Year: 1885

page_text: I, THOMAS BELL LIGHTFOOT, of N° 35 Queen Victoria Street, in the City of
London, Consulting Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention has reference to machinery or apparatus of the kind in which the
temperature of a fluid or body to be frozen or cooled is reduced by means of the
evaporation of a liquid of low boiling point, such as anhydrous ammonia, which
after evaporation is subsequently condensed into the liquid form by the combined
action of pressure and cold in order that it may be again evaporated and utilized
for the abstraction of heat, the complete series of operations being carried out in
a closed cycle. Such a machine for cooling comprises, inter alia, evaporating
apparatus, (commonly called the refrigerator), a condenser, and a pump whereby
the vaporized refrigerating medium is compressed and delivered into the condenser,
while for the production of ice it is usual to have, in addition, a tank or series of
tanks or vessels containing moulds in which the water to be frozen is placed, and
which are surrounded by brine or other uncongealable fluid previously cooled by
the evaporation of the refrigerating medium in the refrigerator.
In such apparatus as applied to ice making the refrigerator has been made
separate from the vessels (hereinafter called the ice tanks) containing the moveable
moulds in which the ice is to be formed, or is placed in a distinct and separate
compartment of this tank, in either case the circulation of the brine or uncon-
gealable fluid being effected by means of a pump or other device which causes it
to flow through pipes or openings into the ice tank, around the moulds, and back
to the refrigerator where the acquired heat is abstracted and the fluid returned
again to the ice tank, the operation being continuous. In such an arrangement
not only is considerable power absorbed in working the pump or other device, but
heating of the brine is caused by friction in passages and by conduction so reducing
the production of ice-Moreover considerable space is occupied.
Now according to my invention, a combined refrigerator and ice tank is
employed in which the moulds are arranged between coils or pipes through
which the vapourized freezing medium is caused to circulate, the moulds and the
coils or pipes being arranged within the tank, which is charged with brine or
uncongealable fluid that surrounds the coils or pipes and the moulds, but is not
073

page_text: mechanically circulated in the tank. The heat is therefor abstracted directly from
the moulds by the freezing medium within the adjacent coils or pipes, the brine
merely serving as a conductor between the two surfaces.
Condensers for condensing liquified gases have been made with a single
rectangular or circular tank having therein rows or coils of pipes in which the
gases have been condensed, the cooling water merely entering at the bottom and
escaping by an overflow at the top.
In order to economise water and reduce the pressure at which liquifaction occurs
at any given initial, temperature of cooling water, it is necessary that the water
should be kept a long time in contact with the cooling surfaces, travelling all the
time in an opposite direction to the gas or vapour so that the cold water entering,
shall meet the liquified freezing medium and reduce it to the lowest possible
temperature. To attain this end in a very simple manner according to my
invention, I use a condenser of peculiar construction according to which, coils
or zigzag pipes each of great length are arranged within a rectangular tank that
is provided also with a series of partial divisions or shelves proceeding alternately
from the opposite ends of the tank, the arrangement being such that the vapour or
gas to be condensed travels in a zigzag course downward, whilst the cooling fluid
ascends, also in a zigzag course, so that a large area of cooling surface is provided
and the cooling fluid is kept in contact with the outer surface of the pipe in which
the vapour or gas is travelling in an opposite direction.
Such an arrangement may be applied in the construction of a refrigerator for
cooling water or other fluid, the liquid refrigerating medium entering the coils or
zigzag pipes at the bottom, the vapour being drawn off by the pump at the top,
while the water or fluid to be cooled enters at the top of the tank, and after
travelling along the whole length of each coil or zigzag pipe is drawn off at the
bottom In this way great efficiency is obtained and by employing a suitable
uncongealable fluid its temperature may be reduced almost as low as that due to
the pressure at which the evaporation of the liquid refrigerating medium occurs.
The containing vessel may be made water-tight to admit of circulation under
pressure of the fluid surrounding the pipes or coils.
In compressing a condensable gas or vapour of the kind hereinabove mentioned
to the high pressure necessary to cause the same to take a liquid form at ordinary
temperatures, there is considerable loss of effect due to the clearance spaces of the
pumps and of power due to the friction through the valves and passages which in
ordinary constructions, are kept down in size to admit of placing the suction and
delivery valves both in the pump cylinder cover.
According to my invention, I use a pump of the class in which compression is
effected at one side only of the piston, the other side being exposed merely to the
comparatively low pressure at which the vapour is drawn in from the refrigerator
Bo as to relieve the gland from the much higher pressures that obtain during and
after compression. The suction valve is placed concentrically within the piston
and the delivery valve is arranged within the cylinder cover. In this way a
longer stroke and consequent reduction in clearance can be obtained, and. at the
same time, valves of large area may be advantageously employed.

page_text: COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Refrigerating or
Producing Ice.
I, THOMAS BELL LIGHTFOOT, of N° 35 Queen Victoria Street, in the City of
London, Consulting Engineer, 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 has reference to machinery or apparatus of the kind in which
the temperature of a fluid or body to be frozen or cooled is reduced by means of
the evaporation of a liquid of low boiling point, such as anhydrous ammonia, which
after evaporation is subsequently condensed into the liquid form by the combined
action of pressure and cold in order that it may be again evaporated and utilized
for the abstraction of heat, the complete series of operations being carried out in
a closed cycle. Such a machine for cooling comprises, inter alia, evaporating
apparatus, (commonly called the refrigerator), a condenser, and a pump whereby
the vaporized refrigerating medium is compressed and delivered into the condenser,
while for the production of ice it is usual to have in addition, a tank or series of
tanks or vessels containing moulds in which the water to be frozen is placed, and
which are surrounded by brine or other uncongealable fluid previously cooled by
the evaporation of the refrigerating medium in the refrigerator.
In such apparatus as applied to ice making the refrigerator has been made
separate from the vessels (hereinafter called the ice tanks) containing the moveable
moulds in which the ice is to be formed, or is placed in a distinct and separate
compartment of this tank, in either case the circulation of the brine or uncongeal-
able fluid being effected by means of a pump or other device which causes it to
flow through pipes or openings into the ice tank, around the moulds, and back to
the refrigerator where the acquired heat is abstracted and the fluid returned again
to the ice tank the operation being continuous.
.
In such an arrangement not only is considerable power absorbed in working the
pump or other device, but heating of the brine is caused by friction in passages
and by conduction so reducing the production of ice. Moreover considerable space
is occupied.
Now according to my invention, a combined refrigerator and ice tank is
employed in which the moulds are arranged between coils or pipes through which
the vaporized freezing medium is caused to circulate, the moulds and the coils or
pipes being arranged within the tank, which is charged with brine or uncongealable
fluid that surrounds the coils or pipes and the moulds, but is not mechanically
circulated in the tank. The heat is therefore abstracted directly from the moulds
by the freezing medium within the adjacent coils or pipes, the brine merely
serving as a conductor between the two surfaces.
Fig. 1 of the drawings is a vertical section and Fig. 2 a plan partly in section
of a combined refrigerator and ice tank according to my invention. 1 is a
rectangular tank; 2.2. are moulds supported therein by cross-bars 3; 4.4 are coils
or pipes through which vapourised freezing medium is caused to, circulate. The

page_text: tank is charged with brine or uncongealable fluid which surrounds the coils or
pipes and the moulds, but, as already stated, is not mechanically circulated in the
tank.
Condensers for condensing liquified gases have been made with a single
rectangular or circular tank having therein rows or coils of pipes in which
the gases have been condensed, the cooling water merely entering at the bottom
and escaping by an overflow at the top. In order to economise water and reduce
the pressure at which liquefaction occurs at any given initial temperature of
cooling water, it is necessary that the water should be kept a long time in contact
with the cooling surfaces, travelling all the time in an opposite direction to the
gas or vapour so that the cold water entering shall meet the liquified freezing
medium and reduce it to the lowest possible temperature. To attain this end in a
very simple manner according to my invention I use a condenser of peculiar
construction according to which, coils or zigzag pipes each of great length are
arranged within a rectangular tank that is provided also with a series of partial
divisions or shelves proceeding alternately from the opposite ends of the tank, the
arrangement being such that the vapour or gas to be condensed travels in a zigzag
course downward, whilst the cooling fluid ascends also in a zigzag course, so that
a large area of cooling surface is provided and the cooling fluid is kept in contact
with the outer surface of the pipe in which the vapour or gas is travelling in an
opposite direction.
Such an arrangement may be applied in the construction of a refrigerator for
cooling water or other fluid, the liquid refrigerating medium entering the coils or
zigzag pipes at the bottom, the vapour being drawn off by the pump at the top,
while the water or fluid to be cooled. enters at the top of the tank and after
travelling along the whole length of each coil or zigzag pipe is drawn off at the
bottom.
In this way great efficiency is obtained and by employing a suitable uncongeal-
able fluid its temperature may be reduced almost as low as that due to the pressure
at which the evaporation of the liquid refrigerating medium occurs.
The containing vessel may be made watertight to admit of circulation under
pressure of the fluid surrounding the pipes or coils.
Figure 3 of the drawings is a vertical section and Fig. 4 a plan partly in section
of a condenser according to my invention. 5 is a rectangular tank. 6.6. are
partial divisions or shelves proceeding alternately from the opposite ends of the
tank so as to produce a zigzag passage 7. 8.8 are coils or zigzag pipes, each of
great length arranged within the zigzag passage 7 in the tank.
The cooling fluid is caused to circulate upward through the zigzag passage 7 in
contact with the outer surfaces of the pipes 8 in which the vapour or gas to he
condensed travels downward. 9 is the inlet for cooling fluid and 10 the outlet.
When using such an arrangement as a refrigerator for water or other fluid, the
water or fluid to be cooled enters by 10 descends by the passage 7 and the
refrigerating medium enters at the bottom and ascends in the pipes 8.
In compressing a condensable gas or vapour of the kind hereinabove mentioned
to the high pressure necessary to cause the same to take a liquid form at ordinary
temperatures there is considerable loss of effect due to the clearance spaces of the
pumps and of power due to the friction through the valves and passages which in
ordinary constructions are kept down in size to admit of placing the suction and
delivery valves both in the pump cylinder cover.
According to my invention I use a pump of the class in which compression is
effected at one side only. of the piston, the other side being exposed merely to the
comparatively low pressure at which the vapour is drawn in from the refrigerator
so as to relieve the gland from the much higher pressures that obtain during and
after compression. The suction valve is placed concentrically within the piston
and the delivery valve is arranged within the cylinder cover.
In this way a
longer stroke and consequent reduction in clearance can be obtained, and at the

page_text: same time valves of large area may be advantageously employed so as to produce
great efficiency with a high speed of working.
Fig. 5 shows in vertical section a pump according to my invention and Fig. 6 is
a cross-section in line a. b. 11 is the pump cylinder; 12 is the delivery chamber;
13 the delivery valve kept normally against its seat by the action of a spring 14.
Within the cylinder works a hollow piston 15 provided with suitable packing
rings 16. The cavity or chamber within this piston communicates with the lower
end of the cylinder 11 by a series of holes one of which is shown and numbered 17
and with the upper end of the cylinder by the suction valve 18 the gases passing
through holes formed in the seating as shewn at 17. The suction valve is kept.
normally against its seat in the upper end of the piston by the action of a spring 19.
The piston rod 20 works through the stuffing box 21, a cavity 22 being provided
for containing lubricant.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I hereby declare
that what I claim in machinery or apparatus for refrigerating or producing ice, is:―
. A combined refrigerator and ice tank in which moulds are arranged between
coils or pipes through which vapourized freezing medium is caused to circulate,
the said moulds and pipes being surrounded by brine or uncongealable fluid (not
mechanically circulated) substantially as described.
2. A condenser comprising coils or zigzag pipes arranged within a zigzag passage
or passages formed in a tank or vessel, the arrangement being such that vapour or
gas to be condensed travels in a zigzag course in one direction whilst cooling fluid
travels in the contrary direction also in a zigzag course and in contact with the
outer surfaces of the pipes in which the vapour or gas is travelling in an opposite
direction as described with reference to and illustrated in Figs. 3 and 4 of the
drawings annexed.
3. A refrigerator comprising coils or zigzag pipes arranged within a zigzag
passage or passages formed in a tank or vessel the arrangement being such that
the refrigerating medium enters the coils or zigzag pipes at the bottom the vapour
being drawn off by the pump at the top while the water or fluid to be cooled
enters at the top of the tank and after travelling along the whole length of each
coil or zigzag pipe is drawn off at the bottom as described.
4. A pump for compressing condensable gas or vapour in which compression is
effected at one side only of the piston, the other side being exposed merely to the
pressure of. the vapour as drawn in from the refrigerator, the suction valve being
placed concentrically within the piston and the delivery valve within the cylinder
cover substantially as described.