IMPROVEMENTS IN FUR- NACES USED IN THE MANUFACTURE OF WELDED IRON AND STEEL TUBES
Year: 1879

page_text: LETTERS PATENT to Charles Edward Smith, of Wednesbury, in the County of
Stafford, Tube Manufacturer, for the Invention of "IMPROVEMENTS IN FUR-
NACES USED IN THE MANUFACTURE OF WELDED IRON AND STEEL TUBES."
PROVISIONAL SPECIFICATION left by the said Charles Edward Smith at the
Office of the Commissioners of Patents on the 30th April 1879.
CHARLES EDWARD SMITH, of Wednesbury, in the County of Stafford, Tube
Manufacturer. "IMPROVEMENTS IN FURNACES USED IN THE MANUFACTURE OF
WELDED IRON AND STEEL TUBES."
A furnace used in the manufacture of welded iron and steel tubes as ordinarily
constructed consists essentially of an arched chamber of a length exceeding that of
the skelps from which the welded iron and steel tubes are to be made. A series of
four or other number of firegrates extends from end to end of the said chamber on
one side, and at the opposite side is a series of small horizontal flues by which the
flame and products of combustion pass into a large common flue parallel with the
arched chamber. A wall constituting the back of the ash pits of the grates and
bridge of the furnace runs from end to end of the arched chamber nearly under the
middle of the arch. The level of the bottom of that part of the arched chamber
separated by the bridge from the fire grates is somewhat higher than that of the
fire grates, and constitutes the bed of the furnace or a heating chamber in which
the skelp to be made into a tube is raised to a welding heat. This heating
chamber has an opening at each end for the introduction and removal of the skelps.
The several openings in the furnace are provided with doors or dampers for closing
them when required. The waste heat from the furnace is usually utilized by being
made to heat a steam boiler. In constructing the said furnaces according to my
Invention I convert the common flue of the furnace into a preliminary heating
chamber, in which the iron or steel skelp to be made into a welded tube undergoes
a preliminary heating before it is introduced into the bed of the furnace. I. effect
this by making an opening at each end of the common flue, the said openings being
provided with doors or dampers. Where it is convenient to do so I prefer to make
the bed of the said common flue on the same level, or nearly so, as that of the
bed of the principal heating chamber. The heated air and products of combustion
I Price fid1

page_text: in passing from the preliminary heating chamber into which the common flue has
been converted may be utilized for heating a steam boiler, or may be utilized for
other purposes.
Instead of conducting the heated air and products of combustion from the pre-
liminary heating chamber to the steam boiler or the chimney stack or elsewhere by
one flue, I prefer, where it is convenient to do so, to conduct them by two or more
small flues in place of one larger one, and to provide the said small flues with
dampers. By these means the heat of the preliminary heating chamber can be
made more uniform in all parts than when only one large exit flue is employed.
By the use of furnaces constructed according to my Invention great economy is
effected in the manufacture of welded iron and steel tubes.
By the preliminary heating of the skelp before its introduction into the principal
heating chamber it is raised to the required welding heat in the principal heating
chamber in about one half the time ordinarily required; the heat of the principal
heating chamber is not reduced by the introduction of cold skelps, and two or more
skelps are under treatment at the same time, one or more skelps being raised to a
red heat in the preliminary heating chamber while one is being raised to a welding
heat in the principal heating chamber. There is thus effected great economy both
in time and fuel.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Edward Smith in the Great Seal Patent Office on the 15th
October 1879.
"
CHARLES EDWARD SMITH, of Wednesbury, in the County of Stafford, Tube
Manufacturer. IMPROVEMENTS IN FURNACES USED IN THE MANUFACTURE OF
WELDED IRON AND STEEL TUBES."
A furnace used in the manufacture of welded iron and steel tubes as ordinarily
constructed consists essentially of an arched chamber of a length exceeding that of
the skelps from which the welded iron and steel tubes are to be made. A series of
four or other number of fire grates extends from end to end of the said chamber on
one side, and at the opposite side is a series of small horizontal flues by which the
flame and products of combustion pass into a large common flue parallel with the
arched chamber. A wall constituting the back of the ash pits of the grates and
bridge of the furnace runs from end to end of the arched chamber nearly under the
middle of the arch. The level of the bottom of that part of the arched chamber
separated by the bridge from the fire grates is somewhat higher than that of the
fire grates, and constitutes the bed of the furnace or a heating chamber in which
the skelp to be made into a tube is raised to a welding heat. This heating chamber
has an opening at each end for the introduction and removal of the skelps. The
several openings in the furnace are provided with doors or dampers for closing them
when required. The waste heat from the furnace is usually utilized by being made
to heat a steam boiler,

page_text: In constructing the said furnaces according to my Invention I convert the
common flue of the furnace into a preliminary heating chamber, in which the iron
or steel skelp to be made into a welded tube undergoes a preliminary heating
before it is introduced into the bed of the furnace. I effect this by making an
opening at each end of the common flue, the said openings being provided with
doors or dampers. Where it is convenient to do so I prefer to make the bed of the
said common flue or preliminary heating chamber on the same level, or nearly so, as
that of the principal heating chamber.
The heated air and products of combustion in passing from the preliminary
heating chamber, into which the common flue has been converted, may be utilized
by heating a steam boiler, or may be utilized for other purposes.
Instead of conducting the heated air and products of combustion from the pre-
liminary heating chamber to the steam boiler, or chimney stack, or elsewhere by
one flue, I prefer, where it is convenient to do so, to conduct them by two or more
small flues in place of one large one, and to provide the said small flues with
dampers. By these means the heat of the preliminary heating chamber can be
made more uniform in all parts than when only one large exit flue is employed.
By the use of furnaces constructed according to my Invention great economy is
effected in the manufacture of welded iron and steel tubes.
I will now proceed to describe, with reference to the accompanying Drawings, the
manner in which my Invention may be performed.
Figure 1 represents in front elevation; Figure 2, in back elevation; Figures 3
and 4, elevations taken at opposite sides; Figure 5, in horizontal section; and
Figure 6, in cross section, a furnace constructed according to my Invention to be
used in the manufacture of welded iron and steel tubes.
The same letters of reference indicate the same parts in the several Figures of
the Drawings.
a, a, is the ordinary heating chamber of the furnace, and b, b, is the ordinary
heated chamber in connection therewith, the said chambers a and b being situated
parallel to one another, as best seen in Figure 5. The heating chamber a las an
opening c at each end, the said openings being closed by sliding doors d, d, and the
preliminary heating chamber b has also an opening e at each end, closed by the
doors or dampers f. f. By raising the said doors or dampers at d and f the skelps
to be heated may be introduced into and removed from the chambers. g, g, are the
fire places situated on one side, and extending from end to end of the principal
heating chamber a. The openings to the fire grates g, g, are closed by the doors or
dampers h, h. i is the wall constituting the backs of the ash pit l, l, and the
bridge of the furnace. The said wall i runs from end to end of the arched chamber,
and has the position best seen in Figures 5 and 6. a² is the bed of the principal
heating chamber a, on which the skelps are placed to be raised to a welding heat,
and 62 is the bed of the preliminary heating chamber b, on which the skelps are .
placed to receive a preliminary heating. In the wall p dividing the principal
heating chamber a from the preliminary heating chamber b is a series of small
horizontal flues m, m, by which the flame and products of combustion from
the said principal chamber a pass into the preliminary heating chamber b
(see Figure 5). In the Drawing the bed 62 of the preliminary heating
chamber b is represented at a lower level than the bed a² of the principal
beating chamber a, but the beds of the two chambers a and b may be situated at
or about the same level. The waste heat and products of combustion from the
preliminary heating chamber 6 are conducted to the chimney stack by three or
other number of small flues n, n, as represented in Figure 5, the said flues being
provided with dampers. By means of the said flues and dampers the heat of the
preliminary heating chamber can be made very uniform. Or the waste heat from
the preliminary heating chamber b may be conducted by a flue or flues in connection
with the said chamber b to a steam boiler for heating the said boiler. In Figures 1,
2, and 3 a steam boiler is represented in combination with my improved furnace to
be heated by the waste heat from the preliminary heating chamber b. In this case

page_text: the flues from the chamber b open into flues passing around the boiler, as in the
ordinary furnace where a boiler is heated by the waste heat of the furnace..
In using my improved furnace the furnace is heated by the combustion of fuel on
the fire grates at g, g, the heat from the said fire grates passing over the bridge i
and heating the principal chamber a. The heated air, and products of combustion
from the said chamber a pass by means of the horizontal flues m, m, into the
preliminary heating chamber 6 and heat the said chamber, the waste heat and
products of combustion escaping by the flues n, n, n, to the chimney stack, or being
conducted to a steam boiler as before described, The skelps to be subjected to a
preliminary heating are introduced into the preliminary heating chamber 6 and the
heated skelps are afterwards transferred from the said heating chamber b to the
principal heating chamber a where they are raised to a welding heat. By the
preliminary heating of the skelp before its introduction into the principal heating
chamber it is raised to the required welding heat in the principal heating chamber
in about one half the time ordinarily required. The heat of the principal heating
chamber is not reduced by the introduction of cold skelps, and two or more skelps
are under treatment at the same time, one or more skelps being raised to a red
heat in the preliminary heating chamber while one is being raised to a welding
heat in the principal heating chamber; there is thus effected great economy both in
time and fuel.
Having now described the nature of my Invention, and the manner in which the
same is to be performed, I wish it to be understood that I do not limit myself to
the precise details herein described and illustrated, as the same may be varied
without departing from the nature of my Invention,―
But I claim as my Invention the improvements in furnaces used in the manufacture
of welded iron and steel tubes herein before described and illustrated in the
accompanying Drawings, that is to say, converting the common flue of the furnace
(into which common flue the flame and products of combustion from the principal
heating chamber pass) into a preliminary heating chamber, in which preliminary
heating chamber the iron or steel skelps to be made into welded tubes undergo a
preliminary heating before they are introduced into the principal heating chamber
to be raised to a welding heat, substantially as described and illustrated.
In witness whereof, I, the said Charles Edward Smith, have hereunto set
my hand and seal, this Thirtieth day of September, in the year of our Lord
One thousand eight hundred and seventy nine.
Witness,
EDWARD HOBBINS SMITU,
Wednesbury.
CHARLES EDWARD SMITH. (L.S.)