Improvements in Process and Apparatus for Generating and Liquefying Acetylene.
Year: 1896

page_text: Date claimed for Patent under Sect. 103 of Act,
being date of first Foreign Application (in 21st Feb. 1896
United States of America),
Date of Application (in United Kingdom), 10th Aug., 1896
Complete Specification Left, 7th May, 1897-Accepted, 19th June, 1897
United States of America),
Date of Application (in United Kingdom), 10th Aug., 1896
Complete Specification Left, 7th May, 1897-Accepted, 19th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in Process and Apparatus for Generating and
Liquefying Acetylene.
I, ARTHUR CLEVELAND FRASER, of Temple Court, New York City, in the
County and State of New York, United States of America, Solicitor of Patents,
do hereby declare the nature of this invention to be as follows:-
This invention relates to means for generating and liquefying acetylene gas.
This gas is generated by the mutual decomposition of water and calcium carbide,
or other analogous gas-producing carbide, such as barium or magnesium carbides.
The mode of liquefying acetylene at present practised, is to bring the water
and carbide into contact in a closed chamber of great strength, so as to confine
the gas as it is generated and raise it under its own pressure of generation
to a pressure sufficient to liquefy it upon its being cooled by water. This process
of liquefying acetylene under its own pressure of generation is, however, subject to
certain practical defects. In working on this system, disastrous explosions have
resulted, the cause of which is involved in obscurity, but which may reasonably
be attributed to a certain instability of acetylene by which it is liable to
decomposition at bigh temperatures.
I have conceived of a process for liquefying acetylene in which the use of high
pressure combined with high temperature is avoided, my invention being based
upon the theory that the pressure and heat involved in the ordinary processes are
largely if not entirely responsible for the explosions that occur. According to my
invention therefore, I provide means for preventing the accumulation of an excessive
pressure by the newly generated gas, and prevent the generation thereof at a high
temperature, and after cooling the gas I provide means for mechanically increasing
its pressure to such extent as to liquefy it. By these means I am enabled to
generate the gas at a comparatively low pressure, and consequently at a pro-
portionately lower temperature than heretofore, while at the same time preferably
utilizing to a great extent the pressure of generation of the gas to contribute to its
liquefaction.
I prefer to effect the final liquefaction of the gas at a very low temperature, to
enable it to be liquefied at a low final pressure; and to this end I prefer to
refrigerate the gas either before or after compressing it, or preferably both.
To enable the advantages of my invention to be understood, I will give one
example of practical conditions for carrying it into effect. Employing a cooling
medium capable of cooling the stream of gas to approximately 32 degrees F., the
gas may be compressed by its own generation to 120 pounds above atmospheric
pressure (9 atmospheres). Under this pressure its initial temperature cannot rise
D

page_text: above the corresponding vaporizing point of water, that is, 350 degrees F. The
generation of the gas is so controlled. that it is evolved no faster than just sufficient
to maintain this pressure, and immediately it is cooled by condensing water or
other cooling medium, whereby all steam which passes off with the gas is condensed
and drained off. The gas is preferably then further cooled by a cooling medium,
and then passes to a compressing pump, whereby its pressure is raised for example
to 308 pounds (21+ atmospheres), and it is then again cooled to approximately
32 degrees F. to liquefy it.
Or, as another example, the gas may be generated under a pressure of 165 pounds,
80 that its temperature cannot rise above 373 degrees F.; immediately it is cooled
by condensing water to say 56 degrees F., and is then further cooled by the
circulation of a refrigerant liquid from an ice machine, being thereby reduced
approximately to zero Fahrenheit. This causes any remaining aqueous vapor to be
deposited as snow upon the cooling surfaces. The cold and dry gas then passes to a
compressing pump, whereby its pressure is mised for example by 30 pounds,
thereby compressing it to 195 pounds pressure, and at the same time somewhat
raising its temperature. The gas is then passed through a condenser cooled by the
refrigerant liquid to say zero Fabrenheit, whereupon at this increased pressure the
gas liquefies. Any other gases, as oxygen, hydrogen, etc., which may have been
mingled with the acetylene as impurities, are separated from it by its liquefaction,
and in the receiving vessel these gases accumulate at the top over the liquid
acetylene, and may be blown off from time to time, the low temperature by which
the acetylene is maintained liquid preventing any wasteful blowing off of acetylene
at the same time.
By a modification involving part of my invention, the employment of mechanical
compression may be wholly dispensed with, although to less advantage. For
example, by employing a refrigerant at the same temperature as above instanced,
the original pressure of generation must be raised to 195 pounds, which involves an
initial temperature of 386 degrees Fahrenheit instead of 373 degrees.
To enable my invention to be understood and practised by those skilled in
analogous arts, I will now proceed to describe it in detail with reference to the
accompanying drawings, which show the apparatus which I have devised for best
practising my improved process.
Fig. 1 is an elevation of the entire apparatus, portions thereof being in section;
Fig. 2 is a sectional elevation on a larger scale of the generator and its
accessories;
Fig. 3 is a front elevation of the mechanism shown in Fig. 2 viewed from the left
in that figure;
Fig. 4 is a transverse section on a larger scale through one of the generators on
the line 4-4 in Fig. 2;
Fig. 5 is a longitudinal section of the gas cooling dehydrator on the same scale
as Fig. 2;
Fig. 6 is a transverse section on the line 6-6 in Fig. 5;
Referring to Figs. 1 to 6 inclusive, let A A designate the gas generators in
which the carbide and water are brought into contact to evolve the acetylene.
There are preferably two, three, or more of these. Connected to each generator
is a separate water reservoir B. C and C' are gas coolers through which cold
water circulates. D is a condensed water separator. E is a gas storage tank.
F and F are gas dehydrating refrigerators. F' is a pump accessory to these.
Gis a gas pressure pump or compressor. H is the acetylene liquefier. I is the
liquid acetyleue receiving and storing tank. J is a refrigerating tank. K K are the
liquid acetylene cylinders or tanks, made strong enough to withstand the pressure
Decessary to retain the acetylene in liquid form.
The pipes through which the acetylene circulates are lettered a a. Those
circulating cold water are lettered w w. Those circulating cold brine or other
refrigerant liquid are lettered b b. Those circulating ammonia or other
refrigerant in the operation of an ice machine which is alternately compressed,

page_text: cooled, liquefied and vaporized for the purpose of cooling the refrigerant liquid in
the pipes bb, are lettered r r.
Hence the apparatus includes what in refrigerating apparatus is familiarly
called a brine circuit b b, and an ammonia circuit rr. The latter is shown in
dotted lines, and includes a compressor L, a condenser M, a liquid ammonia tank N,
and a liberation valve r. P is a chill tank wherein the brine returning from the
circuit bb is cooled by exposure to surfaces chilled by the vaporized ammonia.
a
I will now describe in detail the specific apparatus shown. Each of the
generators A consists of an inner shell c of great strength, whereby is formed a
reaction chamber A' (Fig. 2) into which is slid a tray or sheet metal shell A',
containing a suitable quantity of calcium carbide or other suitable carbide. The
mass of carbide should not exceed one-third the capacity of the chamber, to
provide room for the expansion of the lime resulting from the reaction. The
end of the shell c is closed by a cap c¹ strongly fastened thereon in any
suitable manner, as by screwing it on. Around the shell c is formed a cooling
jacket d, through which cooling water circulates. The generator is arranged
obliquely, preferably at about the angle shown. The water reservoir B is
placed at any suitable elevation above the generator A. From the bottom of
the water reservoir leads a pipe 10 which enters the lower end of the generator,
and preferably extends up within the generator as a perforated pipe 11 (Fig. 2).
From the upper end of the generator lends a gas outlet pipe 12, which passes
to a reducing valve or pressure governor e of any suitable type. A cock or
valve 13 is introduced in the pipe 12 for shutting it off. A similar valve 14
is introduced in the pipe 10. By closing these two valves the generator is
isolated from the remainder of the apparatus. From the pressure valve e
pipe 15 leads to a transverse pipe or header 16. All the generators are
connected in this manner to the pipe 16. From the pipe 16 there leads a
single pipe 17, which passes through the cooler C. This cooler is or may be
constructed in any manner by which the gas flowing through the cooler shall
pass over surfaces which are cooled by water or other cooling medium. A
convenient construction is that shown, wherein the gas flows in one direction
through the pipe 17, while water flows around this pipe in the contrary direction.
The cold water enters by a pipe 18, and leaves the cooler by a pipe 19, partitions
being provided in the cooler for directing the flow of the water. The water
discharged from this cooler may flow by a pipe 20 to the cooling jacket d of the
generator, by connecting the pipes 19 and 20 as shown in Fig. 1.
Or an
independent source of water may be admitted to cool the generator, entering it
at the pipe 20 and leaving it by a pipe 21. From the cooler C extends a pipe 22
which enters the separator D. This separator is preferably an upright vessel
as shown, the pipe 22 entering deeply into it. It is provided with a water gage for
determining the level of the accumulated condensed water, and with a blow-off
cock for blowing off the accumulated water. From the upper part of this
separator a pipe 23 leads into the gas storage tank E. This tank is preferably
an upright vessel as shown, and by preference the pipe 23 extends down to its
lower portion as shown. As some further water vapor may condense in this tank,
it is preferable to provide it also with a blow-off valve f. From the top of
this tank a pipe 24 leads to the refrigerating dehydrators F F¹.
These dehydrators are designed to be used in alternation, one of them ordinarily
being out of service. In the construction shown, each consists of a base plate or
head g, and a shell g' which is united to the head by a separable joint, so that on
removing fastening bolts or other fasteners the shell may be taken off.
Within
the shell are flat-surfaced chambers or hollow plates g, through which
circulates cold brine. The hollow plate g is alternated in position with the other
plates, so that the gas entering by pipe 25 circulates back and forth between the
plates from end to end of the shell, and finally passes out by branch pipe 26 to the
main pipe 27, which leads to the gas compressor G. The pipes 25 and 26 are provided
with valves 25 and 26' for closing them off when this refrigerator is to be thrown

page_text: out of use, in which case corresponding valves in the same branch pipes leading
to the other refrigerator F are opened to direct the gas through the latter.
The
two refrigerators are directly connected by a pipe 28, having valves 28¹ at its
junction with the respective refrigerators, and between these valves communicating
by a pipe 29 with the suction of the special pump F, from the discharge of which 5
leads a pipe 30 having a valve 30' which joins the pipe 27.
The pipe 27 leads to the suction of the gas compressor G, and from the
discharge thereof a pipe 31 leads to the gas cooler C. This cooler may be cooled
by ordinary condensing water, or by ice water coming from the ice machine or other
source, or by brine which has been warmed to a higher temperature than that 1
which cools the liquefier H. This cooler may be of any construction in which the
gas in flowing through it passes over surfaces cooled by the flow of the cooling
medium. Preferably this medium flows past these surfaces in the contrary
direction to the flow of gas, according to the construction of what are called
reverse-flow coolers. Hence the water or cooling medium enters by a pipe 32 and
passes out by a pipe 33. From the cooler C¹ the gas passes out through a pipe 34,
which conducts it to the liquefier H. In the construction of liquefier shown, a coil 35
forming a continuation of the pipe 34, is arranged in a descending spiral, so that the
gas as it liquefies and condenses on the surface of the pipe, will run down the
descending coil and flow out through the outlet pipe 36 thereof, which leads to
the liquid acetylene tank I. The liquefier H is cooled by brine, which enters by a
pipe at 37 and passes off at 38.
The liquid acetylene tank I, since it contains acetylene cooled approximately to
zero F., is provided with an outer cooling jacket through which the cold brine
is circulated, entering by a pipe 38 and descending to a pipe 39.
The gases
which are not liquefiable at this temperature and pressure, accumulate in the
upper part of the tank I, and can be blown off from time to time by a blow-off
cock h. To determine the extent of accumulation of these gases, a liquid gage h
is provided.
From the bottom of the acetylene tank I there leads a delivery pipe 40, having
valved branches 41, 41, terminating in couplings 42, by which may be coupled to
them the valved necks of the liquid acetylene tanks or cylinders K K. These
cylinders are placed in a tank J containing cold brine, in order to keep the cylinders
at the same low temperature as the liquid acetylene which is to enter them, and
prevent any vaporization of the entering liquid. The tank J is provided with a
cold brine inlet 43 and outlet 44.
The cold brine inlets and outlets are preferably connected in one continuous
circuit bb as shown. Thus the brine cooled in the chill tank P passes by a pipe 45
to the inlet 43, circulates thence through the tank J, is drained off by the outlet 44,
and passes by a pipe 46 which is provided with a check-valve 47 to prevent back
flow to the brine inlet 38 for the jacket h, and on flowing through this jacket passes
out by the outlet 39 which connects by the pipe 48 to the inlet 37 of the liquefier,
and after passing through the liquefier passes out by its outlet 38, and flows through
a pipe 49 to the brine inlet 50 (Fig. 5) of the refrigerating dehydrator For F
The brine then circulates back and forth through the hollow spaces 9 g thereof,
and passing out therefrom by the branch pipe 51, enters a pipe 52, which conducts
it to the brine pump P', whence it passes by a pipe 53 back to the chill tank P.
The water reservoirs B B (Fig. 3) are connected each by a valved pipe 54 with
a pipe 55 leading to a water pressure pump Q. The top of each reservoir B is
connected by a valved branch pipe 56 with a header 57, which connects by a pipe 58
with any part of the apparatus containing acetylene gus between the pressure
reducing valve e and the pressure increasing pump G. Thus the gaseous pressure
is admitted to the top of the column of water. Inside each water reservoir is
arranged a float valve i adapted when the water level in the reservoir rises to
practically the top thereof, to close the outlet through the valved branch pipe 56.
In the description of the detailed process and operation of the apparatus which
I will now give, I will assume that the process is practised under the general

page_text: conditions second herein before stated, namely, a generating pressure of 165 poun 13
and a liquefying pressure of 195 pounds.
In starting the operation, the water reservoirs B B are first filled with water by
pumping it into them by means of the pump Q, the valves 54 being open and the
valves 14 closed. The trays A of the generators are filled to the proper level
with carbide and slid into the generator shells, and the caps c fastened on. The
pressure reducing valves e are set to deliver at (for example) 165 pounds. The
entire apparatus now contains air. The valves 251, 26', are open to one refrigerator
as F, and closed to the other as F. The valves 41, 41 and all other outlets from
the apparatus are closed. One, two or more generators A are then set in operation.
I will assume the operation of only one generator. Its outlet valve 13 is opened,
and the water inlet valve 14 is opened. At the same time a circulation of water is
started through the cooler C and jacket d, and then or shortly afterward a
circulation of the cooling medium should be started in the cooler C', and the
refrigerating apparatus should be set in operation so as to cause cold brine to
circulate in the brine circuit.
Upon admitting water to the bottom of the generator A, it enters the samne under
the head afforded by the elevation of the reservoir B, and immediately on coming
in contact with the carbide, generates acetylene gas in large quantities, and this
gas, which is evolved first from the lower end of the generator, passes up through
it, expelling the air from the generator and forcing the air out through the pipe 12
and through the valve e and pipes 15, 16, 17 to the cooler C, and through this and
the vessels D and E to the refrigerating dehydrator F, and on to the pump G
At first the valve 14 should be opened but little so as to admit only a limited
stream of water. As the acetylene gas expels the air, the successive evolution of
gas causes an outflow of the gas through the valve e and the several apparatus
until between the generator A and pump G a pressure is developed which is
indicated by the gage j. When this gage indicates the determined pressure (say
165 pounds) the gas pump G is set in operation and is driven at such speed as to
take the gas as fast as it is generated and force it on through the cooler C and
liquefier H into the reservoir I. The proper rate of speed for the pump G can be
determined by means of the gage j. The pump at first pumps air, and subsequently
mingled air and acetylene, and finally acetylene. As the pumping proceeds, the
pressure beyond the pump G gradually rises as indicated by the gage j', until the
prescribed pressure (say 195 pounds) is reached, whereupon assuming the brine
circuit to maintain a temperature approximating zero F., the liquefaction of the
acetylene commences. Thereafter all acetylene gas that is pumped at this pressure
through the liquefier is caused to liquefy. At first the air can be permitted to
escape by slightly opening the blow-off h¹ until the odour of acetylene becomes
marked, whereupon this blow-off should remain closed until the liquefaction has
proceeded sufficiently to condense the gaseous acetylene in the receiver, whereupon
the remaining air can be blown off from time to time, the liquefied acetylene
gradually accumulating in the receiver I, until its level becomes apparent on the
gage h. By this time the apparatus will have reached the stage of normal operation,
all air having been driven into the receiver I and most of it expelled, and its place
taken in the remaining apparatus by acetylene.
Having thus described the starting of the operation, I will now proceed to
describe the normal action of the apparatus. As fast as water and carbide come
in contact in the generator A, acetylene gas is given off. The heat of combination
vaporizes part of the water, and the gas and steam pass out together through the
pipe 12 to the reducing valve e. As long as the generation is not so rapid as to
increase the pressure in the apparatus beyond this valve to above the determined
pressure (say 165 pounds), this valve remains open, and the gas and steam flow out
freely through it. But as soon as the generation of gas becomes more rapid than
the rate at which it is drawn off by the pump G, so that the pressure exceeds the
determined pressure, the valve e closes and ceases discharging gas, so that the

page_text: pressure is confined in the generator and immediately reacts against the water which
has entered the reaction chamber, and opposes the inflow of the water, and if the
action be sufficiently rapid will even cause an outflow of water, which will be forced
back through the pipe 10 to the reservoir B until an equilibrium is established.
In practice, the valve e will not ordinarily entirely close, but being a diaphragm
pressure regulator will partially close so as to restrict the outflow. Hence normally
a pressure will exist in the generator equal to that beyond the valve e (say 165
pounds) plus the pressure equal to the head of water in the reservoir B, so that if
this head be for example six feet, the normal pressure in the generator will be
about three pounds greater than that beyond the valve e (say 168 pounds). By
this simple means, and at the expense of this trifling increase in initial pressure of
generation, the rapidity of generation is regulated automatically and effectively so
as to exactly equal the rate of consumption or. drawing off of the gas by the
pump G.
As the acetylene is evolved in the generator it comes at once into contact with
the inner walls of the reaction chamber, and is cooled by the water circulating
in the jacket d, so that part of the vapor is at once condensed. Another portion of
the vapor is taken up by that portion of the carbide which lies in the upper part
of the generator, effecting thus a further evolution of gas. The moist gas flows
beyond the valve e and through the cooler C, which being cooled by ordinary
condensing water for example, so reduces the temperature of the gas that the vapor
carried thereby is condensed, and the condensation water runs into the separator D,
where it can be blown out from time to time. The gas thus almost wholly freed
from vapor, then passes over into the storage tank E. If desired this tank may be
cooled by
water jacket in order to promote a further condensation of moisture,
or instead of a water jacket, any cold medium of a temperature above the freezing
point of water may be used. Any water that collects in this tank may be blown
out from time to time. The almost wholly dry gas then passes on through the
pipe 24 and branch pipe 25, into the refrigerating dehydrator F, which is cooled
by brine and circulates back and forth around the plates ggs, which being cooled
to below the freezing point of water, freeze upon their surfaces in the form of
snow or frost any remaining moisture that may be carried by the gas, whereby the
gas is simultaneously dehydrated and cooled to a very low temperature. This
temperature, approximating zero F., is so low that the subsequent compression by
the pump G will not raise the gas to un inconveniently high temperature. The
cooled gas is then drawn into the pump G and its pressure raised to the pre-
determined extent proportional to the temperature finally imparted to the liquid
acetylene (say 195 pounds). In so doing the gas is somewhat heated or warmed.
In case of but slightly raising the pressure of the gas, and consequently of but
slightly increasing its temperature, the cooler C will not be required, but in case of
a considerable compression of the gas, the use of this cooler is desirable. The
purpose of this cooler is to lower the temperature of the gas from that at which it
comes from the pump G down to just above the liquefying point. The gas thus
cooled then passes to the liquefier H, where it is further cooled by the circulation
of cold brine around the coil thereof. Under the stated pressure, a cooling to
zero F. effects liquefaction of the acetylene, which trickles down and runs into the
receiver I. Under the low temperature maintained no water will have found its
way over with the liquid acetylene, and in case of the presence of oxygen,
hydrogen, or other impurities, they are maintained so cold as to prevent the
possibility of explosion. Further, these extraneous gases are maintained almost
absolutely free from admixture with acetylene, since the latter at this low
temperature is liquefied. Consequently it becomes an easy matter to separate these
impurities by blowing them off occasionally by the valve h'.
Whenever it is desired to fill a cylinder or "bottle" K with liquid acetylene, it
is placed in the tank J and coupled on to one of the valved pipes 41. Being
immersed in the cold brine, the cylinder is cooled to the same temperature,
whereupon the valve 41 and the valve in the cylinder are opened, and the cold

page_text: liquid acetylene is caused to flow into the cylinder, escaping thereinto first under such
reduction of pressure that it vaporizes, and thereby quickly abstracts any remaining
heat from the acetylene gas existing in the cylinder, so that when the full pressure his
been let into the cylinder, the gas it contained is liquefied and mingles with the liquid
acetylene which enters it. Thus the cylinder is completely filled with liquid
acetylene. If, however, the cylinder contained air, this would under the given
pressure be compressed to about one fourteenth the capacity of the cylinder, and
would upon an equilibrium of pressure being reached, bubble up through the
pipes 41, 40, to the receiver I and take its place at the top thereof, whence it would
be blown out. By closing the valve 41, and the valve of the cylinder, the latter
can be uncoupled and removed.
c¹
As soon as the carbide in one generator A has been decomposed, this generator
can be cut out of the apparatus, and one or more others can be put into communi-
cation therewith in its place. The capacity of the reservoir B should be sufficient
when added to the bulk of residual lime in the reaction chamber to completely
fill the latter and thereby expel all gas by the outlet pipe 12, thereby avoiding
all necessity for pumping off the residue of gas within the generator, as has
heretofore been necessary. To determine when the generator is thus filled with
water, the reservoir B may be provided with a water gage k (Fig. 2). Thereupon
the valves 14 and 13 are closed, and the valve in the pipe 21 should also be closed.
The cap is then to be taken off and the lime and water removed from the
generator. To accomplish this it is only necessary to pull out the tray A', which
carries with it all the residual lime and the greater part of the water. The
remaining water may readily be drawn off or siphoned or pumped out.
A tray
filled with the proper quantity of dry fresh carbide is then thrust in, and the cap
restored. The reservoir B has then to be refilled with water, which is done by
opening the cock 54 and driving the pump Q, whereby water is pumped into the
reservoir B and its level rises therein, driving out the superincumbent acetylene
gas through the pipe 58 until the water lifts the float-valve i, and closes it, where-
upon very quickly a pressure is developed which being indicated on the gage,
(Fig. 3), indicates that the pump Q should be stopped. The valve 54 is then
closed, and the generator may at any time be set in operation again by opening
the valves 14, 13 and 21. The generators A A are preferably arranged side by
side as shown in Fig. 3, each having its own reservoir B and pressure reducing
valve. The generators are best operated in rotation, or, by providing a sufficient
number of generators in the battery, two, three, or more may be in operation
simultaneously. Each generator operates independently of the others, and each
is self-governing under the control of its pressure valve e.
I construct the generators A of considerable length and small diameter, in order
to enable the gas to be readily cooled by jacketing the generator. The gas in
Blowing out from the generator flows necessarily in close proximity to its walls,
which are cooled by the jacket. Further, the source of heat which is located at
the points of contact between the water and the carbide, is circumscribed and
brought into close proximity to the cooling surfaces. By these means the
accumulation of any considerable heat in the generator is avoided, and in fact the
temperature maintained therein is considerably lower than the theoretical
temperature, namely, the vaporizing point of water at the given pressure. The
tubular form of the generator is adopted for the purpose of enabling it with the
least weight to withstand the required pressure. Its inclined position has been
adopted to contribute to the effectiveness of the self-regulation by causing the water
to enter at one end and gradually fill it, coming in contact in its progress with
continually fresh portions of the carbide, and being at any moment capable of being
arrested in its flow by the generation of an abnormal pressure, and of being forced
back slightly so as to almost wholly cease its decomposing action upon the carbide.
The same result could he accomplished by placing the slender tubular generators in
vertical positions, but this would involve difficulty in removing the residual lime,

page_text: and also would involve the choking or obstruction of the flow of water by the
falling of the residual lime to the bottom end of the chamber, which disadvantages
are overcome by my novel arrangement of the generator as an inclined tubular
chamber receiving water at its lower back end and discharging the gas at its upper
front end. The exact angle of inclination is not material, but the angle shown is
preferred.
After the filling of a certain number of cylinders K, as may be determined by
experience, the refrigerating dehydrator (F for example) which has been in use,
will have become so encrusted with the frozen moisture withdrawn from the gas as
to make it desirable to throw it out of use and transfer the operation to the other
dehydrator (as F¹). To do this, assuming the dehydrator F to be the one in use,
the valves 25' 26' thereof should first be closed to cut off the flow of acetylene,
whereupon by opening the valves in the pipe 28, the acetylene under pressure in
the dehydrator F flows across into F' until their pressures are equalized, whereupon
the valve 281 of F is closed, and the valves 25' 26' of F are opened, thereby
putting F1 into connection. At the same time or previously, the brine circuit
should be turned into F1 by turning the two three-way cocks (Fig. 5) so that the
brine circulating in F becomes quiescent, and the circulation takes place through F
The residual gas in F, which is at half pressure, is then pumped out through
pipes 28, 29 to pump F', and forced through pipe 30 by opening valve 30' into the
main pipe 27. When pumped down to approximately atmospheric pressure, the
pump may be stopped and valve 28' of the dehydrator should be closed. This
dehydrator F may then be dismounted by detaching and taking off its shell g
thereby exposing its refrigerating plates 92, which, having flat surfaces, are easily
cleaned by scraping or rubbing to remove the adhering frost or ice. Or the latter
may be permitted to thaw and run off as the quiescent brine becomes warm.
Instead of operating the apparatus under the conditions as to relative pressure
and temperature already stated, these_conditions may be considerably varied
without departing from my invention. For example a gas may be compressed by
its own generation to 120 pounds (9 atmospheres), and subsequently may be pumped
up to 150 pounds, and then cooled by refrigeration to minus 10 degrees F. Or it
may be compressed by its own generation to 200 pounds (13 atmospheres), and
after cooling be then pumped up to 17 atmospheres, and then cooled to plus
14 degrees F. Or, as another example, it may be generated at 18 atmospheres,
and after cooling be pumped up to 21 atmospheres, and then cooled to slightly
below 32 degrees F., to liquefy it. The last example is within my invention, but is
not recommended, as the pressure of generation is undesirably high, and the
corresponding temperature is in excess of that which should be permitted.
I consider it preferable to adopt a liquefying temperature as low as can readily be
effected by existing commercial refrigerating apparatus, say for example froin 10
above zero. F., to 10 below zero, and preferably in the neighbourhood of zero F.
The pressure at which the gas should be generated should then be limited to a
convenient amount below the pressure corresponding to the temperature thus
determined at which the gas liquefies, in order that the cooling of the gas to the
extreme liquefying temperature will not liquefy it at the pressure at which it is
generated, but will require that the pressure be raised before the gas can be
liquefied. A difference in pressure between the generating and the liquefying
pressures of from one to two atmospheres, is considered preferable. For cooling to
temperatures not below zero F., ordinary brine of sodium chloride and water is
suitable; but for very low temperatures, a brine of for example calcium chloride
and water may be used, or any other liquid non-congealable at the low temperature
adopted may be substituted. Any such non-congealable liquid is to be understood
as within the term "brine" as used in this specification.
It should be understood that the preliminary cooler C has two functions which
are not necessarily combined, namely, first, that of cooling the gas from its
comparatively high temperature of generation to a normal temperature, and second,
that of condensing the steam or aqueous vapor for drying or partially dehydrating

page_text: the gas. This second function might be performed by any other means known in
the arts for dehydrating, as for example by passing the gas immediately into
contact with some substance having an affinity for water, such as calcium chloride
or calcium carbide for example. By using any such means of dehydration, the
function of the cooler C would be reduced to that of merely lowering the
temperature of the gas, and such change would not take the process outside of my
invention. Instead of using the preliminary cooler C, the gas might be introduced
directly to the refrigerating cooler F, but I consider it preferable to first cool the
gas by ordinary cold water to a normal temperature, by which means the
refrigerating cooler is made more effective to complete the cooling of the gas.
It is desirable to cool the gas by the refrigerating cooler F sufficiently to
counteract the latent heat given out during the compression of the gas by the
compressor G.
Dated this 10th day of August 1896
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.
Improvements in Process and Apparatus for Generating and
Liquefying Acetylene.
1, ARTHUR CLEVELAND FRASER, of Temple Court, New York City, in the
County and State of New York, United States of America, Solicitor of Patents,
do hereby declare the nature of the 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 means for generating and liquefying acetylene gas..
This gas is generated by the mutual decomposition of water and calcium carbide or
other analogous gas-producing carbide, such as barium or magnesium carbides..
The mode of liquefying acetylene at preseut practiced, is to bring the water and
carbide into contact in a closed chamber of great strength, so as to confine the gas.
as it is generated and raise it under its own pressure of generation to a pressure
sufficient to liquefy it upon its being cooled by water. This process of liquefying
acetylene under its own pressure of generation is, however, subject to certain
practical defects. In working on this system, disastrous explosions have resulted,
the cause of which is involved in obscurity, but which may reasonably be attributed.
to a certain instability of acetylene by which it is liable to decomposition at high
temperatures.
I have conceived of a process for liquefying acetylene in which the use of high
pressure combined with high temperature is avoided, my invention being based
upon the theory that the pressure and heat involved in the ordinary processes are
largely if not entirely responsible for the explosions that occur. According to my
invention therefore, I provide means for preventing the accumulation of an
excessive pressure by the newly generated gas, and prevent the generation thereof
at a high temperature, and after cooling the gas I provide means for mechanically
increasing its pressure to such extent as to liquefy it. By these means I am enabled
to generate the gas at a comparatively low pressure, and consequently at a
proportionately lower temperature than heretofore, while at the same time preferably
utilizing to a great extent the pressure of generation of the gas to contribute to its
liquefaction.
I prefer to effect the final liquefaction of the gas at a very low temperature, to
B

page_text: enable it to be liquefied at a low final pressure; and to this end I prefer to
refrigerate the gas either before or after compressing it, or preferably both.
To enable the advantages of my invention to be understood, I will give one
example of practical conditions for carrying it into effect. Employing a cooling
medium capable of cooling the stream of gas to approximately 32 degrees F., the
gas may be compressed by its own generation to 120 pounds above atmospheric
pressure (9 atmospheres). Under this pressure its initial temperature cannot rise
above the corresponding vaporizing point of water, that is, 350 degrees F. The
generation of the gas is so controlled that it is evolved no faster than just sufficient
to maintain this pressure, and immediately it is cooled by condensing water or other
cooling medium, whereby all steam which passes off with the gas is condensed and
drained off. The gas is preferably then further cooled by a cooling medium, and
then passes to a compressing pump, whereby its pressure is raised for example to
308 pounds (21 atmospheres), and it is then again cooled to approximately
32 degrees F. to liquefy it.
Or, as another example, the gas may be generated under a pressure of 165 pounds,
so that its temperature cannot rise above 373 degrees F.; immediately it is cooled
by condensing water to say 56 degrees F., and is then further cooled by the
circulation of a refrigerant liquid from an ice machine, being thereby reduced
approximately to zero Fabrenheit. This causes any remaining aqueous vapor to
be deposited as snow upon the cooling surfaces. The cold and dry gas then passes
to a compressing pump, whereby its pressure is raised for example to 30 pounds,
thereby compressing it to 195 pounds pressure, and at the same time somewhat
raising its temperature. The gas is then passed through a condenser cooled by the
refrigerant liquid to say zero Fahrenheit, whereupon at this increased pressure the
gas liquefies. Any other gases, as oxygen, hydrogen, etc., which may have been
mingled with the acetylene as impurities, are separated from it by its liquefaction,
and in the receiving vessel these gases accumulate at the top over the liquid
acetylene, and may be blown off from time to time, the low temperature by which
the acetylene is maintained liquid preventing any wasteful blowing off of acetylene
at the same time.
By a modification involving part of my invention, the employment of mechanical
compression may be wholly dispensed with, although to less advantage. For
example, by employing a refrigerant at the same temperature as above instanced,
the original pressure of generation must be raised to 195 pounds, which involves an
initial temperature of 386 degrees Fahrenheit instead of 373 degrees.
To enable my invention to be understood and practiced by those skilled in
analogous arts, I will now proceed to describe it in detail with reference to the
drawings which accompanied my Provisional Specification, which show the
apparatus which I have devised for best practicing my improved process.
Fig. 1 of the said drawings is an elevation of the entire apparatus, portions
thereof being in section;
Fig. 2 is a sectional elevation on a larger scale of the generator and its
accessories;
Fig. 3 is a front elevation of the mechanism shown in Fig. 2 viewed from the
left in that figure;
Fig. 4 is a transverse section on a larger scale through one of the generators on
the line 4-4 in Fig. 2;
Fig. 5 is a longitudinal section of the gas cooling dehydrator on the same scale
as Fig. 2;
Fig. 6 is a transverse section on the line 6-6 in Fig. 5.
Referring to Figs. 1 to 6 inclusive, let A A designate the gas generators in
which the carbide and water are brought into contact to evolve the acetylene.
There are preferably two, three, or more of these. Connected to each generator
is a separate water reservoir B. C and C' are gas coolers through which cold
water circulates. D is a condensed water separator. E is a gas storage tank.
Fand Faro gas dehydrating refrigerators. F is a pump accessory to these.

page_text: Gis a gas pressure pump or compressor. H is the acetylene liquefier. I is the
liquid acetylene receiving and storing tank. J is a refrigerating tank. K K are
the liquid acetylene cylinders or tanks, made strong enough to withstand the pressure
necessary to retain the acetylene in liquid form.
The pipes through which the acetylene circulates are lettered a a. Those
circulating cold water are lettered wow. Those circulating cold brine or other
refrigerant liquid are lettered bb. Those circulating ammonia or other refrigerant
in the operation of an ice machine which is alternately compressed, cooled, liquefied
and vaporized for the purpose of cooling the refrigerant liquid in the pipes bb,
are lettered r r.
Hence the apparatus includes what in refrigerating apparatus is familiarly
called a brine circuit bb, and an ammonia circuit rr. The latter is shown in
dotted lines, and includes a compressor L, a condenser M, a liquid ammonia
tank N, and a liberation valve r'. 'P is a chill tank wherein the brine returning
from the circuit bbis cooled by exposure to surfaces chilled by the vaporized
ammonia.
I will now describe in detail the specific apparatus shown. Each of the
generators A consists of an inner shell e of great strength, whereby is formed a
reaction chamber A' (Fig. 2) into which is slid a tray or sheet metal shell A',
containing a suitable quantity of calcium carbide or other suitable carbide. The
mass of carbide should not exceed one-third the capacity of the chamber, to
provide room for the expansion of the lime resulting from the reaction. The end
of the shell c is closed by a cap c¹ strongly fastened thereon in any suitable manner,
as by screwing it on. Around the shello is formed a cooling jacket d, through which
cooling water circulates. The generator is arranged obliquely, preferably at about
the angle shown. The water reservoir B is placed at any suitable elevation above
the generator A. From the bottom of the water reservoir leads a pipe 10 which
enters the lower end of the generator, and preferably extends up within the
generator as a perforated pipe 11 (Fig. 2). From the upper end of the generator
leads a gas outlet pipe 12, which passes to a reducing valve or pressure governor e
of any suitable type. A cock or valve 13 is introduced in the pipe 12 for shutting
it off. A similar valve 14 is introduced in the pipe 10. By closing these two
valves the generator is isolated from the remainder of the apparatus. From the
pressure valve e a pipe 15 lends to a transverse pipe or header 16. All the
generators are connected in this manner to the pipe 16. From the pipe 16 there
leads a single pipe 17, which passes through the cooler C. This cooler is or may
be constructed in any manner by which the gas flowing through the cooler shall
pass over surfaces which are cooled by water or other cooling medium. A
convenient construction is that shown, wherein the gas flows in one direction
through the pipe 17, while water flows around this pipe in the contrary direction.
The cold water enters by a pipe 18, and leaves the cooler by a pipe 19, partitions
being provided in the cooler for directing the flow of the water.
discharged from this cooler may flow by a pipe 20 to the cooling jacket d of the
generator, by connecting the pipes 19 and 20 as shown in Fig. 1. Or an independent
source of water may be admitted to cool the generator, entering it at the pipe 20
and leaving it by a pipe 21. From the cooler extends a pipe 22 which enters the
separator D. This separator is preferably an upright vessel as shown, the pipe 22
entering deeply into it. It is provided with a water gauge f for determining the
level of the accumulated condensed water, and with a blow-off cock for blowing
off the accumulated water. From the upper part of this separator a pipe 23 leads
into the gas storage tank E. This tank is preferably an upright vessel as shown,
and by preference the pipe 23 extends down to its lower portion as shown. As
some further water vapor may condense in this tank, it is preferable to provide it
also with a blow-off valve f. From the top of this tank a pipe 24 leads to the
refrigerating dehydrators FF.
These dehydrators are designed to be used in alternation, one of them ordinarily
being out of service. In the construction shown, each consists of a base plate or

page_text: head 9, and a shell g which is united to the head by a separable joint, so that on
removing fastening bolts or other fasteners the shell may be taken off. Within
the shell are flat-surfaced chambers or hollow plates gg, through which circulates
cold brine. The hollow plate g³ is alternated in position with the other plates, so
that the gas entering by pipe 25 circulates back and forth between the plates from
end to end of the shell, and finally passes out by branch pipe 26 to the main
pipe 27, which leads to the gas compressor G. The pipes 25 and 26 are provided
with valves 25 and 26' for closing them off when this refrigerator is to be thrown
out of use, in which case corresponding valves in the same branch pipes leading to.
the other refrigerators F are opened to direct the gas through the latter. The
two refrigerators are connected directly by a pipe 28, having valves 28¹ at its
junction with the respective refrigerators, and between these valves communicating
by a pipe 29 with the suction of the special pump F, from the discharge of which
leads a pipe 30 having a valve 30' which joins the pipe 27.
The pipe 27 leads to the suction of the gas compressor G, and from the discharge
thereof a pipe 31 leads to the gas cooler C¹. This cooler may be cooled by
ordinary condensing water, or by ice water coming from the ice machine or other
source, or by brine which has been warmed to a higher temperature than that
which cools the liquefier H. This cooler may be of any construction in which
the gas in flowing through it passes over surfaces cooled by the flow of the cooling
medium. Preferably this medium flows past these surfaces in the contrary
direction to the flow of gas, according to the construction of what are called
reverse-flow coolers. Hence the water or cooling medium enters by a pipe 32 and
passes out by a pipe 33. From the cooler C¹ the gas passes out through a pipe 34,
which conducts it to the liquefier H. In the construction of liquefier shown, a
coil 35 forming a continuation of the pipe 34, is arranged in a descending spiral,
so that the gas as it liquefies and condenses on the surface of the pipe, will run
down the descending coil and flow out through the outlet pipe 36 thereof, which
leads to the liquid acetylene tank I. The liquefier H is cooled by brine, which
enters by a pipe at 37 and passes off at 38.
The liquid acetylene tank 1, since it contains acetylene cooled approximately to
zero F., is provided with an outer cooling jacket h through which the cold brine
is circulated, entering by a pipe 38 and descending to a pipe 39. The gases
which are not liquefiable at this temperature and pressure, accumulate in the
upper part of the tank I, and can be blown off from time to time by a blow-off
cock . To determine the extent of accumulation of these gases, a liquid gange h
is provided.
From the bottom of the acetylene tank I there leads a delivery pipe 40, having
valved branches 41, 41, terminating in couplings 42, by which may be coupled to
them the valved necks of the liquid acetylene tanks or cylinders K K. These
cylinders are placed in a tank J containing cold brine, in order to keep the cylinders
at the same low temperature as the liquid acetylene which is to enter them, and
prevent any vaporization of the entering liquid. The tank J is provided with a
cold brine inlet 43 and outlet 44.
The cold brine inlets and outlets are preferably connected in one continuous
circuit bb as shown. Thus the brine cooled in the chill tank P passes by a pipe 45,
to the inlet 43, circulates thence through the tank J, is drained off by the outlet 44,
and passes by a pipe 46 which is provided with a check-valve 47 to prevent back
flow to the brine inlet 38 for the jacket h, and on flowing through this jacket
passes out by the outlet 39 which connects by the pipe 48 to the inlet 37 of the
liquefier, and after passing through the liquefier passes out by its outlet 38, and
flows through a pipe 49 to the brine inlet 50 (Fig. 5) of the refrigerating
dehydrator For F. The brine then circulates back and forth through the
hollow spaces g g thereof, and passing out there from by the branch pipe 51, enters
a pipe 52, which conducts it to the brine pump P', whence it passes by a pipe 53
back to the chill tank P.
The water reservoirs B B (Fig. 3) are connected each by a valved pipe 54 with

page_text: a pipe 55 leading to a water pressure pump Q. The top of each reservoir B is
connected by a valved branch pipe 56 with a header 57, which connects by a pipe 58
with any part of the apparatus containing acetylene gas between the pressure
reducing valve e and the pressure increasing pump G. Thus the gaseous pressure
is admitted to the top of the column of water. Inside each water reservoir is
arranged a float valve i adapted when the water level in the reservoir rises to
practically the top thereof, to close the outlet through the valved branch pipe 56.
In the description of the detailed process and operation of the apparatus which
I will now give, I will assume that the process is practiced under the general
conditions second herein before stated, namely, a generating pressure of 165 pounds
and a liquefying pressure of 195 pounds.
In starting the operation, the water reservoirs B B are first filled with water by
pamping it into them by means of the pump Q, the valves 54 being open and the
valves 14 closed. The trays A of the generators are filled to the proper level
with carbide and slid into the generator shells, and the caps c fastened on. The
pressure reducing valves e are set to deliver at (for example) 165 pounds. The
entire apparatus now contains air. The valves 25¹, 261, are open to one refrigerator
as F, and closed to the other as F. The valves 41, 41 and all other outlets from
the apparatus are closed. One, two or more generators A are then set in operation.
I will assume the operation of only one generator.
Its outlet valve 13 is opener,
and the water inlet valve 14 is opened. At the same time a circulation of water is
started through the cooler C and jacket d, and then or shortly afterward a circulation
of the cooling medium should be started in the cooler C, and the refrigerating
apparatus should be set in operation so as to cause cold brine to circalate in the
brine circuit.
Upon admitting water to the bottom of the generator A, it enters the same
under the head afforded by the elevation of the reservoir B, and immediately on
coming in contact with the carbide, generates acetylene gas in large quantities, and
this gas, which is evolved first from the lower end of the generator, passes up
through it, expelling the air from the generator and forcing the air out through
the pipe 12 and through the valve e and pipes 15, 16, 17 to the cooler C, and
through this and the vessels D and E to the refrigerating dehydrator F, and on to
the pump G. At first the valve 14 should be opened but little so as to admit only
a limited stream of water. As the acetylene gas expels the air, the successive
evolution of gas causes an outflow of the gas through the valve e and the several
apparatus until between the generator Å and pump G a pressure is developed
which is indicated by the gauge j. When this gauge indicates the determined
pressure (say 165 pounds) the gas pump G is set in operation and is driven at such
speed as to take the gas as fast as it is generated and force it on through the
cooler C and liquefier H into the reservoir I. The proper rate of speed for the
pump G can be determined by means of the gauge j. The pump at first pumps
air, and subsequently mingled air and acetylene, and finally acetylene. As the
pumping proceeds, the pressure beyond the pump G gradually rises as indicated by
the gauge, until the prescribed pressure (say 195 pounds) is reached, whereupon
assuming the brine circuit to maintain a temperature approximating zero F., the
liquefaction of the acetylene commences. Thereafter all acetylene gas that is
pumped at this pressure through the liquefier is caused to liquefy. At first the
air can be permitted to escape by slightly opening the blow-off until the odor
of acetylene becomes marked, whereupon this blow-off should remain closed until
the liquefaction has proceeded sufficiently to condense the gaseous acetylene in the
receiver, whereupon the remaining air can be blown off from time to time, the
liquefied acetylene gradually accumulating in the receiver I, until its level becomes
apparent on the gauge h. By this time the apparatus will have reached the stage
of normal operation, all air having been driven into the receiver I and most of it
expelled, and its place taken in the remaining apparatus by acetylene.
Having thus described the starting of the operation, I will now proceed to
describe the normal action of the apparatus. As fast as water and carbide

page_text: come in contact in the generator A, acetylene gas is given off. The heat of
combination vaporizes part of the water, and the gas and steam pass out together
through the pipe 12 to the reducing valve e. As long as the generation is not
so rapid as to increase the pressure in the apparatus beyond this valve to above
the determined pressure (say 165 pounds), this valve remains open, and the gas
and steam flow out freely through it. But as soon as the generation of gas
becomes more rapid than the rate at which it is drawn off by the pump G, so
that the pressure exceeds the determined pressure, the valve e closes and ceases
discharging gas, so that the pressure is confined in the generator and immediately
reacts against the water which has entered the reaction chamber, and opposes
the inflow of the water, and if the netion be sufficiently rapid will eveu cause an
outflow of water, which will be forced back through the pipe 10 to the
reservoir B until an equilibrium is established. In practice, the valve e will
not ordinarily entirely close, but being a diaphragm pressure regulator will
partially close so as to restrict the outflow. Hence normally a pressure will exist
in the generator equal to that beyond the valve e (any 165 pounds) plus the
pressure equal to the head of water in the reservoir B, so that if this head be
for example six feet, the normal pressure in the generator will be about three
pounds greater than that beyond the valve e (say 168 pounds). By this simple
means, and at the expense of this trifling increase in initial pressure of generation,
the rapidity of generation is regulated automatically and effectively so as to
exactly equal the rate of consumption or drawing off of the gas by the pump G.,
As the acetylene is evolved in the generator it comes at once into contact with
the inner walls of the reaction chamber, and is cooled by the water circulating in
the jacket d, so that part of the vapor is at once condensed. Anther portion
of the vapor is taken up by that portion of the carbide which lies in the upper
part of the generator, effecting thus a further revolution of gas. The moist gas
flows beyond the valve e and through the cooler C, which being cooled by ordinary
-condensing water for example, so reduces the temperature of the gas that the vapor
carried thereby is condensed, and the condensation water runs into the separator D,
where it can be blown out from time to time. The gas thus almost wholly freed
from vaper, then passes over into the storage tank E. If desired this tank may be
cooled by a water jacket in order to promote a further condensation of moisture, or
inetead of a water jacket, any cold medium of a temperature above the freezing
point of water may be used. Any water that collects in this tank may be blown
out from time to time. The almost wholly dry gas then passes on through the
pipe 24 and branch pipe 25, into the refrigerating dehydrator F, which is cooled
by brine and circulates back and forth around the plates gg, which being cooled
to below the freezing point of water, freeze upon their surfaces in the form of snow
or frost any remaining moisture that may be carried by the gas, whereby the gas
is simultaneously dehydrated and cooled to a very low temperature. This
temperature, approximating zero F., is so low that the subsequent compression by
the pump G will not raise the gas to an inconveniently high temperature. The
cooled gas is then drawn into the pump G and its pressure raised to the
predetermined extent proportional to the temperature finally imparted to the liquid
acetylene (say 195 pounds). In so doing the gas is somewhat heated or warmed.
In case of but slightly raising the pressure of the gas, and consequently of but
alightly increasing its temperature, the cooler C will not be required, but in case
of a considerable compression of the gas, the use of this cooler is desirable. The
purpose of this cooler is to lower the temperature of the gas from that at which it
comes from the pump G down to just above the liquefying point. The gas thus
.cooled then passes to the liquefier H, where it is further cooled by the circulation
of cold brine around the coil thereof. Under the stated pressure, a cooling to
zero F., effecte liquefaction of the acetylene, which trickles down and runs into
the receiver 1. Under the low temperature maintained no water will have found
its way over with the liquid acetylene, and in case of the presence of oxygen,
hydrogen, or other impurities, they are maintained so cold as to prevent the

page_text: possibility of explosion. Further, these extraneous gases are maintained almost
absolutely free from admixture with acetylene, since the latter at this low
temperature is liquefied. Consequently it becomes an easy matter to separate
these impurities by blowing them off occasionally by the valve h.
Whenever it is desired to fill a cylinder or "bottle" K with liquid acetylene, it
is placed in the tank J and coupled on to one of the valved pipes 41. Being
immersed in the cold brine, the cylinder is cooled to the same temperature, where-
upon the valve 41 and the valve in the cylinder are opened, and the cold liquid
acetylene is caused to flow into the cylinder, escaping thereinto first under such
reduction of pressure that it vaporizes, and thereby quickly abstracts any remaining
heat from the acetylene gas existing in the cylinder, so that when the full pressure
has been let into the cylinder, the gas it contained is liquefied and mingles with the
liquid acetylene which enters it. Thus the cylinder is completely filled with liquid
acetylene. If, however, the cylinder contained air, this would under the given
pressure be compressed to about one-fourteenth the capacity of the cylinder, and
would upon an equilibrium of pressure being reached, bubble up through the
pipes 41, 40, to the receiver I and take its place at the top thereof, whence it would
be blown out. By closing the valve 41, and the valve of the cylinder, the latter
can be uncoupled and removed.
As soon as the carbide in one generator A has been decomposed, this generator can
he cut out of the apparatus, and one or more others can be put into communication
therewith in its place. The capacity of the reservoir B should be sufficient when
added to the bulk of residual lime in the reaction chamber to completely fill the
latter and thereby expel all gas by the outlet pipe 12, thereby avoiding all
Decessity for pumping off the residue of gas within the generator, as has heretofore
been necessary.
To determine when the generator is thus filled with water, the
reservoir B may be provided with a water gauge k (Fig. 2). Thereupon the
valves 14 and 13 are closed, and the valve in the pipe 21 should also be closed..
The cap c¹ is then to be taken off and the lime and water removed from the
generator. To accomplish this it is only necessary to pull out the tray A', which
carries with it all the residual lime and the greater part of the water. The
remaining water may be readily drawn off or siphoned or pumped out.
A tray
filled with the proper quantity of dry fresh carbide is then thrust in, and the cap c¹
restored. The reservoir B has then to be refilled with water, which is done by
opening the cock 54 and driving the pump Q, whereby water is pumped into the
reservoir B and its level rises therein, driving out the superincumbent acetylene
gas through the pipe 58 until the water lifts the float-valve i, and closes it, where-
upon very quickly a pressure is developed which being indicated on the gauge j
(Fig. 3), indicates that the pump Q should be stopped. The valve 54 is then.
closed, and the generator may at any time be set in operation again by opening the
valves 14, 13 and 21. The generators A A are preferably arranged side by side.
as shown in Fig. 3, each having its own reservoir B and pressure reducing valve e.
The generators are best operated in rotation, or, by providing a sufficient number
of generators in the battery, two, three, or more may be in operation simultaneously..
Each generator operates independently of the others, and each is self-governing
under the control of its pressure valve e.
I construct the generators A of considerable length and small diameter, in order
to enable the gas to be readily cooled by jacketing the generator. The gas in
flowing out from the generator flows necessarily in close proximity to its walls,
which are cooled by the jacket. Further, the source of heat which is located at
the points of contact between the water and the carbide, is circumscribed and
brought into close proximity to the cooling surfaces. By these means the
accumulation of any considerable heat in the generator is avoided, and in fact.
the temperature maintained therein is considerably lower than the theoretical
temperature, namely, the vaporizing point of water at the given pressure. The
tubular form of the generator is adopted for the purpose of enabling it with the
least weight to withstand the required pressure. Its inclined position has been.

page_text: adopted to contribute to the effectiveness of the self-regulation by causing the
water to enter at one end and gradually fill it, coming in contact in its pr gress
with continually fresh portions of the carbide, and being at any moment capable
of being arrested in its flow by the generation of an abnormal pressure, nn.l of
being forced back slightly so as to almost wholly cease its decomposing action upon
the carbide. The same result could be accomplished by placing the slender tubular
generators in vertical positions, but this would involve difficulty in removing the
residual lime, and also would involve the choking or obstruction of the flow of
water by the falling of the residual lime to the bottom end of the chamber, which
disadvantages are overcome by my novel arrangement of the generator as an inclined
tubular chamber receiving water at its lower back end and discharging the gas at
its upper front end. The exact angle of inclination is not innterial, but the angle
shown is preferred.
After the filling of a certain number of cylinders K, as may be determined by
experience, the refrigerating dehydrator (F for example) which has been in use,
will have become so encrusted with the frozen moisture withdrawn from the gas as
to make it desirable to throw it out of use and transfer the operation to the other
dehydrator (as FI). To do this, assuming the dehydrator F to be the one in use,
the valves 251 26' thereof should first be closed to cut off the flow of acetylene,
whereupon by opening the valves in the pipe 28, the acetylene under pressure in the
dehydrator Fflows across into F' until their pressures are equalized, whereupon the
valve 28' of F¹ is closed, and the valves 25' 26' of Fare opened, thereby putting F
into connection. At the same time or previously, the brine circuit should be turned
into F¹ by turning the two three-way cocks 11(Fig. 5) so that the brine circulating
in F becomes quiescent, and the circulation takes place through F. The residual
gas in F, which is at half pressure, is then pumped out through pipes 28, 29 to
pump F, and forced through pipe 30 by opening valve 30' into the main pipe 27.
When pumped down to approximately atmospheric pressure, the pump may be stopped
and valve 28' of the dehydrator should be closed. This dehydrator F may then be
dismounted by detaching and taking off its shell g', thereby exposing its refrigerating
plates 9', which, having flat surfaces, are easily cleaned by scraping or rubbing to
remove the adhering frost or ice. Or the latter may be permitted to thaw and run
off as the quiescent brine becomes warm.
Instead of operating the apparatus under the conditions as to relative pressure
and temperature already stated, these conditions may be considerably varied without
departing from my invention. For example a gas may be compressed by its own
generation to 120 pounds (9 atmospheres), and subsequently may be pumped up
to 150 pounds, and then cooled by refrigeration to minus 10 degrees F. Or it
may be compressed by its own generation to 200 pounds (13 atmospheres), and after
cooling be then pumped up to 17 atmospheres, and then cooled to plus 14 degrees F.
Or, as another example, it may be generated at 18 atmospheres, and after cooling
be pumped up to 21 atmospheres, and then cooled to slightly below 32 degrees F.,
to liquefy it. The last example is within my invention, but is not recommended,
as the pressure of generation is undesirably high, and the corresponding temperature
is in excess of that which should be permitted. I consider it preferable to adopt a
liquefying temperature as low as can readily be effected by existing commercial
refrigerating apparatus, say for example from 10 above zero F., to 10 below zero,
and preferably in the neighborhood of zero F. The pressure at which the gas
should be generated should then be limited to a convenient amount below the
pressure corresponding to the temperature thus determined at which the gas
liquefies, in order that the cooling of the gas to the extreme liquefying temperature
will not liquefy it at the pressure at which it is generated, but will require that
the pressure he raised before the gas can be liquefied. A difference iu pressure
between the generating and the liquefying pressures of from one to two atmospheres,
is considered preferable. For cooling to temperatures not below zero F., ordinary
brine of sodium chloride and water is suitable; but for very low temperatures, a
brine of for example calcium chloride and water may be used, or any other liquid

page_text: non-congealable at the low temperature adopted may be substituted. Any such
non-congealable liquid is to be understood as within the term "brine" as used in
this specification.
It should be understood that the preliminary cooler C has two functions which
are not necessarily combined, namely, first, that of cooling the gas from its
comparatively high temperature of generation to a normal temperature, and second,
that of condensing the steam or aqueous vapor for drying or partially dehydrating
the gas. This second function might be performed by any other means known in
the arts for dehydrating, as for example by passing the gas immediately into
contact with some substance having an affinity for water, such as calcium chloride
or calcium carbide for example. By using any such means of dehydration, the
function of the cooler C would be reduced to that of merely lowering the
temperature of the gas, and such change would not take the process outside of
my invention. Instead of using the preliminary cooler C, the gas might be
introduced directly to the refrigerating cooler F, but I consider it preferable to
first cool the gas by ordinary cold water to a normal temperature, by which
means the refrigerating cooler is made more effective to complete the cooling of
the gas. It is desirable to cool the gas by the refrigerating cooler F sufficiently
to counteract the latent heat given out during the compression of the gas by the
compressor G.
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. The described process which consists in combining water and carbide, thereby
generating acetylene, cooling the generated gas, and then raising its pressure by
mechanical compression sufficiently to liquefy it, substantially as set forth.
2. The described process which consists in combining water and carbide in a
closed chamber, thereby generating acetylene at a pressure less than its liquefying
pressure for a given temperature, cooling it insufficiently to liquefy it at its
generating pressure, then compressing it to its liquefying pressure for said
temperature, and finally cooling it to said temperature, to liquefy it, substantially
as set forth.
3. The process which consists in combining water and carbide in a closed
chamber, thereby generating acetylene under pressure, cooling the gas to condense
ány aqueous vapor, separating such condensation, subsequently raising the pressure
of the gas by mechanical compression, and then cooling it sufficiently to liquefy it
at its increased pressure.
4. The described process which consists in combining water and carbide in a
closed chamber, thereby generating acetylene under pressure, cooling the gas,
raising its pressure by mechanical compression, and then cooling it by refrigeration
sufficiently to liquefy it, whereby the necessity of generating the gas under high
pressure is avoided, substantially as set forth.
5. The described process which consists in combining water and carbide in a
closed, chamber, thereby generating acetylene under pressure, conducting this
operation at a rate so slow as to limit the pressure to twenty one atmospheres,
cooling the gas, increasing the pressure of the gas by mechanical compression,
and finally cooling it by refrigeration to below zero Centigrade, to liquefy the
acetylene, substantially as set forth.
6. The described process which consists in combining water and carbide in a
closed chamber, thereby generating acetylene under pressure, cooling the gas
sufficiently to condense but not congeal any aqueous vapor, separating such con-
densation, then refrigerating the gas to separate by congelation any remnant of
aqueous vapor, then increasing the pressure of the gas by mechanical compression,
and again cooling the gas sufficiently to liquefy it at its increased pressure,
substantially as set forth.
7. The process which consists in combining water and carbide in a closed

page_text: .
chamber, thereby generating acetylene under pressure, conducting this operation
at a rate so slow as to limit the pressure to an amount less than the liquefying
pressure for a given temperature, cooling the gas sufficiently. to condense any
aqueous vapor, separating such condensation, then increasing the pressure of the
gas by mechanical compression to its liquefying pressure at said given teinperature,
then cooling the compressed gas to just above its liquefying temperature, and finally
refrigerating the compressed gas to or below said given temperature to liquefy it,
8. The described process which consists in combining water and carbide in a
closed chamber, thereby generating acetylene under pressure, suspending the
generation by separating the water and carbide whenever the pressure exceeds
a predetermined pressure, cooling said gas, and finally liquefying it in substantially
the manner set forth.
9. The process of generating acetylene and liquefying the same for storage in
receiving cylinders, which consists in immersing the receiving cylinder in a
refrigerating liquid, generating acetylene gas under pressure by bringing water
and carbide into contact in a closed chamber, conducting the gas thus generated
under pressure into contact with refrigerating surfaces to liquefy it, and bringing
the liquefied acetylene while thus refrigerated and under pressure into communi-
cation with the interior of said refrigerated cylinder, whereby the liquid acetylene
flows into said cylinder, and the acetylene gas originally contained in said cylinder
is liquefied.
10. An apparatus for generating and liquefying acetylene, comprising a generator,
means for introducing water thereto, an acetylene outlet passage therefrom lending
to a compressor, a cooler for cooling the gas flowing through said passage, the said
compressor, and a liquefier for cooling the gas delivered from said compressor
combined and adapted to operate substantially as set forth.
11. The combination of an acetylene generator, a cooler, a condensation water
receiver, a secondary cooler, a compressor, and a liquefying cooler, with connecting
pipes, combined and adapted to operate substantially as set forth.
12. The combination of an acetylene generator, a condensing cooler, a con-
densation receiver, a refrigerating cooler, a compressor, a refrigerating liquefier,
and connecting pipes, with a refrigerating machine, the brine circuit of which is
connected to said refrigerating cooler and liquefier.
13. In an acetylene apparatus, a refrigerating dehydrator constructed and
operating substantially as set forth.
14. In an acetylene apparatus, the combination of two refrigerating dehydrators
connected, for alternate operation in substantially the manner set forth.
15. In an acetylene apparatus, à generator A, source of water under
pressure, B, pressure-reducing valve e governing the gas outlet, and connecting
pipes, arranged and adapted to operate in substantially the manner set forth.
16. In an acetylene generating apparatus, a generator A consisting of an
inclined cylindrical shell having a valved water inlet pipe connected to its lower
end, a valved gas outlet pipe connected to its upper end, and a removable cap or
cover for closing its upper end, and a removable tray A fitting within said shell
for containing the original charge of carbide or the residual oxide or lime, whereby
on charging and closing said generator and admitting water at said lower inlet, the
carbide is progressively decomposed from the lower, to the upper end of the
chamber, and finally the chamber may be entirely filled with the residual oxide
and water, and by closing the water inlet and gas outlet valves and removing said
cap, the generator may be opened for recharging without the necessity of pumping
it out, and without loss of gas, substantially as set forth.
Dated this 6th day of May 1897.
J. C. MEWBURN & ELLIS,
55 & 56 Chancery Lane, London, Chartered Patent Agents.