U.S. patent number RE43,334 [Application Number 11/274,720] was granted by the patent office on 2012-05-01 for apparatus to control fluid flow rates.
This patent grant is currently assigned to IMI Cornelius Inc.. Invention is credited to Philip Andrew Simmons.
United States Patent |
RE43,334 |
Simmons |
May 1, 2012 |
Apparatus to control fluid flow rates
Abstract
Apparatus for mixing two fluids has separate supply lines for
delivering the fluids to a mixing head. Flow rate of fluid in one
supply line is monitored by arranging a pressure transducer to
measure a pressure drop across an orifice in an orifice plate
arranged in the supply line and a controller is responsive to the
detected flow rate to control flow rate of fluid in the other
supply line to achieve a desired flow ratio of both fluids at the
mixing head for producing a mixed fluid having the correct
proportions of both fluids. The fluids may be a concentrate syrup
and a plain or carbonated water to produce a beverage.
Inventors: |
Simmons; Philip Andrew
(Alcester, GB) |
Assignee: |
IMI Cornelius Inc. (Anoka,
MN)
|
Family
ID: |
9892676 |
Appl.
No.: |
11/274,720 |
Filed: |
November 15, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
09870297 |
May 30, 2001 |
6648240 |
Nov 18, 2003 |
|
|
Foreign Application Priority Data
|
|
|
|
|
Jun 1, 2000 [GB] |
|
|
0013174.8 |
|
Current U.S.
Class: |
239/63; 239/399;
239/302; 239/398; 239/406; 239/67 |
Current CPC
Class: |
B67D
1/0032 (20130101) |
Current International
Class: |
A01G
25/00 (20060101); A01G 27/00 (20060101) |
Field of
Search: |
;239/63,67-69,74,398,407,413,569,596,601,302-304,399,406,410,412,418,570
;222/129.1,129.2,129.3,129.4,145.5,504,59,63 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
0 266 202 |
|
May 1988 |
|
EP |
|
332116 |
|
Jul 1930 |
|
GB |
|
2 362 873 |
|
Dec 2001 |
|
GB |
|
WO 99/29619 |
|
Jun 1999 |
|
WO |
|
Primary Examiner: Hwu; Davis
Attorney, Agent or Firm: Pyle & Piontek, LLC
Claims
In the claims:
1. A dispensing .[.valve.]. .Iadd.system .Iaddend.for mixing
therein and dispensing there from a first fluid and a second fluid
at a predefined ratio, comprising: a dispensing valve body having a
first inlet and a second inlet for providing connection to
pressurized sources of the first fluid and the second fluid
respectively, the first inlet delivering the first fluid to a first
channel, the first channel having a pressure based flow sensing
means, the second inlet delivering the second fluid to a second
channel and the second channel having a second fluid flow sensing
means therein for sensing the flow rate of the second fluid there
through, and the second flow sensing means and the pressure based
flow sensing means connected to a microcontroller for determining
the flow rates of the second and first fluids respectively, a valve
in the first channel and operated by the microcontroller for
regulating the flow of the first fluid there thorough in an on/off
manner, a linear actuator controlled by the microcontroller for
operating a rod extending in the second channel, the rod having a
rod end movable to a stop position for stopping the flow of the
second fluid and to a full flow position for permitting a maximum
flow of the second liquid and movable to a plurality of positions
between the stop and full open positions for regulating the flow
rate of the second fluid as a function of the size of a flow
orifice created between the rod and the second channel relative to
the position of the rod end between the stop and full flow
positions, and the microcontroller regulating the flow rate of the
second fluid as a function of the sensed flow rate of the first
fluid so as to maintain the predetermined ratio there between.
2. The dispensing .[.valve.]. .Iadd.system .Iaddend.as defined in
claim 1, and where the first fluid is a syrup concentrate and the
second fluid is a water diluent.
3. The dispensing .[.valve.]. .Iadd.system .Iaddend.as defined in
claim 1, and the pressure based flow sensing means including an
orifice plate in the first channel and extending therein transverse
to the flow of the first fluid there through and the orifice plate
having two side surfaces and a central hole there through and the
central hole having a chamfered edge around a perimeter thereof
formed into a portion of one of the side surfaces.
4. The dispensing .[.valve.]. .Iadd.system .Iaddend.as defined in
claim 2, and the pressure based flow sensing means including an
orifice plate in the first channel and extending therein transverse
to the flow of the first fluid there through and the orifice plate
having two side surfaces and a central hole there through and the
central hole having a chamfered edge around a perimeter thereof
formed into a portion of one of the side surfaces.
.Iadd.5. An apparatus for providing a mixture of at least two
fluids, which comprises a first fluid supply line connectable to a
source of the first fluid, a second fluid supply line connectable
to a source of the second fluid, and a mixing head into which the
two fluids can be supplied through their respective supply lines
and mixed therein, the first fluid supply line including an orifice
plate, the orifice plate having a chamfered edge leading into its
orifice in the direction of flow, and pressure transducer means for
measuring the pressure drop in the first fluid as it passes through
the orifice plate, the pressure transducer means providing the
measured pressure drop to a controller, the controller being
pre-programmed with flow rate values determined over a range of
pressure drops for the first fluid and to control the rate of flow
of the second fluid to the mixing head in response to the flow rate
of the first fluid to achieve a desired flow ratio of the two
fluids, in which the first fluid supply line contains a multiple
position on/off valve controllable to provide a range of flow rates
of the first fluid, and in which the controllable on/off valve
comprises a substantially rigid housing containing a passageway
between an inlet to and an outlet from the valve, a closure member
movable in the passageway from a first position in which the valve
is fully closed to a second position in which the valve is fully
open, the closure member engaging the wall of the passageway to
seal the passageway, at least one of the wall of the passageway and
the closure member defining at least one groove, the groove having
a transverse cross-section that increases in area in one of the
downstream and upstream directions, such that movement of the
closure member from the first position towards the second position
progressively opens a flow channel through the groove..Iaddend.
.Iadd.6. An apparatus according to claim 5, in which the at least
one groove is of tapering V-shape..Iaddend.
.Iadd.7. An apparatus for providing a mixture of at least two
fluids, which apparatus comprises a first fluid supply line
connectable to a source of the first fluid, a second fluid supply
line connectable to a source of the second fluid, a mixing head
into which the two fluids can be supplied through their respective
supply lines and mixed therein, and pressure based flow sensing
means in which a pressure transducer measures fluid pressure on one
side of an orifice plate having an orifice while an opposite side
of the orifice plate vents to atmosphere, said pressure based flow
sensing means comprising an orifice in an orifice plate arranged to
vent to atmosphere and through which orifice the first fluid supply
line passes, a pressure transducer immediately upstream of the
orifice plate to measure the pressure drop in the fluid passing
through the plate, the pressure transducer providing the measured
pressure drop to a controller that is pre-programmed with flow rate
values determined over a range of pressure drops for the first
fluid and to control the rate of flow of the second fluid to the
mixing head in response to the flow rate of the first fluid to
achieve a desired flow ratio of the two fluids, in which the first
fluid supply line contains a controllable on/off valve upstream of
the orifice plate and pressure transducer, and in which the
controllable on/off valve comprises a substantially rigid housing
containing a passageway between an inlet to and an outlet from the
valve, a closure member movable in the passageway from a first
position in which the valve is fully closed to a second position in
which the valve is fully open, the closure member engaging the wall
of the passageway to seal the passageway, at least one of the wall
of the passageway and the closure member defining at least one
groove, the groove having a transverse cross-section that increases
in area in one of the downstream and upstream directions, whereby
movement of the closure member from the first position towards the
second position opens a flow channel through the
groove..Iaddend.
.Iadd.8. An apparatus according to claim 7, in which the grooves
are of tapering V-shape..Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates to an apparatus to control of the flow rates
of fluids. It is particularly concerned to provide a means whereby
the flow rates of two or more fluids to be mixed are controlled and
is especially intended for use in the mixing of the components of a
post-mix beverage.
In the dispensing of a post-mix beverage, i.e. in which the
components of the beverage are mixed at the point of sale from one
or more fluid components, e.g. a concentrated syrup and a diluent,
usually plain or carbonated water, it is obviously desirable to
provide a mixed beverage of the correct ratio of components and it
is important that this ratio should not vary beyond tightly
controlled limits. It is, therefore, desirable to have some means
of determining the amount of each component being provided to, for
example, a dispense nozzle. One way of achieving this is to
determine the flow rate of each component, either by direct
measurement or by calculation after measurement of another
property, and to calculate the amount dispensed from a series of
flow rate determinations with respect to elapsed time.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
means of accurately mixing fluids, particularly beverage fluid
components, in a desired ratio. It is also an objet of the present
invention to provide an improved means of determining fluid flow
rate values.
Accordingly the invention herein provides an apparatus for the
mixing of at least two fluids, which comprises a first fluid supply
line connectable to a source of the first fluid, a second fluid
supply line connectable to a source of the second fluid. The
invention also includes a mixing head into which the two fluids can
be supplied through their respective supply lines and mixed therein
and dispensed there from. The first fluid supply line passes
through an orifice in an orifice plate and a pressure transducer is
positioned to measure the pressure drop in the fluid passing
through the plate. The pressure transducer provides the measured
pressure data to a controller, the controller being pre-programmed
with flow rate values determined over a range of pressure drops for
the first fluid and to control the rate of flow of the second fluid
to the mixing head in response to the flow rate of the first fluid
to achieve a desired flow ratio of the two fluids. The controller
may allow flow for a predetermined time dependent on the monitored
flow rates in order to achieve a specific volume of dispensed
fluids.
As indicated above, the invention is particularly intended for use
in the dispensing of post-mix beverages and will, therefore, be
more particularly described below with particular reference to that
embodiment. The mixing head may conveniently include a dispense
nozzle from which the mixed beverage maybe dispensed into a
suitable receptacle. The first fluid is preferably a concentrated
syrup and the second fluid is preferably a diluent, e.g. plain or
carbonated water. The second fluid supply line may contain any
suitable flow rate measuring device e.g. a flow turbine, and this
is flow rate sensor is also connected to the controller. Thus, the
flow rate of the second fluid/diluent may also be monitored in
addition to the pressure transducer monitoring of the first
fluid/syrup. The controller is also connected to a valve in the
second fluid supply line and can cause that valve to be opened to
the desired amount to achieve the required flow rate for the
dispense ratio for the particular beverage being dispensed.
By monitoring the second fluid rate in conjunction with that of the
first fluid rate and, where necessary, adjusting the second fluid
flow rate to correspond to any variations in the monitored first
fluid flow rate, the ratio of the dispensed beverage can be
accurately maintained at the required value. Thus any variations in
the flow rate of the concentrate of a post-mix beverage, e.g. due
to pressure variations in the supply line or delays in response of
the on/off valve through which the concentrate is supplied, can be
monitored and taken into account by rapid consequential adjustments
to the diluent flow rate.
The concentrate supply line may contain a simple on/off valve to
allow the concentrate to flow when a beverage dispense is signalled
to the controller. The controller then causes the valve, e.g. a
solenoid or diaphragm valve, to open while at the same time, or
fractionally earlier, opening the on/off valve in the diluent
supply line and commencing monitoring of the two flow rates. In
this embodiment, therefore, the concentrate valve is either open or
closed and when open it remains fully open to provide a particular
nominal flow rate. The valve may have, e.g., a manual adjuster to
fine tune this nominal flow rate for particular concentrates. The
pressure transducer in this embodiment is essentially, therefore,
providing monitoring of flow rate fluctuations above and below the
nominal rate through the fully opened valve.
In another embodiment, the on/off valve in the concentrate flow
line may be controllable to provide a range of flow rates of the
concentrate whereby the controller maybe programmed to control
dispense of a wider range of beverages based on a greater number of
different concentrates that may be supplied one at a time through
the first fluid supply line. In a particular preferred version of
this latter embodiment, the valve in the concentrate supply line is
of the type described and claimed in our international patent
publication WO99/29619 (application no. PCT/GB98/03564). That
international application describes and claims a valve comprising a
substantially rigid housing containing a passageway between an
inlet and an outlet of the valve, a closure member movable in the
passageway from a first position in which the valve is fully closed
to a second position in which the valve is fully open, the closure
member engaging the wall of the passageway to seal the passageway,
the wall of the passageway or the closure member defining at least
one groove, the groove having a transverse cross-section that
increases in area in the downstream or upstream direction, whereby
movement of the closure member from the first position towards the
second position opens a flow channel through the groove. The
groove(s) may be, for example, of tapering V-shape and will, for
convenience, hereafter be referred to as "V-grooves" and the valves
of this general type as "V-groove valves", although it will be
appreciated that the grooves may, if desired, have a different
tapering cross-section, e.g. of circular, rectangular or other
shape.
The progressive increase or decrease in area of the groove flow
channels can produce excellent linear flow through these V-groove
valves, i.e. for a given pressure the flow rate is more directly
proportional to the valve position than for conventional valves.
This enables better control of the flow rate over the entire
operating range of the valve. Alternatively the V-groove valve may
be replaced, for example, by a solenoid, on/off valve upstream of a
needle valve to provide the desired range of concentrate flow
rates. The means to open and close the adjustable concentrate valve
may be any suitable mechanism. A stepper motor or a linear solenoid
actuator are amongst the preferred mechanisms.
The valve to control the flow of diluent may also be, if desired, a
V-groove valve. Pressure transducers are well known in the art and
the skilled man will readily be able to choose one suitable for his
particular needs. Essentially, the pressure transducer measures
fluid pressure at a particular point or surface and converts this
measurement into an electrical signal. The electrical signal is fed
to the control means which, therefore, is programmed to receive the
pressure data in this electrical form.
The orifice plate may be positioned upstream or downstream of the
on/off valve in the concentrate supply line but it is preferred
that it be upstream as this arrangement, although possibly subject
to static pressure variations, is less Lady to be affected by
variations in flow characteristics through the orifice plate.
Nevertheless, it may be desirable in certain circumstances to
position the orifice plate downstream of the on/off valve and, in
one such embodiment, the orifice plate may be positioned
immediately before the outlet of the concentrate supply line to the
mixing head. In this arrangement the plate can vent to atmosphere
and the pressure transducer measures the pressure immediately
upstream of the plate. However, it is preferred to measure the
pressure difference across the orifice in the plate and this may be
done whether the plate is positioned upstream or downstream of the
on/off valve. Preferably, the positioning of the orifice plate,
when not venting to a atmosphere as described above, in the supply
line should be such that the supply line at the downstream side of
the plate remains full of the concentrate. Thus the flow line
through the plate should preferably be uphill or at least
horizontal. By this means there is less likelihood of trapped air
affecting the pressure measurements and hence the flow rate
values.
It will be appreciated that fluid flow characteristics through the
orifice plate are affected inter alia by the size of the orifice,
the sharpness of the edge leading into the orifice and the
thickness of the plate. In principle, the thinner the plate the
better in that the fluid can then effectively be considered to be
passing through a very short tube. The shorter the tube the less
"re-attachment" effect of the fluid to the wall of the tube and the
less undesirable effect on the flow and the flow rate measurement.
Clearly too thin a plate may buckle under the fluid pressure and we
have, therefore, found, that as an alternative to a very sharp
orifice edge on a slightly thicker plate, which edge maybe
expensive to manufacture, a chamfered edge leading into or leading
out of the orifice may be usefully employed to give a predictable
characteristic at the cost of slight increase in viscosity
sensitivity.
Where the concentrate valve is adjustable to provide a range of
concentrate flow rates, the controller may be programmed to provide
a "profiled" dispense for the beverage. In other words, the initial
portion of the dispense may, for example, be at a low flow rate,
e.g. to prevent initial over-foaming of a carbonate beverage, and
then the rate may be increased to fall for the majority of the
dispense period and then reduced to a slower rate again for the
final filling of the glass or other receptacle. Thus the dispense
pour may be controlled to suit the particular beverage in
question.
As indicated above, the controller may be programmed to dispense a
number of different beverages. It may also be programmed to
dispense different volumes, e.g. a small portion and a large
portion, of each beverage. The controller may also be programmed to
take into account viscosity changes due to temperature variations.
This can be achieved by the appropriate positioning of a
temperature sensor in one or each fluid supply lines so that the
correct ratios of fluids can be maintained regardless of
temperature variations.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the structure, function, objects and
advantages of the of the present invention can be had by reference
to the following detailed description with reference to the
accompanying drawings, wherein:
FIG. 1 is a diagrammatic, representation of one apparatus of the
invention;
FIG. 2 is a part sectional view through a first orifice plate and
pressure transducer arrangement for use in the invention;
FIG. 3 is a sectional view of second orifice plate and pressure
transducer arrangement for use in the invention;
FIG. 4 is a sectional view of a third orifice plate and pressure
transducer arrangement for use in the invention; and
FIG. 5 is an enlarged sectional view of an orifice plate for use in
the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As seen in FIG. 1, an apparatus .Iadd.or system .Iaddend.for
dispensing a post-mix beverage from a mixing/dispense head 10 is
shown. .[.A.]. .Iadd.The apparatus includes a dispensing valve
having a dispensing valve body and a .Iaddend.concentrate flow line
A from a source of concentrate (not shown) is indicted by
single-headed arrows. A diluent, e.g. carbonated water, flow line
B, again from a source not shown, is indicated by double-headed
arrows. Concentrate flow line A passes through the orifice 12 of an
orifice plate 14 and the pressure drop across the plate is measured
by pressure transducer 16. Between the orifice plate and the mixing
head 10 is a variable on/off V-groove valve 18. Valve 18 has a
through passageway 20 and a pair of opposed V-grooves 22 across the
passageway, the cross-section of the grooves narrowing in the
direction of flow of flow line A.
A piston 24 controlled by an actuator (not shown) completely closes
passageway 20 in its fully lowered position by mating with internal
walls 26 beyond the narrow end of grooves 22. As the piston is
moved upwards, the valve 18 opens and the through flow of
concentrate increases with increasing V-groove cross section until
the fully open position illustrated is reached. Diluent flow line B
passes through a regulating valve 28 and a flow turbine 30 to reach
mixing head 10. A controller 32.Iadd., such as a microcontroller,
.Iaddend.receives signals from the pressure transducer 16 and from
flow turbine 30. It is also connected to a control panel 34 via
which a range of mixed beverages may be commanded. On receiving a
command for a particular beverage, controller 32 opens valve 28 to
allow flow of diluent and simultaneously, or marginally later,
opens valve 18 by raising piston 24 to an appropriate degree. By
monitoring the flow rate of concentrate through line A and
adjusting the flow rate through line B accordingly, the controller
ensures that the desired ratio of fluids for the commanded beverage
is maintained. It may close the valves after a predetermined time
or volume has been dispensed.
In FIG. 2, there is shown one orifice plate/pressure transducer
arrangement for the concentrate flow line. Direction of fluid flow
is indicated by the arrows. An orifice plate 40 having a central
orifice 42 is positioned across the flow line passage 44
immediately above an outlet nozzle 46 whereby the plate 40 vents to
atmosphere. Hence the orifice plate here will be positioned
downstream of the on/off valve for the concentrate. A pressure
transducer 48 measures the fluid pressure immediately above plate
40 and by virtue of the venting to atmosphere can feed the pressure
drop values across the plate to a suitable controller, such as
controller 32 in FIG. 1.
In FIG. 3, an orifice plate 50 having a central orifice 52 is
moulded in-situ to lie across a portion 54 of second fluid flow
line. A pressure transducer 56 reads the fluid pressure values
immediately upstream and downstream of the plate 50 via stem tubes
58, 60 respectively. Stem tubes 58, 60 are a snap fit into orifices
62, 64 in the flow passageway and are sealed into position by their
respective O-rings 66, 68. Again the pressure transducer feeds
pressure data to a suitable controller, as described above. The
pressure transducer with the attachment stem tubes as shown in FIG.
3 is a well known attachment means but is not essential. An
alternative arrangement is shown in FIG. 4. Here orifice plate 70
with central aperture 72 is again moulded in-situ to lie across a
portion 74 of the second fluid flow line. Again pressure transducer
76 reads the fluid pressure values immediately upstream and
downstream of plate 70 but directly via orifices 78, 80 i.e.
without the stem tubes of FIG. 3. Although flow through the orifice
plates in FIGS. 3 and 4 is shown horizontal, as suggested above, it
may be preferable for the flow to be uphill.
One suitable form of orifice plate 90 is shown in FIG. 5. It has a
central orifice 92, which has a chamfered edge 94 on one side of
the plate. As indicated above, the chamfer may be on the upstream
or downstream side of the plate. By way of example only, the
following dimensions may be found to be suitable where the diluent
to concentrate ratio is 5 to 1 respectively and where the total
flow rate of the two fluids is in the range of 1 and 1/2 to four
ounces per second. Plate thickness EE--about 1 mm. Chamfer axial
thickness DD--about 0.5 mm. Orifice diameter CC--about 1.4 mm to
1.9 mm. Chamfer angle x.degree.=90.degree.. Pressure change at
maximum concentrate flow rate between 10-30 p.s.i.
* * * * *