An Improved Method or Process for the Preservation and Storage of Perishable Organic Substances by Cold.
Year: 1895

page_text: Date of Application, 24th Sept
1805
Complete Specification Left, 21st Dec., 1895-4ccepted, 25th Jan.,
1896
Complete Specification Left, 21st Dec., 1895-4ccepted, 25th Jan., 1896
PROVISIONAL SPECIFICATION.
An Improved Method or Process for the Preservation and Storage
of Perishable Organic Substances by Cold.
I, JOHN DAVY POSTLE, of Elizabeth Street, Sydney, New South Wales,
Civil Engineer, do hereby declare the nature of this invention to be as
ollows:-
.
The present invention of an improved method or process for the preservation and
storage for lengthened periods, of meat and other perishable, comestible and other
organic substances by the agency of cold has been devised with the object of
combining the advantages now obtainable in the freezing and the chilling processes
whilst eliminating the chief disadvantages which are found to arise from the use of
these said processes. The invention has been specially devised with a view to the
effective preservation and storage of fresh meat within a minimum space, as on
shipboard, and it is of most utility where the individual bodies to be acted upon are
of maximum size. The following description refers to the process and apparatus
employed in the preservation and storage of meat, but its application to other goods
will be self-evident.
In the carrying into practice of my said method or process the employment of
certain apparatus of simple construction is necessary; and as its nature lends itself
readily to the use of apparatus differing substantially in form, I would have
it understood that I do not restrict myself to any specific structure or combination
of parts and claim the right of adopting any design of apparatus on the principle
herein broadly described whereby the several operations and effects set forth may
be carried out and obtained.
It is known that chilled meat will keep in fair condition for a limited time, but
as chilling leaves the meat in a comparatively soft state it is not possible to stow
it to advantage in a ship's hold owing to its being liable to crushing and bruising
from the weight of superimposed carcasses: whence the necessity for hanging it
and thereby using up considerably more space than would be requisite were it
stowed as is frozen meat. The increased cost of freight and expense of fittings
together with similar expenses for storage on shore is found to be nearly if not
quite as much as the increased price obtained for the meat, and hence the producer
reaps little or no benefit; and, as the time during which chilled meat will keep
sweet is limited, it is impracticable to use the chilling process if there is risk of
the meat having to be stored for any extended period either before or after
shipment.
The objects at which I aim are to protect the surfaces of chilled carcasses and at
the same time to make the carcasses capable of being stowed in the same manner
As ordinary frozen meat. The advantages due to chilling and freezing are thus
Ittained whilst the corresponding disadvantages arising where either of the processes
is used separately are eliminated.
The initial expense of treating meat by my invention is greater than the cost of
chilling though substantially less than the cost of freezing, and it involves
comparatively small expense in thawing as its temperature can be brought down
much more readily and consequently at less expense of time and money than can
the temperature of frozen meat.
In carrying out my invention I first bring down the temperature of the meat

page_text: to 32° Fahr.; not so as to freeze it, but only to bring it into the condition known
as "chilled."
At the next step which may be a continuation of the first, I treat the chilled
meat by exposing it to a freezing temperature whereby the latent heat is abstracted
from the water of the meat, causing a corresponding freezing and hardening of the
ment; and I continue this treatment until the surface of the meat is frozen
to a depth of preferably one-half-inch to an inch-and-a-half, depending upon the
mass of the carcass, it being preferable to freeze large bodies to a greater depth
than small ones. In this state the meat is in a suitable condition for storage
or transport, for which purpose it is stowed like, frozen meat (in some cases the
carcasses being preferably stowed on end and not on side) in a chamber or interior
whose walls are perforated so as to admit of free passage and perfect distribution of
air into, through, and out of it.
This chamber or interior is enclosed on two or four opposite sides but preferably
on all sides, by outer walls forming, as it were, another chamber or exterior room
which is close and well insulated, and between the walls, floor, and ceiling of the two
chambers or rooms there is an air space of sufficient capacity to allow of free passage
of the air serving the interior chamber. In the intermural space partitions are placed
in such a manner as to cause the whole body of air to pass into and circulate through
the interior chamber; in a port in one of these partitions an air fan works and
maintains a liberal air circulation and a consequent isothermal condition at all
places. within the inner chamber. In an alternative arrangement the interior
chamber is completely closed and completely enclosed on all sides by outer walls,
which constitute an outer room, air at a regulated temperature being circulated
through the intermural space, (but not through the interior chamber), in order to
maintain the temperature of the interior chamber at the required point...
The perforated and closed interior chambers may be made convertible by the
employment of dampers or shutters adapted to close the perforations and thus
convert the perforated chamber into a close chamber or vice versa.
The object to be aimed at is to maintain such an uniform temperature in the
interior chamber as will prevent thawing but not effect any considerable additional
freezing. Now it is evident that the quantity of heat which infiltrates must be
abstracted, and this abstraction of heat I effect automatically by providing a
refrigerating coil or its equivalent in a by chamber which may be formed in the
intermural space or inay be connected therewith by air ducts. The entrance duct
to this coil chamber is controlled by a damper or shutter which is so arranged as
when, in one position to shut off the coil chamber from the intermural space and so
prevent the circulating air from meeting the coil in its passage back to the fan, and
when in the other position to block the iutermural space and shunt the circulating
air through, the coil chamber and in contact with the coil, whereby heat will be
abstracted from it and its temperature lowered. The damper or shutter is operated
by any suitable mechanical or electrical mechanism controlled by a thermostat
acted, upon by the air which has just finished its course through the interior
chamber. The damper or shutter is thus made to respond to the variations of
temperature in the interior, directing the air to be cooled when the temperature has
risen above the predetermined critical point at which the thermostat is regulated to
In this way a practically uniform temperature at any required point always
maintained, and if this temperature be predetermined accurately the meat will be
maintained for an indefinite period in substantially the same condition as at the
beginning of the time of storage.
act.
Means or mechanism should be provided for periodically opening or closing
a, by-pass to the external atmosphere, by preference automatically by aid of a
connection to the fan, spindle.or some other moving part, in order that a portion of
the vitiated air may if required be expelled and its place taken by fresh atmospheric
air at any required, temperature..
Variations in the temperature of the air in the interior chamber may be made
from time to time by introducing fresh air (either above or below external

page_text: temperature) at a temperature and in a quantity calculated to bring about the
required change; provision being made for discharging a corresponding portion of
air from the interior at the same time.
The system or process of controlling the temperature of the air contained in
a chamber and maintaining it at a predetermined point, and the apparatus therefor
described, may be used in any other system or process of storage or preservation
wherein is required an uniform temperature with or without ventilation.
Deted this 94th day of September 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
An Improved Method or Process for the Preservation and Storage
of Perishable Organic Substances by Cold.
1, JOHN DAVY POSTLE, of Elizabeth Street Sydney, in the Colony of New
South Wales, Civil 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 :-
The present invention of an improved method or process for the preservation
and storage for lengthened periods of meat and other perishable comestible and
other organic substances by the agency of cold has been devised with the object of
combining the advantages now obtainable in the freezing and the chilling processos
whilst eliminating the chief disadvantages which are found to arise from the use of
the said processes. The invention has been specially devised with a view to the
effective preservation and storage of fresh meat within a minimum space, as on
shipboard, and it is of most utility where the individual bodies to be acted upon
are of maximum size. The following description refers to the process and
apparatus employed in the preservation and storage of meat, but its application to
other goods will be self-evident.
In the carrying into practice of my said method or process the employment of
certain apparatus of simple construction is necessary, and as its nature lends itself
readily to the use of apparatus differing substantially in form, I would have it
understood that I do not restrict myself to any specific structure or combination of
parts and claim the right of adopting any design of apparatus on. the principle
herein broadly described whereby the several operations and effects set forth may
be carried out and obtained.
It is known that chilled meat will keep in fair condition for a limited time but
as chilling leaves the meat in a comparatively soft state it is not possible to stow it
to advantage in a ship's hold owing to its being liable to crushing and bruising
from the weight of superimposed carcasses; whence the necessity for hanging it
and thereby using up considerably more space than would be requisite were it
stowed as is frozen meat. The increased cost of freight and expense of fittings
together with similar expenses for storage on shore is found to be nearly if not
quite as much as the increased price obtained for the meat and hence the producer
reaps little or no benefit; and as the time during which chilled meat will keep
sweet is limited it is impracticable to use the chilling process if there is risk of the
meat having to be stored for any extended period either before or after shipment.
The objects at which I aim are to protect the surfaces of chilled carcasses and
at the same time make the carcasses capable of being stowed in the same manner
as ordinary frozen meat. The advantages due to chilling and freezing are thus
attained whilst the corresponding disadvantages arising where either of the
processes is used separately are eliminated.
The initial expense of treating meat by my invention is greater than the cost of

page_text: chilling but substantially less than the cost of freezing, and it involves com-
paratively small expense in thawing as its temperature can be brought down much
more readily and consequently at less expense of time and money than can the
temperature of frozen meat.
In carrying out my invention I first bring down the temperature of the meat
to 32 Fahr., not so as to freeze it, but only to bring it into the condition known
as "chilled."
At the next step which may be a continuation of the first-I treat the chilled
meat by exposing it to a freezing temperature whereby the latent heat is extracted
from the water, of the meat causing a corresponding freezing and hardening of the
meat, by reason of the congelation of the water particles contained therein; I
continue this treatment until the surface of the meat is "frozen " to a depth of
say one-half inch to an inch-and-a-half, depending upon the mass of the carcass, it
being desirable to freeze large bodies to a greater depth than small ones. In this
state the meat is in a suitable condition for storage or transport, for which purpose
it is stowed like frozen meat (in some cases the carcasses being preferably stowed
on end and not on side) in a chamber or interior whose walls are perforated so as
to admit of free passage and perfect distribution of air into, through, and out of it.
This chamber or interior is enclosed on two or four opposite sides but preferably
on all sides by outer walls forming as it were another chamber or exterior room
which is close and well insulated, and between the walls, floor and ceiling of the
two chambers or rooms there is a space of sufficient capacity to allow of free
passage of the air serving the interior chamber. In the intermural space partitions
are placed in such a manner as to cause the whole body of air to pass into and
circulate through the interior chamber. In a port in one of these partitions an air
fan works and maintains a liberal air circulation and a consequent isothermal
condition at all places within the interior chamber. In an alternative arrangement
the interior chamber is completely closed and completely enclosed on all sides by
outer walls, which constitute an outer room, and air at a regulated temperature is
circulated through the intermural space, (but not through the interior chamber) to
maintain the temperature of the interior chamber at the required point.
The perforated and closed interior chambers may be made convertible by the
employment of dampers or shutters adapted to close the perforations and thus
convert the perforated chamber into a close interior chamber or vice versa.
The object to be aimed at is to maintain such an uniform temperature in the
interior chamber as will prevent thawing but not effect any considerable additional
freezing. Now it is evident that the quantity of heat which infiltrates must be
abstracted, and this abstraction of heat I effect automatically by providing
apparatus housed in a by-chamber which may be formed in the intermural space or
may be connected therewith by air ducts. The entrance duct to this coil chamber
is controlled by a damper or shutter which is so arranged as when in one position
to shut off the coil chamber from the intermural space and so prevent the air
circulating from meeting the coil in the passage back to the fan, and when in the
other position to block the intermural space and shunt the circulating air through
the coil chamber and in contact with the coil whereby beat will be abstracted from
it and its temperature lowered. The damper or shutter is operated by any suitable
mechanical or electrical mechanism controlled by a thermostat acted upon by the
air which has just finished its course through the interior chamber. The damper
or shutter is thus made to respond to the variations of temperature in the interior,
directing the air to the coil chamber there to be cooled when the temperature has
risen above the predetermined critical point at which the thermostat is regulated
to act. In this way a practically uniform temperature at any required point is
always maintained, and if this temperature be predetermined accurately the meat
will be maintained for an indefinite period in substantially the same condition as
at the beginning of the storage.
During circulation means may in some cases be provided for sterilizing and
drying the air to arrest surface fungoid growths on the meat.

page_text: Means or mechanism should be provided for periodically opening and closing
a by-pass to the external atmosphere, by preference automatically by aid of a
connection to the fan spindle or some other moving part, in order that a portion of
the vitiated air may if required be expelled and its place taken by fresh atmo-
spheric air at any desired temperature.
Variations in the temperature of the air in the interior chamber may be made
from time to time by introducing fresh air (either above or below external
temperature) at a temperature and in a quantity calculated to bring about the
required change in the air in the said interior chamber by admixture with it;
provision is made for discharging a corresponding portion of the air from the
interior at the same time as the new air is admitted.
The system or process of controlling the temperature of the air contained in a
chamber and maintaining it at a predetermined point and the apparatus therefor
described may be used in any other system or process of storage or preservation
wherein is required an uniform temperature with or without ventilation.
Referring to the annexed sheet of explanatory drawings Fig. 1 is a longitudinal
section through a cold storage or preserving chamber as used in carrying out my
invention. Fig. 2 a transverse vertical section through the same.
A is the "iuterior" in which the meat is stowed; it is a chamber or room with
uninsulated walls B pierced as shewn by numerous holes or draft vents V on all
sides. It is completely enclosed by insulated walls C forming an external shell;
these walls C are not pierced except by one doorway. In the intermural space D
partitions E are placed they are arranged on any plan which will prevent the air
delivered by the fan F from reaching the fan again without passing on its way to
it through the interior vessel, in which latter the distribution of air should be as
complete as practicable.
T'he
The apparatus operating in conjunction with the circulating arrangements last
described, for maintaining an isothermal state at all places within the outer walls,
consists of a coil through which a refrigerant is caused to circulate, a thermostat,
and an automatic damper movement thrown into action by the thermostat.
refrigerating coil, for which there may be substituted any known efficient meaus or
mechanism for reducing the temperature of air is. placed in such a position that
the damper can direct to it the whole or shunt to it a portion of the air current
after it (the air current) has left the interior chamber and before it reaches the
fan. The most convenient position is in the intermural space which at one place is
formed to receive it as shewn in Fig. 1. In contiguity to it the bulb G or
equivalent part of the thermostat is placed so that the passing current of air will
impinge upon it and act upon the fluid contained in it, so that when the temperature
rises above a predetermined point the said fluid will expand and by its pressure or
increased volume operate or throw into gear a mechanical pneumatic or electrical
connection whereby the damper H will be moved so as to direct the air into the
chamber K in which the cooling of the air is effected; the thermostat must be of
such construction and so adjusted that when the predetermined critical thermometric
point below which the air must not be cooled has been attained, the damper
mechanism will, be caused to be reversed or permitted to reverse so as to direct the
air through the passage L to the fan aud prevent it from passing through the
chamber K.
Many known forms of thermostats can be used and hence the particular con-
struction of that portion of the apparatus need not be described; in practice I
prefer to use a thermostat provided with regulating mechanisin in order that by a
simple adjustment the point at which the damper connections are thrown into gear
may be varied.
In a mercury column electrical thermostat such an adjustinent is
effected by putting the contact point on the end of the screwed rod, by rotating
which in its carrier the height of the contact is altered, and correspondingly with
5. such alterution the degree of temperature at which the "make" and "break" in
the current occurs.
The draught vents V are, in cases where control is desirable provided with

page_text: sliding shutters or with dampers, or in lieu of them a lesser number of large
openings provided with louvres are used. These shutters, dampers, or louvres are
connected, and rods for operating them are passed through stuffing boxes in the
walls C so as to be under control externally.
The meat having been chilled and then surface frozen as before described is
placed in an interior chamber whose temperature and ventilation is completely
under control, preferably under automatic control. The thermostat is set to
maintain such a temperature of the circulating air as will prevent thawing, but not
necessarily produce any further freezing. If the adjustments are carefully made,
the condition of the meat will remain fairly constant; that is to say the freezing
will not penetrate through the carcass, because the change of state of the chilled
portion would necessitate the abstraction of a considerable amount of latent heat,
to do which work the temperature of the ambient air is insufficient, though it is
sufficient to prevent thawing of the part originally frozen.
In some or all cases it may appear desirable to withdraw periodically a small
portion of the air and substitute new refrigerated air (sterilized if required) for it.
This can be done automatically by providing two air doors, one on the near side
and one on the far side of one of the partitions E, and connecting these doors by
any periodically moving part such as the mechanism operating the damper H, or
with periodical action mechanism for receiving its initial motion from a constantly
moving part such as the fan spindle. Upon the coincident opening of these air
doors, the slight excess of pressure of air on the near side of the partition E will
cause the expulsion of a volume of air depending on the size of the door and the
time for which it remains open, whilst the slight vacuum on the far side of the
partition E will induce a corresponding indraught of new air and make good
:the deficiency.
Where there are intermural spaces only on two opposite sides of the interior
chamber they must be connected by an air trunk.
It may be necessary to occasionally expose the chilled and surface frozen meat
to the external atmosphere during its removal from the cold rooms on shore to the
ship's hold, and vice versa, when the external temperature is above the freezing
point. In this case it may, perhaps, be sometimes found desirable to subject the
surface of the meat to a sharp short chill, sufficient to bring down its temperature
to about 15 degrees Fahr. below freezing point. Care however must be exercised
'not to expose it to this temperature long enough to permit of the material
thickening of the frozen surface, the object merely being to extract from the
'surface of the meat of about as much beat as is likely to be imparted to it during
such removal.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is,―
1. A process for the preservation and storage of perishable organic substances
"by cold consisting essentially in chilling said substances and subsequently surface
freezing them, and then confiuing them in a chamber whose temperature is
maintained constant or approximately so at a point which will not effect further
freezing but which is sufficiently low to prevent the thawing of the initial freezing,
substantially as described.
2. A process for the purposes described wherein the goods are chilled
interiorly and frozen exteriorly and maintained in that condition, substantially
.as described.
3. In a process for the purposes described wherein it is required to store cold
treated goods in an air current having an approximately uniform temperature, a
storeroom means for circulating air therethrough, means for cooling the air, and
mechanism operating or controlled by a thermostat for bringing the air current in
contact with the cooler when its temperature has risen above the critical point,
substantially as described.

page_text: 4. Freezing the surface of chilled meat to make it sufficiently rigid for stowing ·
like frozen meat without injury, substantially as described.
5. Freezing the exterior portion of bodies of chilled meat and storing the meat
so treated in a temperature capable of preventing thawing but incapable of freezing
the chilled portion of the meat, substantially as described.
6. Automatically maintaining an isothermal condition in a storeroom by circulating
through it a current of air which is directed through a cooling chamber by
mechanism operated by a thermostat, (which is sensitive to variations in the
temperature of the said current of air), when its temperature has fallen below a.
predetermined critical point, substantially as described.
Dated this 20th day of December 1895.
A. M. & WM. CLARK,
53 Chancery Lane, London, Chartered Patent Agents.