Note: Descriptions are shown in the official language in which they were submitted.
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BACKGRCUNI~ OF THE INVENTICW
FI~:~.D OF THE INVENTION
Thi3 inven~ion pertainq to an apparatu~ and a method for
pr~ci~ely filling compre~ed ga~ bottles wi~h a preci3e quantity of
eompres~ed carbon dioxld~ determined on the ba~is o~ maB
THE PRIOR ART
The filliny of compres~ed gas bottle~ i~ a ~ommon practice.
A bottle, or a cylinder a3 they are o~ten re~erred to, cannot legally
contaln more C02 than 68~ by weight of its ~ater cap~city. For example,
i~ a bottle will hold 100 pcund~ of ~ater when filled, it should not
have ~e than 68 ~ound~ of GC2. I~ a bottle i~ overfilled, exce~ive
pre~s~re3 may develop and burst a rupture disc, dependin~ on a~ount
of o~r~ill and temperature. The only known and u~ed ~afety devicR
~orcompres~edgas bot~le~ are rupt~re discs. Only one rup~ure di~c
o~ the proper type, ~aterial and manufacturer 3hould ~ us~d or~ any
one bottle. One o~` the problems previou~1y seen is that pecple in~tall
two or more ruptu~e discs, the wrong disc, or back-up the rupture
disc with a coin or ~lug and the r~pture disc become3 inocerative.
In many lnstance~ like thi~l a bottle ha3 exploded ~ith ~0~9 o property,
llmb, and even life. The ~ottie~ ~ravel in commerce and for the mo~t
p3rt 1~ i9 impo3~ible to ea~ily a~certain i~ a rupture di~c ha~ be~n
rendered inop~rative by other partie~. Cylinder filllng is criti~
incorrect filling ~ay caus~ haz~rds, a~d s~fety eannot ~e oYerempha~ize~.
C02 .is mea3ured by weight. ~02 can be fill~d by gravity
or from extrb~ely high pressure dry ice converter~, Mo9t C02 ~illir.g
1~ done with pump~. C02 fllling pump~ are made by Liq~id C~bonic
Divi~ion o~ General DynamlC~ and by Walt~r Kidde co~pany. Use of
a ~uitable C02 filling p~np offer~ th~ ~ost convenient ~nd mo~t efficiant
method of filling bottles and blow down a~d/or cooling p~rge~ of hottl~s
i3 not nece~sary to obtain a full fill.
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~;~;29~28
Re~ardless of the known ~illing method~ 3elected and reg~rdle~
of the apparatus employed, a ~cale, ~uch aA ~ reccmmended bea~ ~cale
meetin~ regul~tory accu~dCy requirement~, mu~t be u~ed to d~te~nine
when a bottle iR properly filled. ~hi~ i~ done by voiding the bottle
~nd deterrnining its empty or tare welght. To the tare wei~ht i~ added
it~ C02 capacity in po~nds, and then th~ bottle i~ filled to such
gros~ weight. There are many problems including ~ignificant variance
in bottle weight and lack of an automatic 3hut-off. ~o one has devised
a weighing device which i~ ~f~icien~ly accurate to be t~usted durinq
illin~, the bottle must again be weighed after filling. Mistake~
are co~monplace and over and ~nder fill a ~requent occurrence; rni~takes
and oversights can produce explo~ive result~.
C02 is a very difficult compres~ed ga3 ~0 ~ill and to mea~ure.
At -69.9QF, C02 e~i3ts as a solid and a v~por: at 69.9F, C02 ~xlstg
aq a ~olid, liquid or vap~. between -6~F and +~8F, C02 exist~ a~
a vapor and a liquid, above 88 F, all C02 exi~t~ ~ a va~or. Compressed
gas bottle~ are u3ually filled ~ith compres3ed C02 in its liql~id form.
Llquid C02 is hlghly compressible at temperature~ approaching nor~al
ambient tempe~atures and th~ quantity of C02 cannot be acc~rately
dete~nined on a volumetric ba3i3. For ex~mple, at 88 ~ and 1050 PSI,
~h~ ~pecl~ic gravity of C02 i3 about 0.59, whereas at 1400 PS~ the
~pecific gravity i~ about 0.77. A~ a ~urther exa~ple, at 774F and
1000 PSI, the ~pecific ~ravity is 0.74 and at 1400 PSI the 3p~cific
gravlty i~ 0~84. At 32~ and 1400 PSI ~he ~pecsific gravlty i3 0.9~.
'rhere is a trend toward s~aller bottla~, speclfically S
pound and 2 1/2 pound bottlec. It ~ecom~s e~t~emely di~fi~ult to
fill the3e bottles based upon welght because the bottles v~ry 3ignif~cantly
in their metal cont~nt and the tot~l weight 19 quite small ond these
~mall bottle~ are almo~ lmpos~i~le to ~eigh during ~ ing becau~e
thc hos~ conn~ctlons are an influence of erratiç ~u~ntity. There
i~ no appa~atuq or ~ethod l~nabling a ~etailer to fill these ~mall
bottle~ eEiciently and ~afely.
~Z25~
OBJEC'rS OF ~ INVE~'~ION
It i~ an obje~t of the present lnvention to pro~ide an improved
apparatu~ and method for filling bottle~ ~ith highly compfessed carbon
dloxide, ba~ed upon ~he ~a~s of the compressed carbon dioxide.
It i~ an objeç~ of the pre~ent invention to provide an impeoved
apparatus ~nd meth~d for filling bottles with a predetermined mass
o colnpre~sed carbon dioxide in a compre~3ible liquid or ga3eou~ stat~.
It i~ an object of the pre~ent invention to provide ~n improved
~pparat~s and method for filllng bottle~ with a predetermined ma~s
o carbon dioxide in either ga~eous and/or compressibl~ liquid 6t~te.
App~rat~s for filling compre~sed ga~ bottle~ with a predetermlned
ma3s of compressed carbon dioxide, has an inlet for connection to
a 30~rce of compr~ssed ~a~, ~ pump for co~pre~ed car'~c,n dioxide,
a m~ss flow met r connected to the pump and having a ~ignal generator
whlch will produce ~ signal ~or unit~ of ma~ of compre33ed e~rbon
dioxide flow, a nor~ally clo~ed fill valv~, an outlet connector for
connecting to a compress4d ga~ bottle, means for opening the fill
valve, and me~n3 for quantifying the ~ccum~lative additive count from
the ma~s L-low meter and terminating filling of the bottle ~pon reaching
a predetermined ~ount.
A method o~ filling compre~sed gas bottle~ ~ith ~ predetermlned
ma~3 of compres,~ed car~on dioxide includes the ~tey3 o~ propelling
compres~ed carbon dioxide illtO th~ bottle, measuring the m~ flow
o~ the compre3~ed carbon dioxide, gener~ti~g a 3ignal proportionate
to the amount of mac~ per unit~ o-~ time, accumulatlng the sign~ls,
and terminating flow upon accurn-llatior of a ~redetermined nurnber of
slgllals~
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3RI~F DBscRIpTIo~ 0~ THE DRP.WINGS
FIG. 1 i~ a 3chematic diagr~m of the apparatus o~ th~ pre~err~d
el~bodlment of thi~ invention; and
~ IG. 2 is a detail view of ~truct~re for connecting the
appar~tu~ according ~o FIG. 1 to a compressed gas bo~le.
AS SHOWN ON T~E DRAWI~G5
., . ., _
The principles of the present invention Are par~icularly
u~eful when embodied in the appa~atus, generally indi~ated by the
numeral 10 in FIG. 1, for precisely filling comp~es~ed gas bottles
with a pred~termined mas~ of compressed carbon dioxide in either or
both of ga~eous or compre~sible liquld 5tates.
The apparatus 10 has a compre~sed gas fluid line lS hav~ng
a fluid inlet 11 ~or belng connected to a bulk sourc~ 12 o co~pres~ed
9~8.
.~L~d~
The source 12 may be a large cylinder or a bulk tank; the expected compressed
gas is highly compressed carbon dioxide substantially in a liquid state
at a pressure of 1500 PSI more or less. Downstream of the fluld lnlet ll
is a check valve 13 for preventing loss of compresaed ga~ when the fluid
inlet ll is disconnected and a change is made in the source 12. Further
downstream of the fluid inlet ll is a relief valve 14 which will open when
pressure in the compressed gas line 15 exceeds 1500 PSI. A high prassure
pump 16 is fluidly co~nected to draw compressed gas from the source 12
and to propel the compressed gas through a mass flow meter, generally
ind-Lcated by the numeral 17, to a bottle connector 18. The pump 16 is of
a known type and may be either electrical or pnet~tic powered. A pneu-
matic power line 19 supplies compressed propellant to the pump 16. Down-
stream of the pump 16 is a second relief valve 20 which will open if
pressure downstream of ~he ptLmp 16 exceeds lS00 PSI. Downstream of the
, .
ma53 flow meter 17 is a normally closed solenoid powered valve 21 herein-
after referred to as the fill ~alve 21. Between the fill valve 2L and the
bottle connector 18 is a solenoid powered normally open vent valve 22
fluidly connected to the line 15 by a very small diameter refrigerant c~p-
illary ttlbe 23. The bottle connector 18 has a seal 24 and is adapted to
sealingly receive the neck o~ a compressed gas bottle 26. Wlthi~ the bottle
neck 25 is a olte-way valve 27, commonly referred to as a Schrader ~alve o~
the same type as used in tubes and tires~ The volu~e of the line 15 down-
stream of t.he fill valve 21 is intentionally minimized by the usRge of the
capilla~y tube 23 which effectively minimizes the 1083 of gas during ventin~
by opening of the vè~t valve 22 prior to disconnection o~ a bottle 26 front
the bottle connector l8.
The mass flow meter 17 i9 connected to a signal counting con-
troller 28 which ls operatlvely connected to the fill valve 21 and vent
valve 22; the valves 21, 22 are connected in parallel to the c~troller 28.
The mass flow meter 17 has a U-shaped torque tube 30 which i9 a part of
the ~luid line 15 and which i3 ~ide open a~d devoid of obstructLolls to
fluid flow. The tube 30 i5 continually vibrated by an electro~1gnet 31.
When there is movement of a mass through the ttlbe 30, the moYing mass
exerts a torque upon the tube 30 and sensors 3~ detect and measure the
tor~ional twis~ of the tube 30. The sensors 32 ~ay be either magnetîc
~,,~
~2~
or electro-optical and are connected to the controller 24. Whenever the
tube 30 twists, the sensors 32 detect the twist and send a signal to the
counter ?4 that is directly proportional to ~he mags th~t la flowing through
the tube 30 during the period of time of measurement. The tube 30 is
excited at a suitable frequency anywhere be~Jeen 0-15,000 ~z. The increment
of time Eor a measurement of a unit of mass, and the quantity of a unit of
mass c~n both be very s~all. The preferred mass flow meter is made by
~icro Motion, Boulder, Colorado, is referred to as a Model C and is repre-
sented as being the subject of UOSO Patents 4,109,523; 4,109,524 and
7,721.
The controller 24 is a multi-decade electronic predetermining
counter. An upper window has a multi-digit L~D read-out window 35 and
the controller 24 can be adjusted or programmed by thumbwheel switches 36
to enter a predetermined accumulated additive count required by the con-
troller 24 for an output signal by the controller 24. A reset switch 37
is provided to return the controller 24 to zero after a fill cycle and
a start switch 38 will initiate a fill cycle. The preferred controller 24
i5 a M~del 7907 by Veeder-Root, Digital Systems Division, o~ Hartford,
Connecticut. The controller 24 is continually energized as ls the mass
ilow meter exciter magnet 31. If the pump 16 ls electr~cal, the p~mp 16
ls also continually energized.
In the mathod of the pre~ent inven~ion and in operation of the
apparatus 10, the inlet 11 is connected to a supply o~ compre~sed gas;
the speciflc intended gas is carbon dioxide. The pump 16 begins to propel
compressed gas through the lina 15 and fills the line 15 to the flll
valve 21. The compressed gas i~ highly compre3sed and is ~u~?stantially
in a llquid atate in the source 12 and throughout the line 15. The check
valve 13 prevents backflow or emptying of the line 15 during char~ging of
supplies 12, and minimlzeLl the loss of compressed gas. If pressure withln
the line 15 goes above 1500 PSI, elther or both of relief valves 14, 20
will open and relie~e down to 1500 PSI. When the line 15 is ~illed, the
pump 16 stops due to back pressure and/or hydrostatic lock even though
the propellant line 19 is kept pressurized and th~ pump 16 iY continually
energized and ready to go,
$
A gas bottle 26 is prepared for filling by first being placed
upside down in a cage. The valve 27 is opened and th~ bottle 26 is com-
pletely voidedO The bottle is then weighed on a G0 - N0 G0 scale to be
certain there is no water, rer~inlng gas or ~oreign material in the bottle.
The gas bottle 26 is then placed in the apparatus 10 and the bGttle neck 25
is held in the bottle connector 18 and against the seal 18. The reset 37
is used to reset the controller 28 and the LED window 35 to zero or an
appropriate basP. The switches 36 have been previously adjusted to pre-
program the controller 2~ for terminating fill upon receipt of a predeter-
mined quantity of 3ignals from the mass flow control 17.
The operator o~ the apparatus 10 actuates the start button 38
and the controller 28 effects simultaneous opening o~ the flll valve 21
and closing of the vent valve 22. Highly compressed gas, speciically
highly compressed carbon dioxide gas which is substant~ally in a liquid
state, i~ propelled by the pressure of the source 12 and the pump 16
through the fill valvc 21 and through the bottle valve 27 and into the
bottle 26.
Any and all flow of the highly compres3ed gas through the r~s
flow meter 17 effects a torque upon the U-shaped tube 30 and the rnass
1OW meter measure~ this flo~ on the bQ~is of mass. The tub~ i9 con-
tinually vibrated at 0-15,000 ~Iz, but the vibration is linear ln the
absence oE flow. During flow, the tube 30 ~ists and the sensors 32
detect the twi3t uhich L~ proportlonal only and directly to the mas~ flow
throu~h the tube 30, the twist ignores the constraints of pressure~ tern-
perature, dens-Lty, compressibility o liquid ca~bon dlo~lde, velocity
and li~uid or vapor ~tate. The tube twists directly proporcional to the
rnQs~ ~low. The sensors send a signal during each twiRt of the tube 30
that i~ proportionate to and which indicate~ how many units of l~t~8 flowed
through the tube 30 ~uring the time pe~iod of the tw13t.
The controller 28l which is ~Iso a counter~ accu~ulates the
sign~ls and wilen a predetermined ndditiva counC n~tch~s the pre3et number
count previously entered Witll the thun~heal swltches 3b, Cha controller 28
Eire~ an output thet w~ tern~nate fkJw by simult~lneously closin~ the fill
valvQ 21 and openin~ the vent valv~ 22. The pun1p 15 rem~ins energi~ed and
~ 7
ceases to operate because o~ hydrostatic back pressure. The second rellef
valve 20 protects tha~ part of the line do~mstream of the pump 16. ~te
exciter 31 remains energi~ed and the tube 30 keeps vibrating ~te LED
window 35 will indicate how many units of highly compressed gas have
passed through the mass flow meter 17. The accurqcy of the measurement
is ~1/2% based upon mass. ~hen flow is terminated, the bottle valva 27
will automatically close.
Opening of the vent valve 22 vents to atmosphere the compressed
gas between the fill valve 21 and the bottle 26 prior to the bottle 26
being disconnected from the bottle connector 18. This venting prevents
compressed gas from blowing out on an operator of the apparatus 10 when
the bottle 26 is disronnected. During the venting, the flow of compres~ed
gas is restricted by small tube 23. The small tube 23~ which is preferably
a capillary tube, also reduces the volume of the line 15 in between the
fill valve 21 and the bottle 26. The restrirting of the vented flow also
eliminates the loud noise of sudden release of the compressed gas~
The improved apparatus and method of this invention enable accurate
and safe illing of relatively small compressed gas bottles wlth liquid
carbon dioxide. A specific small botkle is a 2 1/2 pound capaeity aluminum
bottle by Luxer. This invention will enable retailers, such a~ large
grocery stores, to reill carbon dioxide bottles for domestic sot dri~c,
wine and beer systems.
Although various minor modlfications may be sugge3ted by others
versed or experlenced in the art~ it should be understood that I wish to
embody within the scope o the patent warranted hereon, all such embodi-
ments as reasonably and properly come wlthin the scope of my contrlbution
to the art.
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