IMPROVEMENTS IN THE MANUFACTURE OF GASES FOR THE PRODUCTION OF LIGHT, HEAT, AND MOTIVE POWER, AND IN APPARATUS FOR THAT PURPOSE
Year: 1867

page_text: LETTERS PATENT to Paul Alexandre Rohart, of Rue du Canteleux, Douai,
in the Department du Nord, in the Empire of France, Gentleman, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF GASES FOR THE
PRODUCTION OF LIGHT, HEAT, AND MOTIVE POWER, AND IN APPARATUS FOR
THAT PURPOSE."
Sealed the 11th January 1868, and dated the 27th July 1867.
PROVISIONAL SPECIFICATION left by the said Paul Alexandre Rohart
at the Office of the Commissioners of Patents, with his Petition,
on the 27th July 1867.
I, PAUL ALEXANDRE ROHART, of. Rue du Canteleux Douai, in the De-
partment du Nord, in the Empire of France, Gentleman, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF GASES FOR THE PRODUCTION OF LIGHT, HEAT, AND MOTIVE POWER, AND IN
APPARATUS FOR THAT PURPOSE," to be as follows:-
1. The said Invention consists of the saturation of gas or air with the
volatile emanations or vapor of fluids containing carbon, usually called
hydrocarbons, by the process and with the apparatus herein-after described.
2. For this purpose I employ a case or vessel in which is a fan-wheel or
series of rotating vanes (herein-after termed "fan,") working free or
enveloped in a drum or cylinder and kept in continuous revolution so long
as the saturation is required to act.
3. These vanes may be either fixed or moveable. In the former case I
preferentially give them an inclination angular to the radius so as to reduce
the dead plunge in the liquid contents consequent on a direct radial action.

page_text: If moveable I adapt an excentric or cambial contrivance to act from the
axis in a manner analogous to the system of feathering floats of steamer
side wheels, but so varied as to suit the object in view of raising partially the
fluid on one side, and in descending on the other side, to lower the floats as
nearly vertical as may be practically necessary. The fan may be also
composed of vanes set helically with uniform or varying pitch, so as to work
on the principle of a turbine or rotatory pump of that nature.
4. The gas or air is passed into this case or vessel by a tube or passage,
and if a cylinder as above mentioned be used, it is admitted into the interior
thereof through lateral apertures, at the side of each space between the vanes
or otherwise by any convenient method and then carried or impelled by the
action of the rotating vanes before mentioned, or by external pressure, or both
combined. The fluid is supplied in like manner through a passage into the
same case or vessel and maintained at the level of the axis of the wheel or
nearly to that level by any of the usual expedients for such or the like
purposes. This fluid is partially raised and kept in motion by the "fan;"
the vanes of the fan have attached to them fittings, flaps or bands of felt or
other porous substance, connected in such manner as to promote the saturation.;
and these fittings, flaps or bands being successively submerged in the fluid
and brought in contact with the air or gas (as the case may be) are conducive
to an efficient combination of the elements.
5. The fan is worked by any suitable motive power acting directly or by
gearing or other connexion.
6. By this operation the volatilized emanations of the fluid become mixed
with the air or gas or with certain combinations of air and gas applicable to
the proper composition of inflammable gas; the saturation resulting in what
is generally denominated carburetted gas; and according to this process,
the product is eminently suited to all purposes of artificial light and heat
or for generating motive power and other purposes of utilizing caloric.
7. The saturated gas is expelled from the case or vessel, through a lead
or conduit if no drum or cylinder be used, or from the drum through proper
passages over the extremities of the vanes, or otherwise according to the
nature of the fan employed or other circumstances of the case.
8. In order to render the saturation more effective and continuously
regular, the apparatus is provided with an extraneous of caloric (in which
I include caloric, resulting from the saturated gas,) for the purpose of
raising the internal temperature to a proximate, uniformity and maintaining
it at the degree, which by experiment may be found practically most
beneficial in reference to the elements employed and the action of the process.

page_text: This may be accomplished either by adapting to the vessel in which the
saturation is effected conduits, cases, or jacketting, passing or containing
heated air, vapor, water, or other fluid, or by any other convenient way of
imparting such caloric, with the proper precautionary appliances to preclude
excess or otherwise for the prevention of accidents.
9. The saturated gas produced is passed from the generating vessel into a
reservoir or gasometer or otherwise directly applied for the purpose of
distribution to the jets or burners, or other apparatus for use.
10. For such purpose in developing light, heat, or motive power I use
preferentially two special burners, the one allowing of the passage of air
into the jet by apertures cut or perforated at the base of the crown or tip
at the extremity of the tube; and the other having the crown or tip cut with
a double slit. Both these have the property of more efficiently determining
the combustion or incandescence of the gas. These jets are in no wise
identical, so far as I am informed with any previously invented jet or burner,
although I do not particularly claim them except in combination with the
said apparatus.
11. In order to prevent explosion in the apparatus I apply suitable
intercepting diaphragms of metallic webbing in the conduits at any convenient.
distance from the point of incandescence, to which however I claim no-
exclusive right (the same expedient being previously in use) except as &
part in combination with the apparatus herein-before described..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed'
by the said Paul Alexandre Rohart in the Great Seal Patent Office
on the 13th January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PAUL
ALEXANDRE ROHART, of Rue du Canteleux, Douai, in the Departement du
Nord, in the Empire of France, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of July, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Paul Alexandre Robart, Her special licence, that I, the said
Paul Alexandre Rohart, my executors, administrators, and assigns, or such
others as 1, the said Paul Alexandre Rohart, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time

page_text: and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise and vend, within the United Kingdom of
Great Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF GASES FOR THE PRODUCTION
OF LIGHT, HEAT, AND MOTIVE POWER, AND IN APPARATUS FOR THAT PURPOSE,"
upon the condition (amongst others) that I, the said Paul Alexandre Rohart,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Patent Seal
Office within six calendar months next and immediately after the date of the
said Letters Patent,
NOW KNOW YE, that
the said Paul Alexandre Robart, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement:-
To carburize or saturate a gas or the atmospheric air with the vapours of a
volatile hydrocarburet so as to render it combustible, light giving, and
explosive, according to the use it is intended to make of it, several indispensable
conditions must be fulfilled to ensure success, to wit:-
1º. As far as possible the gas must be free from steam, the presence of
which, when abundant relatively to the extent of saturation of the gas
impeding the assimilation of the hydrocarburetted vapours.
2º. An internal source of heat must ceaselessly replace the considerable
amount of latent caloric which is absorbed by the vaporisation of the liquid.
Without this precaution the apparatus cools, the volatility of the liquid dimi-
nishes, and the gas may be less easily saturated, which results in a great
reduction in the amount of vapours carried away by the gas, and, it follows, in
the intensity of the light which is produced. By properly using, on the
contrary, a source of heat ceaselessly renewed, the temperature and tension
of the liquid will be maintained constantly the same, as also the light giving
powers of the gas.
30. The surfaces of contact between the gases and the liquid must be
multiplied as much as possible to facilite vaporization, but without offering
impediments to the flow of the gas.
4°. The apparatus must be so constructed as to preclude the possibility of
its being shaken, and all sudden changes which are manifested by a trepidation
of the flame should be avoided.
5º. The internal level of the liquid should be constantly maintained so that

page_text: the flow of the gas take place in a regular manner, and that the carburation be
always the same.
6°. Finally, the burner must be disposed in a manner to effect to the best
advantage the combustion of the carburetted vapours.
All these dispositions are realized by the apparatus herein-after described,
the combinations of which are fully set forth in the accompanying Drawings.
In a sheet-iron envelope E, Fig. 1, or other such like analogous material,
and around a horizontal axis A, moves a wheel or cylindrical drum completely
closed at both its ends and divided into four or more compartments by the
partitions or plates C, C; these partitions are directed tangentially to the
axle or internal cylinder on which they rest, in order to avoid by their radial
obliquity and the gradual and successive immersions which ensue, the
fluctuations which would otherwise be produced in the flame if these plates
were directed in the sense of the radius and the whole of their surfaces struck
the liquid at the same time; these plates may be constructed of a curvilinear
shape. The envelope E is filled to a level with the axis with the carburating
liquid, so that the drum is always half immersed and all its parts are succes-
sively steeped by the rotation of the same.
The circular metal plate M, Fig. 2, which forms the internal side of the
wheel, is perforated towards the centre with four orifices O, O, Fig. 1, placed
above each partition in the direction of the rotation movement, and which
allow the air to penetrate into the internal chambers of the wheel and after-
wards released by being replaced by the liquid. The air has no other issue
than that afforded by the narrow conduits G, G, between the two neighboring
chambers; these conduits are thereabouts covered with felt or any other such
like spongy and absorbing material, which being constantly impregnated by
reason of the successive immersions, ensure the complete saturation of the gas
or air. The carburetted gas when driven from the drum is delivered to the
burners by the outlet pipe T.
When this apparatus is used to carburize the ordinary illuminating gas the
sole pressure of the gasometer is sufficient to actuate the wheel of the car-
burating apparatus, but when the apparatus is applied to the saturation of
the atmospheric air the motion will be imparted by a counterweight P by
means of the drum V and a convenient combination of gearing; this counter-
weight might be replaced by any strong clockwork movement. The air is
introduced by the inlet pipe I opening into a compartment separated from
that wherein moves the wheel by the diaphragm R, Fig. 2, which plunges in
the liquid, and carries at its centre an opening which alone gives access to
the air in the interior of the wheel.

page_text: On the inlet pipe I branches a pipe divided into two conduits X, Y, each
furnished with a regulating tap, Fig. 1. One of these two branches brings
the free air into the apparatus; the other, on the contrary, extends as far as a
steam generator or any constant source whatever of heat; this branch there
assumes the spiral form or any other such like convenient disposition calculated
to raise the temperature of the air which courses through it. By properly
regulating the tops of these two branches the introduction of a mixture of hot
and cold air at the proper temperature into the apparatus will be determined
in order to compensate the cooling produced by the forced evaporation of the
liquid. The whole apparatus might also be plunged into a case through
which is made to circulate either a current of hot water or injected steam, as
locally may be most convenient. Finally, if a source of heat sufficiently
constant were wanting, by means of a burner taken on the outlet conduits a
gas burner might be brought under the inlet air pipe and heat it thus by
compelling it to travel a long way in contact with the flame. The Fig. 3
and 4 set forth one of the dispositions which may be employed to that effect;
the pipe T, Fig. 3, is taken on the outlet conduit which brings the gas to the
burner B. The inlet air pipe I penetrates into a case C, C, filled with water,
where it develops itself into a spiral. A double envelope E compels the
products of the combustion to surround the case C and the tube I at its
outlet so as to utilize the better possible the heat produced. Fig. 4 shows
another disposition equally simple and economical which I may apply to the
same end; it consists in a capacity or spherical funnel reversed, I, having a
double envelope, and at the centre of which burns a burner B; the heat thus
engendered heats the metallic envelope, and consequently the air which it
contains, and determines the ascensional current of the fluid. The tem-
perature may also be maintained in the apparatus either by means of a
thermosyphon or water circulation heated by a burner taken on the outlet
conduits of the gas, or by means of metallic rods which, travelling through the
carburating apparatus, issue from thence separately, and then meet in a
bundle; a gas burner or other source of heat will suffice also to heat them,
and cause them to communicate the heat into the apparatus by reason of their
being good conductors.
It is well to remark, that by heating the gas before introducing it into the
carburating apparatus two different effects at the same time are produced.
Whilst maintaining the temperature, and consequently the volatility of the
liquid, one acts also as if drying the gas by raising the temperature, and con-
sequently its property of saturation. To burn the gaseous mixture thus
produced to the best advantage, it is well to use either burners with a double

page_text: draught and glass tubes or such as are freely open to the air, or burners, as
herein-after described. At the lower part of the crown, and on each side of
the common split burners, I add a hole of small diameter communicating with
the conduit which brings the gas; the object of this addition is to augment
considerably the surfaces of contact of the gas and air, and consequently to
lend more expansion and greater brilliancy to the flame, and at the same
time to give it a shape more agreable to the eye; this disposition is repre-
sented in Fig. 5.
My application rests on the construction of an apparatus which realizes
by means of various essential dispositions the necessary conditions required in
order to saturate gases or air by the vapours of any volatile hydrocarburet; the
form, dimensions, and material of my apparatus may be varied at will.
Having now fully described the nature of my said Invention, and the
manner of carrying the same into effect, I would have it understood that I
do not confine myself to the precise details above enumerated, as these may
obviously be modified without departing from the principle of the Invention ;
but what I claim is,―
1°. An apparatus without water.
2º. Previous heating of the gas or air and the renewal of the heat taken
away from the apparatus by the vaporization of the liquid.
3°. The flow of the gas to be carburized through absorbing surfaces con-
stantly impregnated with the carburizing liquid.
4°. The constant level of the liquid inside the apparatus so as to maintain
equality in the production of the carburizing vapours and uniformity of
saturation.
5°. The oblique or curvilinear direction of the partitions or plates of the
wheel.
6°. The disposition of the heater of the ambient air.
And, 7°, the burners above described and represented in Fig. 5.
In witness whereof, I, the said Paul Alexandre Rohart, have hereunto
set my hand and seal, this Ninth day of January, in the year of our
Lord Eighteen hundred and sixty-eight.
PAUL A. ROHAKI. (L.B.)