Improvements in Incandescent Lighting with an Intimate Mixture of Gas and Air.
Year: 1896

page_text: Date of Application, 22nd Jan., 1896
Complete Specification Left, 17th Sept., 1896-Accepted, 19th Dec., 1896
PROVISIONAL SPECIFICATION.
Improvements in Incandescent Lighting with an Intimate Mixture
of Gas and Air.
I, LOUIS DENAYROUZE, of 70 Boulevard Victor-Hugo, Neuilly, (Seine)
France, Engineer, do hereby declare the nature of this invention to be as
follows:-
I. In previous Specifications No. 22615 of 1894, No. 4494 of 1895, No. 7722
of 1895 and No. 14053 of 1895 I have described means which I have been the
first to employ in order to obtain new industrial results in respect of incandescence
gas lighting. By a rational preparation of a mixture of gas and air for
incandescence mantles, burned on Bunsen or analogous burners I have realised a
lighting power at least five times that obtained in the way in which these burners
have been used for two years.
In these arrangements the mixture of air and gas is effected as follows. A
very small power is applied causing the molecules of air and gas to interpenetrate
each other intimately, by means of a mixer the most simple type of which is a fan.
The gaseous mixture thus formed at or near the burner reaching the mantle under
conditions most favourable for combustion produces the maximum effect.
On closely studying the phenomenon, after having practically realised it, I have
been led to determine very exactly the manifold conditions which have to be
satisfied by mixtures capable of producing such results.
Once these conditions were known, I have been able to modify and extend as
I shall describe, the means which I at first employed for producing by such a
mixture a light which is new not only in respect of its splendour, but also in respect
of certain special qualities which practice alone has revealed.
11. The mixture of air and gas formed as above mentioned should fulfil the
following necessary and sufficient conditions.
1. It should have a certain chemical composition,
2. Also a certain physical constitution
3. And it should reach the mantle with a certain velocity.
When these three conditions are all properly fulfilled together as I shall
hereafter explain, the complete luminous effect is produced.
If any one of the conditions is wanting the effect is lessened the more the more
the conditions are departed from by practical arrangements incomplete in respect
of one or more of "those essentials the combination of which determines the
production of the phenomenon.
111. From what precedes it will be observed that the notion as to the velocity
of the mixture as it reaches the particles which are to be rendered incandescent,
has revealed itself as being important to be considered as distinct from and
complementary to the notion of intimate mixture.
I have observed that the blades of the fan mixer not only triturate and beat the
air and gas, but that an apparatus of this kind causes the mixture to issue at
considerable speed, determined by the tangential velocity of the blades.
I have seen that with a certain mantle the luminous effect goes on increasing up
to a certain velocity beyond which it decreases while the pressure of the gas
supply does not vary.

page_text: 1. SOLUTIONS
WHICH THE COMBUSTIBLE (GAS) IS
IS TAKEN AT THE
SERVICE PRESSURE (20 TO 30 MM.) AND THE AIR AT ATMOSPHERIC
PRESSURE, THE MANTLE HAVING THE USUAL WEIGHT AND VOLUME OF
THOSE EMPLOYED WITH BUNSEN BURNERS.
In this case it is only necessary to adjust within the limits hereinafter stated, the
three conditions for establishing a good luminous system:-
· Chemical composition of the mixture-1 of gas, 3 to 5 of air.
Physical constitution-pulverisation of the two fluids.
Velocity of the mixture 15 to 2.5 metres per second.
Thus is obtained a mean light with 10 litres per Carcel lamp, if the arrangements
are such that:
1. The gas and air are admitted in the proportion of 1 to 3 or 5.'
2. They are intimately mixed :-and
3. The mixture reaches the mantle at a speed of 1.5 to 2.5 metres per
second.
I have not had to change any part of the previous arrangements; I have had
only to modify the initial velocity as required to, produce light by one or several
burners.
With mixers sufficiently large I can supply several mantles arranged to make
one compound light or separately to form lights of a lustre, or scattered over (a
building or several buildings by piping,supplied from one source.
Thus with a little power (electric, or other) a single fan mixer sending the
mixture into a central receptacle with branches leading from it with openings
suitably calculated at the points where the light is to be produced, forms the
system of illumination the most powerful and by far the most rudimentary hitherto
known.
Compared with electric lighting judgment is to be formed on the single ground
that with my system a power of 3 watts suffices to give a light of 100 carcels,
whilst (without considering the combustible used in the, burner) it requires at
least 600 watts to give practically equivalent light with the best known electrical
appliances. When compared with pressure jets of any kind, the process, is
distinguished by dispensing with the pressure and adding to the speed of the jet
the necessary condition of preliminary intimate mixture...
Compared with systems intended to operate the trituration.and mixture of the
fluids at a distance, the process is distinguished in this, that no recourse is had to

page_text: complex apparatus and great expenditure of power to effect a mixture of air and
gas improperly qualified as being permanent, but that the triturated air and gas
do not receive mixture and pressure, but mixture and velocity.
Hitherto efforts have been made to produce in the mixture a kind of stable
molecular equilibrium, whereas experience shews that the effect desired can be
produced only in a fluid in motion.
I need not here describe any new organs except that in the system of pipes
leading from the single mixer, there are made openings proportioned to the
volumes of the mantles, and that the velocity of issue is rendered approximately
the same at all the openings which may be unequal or unequally distant from the
flame by partially throttling them with suitable wire gauzes.
The use of these presents the double advantage that they serve in a very simple
manner to regulate the velocity and at the same time to ensure against explosion
by the flame striking back.
SOLUTIONS IN WHICH, WHILE THE MANTLE IS THAT USUALLY EMPLOYED
WITH BUNSEN BURNERS, THE AIR AND GAS RECEIVE AN INITIAL
PRESSURE HIGHER THAN THAT IN THE SERVICE PIPES AND THE
ATMOSPHERE.
Good mixture can also be obtained in this way, it is only necessary and sufficient
that the two fluids should lose by means of baffles the excess of velocity due to the
initial pressure.
Thus if the blades of the fan mixers were stationary becoming simply baffles,
and if the air and gas arriving separately under pressure had first to divide
themselves in passing between these blades, and then the fan forced their lamine
against each other for intimate mixture through perforated plates or wire gauzes,
the result would be so much the better the more approach by these means were
made to the three conditions, of
Composition, 1 of gas to 3 or 4 of air.
SOLUTIONS IN WHICH THE INCANDESCENT BODIES ARE NO LONGER MANTLES
OF WOVEN FILAMENTS BUT ARE POROUS MASSES RELATIVELY THICK.
In this case the quantity of combustible gas and the velocity of the intimate
mixture have both to be greater, the greater the mass of the body to be incandesced
relatively to its volume. For apparatus of this kind the gas alone or both the gas
and air may be used under pressure.
The speed of issue of the mixture should be greater, the thicker the particles
which it strikes as it issues. There is in this way no other limit to the production
of the luminous effect than the resistance of the particles of the incandescent
body to the mechanical force which tends to disperse them or the heat which tends
to fuse them.
In these latter apparatus violent incandescence effects can be produced by using
amadou or sponges impregnated with usual liquids formed for salts of earths
employed for making Bunsen mantles.
Another good process consists in using naturally porous bodies sufficiently
refractory such as pumice stone or retort carbon, or bodies artificially made having
approximately the same molecular constitution.
The form and texture of these porous bodies may be varied at will. Instead of
very compact bodies, a sort of simple cartridge may be formed containing filaments
close together or entwined.

page_text: Any kind of bundle, faggot, skein or tow of refractory wadding forming a whole
sufficiently strong may give good results, so long as the conditions of chemical
composition, physical constitution and velocity of the issuing mixture are fulfilled.
Dated this 22nd day of January 1896.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Incandescent Lighting with an Intimate Mixture
of Gas and Air.
I, LOUIS DENAYROUZE, of 70 Boulevard Victor-Hugo, Neuilly (Seine) 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 :-
I. In previous Specifications No. 22615 of 1894, No. 4494 of 1895, No. 7722
of 1895 and No. 14053 of 1895 I have described means which I have been the
first to employ in order to obtain new industrial results in respect of incandescence
gas lighting. By a rational preparation of a mixture of gas and air for incandescence
mantles, burned on Bunsen or analogous, burners I have realised a lighting power
at least five times that obtained in the way in which these burners have been used
for two years.
In these arrangements the mixture of air and gas is effected as follows.
A very small power is applied causing the molecules of air and gas to
interpenetrate each other intimately, by means of a mixer the most simple type of
which is a fan. The gaseous mixture thus formed at or near the burner reaching
the mantle under conditions most favourable for combustion produces the maximum
effect.
On closely studying the phenomenon, after having practically realised it, I have
been led to determine very exactly the manifold conditions which have to be
satisfied by mixtures capable of producing such results.
Once these conditions were known, I have been able to modify and extend as
I shall describe, the means which I at first employed for producing by such a
mixture a light which is new not only in respect of its splendour, but also in
respect of certain special qualities which practice alone has revealed.
II. The mixture of air and gas formed as above mentioned should fulfil the
following necessary and sufficient conditions.
1. It should have a certain chemical composition,
2. Also a certain physical constitution
3. And it should reach the mantle with a certain velocity.
When these three conditions are all properly fulfilled together as I shall hereafter
explain, the complete luminous effect is produced.
If any one of the conditions is wanting the effect is lessened the more the
conditions are departed from by practical arrangements incomplete in respect of
one or more of those essentials the combination of which determines the production
of the phenomenon.
III. From what precedes it will be observed that the notion as to the velocity
of the mixture as it reaches the particles which are to be rendered incandescent,
bas revealed itself as being important to be considered as distinct from and
complementary to the notion of intimate mixture.
I have observed that the blades of the fan mixer not only triturate and beat the
air and gas, but that an apparatus of this kind causes the mixture to issue at
considerable speed, determined by the tangential velocity of the blades.

page_text: Compared with systems intended to operate the trituration and mixture of the
fluids at a distance, the process is distinguished in this, that no recourse is had to
complex apparatus and great expenditure of power to effect a mixture of air and
gas improperly qualified as being permanent, but that the triturated air and gas
do not receive mixture and pressure, but mixture and velocity.
Hitherto efforts have been made to produce in the mixture a kind of stable
molecular equilibrium, whereas experience shews that the effect desired can be
produced only in a fluid in motion.
I need not here describe any new organs except that in the system of pipes
leading from the single mixer, there are made openings proportioned to the volumes
of the mantles, and that the velocity of issue is rendered approximately the same
at all the openings, which may be unequal or unequally distant from the flame, by
partially throttling them with suitable wire gauzes.
The use of these presents the double advantage that they serve in a very simple
manner to regulate the velocity and at the same time to ensure against explosion
by the flame striking back.
SOLUTIONS IN WHICH, WHILE THE MANTLE IS THAT USUALLY EMPLOYED
WITH BUNSEN BURNERS, THE AIR AND GAS RECEIVE AN INITIAL
PRESSURE HIGHER THAN THAT IN THE SERVICE PIPES AND THE
ATMOSPHERE.
Good mixture can be also obtained in this way, it is only necessary and sufficient
that the two fluids should lose by means of baffles the excess of velocity due to
initial pressure.
Thus if the blades of the fan mixers were stationary becoming simply baffles,
and if the air and gas arriving separately under pressure had first to divide
themselves in passing between these blades and then forced their particles against
each other for intimate mixture through perforated plates or wire gauzes, the
result would be so much the better the more approach by these means were made
to the three conditions of
Composition, 1 of gas to 3 or 4 of air.
SOLUTIONS IN WHICH THE INCANDESCENT BODIES ARE NO LONGER MANTLES
OF WOVEN FILAMENTS BUT ARE POROUS MASSES RELATIVELY THICK.
In this case the quantity of combustible gas and the velocity of the intimate
mixture have both to be greater, the greater the mass of the body to be incandesced
relatively to its volume. For apparatus of this kind the gas alone or both the gas
and air may be used under pressure.
The speed of issue of the mixture should be greater, the thicker the particles
which it strikes as it issues. There is in this way no other limit to the production
of the luminous effect than the resistance of the particles of the incandescent body
to the mechanical force which tends to disperse them or the heat which tends to
fuse them.
In these latter apparatus violent incandescence effects can be produced by using
amadou or sponges impregnated with usual liquids formed for salts of earths
employed for making Bunsen mantles.
Another good process consists in using naturally porous bodies sufficiently
efractory such as pumice stone or retort carbon, or bodies artificially made having
approximately the same molecular constitution.
The form and texture of these porous bodies may be varied at will. Instead of

page_text: very compact bodies, a sort of simple cartridge may be formed containing filaments
close together or entwined.
Any kind of bundle, faggot, skein or tow of refractory wadding forming a.
whole sufficiently strong may give good results, so long as the conditions of
chemical composition, physical constitution and velocity of the issuing mixture are
fulfilled.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
For incandescent gas lighting, the method of effecting an intimate mixture of
air and gas under the combined conditions as to the composition the pressure and
the velocity of the mixture herein before stated.
ABEL & IMRAY,
Agents for the Applicant.