Improvements in or relating to Crucible Furnaces.
Year: 1898

page_text: Date of Application, 16th Dec., 1898-Accepted, 25th Feb., 1899
Improvements in or relating to Crucible Furnaces.
I, RUDOLF BAUMANN, of Oerlikon, Canton Zurich, Switzerland, Founder, 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:―
This invention relates to an improved crucible furnace in which the blasts
are guided in such a manner so as to communicate an equally high temperature
to all parts the walls as well as the bottom of the melting pot or crucible, and
to produce in a very short time by entirely using the gases of combustion a
great intensity of heat.
The importance of giving the material to be treated
an equal temperature in all its parts accelerates the work and gives a greater
purity of metal.
This is obtained in the present invention by means of a stream of compressed
air entering below the open grate of the furnace and guided into side channels
of the furnace whence it enters the furnace at different levels in streams of
different tangential directions to the crucible. These streams or blasts are
introduced at different elevations and in such a manner that the blasts in any
one plane are directed in an opposite tangential direction to the blasts in the
plane next above or below. By this means the blasts directed one against the
other are intimately mixed with the fire gases and air whereby an intense com-
bustion is effected, together with an important saving of combustibles.
The annexed drawing illustrates the invention.
Fig. 1 is a vertical section through the furnace. Fig. 2 is an elevation, part
of the exterior covering being omitted in order to show more clearly the position
of the blast passages. Fig. 3 a plan view showing the position of the feed
openings h. Fig. 4 is a section on the line, and Fig. 5 a section on the
line yy in two different planes of Fig. 1.
The crucible of the furnace as represented is provided with a receptacle s
for heating the ore or material to be treated. The same is seated directly upon
the crucible and is provided, with a bottom separating it from the former. In
the middle of this bottom is arranged a perforation through which the metal
becoming molten in the heater flows into the crucible. The combustion gases
escaping out through the furnace shaft must pass through the radial directed
perforations c, e in the form of thin flames into the inside of the heater and so
cause the metal or ore in it to melt. The actual furnace is surrounded with a
preferably four cornered mantle a of sheet iron having a fire proof lining b
resting on bars c. Upon the grate e the crucible t rests by means of the stand f.
Shoulders y prevent a lateral displacement of the crucible. Through the openings
between the shoulders g (Figs. 1 and 4) the combustibles are introduced the
openings can be closed by means of covers or doors h. The combustion air enters
below the open grate into the perpendicular passages d arranged in the furnace
wall b and communicating with outlet openings or the like arranged in different
planes one above the other. These outlet openings are arranged so that, those
lying in one level are directed in the opposite direction to those in the next lower

page_text: level; but those openings that are in the same level discharge in the same
tangential direction.
By this arrangement it is impossible for any combustion gases to quit the
furnace unburnt, because they are on their way always reached by an air and
gas current.
Having now particularly described and ascertained the nature of this
invention and in wliat manner the same is to be performed I declare that what
I claim is:
An improved crucible furnace having tangentially directed blast openings and
in which the air draught guided from below into side channels of the furnace
escapes through openings arranged one above the other so that the openings
lying one upon the other are directed in opposite directions but the openings of
the same level are directed in the same direction.
121 1. £ Nanamlau 1000
HERBERT HADDAN & Co.,
Agents to Applicant. 18, Buckingham Street, Strand, W.C., London.