in Incandescence Gas Lamps
Year: 1887

page_text: Date of Application, 13th Apr., 1887
Complete Left, 13th Jan., 1888
Complete Accepted. 23rd Mar., 1888
I BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool Civil Engineer do
hereby declare the nature of this invention to be as follows:-
My Invention relates to improvements in Incandescence Gas Lamps.
Briefly described I utilise the principle of recuperation in conjunction with the
incandescence system of obtaining light from the combustion of illuminating gas.
To effect this arrange the refractory filaments or rods in a novel manner as
follows. I hang suspend or fix rods, thin bars, or filaments, composed of highly
incombustible and refractory material such as calcined magnesia limestone, zirconium,
steatite or soapstone, platinum, siliceous clay or I may coat or deposit on the surface
of the platinum some unoxidisable or already oxidised and highly refractory body
such as the oxide of zirconium.
I arrange two or three concentric rings of these rods, for heating to incandescence,
in such a way that although the rods or filaments do not interfere with the passage of
the products of combustion through them, nevertheless, if the points or rods in the two
inner circles were projected on to the outer circle, the rods would form an almost solid
circle, consequently the rods when incandescent give the appearance of a solid luminous
flame. These rings of incandescent rods are placed around the central air tube, that
leads the air descensionally from the recuperators to the burners of the Bunsen type.
The air passes into an annular and outer cavity in which is fixed a ring of Bunsen
burners or there may be simply an annular space into which the gas issues from
numerous jet pipes from a circular gas supply chamber.
Besides this descensional air space I provide an ascensional one which allows the
air to enter to burners until the recuperator becomes hot, when by an automatic
arrangement resulting from the heat of combustion, the lower air supply is cut off.
The Bunsen burner and incandescent rings are enclosed in a globe or lantern, that
forms when lower air supply is cut off, a practically air tight joint.
The recuperators may be of any well known form but preferably of the type shewn
in figures, 1, 2, 3 and figure. 4 in the specification of my patent numbered 9191
A.D. 1886.
I may pass the rods through a perforated refractory disc or I may hang the rods on
platinum hooks so that when required they can easily be replaced. In another
modification of my Invention instead of the central and descensional air supply from

page_text: recuperator I may utilise two globes one surrounding the other, the annular space
being used for drawing air downwards from recuperator, from which it is distributed
to the central burner or burners of the Bunsen type over which hang the annular
rings of refractory rolls or filaments above them is a plate that diverts the combustion
between the said filaments or rods and from which the said filaments or rods are
lofty
suspended. To produce a strong current of air I may either make use of a
chimney or force the air by means of a fan driven by a small electro motor placed in
the lamp column, or by a small air or water motor, or where there are mains of
an air compression scheme I use part of the air therefrom.
I may make the air tube that leads the descensional air supply as well as the
outer annular tube of some highly refractory material.
In another modification of my invention I lead the air tube, from below, above the
level of the incandescence rings, into the recuperator placed above the level of
the lamp.
The air descends to meet gas through an annular space around the ascensional
air tube.
The complete combustion occurs near and inside the rings of incandescent rods.
The gas may be led into the recuperator in place of the air as just described, and
then descend by an annular tube to the foot of Bunsen burners.
The air supply in this instance being cold,

page_text: Improvements in Incandescence Gas Lamps.
BENJAMIN HOWARTH THWAITE of 37 Victoria Street Liverpool in the County of
Lancaster Civil 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 :-
My Invention relates to improvements in Incandescence Gas Lamps. Before
proceeding to describe the three sheets of drawings that are intended to form part of
this Specification I wish it to be distinctly understood that I do not desire to be
confined to the exact details herein shewn as they may be modified without departing
from the nature of my said Invention.
In sheet 1 of drawings figures 1 2 3 and 4 shew respectively, a vertical section, a plan
in section through A B; a plan in section through CD, of figure 1; and a plan in
section through air regulating arrangement.
The gas supply ascends by pipe 1 to gas and air mixture tube 2, the combustion
being completed at point 3 in the centre of two annular rings of suspended rods
needles or filaments 4, which become heated to a condition of highly luminous
incandescence by the heat of combustion. The arrangement of these rods or filaments
is an important feature of my Invention. It will be seen that in order to obtain, an
apparently solid area of incandescence I use two or more annular rings of these rods,
each one of these rods or filaments being in a radial line, opposite to the space
intervening between the rods or filaments in outer ring.
These rods may be composed of any well known refractory material such as finely
ground compressed and calcined magnesian limestone, steatite or soapstone, anhydrous
clay, alum, zirconium platinum gypsum siliceous clay, or I may deposit on the surface
of platinum, an already oxidised and highly refractory body such as the oxide of
zirconium.
I attach these rods to the suspension plate 5, which may be formed of platinum or
iron coated with gypsum, by means of hooks or by any other arrangement, that will
enable them to be removed and renewed with facility.
The suspension plate may be perforated plate iron or coarse gauze platinum iron
network.
The products of combustion pass through the perforations in suspension plate into
the chimney 6, whose aspiratory action draws the air between the concentrically placed
globes or glass cylinders 7 and 8.
The air becomes heated in contact with the sides of said cylinders, and enters into
the central gas and air mixture tube at 9 by means of openings 10. The chimney 8
and gas and air mixture tube may be supported on the upper edge of outer globe 7 as
shewn in dotted lines, this outer globe being held by a circular frame 11 which is in
ts turn secured to gas pipe 1.
Gas ignition openings are provided at 12 and a secondary and ascensional air supply
s provided by the openings 13 with regulator 14 of which figure 4 is a plan in
ection.

page_text: Figures 5 6 7 and 8, shew my Invention as applied for lighting streets or other
large areas.
The gas pipe 15 has branches 16 by which the gas is distributed to the annular
ring 17; provided with Bunsen gas tubes 18, part of the air enters to annular gas and
air mixing space 19 through a gauze covered opening 20 this supply can be closed by
the slide ring 21. The combustion of the gas, at the point 22 heats the suspended
refractory filaments or rods 23 up to a condition of incandescence, the filaments or
rods 23 can be attached at their lower ends to lip 24.
The products of combustion are led or directed by the flow deflecting light reflector
ring 25 into the annular recuperator chamber 26, and by the cover 27 into
chimney 28.
The air to support combustion flows through the tubes 29 into the central space 30,
and descending to the lower end of central and suspended air tube 31, the air is then
ascensionally deflected at point 32 through annular opening 33, into the gas and air
mixing chamber 19, the air in passing through the recuperator becomes highly
heated.
Besides the air supplied or due by the aspiration of the chimney 28 .I may provide
an additional air supply provided by means of a fan driven by a small self contained
electro-motor, this apparatus may be placed in the lamp standard or post, or I may
use a small gas jet burning in the lamp standard to induce a powerful air current
which I direct to the recuperator above the incandescent zone by means of 2 or 3 or
more tubes as shewn at 34 by dotted lines, this air current may be led direct to the
burner or air and gas mixing tube.
Figure 5 is a vertical section Figure 6 a half plan and half sectional plan in
line EF of figure 5.
Figure 7 is a plan on line G H of figure 5.
Figure 8 is an enlarged plan in section on line, of concentric refractory rods or
filaments.
Referring to sheet 2 of drawings, Figures 9 and 10 show a simple arrangement of
my Invention when applied to an ordinary Bunsen burner. The concentric rings
of filaments or rods are suspended from a circular disc 36, supported by bent arms 37,
over the mouth of Bunsen burner 38, provided with the usual air openings 39.
Figure 11 shews a vertical section of a modification of my Invention, as shewn in
figures 123 and 4.
In this arrangement, instead of cylindrical globes I use spherical ones 40 and 41,
which support a domical sectional form of an annular recuperator provided with heat
radiating fins 42 sec figure 12 and a chimney 43, the air descends through the
recuperator as shewn by arrows, between the two globes, and enters central air and
gas mixing tube 44 through orifices 45, air may also enter to gas and air mixing
chamber by orifices 46.
I suspend the concentric filament rod rings 46 by means of a central plate or
disc 46 held up by suspension bars or rods 48.
Figure 12 shews a plan in section at 1 J through concentric recuperator 41 shewing
hanging rods 48 and disc 47.
Figure 13 shews a sectional plan on line K L through concentric filament
rings 464.
On sheet 3 of drawings figures 14, 15, and 16 shews another arrangement of my
Invention that does not require enclosing glass globes, the Bunsen burner tubes 49
are placed in a circle under the concentric rods or filaments 50, around the annular
cavity or space 51, down or through which by central chimney 52 the products of
combustion are drawn entering the chimney by the annular space 53.
The gas supply is distributed from pipe 54 by branches 55 to the ring 56, and is
fed to the gas and air Mixture or Bunsen tubes 49 by small jet pipes 58.
The filaments or rods 50 are suspended from a ring shaped support 60 attached to
chimney at 61 which chimneys may be slightly decreased in diameter, & inside ring
of incandescence rods at 62. I provide heat transmitting and absorbtive fins 63.
Figure 15 is a sectional plan on line M N, and Figure 16 is a plan in section at O P..

page_text: Figures 17, 18, and 19 represent my Invention as arranged for producing an
exceptionally high intensity of light, suitable for light house and similar purposes.
There are two or more rings of Bunsen burners,-65. The products of combustion
issuing from outer ring of burners, descend through the annular space-66 to the lower
end of central chimney, this space is provided with heat radiating fins 67, by which
the sensible heat of the products of combustion is transmitted to the air and gas
ascending through the two rings of Bunsen burners.
The products of combustion from the inner ring of Bunsen burners descend through
the annular space-68, around and to the chimney-69 this space is also provided
with heat radiating fins.
The two concentric rods or filament rings 70 are suspended over the respective
rings of burners by means of the suspension ring plates 71.
The gas is supplied to burners by two circular pipes-72-connected to main gas
supply tube 73 by four branch pipes-74.
Figure 18 is a plan in section of burner taken at line QR and figure 19 is a plan
in section in line, S T.
By means of my Invention the artificial light produced by the incandescent
suspended rods has a more solid and intense appearance.
The filaments or rods can easily be replaced and the system of recuperation shewn
enables the maximum heat efficiency of the gas to be converted into luminous or
light energy.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same may be performed-I declare that what I
claim is
First. The method of arranging the rods or filaments of incandescence burners in
concentric circles, substantially as herein shewn and described.
Second. The recuperative arrangements in combination with the Bunsen system of
burning gas, for elevating refractory filaments or rods to a condition of brilliant
incandescence in the various modifications herein shewn and described.
Dated this 10th day of January 1888.
B. H. THWAITE.