An Improved Method of and Apparatus for Utilizing Heat for the Production of Power and for Refrigerating Purposes.
Year: 1889

page_text: Date of Application, 27th Nov., 1889
Complete Specification Left, 27th Aug., 1890-Accepted, 8th Nov., 1890
PROVISIONAL SPECIFICATION.
An Improved Method of and Apparatus for Utilizing Heat for the
Production of Power and for Refrigerating Purposes.
We Dr. FRIEDRICH OTTO CORNELIUS ZIMMERMANN, of Ludwigshafen, on the Rhine,
Chemist and ELIAS GOTTLIEB BEHREND, of Hamburg, Civil Engineer, both in the
Empire of Germany, do hereby declare the nature of this invention to be as
follows:-
o
This invention relates to a method of, and apparatus for, utilizing the natural heat
of the earth and sun which is stored up in water and air for the production of power
and for refrigerating purposes.
There are several kinds of vapours possessing at the ordinary temperatures of air
and of water considerable tensions which can be utilized in their expansion for the
production of power or of cold. To this class of vapours belong those of sulphurous
In a so-called counter-
acid, methilic ether, ammonia, carbonic acid, and others.
current apparatus of suitable construction the above mentioned liquids and their
saturated vapours can be caused to pass in the opposite direction to that of a current
of water or air so that the vapour which is in a closed space, for instance in a tube,
gradually obtains the temperature of the said water or air.
-
Ordinary well-water at 15 degrees Centigrade can in this manner yield so much
heat to the vapour that its temperature sinks close to the freezing point, +1 to
1 degree. The temperature of the vapour which withdraws the heat from the water
will accordingly be at about + 10 degrees Centigrade and 4 degrees Centigrade.
Suppose our calculations and examples have reference to ammonia, the ammonia-
vapours, at the above-mentioned temperatures, will have a tension of 6,27 atmospheres,
or of 3.70 atmospheres. When these heated and saturated vapours at a tension of
6,27 atmospheres are allowed to expand to a tension of 3,70 atmospheres in the
cylinder of an engine which is constructed like an ordinary good steam engine, say
one having an expansion-gear, a corresponding amount of work can be performed.
The expanded vapours and the ammonia which has been partially condensed in the
expansion return to the end of the counter-current apparatus at which the low
temperature and tension exist.
In an ordinary condensing steam-engine of about thirty horse-power use is some-
times made of 6000 litres of water per hour simply for condensing the steam. We
will examine how great the advantage will be if only this quantity of water at an
ordinary temperature be employed for the purposes, of our invention.
6000 litres of water at + 15 degrees Centigrade, from which so much heat is
withdrawn by the expanded ammonia that it is cooled to + 1 degree Centigrade yields
to this ammonia 6000 × 14 84000 units of heat, wherewith in the expansion of the
ammonia-vapours 84000 x 424 = 35616000 kilogramme-meters are produced in an
hour or
35616000
3600
-
9893 kilogramme-meters per second, or about 132 horse-powers.
In case the counter-current apparatus is of suitable construction and the expansion
cylinder is well isolated about half of the aforesaid amount, that is to say 65 horse-
powers, can be utilized.
This engine therefore requires only 6000 litres of water per hour in order to produce
65 horse-powers, which water is caused to flow through a counter-current apparatus
wherein it is considerably cooled. There is in this case no consumption of fuel
whatever. Differences of temperature of 5 degrees Centigrade between the ammonia-
vapours and the surrounding water are quite usual in condensers of existing ammonia
Raine &dom
3

page_text: compression refrigerating-machines, the only difference being that no counter-current
proper is used in the latter and that the heat is imparted from the ammonia to the
water.
=
_
-
If the counter-current apparatus is. prolonged a certain length and the prolonged
part surrounded by a solution of salt as employed in refrigerating machines, we are
enabled to continue the expansion of the vapours up to temperatures and tensions such
as are used in the evaporators of refrigerating machines, for instance to
15 degrees
Centigrade 2,37 atmospheres when ammonia is employed. In this manner the
solution of salt is cooled to about 10 degrees Centigrade, and used for the pro-
duction of ice or the cooling of rooms and after its temperature has been raised a few
degrees it is conveyed back to the counter-current apparatus. The heat thus taken
up is again withdrawn from the solution of salt by the ammonia, and employed for the
operation of the refrigerating machine by utilizing the expansion. We can in this
manner also produce cold by means of the described engine without at all reducing its
effectiveness, as we simply allow the ammonia-vapours to expand further. For this
purpose use is made of a second expansion-cylinder into which the vapours are passed
after their action in the engine cylinder. In case, however, a reduction of the
effectiveness of the said engine is immaterial a further expansion can take place in the
engine-cylinder itself by closing the admission passage for the vapours to the engine
cylinder at an earlier period.
If the water or the air used for heating the vapours is warmer than stated in the
above-described case the vapours are likewise warmer and at a higher tension,
therefore the effectiveness is also greater; whereas it is less at a lower temperature.
Whenever it is therefore desired to exert power without incurring any expense, use
must be made in winter of well-water which is at a uniform temperature throughout
the year.
=
If in winter the water is too cold for the purposes of our invention, for instance
+8 degrees Centigrade, and is to be heated to + 15 degrees Centigrade, 6000 × 7
= 42,000 units of heat are required for the 65 horse-power engine referred to in the
above-mentioned example or for coal having available heating power of 5000 units of
heat, about 8 kilogrammes of coal per hour. The heating can be effected in an
ordinary water-tube boiler.
In cases where water is to be saved, and where the consumption of a moderate
quantity of coals is of small moment the use of the heat of the earth and sun stored
up in water and air can be dispensed with, the same water being heated again and
again for further use. In the example above mentioned 6000 x 14 = 84000 units of
heat, or about 17 kilogrammes of coal are then required per hour for the operation of
the 65 horse power engine.
When always the same water is used the limits of the temperature may be wider
and if ammonia is used, the heating may well be carried to +40 degrees, that is to
say until a tension of 16 atmospheres is obtained. By this means the dimensions of
the engines will be rendered small, inasmuch as an effective pressure of 12 atmospheres
will be on the piston in the said engines.
Any portable, locomotive, marine and other engines can be driven in this manner.
We will now proceed to describe an example of the manner in which our said
invention may be carried into practice. In connection with an engine we provide a
counter-current apparatus comprising a vessel in which a number of serpentine tubes
are placed one above the other. By the walls at the bottom and top of the vessel the
water or the air designed for the heating is compelled to take a serpentine path
around the serpentine tubes. The water or the air enters at one end and leaves at the
other end of the vessel. In case cold is to be produced a compartment of the counter-
current apparatus serves for the reception of the salt water in the above-described
manner. In the said serpentine tubes are the vapours to be heated which vapours are
conducted in the expanded state from the cylinder of the engine to one end of the
counter-current apparatus, and passing through this apparatus, leave the same at a
nigher pressure at its other end in order to again enter the aforesaid cylinder wherein

page_text: they exert pressure as they expand, so that the heat taken up in the counter-current
apparatus is converted into work in the engine.
In the expansion a portion of the ammonia vapours is liquefied, which vapours
together with the condensed ammonia are caused to enter the aforesaid serpentine
tube either at the end of the above-mentioned compartment or in front of the same.
As during the movement of the engine one quantity of vapour after another will leave
the pressure side of the cylinder, the ammonia is caused to pass into and through the
counter current apparatus wherein it is at the same time heated and its tension
increased, so that a cycle is established.
The said counter-current apparatus is provided with the necessary pressure-gauges
and thermometers, and is well isolated so as to be protected against external cooling.
The serpentine-tubes for the saturated vapours consist of several sections which are
connected with each other by valves adapted to open towards the pressure side. In
this manner the vapours are enabled to pass from the expansion side to the pressure
side, but not in the opposite direction, so that the tensions of the vapours are not
liable to become equalized during a short stoppage of the engine. But in order to
obviate an equalization of the tensions during a protracted stoppage, the aforesaid
valves are provided with a pressing screw by which they can be firmly pressed upon
their seat during such a stoppage. When the counter-current apparatus is properly
isolated the tensions are approximately maintained for a comparatively long time.
The apparatus is filled at two points from vessels containing liquid ammonia, which
are connected to the apparatus at the said points. At one of these only such a
quantity of ammonia is at first introduced into the serpentine tube that the tension on
the expansion side will be throughout at the desired height. During the operation of
the engine vapours are allowed at the second of the aforesaid points to pass gradually
into the expansion-cylinder until the serpentine tube is suitably filled, and until the
necessary tension exists on the
pressure side.
For preventing the escape of ammonia to the exterior the piston-rod is provided
either with a jacket or with a double stuffing-box having a chamber formed in it,
which jacket or chamber is connected with the expansion side of the serpentine tube
by means of a small pipe provided with a cock or other closing device. The form of
the serpentine tube inay be varied in accordance with the requirements of each
particular case.
In other respects the engine employed can be constructed like a steam engine having
an expansion gear.
The value of our invention consists firstly in enabling the engine to perform work
free of expense by utilizing the heat of the earth and sun, and secondly in that, if it
is preferred, to employ engines of smaller dimensions or to always use the same water,
the consumption of fuel is very small as compared with that of the steam-engine,
because we do not require the great amount of heat which is necessary in steam boilers
for generating steam and for the latent heat of the steam.
A still further difference in the tensions on both sides of the cylinder can be pro-
duced by the absorption of the escape vapours, which may be effected in the case of
ammonia by water or glycerin. Heat is thus set free which can again be used as
additional heat in the evaporation. In connection with the absorption apparatus wė
use a water receptacle from which water can pass into the said apparatus and also into
a distilling apparatus. The former apparatus has a coil filled with water or glycerin.
As the expanded vapour coming from the engine enters the apparatus it is absorbed.
The liquid saturated with vapour is caused to pass through a return-valve into the coil
of the distilling apparatus being if necessary forced in by means of a pump. Through
the agency of a water bath, the heat of the air, or if necessary a small fire, the vapour
is bere distilled over to an evaporator. In this manner a cycle is established in the
apparatus.
Locomotive engines, besides being operated with heated water, can also conveniently
be driven in summer by allowing the air to pass through the counter-current
apparatus in the movement of the engine, and thus effect the heating of the
vapours.

page_text: Under these circumstances the air required is determined in the case stated by way
of example as follows:
For the 65 horse-power engine, with 50 per cent. of useful effect, 84,000 units of
heat are necessary per hour. A kilogramme of air when its temperature is lowered
1 degree Centigrade, yields 0,2377 units of heat, therefore if its temperature is lowered
14 degrees, 0-23774 x 14 = 3,3278 units of heat are given off. Accordingly
the
84,000
05040 ilarammas
care needed
84,000
3,3278
05040 1:
kilogrammes of
noaded
At + 15 degrees a cubic meter of air weighs 1,2095 kilogrammes, so that every
25242
1,2095
hour
metres.
= 20870 cubic meters of air are necessary or per second about 6 cubic
All the above-mentioned figures show that the objects aimed at can be realized in
practice, for a pump which has to raise per hour 6000 litres of water 20 metres
requires only horse-power, and a fan for the supply of 20,000 cubic metres of air
per hour can be driven by 5 or 6 horse-power.
Another method of utilizing the heat communicated by water or air to the liquid
employed which boils at a low temperature, and to its vapours, for the purpose of
performing work or for producing cold is as follows.
In lieu of the above-described counter-current apparatus for the reception of heat
(evaporator), an ordinary tubular heater, surface condenser, or an apparatus having
horizontal or vertical serpentine tubes, or a simple vessel can be employed for the
evaporation.
As a receiver for the potential energy inherent in the vapours under tenison use
may be made of any expansion steam-engine, but preferably one in which the
distribution is effected by means of lift valves.
The evaporator is surrounded by water which is at the ordinary temperature, and
which renews itself as it flows from the inlet to the outlet.
The principles on which the improved apparatus works for converting heat into
work are based on the following theories established by science viz. :-
1. In the expansion of saturated vapour a certain portion of the heat contained in
the vapour is converted into work.
2. When the expansion is sufficiently great, not only all the free heat is used as
such but also a portion of the latent heat contained in the vapour a partial condensation
of the vapour taking place.
From this follows that during the admission and expansion of the vapour in the
engine more work is transmitted than must be used again in the return movement of
the piston, in order to force the quantity of vapour lessened by the partial condensa-
tion back again into the evaporator. There is consequently an excess of power which
keeps the engine in motion. The production of cold is caused from the use of heat
necessitated by the re-evaporation of the ammonia or the like which has been liquefied
by the expansion.
The action is accordingly of a differentiating nature, inasmuch as only the latent
beat of the ammonia or the like which has been liquefied during the expansion i
converted into an excess of power, and only this quantity of beat can be considered to
have been used and to be applicable to the production of cold.
The effectiveness of the engine increases with the tension of the vapour in the
evaporator, and will therefore be considerably greater when use is made of liquid
carbonic acid, and of equally large dimensions of the cylinder, than in the case of
ammonia
In this engine, too, an increase in the tension can be produced by heating the water
by artificial means, or by mixing air with the saturated vapours in the evaporator.
Under these conditions more ammonia or other vapour is liquefied in the expansion,
as the degree of expansion can be higher and consequently the use of heat greater.
The effectiveness of the engine, when for example use is made of ammonia is deter-
mined in the following manner.

page_text: sion 286,99-280,06 = 6,93 units of heat have been supplied by the heat of the
vapour itself 28,98 - 6,93 = 22,05 units of heat have had to be supplied for the
effective work which units can only have been withdrawn from a portion of the vapour
22,05
294,30
itself and have had the effect of liquefying
(internal latent heat of the expanded
ammonia vapour) = 0,075 kilogrammes of ammonia vapour which may be employed
for the production of cold. That indeed amounts only to 1,7 per cent. of the vapour
employed, but a refrigerating machine worked on the aforesaid principle with a
cylinder having a diameter of 50 centimetres, and even with a useful effect of only
50 per cent., is yet capable of producing per hour 60 kilogrammes of ice free of
expense.
The higher the tension is kept under these conditions by the introduction of heated
water, the more favourable will be the dimensions of the engine. The cost of working
when the water is heated, as compared with the cost of working of the steam-engines
heretofore employed for actuating the refrigerating machines at present in use is
in the same favourable proportion as set forth with reference to the first described
arrangement.
If then the ammonia-vapours are heated to + 40 degrees Centigrade, 80 units of
heat are required for liquefying 0,27 kilogrammes, that is to say, nearly four times as
much as above calculated. In that case, with a cylinder having a diameter of
50 centimeters and with a useful effect of 50 per cent., about 230 kilogrammes of ice
can be produced at a very small cost for fuel."
In order to set this engine in action it is first necessary to produce an excess of
pressure until the engine performs its normal number of revolutions and the frictions
and resistances in the engine are overcome by the excess of power obtained in the
expansion as compared with the compression. The amount of this excess of power
can be immediately determined from the figures above stated.
The aforesaid increase of pressure is produced by a smal! heater which is connected
with the large evaporator by means of two cocks or valves and the coil of which also
contains ammonia. The two cocks or valves are closed so that the communication
between the small heater and evaporator is interrupted. Then the small heater is
surrounded with warm water so that a higher tension produced in the ammonia
contained in the coil, which tension is sufficient for setting the engine in action.
Thereupon one of the said valves is opened and the engine carries out its regular
movement.
The above stated calculations have been performed in respect of ammonia-vapours,

page_text: in order to furnish an example. For different requirements and under different
-conditions other liquids are adapted for the same purpose, their use necessitating only
a change in the dimensions of the expansion-cylinder. Thus for instance in case the
natural heat of the earth and sun stored up in water and air is used alone, carbonic
acid is well adapted for use in our apparatus. It has at + 10 degrees Centigrade
a tension of 46,05 atmospheres, and at 15 degrees Centigrade a tension of
23,13 atmospheres.
-
We mention a number of available vapours and their tension at the temperatures
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Utilizing Heat for the
Production of Power and for Refrigerating Purposes.
We, Dr. FRIEDRICH OTTO CORNELIUS ZIMMERMANN, of Ludwigshafen on the
Rhine, Chemist, and ELIAS GOTTLIEB BEHREND, of Hamburg, Civil Engineer,
both in the Empire of Germany, do hereby declare the nature of this invention and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
This invention relates to a method of, and apparatus for, utilizing the natural heat
of the earth and sun which is stored up in water and air, for the production of power
and for refrigerating purposes.
There are several kinds of vapours possessing at the ordinary temperatures of air
.and of water considerable tensions which can be utilized in their expansion for the
production of power or of cold. To this class of vapours belong those of sulphurous
acid, methylic ether, ammonia, carbonic acid, and others.
In a so called counter-current apparatus of suitable construction the above
mentioned liquids and their saturated vapours can be caused to pass in the opposite
.direction to that of a current of water or air, so that the vapour which is in a closed
space, for instance in a tube, gradually obtains the temperature of the said water
or air.
Ordinary well-water at 15 degrees Centigrade can in this manner yield so much
heat to the vapour that its temperature sinks close to the freezing point, + to
1 degree. The temperature of the vapour which withdraws the heat from the
water will accordingly be at about + 10 degrees Centigrade and 4 degrees
Centigrade.
-
Suppose our calculations and examples have reference to ammonia, the ammonia-
vapours, at the above mentioned temperatures, will have a tension of 6,27 atmospheres,
or 3,70 atmospheres. When these heated and saturated vapours at a tension of

page_text: 6,27 atmospheres are allowed to expand to a tension of 3,70 atmospheres in the-
cylinder of an engine which is constructed like an ordinary good steam engine, say
one having an expansion gear, a corresponding amount of work can be performed.
The expanded vapours and the ammonia which has been partially condensed in the
expansion return to the end of the counter current apparatus at which the low
temperature and tension exist.
In an ordinary condensing steam-engine of about thirty horse power use is some--
times made of 6000 litres of water per hour simply for condensing the steam.
We
will examine how great the advantage will be if only this quantity of water at an
ordinary temperature be employed for the purposes of our invention.
6000 litres of water at + 15 degrees Centigrade from which so much heat is-
withdrawn by the expanded ammonia that it is cooled to + 1 degree Centigrade-
yields to this ammonia 6000 × 14 84000 units of heat, wherewith in the expansion
35616000 kilogramme meters are produced
=
of the ammonia-vapours 8400 × 421-
in an hour or
35616000
3600
=
132 horse-power.
=
9893 kilogramme meters per second, about equal to
In case the counter-current apparatus is of suitable construction and the expansion
cylinder is well isolated about half of the aforesaid amount, that is to say 65 horse
power, can be utilized.
This engine therefore requires only 6000 litres of water per hour in order to
produce 65 horse-powers, which water is caused to flow through a counter-current
apparatus wherein it is considerably cooled. There is in this case no consumption of
fuel whatever. Difference of temperature of 5 degrees Centigrade between ammonia
vapours and the surrounding water are quite usual in condensers of existing ammonia
compression refrigerating-machines, the only difference being that no counter-current
proper is used in the latter and that the heat is imparted from the ammonia to the
water.
-
-
If the counter current apparatus is prolonged a certain length and the prolonged
part surrounded by a solution of salt as employed in refrigerating machines, we are
enabled to continue the expansion of the vapours up to temperatures and tensions.
such as are used in the evaporators of refrigerating machines, for instance to
15 degrees Centigrade = 2,37 atmospheres when aminonia is employed. In this.
manner the solution of salt is cooled to about
10 degrees Centigrade, and used for
the production of ice or the cooling of rooms and after its temperature has been
raised a few degrees it is conveyed back to the counter-current apparatus. The heat.
thus taken up is again withdrawn from the solution of salt by the ammonia, an
employed for the operation of the refrigerating machine by utilizing the expansion..
We can in this manner also produce cold by means of the described engine without
at all reducing its effectiveness, as we simply allow the ammonia vapours to expand
further. For this purpose use is made of a second expansion cylinder, into which the
vapours are passed after their action in the engine cylinder. In case, however a
reduction of the effectiveness of the said engine is immaterial a further expansion can
take place in the engine-cylinder itself by closing the admission passage for the
vapours to the engine-cylinder at an earlier period.
If the water or the air used for heating the vapours is warmer than stated in the
above-described case the vapours are likewise warmer and at a higher tension,
therefore the effectiveness is also greater; whereas it is less at a lower temperature.
Therefore whenever it is desired to exert power without incurring any expense, use
must be made in winter of well-water which is at an uniform temperature throughout
the year.
If in winter the water is too cold for the purpose of our invention, for instance
+ 8 degrees Centigrade, and is to be heated to 15 degrees Centigrade,.
6000 × 7 = 42000 units of heat are required for the 65 horse-powers engine
referred to in the above mentioned example or for coal having available heating.

page_text: power of 5000 units of heat, about 8 kilogrammes of coal per hour. The heating
can be effected in an ordinary water-tube boiler.
In cases where water is to be saved, and where the consumption of a moderate
quantity of coal is of small moment the use of the heat of the earth and sun stored
up in water and air can be dispensed with the same water being heated again and
again for further use. In the example above mentioned 6000 x 14 = 81000 units
of heat, or about 17 kilogrammes of coal are then required per hour for the operation
of the 65 horse-power engine.
When the same water is always used the limits of the temperature may be wider
and if ammonia is used, the heating may well be carried to + 40 degrees, that is to
say, until a tension of 16 atmospheres is obtained. By this means the dimensions of
the engines will be rendered small, inasmuch as an effective pressure of 12 atmospheres
will be on the piston in the said engines.
Any portable, locomotive, marine and other engines can be driven in this
manner.
In order to make our invention more clearly understood we will proceed to
describe by way of example, the manner in which our said invention may be
carried into practice, reference being had to the accompanying drawing, in
which :-
Figure 1 is a vertical section of a counter-current apparatus as may be preferably
employed;
Figure 2 is a top view of the same in connection with a motive-power engine;
Figure 3 is a side elevation of the counter-current apparatus and the engine, the
former partly in section;
Figure 4 is a section through the stuffing box at the front cover, and
Figure 5 is a section through the stuffing box at the rear cover of the cylinder for
the piston-rod of the engine;
Figure 6 is a cross-section through a somewhat modified serpentine to be used in
the said counter-current-apparatus ;
Figure 7 is a vertical section of an absorption apparatus in connection with a water
receptacle and a distilling apparatus, and
Figures 8 and 9 are a vertical section and a top view of a pressure-increasing
apparatus in connection with an evaporator as employed to carry our invention into
practice.
In connection with an engine we provide a counter-current apparatus comprising
a vessel b in which a number of serpentine tubes a are placed one above the other.
By the walls c and d at the bottom and top of the vessel the water or the air designed
for the heating is compelled to take a serpentine path around the serpentine tubes.
The water or the air enters at one end at e, and leaves at the other end of the vessel
at f. In case cold is to be produced one compartment g of the counter-current-
apparatus may serve for the reception of the salt water in the above-described manner.
In the said serpentine tubes a are the vapours to be heated which vapours are
conducted in the expanded state from the cylinder i of the engine to one end of the
counter-current-apparatus through the valve h and passing through this apparatus
leave the same at a higher pressure at its other end through the valve k in order to
again enter the aforesaid cylinder i wherein they exert pressure as they expand, so
that the heat taken up in the counter-current-apparatus is converted into work in the
engine.
In the expansion a portion of the ammonia vapours is liquefied, which vapours
together with the condensed ammonia are caused to enter the aforesaid serpentine tube
either at for at h. As during the movement of the engine one quantity of vapour after
another will leave the pressure side of the cylinder, the ammonia is caused to pass into
and through the counter-current-apparatus wherein it is at the same time heated and
its tension increased so that a cycle is established.
The said counter-current-apparatus is provided with the necessary pressure-gauges
and thermometers, and is well isolated so as to be protected against external

page_text: cooling.
The serpentine tubes for the saturated vapours consist of several
sections 1, 2, 3, 4, 5
which are connected with each other by valves?
adapted to open towards the pressure side. In this manner the vapours are enabled
to pass from the expansion side to the pressure side, but not in the opposite direction,
so that the tensions of the vapours are not liable to become equalized during a short
stoppage of the engine. But in order to obviate an equalization of the tensions
during a protracted stoppage, the aforesaid valves are provided with a pressing
screw by which they can be firmly pressed upon their seat during such a stoppage.
When the counter-current apparatus is properly isolated the tensions are approximately
maintained for a comparatively long time.
The apparatus is filled through the pipes m and n from vessels containing liquid
ammonia, which are connected thereto. Through one of these pipes, for instance m
only such a quantity of ammonia is at first introduced into the serpentine tube that
the tension on the expansion side will be throughout at the desired height. During
the operation of the engine vapours are then allowed through the pipe n to pass
gradually into the expansion cylinder until the serpentine tube is suitably filled, and
until the necessary tension exists on the pressure side.
For preventing the escape of ammonia to the exterior the piston rod is provided at
the rear end of the cylinder with a jacket o and at the front end with a double stuffing
box having a chamber p formed in it, which jacket and chamber are connected with
the expansion side of the serpentine tube by means of small pipes g g¹ preferably
provided with a cock or other closing device. The form of the serpentine tube may
be varied in accordance with the requirements of each particular case as for instance
shown by Figure 6.
In other respects the engine employed can be constructed like a steam engine
having an expansion gear.
The value of our invention consists firstly in enabling the engine to perform work
free of expense by utilizing the heat of the earth and sun, and secondly in that, if it
is preferred to employ engines of smaller dimensions or to always use the same water,
the consumption of fuel is very small as compared with that of the steam engine,
because we do not require the great amount of heat which is necessary in steam boilers
for generating steam and for the latent heat of the steam.
A still further difference in the tensions on both sides of the cylinder can be
produced by the absorption of the escape vapours, which may be effected in the case
of ammonia by water or glycerine. Heat is thus set free which can again be used as
additional heat in the evaporation. In connection with the absorption apparatus
(Figure 7) we use a water receptacle r from which water can pass into the said
apparatus s and also into a distilling apparatus t. The former apparatus has a coil s
filled with water or glycerine. As the expanded vapour coming from the engine
enters the apparatus through the check-valve u it is absorbed. The liquid saturated
of the
with vapour is caused to pass through a return valve v into the coil
distilling apparatus being if necessary forced in by means of a pump. Through the
agency of a water bath, the heat of the air, or if necessary a small fire, the vapour
is here distilled over to the evaporator w. In this manner a cycle is established in
the apparatus.
Locomotive engines, besides being operated with heated water, can also conveniently
be driven in summer by allowing the air to pass through the counter-current
apparatus in the movement of the engine and thus effect the heating of the vapours.
Under these circumstances the air required is determined in the case stated by way
of example as follows :-
--
For the 65 horse power engine, with 50 per cent. of useful effect, 84000 units of
heat, are necessary per hour. A kilogramme of air, when its temperature is lowered
1 degree Centigrade, yields 0,2377 units of heat, therefore if its temperature is
lowered 14 degrees, 0,2377 x 14 = 3,3278 units of heat are given off. Accordingly
8100

page_text: At + 15 degrees a cubic metre of air weighs 1,2095 kilogrammes, so that every
hour
25242
12095
metres.
=
20,870 cubic metres of air are necessary or per second about 6 cubic
All the abovementioned figures show that the objects aimed at, can be realized in
practice, for a pump which has to raise per hour 6000 litres of water 20 metres,
requires only horse-power, and a fan for the supply of 20000 cubic metres of air
per hour can be driven by 5 or 6 horse-power.
Another method of utilizing the heat communicated by water or air to the liquid
employed which boils at a low temperature, and to its vapours; for the purpose of
performing work or for producing cold is as follows:-
In lieu of the abovedescribed counter-current-apparatus for the reception of heat
(evaporator), an ordinary tubular heater, surface condenser, or an apparatus having
horizontal or vertical serpentine tubes, or a simple vessel can be employed for the
evaporation.
As a receiver for the potential energy inherent in the vapours under tension use
may be made of any expansion steam-engine, but preferably one in which the distri-
bution is effected by means of lift valves.
The evaporator is surrounded by water which is at the ordinary temperature, and
which renews itself as it flows from the inlet to the outlet.
The principles in which the improved apparatus works for converting heat into
work are based on the following theories established by science viz. :--
1. In the expansion of saturated vapour a certain portion of the heat contained in
the vapour is converted into work.
2. When the expansion is sufficiently great, not only all the free heat is used as
such but also a portion of the latent heat contained in the vapour a partial condensation
of the vapour taking place.
From this it follows that during the admission and expansion of the vapour in the
engine more work is transmitted than must be used again in the return movement
of the piston, in order to force the quantity of vapour lessened by the partial
condensation back again into the evaporator. There is consequently an excess of
power which keeps the engine in motion. The production of cold is caused from
the use of heat necessitated by the re-evaporation of the ammonia or the like which has
been liquefied by the expansion.
The action is accordingly of a differentiating nature, inasmuch as only the latent
heat of the ammonia or the like which has been liquefied during the expansion is
converted into an excess of power, and only this quantity of heat can be considered to
have been used and to be applicable to the production of cold.
The effectiveness of the engine increases with the tension of the vapour in the
evaporator, and will therefore be considerably greater when use is made of liquid
carbonic acid and of equally large dimensions of the cylinder, than in the case of
ammonia.
In this engine, too, an increase in the tension can be produced by heating the water
by artificial means or by mixing air with the saturated vapours in the evaporator.
Under these conditions more ammonia or other vapour is liquefied in the expansion, as
the degree of expansion can be higher and consequently the use of heat greater.
The effectiveness of the engine, when for example use is made of ammonia is
determined in the following manner.
In the evaporator which is used in this case the ammonia-vapours obtain the mean
temperature of the water, that is to say about × 8 degrees Centigrade=5,84 atmo-
spheres. When the specific weight of the same is 4,454, the tension
heat of the vapour 1
==
P 5,84 and the
A 1:1
= 286,99.
1

page_text: =
in the expansion 286,99 - 280,06 : 6,93 units of heat have been supplied by the
heat of the vapour itself 28,986,93 = 22,05 units of heat have had to be supplied
for the effective work which units can only have been withdrawn from a portion of
the vapour itself and have had the effect of liquefying
22,05
29430
(internal latent heat of
the expanded ammonia vapour) = 0,075 kilogrammes of ammonia vapour which may
be employed for the production of cold. That indeed amounts only to 17 per cent. of
the vapour employed but a refrigerating machine worked on the aforesaid principle
with a cylinder having a diameter of 50 centimetres, and even with a useful effect of
only 50 per cent. is yet capable of producing per hour 6 kilogrammes of ice free of
expense.
The higher the tension is kept under these conditions by the introduction of heated
water, the more favourable will be the dimensions of the engine. The cost of working
when the water is heated, as compared with the cost of working of the steam engines
heretofore employed for actuating the refrigerating machines at present in use
is in the same favourable proportions as set forth with reference to the first-described
arrangement.
If then the ammonia vapours are heated to + 40 degrees Centigrade 80 units of heat
are required for liquefying o, 27 kilogrammes, that is to say, nearly four times as
much as above calculated. In that case, with a cylinder having a diameter of
50 centimetres and with a useful effect of 50 per cent. about 230 kilogrammes of ice
can be produced at a very small cost for fuel.
In order to set this engine in action it is first necessary to produce an excess of
pressure until the engine performs its normal number of revolutions and the frictions
and resistances in the engine are overcome by the excess of power obtained in the
expansion as compared with the compression. The amount of this excess of power
can be immediately determined from the figures above stated.
The aforesaid increase of pressure is produced by a small heater y (Figures 8 and 9)
which is connected with the large evaporator w¹ by means of two cocks or valves z z¹
and the coil of which also contains ammonia. The two cocks or valves are closed
so that the communication between the small heater and evaporator is interrupted.
Then the small heater y is surrounded with warm water so that a higher tension is
produced in the ammonia contained in the coil a, which tension is sufficient for setting
the engine in action. Thereupon the valve z is opened and the engine carries out its
regular movement.
The above stated calculations have been performed in respect of ammonia-vapours,
in order to furnish an example. For different requirements and under different con-
ditions other liquids are adapted for the same purpose, their use necessitating only
a change in the dimensions of the expansion cylinder. Thus for instance in case the
natural heat of the earth and sun stored up in water and air is used alone, carbonic
acid is well adapted for use in our apparatus. It has at + 10 degrees Centigrade
tension of 46,05 atmospheres and at 15 degrees Centigrade a tension of 23,13
atmospheres.
-
a

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
==
First. The process of utilizing the natural heat of the earth and sun stored up in
water and air for the production of power by evaporating liquids having a considerably
low boiling point, expanding the produced vapours and re-conducting thereafter the
vapours cooled and partly liquefied by the expansion to the generator of the machine
illustrated in Figures 1 to 7 of the accompanying drawings.
Second. The process of utilizing the natural heat of the earth and sun stored up in
water and air for refrigerating purposes, substantially as and for the purpose set
forth.
Third. In the process of utilizing the natural heat contained in water and air the
additional supply of artificially produced heat, for the purpose of increasing the useful
effect in the conversion of power, substantially as specified.
Fourth. In the utilization of heat for the production of power by means of an
expansion engine, the counter-current apparatus having several compartments which
are separated from each other by combined return and stop-valves.
Fifth. The double stuffing box provided with a separate chamber and the jacket
surrounding the piston rod.
Sixth. The apparatus for absorbing the vapours and distilling the same back into
the generator all substantially as, and for the purposes, set forth.
Seventh. The utilization of artificial heat for starting expansion and compression
engines for refrigerating purposes, substantially as specified.
Til: L 1
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.