Improvements in Furnace Tuyeres.
Year: 1897

page_text: Date of Application,
44th June,
4007
Complete Specification Left, 17th Mar., 1898-Accepted. 23rd Apr. 1898
Complete Specification Left, 17th Mar., 1898-Accepted. 23rd Apr.. 1898
Improvements in Furnace Tuyeres.
I, FRANK C. ROBERTS, of corner of Chestnut and Fourth Streets, Philadelphia,
County of Philadelphia, and State of Pennsylvania, United States, America, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
My invention relates to improvements in the tuyeres through which air, under
pressure, is delivered into a smelting furnace whereby the air is more uniformly
distributed in the furnace and a more efficient and thorough combustion of
the fuel thus secured.
Generally, that part of a furnace into which air is forced under pressure, is
circular in shape and is termed the hearth; the air being forced into the hearth
through a number of tuyeres located on approximately radial lines at various
points of the circumference. In consequence of this arrangement of tuyeres, the
air or blast which is forced into the hearth under pressure takes direction towards
the centre of the hearth and causes active combustion of the fuel along the
radial lines of its course. The fuel located between the tuyeres, i.e., in the sectors
of the hearth circle between the lines along which the air is forced towards the
centre of the hearth, is not subjected to the same intense action of the blast or
air as the fuel in front of the tuyeres, but has to depend for its combustion upon
the diffusion of the air throughout the hearth. Manifestly the more fuel brought
into the course of the air as it enters the hearth, the more rapid and thorough will
be the combustion. This end can be secured by increasing the number of tuyeres,
but the mechanical difficulties and inconveniences of operation involved in the
increase of the number of tuyeres and accompanying parts to an extent sufficient
to secure the desired end, render this means undesirable.
The object of my invention is to secure a more intimate contact of the air
introduced into the hearth of a smelting furnace with the fuel therein contained
without the accompanying disadvantages of a large increase in the number of
tuyeres and accompanying parts. I attain this object in the provision of a
tuyere as hereafter described.
My invention consists in a tuyere located at points of the circumference of the
furnace hearth, having an opening for the admission of the blast into the tuyere
and two or more openings communicating with said inlet openings for the dis-
charge of blast into the hearth, the latter openings being so designed that the
directions of the discharge of blast into the hearth will be divergent.
In carrying my invention into effect I provide a tuyere consisting of a metal
casing comprised of a shell enclosing communicating spaces wherein water is
caused to circulate in order to cool the tuyere when subjected to the high heats
of the furnace. An inlet opening is provided for the admission of the air into
the tuyere and two three or more outlets are also provided through which the
air is discharged into the furnace. The tuyeres are arranged about the circum-
ference of the hearth and rest in breast castings which have at their inmost ends
seats to take the tuyeres. Pipes are provided leading from the air pipe containing

page_text: the air under pressure to the inlet opening in the tuyeres, connection being made
to the tuyeres in an approved manner.
As usually constructed tuyeres are only provided with one discharge opening,
and it will be apparent that in such case the air will be discharged into the hearth
in approximately radial lines. If however tuyeres having three discharge openings
are substituted for tuyeres having one discharge opening, it is evident that the
air blast is more thoroughly distributed throughout the hearth and brought into
more intimate contact with the fuel contained in the hearth. It is also evident
that in order to attain the desired distribution of the blast it is necessary that
the discharge openings of the tuyeres shall be so located that the directions of the
discharge blast into the hearth shall be divergent.
In order to secure the desired distribution of blast in the hearth it is essential
that the tuyeres be located at points of the circumference of the hearth and that
more than one tuyere be provided. It is also apparent that in a furnace equipped
with the usual single opening tuyeres, discharging approximately towards the
. centre of the hearth, the distribution of the blast in the hearth can be made by
replacing even one of the single opening tuyeres with one of the tuyeres made
in accordance with the present invention, and that the degree of improved distribu-
tion depends upon the number of such improved tuyeres employed. The invention
is not confined to any particular size or shape of the inlet or discharge openings,
but a proportion is preferable in which the discharge openings shall have an
effective area equal to or less than the effective area of the inlet opening. By
"effective area
is meant an area which has been increased or decreased according
as the periphery enclosing the area has been increased or decreased in order to
allow of the resulting increase or decrease in friction.
,,
The invention is not limited to tuyeres having three discharge openings; any
desired number of discharge openings may be used, and any inclination of the
discharge openings may be used provided the direction of such openings are
divergent.
It is obvious that the invention is not limited to the actual arrangements herein-
before described in which the invention is applied.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
Improvements in Furnace Tuyeres.
I, FRANK C. ROBERTS, of corner of Chestnut and Fourth Streets, Philadelphia,
County of Philadelphia, and State of Pennsylvania, United States of America, Civil
Engineer, 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:
--
My invention relates to improvements in the tuyeres through which air, under
pressure, is delivered into a smelting furnace whereby the air is more uniformly
distributed in the furnace and a more efficient and thorough combustion of
the fuel thus secured.
Generally, that part of a furnace into which air is forced under pressure, is
circular in shape and is termed the hearth; the air being forced into the hearth
through a number of tuyeres located on approximately radial lines of various
points of the circumference. In consequence of this arrangement of tuyeres, the

page_text: air or blast which is forced into the hearth under pressure takes direction towards
the center of the hearth and causes active combustion of the fuel along the
radial lines of its course. The fuel located between the tuyeres, i.e., in the sectors
of the hearth circle between the lines along which the air is forced towards the
center of the hearth, is not subjected to the same intense action of the blast or
air as the fuel in front of the tuyeres, but has to depend for its combustion upon
the diffusion of the air throughout the hearth. Manifestly the more fuel brought
into the course of the air as it enters the hearth, the more rapid and thorough will
be the combustion. This end can be secured by increasing the number of tuyeres,
but the mechanical difficulties and inconveniences of operation involved in the
increase of the number of tuyeres and accompanying parts to an extent sufficient
to secure the desired end, render this means undesirable.
The object of my invention is to secure a more intimate contact of the air
introduced into the hearth of a smelting furnace with the fuel therein contained
without the accompanying disadvantages of a large increase in the number of
tuyeres and accompanying parts. I attain this object by means of the type of.
tuyere illustrated in the accompanying drawings, in which Figs. 1 and 2 are
respectively sectional elevation and plan of a tuyere having three openings for
the discharge of air into the hearth. Fig. 3 is a plan showing a horizontal
section taken through the hearth and tuyeres of a blast furnace equipped with the
tuyeres illustrated in Figs. and 2. Figs. 4 and 5 illustrate a tuyere having two
discharge openings instead of three as Figs. 1 and 2.
In Figs. 1 and 2 the tuyere is represented as a metal casting comprised of shell E
enclosing communicating spaces F wherein water is caused to circulate in order to
cool the tuyeres when subjected to the high heats of the furnace. A is the inlet
opening for the admission of the air into the tuyere and B, C and D are the outlets
through which the air is discharged into the furnace. In Fig. 3, H is the diameter
of the hearth around the circumference of which are located the tuyeres, said
tuyeres resting in breast castings I, having at their inmost ends seats to take
surface G of the tuyeres (see Fig. 1). Pipes K, lead from the air pipe containing
the air under pressure, to the opening A (see Fig. 1), in tuyeres, connection being made
to the tuyeres in any approved manner. L represents the directions of the air
currents as forced into the hearth through the openings B, C, and D. (See Fig. 1).
As usually constructed, tuyeres are only provided with one discharge opening,
as C (see Fig. 1) and by reference to Fig. 3 it will be apparent that in such case
the air will be discharged into the hearth in approximately radial lines. If,
however, tuyeres having three discharge openings, (See Fig. 1) are substituted
for tuyeres having one discharge opening, it is evident, from Fig. 3, that the
air blast is more thoroughly distributed throughout the hearth and brought into
more intimate contact with the fuel contained in the hearth. It is also evident
that in order to attain the desired distribution of the blast, it is necessary that
the discharge openings of the tuyeres shall be so located that the directions of the
discharge of blast into the hearth shall be divergent.
Again, by reference to Fig. 3, it will be seen that, in order to secure the desired
distribution of blast in the hearth, it is essential that the tuyeres be located at
points of the circumference of the hearth and that more than one tuyere be
provided. It is also apparent that in a furnace equipped with the usual single
opening tuyeres, discharging approximately towards the center of the hearth,
the distribution of the blast in the hearth can be improved by replacing even one
of the single opening iuyeres with one of my tuyeres and that the degree of improved
distribution depends upon the number of my tuyeres employed.
While I do not limit my invention to any particular shape or size of the inlet
and discharge openings, yet I prefer to proportion the discharge openings so that
the combined effective areas of the discharge openings (as B, C, D,) are equal to
or less than the effective area of the inlet opening A. By "effective area," I
mean an area which has been increased or decreased according as the periphery

page_text: •
enclosing the area has been increased or decreased in order to allow for the resulting
increase or decrease in friction.
I do not limit my invention to tuyeres having three discharge openings; any
desirable number of discharge openings may be used. Figs. 4 and 5 illustrate
a tuyere having two discharge openings B and D. I do not limit my invention
to the design of tuyeres shown in the drawings; the tuyeres may be of any
improved design and the various openings may be inclined to each other at any
angle, provided the direction of said openings are divergent.
I do not limit my invention to the use of metal tuyeres; the tuyeres may be of
any suitable material.
I do not limit my invention to a tuyere cooled by water; any cooling medium
or combination of mediums may be employed.
I do not limit my invention to a tuyere cooled by water or any other medium.
I do not limit my invention to a circular hearth; the tuyeres may be applied
to any hearth.
I do not limit my invention to the method of support for the tuyeres indicated
on the drawings whereby surface G of the buyeres rests in a corresponding surface
on the breast casting I; any approved method of support may be used.
I do not limit my invention to the introduction of air into the furnace; any
suitable gas may be forced into the furnace through these tuyeres, provided the gas
is under pressure and the word "blast" in the claim shall be interpreted as
meaning air or any suitable gas under pressure.
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:
The combination of the hearth of a furnace, tuyeres located at points of the
circumference of said hearth, one or more of said tuyeres having an opening for
the admission of blast into the tuyere and two or more openings communicating
with said inlet opening for the discharge of blast into the hearth, the latter
openings being so designed that the directions of the discharge of blast into the
hearth will be divergent.