into the
furnace, which air I introduce from the cellar or passages under or con-
tiguous to the said reverberatory furnaces by suitable air passages, which
are so placed as to cause the current of air to impinge upon such parts of
the fire as will best assist combustion.
As a further means of increasing the draft and combustion in rever-
beratory furnaces I introduce a boiler or pipes, or a series of the same, in
or near the fire or ash-pit for the purpose of making steam, which steam I
allow to escape into the reverberatory furnace, or neck of the furnace, or
into the chimney or flue of the furnace, whereby the steam coming into
contact with the heat of the furnaces causes a vacuum or partial vacuum,
and hence considerably increases the draft.
The third part of my improvements consists in the arrangement of the
centre or ladle lift, the object of which is to cause the ladle to move in
different radii so as to be able to fill two or more rows of moulds with
metal; to effect this object I fix the ladle upon suitable bearings. The
Hadle is caused to move in or out to the required distance by convenient
gearing; but the mode which I prefer is by pinions and screws, and the
ladle moves upon wheels or bowls so as to lessen the friction when working.
A similar effect may be obtained by fixing the ladle upon a turntable fixed
at the end of the jib of the lift, or other modes may be adopted for the
same object.
The last part of my Invention relates to the valves of the horizontal
blast engines usually employed in the manufacture of steel and iron. In
dieu of the india-rubber valves heretofore used I substitute the ordinary
flap valves, which are placed in the horizontal outside air passages of the
blast.engine.
Another mode of altering the said blast engines is to entirely remove the
present india-rubber valves both in the cylinders and pistons, and to fix to
the outside of the two ends of the cylinders compound slide valves, which
are worked by suitable gearing actuated by the fly-wheel or other shaft,
and adjusted as to open and shut at the required times. These valves are
so arranged as to have any amount of lap or lead as may be found most
advantageous.