IMPROVEMENTS IN HOT-BLAST STOVES FOR BLAST FURNACES
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and
W. Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents, for an Invention of IMPROVEMENTS IN HOT-BLAST
STOVES FOR BLAST FURNACES communicated to him from abroad by Charles
Alger, of Hudson in the County of Columbia and State of New York, United
States of America
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 1st October 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
IMPROVEMENTS IN HOT-BLAST STOVES FOR BLAST FURNACES [communicated to
him from abroad by Charles Alger, of Hudson in the County of Columbia and
State of New York, United States of America]
"
The object of this Invention is to facilitate the heating of air blasts for blast
furnaces; and it consists in the peculiar construction of the air heating pipes as
hereinafter described.
These pipes are contained in a heating chamber communicating with a com-
bustion chamber beneath, to which gas from a gas culvert or furnace is introduced,
as also air to support combustion, and the heating chamber is provided with
outlet chimneys for the incombustible products, all being under the control of
suitable valves.
Within this heating chamber at either side of the central apertures leading from
the combustion chamber, is a row of inverted U pipes, so connected as to form a
zigzag series, so that the blast will pass successively through all the pipes of each
row the rows being connected at one end with a pipe leading from a blowing
engine and at the other with another pipe leading to the blast furnace the inlet
and outlet being controlled by valves.
These inverted U pipes are lined with fire bricks which are made of different
widths so as to form a rough inner surface, and thus cause a thorough intermingling,
and an even heating of the air passing through the said pipes.

page_text: The outer surfaces of the said pipes are faced with fire bricks, so as to thoroughly
protect the said pipes from the heat, and the return flues which connect the
U pipes together in series are lined and faced internally and externally with fire
bricks to protect the said connections from the heat.
Two or more heating chambers and combustion chambers and their pipes and
other appliances can be connected with the same inlet and outlet blast pipes, as
may be desired.
.
With this construction, the blast can be heated to, and kept at any desired
temperature with a comparatively small amount of waste furnace gases or other
fuel, and without any injury to the various parts of the stove.
The U pipes can be made of wrought irou, or steel, if desired, to allow them to
be made lighter than would otherwise be practicable, and to prevent them from
being cracked and broken by the heat. This construction allows the U pipes to
be made of greater length or height than has usually been adopted or considered
practicable by iron-musters.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Patent Office on the 20th March
1884.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex Fellow of the Institute of Patent Agents,
"IMPROVEMENTS IN HOT BLAST STOVES FOR BLAST FURNACES ". A communication
to me from abroad by Charles Alger, of Hudson in the county of Columbia and
state of New York, United States of America.
: ;
The object of this invention is to facilitate the heating of air blasts for blast
furnaces; and it consists in the peculiar construction of the air heating pipes as
hereinafter fully set forth, and pointed out in the claims.
Reference is to be had to the accompanying drawings forming part of this
Specification in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a sectional side elevation of the improvement, parts being broken
away. Figure 2 is a sectional end elevation of the same, taken through the
line xx figure 1 Figure 3 is a sectional plan view of an arm of one of the pipes,
and showing a portion of the base connections. Figure 4, is a sectional elevation
of the same taken through the line y y figure 3. Figure 5, is a front elevation
of the gas and air inlet pipe. Figure 6 is a sectional elevation of the same taken
through the line << figure 5.
A represents the walls of the heating chamber B in the bottom of which are
openings C leading into the combustion chamber D, placed beneath the said heating
chamber B. Gas from a gas culvert E, or from a furnace is introduced into the
combustion chamber D, through an elbow pipe F, in the lower arm of which is a
valve G, for regulating the admission of gas.
Air to support combustion is introduced into the combustion chamber D through
three more or less small pipes H leading in through the upper arm of the pipe F,
and the amount of air admitted is regulated by a damper or valve I, pivoted to
the pipe F so that it can be turned to partly or wholly cover the ends of the said
pipes H
The incombustible products of combustion escape from the heating chamber B,
through the chimneys J placed at the side parts of the top of the said chamber B,
and which are provided with valves K operated by levers L and chains M, so
that the said chituneys can be opened and closed as required.
Within the heating chamber B at the opposite sides of the row of apertures C
are placed two rows of inverted U pipes N, the adjacent ends of which are
connected by short return connections so that the blast will pass successively
through all the pipes of each row. The first connection of each row of pipes N
is connected by a pipe P with the pipe leading from a blast blowing engine, or
engines.
The last connection O of each row of pipes N is connected by a pipe R with the
pipe S leading to the blast furnace. The entrance of the cold blast into the stove
is regulated by a valve T placed in the pipe P; and the passage of the heated blast
to the furnace is regulated by a valve U placed in the pipe R. The U pipes N
are lined' with fire bricks V which are made of different widths so as to form a
rough inner surface, as shown in figures 3 and 4, and thus cause a thorough
intermingling, and an even heating. of the air passing through the said pipes.
The outer surfaces of the pipes N are faced with fire bricks W so as to thoroughly
protect the said pipes from the heat. The return connections ○ are lined with

page_text: fire bricks X and their outer surfaces are faced with fire bricks Y to protect the
said connections from the heat. Two or more heating chambers B and combustion
chambers D and their pipes and other appliances can be connected with the same
inlet and outlet blast pipes Q, S, as may be desired. With this construction, the
blast can be heated to, and kept at any desired temperature with a comparatively
small amount of waste furnace gases or other fuel, and without any injury to the
various parts of the stove.
The U pipes N can be made of wrought iron or steel if desired, to allow them to
be made lighter than would otherwise be practicable, and to prevent them from
being cracked and broken by the heat. This construction allows the U pipes to
be made of greater length or height than has usually been adopted or considered
practicable by iron-masters.
Having described the nature of the said Invention and the manner of performing
the same I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is:
1 In a hot blast stove for blast furnaces, the metallic air heating U pipes N
faced inside and outside with fire bricks, substantially as herein shown and
described to prevent the said pipes from being injured by the heat, as set forth.
2nd In a hot blast stove for blast furnaces, the metallic air heating U pipes N
faced outside with fire bricks W and faced inside with fire bricks V, made of
different widths, so as to form a rough inner surface, substantially as described and
for the purpose set forth.
3rd In a hot blast stove for blast furnaces, the return connections O faced inside
and outside with fire bricks X, Y, substantially as herein shown and described to
protect the said connections from the heat as set forth.
In witness whereof I the said Alexander Melville Clark bave hereunto set my
hand and seal this 20th day of March A.D. 1884