TWI846750B - Machine for producing cooled food or drinks, machine for reducing the temperature of ingredients, and method of reducing the temperature of ingredients in a pod - Google Patents

Abstract

Systems and methods have demonstrated the capability of rapidly cooling the contents of pods containing the ingredients for food and drinks.

Description

Machine for producing cooled food or drink, machine for lowering the temperature of ingredients and method for lowering the temperature of ingredients in a container

The present invention relates to a system and method for rapidly cooling food and beverages.

Beverage brewing systems have been developed that quickly prepare single servings of hot beverages. Some of these brewing systems rely on a single-use pod to which water is added before brewing occurs. The pods can be used to prepare hot coffee, tea, cocoa, and dairy-based beverages.

Home ice cream machines can be used to make larger batches (e.g., 1.5 quarts or more) of ice cream for personal consumption. These ice cream machine appliances typically prepare the mixture by employing a hand crank method or by employing an electric motor, which in turn is used to help stir the ingredients within the appliance. The resulting preparation is typically refrigerated using a pre-chilled vessel inserted into the machine.

This specification describes systems and methods for rapidly cooling food and beverages. Some of these systems and methods can cool food and beverages in a container inserted into a countertop or mounted machine from room temperature to frozen in less than two minutes. For example, the methods described in this specification have successfully demonstrated the ability to make soft serve ice cream from a room temperature bin in approximately 90 seconds. This method has also been used to refrigerate cocktails and other beverages, including for the production of frozen beverages. These systems and methods are based on a consistent cold cycle with a low startup time and a bin machine interface that is easy to use and provides extremely efficient heat transfer. Some of the described cassettes are filled with ingredients in a manufacturing line and subjected to a sterilization process (e.g., retort, aseptic packaging, ultra-high temperature processing (UHT), ultra-heat processing, ultra-high temperature pasteurization, or high pressure processing (HPP)). HPP is a low-temperature pasteurization technology by which the product, already sealed in its final packaging, is introduced into a vessel and subjected to a high level of equalized pressure (300 megapascals (MPa) to 600 MPa (43,500 pounds per square inch (psi) to 87,000 psi transmitted by water). The cassettes can be used to store ingredients including, for example, dairy products, for long periods of time (e.g., 9 to 12 months) at room temperature after sterilization.

Cooling is used to refer to the transfer of heat energy that lowers the temperature of components contained in a box, for example. In some cases, cooling refers to the transfer of heat energy that lowers the temperature of components contained in a box, for example, to below freezing.

Certain machines for producing refrigerated food or beverages from ingredients in a cassette containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette; and wherein the refrigeration system has a working fluid loop and also includes a first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve or capillary tube and returning to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator.

Certain machines for reducing the temperature of components in a box containing the components and at least one mixing impeller include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the box; a motor operable to move the at least one internal mixing impeller of a box in the receptacle; wherein the refrigeration system has a working fluid loop and also includes a first bypass line and a bypass valve located on the first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve and returning to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator.

Certain machines for producing a refrigerated component in a box containing the component and at least one internal mixing impeller include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive a disposable box; and a motor operable to move the at least one internal mixing impeller of a box in the receptacle; wherein the refrigeration system has a working fluid loop and also includes a first bypass line and a bypass valve located on the first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve and returning to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator.

Certain machines for producing a cooling component in a box containing the component and at least one internal mixing impeller include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the box; and a motor operable to move the internal mixing impeller of a box in the receptacle; wherein the refrigeration system has a working fluid loop and also includes a first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve and back to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the evaporator and the compressor.

Certain machines for producing a refrigerated component in a box containing the component and at least one internal mixing impeller include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the box; and a motor operable to move the internal mixing impeller of a box in the receptacle; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to a pressure vessel, to an expansion valve and back to the evaporator, and the working fluid loop includes a first isolation valve between the pressure vessel and the expansion valve and a second isolation valve between the compressor and the condenser.

Certain machines for producing a refrigerated component in a bin containing the component and at least one internal mixing impeller include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the bin; and a motor operable to move the internal mixing impeller of a bin in the receptacle; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve and back to the evaporator, and the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion valve.

Certain machines for producing refrigerated food or beverage from ingredients in a bin containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the bin; and wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve or capillary tube and back to the evaporator; and wherein the evaporator is made of a material having a thermal conductivity of at least 160 W/mk.

Certain machines for producing refrigerated food or beverage from ingredients in a cassette containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve or capillary tube and returning to the evaporator; and wherein a refrigerant is selected from the group consisting of: R143A, R134a, R410a, R32 and R404a, carbon dioxide, ammonia, propane and isobutane.

Certain machines for producing refrigerated food or beverage from ingredients in a cassette containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion subsystem and back to the evaporator, the expansion subsystem including a plurality of orifices or expansion devices in parallel.

Certain machines for producing cooled food or beverages from ingredients in a cassette containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion valve or capillary tube, to a refrigerant line and back to the evaporator, the refrigerant line precooling a water tank.

Certain machines for producing cooled food or beverages from ingredients in a cassette containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette; wherein the refrigeration system has a working fluid loop extending from the evaporator to one side of a thermoelectric cell, to a compressor, to a condenser, to the other side of a thermoelectric cell, to an expansion valve or capillary tube and back to the evaporator.

Implementations of these machines may include one or more of the following features.

In certain embodiments, the machine also includes a bypass valve located on the first bypass line.

In some embodiments, the machine also includes a second bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the evaporator and the compressor. In some cases, the machine also includes a bypass valve on the second bypass line. In some cases, the machine also includes a suction line heat exchanger.

In some embodiments, the working fluid loop passes through a reservoir of phase change material disposed between the compressor and the condenser. In some cases, the phase change material comprises a glycol and water mixture, saline, paraffin, alkane or pure water or a combination thereof. In some cases, the working fluid loop comprises a pressure vessel between the condenser and the evaporator, a first isolation valve between the pressure vessel and the expansion valve, and a second isolation valve between the compressor and the condenser. In some cases, the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion valve.

In some embodiments, the machine also includes an aluminum evaporator having a mass not exceeding 1.50 pounds.

In some embodiments, the machine also includes a pressure drop of less than 2 psi across the refrigeration system.

In certain embodiments, the machine also includes a box-to-evaporator heat transfer surface of up to 50 square inches.

In certain embodiments, the machine also includes an evaporator having cooling channels therein to allow fluid mass velocities of up to 180,000 lb/(hr·ft2), the evaporator having up to 200 square inches of refrigerant wetted surface area.

In certain embodiments, the machine also includes an evaporator refrigerant-wetted surface area of up to 200 square inches.

In some embodiments, the machine also includes an evaporator clamped down onto the cassette.

In some embodiments, the machine also includes an evaporator having a copper interior wall adjacent to the cassette.

In some embodiments, the machine also includes an evaporator formed by microchannels.

The systems and methods described in this specification can provide several advantages. Certain embodiments of these systems and methods can provide a single serving of chilled food or drink. This method can help consumers with portion control. Certain embodiments of these systems and methods can provide consumers with the ability to choose the flavor of their single serving of (for example) soft serve ice cream. Certain embodiments of these systems and methods incorporate storage-resistant bins that do not require pre-cooling, pre-freezing, or other preparation. Certain embodiments of these systems and methods can produce frozen food or drinks from room temperature bins in less than two minutes (in some cases, less than one minute). Certain embodiments of these systems and methods do not require post-processing cleanup once the chilled or frozen food or drink is produced. Certain embodiments of these systems and methods utilize reusable aluminum cassettes.

The details of one or more embodiments of these systems and methods are set forth in the accompanying drawings and the following description. Other features, objectives, and advantages of these systems and methods will become apparent from the description and drawings, as well as from the scope of the claims.

Related Applications This application claims priority to U.S. Patent Application Nos. 16/459,388 filed on July 1, 2019, 16/459,176 filed on July 1, 2019, and 16/459,322 filed on July 1, 2019, and claims the benefit of the following provisional patent applications: U.S. Patent Nos. 62/758,110 filed on November 9, 2018, U.S. Ser. No. 62/801,587 filed on February 5, 2019, U.S. Ser. No. 62/831,657 filed on April 9, 2019, U.S. Ser. No. 62/831,600 filed on April 9, 2019, U.S. Ser. No. 62/831,646 filed on April 9, 2019, and U.S. Ser. No. 62/831,666 filed on April 9, 2019, all of which are hereby incorporated by reference in their entirety.

This specification describes systems and methods for rapidly cooling food and beverages. Some of these systems and methods use a countertop or mounted machine to cool food and beverages in a container from room temperature to frozen in less than two minutes. For example, the methods described in this specification have successfully demonstrated the ability to make soft serve ice cream, frozen coffee, frozen smoothies, and frozen cocktails from a room temperature container in approximately 90 seconds. This method can also be used to refrigerate cocktails, make frozen smoothies, frozen protein and other functional beverage shakes (e.g., collagen-based shakes, energy shakes, plant-based shakes, non-dairy shakes, and CBD shakes), frozen coffee drinks with and without nitrogen and refrigerated coffee drinks, make hard ice cream, make milk shakes, make frozen yogurt, and refrigerate probiotic drinks. These systems and methods are based on a consistent cold cycle with low startup time and a bin-machine interface that is easy to use and provides extremely efficient heat transfer. Some of the illustrated boxes can be sterilized (e.g., using a retort) and used to store ingredients containing, for example, dairy products at room temperature for up to 18 months.

Fig. 1A is a perspective view of a machine 100 for cooling food or beverage. Fig. 1B shows the machine without its housing. The machine 100 reduces the temperature of the components in a cassette containing the components. Most cassettes include a mixing paddle for mixing the components before dispensing cooled or frozen products. The machine 100 includes a main body 102 with a housing 104 and a cassette machine interface 106, which includes a compressor, a condenser, a fan, an evaporator, capillary tubes, a control system, a capping system and a dispensing system. The cassette machine interface 106 includes an evaporator 108 of a refrigeration system 109, and other components of the refrigeration system are placed in the housing 104 inside. As shown in FIG. 1B , the evaporator 108 defines a receptacle 110 sized to receive a cassette.

A cover 112 is attached to the housing 104 via a hinge 114. The cover 112 can be rotated between a closed position covering the receptacle 110 (FIG. 1A) and an open position exposing the receptacle 110 (FIG. 1B). In the closed position, the cover 112 covers the receptacle 110 and is locked in place. In the machine 100, a latch 116 on the cover 112 engages with a latch recess 118 on the cassette machine interface 106. A latch sensor 120 is disposed in the latch recess 118 to determine whether the latch 116 is engaged with the latch recess 118. A processor 122 is electronically connected to the latch sensor 120 and recognizes that the cover 112 is closed when the latch sensor 120 determines that the latch 116 is engaged with the latch recess 118.

When the lid 112 moves from its closed position to its open position, an auxiliary cover 115 is rotated upward. Some auxiliary covers slide into the housing when the lid moves to the open position.

In the machine 100, the evaporator 108 is fixed in position relative to the main body 102 of the machine 100 and access to the receptacle 110 is provided by movement of the cover 112. In some machines, the evaporator 108 is displaceable relative to the main body 102 and movement of the evaporator 108 provides access to the receptacle 110.

A motor 124 disposed in the housing 104 is mechanically connected to a drive shaft 126 extending from the cover 112. When the cover 112 is in its closed position, the drive shaft 126 extends into the receptacle 110 and, if a cassette is present, engages with the cassette to move one or more paddles within the cassette. The processor 122 communicates electronically with the motor 124 and controls the operation of the motor 124. In some machines, the shafts associated with the paddles of the cassette extend outwardly from the cassette, and the cover 112 has a rotating receptacle mechanically connected to the motor 124 (instead of the drive shaft 126).

FIG. 1C is a perspective view of the cover 112, which is shown alone so that the belt 125 extending from the motor 124 to the drive shaft 126 is visible. Referring again to FIG. 1B, the motor 124 is mounted on a plate that runs along a track 127. The plate can be moved approximately 0.25 inches to adjust the tension on the belt. During assembly, the plate slides along the track. A spring disposed between the plate and the cover 112 biases the cover 112 away from the plate to maintain tension in the belt.

FIG. 2A is a perspective view of the machine 100, wherein the cover of the cassette machine interface 106 is illustrated as transparent to allow a more detailed view of the evaporator 108 to be seen. FIG. 2B is a top view of the machine 100 without the housing 104 and a portion of the cassette machine interface 106 without the cover 112. FIG. 2C and FIG. 2D are a perspective view and a side view, respectively, of the evaporator 108. Other cassette machine interfaces are described in more detail in U.S. Patent Application No. 16/459,176 (Attorney Docket No. 47354-0009001), filed concurrently with the present application and incorporated herein by reference in its entirety.

The evaporator 108 has a clamshell configuration with a first portion 128 attached to a second portion 130 by a movable hinge 132 on one side and separated on the other side by a gap 134. Refrigerant flows from other components of the refrigeration system to the evaporator 108 through fluid passages 136 (best seen in FIG. 2B ). The refrigerant flows through the evaporator 108 in an internal passage through the first portion 128, the movable hinge 132, and the second portion 130.

The space 137 (best seen in FIG. 2B ) between the outer wall of the evaporator 108 and the inner wall of the outer shell of the cassette machine interface 106 is filled with an insulating material to reduce heat exchange between the environment and the evaporator 108. In the machine 100, the space 137 is filled with an aerogel (not shown). Some machines use other insulating materials, for example, an annular belt (such as an air barrier), insulating foam made of various polymers, or fiberglass wool.

The evaporator 108 has an open position and a closed position. In the open position, the gap 134 is open to provide an air gap between the first portion 128 and the second portion 130. In the machine 100, in the closed position, the first portion 128 and the second portion 130 are pressed together. In some machines, in the closed position, the first portion and the second portion are pressed toward each other and the gap is reduced, but is still defined by a space between the first portion and the second portion.

The inner diameter ID of evaporator 108 is slightly larger in the open position than in the closed position. When evaporator 108 is in the open position, a cassette can be inserted into the evaporator and removed therefrom. After inserting a cassette, evaporator 108 is shifted from its open position to its closed position to tighten the outer diameter of the cassette around the evaporator 108. For example, machine 100 is configured to use a cassette with an outer diameter of 2.085''. Evaporator 108 has an inner diameter of 2.115'' in the open position and has an inner diameter of 2.085'' in the closed position. Some machines have evaporators that are sized and configured to cool other cassettes. The cassette may be formed from commercially available can sizes, for example, "slim" cans having diameters ranging from 2.080 inches to 2.090 inches and capacities of 180 milliliters (ml) to 300 ml, "round" cans having diameters ranging from 2.250 inches to 2.400 inches and capacities of 180 ml to 400 ml, and "standard" sized cans having diameters ranging from 2.500 inches to 2.600 inches and capacities of 200 ml to 500 ml. The machine 100 is configured to use a cassette having an outer diameter of 2.085 inches. The evaporator 108 has an inner diameter of 2.115 inches in its open position and an inner diameter of 2.085 inches in its closed position. Some machines have evaporators that are sized and configured to cool other boxes.

The closed position of the evaporator 108 improves heat transfer between the box 150 and the evaporator 108 by increasing the contact area between the box 150 and the evaporator 108 and reducing or eliminating an air gap between the wall of the box 150 and the evaporator 108. In some boxes, the pressure applied to the box by the evaporator 108 is offset by mixing blades, pressurized gas, or both within the box to maintain the outer shell shape of the box.

In the evaporator 108, the relative position of the first portion 128 and the second portion 130 and the size of the gap 134 therebetween are controlled by two rods 138, which are connected by a bolt 140, and two springs 142. Each of the rods 138 has a threaded center hole through which the bolt 140 extends and two end holes that engage a pin 144. Each of the two springs 142 is disposed around a pin 144 extending between the rods 138. Some machines use other systems to control the size of the gap 134, for example, a circumferential cable system having a cable extending around the outer diameter of the evaporator 108, wherein the cable is tightened to close the evaporator 108 and is relaxed to open the evaporator 108. In other evaporators, there are multiple bolts and end holes, one or more springs, and one or more dowel pins.

One rod 138 is mounted on the first portion 128 of the evaporator 108 and the other rod 138 is mounted on the second portion 130 of the evaporator 108. In some evaporators, the rods 138 are integral with the body of the evaporator 108 rather than mounted on the body of the evaporator. The spring 142 presses the rods 138 away from each other. The spring force biases the first portion 128 and the second portion 130 of the evaporator 108 away from each other with the gap 134. Rotation of the bolt 140 in one direction increases a force that pushes the rods 138 toward each other and rotation of the bolt in the opposite direction decreases this force. When the force applied by the bolt 140 is greater than the spring force, the rod 138 forces the first and second portions 128, 130 of the evaporator to snap together.

The machine 100 includes an electric motor 146 (shown in FIG. 2B ) operable to rotate the bolt 140 to control the size of the gap 134. Some machines use other mechanisms to rotate the bolt 140. For example, some machines (for example) use a mechanical linkage between the cover 112 and the bolt 140 to rotate the bolt 140 when opening and closing the cover 112. Some machines include a handle that can be attached to the bolt to manually tighten or loosen the bolt. Some machines have a wedging system that forces the rod into a closed position when the machine cover is closed. This method can be used instead of the electric motor 146 or can be provided as a backup method in the event of a motor failure.

The electric motor 146 communicates with and is controlled by the processor 122 of the machine 100. Some electric drives include a torque sensor that sends torque measurements to the processor 122. For example, when a cassette sensor indicates that a cassette is placed in the receptacle 110 or when the latch sensor 120 indicates that the cover 112 is engaged with the cassette machine interface 106, the processor 122 signals the motor to rotate the bolt 140 in a first direction to press the rod 138 together. It is desirable that the clamshell evaporator be closed and the cassette be held in a tightly secured position before the cover is closed and the shaft pierces the cassette and engages the mixing paddle. This positioning can be important for drive shaft-mixing paddle engagement. For example, after the food or beverage being produced has been cooled/frozen and dispensed from the machine 100, the processor 122 signals the electric drive to rotate the bolt 140 in the second direction, thereby opening the evaporator gap 134 and allowing the cassette 150 to be easily removed from the evaporator 108.

The base of the evaporator 108 has three bores 148 (see FIG. 2C ) for mounting the evaporator 108 to the floor of the cassette machine interface 106. All three bores 148 extend through the base of the second portion 130 of the evaporator 108. The first portion 128 of the evaporator 108 is not directly attached to the floor of the cassette machine interface 106. This configuration achieves the opening and closing movement explained above. Other configurations that achieve the opening and closing movement of the evaporator 108 may also be used. Some machines have more or less than three bores 148. Some evaporators are mounted to components other than the floor of the cassette machine interface, for example, a dispensing mechanism.

Many factors affect the performance of a refrigeration system. Important factors include the mass rate of refrigerant flow through the system, the surface area wetted by the refrigerant, the refrigeration process, the area of the cassette/evaporator heat transfer surface, the mass of the evaporator, and the thermal conductivity of the material of the heat transfer surface. Extensive modeling and empirical studies in the development of the prototype system described in this specification have determined that the proper selection of the mass rate of refrigerant flow through the system and the surface area wetted by the refrigerant are the most important parameters to balance to provide a system capable of freezing up to 12 ounces of dessert in less than 2 minutes.

The evaporator described in this specification may have the following characteristics: Table 1 - Evaporator parameters Quality Speed 60,000 lb/(hour·sq.ft) to 180,000 lb/(hour·sq.ft) Surface area wetted by refrigerant 35 square inches to 200 square inches Pressure drop through the refrigeration process Less than 2 psi pressure drop across the evaporator Box/Evaporator Heat Transfer Surface 15 square inches to 50 square inches Evaporator quality 0.100 lbs to 1.50 lbs Minimum conductivity of the material 160 W/mK

The following paragraphs explain the importance of these parameters in more detail.

The mass velocity describes the multiphase nature of the refrigerant flowing through an evaporator. The two-phase process utilizes the high amount of heat absorbed and consumed when a refrigerant fluid (e.g., R-290 propane) changes state from a liquid to a gas and from a gas to a liquid, respectively. The heat transfer rate depends in part on exposing the inner surface of the evaporator to a new liquid refrigerant to evaporate and cool the liquid ice cream mixture. To do this, the velocity of the refrigerant fluid must be high enough to transport or flow down the center of the flow path in the wall of the evaporator and push the liquid refrigerant through these channel passages in the wall. An approximate measure of fluid velocity in a refrigeration system is mass velocity, which is the mass flow of refrigerant per unit cross-sectional area of flow passage in a system, in lb/hr ft^2. Velocity measured in ft/s (a more common way to measure "velocity") is difficult to apply to a two-phase system because the velocity (ft/s) is constantly changing as the fluid stream changes state from liquid to gas. If the liquid refrigerant is constantly sweeping across the evaporator wall, it can be evaporated and new liquid can be pushed to the walls of the cooling channel by a "core" of vapor flowing down the middle of the channel. At low velocities, the flow separates based on gravity and the liquid remains on the bottom of the cooling channel in the evaporator and the vapor rises to the top side of the cooling channel channel. For example, if the area exposed to the liquid is reduced by half, this can reduce the amount of heat transferred by almost half. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), a mass velocity of 150,000 lb/hr ft^2 maximizes the efficiency of most evaporator flow paths. Mass velocity is one of the parameters that must be balanced to optimize a refrigerant system. The parameters that affect the efficiency of the evaporator are mass flow rate, convective heat transfer coefficient, and pressure drop. The nominal operating pressure of the evaporator is determined by the desired temperature of the evaporator and the properties of the refrigerant used in the system. The mass flow rate of the refrigerant passing through the evaporator must be high enough so that it absorbs a certain amount of heat energy from the dessert and thus freezes the dessert within a given amount of time. The mass flow rate is primarily determined by the size of the compressor. It is desirable to use the smallest possible compressor to reduce cost, weight and size. The convective heat transfer coefficient is affected by the mass velocity and the wetted surface area of the evaporator. The convective heat transfer coefficient will increase as the mass velocity increases. However, the pressure drop will also increase with the mass velocity. This in turn increases the power required to operate the compressor and reduces the mass flow rate that the compressor can deliver. It is desirable to design an evaporator that meets performance targets while using the smallest and cheapest compressor possible. It has been determined that an evaporator with a mass velocity of 75,000 lb/hr ft^2 to 125,000 lb/hr ft^2 is effective in helping to provide a system capable of freezing up to 12 ounces of dessert in less than 2 minutes. The latest prototype has a mass velocity of approximately 100,000 lb/hr ft^2 and provides a good balance of high mass velocity, manageable pressure drop in the system, and a reasonably sized compressor.

Another important factor affecting the performance of an evaporator is the surface area wetted by the refrigerant, which is the area of all cooling channels in the evaporator that are exposed to the refrigerant. Increasing the wetted surface area can improve the heat transfer characteristics of an evaporator. However, increasing the wetted surface area can increase the mass of the evaporator, which will increase thermal inertia and degrade the heat transfer characteristics of the evaporator.

The amount of heat that can be transferred from the liquid in a box is proportional to the surface area of the box/evaporator heat transfer surface. A larger surface area is desirable, but an increase in surface area may require an increase in the mass of the evaporator, which will degrade the heat transfer characteristics of the evaporator. It has been determined that an evaporator having an area of box/evaporator heat transfer surface between 20 square inches and 40 square inches effectively combines with other features to help provide a system capable of freezing up to 12 ounces of dessert in less than 2 minutes.

Thermal conductivity is an intrinsic property of a material that is related to the material's ability to conduct heat. Heat transfer due to conduction involves the transfer of energy within a material without any movement of the material as a whole. An evaporator with walls made of a high conductivity material (e.g., aluminum) reduces the temperature difference across the evaporator wall. Reducing this temperature difference reduces the work required by the refrigeration system to cool the evaporator to the proper temperature.

In order for the desired heat transfer to occur, the evaporator must be cooled. The greater the mass of the evaporator, the longer this cooling will take. Reducing the mass of the evaporator will reduce the amount of material that must be cooled during a freezing cycle. An evaporator with a large mass will increase the time required to freeze a dessert of up to 12 ounces.

The effects of thermal conductivity and mass can be balanced by a proper choice of one of the materials. There are materials that have higher thermal conductivity than aluminum, such as copper. However, the density of copper is greater than the density of aluminum. For this reason, some evaporators have been constructed that use high thermal conductivity copper only on the heat exchange surfaces of the evaporator and aluminum everywhere else.

3A-3F show components of a cassette machine interface 106 operable to open a cassette in an evaporator 108 to dispense food or beverage being produced by the machine 100. This is one example of one method of opening a cassette, but some machines and associated cassettes use other methods.

FIG. 3A is a schematic partial cross-sectional view of the cassette machine interface 106 with a cassette 150 placed in the evaporator 108. FIG. 3B is a schematic plan view looking upwards showing the relationship between the end of the cassette 150 and the bottom plate 152 of the cassette machine interface 106. The bottom plate 152 of the cassette machine interface 106 is formed by a dispenser 153. FIG. 3C and FIG. 3D are perspective views of a dispenser 153. FIG. 3E and FIG. 3F are perspective views of an insert 154 disposed in the dispenser 153. The insert 154 includes an electric motor 146 that is operable to drive a worm wheel 157 bottom plate 152 of the cassette machine interface 106. The worm gear 157 engages with a gear 159 having an annular configuration. An annular member 161 mounted on the gear 159 extends from the gear 159 into an interior region of the cassette machine interface 106. The annular member 161 has protrusions 163 configured to engage with a cassette inserted into the cassette machine interface 106 to open the cassette. The protrusions 163 of the annular member 161 are four nail-shaped protrusions. Some annular gears have more or fewer protrusions, and the protrusions may have other shapes, such as a "tooth" shape.

The cassette 150 includes a body 158 that houses a mixing paddle 160 (see FIG. 3A ). The cassette 150 also has a base 162 that defines an opening 164 extending across the base 162 and a cap 166 (see FIG. 3B ). The base 162 is joined/secured to the body 158 of the cassette 150. The base 162 includes a protrusion 165. The cap 166 mounted above the base 162 can rotate around the circumference/axis of the cassette 150. In use, when the product is ready to be dispensed from the cassette 150, the dispenser 153 of the machine engages the cap 166 and rotates the cap around the first end of the cassette 150. The cap 166 is rotated to a position to engage and then the tab 165 is separated from the remainder of the base 162. The cassette 150 and its components are described in more detail with respect to FIGS. 6A-10.

The aperture 164 in the base 162 is opened by the rotation of the cap 166. The cassette machine interface 106 includes an electric motor 146 having threads that engage the outer circumference of a gear 168. The operation of the electric motor 146 causes the gear 168 to rotate. The gear 168 is attached to an annular member 161 and the rotation of the gear 168 causes the annular member 161 to rotate. The gear 168 and the annular member 161 are both annular and together define a central bore through which food or drink can be dispensed from the cassette 150 through the aperture 164 without contacting the gear 168 or the annular member 161. When the cassette 150 is placed in the evaporator 108, the annular member 161 engages the cap 166 and the rotation of the annular member 161 causes the cap 166 to rotate.

FIG. 4 is a schematic diagram of a refrigeration system 109 including an evaporator 108. The refrigeration system also includes a condenser 180, a suction line heat exchanger 182, an expansion valve 184 (an example of an expansion device), and a compressor 186. High pressure liquid refrigerant flows from the condenser 180 through the suction line heat exchanger 182 and the expansion valve 184 to the evaporator 108. When the liquid refrigerant leaves the expansion valve 184, the expansion valve 184 restricts the flow of the liquid refrigerant and reduces the pressure of the liquid refrigerant. The low pressure liquid then moves to the evaporator 108 where heat absorbed from a cassette 150 and its contents in the evaporator 108 changes the refrigerant from a liquid vapor mixture to a gas. The vapor phase refrigerant flows from the evaporator 108 to the compressor 186 through the suction line heat exchanger 182. In the suction line heat exchanger 182, the cold vapor leaving the evaporator 108 precools the liquid leaving the condenser 180. The refrigerant enters the compressor 186 as a low pressure gas and leaves the compressor 186 as a high pressure gas. The gas then flows to the condenser 180 where the heat exchange cools the refrigerant and condenses it into a liquid.

The refrigeration system 109 includes a first bypass line 188 and a second bypass line 190. The first bypass line 188 directly connects the discharge of the compressor 186 to the inlet of the compressor 186. Bypass valves are disposed on both the first bypass line and the second bypass line, which open and close passages to allow refrigerant to bypass flow. Directly diverting refrigerant from the compressor discharge to the inlet provides evaporator defrosting and temperature control without injecting hot gas into the evaporator. The first bypass line 188 also provides a means for rapid pressure equalization across the compressor 186, which allows rapid restart (e.g., rapid succession of freezer boxes). The second bypass line 190 enables warm gas to be applied to the evaporator 108 to defrost the evaporator 108. For example, the bypass valve may be a solenoid valve or a throttling valve.

Figures 5A and 5B are views of a prototype of a condenser 180. The condenser has internal channels 192. The internal channels 192 increase the surface area for interaction with the refrigerant, thereby rapidly cooling the refrigerant. These images show microchannel tubes, which are used because they have small channels to maintain the velocity of the refrigerant and thin walls for good heat transfer and low mass to prevent the condenser from becoming a heat sink.

Figures 6A and 6B show an example of a cassette 150 for use with the machine 100 described with respect to Figures 1A to 3F. Figure 6A is a side view of the cassette 150. Figure 6B is a schematic side view of the cassette 150 and a mixing paddle 160 disposed in the body 158 of the cassette 150. Other cassette machine interfaces that may be used with this and similar machines are described in more detail in U.S. Patent Application No. 16/459,322 (Attorney Docket No. 47354-0010001), filed concurrently with the present application and incorporated herein by reference in its entirety.

The cassette 150 is sized to fit within the receptacle 110 of the machine 100. The cassette may be sized to provide a single serving of the food or beverage being produced. Typically, the cassette has a capacity between 6 and 18 fluid ounces. The cassette 150 has a capacity of approximately 8.5 fluid ounces.

The body 158 of the box 150 is a tank that houses the mixing blade 160. The body 158 extends from a first end 210 at the base to a second end 212 and has a circular cross-section. The first end 210 has a diameter D _UE that is slightly larger than the diameter D _LE of the second end 212. This configuration facilitates stacking multiple boxes 150 on top of each other, with the first end 210 of one box receiving the second end 212 of another box.

A wall 214 connects the first end 210 to the second end 212. The wall 214 has a first neck 216, a second neck 218, and a barrel 220 between the first neck 216 and the second neck 218. The barrel 220 has a circular cross-section with a diameter _DB . The diameter _DB is larger than both the diameter D _UE of the first end 210 and the diameter D _LE of the second end 212. The first neck 216 connects the barrel 220 to the first end 210 and is inclined as the first neck 216 extends from the smaller diameter D _UE of the barrel 220 to the larger diameter _DB . The second neck 218 connects the barrel 220 to the second end 212 and slopes as the second neck 218 extends from a larger diameter _DB of the barrel 220 to a smaller diameter D _LE of the second end 212. Since the second end 212 has a smaller diameter than the first end 210, the second neck 218 slopes more steeply than the first neck 216.

This configuration of the box 150 provides increased material usage; that is, the ability to use more base material (e.g., aluminum) per box. This configuration further contributes to the columnar strength of the box.

The box 150 is designed for good heat transfer from the evaporator to the contents of the box. The body 158 of the box 150 is made of aluminum and has a thickness between 5 microns and 50 microns. The bodies of some boxes are made of other materials, such as tin, stainless steel, and various polymers such as polyethylene terephthalate (PTE).

The box 150 can be made of a combination of different materials to help the manufacturability and performance of the box. In one embodiment, the box wall and the second end 212 can be made of aluminum 3104 and the base can be made of aluminum 5182.

In some boxes, the interior components of the box are coated with a paint that is used to prevent corrosion of the box when the box comes into contact with the ingredients contained in the box. This paint also reduces the possibility of "off notes" of metals contained in the food and beverage ingredients contained in the box. For example, a box made of aluminum may be coated on the inside with one or a combination of the following coatings: Sherwin Williams/Valspar V70Q11, V70Q05, 32SO2AD, 40Q60AJ; PPG Innovel 2012-823, 2012-820C; and/or Akzo Nobel Aqualure G1 50. Other coatings made by the same or other coating manufacturers may also be used.

Some hybrid blades are made of similar aluminum alloys and painted with similar paints/coatings. For example, Whitford/PPG coating 8870 may be used as one of the coatings for a hybrid blade. The hybrid blade paint may have additional non-stick and hardening benefits for the hybrid blade.

7A-7C illustrate the engagement between the drive shaft 126 of the machine 100 and the mixing blade 160 of a cassette 150 inserted in the machine 100. FIG. 7A and FIG. 7B are perspective views of the cassette 150 and the drive shaft 126. In use, the cassette 150 is inserted into the receptacle 110 of the evaporator 108 with the first end 210 of the cassette 150 facing downward. This orientation exposes the second end 212 of the cassette 150 to the drive shaft 126, as shown in FIG. 7A. Closing the cover 112 (see FIG. 1A ) presses the drive shaft 126 against the second end 212 of the cassette 150 with sufficient force to cause the drive shaft 126 to penetrate the second end 212 of the cassette 150. FIG. 7B shows the resulting hole exposing the mixing paddle 160, wherein the drive shaft 126 is offset for easier viewing. FIG. 7C is a cross-section of a portion of the cassette 150, wherein the drive shaft 126 is engaged with the mixing paddle 160 after the cover is closed. Typically, there is no tight seal between the drive shaft 126 and the cassette 150, allowing air to flow in when the frozen confection is discharged/dispensed from the other end of the cassette 150. In an alternative embodiment, there is a tight seal so that the box 150 retains pressure to enhance the contact between the box 150 and the evaporator 108.

Some mixing paddles include a funnel or receptacle configuration for receiving the pierced end of the second end of the cassette when the second end is pierced by the drive shaft.

8 shows the first end 210 of the cassette 150 with the cap 166 spaced from the base 162 for easy viewing. FIGS. 9A-9D illustrate the cap 166 being rotated about the first end 210 of the cassette 150 to cut and remove the protrusion 165 of the base 162 and expose the aperture 164 extending through the base 162.

The base 162 is manufactured separately from the body 158 of the box 150 and then attached (e.g., by pressing or bonding) to the body 158 of the box 150 so as to cover an open end of the body 158. For example, the protrusion 165 of the base can be formed by stamping, deep drawing, or forging an aluminum plate used to form the base 162. For example, the protrusion 165 is attached to the remaining portion of the base 162 by a weakened score line 173. The score can be a vertical score into the base of the aluminum plate or a horizontal score into the wall of the protrusion 165. For example, the material may be scored from an initial thickness of 0.008 to 0.010 inches to a post-scoring thickness of 0.001 to 0.008 inches. In an alternative embodiment, there is no post-punching score, but rather the wall is intentionally thinned for easier rupture. In another version, there is no variable wall thickness, but rather the force of the cap 166 engaging the machine dispensing mechanism is sufficient to cut a wall thickness of 0.008 to 0.010 inches on the protrusion 165. With the score, the protrusion 165 can be lifted and cut off from the base 162 with a force of 5 to 75 pounds, for example, between 15 and 40 pounds.

The cap 166 has a first orifice 222 and a second orifice 224. The first orifice substantially matches the shape of the orifice 164. When the protrusion 165 is removed, the orifice 164 is exposed and extends through the base 162. The second orifice 224 has a shape corresponding to the two overlapping circles. One of the overlapping circles has a shape corresponding to the shape of the protrusion 165 and the other of the overlapping circles is slightly smaller. A ramp 226 extends between the outer edges of the two overlapping circles. There is an additional 0.020" material thickness at the top of the ramp transition. This additional height helps lift and break the head of the protrusion and open the orifice during rotation of the cap, as described in more detail with reference to Figures 9A to 9G.

As shown in Figures 9A and 9B, the cap 166 is initially attached to the base 162 with the protrusion 165 aligned with and extending through the larger of the overlapping circles of the second aperture 224. When the processor 122 of the machine activates the electric motor 146 to rotate the gear 168 and the annular member 161, the rotation of the cap 166 causes the ramp 226 to slide under a lip of the protrusion 165, as shown in Figures 9C and 9D. Continued rotation of the cap 166 applies a lifting force that separates the protrusion 165 from the remaining portion of the base 162 (see Figures 9E to 9G), and then aligns the first aperture 222 of the cap 166 with the aperture 164 in the base 162 resulting from the removal of the protrusion 165.

Some boxes include a structure for retaining the protrusion 165 after the protrusion 165 is separated from the base 162. In the box 150, the protrusion 165 has a head 167, a stem 169 and a foot 171 (best seen in Figure 9G). The stem 169 extends between the head 167 and the foot 171 and has a smaller cross-section than the head 167 and the foot 171. When the rotation of the cap 166 separates the protrusion 165 from the remaining portion of the base 162, the cap 166 presses laterally on the stem 169, wherein the head 167 and the foot 171 hold the protrusion 165 along the edges of the overlapping circles of the second opening 224. This configuration retains the protrusion 165 when the protrusion 165 is separated from the base 162. This configuration reduces the possibility of the protrusion falling into the waiting receptacle when the protrusion 165 is removed from the base.

Some cassettes include other methods for separating the protrusion 165 from the remainder of the base 162. For example, in some cassettes, the base has a rotatable cutting mechanism riveted to the base. The rotatable cutting mechanism has a shape similar to that described with respect to the cap 166, but this time it is riveted to the base 162 and located within the perimeter of the base, rather than mounted above and around the base 162. When the refrigeration cycle is complete, the machine's handler 122 activates one of the machine's arms to rotate the riveted cutting mechanism about a rivet. During the rotation, the cutting mechanism engages, cuts, and removes the protrusion 165, leaving the orifice 164 of the base 162 in place.

In another example, some cassettes have a cap with a sliding knife that moves across the base to remove the protrusions. The sliding knife is activated by the machine and slides across the base to separate, remove and collect the protrusions 165 when triggered by the controller. Cap 166 has a shears feature that can directly cross the base 162 and slide over the base when activated by the machine. Cap 166 bites, cuts and removes the protrusions 165. In another embodiment, this shears feature can be in the center of the machine instead of the cap 166 of the cassette 150. In another embodiment, this shears feature can be installed as a primary component in the base 162 instead of a primary mounted component like cap 166.

Some cassettes have a dispensing mechanism that includes a pop-up top that can be engaged and released by a machine. When the refrigeration cycle is complete, an arm of the machine engages and lifts a tab of the cassette, thereby depressing and piercing the base and forming an orifice in the base. The refrigerated or frozen product is dispensed through the orifice. During dispensing, the pierced surface of the base remains articulated to the base and retained inside the cassette. Mixing avoids the pierced surface or rotates over the pierced surface, or in another embodiment, allows the mixing paddles to continue to rotate without obstruction. In some pop-up tops, the arm of the machine separates the pierced surface from the base.

10 is an enlarged schematic side view of the cassette 150. The mixing paddle 160 includes a central stem 228 and two blades 230 extending from the central stem 228. The blades 230 are spiral blades shaped to agitate the contents of the cassette 150 and remove components adhered to the inner surface of the body 158 of the cassette 150. Some mixing paddles have a single blade and some mixing paddles have more than two mixing paddles.

As the mixing paddle 160 rotates, fluid (e.g., liquid ingredients, air, or frozen dessert) flows through the openings 232 in the blades 230. These openings reduce the force required to rotate the mixing paddle 160. This reduction can be significant as the viscosity of the ingredients increases (e.g., as ice cream is formed). The openings 232 further help mix and aerate the ingredients within the pod.

The transverse edges of the blades 230 define slots 234. As the mixing paddle 160 rotates, the slots 234 are offset so that a majority of the interior surface of the body 158 is cleared of components adhering to the interior surface of the body by one of the blades 230. Although the mixing paddle 160 is wider than the first end 210 of the body 158 of the cassette 150, the slots 234 are alternating slots that facilitate insertion of the mixing paddle 160 into the body 158 of the cassette 150 by rotating the mixing paddle 160 during insertion so that the slots 234 are aligned with the first end 210. In another embodiment, the outer diameter of the mixing paddle is smaller than the diameter of the opening of the cassette 150, thereby allowing for direct insertion (without rotation) into the cassette 150. In another embodiment, one blade on the mixing paddle has an outer diameter that is wider than the diameter of the second blade, thereby allowing for direct insertion (without rotation) into the cassette 150. In this mixing paddle configuration, one blade is intended to remove (e.g., scrape) ingredients from the sidewall while the second, shorter diameter blade is intended to perform more of an agitation operation.

Some mixing paddles have one or more blades hinged to a central stem. During insertion, the blades may be hinged into a contracted configuration and released into an expanded configuration once inserted. Some hinged blades are fixed open when rotated in a first direction and are foldable when rotated in a second direction opposite the first direction. Once inside the cassette, some hinged blades lock in a fixed outward position regardless of the direction of rotation. Some hinged blades are manually contracted, expanded, and locked.

The mixing paddle 160 rotates clockwise and removes the frozen dessert accumulation from the cassette wall 214. Gravity forces the dessert removed from the cassette wall to fall toward the first end 210. In a counterclockwise direction, the mixing paddle 160 rotates toward the second end 212, lifting and stirring the ingredients. When the paddle changes direction and rotates clockwise, the ingredients are pushed toward the first end 210. When the protrusion 165 of the base 162 is removed (as shown and explained with respect to Figure 9D), the clockwise rotation of the mixing paddle dispenses the manufactured food or beverage from the cassette 150 through the orifice 164. Some paddles mix and dispense the contents of the cassette by rotating in a first direction. Certain paddles mix by moving in a first direction and in a second direction and dispense by moving in the second direction when the cassette is opened.

The central stem 228 defines a recess 236 sized to receive the drive shaft 126 of the machine 100. The recess and drive shaft 126 have a square cross-section so that the drive shaft 126 and the mixing paddle 160 are rotatably constrained. When the motor rotates the drive shaft 126, the drive shaft rotates the mixing paddle 160. In some embodiments, the cross-section of the drive shaft is a cross-section of a different shape and compatibly shaped recess. In some cases, the drive shaft is threadedly connected to the recess. In some cassettes, the recess contains a mating structure that grasps the drive shaft to rotationally couple the drive shaft to the paddle.

FIG. 11 is a flow chart of a method 250 implemented on processor 122 for operating machine 100. Method 250 is described with reference to refrigeration system 109 and machine 100. Method 250 may also be used with other refrigeration systems and machines. Method 250 is described as producing soft serve ice cream, but may also be used to produce other chilled or frozen beverages and foods.

The first step of method 250 is to turn on machine 100 (step 260) and turn on compressor 186 and fan associated with condenser 180 (step 262). Refrigeration system 109 is then idled at the regulated temperature (step 264). In method 250, the evaporator 108 temperature is controlled to maintain approximately 0.75°C, but may fluctuate by ±0.25°C. Some machines operate at other idle temperatures, for example, from 0.75°C to room temperature (22.0°C). If the evaporator temperature is less than 0.5°C, processor 122 opens bypass valve 190 to increase heat to the system (step 266). When the evaporator temperature rises above 1°C, the bypass valve 190 is closed to cool the evaporator (step 268). The machine 100 can be operated from an idle state to produce ice cream (step 270) or can be shut down (step 272).

After inserting a cassette, the user presses the start button. When the user presses the start button, the bypass valve 190 closes, the evaporator 108 moves to its closed position, and the motor 124 is turned on (step 274). In some machines, a motor is used to close the evaporator electronically. In some machines, the evaporator is closed mechanically, for example, by moving a lid from an open position to a closed position. In some systems, a sensor confirms that a cassette 150 is present in the evaporator 108 before taking these actions.

Some systems include radio frequency identification (RFID) tags or other smart barcodes, such as UPC strips or QR codes. The identification information on the cassette can be used to trigger specific cooling and mixing algorithms for a specific cassette. These systems can read the RFID, QR code or barcode as appropriate and identify the hybrid motor speed curve and hybrid motor torque threshold (step 273).

Identification information can also be used to facilitate direct-to-consumer marketing (e.g., via the Internet or using a subscription model). Because the boxes are shelf-stable, the method and system described in this specification can sell ice cream through e-commerce. In a subscription model, consumers pay a monthly fee for a predetermined number of boxes shipped to them. Consumers can choose their personalized box from a variety of categories (e.g., ice cream, healthy smoothie, frozen coffee or frozen cocktail) and their personalized flavor (e.g., chocolate or vanilla).

Identification can also be used to track each box used. In some systems, the machine is connected to a network and can be configured to notify a supplier (e.g., through a weekly shipment) of which boxes are being used and need to be replaced. This approach is more efficient than having consumers go to the grocery store to buy boxes.

These actions cool the bin 150 in the evaporator 108 while rotating the mixing paddle 160. As the ice cream forms, the viscosity of the contents of the bin 150 increases. A torque sensor of the machine measures the torque of the motor 124 required to rotate the mixing paddle 160 in the bin 150. Once the torque of the motor 124 measured by a torque sensor meets a predetermined threshold, the machine 100 moves to a dispensing mode (276). The dispensing port is opened and the motor 124 reverses direction (step 278) to press the frozen dessert out of the bin 150. This lasts for about 1 second to 10 seconds to dispense the contents of the bin 150 (step 280). The machine 100 then switches to defrost mode (step 282). Frost accumulated on the evaporator 108 can reduce the heat transfer efficiency of the evaporator 108. In addition, the evaporator 108 can also be frozen to the cassette 150, the first portion 128 and the second portion 130 of the evaporator can be frozen together, and/or the cassette can be frozen to the evaporator. These problems can be avoided by defrosting the evaporator between cycles by opening the bypass valve 190, turning on the evaporator 108, and turning off the motor 124 (step 282). The machine then defrosts the evaporator by diverting the gas through the bypass valve for about 1 second to 10 seconds (step 284). The machine is programmed to defrost after each cycle unless a thermocouple reports that the evaporator 108 is above freezing. The cassette can then be removed. The machine 100 then returns to the idle mode (step 264). In some machines, a thermometer measures the temperature of the contents of the cassette 150 and identifies the time to dispense the contents of the cassette. In some machines, the dispensing mode begins when a predetermined time is reached. In some machines, a combination of the torque required to rotate the mixing paddles, the mixing motor current draw, the temperature of the cassette and/or the time determines the time to dispense the contents of the cassette.

If the idle time has expired, the machine 100 automatically turns off the power (step 272). A user can also turn off the power of the machine 100 by pressing the power button (286). When the power is turned off, the processor opens the bypass valve 190 to equalize the pressure across the valve (step 288). The machine 100 waits ten seconds (step 290) and then turns off the compressor 186 and the fan (step 292). The machine then shuts down.

FIG. 12 is a schematic diagram of a refrigeration system 310 including the evaporator 108 and an expansion subsystem 312. The refrigeration system 310 is substantially similar to the refrigeration system 109. However, the refrigeration system 310 includes the expansion subsystem 312 instead of the expansion valve 184 shown in the refrigeration system 109. The refrigeration system 310 does not include the first bypass line 188 and the second bypass line 190 that are part of the refrigeration system 109. However, some systems include the expansion subsystem 312, the first bypass line, and the second bypass line.

The expansion subsystem 312 includes a plurality of valves for controlling the expansion of the refrigerant fluid. These valves include a first fixed orifice valve 314, a second fixed orifice valve 316, and a control valve 318. The control valve 318 is upstream of the second fixed orifice valve 316. The control valve 318 and the second fixed orifice valve 316 are connected in parallel with the first fixed orifice valve 314. The expansion device has two modes for controlling the temperature of the refrigerant entering the evaporator 108. In the first mode, the control valve 318 is opened, thereby allowing the refrigerant to flow to the second fixed orifice valve 316. In the first mode, the refrigerant flows through both the first fixed orifice valve 314 and the second fixed orifice valve 316. In the second mode, the control valve 318 is closed and refrigerant does not flow through the second fixed orifice valve 316. All refrigerant flows through the first fixed orifice valve 314.

As discussed with reference to FIG. 4 , the expansion valve 184 or expansion subsystem 312 receives a high pressure refrigerant and releases a low pressure refrigerant. This pressure drop causes the refrigerant to cool. A larger change in pressure (ΔP) results in a larger change in temperature (ΔT). In the second mode (i.e., where the control valve 318 is closed), the pressure drop across the expansion subsystem 312 will be higher than in the first mode, thereby providing a lower evaporator pressure and associated lower evaporator temperature. The effect of the increased temperature difference between the refrigerant and the contents of a cassette in the evaporator 108 on heat transfer is offset to some extent by the fact that the lower pressure refrigerant is of lower density. Since the compressor moves a fixed volume of refrigerant per compression cycle, the mass flow per cycle is reduced, which reduces heat transfer. In the second operating mode, there is a large temperature difference between the cassette and the evaporator, requiring a large heat transfer, which increases the amount of mass flow required.

During initial operation, the refrigeration system 310 is in a first mode. The control valve 318 is open and refrigerant flows through both the first fixed orifice valve 314 and the second fixed orifice valve 316. This causes the evaporator to operate at a temperature of approximately -20°C to -10°C. At this temperature, the cooling system provides greater cooling capacity than it can provide at lower temperatures by utilizing the higher density refrigerant passing through the evaporator.

The cassette 150 is inserted into the evaporator 108 at approximately room temperature (e.g., 22° C.). The initial temperature difference between the evaporator 108 and the cassette 150 is high. Therefore, heat is quickly transferred from the cassette 150 to the evaporator 108. The temperature difference between the cassette 150 and the evaporator 108 decreases as the cassette 150 cools and the heat transfer from the cassette 150 to the evaporator 108 also slows down. At this time, the system 310 enters the second mode and the control valve 318 is closed. The refrigerant only flows through the first fixed orifice valve 314 and the ΔP between the refrigerant entering the first fixed orifice valve 314 and the refrigerant leaving the first fixed orifice valve 314 increases. ΔT also increases, resulting in a cooler evaporator 108 having a temperature of approximately -15°C to -30°C. This reduces the cooling capacity of the system, but increases the temperature difference between the bin and the nest, which allows for rapid final freezing of the ice cream. In the activated second mode, when the temperature difference between the bin and the evaporator is reduced to the point where it affects heat transfer, the lower refrigerant temperature increases the overall heat transfer even though a smaller mass is flowing in the system.

In some embodiments, the temperature of the evaporator in the first mode is above freezing. This configuration can pre-cool the evaporator before use and defrost the evaporator after use.

The configuration of refrigeration system 310 increases temperature control, which can reduce freezing time and reduce required compressor output. The reduction in required compressor output allows one of the compressor sizes to be reduced.

In some refrigeration systems, the expansion subsystem contains more than two valves. Multi-valve subsystems can have more than two modes, thereby further increasing temperature control.

In some refrigeration systems, other types of valves are used, such as thermostatic expansion valves and electronic expansion valves. Both thermostatic expansion valves and electronic expansion valves can adjust the orifice size based on various loads and operating conditions. For example, a thermostatic expansion valve senses the evaporator outlet temperature of the refrigerant and adjusts the flow through the thermostatic expansion valve to maintain a predetermined or desired operating condition. An electronic expansion valve is electrically actuated to adjust the orifice size based on the evaporator outlet temperature and an electronic signal from a control unit 371.

13 is a schematic diagram of a refrigeration system 320 including a refrigerant line 322 that precools a water tank 324 before entering the evaporator 108. The refrigeration system 320 is substantially similar to the refrigeration system 109. However, the refrigeration system 320 includes the precooling line 322 and omits the first bypass line 188 and the second bypass line 190 that are part of the refrigeration system 109. Some systems include a first bypass line, a second bypass line, and a precooling line.

Refrigeration system 320 is used in a machine that includes a water tank 324. The machine with the water tank injects fluid into the box during mixing, for example, to dissolve dry ingredients or dilute the contents of the box. Refrigerated water freezes faster than hot or room temperature water.

In use, a valve 326 is operated to direct the refrigerant through the precooling, directing the refrigerant through the precooling line 322 and leaving the expansion valve 184. The cold low-pressure refrigerant flows through the precooling line 322 which is partially or completely disposed in the water tank 324. If the water tank 324 is filled with water, the precooling line 322 is partially or completely immersed in the water. The refrigerant cools the water in the water tank 324 and leaves the precooling line 322. The refrigerant then enters the evaporator 108 to cool the evaporator 108.

FIG. 14 is a schematic diagram of a refrigeration system 328 including a thermal mass 330 disposed between the compressor 186 and the condenser 180. The refrigeration system 328 is substantially similar to the refrigeration system 109. However, the refrigeration system 328 includes the thermal mass 330. The refrigeration system 328 does not include the first bypass line 188 and the second bypass line 190 that are part of the refrigeration system 109. Some systems include the first bypass line, the second bypass line, and the thermal mass 330.

For example, the heat mass body can be a mixture of ethylene glycol and water, salt water, wax (alkane), or pure water. In some machines, the heat mass body 330 is placed between the condenser 180 and the heat exchanger 182.

Thermal mass 330 stores heat energy and releases it at a later time. When placed between compressor 186 and condenser 180, thermal mass 330 stores heat released from the refrigerant. At this point in the cycle, the refrigerant is a high-pressure vapor. Condenser 180 isothermally releases heat from the high-pressure vapor to produce a high-pressure liquid. Using thermal mass 330 to pre-cool the vapor refrigerant reduces the load on compressor 186. When machine 100 is powered off, thermal mass 330 releases heat to the environment and reaches an equilibrium at the ambient temperature.

Some systems include both a secondary bypass line and a thermal mass. The secondary bypass line redirects refrigerant from the thermal mass, allowing the refrigeration system to idle. During this idle period, the thermal mass releases heat from the previous cycle to the environment.

FIG. 15 is a schematic diagram of a refrigeration system 332 including a pressure vessel 334, a first control valve 336 (also referred to as a second isolation valve), and a second control valve 338 (also referred to as a first isolation valve). The pressure vessel 334 can act as a pressure regulator that enables rapid system startup and reduces the time required to cool (e.g., freeze) the contents of a bin in the evaporator 108. The refrigeration system 332 is substantially similar to the refrigeration system 109. However, the refrigeration system 332 includes the pressure vessel 334, the first control valve 336, and the second control valve 338. Refrigeration system 332 further does not include first bypass line 188 and second bypass line 190 that are part of refrigeration system 109. Some systems include first bypass line, second bypass line, pressure vessel 334, first control valve 336, and second control valve 338.

A first control valve 336 is disposed between the compressor 186 and the condenser 180. A second control valve 338 is disposed between the heat exchanger 182 and the expansion valve 184. A pressure vessel 334 is disposed between the condenser 180 and the heat exchanger 182. The refrigerant leaves the compressor 186 at a high pressure and maintains that high pressure until the liquid refrigerant is released from the expansion valve 184. The system 332 controls the position of the valves 336, 338 (e.g., open or closed) based on the desired result.

During normal operation of the system 332 (e.g., when cooling a bin), both the first control valve 336 and the second control valve 338 are open. Prior to idling, the second control valve 338 is closed and the first control valve 336 remains open. The compressor 186 continues to operate for a short time (e.g., 1 to 5 seconds) before the first control valve 336 is closed. After the first control valve 336 is closed, the compressor shuts down.

When restarting the system 332 (e.g., to produce a portion of cooled food or beverage), the compressor 186 is restarted, the first control valve 336 is opened and the second control valve 338 is opened. Since high pressure fluid is already present in the pressure vessel 334, the high pressure refrigerant flows through the expansion valve 184, where the pressure drop causes the refrigerant to cool. This method reduces the time required to cool the contents of a bin relative to a refrigeration system that allows the system pressure to return to ambient conditions when shut down. If the system is at ambient conditions, then when restarting the system, initially no pressure drop across the expansion valve occurs. This method has been demonstrated to reduce the time required to cool the contents of an 8-ounce container from room temperature to frozen to less than 90 seconds. Refrigeration system 332 is capable of rapidly or instantaneously cooling the refrigerant when system 332 is initialized or powered on (e.g., prior to inserting a container 150).

FIG. 16 is a schematic diagram of a refrigeration system 340 including a thermoelectric module 342 (also referred to as a thermoelectric cooler). Refrigeration system 340 is substantially similar to refrigeration system 109. However, first bypass line 188 and second bypass line 190 that are part of refrigeration system 109 are not included. Some systems include a first bypass line, a second bypass line, and thermoelectric module 342.

Thermoelectric module 342 is a cooling element disposed between condenser 180 and heat exchanger 182. Thermoelectric module 342 cools the refrigerant leaving condenser 180 before transferring heat to the refrigerant vapor leaving evaporator 108 in heat exchanger 182. Cooling the liquid refrigerant before expansion increases the cooling capacity of system 340 and reduces the required compressor output. The reduction in required compressor output reduces the size of the compressor required.

FIG. 17 is a schematic diagram of a refrigeration system 344 including a thermoelectric cell 346, a first battery bypass valve 348, and a second battery bypass valve 350. Refrigeration system 344 is substantially similar to refrigeration system 109, but does not include first bypass line 188 that is part of refrigeration system 109. Some systems having thermoelectric cell 346 and associated valves also include a first bypass line.

The thermoelectric cell 346 has a first portion 352 disposed between the heat exchanger 182 and the expansion valve 184. The first cell bypass valve 348 is disposed on a first branch line 354 that bypasses the first portion 352 of the thermoelectric cell 346. When the first cell bypass valve 348 is open, most or all of the refrigerant flows through the first branch line 354. The thermoelectric cell 346 has a high pressure drop. The refrigerant primarily flows through the branch line 354 because the branch line 354 has a relatively low pressure drop relative to the thermoelectric cell 346. When the first cell bypass valve 348 is closed, the refrigerant flows through the first portion 352 of the thermoelectric cell 346.

The thermoelectric cell 346 has a second portion 356 thermally connected to the first portion 352, the second portion being disposed between the evaporator 108 and the heat exchanger 182. A second battery bypass valve 350 is disposed on a second branch line 358 that bypasses the second portion 356 of the thermoelectric cell 346. When the second battery bypass valve 350 is open, most or all of the refrigerant flows through the second branch line 358. The thermoelectric cell 346 has a high pressure drop. The refrigerant primarily flows through the branch line 358 because the branch line 358 has a relatively low pressure drop relative to the thermoelectric cell 346. When the second battery bypass valve 350 is closed, the refrigerant flows through the second portion 356 of the thermoelectric cell 346.

Thermoelectric cell 346 includes a thermal material that retains heat. Thermoelectric cell 346 includes a reservoir 360 having a phase change material (e.g., wax) that receives heat or emits heat depending on the position of first battery bypass valve 348 and second battery bypass valve 350. Thermoelectric cell 346 is illustrated as an example of using wax as a phase change material. Some thermoelectric cells include other materials that retain heat or consume heat, for example, a glycol and water mixture, saline, or pure water.

When the first battery bypass valve 348 is open and the second battery bypass valve 350 is closed, the thermoelectric cell 346 emits heat from its second portion 356 to the refrigerant. If the wax is warm or molten, the cold refrigerant will refrigerate and solidify the wax in the reservoir 360. By heating the low pressure refrigerant, the thermoelectric cell reduces the likelihood that liquid refrigerant will flow into the compressor.

When the first battery bypass valve 348 is closed and the second battery bypass valve 350 is open, the thermoelectric cell 346 receives heat from the refrigerant at the first portion 352. If the wax is solid, the hot liquid refrigerant will heat and melt the wax in the wax reservoir 360. If the wax is liquid, the hot refrigerant will continue to heat the liquid wax in the wax reservoir 360.

When starting the system 344 and during the cooling cycle, both the first battery bypass valve 348 and the second battery bypass valve 350 are open and little or no refrigerant flow interacts with the thermocell 346. At the end of the cooling cycle, the second battery bypass valve 350 is closed and the reservoir 360 is cooled by the cold low pressure refrigerant. When the next cycle begins with a cooled battery, the second battery bypass valve 350 is opened and the first battery bypass valve 348 is closed. The first portion 352 of the thermocell 346 is then pre-cooled by the hot liquid refrigerant leaving the condenser 180 via the heat exchanger 182.

This configuration can prevent flooding of the end-of-cycle compressor and can reduce the output of the compressor by reducing the heat load on the compressor. Certain waxes may have a melting point in a range of 5°C to 10°C, for example, dodecane wax or tridecane wax.

FIG. 18A is a top view of an evaporator cover 127 and FIG. 18B is a top view of the body of the evaporator 108. The body of the evaporator 108 defines passages 366 through which refrigerant flows to cool the evaporator 108. The passages 366 open at a lip 367 of the evaporator 108, as shown in FIG. 18B. The passages 366 also open at the opposite end of the evaporator 108 having a similarly configured lip.

The cap 127 includes a plurality of recesses 174 that align with four adjacent channels 366 of the evaporator 108 when the cap 127 is attached to the body of the evaporator 108. Some caps include recesses that align with other numbers of adjacent channels. The recesses 174 act as manifolds that fluidly connect the adjacent channels 366. The caps 127 on opposite ends of the body of the evaporator are offset so that the two caps 127 together with the body of the evaporator 108 define a serpentine flow path through the evaporator 108.

The cover 127 has an inlet 370 and an outlet 372 that fluidly connects the evaporator 108 to the refrigeration system 109. The refrigerant flows through the inlet 370, through the passage defined by the body of the evaporator 108 and the recess in the cover 127, and exits the evaporator 108 through the outlet 372. The refrigerant enters the inlet 370 as a cold fluid at a first temperature. As the refrigerant flows through the flow path, the refrigerant warms and evaporates due to the heat received by the evaporator 108 from the cassette 150. The cassette 150 is frozen due to this heat transfer. To maintain a constant flow rate, the diameter of the inlet 370 is approximately 0.25 inches and the diameter of the outlet 372 is approximately 0.31 inches.

The movable hinge 132 defines a connecting passage 373 that connects the channel fluid in the first portion 128 of the evaporator 108 to the channel 366 in the second portion 130 of the evaporator 108. The connecting passage 373 is defined in the evaporator 108 near the lip 367 of the evaporator 108. In some evaporators, the lip of the evaporator defines a groove and the cover defines a corresponding groove, so that when the cover is engaged with the evaporator, the connecting passage is formed between the groove of the cover and the groove of the evaporator. Some connecting passages are defined in the closure 127. This configuration defines a continuous flow path from the inlet 370 to the outlet 372, wherein the channel 366 extends parallel to the axis 369 and allows the fluid to flow parallel to the axis 369.

In some evaporators, the passage 366 is connected at opposite ends of the lip 367 in the evaporator to form a "U" shape. When assembled, the cover 127 is placed on the lip 367 of the evaporator 108. The passage 366 is a series of unconnected "U" shaped units. In each unit, a first passage allows the refrigerant to flow in a first direction and a second passage allows the fluid to flow in a second direction opposite to the first direction.

Channels 366 extend parallel to an axis 369 of the evaporator. In some evaporators, the channels do not extend parallel to the axis, but do extend parallel to each other. In some evaporators, the channels do not extend parallel to each other or parallel to the axis.

FIG. 19A and FIG. 19B are perspective views of an evaporator 380 without and with its closure 127, respectively. The evaporator 380 in FIG. 19A and FIG. 19B operates similarly to the evaporator 108 described in FIG. 18A to FIG. 18E. However, the evaporator 380 includes a recess 382 that fluidly connects the second channel 366b of one unit (the first portion 128 of the evaporator 380) to a first channel 366a of a different unit (the second portion 130 of the evaporator 380). The closure 384 is substantially similar to the closure 127. However, the closure 384 is flat rather than recessed on the surface adjacent the lip 367 and includes multiple inlets and outlets rather than a single inlet and a single outlet. The cap 384 includes a first inlet 388 on the first portion 128, a first outlet 390 on the first portion 128, a second inlet 392 on the second portion 130, and a second outlet 394 on the second portion. The first inlet 388 is fluidly connected to the first outlet 390 to form a first flow path 396 on the first portion 128. The second inlet 392 is fluidly connected to the second outlet 394 to form a second flow path 398 on the second portion 130. This configuration forms two flow paths 396, 398 for the refrigerant to flow in parallel without using a hinged connector. To maintain the flow velocity, the diameters of the flow paths 396, 398 are reduced so that the divided flow path has a flow area similar to the origin flow path.

When the cover 384 encloses the evaporator 380 , the recess 382 is closed and the evaporator 380 and the cover 384 form flow paths 396 , 398 .

In the evaporator described previously, the unit 371 has a "single up/single down" configuration. In some evaporators, the unit defines a "two up/two down" or "three up/three down" configuration. This can maintain appropriate flow rates while minimizing the pressure drop within the evaporator. Different flow path configurations are required for different compressors and different cooling duties. The number of parallel flow paths can be increased for larger compressor and cooling loads and reduced for smaller requirements.

Figures 20A to 20D are schematic diagrams of the flow path formed by the channel of the evaporator and the recess of the evaporator cover 127. Figures 20A and 20B are views of the channel defined in an evaporator. Figures 20C and 20D are perspective views of an evaporator and its cover 127.

FIG. 20A is a flow path 402 that increases in number of channels 400 as the refrigerant evaporates. The refrigerant enters the inlet and flows through one or more single channels 400a. As the refrigerant evaporates, its volume expands and begins to move faster. The vapor can expand about 50 to 70 times a given volume. To slow down the mixed phase refrigerant in the evaporator 108, the flow path 402 branches into two parallel channels 400b that connect at the recess 174 and at a turning point 306 in the evaporator 108. As more refrigerant evaporates, the flow path 402 again branches into three parallel channels 400c that connect at the recess 174 and at the turning point 306 within the evaporator 108. In some evaporators, a "two up/two down" configuration is maintained for multiple units. In some evaporators, a "three up/three down" configuration is maintained for multiple units. In some evaporators, the flow path is increased to a "four up/four down" or "five up/five down" configuration. Increasing the number of channels through the evaporator increases efficiency early in the evaporation process while limiting high velocity/pressure drops toward the outlet of the evaporator.

FIG. 20B is a schematic diagram of a flow path 402 having a sloped recess 408 in the closure 127 that acts as a manifold. The sloped recess 408 has a smoothly increasing and decreasing cross-sectional area that helps maintain the flow velocity of the refrigerant flowing through the manifold. A sloped cross-sectional recess in the closure will help maintain the flow velocity and also reduce the pressure drop and flow separation of the liquid and gas refrigerants due to the low flow velocity areas.

20C shows a flow path 420 including a first manifold at the bottom of the evaporator 108 and a plurality of branches 424 extending from the first manifold 422 toward the cover 127. The first manifold 422 is connected to the inlet 370. The branches 424 are fluidly connected to a second manifold 426 at the top of the evaporator 108. The second manifold 426 is fluidly connected to the outlet 372.

The refrigerant flows from the inlet through the first manifold 422, up along the branch 424 and through the second manifold 426 to the outlet 372. Vapor is less dense than liquid and tends to rise to the top. When the flow direction is downward, this preferential flow direction can create unpredictable flow and performance. This configuration can increase the thermal efficiency of the evaporator 108 by causing the refrigerant to flow in the same direction as the buoyancy that exists when the refrigerant is in vapor form.

FIG. 20D shows a flow path 430 wrapped around the evaporator 108. The flow path 430 is a spiral that follows the outer diameter of the evaporator 108. This configuration increases surface area and reduces pressure drop by reducing or eliminating the number of tight turns in the flow path 430. In some evaporators, when the flow path extends across a first portion of the evaporator and a second portion of the evaporator, multiple hinge connectors are used to connect the first portion and the second portion. Some flow paths define a serpentine passage on the first portion and a serpentine passage on the second portion, the serpentine passages being connected by a "transport passage" across the hinge.

21A to 21C are views of the cassette 150 and an evaporator 438 having a closing mechanism 440. Fig. 21A is a perspective view of the evaporator 438 and the cassette 150. Fig. 21B is a cross-sectional view of the cassette 150 and the evaporator 438. Fig. 21C is a top view of the cassette 150 and the evaporator 438.

The closing mechanism 440 includes a biasing element (e.g., a spring) connecting the first portion 128 of the evaporator 438 to the second portion 130 of the evaporator 438. The closing mechanism 440 also includes a circumferential cable extending around the outer diameter of the evaporator. The cable is tightened to close the cassette and is relaxed to open the evaporator.

The biasing elements in the evaporator 438 include a first spring 442 and a second spring 444 that bias the first portion 128 and the second portion 130 away from each other. The movable hinge 132 promotes the movement of the first portion 128 and the second portion 130 so that the first portion 128 and the second portion 130 rotate about the hinge 132 due to the biasing force of the springs 442, 444. In this configuration, the evaporator 438 is in the open position and a small gap 446 is formed between the first portion 128 and the second portion 130. When the cover 127 is in the open position, the evaporator 438 is in the open position. In some machines, the position of the evaporator is independent of the position of the cover. In the open position, a small air gap exists between the evaporator 438 and the cassette 150.

The evaporator 438 has a closed position in which the air gap between the evaporator 438 and the cassette 150 is eliminated to promote heat transfer. In some evaporators, the air gap is only reduced. In the closed position, the gap 446 is also eliminated. In some evaporators, the gap is reduced rather than eliminated. To move from the open position to the closed position, the closing mechanism 440 applies a force in the direction of arrow 448 to overcome the biasing force of the first spring 442 and the second spring 444.

The closing mechanism generates a force in the range of from 10 lbs to 1500 lbs. To prevent crushing the box 150, the internal pressure of the box 150 is preferably equal to or greater than the force generated by the closing mechanism 440.

For example, the closing mechanism 440 can be an electromechanical actuator, a pulley system, a lever, a protrusion on the cover, a ball screw, a solenoid, or a mechanical latch.

22A and 22B are side and front views, respectively, of an evaporator 108 having a closure mechanism 440 comprising two bolts 450 located inside a spring 456. The bolts 450 bias a rod 466 away from a flange 464. Optionally, a cable 468 is received in a hole defined in the rod 466 and extends around the evaporator 108.

Fig. 23A shows an evaporator 500 that can be produced primarily by extrusion. The evaporator 500 has a body 510 with two end caps 512. The body 510 and the end caps are produced separately and then assembled.

Figures 23B and 23C illustrate the creation of body 510. Evaporator body 510 is created by low-cost extrusion. The body is extruded with channels 514 (see Figure 23B) defined in body 510. Each end of body 510 is machined to provide a shoulder 516 (see Figure 23C) that mates with an end cap. A wall 518 extends beyond shoulder 516.

23D and 23E are perspective views of an end cap 512. The end cap 512 may be forged or machined. The end cap 512 provides mounting, inlet/outlet, and closure features for the evaporator 500. The end cap 512 has a side wall 520 and an end wall 522.

The end cap 512 has a plurality of bosses 524 extending outwardly from the side wall 520. The bosses 524 can be used to install and handle the end cap 512 and to install and handle the evaporator 500 after being assembled with the main body 510. A port 526 extends through the side wall 520. The port 526 of the end cap 512 located on one end of the evaporator 500 serves as an inlet and the port 526 of the end cap 512 located on the other end of the evaporator 500 serves as an outlet.

FIG. 23F illustrates the assembly of the evaporator 500. The end cap 512 is mounted on the shoulder 516 at one end of the body 510. After installation, the joint between the evaporator body 510 and the end cap 512 is easily accessible. This configuration facilitates the use of laser welding, vacuum brazing, friction stir welding, or TIG welding to attach the end cap 512 to the evaporator body 510.

23G and 23H illustrate the relationship between the body 510 and the end cap 512 after assembly. When assembled with the body 510, the side walls 520 and end walls 522 of the end cap and the wall 518 of the body 510 define a chamber that acts as a manifold connecting the channels defined in the body 510 of the evaporator 500. The end cap 512 is shown as having a "hollow" configuration for upward evaporation with all the paths parallel but the end cap can be adapted for a multi-path design with multiple 180 degree turns.

FIG. 24 shows a configuration of an evaporator 500 incorporating an orifice plate 530. The orifice plate 530 is disposed between the body 510 and the end cap 512. The orifice plate 530 defines a plurality of holes 532 that, after assembly, align with the passages 514 in the body 510. The orifice plate can be used to evenly distribute flow to the passages 514 by accumulating refrigerant before the orifice plate 530 and injecting the liquid-gas mixture equally into the passages 514. In some cases, the size of the holes is the same. In some cases, the holes may be of different sizes in the event that there may be a flow misdistribution between the passages 514.

FIG. 25 is a perspective view of an embodiment of the evaporator 380 described with reference to FIGS. 19A and 19B , wherein an interior surface 470 is made of a material different from the rest of the evaporator 380. The interior surface 470 is formed primarily or entirely of copper. Copper has a higher thermal conductivity (approximately 391 W/mK) than aluminum, which has a thermal conductivity of 180 W/mK. A high thermal conductivity allows heat to move quickly and efficiently from the cassette to the refrigerant. A material with a low thermal conductivity transfers heat more slowly and with less efficiency. The tendency of a component to act as a heat sink varies with both its thermal conductivity and its mass. Table 2 lists the thermal conductivity and density of various materials. Table 2 - Conductivity under standard conditions (atmospheric pressure and 293 Kelvin temperature) Material Thermal conductivity [W· m ^-1 · K ^-1 ] Acrylic glass (Plexiglas V045i) 0.170 – 0.200 Alcohols, oils 0.100 Aluminum 237 Alumina 30 Boron Arsenide 1,300 Copper (pure) 401 Diamond 1,000 Fiber glass or foam glass 0.045 Polyurethane foam 0.03 Swelling polystyrene 0.033 – 0.046 Manganese 7.810 water 0.5918 marble 2.070 – 2.940 Silica Aerogel 0.02 Snow (dry) 0.050 – 0.250 Teflon 0.250

Figures 26A-26C are schematic diagrams of coatings. Such coatings can be used in an evaporator that includes both aluminum and copper. Figure 26A shows an overlay coating 490. Figure 26B shows an embedded coating 492. Figure 26C shows an edge coating 494. The coating techniques shown in Figures 26A-26C are applied to the inner surface of the evaporator. Different coating techniques can increase heat transfer and dissipate heat due to the high thermal conductivity of copper.

FIG. 27 is an illustrative view of a material 480 including microchannels 482. When using the material 480 to make, for example, an evaporator, the refrigerant flows through the microchannels 482. The material 480 can be bent to form an evaporator of the cooling box 150. The material 480 is permanently deformed into a cylindrical shape to form a round evaporator. Such an evaporator has a high surface area, which increases evaporator efficiency while keeping costs low.

28A to 28C show a rotary compressor 550 used in some refrigeration systems to replace the reciprocating compressor 186 described previously. The compressor 550 includes a housing 552 having an inner wall 553 defining an inner chamber 554. An inlet 556 and an outlet 558 connect the inner chamber 554 of the compressor 550 to other components of the refrigeration system. When the fluid reaches a predetermined pressure, a pressure valve 559 releases the fluid. A roller 560 having a circular cross section is rotationally and axially constrained to a rod 562 that extends through a bottom section of the housing 552. Some rollers have an elliptical or gear-shaped cross-section. Rod 562 is attached offset from the center of the circular cross-section of roller 560. Rod 562 and roller 560 are rotated relative to housing 552 using a motor (not shown). Roller 560 is disposed in cavity 554 so that an edge 564 of roller 560 extends to the inner wall 553 of the housing. In this configuration, roller 560 forms a seal with housing 552. When rod 562 and roller 560 rotate in the inner cavity 554, the edge 564 of roller 560 remains in contact with wall 553. The housing 552 includes a notched area 566 for accommodating a compressed spring 568. The spring 568 is adjacent to the roller 560. A rubber member 570 surrounds a portion of the spring 568 to form a seal extending from the wall 553 to the roller 560. As the roller 560 rotates within the interior chamber 554, the spring 568 expands and contracts to maintain the seal.

In FIG. 28A , the compressor 550 is in a first state. In FIG. 28B , the rotary compressor 550 is in a second state and in FIG. 28C , the rotary compressor 550 is in a third state. The rotary compressor 550 moves from the first state to the second state, from the second state to the third state and from the third state to the first state. In the first state, the roller 560 receives low pressure cooling steam from the evaporator 108 via the inlet 556. The seal between the contact edge 564 and the wall 553 and the seal between the member 570 and the roller 560 define a suction chamber 572 and a pressurization chamber 574. In some rotary compressors, additional seals are formed to increase the number of chambers. Roller 560 rotates to compress and pressurize the steam in compression chamber 574 and introduce steam into suction chamber 572 from inlet 556. In the second state shown in Figure 28B, roller 560 continues to rotate counterclockwise and increase the pressure of the steam in compression chamber 574 until pressure valve 559 releases high pressure steam from compressor 550. The suction chamber continues to receive low pressure steam from inlet 556. As roller 560 rotates, compression spring 568 extends into the inner chamber 554 to maintain the connection between component 570 and roller 560. In the third state shown in FIG. 28C , high pressure steam has been exhausted from the compression chamber 574 and the spring 568 is compressed into the notched area 566. In this state, only one seal is formed between the contact edge 564 and the member 570. In a short period in the cycle, the number of chambers is reduced by one. In this state in the compressor 550, the suction chamber 572 becomes the compression chamber 574. The suction chamber 572 is re-formed when the contact edge 564 exceeds the member 570 and forms two seals (one formed by the member 570 and the roller 560 and the other formed by the contact edge 564 and the wall 553).

Rotary compressors perform the same thermal work as reciprocating compressors at a much lower weight and in a much smaller size. Rotary compressors have a weight of about 10 lbs to about 18 lbs. Rotary compressors have a consistent refrigerant displacement of about 4 cc to about 8 cc. Rotary compressors have a performance to weight ratio of about 0.3 cc/lb to about 0.5 cc/lb.

Several embodiments of the present invention have been described. However, it will be appreciated that various modifications may be made without departing from the spirit and scope of the present invention. Therefore, other embodiments are within the scope of the following claims.

100: Machine 102: Main body 104: Shell 106: Box machine interface 108: Evaporator 109: Refrigeration system 110: Receptacle 112: Cover 114: Hinge 115: Auxiliary cover 116: Latch 118: Latch recess 120: Latch sensor 122: Processor 124: Motor 125: Belt 126: Drive shaft 127: Evaporator cover/cover/track 128: First part 130: Second part 132: Movable hinge/hinge 134: Gap 136: Fluid channel 137: Space 138: Rod 140: Bolt 142: Spring 144: Pin 146: Electric Motor 148: Bore 150: Box 152: Base 153: Dispenser 154: Insert 157: Gear 158: Body 159: Gear 160: Mixing Paddle 161: Ring 162: Base 163: Protrusion 164: Orifice 165: Protrusion 166: Cap 167: Head 168: Gear 169: Stem 171: Foot 174: Recess 180: Condenser 182: Suction Line Heat Exchanger =Heat exchanger/heat exchanger 184: expansion valve 186: compressor/reciprocating compressor 188: first bypass line 190: second bypass line/bypass valve 192: internal passage 210: first end 212: second end 214: wall/box wall 216: first neck 218: second neck 220: barrel 222: first orifice 224: second orifice 226: ramp 228: center stem 230: blade 232: opening 234: slot 236: recess 250: method 260: step 262: step 264: step驟 266:Step 268:Step 270:Step 272:Step 273:Step 274:Step 276:Step 278:Step 280:Step 282:Step 284:Step 286:Step 288:Step 290:Step 292:Step 310:Refrigeration system/system 312:Expansion subsystem 314:First fixed orifice valve 316:Second fixed orifice valve 318:Control valve 320:Refrigeration system 322:Refrigerant pipeline/precooling pipeline 324:Water tank 326:Valve 328:Refrigeration system

330: Thermal mass

332: Refrigeration system/system

334: Pressure vessel

336: First control valve/valve

338: Second control valve/valve

340: Refrigeration system/system

342: Thermoelectric module

344: Refrigeration system/system

348: First battery bypass valve

350: Second battery bypass valve

352: Part 1

354: First branch pipeline/branch pipeline

356: Part 2

358: Second branch pipeline/branch pipeline

360: Memory/wax memory

366: Channel

366a: First channel

366b: Second channel

367: Lips

369:Axis

370:Entrance

372:Export

373: Connection channel

380: Evaporator

382: Concave part

384: Cap 388: First inlet 390: First outlet 392: Second inlet 394: Second outlet 396: First flow path/flow path 398: Second flow path/flow path 400: Channel 400a: Single channel 400b: Parallel channels 400c: Parallel channels 402: Flow path 408: Inclined concave portion 420: Flow Path 422: Manifold/First Manifold 424: Branch 426: Second Manifold 430: Flow Path 438: Evaporator 440: Closing Mechanism 442: First Spring/Spring 444: Second Spring/Spring 446: Small Gap/Gap 448: Arrow 450: Bolt 456: Spring 464: Flange 466: Rod 468: Cable 470: Interior Surface/Inner Surface 480: Material 482: Microchannel 490: Overlay Coating 492: Embedded Coating 494: Edge Coating 500: Evaporator 510: Body/Evaporator Body 512: End Cap 514: Channel/Passage 516: Shoulder 518: Wall 520: Side Wall 522: End Wall 524: Boss 526: Port 530: Orifice Plate 5 32: hole 550: rotary compressor/compressor 552: housing 553: inner wall/wall 554: inner chamber/chamber 556: inlet 558: outlet 559: pressure valve 560: roller 562: rod 564: edge 566: notched area 568: compressed spring/spring 570: rubber component/component 572: suction chamber 574: pressurized chamber _DB : diameter/larger diameter _DLE : diameter/smaller diameter _DUE : diameter/smaller diameter

Fig. 1A is a perspective view of a machine for rapidly cooling food and beverages. Fig. 1B shows the machine without its housing.

FIG. 1C is a perspective view of a portion of the machine of FIG. 1A .

2A is a perspective view of the machine of FIG. 1A with the cover of the cassette machine interface illustrated as transparent to allow a more detailed view of one of the evaporators to be seen.

FIG. 2B is a top view of a portion of a machine without a housing and a bin machine interface without a cover.

FIG. 2C and FIG. 2D are respectively a perspective view and a side view of the evaporator.

3A-3F show components of a cassette machine interface operable to open and close cassettes in an evaporator to dispense food or beverage being produced.

FIG. 4 is a schematic diagram of a refrigeration system.

5A and 5B are views of a prototype of a condenser.

FIG. 6A is a side view of a cassette.

FIG. 6B is a schematic side view of a cassette and a mixing paddle disposed in the cassette.

7A and 7B are perspective views of a cassette and an associated drive shaft.

7C is a cross-sectional view of a portion of a cassette with the drive shaft engaged with a mixing impeller in the cassette.

FIG. 8 shows a first end of a box with the cap of the box spaced apart from its base for easier viewing.

9A-9G illustrate a cap being rotated about a first end of a box to open an opening extending through a base.

FIG. 10 is an enlarged schematic side view of a cassette.

11 is a flow chart of a method for operating a machine for producing cooled food or beverages.

FIG. 12 is a schematic diagram of a refrigeration system including an evaporator and an expansion subsystem.

FIG. 13 is a schematic diagram of a refrigeration system including a bypass line that pre-cools a water tank upstream of an evaporator.

FIG. 14 is a schematic diagram of a refrigeration system including a thermal mass disposed between a compressor and a condenser.

FIG. 15 is a schematic diagram of a refrigeration system including a pressure vessel, a first control valve, and a second control valve.

FIG. 16 is a schematic diagram of a cooling system including a thermoelectric module.

17 is a schematic diagram of a refrigeration system including a thermoelectric cell, a first battery bypass valve, and a second battery bypass valve.

FIG. 18A is a top view of an evaporator cover 127 and FIG. 18B is a top view of the body of the evaporator.

19A and 19B are perspective views of an evaporator with and without an associated cover.

20A to 20D are schematic diagrams of the flow path formed by the channel of the evaporator and an associated joint cover.

21A to 21C are views of a cassette and an evaporator having a closing mechanism.

22A and 22B are side views of a closing mechanism including a first bolt and a second bolt.

23A-23H illustrate an evaporator having an extruded body.

Figure 24 schematically illustrates an evaporator incorporating an orifice plate.

25 is a perspective view of an evaporator shown in FIGS. 19A and 19B with an interior surface made of a different material than the evaporator.

26A to 26C are schematic diagrams of the coating.

Figure 27 is an exemplary view of a material comprising microchannels.

Figures 28A to 28C are top views of a rotary compressor.

Like reference symbols indicate like elements in the various drawings.

100: Machine

102: Subject

104: Shell

106:Storage box machine interface

112: Cover

114: Hinge

115: Auxiliary sealing

116: Lock

Claims (36)

A machine for producing refrigerated food or drink from ingredients in a cassette containing the ingredients, the machine comprising: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette, wherein the refrigeration system has a working fluid loop and also includes a first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion device and back to the evaporator, the first bypass line A pipeline extends from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion device and the evaporator; and a processor operable to control the refrigeration system to cool the cassette after the cassette is inserted into the receptacle of the evaporator and operable to defrost a surface of the evaporator after the refrigerated food or beverage is dispensed from the cassette and before the cassette is removed from the receptacle of the evaporator. The machine of claim 1, further comprising a bypass valve on the first bypass line. The machine of claim 1 further comprises a second bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the evaporator and the compressor. The machine of claim 3 further comprises a bypass valve on the second bypass line. The machine of claim 3 further comprises a suction line heat exchanger. A machine as claimed in claim 5, wherein the working fluid loop passes through a phase change material reservoir disposed between the compressor and the condenser. A machine as claimed in claim 6, wherein the phase change material comprises a mixture of ethylene glycol and water, saline water, wax, alkane or pure water or a combination thereof. A machine as claimed in claim 7, wherein the working fluid loop comprises a pressure vessel between the condenser and the evaporator, a first isolation valve between the pressure vessel and the expansion device, and a second isolation valve between the compressor and the condenser. A machine as claimed in claim 8, wherein the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion device. A machine for reducing the temperature of components in a cassette containing components and at least one mixing impeller, the machine comprising: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the cassette, wherein the refrigeration system has a working fluid loop and also includes a first bypass line and a bypass valve, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion device and returning to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion device and the evaporator, the a bypass valve on the first bypass line; a motor operable to move the at least one mixing paddle of the box in the receptacle; and a processor operable to: close the bypass valve on the first bypass line and operate the motor to rotate the at least one mixing paddle when the evaporator freezes the ingredients in the box in the receptacle of the evaporator and when the refrigerated food or beverage from the box is dispensed out of the box through an orifice in the box; and open the first bypass line to defrost a surface of the receptacle of the evaporator when the box is in the receptacle of the evaporator. A machine as claimed in claim 10, wherein the working fluid loop comprises a pressure vessel between the condenser and the evaporator, a first isolation valve between the pressure vessel and the expansion device, and a second isolation valve between the compressor and the condenser. A machine as claimed in claim 10, wherein the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion device. The machine of claim 10, wherein after the refrigerated food or beverage from the bin is dispensed out of the bin through the orifice in the bin, the processor is operable to open the first bypass line to defrost the surface of the receptacle of the evaporator. The machine of claim 10 further comprises a second bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the evaporator and the compressor. The machine of claim 14, further comprising a bypass valve on the second bypass line. The machine of claim 14 further comprises a suction line heat exchanger. A machine as claimed in claim 14, wherein the working fluid loop passes through a reservoir of phase change material disposed between the compressor and the condenser. A machine as claimed in claim 17, wherein the phase change material comprises a mixture of ethylene glycol and water, saline water, wax, alkanes or pure water. A machine for producing refrigerated food or beverage from ingredients in a bin containing the ingredients, the machine comprising: a housing; and an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the bin, the evaporator having a bin-to-evaporator heat transfer surface of the evaporator between 15 square inches and 50 square inches, and the evaporator being constructed of a material defining microchannels; wherein the refrigeration system has a working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion device and back to the evaporator; and wherein the evaporator is made of a material having a thermal conductivity of at least 160 W/mk. The machine of claim 19, further comprising an aluminum evaporator having a mass between 0.100 pounds and 1.50 pounds. The machine of claim 19 wherein the evaporator has cooling channels therein which permit fluid mass velocities of up to 180,000 lb/(hour.ft2). The machine of claim 19, further comprising an evaporator refrigerant-wetted surface area between 35 square inches and 200 square inches. A machine as claimed in claim 19, wherein the evaporator is clamped down onto the box. A machine as claimed in claim 19, wherein the evaporator has a copper inner wall adjacent to the cassette. The machine of claim 19 further comprises a bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion device and the evaporator. The machine of claim 19, further comprising a rotary compressor having a refrigerant displacement of less than 6 cubic centimeters. The machine of claim 19, further comprising R-290 propane as a refrigerant. A machine as claimed in claim 19, wherein a pressure drop across the evaporator is less than 2 psi. A method for reducing the temperature of components in a box containing components, the method comprising: inserting the box containing the components into an evaporator of a refrigeration system of a machine, the refrigeration system having a working fluid loop and also including a first bypass line, the working fluid loop extending from the evaporator to a compressor, to a condenser, to an expansion device and returning to the evaporator, the first bypass line extending from the working fluid loop between the compressor and the condenser to the expansion device and on the first bypass line a bypass valve; when the evaporator is used to cool the box and the bypass valve on the first bypass line is closed, a motor of the machine is operated to rotate a mixing blade inside the box; when the cooled food or drink is dispensed out of the box through an orifice in the box, the motor of the machine is operated to rotate the mixing blade inside the box; and when the box is in the receptacle of the evaporator, the first bypass line is opened to defrost a surface of the receptacle of the evaporator. The method of claim 29 further includes opening a second valve on a second bypass line extending from the working fluid loop between the compressor and the condenser to the working fluid loop between the evaporator and the compressor. A method as claimed in claim 29, wherein the refrigeration system has a suction line heat exchanger. The method of claim 29, wherein the working fluid loop includes a pressure vessel between the condenser and the evaporator, a first isolation valve between the pressure vessel and the expansion device, and a second isolation valve between the compressor and the condenser. The method of claim 29, wherein the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion device. The method of claim 29, wherein when the bin is in the receptacle of the evaporator, opening the first bypass line to defrost the surface of the receptacle of the evaporator comprises opening the first bypass line to defrost the surface of the receptacle of the evaporator after the refrigerated food or drink from the bin is dispensed out of the bin through the orifice in the bin. The method of claim 29, wherein the working fluid loop passes through a phase change material reservoir disposed between the compressor and the condenser. The method of claim 35, wherein the phase change material comprises a mixture of ethylene glycol and water, saline, wax, alkanes or pure water.