Providing single servings of cooled foods and drinks

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

TECHNICAL FIELD

This disclosure relates to systems and methods for rapidly cooling food and drinks.

BACKGROUND

Beverage brewing system have been developed that rapidly prepare single servings of hot beverages. Some of these brewing systems rely on single use pods to which water is added before brewing occurs. The pods can be used to prepare hot coffees, teas, cocoas, and dairy-based beverages.

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

SUMMARY

This specification describes systems and methods for rapidly cooling food and drinks. Some of these systems and methods can cool food and drinks in a container inserted into a counter-top or installed machine from room temperature to freezing in less than two minutes. For example, the approach described in this specification has successfully demonstrated the ability make soft-serve ice cream from room-temperature pods in approximately 90 seconds. This approach has also been used to chill cocktails and other drinks including to produce frozen drinks. These systems and methods are based on a refrigeration cycle with low startup times and a pod-machine interface that is easy to use and provides extremely efficient heat transfer. Some of the pods described 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 treatment, ultra-pasteurization, or high pressure processing (HPP)). HPP is a cold pasteurization technique by which products, already sealed in its final package, are introduced into a vessel and subjected to a high level of isostatic pressure (300-600 megapascals (MPa) (43,500-87,000 pounds per square inch (psi)) transmitted by water. The pods can be used to store ingredients including, for example, dairy products at room temperature for long periods of time (e.g., 9-12 months) following sterilization.

Cooling is used to indicate the transfer of thermal energy to reduce the temperature, for example, of ingredients contained in a pod. In some cases, cooling indicates the transfer of thermal energy to reduce the temperature, for example, of ingredients contained in a pod to below freezing.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; and wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve or capillary tube back to the evaporator and also includes a first bypass line that extends from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator.

Some machines for reducing the temperature of ingredients in a pod containing the ingredients and at least one mixing paddle include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; a motor operable to move the at least one internal mixing paddle of a pod in the receptacle; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve back to the evaporator and also includes a first bypass line that extends from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator and a bypass valve on the first bypass line.

Some machines for producing cooling ingredients in a pod containing the ingredients and at least one internal mixing paddle include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the single use pod; and a motor operable to move the at least one internal mixing paddle of a pod in the receptacle; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve back to the evaporator and also includes a first bypass line that extends from the working fluid loop between the compressor and the condenser to the working fluid loop between the expansion valve and the evaporator and a bypass valve on the first bypass line.

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

Some machines for producing cooling ingredients in a pod containing the ingredients and at least one internal mixing paddle include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; and a motor operable to move the internal mixing paddle of a pod in the receptacle; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to a pressure vessel to an expansion valve 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.

Some machines for producing cooling ingredients in a pod containing the ingredients and at least one internal mixing paddle include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; and a motor operable to move the internal mixing paddle of a pod in the receptacle; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve back to the evaporator and the working fluid loop passes through a thermoelectric cooler between the condenser and the expansion valve.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; and wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve or capillary tube back to the evaporator; and wherein the evaporator is made of a material that has at least 160 W/mK thermal conductivity.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve or capillary tube back 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.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion sub-system, comprising multiple orifices or expansion devices in parallel, back to the evaporator.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; wherein the refrigeration system has a working fluid loop that runs from the evaporator to a compressor to a condenser to an expansion valve or capillary tube to a refrigerant line that pre-chills a tank of water, back to the evaporator.

Some machines for producing cooled food or drinks from ingredients in a pod containing the ingredients include: an evaporator of a refrigeration system, the evaporator defining a receptacle sized to receive the pod; wherein the refrigeration system has a working fluid loop that runs from the evaporator to the one side of a thermal battery to a compressor to a condenser to the other side of a thermal battery to an expansion valve or capillary tube, back to the evaporator.

Embodiments of these machines can include one or more of the following features.

In some embodiments, machines also include a bypass valve on the first bypass line.

In some embodiments, machines also include a second bypass line that extends 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, machines also include a bypass valve on the second bypass line. In some cases, machines also include 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 ethylene glycol and water mixture, salt water, paraffin wax, alkanes, or pure water or a combination thereof. In some cases, 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 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, machines also include an aluminum evaporator with a mass of not exceeding 1.50 pounds.

In some embodiments, machines also include a pressure drop through the refrigeration system less than 2 psi.

In some embodiments, machines also include a pod to evaporator heat transfer surface of up to 50 square inches.

In some embodiments, machines also include an evaporator has cooling channels in it allowing for the fluid mass velocity up to 180,000 lb/(hour feet squared) has refrigerant wetted surface area of up to 200 square inches.

In some embodiments, machines also include an evaporator refrigerant wetted surface area of up to 200 square inches.

In some embodiments, machines also include an evaporator that clamps down on the pod.

In some embodiments, machines also include an evaporator that has an internal wall of copper adjacent to the pod.

In some embodiments, machines also include an evaporator that is constructed of microchannels.

The systems and methods described in this specification can provide a number of advantages. Some embodiments of these systems and methods can provide single servings of cooled food or drink. This approach can help consumers with portion control. Some embodiments of these systems and methods can provide consumers the ability to choose their single-serving flavors, for example, of soft serve ice cream. Some embodiments of these systems and methods incorporate shelf-stable pods that do not require pre-cooling, pre-freezing or other preparation. Some embodiments of these systems and methods can generate frozen food or drinks from room-temperature pods in less than two minutes (in some cases, less than one minute). Some embodiments of these systems and methods do not require post-processing clean up once the cooled or frozen food or drink is generated. Some embodiments of these systems and methods utilize aluminum pods that are recyclable.

DETAILED DESCRIPTION

This specification describes systems and methods for rapidly cooling food and drinks. Some of these systems and methods use a counter-top or installed machine to cool food and drinks in a container from room temperature to freezing in less than two minutes. For example, the approach described in this specification has successfully demonstrated the ability make soft-serve ice cream, frozen coffees, frozen smoothies, and frozen cocktails, from room temperature pods in approximately 90 seconds. This approach can also be used to chill cocktails, create frozen smoothies, frozen protein and other functional beverage shakes (e.g., collagen-based, energy, plant-based, non-dairy, CBD shakes), frozen coffee drinks and chilled coffee drinks with and without nitrogen in them, create hard ice cream, create milk shakes, create frozen yogurt and chilled probiotic drinks. These systems and methods are based on a refrigeration cycle with low startup times and a pod-machine interface that is easy to use and provides extremely efficient heat transfer. Some of the pods described can be sterilized (e.g., using retort sterilization) and used to store ingredients including, for example, dairy products at room temperature for up to 18 months.

FIG. 1Ais a perspective view of a machine100for cooling food or drinks.FIG. 1Bshows the machine without its housing. The machine100reduces the temperature of ingredients in a pod containing the ingredients. Most pods include a mixing paddle used to mix the ingredients before dispensing the cooled or frozen products. The machine100includes a body102that includes a compressor, a condenser, a fan, an evaporator, capillary tubes, a control system, a lid system and a dispensing system with a housing104and a pod-machine interface106. The pod-machine interface106includes an evaporator108of a refrigeration system109whose other components are disposed inside the housing104. As shown onFIG. 1B, the evaporator108defines a receptacle110sized to receive a pod.

A lid112is attached to the housing104via a hinge114. The lid112can rotate between a closed position covering the receptacle110(FIG. 1A) and an open position exposing the receptacle110(FIG. 1B). In the closed position, the lid112covers the receptacle110and is locked in place. In the machine100, a latch116on the lid112engages with a latch recess118on the pod-machine interface106. A latch sensor120is disposed in the latch recess118to determine if the latch116is engaged with the latch recess118. A processor122is electronically connected to the latch sensor120and recognizes that the lid112is closed when the latch sensor120determines that the latch116and the latch recess118are engaged.

An auxiliary cover115rotates upward as the lid112is moved from its closed position to its open position. Some auxiliary covers slide into the housing when the lid moves into the open position.

In the machine100, the evaporator108is fixed in position with respect to the body102of the machine100and access to the receptacle110is provided by movement of the lid112. In some machines, the evaporator108is displaceable relative to the body102and movement of the evaporator108provides access to the receptacle110.

A motor124disposed in the housing104is mechanically connected to a driveshaft126that extends from the lid112. When the lid112is in its closed position, the driveshaft126extends into the receptacle110and, if a pod is present, engages with the pod to move a paddle or paddles within the pod. The processor122is in electronic communication with the motor124and controls operation of the motor124. In some machines, the shaft associated with the paddle(s) of the pod extends outward from the pod and the lid112has a rotating receptacle (instead of the driveshaft126) mechanically connected to the motor124.

FIG. 1Cis perspective view of the lid112shown separately so the belt125that extends from motor124to the driveshaft126is visible. Referring again toFIG. 1B, the motor124is mounted on a plate that runs along rails127. The plate can move approximately 0.25 inches to adjust the tension on the belt. During assembly, the plate slides along the rails. Springs disposed between the plate and the lid112bias the lid112away from the plate to maintain tension in the belt.

FIG. 2Ais a perspective view of the machine100with the cover of the pod-machine interface106illustrated as being transparent to allow a more detailed view of the evaporator108to be seen.FIG. 2Bis a top view of a portion of the machine100without housing104and the pod-machine interface106without the lid112.FIGS. 2C and 2Dare, respectively, a perspective view and a side view of the evaporator108. Other pod-machine interfaces are described in more detail in U.S. patent application Ser. No. 16/459,176 filed contemporaneously with this application and incorporated herein by reference in its entirety.

The evaporator108has a clamshell configuration with a first portion128attached to a second portion130by a living hinge132on one side and separated by a gap134on the other side. Refrigerant flows to the evaporator108from other components of the refrigeration system through fluid channels136(best seen onFIG. 2B). The refrigerant flows through the evaporator108in internal channels through the first portion128, the living hinge132, and the second portion130.

The space137(best seen onFIG. 2B) between the outer wall of the evaporator108and the inner wall of the casing of the pod-machine interface106is filled with an insulating material to reduce heat exchange between the environment and the evaporator108. In the machine100, the space137is filled with an aerogel (not shown). Some machines use other insulating material, for example, an annulus (such as an airspace), insulating foams made of various polymers, or fiberglass wool.

The evaporator108has an open position and a closed position. In the open position, the gap134opens to provide an air gap between the first portion128and the second portion130. In the machine100, the first portion128and the second portion130are pressed together in the closed position. In some machines, the first and second portion are pressed towards each other and the gap is reduced, but still defined by a space between the first and second portions in the closed position.

The inner diameter ID of the evaporator108is slightly larger in the open position than in the closed position. Pods can be inserted into and removed from the evaporator108while the evaporator is in the open position. Transitioning the evaporator108from its open position to its closed position after a pod is inserted tightens the evaporator108around the outer diameter of the pod. For example, the machine100is configured to use pods with 2.085″ outer diameter. The evaporator108has an inner diameter of 2.115″ in the open position and an inner diameter inner diameter of 2.085″ in the closed position. Some machines have evaporators sized and configured to cool other pods. The pods can be formed from commercially available can sizes, for example, “slim” cans with diameters ranging from 2.080 inches-2.090 inches and volumes of 180 milliliters (ml)-300 ml, “sleek” cans with diameters ranging from 2.250 inches-2.400 inches and volumes of 180 ml-400 ml and “standard” size cans with diameters ranging from 2.500 inches-2.600 inches and volumes of 200 ml-500 ml. The machine100is configured to use pods with 2.085 inches outer diameter. The evaporator108has an inner diameter of 2.115 inches in its open position and an inner diameter inner diameter of 2.085 inches in its closed position. Some machines have evaporators sized and configured to cool other pods.

The closed position of evaporator108improves heat transfer between inserted pod150and the evaporator108by increasing the contact area between the pod150and the evaporator108and reducing or eliminating an air gap between the wall of the pod150and the evaporator108. In some pods, the pressure applied to the pod by the evaporator108is opposed by the mixing paddles, pressurized gases within the pod, or both to maintain the casing shape of the pod.

In the evaporator108, the relative position of the first portion128and the second portion130and the size of the gap134between them is controlled by two bars138connected by a bolt140and two springs142. Each of the bars138has a threaded central hole through which the bolt140extends and two end holes engaging the pins144. Each of the two springs142is disposed around a pin144that extends between the bars138. Some machines use other systems to control the size of the gap134, for example, circumferential cable systems with cables that extend around the outer diameter of the evaporator108with the cable being tightened to close the evaporator108and loosened to open the evaporator108. In other evaporators, there are a plurality of bolts and end holes, one or more than two springs, and one or more than engaging pins.

One bar138is mounted on the first portion128of the evaporator108and the other bar138is mounted on the second portion130of the evaporator108. In some evaporators, the bars138are integral to the body of the evaporator108rather than being mounted on the body of the evaporator. The springs142press the bars138away from each other. The spring force biases the first portion128and the second portion130of the evaporator108away from each at the gap134. Rotation of the bolt140in one direction increases a force pushing the bars138towards each and rotation of the bolt in the opposite direction decreases this force. When the force applied by the bolt140is greater than the spring force, the bars138bring the first portion128and the second portion130of the evaporator together.

The machine100includes an electric motor146(shown onFIG. 2B) that is operable to rotate the bolt140to control the size of the gap134. Some machines use other mechanisms to rotate the bolt140. For example, some machines use a mechanical linkage, for example, between the lid112and the bolt140to rotate the bolt140as the lid112is opened and closed. Some machines include a handle that can be attached to the bolt to manually tighten or loosen the bolt. Some machines have a wedge system that forces the bars into a closed position when the machine lid is shut. This approach may be used instead of the electric motor146or can be provided as a backup in case the motor fails.

The electric motor146is in communication with and controlled by the processor122of the machine100. Some electric drives include a torque sensor that sends torque measurements to the processor122. The processor122signals to the motor to rotate the bolt140in a first direction to press the bars138together, for example, when a pod sensor indicates that a pod is disposed in the receptacle110or when the latch sensor120indicates that the lid112and pod-machine interface106are engaged. It is desirable that the clamshell evaporator be shut and holding the pod in a tightly fixed position before the lid closes and the shaft pierces the pod and engages the mixing paddle. This positioning can be important for driveshaft-mixing paddle engagement. The processor122signals to the electric drive to rotate the bolt140in the second direction, for example, after the food or drink being produced has been cooled/frozen and dispensed from the machine100, thereby opening the evaporator gap134and allowing for easy removal of pod150from evaporator108.

The base of the evaporator108has three bores148(seeFIG. 2C) which are used to mount the evaporator108to the floor of the pod-machine interface106. All three of the bores148extend through the base of the second portion130of the evaporator108. The first portion128of the evaporator108is not directly attached to the floor of the pod-machine interface106. This configuration enables the opening and closing movement described above. Other configurations that enable the opening and closing movement of the evaporator108can also be used. Some machines have more or fewer than three bores148. Some evaporators are mounted to components other than the floor of the pod-machine interface, for example, the dispensing mechanism.

Many factors affect the performance of a refrigeration system. Important factors include mass velocity of refrigerant flowing through the system, the refrigerant wetted surface area, the refrigeration process, the area of the pod/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 systems described in this specification have determined that appropriate choices for the mass velocity of refrigerant flowing through the system and the refrigerant wetted surface area are the most important parameters to balance to provide a system capable of freezing up to 12 ounces of confection in less than 2 minutes.

The evaporators described in this specification can have the following characteristics:

TABLE 1Evaporator parametersMass Velocity60,000 to 180,000 lb/(hour feet squared)Refrigerant Wetted Surface Area35 to 200 square inchesPressure drop Throughless than 2 psi pressure drop across theRefrigeration ProcessevaporatorPod/Evaporator Heat15 to 50 square inchesTransfer SurfaceMass of Evaporator0.100 to 1.50 poundsMinimum Conductivity160 W/mKof the Material
The following paragraphs describe the significance of these parameters in more detail.

Mass velocity accounts for the multi-phase nature or refrigerant flowing through an evaporator. The two-phase process takes advantage of the high amounts of heat absorbed and expended when a refrigerant fluid (e.g., R-290 propane) changes state from a liquid to gas and a gas to a liquid, respectively. The rate of heat transfer depends in part on exposing the evaporator inner surfaces with a new liquid refrigerant to vaporize and cool the liquid ice cream mix. To do this the velocity of the refrigerant fluid must be high enough for vapor to channel or flow down the center of the flow path within the walls of evaporator and for liquid refrigerant to be pushed thru these channel passages within the walls. One approximate measurement of fluid velocity in a refrigeration system is mass velocity—the mass flow of refrigerant in a system per unit cross sectional area of the flow passage in units of lb/hr ft{circumflex over ( )}2. Velocity as measured in ft/s (a more familiar way to measure “velocity”) is difficult to apply in a two-phase system since the velocity (ft/s) is constantly changing as the fluid flow changes state from liquid to gas. If liquid refrigerant is constantly sweeping across the evaporator walls, it can be vaporized and new liquid can be pushed against the wall of the cooling channels by the “core” of vapor flowing down the middle of the passage. At low velocities, flow separates based on gravity and liquid remains on the bottom of the cooling passage within the evaporator and vapor rises to the top side of the cooling passage channels. If the amount of area exposed to liquid is reduced by half, for example, this could cut the amount of heat transfer almost half. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), a mass velocity of 150,000 lb/hr ft{circumflex over ( )}2 maximizes performance for the majority of the evaporator flow path. Mass velocity is one of the parameters that must be balanced to optimize a refrigerant system. The parameters that affect the performance 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 required temperature of the evaporator and the properties of the refrigerant used in the system. The mass flow rate of refrigerant through the evaporator must be high enough for it to absorb the amount of thermal energy from the confection to freeze it, in a given amount of time. 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 influenced by the mass velocity and wetted surface area of the evaporator. The convective heat transfer coefficient will increase with increased mass velocity. However, pressure drop will also increase with mass velocity. This in turn increases the power required to operate the compressor and reduces the mass flow rate the compressor can deliver. It is desirable to design the evaporator to meet performance objectives while using the smallest least expensive compressor possible. We have determined that evaporators with a mass velocity of 75,000-125,000 lb/hr ft{circumflex over ( )}2 are effective in helping provide a system capable of freezing up to 12 ounces of confection in less than 2 minutes. The latest prototype has a mass velocity of approximately 100,000 lb/hr ft{circumflex over ( )}2 and provides a good balance of high mass velocity, manageable pressure drop in the system, and a reasonable sized compressor.

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

The amount of heat that can be transferred out of the liquid in a pod is proportional to the surface area of the pod/evaporator heat transfer surface. A larger surface area is desirable but increases in surface area can require increasing the mass of the evaporator which would degrade heat transfer characteristics of the evaporator. We have determined that evaporators in which the area of the pod/evaporator heat transfer surface is between 20 and 40 square inches are effectively combined with the other characteristics to help provide a system capable of freezing up to 12 ounces of confection in less than 2 minutes.

Thermal conductivity is the intrinsic property of a material which relates its ability to conduct heat. Heat transfer by conduction involves transfer of energy within a material without any motion 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 walls. Reducing this temperature difference reduces the work required for the refrigeration system to cool the evaporator to the right temperature.

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 evaporator mass reduces the amount of material that must be cooled during a freezing cycle. An evaporator with a large mass will increase the time require to freeze up to 12 ounces of confection.

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

FIGS. 3A-3Fshow components of the pod-machine interface106that are operable to open pods in the evaporator108to dispense the food or drink being produced by the machine100. This is an example of one approach to opening pods but some machines and the associated pods use other approaches.

FIG. 3Ais a partially cutaway schematic view of the pod-machine interface106with a pod150placed in the evaporator108.FIG. 3Bis a schematic plan view looking upwards that shows the relationship between the end of the pod150and the floor152of the pod-machine interface106. The floor152of the pod-machine interface106is formed by a dispenser153.FIGS. 3C and 3Dare perspective views of a dispenser153.FIGS. 3E and 3Fare perspective views of an insert154that is disposed in the dispenser153. The insert154includes an electric motor146operable to drive a worm gear157floor152of the pod-machine interface106. The worm gear157is engaged with a gear159with an annular configuration. An annular member161mounted on the gear159extends from the gear159into an interior region of the pod-machine interface106. The annular member161has protrusions163that are configured to engage with a pod inserted into the pod-machine interface106to open the pod. The protrusions163of the annular member161are four dowel-shaped protrusions. Some annular gears have more protrusions or fewer protrusions and the protrusions can have other shapes, for example, “teeth.”

The pod150includes a body158containing a mixing paddle160(seeFIG. 3A). The pod150also has a base162defining an aperture164and a cap166extending across the base162(seeFIG. 3B). The base162is seamed/fixed onto the body158of the pod150. The base162includes a protrusion165. The cap166mounted over base162is rotatable around the circumference/axis of the pod150. In use, when the product is ready to be dispensed from the pod150, the dispenser153of the machine engages and rotates the cap166around the first end of the pod150. Cap166is rotated to a position to engage and then separate the protrusion165from the rest of the base162. The pod150and its components are described in more detail with respect toFIGS. 6A-10.

The aperture164in the base162is opened by rotation of the cap166. The pod-machine interface106includes an electric motor146with threading that engages the outer circumference of a gear168. Operation of the electric motor146causes the gear168to rotate. The gear168is attached to a annular member161and rotation of the gear168rotates the annular member161. The gear168and the annular member161are both annular and together define a central bore through which food or drink can be dispensed from the pod150through the aperture164without contacting the gear168or the annular member161. When the pod150is placed in the evaporator108, the annular member161engages the cap166and rotation of the annular member161rotates the cap166.

FIG. 4is a schematic of the refrigeration system109that includes the evaporator108. The refrigeration system also includes a condenser180, a suction line heat exchanger182, an expansion valve184, and a compressor186. High-pressure, liquid refrigerant flows from the condenser180through the suction line heat exchanger182and the expansion valve184to the evaporator108. The expansion valve184restricts the flow of the liquid refrigerant fluid and lowers the pressure of the liquid refrigerant as it leaves the expansion valve184. The low-pressure liquid-vapor mixture then moves to the evaporator108where heat absorbed from a pod150and its contents in the evaporator108changes the refrigerant from a liquid-vapor mixture to a gas. The gas-phase refrigerant flows from the evaporator108to the compressor186through the suction line heat exchanger182. In the suction line heat exchanger182, the cold vapor leaving the evaporator108pre-cools the liquid leaving the condenser180. The refrigerant enters the compressor186as a low-pressure gas and leaves the compressor186as a high-pressure gas. The gas then flows to the condenser180where heat exchange cools and condenses the refrigerant to a liquid.

The refrigeration system109includes a first bypass line188and second bypass line190. The first bypass line188directly connects the discharge of the compressor186to the inlet of the compressor186. Disposed on the both the first bypass line and second bypass line are bypass valves that open and close the passage to allow refrigerant bypass flow. Diverting the refrigerant directly from the compressor discharge to the inlet can provide evaporator defrosting and temperature control without injecting hot gas to the evaporator. The first bypass line188also provides a means for rapid pressure equalization across the compressor186, which allows for rapid restarting (i.e., freezing one pod after another quickly). The second bypass line190enables the application of warm gas to the evaporator108to defrost the evaporator108. The bypass valves may be, for example, solenoid valves or throttle valves.

FIGS. 5A and 5Bare views of a prototype of the condenser180. The condenser has internal channels192. The internal channels192increase the surface area that interacts with the refrigerant cooling the refrigerant quickly. These images show micro-channel tubing which are used because they have small channels which keeps the coolant velocity up and are thin wall for good heat transfer and have little mass to prevent the condenser for being a heat sink.

FIGS. 6A and 6Bshow an example of a pod150for use with the machine100described with respect toFIGS. 1A-3F.FIG. 6Ais a side view of the pod150.FIG. 6Bis a schematic side view of the pod150and the mixing paddle160disposed in the body158of the pod150. Other pod-machine interfaces that can be used with this and similar machines are described in more detail in U.S. patent application Ser. No. 16/459,176 filed contemporaneously with this application and incorporated herein by reference in its entirety.

The pod150is sized to fit in the receptacle110of the machine100. The pods can be sized to provide a single serving of the food or drink being produced. Typically, pods have a volume between 6 and 18 fluid ounces. The pod150has a volume of approximately 8.5 fluid ounces.

The body158of the pod150is a can that contains the mixing paddle160. The body158extends from a first end210at the base to a second end212and has a circular cross-section. The first end210has a diameter DUEthat is slightly larger than the diameter DLEof the second end212. This configuration facilitates stacking multiple pods200on top of one another with the first end210of one pod receiving the second end212of another pod.

A wall214connects the first end210to the second end212. The wall214has a first neck216, second neck218, and a barrel220between the first neck216and the second neck218. The barrel220has a circular cross-section with a diameter DB. The diameter DBis larger than both the diameter DUEof the first end210and the diameter DLEof the second end212. The first neck216connects the barrel220to the first end210and slopes as the first neck216extends from the smaller diameter DUEto the larger diameter DBthe barrel220. The second neck218connects the barrel220to the second end212and slopes as the second neck218extends from the larger diameter DBof the barrel220to the smaller diameter DLEof the second end212. The second neck218is sloped more steeply than the first neck216as the second end212has a smaller diameter than the first end210.

This configuration of the pod150provides increased material usage; i.e., the ability to use more base material (e.g., aluminum) per pod. This configuration further assists with the columnar strength of the pod.

The pod150is designed for good heat transfer from the evaporator to the contents of the pod. The body158of the pod150is made of aluminum and is between 5 and 50 microns thick. The bodies of some pods are made of other materials, for example, tin, stainless steel, and various polymers such as Polyethylene terephthalate (PTE).

Pod150may be made from a combination of different materials to assist with the manufacturability and performance of the pod. In one embodiment, the pod walls and the second end212may be made of Aluminum 3104 while the base may be made of Aluminum 5182.

In some pods, the internal components of the pod are coated with a lacquer to prevent corrosion of the pod as it comes into contact with the ingredients contained within pod. This lacquer also reduces the likelihood of “off notes” of the metal in the food and beverage ingredients contained within pod. For example, a pod made of aluminum may be internally coated 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 mixing paddles are made of similar aluminum alloys and coated with similar lacquers/coatings. For example, Whitford/PPG coating 8870 may be used as a coating for mixing paddles. The mixing paddle lacquer may have additional non-stick and hardening benefits for mixing paddle.

FIGS. 7A-7Cillustrate the engagement between the driveshaft126of the machine100and the mixing paddle160of a pod150inserted in the machine100.FIGS. 7A and 7Bare perspective views of the pod150and the driveshaft126. In use, the pod150is inserted into the receptacle110of the evaporator108with the first end210of the pod150downward. This orientation exposes the second end212of the pod150to the driveshaft126as shown inFIG. 7A. Closing the lid112(seeFIG. 1A) presses the driveshaft126against the second end212of the pod150with sufficient force that the driveshaft126pierces the second end212of the pod150.FIG. 7Bshows the resulting hole exposing the mixing paddle160with the driveshaft126offset for ease of viewing.FIG. 7Cis a cross-section of a portion of the pod150with the driveshaft126engaged with the mixing paddle160after the lid is closed. Typically, there is not a tight seal between the driveshaft126and the pod150so that air can flow in as the frozen confection is evacuating/dispensing out the other end of the pod150. In an alternative embodiment, there is a tight seal such that the pod150retains pressure in order to enhance contact between the pod150and evaporator108.

Some mixing paddles contain a funnel or receptacle configuration that receives the punctured end of the second end of the pod when the second end is punctured by driveshaft.

FIG. 8shows the first end210of the pod150with the cap166spaced apart from the base162for ease of viewing.FIGS. 9A-9Dillustrate rotation of the cap166around the first end210of the pod150to cut and carry away protrusion165of base162and expose aperture164extending through the base162.

The base162is manufactured separately from the body158of the pod150and then attached (for example, by crimping or seaming) to the body158of the pod150covering an open end of the body158. The protrusion165of the base162can be formed, for example, by stamping, deep drawing, or heading a sheet of aluminum being used to form the base. The protrusion165is attached to the remainder of the base162, for example, by a weakened score line173. The scoring can be a vertical score into the base of the aluminum sheet or a horizontal score into the wall of the protrusion165. For example, the material can be scored from an initial thickness of 0.008 inches to 0.010 inches to a post-scoring thickness of 0.001 inches-0.008 inches. In an alternative embodiment, there is no post-stamping scoring but rather the walls are intentionally thinned for ease of rupture. In another version, there is not variable wall thickness but rather the cap166combined with force of the machine dispensing mechanism engagement are enough to cut the 0.008 inches to 0.010 inches wall thickness on the protrusion165. With the scoring, the protrusion165can be lifted and sheared off the base162with 5-75 pounds of force, for example between 15-40 pounds of force.

The cap166has a first aperture222and a second aperture224. The first aperture approximately matches the shape of the aperture164. The aperture164is exposed and extends through the base162when the protrusion165is removed. The second aperture224has a shape corresponding to two overlapping circles. One of the overlapping circles has a shape that corresponds to the shape of the protrusion165and the other of the overlapping circles is slightly smaller. A ramp226extends 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 extra height helps to lift and rupture the protrusion's head and open the aperture during the rotation of the cap as described in more detail with reference toFIGS. 9A-9G.

As shown inFIGS. 9A and 9B, the cap166is initially attached to the base162with the protrusion165aligned with and extending through the larger of the overlapping circles of the second aperture224. When the processor122of the machine activates the electric motor146to rotate the gear168and the annular member161, rotation of the cap166slides the ramp226under a lip of the protrusion165as shown inFIGS. 9C and 9D. Continued rotation of the cap166applies a lifting force that separates the protrusion165from the remainder of the base162(seeFIGS. 9E-9G) and then aligns the first aperture222of the cap166with the aperture164in the base162resulting from removal of the protrusion165.

Some pods include a structure for retaining the protrusion165after the protrusion165is separated from the base162. In the pod150, the protrusion165has a head167, a stem169, and a foot171(best seen inFIG. 9G). The stem169extends between the head167and the foot171and has a smaller cross-section that the head167and the foot171. As rotation of the cap166separates the protrusion165from the remainder of the base162, the cap166presses laterally against the stem169with the head167and the foot171bracketing the cap166along the edges of one of the overlapping circles of the second aperture224. This configuration retains the protrusion165when the protrusion165is separated from the base166. Such a configuration reduces the likelihood that the protrusion falls into the waiting receptacle that when the protrusion165is removed from the base.

Some pods include other approaches to separating the protrusion165from the remainder of the base162. For example, in some pods, the base has a rotatable cutting mechanism that is riveted to the base. The rotatable cutting mechanism has a shape similar to that described relative to cap166but this secondary piece is riveted to and located within the perimeter of base162rather than being mounted over and around base162. When the refrigeration cycle is complete, the processor122of the machine activates an arm of the machine to rotate the riveted cutting mechanism around a rivet. During rotation, the cutting mechanism engages, cuts and carries away the protrusion165, leaving the aperture164of base162in its place.

In another example, some pods have caps with a sliding knife that moves across the base to remove the protrusion. The sliding knife is activated by the machine and, when triggered by the controller, slides across the base to separate, remove, and collect the protrusion165. The cap166has a guillotine feature that, when activated by the machine, may slide straight across and over the base162. The cap166engages, cuts, and carries away the protrusion165. In another embodiment, this guillotine feature may be central to the machine and not the cap166of pod150. In another embodiment, this guillotine feature may be mounted as a secondary piece within base162and not a secondary mounted piece as is the case with cap166.

Some pods have a dispensing mechanism that includes a pop top that can be engaged and released by the machine. When the refrigeration cycle is complete, an arm of the machine engages and lifts a tab of the pod, thereby pressing the puncturing the base and creating an aperture in the base. Chilled or frozen product is dispensed through the aperture. The punctured surface of the base remains hinged to base and is retained inside the pod during dispensing. The mixing avoids or rotates over the punctured surface or, in another embodiment, so that the mixing paddle continues to rotate without obstruction. In some pop tops, the arm of the machine separates the punctured surface from the base.

FIG. 10is an enlarged schematic side view of the pod150. The mixing paddle160includes a central stem228and two blades230extending from the central stem228. The blades230are helical blades shaped to churn the contents of the pod150and to remove ingredients that adhere to inner surface of the body158of the pod150. Some mixing paddles have a single blade and some mixing paddles have more than two mixing paddles.

Fluids (for example, liquid ingredients, air, or frozen confection) flow through openings232in the blades230when the mixing paddle160rotates. These openings reduce the force required to rotate the mixing paddle160. This reduction can be significant as the viscosity of the ingredients increases (e.g., as ice cream forms). The openings232further assist in mixing and aerating the ingredients within the pod.

The lateral edges of the blades230define slots234. The slots234are offset so that most of the inner surface of the body158is cleared of ingredients that adhere to inner surface of the body by one of the blades230as the mixing paddle160rotates. Although the mixing paddle is160wider than the first end210of the body158of the pod150, the slots234are alternating slots that facilitate insertion of the mixing paddle160into the body158of the pod150by rotating the mixing paddle160during insertion so that the slots234are aligned with the first end210. In another embodiment, the outer diameter of the mixing paddle are less than the diameter of the pod150opening, allowing for a straight insertion (without rotation) into the pod150. In another embodiment, one blade on the mixing paddle has an outer-diameter that is wider than the second blade diameter, thus allowing for straight insertion (without rotation) into the pod150. 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 a churning operation.

Some mixing paddles have one or more blades that are hinged to the central stem. During insertion, the blades can be hinged into a condensed formation and released into an expanded formation once inserted. Some hinged blades are fixed open while rotating in a first direction and collapsible when rotating in a second direction, opposite the first direction. Some hinged blades lock into a fixed, outward, position once inside the pod regardless of rotational directions. Some hinged blades are manually condensed, expanded, and locked.

The mixing paddle160rotates clockwise and removes frozen confection build up from the pod214wall. Gravity forces the confection removed from the pod wall to fall towards first end210. In the counterclockwise direction, the mixing paddle160rotate, lift and churn the ingredients towards the second end212. When the paddle changes direction and rotates clockwise the ingredients are pushed towards the first end210. When the protrusion165of the base162is removed as shown and described with respect toFIG. 9D, clockwise rotation of the mixing paddle dispenses produced food or drink from the pod150through the aperture164. Some paddles mix and dispense the contents of the pod by rotating a first direction. Some paddles mix by moving in a first direction and a second direction and dispense by moving in the second direction when the pod is opened.

The central stem228defines a recess236that is sized to receive the driveshaft126of the machine100. The recess and driveshaft126have a square cross section so that the driveshaft126and the mixing paddle160are rotatably constrained. When the motor rotates the driveshaft126, the driveshaft rotates the mixing paddle160. In some embodiments, the cross section of the driveshaft is a different shape and the cross section of the recess is compatibly shaped. In some cases the driveshaft and recess are threadedly connected. In some pods, the recess contains a mating structure that grips the driveshaft to rotationally couple the driveshaft to the paddle.

FIG. 11is a flow chart of a method250implemented on the processor122for operating the machine100. The method250is described with references to refrigeration system109and machine100. The method250may also be used with other refrigeration systems and machines. The method250is described as producing soft serve ice cream but can also be used to produce other cooled or frozen drinks and foods.

The first step of the method250is to turn the machine100on (step260) and turn on the compressor186and the fans associated with the condenser180(step262). The refrigeration system109then idles at regulated temperature (step264). In the method250, the evaporator108temperature is controlled to remain around 0.75° C. but may fluctuate by ±0.25° C. Some machines are operated at other idle temperatures, for example, from 0.75° C. to room temperature (22.0° C.). If the evaporator temperature is below 0.5° C., the processor122opens the bypass valve190to increase the heat of the system (step266). When the evaporator temperature goes over 1° C., the bypass valve190is closed to cool the evaporator (step268). From the idle state, the machine100can be operated to produce ice cream (step270) or can shut down (step272).

After inserting a pod, the user presses the start button. When the user presses the start button, the bypass valve190closes, the evaporator108moves to its closed position, and the motor124is turned on (step274). In some machines, the evaporator is closed electronically using a motor. In some machines, the evaporator is closed mechanically, for example by the lid moving from the open position to the closed position. In some systems, a sensor confirms that a pod150is present in the evaporator108before these actions are taken.

Some systems include radio frequency identification (RFID) tags or other intelligent bar codes such as UPC bar or QR codes. Identification information on pods can be used to trigger specific cooling and mixing algorithms for specific pods. These systems can optionally read the RFID, QR code, or barcode and identify the mixing motor speed profile and the mixing motor torque threshold (step273).

The identification information can also be used to facilitate direct to consumer marketing (e.g., over the internet or using a subscription model). This approach and the systems described in this specification enable selling ice cream thru e-commerce because the pods are shelf stable. In the subscription mode, customers pay a monthly fee for a predetermined number of pods shipped to them each month. They can select their personalized pods from various categories (e.g., ice cream, healthy smoothies, frozen coffees or frozen cocktails) as well as their personalized flavors (e.g., chocolate or vanilla).

The identification can also be used to track each pod used. In some systems, the machine is linked with a network and can be configured to inform a vendor as to which pods are being used and need to be replaced (e.g., through a weekly shipment). This method is more efficient than having the consumers go to the grocery store and purchase pods.

These actions cool the pod150in the evaporator108while rotating the mixing paddle160. As the ice cream forms, the viscosity of the contents of the pod150increases. A torque sensor of the machine measures the torque of the motor124required to rotate the mixing paddle160within the pod150. Once the torque of the motor124measured by a torque sensor satisfies a predetermined threshold, the machine100moves into a dispensing mode (276). The dispensing port opens and the motor124reverses direction (step278) to press the frozen confection out of the pod150. This continues for approximately 1 to 10 seconds to dispense the contents of the pod150(step280). The machine100then switches to defrost mode (step282). Frost that builds up on the evaporator108can reduce the heat transfer efficiency of the evaporator108. In addition, the evaporator108can freeze to the pod150, the first portion128and second portion130of the evaporator can freeze together, and/or the pod can freeze to the evaporator. The evaporator can be defrosted between cycles to avoid these issues by opening the bypass valve170, opening the evaporator108, and turning off the motor124(step282). The machine then diverts gas through the bypass valve for about 1 to 10 seconds to defrost the evaporator (step284). The machine is programmed to defrost after every cycle, unless a thermocouple reports that the evaporator108is already above freezing. The pod can then be removed. The machine100then returns to idle mode (step264). In some machines, a thermometer measures the temperature of the contents of pod150and identifies when it is time to dispense the contents of the pod. In some machines, the dispensing mode begins when a predetermined time is achieved. In some machines, a combination of torque required to turn the mixing paddle, mixing motor current draw, temperature of the pod, and/or time determines when it is time to dispense the contents of the pod.

If the idle time expires, the machine100automatically powers down (step272). A user can also power down the machine100by holding down the power button (286). When powering down, the processor opens the bypass valve190to equalize pressure across the valve (step288). The machine100waits ten seconds (step290) then turns off the compressor186and fans (step292). The machine is then off.

FIG. 12is a schematic of a refrigeration system310that includes the evaporator108and an expansion sub-system312. The refrigeration system310is substantially similar to the refrigeration system109. However, the refrigeration system310includes the expansion sub-system312rather than the expansion valve184shown in the refrigeration system109. The refrigeration system310does not include the first bypass line188and the second bypass line190that are part of the refrigeration system109. However, some systems include the with the expansion sub-system312, the first bypass line, and the second bypass line.

The expansion sub-system312includes multiple valves to control expansion of the refrigeration fluid. These valves include a first fixed orifice valve314, a second fixed orifice valve316, and a control valve318. The control valve318is upstream from the second fixed orifice valve316. The control valve318and second fixed orifice valve316are in parallel with the first fixed orifice valve314. The expansion device has two modes to control the temperature of the refrigerant entering the evaporator108. In the first mode, the control valve318is open allowing the refrigerant to flow to the second fixed orifice valve316. In the first mode, the refrigerant flows through both the first fixed orifice valves314and the second fixed orifice valves316. In the second mode, the control valve318is closed and the refrigerant does not flow through the second fixed orifice valve316. All refrigerant flows through the first fixed orifice valve314.

As discussed with reference toFIG. 4, the expansion valve184or expansion sub-system312receives a high-pressure refrigerant and releases low-pressure refrigerant. This pressure drop cools the refrigerant. Larger changes in pressure (ΔP) cause larger changes in temperature (ΔT). In the second mode (i.e., with control valve318closed), the pressure drop through the expansion sub-system312will be higher than in the first mode providing a lower evaporator pressure and associated lower evaporator temperature. The effect on heat transfer of the increased temperature differential between the refrigerant and the contents of a pod in the evaporator108is offset to some extent by the fact that this lower pressure refrigerant is less dense. Since the compressor moves a fixed volume of refrigerant each compression cycle, the mass flow per cycle is reduced, which lowers heat transfer. In the second mode of operation, there is a big temperature difference between the pod and evaporator, requiring large heat transfer, which increases the amount of mass flow needed.

During initial operation, the refrigeration system310is in the first mode. The control valve318is open and the refrigerant flows through both the first fixed orifice valve314and second fixed orifice valve316. This results in the evaporator operating at around a temperature of −20° C. to −10° C. At this temperature, the cooling system provides more cooling capacity than it can at lower temperatures by taking advantage of the higher density refrigerant passing through the evaporator.

The pod150is inserted into the evaporator108around room temperature (e.g., 22° C.). The initial difference in temperature between the evaporator108and the pod150is high. As a result, the heat transfers rapidly from the pod150to the evaporator108. The difference between the temperature of the pod150and the evaporator108decreases as the pod150cools and the transfer of heat from the pod150to the evaporator108also slows. At this point, the system310enters the second mode and the control valve318closes. The refrigerant flows only through the first fixed orifice valve314and the ΔP between the refrigerant entering the first fixed orifice valve314and exiting the first fixed orifice valve314increases. The ΔT also increases resulting in a colder evaporator108with temperatures of approximately −15° C. to −30° C. This reduces the cooling capacity of the system, but increases the temperature difference between the pod and nest, which allows for quick final freezing of the ice cream. In the second mode activated when the temperature difference between the pod and evaporator reduces to the point of impacting heat transfer, the lower refrigerant temperature augments the overall heat transfer even through less mass is flowing in the system.

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

The configuration of the refrigeration system310increases temperature control, which can reduce freezing time and reduce the required compressor output. The reduction in required compressor output allows for a reduction in the size of the compressor.

In some refrigeration systems, the expansion sub-system includes more than two valves. The multi-valve sub-systems can have more than two modes, further increasing temperature control.

In some refrigeration systems use other types of valves such as, for example, thermostatic expansion valves and electronic expansion valves. Both thermostatic expansion valves and electronic expansion valves can adapt the orifice size based on various loads and operating conditions. For example, the thermostatic expansion valves sense the evaporator outlet temperature of the refrigerant and adjusts flow through the thermostatic expansion valve to maintain predetermined or desired operating conditions. The electronic expansion valves are electrically actuated to adapt the orifice size based on evaporator outlet temperature and electronic signals from a control unit371.

FIG. 13is a schematic of a refrigeration system320that includes a refrigerant line322that pre-chills a tank324of water prior to entering the evaporator108. The refrigeration system320is substantially similar to the refrigeration system109. However, the refrigeration system320includes the pre-chilling line322and omits the first bypass line188and the second bypass line190that are part of the refrigeration system109. Some systems include the first bypass line, the second bypass line, and the pre-chilling line.

The refrigeration system320is used in machines include the water tank324. Machines with water tanks inject fluid into the pod during mixing, for example, to dissolve dry ingredients or dilute the contents of the pod. Chilled water freezes more quickly than hot or room temperature water.

In use, a valve326is operated to route refrigerant through pre-chilling to route refrigerant exiting the expansion valve184through the pre-chilling line322. The cold, low-pressure refrigerant flows through the pre-chilling line322that is partially or fully disposed in the water tank324. If the water tank324is filled with water, the pre-chilling line322is partially or fully submerged in the water. The refrigerant cools the water in the water tank324and exits the pre-chilling line322. The refrigerant then enters the evaporator108to cool the evaporator108.

FIG. 14is a schematic of a refrigeration system328that includes a thermal mass330disposed between the compressor186and the condenser180. The refrigeration system328is substantially similar to the refrigeration system109. However, the refrigeration system328includes the thermal mass330. The refrigeration system328does not include the first bypass line188and the second bypass line190that are part of the refrigeration system109. Some systems include the first bypass line, the second bypass line, and the thermal mass330.

The thermal mass may be, for example, ethylene glycol and water mixture, saltwater, paraffin wax (alkanes) or pure water. In some machines, the thermal mass330is disposed between the condenser180and heat exchanger182.

The thermal mass330stores thermal energy and releases thermal energy at a later time. When disposed on between the compressor186and the condenser180, the thermal mass330stores heat emitted from the refrigerant. At this point in the cycle, the refrigerant is a high-pressure vapor. The condenser180isothermally releases heat from the high-pressure vapor to produce a high-pressure liquid. Precooling the vapor refrigerant with the thermal mass330reduces the load of the compressor186. When the machine100powers down, the thermal mass330releases heat into the environment and reaches an equilibrium at ambient temperatures.

Some systems include both the second bypass line and the thermal mass. The second bypass line redirects refrigerant from the thermal mass, idling the refrigeration system. During this idling period, the thermal mass releases heat from previous cycles into the environment.

FIG. 15is a schematic of a refrigeration system332that includes a pressure vessel334, a first control valve336, and a second control valve338. The pressure vessel334can act as pressure reservoir that enables rapid startup of the system and decreases the time required to cool (e.g., to freezing) contents of a pod in the evaporator108. The refrigeration system332is substantially similar to the refrigeration system109. However, the refrigeration system332includes the pressure vessel334, the first control valve336, and the second control valve338. The refrigeration system332further does not include the first bypass line188and the second bypass line190that are part of the refrigeration system109. Some systems include the first bypass line, the second bypass line, the pressure vessel334, the first control valve336, and the second control valve338.

The first control valve336is disposed between the compressor186and the condenser180. The second control valve338is disposed between the heat exchanger182and the expansion valve184. The pressure vessel334is disposed between the condenser180and the heat exchanger182. The refrigerant exits the compressor186at a high-pressure and maintains that high-pressure until the liquid refrigerant is released by the expansion valve184. The system332controls the position of the valves336,338(e.g., open or closed) based on the desired outcome.

During normal operation of the system332(e.g., when cooling pods), both the first control valve336and the second control valve338are open. Prior to idling, the second control valve338closes and the first control valve336remains open. The compressor186continues to run for a short time, for example, 1-5 seconds, before the first control valve336closes. After the first control valve336closes, the compressor shuts down.

When the system332is reactivated (e.g., to produce a serving of a cooled food or drink), the compressor186restarts, the first control valve336opens, and the second control valve338opens. Because high-pressure fluid is already present in the pressure vessel334, high-pressure refrigerant flows through the expansion valve184with the pressure drop cooling the refrigerant. This approach decreases the time required to cool the contents of a pod relative to refrigeration systems that allow to system pressures to return to ambient conditions when shutting down. If the system is at ambient conditions, no pressure drop occurs across the expansion valve initially when restarting the system. This approach has demonstrated to decrease the time required to cool the contents of a 8-ounce pod from room temperature to freezing to less than 90 seconds. The refrigeration system332is able to cool the refrigerant quickly or instantaneously when the system332initiates or boots up, for example prior to the insertion of a pod150.

FIG. 16is a schematic of a refrigeration system340that includes a thermoelectric module342. The refrigeration system340is substantially similar to the refrigeration system109. However, does not include the first bypass line188and the second bypass line190that are part of the refrigeration system109. Some systems include the first bypass line, the second bypass line, and thermoelectric module342.

Thermoelectric module342is a cooling element disposed between the condenser180and the heat exchanger182. The thermoelectric module342cools the refrigerant that exits the condenser180prior to transferring heat to the refrigerant vapor exiting the evaporator108in the heat exchanger182. Cooling the liquid refrigerant prior to expansion increases the cooling capacity of the system340and reduce the required compressor output. The reduction in required compressor output reduces the size of the compressor needed.

FIG. 17is a schematic of a refrigeration system344that includes a thermal battery346, a first battery bypass valve348, and a second battery bypass valve350. The refrigeration system344is substantially similar to the refrigeration system109but does not include the first bypass line188that is part of the refrigeration system109. Some systems with the thermal battery346and associated valves also includes the first bypass line.

The thermal battery346has a first portion352that is disposed between the heat exchanger182and the expansion valve184. The first battery bypass valve348is disposed on a first branch line354that bypasses the first portion352of the thermal battery346. When the first battery bypass valve348is open, a majority or all the refrigerant flows through the first branch line354. The thermal battery346has a high pressure drop. The refrigerant primarily flows through the branch line354because the branch line354has a comparatively low pressure drop to the thermal battery346. When the first battery bypass valve348is closed, the refrigerant flows through the first portion352of the thermal battery346.

The thermal battery346has a second portion356, thermally connected to the first portion352, that is disposed between the evaporator108and the heat exchanger182. The second battery bypass valve350is disposed on a second branch line358that bypasses the second portion356of the thermal battery346. When the second battery bypass valve350is open a majority or all of the refrigerant flows through the second branch line358. The thermal battery346has a high pressure drop. The refrigerant primarily flows through the branch line358because the branch line358has a comparatively low pressure drop to the thermal battery346. When the second battery bypass valve350is closed, the refrigerant flows through the second portion356of the thermal battery346.

The thermal battery346includes a thermal material that retains heat. The thermal battery346includes a reservoir360with a phase change material (e.g., paraffin) receives heat or emits heat, depending on the position of the first battery bypass valve348and the second battery bypass valve350. The thermal battery346is described as using paraffin as an example of a phase change material. Some thermal batteries include other materials that retain heat or expend heat, for example ethylene glycol and water mixture, saltwater or pure water.

The thermal battery346emits heat from its second portion356to the refrigerant when the first battery bypass valve348is open and the second battery bypass valve350is closed. If the paraffin is warm or melted, the cold refrigerant will chill and solidify the paraffin in the reservoir360. By heating the low-pressure refrigerant, the thermal battery reducing the likelihood that liquid refrigerant will flow into the compressor.

The thermal battery346receives heat at the first portion352from the refrigerant when the first battery bypass valve348is closed and the second battery bypass valve350is open. If the wax is solidified, the hot liquid refrigerant will heat and melt the wax in the wax reservoir360. If the wax is liquid, the hot refrigerant will continue to heat the liquid wax in the wax reservoir360.

On activation of the system344and during the cooling cycle, both the first battery bypass valve348and the second battery bypass valve350are open and little to no refrigerant flows interacts with the thermal battery346. At the end of the cooling cycle, the second battery bypass valve350closes and the reservoir360cools due to the cold, low-pressure refrigerant. As the next cycle begins with a cooled battery, the second battery bypass valve350opens, and the first battery bypass valve348closes. The first portion352of the thermal battery346then pre-cools the hot liquid refrigerant exiting the condenser180via the heat exchanger182.

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

FIG. 18Ais top view of an evaporator cover127andFIG. 18Bis a top view of the body of the evaporator108. The body of the evaporator108defines the channels366through which refrigerant flows to cool the evaporator108. The channels366are open at a lip367, as shown inFIG. 18B, of the evaporator108. The channels366are also open at the opposite end of the evaporator108with a similarly configured lip.

The cover127includes multiple recesses174that align with four adjacent channels366of the evaporator108when the cover127is attached to the body of the evaporator108. Some covers include recesses that align with other numbers of adjacent channels. The recesses174act as manifolds fluidly connect the adjacent channels366. The cover127on the opposite ends of the body of the evaporator are offset so that the two covers127and the body of the evaporator108together define a serpentine flow path through the evaporator108.

The cover127has an inlet370and an outlet372that fluidly connects the evaporator108to the refrigeration system109. Refrigerant flows through the inlet370, through the channels defined by recesses in the body of the evaporator108and the cover127, and exits the evaporator108through the outlet372. The refrigerant enters the inlet370as a cold fluid at a first temperature. As the refrigerant flows through the flow path368, the refrigerant warms and evaporates due to the heat received by the evaporator108from the pod150. The pod150freezes due to this heat transfer. To maintain a constant flow speed, the inlet370is about 0.25 inches in diameter and the outlet372is about 0.31 inches in diameter.

The living hinge132defines a connecting channel373that fluidly connects channels in the first portion128of the evaporator108to channels366in the second portion130of the evaporator108. The connecting channel373is defined within the evaporator108near the lip367of the evaporator108. In some evaporators, the lip of the evaporator defines a groove and the lid defines a corresponding groove so that the connecting channel is formed between the groove of the lid and the groove of the evaporator, when the lid and evaporator engage. Some connecting channel are defined within the cover127. This configuration defines the continuous flow path368from the inlet370to the outlet372in which channels366extend parallel to the axis369and flow fluid parallel to the axis369.

In some evaporators, the channels366connect within the evaporator at the opposite end from the lip367, to form a “U” shape. When assembled, the cover127is disposed on the lip367of the evaporator108. The channels366are a series of unconnected “U” shaped units. In each unit, a first channel flows the refrigerant in a first direction and a second channel flows the fluid in a second direction, opposite the first direction.

The channels366extend parallel to an axis369of 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.

FIGS. 19A and 19Bare perspective views of an evaporator380without and with, respectively, its cover127. The evaporator380inFIGS. 19A and 19Boperates similarly to the evaporator108described inFIGS. 18A-18E. However, the evaporator380includes recesses382that fluidly connect the second channel366bof a unit371to a first channel366aof a different unit371. The cover384is substantially similar to the cover127. However, the cover384is flat rather than recessed on the surface that abuts the lip367, and includes multiple inlets and outlets, rather than a single inlet and a single outlet. The cover384includes a first inlet388on the first portion128, a first outlet390on the first portion128, a second inlet392on the second portion130, and a second outlet394on the second portion. The first inlet388and first outlet390are fluidly connected to form a first flow path396on the first portion128. The second inlet392and second outlet394fluidly connect to form a second flow path398on the second portion130. This configuration forms two flow paths396,398that flow refrigerant in parallel and does not use a hinge connector. To maintain flow speed, the diameters of the flow paths396,398are reduced such that the divided flow paths have a similar flow area to the originating flow path.

When the cover384engages the evaporator380, the recesses382are closed and the evaporator380and cover384form the flow paths396,398.

In the previously described evaporators, the units371have “One-up/One-down” configurations. In some evaporators, the units define “Two-Up/Two-Down” or “Three-Up/Three-Down” configurations. This can maintain proper flow speeds while minimizing the pressure drop within evaporator. Different flow path arrangements are needed for different compressors and different cooling tasks. The number of parallel flow paths can be increased for larger compressors and cooling loads and be reduced for smaller requirements.

FIGS. 20A-20Dare schematic views of flow paths formed by the channels of the evaporator and recesses of its cover127.FIGS. 20A and 20Bare views of the channels defined within an evaporator.FIGS. 20C and 20Dare perspective views of an evaporator and its cover127.

FIG. 20Ais a flow path402that increases the number of channels400as the refrigerant evaporates. The refrigerant enters the inlet and flows through one or more single channels400a. At the refrigerant evaporates, it expands in volume and begins to move faster. The vapor may expand about 50-70 times in specific volume. To slow the mixed-phase refrigerant within the evaporator108, the flow path402branches into two parallel channels400bthat connect at the recesses374and within the evaporator108at a turning point306. As the refrigerant evaporates more, the flow path402branches again into three parallel channels400cthat connect at the recesses374and within the evaporator108at the turning point306. In some evaporators, the “Two-Up/Two-Down” configuration is maintained for multiple units. In some evaporators, the “Three-Up/Three-Down” configuration is maintained for multiple units. In some evaporators, the flow path increase to a “Four-Up/Four-Down” or “Five-Up/Five-Down” configuration. Increasing the number of channels throughout the evaporator increases performance early in the evaporating process while limiting high velocity/pressure drop towards the outlet of the evaporator.

FIG. 20Bis a schematic of the flow path402with a ramped recess408in the cover127that acts as a manifold. The ramped recess408has a smoothly increasing and decreasing cross-sectional area that helps maintains the flow speed of refrigerant flowing through manifold. A ramped cross section recess in the cover would help maintain flow velocities and also reduce pressure drop and flow separation of liquid and gas refrigerant due to low flow velocity areas.

FIG. 20Cshows a flow path420that includes a first manifold at the bottom of the evaporator108and multiple branches424extending towards the cover127from the first manifold422. The first manifold422connects to the inlet370. The branches424fluidly connect to a second manifold426at the top of the evaporator108. The second manifold426fluidly connects to the outlet372.

The refrigerant flows from the inlet through the first manifold422, up the branches424, and through the second manifold426to the outlet372. Vapor is less dense that the liquid and tends to rise to the top. This preferential flow direction can create unpredictable flow and performance when flow direction is downward. This configuration can increase thermal performance of the evaporator108by flowing refrigerant the in the same direction as the buoyancy force present when the refrigerant is in vapor form.

FIG. 20Dshows a flow path430that winds around the evaporator108. The flow path430is a spiral that follows the outer diameter of the evaporator108. This configuration increases surface area and reduces pressure drop by reducing or eliminating tight turns in the flow path430. In some evaporators, multiple hinge connectors are used to connect the first portion of the evaporator and the second portion of the evaporator when the flow path extends across the first and second portion Some flow paths define a serpentine passage on the first portion and a serpentine passage on the second portion that are connected by a “transit passage” that spans the hinge.

FIGS. 21A-21Care views of the pod150and an evaporator438with a closing mechanism440.FIG. 21Ais a perspective view of the evaporator438and pod150.FIG. 21Bis a cross-sectional view of the pod150and the evaporator438.FIG. 21Cis a top view of the pod150and the evaporator438.

The closing mechanism440includes biasing elements (e.g. springs) that connects the first portion128of the evaporator438to the second portion130of the evaporator438. The closing mechanism440also includes a circumferential cable441that extends around the outer diameter of the evaporator. The cable is tightened close the pod and loosened to open the evaporator.

The biasing element in evaporator438includes a first and second spring442,444that bias the first portion128and the second portion130away from each other. The living hinge132facilitates the movement of the first and second portions128,130such that the first and second portions128,130rotation about the hinge132due to the biasing force of the springs442,444. In this configuration, the evaporator438is in the open position and a small gap446forms between the first and second portions128,130. The evaporator438is in the open position when the cover127is in the open position. In some machines, the position of the evaporator is independent from the position of the lid. In the open position, a small air gap exists between the evaporator438and the pod150.

The evaporator438has a closed position in which the airgap between the evaporator438and the pod150is eliminated to promote heat transfer. In some evaporators, the air gap is simply reduced. In the closed position, the gap446is also eliminated. In some evaporators, the gap is reduced rather than eliminated. To move from the open position to the closed position, the closing mechanism440applies a force in the direction of arrows448to overcome the biasing force of the first and second springs442,444.

The closing mechanism produces a force within the range of 10 to 1500 lbs. To prevent crushing of the pod150, the internal pressure of the pod150is preferably equal to or greater than the force produced by the closing mechanism440.

The closing mechanism440may be, for example, an electromechanical actuator, a pulley system, a lever, projections on the lid, a ball screw, a solenoid, or a mechanical latch.

FIGS. 22A and 22Bare, respectively, side and front views of an evaporator108with a closing mechanism440that includes two bolts450inside springs456. The bolts450bias the bar466away from flanges464. Optionally, a cable468is received in a hole defined in the bar466and extends around the evaporator108.

FIG. 23Ashows an evaporator500that can be produced primarily by extrusion. The evaporator500has a body510with two end caps512. The body510and the end caps are produced separately and then assembled.

FIGS. 23B and 23Cillustrate production of the body510. The evaporator body510is produced by low cost extrusion. The body is extruded with the channels514defined in the body510(seeFIG. 23B). Each end of the body510is machined to provide a shoulder516that mates with an end cap (seeFIG. 23C). A wall518extends beyond the shoulder516.

FIGS. 23D and 23Eare perspective views of an end cap512. The end caps512can be forged or machined. The end caps512provide the mounting, inlet/outlet, and closure features of the evaporator500. The end cap512has a sidewall520and an end wall522.

The end cap512has multiple bosses524extending outward from the sidewall520. The bosses524can be used for mounting and handling the end cap512and, after assembly with the body510, the evaporator500. A port526extends through the sidewall520. The port526of the end cap512on one end of the evaporator500is used as an inlet and the port526of the end cap512on the other end of the evaporator500is used as an outlet.

FIG. 23Fillustrates assembly of the evaporator500. The end cap512is mounted on the shoulder516on one end of the body510. After mounting, the joints between the evaporator body510and the end caps512are easily accessible. This configuration facilitates use of used for laser welding, vacuum brazing, friction stir welding or TIG welding to attach the end caps512to the evaporator body510.

FIGS. 23G and 23Hillustrate the relationship between the body510and the end cap512after assembly. When assembled with the body510, the sidewall520and the end wall522of the end cap and the wall518of the body510define a chamber that acts as a manifold connecting the channels defined in the body510of the evaporator500. The end cap512is shown with “hollow” configuration for evaporating up with all passages in parallel but it could be adapted for a multipath design with multiple 180 degree turnarounds.

FIG. 24shows a configuration of the evaporator500that incorporates an orifice plate530. The orifice plate530is disposed between the body510and the end cap512. The orifice plate530defines multiple orifices532that, after assembly, are aligned with the channels514in the body510. The orifice plate can be used to distribute flow evenly to the channels514by accumulating refrigerant prior to the orifice plate530and injecting liquid-gas mixture equally to the channels524. In some cases, the orifices are identical in size. In some cases, where there is likely to be maldistribution of flow between passages514, the orifices can be different sizes.

FIG. 25is a perspective view of an embodiment of the evaporator380described with reference toFIGS. 19A and 19Bwith an internal surface470made of a different material than the remainder of the evaporator380. The inner surface470is mainly or completely formed of copper. Copper has a higher thermal conductivity (approximately 391 W/mK) than aluminum that has a thermal conductivity of 180 W/mK. A high thermal conductivity moves heat quickly and efficiently from the pod to the refrigerant. A material with low thermal conductivity pass heat slower and with less efficiency. The tendency of a component to act as a heat sink is a function of both its thermal conductivity and its mass. Table 2 lists the thermal conductivity and density of a variety of materials.

FIGS. 26A-26Care schematic views of claddings. These claddings can be used in an evaporator that includes both aluminum and copper.FIG. 26Ashows an overlay cladding490.FIG. 26Bshows an inlay clad492.FIG. 26Cshows an edge clad495. Cladding techniques as shown inFIGS. 26A-26Care applied to the inner surface of the evaporator. Different clad techniques can increase heat transfer and spread heat out, due to the high thermal conductivity of copper.

FIG. 27is an exemplary view of a material480that includes microchannels482. When the material480is used to make, for example, evaporators, refrigerant flows through the microchannels482. The material480can be bent to form an evaporator that cools the pod150. The material480is permanently deformed into a cylindrical shape to create a round evaporator. Such an evaporator has a high surface area which increases evaporator performance while keep costs low.

FIGS. 28A-28Cshow a rotary compressor550that is used in some some refrigeration systems instead of the reciprocating compressor186previously described. The compressor550includes a housing552with an interior wall553that defines an interior cavity554. An inlet556and an outlet558fluidly connect the interior cavity554of the compressor550to other components of the refrigeration system. A pressure valve559releases fluid when the fluid reaches a predetermined pressure. A roller560with a circular cross section, is rotationally and axially constrained to a rod562that extends through a bottom section of the housing552. Some rollers have ellipse shaped or gear shaped cross sections. The rod562is attached off center from the circular cross section of the roller560. The rod562and roller560rotate relative to the housing557using a motor (not shown). The roller560is arranged in the cavity554such that an edge564of the roller560extends to the interior wall553of the housing. In this configuration, the roller560forms a seal with the housing557. The edge564of the roller560maintains contact on the wall553as the rod562and the roller560rotate within the interior cavity554. The housing557includes a notched area566for containing a compressed spring568. The spring568abuts the roller560. A rubber member570surrounds a portion of the spring568to form a seal that extends from the wall553to the roller560. The spring568expands and contracts as the roller560rotates within the interior cavity554, to maintain the seal.

InFIG. 28A, the compressor550is in a first state. InFIG. 28B, the rotary compressor550is in a second state and inFIG. 28C, the rotary compressor550is in a third state. The rotary compressor550moves 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 roller560receives low-pressure pressure cool vapor from the evaporator108via the inlet556. The seal between the contact edge564and the wall553and the seal between the member570and the roller560define an intake chamber572and a pressurizing chamber574. In some rotary compressors, additional seals are formed that increase the number of chambers. The roller560rotates to compress and pressurize vapor in the pressurizing chamber574and to draw in vapor to intake chamber572from the inlet556. In the second state, shown inFIG. 28B, the roller560continues to rotate counterclockwise and increase the pressure of the vapor in the pressurizing chamber574until the pressure valve559releases the high-pressure vapor out of the compressor550. The intake chamber continues to receive low-pressure vapor from the inlet556. The compressed spring568extends into the interior cavity554as the roller560rotates, to maintain connection between the member570and the roller560. In the third state, shown inFIG. 28C, the high-pressure vapor has been expelled from the pressurizing chamber574and the spring568is compressed into the notched area566. In this state, only one seal is formed between the contact edge564and the member570. For a brief period in the cycle the number of chambers is reduced by one. At this state in the compressor550, the intake chamber572becomes the pressurizing chamber574. The intake chamber572is reformed when the contact edge564passes the member570and two seals are formed, one by the member570and roller560and the other by the contact edge564and the wall553.

The rotary compressor performs the same thermal duty as the reciprocating compressor at a much lower weight and smaller size. The rotary compressor has a weight of about 10 to about 18 lbs. The rotary compressor has a displacement of refrigerant of about 4 cc to about 8 cc. The rotary compressor has a performance vs. weight ratio of about 0.3 cc/lb to about 0.5 cc/lb.

A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure invention. Accordingly, other embodiments are within the scope of the following claims.