MULTI-ZONE PROCESSING SYSTEM FOR APPLYING ELECTROMAGNETIC ENERGY

A material processing system for applying electromagnetic energy to a material includes an energy generating system including a plurality of generators. The material processing system also includes a multi-zone applicator for applying the electromagnetic energy from the generators to a material. A control system is also disclosed that controls the generators and measures material temperatures in the multi-zone application in order to obtain a defined temperature profile for the material.

BACKGROUND

It is often beneficial to process materials by heating them. One technique for heating material is to boil it in a can. Boiling has many drawbacks. One drawback is very low efficiency. Boiling processes can have efficiencies as low as 10 to 20%. Another drawback is that the material is not heated uniformly. Rather, heat is applied from outside of the can, resulting in a cold center and hot perimeter. Heat conducts inward through the can and then through the outermost material until reaching the material in the center. As a result, uniform heating cannot be achieved. Some materials are damaged by such uneven heating, and overcooking of the outermost material is typically required in order to adequately heat the innermost material.

Heating materials using electromagnetic energy, such as microwave energy, can be much more efficient than other forms of heating and can result in much less damage to the materials, and thus higher quality products.

SUMMARY

In general terms, this disclosure is directed to a system for applying electromagnetic energy. In one possible configuration and by non-limiting example, a multi-zone processing system is disclosed for applying the electromagnetic energy. In some embodiments the multi-zone processing system includes a multi-zone applicator. Various aspects are described in this disclosure, which include, but are not limited to, the following aspects.

One aspect is a material processing system comprising: an energy generating system comprising a plurality of electromagnetic energy generators; a pump configured to provide a flow of material to be processed; and a multi-zone applicator spaced from the energy generating system and comprising: a plurality of application zones, each of the application zones configured to receive electromagnetic energy generated at least one of the plurality of generators; a material conduit coupled to the pump to receive the flow of material and extending through the application zones, at least part of the material conduit being transparent to the electromagnetic energy to allow the material to be exposed to the electromagnetic energy as the material passes through the application zones.

Another aspect is a multi-zone applicator comprising: a plurality of application zones, each of the application zones configured to receive electromagnetic energy generated by at least one of a plurality of generators; a material conduit configured to receive a flow of material and extending through the application zones, at least part of the material conduit being transparent to the electromagnetic energy to allow the material to be exposed to the electromagnetic energy as the material passes through the application zones.

A further aspect is a computer readable data storage device storing data instructions that, when executed by at least one processing device, cause the at least one processing device to control a material processing system including an energy generating system comprising electromagnetic energy generators, and a multi-zone applicator comprising application zones, the processing device being controlled to: determine target temperatures for each zone; determine zone exit temperatures for each zone; compare the zone exit temperatures with the target temperatures; and adjust energy output of the generators based on the comparison.

Yet another aspect is a method of controlling a material processing system with a control system, the control system including at least one processing device and at least one computer readable storage device, the material processing system including an energy generating system comprising electromagnetic energy generators and a multi-zone applicator comprising application zones, the method comprising: determining target temperatures for material for each application zone;

controlling the generators using a feed-forward mode; determining that a steady state has been achieved using the feed-forward mode; controlling the generators in a feedback mode after the steady state has been achieved.

Further aspects include any one or more of the systems illustrated in the drawings.

Other aspects include any one or more of the methods illustrated in the drawings.

DETAILED DESCRIPTION

FIG. 1is schematic block diagram illustrating an example material processing system100at an example material processing facility90. The example material processing facility includes a utility room92and a processing room94. The example material processing system100includes an energy generating system102, a processing line104, and an energy transfer assembly106. The material processing system100operates to process materials M input into the system, and to output the final product P, such as a packaged product P.

In some embodiments the material processing facility90is divided into multiple rooms or sections to allow compartmentalization of certain components of the material processing system100. In this example, the material processing facility includes a utility room that houses the energy generating system102, and allows the generators103(including generators1,2,3, . . . N) contained therein to be separated from the rest of the processing line, along with electrical power supplies and the like. An example of the energy generating system102is illustrated and described in more detail with reference toFIG. 2. Walls or dividers can be used to separate and compartmentalize components of the material processing system100within the facility90, for example.

In some embodiments the processing line104is kept in a separate processing room94of the facility. In some embodiments the processing room94is a sterile area of the material processing facility90to reduce the chance of contamination of the material M as it is processed. Additional rooms or dividers can be used in other embodiments. Further, in some embodiments the rooms can be in separate buildings. Alternatively, the material processing system100can also be contained within a single room in another possible embodiment.

An energy transfer assembly106is provided to transfer the electromagnetic energy generated by the energy generating system102to the processing line104where it can be used for processing the material M. In some embodiments the energy generating system102is arranged a distance away from the processing room94, and the energy transfer assembly106is arranged to transfer the energy between the spaced components as discussed in further detail with reference toFIG. 2.

The processing line104can have a variety of processing components, but in some embodiments includes at least a multi-zone applicator110. Additional exemplary components illustrated inFIG. 1include a feed tank112, a pump114, a flow rate sensor116, a cooling system118, a pressure sensor120, a back pressure device122, a holding tank124, and a packaging system126for outputting the final packaged products P.

One or more feed tanks112are provided in some embodiments to receive and store input materials M prior to processing of those materials through the multi-zone applicator110. Other input devices can also be used, such as an input pipe providing a continuous flow of input materials from another system or source.

A variety of materials M can be processed through the material processing system100. Typically such materials will include at least some polar molecules or conducting ions so that the materials will react to exposure to the electromagnetic fields. The electromagnetic fields cause movement or rotation of the molecules and ions resulting in heating of the material. The material can include heterogeneous or homogeneous materials. Materials often include at least some liquid, but can include liquids and solids. Non-liquid materials can also be used when such materials are pumpable by the pump114and flowable through the material conduits. A liquid can also be added to materials to allow such materials to be processed by the material processing system100. Examples of materials include food products (e.g., soup, juice, cranberry sauce, vegetables, mashed potatoes), other biomaterials, pharmaceuticals, chemicals, and waste products (e.g., bio-waste).

The processing line104includes a material conduit113that guides the flow of the material M through the processing line104, such as from the feed tank112to the packaging system126. The material conduit113can include multiple pieces or segments and is connected to or passes through various components of the processing line104as discussed herein. In some embodiments the material conduit113is a continuous length of conduit that supplies a continuous flow of material while the material processing system is applying electromagnetic energy to the material.

The pump114is coupled to the feed tank by the material conduit113to receive the material M from the feed tank112and pump the material into the multi-zone applicator110. A positive displacement pump is typically used to ensure that the material M can only move in one direction through the system. In some embodiments the pump114operates to prevent back flow of the material. The pump114also provides a continuous, consistent flow rate. In some embodiments the flow rate is adjustable by the control system108, such as based on the type of materials M being processed. In some embodiments the pump114is a progressive cavity pump or a piston pump.

Some embodiments include a flow rate sensor116arranged along the material conduit after the pump114and measures the flow rate of the material through the material conduit113. In some embodiments the pump114provides a known flow rate such that the flow rate sensor116may not be required, however even in such cases the flow rate sensor116can be used to ensure a proper flow rate. In a continuous flow system the flow rate sensor116can be arranged anywhere along the length of the material conduit113, or multiple flow rate sensors could be used.

The multi-zone applicator110operates to receive the material M through the material conduit113and to expose the material to electromagnetic energy from the energy generating system102. In this example the multi-zone applicator110includes a plurality of application zones111(including zones1,2,3, . . . N). The material conduit113passes through each of the application zones111where the energy from the generators103is delivered to the material. Temperature sensors128are provided and used in some embodiments to measure the temperature of the material before and after passing through each of the application zones111. In some embodiments the multi-zone applicator110is an aseptic processor. Examples of the multi-zone applicator110are illustrated and described in further detail herein with reference toFIGS. 4-11.

A cooling system118is provided in some embodiments to receive and cool the material M after being processed by the multi-zone applicator110. In some embodiments the cooling system118includes another temperature sensor to measure the temperature of the material M after cooling.

A pressure sensor120and back pressure device122are provided in some embodiments to measure and control the pressure in the material conduit113. The back pressure device122can be used for example to increase the pressure above atmospheric pressure. One benefit is that by increasing the pressure, the boiling point of liquid in the material M is also increased allowing the material M to be heated to higher temperature without changing the phase of the liquid to gas. The option to obtain higher temperatures can improve the effectiveness of the processing. For example, to more effectively kill bacteria that may be present in a food product. However, other embodiments can operate at or near atmospheric pressure and therefore may not include a back pressure device122or pressure sensor120. One example of a back pressure device is a valve operable to increase or decrease a resistance of the material flow through the material conduit113. Another example of a back pressure device is a pump, such as a positive displacement pump, which can be connected to or coupled with the material conduit113and used to hold an appropriate back pressure within the material conduit113.

Some embodiments include a holding tank134to temporarily store the material M after it has been processed. The holding tank134can be used, for example, to store the material M until it is packaged, to allow further cooling of the material M, for mixing of the material M, to allow time for chemical reactions or setting of products to occur, for temporary storage prior to advancing the material to a subsequent material processing system, or combinations of these. In other possible embodiments the material M can proceed directly to a packaging system126without a holding tank124. The holding tank may alternatively be a final destination for the material M without then proceeding to a subsequent packaging system126.

The packaging system126receives the material M and packages it to generate packaged products P. In some embodiments the packaging system126is a filler, such as an aseptic bag or box filler. Some embodiments include a vacuum sealer. The packaging system126can in other embodiments operate to fill other types of packaging, such as cartons, cans, buckets, drums, etc. After being inserted and sealed in the appropriate packaging, the packaged products P are output from the material processing system100.

In this example the material processing system100also includes a control system108. The control system108includes at least a processing device, and at least a computer-readable medium. The control system108in electrical or data communication with the energy generating system102and the processing line104to control the operation of the material processing system100. The control system108can be located in the processing room, or the utility room, or at any other desired location including a location remote from the processing facility90. The control system108can utilize any suitable electrical or data communication system, including direct electrical connection, connection through a data communication network, or a wireless data communication system including such as using a Wi-Fi or cellular data communication network.

In some embodiments the material processing facility90includes multiple material processing systems100, energy generating systems102, processing lines104, energy transfer assemblies106, and/or control systems108.

FIG. 2is a schematic block diagram illustrating an example of the energy generating system102, and a portion of the energy transfer assembly106. The energy generating system102can be located in a utility room92of a processing facility90, such as shown inFIG. 1. In this example, the energy generating system102includes a plurality of generators103including, for example, generators1,2,3, . . . N, and an electrical power source150.

The electrical power source150supplies electricity to power the generators103. The power source150typically receives power from an external power source, such as from AC mains power. The power source150can include one or more terminal boxes, fuses or circuit breakers, and other possible power filtering or conditioning electronics. Electrical wiring152delivers the electrical power from the electrical power source150to the generators103.

The generators103operate to generate electromagnetic energy E. In some embodiments, the generators103are microwave generators that generate microwave energy. The microwave energy is electromagnetic energy having a frequency in a range from 300 MHz to 300 GHz. Typically the microwave generators103generate microwave energy having a frequency of about 915 MHz or about 2.45 GHz, though other frequencies or combinations of frequencies can also be used in other embodiments.

In some embodiments the generators103are industrial microwave generators having maximum power output in a range from about 10 kilowatts to about 150 kilowatts. The inventors have found that the cost per watt of currently commercially available industrial microwave generators103is the lowest for 100 kilowatt generators, therefore in at least some embodiments the generators103are 100 kilowatt generators. Other embodiments can have other maximum power outputs. One example of a suitable generator103is the ATM 1010 Transmitter Assembly 100 kilowatt microwave generator available from Applied Microwave Technology, Inc. of Cedar Rapids, Iowa. Some embodiments generate microwave energy having a frequency of about 896, 915, or 922 MHz, and generate 75 or 100 kilowatts of power.

The generators103also typically have a variable power output, which can be adjusted and controlled by the control system108, such as through the control wiring154. The generators can be turned on and off by the control system108, and the power output can also be adjusted by the control system between a minimum power output and the maximum power output (e.g., 25%, 50%, 75%, or 100%).

The example energy generating system102includes a plurality of generators103.FIG. 2illustrates four generators103, including generator1,2,3, and N. The variable N represents any positive integer, indicating that the energy generating system102may have any number of generators, such as one, two, three, or more. When four generators103are used, each having a maximum power output of 100 kW, the cumulative power output of the energy generating system is 400 kW, for example. In some embodiments the energy generating system102includes one generator103for each zone111of the multi-zone applicator110shown inFIG. 1. In other embodiments the quantity of generators can be a fraction or multiple of the number of zones111of the multi-zone applicator110.

When the generators103are operating, the generators103generate and output electromagnetic energy E into the energy transfer assembly106. In this example the energy transfer assembly106includes a plurality of waveguides that direct the electromagnetic energy from the generators to the multi-zone applicator110(FIG. 1). An example of a waveguide is a hollow conductive metal or dielectric pipe. The waveguide contains the electromagnetic energy therein and guides the energy to propagate along a length of the waveguide and through an open end into the multi-zone applicator110. InFIG. 1the electromagnetic energy generated by each generator is represented by E1, E2, E3, and EN, where the subscript represents the generator (1,2,3, or N) that generated the energy.

In some embodiments the waveguides described herein including portions of the energy transfer system as well as portions of the multi-zone applicator110are made of metal. Examples of suitable metals include aluminum and stainless steel. The waveguides have internal dimensions having a width and a height. In some embodiments the width is in a range from about 4 inches to about 16 inches, or about 6 inches to about 12 inches. In some embodiments the width is about 9.75 inches. In some embodiments the waveguides have a height in a range from about 2 inches to about 12 inches, or about 3 inches to about 7 inches. In some embodiments the height is about 4.875 inches.

In one possible embodiment, the energy transfer assembly106includes a plurality of waveguide segments. Flanges are provided at ends of each waveguide segment for fastening waveguide segments together, such as using bolts and nuts placed through apertures in the flanges. In some embodiments the energy transfer assembly106is elevated, such as to allow the waveguides to be positioned along a ceiling of the processing facility90(FIG. 1). In another possible embodiment the energy transfer assembly106is arranged within a floor of the facility90. The energy transfer assembly106can alternatively be positioned in any desired configuration within the facility.

As discussed above, the energy generating system102can be arranged a distance away from the multi-zone applicator110, such as across a room, in different rooms, or in different buildings.FIG. 2graphically illustrates the space between the energy generating system102and the multi-zone applicator110by a distance L. The distance L can be any desired distance in a range from 0 to 0.5 miles away or more. In some embodiments the distance L is greater than 10, 20, 50, 100, 200, 500, or 1,000 feet away.

FIG. 3illustrates another portion of the energy transfer assembly106where it connects to an example of the multi-zone applicator110.FIG. 3is a center cross-sectional view of the energy transfer assembly106and the example multi-zone applicator110.

In this example, the energy transfer assembly106includes additional waveguide segments that continue to deliver energy E from the energy generating system102shown inFIG. 2to the multi-zone applicator110. Energy E1is delivered to application zone1. Energy E2is delivered to application zone2. Energy E3is delivered to application zone3. Energy ENis delivered to application zone N.

In some embodiments the energy transfer assembly106is connected to input ports of the multi-zone applicator110. In some embodiments each application zone111includes an electromagnetic splitter180. In the illustrated example, the energy transfer assembly terminates at and is connected to an input port182of the splitter180. An example of the splitter180is illustrated and described in further detail herein with reference toFIG. 11.

FIGS. 4 and 5illustrate two isometric side views of an example multi-zone applicator110and portions of the energy transfer assembly106. In this example the multi-zone applicator110includes a stand200, a material input201, a material output203, the material conduit113, and application zones111(including zones1,2,3, . . . N).

Material M from the pump114is delivered to the multi-zone applicator110into the material input201. The material M flows through the material conduit113which passed through each of the application zones111. It then exits the multi-zone applicator110at the material output203and proceeds to further components of the processing line104, such as to the cooling system118.

At least some of the material conduit113is made of a material that is transparent to electromagnetic energy, so that as the material passes through the application zones111the material is exposed to the electromagnetic energy. Several examples of materials that are transparent to electromagnetic energy include ceramics (such as Alumina ceramic), glass (such as Borosilicate glass), and plastic polymers (such as Teflon, polypropylene, polysulfone, polyetheretherketone (PEEK), and polyetherimide (Ultem)). The interaction between the material M and the electromagnetic energy typically causes heating of the material M.

In some embodiments the material conduit113is arranged and positioned within the multi-zone applicator110such that it has a continuously upward slope, such that absent pressure from the pump114, the material M would be pulled by gravity backwards away from the material output203. This prevents material M from reaching the material output203without being fully processed through all of the application zones111, such as during a temporary loss of power, for example. In contrast, a downward slope could potentially allow the material to flow forward toward the material output203even when the pump114and/or the multi-zone applicator were not operating, under the force of gravity.

In some embodiments the material conduit113the continuously upward slope of the material conduit113through the multi-zone applicator110is in a range from about 1 degree to about 20 degrees, or in a range from about 1 degree to about 10 degrees, or in a range from about 1 degree to about 6 degrees. In some embodiments the continuously upward slope of the material conduit113is in a range from 1 degree to 6 degrees. In some embodiments the slope of the material conduit is not greater than 20 degrees, or is not greater than 10 degrees, or is not greater than 6 degrees. In some embodiments the continuously upward slope continues from the material input201to the material output203of the multi-zone applicator110. In some embodiments the continuously upward slope is constant for the multi-zone applicator110.

Although other shapes are also possible, the example multi-zone applicator110has a material conduit113that extends in a rectangular helical shape, starting at the lowest point at the material input201and advancing in a generally rectangular path defined by each zone111of the multi-zone applicator, while maintaining the continuously upward slope until it exits at the material output203.

Embodiments of the multi-zone applicator110can be designed to have any number of zones including one, two, three, four, five, six, or more. Additionally, even when the multi-zone applicator110has a certain number of zones, such as four, each zone does not need to be activated if the particular material being processed does not require as many zones. For example, zones1-3can be used while the generator for the fourth zone can be turned off, such that the fourth zone is not activated. In such a case, the material conduit113can still route the material through the fourth zone if desired, or alternatively the material conduit113can be rerouted to bypass the fourth zone and advance directly to subsequent components such as the cooling system118. In this way the multi-zone applicator is very flexible and can be quickly adjusted or customized for processing of a different material when needed, without requiring any or substantial changes be made to the multi-zone applicator110.

Additionally, a benefit of some example embodiments is that the multi-zone applicator110can have as many zones111added as desired, without increasing the footprint of the multi-zone applicator. Referring toFIG. 4, the width W1and length L1remain fixed regardless of how many zones111are stacked on top, and only the height changes. Therefore the number of zones may be limited only by the height of the processing facility90.

Additionally, then, it can be appreciated that another benefit of at least some embodiments is the compact design of each zone111in all dimensions, but particularly in its height. While some applicators can have other shapes, such as an upright S-shaped configuration that does not have a compact height, the configuration illustrated inFIGS. 4-5(and elsewhere herein) includes zones111having generally a horizontal U-shaped configuration (not including the material conduit113), which is slightly skewed in some embodiments in order to maintain the desired continually upward slope of the material conduit113. Therefore, in this example the height of each zone (H1, H2, H3, . . . HN) is much less than the width or the length, allowing for a fixed footprint and allowing the option for many zones111to be stacked on top of each other within the typical processing facility90.

The total height H of the multi-zone applicator110is equal to (or approximately equal to) the sum of the height of each of the zones (H=H1+H2+H3. . . HN).

Also, the height of each zone is typically equal, and therefore the total height can also be calculated as the product of a height (e.g., H1) of any of the zones111and the number of zones N. In some embodiments the height (e.g., H1) of each zone111is less than, or much less than, the width W1and the length L1.

In some embodiments the height (e.g., H1) of each zone111is less than about 30% of the length of the zone L1, or in a range from about 15 to about 25%. In some embodiments the height (e.g., H1) of each zone111is less than about 20% of a width W1of the zone111, or in a range from about 10% to about 20%. In at least one example, the height H1(including four application zones111) is about 81 inches (about 2 meters), the length L1is about 157″ (about 4 meters) and the width W1is about 75 inches (about 1.9 meters). Other embodiments can have other sizes. As discussed herein, the height can be taller or shorter depending on the number of zones111utilized in the particular implementation.

However, the multi-zone applicator110can be scaled up or down in other embodiments depending on various factors such as the type and characteristics of the material to be processed, the volume of the material, the amount of energy that needs to be applied to the material in order to complete the desired processing of the material, and whether the multi-zone applicator110is to be used for large-scale commercial production, small-scale production, laboratory or experimental testing, or demonstration purposes, for example. Scaling of the power output of the energy generating system102(FIG. 2) can similarly be performed.

FIG. 6is a perspective view of an example stand200of a multi-zone applicator110. In this example the stand200includes a base202, vertical supports204, cross support members206, and applicator supports208.

The example stand200has a frame structure that is configured to be placed on a floor F and to support the other components of the multi-zone applicator110in a spaced relationship above the floor F.

The frame structure is formed of square metal tubing or beams, such as having a cross-sectional dimension in a range from about 1-3 inches, or about 2 inches.

The base202includes feet that rest on the floor F.

The vertical supports204extend vertically upward from the base.

The cross support members206extend between the vertical supports204to form a rigid frame structure that resists twisting and bending.

The applicator supports208are connected to the vertical supports204and extend outward from the vertical supports204. The applicator supports208include flat top surfaces that are arranged and positioned so that the applicators for each application zone111(e.g.,FIGS. 4-5) can be placed on and rest upon the top surfaces. Stops are positioned on the applicator supports208and extend vertically upward from the top surfaces which are positioned to prevent the applicators from sliding off of the top surfaces. The applicators can be placed on the top surfaces where they are held by the force of gravity. Additionally, flanges on edges of the applicators also help to prevent the applicators from sliding off of the top surfaces. In embodiments in which the applicators are supported by resting on top of the top surfaces of the applicator supports, the multi-zone applicator can be easily cleaned, or the configuration of the multi-zone applicator can be easily modified because of the absence of fasteners holding the applicators on the applicator supports—the applicators can simply be lifted off.

FIGS. 7-10illustrate an example of the application zone111of the multi-zone applicator110shown inFIGS. 4-5.

FIG. 7is a top view of the example application zone111, and more specifically an example of the zone1of the multi-zone applicator110shown inFIGS. 4-5. In this example, the application zone111includes the splitter180, an applicator230, an applicator232, and the material conduit113. The example splitter180includes the input port182and output ports220and222. The example applicator230includes an elbow waveguide234, a straight waveguide236, and a reflector plate238. The example applicator232includes an elbow waveguide240, a straight waveguide242, and a reflector plate244. The material conduit113includes an input conduit260, an applicator conduit262, an intrazone transfer conduit264, an applicator conduit264, and a cross zone transfer conduit268. Also shown inFIG. 7are examples of the temperature sensor128and the mixer280.

The splitter180is a waveguide that includes the input port182that is configured to be connected to a waveguide of the energy transfer assembly106. The input port182receives the energy E1generated by the generator1of the energy generating system102(shown inFIGS. 1-3). The splitter180then divides the energy into a plurality of portions and delivers the divided energy portions to the applicators. The illustrated example shows a splitter that divides the energy into two portions E1A and E1B. The splitter180includes the output port220that is connected to an end of, and delivers energy portion E1A into, applicator230. The splitter180also includes the output port222that is connected to an end of, and delivers energy portion E1B into, applicator232. An example of the splitter is illustrated and described in further detail with reference toFIG. 11.

One of the advantages of using the splitter180is that it allows a higher power generator103to be used to power the application zone111. As discussed elsewhere herein, the inventors have found that higher powered applicators are often less expensive per unit power than lower powered applicators, and more particularly that a 100 kilowatt generator is currently thought by the inventors to be the most cost effective generator. However, for many processing operations a 100 kilowatt generator is too much power. Therefore, the splitter180can be used to reduce the power actually applied to the material by splitting it into two or more portions containing only a corresponding fraction of the power (e.g., one half, one third, one quarter, etc.). Thus, in the illustrated example when the energy E1is 100 kilowatts, the energy portions delivered to the applicators230and232are 50 kilowatts.

It is also possible in some embodiments for the splitter180to be designed to divide the energy into two or more portions, such as two, three, four, or more. Further, some embodiments do not include a splitter, and instead the input port182is an input port of a single applicator, which receives the entire energy E1directly from the energy transfer assembly106.

In the same way that energy can be delivered directly to the applicator, or split into two or more portions, the zone111of the multi-zone applicator110can also include one or more applicators. In the illustrated example, the zone111includes two applicators230and232. Other embodiments can have other quantities of applicators, such as one, three, four, or more.

The applicators230and232are formed of waveguides, and in this example include an elbow waveguide234,240, and a straight waveguide236,242, respectively. The elbow waveguides234and240are connected to the output ports220and222of the splitter180, and curve at an angle A1to redirect the energy portions by that angle. In this example the angle A1is 90 degrees. Other angles can be used in other embodiments. An advantage of using an elbow waveguide234,240is that it helps to reduce the overall footprint of the multi-zone applicator110by reducing the width W1(shown inFIG. 4). Another advantage is that it reduces the length of material conduit113that may otherwise be required to transfer the material between application zones.

A further benefit of the elbow waveguides234and240is that it provides space along an outer side edge of the elbow waveguides234and240where a point of exit290or entry292can be selected from numerous possible arrangements. For example, the points of exit290and entry292can be selected to be adjacent the outer side wall of the applicators230and232. The energy density is typically greatest in the centers of the waveguides and therefore the material can be more gradually introduced to or removed from the energy by arranging the points of exit and entry292away from the center of the waveguides. At the distal ends of the applicators230and232the same can be accomplished by arranging the points of entry294and exit296near to the opposite inner side wall of the waveguides236and242, if desired. Alternatively, the energy E1A and E1B may be sufficiently attenuated by the time it reaches these distal ends of the applicators230and232that maximum exposure is desired, in which case the points of entry294and exit296can be arranged at the center of the waveguides236and242, as in the example shown inFIGS. 7-10.

The elbow waveguides234and240deliver the energy portions E1A and E1B into the respective waveguides236and242which constitute the primary regions where the material M is exposed to the energy portions E1A and E1B.

In some embodiments the various waveguides can be connected together using a fastener, such as bolts and nuts arranged through apertures in the end flanges of each waveguide. This also allows for easy adjustment, modification, customization, removal, or cleaning of the waveguides by allowing them to be easily disconnected at any one or more points by simple disconnection of the fasteners securing them together.

In some embodiments any energy remaining at the distal ends of the applicators230and232could be directed into a water load where it is dissipated to prevent reflection of the energy into the applicator, in which case all remaining energy would be waste energy resulting in an undesirable inefficiency in the multi-zone applicator110.

In another embodiment, such as shown inFIG. 7, a reflector plate238,244is arranged at the distal ends of the applicators230and232to reflect any remaining energy back into the applicators230and232where it is again used to expose the material M.

The reflector plates238,244have been found to result in greatly improved efficiencies. For example, an applicator with a water load termination may have 60-70 percent efficiency, whereas the applicator230,232with a reflector plate238,244may have 90 percent or more, or 95% or more efficiency. In some embodiments the applicator230,232has about 97% efficiency. This is in sharp contrast to other heating techniques. For example, boilers used for canning can have efficiencies from about 10% to about 35%.

The material is supplied to and guided through the application zone111by the material conduit113. In this example the material conduit113includes multiple segments including the input conduit260, the applicator conduit262, the intrazone transfer conduit264, the applicator conduit264, and the cross zone transfer conduit268.

The material arrives at the application zone111through the input conduit260. The input conduit260is connected to the applicator conduit262.

The applicator conduit262is made of a material that is transparent to the electromagnetic energy. The applicator conduit262enters the applicator230through the point of entry294through the reflector plate238, and then extends through the applicator waveguide236and into the elbow waveguide234. The material M passing through the applicator conduit262is exposed to the portion E1A of the electromagnetic energy in the applicator230. The applicator conduit262then exits the elbow waveguide234at the point of exit290. The distal end of the applicator conduit is connected to the intrazone transfer conduit264.

The intrazone transfer conduit264connects the applicators230and232, which are both part of the same application zone111. The intrazone transfer conduit264is connected to and conveys the material from the applicator conduit262to the applicator conduit266where it enters the applicator232. In some embodiments the mixer280is arranged at the joint between the conduits264and266, and operates to mix or agitate the material M as it enters the applicator conduit266.

The applicator conduit266enters the applicator232through the point of entry292of the elbow waveguide240and then passes through the applicator waveguide242where, similar to the applicator conduit262, the material M is exposed to the portion E1B of the electromagnetic energy. The applicator conduit266is made of a material that is transparent to the electromagnetic energy so the exposure can occur. The applicator conduit262exits the applicator232and the application zone111through the point of exit296through the reflector plate244. The distal end of the applicator conduit262is connected to the cross zone transfer conduit268.

After the material M exits the applicator232, in some embodiments a temperature sensor128is arranged on the cross zone transfer conduit to measure a temperature of the material M. The temperature reading is communicated from the temperature sensor128to the control system108.

The cross zone transfer conduit268provided to connect adjacent zones of the multi-zone applicator110, to convey the material M from one zone to another zone for further processing. In this example, the cross zone transfer conduit268of zone1acts as the input conduit260for the application zone2, and the material M is delivered from the zone1to the zone2by the cross zone transfer conduit268.

The intrazone transfer conduits264and cross zone transfer conduits can also be used to make a variety of modifications or customizations to a particular implementation of the multi-zone applicator110. For example, additional components can be connected to the application zone using these conduits, as desired. Some examples of additional components include a mixer; a de-aerator; an injection port, such as for the addition of ingredients (flavors, probiotics, vitamins), fluids, chemicals, reactants, and the like; sample ports for removing samples of the material; equilibration hold tubes; a cooling system; and other desired components.

The conduits can also be used as bypass conduits to bypass a particular zone if desired.

In some embodiments the portions of the material conduit113that pass through the applicators, such as including the applicator conduits262and264, are formed of a material that is transparent to the electromagnetic energy generated by the energy generating system102. In some embodiments the portions of the material conduit that do not pass through the applicators (including the input conduit260and a final output conduit, as well as the transfer conduits264and268and conduits between other components of the material processing system100(e.g., tanks, pumps, cooling systems, etc.) need not be made of such a material, and can instead be made of another material such as stainless steel tubing. In some embodiments the material conduit113has an internal diameter in a range from about 1 inch to about 3 inches, such as 1.5 inches or 2 inches.

In some embodiments each of the application zones111has the same or similar structure, and therefore this discussion of the example application zone111for zone1will not be repeated herein for each of the other zones2,3, . . . N, understanding that the structure of such zones is the same as or similar to that discussed herein for zone1.

FIG. 8is a side view of the example application zone111(e.g., zone1) shown inFIG. 7.

The example application zone111has a shape, such as a slightly skewed horizontal U-shape. To illustrate an example of the skew,FIG. 8illustrates a horizontal line HOR and a slope line S1at an angle A2to the horizontal line HOR. The slope line S1corresponds to a slope of a plane passing through centers of the point of entry294, input port182, and point of exit296. In some embodiments the slope line S1has an angle in a range from about 5 degrees to about 25 degrees, and in some embodiments an angle in a range from about 10 degrees to about 20 degrees. In some embodiments the angle A2is about 15 degrees. The skew can also be represented by a height differential. A distance D1is a vertical height difference between a center of the point of entry294of applicator230and a center of the input port182, and the distance D2is a vertical height difference between a center of the input port182and the center of the point of exit296. In some embodiments the distances D1and D2are in a range from about 2 inches to about 8 inches, or in a range from about 3 inches to about 6 inches. A total height difference from the point of entry294to the point of exit296of the zone111is the sum of D1and D2(in a range from about 4 inches to about 16 inches, or in a range from about 6 inches to about 12 inches), or twice either of the D1or D2measurements when the distances are equal.

FIG. 9is another side view of the example application zone111(e.g., zone1) shown inFIG. 7.

The intrazone transfer conduit264extends from the point of exit290of the applicator230to the point of entry292of the applicator232. The intrazone transfer conduit264has an upward slope S2from a horizontal line HOR in a range from about 1 degree to about 20 degrees, or from about 1 degree to about 10 degrees. In some embodiments the intrazone transfer conduit264has a slope of about 4 degrees.

The cross zone transfer conduit264extends from the point of exit296(not visible inFIG. 9) of the applicator232to an point of entry294of a subsequent zone (e.g., zone2). The cross zone transfer conduit264has an upward slope S3from a horizontal line HOR in a range from about 1 degree to about 20 degrees, or from about 1 degree to about 10 degrees. In some embodiments the cross zone transfer conduit264has a slope of about 4 degrees.

FIG. 10is another side view of the example application zone111(e.g., zone1) shown inFIG. 7.

In some embodiments the application zone111has a generally horizontal U-shaped configuration, which is slightly skewed. More specifically, the applicators230and232are skewed up and down from the horizontal, such that they both have an upward slope in the direction of the material flow through the material conduit113. The horizontal line HOR is shown for reference. The slope of the applicator230is illustrated as an angle A4. The slope of the applicator230is also illustrated as an angle A5. In some embodiments the angles A4and A5are in a range from about 1 degree to about 20 degrees, or from about 1 degree to about 10 degrees. In some embodiments the applicators230and232have a slope angle A4and A5that matches a slope of the material conduit113, as discussed herein. In some embodiments the slope angles A4and A5are in a range from about 1 degree to about 20 degrees, or in a range from about 1 degree to about 10 degrees, or in a range from about 1 degree to about 6 degrees. In some embodiments the slope is in a range from 1 degree to 6 degrees. In some embodiments the slope of the applicators is not greater than 20 degrees, or is not greater than 10 degrees, or is not greater than 6 degrees.

In some embodiments the material conduit113extends longitudinally through the applicators230and232in a direction parallel with the height of the applicators. Therefore, in some embodiments the slopes of the material conduit113(e.g., applicator conduits262and266) are the same as angles A4and A5.

In some embodiments at least some of the zones111, applicators, and material conduits113extending through the zones111and applicators are said to be horizontal. As used herein, the term generally horizontal refers to an object which has a slope with respect to the earth or a supporting floor that is less than 45 degrees. On the other hand, a generally vertical object has a slope of greater than 45 degrees. A substantially horizontal object has a slope of less than 20 degrees. In other embodiments a substantially horizontal object has a slope of less than 10, or less than 6 degrees. Slopes of objects can be measured with respect to the earth or a level floor. The slopes described herein refer to the objects when assembled in their operational configuration, such as with the feet of the stand or other support structure resting on a level floor.

Although most of the examples illustrated herein involve horizontally arranged application zones, applicators, and material conduits, many of the principles described herein are also applicable to vertical, generally vertical, or substantially vertical zones, applicators, and material conduits, or such structures having combinations of horizontal and vertical components. As just one example, the capability to utilize multiple individually adjustable generators for separately controlling one or more zones or applicators is equally applicable to horizontal, vertical, or combinations of horizontal and vertical zones, applicators, and material conduits.

FIG. 11is a perspective view of an example splitter180. In this example the splitter includes an input port182and two output ports220and222.

In some embodiments edges of the input and output ports182,220, and222include connection flanges302, with apertures304extending therethrough. The flanges302are used for connecting the ports182,220, and222with other waveguides having similarly arranged flanges and ports, such as using a fastener. One example of a suitable fastener is a bolt and nut. Other fasteners can also be used in other embodiments. In some embodiments the flanges and/or locations of the apertures304are skewed to allow waveguides to be connected at the appropriate angles, such as discussed herein.

FIG. 12is a schematic block diagram illustrating an example of the control system108, shown inFIG. 1. In this example, the control system108includes a computing device320. The computing device illustrated inFIG. 12can be used to execute the operating system, application programs, methods, and software modules described herein.

The computing device320includes, in some embodiments, at least one processing device322, such as a central processing unit (CPU). A variety of processing devices are available from a variety of manufacturers, for example, Intel or Advanced Micro Devices. In this example, the computing device320also includes a system memory324, and a system bus326that couples various system components including the system memory324to the processing device322. The system bus326is one of any number of types of bus structures including a memory bus, or memory controller; a peripheral bus; and a local bus using any of a variety of bus architectures.

Examples of computing devices suitable for the computing device320include a server computer, a desktop computer, a laptop computer, a tablet computer, a mobile computing device (such as a smart phone, an iPod® or iPad® mobile digital device, or other mobile devices), or other devices configured to process digital instructions.

The system memory324includes read only memory328and random access memory330. A basic input/output system332containing the basic routines that act to transfer information within computing device320, such as during start up, is typically stored in the read only memory328.

The computing device320also includes a secondary storage device334in some embodiments, such as a hard disk drive, for storing digital data. The secondary storage device334is connected to the system bus326by a secondary storage interface336. The secondary storage devices334and their associated computer readable media provide nonvolatile storage of computer readable instructions (including application programs and program modules), data structures, and other data for the computing device320.

Although the exemplary environment described herein employs a hard disk drive as a secondary storage device, other types of computer readable storage media are used in other embodiments. Examples of these other types of computer readable storage media include magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, compact disc read only memories, digital versatile disk read only memories, random access memories, or read only memories. Some embodiments include non-transitory media. Additionally, such computer readable storage media can include local storage or cloud-based storage.

A number of program modules can be stored in secondary storage device334or memory324, including an operating system338, one or more application programs340, other program modules342(such as the software engines described herein), and program data344. The computing device320can utilize any suitable operating system, such as Microsoft Windows™, Google Chrome™, Google Android, Apple OS, Apple iOS, Linux, and any other operating system suitable for a computing device.

In some embodiments, a user provides inputs to the computing device320through one or more input devices, such as the touch sensitive display348. Other input devices can also be used, such as a keyboard, mouse, pointer control device (such as a touch pad, touch stick, joy stick, etc.), microphone, and any other suitable input device. The input devices are often connected to the processing device322through an input/output interface346that is coupled to the system bus326. Wireless communication between input devices and the interface346is possible as well, and includes infrared, BLUETOOTH® wireless technology, IEEE 802.11x Wi-Fi technology, cellular, or other radio frequency communication systems.

One or more input/output interfaces346can be used for communicating with external sensors and controllable devices of the material processing system. The input/output interface can include AC, DC, or digital input output interfaces, including for example USB and other i/o interfaces, and can also or alternatively include one or more communication devices such as a wireless communication device, wired network communication device (e.g., a modem or Ethernet communication device), or other wired communication devices (e.g., serial bus). Examples of sensors and other controllable devices are described herein, and include the energy generating system102and generators103, the pump114, the flow rate sensor116, the temperature sensors128, and the back pressure device122, as shown inFIG. 1, or other sensors or controllable devices.

In this example embodiment, a display device348, such as a monitor, liquid crystal display device, projector, or touch sensitive display device, is also connected to the system bus326via an interface, such as a video adapter350. In addition to the display device348, the computing device320can include various other peripheral devices (not shown), such as speakers or a printer.

When used in a local area networking environment or a wide area networking environment (such as the Internet), the computing device320is typically connected to a network354through a network interface352, such as an Ethernet interface, or by a wireless communication device, such as using cellular or Wi-Fi communication.

The computing device320typically includes at least some form of computer readable media. Computer readable media includes any available media that can be accessed by the computing device320. By way of example, computer readable media include computer readable storage media and computer readable communication media.

The computing device illustrated inFIG. 12is also an example of programmable electronics, which may include one or more such computing devices, and when multiple computing devices are included, such computing devices can be coupled together with a suitable data communication network so as to collectively perform the various functions, methods, or operations disclosed herein.

FIG. 13is a screen shot of an example graphical user interface380of the control system108, shown inFIGS. 1 and 12.

In some embodiments the graphical user interface380is generated on a display device by a computing device, such as the display device348and the computing device320, shown inFIG. 12. In some embodiments data instructions are stored in at least one computer readable data storage device, which when executed by at least one computing device, cause the computing device to generate the graphical user interface380. The graphical user interface380can be displayed with multiple windows or pages, in some embodiments, but inFIG. 13is illustrated as being displayed on a single window or page.

In this example, the graphical user interface380includes a material identification section382and a target definition section384.

The material identification section382prompts the user to identify the type of material to be processed by the material processing system. In some embodiments a menu of options is provided for selection, and the user can review the list of materials and select one of the materials from the list.

In some embodiments, the materials contained in the list are associated with one or more material characteristics. An example of a material characteristic is a heat capacity of the material. In another possible embodiment, the material is associated with a recipe, which includes predefined material processing system settings for processing the selected material. Upon selection of that material, the predefined material processing system settings are automatically filled into the graphical user interface380fields where the user can review the settings, accept the settings, or adjust the settings.

Alternatively, if the material is not available in the menu, some embodiments provide an option to add a new material. Upon selection of the add new material option, the user is prompted to provide a name for the material and to identify one or more material characteristics, in some embodiments.

The target definition section384prompts the user to identify a plurality of material processing targets to be used during the processing of the material. In this example the target definition section384includes prompts and data entry fields for target flow rate, target pressure, and target temperatures for each zone (e.g., zones1-N).

To define a target value, the user selects the corresponding data entry field and enters the desired value, or utilizes the up and down arrows to increment an existing value up or down, for example.

In some embodiments (not shown inFIG. 13) target temperatures are provided for at least two stages of operation. A first stage of operation involves a sterilization stage, and the second stage of operation involves a material processing stage. During the sterilization stage, the material processing system100is operated to sterilize the system in preparation for material processing. Often higher temperatures may be used in order to ensure that the material conduit is clean and clear of any contaminants, and therefore a first set of sterilization temperatures can be defined for use during the sterilization stage. Then after the sterilization stage is completed, the system advances to the material processing stage in which the material processing target temperatures that are separately defined, are used for processing the material.

FIG. 14is a flow chart illustrating an example method400of controlling a material flow rate. In some embodiments the method400is performed by the control system108. In this example, the method400includes operations402,404,406, and408.

The operation402is performed to determine a target flow rate. In some embodiments the operation402involves receiving the target flow rate from the user through the graphical user interface380, shown inFIG. 13. In another possible embodiment the target flow rate is retrieved from a database based on a material to be processed, such as a material selected through the graphical user interface380, shown inFIG. 13.

The operation404is performed to determine a material flow rate. In one example the material flow rate is the rate of flow of the material through the material conduit113described herein, such as measured by the flow rate sensor116, shown inFIG. 1. In some embodiments the material flow rate is a current flow rate.

The operation406is performed to compare the material flow rate with the target flow rate. The operation406determines for example, a deviation between the material flow rate and the target flow rate. In some embodiments the deviation is logged in a computer readable data storage device, such as along with a time stamp indicating a time at which the deviation was identified. In some embodiments an alert operation occurs when the deviation is greater than a threshold value. The alert can include an audible alert, a visible alert on the graphical user interface of the display device or by illuminating or activating a visible light, or sending a message (text, e-mail, etc.). Alerts can similarly be generated when a deviation greater than a threshold value is identified for any of the material processing targets described herein.

The operation408is performed to adjust a pump. For example, when the material flow rate and the target flow rate are not equal, or when the deviation is outside of a maximum deviation range, the operation of the pump is adjusted in an effort to make the material flow rate match the target flow rate. In some embodiments the operations404,406,408are repeated to continue monitoring and adjusting the flow rate.

FIG. 15is a flow chart illustrating an example method420of adjusting a pressure of the material processing system. In some embodiments the method420is performed by the control system108, shown inFIGS. 1 and 12. In this example, the method420includes operations422,424,426, and428.

The operation422is performed to determine a target pressure. In some embodiments the target pressure is determined by receiving a target pressure from the user through the graphical user interface380, shown inFIG. 13. In another possible embodiment the target pressure is retrieved from a database based on the material to be processed.

The operation424is performed to determine a material pressure. In one example the material pressure is a pressure within the material conduit113(FIG. 1), and therefore a pressure of the material being processed. In some embodiments the material pressure is determined by reading a value from the pressure sensor120, shown inFIG. 1.

The operation426is performed to compare the material pressure with the target pressure. The operation426determines for example, a deviation between the material pressure and the target pressure. In some embodiments the deviation is logged, such as along with a time stamp indicating a time at which the deviation was identified. An alert can also be generated in some embodiments.

The operation428is performed to adjust the pressure. For example, when a deviation is identified, the operation of a pressure adjustment device, such as a back pressure device, is adjusted to change the pressure up or down based on the determined deviation in an effort to make the material pressure equal the target pressure within at least a predetermined range.

An advantage of applying a back pressure to the material is that it can allow higher temperatures to be obtained without the material undergoing a phase change to gas. A temperature, pressure, phase diagram (or associated data) can be used to determine a pressure needed for a given material in order to maintain the material in the liquid phase. For example, low acid material can require sterilization temperatures in excess of 121 degrees C., and typically reaching up to 140 degrees C. This is above the flash point of liquids and thus requires a significant amount of pressure to keep the material in a liquid state. Typical pressures for a low acid material are in a range from about 60 PSI to about 80 PSI. Further, in some embodiments the control system also monitors the pressure and compares the pressure to a maximum pressure to ensure that the pressure does not exceed the maximum pressure.

FIG. 16is a flow chart illustrating a method440of operating a material processing system. In some embodiments the method440is performed by a control system108, such as shown inFIG. 1. In this example the method includes operations442and444.

The operation442is performed to operate the material processing system in a feed-forward mode. The feed-forward mode utilizes a temperature sensor positioned upstream of an application zone (or prior to an applicator) to determine a temperature of the material as it enters the application zone or applicator, and uses that temperature to predict an amount of energy needed in order to raise the material temperature to a target temperature, and the generator is then controlled in order to output the predicted amount of energy. An example of the operation442is illustrated and described in more detail with reference toFIG. 17. In some embodiments the operation442continues until the material temperature after the zone or applicator has stabilized.

The operation444is performed to operate the material processing system in a feedback mode. The feedback mode utilizes a temperature sensor positioned downstream of an application zone or applicator to determine a temperature of the material after it exist the application zone or applicator. The measured material temperature is then used in a feedback loop to adjust the output of the generator based on a comparison of the material temperature and a target temperature. An example of the operation444is illustrated and described in further detail with reference toFIG. 18.

FIG. 17is a flow chart illustrating an example method of controlling a material processing system.FIG. 17is also an example of the feed-forward mode of operation442, shown inFIG. 16. In this example the method/operation442includes operations460,462,464,466,468, and470.

The operation460is performed to determine a target temperature for each zone. In some embodiments determining the target temperature for each zone is performed by receiving the target temperatures from a user, such as through the graphical user interface380(e.g., target temperature for zone1,2,3, N), shown inFIG. 13. In another possible embodiment, the target temperatures are retrieved from a database, such as based on a recipe defined for the material to be processed. In some embodiments the material to be processed is identified by the user through the graphical user interface380, shown inFIG. 13.

The operation462is performed to determine a material flow rate. In some embodiments the flow rate is measured by the flow rate sensor116, shown inFIG. 1.

The operation464is performed to determine a zone entry temperature. The zone entry temperature is a temperature of the material measured by a temperature sensor located upstream from the zone or applicator, and therefore corresponds with the temperature of the material as it enters the zone or applicator.

The operation466is performed to calculate an application energy required in order to obtain the target temperature for that zone or applicator. The operation466can utilize an energy balance equation in order to determine or estimate the appropriate amount of energy to be applied to the material. As one example, the energy can be computed using Equation 1:

In Equation 1, Q is the energy, m is the mass flow rate, Cp is a heat capacity of the material, and dT (or delta T) is the change in temperature. The change in temperature (dT) is equivalent to the temperature of the material as it exits the zone or applicator minus the temperature of the material as it enters the zone or applicator. Further, the temperature of the material as it exist the zone or applicator is the target temperature (operation460), whereas the temperature of the material as it enters the zone or applicator is the temperature determined in operation464.

Once the application energy has been determined, the operation468is performed to set the generator to provide the application energy. In some embodiments only the generator that is coupled with the zone or applicator, to provide electromagnetic energy to the zone or applicator, is adjusted. In some embodiments the power output of the generator is selected. The power output value that is required to obtain the desired energy output from the generator can be computed directly, or determined from a lookup table, for example, based on the application energy determined in operation466. In some embodiments the power output value is a percentage of the maximum power output.

If the method440, shown inFIG. 16, is being performed, then an operation470can further be performed to determine when to switch between the feed-forward mode and the feedback mode. The operation470is performed to determine whether the temperature of the material has stabilized at the target temperature. In some embodiments the operation470involves receiving a temperature measurement from a temperature sensor downstream of the zone or applicator, and determining when the temperature has reached the target temperature, or when the temperature has stabilized, such as by remaining at the same temperature for a period of time, or a combination of both. If so, the material processing system is then transitioned to the feedback mode, such as shown inFIG. 18. Otherwise, the material processing system continues operating in the feed-forward mode and returns to operation464.

In some embodiments the method/operation442is performed for a multi-zone applicator110, with at least operations464,466,468, and470being performed for each zone, and is also used to control the corresponding one or more generators for each zone.

FIG. 18is a flow chart illustrating an example method of controlling a material processing system.FIG. 18is also an example of the feedback mode of operation444, shown inFIG. 16. In this example, the method/operation444includes operations490,492,494, and496.

The operation490is performed to determine a target temperature for each zone.

The operation492is performed to determine a zone exit temperature. In some embodiments the operation492involves receiving or reading a temperature downstream of the zone or applicator to determine a temperature of the material as it exits the zone or applicator.

The operation494is performed to compare the zone exit temperature with the target temperature. In some embodiments a differential is computed between the zone exit temperature and the target temperature.

The operation496is then performed to adjust the application energy/energy output of the generator associated with the zone or applicator. For example, when a deviation is identified, the output of the generator is adjusted to increase or decrease the energy output in order to increase or decrease the material temperature.

In some embodiments the method/operation444is performed for a multi-zone applicator110, with at least operations492,494, and496being performed for each zone, and is also used to control the corresponding one or more generators for each zone.

FIGS. 19-21illustrate example material temperature profiles that can be achieved using the material processing system100as controlled by the control system108as described herein. These examples illustrate an embodiment in which the material processing system100includes a multi-zone applicator having four zones.

FIG. 19illustrates a temperature profile having a linear ramp profile. In this example, the temperatures for the zones (T1, T2, T3, and T4) are selected so that the material temperature is raised at a steady rate from an initial temperature (T0) to a final temperature (T4).

FIG. 20illustrates a temperature profile having a ramp, soak, ramp profile, including a soak period. In this example, the material is brought up to a first temperature (T1) and is then held at that temperature for a period of time (through zones2and3), and finally is heated to the final temperature (T4). A temperature profile that holds a steady temperature is referred to as a soak period. One example of a material that benefits from a soak period as shown inFIG. 20is a material containing starch. The soak period allows time for the starches to bloom, followed by a final heating to the final temperature in order to sterilize the product.

FIG. 21illustrates a temperature profile having a tapered profile. The tapered profile initially provides rapid heating to T1, and then gradually reduces the rate of temperature increase. As the temperature increases, the control system reduces the rate of increase so that it slowly reaches the final highest temperature T4. An advantage of the tapered profile is that it reduces energy density applied to the material while the material is reaching its highest temperature, and reduces burning or fouling that may otherwise occur for sensitive materials.

In some embodiments the temperature profiles shown inFIGS. 19-21(and many other variations) can be achieved by simply adjusting the target temperatures through the graphical user interface shown inFIG. 13, for example, without requiring any physical changes to be made to the structure or configuration of the material processing system100or multi-zone applicator110.