U.S. patent application number 15/049563 was filed with the patent office on 2016-08-25 for frozen beverage machine control system and method.
This patent application is currently assigned to FBD Partnership, LP. The applicant listed for this patent is FBD Partnership, LP. Invention is credited to Clinton D. FINSTAD, Jimmy I. FRANK, Daniel J. SEILER, Darren SIMMONS, Jun YANG.
Application Number | 20160245564 15/049563 |
Document ID | / |
Family ID | 56689820 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160245564 |
Kind Code |
A1 |
FRANK; Jimmy I. ; et
al. |
August 25, 2016 |
FROZEN BEVERAGE MACHINE CONTROL SYSTEM AND METHOD
Abstract
The inventions disclosed and taught herein relate generally to
frozen beverage machines; and more specifically relate to improved
methods of and apparatuses for controlling the consistency and
quality of the dispensed beverage product.
Inventors: |
FRANK; Jimmy I.; (San
Antonio, TX) ; FINSTAD; Clinton D.; (Canyon Lake,
TX) ; SEILER; Daniel J.; (Schertz, TX) ;
SIMMONS; Darren; (Fair Oaks Ranch, TX) ; YANG;
Jun; (San Antonio, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FBD Partnership, LP |
San Antonio |
TX |
US |
|
|
Assignee: |
FBD Partnership, LP
San Antonio
TX
|
Family ID: |
56689820 |
Appl. No.: |
15/049563 |
Filed: |
February 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62120602 |
Feb 25, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A23G 9/228 20130101;
F25D 21/006 20130101; F25B 49/02 20130101; F25B 2700/1933 20130101;
F25B 40/00 20130101; F25B 2700/1931 20130101; F25B 2700/21151
20130101; F25B 2700/2106 20130101; F25B 5/02 20130101; A23G 9/045
20130101; F25B 47/022 20130101 |
International
Class: |
F25B 47/02 20060101
F25B047/02; A23G 9/22 20060101 A23G009/22; A23G 9/04 20060101
A23G009/04; F25C 1/14 20060101 F25C001/14; F25B 49/02 20060101
F25B049/02 |
Claims
1. A frozen beverage machine, comprising: a remote condensing unit;
a dispensing unit coupled to the remote condensing unit, wherein
the dispensing unit comprises: at least one expansion valve,
wherein an input of the expansion valve is coupled to the output of
remote condensing unit such that the expansion valve is configured
to receive a refrigerant from the remote condensing unit output; at
least one freezing chamber, wherein the output of the at least one
expansion valve is coupled to the at least one freezing chamber; at
least one suction sensor, wherein an output of the at least one
freezing chamber is coupled to an input of the at least one suction
sensor; a compressor, wherein an output of the at least one suction
sensor is coupled to an input of the compressor; a discharge
sensor, wherein the output of the compressor is coupled to an input
of the discharge sensor and wherein an output of the discharge
sensor is coupled to an input of the remote condensing unit; and at
least one hot bypass valve, wherein the output of the compressor is
coupled to an input of the at least one hot bypass valve and
wherein an output of the at least one hot bypass valve is coupled
to the input of the at least one freezing chamber.
2. The frozen beverage machine of claim 1, wherein the at least one
suction sensor comprises an at least one suction pressure sensor
and wherein the discharge sensor comprises an at least one
discharge pressure sensor.
3. The frozen beverage machine of claim 1, wherein the at least one
suction sensor comprises a suction pressure sensor and a suction
temperature sensor, and wherein the discharge sensor comprises a
discharge pressure sensor.
4. The frozen beverage machine of claim 1, further comprising a
mass flow meter coupled between the at least one suction sensor and
the compressor input.
5. The frozen beverage machine of claim 1, further comprising an
ambient temperature sensor located at or near the remote condensing
unit and an air temperature sensor located at or near the at least
one freezing chamber.
6. The frozen beverage machine of claim 1, wherein the remote
condensing unit is located outside of a building and wherein the
dispensing unit is located inside a building.
7. The frozen beverage machine of claim 1, further comprising at
least one inlet temperature sensor coupled to the input of the at
least one freezing chamber.
8. The frozen beverage machine of claim 1, further comprising: a
first isolation device, wherein input of the first isolation device
is coupled to the output of the compressor and wherein an output of
the first isolation device is coupled to the input of the remote
condensing unit; and a second isolation device, wherein input of
the second isolation device is coupled to the output of the remote
condensing unit and wherein an output of the second isolation
device is coupled to the input of the at least one expansion
valve.
9. The frozen beverage machine of claim 1, wherein: the at least
one expansion valve comprises four expansion valves; the at least
one freezing chamber comprises four freezing chambers; the at least
one suction sensor comprises two suction sensors.
10. A method of controlling a frozen beverage machine, wherein the
frozen beverage machine comprises a remote condensing unit and a
dispensing unit, comprising: initiating the defrost cycle;
determining the low side refrigeration pressure of a compressor of
the dispensing unit; determining the high side refrigeration
pressure of the compressor of the dispensing unit; initiating a
refrigeration priming cycle if the low side refrigeration pressure
or the high side refrigeration pressure are not within nominal
operating conditions for the compressor; determining if the low
side refrigeration pressure or the high side refrigeration pressure
are within nominal operating conditions for the compressor; ending
the refrigeration priming cycle if the low side refrigeration
pressure and the high side refrigeration pressure are within
nominal operating conditions for the compressor; and re-initiating
the defrost cycle if the low side refrigeration pressure and the
high side refrigeration pressure are within nominal operating
conditions for the compressor.
11. The method of claim 10, wherein determining the low side
refrigeration pressure comprises measuring the pressure through a
pressure sensing device coupled to the compressor and wherein
determining the high side refrigeration pressure comprises
measuring the pressure through a pressure sensing device coupled to
the compressor.
12. The method of claim 10, wherein determining the low side
refrigeration pressure comprises calculating the pressure through a
temperature sensing device coupled to the compressor and wherein
determining the high side refrigeration pressure comprises
calculating the pressure through a temperature sensing device
coupled to the compressor.
13. The method of claim 10, wherein the low side refrigeration
pressure or the high side refrigeration pressure are not within
nominal operating conditions for the compressor includes the low
side refrigeration pressure is below 50 pounds per square inch or
the high side refrigeration pressure is less than 200 pounds per
square inch.
14. The method of claim 10, wherein initiating the defrost cycle
includes opening at least one defrost solenoid of the dispensing
unit to allow refrigerant to flow from the remote condensing unit
to the dispensing unit.
15. The method of claim 10, wherein initiating the refrigeration
priming cycle comprises closing at least one defrost solenoid,
opening at least one expansion solenoid, and setting a timer.
16. The method of claim 10, further comprising shutting down a
barrel of the dispensing unit if a timer expires and if the low
side refrigeration pressure or the high side refrigeration pressure
are not within nominal operating conditions for the compressor.
17. The method of claim 10, further comprising locating the remote
condensing unit located outside of a building, and further
comprising locating the dispensing unit inside a building.
18. The method of claim 10, further comprising initiating a
refrigeration priming cycle if no freeze cycle has occurred with 20
minutes.
19. The method of claim 10, further comprising shutting down a
barrel of the dispensing unit if after a certain period of time the
low side refrigeration pressure or the high side refrigeration
pressure are not within nominal operating conditions for the
compressor.
20. The method of claim 10, further comprising calculating the flow
rate of the refrigerant in the dispensing unit.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of and priority
to U.S. Provisional Patent Application Ser. No. 62/120,602, filed
Feb. 25, 2015, and the contents of which are hereby incorporated by
reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO APPENDIX
[0003] Not applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The inventions disclosed and taught herein relate generally
to frozen beverage machines; and more specifically relate to
improved methods of and apparatuses for controlling the consistency
and quality of the dispensed beverage product.
[0006] 2. Description of the Related Art
[0007] Frozen beverage machines are known in the art and have been
used for years. These devices produce, for example, a frozen
carbonated beverage by freezing a mixture of ingredients typically
including syrup, water and carbon dioxide in a freezing chamber.
The mixture freezes on the inner surface of the chamber, which is
surrounded by a helical coil through which a refrigerant passes. A
rotating shaft is disposed inside the chamber that has a plurality
of outwardly projecting blades that scrape the mixture off the
inside wall of the freezing chamber. Once the carbonated beverage
is in the desired frozen state, the product is dispensed from the
chamber through a product valve.
[0008] The temperature and viscosity of the ingredients within the
mixing chamber are maintained by a control system that controls the
refrigeration system. The control system also controls the amount
of the ingredients injected into the mixing chamber to maintain the
quantity of such ingredients within the chamber at a prescribed
amount. Such control systems typically include a pressure
responsive device that controls the amount of ingredients fed into
the chamber in response to chamber pressure.
[0009] Typically, the pressure of the carbon dioxide within the
chamber is maintained above atmospheric pressure, and the
temperature of the liquid within the chamber is maintained below
the freezing point of water at atmospheric pressure, but above the
temperature where the liquid readily freezes at the pressure within
the chamber. The viscosity of the liquid typically must also be
maintained within prescribed limits. Under these conditions of
temperature and pressure and with the viscosity suitably
maintained, the beverage is dispensed from the chamber through the
product valve to atmospheric pressure, in a semi-frozen state
similar to frozen foam.
[0010] The quality of the product is also determined by the ratio
of the mixture of the syrup, water, and carbon dioxide content. The
ability to control and adjust this mixture is a function of the
ability to accurately monitor and control liquid levels, pressures,
temperatures, and carbon dioxide content. While other factors such
as syrup content also affect the quality of the product, the amount
of carbonation is a strong contributing factor. A major drawback of
known frozen carbonated beverage machines is their inability to
maintain proper control over the liquid levels, pressures,
temperatures, and the carbon dioxide content entering the mixing
chamber, to produce a consistently high quality product.
[0011] The common current method for controlling a frozen beverage
machines barrels refreeze cycle is based on the beater motor's
torque (or power consumption). When the measured torque on the
motor drops below a specified threshold, the machine initiates a
freeze cycle and freezes the barrel until the torque on the motor
reaches a higher specified torque. One observed issue with using
the motor's torque is that the machine may, over time, begin to
freeze more often. The time between freeze cycles becomes shorter,
and the product in the barrel can become too cold. If the barrel is
not defrosted often, the product in the barrel may not dispense out
of the valve. Another issue is that small dispensed drinks may
trigger a refreeze when the barrel should not be required to
refreeze. All observed issues with the current control method
reinforce the idea that the torque of the motor may not be the best
indicator for triggering a refreeze.
[0012] The common current method for controlling frozen beverage
dispensing utilizes the freezing chamber, which is an evaporator in
a refrigeration system to make frozen beverage product. The
physical behavior and the state of beverage product are constantly
changing within the freezing chamber. The expansion and contraction
of beverage product may be unpredictable.
[0013] Other problems with existing frozen beverage machines:(i)
inconsistent ice crystal size and (ii) inconsistent barrel pressure
which may cause: (a) excessively high barrel pressure leading to
undesirably high dispense rates, (b) fluctuating barrel pressure
leading to inconsistent ice crystal formation, (c) inconsistent
drink quality, (d) "wet drinks" where expansion is too low and/or
liquid/solid separation occurs, (e) cold drinks where the drinks
are too stiff due to over freezing, (f) inconsistent "brightness"
due to excessive pressure and gas within the barrel.
[0014] The inventions and subject matter disclosed and taught
herein are directed to that overcomes, or at least minimizes, some
of these problems.
BRIEF SUMMARY OF THE INVENTION
[0015] As one of many possible brief summaries of the nature and
substance of the inventions claimed herein frozen beverage machine
may comprising a remote condensing unit; a dispensing unit coupled
to the remote condensing unit, wherein the dispensing unit may
comprise at least one expansion valve, wherein an input of the
expansion valve is coupled to the output of remote condensing unit
such that the expansion valve is configured to receive a
refrigerant from the remote condensing unit output; at least one
freezing chamber, wherein the output of the at least one expansion
valve is coupled to the at least one freezing chamber; at least one
suction sensor, wherein an output of the at least one freezing
chamber is coupled to an input of the at least one suction sensor;
a compressor, wherein an output of the at least one suction sensor
is coupled to an input of the compressor; a discharge sensor,
wherein the output of the compressor is coupled to an input of the
discharge sensor and wherein an output of the discharge sensor is
coupled to an input of the remote condensing unit; and at least one
hot bypass valve, wherein the output of the compressor is coupled
to an input of the at least one hot bypass valve and wherein an
output of the at least one hot bypass valve is coupled to the input
of the at least one freezing chamber. The at least one suction
sensor may comprise an at least one suction pressure sensor and the
discharge sensor may comprise an at least one discharge pressure
sensor. The at least one suction sensor may comprise a suction
pressure sensor and a suction temperature sensor, and the discharge
sensor may comprise a discharge pressure sensor. The frozen
beverage machine may further comprise a mass flow meter coupled
between the at least one suction sensor and the compressor input.
The frozen beverage machine may further comprise an ambient
temperature sensor located at or near the remote condensing unit
and an air temperature sensor located at or near the at least one
freezing chamber. The remote condensing unit may be located outside
of a building and the dispensing unit may be located inside a
building. The frozen beverage machine may further comprise at least
one inlet temperature sensor coupled to the input of the at least
one freezing chamber. The frozen beverage machine may further
comprise a first isolation device, wherein input of the first
isolation device may be coupled to the output of the compressor and
wherein an output of the first isolation device may be coupled to
the input of the remote condensing unit; and a second isolation
device, wherein input of the second device valve may be coupled to
the output of the remote condensing unit and wherein an output of
the second isolation device may be coupled to the input of the at
least one expansion valve. The at least one expansion valve may
comprise four expansion valves; the at least one freezing chamber
may comprise four freezing chambers; and the at least one suction
sensor may comprise two suction sensors.
[0016] As another of the many possible brief summaries of the
nature and substance of the inventions claimed herein a method of
controlling a frozen beverage machine, wherein the frozen beverage
machine may comprise a remote condensing unit and a dispensing unit
may comprise initiating the defrost cycle; determining the low side
refrigeration pressure of a compressor of the dispensing unit;
determining the high side refrigeration pressure of the compressor
of the dispensing unit; initiating a refrigeration priming cycle if
the low side refrigeration pressure or the high side refrigeration
pressure are not within nominal operating conditions for the
compressor; determining if the low side refrigeration pressure or
the high side refrigeration pressure are within nominal operating
conditions for the compressor; ending the refrigeration priming
cycle if the low side refrigeration pressure and the high side
refrigeration pressure are within nominal operating conditions for
the compressor; and re-initiating the defrost cycle if the low side
refrigeration pressure and the high side refrigeration pressure are
within nominal operating conditions for the compressor. The step of
determining the low side refrigeration pressure may comprise
measuring the pressure through a pressure sensing device coupled to
the compressor and the step of determining the high side
refrigeration pressure may comprise measuring the pressure through
a pressure sensing device coupled to the compressor. The step of
determining the low side refrigeration pressure may comprise
calculating the pressure through a temperature sensing device
coupled to the compressor and the step determining the high side
refrigeration pressure may comprise calculating the pressure
through a temperature sensing device coupled to the compressor. The
step of the low side refrigeration pressure or the high side
refrigeration pressure are not within nominal operating conditions
for the compressor may include the low side refrigeration pressure
is below 50 pounds per square inch or the high side refrigeration
pressure is less than 200 pounds per square inch. The step of
initiating the defrost cycle may include opening at least one
defrost solenoid of the dispensing unit to allow refrigerant to
flow from the remote condensing unit to the dispensing unit. The
step of initiating the refrigeration priming cycle may comprise
closing at least one defrost solenoid, opening at least one
expansion solenoid, and setting a timer. The method may further
comprise the step of shutting down a barrel of the dispensing unit
if a timer expires and if the low side refrigeration pressure or
the high side refrigeration pressure are not within nominal
operating conditions for the compressor. The method may further
comprise the step of locating the remote condensing unit located
outside of a building, and may further comprise the locating the
dispensing unit inside a building. The method may further comprise
the step of initiating a refrigeration priming cycle if no freeze
cycle has occurred with 20 minutes. The method of claim 10 may
further comprise shutting down a barrel of the dispensing unit if
after a certain period of time the low side refrigeration pressure
or the high side refrigeration pressure are not within nominal
operating conditions for the compressor. The method may further
comprise calculating the flow rate of the refrigerant in the
dispensing unit.
[0017] None of these brief summaries of the inventions is intended
to limit or otherwise affect the scope of the appended claims, and
nothing stated in this Brief Summary of the Invention is intended
as a definition of a claim term or phrase or as a disavowal or
disclaimer of claim scope
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0018] The following figures form part of the present specification
and are included to further demonstrate certain aspects of the
present invention. The invention may be better understood by
reference to one or more of these figures in combination with the
detailed description of specific embodiments presented herein.
[0019] FIG. 1 is a block diagram conceptually illustrating portions
of a frozen beverage machine in accordance with certain teachings
of the present disclosure.
[0020] FIG. 2 is a schematic diagram of a frozen beverage machine
in accordance with certain teachings of the present disclosure.
[0021] FIG. 3 is a view of a portion of the frozen beverage machine
illustrated in FIG. 2 in accordance with certain teachings of the
present disclosure.
[0022] FIG. 4 is a flow diagram illustrating exemplary steps used
in the control of a dynamic charge system in accordance with
certain teachings of the present disclosure.
[0023] FIGS. 5A-5B are a flow diagram illustrating exemplary steps
used in the control of a dynamic charge system in accordance with
certain teachings of the present disclosure.
[0024] FIG. 6 is a flow diagram illustrating an exemplary refreeze
logic of a frozen beverage machine in accordance with certain
teachings of the present disclosure.
[0025] FIG. 7 is a flow diagram illustrating an exemplary fill
logic of a frozen beverage machine in accordance with certain
teachings of the present disclosure.
[0026] FIG. 8 is a schematic diagram for an exemplary refrigeration
system with a remote condensing unit in accordance with certain
teachings of the present disclosure.
[0027] FIG. 9 is a flow chart illustrating an exemplary method for
refrigeration priming for remote condensed applications in
accordance with certain teachings of the present disclosure.
[0028] FIG. 10 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure.
[0029] FIG. 11 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure.
[0030] FIG. 12 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure.
[0031] FIG. 13 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure.
[0032] FIGS. 14A-14B are a flow chart illustrating a further
exemplary method for controlling a refrigeration priming for remote
condensed applications in accordance with certain teachings of the
present disclosure.
[0033] While the inventions disclosed herein are susceptible to
various modifications and alternative forms, only a few specific
embodiments have been shown by way of example in the drawings and
are described in detail below. The figures and detailed
descriptions of these specific embodiments are not intended to
limit the breadth or scope of the inventive concepts or the
appended claims in any manner. Rather, the figures and detailed
written descriptions are provided to illustrate the inventive
concepts to a person of ordinary skill in the art and to enable
such person to make and use the inventive concepts.
DETAILED DESCRIPTION
[0034] The Figures described above and the written description of
specific structures and functions below are not presented to limit
the scope of what Applicants have invented or the scope of the
appended claims. Rather, the Figures and written description are
provided to teach any person skilled in the art to make and use the
inventions for which patent protection is sought. Those skilled in
the art will appreciate that not all features of a commercial
embodiment of the inventions are described or shown for the sake of
clarity and understanding. Persons of skill in this art will also
appreciate that the development of an actual commercial embodiment
incorporating aspects of the present inventions will require
numerous implementation-specific decisions to achieve the
developer's ultimate goal for the commercial embodiment. Such
implementation-specific decisions may include, and likely are not
limited to, compliance with system-related, business-related,
government-related and other constraints, which may vary by
specific implementation, location and from time to time. While a
developer's efforts might be complex and time-consuming in an
absolute sense, such efforts would be, nevertheless, a routine
undertaking for those of skill in this art having benefit of this
disclosure. It must be understood that the inventions disclosed and
taught herein are susceptible to numerous and various modifications
and alternative forms. Lastly, the use of a singular term, such as,
but not limited to, "a," is not intended as limiting of the number
of items. Also, the use of relational terms, such as, but not
limited to, "top," "bottom," "left," "right," "upper," "lower,"
"down," "up," "side," and the like are used in the written
description for clarity in specific reference to the Figures and
are not intended to limit the scope of the invention or the
appended claims.
[0035] The terms "couple," "coupled," "coupling," "coupler," and
like terms are used broadly herein and can include any method or
device for securing, binding, bonding, fastening, attaching,
joining, inserting therein, forming thereon or therein,
communicating, or otherwise associating, for example, mechanically,
magnetically, electrically, chemically, operably, directly or
indirectly with intermediate elements, one or more pieces of
members together and can further include without limitation
integrally forming one functional member with another in a unity
fashion. The coupling can occur in any direction, including
rotationally.
[0036] Particular embodiments of the invention may be described
below with reference to block diagrams and/or operational
illustrations of methods. It will be understood that each block of
the block diagrams and/or operational illustrations, and
combinations of blocks in the block diagrams and/or operational
illustrations, can be implemented by analog and/or digital
hardware, and/or computer program instructions. Such computer
program instructions may be provided to a processor of a
general-purpose computer, special purpose computer, ASIC, and/or
other programmable data processing system. The executed
instructions may create structures and functions for implementing
the actions specified in the block diagrams and/or operational
illustrations. In some alternate implementations, the
functions/actions/structures noted in the figures may occur out of
the order noted in the block diagrams and/or operational
illustrations. For example, two operations shown as occurring in
succession, in fact, may be executed substantially concurrently or
the operations may be executed in the reverse order, depending upon
the functionality/acts/structure involved.
[0037] Applicants have created methods of and apparatuses for
measuring and controlling the liquid in a frozen beverage machine
to control the consistency and quality of the dispensed beverage
product.
[0038] FIG. 1 is a simplified block diagram schematically
illustrating components of a frozen beverage machine 10 in
accordance with certain teachings of or could be used in
conjunction with the present disclosure. In FIG.1, the frozen
beverage machine 10 is a frozen beverage machine. The frozen
beverage machine 10 includes an ingredients supply source 12, a
process flow block 14, a controller 16, and a product chamber or
barrel 18. In the exemplary frozen beverage machine 10, the
ingredient supply source 12 may include, for example, a water
supply, syrup supply and a gas supply. In the illustrated
embodiment, the barrel 18 comprises a freezing chamber having a
refrigeration system 20 associated therewith. The barrel 18 further
comprises a beater 24. The product chamber or barrel 18 may be an
evaporator in the refrigeration system 20. The frozen beverage
machine 10 may alternatively have one or more barrels. Further
descriptions of frozen beverage machines are provided in U.S. Pat.
Nos. 5,706,661; 5,743,097; 5,799,726; 5,806,550; 6,536,224 and
6,625,993 by J. I. Frank, et al. The entire disclosures of these
patents are incorporated by reference. Other known frozen beverage
machine may be used in conjunction with methods and apparatuses
disclosed in the present disclosure.
[0039] The barrel 18 is where product or liquid is frozen and
maintained before dispensing. Initial pull down (IPD) is a process
of freezing a liquid in the barrel 18 from a liquid state to a
frozen ready to serve state. This occurs when barrel is already
liquid and needs to be frozen. The thaw period or thaw cycle occurs
when one of the barrels 18 of the frozen beverage machine 10 is
turned on, but the refrigeration system 20 is off. The product or
liquid in the barrel 10 is frozen and ready to serve, but is
naturally thawing and not being frozen by refrigeration system 20.
The freeze cycle or refreeze cycle occurs when one of the barrels
18 of the frozen beverage machine 10 is turned on and the
refrigeration system 20 is on. The product in the barrel is already
frozen but out of an acceptable range. Thus, freezing/cooling the
product is required in order to maintain drink quality. A freeze
cycle occurs between thaw cycles. Beater percentages (%) is a
software variable displayed, which may be displayed on the user
interface of frozen beverage machine 10, that indicates the torque
load on the motor causing the beater 24 to move. Beater percentage
is inversely proportional to motor load; as the variable drops, the
load increases. In one exemplary embodiment, 1000% is a
liquid-barrel load and a frozen load is 700-900%.
[0040] Ingredients for a frozen beverage mixture are provided from
the ingredient supply 12 to the process flow block 14, which
controls the flow of the ingredients into the freezing chamber 18
as directed by the controller 16. The controller 16 may comprise an
appropriately programmed microprocessor and suitable memory
devices. The frozen mixture consistency is controlled by any of a
number of methods that turns on the refrigeration system 20 to
freeze and turns off the refrigeration system 20 when the mixture
reaches the desired consistency. Suitable operation of the
controller 16 and other control instrumentation using circuit
boards, volatile and non-volatile memory devices, software,
firmware, and the like is described, for example, in U.S. Pat. No.
5,706,661 incorporated by reference above. The product is then
dispensed through a dispensing valve 22.
[0041] Applicants have further created improved methods and
apparatuses to monitor and control active-charge pressure of frozen
beverage system through electronic sensing, although mechanic
sensing is also within the scope of the present disclosure.
[0042] As is shown in more detail in FIGS. 2 and 3, the dynamic
charge control system (DCC) of the present invention typically
consists of a pressure transducer 220, two electrically controlled
solenoids 205, 210 to control supply and venting of gas, and a
common manifold 212. DCC typically utilizes a pressure sensing
technological device to monitor and control charge pressure by
either supply or vent gas based on the user's desired pressure
range, in other words, desired drink profile. The desired pressure
range is dependent on the drink profile desired, and the user has
the ability to change the pressure range electronically through a
user interface.
[0043] FIG. 2 is a schematic diagram of a frozen beverage machine
in accordance with certain teachings of the present disclosure.
Referring to FIG. 2, the main components of a frozen beverage
machine 200 are illustrated.
[0044] In the exemplary machine a general refrigeration system is
provided that includes a compressor 240, a condenser 245, heat
exchanger 235, defrost valve 250 and an expansion valve 255. The
refrigeration system operates to provide refrigerant to the
evaporation coils of a freezing chamber in the form of a barrel 218
either: (a) in the form of expanding liquid refrigerant through the
expansion valves to cool the barrel or (b) in the form of hot gas
form the compressor to defrost the barrel.
[0045] The exemplary machine also includes direct charge control
system that includes an expansion tank 225 that receives beverage
solution through a solution solenoid 260 and gas (typically
CO.sub.2 but may be air or some other inert gas) through a supply
solenoid 205 (or in alternative embodiments a supply regulator). A
pressure transducer 220 is provided to detect the charge pressure
in the expansion tank 225. A pressure transducer 265 is provided to
detect the solution pressure in the entering the expansion tank
225. The output from the pressure transducer 220 is provided to an
electronic interface controller 215 that operates to control the
charge pressure in the expansion tank 225. In alternative
embodiments, multiple expansion tanks may be utilized.
[0046] FIG. 3 is a view of a portion of the frozen beverage machine
illustrated in FIG. 2 in accordance with certain teachings of the
present disclosure. In particular, FIG. 3 shows details of one
embodiment of the expansion tank 225, the barrel 218, the
dispensing valve 222, the supply solenoid 205, the exhaust solenoid
210 (or in alternative embodiments an exhaust regulator) and the
pressure transducer 220. In the example, of FIG. 3, the solenoids
205 and 210 are electronically controlled solenoids and they are
integrated into a single unit with the pressure transducer 220
which will produce a signal that can be received and processed by a
control processor. Pressure may be vented through the pressure vent
230. CO.sub.2 may be added through CO.sub.2 pressure supply line
219.
[0047] FIG. 4 is a flow diagram illustrating exemplary steps used
in the control of a dynamic charge system in accordance with
certain teachings of the present disclosure. FIG. 4 illustrates at
a high level the method 400 used in the control of a dynamic charge
system. In the initial step 410, after the pressure is measured, it
is determined whether the pressure sensed by pressure detector 220
is greater than, less than or within the desired range depending on
the user's preference, in other words, the desired drink profile.
The range may be a range of values including for example a fixed
setpoint/range and/or a dynamic setpoint/range. Setpoints, ranges
and/or control logic for desired active charge pressure can be
variable, and dependent on: (a) desired drink profile (e.g., lower
pressures produce larger ice crystals, less CO2 absorption); (b)
product type (fountain syrup vs FCB syrup; sugared syrup vs. low
cal. Vs diet syrups); (c) machine hardware configuration (size of
evaporator, expansion tank size, etc). Setpoints and/or control
logic may be modified by a user interface. For example, a user may
enter desired drink profile, product type, or machine hardware
configuration. The user interface may include potentiometers, LCDs,
or keypads.
[0048] If the pressure is within the range, in step 420, no change
is made to the expansion tank 225. If the pressure if less than
desired, in step 430, the supply solenoid is activated to provide
medium (typically CO.sub.2 but may be air or some other inert gas)
to the expansion tank 225. If the pressure is greater than desired,
in step 450, the exhaust solenoid 210 is activated to the
exhaust/vent medium from the expansion tank 225 out the pressure
vent 230. After either steps 430 or 450 is completed, in step 440,
a pressure feedback reading from the pressure transducer 220 is
made. After step 440, step 410 is completed and the loop begins
again.
[0049] FIGS. 5A-5B are a flow diagram illustrating exemplary steps
used in the control of a dynamic charge system in accordance with
certain teachings of the present disclosure. FIGS. 5A-5B illustrate
at a more detailed level an exemplary method that may be used in
the control of a dynamic charge system and associated frozen
beverage machine. The method starts at step 502. The control loop
step 504 begins. The active charge pressure (ACP) is read in step
506 from pressure transducer 220. The active charge state may be
read in step 508.
[0050] In step 510, it is determined whether the DCC system is
idle. If the DCC system is idle, step 512 is followed. In step 512,
it is determined whether the ACP is greater than the vent set
point. The set point may be a range of values including for example
a fixed setpoint/range and/or a dynamic setpoint/range. Setpoints
and/or control logic for desired active charge pressure can be
variable, and dependent on: (a) desired drink profile (e.g., lower
pressures produce larger ice crystals, less CO2 absorption); (b)
product type (fountain syrup vs FCB syrup; sugared syrup vs. low
cal. Vs diet syrups); (c) machine hardware configuration (size of
evaporator, expansion tank size, etc). Setpoints and/or control
logic may be modified by a user interface. For example, a user may
enter desired drink profile, product type, or machine hardware
configuration. The user interface may include potentiometers, LCDs,
or keypads.
[0051] If the ACP is greater, in step 514, the vent solenoid 210 is
turned on and the vent timer is started. Next, in step 516, the
state is set to venting. Next, in step 562, the flow diagram
returns to begin loop, which is step 504, and begins again.
[0052] If the ACP is less than the vent set point, in step 518, it
is next determined whether the ACP is less than the fill set point.
If the ACP is less than a fill set point, in step 520, the fill
solenoid 205 is turned on and the fill timer is set. Next, in step
522, the filling state is set. Next, in step 562, the flow diagram
returns to begin loop, which is step 504, and begins again.
[0053] If in step 510, if the DCC system is not idle, next it is
determined if the DCC system is venting in step 524. If it is
determined that the DCC system is venting in step 524, next, in
step, 526 it is determined whether the vent target has been
reached. If the vent target has been reached, next, in step 528,
the vent solenoid 210 is turned off and the vent timer is stopped.
Next, in step 530, the state is set to idle. Next, in step 532,
wait (delay) for a predetermined amount of time. Next, in step 562,
the flow diagram returns to begin loop, which is step 504, and
begins again.
[0054] If in step 526, it was determined that the vent target had
been reached, next in step 534, it is determined whether the vent
timeout has been reached. If the vent timeout of step 534 has been
reached, the vent is turned off in step 536. Next, in step 538, the
state is set to idle. Next, in step 540, wait (delay) for a
predetermined amount of time. Next, in step 562, the flow diagram
returns to begin loop, which is step 504, and begins again. If in
step 534, it is determined that the vent timeout has not been
reached, next, in step 562, the flow diagram returns to begin loop,
which is step 504, and begins again.
[0055] If in step 524 that the DCC system is not venting, next, in
step 542 it is determined if the DCC system is filling. If the DCC
system is filling, next, in step 544, it is determined whether the
fill target has been reached. If the fill target has been reached,
next, in step 546, the fill is turned off and the fill timeout is
cancelled. Next, in step 548, the idle state is set. Next, in step
550, wait(delay) for a predetermined amount of time.
[0056] If in step 544, it was determined that the fill target had
been reached, next in step 552, it is determined whether the fill
timer reached has expired. If the fill timeout of step 552 has been
reached, the vent is turned off in step 554. Next, in step 556, the
state is set to idle. Next, in step 558, wait(delay) for a
predetermined amount of time. Next, in step 562, the flow diagram
returns to begin loop, which is step 504, and begins again. If in
step 552, it is determined that the fill timeout has not been
reached, next, in step 562, the flow diagram returns to begin loop,
which is step 504, and begins again.
[0057] If in step 542, it is determined that the filling is not
occurring, next, in step 560, the state is idle. Next, in step 562,
the flow diagram returns to begin loop, which is step 504, and
begins again.
[0058] The order of steps of FIGS. 5A-4B can occur in a variety of
sequences unless otherwise specifically limited. The various steps
described herein can be combined with other steps, interlineated
with the stated steps, and/or split into multiple steps. Similarly,
elements have been described functionally and can be embodied as
separate components or can be combined into components having
multiple functions.
[0059] The other potential benefits of the methods and apparatuses
disclosed in FIGS. 2-5 and the associated written specification are
as follows: (a) may allow the freezing chamber pressure to be
maintained in a tighter range or with higher accuracy; (b) may
allow a user to interact with the system and make various drink
profiles through a user interface rather than manually adjusting
the regulated pressure or physically change out regulator; (c) may
eliminate over/under pressurization problems that may occur due to
the drift or inaccuracy of the mechanical regulator (high barrel
pressure may lead to undesirably high dispense rates and
unpredictable consistency); (d) may maintain better frozen product
consistency due its ability to control freezing chamber pressure
more precisely and consistently than a mechanically operated active
charge system; (e) may maintain proper barrel liquid level through
its ability to control freezing chamber pressure precisely and
consistently; and (f) maintain better gas solubility due to its
ability to tightly control chamber pressure during freezing.
[0060] Applicants have further created improved methods for
improving the drink quality of drinks dispensed from frozen
beverage machines that includes improvements to one of more of the
following the fill, refreeze, and defrost logic that controls the
frozen beverage machines.
[0061] FIG. 6 is a flow diagram illustrating the refreeze logic of
a frozen beverage machine according to certain teachings of the
present disclosure. The following method for improving the drink
quality of drinks dispensed from frozen beverage machines includes
an improved refreeze logic that controls the frozen beverage
machines. When a barrel 18 is on and has completed its initial pull
down (IPD), the frozen beverage machine 10 is designed to detect
when the drink consistency is not acceptable. Barrel 18 is designed
to be ready to serve consistent drinks at nearly all times. The
frozen beverage machine 10 maintains the liquid consistency in the
barrel in an acceptable range by refreezing the barrel
occasionally. The logic used to initiate a refreeze of the barrel
is based on a combination of conditions. The barrel will refreeze
at the end of the thaw cycle 660 if one or more of the following
conditions are met:
[0062] In the first condition 620, the decision of whether or not
to end the thaw cycle and initiate the freeze cycle 660 is based on
the beater motor's torque/power. For example, if the load/power
consumption of the beater motor decreases below a threshold, the
thaw cycle ends and the freeze cycle is initiated 660. The
threshold used to determine whether this condition is satisfied and
to begin the refreeze cycle is typically a beater percentage
measurement of 950%, but other beater percentages (or ranges) are
contemplated based on various factors. The desired thickness of the
product may be a user setting. If the user wants a thicker drink,
the threshold is lowered and vise versa. If the first condition 620
is satisfied, the thaw cycle ends and the freeze cycle is initiated
660. If the first condition 620 is not satisfied, the second
condition 630 may be checked.
[0063] In the second condition 630, the decision of whether or not
to end the thaw cycle and initiate the freeze cycle 660 is based on
whether to synchronize with a second barrel that is freezing. For
example, when a second barrel is freezing and the barrel in
question is half-way thawed, the half-way thaw point is determined
by the beater motor's load and is calculated by the formula: ([Thaw
% Threshold]+[Freeze % Threshold])/2). Thaw % and Freeze %
thresholds are typically default values in the machine based on
empirical testing; however, the user interface allows for the
thresholds to be shifted up or down based on if the users wants a
thicker or thinner drink. If the second condition 630 is satisfied,
the thaw cycle ends and the freeze cycle is initiated 660. If the
second condition 630 is not satisfied, the third condition 640 may
be checked.
[0064] In the third condition 640, the decision of whether or not
to end the thaw cycle and initiate the freeze cycle 660 is based on
the amount of product dispensed while thawing. For example, has the
barrel been filled for greater than ten cumulative seconds during
the current thaw cycle. This is determined by whether the solution
solenoid 260 (shown in FIG. 2) has been activated for ten
cumulative seconds during the current thaw cycle. As frozen product
is being dispensed from the barrel, the pressure drop in barrel
activates the solution solenoid to allow solution to replenish the
barrel. The solution may be injected at a rate of 1.8 ounces per
second, but other injection rates are contemplated. Assuming a rate
an injection rate of 1.8 ounces per second, eighteen ounces of
solution is typically injected into the barrel when the solution
solenoid is open for ten seconds. After 18 oz of solution is added
to the barrel, the drink quality falls outside of the acceptable
range, the barrel must be frozen. If the third condition 640 is
satisfied, the thaw cycle ends, and the freeze cycle is initiated
660. If the third condition 640 is not satisfied, the fourth
condition 650 may be checked.
[0065] In the fourth condition 650, the decision of whether or not
to end the thaw cycle and initiate the freeze cycle 660 is based on
the length of the thaw cycle. For example, if the time since the
last freeze exceeds 30 minutes, although other times are
contemplated, the machine will turn on the refrigeration system to
refreeze the barrel. If the fourth condition 650 is satisfied, the
thaw cycle ends and the freeze, cycle is initiated 660. If the
fourth condition 650 is not satisfied, the first condition 620 may
be re-checked. This cycle may continue until one of the conditions
is satisfied and the thaw cycle ends and the freeze cycle is
initiated 460.
[0066] The order of the conditions 620, 630, 640, 650 may be set in
any order. One or more of the conditions 620, 630, 640, 650 may be
omitted. For example, the fourth condition 650 may be tested first
and if satisfied the thaw cycle ends and the freeze cycle is
initiated 660.
[0067] The following method for improving the drink quality of
drinks dispensed from frozen beverage machines includes an improved
defrost logic that controls the frozen beverage machines. The
purpose of defrost is to prevent drink quality from falling outside
of the acceptable range over a long period of time, and also to
prevent ice build-up in barrel that could potentially clog up the
dispensing valve. Other machines typically defrost every two to
four hours. One of the main benefits of the freeze logic described
above is that the barrels do not form ice as quickly.
Consequentially, the barrels do not need to be defrosted as often.
Using this method, only defrosts each barrel every six to nine
hours, or a total of three defrosts per day, per barrel. Once a
defrost cycle is initiated, the barrel defrost process is
terminated by the barrel's return temperature exceeding 50.degree.
F. or the length of the defrost exceeding 15 minutes.
[0068] The following method for improving the drink quality of
drinks dispensed from frozen beverage machines includes an improved
fill logic that controls the frozen beverage machines. FIG. 7 is a
flow diagram illustrating the fill logic of a frozen beverage
machine in accordance with certain teachings of the present
disclosure. The following method for improving the drink quality of
drinks dispensed from frozen beverage machines includes an improved
fill logic that controls the frozen beverage machines. Initially,
the barrel is turned on 710. The barrel's pressure is typically
maintained between 26 pounds per square inch (psig) and 28 psig
when filling is enabled for a frozen carbonated beverage (FCB)
syrup. Filling the barrel with additional liquid is not always
allowed and is dependent on the state of the barrel. Filling is
disabled 760 (i.e. not permitted) if one or more of the following
conditions are true: (i) the barrel is defrosting 720, (ii) the
barrel is out of product (e.g. syrup, water, or CO.sub.2) 730; or
(iii) the barrel is doing an initial pull down (I PD) or when the
barrel first freezes down 740.
[0069] If the above conditions are not true, then filling is
enabled 750 when the machine is on. When filling is enabled, the
machine will fill to 28 psig when the pressure in barrel drops
below 26 psig. The refill and full pressures were chosen to be 26
psig and 28 psig respectively in order to be relatively close to
the active-charge pressure on the expansion tanks. The active
charge pressure is set to 30 psig. Having the full pressure 2psig
within the active charge pressure reduces the fluctuation in barrel
pressure over time. The order of the steps 720, 730, 740 may be set
in any order. One or more of the steps 720, 730, 740 may be
omitted. Other pressure ranges are contemplated based on various
conditions within a frozen beverage machine.
[0070] Applicants have further created methods and apparatuses for
refrigeration priming for remote condensed applications in a frozen
beverage machine. These methods and apparatuses utilize various
methods and refrigeration system configurations, such as utilizing
temperature and pressure sensors, mass flow valves and check
valves, to determine if it is necessary to run a priming cycle
before a hot-gas bypass operation can be completed properly on a
remote condenser refrigeration system or frozen beverage dispenser.
This priming cycle attempts to draw refrigerant into the system
from the condenser unit. The priming operation itself may be
implemented by closing the refrigeration bypass and allowing
refrigerant to flow through the expansion devices. Typically, the
priming process will conclude either on a successful priming cycle
or on the expiration of a timer.
[0071] Frozen beverage dispensers operate by cycling between a
frozen and thawed state. Over time ice crystal buildup in the
beverage will effect dispenser operation and so must be
periodically defrosted back to its original liquid state. Utilizing
a hot-gas bypass defrost process in a remote condensed,
vapor-compression refrigeration system can be problematic when the
air temperature surrounding the remote condenser is much colder
than the dispenser evaporator's ambient temperature. Hot-gas bypass
defrosting process may utilize the refrigerants thermal energy
(generated by the compressor's heat of compression & motor
input power) to effect a beverage defrost cycle. During cold
weather, the refrigerant will migrate to the coldest location in
the refrigeration system, i.e. to the condenser unit during
freezing and subfreezing weather conditions. Consequently, the
migration of refrigerant to the remote condenser can reduce the
effectiveness of a hot-gas bypass defrosting operation.
[0072] The objective of these methods and systems of refrigerant
priming is to determine if a thermal condition in the beverage
cooler or dispenser exists that will prevent the effective use of a
hot-gas bypass defrost cycle. If this poor condition exists, the
system will then attempt to rectify the problem by refrigerant
priming or filling the evaporators with refrigerant. The system can
automatically end the refrigerant priming process cycle by
determining if the process was successful using available physical
data.
[0073] On some frozen beverage dispensing equipment, the compressor
will be contained in the dispenser and the liquid refrigerant
receiver will be mounted in the remote condenser housing. In this
arrangement, a hot-gas bypass defrost operation at the evaporator
may only utilize the refrigerant remaining in the dispenser itself.
During cold ambient conditions, enough refrigerant migration may
occur to render a hot-gas bypass defrosting operation ineffective
or non-operational. Compressor damage may also occur because of
refrigeration migration.
[0074] FIG. 8 is a schematic diagram for an exemplary refrigeration
system 800 with a remote condensing unit in accordance with certain
teachings of the present disclosure. This refrigeration system is
designed for a frozen beverage machine, such as those disclosed
herein, but may be utilized in other types of systems that use a
refrigeration system.
[0075] Referring to FIG. 8, the system includes a remote condensing
unit 810 that comprises an air-cooled condenser 816 coupled to a
head pressure control valve 814 and a receiver 812. In general
operation, the air-cooled condenser 816 receives working fluid in
the form of a hot, high-pressure gas. The high pressure gas flows
through the air-cooled condenser 816, and cools to form a liquid.
The pressure across the air-cooled condenser 816 is maintained by
the head pressure control valve 814. The liquid refrigerant flowing
from the air-cooled condenser 816 through the head pressure control
valve 814 is received by receiver 812 where excess refrigerant will
be stored.
[0076] Refrigeration system 800 also includes a dispensing unit 830
that includes check valves 832 and 840, filter/dryer 834, expansion
valves 836a-836d, evaporator barrels 842a-842d and compressor 848.
The check valves 832 and 840 are intended to control the direction
of refrigerant flow through the system and ensure that ensure that
refrigerant flows through the condenser 816 and receiver 812, to
the expansion valves 836a-836d and the evaporator barrels
842a-842d, and then through the condenser (or generally
counterclockwise with respect to the system of FIG. 8). More or
less evaporator barrels (and corresponding expansion valves are
envisioned and in accordance with certain teachings of the present
disclosure).
[0077] In general, when cooling is desired for one or more barrels,
the expansion valve associated with the barrel or barrels to be
cooled will be open and the compressor 848 will be activated.
Liquid refrigerant will then tend to flow from the receiver 812,
through check valve 832 and filter/dryer 834, through the open
expansion valve(s) 836a-836d and then through the corresponding
evaporator barrel 842a-842d where the liquid will absorb heat and
transition to a hot gas. The hot gas will flow into the compressor
848 where the refrigerant will be compressed and the cycle will
repeat.
[0078] In the embodiment of FIG. 8, sensors are provided for
sending the suction temperature 844, suction pressure 846 and
discharge pressure 850. Hot gas bypass valves 838a-838d are also
provided for use in defrost and other processes as described more
fully herein. In general, a hot-bypass defrost operation is
performed for one or more of the freezing barrels by closing the
expansion valves 836a-836d for such barrels while opening the
corresponding hot-bypass valve 838a-838d for such barrels. Under
these situations, refrigerant in the evaporator barrels will flow
through the barrels 842a-842d, into the compressor 848 to be
compressed to a hot gas, and then through the open hot gas bypass
valve(s) 838a-838d, and back through the evaporator barrels
842a-842d associated with the open bypass valves to enable a
defrost application.
[0079] In many applications in which remote condensers, like remote
condensing unit 810 of FIG. 8, are used, the remote condenser is
placed in an exterior location where it is exposed to the
environment and to ambient temperatures. In such applications,
especially during cold outdoor conditions, the refrigerant in the
system can migrate to the outdoor condensing unit and become pooled
in the unit. The migration of the refrigerant to the outdoor
condensing unit can be problematic in systems where hot-bypass
defrost operations are desired. This is because the effectiveness
and efficiency of a hot-bypass defrost operation will depend in
large part on the amount of refrigerant within the dispensing unit
830 at the time the hot bypass operation is initiated. If, at that
time, insufficient refrigerant is in the dispensing unit
830--because it is pooled in the outdoor condensing unit 810--the
hot bypass operation either will operate inefficiently or will not
defrost the barrels to be defrosted in the appropriate time period
or to the desired extent.
[0080] To overcome the issue described above, the system described
herein can use a form of intelligent priming to ensure that an
appropriate amount of refrigerant is in the dispensing unit 830
when a hot bypass operation is initiated.
[0081] FIG. 9 is a flow chart illustrating an exemplary method for
refrigeration priming for remote condensed applications in a frozen
beverage machine like the one illustrated in FIG. 8. The
determination of if a refrigeration prime is necessary is handled
by a control system, which is typically electronic, that monitors
refrigeration pressure, temperature or a combination of the
two.
[0082] In step 910, the defrost cycle is started, the defrost
solenoid (e.g. hot gas bypass valves 838a-838d) is opened, the
compressor is turned on, and a delay of twenty seconds occurs. At
the end of the twenty seconds, in step 915, the low side
refrigeration pressure (e.g. suction pressure) and the high side
refrigeration pressure (e.g. discharge pressure) is checked. This
can be measured directly through pressure transducers or indirectly
through temperature sensors. If the low side refrigeration pressure
and the high side refrigeration pressure are within nominal
operating conditions for the compressor, in step 955, the
defrosting is continued normally. If the low side refrigeration
pressure and the high side refrigeration pressure are not within
nominal operating conditions for the compressor, in step 920, the
defrost solenoid is closed, the expansion solenoid is open, and the
start time is set for four minutes. For this example, if the low
side refrigeration pressure is below 50 pounds per square inch
(PSI) or the high side refrigeration pressure is less than 200 PSI
then, in step 920, the defrost solenoid is closed, the expansion
solenoid is open, and the start time is set for four minutes. Step
920 is when the hot-gas bypassed is suspended and the prime cycle
begins. To prime the system, as is shown in step 920 all bypass
valves (e.g. hot gas bypass valves 838a-838d) are closed and the
expansion devices (e.g. 836a-836d) are utilized in a manner
consistent with the systems normal freezing or cooling routine. If
electronic valves are used, they should be opened fully to allow
the largest amount of refrigerant flow. The system is then allowed
to run and attempt to draw refrigerant from the condenser unit.
[0083] During the priming process, sensor readings may be
continuously monitored. The sensors are looking for the pressures
to cross-operating parameters or temperature sensors to indicate
the flow of refrigerant in the system. This is shown in step 925.
For example, as is shown in step 925, if the high side
refrigeration pressure is above or equal to 200 PSI then, step 935
shows the system waits 20 seconds. Alternatively, in another
example, if the low side refrigeration pressure is above 30 pounds
per square inch (PSI) and the high side refrigeration pressure is
above 100 PSI then, step 935 shows the system waits 20 seconds.
Next, per step 940, the defrost solenoid is open and the expansion
solenoid is closed. Next, per step 945, the system waits 30 seconds
followed by step 950 where the low side refrigeration pressure is
checked again to determine if it is less than 10 PSI. If it is not,
step 955 shows that the defrosting continues normally. If step 950
is not satisfied, then barrel is shut down in step 960 and then a
log system error is registered in step 970. Steps 925-955 show that
once the nominal operating conditions are met, the prime operation
is halted and the hot-gas procedure is resumed. The system may
initialize different timers or none at all during the priming
procedure. If nominal operating conditions are not satisfied in
step 925, a timer is set that will for a period of time continually
check and loop between step 930 and 925 until the timer expires, in
which case the process proceeds to steps 960 (shutting down the
barrel) and 970 (log system error). If the system does not complete
its prime operation in the allotted period of time, the operation
can be halted and a fault triggered such as is shown in step 970.
It should be noted that the equations shown in this and other
figures are only exemplary. Other calculations are shown and other
calculations may be used to accomplish the same goal.
[0084] FIG. 10 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure. FIG. 10 is
similar to FIG. 8, however, FIG. 10 includes a mass flow meter
1010. Mass flow meter 1010 may be used in an alternative and as a
supplement to the various methods and apparatuses disclosed in the
present disclosure. As is shown in FIG. 10, the refrigeration
system has an integrated mass flow meter 1010. During a defrost
cycle, the controller for the system will measure the refrigerant
mass flow rate 1010. If the mass flow rate is below a particular
value, then the controller will initiate a priming cycle, such as
is described in FIG. 9. The priming cycle may continue for a fixed
length of time or until the mass flow rate of the mass flow meter
1010 has reached a desired amount.
[0085] FIG. 11 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure. FIG. 11 is
similar to FIG. 8, however, FIG. 11 includes an ambient temperate
sensor 1110 at or near the remote condensing unit 810 and an air
temperature sensor 1120 at or near the evaporators 836a-d. Ambient
temperate sensor 1110 and air temperature sensor 1120 may be used
in an alternative and as a supplement to the various methods and
apparatuses disclosed in the present disclosure. As is shown in
FIG. 11, the ambient temperature (determined by an ambient
temperate sensor 1110) at or near the remote condenser unit 810 and
the ambient temperature (determined by air temperature sensor 1120)
at or near the evaporators 836a-d can be monitored. The difference
between these temperatures is proportional to the rate at which
refrigerant will migrate to the remove condensing unit 810, or
migrate to the evaporators 836a-d. The rate of refrigerant
migration may then be calculated. Next, it is determined whether
the refrigeration system 800 has enough refrigerant to effectively
complete a hot-gas bypass defrost procedure, such as is shown in
FIG. 9. The amount of refrigerant that a defrost cycle would use is
a function of the time since the machine was last run in freezing
mode and the ambient temperature difference between the
evaporator(s) 836a-d and the remote condensing unit 810.
[0086] FIG. 12 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure. FIG. 12 is
similar to FIG. 8, however, FIG. 12 includes an isolation valve
1210 at the exit of the refrigeration flow from the dispensing unit
830 to the remote condensing unit 810 and an isolation valve 1220
at the entrance or near the entrance to the remote condensing unit
810 from the refrigeration flow from the dispensing unit 830.
Isolation valves 1210, 1220 may be located in other locations to
control the flow of the refrigeration through the refrigeration
system 800. Isolation valves 1210, 1220 may be used in an
alternative and as a supplement to the various methods and
apparatuses disclosed in the present disclosure. As is shown in
FIG. 12, to prohibit the migration of refrigerant to the remote
condensing unit 810 or the compressor 848, isolation valves 1210,
1220 could be placed in the refrigerant lines going between the
dispensing unit 830 and the remote condensing unit 810. The
isolation valves 1210, 1220 would be normally closed. When
freezing, the isolation valves 1210, 1220 would be energized open.
During a refrigerant priming and defrost cycle as described herein
or in other known embodiments, the isolation valves 1210, 1220
would be open or left closed at the appropriate time in the
cycle.
[0087] FIGS. 13, 14 illustrate an exemplary alternative method and
apparatus for controlling a refrigeration system with a remote
condensing unit in accordance with certain teachings of the present
disclosure
[0088] FIG. 13 is a schematic diagram for an exemplary alternative
refrigeration system with a remote condensing unit in accordance
with certain teachings of the present disclosure. FIG. 13 is
similar to FIG. 8, however, FIG. 13 includes an inlet temperature
sensors 1310a-d on the refrigeration inlet line(s) into the
barrel(s) 942a-d and outlet temperature sensors 1320a-d on the
refrigeration outlet line(s) out of the barrel(s) 942a-d. Inlet
temperature sensors 1310a-d and outlet temperature sensors 1320a-d
may be used in an alternative and as a supplement to the various
methods and apparatuses disclosed in the present disclosure. The
refrigeration machine 800 schedules a defrost cycle after one or
more or the barrels 842a-d has completed a freeze cycle. If a
defrost cycle is needed and cannot "piggyback" off of a freeze,
then the refrigeration machine 800 will be prime.
[0089] FIGS. 14A-B shows a flow chart illustrating a further
exemplary method for controlling refrigeration priming for remote
condensed applications in a frozen beverage machine in accordance
with certain teachings of the present disclosure.
[0090] The left-hand side of the flowchart of FIGS. 14A-B
illustrate scheduled defrosts. Typically, frozen beverage machines
have a defrost schedule where each barrel is scheduled to defrost a
particular number of times throughout the day. Typical machines
defrost each barrel 3-6 times a day at set times. The logic on the
left-hand side of the diagram starts to defrost a barrel if: the
machine is within .+-.10 minutes of a scheduled defrost and one or
more barrels has just finished freezing. This ensures that the
refrigeration system is primed. If no barrels freeze during the
20-minute window, the logic forces a priming sequence to occur.
[0091] The right-hand side of the flowchart of FIGS. 14A-B
illustrate a forced priming process and manually initiated defrosts
(operator or service technician initiated defrosts). The frozen
beverage machine does not know if the refrigeration system is
primed; as a result, the system primes the refrigeration system by
turning on the condenser fan (not shown) of the condenser fan 816,
compressor 848, and expansion valve(s) 836a-d (shown in FIG. 13).
The logic used to terminate the refrigerant prime uses a
combination of evaporator inlet & return temperatures, beater %
slope (beverage viscosity level-rate of change), temperature rate
of change, and timer(s). A prime usually takes less than five
minutes but could take longer in a less than ideal scenario.
Instead of forcing every prime to last 5 minutes, the machine uses
the logic in the flowchart to terminate when the machine determines
that the refrigeration system is primed
[0092] Turning to FIGS. 14A-B, the control system will first check
at point 1405 to determine whether the current time is within a
preset interval (in the example +/-10 minutes) of a scheduled
defrost time. This is because priming will only typically be an
issue near the time of a desired defrost operation. If the decision
step at 1405 determines that there is no imminent scheduled defrost
operation, the system will take no action and loop back to step
1405.
[0093] If the system determines at step 1405 that a scheduled
defrost is imminent, it will take steps to determine whether a
priming operation is necessary. Initially, the system will
determine whether two or more barrels are freezing at step 1410. If
there are two or more barrels freezing, the system will presume
that there is adequate refrigerant in the dispensing unit and then
place the barrel or barrels scheduled to be defrosted into a
defrost wait state at step 1435, wait for the freezing barrels to
complete the freezing, and then initiate the defrost process at
step 1445. Under this scenario, no priming is implemented.
[0094] If the system determines at step 1405 that two or more
barrels are not freezing, it will then determine whether one barrel
is freezing at step 1415. If the system determines that one barrel
is freezing, it will determine whether the freezing barrel is the
barrel to be defrosted at step 1430. If so, the system will wait
for the freezing barrel to finish freezing at step 1440 and then
initiate a defrost operation at step 1445. In such a scenario, no
priming is necessary as the operation of freezing the barrel will
ensure that adequate refrigerant is in the dispensing unit for an
efficient defrost operation.
[0095] If the system determines at step 1430 that the freezing
barrel is not the barrel to schedule to be defrosted, the system
will put the barrel to be defrosted into a defrost wait state at
step 1435, wait until the freezing barrel completes its freezing
operation at step 1435 and then initiate a defrost operation at
step 1445 when the freezing barrel has completed its freezing
operation. Again under this scenario, no priming is necessary.
[0096] If the system determines at step 1415 that there are no
freezing barrels it will recheck to ensure that the system is still
within a given time (e.g., ten minutes) or a scheduled defrost
operation. If it is not it will loop back to step 1410. If step
1415 determines that the system is within a given time of a
scheduled defrost, it will then initiate and implement a priming
operation because it is not able to use a freezing operation
associated with one of the barrels to prime the system for the
defrost operation.
[0097] Looking to the right-hand side of FIGS. 14A-B, the priming
operation is illustrated for manual defrosts, such as those that
may be implemented through activating of a user interface, such as
a push button or touch screen selection.
[0098] Initially the system will determine at step 1450 whether the
indicator for a manual defrost has been activated. If not, the
system will continue to repeat step 1450. When a manual defrost is
initiated, the system will not necessarily know whether the system
is primed and will therefore initiate a forced priming operation,
the duration of which will determine on the extent to which the
system was primed when the forced priming operation was
initiated.
[0099] Referring to FIGS. 14A-B, the forced prime operation will
operate for a period defined by a time 1460, in the example one
minute. The forced prime operation will begin at step 1455 by
starting the time 1460, opening the expansion valve(s) associated
with the barrels to be defrosted, and turning on the condenser fan.
The system will then check to determine whether the time has
expired at step 1465, if it has not, it will then look at a variety
of indicators to determine whether the dispensing unit is
adequately primed for a defrost operation at step 1475.
[0100] In the example of FIGS. 14A-B, the system looks at three
independent criteria, any one of which can indicate that the
dispensing unit is adequately primed. It will be understood that
other criterial could be used and that not all of the specified
criteria need to be used. For example, embodiments are envisioned
where only one or two of the criterial set forth in the exemplary
step 1475 are used.
[0101] Referring to step 1475, in the illustrated example, the
system looks to see if the inlet temperature or the return
temperature is below a desired value (e.g., 30 degrees F.) or if
the percentage change in the beater slop is less than or equal to
-1%/second. Existence of any of these conditions is indicative of
adequate priming and, as such, if it is determined at step 1475
that any of these conditions are met, the system will close the
open expansion valve(s), turn the condenser fan OFF and step 1495
and transition the system to the defrost operation at step
1445.
[0102] If step 1475 indicates that conditions associated with
adequate priming are not detected, the system will then continue to
run through the described loop until the 1-minute initial timer has
expired.
[0103] If the system determines at step 1465 that the 1-minute
initial timer has expired, the system will start a second time for
a second period (e.g., four minutes) at step 1470 and them move to
step 1480 where it will check for indicia for adequate priming. In
the example of FIGS. 14A-B, the conditions used in step 1480 are
two of those associated with step 1475 (e.g., inlet temperature or
return temperature below 30 degrees F.) plus the expiration of the
timer set in step 1470. If any of these conditions are met, the
system will transition to step 1495 and operate as described
above.
[0104] If step 1480 does not identify conditions associated with
adequate priming, the system will transition to step 1485 where it
looks at the rate of change of inlet temperature. If the rate of
change of the inlet temperature is determined to meet a set
criterial (in the example a rate of change associated with a slope
of less than or equal to -0.75 degrees F. per second) then it is
assumed that the system is almost primed, and the system will
transition to step 1490 where the forced priming operation is
completed for a defined duration (e.g., 1 minute) and then the
system will transition to step 1495. If the described criterial is
not met, the system will transition to step 1480 and continue to
cycle through the described loop until the time set in step 1470
expires.
[0105] The following examples are included to demonstrate preferred
embodiments of the additional or supplemental methods of
refrigeration priming for remote condensed applications in a frozen
beverage machine. It should be appreciated by those of skill in the
art that the techniques disclosed in the examples that follow
represent techniques discovered by the inventors to function well
in the practice of the inventions, and thus can be considered to
constitute preferred modes for its practice. However, those of
skill in the art should, in light of the present disclosure,
appreciate that many changes can be made in the specific
embodiments which are disclosed and still obtain a like or similar
result without departing from the scope of the inventions.
ALTERNATIVE OR SUPPLEMENTIVE EXAMPLES
Example 1
[0106] If the refrigeration machine is a remote condensing unit,
the control system in the machine could prime the refrigeration
system before attempting to defrost via a hot-gas bypass. The prime
would occur for a fixed amount of time before every defrost
cycle.
Example 2
[0107] The time elapsed since the last refrigeration freeze cycle
could be used to determine if a refrigerant prime is needed. If a
barrel had recently been frozen, then the system may already be
effectively primed and not much refrigerant migration has occurred.
Under this method, the controller would log the occurrence of
freeze cycle and calculate the amount of time since the last freeze
occurred. Before a defrost cycle is to occur, the controller would
determine if a priming cycle is needed based on the amount of the
time since the last freeze and or the last defrost.
Example 3
[0108] Defrosts could only be scheduled immediately after the
machine has been on and freezing one of the barrels. If the
refrigeration machine just finished a freeze cycle, then the system
is already primed with refrigerant. The defrost process would then
wait until after the machine turns on and completes a freeze cycle
on one or more barrel evaporators
[0109] Applicants have further created improved defrost
effectiveness in remote condensers with refrigerant bleed assist
and defrost priming cycle. A refrigerant bleed assist consist of
allowing the refrigerant from the other non-defrosted beverage heat
exchangers to become available for use in the defrost process. The
refrigerant is in a liquid state ahead of the barrel heat
exchangers' electronic metering device valves. The valves can be
opened temporarily for a period of time (45-60 seconds) at the
start of the defrost process to allow the stored up liquid
refrigerant to pass on through the barrel heat exchanger(s) to the
compressor suction line. The metering valves' then close while the
defrost process continues.
[0110] The combination of the defrost priming methods and
apparatuses described herein coupled with the refrigerant bleed
assist may be used to further improve defrost effectiveness by
increasing refrigerant mass for the defrost process. The added
liquid refrigerant mass passes through the one or more barrel heat
exchanger and becomes vapor as it moves toward the compressor
suction line. The defrost process now has an increased volume of
refrigerant for circulation. As the refrigerant vapor moves through
the compressor, the heat of compression and internal motor heat is
absorbed by the vapor raising its pressure and temperature. This
increased temperature of the refrigerant when circulated into the
barrel will lead to shorter defrost times.
[0111] Other and further embodiments utilizing one or more aspects
of the inventions described above can be devised without departing
from the spirit of Applicant's invention. Further, the various
methods and embodiments of the methods of manufacture and assembly
of the system, as well as location specifications, can be included
in combination with each other to produce variations of the
disclosed methods and embodiments. Discussion of singular elements
can include plural elements and vice-versa.
[0112] The order of steps can occur in a variety of sequences
unless otherwise specifically limited. The various steps described
herein can be combined with other steps, interlineated with the
stated steps, and/or split into multiple steps. Similarly, elements
have been described functionally and can be embodied as separate
components or can be combined into components having multiple
functions.
[0113] The inventions have been described in the context of
preferred and other embodiments and not every embodiment of the
invention has been described. Obvious modifications and alterations
to the described embodiments are available to those of ordinary
skill in the art. The disclosed and undisclosed embodiments are not
intended to limit or restrict the scope or applicability of the
invention conceived of by the Applicants, but rather, in conformity
with the patent laws, Applicants intend to fully protect all such
modifications and improvements that come within the scope or range
of equivalent of the following claims.
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