Note: Descriptions are shown in the official language in which they were submitted.
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FLUID DISPENSING SYSTEM AND DUAL-MODE, SYSTEM FLUID
ACTUATED VALVE FOR USE THEREIN
Technical Field
The invention disclosed herein relates generally to fluid dispensing systems,
and more particularly to a fluid dispensing system for controlling the mixing
of a first
fluid (i.e., a diluent such as water) with a second fluid comprising a food
concentrate
(e.g., sauces), a non-carbonated beverage concentrate (e.g., juice or isotonic
drink
concentrate), or a non-food concentrate (e.g., solvents such as windshield
wiper fluids
or cleaning fluids) and the like, at a mixing point within the fluid
dispensing system.
The system comprises a valve positioned in the dispensing system along the
line of
supply of the second fluid upstream of the mixing point, such valve being
simultaneously actuated through application of positive and/or negative
pressure to
allow the second fluid to flow through the valve. Such positive and/or
negative
pressure is generated from the first fluid to be dispensed by the system and
mixed
with the second, such that the termination of flow of the first fluid
immediately
terminates flow of the second fluid to ensure precise mixing of the two fluids
in the
final solution and to prevent inadvertent leakage of the second fluid.
Background Art
Fluid dispensers have long been used in numerous food service locales,
including retail restaurants, juice bars, hospitals, nursing homes, schools,
and the like.
Such fluid dispensers often require the mixing of diluents, such as, water and
a
flavoring agent (such as a soft drink flavoring syrup or juice, dairy, or
isotonic
concentrate), into a final product having a precise water to concentrate ratio
to provide
the consumer with the desired taste of the final product. In order to maximize
the
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appeal of the product to the consumer, and thus obtain continuous customers
and
sales, it is critical that the ratio of water to concentrate be maintained at
a precise level
and mixed thoroughly, and that the system maintain a FDA prescribed level of
sterility.
In the case of traditional dispensing systems, when dispensing soft drinks,
the
flavoring agent ordinarily comprises a generally tacky syrup of relatively low
viscosity. However, when dispensing noncarbonated drinks, such as juices,
dairy
beverages, and isotonic drinks, the flavoring agent ordinarily comprises a
concentrate
which comprises a highly viscous fluid that presents greater difficulty in
flow
regulation than traditional flavoring syrups. Positive displacement pumps,
such as
peristaltic pumps, are often used to regulate the flow of such beverage
concentrate
dispensing systems. However, systems using pumps require that a large physical
space be devoted to housing the pumping apparatus. Further, such systems are
prone
to leaking or clogging after repeated daily use. Moreover, commercial grade,
less
expensive pumps used in dispensing peristaltic pumps have also been found to
provide imprecise dispensing of small volumes of liquid as would be dispensed,
for
example, for a 12 oz. juice drink. Moreover, such fixed ratio pumps tend to
pass a
"slug" of water or other driving fluid at the reversal on each half cycle of
the pump,
resulting in stratification or non-uniformity of the dispensed beverage. Such
pumps
are also prone to dispensing a bit of afterflow concentrate as the pump
terminates
operation at the end of the dispensing cycle, thus either inadvertently
dispensing a
slug of pure concentrate into the drink at the end of the cycle, or
positioning a slug of
pure, unmixed concentrate to be delivered to the cup prior to the
water/concentrate
mixture at the start of the next dispensing cycle, in turn dispensing
beverages of
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highly variable quality. The existing juice dispensers using peristaltic pumps
are not a
self flushing system and require disassembly to be cleaned.
Even outside the field of beverage dispensing systems, the problems
mentioned above plague dispensing systems that attempt to dispense measure
quantities of any fluid comprised of a viscous concentrate and a diluent, such
as
cleaning or other industrial fluids.
Thus, there is a need in the art for a fluid dispensing system which is
capable
of thoroughly and precisely mixing and dispensing fluids formed from a
concentrate
and a diluent, such fluids being of uniform ratio even for small volumes of
dispensed
fluids, which system avoids the problems associated with traditional fluid
dispensing
systems that utilize positive displacement pumps, which is more compact than
traditional fluid dispensing systems, and which is effective in operation
despite the
inherent characteristics and anomalies of viscous concentrates. There is also
a need
for a system that offers a self cleaning rinse mechanism after each use to
insure the
fluids are kept commercially sterile.
Disclosure of Invention
It is, therefore, an object of the present invention to provide a fluid
dispensing
system which avoids the disadvantages of the prior art.
It is another obj ect of the present invention to provide a fluid dispensing
system which can provide a uniform ratio of diluent to concentrate for each
dispensed
dose and maintain commercial sterility levels through a self cleaning process.
Either
hot water and/or hot water in conjunction with an FDA approved hydrogen
peroxide
solution can be automatically attached to flush the lines of the system.
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It is yet another object of the present invention to provide a fluid
dispensing
system which is actuated to dispense a first fluid via pressure applied by a
second
dispensed fluid.
It is still yet another object of the present invention to provide a fluid
dispensing system having a dual-mode, system fluid actuated flow valve which
is
simultaneously and selectively actuated through the application of both
positive and
negative pressure forces in a complimentary fashion.
It is even yet another object of the present invention to provide a fluid
dispensing system which immediately terminates the flow of concentrate upon
the
termination of flow of diluent so as to prevent the dispensing of an afterflow
slug of
concentrate at the end of the dispensing cycle or leakage of flavoring
concentrate into
the dispensing flow line or to allow bacteria to migrate back into the
concentrate
package.
It is even yet another object of the present invention to provide a fluid
dispensing system which provides a dispensed fluid that is thoroughly and
precisely
mixed and blended even in small batches.
It is still even yet another object of the present invention to provide a
fluid
dispensing system wluch ensures the maintenance of a sterile environment for
all non-
dispensed portions of concentrate.
In accordance with the above objects, a fluid dispensing system is disclosed
which enables the consistent, uniform dispensing and mixing of a desired ratio
of
concentrate to diluent, even for small volumes of dispensed fluids. The system
of the
present invention includes a valve positioned between the source of the
concentrate
and the poilzt at which the concentrate is introduced to the diluent, the
valve
comprising a valve body having a first chamber, hereafter indicated as the
"flow
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chamber," and a second chamber, hereafter indicated as the "actuation
chamber," the
flow chamber and the actuation chamber being separated by an intermediate wall
within the valve body, and a plunger configured for reciprocal movement within
the
flow chamber and actuation chamber. A first end of the plunger comprises a
valve
head configured to seat against a valve seat wall in the flow chamber. When
seated
against the valve seat wall, the valve head prevents the flow of fluid through
the flow
chamber from a fluid inlet positioned on a first side of the valve head to a
fluid outlet
positioned on the opposite side of the valve head. A second end of the plunger
comprises a piston head which is resiliently biased towards an end wall of the
actuation chamber by a resilient member, and which in turn resiliently biases
the
valve head against the valve seat in the flow chamber. A flexible diaphragm is
positioned between the piston head and the end wall of the actuation chamber,
and
separates the actuation chamber into a positive pressure actuation zone (the
space
between the diaphragm and the end wall of the actuation chamber) and a
negative
pressure actuation zone (the space between the diaphragm and the intermediate
wall
of the valve body). The end wall of the actuation chamber is provided with two
ports,
namely, a fluid inlet and outlet port fox supplying fluid to and removing
fluid from the
positive pressure actuation zone. Likewise, the side wall of the actuation
chamber is
provided with one port, namely, a vacuum port for supplying a vacuum to the
negative pressure actuation zone.
In operation, fluid applied to the inlet port of the positive pressure
actuation
zone, as well as vacuum applied to the vacuum port of the negative pressure
actuation
zone, each tend to compress the piston head against the resilient member, in
turn
moving the valve head in the flow chamber away from the valve seat to enable
flow
~,5 through the flow chamber.
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The resilient member is so configured as to firmly hold the valve closed when
diluent is not flowing, thus preventing the inadvertent leakage of concentrate
into the
flow system downstream of the valve. By closing the valve at the instant that
diluent
fluid flow is terminated, concentrate has no opportunity to leak into or come
to rest
within the flow system downstream of the valve, such that the entire volume of
undispensed fluid is kept isolated from potential contaminants (e.g.,
bacteria) outside
of the dispensing system.
In a preferred embodiment of the present invention, the valve is employed in a
fluid control system for dispensing a first fluid that is to be mixed with a
second fluid.
In such embodiment, the first fluid to be dispensed (and mixed with the
second)
serves as both (1) the fluid applied to the positive pressure actuation zone,
and (2) the
fluid whose flow generates a vacuum to be applied to the negative pressure
actuation
zone, while the second fluid to be dispensed is that which flows through the
flow
chamber when the valve is actuated. In order to generate a vacuum to be
applied to
the negative pressure actuation zone of the valve, as well as to generate a
vacuum to
draw the second fluid (e.g., concentrate) from its storage vessel and into the
stream of
the first fluid (e.g., diluent), the fluid dispensing system of the present
invention
utilizes a venturi or ejector "pump" to generate the required vacuum. In a
preferred
embodiment of the fluid dispensing system of the present invention, a diluent
supply
source is configured to simultaneously and selectively direct diluent (e.g.,
water) to
the fluid inlet port of the positive pressure actuation zone of the valve, and
through a
venturi positioned downstream of the valve. The flow of diluent through the
venturi
generates vacuum forces which (i) draw the concentrate from its container when
the
valve is open; (ii) supply vacuum to the negative pressure actuation zone of
the valve;
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and (iii) withdraw diluent supplied to the positive pressure actuation zone of
the
valve.
Brief Description Of The Drawings
Other objects, features, and advantages of the present invention will become
more apparent from the following detailed description of the preferred
embodiment
and certain modifications thereof when taken together with the accompanying
drawings in which:
Figure 1 is a perspective view of the dual-mode actuated valve for use in the
fluid dispensing system of the present invention.
Figure 2 is a side, sectional view of the valve of Figure 1.
Figure 3 is a schematic view of a fluid dispensing system according to the
present invention and incorporating the valve of Figures 1 and 2.
Figure 4 is a schematic view of a first alternate embodiment of a fluid
dispensing system according to the present invention.
Figure 5 is a schematic view of a second alternate embodiment of a fluid
dispensing system according to the present invention.
Best Mode(s~ For Carryi~'Out The Invention
As shown in the perspective view and side, sectional view of Figures 1 and 2,
respectively, the dual-mode, system fluid actuated valve for use in the fluid
dispensing system of the present invention comprises a flow control valve
which may
be actuated either through application of a vacuum force generated by the flow
of a
dispensed liquid, or application of positive pressure forces generated by such
dispensed liquid, or the simultaneous application of both vacuum and positive
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pressure forces from such dispensed liquid, to dispense a second dispensed
fluid
which is to be mixed with the first. The valve comprises a generally elongate
valve
body 10 having a fluid inlet port 15 positioned within an end wall of the
valve body, a
fluid outlet port 20 positioned within a side wall of the valve body, and a
vacuum port
25 positioned within a side wall of the valve body. An intermediate wall 30 is
positioned within valve body 10 in such a position as to separate the valve
body into
two chambers, namely, a flow chamber (shown generally at 31), and an actuation
chamber (shown generally at 32), such that inlet port 15 and outlet port 20
provide
fluid communication between the exterior of the valve body and the flow
chamber,
while vacuum port 25 provides fluid communication between the exterior of the
valve
body and the actuation chamber.
The end of actuation chamber 32 opposite intermediate wall 30 is capped with
an end plate 100, which is preferably attached to valve body 10 via a
plurality of
threaded members 110. End plate 100 is configured with two openings, namely,
an
inlet port 105 and an outlet port 106, such that when end plate 100 is affixed
to valve
body 10, inlet and outlet ports 105 and 106 likewise provide fluid
communication
between the interior of the actuation chamber and the exterior of the valve
body.
Positioned within valve body 10 and extending through intermediate wall 30 is
a valve plunger 200. Mounted at a first end of valve plunger 200 is a valve
head 205
configured to seat against a valve seat 16 defined by the angled side wall of
flow
chamber 31. Preferably, an O-ring, gasket, or other flexible sealing means 206
is
positioned between valve head 205 and valve seat 16 when the valve is in the
closed
position to ensure a tight seal and no inadvertent leakage of fluid through
the valve
structure. Mounted at the second end of valve plunger 200 is a piston head
210. A
resilient member 215, such as a coil spring, is juxtaposed between
intermediate wall
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30 and piston head 210 to always bias piston head 210 towards end plate 100.
Because plunger 200, valve head 205, and piston head 210 are a unitary
structure, the
biasing of piston head 210 towards end plate 100 likewise biases valve head
205
towards valve seat 16 in flow chamber 31, such that when no actuation forces
(whether vacuum or positive pressure) are applied, the valve sits in a closed
position,
preventing the flow of fluid through flow chamber 31.
A flexible diaphragm 300 is provided between piston head 210 and end plate
100, and spans the entire width of actuation chamber 32, thus splitting
actuation
chamber 32 into two zones, namely, a vacuum or negative pressure actuation
zone 40
and a positive pressure actuation zone 50. Negative pressure actuation zone 40
extends from intermediate wall 30 to the underside of diaphragm 300, while
positive
pressure actuation zone 50 extends from the top side of diaphragm 300 to end
plate
100. Diaphragm 300 is firmly clamped at its ends between end plate 100 and
valve
body 10, such that negative pressure actuation zone 40 is entirely isolated
from
positive pressure actuation zone 50, and no fluid communication exists between
those
two zones.
In use, fluid concentrate is supplied to inlet port 15. Because no pressure is
being applied to positive pressure actuation zone 50, and no vacuum is being
applied
to negative pressure actuation zone 40, resilient member 215 biases piston
head 210
towards end plate 100, and thus biases valve head 205 in flow chamber 31
against
valve seat 16, compressing flexible sealing means 206 and preventing flow of
the
fluid around valve head 205 and through outlet port 20.
When fluid is delivered to positive pressure actuation zone 50 through port
105 so as to supply a positive pressure force.within zone 50, positive
pressure
actuation zone 50 expands, in turn driving piston head 210 away from end plate
100,
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compressing resilient member 215, and likewise lifting valve head 205 away
from
valve seat 16 in flow chamber 31. Once valve head 205 is lifted away from
valve seat
16, the fluid applied through inlet port 15 is free to flow around piston head
205 and
out of outlet port 20. When the supply of fluid to positive pressure actuation
zone 50
is terminated, resilient member 215 immediately drives piston head 210 in the
opposite direction (now towards end plate 100), in turn driving valve head 205
back
towards valve seat 16 in flow chamber 31, until valve head 205 comes to rest
against
valve seat 16, at which point flow of the fluid is once again immediately
terminated.
Likewise, when vacuum is applied to vacuum port 25 so as to apply a vacuum
or negative pressure force within negative pressure actuation zone 40, zone 40
contracts, in turn pulling piston head 210 away from end plate 100,
compressing
resilient member 215, and likewise lifting valve head 205 away from valve seat
16 in
flow chamber 31. Once valve head 205 is lifted away from valve seat 16, the
fluid
applied through inlet port 15 is free to flow around piston head 205 and out
of outlet
port 20. When the supply of vacuum to negative pressure actuation zone 40 is
terminated, resilient member 215 immediately drives piston head 210 in the
opposite
direction (now towards end plate 100), in turn driving valve head 205 back
towards
valve seat 16 in flow chamber 31, until valve head 205 comes to rest against
valve
seat 16, at which point flow of the fluid is once again immediately
terminated.
As both application of positive pressure to positive pressure actuation zone
50,
and application of vacuum or negative pressure to negative pressure actuation
zone
40, tend to unseat valve head 205 from valve seat 16 in flow chamber 31, it
may
readily be seen that the simultaneous application of both positive pressure to
zone 50
and vacuum to zone 40 may enable an even faster response to initiate flow of
the fluid
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through flow chamber 31, thus providing increased accuracy in the dispensing
of
desired proportions of fluids.
Valve 1 is positioned between the source of the fluid concentrate and the
point at which the concentrate is introduced to the diluent so as to prohibit
the
inadvertent flow of concentrate into the fluid supply line when diluent flow
through
the line is terminated. As shown more particularly in the schematic view of
Figure 3,
the fluid dispensing system of the present invention comprises a container of
concentrate (e.g., flavoring syrup) 500 which supplies concentrate to inlet
port 15 of
valve 1 through conduit 501. Likewise, a diluent (e.g., water) supply 510 is
provided
for dispensing the diluent that will mix with dispensed concentrate. The
supply of
diluent is preferably regulated through pressure regulator 601 and solenoid
valve 602,
as is well known in the art. From solenoid valve 602, the diluent supply
separates into
a first branch 512 and a second branch 513. First branch 512 comprises a
conduit
which directs diluent from solenoid valve 602 to inlet port 105 of valve 1.
The flow
of diluent through inlet port 105 applies a positive pressure actuation force
to positive
pressure actuation zone 50 of valve 1, in turn opening valve 1 so as to allow
concentrate to flow from supply 500. Likewise, second branch 513 comprises a
conduit which directs diluent from solenoid valve 602 to the inlet of a
venturi or jet
pump 700.
Venturi 700 more particularly comprises a differential pressure injector
having
an internal diameter which constricts from the injector inlet to an injection
chamber.
The injection chamber is located at the intersection of the injector inlet,
the injector
outlet, and a suction port 701. As the water enters the injector inlet, it
constricts
toward the injection chamber and changes into a high velocity jet stream. The
increase in velocity through the injection chamber, as a result of the
differential
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pressure between the inlet and outlet sides of the injector, results in a
decrease in
pressure in the injection chamber. This pressure drop enables an additive
material,
such as a concentrate used in the fluid dispensing system of the present
invention, to
be drawn through the suction port and mixed with the motive diluent stream. As
the
jet stream is diffused toward the injector outlet, its velocity is reduced and
it is
reconverted into pressure energy.
Thus, as diluent is supplied to the inlet of venturi 700, its flow through
venturi
700 draws the concentrate from outlet port 20 of valve 1, through conduit 21
to
suction port 701, where the concentrate is introduced into and mixed with the
stream
of diluent, so long as valve 1 is actuated so as to enable concentrate to
flow.
As explained above, diluent may be directed to positive pressure actuation
zone 50 of valve 1 so as to open the valve and allow concentrate to flow
therethrough.
In order to draw off the diluent supplied to positive pressure actuation zone
50, a
diluent return line 514 is provided which directs diluent from outlet port 106
in
positive pressure actuation zone 50 to another suction port 702 positioned
adjacent the
injector outlet of venturi 700, such that the diluent returned through diluent
return line
514 reenters the flow stream where the flow is near atmospheric pressure.
Further, as explained above, vacuum may be applied to negative pressure
actuation zone 40 in order to open valve 1 and allow concentrate to flow
therethrough.
In order to apply such a vacuum to negative pressure actuation zone 40, yet
another
suction port 703 is provided in venturi 700, suction port 703 being positioned
in close
proximity to suction port 701. When diluent flows through venturi 700 and
creates a
decrease in pressure in the injection chamber, such decrease in pressure
applies a
vacuum through conduit 26 to negative pressure actuation zone 40 of valve 1
(as
described in detail above), in turn unseating valve head 205 from valve seat
16 and
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allowing concentrate to flow through outlet port 20. Alternately, a T joint
fluid
coupling nnay be located at suction port 701, each branch of the T joint
receiving one
of conduits 21 and 26. With such a fluid coupling, the single suction port 701
provides both the vacuum used to draw concentrate into the diluent stream, and
the
vacuum supplied to negative pressure actuation zone 40 to open valve 1.
The system set forth above particularly describes actuation of valve 1 through
the simultaneous application of both positive fluid pressure to positive
pressure
actuation zone 50 and negative pressure to negative pressure actuation zone
40, both
of which forces compliment one another to unseat valve head 205 from valve
seat 16
to in turn enable concentrate to flow through valve 1. However, alternate
embodiments of the fluid dispensing system of the present invention provide
for a
single one of positive pressure or negative pressure to actuate valve 1 as set
forth
above, such that the fluid handling system for the alternate pressure
application means
may be removed from the system of the present invention while maintaining the
system's functionality and compact configuration. For example, the alternate
embodiment of the present invention shown in Figure 4 depicts the fluid
handling
system of Figure 3 without vacuum conduit 26 and vacuum port 25 on valve 1,
such
that the sole actuating force for valve 1 is positive fluid pressure applied
through
conduit 512 to inlet port 105 of positive pressure actuation zone 50.
Likewise, Figure
5 depicts yet another alternate embodiment of the present invention in which
fluid
conduit 512, diluent return line 514, and inlet and outlet ports 105 and 106
of positive
pressure actuation zone 50 of valve 1 are eliminated, such that the sole
actuating force
for valve 1 is vacuum pressure applied through conduit 26 to vacuum port 25 of
negative pressure actuation zone 50.
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Alternately, additional valves in fluid conduits 512 and 26 may be provided to
enable the system to selectively operate valve 1 through either positive
pressure
applied to positive pressure actuation zone 50, negative pressure applied to
negative
pressure actuation zone 40, or the simultaneous application of both positive
pressure
and negative pressure in complimentary fashion, thus providing maximum
flexibility
for controlling the flow of a variety of fluids.
It should be noted that, while the system described herein is particularly
designed to overcome the difficulties presented in controlling the flow of
highly
viscous fluids (e.g., juice, dairy, or isotonic concentrate), the system is
equally
efficient in regulating the flow of less viscous constituents, (e.g.,
flavoring syrups for
soft drinks), and may also be used in any application requiring the mixing of
multiple
distinct fluids.
Having now fully set forth the preferred embodiments and certain
modifications of the concept underlying the present invention, various other
embodiments as well as certain variations and modifications of the embodiments
herein shown and described will obviously occur to those skilled in the art
upon
becoming familiar with said underlying concept. It should be understood,
therefore,
that the invention may be practiced otherwise than as specifically set forth
herein.
Industrial Applicability
For the industrial application of fluid dispensing systems for multiple
fluids, it
is desirable to provide a dispensing apparatus which ensures an accurate
mixing
proportion between the fluids and which prevents inadvertent leakage of fluids
from
the system. Herein disclosed is a fluid dispensing system for controlling the
mixing
of a first fluid (i.e., a diluent such as water) with a second fluid
comprising a food
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concentrate (e.g., sauces), a non-carbonated beverage concentrate (e.g., juice
or
isotonic drink concentrate), or a non-food concentrate (e.g., solvents such as
windshield wiper fluids or cleaning fluids) and the like, at a mixing point
within the
fluid dispensing system. The system comprises a valve positioned in the
dispensing
system along the line of supply of the second fluid upstream of the mixing
point, such
valve being simultaneously actuated through application of positive and/or
negative
pressure to allow the second fluid to flow through the valve. Such positive
and/or
negative pressure is generated from the first fluid to be dispensed by the
system and
mixed with the second, such that the termination of flow of the first fluid
immediately
terminates flow of the second fluid to ensure precise mixing of the two fluids
in the
final solution and to prevent inadvertent leakage of the second fluid.
