Note: Descriptions are shown in the official language in which they were submitted.
2~78~
t 3row
C~BON~EU BE~R~ DX~P~NSIN~ AppARp~us
~ lnvent~on rela~es generally to ~rbonal:or~, and in
pa~tic:ular to a carbon~tor ~ppZIr~u8 utllizQd in a po~t-:~ix
bc~erage diap~nsi~g 8~rsta~ls. I~ ~lat~8 pa~ti~ularly to a
c:~rbon~to~ 7n whic~ thQ lev~l o~ carbona~ion ~-q control~.~d
in 8UCI~ a way ag ~o avo1d ~rarious probla~s which ~esul~ ~rom
exc~s~ive carbonation. ~:
The ~cl~at~on orq carbon dioxide ga8 into t~ater iS
enhancad a~ colder ~a~p~ratu~eg and h~gher E)~e~sures. Ga~ : ;
pre88Url~ i9 not ~ cul~ ~o r~3gulate~ ~owe~er, ~he aJnbient
teInp~rature, and the tempQ~atur~ o~ th~ water supply in a
c~rbonat1ng apparatug ~nd to ~rary. a~cau~ o~ these . .
~e~Qperaturc ~tzlria~cion~, co~trol o~ th~ temperature o~ the
water supplled to ~ carbona.ting appa~atu~ llas been di~:~iCUlt
il~ co~n3rcial carbonat~ng ~ulp~ent, and ~n many instance~
ecorlomlcally infaa~ible, par~icula~ly in t}le carbonators or~ ; . -
po~t ~ix b~veragQ d~3p2n3ers. Cor~seguently t~e c0;~ aontsnt `-
o~ dispensed beverag~s ha~ beQ2~ alr~icul~ ~o cont~ol.
Rithe~to, the acc~3pted pract~ce ~ to ~at ths pressure
~ C2 ente~ng the carbonz~t~ng chamber at a l~v~l high
eno~tg}~ to achieve ~d~quata level s o~ carbonat~on at the
highest no~ally arltic~pated wa~er temperature~ Reduced ., ~ -
water supply ~empe~ ur~3 due to daily~ 3ea~0nal ~ or `~ -
geographlc~l tr~3nds, cauæ~3~; exces~i~e le~els o~ ca~bonation
-~ ~; -.
- 2 -
CARBONATED BEVERAGE DISPENSING APPARATUS
Brief Sum~ary_of the Invention
This invention relates generally to carbonators, and in particular to a
carbonator apparatus utilized in a post-mix beverage dispensing system. It
relates particularly to a carbonator in which the level of carbonaticn is
controlled in such a way as to avoid various problems which result from
excessive carbonation.
The solution of carbon dioxide gas into water is enhanced at colder
temperatures and higher pressures. Gas pressure is not di-fficult to regulate
However, the ambient temperature, and the temperature of the water supply in
a carbonating apparatus tend to vary. Because of these temperahlre variations,
control of the temperature of the water supplied to a carbonating apparatus has
been difficult in commercial carbonating equipment, and in many instances
economically infeasible, particularly in the carbonators of post-mix beverage
dispensers. Consequently the CO2 content of dispensed beverages has been
difficult to control.
Hitherto, the accepted practice was to set the pressure of C2 entering
the carbonating chamber at a level high enough to achieve adequate levels of
carbonation at the highest nornally anticipated water temperature. Reduced
water supply temperature due to daily, seasonal, or geographical trends, causes
excessive levels of carbonation to be produced, giving rise to various
undesirable conditions described below.
One of the problems resulting from the inability to control water supply
temperature is CO2 wastage due to out-gassing of excess carbonation at the
point of release to atmospheric pressure (usually at ~e beverage mixing
dispensing valve output).
Another problem is that excessive levels of carbonation at the point of
dispensing cause irregular and inconsistent operation of the fluid flow controlsFurthermore, excessive carbonation levels at the point of dispensing causes the
inconvenience of high foarn levels in the beverage receptacle, and product
wastage due to overflow and repeated topping-off cycles. The undesirable
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3 2~78~ ~
results of excessive carbonation levels in beverage dispensing equipment are
exacerbated with faster beverage dispensing rates, as found in modern beverage
dispensing equipment. - ~ `
It is the principal object of the present inven~ion, therefore, to provide
an apparatus to control carbonation level over a widely varying range of
temperatures in the water used in the carbon~tion process.
It is a further object of the invention to provide an improved apparatus
for effecting carbonation of water in post-mix b~verage dispensers and in other
equipment requiring carbonated water at controlled C2 levels.
It is yet another object of this invention to conserve carbon dioxide, and
thereby reduce operating costs, by limiting carbonation level to a predetermined
. . ~
range, and to eliminate C2 wastage due to out-gassing at the point of release
to atmospheric pressure.
Among other objects of the invention are the improvement of the
performance of beverage dispensing equipment, and especially the beverage
mlxmg valve, and the avoldance of such problems as mconslstent operatlon of
the fluid flow controls, high foam levels in the beverage receptacle, and product
wastage.
These and other objects of the invention are addressed in accordance
with the invention by providing a control system in which a temperature sensor
is arranged to sense the temperature of the water, and control means, responsiveto the temperature sensing means control the pressure at which carbon dioxide
is introduced into the water, the pressure increasing with increasing water
temperature. The relationship between water temperature and CO2 pressure, as
determined by the control means, is preferably such that the carbonation level
in the dispensed carbonated beverage is maintained within a limited range, and
preferably at a substantially constant level.
The temperature sensor senses the temperature of the supply water being
provided to the carbonator tank, or of the carbonated water within the tank
itself. The CO2 pressure can be controlled by a temperature sensing gas
regulator, or an electronically controlled regulator responsive to a temperature
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20~87~6
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transducer. The desired carbonation level or range of carbonation levels can be
selected, and with the apparatus set for the desired carbonation level, the level
will be automatically maintained even though the temperature of the water
supplied to or within the carbonator tank may vary. -~
S Brief Descri~tion of the Drawin~s
FIG. I is a diagram showing the relationship between C02 pressure and
water temperature for a specific carbonation level;
FIG. 2 is a schematic diagrarn of a beverage dispenser in accordance
with a first embodiment of ehe invention, wherein a C2 pressure regul~tor is
mechanically controlled in response to the temperature of the liquid in a
. ~ ... ,,.. ~,
carbonation tank;
FIG. 3 is a schematic diagram of a beverage dispenser in accordance
with a second embodiment of the invention, wherein a C2 presswe regulator
is mechanically controlled in response to the temperature of water being fed
IS toward a carbonation tank;
FIG. 4 is a schematic diagrarn of a beverage dispenser in accordance
with a third embodiment of the invention, wherein a CO2 pressure regulator is
electronically controlled in response to the temperature of the liquid in a
carbonation tank;
FIG. 5 is a schematic diagram of a beverage dispenser in accordance
with a fourth embodiment of the invention, wherein a CO2 pressure regulator
- . ~ ,:. . ...
is electronically controlled in response to the temperature of water being fed
toward a carbonation tank;
FIG. 6 is an elevational view of a temperature sensor and a first -
mechanically controlled CO2 pressure regulation valve, the latter being shown ~ ;
in section;
FIG. 7 is a se~tional view of an electroni~ally controlled CO2 pressure . ~-
regulation valve; i-
FIG. 8 is a sectional view of an alternative mechanically controlled
valve; and ;
FIG. 9 is a sectional view of an alternative electrically con~rolled valve. ` ~ .
... ~...., .;; .
, ... .. :
2 ~ ~ 8 7 ~
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Detailed Description
Carbonation level in soft drink dispensing is defined in terms of the ratio
of the volume of carbon dioxide to the vol~e of water. As shown in FIG. 1,
as temperature increases, it is necessary to increase CO2 pressure to maintain agiven carbonation level. Conversely, at lower temperatures, a lower CO2
pressure is required to maintain a given carbonation level. The relationship
between temperature and pressure is approximately linear. FIG. 1 shows a
typical relationship between gas pressure and water temperature -for a
carbonation level of 5.25. In practice, the relationship between gas pressure and
water temperature may depart from the graph of FIG. 1 for various reasons such
as losses in the system.
Typically, when water temperature is at 68F., 100 ml. of water can
dissolve 90 ml. of CO2 gas when the gas is under one atmosphere of pressure.
If the CO2 is pressurized to 5.25 atmospheres or 77.175 PSIG, then 5.25 times
as much CO2 will dissolve in the water at the same temperature. That is, 472.5
ml. of CO2 (measured at one atrnosphere) will dissolve in 100 ml of water,
when the pressure is raised to S.25 a nospheres. The solubility of CO2
decreases with increasing water temperature, requiring a still higher pressure to
force the same amount of CO2 into solution.
The apparatus of FIG. 2 makes it possible to maintain any desired
,, . ..~: -. . .
carbonation level in the carbonated water in carbonation tank 10. Water, from
a water supply line 12, is supplied to tank 10 throu~ a motor-driven pump 14
and a check valve 16. The check valve is required to maintain CO2 pressure in
ta~ 10. A double check valve ~s preferably used in order to insure ag~nst
flow of liquid or gas back to the water supply through line 12. The motor of
motor-driven p~p 14 is controlled by a level sensor 18, which starts ~e motor
when the liquid level in the ta~ falls below a first predeterrnined level, and
shuts of ~ the motor when the liquid level reaches a second predetermined level
which exceeds the first predeterrnined level. Carbon dioxide from supply ta~
20 is delivered to t~ 10 ~rough a pressure regulator 22, a temperature~
controlled va ve 24 ~d a check valve 26. Carbonated water is delivered to
- 6 - 2C35878~
dispensing valve 28 through line 30.
A temperature sensor 32~ imsnersed in the liquid 34 in t~mk 10, operates
valve 24 through line 34, controlling the pressure regulation in the valve so that,
at higher temperatures, the flow of CO2 through the valve is less restricted. Inthe valve, a sensor bias spring (not shown in FIG. 2) controls the flow of C2
into tank 10 in such a way that the CO2 pressure increases with increasing
temperature in a predetermined manner to maintain a substantially constant
carbonation Icvel.
The temperature sensor 32 can be a bulb type device in which an
expanding fluid flows through tube 34, to operate a diaphragm within valve 24.
The expanding fluid can be a liquid such as an alcohol or glycol, or one of the
several fluorocarbons available under the trademark FREON. Alternatively, the
fluid can be a gas such as nitrogen or carbon dioxide.
Details of the temperature sensor 32 and valve 24 are shown in FIG. 6
Valve 24 comprises a fluid chamber 36 connected through tube 34 to sensor 32.
The chamber is closed by a flexible diaphragrn 38. A spring 52 (the sensor bias
spring referred to above) is located between diaphragm 38 and a second
diaphragm 54, which fvrms part of the boundary of an outlet chamber in
communication with outlet 42. A valve element 44 is mechanically connected
to a center rivet 56 on the bottom of diaphragm 54, and cooperates with a valve
seat 46 to provide a restricted, closable passage between inlet 40 and outlet 42.
Valve element 44 is urged toward its closed condition by a weak spIing 48
which is in compression between the valve element and an adjustable plate 50.
Plate 50 has an opening 51 allowing flDw of CO2 from inlet 40 toward the valve
orifice. CV2 flows through valve 24 from inlet 40 to outlet 42, and is controlled
by the restriction between valve element 44 and valve seat 46. W~en pressure
is reduced at outlet 42 as a result of CO2 consumption, spring 52 moves
diaphragm 54 downward. Rivet 56 on the bottom of the diaphragm forces
valve element 44 to an open condition, allowing CO2 to flow from inlet 40 to
outlet 42 to restore pressure on the outlet side of valve 24, whereupon
diaphragm 54 allows valve element 44 to reclose under the urging of spring 48.
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20~7~6 ;~
- 7 -
Spring 52 is biased by the fluid in charnber 36, acting against diaphragm 38.
When the water temperature being sensed by sensor 32 is higher, the sensor
fluid pressure in chamber 36 increases the downward force on spring 52. This
......................................................................................... .... , -, . .~ .,,,. . ,~j
increased downward force, in turn, produces an increased C2 pressure in the
S carbonator. A reduction in the temperature sensecl by sensor 32 has the
opposite e-ffect, producing a decrease in the C2 pressure in the carbonator.
The carbonator of FIG. 3 is similar to that of FIG. 2 Pxcept that, instead
of sensing the temperature of the carbonated water 34 within tank 10, it senses
the temperature OI the water being supplied to the tank by means of a
temperature sensor 58 in line 60 between motor-driven pump 14 and double
check valve 16. Temperature sensor 58 is also of the expanding fluid type.
Operation of the carbonator of FIG. 3 is essentially the same as that of F]EG. 2in that CO2 pressure applied to the carbonator tanlc is regulated in accordance
with water temperature.
The carbonator of FIG. 4 uses an electrical temperature sensor 60
immersed in the c~rbonated water 34 in tank 10. Sensor 60 is preferably of the
thennistor type. The electrical signal from the sensor is delivered through
electrical lines 62 to an electronic control 64, which delivers operating current
to an electrically controlled valve 66. The electronic co~trol 64 can be any oneof a variety of well-known and available servo amplifiers or other control
.-. :, ;~ . - - ~ .
devices capable of providing an output, the voltage or current of which has a
predetermined relationship to the level of the input signal. Alternatively, the
electronic control can be a more elaborate analog or digital servo controller
The essential requirement is that the output signal of the electronic controllerbe such that the restriction in valve 66 regulates the C2 pressure in tank 10 so
that it bears the desired relationship to the sensed temperature. With an
electronic control, the desired relationship between temperature and pressure can
be easily achieved. Fur~errnore, the carbonation level can be set electrically
. . ~ . ~...
in the controller itself, instead of mechanically by adjustrnent of valve springcompression. -~
As shown in FIG. 7, valve 66 is sirnilar to valve 24 in that it comprises
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20~7~6
- 8 -
a valve element 68 urged by a coil spring 70 toward a valve seat 72. The valve
provides a variable restriction for flow of C2 from inlet 74 to outlet 76.
Movement of valve element 68 against the force of spring 70 is controlled by
a proportioning solenoid 78, the armature of which is mechanically connected
to element 68 through center rivet 80 and spring 82, which presses against
diaphragm 84.
The carbonator of FIC;. S is similar to that of FIG. 4 except that, instead
of sensing the temperature of the carbonated water 34 within tank 10, it senses
the temperature of the water being supplied to the tank by means of an
electronic temperature sensor 86 in line 88 between motor-driven pump 14 and
double check valve 16. Temperature sensor 86 is preferably of the the~nistor
type. Operation of the carbonator of FIG. S is essentially the same as that of
FIG. 4 in that CO2 pressure applied to the carbonator tank is regulated in
accordance with water temperature.
lS The valve of FIG. 8 takes the place of temperature-controlled valve 24
and check valve 26 in FIG. 2. The structure of the valve is similar to that of
the valve of FIG. 6, except that the valve includes a eherk ball arranged to
prevent reverse flow of CO2. As shown in FIG. 8, valve 90 is controlled by
fluid flowing to and from sensor 92 through tube 94. The valve comprises a
CO2 inlet 96, and a CO2 outlet 98, the inlet being connectable to the gas supply,
and the outlet being connected to the carbonator tanlc. The hllet is normally
closed by a check valve comprising a ball 100 urged against a seat 102 by a
small spring 104. Spring 104 is held in the chamber containing seating element
106, and i5 trapped between valve element 108 and check ball 100. Spring 104
is weaker than spring 114, and allows both the check ball 100 and valve
element 108 to be open simultaneously. This allows flow of CO2 through the
valve from inlet 96 toward outlet 98 when increased force applied to spring 114
causes diaphragm 116 to press against center rivet 118, forcing valve element
1 18 open.
The electrically controlled valve of FIG. 9 is similar to the valve of FIG
8, except that it uses a proportional solenoid 120 to press downward on
-, . ,, .~:
9 20a~78~
diaphragm 122 through spring 124, to open valve element 126.
Various modifications can be made to the carbonators described. For
example, while expanding fluid sensors 32, 58 and 92 are shown in FIGs. 2, 3
and 7 respectively, it is possible to use other means, including solid mechanical
linkages for example, to connect the temperature sensor to the pressure
regulating valve. The desired relationship between temperature and pressure ;n
the regulation valve can be achieved in various ways, such as by choosing
appropriate shapes for the valve element and valve seat, or by using special
mechanical linkages between the valve element and the diaphragm. The CO2
check valve and the incoming water check valve can be integrated in a single
housing along with a temperature-responsive valve in the CO2 path and a
temperature sensor in the water path. Another cost-effective variation of the
device is a simple, electronically actuated shut-off valve which is triggered open
and closed by a microprocessor circuitry responsive to pressure and temperature
transducers within the carbonator tank. These and other modifications can, of
course, be made without departing from the scope of the invention as defined
in the following claims.
- .,
.. ~ j. .
: : ... ,. ~
~, . . '
.,,.'.` ,' '.""''~
-,.,;..'`:
, ~, :,.
: ' .
~ . , ~ . . - . . .
2 ~ ~ ~ 7 ~
~ .
ou~put ~ig~l o~ the elnc~onlc con~olle~ he ~u~ the ,, -
~e~tr~ction $n valve ~ ~egul2~ .hE~ COz pr~Bsure ln tan}c 10 .
~o that it bea~s ~e d~lred r~la~ionship to the ~en~ed ~-
~emperatu~e, Wlth ~n ~lactron~s: con~rol~ th~ de~ired :
5 rel~t~on~hlp ~twe~n ~empe~ature and pr~tl2~ can be ~a~ily
achie~ed. Fur~ or~, ~h~ car~onation le~ l can be 3et
electrical}y in ~ha controller lt8elr, ~ngtoad 0
~ch~aically by ad~u~m~nt o~ valvQ ~pril~g compre8~ion~
As shown ln FIG. 7, ~ ve 66 i~ simllar to valv~ 24 ln .; .
that it comprlses a valvb alemen'c ~8 u~ged by ~ coil spring ~;
70 toward a ~ral~e ~eat 72 . ~he valv~ pro~id~ a v~ariable
re~tric~ion r~or ~low o~ C02 ~ro~ inlet 74 to outlet 76. . ;.
~ov~ent Or v~lv~ ment 68 against ~ I!orce o~ sprlng 70
i5 controlled by a proportioning ~olenold 78, 'ch~ armature
15 o~ whlc~ lg m~chanlcall~ connec~ed to element 68 ~hrough
cent~ ri~et 80 ~nd ~pring 82, wh$ch presse~ aga~2~st ~ ;
d~aphrag~ 84 .
~ h~ carbonato~ o~ ~IG. S i~ si~ila~ to ~hat o~ ~IG. 4
except th~t, i~n~tead ~ sonslng tha ~e~pera~u~e o~ the
20 ca~bor~at d wat~t~ 34 wlthin tank lO, it ~en~es the
temperattl~ o~ th~ wa~er ~elng supplLed to the tank by ~eans ~:
o~ an ~leatronlc temperature sensor 86 ln l~ne 88 between
motor-d2iv~ll pump 14 and doubl~ checX val~.re 16. I~emperature
sensor 86 i~ pre~erably o~ thQ th~r~ls~or type. Operatlon
2 ~ o~ the c~rbonator o~ ~IG. 5 1~ a~n~i~lly t}~e ~am~ ~ tha~
1' ' `~ .,
2~8~8~
o~ F~ 4 in that CO;Z p2 e~lare ~pl ~ ed to ~Q ~arbon2tor ~ank
i3 rQgulated in accordarlc~ w~ bra~er t~m~a u~e. .; ~-
I~h~ valve o~ F~ t XG~ ths pl ace ~ pe~ature- - -
oontroll~d ~alv~ 24 ~nd ch~ck ~alve ~6 in '~I~. 2. ~he
~tru~ur~ o~ the ~alv~ iB ~mil~x to th~t ~ th~ valv~ o~
~IG. 6, ~XGept ~ha~ th~ valvo inclu~e~ a c~cX ball arranged
to p~e~nt r3verse ~lo~ ~ ~02~ Ag sho~n ~n ~IG. 8, ~al~Q 90 ; ;
ls sontrolled by ~1u1d ~lowlng to and rrom R~nsor 92 throug~
tube 94. The v~lve comprises a CO2 lnlet 95, and a CO2
outlet 98, t~e lnle~ being connectabl~ to the ga~ ~upply,
and t~a outl~t be~ng connected to ~o ~arbo~ato~ ta~k. The
lnlet i~ no~lly clo~ed by a check ~al~e co~pri~ing a bal1 -- -
lOo u~ged aga1n~ a ~eat ~02 by ~ small s~ring 104. Spring
10~ i~ h~ld in the chamber ~onta~nin~ s~ating 61~ment 106,
and is trapp~d betwe0n valve el~ment 108 and chQc~ ball lOo.
Sprin~ 104 i9 weak~r t~an ~p~ing 1~4, an~ allo~ bot~ t~e
c~ck ball 100 a~d valvo element 108 to be open , ~
slmulta~eously, Th~ allows ~low o~ C0~ through the ~alve
~om inlQt 96 toward outlat 98 when ~ncrea~d ~orc~ applied
to ~pr~ng 1~4 cause3 ~iaphr~g~ 116 ~o p~ again~t c~nter
~v~t 118, ~orcin~ val~e element 118 open.
Th~ electrlcally co~trolled v~lvo o~ F~G. 9 i~ slmilar
to tha Yalve o~ FIG. 8, ~xcept ~at lt U8es a proportlonal
~oleno~d 120 ~o pr~sa dow~war~ on di~phragm 12~ through
~pring 124, to op~n ~alv~ element 126. `~
'', ~ ~"'
.: ' :
P. 13
- 2~78~
12
Va~lous ~odi~ica,~ on~ c~n b~ ma~de to ~he c:arbon~tor~
desar~bed. For examplo, ~hile ~xpandlJ)g ~luld ~en~ox~ 32,
58 and ga a~e sl~ot~m itl FIG3. 2, 3 and 7 re~ec~ively, it i~
po~slble to u~e oth~r m2an~, inclu~ing~ ~l~l mechanlcal
linkag~ ~or ex~pl~ to cor~ ct thel ~p~ cur~ en o~ 'co
t~e prQs~ure r~2gulating valve. ~8 d~sire~l re~l~tlon~h~p
betw~Qn ~emparatu:re and p~e8~ure ln ~ x~gula~lon valve can
be zlchia~red ~n various way~, such as by c~oo~ing appropriate
~hapes ~or th~ ~al~rQ ~lement and valve ~eat, or by uslng
speclal ~chanical linkag~s bet~ en the v21ve ele:nent and
the dlaphxagm. ~he co2 c~e~X valve ~nd t~ incomlng ~ater
check val~3 can b~ lntegra.ted ln ~ glngle housing along with
a temporatu~e-r~spons~e ~alv~ ln the C2 ~ath and a
temperature sensor ~n th~ wa~er p~th. Another cost- r
ef:eQctiY~ Yariation o~ the davic~ ls a ~imple,
~l~ct~onlazllly ac~uated shut-ora~ valve brhich i8 ~riggered
open and closed by a lalcroE~roces~or clrcultry ~Q~pon~vG to .t;~ .
pr~s~ura an~ t~mparature t~ansduc~ thtn ~hs carbonator
tank. ~he~e and othzr ~odi~ications can, or~ cours~, be made ::
~ out daparting ~ro~ t~o ~cope Or the lnvention as degilled
in the ~ollowing al~
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