IMPROVEMENTS IN PUDDLING, HEATING, MELTING, AND OTHER FURNACES
Year: 1877

page_text: LETTERS PATENT to David Caddick, of Middlesbrough, in the County of York,
and Joseph Maybery, of Llanelly, in the County of Carmarthen, for the
Invention of "IMPROVEMENTS IN PUDDLING, HEATING, MELTING, AND OTHER
FURNACES."
Sealed the 1st June 1877, and dated the 26th March 1877.
PROVISIONAL SPECIFICATION left by the said David Caddick and Joseph
Maybery at the Office of the Commissioners of Patents on the 26th March
1877.
DAVID CADDICK, of Middlesborough, in the County of York, and JOSEPH
MAYBERY, of Llanelly, in the County of Carmarthen. "IMPROVEMENTS IN PUDDLING,
HEATING, MELTING, AND OTHER FURNACES."
Our Invention relates to furnaces employed for puddling, heating, and melting
iron, and for other metallurgical operations, having reference chiefly to the com-
bustion chambers of such furnaces.
We make the combustion chamber of a furnace to act as a producer or generator
of combustible gases, constructing it of fire-brick enclosed in an iron casing, and
outside this casing we provide a second casing, so that there is an air space between
the two casings. There are passages from this space through the inner casing and
fire-brick into the combustion chamber, some of these passages being at a low level,
entering that part of the chamber which is occupied by fuel, or entering a closed
ash-pit or space below a fire-grate on which the fuel rests, and others of these
passages opening into the combustion chamber above the level of the fuel therein.
There is also a large passage or throat from the upper part of the combustion
chamber into the bed of the furnace.
The air space between the casings is supplied with air entering by an aperture
from the external atmosphere, or forced in by a fan or other blast. The air entering
this space, and becoming. heated by contact with the inner casing, passes by the
several passages into the combustion chamber. The air which enters by the lower
passages serves to maintain the combustion or partial combustion of the fuel, pro-
ducing inflammable gases, and the air which enters by the upper passages mingles

page_text: with these hot gases, producing flame, which passes by the throat into the bed part
of the furnace, and acts on the metal or material therein; also the passage of air
through the space between the casings has the effect of keeping the outer casing
cool, so that not only is the heat radiating from the combustion chamber thus
utilised for warming the air supplied to it, but also the exterior of the chamber is
so cooled that workmen employed at the furnace are not incommoded by the neigh-
bourhood of the combustion chamber.
A producer or combustion chamber such as we have described may serve for a
single furnace bed, or there may be several furnace beds arranged round one such
producer, a throat therefrom being provided for each of them.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Caddick and Joseph Maybery in the Great Seal Patent Office on
the 21st September 1877.
DAVID CADDICK, of Middlesborough, in the County of York, and JOSEPH
MAYBERY, of Llanelly, in the County of Carmarthen. "IMPROVEMENTS IN PUDDLING,
HEATING, MELTING, AND OTHER FURNACES."
Our Invention relates to furnaces employed for puddling, heating, and melting
iron, and for other metallurgical operations, having reference to the combustion
chambers of such furnaces.
We make the combustion chamber of a furnace to act as a producer or generator
of combustible gases, constructing it of fire-brick enclosed in an iron casing, and
outside this casing we provide a second casing, so that there is an air space between
the two casings. There are passages from this space through the inner casing and
fire-brick into the combustion chamber, some of these passages being at a low level,
entering that part of the chamber which is occupied by fuel, or entering a closed
ash-pit or space below a fire-grate on which the fuel rests, and others of these
passages opening into the combustion chamber above the level of the fuel therein.
There is also a large passage or throat from the upper part of the combustion chamber
into the bed of the furnace.
The air space between the casings is supplied with air entering by an aperture
from the external atmosphere, or forced in by a fan or other blast. The air entering
this space, and becoming heated by contact with the inner casing, passes by the
several passages into the combustion chamber. The air which enters by the lower
passages serves to maintain the combustion or partial combustion of the fuel, pro-
ducing inflammable gases, and the air which enters by the upper passages mingles
with these hot gases, producing flame, which passes by the throat into the bed part
of the furnace, and acts on the metal or material therein; also the passage of air
through the space between the casings has the effect of keeping the outer casing
cool, so that not only is the heat radiating from the combustion chamber thus
utilised for warming the air supplied to it, but also the exterior of the chamber is so
cooled that workmen employed at the furnace are not incommoded by the neigh-
bourhood of the combustion chamber.
A producer or combustion chamber such as we have described may serve for a
single furnace bed, or there may be several furnace beds arranged round one such
producer, a throat therefrom being provided for each of them.
Our Invention is also applicable with advantage to " hollow fire "furnaces, whereby
the ordinary" hollow fires" are superseded.

page_text: side view of the furnace, with the combustion chamber partly in section; and Fig. 3
shews a sectional plan.
The combustion chamber consists of a fire-brick lining A, enclosed by an inner
casing B and an outer casing C, between which is an air space D. The air blast is
admitted into the top of the air space through the pipe E, which is provided with a
regulating valve, and in passing down through the space in close contact with the
heated casing B it becomes heated to a considerable extent before issuing through
perforations b in this casing into the passage I, extending round the sides and back
of the chamber, from which passage the air enters the space F below the fire-grate K
through perforations i.
A certain portion of the air is also admitted to the combustion chamber above
the fire-grate from the air space D by the following arrangement:-Passages a, a,
formed in the fire-brick lining A establish a communication between the com-
bustion chamber and a small chamber L formed in the air space, and cut off from
the upper part and sides of the latter by a framing H, so that the air, in order to
enter the chamber L, has first to pass down at the sides of the framing H, and
entering holes h in the bottom part H¹ of the framing, then ascends in the enclosed
air space D¹, and enters the chamber L.through holes provided with a regulating
valve , by means of which the quantity of air entering above the fire-grate is
regulated, the total quantity of air supplied to the combustion chamber being
regulated by the before-mentioned valve in the pipe E. Opposite the passages a
sight holes c are provided in the outer casing C for observation and for clearing the
said passages, the holes being capable of being closed by means of a slide M, having
holes in positions corresponding to the tubes c.
The combustion chamber and ash-pit are practically closed against the admission
of external air by means of the doors R and G; N is the throat leading from the
combustion chamber into the furnace O, and P is the opening through which the
fuel is introduced.
Having thus described the nature of our Invention, and in what manner the same
is to be performed, we claim, constructing combustion chambers to puddling and
other furnaces with a double casing, between which is an air space, into one point of
which the requisite air is introduced, and from other points of which the air, after
becoming heated, passes through side openings into the spaces above and below the
fire-grate, or into and above the fuel of the combustion chamber, substantially as
and for the purposes herein described.
In witness whereof, I, the said Joseph Maybery, have hereunto set my hand and
seal, this Nineteenth day of September, in the year of our Lord One thousand
eight hundred and seventy-seven.
JOSEPH MAYBERY. (L.S.)