Improvements in Burners for Oil Lamps having Incandescing. Mantles.
Year: 1899

page_text: Date of Application. 20th Dec.. 1899
Complete Specification Left. 21st May, 1900-Accepted, 11th Aug., 1900
Complete Specification Left. 21st May. 1900—Accepted, 11th Aug., 1900
PROVISIONAL SPECIFICATION.
Improvements in Burners for Oil Lamps having Incandescing.
Mantles.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Chartered Institute of Patent Agents, do hereby declare
the nature of this invention (a communication from abroad by Lars Christian
Nielsen, of Frederiksberg, near Copenhagen, Denmark, Constructor,) to be as
follows:-
This invention relates to improvements in burners for oil lamps, in which
incandescing mantles are employed.
The burners of this class known at the present time have various disadvantages,
for instance the flame is inconstant and flickering, points or tongues being formed
which have the effect of blackening the mantle and also of causing singing,
buzzing, and other sounds.
Various experiments have shewn my correspondent that these irregularities are
partly due to the evaporation of the oil and partly to the way in which the air
is supplied which is to be mixed with the vaporized oil, to admit of the latter
being properly burnt.
From a practical point of view it appears an impossibility to render the wick
homogeneous throughout, even at the burning point, where the flame is formed,
and the effect of this is that an uneven amount of vaporized oil is caused to escape
from the various parts of the burning surface of the wick. Supposing that for
one reason or another at one place a comparatively large quantity of vapour is
developed, then from that point a jet of vapour is given off which will carry along
with it a portion of the surrounding air, without such an intimate mixture taking
place between the air and the vapour as is necessary to ensure a complete com-
bustion. Therefore a complete combustion of such a jet of vapour will take place
only upon its surface, and when the jet subsequently impinges against the mantle,
it is a characteristic feature that in such case a black spot is formed on the mantle
at the point where the centre of the jet strikes it, which spot is surrounded by
an intensely luminant edge forming the outline of the jet. It is evident that
such a spot reduces the illuminating power, and in the case of several such spots
being formed, the mantle will ultimately become useless, quite apart from
the fact of its being subjected to injury thereby.
Another point to be taken into consideration is that the air currents when
conveyed to the oil vapours in the manner heretofore employed can not possibly
be homogeneous. Even supposing that the passages through which the air
currents pass, or the edges over which they travel, were originally formed with
mathematical accuracy, a short time only will elapse in use, before they become
uneven, partly owing to the heating of the metal, and partly to the presence of
impurities deposited upon the air passages, the consequence being that lines are
formed in the air currents along which the air moves more intensely than at other

page_text: points. As soon as such lines or split current enters the oil vapour, pointed flame
jets or tongues are at once formed having the effect of blackening the mantle and
causing it to vibrate so as to be quickly destroyed.
The more the wick is raised the larger become its flame tongues and the more
intense the blackening effect. The extent of these tongues may be limited, so
that the incandescent mantle is not directly touched, by lowering the wick, but
in such cases the movements of the tongues frequently become so rapid and
intense that the before mentioned buzzing sounds are produced. In either
case, the intensity of the light is considerably reduced, and it will frequently
occur that the limits intervening between the buzzing sounds and the blackening
of the mantle are so small, that it is impossible to obviate both, in an attempt to
adjust the wick so as to obtain an incandescing effect with the mantle.
The point to be principally aimed at, therefore is to obtain as uniform a
development of oil vapours as possible all over the burning surface of the wick
and further to ensure that the currents of the air and vapour are so directed as to
remain as homogeneous as possible at all points. According to this invention
the former object is achieved by using the vapourizer hereinafter described and
the latter object by utilizing crossing air currents.
As soon as two or more air currents are crossing each other a new current is
produced, which with regard to direction and intensity forms the resultant of
the individual currents. In a certain respect, however, which is of great impor-
tance for the object in view, the resulting current will materially differ from
the currents of which it is made up because the lines or irregularities of the air
currents, above referred to, are considerably reduced. It is evident that when one
of these lines within an air current meets another current at a place where the
latter is not split, the greater part of the said line will be equalized, and even if
two lines impinge against each other they will usually be destroyed and equalized
at the meeting point. If however a line or irregularity should remain in the
resulting current, it can be still further reduced by causing another
lateral curent to cross it or better still by causing another resulting or
compound current to cross the first compound current. The larger the number of
such crossing currents employed, the more efficiently such lines of air currents
will be avoided. The fact that this is true not only theoretically but also prac-
tically is apparent from the improved burner hereinafter described in which two
crossing compound currents are employed, whereby the first object namely the
obtaining of a completely stationary and uniform flame without any trace of
tongues, lines or other defects, is achieved.
In the case of paraffin burners, where incandescent. mantles are employed
generally one air current is passed up inside the wick tube, while another is
passed up outside the tube. According to this invention the arrangement is
such that each of these air currents is divided in two parts crossing each other
and the two resulting currents thus generated are again made to cross each other
so as to form another current directed into the hollow space of the mantle, where
the complete combustion takes place. The first two resulting currents are each
generated separately prior to meeting the oil vapour.
The invention is illustrated in the accompanying drawing, in which:
Fig. 1 represents the new burner in side elevation; and
Fig. 2 the same in plan.
The left half in each figure represents a vertical and a horizontal section
respectively.
The generation and the crossing of the two inner air currents is produced
partly by an inverted bowl-shaped head a, having on its under side a tapering
downward extension 6 which terminates in a stem, by which the part is secured
to the wick tube c; in some convenient way, and partly by a ring d arranged in
the wick tube and provided with passages. As the air ascends in the wick tube,
the air current is divided into two parts; the one ascends through the opening
between the ring d and the extension 6 of the part a and is gradually deflected
P

page_text: from its vertical direction towards the outside where it impinges upon and crosses
with the other part of the air current, which rises in an upward direction through
openings f in the ring d. The resulting current, not only supplies the wick with
the necessary amount of air, but this air feed is also an even and homogeneous
one and yet the speed of the current is not too great, so that even a small flame
is not injuriously affected thereby.
The part a above referred to serves as a vapourizer as it is raised to a high
temperature by the flame so that the heat radiating from the metal impinges
upon the oil leaving the wick. This vapourization takes place evenly from the
bottom surface of the part a and particularly from the edge of same which latter
must be evenly turned off and bent over the wick the arrangement contributing
considerably towards securing a uniform vaporisation of the oil at all points,
even if there should be any irregularities in the supply.
The outer air current passing outside the wick-tube, is likewise divided into two
parts, one of which flows through the opening g and the other through the holes h,
in the ring. The latter however are directed inwardly by an inclined piece k
above holes h so that a crossing is effected with the current passing through the
opening g the result being that with regard to both outer air currents the same
result is obtained as with the two inner currents above referred to.
It will be seen from the preceding, that the oil vapour generated above the
wick is enclosed between the two currents, the consequence being that the
vapour is so imprisoned, that even in the case of any irregularities in the
vapourisation no vapour can escape by way of radiation. On the contrary all
the constituent particles of the vapour are retained and absorbed by said air
currents, and as the main current produced by the resulting currents receives
a direction converging upwardly throughout towards the 'hollow space of the
mantle, any diverging jet of vapour could only meet the mantle at the place
lying diametrically opposite to the place of admission; but before it can reach
that place it has been absorbed by the surrounding air and vapour currents which
will enter into such an intimate mixture, that a complete combustion can be
obtained.
In this manner the air and vapour currents at all points are so limited and
bound that lines splits and streaks in the flame are completely avoided and the
mantle will emit a steady and clear light resembling the well known "Welsbach "
incandescent gas light not only as regards the appearance but also the illuminating
power, as if the wick has once been adjusted to the proper height, no further
regulation is necessary as the mantle will emit a steady and powerful light until
all the oil in the reservoir has been consumed.
It is easy to adjust the wick to its proper height as provision is made for a space
within which the wick can be moved such adjustment only resulting in a modifi-
cation of the intensity of the light, without any blackening, buzzing noise or like
defects being produced. If the mantle should accidentally have been blackened
by screwing the wick too high all that is necessary is to lower the wick slightly
more than is necessary for ensuring the best lighting effect, whereupon the
blackened places will disappear.
The edges of the wick tube (that is to say the top edges of the two hollow
bodies, between which the wick slides) are preferably made of the same height at
all points, and during use the burning surface of the wick is preferably set on
the same plane as these edges so that the wick is not so much subject to burning
down unevenly as would be the case if the flame were burning down a portion of
the side surfaces of the wick, a fact generally met with in burners of the usual
construction, another consideration being that the carbonised parts of the wick
can be wiped off for instance with the tip of the finger, prior to the lamp being
lighted. The wick need never be trimmed in any other manner, and it is not
even necessary that it should be done prior to each ignition, even if the lamp has
burned for many hours.
Even if the incandescent mantle has been injured or is entirely omitted, the

page_text: flame wil burn just as well and steadily the illuminating power being then
naturally less in proportion to the parts of the mantle missing or if the mantle is
entirely omitted, no incandescent effect is obtained it being the method in which
the flame is bound which renders the latter entirely independent of the mantle,
and this fact likewise contributes to the preservation of the latter.
The heat given off by this improved burner to its surroundings is not much
greater than in paraffin lamps of the ordinary kind; and as regards the oil
reservoir it is not heated at all owing to the fact that the combustion takes
place in the hollow space of the mantle.
The lighting of the lamp offers no difficulties. As soon as the vaporizing part
is heated, all parts (the gallery with glass chimney incandescent mantle etc.) can
be put in their proper place, the wick adjusted if necessary and so forth. The
heating of the vapourizer is effected by the first flame of the wick and does not
usually take longer than a minute.
All that has been set forth herein with regard to the improved burner has been
proved by many experiments in which such a burner has burned for days without
any interruption and without regulation yielding a steady and clear light and
providing a lamp satisfactory in every respect.
Dated the 19th day of December 1899
COMPLETE SPECIFICATION.
Improvements in Burners for Oil Lamps having Incandescing
Mantles.
A communication from abroad by LARS CHRISTIAN NIELSEN, of Frederiksberg,
near Copenhagen, Denmark, Constructor.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Chartered Institute of Patent Agents, 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 improvements in burners for oil lamps and is
especially applicable to those in which incandescing hoods or mantles are
employed.
The improved burner belongs to the class in which the air required for the
complete combustion of the oil vapours is conducted partly inside the wick tube
and partly outside and round the same.
After long and minute trials Mr. Nielsen constructed this improved burner
in which the disadvantages connected with this class of lamps (as for example
the smoke issuing from them and the noise caused by the flame) is avoided
partly by making the evaporation of the oil (which. is usually paraffin oil) as
uniform and regular as possible over the whole burning surface of the wick and
partly by conducting the air to the wick and to the flame in such a manner, that
the feeding becomes completely homogeneous (regular) and free from lines or
irregularities, which latter are apt to occur when the current of air is stronger
in one place than in another. The air when passing through narrow channels or
when flowing over solid rims or edges always causes the formation of such lines
or irregularities, of which the disadvantages mentioned before are chiefly the
consequence.
In the present improved burner the uniform and regular generating of the
paraffin oil vapours is obtained by the generator described below and the homo-
geneous (regular) feeding of the air is effected by the formation of resultant
currents of air and by the proper application of the same. When two or more
currents of air are caused to cross one another another current is
formed, which in respect of its direction and strength may be con-
.

page_text: sidered as the resulting current of the different original currents. But the
irregular air lines of the original currents will be considerably effaced in the
resulting current, so that it is practically homogeneous (regular). If however
the feeding with air is effected only by such homogeneous resulting currents, the
mixture of air and the oil vapours must be at all points of the burner much more
uniform than would be the case if the feeding takes place with ordinary currents
of air, and also the combustion of such a mixture is in said case of a much
quieter and more complete nature. That this is not only true in theory but also
practically, must be acknowledged, when considering the present burner, in
which the vapours of the paraffin are enclosed within two resulting currents of
air, each of which emanates separately, one of them inside the wick tube, the
other outside it, by which means is obtained an absolutely quiet and uniform
light.
It is of great importance that the resulting currents are procured immediately
at the flame, for if they have a way to flow after their having been procured they
will lose their peculiar character as resulting currents and operate as common
air currents.
The invention is illustrated in the drawings accompanying the Provisional
Specification in which―
Figure 1 represents in part a side view of the burner, the remaining part being
a section of the same.
Figure 2 shows in part a plan of the improved burner, part of which is
represented in section.
One part of the inner resultant current of air is formed by means of a solid
body having the shape of a reversed cup from the centre of which is a down-
ward extension.
This part ab is carried by or terminates in a stem, by which it is fixed to the
wick tube c. The other part of the inner resultant current of air is formed by
causing the air to pass through a ring d provided with channels and attached to
the wick tube.
Assuming the atmospheric air passes through the wick tube in an upward
direction, the air current in question is divided into two parts one of which
passes through the space e between the ring d and the extension of the body a
and is gradually altered from its vertical direction and deflected towards the
outer side of the tube. Such current is however then met by the
second part of the original current of air which has passed through
the channels of the ring d. The resulting current thus formed by means
of the meeting of the two parts, feeds the wick with the air required by the
burner as a completely homogeneous (regular) current of air, the velocity of which
is so small that even a very weak flame will be able to withstand it.
The said body at the same time serves as a generator of the paraffin oil
vapours. This body as will be seen is situated immediately above the burning
surface of the wick and it is bent with a sharp and accurately turned edge directly
over the said surface. This body is preferably produced on a lathe.
When the lamp is lighted, the combustion of the paraffin vapours takes place
above said body or reversed cup a, and in spite of this latter being underneath
the Hame and of its not being caused to glow the resulting temperature is
sufficiently high to cause the evaporation of the oil absorbed by the wick such
evaporation being caused by the heat radiating from the bottom of the said cup a.
By reason of the accurate shape of the body a and its being placed directly
above the flame the evaporation is effected in a very uniform manner over the
whole burning surface of the wick even if irregularities exist upon this surface,
and the evaporation will not be stronger than sufficient in proportion to the air
currents.
During such use of the lamp the top of the wick forming its burning surface
is placed at the same level with the rim of the wick tube.
The generation of the exterior resultant current of air is obtained by the follow-

page_text: ing arrangement. A ring i provided with channels is arranged outside the
wick tube and a space. g is left free between this tube and the ring. The
atmospheric air ascends at the outer side of the wick tube where it is however
divided into two currents, the one passing through the space g, the other ascend-
ing through the channels h. This latter current is deflected from its vertical
direction by means of an inclined surface k directly situated above the channels h,
so that said current is conducted towards the interior. Hence the exterior
resultant current of air is formed by the meeting of the two original currents.
This second resulting current of air also feeds the flame or light in a completely
homogeneous (regular) manner yielding the air required for the combustion of
the paraffin oil vapours.
From this description it will be gathered that the oil vapours generating above
the rim of the wick are enclosed within the two resulting currents of air, and
it therefore follows that even in case of irregularities occurring upon the burning
surface of the wick, the evaporation of the oil is effected without allowing any
vapours to escape, but that on the contrary all the vapours of the oil are absorbed
by the currents of air.
It will also be seen that the resulting main current of air being formed by the
meeting of the different resulting currents, is caused to take an upward direction
in the interior of the burner, so that all combustible substances are brought
into the hollow space of the incandescent mantle when the combustion proper
is going on.
By means of the said arrangements the end in view is fully attained the
currents of air and those of the vapours being limited and bound on all sides in
such a manner, that tongues of flame and the like are completely avoided, and that
the mantle is caused to become incandescent by means of an absolutely quiet
and clear flame similar to the class of gas incandescent light of the Welsbach
type.
When once the wick of the lamp is adjusted at the right level any further
regulation of same is superfluous. Even in the case of the mantle being injured,
the light has a quiet flame, it being only less bright than in the case where the
mantle is intact. The heat generally produced by the lamp is not considerably
higher than that of ordinary paraffin oil lamps having burners of the same size.
The oil reservoir of this improved lamp will not be raised to a higher tempera-
ture than that of ordinary lamps and the lighting of the wick presents
difficulties.
no
All that has been said of the working of the improved burner has been proved
by many experiments, the lamp having burnt a whole day without any readjust-
ment being required.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is:-
In burners of oil lamps of the class in which incandescence mantles are employed
and to which the atmospheric air is conducted in an upward direction, partly in
the interior of the wick tube and partly outside and round the same.
1. The arrangement inside the wick tube of a generator (a) of oil vapours, such
generator taking the shape of a reversed cup and being placed directly above
the burning surface of the wick, and underneath the flame,in combination with
a ring () provided with channels, also arranged inside the said tube, by means
of which arrangement all the air ascending inside the wick tube is collected into
one resulting internal current of air.
2. The arrangement of a ring (i) provided with channels and attached to the
outer side of the wick tube-in combination with an inclined surface (k), placed
directly over the said channels by means of which arrangement all the air
ascending outside the said tube is collected into an external resulting current of
air, this latter current together with that inside the wick tube enclosing the oil

page_text: vapours of the wick, thus allowing them to be intimately mixed with the air,
the external current of air taking at the same time such a direction, that the
collected vapours mixed with the main resulting current of air are conducted into
the hollow space inside the incandescent mantle, where the combustion proper
takes place.
3. The improved burner constructed substantially as described and illustrated.
Dated the 21st day of May 1900.