for Producing Cold.
Year: 1884

page_text: for Producing Cold.
I, SYDNEY PITT of Sutton in the County of Surrey, Gentleman do hereby
declare the nature of my invention for "NEW VOLATILE LIQUIDS AND THE USE
OF THE SAME IN APPARATUS FOR PRODUCING COLD" a communication to me from
abroad by Raoul Pierre Pictet of Geneva, Switzerland to be as follows:-
Refrigerating machines are at present employed with volatile liquids of various
sorts ammonia, sulphuric ether, and anhydrous sulphurous acid, methylic ether,
chloride of methyl and lastly a mixture of sulphurous acid and sulphuric ether,
known in America under the name of binary liquid. Neither of these liquids
meets all the requirements of the case.
All the conditions are realized in a new liquid or liquids composed of three
simple bodies which are carbon, oxygen and sulphur, and its vapours contain the
three elements in variable proportions according to the temperature of the liquid
and the tension under which the vapours which it emits are confined.
I take carbonic acid and I associate it with oxygen so as to control its volatile
power and bring it to the point required for industrial use.
For this purpose I compress carbonic acid with an oxide of sulphur for example
in such proportions that the vapours forced by a pump into a condenser produce
a liquid of which the elementary composition will be CO* S to which tlie name
"Pictet's liquid" is given. Or it may be CO S or CO³ ³ or on the contrary
C2 0°S, C3 08 S etc. To render these combinations more clear and evident I give
in the following table the boiling points of the different liquids thus obtained.
Tamusrature of

page_text: I call Pictet's liquid the combination CO S which boils at 19 degrees below
zero centigrade which seems to me best to realize all the desiderata of the industrial
problem.
To better explain the capital importance of the physical phenomenon I give
below a table of the pressures on the compression of vapour of Pictet's liquid
from 30 centigrade to + 50.
-
.
It will thus be seen that the pressures increase much slower than for simple
volatile liquids. It results then from this fact that this liquid composed of carbon,
oxygen and sulphur fulfils completely all the conditions necessary for the industrial
and commercial employment of refrigerating machines.
I pass now to the manufacture of these new bodies and especially the industrial
preparation of Pictet's liquid.
I utilize the known reaction of carbon upon ordinary sulphuric acid at 66 degrees
Beaumé. This reaction gives a gaseous mixture at 320 degrees about of carbonic
oxide and oxide of sulphur mixed in the preparation by weight of one equivalent
of carbon 6 equivalents of oxygen and 2 equivalents of sulphur plus 2 molecules of
water. By adding to this mixture an equivalent of carbon and two equivalents
of oxygen, produced by the decomposition of the carbonate of lime by hydro chloric
acid or sulphuric acid a gaseous mixture is obtained which is exactly represented
by the symbol CO' S = Pictet's liquid.
Commercially as represented in the annexed drawings a large retort of cast
iron A, Figures 1 and 2 (elevation and plan) is employed; this retort is surmounted
by a dome B of cast iron, and a cast iron tube C of large diameter rises vertically
above this dome.
A safety tube D allows a thread of commercial sulphuric acid to fall constantly
into the retort. In the retort A there is introduced by the aperture at the top
from 50 to 200 or 300 kilos of carbon or even more if the operation is on a large
scale. fire of coal or coke underneath the retort provides for heating it.
In a large carboy of glass or of iron lined with lead marble is introduced, or any
carbonate, then by a safety tube S, hydrochloric or sulphuric acid is allowed to fall
upon the marble. The carbonic acid which is disengaged enters at the top of the
vertical tube C and mixes at high temperatures with the gases which result from
the reaction of carbon on sulphuric acid. These mixed gases are conveyed into a

page_text: receiver F of cast iron lined with lead where they are purified, thence they pass
into a large cylinder H with double sides.
At the upper part of the interior compartment H the gases coming out of the
purifier Fenter by a pipe of large aren.
The vapours traverse this space and passing out by the other extremity enter
an oil gasometer K from which they are drawn by a pump and liquefied under
pressure in the serpentine M.
The lower end of the serpentine M corresponds by three cocks with three
apparatus. The first passage communicates with the jacket I of the cylinder H.
The second passage communicates with a receiver to be filled P. The third passage
puts the serpentine M in communication with the inner chamber H.
The vapours liquefied in the serpentine M are at the commencement all directed
into the double envelope I, where they accumulate rapidly, surrounding the
capacity H. When the double envelope I is full of liquid the suction of the
pump L is put in communication with the jacket by means of the pipe T T.
Immediately the temperature falls by the evaporation of the volatile liquid and by
means of a thermometer the moment when it attains minus 19 degrees centigrade
is ascertained.
The opening of the cock on the tube T is then regulated in such a manner as to
keep its temperature constant. This point attained the compressor draws the
vapours directly from the gasometer and liquefies them in the serpentine M, from
whence, by the tap N they are drawn off into the chamber H. As this chamber
is always in communication with the gasometer, the pressure within this chamber H
is equal to one atmosphere.
Under the influence of this change of pressure the liquid commences to boil
spontaneously and gives up the slight excess of carbonic acid which has been
systematically added to the gases. This carbonic acid returns to the pump after
being again mixed with the vapours which coming from the retort have passed
into the gasometer.
The progress of the operation is regulated by the height of the gasometer, which
shows at once either an excess or deficiency of carbonic acid. Care is also taken to
keep the temperature minus 19 constant in the double envelope I.
By conducting the process in the manner which I have just described a large
quantity of Pictet's liquid is accumulated in the chamber H. This liquid can be.
transferred directly into iron or copper carboys, or it can be submitted to recti-
fication by the operation of the compressor which withdraws the vapours and
condenses them in the serpentino M and from thence the liquid passes by the
tube Qinto the receiver.
If the production of carbonic acid has been by accident a little too great, the
excess of the gas is sent back from the gasometer by the tube V. The gas so sent
back serves for a time in place of gas from the vessel R produced by means of
carbonate of lime.
1007

page_text: .
COMPLETE SPECIFICATION.
New Volatile Liquids and the Use of the same in Apparatus
for Producing Cold.
I SYDNEY PITT of Sutton in the County of Surrey Gentleman do hereby
declare the nature of my invention for "NEW VOLATILE LIQUIDS AND THE USE
a communication to me from
abroad by Raoul Pierre Pictet of Geneva Switzerland and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement:-
OF THE SAME IN APPARATUS FOR PRODUCING COLD
Refrigerating machines are at present employed with volatile liquids of-various
salts, ammonia, sulphuric ether, and anhydrous sulphurous acid, methylic ether,
chloride of methyl and lastly a mixture of sulphurous acid and sulphuric ether,
known in America under the name of binary liquid. These volatile liquids form
an irregular series if they are compared between themselves in respect to their
vapour tension.
Ammonia, methylic ether and chloride of methyl form the first group; they all
boil at temperatures below 22° Centigrade this volatility induces as a con-
sequence excessive pressures in the condenser and the mechanical appliances for
the condensation of the vapours which strain the mechanism injuriously and
besides leaks become inevitable-and occasion notable loss of the volatile liquid
and danger of fire or explosion.
Anhydrous sulphurous acid by itself forms an intermediate group, it boils at -10
and gives medium tension during compression even in hot countries. These are
qualities which fit it for machines intended for use in tropical regions. The third
group is formed by liquids volatile under low pressure such are sulphuric ether,
sulphide of carbon and the binary liquid-Between anhydrous sulphurous acid and
aminonia, there is a difference of 23° in their boiling point. Consequently at the
temperature of +20° Centigrade the compressor shows for sulphurous acid a
pressure of two and a half atmospheres, whilst it attains to 10 atmospheres with
ammonia, a pressure which is too high for ordinary working.
The two intermediate liquids, chloride of methyl and methylic ether are
dangerous and for this cause they are little used as refrigerating agents.
I have therefore sought after an intermediate liquid such as to be especially
useful in temperate countries.
It is necessary first to set out the physical properties, which it is desired to
obtain they are the following.
1. To have a volatile liquid of a higher tension than anhydrous sulphurous acid,
so that the density of the vapours increasing the yield of the refrigerating machine.
may be augmented in a proportionate degree.
2.-To have a volatile liquid of which the vapours are not inflammable or liable
to explode.

page_text: 3. To have a liquid having no action upon metals and of fixed chemical
constitution.
4. To have a liquid which is itself a lubricant.
5. To have a liquid which at mean temperatures does not give pressures higher
as a maximum than 6. atmospheres which may be considered the commercial limit
of pressure for the working of compressors.
•
6. To have a liquid easy to manufacture and as cheap as possible.
All these conditions are realized in a new liquid which is the complete analogue
of aqua regia.
It is composed of three simple bodies which are carbon, oxygen and sulphur,
and its vapours contain the three elements in variable proportions according to the
temperature of the liquid and the tension under which the vapours which it emits
are confined.
The object of the present Invention is the industrial application in refrigerating
machines of this liquid which it is proposed to call "Pictet's liquid."
If carbon and oxygen he associated in the form of oxide of carbon it liquefies
with great difficulty under enormous pressures and low temperature. If the oxide
of carbon be again oxidized carbonic acid is formed which liquefies much more
easily than carbonic oxide. Again, if there be added the oxide of hydrogen or
water the carbonic acid is liquefied very easily, as ordinary soda water.
The association of more and more oxygen with the carbon has consequently
modified continuously the volatile power of the liquids diminishing the tension
of the vapours. If sulphur be taken in place of carbon the same law holds good.
Anhydrous sulphurous acid is volatile anhydrous sulphuric acid is volatile but
less so than sulphurous acid and finally by adding oxide of hydrogen the volatile
power of the binary liquid is enormously diminished. These associations of
phenomena being recognized led me to proceed in like mauner with carbonic acid.
I take carbonic acid and I associate it with oxygen so as to control its volatile
power and bring it to the point required for industrial use.
For this purpose I compress carbonic acid with an oxide of sulphur for example
in such proportions that the vapours forced by a pump, into a condenser produce
a liquid of which the elementary composition will be CO S to which the name
"Pictet's liquid" is given. Or it may be CO S or CO8 S³ or on the contrary
COS, C³ 08 S etc. To render these combinations more clear and evident I give
in the following table the boiling points of the different liquids thus obtained-
Composition
of the elementary
Temperature of
boiling under 360 millimetres

page_text: Now to the preceding considerations I. add others as to the tension of the
vapours under compression, that is to say at the temperature comprised between
+20 Centigrade and + 50 the solvent power of the oxides of carbon in the oxides
of sulphur increases with the temperature.
This is an absolutely general fact for all the compounds of carbon and of
sulphur. It results that the affinities of these bodies increase with the temperature.
there is decrease of pressure for the compression into the condensor of refrigerating
machines employing Pictets liquid if this pressure be compared with that of
ordinary volatile liquids.
I call Pictets liquid the combination CO S which boils at 19 degrees below
zero Centigrade which seems to me best to realize all the desiderata of the industrial
problem.
To better explain the capital importance of these physical phenomena I give
below a table of pressures on the compression of vapour of Pictets liquid-from
- 30 Centigrade to. + 50.
It will thus be seen that the pressures increase much slower than for simple
volatile liquids. It results then from this fact. that this liquid composed of carbon
oxygen and sulphur fulfills completely all the conditions necessary for the industrial
and commercial employment of refrigerating machines.
-
I claim then that a liquid composed of these three bodies and especially Pictets
liquid which boils at
19° gives in its application in refrigerating machines a
yield 50 per cent better than an-hydrous sulphurous acid with the same dimensions
of compressing cylinder.
I pass now to the manufacture of these new bodies and especially the industrial
preparation of Pictets liquid.
I utilize the known reaction of carbon upon ordinary sulphuric acid at
66° Beaumné. This reaction at 320° about gives a gaseous mixture of carbonic
oxide and oxide of sulphur mixed in the proportions by weight of one equivalent
of carbon six equivalents' of oxygen and two equivalents of sulphur plus two
molecules of water.
By adding to this mixture an equivalent of carbon and two equivalents of
oxygen produced by the decomposition of the carbonate of lime by hydro chloric

page_text: acid or sulphuric acid a gaseous mixture is obtained which is exactly represented
by the symbol CO'S = Pictets liquid.
-
The separate generation of carbonic acid will however usually be found unne-
cessary as carbonic acid in sufficient quantity usually results from the action of
sulphuric acid upon carbon.
.
Commercially as represented in the annexed drawings a large retort of cast
iron A Figures 1 and 2 (elevation and plan) is employed its dimensions are variable
according to the production which it is desired to obtain. This retort is surmounted
by a dome. B of cast iron and a cast iron tube C of large diameter rises vertically.
above this dome.
A safety tube D allows a thread of commercial, sulphuric acid to fall constantly
into the retort. In the retort A. there is introduced by the aperture at the top from
50 to 200 or 300 kilos of carbon or even more if the operation is on a large scale.
A fire of coal or coke underneath the retort provides for heating it.
"
If a separate generation of carbonic acid be judged desirable then in a largo
carboy of glass or of iron lined with lead R marble is introduced or any carbonate
and by a safety tube S hydro chloric or sulphuric acid is allowed to fall upon the
marble.
The carbonic acid which is disengaged enters at the top of the vertical tube C
and mixes at high temperatures with the gases which result from the reaction of
carbon on sulphuric acid.
The production of the gases is so regulated that there shall always be a small
excess of carbonic acid, the above quantity indicated by the formula COS. These
mixed gases are conveyed into a receiver F of cast iron lined with lead where they
deposit the greater part of, their impurities thence they pass by connections G into
a large cylinder H with double sides. The jacket I is formed of two concentric
cylinders separated the one from the other by an annular space of about five:
centimetres. Metallic ends convert the interior of the cylinder into a closed
reservoir.
At the upper part of the interior compartment H the gases coming out of the
purifier F. enter by a pipe of larger area.
The vapours traverse this space and passing out by the other extremity enter
an oil gasometer K from which they are drawn by a pump and liquefied under
pressure in the serpentine M the lower end of the serpentine M cominunicates by
three cocks with three apparatus. The first passage U communicates with the-
jacket I of the cylinder H. The second passage communicates with a receiver
to be filled P.-The third passage O puts the sepentine M in communication with
the inner chamber. H.
The vapours liquefied in the serpentine M are at the commencement all directed
into the double envelope I where they accumulate rapidly surrounding the
capacity H with a cylinder of liquid.
When the double envelope or jacket I is full of liquid the suction of the pump L
is put in communication with the jacket by means of the pipe T.-Immediately
the temperature falls by the evaporation of the volatile liquid and by means of a
thermometer the moment when it attains 19° centigrade is ascertained.
The opening of the cock on the tube T is then regulated in such a manner as to
keep the temperature constant. This point attained the compressor draws the
vapours directly from the gasometer K and liquifies them in the serpentine M from
whence by the tap N they are drawn off into the chamber H. As this chamber is
always in communication with the gasometer the pressure within this chamber H. is
equal to one atmosphere.
Under the influence of this change of pressure the liquid commences to boil
spontaneously and gives up the slight excess of carbonic acid which has been
systematically added to the gases. This carbonic acid returns to the pump after
being again mixed with the vapours which coming from the retort have passed
into the gasometer.

page_text: The progress of the operation is regulated by the height of the gasometer which
shows at once either an excess or deficiency of carbonic acid. Care is also taken to
keep the temperature - 19° constant in the double envelope I.
By conducting the process in the manner which I have just described a large
quantity of Pictet's liquid is accumulated in the chamber H. This liquid can be
transferred directly into iron or copper carboys or it can be submitted to recti-
fication by the operation of the compressor which withdraws the vapours and
condenses them in the serpentine M and from thence the liquid passes by the
tube Qinto the receiver.
If the production of carbonic acid has been in excess of the demand gas is sent
back from the gasometer by the tube V. The gas so sent back serves in place of
gas from the vessel R produced by means of carbonate of lime.
•
The utility of Pictet's. liquid is by no means confined to its employment in
refrigerating machines; it is useful also as a disinfectant, in extinguishing fires
and as a bleaching agent.
It may be stored and sold in "Syphons" of sufficient strength similar to those
used for containing aerated waters and will be useful in laboratories apart from
any special apparatus as a source of cold and to yield sulphurous acid and carbonic
acid gas.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that
what I claim is
(1.) The novel volatile liquids herein described and more especially Pictet's
liquid.
(2.) The employment in refrigerating machines of carbonic acid molecularly
associated with oxides of the metaloids and especially with those of sulphur.
(3.) The employment in refrigerating machines of Pictet's liquid the molecular
composition of which is CO S.
(4.) The manufacture of the above named liquids by the process substantially as
described which is especially applicable to the manufacture of Pictet's liquid.
Dated this 8th day of September 1885.