Process and Arrangement for] Utilizing Liquid Air in Heat Motors.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Process and Arrangement for] Utilizing Liquid Air in Heat Motors.
"GESELLSCHAFT
We, CARL LINDE, Doctor of Philosophy, and the Corporation
FÜR LINDE'S EISMASCHINEN," a Company incorporated according to the Laws of
Prussia, domiciled both at No. 76, Nympfenburger Strasse, München, in the
Kingdom of Bavaria, German Empire, do hereby declare the nature of this inven-
tion to be as follows:-
Since it has been rendered possible to liquify air in any desired quantity it
has often been suggested that liquid air should be used for driving motors.
Closer examination, however, reveals that between the work expended in liqui-
fying the air and the work obtained in the best of cases from the return under
high pressure of liquified air into the gaseous state and then allowing it to expand
in doing work, is so utterly disproportioned as to enable this principle only to
be used when the economic question is not considered.
This however is different when the products of combustion for driving a motor
are used in combination with the oxygen of the liquified air resulting in a very
high pressure owing to the alteration in the state of aggregation of the air.
In this case the volumes of the gases for doing work are so greatly increased that
the before mentioned disproportion no longer exists. The motor suitable for
use herewith is a combustion motor of the kind in which combustible materials
such as coal gas, petroleum, benzene or the like is used for obtaining the driving
power. It is well known that for the proper working of these combustion motors
the oxygen required for combustion is obtained from the atmospheric air which
before combustion is compressed to a high pressure and improvements in the said
motors are mainly directed towards increasing of the compression and working-
pressure generally. The effective work of the motor in this case is therefore the
difference from the expansion and compression.
Now by the use of liquid air the necessity for compressing the air in the work-
ing cylinder in order to obtain increase of pressure by reduction of volume is
obviated, as the pressure is obtained through the constantly increasing volume of
the air during its transformation from the liquid into the gaseous state. More-
over the compression pressure and all the working pressures can be greatly in-
creased without any more complication in the mechanisms than with the means
hitherto known. For these reasons it is possible to adopt very small dimensions
which is especially of value where a motor of little weight with relative high
efficiency is required, such as for instance in driving vehicles.
The invention may be carried out in the following manner.
The liquid air is kept under atmospheric pressure in a vessel well protected
on its exterior against heat from which the same is drawn off by a feed pump
having a variable stroke. The pump supplies the liquid into the conduit or
serpentine at a temperature of less than minus 180° C. where the liquid air
absorbs the heat from the ambiant air through the action of the walls of. the con-
duit in order to enable it to gasify the conduit being in form of a serpent-tube
to afford great conducting surfaces. From the latter the gasified air enters a
:

page_text: combustion chamber in which at the same time is introduced the combustible
material to an amount required for the momentary power to be exerted. This
may be effected by liquid fuel by means of a similar apparatus (pump), as is
generally used for supplying lubricating materials to the pistons of steam-
engines. The ignition can be effected in the same manner as is usual in explosion
engines. In starting an electric igniter may be used and afterwards ignition may
be effected through causing the combustible material to drip upon an asbestos
body which after being rendered incandescent by the combustion is thereby
kept in a state of incandescence.
The combustion may also be obtained by bringing the liquid air directly
together with the combustible material. This enables the gasifier to be omitted
but the consumption of combustion material is increased thereby.
The combustion always takes place with a considerable surplus in oxygen for
the reason that with regard to the safety of working it is unsuitable to raise the
temperature of the gases too much, and that comparatively the liquid air con-
tains more oxygen than the atmospheric air:
The combustion gases are then introduced into the real working mechanisms
which by preference may be a compound engine consisting at least of iwo
cylinders in order to enable the gases, entering at a very high pressure in the
first cylinder, to expand in a profitable manner. The effect may then be still
further increased by the adoption of combustion chambers arranged between the
cylinders in order to raise the temperature of the gases which has fallen by the
expansion, again before entering the next following cylinder.
Dated this Oth Joy of Contamtian 1900
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Process and Arrangement for Utilizing Liquid Air in Heat Motors.
We, CARL LINDE, Doctor of Philosophy, and the Corporation "GESELLSCHAFT
FÜR LINDE'S EISMASCHINEN," a Company incorporated according to the Laws of
Prussia, domiciled both at No. 76, Nympfenburger Strasse, München, in the
Kingdom of Bavaria, German Empire, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:—
Since it has been rendered possible to liquify air in any desired quantity it
has often been suggested that liquid air should be used for driving motors. A
careful investigation however shows that the energy expended in liquifying the
air is so out of proportion to the energy obtained under the most favourable cir-
cumstances by the conversion of the liquified air into the gaseous state, which
while further expanding is utilized for doing work, that the idea of utilizing liquid
air for driving motors can only be applied when the question of economy is not
taken into consideration.
This however is different when the liquid air is used in combination with a
combustible in such a manner that the oxygen of said air is caused to act on the
combustible under the high pressure resulting from its transition from the liquid
into the gaseous state.
My invention may be embodied in a combustion motor of the kind in which
combustible materials such as coal gas, petroleum, benzene or the like are used
tor obtaining the driving power. It is well known that for the proper working

page_text: these motors. the atmospheric air is to be mixed with the fuel requ
plied under a high pressure which is produced by compressing the air in a
ecial cylinder, and improvements in the said motors are mainly directed to-
ards increasing the compression and working pressure generally. The effective
ork of the motor in this case is therefore the difference between the work done.
the gas in its compression and the work performed by its expansion.
Now by the use of liquid air the necessity for compressing the air in a special
orking cylinder in order to obtain increasing of pressure by reduction of volume
obviated as the pressure is produced by the transition of the air from the liquid
nto the gaseous state, this transition performing in a closed space.
Moreover
he compression and consequently the working pressure can be greatly increased
vithout necessitating mechanism more complicated than that already existing.
Accordingly it is possible to adopt very small dimensions, this being of special
alue where a motor of small weight and relatively high efficiency is required, as
for instance in driving vehicles.
The accompanying drawing represents a diagrammatical arrangement of my
improved motor in a side elevation, partly in section.
The liquid air is kept under atmospheric pressure in the vessel which is.
well protected exteriorly against heat, from which vessel the said liquid air is
drawn off by a feed pump p having a variable stroke. The pump supplies the
liquid air to the conduit or serpentine s the walls of which are not protected
against the access of heat but are in direct contact with the atmosphere; conse-
quently the liquid air entering the conduit at a temperature below minus 180° C.,
is allowed to absorb heat whereby it is caused to re-assume the gaseous state;
the conduit being made in the form of a serpentine-tube a to afford a large con-
ducting surface. From the said conduit the gasified air enters a combustion
This material
chamber in which at the same time is introduced the combustible material or
motive fluid to an amount required for the power to be exerted.
may consist of a liquid fuel and may be introduced by means of an apparatus m
similar to that generally employed for supplying lubricating material to the
pistons of steam engines. The ignition can be effected in the manner usually
adopted in explosion engines. In starting, an electric igniter may be used and
afterwards ignition may be effected by causing the combustible material to drop
upon an asbestos body which after being rendered incandescent by the combustion
is thereby kept in a state of incandescence.
The combustion may also be obtained by bringing the liquid air directly to-
gether with the combustible material. This enables the gasifyer or serpentine
to be omitted but the consumption of combustion material is increased thereby.
The combustion should always be caused to take place under such conditions
0 as will prevent the resulting gases from having too high a temperature. This
will easily be obtained by injecting a greater quantity of liquid air than is re-
quired for perfect combustion, as obviously the greater the injected volume of
liquid air the lower the temperature at which the gasified air is allowed to meet
the fuel.
15
'
The combustion gases are then introduced into the working mechanism proper
which by preference may be a compound engine e consisting at least of two
cylinders in order to enable the gases, entering a very high pressure in the firs
The effect may then be still furthe
cylinder, to expand in a profitable manner.
increased by the arrangement of a second combustion chamber c between th
50 cylinders in order to mix the gases with fuel and firing the mixture so that th
temperature of the gases which has fallen by the expansion is raised befor
entering the next following cylinder.
55
Having now particularly described and ascertained the nature of our said in
vention, and in what manner the same is to be performed, we declare that wha
we claim is :-
1
The method of utilizing liquid air in working explosion motors which co

page_text: sists in intermittently gasifying liquid air, causing the gasified air to mix with
fuel under the pressure resulting from its transition from the liquid into the
gaseous state, firing the thus obtained mixture of fuel and compressed air, and
causing the products of combustion to act upon the piston, substantially as and
for the purpose described.
2. The method of utilizing liquid air in working explosion motors which con-
sists in intermittently injecting liquid air, gasifying the same on its passage to
the combustion chamber, causing the gasified air to meet the fuel in the com-
bustion chamber under the pressure resulting from its transition from the
gaseous in the liquid state, firing the thus obtained mixture of fuel and compressed
air, and causing the products of combustion to act upon the piston, substantially
as described.
3. The method of utilizing liquid air in working explosion motors which con-
sists in intermittently injecting liquid air, gasifying the same by means of the
atmospherical heat while passing to the combustion chamber, causing the gasified
air to meet the fuel under the pressure resulting from its transition from the
liquid into the gaseous state, firing the thus obtained mixture of fuel and com-
pressed air, and causing the products of combustion to act upon the piston,
substantially as described.
4. The method of utilizing liquid air in working explosion motors which con-
sists in interimittently injecting a quantity of liquid air greater than needed for
burning a given quantity of fuel, gasifying the injected air on its passage to the
combustion chamber, causing the gasified air to meet the fuel under the pressure
resulting from its transition from the liquid into the gaseous state, firing the thus
obtained mixture of fuel and surplus of compressed air, and causing the products
of combustion and surplus of air to act upon the piston, substantially as described.
5. The method of utilizing liquid air in working explosion motors which con-
sists in intermittently injecting a quantity of liquid air greater than needed for
burning a given quantity of fuel, causing the gasified compressed air to meet the
fuel under the pressure resulting from its transition from the liquid into the
gaseous state, firing the thus obtained mixture of fuel and surplus of air to act
upon the piston, mixing said products and surplus of air with fuel, firing anew
and causing the resulting products to act upon a second piston, substantially as
described.
6. The combination with the combustion chamber of an explosion motor, of
a reservoir containing liquid air, a gasifyer located between such chamber and
reservoir and feeding means located between said reservoir and gasifyer, substan-
tially as described.
7. The combination of a reservoir for containing liquid air, a gasifyer, means
for feeding the gasifyer from the reservoir, a combustion chamber communicating
with the gasifyer, means for supplying the combustion chamber with fuel, a
cylinder communicating with said chamber, a piston working in said cylinder, a
second combustion chamber for receiving the products of combustion from the
said cylinder, means for supplying this second chamber with fuel, a second
cylinder communicating with said second chamber and a piston working in said
second cylinder, substantially as described.
Dated this 6th day of June 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.