Abstract:
A cheese processing system utilizes a liquid flume to convey blocks of cheese between two components of the system. A staging section is provided in the flume to accumulate cheese blocks into groups that are more easily handled by the component at the outlet of the flume. The staging section has a first movable stop mechanism against which the cheese blocks are detained. When a predefined amount of cheese blocks have accumulated, a second stop prevents additional cheese blocks from entering the staging section until the accumulated one can be released by the first movable stop mechanism. A unique flume structure is provided to direct the liquid flow into different channels to aid in rapidly forcing the detained blocks of cheese into and from the staging section.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to equipment for producing cheese, such as mozzarella; and more particularly to equipment for cooling and salting newly formed blocks of cheese. 
     2. Description of the Related Art 
     Mozzarella cheese is commonly produced in five to twenty pound blocks or cylinders which are molded at a typical temperature of 135 degrees Fahrenheit. At this temperature the cheese block is very soft and can be deformed if not handled with care. Thus, before the cheese can be packaged, the blocks have to be cooled to approximately fifty degrees Fahrenheit. In addition, salt has to be added to the cheese if it was not added prior to the molding step. The finished product has from one to two percent salt by weight. 
     There are two processes presently being employed to cool the cheese and add salt after molding. In the first method, cheese emerging from the molding equipment drops into a serpentine open channel, or flume, through which brine flows. Cheese floats in a saturated brine, but sinks in fresh water. The brine flowing through the flume is cooled by refrigeration system to between 30 and 35 degrees Fahrenheit. The flume is sufficiently long so that cheese will be cooled to the desired temperature prior to packaging. 
     A drawback of the open flume system is that the cheese is not fully submerged and the upper surface, which is exposed to air, is not adequately cooled or salted. The exposed portion also dries out and becomes discolored if the block is not turned over periodically alone the flume. In addition hydraulic pressure tends to produce cupping of the top and bottom surfaces of the cheese blocks and bulging of the sides. Thus, workers must be positioned along the flume with tools to rotate the cheese blocks periodically to ensure uniform cooling and salting and to prevent deformation. This becomes very labor intensive. 
     A second cheese cooling system involves submerging the cheese in a large tank or pool of chilled brine. Typically the cheese blocks emerging from the molding machine are placed into a receptacle, such as a basket or rack, which is then mechanically lowered into the brine pool by an operator. This method ensures that all surfaces of the cheese are exposed to the brine and thus are cooled and salted uniformly. However, the submerging system still requires human operators to assist in filling and emptying the receptacles of cheese and manual monitoring of the time that each receptacle has been in the brine to know when cooling is complete. In addition, the last cheese block to be placed into the receptacle usually is the first one taken out, thereby resulting is some blocks being in the brine longer than others, which produces blocks with different salt content and temperature. 
     Regardless of which conventional cooling method is used, a high level of manual labor and supervision is required. Therefore, it is desirable to provide a more automated and efficient process for uniformly cooling and salting cheese products. 
     SUMMARY OF THE INVENTION 
     A cheese processing system employs a liquid flume to convey blocks of cheese between two components of the system, for example between the molding equipment and a brine tank which cools the cheese. A novel staging section is provided in the flume to control the delivery of the cheese blocks to the component at the end of the flume. The staging section enables the cheese blocks which enter the flume one at a time to be delivered in predefined groups at the flume outlet. 
     The staging section comprises a first stop mechanism having one position in which blocks of cheese are detained in the flume and another position in which the blocks of cheese are able to travel in the flume from the staging section. A sensor detects how much cheese has been detained by the first stop mechanism. Although the sensor may provide a count of the number of cheese blocks, the preferred sensor detects accumulation of a predefined length of cheese in the staging section. This preferred embodiment readily accommodates cheese blocks of various individual lengths, yet detects when a uniform amount of cheese has accumulated. That amount can correspond to the capacity of a receptacle in the cooling tank. 
     A controller is connected to the first stop mechanism and the sensor. The controller responds to a predefined amount of cheese being detained by the first stop mechanism by placing the first stop mechanism into the second state to allow the accumulated blocks of cheese pass to exit the staging section. 
     The preferred staging system further comprises a moveable second stop mechanism located in the flume upstream of an inlet to the staging section to restraint additional blocks of cheese from entering the staging area while a previously accumulated group of cheese blocks exits. 
     Another aspect of the present invention is a structure that controls the flow of liquid through the staging area to move the cheese blocks. An internal wall divides the flume in the staging section into first and second channels through which liquid in the flume normally flows, When it is desired to move an accumulated group of cheese blocks out of the staging section, a first flow gate is activated to direct the liquid flow from the second channel into the first channel near the staging section inlet. Thus substantially the full liquid flow in the flume now passes through the first channel which increases the force acting on the cheese blocks and quickly overcomes their inertia. A second flow gate is activated to direct the liquid flow from the second channel into the first channel farther upstream in the flume when it is desired to drive the cheese blocks detained by the second stop mechanism into the staging area. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic diagram of a cheese cooling and salting apparatus incorporating the present invention; 
     FIG. 2 is an isometric, partial cut-away view of one cell in the cheese cooling and salting apparatus; 
     FIG. 3 is a cross-sectional end view along line  3 — 3  in FIG. 2 
     FIG. 4 is a longitudinal cross-sectional view from one side of a primary flume in FIG. 1 showing blocks of cheese accumulating in a staging section; 
     FIG. 5 is a longitudinal cross-sectional view from the side of the primary flume with the staging section fully loaded with blocks of cheese; 
     FIG. 6 is a longitudinal cross-sectional view from one side of the primary flume showing blocks of cheese flowing out of the staging section; and 
     FIG. 7 is a longitudinal cross-sectional view from one side of the primary flume showing new blocks of cheese entering the staging section while a group of previously accumulated cheese blocks exit. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     References herein to directional relationships and movement, such as upper and lower, or left and right, refer to the relationship and operation of the apparatus in the orientation illustrated in the drawings, which may not be the operational orientation in every application of the present invention. 
     With initial reference to FIG. 1, an apparatus  10  for cooling and salting cheese is connected to the outlet of a conventional cheese molding machine, such as one that produces blocks of mozzarella. Each cheese block emerging from the molding machine enters an inlet  12  of an input flume system  15  formed by a primary flume  16  and four branch channels  21 ,  22 ,  23 , and  24 . The primary flume  16  is a U-shaped, open channel having a width that is less than twice the width of a cheese block thus ensuring that the blocks travel in single file and will not wedge side-by-side clogging the flume. As will be described in greater detail, a variable speed pump creates a flow of brine through the input flume system  15  at a rate up to 300 gallons per minute in a direction indicated by arrow  20 . The flow of brine propels floating blocks of cheese through the primary flume  16  and the flow rate determines the speed of the cheese blocks. The cheese blocks enter a staging section  26  of the primary flume  16  where a plurality of blocks accumulate into a group before flowing onward through the remainder of the primary flume, as will be described. 
     Upon exiting the staging section  26 , the group of cheese blocks is directed by a plurality of gates  28  into one of the branch channels  21 ,  22 ,  23 , and  24  of the flume system. A plurality of sensors, spaced along the primary flume  16 , detect the presence of a cheese block at the respective locations and provide input signals to a microcomputer based controller  25  which governs the operation of the gates  28  and other components of the cheese cooling apparatus  10 . The series of open U-shaped branch channels  21 ,  22 ,  23  and  24  lead to the top of a separate cell  31 ,  32 ,  33 , or  34 , respectively, of a cooling tank  19 . 
     The cooling apparatus  10  can process large blocks of cheese which have a width approximately equal to the width of the entrance of each cell  31 - 34  of the cooling tank  19 . Alternatively smaller blocks that are slightly less than one-half the entrance width can be processed. For this latter version, each branch channel  21 - 24  has a secondary gate  36  that is operated by a second actuator, such as pneumatic or hydraulic cylinder. Beyond the secondary gate  36 , the branch channel  23  is divided in half longitudinally by a vertical wall. The secondary gate  36  directs the smaller cheese blocks into one side of that wall and then into the other side. Additional sensors, located between the secondary gates  36  and the cell entrances, provide sensor signals to the controller  25 . 
     The cooling tank  19  in FIG. 1 is subdivided into four identical cooling cells  31 ,  32 ,  33 , and  34  defined by walls  38  extending the full height and width of the cooling tank. Four cooling cells are shown for ease of illustration, with the understanding that additional cooling cells can be provided to increase the capacity of the cooling apparatus  10 . The cooling tank  19  further includes a brine reservoir  30  which does not receive blocks of cheese. Each of the brine reservoir  30  and cooling cells  31 - 34  are separate water tight compartments and can be independently drained and filled with brine. 
     Referring to FIGS. 2 and 3, a separate carousel  40  is located within each cooling cell  31 - 34 . The carousel  40  has lower and upper sprockets  50  and  51  with chains  42  mounted thereon. A plurality of elongated tubes  44  fabricated of perforated sheet metal or welded rods at attached to the chains  42 , thereby forming receptacles for the cheese blocks. For example, the carousel  40  can have twenty tubes  44  with ten tubes residing in each cooling cell section  45  and  46  at any given time. The tubes  44  rotate in a vertical loop through the cooling cell around the internal wall  48  when the chains  42  are driven by a motor  47  connected to the lower sprocket  50 . Thus the chain  42 , sprockets  50  and  51  and motor  47  form a drive mechanism for the carousel  40 . As the chain rotates  48  in a clockwise direction indicated by arrow  52  in FIG. 3, the tubes  44  in the first section  45  move downward while the tubes move upward in the second section  46 . The tubes  44  travel above and below the internal wall  48  between the two sections  45  and  46  of the cooling cell. 
     The cooling cells  31 - 34  are filled with brine to a level  54  that is slightly below the top of the upper most tubes  44 . As will be described, this level allows the cheese blocks  56  to float into and out of the tube at the top of the first section  45  in each cooling cell. The cheese blocks are not entering or exiting the cell, the level of the brine is raised to cover all the tubes and the cheese contained therein. 
     Referring again to FIG. 1, each cooling cell  31 - 34  has an exit opening  58  in a wall that is opposite to the wall having the entrance. A pair of electrically operated exit stops are located side by side in different halves of each exit opening  58  to control the movement of cheese blocks through that opening. Each exit opening  58  of the cooling tank  19  is connected by a separate outlet channel  61 ,  62 ,  63  or  64  to an outlet flume  66  of an outlet flume system  60 . A control gate  68  is located at the junction of each outlet channel  61 - 64  with the outlet flume  66  and has an actuator operated by controller  25 . A plurality of third sensors are located in the outlet channels  61 - 64  and in the outlet flume  76  to provide sensor signals to the controller  25 . The outlet flume  76  leads to equipment (not shown) for packaging the cheese blocks. 
     The cheese cooling apparatus  10  includes a brine circulation system  80  that comprises a flume circuit  82  and a cooling circuit  88  shown in FIG.  1 . The flume circuit  82  creates a flow of brine that moves the blocks of cheese through the cooling apparatus  10 . A first variable speed pump  84  draws brine from the reservoir  30  at a rate up to 300 gallons per minute. The speed of the first variable speed pump  84  and an electrically operated flow valve  83  in the flume circuit  82  are governed by the controller  25 . The flow of brine from the first variable speed pump  84  is supplied to the inlet  12  of the primary flume  16 , as indicated by arrow  20 . This creates flow of brine at a high rate that carries the cheese blocks into the cooling tank  19 . 
     Another electrically operated, proportional valve  85  controls the flow of brine from the outlet flume  76  back to the reservoir  30  and provides the primary means of controlling the fluid levels in the system. The difference in the flow rate from the first variable speed pump  84  and that through the outlet valve  85  determines the rate of level change in the flume systems  15  and  66  and in the cooling cell  33  in which cheese is being exchanged. The pump rate is set for a desired flow velocity in the primary flume  16 . Accurate level control is required for proper movement of the cheese. 
     In addition to the flume circuit  82  that creates a liquid flow which moves the blocks of cheese, the fluid circulation system  80  includes a cooling circuit  88  which circulates refrigerated brine through the cooling tank  19 . With continuing reference to FIG. 1, the cooling circuit  88  has a second variable speed pump  89  with an inlet connected to an outlet of the brine reservoir  30 . The second variable speed pump  89  supplies brine at a flow rate of 50-100 gallons per minute to a conventional heat exchanger  90  of a refrigeration system, which reduces the temperature of the brine to 25-40 degrees Fahrenheit. The chilled brine from the heat exchanger  90  flows through a distribution conduit  92  to which each of the cooling cells is connected by control valve, which are independently operated by the controller  25 . The cooling cells  31 - 34  also are coupled by another set of independently operated control valves to a drain conduit  94  which leads to the input of a drain pump  98 , that feeds into the brine reservoir  30 . By selectively operating the selected ones of these control valves the drain pump can be used to empty brine from a cooling cell  31 - 34  that needs maintenance. 
     The rotational movement of the carousel  40  in each cooling cell  31 - 34  acts as a paddle wheel pushing the brine solution from one cell over the walls  43  into the adjacent cooling cell. This action causes the brine to flow through the cooling cells in a sequential manner. Alternatively, inter-cell pumps can be provided to transfer the brine from one cell to another. 
     The cheese to be cooled enters the primary flume inlet  12  and the flow of brine carries the floating cheese into the cooling apparatus  10 . This enables the cheese blocks to be loaded into and removed from the cooling tank  19  entirely without human intervention. 
     In order to coordinate the flow of cheese blocks into the carousel tubes  44  in a selected cooling cell  31 - 34 , the cheese blocks are assembled into groups in the staging section  26  of the primary flume  16  as shown in detail in FIG.  4 . This flume section  26  has a bottom wall  100  and a horizontal interior wall  102  extending across the width of the primary flume  16 , thereby forming a false bottom which divides the primary flume into upper and lower channels  104  and  105 , respectively. The flow of liquid brine through the staging section  26  is evenly divided between the two channels, as the cheese blocks accumulate in the staging section  26 . Beyond the outlet of the staging section an outlet flow control gate  106  is lowered by an actuator  107  to direct the full flow volume into the upper channel  104  thereby increasing the flow rate in that portion of the primary flume. 
     In the state depicted in FIG. 4, a first stop mechanism  110  detains a plurality of cheese blocks  118  in the staging section  26 . In the preferred embodiment, the first stop mechanism  110  comprises an actuator, such as an endless conveyor  111  driven by a motor  112 , and a pair of stop members  108  and  109  attached to the conveyor. Each stop member  108  and  109  may be a metal rod or an open fence which forms a barrier to the cheese blocks in the upper flume channel  104 , yet does not significantly impede brine flow. The endless conveyor  111  extends along side the staging section. When one of the stop members (e.g.  108 ) is positioned downward into the brine solution  114 , the other stop member (e.g.  109 ) is facing upward at the opposite end of the endless conveyor  111 . A proximity sensor  116  detects the presence of the other stop member in this position and produces a signal indicating that the first stop mechanism  110  is in a first position that obstructs blocks of cheese in the primary flume. This position of the stop member  108  defines an outlet boundary of the staging section  26 . 
     The blocks of cheese  118  float on the surface of the brine  114  as they flow along the upper channel  104  from the inlet  12 . These blocks pass beneath a sensor  120  which has an arm  122  with a wheel  124  located at the remote end. Each moving cheese block  118  strikes the wheel and pushes the arm upward, as shown in FIG. 4, so that the block is able to pass beneath the sensor  120 . The cheese block sensor  120  detects the upward movement of the arm and the rotation of the wheel  124 . This detection provides a pair of signals to the controller  25  of the cooling system  10 . 
     The cheese block sensor  120  defines an inlet boundary of the staging section  26  which has a length approximately equal to the length of each carousel tube  44  in the cooling tank  19 . Therefore, the group of cheese blocks which accumulates in the staging section will fill a single carousel tube. It should be noted that the group of cheese blocks may be shorter than the tube length, but should not be longer than the carousel tubes. By grouping the cheese blocks by length, rather than by quantity, the cooling system  10  can accommodate cheese blocks of different sizes. It will be understood by cheese makers that different types of cheese are formed in blocks of different lengths. Thus, ten blocks of mozzarella may fit within a tube of the carousel, whereas only eight larger blocks of provolone may be so received. Thus, operation of the staging section is unperturbed by variation in the length of the individual cheese blocks and thus the number of blocks, because the operation responds to the overall length of the group of cheese blocks that accumulate. 
     With reference to FIG. 5, eventually the requisite length of cheese blocks  118  accumulates in the staging section  26 . When this occurs, the arm  122  of the cheese block sensor  120  remains in the raised position and the wheel  124  does not turn. This condition of the detector  20  is recognized by the controller  25  as indicating that the staging area  26  is now filled with the proper amount of cheese to fill a carrousel tube  44 . 
     The controller  25  responds to this indication by activating an actuator  125  that raises a second stop mechanism, formed by stop gate  126 , along the internal horizontal wall  102  at the inlet of the staging section. This stop gate  126  presents a barrier to additional cheese blocks entering the staging section  26 , but has an open structure which does not impede the brine flow. The force of the brine flow through the primary flume  16  may cause the next cheese block  119  to rise onto the stop gate  126  slightly above the level of the brine  114 . However, the force of that brine flow is insufficient to drive that cheese block  119  over the stop gate  126 . Additional cheese blocks  121  from the molding equipment will be detained behind the second stop mechanism, formed by stop gate  126 . 
     Once the stop gate  126  has been raised, the first stop mechanism  110  is activated so that the conveyor  111  raises the stop members  108  and  109  out of the primary flume  16  and into a horizontal position, shown in FIG.  6 . With the first stop mechanism  110  in this second position, the accumulated group of cheese blocks  118  is able to exit the staging section  26 . To facilitate movement of the cheese blocks, a first flow control gate  128 , located in the horizontal interior wall  102  at the inlet of the staging section, is pivoted downward by an actuator  127  until abutting the bottom wall  100  of the primary flume. The solid panel of the first flow control gate  128  directs the flow of brine in the lower channel  105  into the upper channel  104  so that the full volume of liquid flowing in the primary flume passes through the upper channel in the staging section  26 . The concentration of the liquid flow into the upper channel  104  provides force which quickly overcomes the inertia of the stationary blocks of cheese  118  that had accumulated in the staging section  26 . This drives the accumulated cheese blocks  118  out of the staging section, leftward in the drawings, through the remaining portion of the input flume system  15  and into the cooling tank  19 . Although the lesser flow rate previously present in the upper channel  104  eventually would have driven the accumulated cheese blocks  118  from the staging section  26 , directing the full amount of the flume flow into the upper channel rapidly clears the staging section so that additional cheese blocks  121  can be received from the cheese molding machine at the primary flume inlet  12 . 
     With reference to FIG. 7, the sensor arm  122  dropping down indicates that the accumulated group of cheese blocks has begun to move from the staging section  26 . After a short delay to ensure that the last cheese block  118  in that group has moved far enough into the staging section  26 , the first stop mechanism  110  is activated to rotate the endless conveyor  111  in a direction indicated by arrow  115 . This rotation causes the second stop member  109  to drop into the brine solution  114  and move with the flow of liquid in the upper channel  104 . Then the second stop mechanism is activated to move the stop gate  126  downward parallel to the interior wall  102  so that another group of cheese blocks  119  and  121  can accumulate in the staging section  26  behind the second stop member  109 . 
     At the same time, the first control gate  128  is raised and a second flow control gate  130 , between the first flow control gate  128  and the primary flume inlet  12 , is lowered by an actuator  131 . This second flow control gate  130  directs the full volume of the brine flow into the upper channel  104  providing a force which overcomes the inertia of the stationary cheese blocks  119  and  121  which were retained by the second stop mechanism, stop gate  126 . The increased flow forces those stationary cheese blocks forward into the staging section  26  behind the second stop member  109 . Thus, as the second stop member  109  moves toward the outlet end of the staging section  26 , cheese blocks flow with it. 
     Eventually, the first stop member  108  passes under the proximity sensor  116  which signals the controller  25  of that event. The controller responds by stopping the endless conveyor  111 , thereby placing the second stop member  109  at the outlet end of the staging section  26  in the position where the first stop member  108  had been previously positioned, as shown in FIG.  4 . At this time both the second and third flow control gates  128  and  130  are raised to again divide the liquid flow in the staging section between the upper and lower channels  104  and  105 . The outlet flow control gate  106  is lowered. This provides a region for another group of cheese blocks  119  and  121  to accumulate in the staging section  26 , thus repeating the staging cycle depicted in FIGS. 4-7. 
     By accumulating of a group of cheese blocks  118  within the staging section  26 , the arrival of cheese blocks at the entrance of the selected cooling cell  33  is spread out in time, providing time for the carousel  40  to align each tube  44  sequentially with the cooling cell entrance to receive cheese blocks. This action facilitates automation of the cheese cooling process and reduces the human intervention required to move the blocks of cheese. 
     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.