Abstract:
A foamed beverage system for creating foamed beverages from a powder, a liquid, and air. The foamed beverage system may include a mixing chamber having a mixing zone and a pressurized zone. An impeller is positioned between the mixing zone and the pressurized zone. The powder and the liquid are added to the mixing chamber and the air is entrained within the mixture of the powder and the liquid within the pressurized zone.

Description:
TECHNICAL FIELD 
       [0001]    The present application relates generally a beverage dispenser system and more particularly relates to dispenser systems and methods for producing highly foamed milk from milk powder and the like. 
       BACKGROUND OF THE INVENTION 
       [0002]    Hot beverages such a cappuccinos and lattés are becoming increasingly popular. In addition to traditional coffee outlets and restaurants, retail outlets from fast food restaurants to convenient stores are providing these and other types hot beverages to their customers. Likewise, various types of vending machines and office dispensers are available. Consumers often desire freshly made foam milk in their hot beverage. The foamed milk generally is of higher quality if it is made fresh for each customer. 
         [0003]    Generally described, foamed milk may be produced from steam, milk, and air. Foamed milk also can be made from milk powder by combining the powder with hot water and air. The use of milk powder often is preferred given its longer shelf life and ease of use. The milk powder, the water, and the air, however, need to be sufficiently mixed. Insufficient mixing may result in some of the powder not being converted to foam and possibly an off taste. 
         [0004]    There is a desire, therefore, for a foamed milk dispenser that can produce foamed milk from milk powder in an efficient, high quality, and high-speed manner to consumers in individual servings or otherwise. The foamed milk dispenser preferably should be easy to use, easy to maintain, and be competitive in terms of costs. 
       SUMMARY OF THE INVENTION 
       [0005]    The present application thus describes a foamed beverage system for creating foamed beverages from a powder, a liquid, and air. The foamed beverage system may include a mixing chamber having a mixing zone and a pressurized zone. An impeller is positioned between the mixing zone and the pressurized zone. The powder and the liquid are added to the mixing chamber and the air is entrained within the mixture of the powder and the liquid within the pressurized zone. 
         [0006]    The pressurized zone may be pressurized to about five (5) to about fifteen (15) pounds per square inch (about 0.34 to about one (1) bar). The mixing chamber may include a liquid inlet and a powder inlet positioned about the mixing zone and an air inlet positioned about the pressurized zone. The pressurized zone may include a tapered wall. The foamed beverage system further may include an expansion orifice positioned adjacent to the pressurized zone and an expansion nozzle adjacent to the expansion orifice. 
         [0007]    The present application further describes a method of mixing a powder, a liquid and air to make a foamed beverage. The method may include the steps of mixing the powder and the liquid to form a powder and liquid mixture, pressurizing the powder and liquid mixture, entraining air into the powder and liquid mixture to make a entrained mixture, and forcing the entrained mixture through an expansion orifice to make the foamed milk. 
         [0008]    The pressurizing step may include creating a pressurized area via an impeller. The impeller may rotate at about 50 to about 500 revolutions per minute. The forcing the entrained mixture step may include creating a Venturi effect via the expansion orifice. The method further may include the step of pressurizing the air. 
         [0009]    The present application further describes a foamed beverage system. The foamed beverage system may include a liquid system for providing water, a powder system for providing powder, an air system for providing air, and a chamber for mixing the powder, the liquid, and the air. The chamber may include an impeller and an expansion orifice. 
         [0010]    The pressurized zone may be pressurized to about five (5) to about fifteen (15) pounds per square inch (about 0.34 to about one (1) bar). The chamber may include a mixing zone and a pressurized zone with the impeller positioned in between. The mixing zone may include a liquid inlet and a powder inlet. The pressurized zone may include an air inlet and a tapered wall leading to the expansion orifice. The chamber may include an expansion nozzle adjacent to the expansion orifice. The air system may include an air pump so as to pressurize the air. 
         [0011]    These and other features of the present application will become apparent to one or ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a schematic view of the foamed milk system as is described herein. 
           [0013]      FIG. 2  is a side cross-sectional view of the mixing nozzle of the foamed milk system of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring now to the drawings in which like numerals indicate like elements throughout the several views,  FIGS. 1 and 2  show a foamed milk system  100  as is described herein. The foamed milk system  100  may include a hot water system  110 . The hot water system  110  may include a water reservoir  120  with a volume of hot water  130  therein. The water reservoir  120  may be heated via conventional means. The hot water reservoir  120  may be fed via a pump  140  or other types of conventional means. Although the hot water reservoir  120  is shown, any method of producing hot water may be used herein. 
         [0015]    The foamed milk system  100  may include a milk powder system  150 . The milk powder system  150  may include a milk powder hopper  160  with an amount of milk powder  170  positioned therein. Powdered milk is typically made by spray drying nonfat skim milk. Pressurized milk is first concentrated in an evaporator to about fifty percent (50%) milk solids. The resulting concentrated milk is sprayed into a heated chamber where the water almost instantly evaporates, leaving behind fine particles of powdered milk solids. Alternatively, the milk can be dried by drum drying. Milk is applied as a thin film to the surface of a heated drum, and the dried milk solids are then scraped off with a knife. Yet another process is the use of freeze drying. Freeze drying has the advantage of preserving many nutrients in milk compared to drum drying. Although the use of the milk powder  170  is described herein, any type of powdered or granular substance may be used. For example, chocolate, tea, soy and other substances may be used herein. 
         [0016]    The milk powder  170  may be fed from the hopper  160  via an auger drive or via similar types of transfer methods. The milk powder  170  also may be feed via gravity or in combination with a transport device and gravity. 
         [0017]    The foamed milk system  100  further may include a pressurized air system  180 . The pressurized air system  180  may provide pressurized air  190  via an air pump  200  as will be described in more detail below. The pressurized air may be between about two (2) to about forty (40) psi (about 0.14 to about 2.8 bar) depending upon the desired flow rate. Any desired pressure or flow rate may be used herein. The air pump  200  may be of conventional design. 
         [0018]    The foamed milk system  100  further includes a mixing chamber  210 . The mixing chamber  210  may be made out of conventional types of substantially non-corrosive materials. The mixing chamber  210  may have an upper mixing zone  220 . The upper mixing zone  220  receives a supply of the hot water  130  from the hot water system  110  via a water inlet  135  and the milk powder  170  from the milk powder system  150  via a milk powder inlet  155 . 
         [0019]    An impeller  230  is positioned about the bottom of the upper mixing zone  220 . The impeller  230  may be a conventional rotating device with a number of blades  240  attached to a shaft  250 . Likewise, by the use of the term “impeller”, we refer to any type of rotating structure. An impeller motor  260  may drive the impeller  230 . The impeller motor  260  may be any type of conventional drive device so as to rotate the shaft  250 . The impeller  230  may rotate at about fifty (50) to about 500 revolutions per minute or so. Any speed may be used herein. The distance between the blades  240  and the wall of the mixing chamber  210  preferably is minimized so as to maintain a pressure differential therethrough. 
         [0020]    The mixing chamber  210  further includes a lower pressurized zone  270 . The lower pressurized zone  270  may have an internal pressure of about five (5) to about fifteen (15) pounds per square inch (about 0.34 to about one (1) bar) or so. Any desired pressure may be used herein. The lower pressurized zone  270  decreases in diameter as compared to the upper mixing zone  220 . For example, if the upper mixing zone  220  has a diameter of about two (2) to about four (4) inches (about 50 to about 100 millimeters) or so, the lower pressurized zone may start with a similar diameter and then taper to about 0.8 to about one (1) inches (about 20 to about 25 millimeters) or so. Any dimensions may be used herein. The lower pressurized zone  270  also has an air inlet  280  in communication with the pressurized air system  180  for the insertion of the pressurized air  190 . 
         [0021]    Positioned beneath the lower pressurized zone  170  may be an expansion orifice  290 . Based upon the dimensions described above, the expansion orifice  290  may have a diameter of about 0.2 to about 0.8 inches (about five (5) to about twenty (20) millimeters) or so. Any dimensions may be used herein. The pressure of the mixture passing therethrough will drop across the expansion orifice  290  so as to promote the foaming of the milk. The expansion orifice  290  then leads to an expansion nozzle  300  of increasing diameter. 
         [0022]    The hot water system  110 , the milk powder system  150 , the pressurized air system  180 , and the mixing chamber  210  may be connected by a number of lines  310 . The lines  310  may be made out of rubber, silicon, stainless steel, other types metals, plastics, or other types of substantially non-corrosive materials. The materials used preferably are food grade. One or more of the lines  310  may be disposable. 
         [0023]    In use, the hot water  130  from the hot water system  110  and the milk powder  170  from the milk powder system  150  are mixed within the upper mixing zone  220  of the mixing chamber  210 . The hot water  130  and the milk powder  170  are mixed together with the aid of the impeller  230  to form a product stream. The hot water  130  and the milk powder  170  within the product stream continue mixing as they pass through the impeller  230  into the lower pressurized zone  270 . 
         [0024]    The pressurized air  190  from the pressurized air system  180  is injected into the lower pressurized zone  270  via the air inlet  280 . As described above, the use of the impeller  230  creates pressure within the lower pressurized zone  270  such that the pressurized air  190  becomes entrained into the resultant product stream as the pressurized air passes through the air inlet  280 . The tapered of the lower pressurized zone  270  leading to the expansion orifice  290  also increases the speed of the product stream and creates a Venturi effect therethrough. Specifically, lower pressure behind the impeller  230  pulls more of the product stream towards the blades  240  with increasing speed. The resultant mixture is then expanded through the orifice  290  so as to create a foamed milk product  320 . 
         [0025]    Through the use of the lower pressurized zone  270 , the impeller  230 , and the expansion orifice  290 , the pressurized air is thoroughly mixed and entrained within the product stream so as to create a higher quality foamed milk product  320 . The foamed milk system  100  as a whole is more resistant to plugging as the impeller  230  drives the product stream through the mixing chamber  210  rather than simply relying on a gravity feed. 
         [0026]    It should be apparent that the foregoing only relates to the preferred embodiments of the present application and that numerous changes and modification may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.