Improvements in Incandescent Burners or Lamps:
Year: 1898

page_text: Date of Application, 1st Oct., 1898-Accepted, 4th Feb., 1899.
COMPLETE SPECIFICATION.
Improvements in Incandescent Burners or Lamps:
I, KURT SCHULTZE, of 4, Neue Promenade, Berlin, in the Kingdom of Germany,
Manager, 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:-
-
The principle of the preliminary heating of the air necessary for combustion
already made known by the earlier regenerative lamps of Siemens, and since then
generally employed by others in gas lamps properly so called, has not hitherto
been put into practical use in lamps having burners which produce a non-illu-
minating flame. No construction at least has, up to the present been found in
which the great advantages of the preliminary heating of the air of combustion
have been utilised in the so called blue-flame burners, and especially for the
purposes of illumination by incandescent gas light. And, indeed, it is a great
step from the mere acknowledgement of the utility of the principle in question
with Bunsen burners, to the manufacture of a practically useful construction because,
in the first place, from a technical point of view, the lamp must not suffer any
depreciation in respect of its simplicity or with regard to its commercial value,
or cheapness of manufacture.
Taking these two requirements fully into account, the burner of the incandescent
lamp described below, has above all, been constructed in accordance with these
precepts. The peculiarities of the said burner consist in the employment of a
central tube inserted in and extending from the top of the comparatively long
burner tube down to the nozzle of the gas inlet, and in the position of the apertures
through which the air is to enter above the top of the inserted tube. This latter
imparts a downward direction to the current of air entering the tube of the
burner and compels it first to flow in a contrary direction until it reaches the
nozzle of the gas inlet, where it comes within the sphere of the gas current flowing
in through the said nozzle. The tube of the burner as well as that inserted into
it, are both strongly heated at the head of the burner. This heat is conducted
downwards along the channel formed by the two hollow cylinders, and the air
This heating, of
passing through this channel will be strongly heated as well.
course, produces an expansion of the combustion air, and the specific gravity of
the latter will then very nearly approximate to that of the, as yet, unheated gas.
Thus the mixing of the two constituents will be an exceedingly easy task.
When now, the mixture ascends in the reversed direction to its former course,
that is to say, upwards and along the inserted tube, this latter will become still
further heated, and the intensity of the heat will increase at the top of the tube,
so that, finally, the mixture which has been heated to a very high degree, enters
the head of the burner and reaches the burning surface, where it undergoes com-
plete combustion, with a blue, that is to say, a non-illuminating .flame.
The strong heating of the burner tube and of the tube inserted therein is
effected, on the one hand, by the non-illuminating flame and, on the other hand,
by the incandescent body. In this latter however, the heating of the head of

page_text: the burner is mainly effected by the lower part alone, whilst the upper part,
which is by far the larger portion, has not yet been utilized for the preliminary
heating of the air of combustion.
In order to accomplish this purpose also in the present improved lamp, the
enclosing globe of the incandescent body, (which globe may be constructed in
any suitable shape, for example as a cylinder as in Fig. 1 or in the form of a
pear as at Fig. 2,) is made with double walls in the lower portion, and extending
so far up that it corresponds at least approximately to the height of the incan-
descent body that is to say, this lower portion which is nearest to the incandes-
cent body, will be specially surrounded by a second enclosure of glass, thus form-
ing an annular channel with the corresponding part of the tube. This channel
is, however, closed at the bottom, and thus prevents the atmospheric air from
entering, but it is in communication with the inner cylinder, or with the bottom
part of the pear shaned enclosure, in such a manner, that the air of combustion
which is to be conducted through the cylinder or the pear, may reach these
devices either by the said annular channel alone, or may, in part, enter the
apertures of the true counter current described above.
The air. in passing through the said annular channel, is very strongly heated
by the influence of the incandescent body, and in this heated state it approaches
the incandescent body, especially the outer surface of the same, thus effecting
the complete combustion of any portions of the gaseous mixture, which may,
perhans, have been incompletely consumed un to this moment, and hence does
not leave the smallest residue unconsumed. In this way the entire quantity of
the gaseous mixture flowing to the Bunsen burner is utilized. Both for the pur-
pose of illumination and for the continuous further heating of the air of
combustion.
Whenever, therefore, this air of combustion, heated to such a high tempera-
ture, is not only conducted to the exterior of the incandescent body, but also to
the annular channel between the burner tube and the central tube inserted therein,
a two fold heating of that portion of the air of combustion is effected, so that
the air will be heated to the highest degree possible, and consequently an extremely
bright light is obtained from the lamp, and a perfectly white colour of the said
light will be the result.
It must be considered as an essential feature in both parts of the arrangement,
that the area of the said annular channel increases from the top downwards, so
that in consequence of the strong heating, the considerably increased volume of
the air is allowed a correspondingly larger space, and the entire mass of very hot
air is thus enabled to take the prescribed course instead of (probably) moving in
a direction where it would meet the fresh air, which is not yet heated at all.
According to this feature, the upper arrangement for the preliminary heating
of the air of combustion is such, that the outer enclosing globe is made approxi-
mately the same shape as the inner enclosure.
In Fig. 1 of the accompanying drawings the central tube inserted into the
burner tube c is indicated by d, while the tube c carries at its top the burner
head d, supporting a cap C, the burning surface of which is provided with very
fine perforations. The nozzle f of the gas inlet serves as a support to the said
tube c.
In the case represented in the drawings, the central tube forms an exten-
sion of the burner head, and ends closely above the nozzle, while the apertures c¹
for admitting the atmospheric air are made in the tube c just opposite the beginning
of the true central tube. The tube c is fitted, opposite the end of tube d, with a
boss supposed to serve as a handle, by which the tube c can be moved up and
down on the nozzle f. These movements are effected for the purpose of regulating
the proportion in which the air is mixed with the gas, and of altering and adjust-
ing the proportion in such a manner that any (cooling) excess of air may be
prevented, and that the air supply may enter in such quantity only, as is required
for the complete combustion of the gas. This regulation is of great importance

page_text: to the working of the burner, because any surplus of air would exert an effect
the reverse of heating on the central. tube, which latter will only fulfil its pur-
pose completely, when it is allowed to impart the highest possible temperature
to the air, or to the mixture of air and gas.
The mixing of the gas and air is effected in the bottom chamber of tube c.
The tubular extension of c, which forms the part by means of which the burner
rests upon the nozzle f, is preferably joined to the latter by screw threads, and
in this case the two threaded parts are made a little longer than usual, so that on
the one hand, a better control of the adjustment is obtained, and on the other
hand, that the burner, even when in its highest position, will find a solid and
perfectly secure support upon the nozzle of the gas inlet.
The mixture of gas and air, being strongly heated and ascending inside the
central tube, will, in consequence of its considerably diminished specific gravity,
greatly assist, by its own power of suction, the similar action of the gas- nozzle
with reference to the air, so that one is enabled to work the lamp at considerably
less gas pressure than is required with the Bunsen burners hitherto known.
That through this circumstance also the use of gas is advantageously diminished
need not be mentioned anew.
In all the figures of the drawings the herein before described burner, with
counter current of air is represented as applied to incandescent lamps, Fig. 1
showing such a lamp with a cylindrical enclosing glass globe, and Fig. 2 the same
with a pear shaped globe. In Fig. 1 A is the cylinder, and in Fig. 2 the pear
is indicated by A¹ and A. B (Fig. 1) and B (Fig. 2) are the improved exterior
globes, supported, in Fig. 1, by means of the gallery b, and the solid disc or
plate (for distributing the air) this disc being attached to the burner tube_c,
(which as has been already mentioned) is provided with the burner head d, the
arms a of which (or a perforated disc) carry the gallery a, which holds the
cylinder A. The course taken by the air is indicated by arrows in both figures.
The perforated surface of the burner head, over which is placed the incandescent
body held by a vertical rod is formed by a cap C, which sits loosely, as a separate
part, upon the burner head d, and can be removed from this head or from the
burner together with the incandescent body and the cylinder. This arrangement
can also be applied to lamps having pear shaped globes as shewn in Fig. 2,
where it is distinctly represented. Here another example is indicated when the
cap is enlarged at the lower end, like a gallery, and carries, in addition to. the
actual pear shaned enclosure, the outer globe, so that the whole device may be
taken off together.
As already mentioned in the introduction, it is not absolutely necessary that
the air which flows through the annular channel between the parts A and B
(Fig. 1) or A2 and B₁ (Fig. 2) and is heated therein, should enter the cylinder or
the pear shaped globe in its entirety, that is to say, flow to the outer surface of
the incandescent body: but this air may be partly conducted direct into the
burner and be again heated therein.
With the lamp shewn in Fig. 3 an arrangement of this kind is employed.
Here the disc b' for the distribution of air is extended at 6 down below the aper-
tures for admitting the air into the burner tube c, so that, now, only part of the
hot air flowing through the upper annular channel enters the cylinder A, whilst
the remaining portion of the air reaches the burner tube c, where it mixes with
the gas, whereupon the already strongly heated mixture of air and gas is again
heated in the central tube d to a maximum temperature.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is;-
J
1st. An incandescent lamp, the burner of which has a central tube inserted

page_text: in its comparatively long burner tube, by means of which central tube the air of
combustion entering through the upper apertures of the burner tube is subjected
to a preliminary heating when flowing in a counter current to meet the gas, while
the mixture of gas and air is afterwards separately heated inside the said central
tube substantially as herein set forth and shewn.
2nd. An incandescent lamp with a burner characterized by the first claim, in
which the burner tube together with the central tube are both vertically and
adjustably arranged upon the nozzle of the gas inlet, in such a manner, that the
distance between this nozzle and the central tube may be altered for the purpose
of regulating the proportion of the mixture substantially as herein described and
shewn.
3rd. An incandescent lamp with a burner as characterized by the first claim,
in which the internal area of the annular channel between the burner tube and
the central tube increases from the top downwards substantially as described and
shewn.
$
4th. An incandescent lamp with a burner as characterized by the first claim,
in which a removable cap is placed upon the head of the burner, said cap carrying
the incandescent body and the cylindrical or pear shaped globe, whereby, in the
latter case, the globe may consist of two parts substantially as described and
shewn.
5th. An incandescent lamp as characterized by the first claim, in which the
bottom part of the glass globe approximately up to the height of the incandescent
body, is constructed with double walls, and in which the area of the annular
channel thus formed increases from the top downwards, whereby the said channel
is in communication at the bottom with the internal space surrounded by the
inner globe substantially as herein described and shewn.
6th. An incandescent lamp as characterized by the 5th claim in which the
annular channel between the two bottom walls of the enclosing globe is also in
communication with the annular channel of the counter current burner sub-
stantially as set forth.
1000
GEO. THOS. HYDE.
1, Broad Street Buildings, Liverpool Street, London, E.C.,
Patent Agent for the Applicant.