Year: 1887

page_text: Date of Application, 2nd Sept., 1887
Specification Accepted, 4th Oct., 1887
I, EUGÈNE DERVAL, of 36 Boulevard St. Michel, Paris, in the Republic of France,
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; reference being had to the accompanying drawings and to the letters and
figures marked thereon, that is to say :-
This invention relates to regenerative gas lamps and burners, and has for object
the rendering of such lamps and burners more practical than heretofore, and to
improve their lighting power.
In the Drawings hereto annexed, Figure 1 is a vertical section of a lamp constructed
in accordance with my invention, arranged to receive the gas from below, and
capable of being lighted from the top of the chimney as in ordinary burners. Figure 2
shows in vertical section the general arrangement of the lamp when the gas enters
from above and is lit from below. Figure 3 is a section, to a larger scale, of the burner
shown in Figure 1, and Figure 4 is a horizontal section, also to a larger scale, taken at
X X of Figure 1.
The arrows a show the course of the gas, and the arrows b that of the products
of combustion; the arrows not lettered show the course of the air for feeding the
flame.
T is the gas inlet, S a spiral tube in which the gas is heated, H the chimney, k an
annular burner fixed on the concentric tubes m and n between which the gas passes on
its way to the burner, see Figure 3. D is a metallic plate screwed to the centre of
the piece A which forms with it a regenerator box into which open the small gas
feeding tubes and the pipe by which the gas is introduced either at the top or bottom
of the lamp. R is a regenerator, formed of a tube of cast iron or inoxidisable metal,
conducting the air, which enters by the central tube m, into contact with the flame.
In Figure 2, this tube carries a series of small curved pipes R' which increase the
regenerative surface. The lower part of the tube R is slightly conical and may be
perforated with a large number of small holes as shown in the Drawings. vare small
metallic screws, or wires, passing through the side of the regenerator R, so as to increase
the extent of the metallic surfaces in contact with the air (see Figure 4). Z is a

page_text: piece of copper, or other suitable metal, guiding the air to the lower part of the flame.
In the type of lamp shown in Figure 1, this piece is perforated at its lower_part and
contains a perforated plate 2 for securing a complete division of the air. Its upper
part is slightly conical, and should be enamelled, or platinized, carefully, so as to reflect
the rays of light. P is a ring of white refractory material which may be replaced,
when necessary, by a conical refractory piece over which the flame spreads itself.
Referring to Figure 2, F is a cast iron piece resting on the piece A and serving to support
the chimney H and the sleeve E, which latter forces the air to pass down in contact with
the chimney before entering the glass cup G through the holes i. e is a movable ring per-
forated with holes corresponding to those in the tube m; by turning this ring so as to open
or close the holes, more or less, the quantity of air admitted into the regenerator can
be regulated at pleasure. O are ventilating holes in the top of the air regenerator
tube. The glass cup G rests on a copper or other metallic piece G¹ arranged so as to
close hermetically the lower part of the lamp. This piece is supported by a spring
with two branches r, through which spring passes a tightening screw V screwed into
the bottom of the tube m. t is a metallic rod carrying the lamp. f is an adjustable
smoke deflector by which the draft of the chimney may be regulated as required. J is
an ordinary lamp shade.
It will now be understood that the gas, previously raised to a high temperature by
its passage through the regenerator formed by the spiral tube S and the distributing
box above the air regenerator R, takes fire on coming in contact with two currents of
air one of which reaches it through openings formed between the burner and the tube R
and the other through the opening between the tube m and the piece Z. The upper
current of air is supplied through the central tube m, and is heated in the regenerator R,
whilst the lower current only receives the heat transmitted by radiation and conduction
to the various metallic pieces forming the bottom of the lamp.
In the lamp shown in Figure 2, the air supplied to the top of the flame is strongly
heated in the special regenerator formed by the sides of the tube R and those of the
series of bent tubes R' arranged so as to conduct the air, which enters through the
middle of the burner, to the top of the flame.
This arrangement, which forms a special feature of my invention, is equally
applicable to lamps in which the gas enters from below, and allows of obtaining a
much more complete regenerative effect than when the regenerator is formed by the
sides of the tube R only, as is the case in the type of lamp shown in Figure 1. As the
heating of this tube is effected chiefly by the contact therewith of the products of
combustion, it is advisable to diminish its external radiation by making it of polished
metal. The internal sides of the regenerator should, on the contrary, be blackened,
so as to increase the internal radiation, and facilitate the heating of the metallic pieces
not in contact with the products of combustion.
The type of lamp shown in Figure 2 also allows of heating, to some extent, the air
which passes through the holes by surrounding the base of the chimney with the
sleeve or jacket E, open at the top, and furnished with a metallic gauze when it is
necessary to protect the flame from currents of air.
In order to light the lamp, it is only necessary to remove the glass cup G by
easing back the screw V and pressing lightly with the fingers on the two branches r of
the spring which serve as supports. This plan of opening and closing enables the
construction of the lamps to be simplified, and breakages due to the expansion of the
cup under the influence of heat to be avoided.
In small lamps of the type shown in Figure 1, it is necessary to cool the sides of
the chimney by perforating the base of the cone Z, the upper part of which is arranged
as usual so as to reflect a part of the luminous rays emitted by the flame. This cone
contains a small perforated plate Z intended to strain and divide the air which enters
beneath the flame; but a plain plate may be employed, and the base of the flame be
fed through a number of holes formed in the part of the tube m situated between the
plate and the burner. This latter arrangement offers the advantage of allowing the
quantity of air fed to the two sides of the flame to be regulated by the employment of
a perforated ring analogous to the ring e shown in Figure 2.

page_text: Figure 4 shows a horizontal section of the regenerator tube R which is furnished
with a number of small inoxidisable metal screws such as aluminium-bronze, or nickel,
for example, the object of which is to divide the currents of gas and to facilitate
the transmission of heat from the products of combustion to the air supplied to the
upper part of the flame.
It may be observed that in the two types of lamps above described, the regenerator
in which the gas is heated is placed above that in which the air is heated, and that
the latter regenerator, by reason of its greater proximity to the flame, absorbs the
radiant heat as well as the major part of the caloric contained in the products of
combustion, consequently, the partial decomposition of the gas under the influence of
a high temperature, which occurs in some lamps of this class, does not occur in lamps
constructed in accordance with my invention, because the length of the spiral tube S
can always be calculated so as to avoid too great heating, and the current of cold air
entering through the central pipe m prevents an excess of heat in the immediate
neighbourhood of the burner. This feature of my improved lamp, with central feed,
prevents the obstruction of the holes of the burner, and of the pipes, by carbonaceous
deposits, without the necessity of abandoning, for that purpose, the heating of the
gas. The lamps may be simplified by omitting the spiral tube S, thereby reducing
the gas regenerator to the sides of the distributing box placed immediately over the
air regenerator.
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 :-
First The regenerative gas lamp or burner constructed and arranged as heroin-
before described, and illustrated in the Drawings hereto annexed.
Second-The means of heating and conducting to the upper part of the flame a
certain quantity of air, by the employment of a regenerator formed of a tube placed
above the burner and having fixed thereto several small bent tubes arranged so as to
conduct to the upper part of the flame the air introduced into the regenerator by a
metallic tube open at the bottom and passing up through the centre of the lamp or
burner, as hereinbefore described, and illustrated in the Drawings hereto annexed.
Third The use, for heating the gas, of a regenerating box placed immediately
over the air regenerator, the gas being delivered to such box by a simple tube, or
by means of a spiral tube placed in the upper part of the chimney, in combination
with the arrangements for cooling the annular burner and the feeding passages by
means of a current of cold air passing through the centre of the lamp or burner,
as hereinbefore described, and illustrated in the Drawings hereto annexed.
Fourth For increasing the power of the air regenerator, the use of a number of
small screws or metallic wires passing through the sides of the regenerator, as
herein before described, and illustrated in Figure 4 of the Drawings hereto annexed.
Fifth The devices for opening and closing the glass cup, consisting of a spring
with two branches capable of being tightened more or less by means of a pressure
screw placed below the lamp, as hereinbefore described, and illustrated in Figure 2 of
the Drawings hereto annexed.
1000