IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR THE MANUFACTURE AND PURIFICATION OF GASES FOR PRESERVING PURPOSES
Year: 1881

page_text: LETTERS PATENT to Charles Francis Lawton, Arthur William Lawton, and
Albert Lindel Lawton, all of Rochester, Monroe County, State of New
York, United States of America, Manufacturers, for an Invention of
"IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR THE MANUFACTURE
AND PURIFICATION OF GASES FOR PRESERVING PURPOSES."
E
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, State of New York, United States
of America, Manufacturers. "IMPROVEMENTS IN THE METHOD OF AND APPA-
RATUS FOR THE MANUFACTURE AND PURIFICATION OF GASES FOR PRESERVING
PURPOSES."
Our Invention relates to improvements in the method of and apparatus for
effecting the cheap and rapid production and purification of carbonic oxide gas
mixed with nitrogen gas for preserving organic substances, the said apparatus being
illustrated in the accompanying Drawing, in which
Figure 1 is a vertical longitudinal section of the said apparatus; and
Figure 2 is a section of a valve Hereinafter described drawn to an enlarged
scale.
A represents a retort or furnace of considerable height, and of comparatively
small diameter. This retort or furnace is built of or lined with fire brick, fire clay,
or other suitable material, and its top is open, whilst at its bottom it is provided
with a small opening a for the withdrawal of ashes, the said opening being covered
by a tight door. B represents bellows having a long nozzle b which enters the
bottom of the retort and through which air is forced in; C, C', are two cylinders
forming jackets which surround the retort, the said cylinders being located one
outside the other and at some distance apart, as shown. The inner cylinder is
formed of iron and the outer one of wood. The annular spaces between the said

page_text: retort and cylinders are packed with dry calcined gypsum, burnt alum, iron, wool,
dry lime, dry ashes, magnesia, asbestos, or other materials which serve as non-
conductors of heat.
The top of the inner casing or jacket is arched over the retort, and has at its top
an opening over which rests a hinged cover D. This cover has a sharp edged or
V-shaped flange c which shuts down into or enters a corresponding V-shaped
groove d in the top of the casing. This groove is filled with a luting of pasty
material into which the flange of the cover enters to make an air tight packing.
The said inner casing C has a closed bottom, and forms practically a gas-tight
casing enclosing the retort; E is a waste pipe which communicates with the
interior of the casing C above the retort, and F is a gas pipe by which the gas
escapes from the retort, and is conveyed to the purifying apparatus. At the
junction between the waste and gas pipes is a valve which is capable of being
shifted so as to cover one pipe and open the other, and vice versa. The surface of
this valve is covered with asbestos paper r which serves as a non destructible
packing to close the pipes gas tight. The said valve has a lever f¹ upon the
outside of the said pipes by which it is readily operated. G is a high cylinder of
comparatively small diameter closed at the bottom and having a removable cover
at the top. The gas pipe F opens into the lower end of this cylinder. A bent
water induction pipe g of syphon form forming a trap and having a funnel head
enters the top of the said cylinder, and a similar bent eduction pipe h forming a
trap leads from the bottom of the cylinder. These pipes g, h, permit the automatic
entrance and exit of the liquid. A grating or strainer i rests in the top of the
cylinder through which the water is strained for the purpose of causing a slow and
even distribution of the same over the contents of the cylinder.
F¹ is a gas pipe extending from the top of the closed cylinder G, and opening
into the side of a receptacle H. In this receptacle is a revolving brush I consisting
of a shaft with projecting spines of wood, metal, or other material, or fan shaped
paddles made of wire gauze or perforated sheet metal adapted to enter the liquid
in the bottom of the receptacle, and raise it by contact therewith so that the gas
will pass through the same. On the top of this receptacle H is a double bent
filling pipe k forming a trap, and at the bottom is a flexible or jointed pipe / which
can be raised or lowered at pleasure to permit the discharge of the liquid contents
of the receptacle.
Fa is a gas pipe leading from the receptacle H, and K is a cylinder similar to the
cylinder G; to the bottom of this cylinder K. the said gas pipe is connected. The
said cylinder K has bent induction and eduction pipes m, n, similar to those of
the cylinder G; F³ is a gas pipe extending from the cylinder K, and opening into
the bottom of a cylinder L. This cylinder has simply a discharge pipe F4 at its
top which conveys the purified gas to a gasometer or other storing receptacle. The
several receptacles G, H, K, and L, serve as purifiers.
The operation of the said apparatus is as follows, that is to say:--
A fire is first kindled at the bottom of the retort A which is then filled to the
top with hard coal, charcoal, or coke. Air is then forced in at the bottom of
the said retort by means of the bellows, so that while the retort is becoming
heated a large quantity of air is supplied to the same to support combustion and
produce great heat, at which time no gas but carbonic acid or dioxide is produced,
and this gas is allowed to escape through the waste pipe E or through the opening
at the upper part of the furnace. When the bottom of the furnace becomes red
hot the cover D and the waste pipe E are closed, and gas is allowed to flow
through the gas pipe F. At the same time less air is blown in from the bellows,
that is to say, enough air only is admitted to support combustion in the bottom
of the retort, and to produce such a pressure in the retort as will drive the
carbonic acid gas upward through the same. The body of coal however extending
high up in the retort, and above the combustion remains red hot. The carbonic
acid gas rising through the fuel is decomposed by the red hot carbon, which,
taking half of its oxygen, is thereby converted into carbonic oxide gas. At the

page_text: same time nitrogen gas, supplied by the air which is blown in by the bellows, is
mixed with the carbonic oxide producing mixed carbonic oxide and nitrogen
gases.
As the process of converting the gases is a cooling one, the tendency is to
produce chilling of the retort, in which case no conversion would take place; but
to obviate this the two layers of non heat conducting medium are used outside the
retort, embedding the same so deeply that it retains nearly all the heat generated.
At the same time the inner casing extends high enough above the retort to form
a dome, and has a self packing door or cover, as above stated, by which the retort
is filled.
The inside casing serves as a gas tight enclosure to the retort by which all the
gas that is produced is retained, and air is prevented from entering except as it is
blown in from the bellows. The purifier G is filled with some coarse broken hard
material, presenting open interstices that will allow water a free passage downward
and the gas a free passage upward through the same. Hard coke has been found
most suitable for this purpose. The water enters through the bent trap pipe at
the top, trickles through the whole mass of material in the case or purifier, wetting
the said material, and finally escapes through the bent pipe at the bottom, while
the gas passes in an opposite direction to such water, and by coming in contact
with the latter covering a large surface is thoroughly washed. The object
of this is more particularly to remove carbonic acid and other impurities from
the gas.
The receptacle H is partially filled with a liquid compound, consisting of caustic
lime, ferric protosulphate, and sulphite or bisulphite of lime or soda mixed with
water. The brush or paddles constantly tend to bring the liquid up and expose
a large surface of the same to the gas flowing through it. The flexible or jointed
pipe ž, in addition to serving as a discharge pipe, may be used to gauge the height
of the liquid in the receptacle by raising its outer end more or less, thus securing
the desired height in the receptacle.
The caustic lime in the said compound removes from the gas any carbonic acid
which passes from the first purifier, and also removes any sulphuretted or phospho-
retted hydrogen in the gas. It also decomposes the ferric protosulphate and
reduces it to protoxide of iron. The ferric monoxide or protoxide of iron resulting
from this decomposition fixes or removes any free or loosely or feebly combined
oxygen. The sulphites or bisulphites of lime or soda have a similar effect in
removing oxygen.
The third purifier K is also filled with hard coke or equivalent coarse material,
and strong sulphuric acid is passed down through it while the gas ascends, as in
the first purifier. The object of this purifier is to remove any ammonia or weak
ammonia compounds that remain in the gas after having passed the previous
purifiers, and also to remove from the gas all excess of moisture that has been
carried along from the other purifiers.
The fourth purifier L is filled with a mixture or packing of dry calcined asbestos
and magnesia, or magnesia and bone black. The gas entering the bottom of this
purifier flows in a steady current upward through the packing to the top of the
purifier where it escapes through the pipe F to the storing tank. The magnesia
or mixture of magnesia and bone black neutralizes whatever acid properties are
carried over with the gas from the acid purifier. The asbestos is a powerful
absorbent of odors and impurities, and it presents a large amount of surface in a
small bulk. The packing in this last purifier forms a filter, and when the gas
finally escapes it is in a very pure state. The bent or crooked inlet and exit pipes
in the first three purifiers allow the liquids to be admitted and removed in a
continuous manner and without escape of gas, each pipe forming a trap, as above
described. In the first purifier the water is kept running in a steady stream
downward and outward.
The pure mixed carbonic oxide and nitrogen gases thus produced are then fit to
be used for preserving organic substances.¦

page_text: 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 generating and purifying mixed carbonic
oxide and nitrogen gases, which method consists in first subjecting hard coal, coke,
or charcoal to fire in a closed retort, and blowing air therein from a bellows; then
passing the generated gases through a purifier packed with coarse material through
which water passes in fine streams for the purpose of washing the gases; then
passing them through a second purifier containing a solution of caustic lime,
ferric protosulphate, and sulphite or bisulphite of lime or soda for the purpose of
removing any carbonic acid, sulphuretted and phosphuretted hydrogen, and any
free or loosely combined oxygen from the gases; then passing them through a third
purifier filled with coarse material through which passes sulphuric acid for the
purpose of removing ammonia and weak ammonia compounds; and finally passing
them through a fourth purifier filled with dry calcined asbestos and magnesia, or
magnesia and bone black, for the purpose of neutralizing acid vapors, absorbing
odors, and for filtering the gases, às above set forth and for the purpose specified.
Second. In the purification of mixed carbonic oxide and nitrogen gases, sub-
jecting the gases in their passage through the apparatus to a solution of caustic
lime, ferric protosulphate, and sulphite or bisulphite of lime or soda for the
purpose of removing carbonic acid, sulphuretted or phosphuretted hydrogen and
oxygen, as herein described for the purpose specified.
Third. In the purification of mixed carbonic oxide and nitrogen gases, sub-
jecting the gases in their passage to a compound of dry calcined asbestos and
magnesia or magnesia and bone black for the purpose of neutralizing acid vapors,
absorbing odors, and filtering the gases, as herein described and for the purpose
specified.
Fourth. In an apparatus for generating aud purifying carbonic oxide and
nitrogen gases, the retort inclosed or encased in a gas tight casing C, having a dome
over the retort and with an exterior casing C', the spaces between the retort and
inner casing, and between the inner and outer casing being packed with non heat
conducting packing, as above set forth and for the purposes specified.
.
Fifth. The combination with the closed purifying case or cylinder G of the bent
induction pipe g. and the bent éduction pipe h at the top and bottom of the said
cylinder, which pipes allow the automatic entrance and exit of the liquid, and
serve as traps to prevent the escape of the gas from the purifier, as above set forth
and for the purposes specified.
Sixth. The combination with the purifying receptacle H of the revolving brush
revolving within the same, and provided with spines or paddles. for raising the
liquid and exposing it to the gas as it passes through the said receptacle, 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
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CHARLES FRANCIS LAWTON. (L.B.)
ARTHUR WILLIAM LAWTON.
ALBERT LINDEL LAWTON.
(L.S.)
(L.S.)