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

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DIEVITICATION
CHRISTOPHER THOMPSON No. 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, steam, gas or where a combination of two or more agents
are forced into or through liquid metal, in a furnace or converter.
The principle of the Invention is illustrated by the accompanying Drawings.
Instead of having small round holes through the tuyere for the admission of air
into the converter or furnace. The apertures are made thin broad slot holes at the
outlet for the admission of thin streams of air amongst the liquid metal. The thin
apertures may be in any form of section, and extends nearly the full length of the
useable or wearing part of the tuyere, and is enlarged towards the inlet end,
commencing from 5 to 7 inches from the mouth of the inlet.
Drawing. Sheet No. 1. Fig. No. 6. is a section of a tuyere through the aper-
tures. Fig. No. 6 B. is a plan of the inlets. Fig. No. 7 is a section of tuyere with
angular apertures. Fig. No. 7 C. is a plan of inlets.
:Drawing. Sheet. No. 2. Figs. No. 1. No. 2. No. 4. No. 5. and No. 5 A, shew
several tuyeres with different apertures, and plan of inlets and outlets.
The apertures may be grouped together at the mouth of the inlets, and carried
down to a depth equal to the thickness of the tuyere-plate, then taken down
single with a slight taper, joining the thin fixed size 6 inches from the mouth
of the inlets.
This improved tuyere, with thin outlets, may be applied to any system of
steel or iron manufacture, where compressed air, or gas, or steam is forced into
or through liquid metal.
And the principle of the thin aperture is also applicable to those converters
that have the air passages formed in the end or bottom of the converter, such as
those in use in the basic process. The thin apertures can be formed in the bottom,
for admitting the air into the converter in thin streams, same as if the bottom was
Duin Q.71

page_text: in one tuyere, with the necessary number of outlets in place of the present form of
holes.
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Drawing. Sheet. No. 3. shews the principle, and the tuyeres as applied for
horizontal blowing, and will be readily understood. The tuyeres are placed in a
row in one blast box, and plug, in the side of the converter. Fig. No. 6 is a section
through the centre of a converter. A. A. is the lining of ganistér brick. B. is
the bottom made of hard ganister brick, and tapered at the sides similar to an
ordinary tuyere-plug, which can be withdrawn and renewed when necessary,
without destroying the side walls A. C is an outer case of cast or wrought iron,
secured to the round shell, having four lugs for eye bolts, for securing the blast
box. D is the blast-box with branch pipe for blast entrance. The tuyere plate
contains the requisite number of tuyeres, placed side by side with a thin course of
ganister between them. The tuyeres are secured in the tuyere-plate, and
surrounded by ganister walls H to form the plug in connection with the blast box.
Fig. No. 5 is an elevation of the converter, shewing the front of the blast-box with
the door removed, to shew the tuyeres in position. Fig. No. 8. is a plan section
through centre line of tuyeres, plug and blast box. Fig. No. 7. is a plan of
converter shewing outline of case C with the two top bolts for securing the blast
box. The plug containing the tuyères is attached with the blast box, the ganister
being rammed firmly round the tuyeres, and is secured by the eye bolts.
Drawing. Sheet., No. 4. Fig. 1. Front elevation of converter.
*
Fig. No. 2. Side elevation of converter.
Fig. No. 3. Plan of converter.
Fig. No. 4. is a plan section of 3 tuyeres, with inlets and outlets.
Although the Drawing shews the tuyeres in a horizontal position, they may be
inserted at an angle, above or below the horizontal line as required.
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The advantages gained by the improved tuyere with thin apertures, namely,
6 tuyeres of 4 outlets 2 inches by "inh will convey more compressed air into
the converter than 12 ordinary tuyeres of 13 inlets inch. diameter, and more than
15 tuyeres of 13 inlets inch. diameter, thereby effecting a saving in the
consumption of tuyeres, and cost in the manufacture of iron or steel.
There will be a great reduction in friction in the compressed air passing through
the thin apertures compared with the small round holes of the ordinary tuyere ;
the working surface for friction being greately reduced, less pressure of blast is
required from the blowing engines, which will result in a saving of fuel.
The full pressure of blast that is in the blast-box, will extend up the tuyere to
the fixed size of the thin aperture, so that, when the tuyere wears down to the
enlarged part, a larger volume of air will pass into the converter, and apprise the
superintendent blower, that the hot metal is approaching the tuyere-plate.
The improved tuyeres with the thin apertures, will overcome some of the 4
difficulties connected with fixed converters, and renders the system of horizontal
blowing a success in moveable converters, which up to the present time has been
impracticable, and which possesses some advantages over the ordinary system of
vertical blowing. The blast being admitted in the side of the converter, there is
no tendency in the action of the blast to throw the metal out of the converter, 4
which is often done, and sometimes to a great extent with the vertical blowing;
making a large amount of scrap and waste.
The voilent scouring action of the hot metal which takes place in the converters
during the blowing, will be on the hard compact refractory bottom instead of on
the plug and tuyeres. The pressure of the vertical head of metal, will be more 5
constant over the tuyere surface, and less pressure of blast will be necessary to
maintain the clearance at the inlets; there being no increase of pressure to over-
come, by the wearing down of one or more of the tuyeres, or by the falling action
of the liquid metal as produced by vertical blowing. A much less pressure of air
being required throughout.
A charge of 7 to 8 tons of metal may be blown in the same capacity allowed
for an ordinary 6 ton converter with vertical blowing.
5

page_text: The plug and tuyeres, exposed to the liquid metal, have a much smaller surface
in proportion to the outlet area of the blast, and an atmosphere can be better
maintained at the mouth of the outlets, than with the ordinary plug and tuyeres,
so that the tuyeres and plug will last longer.
The blast-box, also the tuyere-plate are very much smaller than those used in
vertical blowing. There will be less weight to deal with, when changing the plugs
and tuyeres, which can be readily done when necessary. There is no cause for
delay, same as with the ordinary tuyere-plug, and the joint can be rammed up
firmly from the outside.
In case the vessel tenter neglect to change the tuyeres, plug, or converter bottom
at the proper time, or that there should be a defect in any of the apertures; that
would require plugging; this could be done effectually, and more readily, with the
apertures enlarged at the inlets.
The apertures being enlarged from the mouth of the inlet, joining with the thin
aperture at the depth of the useable or wearing part of the plug, bottom, or tuyere.
The full pressure of blast that is in the blast-box, will be at this point, so that
the friction of the air in its passage through the apertures, will be reduced according
to the depth of the enlarged part.
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,
1 An improved form of apertures through tuyeres, to convey in large quantities,
air, gas, or other agents, in thin streams into a converter or furnace as shewn on
Drawings and further described herein.
2nd An improved form of apertures through the bottom or end of converter,
acting in the nature of a tuyere; to convey, air, gas, or other agents in thin
streams into a converter or furnace as herein named.
3rd The enlargement of the apertures at the inlet end to the size, form, and
depth required for the purpose named herein and described, and shown by the
accompanying Drawings.
Dated this 16th day of July 1884.