Abstract:
The present invention relates generally to a product recovery system for recovering residual product from processing food or feed in manufacturing facilities, and more particularly to a product recovery system for recovery of residual raw or processed food or feed from processing plant lines and equipment. The product so recovered is useful as an ingredient in further food or feed manufacture. The product recovery system provides the further utility of removing the residual product from the waste effluent stream of the manufacturing facility.

Description:
[0001]    This application claims the benefit of copending U.S. Provisional Application No. 60/190,628, filed Mar. 20, 2000, the subject matter of which is incorporated by reference in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to a product recovery system (PRS), and more particularly to a product recovery system for the recovery of residual raw or processed food or feed from processing plant lines and equipment.  
         BACKGROUND OF THE INVENTION  
         [0003]    Large-scale commercial food processing plants have the problem of processing losses and biological waste. Processing losses can result from spills, spoiled product, product that does not conform to quality and or legal standards, and processing residues left in the equipment. In particular, when processing residues are disposed as waste, the efficiency and profitability of food processing decrease, and the cost of disposal and waste treatment increase. Unfortunately, existing attempts to utilize or reduce processing residues, or minimize disposal costs, have not been satisfactory.  
           [0004]    Residues are created when fluid or solid foods are processed, transported, stored, and conveyed throughout the processing plant. Residues exist in tankers, trucks, rail tank cars, tanks, silos, vats, and other storage vessels, including the pipes and pumps used to convey the fluids or solid food.  
           [0005]    Examples of fluid food products residues include milk, drinks and juices, along with thicker fluid foods, for example yogurt, sour cream, condiments (such as ketchup, mustard, relish, and sauces), and solid food products include preserves, jellies, frozen food products like ice cream, grains, and animal feed.  
           [0006]    Another problem in the food processing industry is the environmental impact of food waste. For example, in the cheese manufacturing industry as much as 90% of the incoming milk volume remains as whey after processing. Residual whey is a major source of biochemical oxygen demand (BOD) and very costly to dispose as waste or sewage due to the discontinued use of land application disposal. Residual whey is also difficult to store and expensive to process, despite the value of the lactose, protein, and minerals contained in the whey. As a consequence, it is costly for cheese plants to have equipment for recovering, utilizing, or treating product residue.  
           [0007]    Unsuccessful attempts to address the problem of residue recovery include the use of compressed air, and line cleaning devices known as “pigs” for clearing equipment lines. These methods are not effective, particularly for large or open equipment. Other systems include treating the waste stream by means of chemical or enzymatic treatment. Because of this continuing problem of disposal and the need to increase efficiency in sanitary recovery and production profits, there is a long felt need for a solution to recover residual product in the food product processing industry.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is a product recovery system for recovering residual product in food processing equipment and the lines connecting such equipment.  
           [0009]    In one aspect of the invention, a product recovery system includes a controlled supply of fluid or solid matter that is connected to the lines of a processing plant. The fluid or solid is used to displace product or a product residue in the equipment or its connecting lines. At least one sensor is placed in communication with the recovered product. The sensor measures a predetermined characteristic of the recovered product and sends a signal to a controller to control the supply of fluid or solid as a function of the received signal. A balance tank is used to collect the recovered product.  
           [0010]    This invention is used for processing plants and related equipment, particularly for fluid food processing such as the fluid dairy product processing industry. The system may be employed at the conclusion of normal food processing operations and before sanitation operations such as cleaning-in-place (CIP).  
           [0011]    In one of its several aspects, the invention includes a controlled fluid that is treated and temperature controlled, such as treated chilled potable water. In a particular embodiment, the treated chilled potable water is maintained at a temperature below 45° F. The fluid is treated with either heat, chemical, ionizing radiation, sterilization, filtration, ozone, or ultraviolet light. In another aspect, the fluid is introduced by a Clean-in-Place (CIP) system, which is commonly used in the food processing industry. In another aspect, solid matter is pelletized plastic maybe used when solid food is the subject of recovery.  
           [0012]    In another aspect of the invention, the product recovery system includes at least one Pasteurized Milk Ordinance (PMO) approved mix-proof valve and a balance tank. PMO refers to the United States Department of Health and Human Services Grade “A” Pasteurized Milk Ordinance. The PMO valve is used to connect at least one line of the processing plant to the controlled supply of fluid, a CIP system, or a balance tank, or any combination thereof. In addition, a controller is used to control the PMO valve, and may be used to prevent or inhibit the operation of the CIP system during product recovery cycles.  
           [0013]    In a particular embodiment of the product recovery system, the PMO valve and balance tank are combined to form a sanitary recovery of Grade A milk product. In another aspect, the balance tank has at least one non-submerged entry port for receiving recovered product. The balance tank may also be insulated, mechanically agitated, and refrigerated. The system may also include a temperature control system, a heat exchanger, and a recovery tank for collecting the recovered product from the balance tank.  
           [0014]    In another embodiment, the present invention provides a method of recovering product from a processing plant. The method includes the steps of controlling a supply of fluid connected to the lines of a processing plant, displacing a product contained within the lines with the fluid; receiving, with a controller, a signal from at least one sensor in communication with the recovered product, controlling the supply of fluid as a function of the received signal, and collecting the recovered product in a balance tank.  
           [0015]    In another aspect of the invention, the method includes a controller for controlling at least one PMO-approved mix-proof valve. The controller also prevents the operation of the CIP system as the product is recovered, in another aspect of the method. The method also provides for the recovery of Grade A milk product. These and other objects and advantages of the present invention will be apparent from the drawings, the description of the embodiments, and the claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentation shown, but rather can be modified or alternatively implemented in a variety of ways.  
         [0017]    [0017]FIG. 1 is an illustration of a product recovery system according to the present invention.  
         [0018]    [0018]FIG. 2 is an illustration of a process flow chart of a method for a product recovery system according to the present invention.  
         [0019]    [0019]FIG. 3 is an illustration of a product recovery system according to the present invention for a High Temperature Short Time (HTST) Pasteurization Unit.  
         [0020]    [0020]FIG. 4 is an illustration of a product recovery system adapted to a vacuum dispenser.  
         [0021]    [0021]FIG. 5 is a product recovery system adapted to a plurality of controlled processing stations. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    Referring to the drawings, wherein like numerals indicate like elements, there is shown in FIG. 1 an illustration of a product recovery system (PRS)  10  for recovering raw product residue from a food processing plant such as a fluid milk plant, ice cream plant, cheese plant, and their related equipment.  
         [0023]    The PRS  10  includes a supply of fluid or solids  12  such as potable water or pelletized plastic used to recover the desired food product. The PRS system also includes an optical detector  38 , a balance tank  20 , and a recovery tank  22 . When applied to a fluid milk processing plant, residual milk is recovered from the plant and processing equipment  16  or related equipment. Although FIG. 1 illustrates a tanker  16 , it is understood that the equipment  16  may include, but is not limited to, processing equipment, tankers, transfer lines, silos, or High Temperature Short Time (HTST) pasteurizing units or some combination and plurality thereof. In addition, the PRS  10  may be adapted to a conventional Clean-In-Place (CIP) system  14 .  
         [0024]    For example, the PRS  10  is connected to a tanker  16  by means of a conventional CIP system  14 . A potable water supply  12  is connected to the CIP system  14  through a valve  26 . In a preferred embodiment, the equipment associated with the PRS  10  is of a 3A sanitary and PMO standard for Grade A milk products. In addition, in the preferred embodiment the water is chilled to a desired temperature by means of a refrigeration or heat exchanger system  28  and the water is of sufficiently high quality to be free of chemical contaminants and treated with by heat, ozone, or filtration to remove microbial contamination. The treated and chilled water allows the recovered milk product to be collected in a sanitary manner and reused in another milk product.  
         [0025]    In one aspect of the invention, a flow meter  30  measures the amount of fluid fed into the processing equipment  16 . A pressure sensor  32  is used to monitor fluid pressure.  
         [0026]    Chilled treated water is fed into the PRS  10  through a first valve  34  and a second valve  36  to ensure proper flow direction and isolation between product recovery lines and CIP lines. The first and second valves  34 , 36  are of a type meeting Pasteurized Milk Ordinance (PMO) standards, which are controllable by a programmable controller  100  connected to the valves, pumps and sensors by connector  110 . The first and second valves  34 , 36  are regulated by a feedback control signal from the flow meter  30 , pressure sensor  32 , or an optical sensor  38 .  
         [0027]    The treated water enters through line  40  of the CIP system  14 . The water is injected into the equipment to remove residual product. For example, the water is sprayed by a series of spray balls  42  that are placed inside the tanker  16 . The chilled treated water flushes the raw milk product out of the tanker  16  through outlet port  44 . A pump  46  is used to move the recovered milk past the optical sensor  38  for detection of milk solids. The residue milk product is then captured by a recovery tank  20 . The optical sensor  38  is used to detect a pre-determined condition of the recovered milk such as, but not limited to, milk solid content. The optical sensor  38  generates a signal that is received by the controller  100 , which regulates the first and second valves  34  and  36  controlling the flow and direction of the recovered milk. It is to be understood that other detectors and criteria may also be used, such as temperatures and pressures.  
         [0028]    The flow of the recovered milk is directed to either a recovery balance tank  20  or discarded depending on the pre-determined condition measured by the optical sensor  38 . If the measurement sensed by the optical sensor  38  is within a desired predetermined level, the flow is diverted to an insulated balance tank  20 . The balance tank  20 , meeting 3A or PMO standards, is outfitted with a level probe or level sensor  48  for activating a pump  50  when a desired level is reached. The recovered raw milk is pumped through a heat exchanger  52  to adjust the temperature of the recovered milk as it is transferred to a milk recovery tank  22 . When the measurement made by the optical sensor  38  is outside a desired range, the flow of diluted product is diverted to a drain  58 .  
         [0029]    [0029]FIG. 2 illustrates a process flow chart of a recovery process according to one aspect of the invention. Chilled treated potable water is introduced  200  in the equipment or lines associated with a product recovery system  10 . The water enters the system  10  through a CIP circuit  14  by means of a pair of mix-proof sanitary valves  34 , 36 . Optionally, the amount, temperature and pressure of the water is determined  220  by a flow meter  30  and its temperature is adjusted as required. The water displaces raw product from the equipment and the lines in the system  10 . An optical sensor  38  measures  240  the recovered raw product, and allows the recovered raw product to be collected provided it meets predetermined criteria, such as a desired milk solid level. The collection process may be terminated by a predetermined limit determined from the optical sensor  38 , flow meter  30 , temperature, or other process data. The flow of product fluid/solid is directed, controlled and diverted  245  to either a balance tank for sanitary reuse  260 , storage recovery  270  by a tank, or discarded  250 . It is understood that the recovered product in the balance tank is delivered to a recovery tank for further processing. It is also to be understood that the product discarded for human consumption may also be diverted to a recovery container for animal consumption. In this embodiment, the discard step includes a recovery container for further processing.  
         [0030]    [0030]FIG. 3 illustrates a product recovery system  10  connected to a High Temperature Short Time (HTST) pasteurizer unit  77 . The milk flows through connecting lines to an HTST balance tank  78 . Cold raw milk from the HTST balance tank  78  is delivered to a pump  80  through a valve  82  to a first entry point  84  of a product-to-product regeneration section  90  of the heat exchanger unit  76 .  
         [0031]    Incoming cold milk is heated by outgoing heated pasteurized milk on the opposite side of the heat plates  86 . Upon exiting at a first exit point  88  of the regeneration section  90  of the heat exchanger unit  76 , the heated unpasteurized milk is pumped by a pump  92  through a homogenizer  94  to a heating section  96  of the heat exchanger unit  76 . After reaching an established temperature for an established time in the holding tube  98 , properly pasteurized milk passes through the divert valve  102 , 104  and temperature sensor  100 . The milk continues on to a product-to-product regeneration section  90  of the heat exchanger unit  76  where it is cooled by incoming cold raw milk.  
         [0032]    The milk exits the regeneration section  90  through exit point  106 . The warm pasteurized milk is then chilled upon entering a third entry point  107  and passing through a cooling section  108  of the heat exchanger unit  76 . Chilled pasteurized milk is then transported through a transport line  110  to a storage tank (not shown). Inadequately pasteurized milk is automatically diverted by the measurement of temperature sensor  100  detected by controller  111  controlling valve  102  which diverts the milk back to the balance tank  78  for reprocessing.  
         [0033]    In another aspect of the invention, the product recovery system  10  operates during a change over from one product to another, by flushing the product from milk to water or water to milk in a forward flow condition. Potable water enters the balance tank  78  from a source  12 . The flow of the water flushes the milk from the balance tank  78 , and the flushed milk is transported through the processing lines  24  and the product-to-product regeneration section  90  of the heat exchanger unit  76 . As the recovered product exits the regeneration section  90  it is sent through a holding tube  98  and temperature sensor  100 .  
         [0034]    The pasteurized product passes through the second side of the regeneration section  90 , into the cooling section  108  of the heat exchanger unit  76 . The chilled product exiting the heat exchanger  76  is monitored by one or more flow meters  114 , a pressure sensor  116 , or an optical sensor  118 . In a preferred embodiment, the valves  120 , 122 , 124  are sanitary valves. The valves  120 , 122 , 124  are controllable by a programmable controller  100 , which are regulated by a variety of signal feedback mechanisms carried by connection  110 . The feedback mechanisms include signals from the pressure sensor  116 , the flow meter  114 , or the optical sensor  118 .  
         [0035]    If the flushed product meets pre-determined standards such as milk solids, temperature, or pressure, the controller  110  controls the valves  120 , 122 , 124  to direct the flow of flushed product to balance tank  20  for holding. The balance tank  20  meets current PMO standards and is outfitted with a level probe or level sensor  48  which activates a pump  50  when the desired level is reached. The pump  50 , when activated, pumps the recovered product through an optional heat exchanger  52  to adjust temperature prior to passage into a bulk pasteurized recovery tank  22  through port  53 .  
         [0036]    If the recovered product fails to meet a predetermined characteristic, the flow is diverted through valve  120  to a drain, or recycled through balance tank  78  for some other purpose.  
         [0037]    [0037]FIG. 4 illustrates a product recovery system  10  for recovery of pasteurized milk residue from packaging equipment, such as a filling machine found in many dairy processing plants.  
         [0038]    Milk from a pasteurized milk tank  70  flows through an outlet port  72  and is pumped by a pump  74  to a filling line equipment  130  for filling containers. At the conclusion of processing and packaging, or prior to changeover of the filling equipment  130  from one product type to another, product is typically lost to the waste disposal system or sewer drains. This includes product that is located within the filler bowl and the residual product in a filler receiving tank  132 . The system of the present invention overcomes the problems of lost product and sewer discharge.  
         [0039]    Vacuum is maintained in a vacuum vessel  134  by means of a vacuum pump (not shown). The milk product residue from the filler receiving tank  132  is suctioned into the vacuum vessel  134 . A temperature sensor  136  monitors the temperature to ensure that the temperature is maintained at or below 45° F.  
         [0040]    A level probe  138  on the vacuum vessel  134  control a filler pump  140 , which conducts the product residue as it is measured for a predetermined characteristic by an optical sensor  118 . The product residue is divided to a to an insulated jacketed balance tank  20  for holding. The balance tank  20  meets current PMO standards and is outfitted with a level probe  48  which activates a pump  50  when desired level is reached. The pump  50 , when activated, pumps the recovered milk product through a heat exchanger  52  to adjust temperature prior to passage into the milk product recovery tank  22  through an inlet port  53 .  
         [0041]    Chilled treated potable water enters from a source (not shown), through line  142 . flow of the chilled treated water displaces a remaining milk product which flows through the filling equipment  130  to the balance tank  20  and on to the recovery tank  22 . Product residue from the milk tank  70  is recovered as previously described by flowing a chilled treated water through a spray ball  71  and recovering the product accordingly.  
         [0042]    Although the examples provide for the invention are for use in dairy processing plants, the system and method of the instant invention are not limited to such and are useful in any processing plant wherein there are product residues which may be recovered and collected according to the methods described herein. Processing plants in the food industry are particularly of utility with respect to the invention disclosed. Applicable fluid processing and transport operations in other industries include pharmaceutical, biotechnological, petrochemical, agrochemical and industrial chemical operations.  
         [0043]    For the purposes of this disclosure, the term fluid as applied to fluid processing includes liquids, gases, plasma, supercritical fluids, and solids which behave as fluids, or have properties of fluids, such as fluidized materials, or materials which have properties of flow or flow characteristics under one or more set of conditions as may be achieved in a processing operation. In addition the term fluid as applied to a controlled supply of fluid for displacing product includes any of the above mentioned fluids, or mixtures of the above, or the any of the above fluids with additives useful in displacing or recovering a product residue from a processing plant.  
         [0044]    [0044]FIG. 5 illustrates a PRS  10  having a plurality of recovery stations  300 ,  400 ,  500 ,  600  comprising individual complex processing plant operations. The PRS  10  controls the plurality of processing stations by means of a controller  510 , plurality of sensors  310 , and plurality of control valves  320 . Control  510  controls the valves  320  to allow recovered product to flow into a storage recovery tank  610  when the recovered product meets a predetermined characteristic as measured by sensors  310  and analyzed by controller  510 .  
         [0045]    These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.