IMPROVEMENTS IN OBTAINING OXYGEN FOR MANUFACTURING PURPOSES
Year: 1853

page_text: LETTERS PATENT to George Michiels, of Holywell Street, West-
minster, for the Invention of "IMPROVEMENTS IN OBTAINING OXYGEN
FOR MANUFACTURING PURPOSES."
Sealed the 4th May 1853, and dated the 12th March 1853.
PROVISIONAL SPECIFICATION left by the said George Michiels at
the Office of the Commissioners of Patents, with his Petition, on
the 12th March 1853.
I, GEORGE MICHIELS, of Holywell Street, Westminster, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN OBTAIN-
ING OXYGEN FOR MANUFACTURING PURPOSES" to be as follows:-
This Invention has for its object the employment of the known
chemical fact, that the oxyde of baryta at one temperature will absorb
oxygen, and at another temperature will evolve oxygen, in a manner
to obtain oxygen for various manufacturing purposes.
And the Invention consists of causing a retort containing oxyde of
baryta to be heated to and kept at a low red heat when atmospheric

page_text: nir is being passed amongst the oxyde of baryta, and then to exclude
the atmosphere, and to open a passage to a gasometer or receiver,
raising the heat of the retort to cherry red; and this is done by employ-
ing gus with atmospheric air as a means of heating the retort, by which
the desired alternations of heat may be readily obtained; and in order to
get the atmospheric air to pass into the retort, a fan or other mechanical
apparatus is used.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Michiels, in the Great Seal Patent Office,
on the 12th September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, J,
GEORGE MICHIELS, of Holywell Street, Westminster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of March, in the year
of our Lord One thousand eight hundred and fifty-three, in the six-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said George Michiels, Her special licence
that I, the said George Michiels, my executors, administrators, and
assigns, or such others as I, the said George Michiels, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time 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 Islo of Man, an Invention for "IMPкOVELLES
IN OBTAINING OXYGEN FOR MANUFACTURING PURPOSES," upon the condition
(amongst others) that I, the said George Michiels, by an instrument in
writing under my hand and seal, should particularly describe and ascer-
tain 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 Seal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE that I, the said George Michiels, do hereby
declare the nature of the said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement thereof (that is to say):
This Invention has for its object the employment of the known che-
mical fact, that the oxide of baryta at one temperature will absorb
oxygen, and at another temperature will evolve oxygen, in a manner
to obtain oxygen for various manufacturing purposes. And the Inven-
tion consists of causing a retort containing oxide of baryta to be
heated to and kept at a low red heat, when atmospheric air is being
passed amongst the oxide of baryta, and then to exclude the atmo-
sphere, and to open a passage to a gasometer or receiver, raising the
heat of the retort to cherry red; and this is done by employing gas
with atmospheric air as a means of heating the retort, by which the
desired alternations of heat may be readily obtained; and in order to
get the atmospheric air to pass into the retort, a fan or other mechani-
cal apparatus is used.
It is a fact well known to chemists that the earth baryta, or
protoxide of barium, will absorb oxygen gas at one temperature, and
evolve or part with that oxygen at another. But this fact has not
hitherto received any practical application, or been rendered publicly
useful in the arts and manufactures; nor has it, that I am aware of,
been put into operation as a means of obtaining oxygen at a cheap
rate in any part of the United Kingdom.
Nevertheless, the want of oxygen gas at an economical rate has long
been severely felt in many branches of industry; not a few of which
suffer great loss and inconvenience by this very want. To fill in the
gap thus existing in the circle of our manufacturing capabilities was
therefore a desideratum; and this I have done by taking advantage of
the fact above alluded to, and rendering it subservient to public use in
the following manner :-
Construct a D shaped cast-iron retort, open at both ends, and set
this retort in an arch, to be built in the manner followed in gas works;
fix to it two mouth pieces with lids, one of which must communicate
with an air receiver, by a pipe provided with a sluice valve. This pipe
I shall call the adducting-air-main. The other mouth piece must be

page_text: placed in communication with a gas holder, by a pipe furnished with a
sluice valve, and also must have an outlet into the atmosphere by a
pipe shut by a valve that opens under a pressure of forty inches on the
water guage. The pipe leading to the gas holder I shall call the
oxygen abducting main; and the outlet to the atmosphere I shall call
the nitrogen abducting main. The air receiver must be kept, by a
proper valve, under a constant pressure equal to a column of 45 inches
measured on the water guage; the air to be driven into this receiver by
a suitable blowing apparatus. On its way from this high-pressure air
receiver to the retort the air must pass through a wet purifier, such as is
employed in gasworks; this purifier to be charged with water and lime,
or water and caustic potash or soda, so as to deprive the air of its car-
bonic acid gas. From the purifier, the air, on its way to the retort,
must be made to pass through a heating apparatus, to be kept hot at
the expence of the waste heat from the main flues.
Erect or construct under the retort a gas burner, fed by combustible
gas and air, both driven into the burner under a constant pressure, con-
trolled by suitable regulators.
To put this apparatus in action for obtaining oxygen gas, open the
cocks which admit the air and the combustible gas to the burner, and
cause them to be lighted by a sinall safety jet kept always burning for
that purpose; and when you shall have brought the brickwork to such
a temperature that the retort be cherry red, you can easily ascertain
by experiment how much it is needful to open or shut the air and gas
cocks of the burner, in order to raise or lower the temperature, so as to
keep the retort at one time at a cherry red heat, and at another at a
dark red heat, and so on, alternately. Before beginning to operate you
must take care to cover over with a brush the interior surfaces of the
retort with a coating of varnish, composed of 2 parts of borax, and
five parts by weight of ground Stourbridge fireclay, mixed together, with
water, into a thick paste.
Whilst experimenting with a dark red heat, you must take care to
open the sluice valve of the air adducting main, and to shut the sluice
valve of the oxygen abducting main; and whilst experimenting with a

page_text: cherry red heat, you must cut off the communication between the retort
and the air receiver.
In order to ascertain the temperature of the retort with all possible
ease, sight holes, with moveable plugs, must be provided in the
brickwork, in the manner usually practised in gas retort beds; and the
keys of the gas and air cocks should be fitted with graduated dials,
having hands upon them, to enable you to mark what are the most
effective positions of these hands for commanding at will the two
temperatures which it is so important for the success of the process
to maintain.
When you shall, by means of a series of experiments conducted in
the manner I have just described, have obtained an exact appreciation
of the way and mode of managing this apparatus, so as to be able to
obtain at pleasure the two different temperatures already mentioned,
then you will be in the proper condition to put the apparatus to work.
For this purpose remove the lid from one of the mouth pieces, and
charge the retort with powdered oxide of barium, or earth of baryta,
in layers of 2 inches, namely, one layer on the bottom of the retort, and
three layers upon as many shelves; these shelves to be of cast iron, and
perforated with as many inch holes as they can safely contain. This
done, lute the lid on again, (the other lid having been so luted on origin-
ally,) and keep the retort at a dark red heat. The sluice valve of the
air adducting main being now opened, by which means the air coming
from the heating apparatus will be driven, under 45 inches pressure,
through the layers of baryta in the retort, the oxygen of the air will in
a great measure be absorbed by this earth, and the nitrogen will escape
through the loaded valve on the nitrogen abducting pipe, the sluice
valve on the oxygen abducting main being kept shut. At the end of
two hours, or when the absorption of the oxygen has ceased, which
period is easily ascertained by testing the gas escaping through the
nitrogen abducting pipe, close the sluice valve of the air adducting pipe;
open the sluice valve of the oxygen abducting main; open also the
cocks of the burner, so as to bring the retort to cherry red heat, and
keep it to that temperature for about half an hour, or till such time as

page_text: the oxygen ceases to bubble through a water dip, placed on its way to
the oxygen holder. At that period lower the heat to a dark red, and
recommence the process already described for the absorption of the
oxygen of the air, as at first.
It would be useless to describe how the blowing apparatus, the air
receiver, the purifiers, the governors, the valves, &c., have to be con-
structed, as these are well known apparatus; but I think it proper to
exhibit a drawing of the setting of the retort, with the burner and
heating apparatus, and to give a description of the principal component
parts of this apparatus. And I would remark that, as the air of the
atmosphere is liable to vary in the amount of the moisture it contains,
I sometimes use, mixed with the air as it passes over or through the
baryta, a portion of steam or vapour of water, in order to compensate
for the variation of the atmosphere; and this steam or vapour I intro-
duce by a steam jet, or in any other convenient manner.
DESCRIPTION OF THE DRAWINGS.
Nos. 1, retort. 2, mouthpieces of retort. 3, perforated shelves in
retort, upon which baryta is laid. a, a', openings used alternately for
the admission of the air. 6, 6', openings used alternately for the exit
of the nitrogen. Thus, when the air is admitted by a, the nitrogon
escapes through b, and when a', is the inlet, b', is the outlet.
4, outlet
for the oxygen evolved from the baryta. 5, sight holes. 6, transverse
bearers for supporting the retort. 7, longitudinal bearers for supporting
the retort. 8, wrought-iron flanged pipes, forming part of 9, burner,
composed of four separate pieces of cast iron, bolted and cemented
together with iron cement, in such a manner as to form two boxes,
E, & F, each with one inlet, as shown on drawings; these inlets are
marked e, and f. In the partition g, separating these two boxes, holes
(conical on the upper part to allow of cement being used) are bored,
and into these holes the flanged pipes 8, are tightly fitted and cemented
perpendicularly, so as to maintain the separation hermetically between
the two boxes E, and F. The top picce of the burner h, is furnished

page_text: with longitudinal slots, into which the pipes 8, rise. Through f, one
of the before-mentioned inlets of the burner, combustible gas is to be
introduced; whilst through e, the other inlet, air is to be caused to
enter, only with a different velocity, in order to obtain a thorough
mixture of the two at the top of the pipes 8; a short distance from the
top of which combustion takes place. In order to lessen the rapid
burning away of the metal from this cause, in this top piece h, grooves
on the surface, parallel with the slots, are provided, and filled in with
fire clay, as shown on drawings; the grooves on the under side are
merely to lessen the weight. 10, nostrils in the brickwork, through
which the products of combustion from the burner pass around the
retort, and are then drawn through 11, the downward flues into 12,
the heating chamber, from whence they pass through 13, the openings
reserved in the arch of 14, the flue leading to the chimney. 15, large
pipes of apparatus for heating air, provided with sockets, into which
16, the small curved pipes fit. The air is admitted at one end of
one of the large pipes 15, and has to circulate, in the direction shewn
by the arrows, through these curved pipes, to 17, the outlet place on
the other large pipe 15; this outlet is put in connection with the
inlets a, and a', in the mouth piece of the retort.
It will be observed in the preceding description, that the retort is
provided with an upper and lower inlet for the air, and a corresponding
lower and upper outlet for the nitrogen. This arrangement has for its
object to drive the air downwards, and then upwards, through the
layers of the baryta alternately, in the same or in succeeding opera-
tions, in order to keep the baryta quite permeable to the air, and to
multiply the surfaces of contact.
I know that the mode of operating, here fully given, might be varied
in many different ways. I am also aware that the burner, and the use
of combustible gas, might be done away with, to be superseded less
advantageously by common fuel. I have, however, here described the
process and apparatus which I consider for the present to be the most
efficient; but do not hold myself limited to this.

page_text: What I claim is the use of the earth baryta in the production of
oxygen for manufacturing purposes by the application of heat, as set
forth in this Specification.
In witness whereof, I, the said George Michiels, have hereunto
set my hand and seal, the 7th day of September, in the year
of our Lord One thousand eight hundred and fifty-three.
G. MICHIELS. (L.B.)
Witness, C. L. MADAM.