Improvements in Metallurgical Furnaces and Ovens.
Year: 1891

page_text: Date of Application, 29th Oct., 1891-Accepted, 5th Dec., 1891
COMPLETE SPECIFICATION.
Improvements in Metallurgical Furnaces and Ovens.
I FRANCIS GORDON BATES of 2005 North College Avenue in the City of
Philadelphia State of Pennsylvania United States of America Mechanical
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 metallurgical furnaces such as are employed for heating
or re-heating metals or for the melting or puddling of the same and to converting
ovens and the like, the object of my invention being to so construct such a furnace
or oven as to provide for the effective combustion of the gases arising from the
fuel and to produce and maintain an intense heat in the working chamber of the
furnace.
I will describe my invention with reference to the accompanying drawings, in
which:-
Figure 1 is a longitudinal section of a metallurgical furnace or oven constructed
according to my invention.
Figure 2 is a sectional plan view of the same on the line 1, 2 Figure 1.
Figure 3 is a plan view partly in section on the line 3-4 Figure 1.
Figure 4 is a transverse section on the line 5-6 Figure 2 and
Figure 5 is a transverse section on the line 7-8 Figure 1.
A represents the outer wall or casing of the furnace within which is the working
chamber B access to which may be had in any convenient manner as for instance
through an arched opening or passageway B' at the front of the furnace as shewn
in Figures 1 and 2 or through suitable openings at the sides of the furnace, as in an
ordinary heating or puddling furnace.
At each of the front corners of the furnace is a fire place D preferably inclined
towards the centre of the furnace each of these fire places communicating through
a short lateral passage D¹ with the arched passage B₁ and thence with the working
chamber B of the furnace.
a
At the centre of the front portion of the furnace and in a plane below that of
the corner fire places D and also below the floor or bottom of the working chamber B
of the furnace is a third fire place F the products of combustion from which pass
beneath the bottom of the furnace chamber B first rearwardly through a flue F¹
to the rear end of the furnace and then forwardly through flues F2 on each side to
position adjacent to the corner fire places D where they are deflected into the
side walls of the furnace and rise through flues F3 on the outer sides of the corner
fire places until they reach a point above the level of the fuel in said fire places,
whereupon they discharge into the corner fire places or rather into the combustion
chambers formed in the upper portions of said fire places the unconsumed products
of combustion from the lower central fire place being thus re-ignited and consumed
in their passage through the working chamber of the furnace."
Above each of the fire places D D is a chamber G closed except for a gas inlet
referred to hereafter and a downwardly inclined communication with the passage B¹
leading into the working chamber of the furnace and within each of these
chambers G is located a coiled pipe G¹ which serves to supply air from a branch G²
(Fig. 4) of the blast pipe H which supplies the forced draught for the fire place D.
The delivery end of this coiled pipe is bent downward at an angle and extends
partway through the opening or passage whereby the chamber Ğ communicates
with the passage B¹.
When the blast of air passes through the coil G¹ and is discharged from the end

page_text: of the same a partial vacuum is created in the chamber G hence in the absence of
any admission of gas to the chamber, heat is radiated from the crown of the fire
place D onto the coil G¹ with much greater force than if the chamber was open for
the admission of air while at the same time the coil G¹ is more accessible than if
it was imbedded in the brick work above the fire place and is not so liable to become
burnt out.
The furnace has two outlet flues II one near each rear corner of the chamber B
and also two side outlet flues J J near the front end of said chamber but I find it
preferable to divide the lower or inlet end of each of these outlet flues by means of
à central slab or tile a so as to provide each flue with two contracted mouths meeting
at a short distance above the inlet.
By reason of the described arrangement of fire places and flues the passage of
the products of combustion through or their disposal in the heating chamber can
be readily governed, for instance, if the dampers in the flues I are open, and the
dampers in the flues J are closed, the products of combustion from the furnaces D
on entering the heating chamber, will have a tendency to converge and after
meeting in the centre of said chamber, will diverge, a portion escaping through
each of the flues I.
If it is desired to modify the tendency of the products of combustion to converge,
and cause said products to spread more evenly throughout the width of the heating
chamber, this may be donc, by opening the dampers in the side flues J which thus
tend to draw a portion of the products of combustion laterally in the front portion
of the heating chamber.
On the roof of the furnace, at the rear end thereof, is a dome M containing a
short chimney K and enclosing a chamber M', a portion of the products of com-
bustion rising through the chimney being discharged into this dome which may also,
if desired, receive the products of combustion from the side flues J J through short
lateral passages J' controlled by suitable dampers.
The side flues J also have dampered branch flues or passages J2 (see Figure 3)
communicating with the chambers G, so that when desired, a portion of the gases
from the chamber B can be directed into the said chambers G and then be ejected
therefrom by the heated jets from the pipes G₁, the hot air mixing with the gases in
their discharge.
Extending downwardly at an angle from the front of the dome into the working
chamber of the furnace are passages which receive the discharge ends of air
pipes N communicating with the branches G' of the blast pipes H, the jets thereby
formed serving to return to the working chamber of the furnace the products of com-
bustion which enter the chamber M of the dome, the air being also mixed with
these products of combustion so as to regenerate the same and cause their ignition
when they again enter said working chamber.
Mounted on the short chimney K are a series of internally projecting slabs or
blocks K¹ which closely approach at their inner ends, and form a central contracted
flue, through which a portion of the products of combustion can rise directly to
the contracted discharge stack P mounted on the dome, the remaining portions of
the products of combustion escaping through the openings between the slabs into the
chamber M of the dome, and being thence returned into the working chamber of
the furnace.
Having thus described and particularly ascertained the nature of my invention
I claim as new and desire to secure by Letters Patent :-
1. The combination in a metallurgical furnace or oven, of the two fire places at
or near the front corners of the heating chamber and the two outlets at or near the
rear corners of the same, so that the products of combustion are first caused to
converge towards the centre of the furnace and then to diverge towards the
separated outlet flues substantially as hereinbefore described.
2. The combination in a metallurgical furnace or oven of the two front fire places,
at or near the opposite corners of the heating chamber, the two rear exit flues and

page_text: side exit flues communicating with the heating chamber near the front end of the
same, substantially as hereinbefore described.
3. The combination in a metallurgical furnace or oven of the opposite side fire.
places discharging their products of combustion into the working chamber of the
furnace, a lower central fire place and flues whereby the products of combustion
from the said central fire place are first caused to circulate beneath the bottom of
the working chamber and are then discharged directly into the products of
combustion from the side fire places substantially as hereinbefore described.
4. The combination in a metallurgical furnace or oven, of the working chamber
having fire places at one end, with outlet flues having their inlets near the bottom
of the working chamber and having slabs or blocks at said inlet ends, so as to
divide and contract the mouths of the flues substantially as hereinbefore described.
5. The combination in a metallurgical furnace or oven of the working chamber
having front fire places, with chambers above the same closed to the external air
and air pipes forming heating coils in said chambers and discharging through
contracted outlet passages so as to cause a partial vacuum in the said chambers,
substantially as hereinbefore described.
6. The combination in a metallurgical furnace or oven, of a working chamber
having front fire places and side and rear outlets, chambers above the fire places the
said chambers being closed to the external air, heating pipes located in the said
chambers and discharging through contracted outlets therefrom, and communications
between the said chambers and the side outlets of the working chamber so as to
cause a portion of the products of combustion from the said side outlets to seek the
chambers and to be expelled therefrom mixed with the heated air, substantially as
hereinbefore described.
7. The combination in a metallurgical furnace or oven of the working chamber
having fire places at the front end, a dome surmounting the said working chamber
at the rear end and receiving products of combustion from the outlet flues, a passage
or passages through which the said dome communicates with the working chamber
and a heating coil in the said dome discharging into the said passage or passages,
80 as to cause a return of a portion of the products of combustion, mixed with hot
air into the working chamber at the rear end of the same, substantially as herein-
before described.
8. The combination in a metallurgical furnace or oven, of the working chamber,
the dome surmounting the same, and having an air jet pipe, the discharge stack and
a short chimney located in the chamber of the dome and having inwardly pro-
jecting slabs at the top, said slabs surmounting a central flue but having spaces
between them, substantially as hereinbefore described.
Dated this 29th day of October 1891
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.