Abstract:
A cheese cooker and mixer includes a tank containing heated water. The tank has an outer cylindrical housing with an concentric inner cylindrical screen. An inlet proximate to a top of the tank provides an opening by which cheese curds are introduced within the cylindrical screen. The heated water is fed into the tank tangentially to the curvature of the cylindrical screen to create a vortex therein which aids in directing the cheese downward in the tank. After melting and forming a large mass, the cheese is extracted through an outlet proximate to a bottom of the tank. A conveyor with counter rotating augers mixes the cheese exiting the tank.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not Applicable  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable  
         BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    The present invention relates to cheese processing equipment; and more particularly to equipment which cooks and mixes the cheese prior to molding or extrusion.  
           [0005]    2. Description of the Related Art  
           [0006]    Mozzarella cheese is processed by dropping curds into a tank of hot water in which the cheese cooks. This causes the curds to melt and sink to the bottom of the tank where a large mass of relatively soft cheese forms. One or more augers at the bottom moves the cheese out of the tank and up an inclined enclosure. The augers stretch and mix the softened cheese into a homogeneous mass at a relatively uniform temperature. That homogeneous cheese mass then is expelled through an outlet into an extruder or a molding machine. U.S. Pat. No. 5,988,052 describes this type of cheese processing equipment.  
           [0007]    The water in the tank is maintained at the proper cooking temperature (e.g. 77° C.) by circulation through an external heater. Specifically, water leaves the tank through a drain at the bottom of the tank A pump draws the water from the drain and forces the liquid through a heater in which electricity or steam is used to raise the temperature of the water. The heated water then is returned to the top of the tank completing the circulation cycle.  
           [0008]    The capacity of a given cooker/mixer is determined by how much cheese can be dropped into the tank before unmelted cheese enters the output conveyor. When this occurs the cheese expelled from the auger assembly will not be fully heated and will not be properly stretched.  
           [0009]    The through put of the processing equipment also is adversely affected by stagnant water which allows clumps of cheese to matt, thereby inhibiting proper melting as the cheese descends in the tank. This allows cheese curds to float in the liquid, as the curd are too buoyant to be pressed into the augers. The tendency of the curds to float is increased when a brine solution is used in the tank to add salt to the cheese. As a consequence, the cheese maker previously had to monitor the tank and use a shovel or other implement to push the floating cheese curds downward into the augers.  
           [0010]    Thus there still exits a need for a more automated cheese cooker/mixer.  
         SUMMARY OF THE INVENTION  
         [0011]    A cheese processing apparatus has a tank for containing a liquid, such as water, that is heated to a temperature which will soften or melt cheese placed into the tank. An inlet proximate to a top of the tank is provided in order to introduce the cheese into the liquid and an outlet proximate to a bottom of the tank enables the softened cheese to be removed. A mechanism is included to create a vortex of the liquid within the tank. The rotating action of the vortex aids in directing the cheese toward the center of the tank as the cheese descends in the tank. In addition, the swirling liquid prevents the cheese from sticking to the walls of the tank.  
           [0012]    In a preferred embodiment of the cheese processing apparatus, the tank has a cylindrical inner wall formed by a screen and within which the vortex is created. The liquid is fed into the tank through a supply conduit that has an outlet aperture from which the liquid flows into the tank in a direction that produces the vortex. For example, the liquid is directed substantially tangential to the curvature of the cylindrical inner wall. A portion of the liquid flows outward through the screen of the inner wall and is exhausted via a drain opening in the tank. The liquid exhausted from the tank preferably is recycled by a pump to the supply conduit.  
           [0013]    Another aspect of the present invention is the provision of a conveyor that carries the processed cheese from the outlet of the tank. Preferably the conveyor is an auger type which mixes the cheese being conveyed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a side view of a cheese cooker/mixer according to the present invention;  
         [0015]    [0015]FIG. 2 is a top view of the tank on the cheese cooker/mixer, and  
         [0016]    [0016]FIG. 3 is a cross sectional view through the tank along line  3 - 3  in FIG. 2.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0017]    With initial reference to FIG. 1, a cheese processing apparatus  10 , such as cooker/mixer, has a circular cylindrical tank  12  which is mounted on an inclined mixing conveyer  14 . A frame  32  supports these and other components of the cooker/mixer  10 . The tank  12  has an open top serving as an inlet  15  through which cheese curds are received. As will be described, the tank is filled with hot water through which the cheese curds sink into an outlet at the bottom of the tank. The tank outlet is connected to the mixer/conveyer  14  driven by a first electric motor  10  and a gear transmission  20 . The melted cheese flows through the outlet and is transported up the inclined mixer/conveyer  14  from which the cheese is expelled through an outlet tube  16  at the top of the incline. As will be understood by those skilled in the art, the stream of cheese flows from the outlet tube  16  will into an extruder or molder depending upon the particular cheese manufacturing process.  
         [0018]    A pair of drain pipes  22  extend from openings on opposite sides of the tank to a pump  24  that is driven by a second electric motor  26 . An outlet connection  28  of the pump  24  is connected to the conventional heater  29  which raises the temperature of the water to the desired temperature (e.g. 77° C.). Two inlet pipes  30  on opposite sides of the tank  12  receive water from the heater  29  and emit that liquid into the tank  12 , as will be described.  
         [0019]    With the reference to FIGS. 2 and 3, the tank  12  comprises a cylindrical outer wall  40  with a concentric, cylindrical inner wall  42  which divides the tank into a central inner region  41  and a surrounding outer region  43 . The outer wall may be rectangular or other geometric shapes, and as a further alternative the outer region  43  may extend only partially around the inner region  41 . The inner wall  42  is formed by a screen which has a plurality of apertures there through which are small enough so that the curds and other typical sized particles of cheese cannot pass through while allowing water to fully flow through the inner wall. The material of the screen may comprise a two dimensional array of interwoven wires, hardware cloth, expanded metal, a metal sheet with apertures, or equivalent material that forms a suitable mesh pattern. However, the inner wall  42  is not required to have a two dimensional array of apertures, as long as there are a sufficient number of apertures to allow an adequate flow of water there through. Both the outer and inner walls  40  and  42 , as well as other metal components of the cheese processing apparatus  10 , are preferably formed of stainless steel.  
         [0020]    An inclined bottom wall  44 , that matches the incline of the mixer/conveyor  14 , extends abuts the lower edges of the outer and inner walls  40  and  42  (see also FIG. 1). The section of the bottom wall  44  within the inner wall  42  has an opening into a lower section  48  of the tank  12 . That lower section  48  couples inner region  41  of the tank to an outlet  46  into the mixer/conveyor  14  and provides a passageway for cheese to descend into the mixer/conveyor.  
         [0021]    With reference to all three Figures, a pair of drain openings  50  are located in the outer region  43  of the tank through the bottom wall  44  and connect to the drain pipes  22 . The water inlet pipes  30  extend upward through the bottom wall  44  and vertically through the interior of the tank  12 . In the preferred embodiment shown in FIG. 2, the inner wall  42  is formed by two nearly semi-cylindrical sections  51  and  52  each extending between the two inlet pipes  30  on opposite sides within the outer housing. The section of each of the inlet pipes  30  within the inner wall  42  has a vertical outlet slot  53  (as seen FIG. 3) which runs substantially the full height of that inner wall. The outlet slot  53  is oriented to emit a stream of water substantially tangential to the interior curved surface of the inner wall  42 , as denoted by arrows  54  in FIG. 2. As will be described in greater detail, this emission of water from the inlet pipes  30  creates a vortex within the tank  12  which forces the cheese curds inward and downward within the tank and into the mixer/conveyer  14 . It should be understood that the stream of water upon exiting the inlet pipe  30  does not have to be precisely tangential to the curved inner wall, as long as the direction of that water stream is substantially tangential so as to create the vortex within which the cheese moves. Alternatively, instead of a single outlet slot  53 , each inlet pipe  30  may have a series of apertures or nozzles which produce a plurality of water jets that create the vortex.  
         [0022]    Although the preferred embodiment of the present invention generates the vortex by selectively directing the flow of water into the tank and thus does not employ any additional moving parts for that purpose, other mechanisms may be employer to create the vortex. For example, a rotating agitator driven mechanically or magnetically by another motor could produce the swirling motion of the water in the tank.  
         [0023]    With continuing reference to FIGS. 2 and 3, the mixer/conveyer  14  has a pair of augers  56  and  58  extending longitudinally at an upward angle within a casing  60 . The augers  56  and  58  are slightly intermeshed so that when rotating the mass of melted cheese which enters from the tank  12  is driven upward to the outlet tube  16 . The first electric motor  18  and transmission gear box  20  (FIG. 1) at the lower end of the mixer/conveyer  14  counter rotates the two augers  56  and  58 .  
         [0024]    Prior to operation of the cheese cooker/mixer  10 , the tank  12  is filled with water that has been heated to the desired temperature (e.g. 77° C.). The pump  24  draws water from the tank through the drain openings  50  and the outlet pipes  22 . This water is then forced through the heater  29  and returns via the inlet pipes  30  on each side of the tank  12 . The water enters tangentially to the curvature of the inner wall  42  in the tank  12  and causes the hot water to swirl therein creating a vortex. When cheese curds are dropped into the inner region  41  through the open top of the tank  12 , the swirling water generates a vortex which draws the curds downward to the center of the tank and into the pair of augers  56  and  58 . This prevents the cheese from adhering to the lower surfaces of the tank and thus not entering the mixing conveyer  14 . The swirling water in the upper portion of the tank  12  moves the curds away from the inner wall  42  thereby providing a self-cleaning effect should any cheese become lodged in an screen opening. This vortex action also separates the individual curds to more rapidly heat each curd while descending through the vortex to the augers  56  and  58 . This further ensures that as melted cheese accumulates in the lower portion of the tank, that accumulated large mass of cheese continues to move downward into the mixer/conveyer  14  where the augers force the mass upward toward the outlet tube  16 .  
         [0025]    The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.