An Improved Process and Apparatus for Separating and Extracting Gases from a Gaseous Mixture, Purifying, Exhausting, and Com- pressing Gas, and Increasing its Illuminating Power.
Year: 1899

page_text: Date of Application, 12th Oct., 1899-Accepted, 7th Apr., 1900
COMPLETE SPECIFICATION.
An Improved Process and Apparatus for Separating and Extracting
Gases from a Gaseous Mixture, Purifying, Exhausting, and Com-
pressing Gas, and Increasing its Illuminating Power.
I, EDOARDO NATALE MAZZA, of Via Arcivescovado 1, Turin, in the Kingdom
of Italy, formerly Military Engineer Officer, do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be parti-
cularly described and ascertained in and by the following statement:-
―
The mechanical apparatus forming the object of this specification has been
suggested by the laws governing centrifugal force arising in bodies that are
made to revolve on a point or on a right line.
If a sufficiently rapid rotary movement is given to a gaseous mixture whose
components are sensibly different in specific gravity (and so much better as
this difference is greater), by the action arising from centrifugal force, the
denser gases will go to the periphery and the lighter gases will gradually dispose
themselves near the centre.
I will describe my invention by means of the accompanying drawings, in
which:- -
Fig. 1 is an elevation of an apparatus constructed according to the invention.
Fig. 2 is a vertical section thereof.
Fig. 3 is a horizontal section on the line X-X of Fig. 2.
Fig. 4 is a horizontal section on the line Z-Z of Fig. 2.
A is a drum revolving on a shaft B to which it is rigidly fixed by means of
several diaphragms 1), D¹, D. The drum (which revolves vertically on its
shaft) is closed at the bottom, leaving a central inlet P for the gaseous mixture
to be decomposed. It is divided into several compartments by these diaphragms,
and it has one or more other compartments CC, according as two or more
constituents have to be separated from the mixture. If the shaft, and the drum
and diaphragms with it, are made to revolve at a suitable speed, it will cause
in the middle a rarefaction, which will cause the gaseous mixture to rise through
the central flue I. The diaphragms violently force the mixture towards the
drum, and at the same time it ascends; when it arrives at the upper part, the
separation will be complete and the gases of the mixture can be distributed in
concentric rings according to their different densities. The denser will go out
by the openings a, a, a, and the less dense by the openings d d and will
finally pass out of the opening I.
Hydrogen is the lightest of known gases; its density is sensibly different from
that of the gases with which it can be mixed in the greater number of industrial
uses consequently its separation and extraction from coal gas, Dowson and other
water gas and the gas of blast furnaces will be easy by means of the apparatus
above described.
I will now give some practical applications of my invention. As is known,
common illuminating coal gas is essentially a mixture two thirds of which are
hydrocarbons that give its illuminating power, and the remaining third is
071

page_text: hydrogen giving only heat. The same illuminating gas is employed for lighting,
heating, motive power, and in some cases for smelting, etc. In the first instance
it would be desirable to have it of great illuminating power, which, if necessary,
is artificially increased (for instance, by carburetting the gas). For the other
applications it would be preferable if it were of great heating power.
On
Several means have already been invented for increasing the illuminating
power, particularly where it is controlled by public service or otherwise.
account of the facility with which, by means of the separator and extractor
herein described, centrifugal force can be applied to totally or partially collect
the hydrogen of coal gas, it is proposed to extract by this apparatus a sufficient
portion of it, in order that the remaining hydrocarbons could give the desired
greater illuminating power.
By this means the problem of adding some carburetting substances in order
to increase the illuminating power of a gaseous mixture in ignition, would be
substituted by the simpler and also less expensive one of taking away a portion
of hydrogen (which by its presence could but lower the light of the mixed
incandescent hydrocarbons) and so indirectly increase the luminosity of the
hydrocarbons.
Therefore the physical and mechanical process and the apparatus herein
referred to, make it possible to separate, with very little expense, the pure
hydrogen gas from the hydrocarbons as soon as they issue from the retorts. in
which they are produced, and then to forward them to two distinct reservoirs.
One of these reservoirs can be applied to lighting and the other to industrial
uses.
By comparing the apparatus just described with air ventilators and with
the gas compressing extractors, even, of the more improved systems, it will be
easily understood that it can accomplish all that they can do and requires less
motive power.
It is a known mechanical law that the resistance of bodies to the fluids
striking them, changes proportionally to the square of the speed for the same
surface. Consequently the motive power necessary for obtaining a given amount
of work would be saved in proportion as the striking surface of the bodies and
fluids would be lessened. In the compressing extractors now in use, the shock
of the gas against the vanes is produced on the two lateral surfaces and on the
imaginary belt that would envelope the vanes. On the contrary, in the apparatus
hereindescribed, in which the diaphragms take the place of the vanes with the
same object of imparting a rotary velocity to the gas molecules, the fluid is
struck by the diaphragms only in the inlet and outlet openings strictly cal-
culated, and in the whole passage in the drum I have only the transporting in
the interior and the friction on the exterior face of the drum.
Then, before acting as a separator, the apparatus acts as a rotary extractor by
the aspiration produced near its axis by centrifugal force acting at the periphery
and consequently in its greatest intensity; between the axis and the periphery
of the revolving fluid cylinder there not, and cannot be, any interruption.
The centrifugal force to which the fluid is submitted when in the moving
drum, produces the separation of its components of different density, and the
gas, by the acquired rotation, escaping from the drum will have a projecting
velocity that can always be utilized for augmenting the pressure and the apparatus
can be used as a compressor. It would be sufficient to enclose it, as described,
in a sufficiently strong, fixed gas-proof casing, having at its two ends the
necessary orifices for the gaseous mixture at first, and for its constituents after
the operation of the rotary motion.
Then, as a compressing-extractor, the apparatus herein described is dis-
tinguished from the other actually in use, by having the vanes or diaphragms.
rotating with the drum; and the shock of the fluid or gas being only produced
at the orifices of inlet and outlet on a surface that is always less than that of
the vanes against which the fluid or gas strikes in the ordinary apparatus. At

page_text: the same time the said apparatus could always be used as a separator, if the
coal employed in the production of the illuminating gas was of inferior quality
or giving a gas without the necessary degree of luminosity; and it would not
be necessary to have two different systems of pipes, but it would be sufficient to
have two gasometers.
In gas works the apparatus could be used in an important manner and more
continually.
As it is known, the greater impurities of illuminating gas (say the tar, the
carbonic acid, the hydrogen sulphide) are all denser than the illuminating gas
itself. It is easy by means of the said apparatus, to collect the whole mass
of the impurities in a single operation or in two consecutive operations.
By this manner the condensers and the lime, iron or other cleansing means
would be abolished, with the consequent economy of the power necessary to
work them, and this is an important item of gas works. It must be also noted
the large economy in the workmanship, in the re-agents, in space etc.
The impurities could be collected and utilized better than at present. The
cyanogen collected could be made into cyanides, the hydrogen sulphide into
sulphuric acid (without needing the special furnaces now necessary for the
sulphides and sulphates) etc.
Another advantage for gas works would be in the suppression of the washing
of the heavy hydrocarbons in order to obtain the ammonia mixed with them.
The ammonia by the action of centrifugal force would be separated with the
hydrogen and the methane (marsh gas) which would not be affected by washing
in ammoniacal liquor while the heavy hydrocarbons would lose about 5% of
their illuminating power.
By means of my invention I am enabled to obtain by centrifugal force from
the atmosphere, air rich in oxygen or almost pure oxygen and I am enabled to
free the atmosphere from impurities such as injurious gases or solid particles &c.
Water gas, gas of blast furnaces and other gases may be purified by ridding
them by centrifugal force of solid substances such as ashes or mineral particles
and of gases such as carbonic acid gas &c.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The practical application of centrifugal force arising in a gaseous mixture,
for the separation and extraction of the constituent gases substantially as herein
set forth.
2. A mechanical separator and extractor, intended to develop with less loss
of power the centrifugal force in a gaseous mixture, in order to practically
obtain the separation and extraction of the gases, substantially as set forth.
3. The process of obtaining by centrifugal force from the atmosphere, air
rich in oxygen, or almost pure oxygen and also to free the atmosphere from
impurities (injurious gases, solid particles, etc.) substantially as set forth.
4. The process for the total or partial separation and extraction of the hydrogen
gas contained in coal gas, in order to indirectly increase the illuminating power
of the remaining gas by the increased proportion of hydrocarbons, obtained by
centrifugal force as before described.
5. The process of employing the centrifugal force for purifying industrial
gases (such as coal gas, water gas, gas of blast furnaces etc.) from the solid
substances (tar, ashes, sulphides, mineral particles) and from the fluids (cyanogen,
carbonic acid, hydrogen sulphide, &c.) that can be found in them, substantially
as set forth.
6. The process of separating and extracting hydrogen gas by centrifugal force,
from the gaseous mixture containing it, such as coal gas, Dowson gas and the
different kinds of water gas, the gas of blast furnaces, substantially as set
forth.

page_text: 7. The employment of the separator and extractor for exhausting gases or
gaseous mixtures, for purifying and separating them if desired, and for com-
pressing them under fixed pressure, substantially as set forth.
Dated this 12th day of October 1899.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.