Improvements in the Manufacture of Incandescing Media for Lighting Purposes.
Year: 1896

page_text: Date of Application, 4th July, 1896
Complete Specification Left, 5th Apr., 1897-Accepted, 15th May, 1897
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Incandescing Media for
Lighting Purposes.
I, RUDOLF LANGHANS, of 12B, Elisabeth Strasse, Berlin, in the German
Empire, Electrician, do hereby declare the nature of this invention to be as
follows:-
This invention relates to the manufacture of incandescing bodies in which
vanadiferous zirconia is made use of as an illuminant.
As is known, zirconia, i.e. the oxide of the earth metal zirconium, is subject to
sintering or fritting when exposed to the heat of a Bunser flame; its light-emitting
capacity being in consequence rapidly reduced. Moreover, this earth has but a
weak illuminating power as compared with the incandescing compositions prepared
with the so-called "rare" earths.
Now I have found that both the refractive and the light-emitting capacities
of zirconia are largely increased by combining it with pentoxide of vanadine,
(V₂O₂).
When zirconia is intimately mixed with some tenths of a per cent. of vanadine
pentoxide and the mixture calcined in a Bunsen flame, it will finally emit a brilliant
white light, the illuminating power of which is far superior to that of pure zirconia.
When zirconia is combined with a larger proportion of vanadine pentoxide, say
one per cent., a yellowish light of great power will be emitted; but when the
proportion of vanadine pentoxide is still more increased, say up to two per cent.,
the light emitted will be of an orange tint and of less power. In all these cases,
the new incandescing compound does not however manifest the slightest tendency
to sintering or fritting, which is surprising when it is remembered that vanadine
pentoxide is readily fusible at a dull red heat. When cooled down, the mass shows
a characteristic brown-yellowish coloration.
In the manufacture of the improved zirconia incandescing media, I may proceed
in any of the known ways. For instance, I may impregnate zirconia with an
aqueous solution of pentoxide of vanadine or of a vanadyle salt. (It is known to
chemists that vanadyle salts are formed by dissolving vanadine pentoxide in an
acid, and that, when subjected to calcination, they are reduced to vanadine
pentoxide.) The required bodies formed from the paste or mass thus produced
are calcined in the Bunsen flame until they radiate light. Or I may first form
the body from zirconia and then impregnate the same with the watery vanadini-
ferous solution. Or I may dissolve a zinconia salt, for instance nitrate of zirconium,
in an aqueous solution of pentoxide of vanadine or a vanadyle salt, impregnate a
fabric or other fibrous foundation with the said solution, the impregnated fabric or
body being then dried and finally calcined. Or I may evaporate the vanadini-
ferous zirconia solution to dryness, form the residue into the shape desire.] and
calcine the body thus obtained. Or I may produce the zirconia body by means of
electrolysis, as described in the Specification to Letters Patent bearing date
22nd November, 1893, No. 22,396, impregnate the same with an aqueous solution
of pentoxide of vanadine or of a vanadyle salt, and calcine the impregnated body
after drying it.
The watery solution of pentoxide of vanadine is made use of when incandescing
media for white light are to be produced; whilst the aqueous solution of a

page_text: vanadyle salt is employed in the production of incandescing media for yellow or
orange light.
For white light, I prefer to use the two ingredients in the proportion of 99-6 of
zirconia to 0.4 of vanadine pentoxide. This may be readily obtained by dissolving
in 27 grammes of water so much pentoxide of vanadine that a saturated solution
is obtained, and dissolving in the latter 25 grammes of crystallised nitrate of
zirconia.
Improvements in the Manufacture of Incandescing Media for
Lighting Purposes.
I, RUDOLF LANGHANS, of 12B, Elisabeth Strasse, Berlin, in the German
Empire, Electrician, 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 the manufacture of incandescing bodies in which
vanadiniferous zirconia is made use of as an illuminant.
As is known, zirconia, i.e., the oxide of the earth metal zirconium, is subject to
sintering or fritting when exposed to the heat of a Bunsen flame; its light-
emmitting capacity being in consequence rapidly reduced. Moreover, this earth
has but a weak illuminating power as compared with the incandescing compositions
prepared with the so-called "rare" earths.
Now I have found that both the refractive and the light-emitting capacities of
zirconia are largely increased by combining it. with a small per centage of
vanadium pentoxide (V₂O).
When zirconia is intimately mixed with some tenths of a per cent. of vanadium
pentoxide and the mixture calcined in a Bunsen flame, it will finally emit a
brilliant white light, the illuminating power of which is far superior to that of
pure zirconia. When zirconia is combined with a larger proportion of vanadium
pentoxide, say one per cent., a yellowish light of great power will be emitted; but
when the proportion of vanadium pentoxide is still more increased, say up to
two per cent., the light emitted will be of an orange tint and of less power. In all
these cases, the new incandescing compound does not however manifest the
slightest tendency to sintering or fritting, which is surprising when it is
remembered that vanadium pentoxide is readily fusible at a dull red heat. When
cooled down, the mass shows a characteristic brown-yellowish coloration.
In the manufacture of the improved zirconia incandescing media, I may
proceed in any of the known ways. For instance, I may impregnate zirconia with
an aqueous solution of vanadium pentoxide or of a vanadyle salt. (It is known to
chemists that vanadyle salts are formed by dissolving vanadium pentoxide in au
acid; and that, upon being subjected to calcination, such salts are reconverted to
vanadium pentoxide.) The required bodies, formed from the paste or mass thus
produced, are calcined in the Bunsen flame until they radiate light. Or I may
first form the body from zirconia and then impregnate the same with the watery
vanadiniferous solution. Or I may dissolve a zirconia salt, for instance zirconium
nitrate, in an aqueous-solution of vanadium pentoxide or of a vanadyle salt, and

page_text: impregnate a fabric or other fibrous foundation with the said solution, the
impregnated fabric or body being then dried and finally calcined. Or I may-
evaporate the vanadiniferous zirconia solution to dryness, form the residue into.
the shape desired, and calcine the body thus obtained. Or I may produce the
zirconia body by means of electrolysis, as described in the Specification to Letters
Patent bearing date 22nd Nov., 1893, No. 22,396, impregnate the same with an
aqueous solution of vanadium pentoxide or of a vanadyle salt, and calcine the-
impregnated body after drying it.
The watery solution of vanadium pentoxide is made use of when incandescing.
media for white light are to be produced; whilst the aqueous solution of a
vanadyle salt is employed in the production of incandescing media for yellow or
orange light.
For white light, I prefer to use the two ingredients in the proportion of 99.6:
of zirconia to 0-4 of vanadium pentoxide.
The bath may be readily prepared by dissolving in 27 grammes of water so
much vanadium pentoxide that a saturated solution is obtained, and dissolving in
the latter 25 grammes of crystallised zirconium nitrate.
Having now particularly described and ascertained the nature of this inven-.
tion and what manner the same is to be performed, I claim :-
1. The manufacture of incandescing media for use in gas lighting substantially
as herein described and in which vanadiniferous zirconia is employed.
2. In the manufacture of incandescing media consisting essentially of zirconia, .
the employment of one per cent. or thereabouts of vanadium pentoxide, substantially
as herein described.
3. In the production of vanadiniferous zirconia bodies for use as incandescing
media, the employment of zirconia dissolved in an aqueous solution of vanadium.
pentoxide or of a vanadyle salt, substantially as herein described.
4. In the production of vanadiniferous zirconia bodies for use as incandescing.
media, impregnating zirconia with an aqueous solution of vanadium pentoxide or
of a vanadyle salt, forming the incandescing bodies from the resultant paste,.
drying, and ultimately calcining the same in the Bunsen flame, substantially as
herein described.