IMPROVEMENTS IN APPARATUS FOR HEATING THE BLAST FOR BLAST FURNACES
Year: 1881

page_text: LETTERS PATENT to Thomas Fletcher Harvey, of Dowlais, in the County of
Glamorgan, Engineer, for an Invention of "IMPROVEMENTS IN APPARATUS
FOR HEATING THE BLAST FOR BLAST FURNACES."
PROVISIONAL SPECIFICATION left by the said Thomas Fletcher Harvey at
the Office of the Commissioners of Patents on the 22nd November 1881.
THOMAS FLETCHER HARVEY, of Dowlais, in the County of Glamorgan,
Engineer. "IMPROVEMENTS IN APPARATUS FOR HEATING THE BLAST FOR BLAST
FURNACES."
My Invention has for its object increased compactness and economy of
construction as well as increased facility in cleaning, and consists in combining
the regenerating hot blast stoves in one structure with the furnace by forming the
said stoves in an annular space between the furnace and the outer iron casing by
which the whole building is enclosed.
The said annular space is divided from top to bottom into two, three, or more
independent stoves, which alternately are first heated with gases and afterwards
give off the accumulated heat to the blast forced through in a contrary direction.
The combined furnace and stoves are or may be constructed in the manner of an
ordinary blast furnace, but with increased diameter from the top of the supporting
columns upwards, in order to allow of sufficient heating capacity being provided in
the stoves surrounding the furnace.
The combustion chamber is by preference constructed horizontally at the bottom
of the stoves the whole length of each stove, which for two or more stoves will
include the whole extent of the annular space. This combustion chamber has at
the top a perforated arch throughout its entire length except where intersected by
cross walls or radial partitions, by which the stoves are divided respectively into
compartments, such cross walls or partitions forming diaphragmns which connect
the outer casing of brickwork with the inner wall or walls surrounding the blast
furnace. The said perforated arch supports vertical flues constructed of firebrick
forming the regenerator, which extends nearly the whole height of the stove.

page_text: The waste gases from the furnace are admitted by suitable valves into the
bottom of the combustion chamber near one end of the stove, and air for their
combustion is admitted conveniently close thereto. The products of combustion
pass through the said perforated arch upwards and through the flues of the
regenerator, heating the surfaces of the same, and they escape through suitable
valves at the top of the stoves at the end opposite to that at which the gases enter,
thereby traversing the whole network of flues forming the regenerator. A further
supply of air or a supply of hot or cold blast may be admitted into the vertical
flues forming the regenerator at any convenient, height or heights, for the purpose
of more perfectly consuming the gases.
The regenerator having during a convenient time absorbed the heat or the
greater part thereof from the consumed gases, the valves for admitting the gas and
air for combustion are closed, and the cold blast is admitted at the top of the
stove near to the outlet for the spent gases and travels in a contrary direction over
the same surfaces which have been previously ascended by the burning gases and
through suitable valves into the blast furnace. By means of the above described
horizontal chamber and mode of consuming and passing the gases, the cooler end
of the stove is at the top, thereby affording greater facility for cleaning. Some of
the supporting columns of the combined structure are utilized for the purpose of
admitting the gases into the combustion chamber and discharging the hot blast
into the furnace, such columns as aro so used being lined with firebrick to resist
the high temperature.
Instead of the above described horizontal combustion chamber a vertical chamber
may be used, and the burning gases caused to pass down through the regenerator
and away to a chimney. Or the gases may be caused first to ascend such chamber
and afterwards alternately descend and ascend the different compartments into
which the annular stoves are divided, until they reach the valve leading to the
chimney.
The above described horizontal chamber and mode of consuming and passing
the gases by admitting the gas at the bottom, letting it ascend once and out at the
top while the blast is admitted and caused to pass in a contrary direction may
also be applied to separato stoves of circular form in horizontal section or of other
suitable form.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Fletcher Harvey in the Great Seal Patent Office on the
22nd May 1882.
THOMAS FLETCHER HARVEY, of Dowlais, in the County of Glamorgan,
Engineer. "IMPROVEMENTS IN APPARATUS FOR HEATING THE BLAST FOR BLAST
FURNACES."
My Invention of "Improvements in Apparatus for Heating the Blast' for Blast
Furnaces has for its object increased compactness and economy of construction, as
well as increased facility in cleaning, and consists in combining the regenerative
hot blast stoves in one structure with the furnace by forming the said stoves in an
Annular space between the furnace and the outer iron casing by which the whole.
building is enclosed.
The said annular space is divided from top to bottom into two, three, or more
independent stoves, which alternately are first heated with gases, and afterwards
..give off the accumulated heat to the blast forced through in a contrary direction.
The combined furnace and stoves are or may be constructed in the manner of an
ordinary blast furnace, but with increased diameter from the top of the supporting
columns upwards in order to allow of sufficient heating capacity being provided in
the stoves surrounding the furnace. The combustion chamber is by preference
constructed horizontally at the bottom of the stoves the whole length of each stove,
which for the two or more stoves will include the whole extent of the annular
space. This combustion chamber has at the top a perforated arch throughout its
entire length, except where intersected by cross walls or radial partitions, by which
the stoves are divided respectively into compartments, such cross walls or radial
partitions forming diaphragms which connect the outer casing of brick work with
the inner wall or walls surrounding the blast furnace. The said perforated arch
supports vertical flues constructed of firebrick, forming the regenerator, which
extends nearly the whole height of the stove.
The waste gases from the furnace are admitted by suitable valves into the bottom
of the combustion chamber near one end of the stove, and air for their combustion is
admitted conveniently close thereto. The products of combustion pass through the
said perforated arch upwards, and through the flues of the regenerator, beating the
surfaces of the same, and they escape through suitable valves at the top of the stoves
at the end-opposite to that at which the gases enter, thereby traversing the whole
net-work of flues forming the regenerator. A further supply of air or a supply of
liot or cold blast may be admitted into the vertical flues forming the regenerator at
any convenient height or heights for the purpose of more perfectly consuming the
gases. The regenerator having during a convenient time absorbed the heat or the
greater part thereof from the consumed gases, the valves for admitting the gas and
air for combustion are closed, and the cold blast is admitted at the top of the stove
near to the outlet for the spent gases, and travels down in a contrary direction over
the same surfaces which have been previously ascended by the burning gases, and
through suitable valves into the blast furnace. By means of the above described
horizontal chamber and mode of consuming and passing the gases, the cooler end of
the stove is at the top, thereby affording greater facility for cleaning. Some of the
supporting columns of the combined structure are utilized for the purpose of
admitting the gases into the combustion chamber and discharging the hot blast
into the furnace, such columns as are so used being lined with firebrick to resist the
high temperature.
*The above described horizontal chamber and mode of consuming and passing the

page_text: gases by admitting the gas at the bottom, letting it ascend once and out at the top,
while the blast is admitted and caused to pass in a contrary direction, may also
be applied to separate stoves of circular form in horizontal section, or of other
suitable form.
Having thus stated the nature of the said Invention I will proceed to describe!
more particularly in what manner the same is to be performed by the aid of the
accompanying Drawings, in which are represented the mode of combining hot blast
stoves in one structure with the furnace, and also two forms of separate or
independent stoves, as above referred to.
stoves in one structure with the furnace, and also two forms of separate or
independent stoves, as above referred to.
DESCRIPTION OF THE DRAWINGS.
In Sheet I., Fig. 1 is a vertical section of the combined regenerative stoves and
furnace taken on the line a, b, of Fig. 3. In Sheet II., Fig. 2 is a horizontal
section on the line c, d, of Fig. 1; and Fig. 3 is a similar section in the line e, f, of
Fig. 1.
A is the valve through which the gas is admitted from the main below into
brick lined supporting column B, where the gas meets the air which is admitted
by suitable valves at in the combustion chamber D, which, as stated above, is
constructed horizontally at the bottom of the stoves. The products of combustion
pass up from this chamber through the regenerator or regenerative stoves E, and
escape through the chimney F fitted with a valve at the top of the stove, as shown.
The cold blast to be beated enters the stove near the top at G, and passes down
through the regenerator E in a direction contrary to that taken by the gas, and
issues through the hot blast valve H into the crescent pipe J of the furnace.
The stoves are constructed of an annular form around the furnace, each of which
stoves consists of an airtight casing K lined with fire brick L supported on strong
girders M, which are fastened to and rest upon the top of the supporting columbs N.
The part of the casing K which is next the furnace is prevented from acquiring
too high a temperature by means of air spaces at O.
Instead of the casing being supported on columns, as shown, it may be made to
rest on the foundation at the hearth level of the furnace, and have the necessary
openings and archways formed in it.
The regenerator or regenerative stove consists of fire brick walls arranged so as
to form cells P, P, (which may be of any suitable shape) supported upon perforated
arches Q, and it is divided into compartments by the radiating walls in order to
strengthen tho structure and prevent the gas from taking a diagonal course in
passing from the combustion chamber to the chimney F. The radiating walls R
are carried the whole height of the stove, and both at the bottom below the walls
of tho regenerator and at the top above the same apertures S are formed for the
passage of the gases from one compartment to the other, as shewn in Figures 1
and 2. The apertures at the top of the stove may be either reduced or enlarged
so as to regulate the quantity of gas passing upwards through each compartment.
The inlet of air and gases at the points B and C is at the opposite end of the
stove to that of the chimney F, so as to give the products of combustion an equal
length of travel through whichever compartment they may take.
T, T, are cleaning holes which may be placed in any convenient position; U is
a short deflecting arch fixed over the air and gas inlet to prevent the escape of
unburnt gases up the first compartment of the stove.
In the Drawings three stoves are represented as combined in one structure with
the furnace, but any other suitable number can be so combined.
In Shoet III., Fig. 4 is a vertical section of a separate regenerative hot blast
stove; Fig. 5 is a horizontal section on the line g, h; and Fig. 6, a similar section
on the line i, k, of Fig. 4.
The gas for combustion enters through the valve X into the flue A, and the air
is admitted by a suitable valve at Y into the flue B, and the gas and air meet at
C, C, in passing into the combustion chamber D. The products of combustion

page_text: pass out from the chamber D through openings O, O, and up into and through the
regenerator E, and escape through the chimney F fitted with a valve at the top
of the stove. The cold blast to be heated enters the stove near the top at G, and
passes down through the regenerator in a direction contrary to that taken by the
gas, and issues through the hot blast valve H into the hot blast pipe leading to the
furnace.
The stove consists of an air-tight casing L lined with fire-brick resting upon a
foundation M. The regenerator consists of walls forming cells J (which may be of
any suitable form in section) supported upon arches K, K. Openings are formed
above the combustion chamber at N, N, to allow the gas to ascend into the middle
compartiment of the regenerator.
The inlets for air and gases at the points C, C, are made near the centre of the
bottom of the stove so as to give the products of combustion a nearly equal distance
to travel, whether they pass up through the middle or the outside compartment of
the regenerator E; S, S, are sinall openings placed over the air flue B, in order to
prevent the escape of unburnt gases and ensure their perfect combustion; T, T, are
cleaning holes fitted with air tight doors which may be placed in any convenient
position.
In Sheet IV. Figures 7 and 8 are vertical sections, and Figures 9 and 10 are
horizontal sections of the bottom part of a regenerative hot blast stove. In Fig. 7
the section is taken on the line v, w, and in Fig. 8 on the left hand of the centre
on the line x, y, and on the right hand on the line y, z, of Fig. 9. The sections in
Fig. 9 are respectively on the top of the arches and on lines R, S, and S, T, in
Fig. 7, and the sections in Fig. 10 are on the lines T, U, and U, V, of Fig. 8.
The gas for combustion enters through the flues A, A, and the air to support
combustion enters through the flues B, B. The air and gas issue from the
flues through the openings C, C, into the combustion chambers D, D, where the
gases are ignited, and the products of combustion then ascend into the regenerator E,
passing upwards through it and away through the chimney which is placed on the
top of the stove.
The cold blast to be heated enters the stove near the top and traverses it in
a direction contrary to that described for the gas, leaving the stove through the
flues A, A, the working of the stove being controlled by suitable valves.
The regenerator in this case consists of hexagonal cells F, F, built of firebrick
and supported upon arches G, G, the arches as well as the spandrils being bonded
together by bonding bricks H, H, in order to prevent distortion.
The openings C, C, are distributed throughout the area of the stove nearly
equally, with the view of dividing the products of combustion uniformly among
the regenerator cells; and the flues A, A, and B, B, are made straight for facility
of cleaning.
In the foregoing description (Figures 4 to 10) of separate stoves it will be seen
that the parts are arranged so that the air and gas are admitted into the horizontal
combustion chamber at the bottom of the stove, and passed up through the
regenerator and out at the top, while the blast is admitted and caused to pass in a
contrary direction.
Having thus described the nature of the said Invention and in what manner the
same is to be performed, I hereby declare that I do not claim as of my Invention
the construction and use of regenerative hot blast stoves, except when combined in
one structure with the furnace as described, and constructed so as to adinit of the
heated air and gases being caused to traverse the flues of the regenerator and escape
in the manner described while the cold blast is admitted at the top and caused to
pass down in a contrary direction as described, but what I do claim as of my
Invention is,
First. The combination in one structure of two or more regenerative hot blast
stoves with the furnace by forming them in an annular space between the furnace
and the outer iron casing, whereby increased compactness and economy of
construction are secured, as hereiubefore described.

page_text: Secondly. The combination and arrangement of the parts so as to admit of the
gases being consumed and passed through the stoves in such a manner as to preserve
the comparative coolness at the top of the stove, thereby affording greater facility
for cleaning, all substantially as described with reference to Figures 1, 2, and 3 of
the Drawings.
And, Lastly. The construction of separate or independent stoves adapted to work
in the same manner as when combined with the furnace, substantially as described
with reference to Figures 4 to 10 of the Drawings.
In witness whereof, I, the said Thomas Fletcher Harvey, have hereunto set
my hand and seal, the Sixteenth day of May, in the year of our Lord One
thousand eight hundred and eighty two.
Witness,
JOHN VAUGHAN,
Odessa St., Dowlais,
Engineer.
THOMAS FLETCHER HARVEY. (LS.)

page_text: C.8.