1. Technical Field
The present disclosure generally relates to refrigeration systems and, more particularly, to apparatus for freezing and dispensing semi-frozen products.
2. Description of the Related Art
Semi-frozen product dispensers employ refrigeration systems to freeze the product dispensed thereby. By way of background, a refrigeration system uses a refrigeration cycle which is employed in refrigerators, heat pumps and air conditioners. The refrigeration system becomes a heat pump when it is used to produce a heat flow into or out of a building. When it causes a heat flow out of the building it is then also called an air conditioner. As shown in the background diagram of
COPcooling=enthalpy change at evaporator/enthalpy change at the compressor
For the following equations, h represents enthalpy and the letter following h represents the refrigerant state on
COPcooling=(hd−hb)/(he−hd)
If the desired output is heating, then:
COPheating=enthalpy change at condenser/enthalpy change at compressor
COPheating=(he−ha)/(he−hd)
If the desired output is both cooling and heating, then:
COPcooling and heating=(hd−hb+he−ha)/(he−hd)
It can be seen that the highest COP may be obtained from the COPcooling and heating equation.
Semi-frozen product dispensers may dispense various types of food stuffs, such as soft-service ice cream, yogurt, custard and other semi-frozen food products, as well as semi-frozen drinks, sometimes referred to as slushes. The dispensers typically include a freezing cylinder through which the product is dispensed. The freezing cylinder, also referred to as a barrel, defines a longitudinally elongated freezing chamber. Typically, unfrozen liquid product mix is added to the freezing chamber at the aft end of the freezing cylinder and selectively dispensed at the forward end of the freezing cylinder through a manually operated dispensing valve. A rotating beater, typically formed by two or more helical blades driven by a drive motor at a desired rotational speed, scrapes semi-frozen mixture from the inner wall of the freezing cylinder and moves the product forwardly through the freezing chamber defined within the freezing cylinder as the product transitions from a liquid state to a semi-frozen state. The product within the freezing chamber changes from a liquid state to a semi-frozen state as heat is transferred from the product to a refrigerant flowing through an evaporator disposed about the freezing cylinder. The evaporator is operatively associated with and part of a conventional refrigeration system that also includes a compression device and a refrigerant condenser arranged in a conventional refrigerant cycle in a closed refrigerant circuit. Dispensing apparatus of this type may have a single freezing cylinder for dispensing a single flavor of product or a plurality of freezing cylinders, each housing a selected flavor of product, for dispensing each of the selected flavors and even a mix of flavors. U.S. Pat. No. 5,205,129, for example, discloses a semi-frozen food dispensing apparatus having a pair of freezing chambers.
As noted previously, heat is removed from the product within the freezing cylinder and carried away by a refrigerant circulating through an evaporator disposed about the freezing cylinder. In dispensing apparatus having more than one freezing cylinder, an evaporator is typically configured either as a tube wound around and in contact with the outside wall of the freezing cylinder or as an annular chamber from between the outside wall of the freezing cylinder and the inside wall of an outer cylinder disposed coaxially about the freezing cylinder.
Refrigerant exits the condenser primarily as vapor. The vapor is drawn through a compressor, which elevates both the temperature and pressure of the refrigerant vapor. An air heat exchanger, in combination with an air mover, is typically provided to cool the refrigerant vapor. This conventional arrangement, however, discharges heated air into the surrounding environment, thereby increases the load on any interior space HVAC system. Depending on the temperature of the vapor refrigerant, operation of the air heat exchanger may be excessive, thereby reducing the energy efficiency of the dispenser. Still further, the heated air is typically treated as a waste by-product that is simply discharged into the interior space.
In accordance with one aspect of the disclosure, a semi-frozen product dispenser is provided for at least partially freezing and dispensing a product. The dispenser may include at least one freezing barrel defining a freezing chamber configured to receive the product, an evaporator operably coupled to the freezing barrel and including a refrigerant inlet and a refrigerant outlet, and a compressor having a suction inlet in fluid communication with the evaporator outlet through a low pressure refrigerant line and a discharge outlet. A high pressure refrigerant line may extend between the compressor discharge outlet and the evaporator refrigerant inlet, and an air heat exchanger may be operatively coupled to a portion of the high pressure refrigerant line. A fluid tank may be sized to hold a predetermined volume of fluid, and a fluid heat exchanger fluidly communicates with the high pressure refrigerant line to receive heated refrigerant and is configured to transfer heat from the heated refrigerant to the volume of fluid in the fluid tank.
In accordance with another aspect of the disclosure, a semi-frozen product dispenser is disposed in an interior space for at least partially freezing and dispensing a product. The dispenser may include at least one freezing barrel defining a freezing chamber configured to receive the product. A refrigeration system may be provided that includes an evaporator operably coupled to the freezing barrel, a refrigerant inlet, and a refrigerant outlet. The refrigeration system may further include a compressor having a suction inlet in fluid communication with the evaporator outlet through a low pressure refrigerant line and a discharge outlet, a high pressure refrigerant line extending between the compressor discharge outlet and the evaporator refrigerant inlet, and an air heat exchanger operatively coupled to a portion of the high pressure refrigerant line. The dispenser may further include a water heating system having a fluid tank sized to hold a predetermined volume of fluid, and a fluid heat exchanger fluidly communicating with the high pressure refrigerant line to receive heated refrigerant and configured to transfer heat from the heated refrigerant to the volume of fluid in the fluid tank.
In accordance with yet another aspect of the disclosure, a semi-frozen product dispenser is disposed in an interior space for at least partially freezing and dispensing a product. The dispenser may include an enclosure defining a housing space, and at least one freezing barrel disposed within the housing space and defining a freezing chamber configured to receive the product. An evaporator is disposed within the housing space, operably coupled to the freezing barrel, and includes a refrigerant inlet and a refrigerant outlet. A compressor is disposed within the housing space and has a suction inlet in fluid communication with the evaporator outlet through a low pressure refrigerant line and a discharge outlet. A high pressure refrigerant line is disposed within the housing space and extends between the compressor discharge outlet and the evaporator refrigerant inlet, and an air heat exchanger is disposed within the housing space and operatively coupled to a portion of the high pressure refrigerant line, the air heat exchanger discharging heated air into the interior space. A fluid heat exchanger is disposed in the high pressure refrigerant line and defines a refrigerant path and a fluid path, the fluid heat exchanger being configured to transfer heat from refrigerant in the refrigerant path to fluid in the fluid path. The dispenser may further include a fluid tank sized to hold a predetermined volume of fluid, the tank including a tank inlet fluidly communicating with the fluid heat exchanger fluid path and a tank outlet, and a fluid pump having a pump inlet in fluid communication with the tank outlet and a pump outlet in fluid communication with the fluid heat exchanger fluid path.
These are other aspects and features of the disclosure will become more apparent upon reading the following detailed description when taken in conjunction with the accompanied drawings.
While the present disclosure is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof will be shown and described below in detail. It should be understood, however, that there is no intention to be limited to the specific embodiments disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the present disclosure.
Referring now to the drawings, and with particular reference to
In the illustrated embodiment, the dispenser 10 is disposed inside an interior space 12 and includes two freezing chambers C1 and C2 for dispensing food products of different flavors or types. The freezing chambers C1 and C2 are defined within the axially elongated cylindrical barrels 20-1 and 20-2, respectively. Although shown as a dual barrel dispenser, it is to be understood that the apparatus 10 may have only a single barrel for dispensing a single product or may have three or more barrels for dispensing a plurality of flavors or types of products. Each of the barrels 20-1, 20-2 includes an inner cylinder 30, an outer cylinder 40 circumscribing the inner cylinder 30, and an evaporator 50 formed between the inner cylinder and the outer cylinder 40. Refrigerant is supplied from a refrigeration system 60 to the evaporators 50 of the respective barrels 20-1, 20-2 for refrigerating product residing inside the respective freezing chambers C1 and C2.
A beater 22 is coaxially disposed and mounted for rotation within each of the chambers C1 and C2. Each beater 22 is driven by a drive motor 23 to rotate about the axis of its respective barrel 20-1, 20-2. In the embodiment of
The refrigeration system 60 includes a single refrigerant vapor compressor 62 driven by a compressor motor 65 operatively associated with the compressor 62, and a condenser 64 connected with the evaporators 50 in a refrigerant circuit. The compressor 62 is connected in refrigerant flow communication by high pressure outlet line 61 connected to the refrigerant inlet of the condenser 64, and the refrigeration outlet of the condenser 64 is connected through a high pressure refrigerant supply line 63 to refrigerant flow control valves 66. Each refrigerant flow control valve 66 is operatively associated with a respective one of the evaporators 50 by a refrigerant line 67. A respective refrigerant outlet of each evaporator 50 is connected through a low pressure refrigerant return line 69 and an accumulator 68 to the suction side of the compressor 62 through line 27. The refrigerant flow control valves 66 may comprise, for example, on/off solenoid valves of the type which can be rapidly cycled between open and closed positions. The valves 66 may be pulse width modulated solenoid valves, electronic motor operated valves, automatic expansion valves, or similar restriction devices.
Different products have different thermal heat transfer rates and different freezing points. Therefore, operation of the refrigeration system 60 will vary depending upon the products being supplied to the freezing chambers C1 and C2. A control system 70 may control operation of the refrigeration system 60 by controlling operation of the compressor drive motor 65, the beater motor 23, and the flow control valves 66. The control system 70 includes a programmable controller 72 having a central processing unit with associated memory and temperature sensors for sensing the temperature of the product within the chambers C1 and C2. For a more thorough discussion of the design and operation of an exemplary control system 70, reference is made to U.S. Pat. No. 5,205,129, the disclosure of which is hereby incorporated by reference.
In the depicted embodiment, each barrel 20 is equipped with a selectively operable dispensing valve 11 disposed at the forward end of the barrel 20 for receiving product form the freezing chamber. The dispensing valve system, however, may include a third dispensing valve selectively operable to dispense a mix of the two flavors or types of products present in the mixing chambers C1 and C2. The dispensing valve system may also comprise a single selectively operable valve that is selectively positionable in a first position to dispense product from chamber C1 only, a second position to dispense product from chamber C2 only, and a third position to dispense a mix of the products from both chambers C1 and C2.
Briefly, in operation, product to be frozen is supplied to each of the chambers C1 and C2 from the respective product supply 24 associated therewith from a supply tube 27 opening into the chamber at the aft end of each barrel 20-1, 20-2. The product supplies 24 are arranged to feed as required a liquid comestible product mix and generally, but not always, an edible gas, such as for example air, nitrogen, carbon dioxide, or mixtures thereof, in proportions to provide a semi-frozen food product having the desired consistency. The liquid comestible product mix may be refrigerated by suitable apparatus (not shown) to pre-cool the product mix to a preselected temperature above the freezing temperature of the product mix prior to delivery to the chambers C1 and C2. Each beater 22 rotates within its respective chamber C1, C2 to churn the product mix resident within the chamber and also move the product mix to the forward end of the chamber for delivery to the dispensing valve 11. The blades of the beaters 22 may also be designed to pass along the inner surface of the inner cylinder 30 as the beater rotates, thereby to scrape product from the inner surface of the inner cylinder 30. As the product mix churns within the chambers C1 and C2, it is chilled to the freezing point temperature to produce a semi-frozen product ready on-demand for dispensing. If gas is added to the product mix, the gas is thoroughly and uniformly dispersed throughout the product mix as the beaters rotate.
A simplified schematic of the refrigeration system 60 coupled to one freezing chamber C1 is shown in
A fluid heating system 80 for heating a fluid, such as water, is also illustrated in
As best shown in
The fluid heating system 80 may also include a pump 96 for circulating fluid through the system. In the illustrated embodiment, the pump 96 has an inlet 98 fluidly communicating with the tank cold water outlet 88 and an outlet 100. While any known pump suitable for circulating fluid may be used, the pump 96 may be configured and/or rated for use in a potable water system.
The fluid heating system 80 may further include a fluid heat exchanger 102 for transferring heat from the refrigeration system 60 to fluid in the heating system 80. In the illustrated embodiment, the fluid heat exchanger 102 includes a fluid path 101 having a fluid inlet 104 in fluid communication with the pump outlet 100 and a fluid outlet 106 in fluid communication with the tank warm water inlet 90. The fluid heat exchanger 102 may further include a refrigerant path 107 having a refrigerant inlet 110 and a refrigerant outlet 108, both of which may fluidly communicate with the high pressure line 67 of the refrigeration system 60. The fluid heat exchanger 102 may be configured to transfer heat from refrigerant in the refrigerant path 107 to fluid in the fluid path 101, thereby to preheat the water while simultaneously cooling the refrigerant. In certain applications, the fluid heat exchanger 102 may be configured and/or sized to heat water flowing therethrough by at least approximately 10 degrees. The pre-heated water then flows from the fluid heat exchanger 102 to the tank 82.
While the pump 96 is shown in
An optional temperature sensor 112 may be provided with the tank 82 to provide temperature feedback regarding the fluid in the tank 82. In certain embodiments, the temperature sensor 112 and pump 96 may be operatively coupled to the controller 72 (
The location of the fluid heat exchanger 102 may enhance operation of both the refrigeration system 60 and the heating system 80, and may be selected based on a user's desired objectives. With the fluid heat exchanger 102 positioned upstream of the air heat exchanger 64, as illustrated in
The fluid heating system 80 may be integrally housed with the refrigeration system 60, such as for new equipment, or it may be provided in modular form for retrofit applications. As schematically shown in
An alternative semi-frozen product dispenser 200 is illustrated in
As briefly noted above, the fluid heat exchanger 302 is disposed within the fluid tank 282, thereby to directly transfer heat from the heated refrigerant to the fluid in the tank 282. The fluid heat exchanger 302 may include a refrigerant line forming a heat exchange section 330 in fluid communication with the high pressure refrigerant line 267. The heat exchange section 330 is disposed in heat transfer relationship with the fluid in the tank 282, such as by being submersed in the fluid. The tank 282 may include a cold water inlet 284 fluidly communicating with a cold water source 286 and a warm water outlet 292 fluidly communicating with an auxiliary system, such as a water heater 294. This alternative embodiment does not require a pump to circulate fluid from the fluid heat exchanger 302 to the tank 282, and therefore it has been omitted. The heat exchange section 330 may be oriented to create a counterflow arrangement in which hot refrigerant enters a top of the tank 282 though inlet 290 while cooled and at least partially condensed refrigerant exits a bottom of the tank 282 through outlet 288. The dispenser 200 may operate in a manner similar to dispenser 10 described above.
It is to be understood that while the foregoing description has been given with reference to a semi-frozen product dispenser, the teachings of this disclosure can be used in conjunction with other types of refrigeration systems known to those of ordinary skill in the art to remove heat from the high pressure side of the refrigeration system and add heat to a water tank provided on the premises associated with the refrigeration system, thereby to improve the energy efficiency of the refrigeration system as well as the energy requirements of the surrounding environment.
Based on the foregoing, it can be seen that the present disclosure sets forth a dispenser for flowable products, such as but not limited to, milkshakes. The teachings of this disclosure can be employed to use waste heat from a refrigeration system in an auxiliary process to heat a fluid such as water. Such an arrangement may decrease operation of an air heat exchanger, thereby lowering the energy cost for operating the dispenser. Additionally, reduced air heat exchanger operation will reduce the amount of heat discharged into the interior space in which the dispenser is disposed, thereby lowering the heat load on the HVAC system provided with the interior space. Still further, energy costs associated with the auxiliary system, such as a water heater, are reduced due to the pre-heating of the water.
While only certain embodiments have been set forth, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims.
This is an non-provisional US patent application claiming priority under 35 USC §119(e) to U.S. Provisional Patent Application Ser. No. 61/252,828 filed on Oct. 19, 2009.
Number | Date | Country | |
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61252828 | Oct 2009 | US |