Improvements in Refrigerating Apparatus.
Year: 1884

page_text: Improvements in Refrigerating Apparatus.
"
I SYDNEY PITT of Sutton in the County of Surrey Gentleman do hereby
declare the nature of my invention for IMPROVEMENTS IN REFRIGERATING
APPARATUS" A communication to me from abroad by Raoul Pierre Pictet of
Geneva Switzerland to be as follows: -
The present Invention has for its object improvements in refrigerating apparatus
and is applicable to machines employing hydrous sulphurous acid. The improve-
ments relate both to the construction of the machine and its method of action.
Formerly the condenser was made of copper and composed of a system of
parallel tubes traversed by a current of common water. This arrangement presents
grave inconveniences.
In the new machine iron tubes welded with lap joints are employed.
The volatile liquid is put inside the tubes in place of putting it around the
tubes.
'
t
In this new condenser the vapours forced into it by the pump enter a long tube
of wrought or cast iron A Figure 1. On the side of this tube parallel coils or
serpentines are connected of which the total section is very nearly the same as the
section of the tube which brings the vapours from the pump.
}
These serpentines are composed of straight iron tubes with seni circular bends at
the end of each straight part as is shown. at B¹ B¹ in Figure 2 which represents a
plan and an élevation.
All these serpentines are parallel the one to the other.
The straight end which terminates the serpentine at the bottom is connected to a
second horizontal collecting tube of wrought or cast iron C Figure 1.
The end of the tube C receives a large tube of wrought or cast iron H Figure 1
of a diaineter greater than C and preferably it is vertical. The end cover of this
tube H is traversed by a tube of small diameter G, which passes to the bottom of;
the large collecting tube at E. It is by this tube that the condensed liquids retura,
to the refrigerator.
'
""" ..
This arrangement, putting a large reservoir at the end of the serpentines, has for
its object the collection of foreign gases. The active condensation which takes
Davis 27

page_text: place in the tubes always carries mechanically to the terminal ends of the tubes
gases which escape condensation and which otherwise would interfere with the
liquification of the operative gas.
Diffusion of the gases in the serpentines is impossible from the small section of
these tubes compared with the very large section of the spaces which existed
between the tubes in the old condenser.
All the tubular system and the collecting tubes A, C and H are immersed in a
large cistern of sheet iron II Figure 1 designed to receive cold water at the
bottom through a descending tube and to allow the water to escape by an
overflow.
The water becomes heated by the condensation of the volatile liquid and it
arranges itself in isothermal layers and escapes when it has attained the maximum
temperature. This arrangement saves a large quantity of water.
Horizontal baffle plates cause the water to circulate horizontally which further
increases the effect produced.
.
The refrigerator is very similar to the condenser in respect to the parts of which
it is composed but its function is entirely different.
Figure 2 represents a plan and end elevation of this apparatus. The volatile
liquid is accumulated in a large vertical column of wrought or cast iron M which
communicates at the bottom with a long collecting tube of wrought or cast iron L.
The serpentines B¹ B' are inserted into the tube L perpendicularly to the direction
of this tube. These serpentines are identical with those of the condenser and at
their upper ends they meet a second collecting tube K which itself is attached to
the upper column M. The upper part of the column M is connected to the pump.
In consequence of these arrangements the volatile liquid in all the serpentines
and in the vertical column M is at the same height.
These systems are plunged into a large sheet iron tank O O, full of liquid which
cannot be frozen, as salt water, glycerine etc: The pump being set in action a
circulation of extreme energy, is set up in each serpentine.
The volatile liquid is forced with violence into each serpentine, and the mixture
of liquid and vapour issues energetically by the upper extremity into the collector K,
the liquid falls back into the cylinder M to recommence the circulation already
described. Thus with a small quantity of volatile liquid the total surface of the
refrigerator is maintained in activity, which never took place when working on the
old system.
Vertical plates are arranged to regulate the circulation of the salt water through
all the serpentines, whether a screw be used or pumps be employed for the general
circulation.
Condensers and refrigerators constructed in the manner just described will be
able to resist a pressure from 15 to 20 atmospheres, remaining perfectly tight.
In the compressing pump as at present constructed the shock of the suction and
delivery valves against their stops frequently gives rise to breakages and is the
cause of a disagreeable noise.
These shocks also prevent working at a high speed and the number of revolutions
of the machine is limited almost entirely by this consideration.
To obviate these inconveniences and to hasten without noise the closing of the
valves at each end of the travel of the piston valves with double springs are
employed. One of the springs is long flexible and very elastic and the other
is short and stiff.
The first of these springs controls the valves in the usual way only the length of
this spring is increased to ensure its durability. The other spring serves to limit
the course of the valve. Figure 3 shows the suction valve. A is the cross bar
which separates the valve chamber from the cylinder. It is upon this cross bar
that the valve strikes in the ordinary system. In the present case this bar is
a simple precaution, provided in case of breakage of the steam valve. B is the
valve itself consisting of a steel rod formed into a disc at the lower end and
resting against its seat. O is a nut which is fixed upon the top of the valve rod
"

page_text: by a lock nut F. Two springs D and E press against the piece C. E is the
ordinary spring. D is a more powerful spring which abuts against the part L
when the opening of the valve is sufficient for the passage of the gas into the-
cylinder.
L is a shoulder formed in the bronze socket which guides the valve. Thus, when
the valve opens it first meets only with the resistance of the first spring E; then at
a certain distance from 6 to 8 millimeters from the seat the second spring D takes
its bearing against the part Li and arrests the movement of the valve without
shock.
"
Figure 4 represents the compression valve. B is the valve itself resting against
its bronze seat: KK are abutments against which up to the present time the
valve has struck at the end of its course. They are now only retained by way of
precaution in case of breakage. E is the ordinary spring which acts constantly
upon the valve during its travel. C is a nut fixed and locked upon the top of the
valve rod; it receives the strong spring D. D D is a powerful and short spring
which abuts against the end of the cap L when the valve is raised from its seat so
far as to leave a sufficient passage for the compressed gas.
The spring D stops the valve without shock and returns it without delay to its
seat at the end of the travel of the piston.
n.
All the arrangements described above are perfectly suitable for operating with;
anhydrous sulphurous acid, but this in temperate countries presents so small a
tension that it may advantageously be replaced by a new volatile liquid giving
about one atmosphere more tension than sulphurous acid in the same conditions of
temperature. This liquid which I will call Pictet's liquid gives on analysis the
following elementary chemical composition SC O = Pictet's liquid. it is perfectly
stable, does not act upon metals, avoids all, lubrication and allows of temperature,
84 degrees below zero. Centigrade being obtained. The manufacture of this body
will be the object of a separate Patent.
1100A

page_text: Improvements in Refrigerating Apparatus.
"
I SYDNEY PITT of Sutton in the County of Surrey Gentleman do hereby declare
the nature of my invention for "IMPROVEMENTS IN REFRIGERATING APPARATUS
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:-
The present Invention has for its object improvements in refrigerating apparatus
and is applicable to machines employing anhydrous sulphurous acid The improve-
ments relate both to the construction of the machine and its method of action.
These improvements consist in the new arrangements hereinafter described by the
aid of the annexed drawings.
First The condenser-Formerly the condenser was made of copper and com-
posed of a system of parallel tubes traversed by a current of common water―This
arrangement presents three grave inconveniences as follows.
A The cold water can only once traverse the tubes-The central bundle
receives too intense a current whilst the tubes at the periphery receive an
insufficient current and consequently there is a large consumption of water and it
is imperfectly utilized.
B-Any quantity of foreign gas as atmospheric air, hydrogen etc affects the
compression and the tension of liquefaction according to the Law of Dalton and
often increases in a very disadvantageous way the pressure of the vapours in the
condenser,
C-Any leakage happening in any one of the tubes of the system involves serious
complications, loss of the volatile liquid, the entrance of water is possible and it
becomes necessary to plug the injured tubes.
This last operation is always difficult and is never perfectly performed besides it
diminishes the active surface of the condenser.
In the new machine iron tubes welded with lap joints are employed.
The volatile liquid is put inside the tubes in place of around the tubes.
In this new condenser the vapours forced into it by the pump enter a long tube
of wrought or cast iron A Figure 1. On the side of this tube parallel or serpentine
coils are connected of which the total section is very nearly the same as the section
of the tube which brings the vapours from the pump.
These serpentines are composed of straight iron tubes with semi-circular bends
at the end of each straight part, as is shewn at B in Figure 2 which represents a
plan and an elevation.
All these serpentines are parallel the one to the other and as I have said their
number is such that the sum of the sections of each of these serpentines is equal to
the total section of the tube which leads in the vapours.
The straight end which terminates the serpentine at the bottom is connected to
a second horizontal collecting tube of wrought or cast iron C. Figure 1-This 4
large tube is parallel to the inlet tube A and perpendicular to the general direction
of the serpentines-In Figure 1 I have shown one only of these serpentines at D:
the others are indicated by lines showing where their ends are connected.

page_text: The number of these serpentines and the length of their straight parts will vary
according to the power of the cooling section The attachments of these serpentines
to the collecting tubes A and C. Figure can be made in any convenient manner
so long as they are perfectly tight-The end of the tube C. receives a large tube of
wrought or cast iron H Figure 1 of a diameter greater than C and preferably it is
vertical-The end cover of this tube H is traversed by a tube of small diameter G
which passes to the bottom of the large collecting tube at E-It is by this tube that
the condensed liquids return to the refrigerator.
. This arrangement putting a large reservoir at the end of the serpentines has for
its object the collection of foreign gases-The active condensation which takes
place in the tubes always carries mechanically to the terminal ends of the tubes
gases which escape condensation and which otherwise would interfere with 'the
liquefaction of the operative gas-In consequence of this circumstance Dalton's law
does not come into play because diffusion of the gases in the serpentines is impossible
from the small section of these tubes compared with the very large section of the
spaces which existed between the tubes in the old condenser. This point is very
important it economizes fuel and diminishes often to a very marked extent the work
of the motor.
Testing the condenser is also more easy because all the tubes are exposed. All
the tubular system and the collecting tubes A. C. and H are immersed in a large
cistern of sheet iron I. I Figure 1 simply designed to receive cold water at the
bottom through a descending tube and to allow the water to escape by an
overflow.
The water becomes heated by the condensation of the volatile liquid and it
arranges itself in isothermal layers and escapes when it has attained the maximum
temperature This arrangement saves a large quantity of water.
Horizontal baffle plates cause the water to circulate horizontally which further
increases the effect produced.
2-Refrigerator-The Refrigerator is very similar to the condenser in respect to
the parts of which it is composed, but its function is entirely different.
Figure 2 represents a plan and end elevation of this apparatus-The volatile
liquid is accumulated in a large vertical column of wrought or cast iron M which
communicates at the bottom with a long collecting tube of wrought or cast iron Ľ
The serpentines B¹ B¹ are inserted into the tube L perpendicularly to the direction
of this tube-These serpentines are identical with those of the condenser and at
their upper ends they meet a second collecting tube K which itself is attached to
the column M Thus in the refrigerator the two extremities of the serpentines
abut the one upon the tube L and the other upon the collector K and the two
collectors are connected across by the vertical column M The upper part of the
column M is connected to the compressing pump and communicates with the
suction valves.
In consequence of these arrangements the volatile liquid is at the same height in
all the serpentines and in the vertical column M.
These systems are plunged into a large sheet iron tank O. O. full of liquid which
cannot be frozen, as salt water glycerine etc and the pump being set in action a
circulation of extreme energy is set up in each serpentine in fact evaporation
divides the liquid column of each serpentine into numerous particles separated by
spaces containing vapour-The density of this liquid column diminishes con-
siderably whilst the hydrostatic pressure at the bottom of the vertical cylinder M
is constant-Hence the volatile liquid is, forced with violence into each serpentine,
and the mixture of liquid and vapour issues energetically by the upper extremity
into the collector K the liquid falls back into the cylinder M to recommence the
circulation already described-Thus with a small quantity of volatile liquid the
total surface of the refrigerator is maintained in activity which never took place
when working on the old system-Leaks if they occur are immediately seen and it
is very easy to clean and to empty the refrigerator by removing the covers which
close the ends of the collectors K L and M.

page_text: '
Vertical plates are arranged to regulate the circulation of the salt water through
all the serpentines whether a screw be used or pumps be employed for the general
circulation.
"'
T
נ'
Here also the size of the tank O and the number and diameter of the
serpentines and of the collecting tubes vary according to the power of the refri
gerating machine.
Condensers and refrigerator's constructed in the manner just described will be
able to resist a pressure from 15 to 20 atmospheres remaining perfectly tight and
their price is small when compared with condensers and refrigerators of equal
surface made on the old system of copper.
•
3: The compressing pump, t
the shock of the suction and delivery valves against
their seats and stops in pumps as at present constructed frequently gives rise to
breakages and is the cause of a disagreeable noise which annoys neighbours and
causes the working of the apparatus at night to be in some cases prohibited.
These shocks which are inevitable with the apparatus as it is at present con-
structed also prevent working at a high speed and the number of revolutions of the
machine is limited almost entirely by this consideration.
To obviate these inconveniences and to Hasten without noise the closing of the
valves at each end of the travel of the piston valves with double springs are
employed One of the-springs is long flexible and very elastic it should be made
of steel or copper much hardened by hammering and the other is short and stiff.
The first of these springs controls the valves in the usual way, only the length of
this spring is increased to ensure its durability The other spring serves to limit
the course of the valve. Figure 3 shows the suction valve A is the cross 'bar
which separates the valve chamber from the cylinder. It is upon this cross bar
that the valve strikes in the ordinary system. In the present case this bar is a
simple precaution provided in case of breakage of the stem of the valve B is the
valve itself consisting of a steel rod formed into a disc at the lower end and resting
against its seat, C.is a nut which is fixed upon the top of the valve rod by a lock
nut F two springs D and E press against the piece C-E is the spring for the
working of the suction valve it acts like the ordinary spring-D is a more powerful
spring which abuts against the part L when the opening of the valve is sufficient
for the passage of the gas into the Cylinder.
L is a shoulder formed in the bronze socket which guides the valve. Thus
when the valve opens it first meets only with the resistance of the first spring E
then at a certain distance from 6 to 8 millimetres from the seat, the second
spring D takes its bearing against the part L and arrests the movement of the
valve without shock.
Crystallization of the metal is thus almost entirely avoided which ensures great
durability in these valves.
Figure 4 represents the compression valve, B is the valve itself resting against
its bronze seat K K are abutments against which up to the present time the valve
has struck at the end of its course. They are now only retained by way of
precaution in case of breakage E is the ordinary spring which acts constantly
upon the valve during its travel. C is a nut fixed and locked upon the top of the
valve rod it receives the strong spring D-D. D is a powerful and short spring
which abuts against the end of the cap L when the valve is raised from its seat so
far as to leave a sufficient passáge for the compressed gas.
The Spring. D stops the valve without shock and returns it without delay to its
seat at the end of the travel of the piston.
The other parts of these valves are similar to those of the valves at present in
The diameters of these supplementary springs D vary according to the power
of the machine and the speed which it is desired to give to the compressor.
• use
The speed of rotation may be doubled by this new system of valves without there
being any risk of damage to the compresser.
4. Volatile. liquids All the arrangements described above are perfectly suitable
for operating with anhydrous sulphurous, acid but this in temperate countries such

page_text: France, Germany Austria England presents so small a tension say two or three
atmospheres that it may advantageously be replaced by a new volatile liquid giving
about one atmosphere more tension than sulphurous acid in the same conditions of
Temperature and which has the advantage of giving a yield from 30 to 50 per
cent higher than that of sulphurous acid. This liquid which I will call Pictets
liquid gives on analysis the following elementary chemical composition S.C. O. 4 =
Pictets liquid. It is perfectly stable does not act upon metals, avoids all lubrication ⚫
and allows of a temperature 84 degrees below zero Centigrade being obtained. The
manufacture of this special body as a volatile liquid is the object of a separate
patent bearing even date with the present.
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 tubular condenser with parallel serpentines of iron tubes in which the
volatile liquid is condensed whilst the methodical circulation of water carries away
the heat of condensation, also with a large terminal reservoir preventing high
pressures by receiving any foreign gases there may be in the circuit, preferably the
total sectional area of the serpentines is nearly the same as that of the channel by.
which the vapours enter from the condenser and the tubes of which the serpentines
are composed have lap welded joints.
2. The tubular refrigerator similarly constructed and producing a rapid circulation
of the volatile liquid in the serpentines.
3. The arrangement of the valves with double springs by which they are caused
to work without shock and rapidly.
4. The apparatus substantially as described and the employment therein of
anhydrous sulphurous acid or other volatile liquid as ammonia chloride of methyl
the oxide of methyl or Pictets liquid of which the elementary formula is S.C. O. 4
that is to say one molecule of sulphur, one molecule of carbon and four molecules of
oxygen united and forming a liquid.