IMPROVEMENTS IN THE PRESERVATION OF FOOD, AND IN THE CONSTRUCTION AND REFRIGERATION OF ENCLOSED CHAMBERS TO BE USED FOR THIS AND OTHER PURPOSES
Year: 1873

page_text: LETTERS PATENT to James Harrison, of 52, Mornington Road, in
the County of Middlesex, for the Invention of "IMPROVEMENTS IN
THE PRESERVATION OF FOOD, AND IN THE CONSTRUCTION AND REFRIGERATION
OF ENCLOSED CHAMBERS TO BE USED FOR THIS AND OTHER PURPOSES.”
Sealed the 20th March 1874, and dated the 19th November 1873.
PROVISIONAL SPECIFICATION left by the said James Harrison at the
Office of the Commissioners of Patents, with his Petition, on the
19th November 1873.
I, JAMES HARRISON, of 52, Mornington Road, in the County of
Middlesex, do hereby declare the nature of the said Invention for "Im.
PROVEMENTS IN THE PRESERVATION OF FOOD, AND IN THE CONSTRUCTION AND
REFRIGERATION OF ENCLOSED CHAMBERS TO BE USED FOR THIS AND OTHER PURPOSES,"
to be as follows:-
This Invention relates mainly to improvements in apparatus and
processes for economically applying ice and freezing mixtures to the
preservation of perishable animal and vegetable substances, and to the
cooling of enclosed spaces in which they are kept, handled, or carried,

page_text: The improvements are based upon rules not hitherto known for
ascertaining the line of mean temperature in the imperfectly conducting
envelope of the refrigerating or preserving chamber, and in the
regulation of currents of cooled air and liquids, so as to produce the
required effect without unnecessary waste. These rules are based on
the relative extent of the outer heat absorbing and inner cold surfaces,
the line of mean temperature being nearer the latter than the former
and bending inwards at the corners when the figure enclosed is other
than a sphere. To counteract this tendency the envelope is made of the
most efficient heat-resisting material, such as wool, hair, or charcoal, at
the points where the line of mean temperature approaches the interior
surface, while sawdust, straw, bark, or other inferior protector suffices
e
12

page_text: The improvements further consist in the modes of cooling, desiccating,
and purifying air, and regulating its flow in interspaces surrounding the
chamber and among the articles placed therein.
The air of the chamber is manipulated over and over again so that
the ventilation involves no accession of heat. The air is first passed
through a vessel containing ice and salt, or crystallized chloride of
calcium, or other deliquescent salt and water, and then through an inner
compartment where it is brought in contact with dry chloride of
calcium or strong sulphuric acid. The air thus cooled and desiccated
passes downward through and among the articles to be preserved and
returns by the interspace surrounding the chamber. The air on its
return is passed through a loose plug of cotton wool, one layer of which
is impregnated with sublimed sulphur, or through a chamber containing
any of the known inoderous disinfectants. The motion of the air by
this arrangement is automatic, but when it is requisite that its speed
should be accelerated, or when it is desirable to reverse the current so
that it shall first pass round the interspace surrounding the chamber, a
fan or other blast is employed, the necessity for the use of which will be
indicated by the temperature of the returned air.
An arrangement is also provided whereby sulphurous anhydride and
carbonic dioxide, obtained from the incineration of sawdust or sugar by
strong sulphuric acid, are mingled with the air prior to passing through
the refrigerator and desiccator.
When the chamber to be cooled is a fixture on land and is only partly
filled with the articles to be refrigerated the tube and interspaces in
which cold brine and air circulate are dispensed with, the brine is caused
to flow down the naked wall, and the air to circulate freely in the
chamber.
When it is requisite that the air of the room should be changed this
is effected by providing two or more passages filled with scrap iron or
other good heat absorber, the used cold air and the entering warm air
being conveyed through them alternately, so that the outgoing air cools
one passage while the incoming air is cooled in another.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Harrison in the Great Seal Patent Office on
the 19th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HARRISON, of 52, Mornington Road, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said James Harrison, Her special
licence that I, the said James Harrison, my executors, administrators,
and assigns, or such others as I, the said James Harrison, my executors,
administrators, and assigns, should at any time agree with and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, exercise, use, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE PRESERVATION OF FOOD, AND IN THE CONSTRUCTION AND REFRIGERATION OF
ENCLOSED CHAMBERS TO BE USED FOR THIS AND OTHER PURPOSES," upon the
condition (amongst others) that I, the said James Harrison, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Harrison, do hereby declare
the nature of my said 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 improvements in the apparatus and processes
for economically applying ice and freezing mixtures to the preservation.
of perishable, animal, and vegetable substances, and to the cooling of
enclosed spaces wherein they are kept, handled, or carried.

page_text: Heretofore it has been the practice to surround such spaces with a
protecting envelope of sawdust, charcoal, or other bad conductor of
heat, such envelope being of equal thickness and quality throughout,
and fitted without due regard to the relation of the thickness and quality
to the amount of protection required. The rules laid down in the text
books on the conduction of heat are based on the experiments with
plates having parallel surfaces and of practically unlimited area; but in
practically dealing with enclosed spaces I have ascertained by experi-
ment that there is an inequality in the conduction due to the shape of
the enclosure and to the fact that owing to the external radiating surface
of the envelope being greater than the internal surface, and to the dis-
proportion of these surfaces increasing with the thickness of the
envelopes, the quantity of heat which passes in an unit of time through
a unit of thickness is not uniform throughout the mass of the
envelope.
In the case of circles or cross sections of cylinders, as in Figures 1 and
2, the relative heat protecting efficacy of the envelopes cannot be inferred
from their thickness, but from the distance of the dotted line a or line
of mean temperature from the inner surface. The distances of this line
from the inner and outer surfaces are approximately in proportion to the
circumferences of the inner and outer circle. Where the enclosure is a
square or section of a parallelogram, as in Figure 3, the same proportions
between the inner and outer surfaces and the line of mean temperature
exists, but the mean line at a³ is nearly halfway between the inner and
outer surface, while at all it approaches nearer the inner surface than in
a corresponding circle.
The object to be kept in view in surrounding a cold chamber with a
protecting envelope is to make it equally invulnerable in all its parts to
the external heat, and this is attained by so arranging the material as to
thickness and quality that the line of mean temperature shall be as
nearly as possible equidistant from the interior surface of the walls of
the chamber. I therefore either make the enclosed chamber approxi-
mate to the spherical form by rounding off the interior corners, or when
it is requisite to preserve a square or angular interior I employ a better
non-conducting material, such as wool, hair, or charcoal, at the corners
as at c, than at the sides where sawdust, bark, or straw will suffice, thus
securing economy of material and space, but I do not claim the exclusive
use of any particular non-conducting material,

page_text: I maintain the cold of such an enclosed chamber by the circulation
round the sides and bottom of streams of brine, resulting from a mixture
of ice and salt or of deliquescent salts and water. The production of
cold by such mixtures is already well known. My improvements consist
in regulating the temperature of such mixtures so as to produce a steady
and uniform result at any required temperature.
For some purposes the water from melting ice without an admixture
of salt will suffice, but it is always desirable to have the temperature
under control to a lower point than that theoretically required.
To maintain a temperature at or below 32° F. I either mix salt with
the ice or pass over and through the ice a stream of salt and water.
The per centage of common salt which the brine should contain to
produce a given degree of cold is ascertainable on inspection of the
following table of the cold produced by solutions of various strengths :—
"
"
To produce these effects the brine must be of the specified strength
after its augmentation of bulk by the water from the melted ice. The
strength of brine before use must therefore be in excess by a variable
quantity proportioned to the temperature at which it is used, and conse-
quently to the quantity of ice which it is capable of melting. After
the lowest temperature due to the strength of the resulting brine is
reached the ice ceases to melt, and the remainder of the ice will remain
unmelted for so long a time as the ice alone would remain, the rate of
melting in either case being due to the difference in temperature between
the enclosed space and the external air, and to the thickness of the
envelope and its co-efficient of conductivity.
The rule for ascertaining the quantity of brine required to produce
any given effect is this:-Take the number of degrees which the brine
before mixture is above the temperature required, with this number
divide 140 the number of units of heat required to melt the ice, this will
give the number of gallons required to melt 10 lbs. of ice. The

page_text: cold brine of strength and temperature thus regulated is circulated
through pipes embedded in the imperfectly conducting envelope near the
inner surface, which pipes need not be closer together than the distance
of that surface from the line of mean temperature. After circulating
in the pipes the brine is pumped out and mixed with a further quantity of
salt sufficient to maintain its strength, and again passed among the ice.
The quantity in excess of that required to keep the pipes full is allowed
to flow away through a waste pipe embedded in the envelope.
When the cooling is to be produced by the solution of deliquescent
salts, water is supplied to them in the quantity required to produce the
requisite temperature, and the resulting brine is used over and over
again until it is saturated at the temperature of the salts, which are
from time to time added.
Another improved arrangement, which in the greater number of cir-
cumstances will be found preferable to pipes, consists in the employment
of a porus textile fabric to regulate the flow of brine or other cold
liquid between sheets of metal instead of carrying it through tubes.
In Figures 4 and 5, the former of which is a section and the latter a
plan, A, A, is the chamber wherein the perishable substances are stowed;
B¹, B, B, the vessels in which the brine is passed over and among the
ice, or the water, or weak solution over and among the deliquescent
salt; C, C, the compartment where the stock of ice or deliquescent salt
is kept; D, D, D, the protecting envelope of low conductivity; e, e,
sheets of metal forming the walls of the chamber A with a sheet of
textile fabric, such as coarse blanketing represented by the waved line
between the side plates. The textile fabric is connected with pipes Q, Q,
leading from the vessels B", B¹¹¹, in the way shewn in the enlarged
Figures 6 and 7, in the former of which it dips into the pipe through a
slit along the top, and acts as a syphon in drawing off the cold solution.
which descends slowly down the space between the two sheets of metal.
In Figure 7 the textile fabric is wrapped round the pipe which has
perforations in its upper half, and the contained liquid moistens the
fabric equally along its length. The solution in B' descends directly
to the space between the bottom plates, the object being to keep the
bottom at a temperature below rather than above the sides and top, so
that any vapor contained in the chamber A. shall be deposited on the
bottom.

page_text: :
The brine after circulating over the bottom and down the sides is with-
drawn through the pipes f, f, by pumps which are not shown in the
Drawing, and is conveyed from the pipes by lengths of hose which may
be directed into either of the vessels B at pleasure. g, g, are overflow
pipes which carry off the solution when its accumulation would cause
too much pressure on the metal plates. The surplus brine from the
mixture of ice and salt may be allowed to run to waste, but when deli-
quescent salt is employed it is desirable to keep the level of its solution
below the overflow by pumping and passing it as near its point of satu-
ration as possible into casks or a cistern, with a view to the subsequent
recovery of the salt by evaporation. For this purpose the compartment
C or a portion of it is made the recipent of the surplus solution to a
depth of a few inches, and the temperature of the compartment
regulated by the slow dissolution of the salt. The bottom of the
chamber A is covered a few inches deep with charcoal on which a per-
forated false bottom h, h, rests, while i, i, are waste pipes through which
any liquid which may leak into or be condensed in A flows off; j is a
man-hole through which the contents of A. are passed in or out.
The chamber constructed as described is more suitable for the storing
of perishable articles on shore than for the conveyance of such articles
on board ship.
Another form of refrigerating chamber, suitable as a fixture on shore,
or where perishable articles are handled or operated upon, is a
simplification of the preceding. The double plates are dispensed with,
and the cold solution, after descending to or beneath the floor
through B' or any equivalent vessel, is pumped up into a pipe Q, which
occupies the place of a cornice, and the cold solution flows down the
naked walls or down a sheet or surface of textile material k connected
with the pipes Q, as in Figures 6 or 7. The cold solution may also if
required be pumped over a false ceiling and thence flow down a sheet
of textile fabric on or near the walls, in which case the cornice pipes
will not be required. In Figure 8 the references are the same as in
4 and 5, but the tubes and pumping arrangements are not shewn,
no novelty in respect to them being claimed, and they may be con-
veniently arranged outside the building; the renewal of the air in such
a building with a minimum loss of the cold in the effluent air is
provided for by causing the outgoing air to traverse a channel or
passage filled with pieces of old iron or other good heat absorber, while

page_text: the incoming air traverses a similar passage. When the iron in one of
these passages has become cold the currents are reversed, the incoming
air being forced through the cold passage while the outgoing air is
gradually cooling the other. The currents are reversed or alternated
at discretion, the flow of the air being kept up by a fan and blast or
bellows and its direction regulated by dampers or valves placed in the
respective passages. The fan or bellows may be employed either to
exhaust or force the air through one of the passages, the reverse
current through the other resulting as a matter of course. The outlets
of these passages are close together, so that they may be regulated by
one set of dampers or valves; but they may be connected with any
part of the interior which is considered most desirable or convenient
for the introduction or withdrawal of the air.
In Figure 9 the bellows or fan is connected with the passage E, and
the direction of the air current is determined by the position of the
valves v, v.
When set, as in the Figure, the current will flow in
through F¹ and out through G³, G³; when the valves are in the position
shewn by the dotted lines the current will flow in through G' and out
through F¹, F. The pieces of iron or other heat absorber are loosely
packed in the passages F¹ and G¹. Where lightness of construction
is an object sheets of wire gauze may be employed as the absorber, but
the greater the mass of absortient the less frequently will the valves
require to be regulated and the course of the current changed.
My improvements further consist in a mode of cooling, desiccating,
and purifying air and regulating its flow in interspaces surrounding
the chamber and among the articles placed therein.
Fig. 10 represents a cross section of the hold of a ship fitted up with
the requisite arrangements.
Fig. 11 is a fore-and-aft section of the space occupied by the chamber
and its surroundings. The imperfectly conducting material is packed
between wooden ribs in the space D¹, D', which run down to and across
the bottom of the hold, and these ribs are lined on the inner face with
iron or wood. On this face there is fixed a latticework of battens
H, H, H, one set of battens being perpendicular and athwart ship, and
the other fore and aft; and this is covered with a lining of strong
canvas, which forms the walls of the chamber containing the perishable
articles. Where extra strength is required a lining of woven galvanized

page_text: wire is placed between the canvas and the latticework; I is a grating,
which runs fore and aft, below which there is no canvas covering, as
it is through this grating that the air passes from the chamber to the
latticed interspace between the chamber and the envelope; J, J, are
bulkheads, fitted similarly to the sides and bottom with ribs, lining,
latticework, and canvas; K is a vessel containing ice, through and
among which a brine of regulated strength is kept flowing, or
containing crystallised chloride of calcium or other deliquescent salt,
which is similarly subjected to the action of water or of weak solutions
of the salt. In this vessel the air withdrawn from and returned to the
lower hold is brought in contact with the dissolving ice or salt;
L represents a simple form of bellows, with flap valves v, v, and a
diaphragm Z of leather or india-rubber cloth on hoops, the rise and
fall of which alternately diminishes and enlarges the space on either
side, worked from the upper deck by either manual or steam power,
whereby the air is circulated in the direction shewn by the arrows.
The brine is circulated by pumps with pipes M, M, which draw it
out from the lower corners of K and discharges it through roses or
champignons in a shower over the ice or soluble salt at the opposite
uper corners. The ice or salt is fed in at intervals once or twice a
day, as may be required, through the opening r with a removeable cover s
on to the perforated false bottom t. The surplus brine when it reaches
the level of the pipe p¹ overflows through p² or p³, according to the tack
on which the ship is sailing. The waste brine pipe is led through the
protecting envelope to the most convenient outlet so that as little as
possible of the cold may be lost. If from ice and salt the brine is
allowed to run to waste, but if from a deliqusscent salt which it is
desirable to recover, it is conveyed to a tank or cask there to bo
stored.
The temperature of the deliquescent salt stored in C may be reduced
by allowing the waste solution to flow amongst it, in which case the
chamber C is to a certain extent converted into a waste solution tank as

page_text: oxide and the apparatus therefor, substantially as described in connection
with Figure 12 of the Drawings.
In witness whereof, I, the said James Harrison, have hereunto
set my hand and seal, this Eighteenth day of May, in the
year of our Lord, One thousand eight hundred and seventy-
four.
Witness,
T. MORGAN,
Secretary,
Inventors' Patent Right Ass"., Limited,
21, Cockspur Street,
S.W.
JAMES HARRISON. (L.S.)