IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PRESERVING ORGANIC SUBSTANCES BY GAS.
Year: 1881

page_text: LETTERS PATENT to Charles Francis Lawton, Arthur William Lawton, and
Albert Lindel Lawton, all of Rochester, Monroe County, and State of New
York, United States of America, Manufacturers, for an Invention of
"IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PRESERVING
ORGANIC SUBSTANCES BY GAS.".
COMPLETE SPECIFICATION filed by the said Charles Francis Lawton,
Arthur William Lawton, and Albert Lindel Lawton at the Office of the
Commissioners of Patents on the 23rd March 1881.
CHARLES FRANCIS LAWTON, ARTHUR WILLIAM LAWTON, and ALBERT LINDEL
LAWTON, all of Rochester, Monroe County, and State of New York, United States
of America, Manufacturers. IMPROVEMENTS IN THE METHOD OF AND APPARATUS
FOR PRESERVING ORGANIC SUBSTANCES BY GAS."
Our Invention relates to an improved method of and apparatus for preserving
fruit, meat, vegetables and other organic substances in a closed chamber, chambers,
or receptacles, by the use of mixed carbonic oxide and nitrogen gases, which are
forced into the said chamber or chambers, and there confined while the materials to
be preserved are retained therein. It is well known that no kind of animal or
microscopic life can exist in these gases when they are free from oxygen. They
are also odorless and tasteless, hence fruits and other perishable materials in contact
therewith retain their natural flavour, and will be preserved infinitely, provided
the gases are kept in close and constant contact therewith.
which
and
Our improved apparatus is illustrated in the accompanying Drawing, in
Figure 1 is an elevation partly in longitudinal section of the said apparatus ;
Figures 2 and 3 represent in horizontal and vertical section, portions of one
of the preserving chambers with certain pipes, hereinafter described, combined
therewith.

page_text: Figure 4 is a plan or top view of a temperature regulator or thermostat,
hereinafter described; and
Figure 5 is an end elevation partly in section of the same and devices in
connection therewith.
Figure 6 is a section of a portion of the said regulator;
Figure 7 is a vertical section on the line 1, 2, Figure 4.
Figures 2 to 7 are drawn to an enlarged scale.
and
In carrying our said Invention into practice, the gases are first generated and
purified in a suitable manner, and are then conveyed to a gas bolder,. which
consists of a water tank A and an inverted vessel B, similar to a gasometer for
storing ordinary illuminating gas. This vessel B however is partially balanced
by a cord a passing over pulleys and having a weight b attached to it, that is to
say, the said vessel has just sufficient access of weight to produce the proper
pressure of gas in the preserving chambers, and yet to yield by the reaction or
back pressure of the gas caused by its expansion or contraction, resulting from any
change of temperature in the preserving chambers and according to the variation of
the supply of such gas.
We in some cases use vessels in which to store the gas under considerable
pressure, as, for instance, for use on railway wagons or carriages, steamships, or
the like, for supplying the requisite quantity of gas for preserving purposes during
transit, thereby obviating the necessity of transporting the generating apparatus.
In this case the gas can be delivered from such vessels to the preserving chambers
on board at any desired pressure by regulating apparatus such as that now
commonly employed to regulate the pressure of illuminating gas under_similar
circumstances.
From the gas holder the gases are conveyed through a continuous induction
pipe C to the series of preserving chambers D, D, which are preferably sunk in the
ground to a sufficient depth to retain an even temperature; if desired however
these chambers may be located in buildings and covered, or surrounded with
suitable non heat conducting material. The pipe C passes longitudinally behind
the preserving chambers, and is connected with all of them by means of branch
pipes c, in which are cocks or other cut offs d. By this means all the chambers
may be filled with the gases, and each chamber may be opened to obtain access to
the contents after simply turning the cock to cut off the supply of gas and without
affecting the supply of the other chambers.
At other times and during the whole time of preserving the cocks are all kept
open, so that the gases flow into all the chambers and remain under constant or
sufficient pressure from the gasometer to ensure an automatic replacing of the
gases should they leak from the chambers.
A continuous eduction pipe O¹ similar to the pipe C, extends longitudinally
beneath the chambers and is connected with their bottoms by branches c¹, c³,
provided with cocks d', d'; the object of this pipe is to let off air from the chambers
while they are being filled with the gases.
Each of the chambers D.has an annular open groove or trough fat its top, which
trough is filled with water or other suitable material; in this trough rests the
vertical flange of a gas tight cover g, as shewn in Figure 1. This cover allows
access to the interior, and also serves as a gas tight packing or seal. When the
gas is turned or let on, the cover is packed or covered with straw, shavings, or
other light material, and if desired waterproof canvas or wood may be placed over
such material.-
In some cases it will be desirable to make the joint under the cover gas tight by
suitable packing or gaskets and to hold the cover firmly against the said gaskets or
packing. In some cases also the opening into the chamber will be preferably from
the side of the chamber instead of from the top, in which case the joint will neces-
sarily be made in the manner last above mentioned.
By the means above described the fruit or other substances in the preserving
chambers are kept in constant and close contact with the gases. These gases

page_text: entering the structure or body of the fruit permeate the same, and are retained
therein during the whole time of preserving. This process differs materially from
those in which fruit is subjected to the action of gas for a limited time, and is then
removed and exposed to the influence of the atmosphere. The light weight of the
inverted vessel of the gasometer allows the said vessel to adapt itself to any reaction
of the pressure of the gases in the preserving chambers caused by the varying
pressure of the atmosphere or otherwise.
We interpose in the supply pipe C at any convenient point the following
arrangement for equalizing the temperature of the gases, that is to say:-E, E¹,
are two cylinders, each having jacket spaces h, h, at opposite ends, and a series of
small tubes i, i, which connect the said jacket spaces. The induction end of the
supply pipe Centers one end of the cylinder E, and a branch k of the said pipe
enters the corresponding end of the cylinder E¹, which contains cold water. At
their other end the said two cylinders discharge their contents by pipes and l¹
into one and the same box shaped receptacle G. The space around the tubes i, i,
in the cylinder E is filled with warm water, so that the gas which passes through
this cylinder will be warmed. This water is heated by means of a circuit pipe m,
Figure 5, which extends from the bottom of the cylinder outward some distance,
then upward, and then back, and connects with the top of the cylinder. The
longitudinal portions of the pipe are enclosed in a non heat conducting
covering n, n, while the vertical portion of the pipe is enclosed in a funnel or
casing o, at the bottom of which is a furnace or heater, by which the water in the
pipe is heated: By this means a circuit of warm water is ensured. The said heater
is removed some distance from the cylinder to prevent the inflammable gas from
taking fire.
Upon the top of the cold water cylinder E' is a tank r, which partially envelops
the said cylinder, and into which cold water or ice is placed, which enters the body
of the cylinder through suitable holes, and surrounds the tubes of the same. The
warmer water from this cylinder escapes through a curved pipe s at the top of the
cylinder at one end, which pipe may be provided with a stop cock. The gases in
passing through these two cylinders will be correspondingly warmed or cooled. The
ends of the pipes 7, 7, which discharge the gases from the two cylinders into the
saine receptacle G, have at their top and within the said receptacle open cups t, t¹,
filled with oil, glycerine, or other material. Into these cups dip corresponding
inverted cups u, u³, which form valves and are attached to a rocking lever having
its fulcrum at j¹, Figure 6. When one valve is open to allow the escape of gas into
the receptacle the other is closed, and vice versa.
On the rear side of the receptacle G is a vertical tube or case H, with which the
receptacle communicates by a passage v³, and with the rear side of the case H the
eduction end of the pipe C connects, as shewn in Figures 4 and 7. In the case H
is an iron tube w suspended by a glass neck piece in the top of the case and filled
with mercury. In the top of this tube wis inserted a glass tube x having a small
bore; this tube communicates with the said iron tube w. In the glass tube rests
loosely a fine iron wire y attached at its upper end to a lever I pivoted at its centre
and provided at its outer end with a pointer Z, which moves over a graduated
scale a divided into degrees. The pivot of this lever is a set screw, by which the
lever may be tightened in any position to which the pointer is set on the scale.
Attached to the top of the wire y is one end of a flexible brass or copper wire 6³,
which is connected at its other end with one pole of a galvanic battery K. From
the opposite pole of this battery a wire c³ leads to one pole of an electro-magnet L,
and from the opposite pole of this magnet a wire d³ extends to the iron tube w, so
that the electric current may pass into the mercury contained therein. Beneath
this magnet is an armature L², to which is attached a crank f' on the end of the
shaft of the rocking lever v. At each charge of the magnet this armature will be
drawn up, thereby shifting the valves u, u¹, and at each break of the circuit the
said armature will fall shifting the said valves in the opposite direction. By this
means the change in the currents of the warm and cold gas, which enter from the

page_text: warm and cold cylinders if effected, and the result is that a uniform temperature of
the mingled gas is produced.
The closing and breaking of the electric circuit is produced by the rising and
falling of the quicksilver in the tubes w, x. When the mercury rises so as to touch
..the end of the wire y the circuit will be closed, and when it falls so as to leave the
said wire the circuit will be broken. The mercury is caused to rise and fall by the
difference in temperature of the gas which surrounds the iron tube w. By setting
the pointer Z higher or lower on the scale at the valve will be shifted at a
corresponding higher or lower temperature, and consequently the apparatus may be
set to admit the gas to the preserving chambers at any given temperature
desired.
As thus arranged the materials in the chambers are in contact with the gases at
quite an even temperature, and if desired may be kept under pressure and the
gases will permeate every part of the said materials. The gas holder being evenly
balanced as above described, produces an even pressure of the gases which a change
of temperature in the chambers or a change of barometric pressure outside would
cause to vary. The gas holder moreover adapts itself to the action of the gases
moving forward or backward, the said gas holder correspondingly rising and falling.
By the means above described a given temperature is substantially preserved in
the chambers.
It is not material at what degree of temperature the gas is kept as the fruit
will be preserved at any temperature; but it is quite essential that a uniform
temperature should be maintained as fluctuations cause shrinkage and disin-
tegration especially in soft fruits.
To ensure the maintainance of the purity of the preserving gas, we place in
suitable receptacles in the chambers wherein the gas and substances to be preserved
are kept, ferric protoxide, sulphites of lime, soda, or ammonia, and caustic lime, so
that the slowly circulating gas can come in contact therewith. In other small
receptacles placed in different parts of the same chambers we expose to the gases a
small quantity of sulphuric acid, which may be placed upon broken coke or
other material that will expose considerable surface.
The ferric protoxide and sulphites of lime, soda, or ammonia, help to maintain
the purity and efficiency of the preserving gas by absorbing any free or loosely or
feebly combined oxygen that may be evolved by the substances in the chambers for
preservation. The caustic lime frees the gas from any carbonic acid that may be
evolved by the same substances, and the sulphuric acid further maintains the purity
of the preserving gas by absorbing any ammonia or weak ammonia compounds
that may come from any substances which may be put into the preserving chambers
for preservation in a state of incipient decay.
Having thus fully described the said Invention, and shewn how the same may
be conveniently and advantageously carried into practice, we wish it understood
that we claim,-
First. The method herein described of preserving organic substances, which
consists in placing the same in a closed chamber or chambers, and subjecting them
to mixed carbonic oxide and nitrogen gases retained in the said chamber, chambers,
or receptacles, while the preserving action continues as above set forth.
Second. In an apparatus for preserving organic substances by gas, the com-
bination of the gas bolder, the gas pipe C leading from the said gas holder and a
chamber or chambers D with which the said gas pipe communicates, and within
which the substances to be preserved are placed, whereby the gas is held in the
preserving chamber or chambers while the preserving action continues as herein
described.
Third. In an apparatus for preserving organic substances by gas, the combination
with the series of preserving chambers of a continuous induction pipe C and a
continuous eduction pipe C, each communicating with the several chambers by
separate branches c, c', and the several branches being provided with independent
cocks, as above set forth and for the purposes specified.

page_text: Fourth. In an apparatus for preserving organic substances by gas, the com-
bination with the closed chamber D of the groove or trough fat its top filled with
water or other suitable material, and the gas tight cover g provided with a
vertical flange resting in the said groove or trough, as above set forth and for the
purpose specified.
Fifth. In an apparatus for preserving organic substances by gas, the combination
with the gas holder and the preserving chamber or chambers of an automatic
temperature regulator interposed in the supply pipe between the gasholder and the
said chamber or chambers, whereby the gas in its passage will be warmed or
cooled to a mean temperature before it reaches the preserving chamber or chambers,
as above set forth and for the purpose specified.
Sixth. In an apparatus for preserving organic substances by gas, the temperature
regulator consisting of the hot and cold water cylinders E, E', the discharge
pipes, the receptacle G, the cups t, t¹, the valves u, u¹, the lever v, and crank f
connected with an armature, operated by an electro-magnet for the purpose of
shifting the valves and changing the currents of the gas through the cylinders, as
above set forth and for the purpose specified.
Seventh. In an apparatus for preserving organic substances by gas, the
combination of the iron tube w, located in the case H and filled with mercury, a
glass tube x, and the rocking lever I provided with a wire y, resting in the glass
tube and connected with a battery whereby the electric current is broken and
closed by the rising and falling of the mercury, as above set forth and for the
purposes specified.
In witness whereof, we, the said Charles Francis Lawton, Arthur William
Lawton, and Albert Lindel Lawton, have hereunto set our hands and seals,
this Second day of March, in the year of our Lord One thousand eight
hundred and eighty one.