FIELD OF THE INVENTION

This invention relates to a pasteurization system such as may be used in the food and beverage industry, and in particular for pasteurizing dairy products.

BACKGROUND OF THE INVENTION

Many different types of products are pasteurized to reduce or to eliminate microorganisms. During a pasteurization process, a product is heated for a sufficient amount of time and at a sufficient temperature to kill all or substantially all of the microorganisms present in or on the product. The Food and Drug Administration (FDA) and other regulating entities have established standards for the pasteurization of specific products, such as for dairy products. These standards include the

recommended minimum temperature to which the product should be heated and the recommend minimum time during which the product should be at or above the minimum temperature. If a product is not heated for a sufficient amount of time and/or at a sufficient temperature, serious consequences can result. The survival of

microorganisms intended to be killed in the pasteurization process can create a health risk for the consumer and/or an economic loss for the producer.

Assuring the safety of food, beverage and dairy products while maintaining quality and increasing the shelf life is a significant challenge for the food industry.

Originally, a batch process was relied upon to pasteurize dairy products, but this method has largely been replaced by continuous processes, which are more efficient and result in higher quality products. Several continuous pasteurization processes are available; for example, High-Temperature, Short-Time (HTST) pasteurization, Higher- Heat, Shorter-Time (HHST) pasteurization, or Ultra-High Temperature (UHT) pasteurization. The FDA specifies the range of acceptable process conditions for such pasteurization processes.

A typical prior art milk pasteurization circuit 1 0 is illustrated in FIG. 1 . Raw unpasteurized product is delivered from a holding tank 12 through a regenerative heat exchanger 14 and a homogenizer 16 to a pasteurization heat exchanger 18, where it is heated to a desired temperature. Heat energy is supplied to the pasteurization heat exchanger 1 8 via a separately controlled hot water or steam circuit 20. The

temperature and flow rate of the heated milk are measured continuously by a thermometer device 22 and flow metering device 24 respectively, and that data along with pressure data from differential pressure switch 25 is recorded by a circular chart recorder 26. If the temperature and flow rate of the milk are within acceptable limits, the desired degree of pasteurization will occur as the heated milk traverses a section of piping 28 downstream of the pasteurization heat exchanger toward a flow diverter valve 30, whereupon it is directed by the valve 30 to a finished product tank 32 via the regenerative heat exchanger 14 and a cooler 34. If the pasteurization variables were not adequate to achieve the desired degree of pasteurization, the milk is directed back to the holding tank 12 by the diverter valve 26 for further processing.

A dairy product processing plant may include multiple pasteurization circuits such as the one shown in FIG. 1 . Each circuit is controlled by a separate controller and has its own data recorder, typically configured as a Safety Thermal Limit Recorder (STLR). The control setpoints for each circuit may be adjusted independently for proper pasteurization of the particular type of product processed at any given time, such as skim milk, whole milk, yogurt, etc.

Until the late 1980's, mechanical STLR's were used to control and to record process variable data, such as temperature and flow rate, for example. The STLR includes a circular paper chart recorder 26 which provides a hard copy record of measured process data over time. FIG. 2 illustrates an STLR 36 showing the circular paper chart recorder 26. The paper chart is pre-marked with one or more scales, such as gallons per minute (gpm) and/or degrees Centigrade ( °C.), which are graduated in terms of distance from a center axis of rotation of the chart. The radial position of one or more marking pens from the center axis of rotation is controlled in response to the actual measured process data such that each pen draws a line on the paper chart in response to the measured data. FIG. 3 is a closer view of a portion of one such chart 38 where two data lines 40, 42 have been recorded.

Such circular paper charts have become the standard in the industry for recording dairy product pasteurization data. While the control side of the system has continued to evolve with improved technology, such as with the introduction of electronic and then microprocessor-based STLR's in the 1990's, the data recording side of dairy product pasteurization systems is still based upon the circular paper chart.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in the following description in view of the drawings that show:

FIG. 1 is a schematic illustration of a prior art milk pasteurization system.

FIG. 2 is a prior art Safety Thermal Limit Recorder (STLR) as is used in a milk pasteurization process.

FIG. 3 is a close-up view of a portion of a prior art circular paper chart used to record process data by the STLR of FIG. 1 .

FIG. 4 is a block diagram of an improved pasteurization control system in accordance with one embodiment of the invention.

FIG. 5 is a screen display from the system of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

The present inventors have recognized a need to improve the data collection, manipulation and control aspects of dairy product pasteurization systems. Further, the present inventors have recognized that the traditional circular paper chart, which has become ubiquitous throughout the industry, represents a hindrance to the

implementation of such improvements because it is anticipated that there would be significant resistance in the industry to the elimination of the circular paper chart. The improved pasteurization control system described herein overcomes such anticipated resistance to change, while at the same time providing for critical innovations in the ways that data are collected, secured, processed and displayed.

Fig. 4 is a block diagram of a pasteurization system 50 in accordance with one embodiment of the invention. A dairy product pasteurization system will be described herein, but one skilled in the art will recognize that the inventive concepts are not limited to dairy pasteurization, but may be also be applied to any food or beverage

pasteurization system. The dairy product pasteurization system 50 illustrated in FIG. 4 includes a plurality of pasteurization circuits 52, 52', 52" for processing a respective plurality of dairy products, such as whole milk, skim milk, yogurt, etc. Each pasteurization circuit 52', 52', 52" includes a dairy product circuit, similar to the product circuit 10 illustrated in FIG. 1 , wherein a respective dairy product flows from a raw product end 54, 54', 54"to a finished product end 56, 56', 56"through a heat input element 58, 58', 58", and wherein the respective dairy product is pasteurized. Each pasteurization circuit 52, 52', 52" includes respective control inputs 60, 60', 60"operative to control operation of the respective circuit in response to input data. Control may be provided for the positions of valves and the operation of pumps, for example. Each pasteurization circuit also includes respective process data outputs 62, 62', 62" which are responsive to respective measured process data variables of the respective circuit. Typical data may include dairy product flow rate and temperature, heat supply temperature and flow rate, tank levels, and valve positions, for example. One or more computing device 64 with associated computer program code 66 is operatively connected to the control inputs 60, 60' 60" and the process data outputs 62, 62', 62" of each of the plurality of pasteurization circuits 52, 52', 52" to enable centralized control, data collection and data manipulation for the dairy product pasteurization system 50, as is discussed more fully below.

The separate pasteurization circuits 52, 52', 52" may be separately configured and controlled with respective safety thermal limit recorders (STLR). Unlike prior art systems, the system of FIG. 4 enables the centralized recording and processing of measured process data from all of the individual pasteurization circuits 52, 52', 52". Optionally, the computing device 64 may be configured to control selected or all control functions for the system 50, although such centralized control capability may be enabled separately from the centralized data recording and processing functions. In one embodiment, up to twenty four pasteurization units may be connected together via a single data network. Information produced by each of the pasteurization circuits may be stored as digital data on the computer storage media 68. Advantageously, the computer program code may be executable by the computing device 64 to date stamp the data when it is recorded on the computer storage media 68. The term "date stamp" is understood herein to include any unique time-oriented identifier that can be subsequently interpreted to identify a time sequence of when the data was recorded, and most commonly will include month, day, year and time information. This allows the data to be recorded digitally in real time and then processed or reproduced at any later time as desired. Whereas the industry now relies on physically bulky and expensive hard copy circular paper charts for capturing and retaining the pasteurization process data, the system 50 of FIG. 4 can store essentially unlimited amounts of data with very little physical or economic expense.

The system 50 of FIG. 4 also includes an operator input and output device(s) 70 operative to generate operator data in response to manipulation by an operator, and further may include a printing device 72. This provides for the capability of printing a circular paper chart 38 representative of data recorded on the computer storage media for any operator-selected period of time, thereby overcoming a potential resistance in the dairy industry to the conversion to this potentially paperless pasteurization control system. The data may also be displayed on a screen 74 in the image of a circular chart 76 as illustrated in FIG. 5.

The computer program code may include instructions executable by the computing device for associating operator data with selected process data recorded on the computer storage media, and for date stamping such association. The operator data may be an indication of the operator's review and acceptance of specifically selected process data. This functionality is beneficially applied to the situation when a batch of dairy product is being held following an Ultra-High Temperature pasteurization process pending a final "chart review" by one or more authorized individuals. A digital batch hold may be associated with selected process data until operator data indicative of acceptance of the selected data is associated with the selected data. The historical sequence of the batch data is maintained on the computer storage media, including date stamps indicating when the data was recorded, when the data was reviewed and/or approved, and when any change is made to the data. More than one review may be associated for any process data set by associating first operator data with the selected process data indicative of a first operator's review of the data, and further associating second operator data with the same selected process data indicative of a second operator's review of the same data. Furthermore, operator comments or notations may be digitally associated with selected process data in the computer storage media. The system may include computer program code for printing out a paper circular chart or strip chart showing both the recorded process data and the operator data associated with that process data in a format that is similar to the format of prior art paper charts having handwritten operator comments marked on them.

In the prior art systems, all such approvals and notations are simply written on the paper circular charts, and there is no automatic verification of who actually wrote the approval or notation on the chart or when it was actually written. With the system of FIG. 4, the computer program code may be executable by the computing device to permit associating operator-generated data with selected process data in the computer storage media only if the operator data is accompanied by a valid digital signature or other digitally enabled security identifier, and each such association may be date stamped, thereby providing an independent confirmation as to the validity of the operator data and the association. Such a system may be used to improve consumer safety and to reduce the risk of unapproved or improperly pasteurized dairy product from being released, and it essentially eliminates the chance of fraudulent marking of the pasteurization records.

Data integrity can be further enhanced by digitally encrypting the data stored on the computer storage media such that only authorized users of the system can view the data. Encryption ensures that any attempt to tamper with the data is more easily identifiable and it significantly improves the privacy of the data files.

With prior art systems there is often a need to calculate the total flow volume over a period of time for a dairy product being pasteurized, and this is accomplished by retrieving the proper circular paper chart, then calculating an area under the line on the chart where flow rate is recorded, such as is shown by the use of the ruler 78 in FIG. 3. This prior art technique is cumbersome because of the need to locate and handle the paper chart 38, and it is inaccurate because the area under the curve is, at best, estimated by "eye-balling" an average value of the line over a distance corresponding to a length of time. The system 50 of FIG. 4 may include computer program code 66 executable by the computing device 64 for calculating an integrated flow volume in response to operator data identifying any selected starting point and ending point on a continuum of flow rate data recorded on the computer storage media 68. Such machine-based calculation is more convenient and more accurate than the prior art manual chart-based system. Once the time stamped process data is stored on the computer storage media 68, various data analyses may be performed on the data. For example, the data for one or more dairy product circuits 52, 52', 52" can be reviewed for a defined historical time period to determine how often the dairy product exceeded a predetermined temperature. The results of such an analysis may be helpful in diagnosing a system operating problem, for example. Various data mining and report generation applications may be applied to the stored data, and all or portions of the data may be exported to other physical locations or processors for review and use. All such activities may be subject to security measures such as being enabled for only pre-authorized users, and all such activities and reports may be time stamped for historical purposes.

An exemplary system for implementing the invention includes a computing device or a network of computing devices. In a basic configuration, computing device may include any type of stationary computing device or a mobile computing device. Computing device typically includes at least one processing unit and system memory. Depending on the exact configuration and type of computing device, system memory may be volatile (such as RAM), non-volatile (such as ROM, flash memory, and the like) or some combination of the two. System memory typically includes operating system, one or more applications, and may include program data. Computing device may also have additional features or functionality. For example, computing device may also include additional data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Computer storage media may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules or other data. System memory, removable storage and non-removable storage are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other physical medium which can be used to store the desired information and which can be accessed by computing device. Any such computer storage media may be part of a computing device. Computing device may also have input device(s) such as a keyboard, mouse, pen, voice input device, touch input device, etc. Output device(s) such as a display, speakers, printer, etc. may also be included. Computing device also contains communication connection(s) that allow the device to communicate with other computing devices, such as over a network or a wireless network. By way of example, and not limitation, communication connection(s) may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.

Computer program code for carrying out operations of the invention described above may be written in a high-level programming language, such as C or C++, for development convenience. In addition, computer program code for carrying out operations of embodiments of the present invention may also be written in other programming languages, such as, but not limited to, interpreted languages. Some modules or routines may be written in assembly language or even micro-code to enhance performance and/or memory usage. It will be further appreciated that the functionality of any or all of the program modules may also be implemented using discrete hardware components, one or more application specific integrated circuits (ASICs), or a programmed digital signal processor or microcontroller. A code in which a program of the present invention is described can be included as a firmware in a RAM, a ROM and a flash memory. Otherwise, the code can be stored in a tangible computer- readable storage medium such as a magnetic tape, a flexible disc, a hard disc, a compact disc, a photo-magnetic disc, a digital versatile disc (DVD). The present invention can be configured for use in a computer or an information processing apparatus which includes a memory, such as a central processing unit (CPU), a RAM and a ROM as well as a storage medium such as a hard disc.

The step-by-step process for performing the claimed functions herein is a specific algorithm, and may be shown as a mathematical formula, in the text of the specification as prose, and/or in a flow chart. The instructions of the computer program code create a special purpose machine for carrying out the particular algorithm. Thus, in any means-plus-function claim herein in which the disclosed structure is a computer, or microprocessor, programmed to carry out an algorithm, the disclosed structure is not the general purpose computer, but rather the special purpose computer programmed to perform the disclosed algorithm. A general purpose computer, or microprocessor, may be programmed to carry out the algorithm/steps of the present invention creating a new machine. The general purpose computer becomes a special purpose computer once it is programmed to perform particular functions pursuant to instructions from program software of the present invention. The instructions of the computer program code that carry out the algorithm/steps electrically change the general purpose computer by creating electrical paths within the device. These electrical paths create a special purpose machine for carrying out the particular algorithm/steps.

Unless specifically stated otherwise as apparent from the discussion, it is appreciated that throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.