IMPROVEMENT IN TUYERES USED IN THE MANUFACTURE OF IRON AND STEEL
Year: 1884

page_text: CHRISTOPHER THOMPSON 9 Elmwood Street Sunderland Co. Durham Engineer do
hereby declare the nature of my Invention for IMPROVEMENT IN TUYERES USED IN
THE MANUFACTURE OF IRON AND STEEL and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
--
The Invention relates to an improvement in the apertures through tuyeres for
conveying compressed air, gas or steam into converters or where two or more
agents are forced into or through liquid metal.
The principal of the Invention is illustrated by the accompanying Drawings
having for its object a reduction of the friction of the air, gas &c. in their passage
through the tuyeres into the converter, causing a reduction in the consumption of
fuel used for the blowing engines thereby effecting considerable saving in the cost
of manufacture of iron and steel.
The ordinary tuyere now in use for converters have small round holes the full
length of the tuyere for conveying the compressed air into the converter. There
is great friction in driving the air through the long length of the small holes in the
tuyere. When the tuyeres are worn down to 7 or 9 inches long, they are considered
short enough to work with safety. During the operation of blowing, there is
nothing reliable to indicate to the forman, that the tuyeres are worn down
sufficiently short, and sometimes a tuyere is defective in the last 10 inches of its
length; which causes the hot steel to find its way to the tuyere-plate, which melts
its way through into the blast-box, causing serious damage and loss.
The improved tuyere has the apertures enlarged at the inlet end, to a depth
from 5 inches to 7 inches, thereby reducing the length of the small hole or aperture
of fixed diameter. Drawing. No. 1. Fig. A. is a section through the centre, part
full size, shewing three forms of conical apertures at inlet, tapering to fixed size of
small hole, about 6 inches from the mouth of the inlet; two of the apertures being
slightly larger, than the fixed size of the small hole at the termination of the
enlarged inlet. Fig. D is a section, through the centre of tuyere, shewing enlarged
conical aperture at inlet, tapering down to about 1 inch larger than the fixed
diameter of the small hole at a depth of 6 inches. Fig. B. and Fig. C. shew plans
of inlets.
Drawing. No. 2. Fig. No. 1, No. 2. No. 3. No. 4. No. 5. and No. 6. are full
sections through the centre of tuyeres, (on quarter scale,) with plans of inlets
and outlets. Fig. No. 6 shows two inlets joined to-gether and carried down the
usual depth, and joining with the small hole of fixed diameter. Fig. No. 5. shews

page_text: all the inlets grouped together, and carried down about 3 inches, the usual depth
of the tuyere-plate, then carried down singly to the usual depth in conical form,
joining with the small hole of fixed diameter. Fig. No. 3. shews the enlarged
inlets in hexagonal section. Fig. No. 4. shews the enlarged inlets in square
section. Fig. No. 2. shews the enlarged apertures slightly enlarged over the fixed
size of the small hole, and parallel the usual depth of the enlarged aperture. Three
or more holes may be grouped together, and be made similar to Fig. No. 6, and
carried down in single hole to the fixed depth, retaining sufficient length of small
hole of fixed diameter, for wearing down that is consistant to work with safety.
The advantage gained by enlarging the apertures at the inlets, is, a reduction
in the length of the small holes of fixed diameter; thereby reducing the friction of
the compressed air in its passage through the tuyere into the converter; less
pressure is required from the blowing engines, so that a considerable saving of fuel
will be effected.
In case of neglect or error of judgement on the part of the converter tenter, in
not changing the worn tuyeres in time; the improved tuyere will give a steady
warning to the superintendent blower, when the bottom is wearing near the
tuyere-plate, who may order the converter to be turned down, before the hot steel
finds its way through into the blast-box, which would cause serious damage.
The full pressure of air is at the terminal point of the enlarged aperture, same
as is in the blast-box; so that a charge of steel may be blown a little longer if
necessary, after the tuyere is worn down to the enlarged aperture.
The enlarged inlets may be rammed up solid, much sooner than the ordinary
inlets; which is necessary sometimes, when the charge is in the converter. The
tuyeres may be cut out a little more readily than the ordinary tuyere, when
renewals or retuyereing is being done.
Tuyeres with enlarged apertures at the inlets can be made sounder and more
perfect, and not exceed in cost (in manufacture) the ordinary tuyere. And can be
made the same shape externally, or any desired shape. And may be used in the
converter together with the ordinary tuyere or alone. No special moulds are
required over those in present use for their manufacture; (a small outlay for
piercing rods is all that is necessary.). Less ganister composition is required in
each tuyere, so that they will be a little lighter in weight, which will effect some
little saving to the manufacturer and consumer.
This improvement in the apertures is applicable to any class of tuyere, or
aperture in the nature of a tuyere used in the manufacture of iron or steel; in the
processes known as the "basic," "acid," or ordinary "Bessemer" process, or where,
air, gas, or other agents are forced into liquid metal.
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, is,
1st In tuyeres employed in the manufacture of iron and steel. The enlargement
of the apertures at the inlet end to a depth of 5 to 7 inches, and within that part
of the tuyere, that is usually not worn or melted away; and as shown on the
accompanying Drawings; and for the purposes herein described.
2nd In converter plugs and bottoms, with apertures in the nature of a tuyere.
The enlargement of such apertures at the inlet ends, to a depth of 5 to 7 inches,
or about the usual thickness that is allowed for a bottom when worn down; for
the benefits and purposes described herein.
Dated this 24th day of July 1884.