WO2017218568A1 - Appareil et procédé de torréfaction de grains de café - Google Patents

Appareil et procédé de torréfaction de grains de café Download PDF

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Publication number
WO2017218568A1
WO2017218568A1 PCT/US2017/037300 US2017037300W WO2017218568A1 WO 2017218568 A1 WO2017218568 A1 WO 2017218568A1 US 2017037300 W US2017037300 W US 2017037300W WO 2017218568 A1 WO2017218568 A1 WO 2017218568A1
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WO
WIPO (PCT)
Prior art keywords
roasting
microwave
roasting chamber
beans
coffee beans
Prior art date
Application number
PCT/US2017/037300
Other languages
English (en)
Inventor
John Mccullough
Stephen C. Jacobsen
Original Assignee
Sterling L.C.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US15/180,780 external-priority patent/US10412988B2/en
Application filed by Sterling L.C. filed Critical Sterling L.C.
Priority to EP17813955.6A priority Critical patent/EP3469857A4/fr
Priority to CA3027499A priority patent/CA3027499A1/fr
Publication of WO2017218568A1 publication Critical patent/WO2017218568A1/fr

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/80—Apparatus for specific applications

Definitions

  • the present invention relates to novel devices and methods for roasting beans, such as coffee beans, using microwave energy.
  • Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products.
  • the roasting process is what produces the characteristic flavor of coffee by causing the green coffee beans to change in taste.
  • Unroasted beans contain similar if not higher levels of acids, protein, sugars and caffeine as those that have been roasted, but lack the taste of roasted coffee beans due to the Maillard and other chemical reactions that occur during roasting.
  • the Maillard reaction is a chemical reaction between amino acids and reducing sugars that gives browned food its desirable flavor.
  • the coffee-roasting process follows coffee processing and precedes coffee brewing. It consists essentially of sorting, roasting, cooling, and packaging but can also include grinding in larger-scale roasting houses.
  • bags of green coffee beans are hand- or machine-opened, dumped into a hopper, and screened to remove debris.
  • the green beans are then weighed and transferred by belt or pneumatic conveyor to storage hoppers. From the storage hoppers, the green beans are conveyed to the roaster. Initially, the process is endothermic (absorbing heat), but at around 175 °C (347 °F) it becomes exothermic (giving off heat).
  • the roaster because the beans are heating themselves, an adjustment of the roaster's heat source might be required.
  • the roasted beans are dumped from the roasting chamber and air-cooled with a draft inducer.
  • roasting machines In Vietnam coffee is often coated with oil (traditionally clarified butter) and a small amount of sugar prior to roasting to produce a "butter roast". The roasting process results in an additional caramelized coating on the beans.
  • the most common roasting machines are of two basic types: drum and hot air. There are also packed-bed, tangential and centrifugal roasters. Roasters can operate in either batch or continuous modes.
  • Drum roasting machines consist of horizontal rotating drums that tumble the green coffee beans in a heated environment.
  • the heat source can be supplied by natural gas, liquefied petroleum gas (LPG), electricity or wood.
  • LPG liquefied petroleum gas
  • the most common employ indirectly heated drums where the heat source is under the drum.
  • Direct-fired roasters are roasters in which a flame contacts the beans inside the drum. Fluid Bed or hot air roasters force heated air through a screen or perforated plate under the coffee beans with sufficient force to lift the beans. Heat is transferred to the beans as they tumble and circulate within this fluidized bed.
  • U.S. Patent No, 4,326, 114 discloses a microwave oven incorporated in a coffee bean roasting system and includes a rotatable microwave transparent tube or drum positioned within the same and at an angle to the horizontal, through which coffee beans are introduced at an upper end and flow in continuous agitation to the lower end while being subjected to microwave fields within the oven.
  • a separate section is preferably provided for subjecting the coffee beans to selective treatment during the final stages of the roasting process.
  • the separate section is provided by a conductive septum, which separates the oven into sections in which the power level is different. In the last section the power level is adjusted to control the final critical phase of the roasting process.
  • the oven terminates into a cooling and quenching chamber from which the beans are delivered through a microwave trap to a further cooling stage to rapidly reduce their temperature to well below roasting.
  • a roast profile can be presented as a graph showing time on one axis and temperature on the other, which can be recorded manually or using computer software and data loggers linked to temperature probes inside various parts of the roaster.
  • roasting As the coffee beans absorb heat during roasting, the color shifts to yellow and then to increasingly darker shades of brown. During the later stages of roasting, oils appear on the surface of the bean. The roast will continue to darken until it is removed from the heat source. Coffee also darkens as it ages, making color alone a poor roast determinant. Most roasters use a combination of temperature, smell, color, and sound to monitor the roasting process. The most popular, but probably the least accurate, method of determining the degree of roast, however, is to judge the bean's color by eye. To obtain more accurate roasts, devices that quantitatively measure the roast have also been developed. For example, Agtron, Inc.
  • the Agtron analyzers use a narrow band of near-infrared energy to evaluate the coffee roast both as a whole bean and in a ground form.
  • green coffee beans can be stored for approximately 12-18 months before quality loss is noticeable. However, for coffee beans to be considered part of the "current crop,” the storage time cannot exceed one year. If the green coffee remains in storage for longer than a year, it is considered old crop, and is less valuable because of its drier state. Once the coffee is roasted, however, the shelf life is significantly reduced.
  • the coffee beans After roasting, the coffee beans contain carbon dioxide that is emitted from the beans over time.
  • the beans can emit up to 10 liters per kilogram of coffee.
  • the roasted coffee beans rapidly emit carbon dioxide over the first few days after roasting, then more gradually over the remainder of what is referred to as the degassing period.
  • the carbon dioxide in the roasted coffee beans forms a barrier against oxidation, which is part of staling that degrades quality by altering the roasted coffee bean's essential oils and aromatic components. Exposure to moisture, high temperature and light after coffee beans have been roasted are also known to
  • roast coffee bean results are sensitive to the rate of rise of the temperature of the coffee beans during roasting.
  • the prior art teaches preheating a roasting pan to about 260 °C (500 °F), which is extremely hot and can result in sever burns if not handled correctly. At this temperature, the roasting takes about 8-10 minutes, with the first crack at approximately 5 minutes. After roasting, the beans must be quickly cooled to prevent further internal roasting as a result of heat that is retained in the beans from the roasting process.
  • the present invention relates to improved systems and devices for producing roasted beans, grains or seeds rapidly to provide various improvements over
  • Various aspects of the invention can be used to produce roasted beans more rapidly and having greater control over roasting quality and type, without burning the beans, despite the significantly higher intensity of microwave energy used.
  • the present invention relates to a microwave device for roasting coffee beans.
  • the microwave device comprises a roasting chamber for containing beans; a microwave emitter configured to produce microwave energy within the roasting chamber; a microwave energy focusing device configured to generate focused microwave energy within the roasting chamber and creating a stable microwave high intensity microwave region in the roasting chamber; and an air blower for causing movement of the beans within the roasting chamber and causing the beans to move within the roasting chamber.
  • the air blower is configured to move beans in the roasting chamber at a sufficient speed to substantially uniformly heat the beans.
  • the air blower is configured to circulate beans within the roasting chamber at a velocity greater than 1 revolution per second.
  • the air blower may be any type of air blower, for example, an axial or propeller fan, a centrifugal or radial fan, a turbine, an air compressor, cross-flow fans, combinations of such air blowers, and the like.
  • the moving beans are subjected to focused microwave energy within the roasting chamber, sufficient to more uniformly heat the beans and cause the beans to roast.
  • the type of roast desired for the beans can be precisely controlled.
  • an apparatus for roasting beans comprising: a roasting chamber for containing beans; a microwave emitter configured to produce microwave energy within the roasting chamber and heat the beans to a roasting temperature; and at least one air blower disposed in communication with the roasting chamber for moving beans within the roasting chamber.
  • the roasting chamber is at least partially disposed within a waveguide for channeling microwave energy into the roasting chamber.
  • the roasting chamber is smaller than a wavelength of the microwave.
  • an apparatus for roasting beans comprising: a roasting chamber configured to contain beans; a microwave emitter configured to produce microwave energy within the roasting chamber and heat the beans; a single- mode resonant microwave applicator configured to generate a stable focused high intensity microwave region within the roasting chamber; and an air blower configured to create airflow within the roasting chamber sufficient to move the beans within the roasting chamber.
  • an apparatus for roasting beans comprising: a roasting chamber for containing beans; a microwave emitter configured to produce microwave energy within the roasting chamber and heat the beans; a single- mode resonant microwave applicator configured to generate a standing microwave energy field comprising an array of one or more high intensity microwave regions; and a device configured to move beans within the high intensity microwave regions.
  • the device configured to move beans within the high intensity microwave region comprises a stirring or mixing device within the roasting chamber to move the beans within the roasting chamber.
  • the device configured to move beans within the high intensity microwave region comprises a spinning cup within which the beans are positioned.
  • an air blower is configured to blow air into the roasting chamber to remove chaff during the roasting process.
  • Chaff is the brown flaky skin of the bean that comes off the bean during the roasting process.
  • the air blower is configured to blow air hot air into the roasting chamber during the roasting process to aid in the roasting process and to blow cool or ambient temperature air into the roasting chamber after the roasting process to aid in quickly cooling the roasted beans.
  • the air blower may also comprise a heater for heating the airflow to be passed through the roasting chamber.
  • the present invention also provides a coffee roasting vending machine, comprising: a bean holding chamber configured to store and dispense unroasted beans; a roasting chamber comprising an inlet configured to receive unroasted beans from the bean holding chamber; a microwave emitter configured to produce microwave energy within the roasting chamber and heat the beans; a single-mode resonant microwave applicator configured to generate a stable focused high intensity microwave region within the roasting chamber; a device disposed in the roasting chamber for circulating and/or moving the beans within the stable focused high intensity microwave region.
  • the machine is adapted to be activated by a purchase transaction.
  • the purchase transaction comprises payment by any one or more of a coin, paper bill, plastic charge card, or token.
  • the purchase transaction comprises electronic payment.
  • the apparatus may also comprise an outlet channel connected to the roasting chamber for discharging roasted beans.
  • the apparatus may also comprise a heater for heating the airflow to be passed through the roasting chamber.
  • the apparatus may comprise a control module for controlling the temperature, flow rate, and flow path of the air.
  • the apparatus may comprise a metering system for delivering a specified quantity of beans to the roasting chamber.
  • the high intensity microwave region includes a microwave energy maxima located within the roasting chamber.
  • a single high intensity microwave region is located within the roasting chamber.
  • a plurality of high intensity microwave regions are located within the roasting chamber.
  • the high intensity microwave region excludes a microwave energy maxima located within the roasting chamber.
  • a plurality of high intensity microwave regions are located within the roasting chamber.
  • the high intensity microwave region includes a microwave energy maxima located within the roasting chamber.
  • a single high intensity microwave region is located within the roasting chamber.
  • a plurality of high intensity microwave regions are located within the roasting chamber.
  • the roasting chamber has a diameter that is greater than the microwave wavelength.
  • the diameter of the roasting chamber is such that beans circulating within the roasting chamber pass through a microwave energy maxima of two adjacent high intensity microwave regions.
  • the roasting chamber encompasses a perimeter of two adjacent high intensity microwave regions that excludes a microwave energy maxima.
  • the device is configured such that the roasting chamber is between two adjacent microwave energy minima nodes.
  • a sidewall of the roasting chamber is positioned such that beans at a roasting chamber sidewall pass through a portion of the high intensity microwave region wherein the energy intensity is at least 50% of the energy maxima, the energy intensity is at least 60% of the energy maxima, the energy intensity is at least 70% of the energy maxima, the energy intensity is at least 80% of the energy maxima, the energy intensity is at least 90% of the energy maxima, or the energy intensity is 100% of the energy maxima.
  • the diameter of the roasting chamber is approximately equal to one-half wavelength and the roasting chamber is positioned such that beans at a roasting chamber sidewall pass through two adjacent high intensity microwave regions.
  • the diameter of the roasting chamber is approximately equal to one-half wavelength and the roasting chamber is positioned such that beans at a roasting chamber sidewall pass approximately through the energy maxima of two adjacent high intensity microwave regions.
  • the apparatus comprises a plurality of anti-node high intensity microwave regions.
  • the roasting chamber is approximately equal to one-half wavelength and the roasting chamber is positioned such that beans at a roasting chamber sidewall pass approximately through the energy maxima of two adjacent high intensity microwave regions.
  • the apparatus comprises a plurality of anti-node high intensity microwave regions.
  • the roasting chamber is approximately equal to one-half wavelength and the roasting chamber is positioned such that beans at a roasting chamber sidewall pass approximately through the energy maxima of two adjacent high intensity microwave regions.
  • the apparatus comprises a plurality of roasting chambers, wherein substantially all of each of the one or more high intensity microwave regions is located within one of the plurality of roasting chambers.
  • the single-mode resonant microwave applicator is configured to generate microwave intensity within the roasting chamber to subject the beans to microwave energy sufficient to roast one or more of the beans within approximately 13-50 seconds.
  • the device comprises two or more microwave energy sources such that the two or more microwave energy sources constructively interfere at approximately the same location within the roasting chamber.
  • the apparatus comprises an airflow input and an airflow outlet and the air blower causes airflow to pass in the airflow input, through the roasting chamber, and out of the airflow outlet.
  • the air blower is configured to cause airflow within the roasting chamber in a horizontal direction sufficient to move beans in a generally horizontal and generally circular path in the roasting chamber.
  • the apparatus comprises an air input in the side of the roasting chamber, wherein the horizontal airflow comprises airflow input into the roasting chamber from the side of the roasting chamber at an angle generally tangential to the roasting chamber.
  • the air blower may be one or more blowers for creating an airflow pattern within the roasting chamber to thereby move the beans.
  • the roasting chamber is generally cylindrical in shape and the air blower is configured to cause airflow within the roasting chamber in an approximately circular path and move the beans horizontally within the roasting chamber in an approximately circular path.
  • the air blower is configured to cause airflow within the roasting chamber in a vertical direction, from a lower portion of the roasting chamber upwardly to an upper portion of the roasting chamber. This may include an airflow that starts generally horizontally to cause the beans to move in a generally circular direction within the roasting chamber.
  • the airflow may also be configured to form a helical movement path so that it causes the beans to move generally circularly within the roasting chamber and then moves upwardly in a helical or spiral configuration to carry chaff from the roasted beans out of the roasting chamber.
  • the air blower is configured to cause the vertical airflow at a rate sufficient to selectively move chaff from roasted beans out of the roasting chamber when roasted.
  • the air blower is configured to create airflow in both a vertical direction and a horizontal direction.
  • airflow may be directed from two different sources to create a desired movement pattern for beans during roasting and then to cool the beans after roasting.
  • One pattern may be configuration to provide substantially circular airflow of the beans prior to roasting while the other may be configured to cool the beans after roasting.
  • a single airflow source may be provided to perform both functions.
  • the beans may be moved within the high intensity microwave region by means of a rotating roasting chamber, such as a spinning cup, which causes the beans to circulate with the roasting chamber while they are subjected to microwave energy.
  • a rotating roasting chamber such as a spinning cup
  • the spinning cup has sides that are longitudinally sloping.
  • the spinning cup has an internal flange forming a lip, wherein the lip prevents beans from escaping the spinning cup, but allows chaff to escape the spinning cup.
  • the roasting chamber comprises a spinning cup that is configured to move beans within the high intensity microwave regions.
  • the beans may be moved within the roasting chamber with a rotating stirring rod, which causes the beans to circulate with the roasting chamber while they are subjected to microwave energy.
  • the stirring rod is positioned proximate a bottom surface of the roasting chamber. In another configuration, the stirring rod is positioned along a sidewall of the roasting chamber.
  • a heating element may be used to heat air passing into the roasting chamber.
  • the air being blown into the airflow chamber may, for example, above ambient room temperature of about 20°C up to about 245°C to assist in the roasting process.
  • the present invention involves a roasting chamber for containing beans and a single-mode resonant microwave applicator for generating a standing microwave energy field comprising an array of one or more anti-node high intensity microwave regions.
  • the beans are subjected to the microwave energy in the one or more high intensity microwave regions, sufficient for the beans to achieve a substantially uniform distribution of heat to cause the beans to roast.
  • a microwave device for roasting cereal grain and seed beans includes a microwave energy source; a single-mode resonant waveguide applicator wherein the waveguide is configured to focus microwave energy from the microwave energy source at one or more regions within the waveguide; a roasting chamber for heating beans, and an outlet in
  • roasting chamber for discharging roasted beans
  • at least one air source for circulating air within the lower portion of the roasting chamber and for passing air from the lower portion of the roasting chamber to the upper portion of the roasting chamber.
  • the system may also comprise a venting system for venting smoke from the device.
  • air from an air blower is used to transport the smoke from the roasting chamber through a smoke vent and into a vent duct of a structure within which the system is installed.
  • the air from the air blower is used to transport the smoke from the roasting chamber through a filter to remove smoke particles.
  • the improved system and method of making roasted beans heats beans with microwave electromagnetic radiation by creating high intensity microwave regions within a roasting chamber.
  • the beans are heated in the high intensity microwave regions until they roast to a desired degree.
  • airflow that passes through the roasting chamber from a lower portion of the chamber to an upper portion of the chamber may be used to remove chaff from the roasting chamber.
  • the present invention also contemplates novel methods for roasting beans, comprising moving beans within a roasting chamber and subjecting the beans to focused microwave energy sufficient to cause the beans to roast, resulting in roasted beans.
  • the present invention comprises a method for roasting beans, comprising generating a standing microwave energy field in a single-mode resonant microwave applicator, wherein the standing microwave energy field comprises an array of one or more high intensity microwave regions and subjecting beans to the microwave energy in the one or more high intensity microwave regions, sufficient to cause the beans to roast and produce roasted beans.
  • a method comprises the steps of passing electromagnetic microwave radiation through a roasting chamber and maintaining at least one anti-node of at least one microwave at a fixed location within the roasting chamber.
  • the beans are heated with the microwave radiation at approximately the location of the one or more anti-node.
  • the present invention provides a method of roasting beans, comprising moving beans within a roasting chamber with a stirring device or airflow; and subjecting the beans to microwave energy sufficient to cause the beans to roast, resulting in roasted beans.
  • the microwave energy is focused microwave energy.
  • the present invention provides a method for roasting beans, comprising generating in a single-mode resonant microwave applicator a standing microwave energy field comprising an array of one or more anti-node high intensity microwave regions, and subjecting beans to the microwave energy in the one or more high intensity microwave regions, sufficient for the beans to achieve a substantially uniform distribution of microwave energy heat to cause the beans to roast.
  • the present invention provides a method for roasting beans comprising generating in a single-mode resonant microwave applicator a standing microwave energy field comprising an array of one or more high intensity microwave regions; providing a roasting chamber encompassing the one or more high intensity microwave regions; delivering beans to the roasting chamber, wherein the beans are moved through the microwave high intensity microwave region within the roasting chamber to achieve a highly uniform distribution of microwave energy heat until roasted; and selectively discharging roasted beans from the roasting chamber.
  • the present invention includes the roasting chamber being smaller than the wavelength of the microwave energy being passed through the roasting chamber, such that the beans can circulate around and through the high intensity microwave region located within the roasting chamber.
  • the diameter of the roasting chamber is between about 1 .75 inches (4.45 cm) and about 3 inches (7.62 cm). In another embodiment, the diameter of the roasting chamber is between about 2 inches (5.08 cm) and about 2.5 inches (6.35 cm). The small diameter of the roasting chamber subjects the beans to a high dose of microwave energy, causing it to roast rapidly. Movement of the beans within the roasting chamber makes the bean heat evenly to provide an evenly roasted bean.
  • the present invention allows for rapid roasting without many of the drawbacks identified in the art.
  • the single-mode resonant microwave applicator generates a standing microwave pattern comprising an electric field distribution of n half-wavelengths, where n is an integer. This may include where n is greater than 1 .
  • the present invention may include a plurality of roasting chambers. The microwave energy may be channeled such that each roasting chamber has a high intensity microwave region disposed therein and so that the beans move within the high intensity microwave region.
  • the single-mode resonant microwave applicator may be configured to generate microwave energy at a frequency from between approximately 800 MHz and 30 GHz.
  • the microwave frequency is from between approximately 1 GHz to 5GHz. In more typical applications, the microwave frequency is from between approximately 2 GHz to 3 GHz.
  • Many commercial microwaves use microwave frequency at about 2.54 GHz.
  • the microwave energy source may comprise a magnetron as is known in the art of microwave ovens or one or more microwave emitting chips. Such microwave chips may be arranged in an array to provide sufficient microwave energy for roasting the beans.
  • a control system may be employed to vary the microwave energy being emitted from the microwave chips to control roasting at various stages of the roasting process.
  • the microwave energy from the chips can be varied during the roasting process so that the beans are roasted at different microwave energies at different stated of roasting.
  • a single-mode resonant microwave applicator may be configured to generate microwave intensity within the roasting chamber to subject the beans to microwave energy sufficient to roast one or more of the beans within approximately 25-50 seconds.
  • an entire batch of beans may be roasted in less than 30 seconds depending on the desired roast.
  • the present invention may include a device with two or more microwave energy sources such that the two or more microwave energy sources constructively interfere at approximately the same location within the roasting chamber.
  • the present invention may include a device for continuously feeding beans into the roasting chamber.
  • the present invention includes a conveyor or bean feeding system for moving the beans through the focused microwave energy in a continuous or semi-continuous process.
  • roasting coffee beans eliminates the guesswork of prior art roasting methods by providing a rapid and controlled roasting of coffee beans using focused microwave energy.
  • FIG. 1 shows a perspective view of an apparatus for roasting coffee in accordance with the principles of the present invention.
  • FIG. 2 shows a cross-sectional side view of another embodiment of an apparatus for roasting coffee in accordance with the principles of the present invention.
  • FIG. 3 shows a top view of a roasting chamber for roasting coffee in accordance with the principles of the present invention.
  • FIG. 4 shows a top view of another embodiment of a roasting chamber for roasting coffee in accordance with the principles of the present invention.
  • FIG. 5 shows a top view of yet another embodiment of a roasting chamber for roasting coffee in accordance with the principles of the present invention.
  • FIG. 6 shows a top view of the roasting chamber for roasting coffee show in FIG. 5.
  • FIG. 7 shows a cross-sectional side view of yet another embodiment of an apparatus for roasting coffee in accordance with the principles of the present invention.
  • FIG. 8 shows a cross-sectional side view of yet another embodiment of an apparatus for roasting coffee in accordance with the principles of the present invention.
  • FIG. 9 shows a schematic block diagram of a method of roasting coffee in accordance with the principles of the present invention.
  • FIG. 10 shows a side view of a wave guide and roasting chamber in accordance with the principles of the present invention.
  • FIG. 11 shows a side view of an alternative embodiment of a wave guide and roasting chamber in accordance with the principles of the present invention.
  • FIG. 12 shows a side view of another alternative embodiment of a wave guide and roasting chamber in accordance with the principles of the present invention.
  • FIG. 13 shows a side view of yet another embodiment of an apparatus for roasting coffee in accordance with the principles of the present invention.
  • the drawings are illustrative and not limiting of the scope of the invention, which is defined by the appended claims.
  • the embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention. Elements and acts in the figures are illustrated for simplicity and have not necessarily been rendered according to any particular sequence or embodiment.
  • noun, term, or phrase is intended to be further characterized, specified, or narrowed in some way, then such noun, term, or phrase will expressly include additional adjectives, descriptive terms, or other modifiers in accordance with the normal precepts of English grammar. Absent the use of such adjectives, descriptive terms, or modifiers, it is the intent that such nouns, terms, or phrases be given their plain, and ordinary English meaning to those skilled in the applicable arts as set forth above. Further, the inventors are fully informed of the standards and application of the special provisions of 35 U.S.C. ⁇ 112(f) or pre-AIA 35 U.S.C. ⁇ 112 1J 6.
  • bean means any one or more of several varieties of beans, such as coffee beans, that are commonly roasted to produce a product that can be ground or otherwise processed for producing a beverage or food product. Suitable beans capable of being roasted include, for example, coffee beans, cocoa beans, and the like. Although the specification herein refers frequently to "coffee” as the exemplary bean, it is understood that the various apparatus, device and method embodiments described herein may be used for roasting other beans, grains or seeds other than coffee beans and that the scope of the claims referring to a "bean” or “beans” encompasses all such varieties of beans, grains or seeds capable of being roasted, and shall not be limited by any particular references in the specification to "coffee beans.”
  • cracked bean means a bean that has been heated sufficiently to cause the bean to expand and emit an audible crack.
  • roast bean means a bean that has been heated sufficiently to achieve a desired roast.
  • focused microwave energy means microwave energy that has been directed or focused into a defined area, resulting in a substantially stable and
  • Focused microwave energy may be generated, for example, by reflecting microwaves in a multi-mode microwave applicator having multiple resonant modes of microwave energy propagation, or by generating a standing wave pattern in a single resonant mode (i.e., single-mode) microwave applicator, where the standing microwave pattern generates microwaves that constructively interfere to generate stable areas of high intensity microwave energy.
  • the term "high intensity microwave region” means a region of focused microwave energy in a microwave applicator, wherein the microwaves are of sufficiently high intensity to cause rapid heating and roasting of beans.
  • a high intensity microwave region typically includes the location of maximum energy intensity. Although a high intensity microwave region may encompass the location of energy maxima, it does not necessarily include the point of energy maxima.
  • a high intensity microwave region may also encompass the region of energy intensity that is less than the energy maximum while excluding the actual location of energy maximum.
  • a roasting chamber may encompass two high intensity microwave regions, without encompassing the points of energy maxima, where the perimeter of the roasting chamber (i.e. , the sidewalls) passes through the region between the two energy maxima without actually passing through the energy maxima. Accordingly, a "high intensity microwave region" shall be construed to comprise those locations having a microwave energy greater than the microwave energy minima and having a stable well-defined microwave energy maxima.
  • single-mode means that the superposition of incident and reflect waves in a resonant cavity results in a standing wave pattern with a single resonant mode of microwave energy, thereby generating high intensity microwave regions containing energy maxima that are stable at well-defined and predictable positions within the applicator.
  • traditional multi-mode microwave applicators propagate microwaves with multiple modes of energy, each with varying intensity and at irregularly spaced intervals.
  • a single-mode resonant microwave applicators establish significantly higher electric field strengths compared to a traveling wave or a multi-mode applicator, and are generally more compact, as the dimensions of the resonant cavities are a function of the wavelength typically used for microwave heating (e.g., 2.45 GHz) of food articles.
  • the particular size and dimensions of a single-mode microwave applicator can be determined by those skilled in the art of microwave heating, by utilizing Maxwell equations, which contain all the necessary parameters needed to define the standing wave pattern desired to be established in a particular case, including the geometry and dimensions of a resonant waveguide applicator operating in single-mode.
  • the present invention generally relates to novel devices and methods for roasting beans which may achieve a variety of desired outcomes, such as decreased roasting times and improved roasting characteristics as set forth herein.
  • the novel devices and method may utilize focused microwave energy to create a high intensity microwave field density that more uniformly heats beans at a high rate to cause the beans to achieve a desired final bean temperature, depending on the desired roast, substantially
  • the present invention relates to the discovery that focused microwaves, such as single-mode microwave applicators, may result in improved roasting efficiency, as well as improved speed of roasting.
  • the focused microwaves may result in improved roasted beans having lower density, larger size, higher roasting efficiency and improved taste characteristics.
  • the devices and methods described herein confer significant advantages over the prior art, including, for example, providing devices that are significantly smaller in size, which enables ease of storage and improved portability, and consume significantly less energy.
  • such devices may be used to provide roasted coffee beans for emergency humanitarian aid, disaster relief or military purposes, where there is a need to produce high volumes of roasted beans, inexpensively, in remote locations where there may be no significant energy infrastructure.
  • the portability of the devices disclosed herein may also be a significant advantage where there is a demand for large quantities of freshly roasted coffee beans in restaurants or production facilities, as the devices enable high volume output of freshly roasted coffee beans, and avoid the need of advance production of roasted coffee beans that may not be fresh or that requires roasting off-site and transportation.
  • roasting coffee beans can be achieved by placing coffee beans in a roasting chamber disposed within a within a single high intensity microwave region, i.e. the chamber closely surrounds or encompasses the area of peak energy of a standing microwave signal.
  • the beans move within the high intensity microwave region, the beans are able to heat rapidly, thereby causing the beans to heat and roast in a much shorter period of time than conventional conduction, convection, air or microwave roasting systems known in the art.
  • all of the beans are subject to a substantially equal amount or dose of microwave energy over time to thereby more substantially simultaneously and uniformly heat each bean than conventional methods. This results in the beans being more rapidly and uniformly roasted in a relatively short period of time.
  • the present invention significantly improves roasting time.
  • roasting started and was completed within a significantly shorter period of time. With the time to first crack happening in as little as about 13-20 seconds, (on average within about 18 seconds), while roasting was completed within 24-50 seconds depending on the desired roast.
  • the methods and systems of the present invention provide a significant improvement in the time it takes of initiate and finish roasting a batch of green coffee beans, showing a reduction in the average time of over 1200% for the darkest roasts.
  • the systems and methods of the present invention roast the coffee beans faster, it has been found that systems and methods of the present invention produces uniformly roasted beans.
  • the rapid heating and roasting of the beans in accordance with the present invention resulted in roasted beans that have equivalent flavor as those that are roasted using traditional bean roasting techniques. Accordingly, the methods and systems of the present invention provide significant improvements to time required to roast coffee beans while maintaining the consistency, quality, flavor and aroma of the roasted coffee beans.
  • roasted beans made by the methods and devices of the present invention when compared to roasted beans made by methods and devices previously used (such as standard roasting pans), show significant reduction in burned or charred beans, which could potentially be toxic or carcinogenic.
  • the basic configuration of the systems and devices of the present invention comprises a microwave emitter, such as a magnetron or a microwave emitting semiconductor chip, connected to a microwave antenna for emitting microwave energy into a roasting chamber.
  • the systems and devices may include a waveguide cavity or microwave focusing device, such as a single-mode resonant cavity, within which a roasting chamber is located.
  • the purpose of the microwave cavity and associated hardware is to maximize the energy field at the load (the beans) and optimize the microwave coupling efficiency.
  • the microwave applicators of the present invention generate high intensity microwaves within the roasting chamber to subject the beans to microwave energy sufficient to roast the beans to various degrees depending upon the desired roast, such as by way of example and not by limitation light roast, medium roast or dark roast.
  • FIG. 1 One embodiment of a system for roasting beans in accordance with the present invention is shown in FIG. 1 .
  • a bean roasting system generally indicated at 10, utilizes a microwave energy emitter for producing microwave energy within a roasting chamber within which a batch of uncooked beans 12 dispensed from a hopper 14 are positioned.
  • the roasting system 10 is a self-contained unit that allows a user to select the degree of roast.
  • a selector knob 16 allows the user to select a light, medium or dark roast of the beans 12. The, user then presses the start button 17 to roast the beans according to the selected roast.
  • the system for roasting beans 10 can be configured to in provide a number of roasting options as will be discussed in more detail herein.
  • the roasted beans are dispensed into a container to be used in making a brewed beverage, such as espresso or coffee, depending on the roast and subsequent grinding of the beans.
  • a brewed beverage such as espresso or coffee
  • the system 10 is provided with a smoke filtration system 20.
  • the smoke filtration system draws smoke from the roasting process through a conduit 22 and into filter 24.
  • the filter 24 may comprise a HE PA filter capable of filtering smoke, an oil-based filter, water based filter, or other smoke filtration systems known in the art.
  • the bean roasting system 100 includes microwave energy emitter 114 for producing microwave energy within a roasting chamber 118.
  • microwave energy emitters 114 are known and may be selected according to various design considerations known to those skilled in the art and determined without undue experimentation.
  • some microwave energy emitters comprise a magnetron 122 for generating microwaves and a magnetron antenna 124 disposed within a waveguide 126.
  • Other microwave energy emitters comprise microwave semiconductor ships that may be arranged in an array to produce sufficient microwave energy within the waveguide to rapidly roast the beans.
  • the waveguide 126 is configured to form a standing wave within the waveguide 126.
  • the waveguide 126 thus serves to form a standing wave within the waveguide, and because the roasting chamber 118 is positioned within the waveguide, the waveguide also serves as a microwave applicator.
  • the magnetron 122 may generate microwave energy at any frequency suitable for roasting beans 12.
  • beans may be heated with microwaves at a frequency ranging from 1 MHz up to 30 GHz. The range of frequencies more commonly used is from about 400 MHz to about 20 GHz.
  • the magnetron is tuned to generate microwave energy at a frequency that maximizes the rapid oscillation of water molecules in the load being heating, such as 2.45 GHz.
  • other operating frequencies may also be used effectively.
  • the present invention contemplates use of microwave energy at any frequency suitable for roasting beans.
  • microwave generators utilize magnetron oscillators, which may include continuous wave generators to produce a relatively narrow output frequency spectrum for use with small loads, as in the case of small batch volumes of beans.
  • Microwave emitting semiconductor chips are also considered to be useful as an appropriate microwave generator for the bean roasting devised of the present invention.
  • the present invention employs focused microwaves as a means of creating high intensity microwave energy for rapid high-temperature roasting of coffee beans.
  • Microwave energy may be focused, for example, by reflecting microwaves in a multi- mode applicator so as to create a stable and homogeneous "high intensity microwave region" (defined below) at a defined location, such as within a small roasting chamber.
  • microwave energy may be focused through use of adaptive microwave phased arrays to concentrate the microwave energy at a predetermined area.
  • suitable adaptively focused microwave systems may be constructed having a phased array of multiple radiating antenna elements for a tightly focused microwave beam having a maximum dimension on the order of 2-10 cm or larger, as described by Fenn AJ , Adaptive Antennas and Phased Arrays for Radar and Communications, Norwood, MA, Artech House Publishers, 133-160 (2008).
  • microwave energy may be focused by use of a single-mode microwave applicator, which generates a stable standing wave pattern having one or more "high intensity microwave region" of energy maxima.
  • Other techniques and devices for focusing microwaves are also contemplated to be within the scope of the present invention.
  • the microwave energy focusing device of the present invention as shown in FIG. 2 comprises a waveguide 126, which defines a microwave cavity 128 within which a roasting chamber 118 containing coffee beans 12 is located.
  • the microwave energy focusing device provides for high intensity focused microwave energy within the roasting chamber 118 and creates one or more stable evenly-spaced microwave anti-node high intensity microwave regions in the roasting chamber.
  • the waveguide 126 is comprised of a plurality of walls 130-134 that form a substantially enclosed waveguide within which a standing wave of microwave energy is generated by the microwave emitter 144.
  • the walls 130-134 are formed from waveguide material known in the art that contains the microwaves within the waveguide 126.
  • microwave energy may be focused by reflecting microwaves from a shaped surface that is highly reflective of microwave energy, so that radiation emitted from the microwave source is reflected towards the roasting chamber containing the coffee beans.
  • microwaves may be focused by reflecting off a surface such as a parabolic dish, a horn antenna, a hemispherical dome, etc.
  • microwaves may be focused by means of a microwave lens.
  • the focused microwaves may be achieved by use of a single-mode resonant microwave applicator.
  • a single-mode resonant microwave applicator has the ability to create a standing wave pattern, which is generated by the interference of fields that have the same amplitude but different oscillating directions. This interface generates an array of nodes where microwave energy intensity
  • Single-mode resonant applicators are designed so that the distance of the sample from the magnetron is such that the sample can be placed at the antinodes of the standing electromagnetic wave pattern.
  • Single-mode resonant applicators may be designed such that the standing electromagnetic wave pattern generates an array of one or more anti-node high intensity microwave regions where the magnitude of microwave energy is at a maximum. As further shown and described herein, these anti-nodes are generated at evenly spaced intervals (where there is a plurality) and are sufficiently stable and localized that a load can be accurately placed within the anti-node high intensity microwave region with predictable and repeatable results.
  • the single-mode resonant microwave applicator is comprised of a shorted rectangular waveguide 126 that forms a microwave cavity 128 comprising a metal tube of waveguide material having a generally rectangular cross section and one or more short-circuit walls 130 and 132 at the ends of the metal tube. It is contemplated that single-mode resonant microwave applicators may also be constructed of tubular or circular waveguides. In another embodiment, the microwave focusing device may be circular self-tuning single-mode resonant cavity (made by CEM Corporation, Matthews, NC).
  • the superposition of the incident and reflected waves establish a standing wave pattern that is stable, well-defined in space, and has evenly and predictably spaced positions of energy maxima.
  • a dielectric material such as coffee beans
  • the single-mode resonant microwave applicator may be configured to generate a plurality of anti-node high intensity microwave regions.
  • at least one of the one or more high intensity microwave regions is located within the roasting chamber.
  • the roasting chamber encompasses a single high intensity microwave region.
  • the roasting chamber encompasses a plurality of high intensity microwave regions.
  • the device may comprise a plurality of roasting chambers, wherein each high intensity microwave region is located within a single roasting chamber.
  • a single roasting chamber may span two adjacent high intensity microwave regions.
  • the device may include two or more microwave energy sources such that the two or more microwave energy sources constructively interfere at approximately the same location within the roasting chamber.
  • waveguide size depends on such considerations as operating frequency, power rating, component availability and cost.
  • Various waveguide sizes commonly used for industrial microwave heating include 2450 MHz (S band) and 915 MHz (L band) include.
  • S band 2450 MHz
  • L band 915 MHz
  • Waveguides may be made of such materials as aluminum, copper, or stainless steel.
  • a roasting chamber for roasting coffee beans may encompass one or more high intensity microwave region within a single high intensity microwave region. In some embodiments, the roasting chamber encompasses a single high intensity microwave region. In other embodiments, the roasting chamber encompasses two high intensity microwave regions.
  • the entire waveguide comprises the roasting chamber, and coffee beans may pass through a plurality of high intensity microwave regions as they cascade down the length of the waveguide.
  • the devices of the present invention may include multiple outlets corresponding to each of the one or more roasting chambers. Thus, by using multiple roasting chamber and multiple outlets, one may significantly increase the quantity of roasted beans produced.
  • microwave devices may require appropriate isolators to allow microwave power to pass through in the forward but not reverse direction, so as to protect the microwave generator (i.e., the magnetron) from the damaging effects of reverse power.
  • microwave devices may also include circulators, which do not absorb power and therefore require a separate "dummy" waveguide load connected to the circulator to absorb the reverse power.
  • the systems and devices of the present invention may also include impedance tuners, which couple microwave power to a load by matching the respective complex impedances between the load and the microwave power source.
  • the present invention contemplates achieving enhanced heating uniformity in a single-mode applicator by reciprocating a standing wave inside the applicator.
  • the system may split the generate microwave power into two equal and coherent wave fronts.
  • the two forward power wave fronts are then diverted through rotating phase shifters and then reflected back through the phase shifters before being routed to opposite ends of the applicator.
  • the two coherent wave fronts converge inside the applicator to generate a pattern of standing waves.
  • the phase shifters operate by rotating a thin dielectric slab inside the waveguide with its rotational axis in the plane of the electric field.
  • phase shift alternates sinusoidally from near zero to maximum. Adjusting the slab geometry varies the phase shift amplitude. Rotating both phase shifters synchronously and exactly 90 degrees out of phase with each other will then cause a sinusoidal reciprocation of the standing wave pattern inside the applicator at constant amplitude.
  • the microwave cavity may be a single- mode resonant cavity furnace, comprising a rectangular waveguide designed to support TEio3 rectangular waveguide mode, and is constructed from WR284 copper waveguide (7.21 cm x 3.40 cm).
  • a bean loading inlet is located at approximately 17.50 cm from the source end (near the half-way point from each end), where the roasting chamber is located at a field maximum (a high intensity microwave region) at resonance.
  • single-mode resonant cavity furnaces having different dimensions that are suitable for roasting coffee beans.
  • Larger single-mode resonant cavity furnaces may be used, for example, to roast larger quantities of coffee on a commercial or industrial scale.
  • microwave focusing devices such as microwave reflectors and lenses.
  • microwave reflectors may be used, having a parabolic or hemispherical shape, for focusing microwaves at a specific location.
  • the bean roasting device 100 is contained within a housing
  • the roasting chamber 118 is positioned proximate the energy maxima of the standing wave of microwaves within the waveguide 126 that is generated by the magnetron 122.
  • the roasting chamber is comprised essentially of a cylindrical cup 118' that is spun or rotated relative to the waveguide 126 by a rotating shaft 142.
  • the shaft 142 is supported by a bearing assembly 144 and is rotated by a motor 146 that is coupled to the shaft with a belt and pulley system 148.
  • the cup 118' is rotated by the shaft 142 at a high rate (e.g.
  • each bean 12 is exposed to substantially the same dose of microwave energy over time so that each bean 12 is roasted at the same rate to cause consistent roasting of the beans 12 throughout the batch.
  • a fan or blower 150 is coupled to an exterior wall of the housing 140 to cool the magnetron 122 and other electronic components, such as power supply transformer 154 and control circuitry 156.
  • the bottom of the cup 118' includes ports that are small enough to prevent beans 12 from passing there through but that allow air from the blower to pass around the magnetron and through the cup 118'. Because the beans 12 emit water as they are roasted, the air from the blower 150 helps to dry the beans as they are roasted to prevent the resulting chaff from sticking to the inside of the cup 118'.
  • the system and devices of the invention includes a roasting chamber 218 for containing the coffee beans (not shown) while being heated.
  • the roasting chamber 218 is configured to contain the coffee beans within a defined area that encompasses one or more high intensity microwave regions.
  • the microwave energy focusing device such as waveguide 126, is configured such that at least a portion of one microwave energy maxima is located within the roasting chamber 218.
  • the roasting chamber 218 is constructed so as to permit or cause the beans to move within or through one or more high intensity microwave regions.
  • the roasting chamber 18 encompasses a single high intensity microwave region or a portion of a single high intensity microwave region.
  • the roasting chamber may encompass more than one high intensity microwave region, or a portion of more than one high intensity microwave region.
  • the roasting chamber is constructed of a material that is generally transparent to microwaves, such as Teflon, glass, plastic or ceramic, so as to allow the microwaves to pass through the roasting chamber walls and heat coffee beans disposed within the roasting chamber.
  • the dimensions of the roasting chamber wall may also vary without significantly altering the microwave characteristics.
  • the roasting chamber wall may, for example, be anywhere from 1 -15 cm, or in come embodiments from 2-10 cm, or in other embodiments from 3-5 cm. A suitable thickness would, for example, be approximately 4 cm.
  • the devices of the present invention may comprise a plurality of high intensity microwave regions within a single microwave applicator.
  • the devices may also contain a plurality of multiple roasting chambers within the microwave applicator.
  • a single roasting chamber may encompass more than one high intensity microwave region.
  • the roasting chamber need not be concentric with a single high intensity microwave region.
  • the roasting chamber may, for example, pass through the high intensity microwave region on one side of the roasting chamber while the other side of the roasting chamber is not located in a high intensity microwave region.
  • the roasting chamber may pass through all or part of a high intensity microwave region on one side of the roasting chamber, while passing through all or part of a high intensity microwave region on the other side of the roasting chamber.
  • the coffee beans may achieve a sufficiently high level of high intensity microwave heating as long as they are cycling through the roasting chamber and through the separate high intensity microwave regions fast enough that the heating effect of the high intensity microwave region averages out.
  • the roasting chamber 218 for heating coffee beans may include a lower portion 230 and an upper portion 232.
  • the lower portion 230 may be disposed within the waveguide cavity 128 at the location of focused microwave energy within the waveguide.
  • the roasting chamber 218 is configured to be a spinning cup as previously described.
  • the bottom surface 233 is provided with a plurality of apertures 234 through which air can pass as previously discussed with reference to FIG. 2.
  • FIG. 4 is an alternative embodiment of a roasting chamber 250 according to the present invention.
  • the roasting chamber 250 is comprised of a cylindrical cup 252 that is configured to be fixed in place relative to the waveguide.
  • a rotating member 254, such as a bar or paddle is positioned proximate the bottom 256 of the cup 252.
  • the rotating member 254 stirs the beans within the cup 256 as it spins at a relatively high rate (e.g., 300 rpm).
  • a cup 260 having a configuration similar to the cup shown in FIG. 3 may include a bean dispensing opening 262 that is opened and closed with a rotating plate 264.
  • the plate 264 is selectively movable between a first position in which the plate substantially covers the opening 262 to prevent beans from falling from the cup 260 to a second open position shown in FIG. 6 in which beans can be dispensed through the bottom of the cup 260.
  • the roasting chamber 118 may be connected to at least one air source, such as the air blower 150, for circulating air within the lower portion of the roasting chamber 118 and/or for passing air from the lower portion of the roasting chamber 118 to the upper portion of the roasting chamber 118 and out of the top opening of the roasting chamber 118.
  • the air blower 150 for circulating air within the lower portion of the roasting chamber 118 and/or for passing air from the lower portion of the roasting chamber 118 to the upper portion of the roasting chamber 118 and out of the top opening of the roasting chamber 118.
  • the roasting chamber 118 may be configured to allow coffee beans to move within and the through one or more high intensity microwave region within the roasting chamber.
  • the beans may be moved through the high intensity microwave region by airflow within the roasting chamber 118 generated by the air source 150, such as a blower 150.
  • the beans 12 may be moved through the high intensity microwave region by a rotating container 302 within which the beans 12 are disposed.
  • the beans 12 may be moved through the high intensity microwave region by a combination of airflow and a moving container.
  • the rotating container 302 may also include an inwardly facing lip, sufficient to prevent un-roasted coffee beans 12 from being removed from the container 302 by airflow or by centrifugal force of the rotating container.
  • airflow is generated by an air source 320, which then passes around the magnetron 312 and into the container 302. The air flow from the blower 320 then draws smoke generated from the roasting process through the chimney or vent passage 322.
  • the roasting chamber 302 is stationary.
  • a rotating member 324 is rotatably coupled to the cup 302 and positioned in a bottom portion thereof.
  • the rotating member 324 is in the form of a stirring device, such as a rod or paddle that causes stirring or mixing of beans within the cup 302 during roasting.
  • the stirring device may be formed from a material such as Teflon, glass, plastic or ceramic, so as to allow the microwaves to pass through the stirring device.
  • Such stirring provides a substantially even dose of microwave energy to each bean 12 during the roasting period.
  • the stationary cup 302 may rely on airflow to move the coffee beans within or through the high intensity microwave regions.
  • the roasting chamber may rotate or move so as to cause the coffee beans to move within or through the high intensity microwave regions.
  • the air source may cause the beans to travel in a generally circular path in the roasting chamber while the beans are heated to cause more equal roasting of the beans.
  • the air may be heated so as to further decrease the roasting times and to help the exterior of the bean to roast more rapidly as the inside of the bean is roasted with microwave energy.
  • the same air source or an alternate air source may also be used lift roasted beans out of the roasting chamber. It will be appreciated that a bean has a much greater volume for the given mass (which essentially remains the same before and after roasting, less any dissipated moisture after roasting) and thus has increased drag compared to an un-roasted bean.
  • the airflow through the roasting chamber may be configured to have sufficient velocity to carry a coffee bean out of the roasting chamber after the roasting process is complete. That is, the air flow through the bottom of the roasting chamber may be increased to carry out the roasted beans from the roasting chamber upon completion of roasting.
  • the rotating member 324 is rotated relative to the cup 302 with the shaft of electric motor 330.
  • the magnetron 312 is positioned above the waveguide 340 with the antenna 342 extending down into the waveguide 340.
  • a capacitor 344, transformer 346 and other circuitry 348 are positioned within the housing 350.
  • the roasting chamber functions to circulate un-roasted coffee beans within and through one or more high intensity microwave region of high intensity microwave energy, so as to achieve rapid and uniform heating of the coffee beans.
  • the roasting chamber may comprise a container within which un-roasted coffee beans are disposed.
  • the container may be cylindrical in shape or conical or funnel (frustoconical) in shape.
  • the container may be adapted to include one or more air inlets and an outlet. Airflow within and through the container may be utilized to move the coffee beans and achieve a more even distribution of heating of the beans as the movement within and through the one or more high intensity microwave regions results in a sufficiently high average heating of the coffee beans.
  • the container may be configured to rotate so as to move the beans within or through one or more high intensity microwave region, with or without airflow, thereby achieving an average high intensity heating sufficient to cause rapid and uniform heating of the coffee beans.
  • the container may be configured to rotate so as to move the beans horizontally within or through one or more high intensity microwave region, while also being configured to include an air inlet and air outlet for vertical airflow, so as to selectively remove roasted beans from the container with the upward vertical flow of air after roasting.
  • the rotation of the roasting chamber may also be used advantageously to hold coffee beans against the side wall of the roasting chamber by centrifugal force created by rotation of the roasting chamber, thereby increasing the required force of airflow to remove the bean before roasting, and permitting increased force of airflow to achieve selective removal of roasted beans from the container.
  • the rotation of the container further forces un-roasted beans to line up against the side wall, creating a trajectory of the beans at a constant radius through the one or more high intensity microwave region that is well-defined, so as to achieve a more uniform average high intensity heating of the beans.
  • the container may also be configured in the form of a cylinder or cone, with an inwardly facing lip at the top sufficient to prevent beans from exiting the container when the container is rotating. While rotation of the container forces coffee beans to the top by centrifugal force, the lip prevents beans from exiting the container.
  • the roasting chamber may be substantially cylindrical in shape, with vertical side walls, with an inwardly facing lip at the top of the container.
  • the inwardly facing lip is sized so as to prevent beans from exiting the container until roasting is complete.
  • the roasting chamber may be connected to one or more air sources, such as a fan or air blower, for creating airflow within the roasting chamber and causing the coffee beans to move within the roasting chamber.
  • the device comprises one or more airflow inlets and an airflow outlet.
  • the blower causes airflow to pass through the roasting chamber.
  • the blower is configured to cause airflow within or through the roasting chamber from a lower portion of the roasting chamber to an upper portion of the roasting chamber and through the airflow outlet of the roasting chamber.
  • the blower may be configured to cause airflow within the roasting chamber in a horizontal direction so as to cause the beans of coffee to circulate within and through the microwave high intensity microwave region.
  • the roasting chamber may further comprise an air input in the side wall of the roasting chamber, wherein the horizontal of airflow comprises airflow input tangentially into the roasting chamber from the side wall of the roasting chamber at an angle generally perpendicular to the radius of the cylindrical roasting chamber.
  • the blower or other air source may also be configured to cause airflow within the roasting chamber in an approximately circular path and move the coffee beans generally horizontally within the roasting chamber in an approximately circular path within and through the high intensity microwave region.
  • the roasting chamber is cylindrical and substantially circular in cross-sectional shape and the blower is configured to cause airflow within the roasting chamber in an approximately circular path and move the coffee beans horizontally within the roasting chamber in an approximately circular path.
  • an air source may also be provided to cause airflow within and through the roasting chamber in a vertical direction, so as to selectively lift roasted coffee beans upwardly and out of the roasting chamber.
  • the device may be configured with two air blowers, air blower and a second air blower.
  • the blower may be configured to cause vertical airflow from a lower portion of the roasting chamber 18 upwardly to an upper portion 32 of the roasting chamber 18 and thereby selectively move the roasted coffee out of the roasting chamber when roasted.
  • one or more air sources may be configured to create airflow in both a vertical and horizontal direction.
  • the blower may be configured to create airflow in an upwardly spiral direction.
  • the airflow may be configured to form a vortex with the roasting chamber and/or outlet tube.
  • Two separate air sources may be utilized to provide vertical and horizontal airflow.
  • the airflow may be generated, for example, by a first blower and a second blower, wherein the first blower is configured to create airflow in a horizontal direction and the second blower is configured to create airflow in a vertical direction.
  • single blower may be configured to provide airflow in both a vertical and horizontal direction by providing two separate air ducts from the blower to each of the air inlets.
  • each blower may be configured to independently provide a different rate of airflow for the vertical and horizontal airflows.
  • one or more of the blowers may be configured to independently provide sudden or increased airflow for the purpose of removing roasted beans of coffee from the roasting chamber.
  • the vertical and horizontal airflows may independently provide hot air or cold air.
  • the airflow has a flow-rate that will move a volume of beans through a high intensity microwave region sufficient to rapidly and uniformly heat the load of unroasted beans, while maintaining the unroasted beans within the high intensity microwave region without being expelled.
  • heated airflow may be used to remove residual moisture from the roasted coffee beans.
  • the present invention provides a heat source for preheating the one or more beans prior to being disposed within the roasting chamber.
  • the devices of the invention may include a heater for heating the airflow to be passed through the roasting chamber.
  • the un-roasted coffee beans may be preheated by the heated airflow so as to increase the efficiency of the final microwave roasting.
  • the systems and devices may further comprise a heating element to cause heating of the airflow.
  • the air source or blower may include heating elements, which heat the airflow.
  • the air being blown into the airflow chamber may, for example, between ambient room temperature of about 20°C to about 232°C, or alternatively from about 50°C to about 150°C, or alternatively from about 70°C to about 180°C, or alternatively from about 80°C to about 95°C.
  • the coffee beans may be preheated, without resulting in roasting, when heated to a temperature less than 196 °C (385 °F).
  • the roasting chamber within which the coffee beans are dispose may itself be heated.
  • the coffee beans may be preheated within the storage container used to dispense the coffee beans into the roasting chamber.
  • the systems and devices of the invention may also comprise a heat source for preheating the one or more beans prior to being disposed within the roasting chamber.
  • the beans may be preheated with a heat source selected from one or more of a flame, infrared heat, convection heat or heat from a resistive element.
  • the devices of the invention further comprise a control module for controlling the temperature, flow rate, and flow path of the air.
  • a coffee bean storage container 420 which dispenses green coffee beans 422 through the portioning device 486 and into the roasting chamber 423.
  • An inlet in plate 429 is configured to dispense a quantity of coffee beans into the roasting chamber 423. While shown above the roasting chamber, it is contemplated that the inlet may be located either on the side wall, the bottom or the top of the roasting chamber 423.
  • FIG. 8 shows an inlet plate 429 into the top of the roasting chamber 423, allowing coffee beans 422 to be dispensed into the roasting chamber 423 by force of gravity.
  • Coffee beans 422 may be dispensed into the roasting chamber from a storage chamber 420 that is connected to the roasting chamber 423 by means of a dispensing tube.
  • the storage chamber 420 may be located above the roasting chamber 423, where it can dispense coffee beans to the roasting chamber by gravity, or may alternative be located to the side of or below the roasting chamber, where coffee beans would need to be dispense to the roasting chamber by means of a conveyor, lift, plunger or airflow.
  • the inlet plate 429 is configured to dispense the coffee beans 422 into the roasting chamber 423 in such a manner that coffee beans 422 circulating within the roasting chamber 423 do not reenter the dispensing tube.
  • the inlet plate may connect to the roasting chamber at an angle, such that coffee beans circulating in one direction bypass the inlet at an acute angle relative to the angle coffee beans enter the roasting chamber through the inlet and do not reenter the dispensing tube.
  • the storage chamber 420 may also include a metering and dispensing device 486 for controlling the number of coffee beans being released into the roasting chamber 423 in batch mode.
  • the metering and dispensing device 486 may control the rate of flow of coffee beans being released into the roasting chamber 423 for dispensing beans in a continuous mode.
  • the metering and dispensing device 486 may regulate the rate of flow to enable continuous feeding beans into the roasting chamber 423.
  • Such a metering device includes, for example, a microphone for detecting the sound of a bean roasting or a temperature sensor for detecting bean temperature during a roast, coupled to a controller that regulates one or more process parameter, including air velocity, speed of circulating beans, input of new beans, output of roasted beans, microwave intensity, etc.
  • the device of the invention further includes an outlet plate 429 at the bottom of the roasting chamber to selectively discharge roasted beans from the roasting chamber 423.
  • An outlet tube 425 is coupled relative to the outlet plate 429 of the roasting chamber 423 to direct the roasted beans 422' dispensed from the roasting chamber 423 to a grinding mill 424.
  • the microwave devices of the present invention may also include any one of numerous sensory inputs that regulate the flow of coffee beans into the roasting chamber, the rate of airflow, the degree of preheating, etc.
  • the present invention contemplates the use of a microphone roast detector for sensing the sound created by the roasting bean and/or the frequency of the noise of roasting, coupled with the bean flow metering unit that dispenses additional quantities of coffee when the roasting ceases or the frequency of roasting falls below a selected threshold.
  • such inputs may include sudden increased airflow to clean passageways of un-roasted beans or roasted beans that may occasionally adhere to surfaces.
  • beans may be sprayed onto a strip of paper having an edible adhesive surface and the strip of paper with adhere beans may then be fed through the high intensity microwave region where the beans roast and release from the paper, or alternatively roast and remain adhered to the paper.
  • a combination coffee bean roasting, grinding, portioning, and pressing device 410 is constructed in accordance with the present invention with a mounted, detachable delivery filter 414, While such systems for grinding, portioning and pressing coffee are known in the art, the device 410 of the present invention also includes a bean roasting device 421 to uniquely allow raw coffee beans 422 to be freshly roasted for each batch of coffee prepared.
  • the roasting, grinding, portioning, and pressing device 410 includes a whole bean coffee storage container 420 for storage of coffee beans 422.
  • Coffee grinding mills 424 are located under the roasting device 421 and storage container 420.
  • the coffee beans 422 are ground in the mills and delivered from the grinding mills 424 into a ground coffee collection chamber 440.
  • the ground coffee 438 passes from the collection chamber 440 through a motor-driven, rotating pressing tool 450 directly into the detachable delivery filter 414, which is temporarily attached to the device 410, Specifically, the shape and rotational motion of the pressing tool 450 causes the ground coffee 438 to be directed through the tool 450 and into the delivery filter 414.
  • the motorized pressing tool 450 is biased downwardly by a spring tensioning mechanism 470, which transmits force to the pressing tool 450 through a tensioning drive axle 474.
  • the pressing tool 450 transmits this downward force onto the ground coffee 438 as the tool 450 rotates and incrementally and uniformly tamps the coffee into the delivery filter 414.
  • the continual accumulation of compressed ground coffee 456 underneath the pressing tool 450 applies upward pressure against the spring tensioning mechanism 470 and causes the pressing tool 450 to rise upwardly as the tool rotates.
  • a shut-off switch 478 of a portioning control mechanism 480 is activated, completing the portioning process and ceasing the further introduction of ground coffee 438.
  • the amount of ground coffee 438 that is compacted into the delivery filter 414 can be modified using a volume portioning adjustment mechanism 484 which changes the activation position of the predetermined shut-off switch in the portioning control mechanism 480.
  • the coffee bean storage container 420 is located in the upper right hand comer of the coffee roasting, grinding, portioning, and pressing device 410.
  • the storage container 420 generally acts as a funnel for channeling coffee beans 422 to the coffee roasting device 421 .
  • the size and shape of the storage container 420 can be altered in numerous ways without affecting the functionality of the container 420 or departing from the scope of the present invention.
  • the storage container 420 can hold a substantial amount of raw coffee beans 422, so that frequent refilling of the device 410 is not required during extended periods of continuous or near-continuous coffee roasting, grinding and brewing production. Further, the storage container 420 is preferably configured so that gravity alone is sufficient to direct the coffee beans 422 to the roasting device 421 .
  • Raw coffee beans 422 enter the coffee roasting device 421 (configured similarly to the roasting device shown and described in FIG. 7). Once roasted, the roasted coffee beans are dispensed to the grinding mills 424, where the coffee is finely ground and then discharged to the left into the ground coffee collection chamber 440.
  • ail parallel and conical (flat) grinding mills 424 (not shown, but known in the art) are utilized.
  • the grinding mills 424 employ two sets of grinding mills, one conical and one parallel (also not shown). This combination of conical and parallel sets of mills produces a highly beneficial and consistent particle grind uniformity for optimum release of flavor. Additionally, this combination of conical and parallel grinding mills 424 allows the device 410 to grind at a slow, uniform rate that helps prevent over-heating of the mills which can damage the coffee and harm its flavor.
  • the mill drive motor 430 is located in the lower right-hand corner of the coffee roasting, grinding, portioning, and pressing device 410.
  • the motor drive shaft 431 extends upward from the top of the mill drive motor 430.
  • a mill shaft 432 extends parallel to the motor drive shaft 431 and downward from the bottom of the grinding mills 424.
  • the motor drive shaft 431 is connected to the mill shaft 432 by a mil! drive belt 433, thereby connecting the mill drive motor 430 to the grinding mills 424.
  • An internal fan 434 is also connected to the motor drive shaft 431 , just above the mill drive belt 433.
  • the same motion created by the mill drive motor 430 which powers the grinding mills 424 also powers the rotation of the internal fan 434, since the fan is connected to the motor drive shaft 431 .
  • the simultaneous activation of the internal fan 434 in conjunction with the use of the grinding mills 424 acts to cool and prevent overheating of the internal components contained in, and associated with the grinding mills 424. The overheating of these interna! components can result in damaging the flavor of the coffee and in the premature failure of the grinding mills 424 and associated components.
  • the internal fan 434 draws in air from an inlet duct 436 located directly above the fan.
  • the ground coffee 438 is delivered into the ground coffee collection chamber 440.
  • the ground coffee collection chamber 440 is frustoconical in shape, and tapers downward to the helical-shaped pressing too! 50 located in a bottom opening, Beneath the pressing tool 450 is a detachable delivery filter 414, which is temporarily attached to the device 410 by delivery filter attachment, mounts 484. Lining the inside of the delivery filter 414 is a filter container 88.
  • the pressing tool 450 undergoes a rotational motion when activated.
  • the helical shape of the pressing tool 450 provides a path for the ground coffee 438 to pass through the pressing tool and into the delivery filter 414.
  • the helical-shaped pressing tool 450 includes two ramping fins.
  • the pressing tool drive motor 476 is located in the upper left-hand corner of the coffee grinding, portioning, and pressing device 410.
  • the drive motor 476 is connected to the pressing tool 450 by a drive axle 474, and is responsible for powering the rotational motion of the pressing tool 450.
  • the helical configuration and rotational motion of the pressing tool 450 directs the ground coffee 438 through the pressing tool 50 and into the delivery filter 14.
  • a spring tensioning mechanism 470 is connected to the drive axle 474 and transmits a downward force onto the pressing tool 450 through the drive axle 474.
  • the drive axle 474 is slidably received with a rotor 471 that is located above the spring mechanism 470.
  • the upper end of the spring tensioning mechanism 470 attaches to the lower side of the rotor 471 ,
  • the lower end of the spring tensioning mechanism 470 attaches to a concentric disc 472 that in turn is affixed to the drive axle 474.
  • the spring tensioning mechanism 470 biases the drive axle 474, and thus the pressing tool 450 downward, via the attached concentric disc 472, while also allowing the rotation of the drive axle 474 by the drive motor 478 to be compensated for by the rotor 471 .
  • a spring is used to provide the tensioning force in the tensioning mechanism 470, any number of known biasing mechanisms could be utilized therein.
  • An extended disc 475 is also connected to the drive shaft 474 above the rotor 472.
  • the disc 475 provides a substantially flat, circular surface that makes roiling contact with the roller shut-off switch 478 as the extended disc 475 is rotated by the drive motor 476, via the drive shaft 474.
  • the roller shut-off switch 478 activates when the switch has been elevated a predetermined distance (by the extended disc 75).
  • the delivery filter 414 is temporary attached to the device 410 by placing the filter over the depending pressing tool 450 and into matable contact with the attachment mount 464. The delivery filter 414 is then rotated 90 degrees locking the filter 414 into secured engagement with the attachment mount 464. The filter 414 is then removed after being filled with a portioned and compacted amount of ground coffee 456, by rotating the filter 90 degrees in the opposite direction.
  • the operator places coffee beans 422 in the storage container 420, attaches a portable delivery filter 414 to the attachment mount 484, and turns on the machine 410.
  • Turning on the machine 410 activates the roasting device 421 , grinding mills 24 and the rotating pressing tool 50.
  • the roasting device 421 roasts the raw beans 422, mills grinds the whole beans 422 into ground coffee 438, which is directed into the collection chamber 440, the pressing tool 450 at the bottom the chamber 440 and into the delivery filter 414.
  • the pressing tool 450 transmits downward force from the spring tensioning mechanism 470 onto the ground coffee 438 in the delivery filter 414 as ground coffee 438 passes underneath the rotating pressing tool 450.
  • This uniform incremental tamping is produced by the helical pressing tool 50 using a single continuous rotational motion and substantially constant downward force. In this manner, incremental tamping of the coffee is performed as the collection filter 466 is filled from the bottom to the top, producing a compacted coffee "puck" 456 of substantially uniform density.
  • the continual incremental compaction produced by the helical pressing tool 450 avoids the density gradient variations typically found in coffee pucks produced using traditional tamping techniques, which detract from optimal coffee flavor creation. Additionally, the density of the compacted coffee 456 produced by this device can be modified by altering the strength of the spring or other biasing device utilized in the tensioning mechanism 470.
  • the roasting device 421 is positioned below a bean portioning device 486 that selectively receives beans 422 from the container 420.
  • the bean portioning device 486 is sized to receive a quantity of beans 422 from the container 420 sufficient for a single batch of roasted coffee beans for one serving of coffee.
  • the portion of beans 422 in the bean portioning device 486 are then deposited in the roasting chamber 423 of the bean roasting device 421 . After roasting, the roasted beans 422' are passed through a chute 425 to the grinding mill 424.
  • the shaft 431 of the motor 430 is operably coupled to each of the fan 434, roasting device 421 and portioning device 486.
  • the shaft 431 In a forward direction of rotation, the shaft 431 is rotated by the motor at a relatively high RPM, such as about 300 RPM to cause adequate air flow through the system by the fan 434 and to spin the mixing device 427 so as to rotate the beans 422 within the roasting chamber 423 during the roasting cycle.
  • a relatively high RPM such as about 300 RPM to cause adequate air flow through the system by the fan 434 and to spin the mixing device 427 so as to rotate the beans 422 within the roasting chamber 423 during the roasting cycle.
  • beans 422 are prevented from entering the portioning device 486 or the roasting chamber 423.
  • the shaft 431 After roasting, the shaft 431 is rotated in an opposite direction, which may be at a relatively slow RPM, such as about 60 RPM.
  • Each interface between the container 420 and the portioning device 486, between the portioning device 486 and the roasting device 421 and between the roasting device 421 and the grinding mill 424 includes a dispensing plate 429 that is operably controlled by the shaft via a clutch mechanism 431 .
  • the dispensing plate 429 is generally circular with an opening spanning approximately 1/3 of the plate.
  • the bottom end plates 433 of each of the container 420, portioning device 486 and roasting chamber 423 include an opening also approximately equal to 1/3 of the end plate 433.
  • the clutch mechanism 431 causes the dispensing plate 429 to rotate relative to the end plate 433 to align the opening in the end plate 433 with the opening in the dispensing plate 429 thus allowing beans to move between respective components.
  • dispensing from the container 420 to the bean portioning device 486 can occur while the end plate 433 of the bean portioning device is closed.
  • the plates between the container 420 and the bean portioning device 486 are closed and the plates between the bean portioning device 486 and the roasting chamber 423 are opened.
  • water for brewing the coffee cold be dispensed through the roasting chamber and into the brewing portion of the machine. This would be beneficial in cleaning out the roasting chamber after each roast to remove oils and chaff produced during roasting that may remain in the roasting chamber after each roast.
  • water from the espresso machine rinse cycle could be used to clean the roasting chamber.
  • the coffee beans are roasted and espresso is made in a continuous process rather than in single servings. That is, coffee beans are conveyed along a conveyor belt through a roasting device, through a grinding device and then to water extraction. Thus, each bean or at least as small cluster of beans proceeds through the process on a micro scale. A person can then make as small or large of an espresso as desired.
  • the process can be changed throughout the course of making an espresso. For example, one could starting with a light roast and slowing water extraction and then move to a heavy or darker roast with a light water extraction. Vending Machines
  • the systems, devices and methods of the present invention may also be utilized to provide coffee vending machines, for rapid, automated and convenient dispensing of coffee at entertainment venues.
  • automated vending machines may be configured to dispense a specified quantity of coffee to a purchaser upon activation of a purchase transaction via a customer interface, which is used to initiate the transaction by a purchaser.
  • the purchase transaction may comprise payment by coin, paper bill, a debit card or credit card, pre-paid credit/debit card or gift card, internet banking service, token, near-field transmission card (radio frequency identification, or RFID), QR code, or the like.
  • the device may include any suitable customer interface capable of interacting with such payment methods.
  • Such customer interface may include, for example, a magnetic card reader, a near-field reader, a QR reader, or a keypad to manually enter credit card information.
  • the purchase transaction may comprise electronic payment activated by a mobile device. Any suitable method for initiating such a purchase transactions is contemplated herein.
  • the machines may, for example, be connected to the Internet, either by wireless or telephone cable signal, with encrypted transactions being activated by the purchaser on demand, and dispensing of product upon receipt of payment.
  • vending machines contemplated by the present invention will be highly efficient in dispensing coffee to purchasers as a result of the rapid roasting and the unique physical properties of the resulting coffee.
  • the relatively small size of the devices disclosed herein are particularly suitable for vending machines, which may be moved from one venue to another, thus avoiding the need for dedicated machines that remain at a venue permanently, even when no activities at the venue are taking place.
  • the significantly increased roasting rates achieved through the devices and methods of the present invention further expand the utility of coffee roasting machines in commercial, military and humanitarian applications.
  • the high intensity microwave region roasting machines can produce significantly larger quantities of coffee on demand, within less than 20-30 seconds, such that it can keep up with customer demand at large entertainment venues, thereby increasing total sales.
  • the relatively small size of the high intensity microwave region coffee roasting machines makes the machines significantly more portable, such that a single machine can be moved from one venue to another venue, thereby achieving a higher utilization of a given machine.
  • the microwave roasting machines disclosed herein may be operated from any suitable power source, include a standard electrical outlet.
  • Portable machines may be powered either by standard electrical outlets available at the venue source, or may be operated by generator, battery, solar power, automotive power, or other available power supply.
  • Battery or solar powered devices may be useful, for example, when the device is used in remote locations where standard electrical power source is unavailable. It is understood by those skilled in the art that battery or solar powered devices may require modifications to the electronics system that regulates operation of the device.
  • vending machines disclosed herein may also comprise a high capacity storage chamber, suitable for storing sufficient quantities of beans to be dispensed during high demand or for large groups of individuals.
  • Vending machines may also include, for example, metering devices for controlling the quantity of beans dispensed into the roasting chamber.
  • a method for roasting coffee beans 500 includes the steps of selecting a roast type 510, adjusting roasting time 520 according to the desired roast type, powering the microwave emitter 530, detecting roast conditions 540 and dispensing the roasted beans 560 once roasting is complete 550.
  • the system of the present invention allows one to select a light roast 511 , a medium roast 512 or a dark roast 513. Because of the ability to precisely control the roast produced according to the present invention based on time of the roasting alone, it is contemplated that more precisely defined roasts can be selected, such as for example, a city roast, a full city roast, a French roast, a Spanish roast, etc.
  • roasting time can be adjusted based on the rate in which the beans are actually being roasted. For example, roasting times can be affected by a variation in the quantity of beans within the roasting chamber, the elevation at which the roasting is occurring, humidity in the ambient air, etc.
  • the system 500 can adjust the roasting time 520 to produce more accurate roasts based on the roast selected 510 by the user.
  • a system 600 that comprises the steps of passing electromagnetic microwave radiation through a roasting chamber 602 and maintaining at least one antinode 604 of at least one microwave 606 at a substantially fixed location within the roasting chamber 602.
  • the coffee beans 608 are heated with the microwave radiation at approximately the location of the one or more antinode 604.
  • the present invention provides a method for roasting coffee beans, comprising generating in a single-mode resonant microwave applicator 610 a standing microwave energy field comprising an array of one or more anti-node high intensity microwave regions 612 and 614, and subjecting coffee beans 616 to the microwave energy in the one or more high intensity microwave regions 612 and 614, sufficient for the coffee beans to achieve a uniform distribution of microwave energy heat to cause the coffee beans to roast.
  • the roasting chamber 618 encompasses the one or more high intensity microwave regions 612 and 614.
  • the coffee beans are moved, as indicated by the arrow through the microwave high intensity microwave regions 612 and 614 within the roasting chamber 618 to achieve a highly uniform distribution of microwave energy heat until roasted.
  • the present invention provides a method for roasting coffee beans, comprising generating in a resonant microwave applicator 620 a standing microwave energy field comprising an array of anti-node high intensity microwave regions 622-626, and subjecting coffee beans 628 contained within one of a plurality of roasting chamber 630 to the microwave energy in a respective high intensity microwave region 622-626, sufficient for the coffee beans to achieve a uniform distribution of microwave energy heat to cause the coffee beans to roast.
  • Each roasting chamber 630 is positioned at least partially within a respective one of the high intensity microwave regions 622-626.
  • the coffee beans are moved through the microwave high intensity microwave regions 622-626 within the roasting chamber 630 as herein described with respect to other embodiments shown and described herein to achieve a highly uniform distribution of microwave energy heat until roasted.
  • the methods and devices of the present invention are surprisingly effective in rapid and highly complete roasting of coffee beans. Indeed, it has been discovered that the above methods and devices produced coffee produced coffee having unique and unexpected physical properties. While it has previously been believed by those of skill in the art that roasting coffee too quickly or brewing coffee from freshly roasted beans is disadvantageous because of the amount of CO2 still contained in the beans, the coffee beans roasted in accordance with the principles of the present invention have achieved surprising results that appear to show superior and/or at least comparable creme while maintaining desired oils from the beans in the brewed coffee, as compared to coffee brewed from the same coffee beans that have been roasted using traditional methods.
  • the coffee beans are roasted for a significantly longer period of time (e.g., 10-13 minutes) compared to coffee beans that are roasted in accordance with the principles of the present invention (e.g. , 30-40 seconds).
  • oils from the coffee beans roasted by traditional methods have time to seep from the coffee beans That is, despite the retention of oil in the freshly roasted beans of the present invention, which is the creme content and quality remains at least as high as that found when brewing coffee beans roasted by traditional methods.
  • the methods and devices of the present invention improved roasting efficiency (i.e., the completeness of roasting of individual beans).
  • green coffee beans can be completely roasted in a matter of seconds in accordance with the present invention. This allows for use of freshly roasted beans to make coffee once the beans are ground. For example, in preliminary testing using a roasting device of the present invention, 20 ml_ batches of green beans 20 mL of beans were roasted for various times to produce roasts of varying degrees.
  • the drying phase is reached at a bean temperature of 329°F
  • a Cinnamon Roast is reached at a bean temperature of 385°F
  • a New England Roast is reached at a bean temperature of 401 °F
  • an American Roast is reached at a bean temperature of 410°F
  • a City Roast is reached at a bean temperature of 426°F
  • a Full City Roast is reached at a bean temperature of 437°F
  • a Vienna Roast is reached at a bean temperature of 446°F
  • a French Roast is reached at a bean temperature of 464°F
  • an Italian Roast is reached at a bean temperature of 473°F
  • a Spanish Roast is reached at a bean temperature of 482°F If the roast is allowed to progress beyond a Spanish Roast, the coffee will fully carbonize and eventually combust.
  • the coffee roasting system of the present invention it is important for the coffee roasting system of the present invention to be time and/or sensor controlled to prevent over-roasting of the coffee beans that could result in combustion. Moreover, it is important for the coffee roasting system of the present invention to be made of heat resistant materials so as to prevent damage to the components of the coffee roasting system as a result of the high bean temperatures during roasting. Based on the size of the batch of green beans, the roasting times may vary slightly due to the thermal load and other factors, such as elevation, humidity, ambient temperature, etc..
  • FIG. 1 shows a coffee roasting system 10.
  • beans are dispensed into a roasting chamber 18. This may be done from a storage container 66 through a dispensing tube 68 and through an inlet 69.
  • the coffee beans are subjected to microwave energy emitted from an antenna 24 connected to a magnetron 22.
  • the microwave energy is contained in a waveguide 28 to establish a substantially standing wave so that the microwave energy has nodes of minimal energy and anti-nodes of maximal energy.
  • the roasting chamber 18 is disposed about the anti-node so that the coffee beans disposed therein are exposed to high levels of focused microwave energy.
  • the focused microwave energy quickly heats the coffee bean and causes it to "crack."
  • rapid heating of the bean can actually provide improvements.
  • the beans revolve through the area within and around an anti-node, and may be heated more uniformly within the individual beans and as a group. This, in turn, allows the coffee beans to roast to a greater degree.
  • the movement of the coffee beans in the roasting chamber 18 can be any movement of the coffee beans in the roasting chamber 18.
  • the movement of the coffee beans may be accomplished by a spinning cup.
  • the movement of the coffee beans may be accomplished by a stirring device 324 within the cup 302.
  • the movement of the coffee beans may be accomplished by a combination of a spinning cup and a stirring rod, with the stirring rod having one or more upwardly extending arms adjacent the side wall of the cup to cause mixing of the beans within the cup.
  • the stirring rod may be stationary with the cup spinning around the stirring rod.
  • the stirring rod may rotate in a direction opposite the spinning cup to cause the same tumbling effect of the beans within the cup while being roasted to cause each of the beans to be subjected to substantially the same average does of microwave energy during a roasting cycle.
  • a flow of air through the cup to circulate the beans within the cup may be provided in addition to or alternatively to either the spinning cup or the stirring rod as described herein.
  • heating elements may be disposed along the flow of air from the air source to preheat the air. It has been found that preheating the air can improve bean roasting, especially on the exterior of the bean.
  • the heating element is advantageous as it provides additional control over the heating gradient occurring with the coffee beans.
  • the microwave energy heats the water contained in the beans, while the heated air can be used to facilitate exterior roasting within a desired window of time.
  • the airflow can also be used to regulate humidity.
  • the air flow reduces residual moisture within the roasting chamber that may cause chaff from the roasted beans to stick to the sides of the chamber.
  • the air flow through the roasting chamber reduces moisture deposits on the walls of the roasting chamber and also can be used to carry the chaff out of the roasting chamber and collected by a filter or other collection device
  • FIG. 13 there is shown a roasting chamber 718 and a wave
  • the microwave energy 720 has nodes 723 of minimal energy and anti-nodes 724 of maximal energy. At a frequency of 2.45 GHz, the wavelength is approximately 12.2 cm. Thus, the nodes 723 are spaced apart approximately 6.1 cm. Likewise, the anti-nodes 724 are spaced apart a similar distance. In order to contain the un-roasted beans 726 in the area of the anti-node 724 and subject them to maximal energy, the coffee beans are preferably contained in the area most closely surrounding the anti-node 724.
  • the diameter of the roasting chamber 718 may be less than one-half of the wavelength of the microwave energy , or alternatively about one-quarter of the wavelength, such as between about 2.5 and 3.1 cm (1 and 1.25 inches) for 2.45 GHz. As the beans revolve and pass through the anti-node 724, the beans more evenly heat.
  • the roasting chamber 718 is coupled to motor 730, which may be used to rotate the chamber or to rotate a stirring device as previously described to move the beans 726 relative to the microwave energy field 720.
  • Both the motor 730 and the microwave emitter 732 draw power from an electrical power source 734.
  • the motor 730 and the microwave emitter 732 are controlled by a controller 740.
  • the controller includes a processor 742 for executing instructions in firmware or software contained in memory 744 that control the length of time of the roast depending on user selection, or in the case of an espresso machine, to produce a proper roast for making espresso.
  • the controller 740 may also be in communication with one or more sensors 746 to detect roast status during the roast to more accurately produce a specific roast.
  • an annular lip 151 or a series of projections may be disposed adjacent the top of the spinning cup.
  • the lip 151 is preferably sized to contain un-roasted beans.
  • the lip 151 may extend between about 1 -10 mm. Unroasted beans will run into and be held in the roasting chamber by the lip.
  • FIG. 2 shows one embodiment of a microwave wave guide, which can be used in accordance with the principles of the present invention, it will be appreciated that other types of wave guides may be used.
  • an alternative microwave waveguide applicator for roasting coffee beans may includes a magnetron, an antenna and a wave guide, which is generally circular, and a roasting chamber in which the coffee beans may be disposed.
  • the devices of the present invention may also be configured with a portable power supply, such as a battery, solar power generator, or hookup for an automobile battery.
  • a portable power supply such as a battery, solar power generator, or hookup for an automobile battery.
  • the portable device may include, for example, a customer interface operably connected to the electronics system that communicates with a payment source where funds are located for payment of the product resulting from the device.
  • any method or process claims may be executed in any order and are not limited to the specific order presented in the claims.
  • the components and/or elements recited in any apparatus claims may be assembled or otherwise operationally configured in a variety of permutations and are accordingly not limited to the specific configuration recited in the claims.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Tea And Coffee (AREA)
  • Apparatuses For Bulk Treatment Of Fruits And Vegetables And Apparatuses For Preparing Feeds (AREA)

Abstract

L'invention concerne un appareil pour torréfier des grains de café, comprenant une chambre de torréfaction destinée à contenir des grains de café. La chambre de torréfaction est positionnée à l'intérieur d'une cavité résonnante d'un guide d'ondes. Un émetteur de micro-ondes produit de l'énergie micro-onde à l'intérieur du guide d'ondes avec une ou plusieurs régions de micro-ondes à haute intensité stables à l'intérieur de la chambre de torréfaction pour chauffer les grains de café dans la chambre de torréfaction jusqu'à une température suffisante pour torréfier les grains de café. Un dispositif conçu pour déplacer les grains de café à l'intérieur de la ou des régions de micro-ondes à haute intensité est couplé à la chambre de torréfaction.
PCT/US2017/037300 2016-06-13 2017-06-13 Appareil et procédé de torréfaction de grains de café WO2017218568A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP17813955.6A EP3469857A4 (fr) 2016-06-13 2017-06-13 Appareil et procédé de torréfaction de grains de café
CA3027499A CA3027499A1 (fr) 2016-06-13 2017-06-13 Appareil et procede de torrefaction de grains de cafe

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US15/180,780 2016-06-13
US15/180,780 US10412988B2 (en) 2013-03-11 2016-06-13 Apparatus and system for roasting coffee beans

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WO2017218568A1 true WO2017218568A1 (fr) 2017-12-21

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US3492454A (en) * 1965-02-09 1970-01-27 Lyons & Co Ltd J Electronic oven
US5269072A (en) * 1992-05-22 1993-12-14 Felknor International Coffee roaster
US20050238767A1 (en) * 2002-10-16 2005-10-27 Poss Glen T Roasting coffee beans
US20140255569A1 (en) * 2013-03-11 2014-09-11 Sterling L.C. Methods for popping kernels to achieve improved popping yield
EP2729024B1 (fr) * 2011-07-07 2015-09-30 Nuroast, Inc. Contenant, système et procédé pour chauffer des produits alimentaires
KR20150146191A (ko) * 2014-06-23 2015-12-31 심대흠 마이크로웨이브를 이용한 커피볶음기

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US4326114A (en) * 1978-12-11 1982-04-20 Gerling-Moore, Inc. Apparatus for microwave roasting of coffee beans
WO2008087622A2 (fr) * 2007-01-19 2008-07-24 La Miscela Ltd. Torréfacteur café domestique
US8759727B2 (en) * 2010-08-09 2014-06-24 Coffee Technologies, International, Inc. Microwave oven for roasting low moisture foods

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US3492454A (en) * 1965-02-09 1970-01-27 Lyons & Co Ltd J Electronic oven
US5269072A (en) * 1992-05-22 1993-12-14 Felknor International Coffee roaster
US20050238767A1 (en) * 2002-10-16 2005-10-27 Poss Glen T Roasting coffee beans
EP2729024B1 (fr) * 2011-07-07 2015-09-30 Nuroast, Inc. Contenant, système et procédé pour chauffer des produits alimentaires
US20140255569A1 (en) * 2013-03-11 2014-09-11 Sterling L.C. Methods for popping kernels to achieve improved popping yield
KR20150146191A (ko) * 2014-06-23 2015-12-31 심대흠 마이크로웨이브를 이용한 커피볶음기

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EP3469857A4 (fr) 2020-02-26
EP3469857A1 (fr) 2019-04-17
CA3027499A1 (fr) 2017-12-21

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