Transducer-horn assemblies and applications thereof

Abstract

Extraction devices are provided comprising for the extraction of at least one component of a first phase into a second phase. A holding device is provided for receiving and holding the phases. One or more transducer-horn assemblies are provided, each transducer-horn assembly comprising a transducer and a horn, the horn comprising a base portion and an engagement portion comprising a holding device engaging edge configured for engaging the holding device.

Description

"Transducer-horn assemblies and applications thereof"Technical Field

[0001] The present disclosure relates to transducer-horn assemblies and applications thereof. The present disclosure further relates to extraction devices and methods utilising transducer-horn assemblies. In some embodiments, the present disclosure relates to devices and methods for brewing beverages such as coffee or reducing moisture content in solids materials such as fruits and vegetables.Background

[0002] Extraction processes find application in numerous fields, with many devices and methods provided for performing the extractions. In one such process, solutions may be formed through the contact of solid materials with a solvent to extract components of the solid material into the solvent. One application of such extraction is the preparation of brewed beverages such as coffee, tea and cocoa. Infusion is the inverse process in which components on the liquid solvent enters into the solid material.

[0003] The palatability of a brewed beverage can be impacted by a number of factors such as the brewing temperature and the brewing time. Over-extraction caused by high temperatures and / or long brewing times can produce bitter-tasting beverages. While brewing at lower temperatures can reduce the extraction of bitter-tasting compounds from the coffee grounds or tea, much longer brewing times are required to produce a beverage of sufficient strength and flavour.

[0004] With coffee being among one of the most widely consumed beverages, many techniques have been developed for brewing coffee from ground, roasted coffee beans. Some commonly used brewing techniques include filter coffee, French press, espresso, and Aeropress. More recently, cold brewed coffee has gained popularity.

[0005] The differences between the various methods play a significant role in determining the chemical composition and organoleptic properties of the final beverage.

[0006] In filter coffee, hot water is dripped over ground coffee contained in a coffee filter. The water percolates through the coffee, extracting coffee components such as oils and caffeine, and passes through the filter for collection of the brewed beverage.

[0007] French press involves mixing ground coffee and hot water in a vessel. After the mixture has been allowed to steep for a sufficient amount of time, a strainer is pushed through the mixture via a plunger to trap the coffee solids at the bottom of the vessel. The extracted coffee beverage can then be decanted from the vessel for consumption.

[0008] Espresso is a popular coffee amongst consumers. In this method, finely ground coffee is provided in a filter basket. The coffee is tamped in the filter in order to provide a compact puck. Hot water and / or steam is then forced under high pressure through to produce the coffee beverage. This method is commonly used at commercial cafes and restaurants and forms the base for popular drinks such as lattes and cappuccinos. Espresso has increased in popularity with the availability of home espresso machines allowing consumers to prepare espresso at home.

[0009] AeroPress is a manually operated device comprising a container and a plunger having an airtight seal. Ground coffee and hot water are steeped inside the container in a similar method to the French press. When sufficiently brewed, the liquid is forced under pressure through a filter by moving the plunger through the container.

[0010] Increasing the temperature of the water can assist in reducing time to extract the various components of the coffee into the water. However, increased temperatures can also increase the extraction of components that provide undesirable flavour characteristics such as bitterness to the brewed coffee. As a result, cold brewed coffee has become more popular.

[0011] In cold-brewing techniques, the coffee grounds are contacted with cold or room-temperature water and steeped for relatively long periods of time, typically 12 to 24 hours. The resulting cold-brewed coffee can be preferred by consumers since many of the bitter compounds and acids contained in the coffee are mostly soluble at high temperatures and therefore are not extracted during the cold-brewing technique.

[0012] As one of the most popular and widely-consumed beverages worldwide, consumers continue to seek for improved methods in the preparation of coffee which balance minimising the extraction of undesirable components that can negatively impact the consumers’ enjoyment of the coffee with convenience and consistency.

[0013] The improvement of extraction techniques finds use in many other processes and applications.Summary

[0014] According to one aspect of the present disclosure, there is provided a coffee brewing device comprising: a coffee brewing vessel configured for receiving ground coffee beans and water; and a transducer-horn assembly comprising: a transducer; and a horn comprising: a base portion; and an engagement portion comprising a brewing vessel engaging edge configured for engaging the brewing vessel.

[0015] According to another aspect, there is provided an extraction device comprising for the extraction of at least one component of a first phase into a second phase: a holding device formed of a sheet material, the holding device configured for receiving and holding the phases such that at least one phase contacts one side of the sheet material; a transducer-horn assembly comprising: a transducer; and a horn comprising: a base portion; and an engagement portion comprising a holding device engaging edge configured for engaging the holding device;wherein the transducer-horn is positioned on the other side of the sheet material in a region of maximal acoustic displacement to reinforce the resonance of the holding device.

[0016] It will be appreciated such devices could be used to facilitate extraction of a wide variety of materials, such as soy milk, tea and cannabinoids, with different solvent for extraction, such as water and ethanol, and to enhance the performance of a variety of processes such as crystallization, emulsification, freeze concentration, drying, and processes in aquaculture that require ultrasonic frequencies. Furthermore, it will be appreciated that such devices could be applied to various scales of production, from the production of relatively small- volume batch processes such as brewed coffee, to large- volume industrial scale operations.

[0017] According to another aspect of the present disclosure, there is provided a brewing device comprising: a brewing vessel; and a transducer-horn assembly comprising: a transducer; and a horn comprising: a base portion; and an engagement portion comprising a brewing vessel engaging edge configured for engaging the brewing vessel.

[0018] The transducer-horn is preferably positioned on the other side of the sheet material in a region of maximal acoustic displacement to reinforce the resonance of the holding device.

[0019] According to another aspect of the present disclosure, there is provided a drying device for reducing the moisture content in solid materials, a drying plate configured for receiving the solid materials to be dried; and a transducer-horn assembly comprising: a transducer; and a horn comprising: a base portion; andan engagement portion comprising a drying plate engaging edge configured for engaging the drying plate.

[0020] According to another aspect of the present disclosure, there is provided a method of brewing coffee with a coffee brewing device according to the present disclosure, the method comprising: introducing ground roasted coffee beans and water into the brewing vessel; contacting the engaging edge of one or more transducer-horn assemblies with an outer surface of the brewing vessel; and sonicating the coffee and water mixture.

[0021] According to another aspect of the present disclosure, there is provided a method of reducing the moisture content in solid materials with a drying device according to the present disclosure, the method comprising: introducing the solid materials to be dried onto a surface on one side of the drying plate; contacting the engaging edge of one or more transducer-horn assemblies with a surface on the other side of the drying plate; and sonicating the solid materials.

[0022] The solid materials may be, for example, slices of fruits or vegetables. The solid materials may be flowable, for example a slurry.Brief Description of Drawings

[0023] Embodiments of the present disclosure will now be described by way of example only with reference to the accompanying drawings in which:

[0024] Figure 1 is a perspective view of a first embodiment of a transducer-horn assembly according to the present disclosure, the transducer-horn assembly shown engaged with a filter basket;

[0025] Figure 2 is an eigenfrequency simulation of the total displacement (in meters) of the transducer-horn assembly of Figure 1 at a frequency of 39.8 kH

[0026] Figure 3 shows the horizontal displacement through the centre line of the transducer-horn assembly of Figure 1 at a frequency of 39.8 kH;

[0027] Figure 4 shows the horizontal displacement through a line between the centre line and the edge of the transducer-horn assembly of Figure 1 at a frequency of 39.8 kHz;

[0028] Figures 5A and 5B are perspective views of a first embodiment of a horn according to the present disclosure;

[0029] Figures 6A and 6B are perspective views of a second embodiment of a horn according to the present disclosure;

[0030] Figures 7A and 7B are perspective views of a third embodiment of a horn according to the present disclosure;

[0031] Figures 8 A and 8B are perspective views of a fourth embodiment of a horn according to the present disclosure;

[0032] Figures 9A, 9B and 9C are perspective views of a fifth embodiment of a horn according to the present disclosure;

[0033] Figure 10 is a perspective view of a sixth embodiment of a horn according to the present disclosure;

[0034] Figures 11 A and 1 IB are perspective views of a second embodiment of a transducer-horn assembly according to the present disclosure;

[0035] Figures 12A and 12B are perspective views of a third embodiment of a transducer-horn assembly according to the present disclosure, the transducer-horn assembly shown engaged with a filter basket;

[0036] Figure 13 shows the horizontal displacement through the centre line of the transducer-horn assembly of Figures 12A and 12B at a frequency of 39.8 kHz;

[0037] Figures 14A and 14B are perspective views of a fourth embodiment of a transducer-horn assembly according to the present disclosure, the transducer-horn assembly shown engaged with a filter basket;

[0038] Figure 15 shows the horizontal displacement through a line between the centre line and the edge of the transducer-horn assembly of Figures 14A and 14B at a frequency of 27.7 kHz;

[0039] Figure 16 is a perspective view of a transducer-horn assembly of the type shown in Figures 14A and 14B, shown with a partially transparent transducer;

[0040] Figure 17 shows surface displacement on an elongate brewing vessel with a set of four transducer-horn assemblies engaged with the vessel;

[0041] Figure 18 is a perspective view of an elongate brewing vessel with two sets of four transducer-horn assemblies engaged with the vessel;

[0042] Figures 19A and 19B are perspective views showing the surface displacement on an elongate brewing vessel at resonance where the transducer-horn assembly is engaged with the vessel in a region of maximum displacement;

[0043] Figures 20A and 20B are schematics of methods for industrial extractions in resonating vessels;

[0044] Figures 21A-21D are perspective (21A-21C) and top (2 ID) views showing displacement of a resonating flat plate with five transducer-horn assemblies positioned to reinforce resonance;

[0045] Figure 22 shows the pattern formed by sand on the plate from Figures 21A- 21D;

[0046] Figure 23 is a perspective view of an embodiment of an espresso machine according to the present disclosure, including an exploded view of the portafilter / filter basket / transducer-horn assemblies;

[0047] Figure 24 is a graph showing experimental data of total fatty acids extracted, with and without sonication, as a function of basket loading percentage;

[0048] Figure 25 is a graph showing experimental data of extraction yield, with and without sonication, as a function of basket loading percentage;

[0049] Figure 26 is a graph showing experimental data of total solids, with and without sonication, as a function of brew ratio;

[0050] Figure 27 is a graph showing experimental data of extraction yield, with and without sonication, as a function of brew ratio;

[0051] Figure 28 is a graph showing experimental data of extraction yield, with and without sonication, as a function of sonication time;

[0052] Figure 29 is a graph showing experimental data of extraction yield, with and without sonication, as a function of temperature;

[0053] Figure 30 is a graph showing experimental data of the effect of ultrasound power on drying 2mm thick apple slices at 0 °C; and

[0054] Figure 31 is a graph showing experimental data of the effect of temperature on drying 2mm thick apple slices at various temperatures.Description of EmbodimentsGENERAL DEFINITIONS

[0055] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0056] Each example of the present disclosure described herein is to be applied mutatis mutandis to each and every other example unless specifically stated otherwise. The present disclosure is not to be limited in scope by the specific examples described herein, which are intended for the purpose of exemplification only. Functionally- equivalent products, compositions and methods are clearly within the scope of the disclosure as described herein.

[0057] The term "and / or", e.g., "X and / or Y" shall be understood to mean either "X and Y" or "X or Y" and shall be taken to provide explicit support for both meanings or for either meaning.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the presentspecification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0059] The term “about” as used herein means within 5%, and more preferably within 1%, of a given value or range. For example, “about 3.7%” means from 3.5 to 3.9%, preferably from 3.66 to 3.74%. When the term “about” is associated with a range of values, e.g., “about X% to Y%”, the term “about” is intended to modify both the lower (X) and upper (Y) values of the recited range. For example, “about 20% to 40%” is equivalent to “about 20% to about 40%”.EXTRACTION DEVICE

[0060] According to one aspect of the present disclosure, there is provided an extraction device 100 for the extraction of at least one component of a first phase into a second phase, for example: preparing brewed liquids in which components of a solid are extracted into a liquid; preparing solids of reduced moisture content in which liquid present in a solid material are extracted into a gas or under vacuum (drying); or preparing infusions in which components of a liquid are extracted into a solid material. It will be appreciated that various other combinations of phases and extraction direction may be used without departing from the spirit of the present disclosure.

[0061] Although it may be used for many applications and purposes as outlined above, the extraction device 100 will be primarily described for the preparation of brewed liquids from the extraction of components from solid materials, and more particularly for the preparing of brewed coffee from ground roast coffee beans. The device 100 will further be described for the preparation of dried solid materials from the extraction of liquid from the solids to reduced moisture content, and more particularly for the drying of fruits and vegetables such as apple slices.

[0062] The extraction device 100 comprises a holding device for receiving and holding at least one of the phase(s) to which extraction is to occur. The holding device may be formed of a sheet material, for example sheet metal. The extraction device 100 further comprises one or more transducer-horn assemblies 120 configured forengagement with a surface 111 of the holding 110 and sonicating the phase(s) such that extraction occurs.

[0063] The holding device may comprise an extraction vessel 110 or an extraction plate 310.

[0064] In an embodiment, the extraction is the preparation of a brewed liquid from the extraction of components from solid materials and the holding device comprises an extraction vessel 110 for receiving a solid-liquid mixture and the one or more transducer-horn assemblies 120 are configured for engagement with an external surface 111 of the brewing vessel 110 and sonicating the solid-liquid mixture to produce a brewed liquid.

[0065] In another embodiment, the extraction is the reduction of moisture content in a solid from the extraction of liquid from solid materials, and the holding device comprises an extraction plate 310 for receiving the solid materials on one side and the one or more transducer-horn assemblies 120 are configured for engagement with the other side of the extraction plate 310, and sonicating the solid materials on the plate 310 to produce a dried solid material.

[0066] It will be appreciated that the design of the transducer-horn assemblies described herein allow for sonification to be produced directly into the holding device itself. According to the present disclosure, the acoustic waves, which are generated by the transducer 130, are transmitted directly into the holding device through its wall(s). Furthermore, the described extraction devices can induce acoustic waves around the wall(s) of the holding device, and resonate at natural resonance frequencies of the brewing vessel, helping to homogenise the injection of sound waves, allowing for efficient extraction.TRANSDUCER-HORN ASSEMBLY

[0067] Referring initially to Figures 1 to 4, the transducer-horn assembly 120, shown engaging an extraction vessel 110, comprises a transducer 130 and a horn 140.

[0068] The transducer 130 and the horn 140 may be clamped together with a set screw. The horn 140 provides a connecting transition between the transducer 130 andthe extraction vessel 110, matching the acoustic impedances and allowing for resonance between the three parts of the system: transducer, horn and the extraction vessel.

[0069] Figure 2 shows an eigenfrequency simulation of the assembly for a coffee filter basket 110 filled with water. The model shows a resonance at 39.80 kHz producing sound waves that move through the side of the filter basket 110, permitting sound to be injected into liquid contained in the filter basket 110 not only in the contact point of the horn 140 with the filter basket 110, but in multiple sections of the filter basket 110.

[0070] Referring to Figures 3 and 4, horizontal displacement at a frequency of39.8 kHz through the centre line X and a line X’ between the centre line and the edge of the transducer-horn assembly 120 are shown, respectively.

[0071] On the centre line, the displacement on the transducer section corresponds to a half wavelength, while a second half wavelength occurs in the horn, which amplifies 6 times the displacement in the contact point of the basket. As shown in Figure 3, the displacement ranges from a minimum amplitude of -1.7 x 10'12m to a maximum of10.8 xlO'12m. Greater amplification can be achieved with smaller areas on the edge of the horn 140 that contacts the brewing vessel 110 relative to the area of the horn 140 that contacts the transducer 130. The total horizontal displacement on the assembly on the centre line corresponds to one wavelength (half in each section, the transducer, and the horn).

[0072] Moving away from the centre line, the displacement is slightly larger than one wavelength due to the longer distance through the horn 140. The sound amplitude therefore reaches a maximum before contacting the brewing vessel 110, with the amplitude decreasing prior to the contact point with the brewing vessel 110. These changes from the centre line towards the edges of the transducer-horn assembly 120 matches the formation of sound waves that are induced on the side of the coffee basket, as best seen in Figure 2. This is a result of the resonance achieved between the transducer 120, horn 140 and coffee basket 110, as confirmed by the eigenfrequency model.

[0073] Referring to Figures 21A-21D, the transducer-horn assembly 120 is shown in an alternate embodiment engaging an extraction plate 310.

[0074] As with the extraction vessel embodiment, the transducer 130 and the horn 140 may be clamped together with a set screw with the horn 140 providing a connecting transition between the transducer 130 and the extraction plate, matching the acoustic impedances and allowing for resonance between the three parts of the system: transducer, horn and extraction flat plate.

[0075] The horn 140 comprises a base portion 141, a transition portion 142 and an engagement portion 143 for engaging the extraction vessel 110. The base portion 141 may be of any suitable shape for engaging the transducer 130, for example the base portion may be a cylindrical-base portion. Figures 5-10 show a number of non-limiting embodiments of horn 140 designs with different transitions from the base portion 141 to the engagement portion 143, each capable of achieving resonance with the transducer 130 and the extraction vessel 110 or plate 310.

[0076] In each of the horn designs, the base portion 141, which engages the transducer 130, is provided with a flat surface 144 for engagement with the transducer 130. The engagement portion 143, which engages with the extraction vessel 110, is provided with an engagement edge 145 configured for contacting a surface of the holding device, for example the outer surface 111 of the brewing vessel 110. The edge 145 may be any suitable shape for engaging with the brewing vessel. For example, the edge 145 may have a concave shape such as is shown in the embodiments of Figures 5- 8, a plane shape such as is shown in Figures 9A-10 or a convex shape. It will be appreciated that the horn design may be varied while providing configurations that resonate at the working frequency with the transducer 130 and the extraction vessel 110 or extraction plate 310. The details and dimensions of such configurations may be determined, for example, with mathematical modelling.

[0077] Figures 5A-5B shows an embodiment of a horn 140 with a transition from the cylindrical portion 141 to a hexahedral transition portion 142 to the engagement portion 143. The edge 145 has a concave shape. Figures 6A-6B show an embodiment in which a sloped transition portion from the cylindrical portion 141 to the engagementportion 143 is provided. In another embodiment, shown in Figures 7A-7B, the engagement portion 143 is stepped from the base portion 141. That is, in the embodiment of Figures 7A-7B, there is provided a direct change from the cylindrical to the engagement portion of the horn without a transition portion.

[0078] Figures 8A-8B show an embodiment of a horn 140 with a hexahedral transition portion 142 from the base portion 141 to the engagement portion 143, with the engagement portion 143 being narrower and taller than the embodiments of Figures 5-7. In this embodiment, the engagement edge is concave in shape. In the embodiment of Figures 9A-9C, the horn 140 shows a conical transition 142 with an engagement portion 143 that is cylindrical in shape but with smaller diameter than the cylindrical- base portion 141. In the embodiment of Figure 10, the transition 142 is similar to that of Figures 9A-9C with a rounded transition between portions 142 and 143. The engagement edge 145 of this embodiment is a plane. Figure 9C exemplifies the placing of a node 146 in the horn from Figures 9 A and 9B.

[0079] As seen in figure 9C, 146 is a narrow extension of the cylindrical shape of the horn 140, placed at an acoustic nodal position, used to hold the transducer-horn assembly 120. The shape of the 146 extension can have sharp edges, as in the Figures 9C and 10, or it can be smoothed with concave shapes and smoothed edges and angles.

[0080] Figures 8 and 9 demonstrate that the present disclosure allows for engagement portions 143 having cylindrical or more prismatic shapes while still achieving the intended results. Likewise, in accordance with the present disclosure, the edge 145 that engages with the surface of the holding device may have a concave, convex or plane shape.

[0081] The ratio between the area of the surface of the horn 144 that connects to the transducer and the area 145 that contacts the surface of the holding device permits the amplification of the sound oscillations.

[0082] Although the embodiments described above detail the horn 140 as being a separate element connected to a front side of the transducer 130, in other embodiments the horn 140 may be integrally formed with one or more elements of the transducer 130. For example, as shown in Figures 11A-11B, the front driver 131 of a transducermay be modified to provide the desired horn shape for engagement with an extraction vessel 110 or plate 310.

[0083] With reference to Figures 11A-11B, a Langevin type transducer 130 may be constructed as a halfwave resonator without the need of coupling a horn with a transducer. That is, the front driver 131 of the transducer can be redesigned to contact directly with a surface of the holding device. Figures 11A-1 IB show a transducer design with two piezoceramic materials 133, e.g. PZT-4 ceramics, that are boltclamped between the front and back drivers 131, 132.

[0084] Although the horn 140 will primarily be described herein with regard to the embodiment of the horn as a separate element to the transducer, it will be appreciated the teachings similarly apply to the embodiment of the horn 140 forming part of the transducer 130 (and vice versa).

[0085] Additional embodiments of transducer-horn assemblies 120 are shown at Figures 12A, 12B, 14A, and 14B. In these embodiments, the transducer-horn assembly 120 is provided with a secondary back mass 134. In the embodiment shown in Figures 12A-12B, no gap is provided between the secondary back mass 134 and the transducer 130. In an alternate embodiment shown in Figures 14A-14B, a gap 135 is provided between the transducer 130 and the secondary back mass 134.

[0086] The secondary back mass 134 may be a half wave resonator length, a multiple of half wavelength, or a just a fraction of a wavelength.

[0087] Figure 13 demonstrates that, through the centre line of the “no-gap” embodiment of Figures 12A-12B, a half wave is formed in the secondary back mass 134, in the transducer and in the horn. Figure 15 shows a 3 mm gap, which can range from 0.2 mm to about 20 mm, ensures that there is a half wavelength in the transducer 130 and in the horn 140 of the embodiment of Figures 14A-14B.

[0088] In some embodiments, the secondary back mass 134 may be used to clamp the front and back drivers 131, 132 of the transducer. The secondary back mass 134 may act as a bolt or allow for a bolt to pass through for the mechanical compression of the Langevin transducer. For example, as shown in the partially transparent depiction in Figure 16, showing a transducer-horn assembly 120 of the type shown in Figures 14Aand 14B, the secondary back mass 134 acts as a screw compressing the front and back drivers 131, 132 of the transducer 130.

[0089] Although the application of the disclosed transducer-horn assembly in preparing coffee will be described primarily with regard to espresso machines, it will be appreciated that the described apparatus may be used for other coffee brewing methods and techniques, for example filter coffee, Aeropress and fully automatic coffee machines, among others. Moreover, it will be appreciated such device and methods need not be limited to coffee but could be used to facilitate extraction of a wide variety of materials, or even to other processes such as crystallization, emulsification, freeze concentration, drying, and processes in aquaculture that require ultrasonic frequencies.

[0090] Furthermore, it will be appreciated that the devices and methods disclosed herein could be applied to various scales of production, from the production of relatively small-volume batch processes such as brewed coffee, to large-volume industrial scale operations. Moreover, resonance may be applied to various processing equipment including rotating disk columns, spinning cone columns and centrifugal systems.

[0091] In one such example, the multiple transducer-horn assemblies 120 may be utilised for an elongate vessel 110, such as an industrial cylindrical vessel. In the embodiment shown in Figure 17, a set of four transducer-horn assemblies 120 are provided for contacting the cylindrical vessel 110. The transducer-horn assemblies 120 are each placed at the same height on the cylindrical vessel 110 and are spaced equidistantly around the circumference. As seen in the depiction of surface displacement for this arrangement in Figure 17, sound waves moving in the longitudinal direction of the vessel are produced.

[0092] In another embodiment, as shown in Figure 18, multiple sets of transducerhorn assemblies 120 could be placed at different positions along the vessel 110 in order to induce resonance and sound waves through the walls of the vessel.

[0093] With reference to Figures 19A and 19B, in another embodiment, the transducer-horn assemblies 120 are placed in regions of maximal acoustic displacement in a vessel 110 in order to reinforce the resonance of the vessel 110. Inthese figures, maximal displacement is depicted in black and minimal displacement is depicted in white. Gray tones represent intermediate values.

[0094] In the embodiment shown in Figures 19A and 19B, a horn of the type shown in Figure 10 is used. For simplification, the only one transducer-horn assembly is shown, however it will be appreciated other transducer-horn assemblies 120 can be placed on the maximal displacement regions to reinforce the resonance of the vessel. The number and distribution of the transducer-horn assemblies 120 can be determined depending on the desired acoustic energy and its distribution within the vessel.

[0095] Extraction processes may be performed in batch or in a continuous process, and may be co-current or counter-current. For instance, in a batch process, the Shanks method can implemented.

[0096] In the example shown in Figures 20A and 20B, six extraction vessels are utilised. It is understood that the vessels of Figures 20A and 20B are resonating acoustically via horns located around them as described above. At the beginning of operation, all vessels are filled with fresh solids with the exception of vessel 6. The solvent flows counter-current with respect to the vessels containing the solids. Solvent enters at vessel 1, extract flows from 1 to 2, then 3, 4, 5. The final extract is taken from tank 5 and fresh solids are introduced into vessel 6, completing the first cycle (Figure 20A).

[0097] In the second cycle, depicted in Figure 20B, vessel 1 is removed from the system to clean and to then fill with fresh solid for next cycle. Vessel 6 is connected in the system receiving the extract from vessel 5. Fresh solvent enters vessel 2, and the extracts flow from 3 to 3, 4, 5 and 6 and the final extract is taken from vessel 6. The process continues in the next cycle with vessel 1 receiving the extract from vessel 6, vessel 2 taken out of the system for cleaning, and fresh solvent entering in vessel 3. Subsequent cycles continue in the same manner.

[0098] Referring now to Figures 21A-21D, embodiments in which the holding device is an extraction plate are provided. As can be seen, resonance between the transducer and flat surfaces can be applied to flat plates via horns in a manner similar to that described for extraction vessels. In these figures, maximal displacement is depicted inblack and minimal displacement is depicted in white. Gray tones represent intermediate values.

[0099] As with Figures 19A and 19B, in Figures 21A-21D the transducer-horn assemblies are placed in regions of maximal acoustic displacement (depicted in black in the figures) to reinforce the resonance of the flat plate 310. This can be visualised through the application to a plate having sand particles on its surface, for example as shown in Figure 22.

[0100] Also similarly, the number and distribution of the horns can be determined depending on the desired acoustic energy and its distribution within the surface, with the position of the sand particles corresponding to the nodal regions of the simulation (i.e that correspond with the minimal displacement depicted in white colour in the simulation of Figures 21A-21D).

[0101] In some embodiments, for example where the phase(s) for extraction do not require further containment (e.g. apple slices on the plate surface as described below), the holding device may be the flat plate 310. Alternatively, the holding device may comprise the plate 310 which is further enclosed to hold the phase(s) for the extraction process.

[0102] The plate may be positioned in any suitable orientation for the application, for example the plate may be positioned horizontally, vertically or at an angle. For example, in the example of positioning the plate at an angle, a liquid or a slurry can flow over the surface of the plate due to gravity. Alternatively, the plate may be positioned horizontally with the slurry sitting on the upper surface of the plate. The plate may be used, for example, in drying applications for reducing the moisture content of the slurry or vegetable / fruit placed on the surface.ESPRESSO MACHINE

[0103] With reference to Figure 23, there is provided an espresso machine 200 configured for sonication during coffee brewing.

[0104] The espresso machine 200 comprises a housing 210 having a group head, and a portafilter 220. The portafilter 220 comprises a portafilter head 221 for carrying acoffee filter basket 110, and a handle 222 extending from the portafilter head 221. The portafilter head 221 is selectively engageable with the group head 211.

[0105] The portafilter head 221 is provided with one or more windows 223 in the side wall. In this way, portions of the wall 111 of the filter basket 110 are accessible when positioned in the portafilter head 221.

[0106] The espresso machine 200 further comprises one or more transducer-horn assemblies 120, for example as described above. The horn 140 is configured for engagement with an outer surface 111 of the filter basket 110.

[0107] In an embodiment, the one or more transducer-horn assemblies 120 are movably mounted to the housing 210 in such a way that they are movable between a storage position in which the portafilter head 221 can be brought into and out of engagement with the group head, and a brewing position in which the horns 140 of the transducer-horn assemblies 120 extend through the portafilter head windows 223 and into engagement with the filter basket 110 carried by the portafilter head 221. In an example, the transducer-horn assemblies 120 are rotatably and / or slidable mounted to the housing 210 for moving between the brewing position and storage position. The transducer-horn assembly 120 may connect to the housing 210 through acoustic nodes on the horn or transducer, or through the bolt of a bolt-clamped transducer.

[0108] The machine 200 may be configured to automatically move the transducerhorn assemblies 120 into and out of engagement with the filter basket 110. In some embodiments, the machine 200 may be configured for the operator to manually move the transducer horn-assemblies 120 between positions.

[0109] A locking mechanism may further be provided to hold the transducer-horn assemblies 120 in place during the brewing process. Additionally or alternatively, biasing means may be provided such that the horns 140 apply a pressure in the range of 0 to 10 psi, or more, to the filter basket 110.

[0110] It will be appreciated that existing espresso machines could be modified to incorporate the transducer-horn assemblies and modified portafilters as described herein. Furthermore, the described espresso machine could be implemented oncommercial- size machines as used, for example, in cafes and restaurants, or in household versions of espresso machines.METHOD OF PREPARING BREWED COFFEE

[0111] According to the present disclosure, there is further provided a method of preparing brewed coffee. The method comprises adding ground roasted coffee beans and water into the brewing vessel 110, contacting one or more transducer-horn assemblies 120 with the brewing vessel 110, and sonicating the coffee and water mixture.

[0112] In one embodiment, the method may be undertaken with an espresso machine, for example of the type shown in Figure 23. A method of preparing brewed coffee using an espresso machine comprises providing ground roasted coffee beans to the coffee filter basket 110 carried by a portafilter 220. Preferably, the roasted coffee beans are ground on demand, just prior to preparation of the brewed coffee. In contrast to standard espresso production, the ground coffee does not require tamping in the filter basket 110 as mobility of the coffee-water mixture facilitates extraction via sonication.

[0113] Once the ground coffee is loaded in the filter basket 110, the portafilter 220 is connected to the espresso machine in the conventional manner. Once positioned, one or more transducer-horn assemblies 120 are moved through corresponding windows 223 in the portafilter head 221 and into engagement with the filter basket 110. In the engaged position, the transducer-horn assemblies 120 may apply a pressure in the range of 0 to 10 psi, or more, to the filter basket 110.

[0114] Once the portafilter head 221 is sealed to the group head 211 and the transducer-horn assemblies 120 are engaged, water may be fed to the filter basket 110 to begin the brewing process. This may include a pre-infusion of an amount of water to fill the filter basket 110. The water may be at any suitable temperature, for example from ambient temperature to up to 95°C. Sonication is then applied via the engaged transducer-horn assemblies 120 to produce the brewed coffee.

[0115] Sonication may be applied for a period of time ranging from a few seconds to a few minutes, for example from 10 seconds to 5 minutes. During sonicationultrasound powers ranging from 5 W to 500 W can be applied. The power level depends on the size of the brewing vessel. For instance, industrial vessels may require acoustic powers above 500W. Sonication can be undertaken in a continuous manner, or alternatively two or more periods of sonication may be applied with periods of no sonication in between. In addition, water may be added or brewed coffee collected at various times during the brewing process.

[0116] When properly connected, the portafilter head 221 will seal the contents of the filter basket 110. As such, back pressure may retain most of the liquid in the filter basket 110 during brewing. Depending on the desired properties of the final product, water may pumped to release the brewed coffee in various patterns, such as extracting the brewed coffee at the end of the sonication cycle or with various pump injections at different times during sonication. Cycles of sonication followed by water pumping can also be programmed for longer shots with higher brew ratios.

[0117] Once the brewed coffee extraction is complete, the transducer-horn assemblies 120 are moved from the brewing position to the storage position such that the portafilter 220 containing the spent coffee grounds can be removed.EXAMPLES - COFFEE BREWING

[0118] A method of producing brewed coffee was formed using a transducer-horn assembly in accordance with the embodiment shown in Figure 16. The horn comprised a cylindrical base, a hexahedral transition portion and a planar engagement portion 143. The planar engagement portion 143 has a concave surface 145 at one end that contacts the wall 111 of the brewing vessel 110, the engagement surface 145 being complimentary in shape to that of the outer surface of the filter basket. A Hesentec HS- 4SH-4528 transducer was used in the transducer-horn assembly. A secondary back mass acts as a bolt for clamping the back and front drivers of the transducer, with a 3 mm gap between the secondary back mass and the transducer.

[0119] In the following examples, the coffee was brewed operating the transducerhorn assembly at 38.8 kHz.

[0120] Referring initially to Figures 24 and 25, the effect of basket loading on coffee properties was investigated, where “basket loading percentage” is defined as the mass of coffee in grams divided by the size (capacity) of the filtering basket in grams. The latter is given by the manufacturers of espresso coffee baskets, and it is generally understood as the grams of grounded coffee collected from a grinder that will fill the basket to the top without pushing down or tamping the coffee. The experimental data (with sonication) obtained were compared with control data (without sonication). A Breville 18 g double basket was used in preparing the coffee brews. Sonication was performed following a pattern of equal extractions every minute at room temperature with 100 W of ultrasonic power at 38.8 kHz.

[0121] Fatty acids such as triglycerides contribute to the look, flavour and mouthfeel of a brewed coffee. In an espresso, the fatty acids form the ‘crema’, the foam that floats on top of the coffee.

[0122] Figure 24 shows the total fatty acids extracted with and without sonication for 5 minutes at room temperature as a function of basket loading. As can be seen in Figure 24, extraction of fatty acids when using sonication increases with reduced basket loading percentage. It is understood that this is primarily due to the effects of acoustic cavitation on extraction increases with the water content in the basket. The fatty acid content in coffee brewed without sonication was substantially constant with basket loading percentage, however significantly lower than that with sonication at lower basket loading percentages.

[0123] It has further been observed that brewed coffee prepared with sonication not only increases the presence of fatty acids compared to espresso, but also that sonication leads to emulsification of the fatty acids in the brewed coffee rather than a separate ‘crema’ as seen in espresso. As a result of the emulsification, brewed coffee prepared with sonication lead to milky-looking beverages with caramel tones. In addition, the taste and body (mouthfeel) of the beverage are also improved.

[0124] Figure 25 shows the total extraction yield of solids (dissolved, suspended and undissolved) extracted with and without sonication for 5 minutes at room temperatureas a function of basket loading. As with the fatty acids, the extraction yield was found to increase with reduced basket loading percentage.

[0125] The results shown in Figures 24 and 25 demonstrate that the preparation of brewed coffee with sonication utilising transducer-horn assemblies in accordance with the present disclosure can be achieved with basket loading percentages in the range of 30% to 100%.

[0126] Referring to Figures 26 and 27, the effect of brew ratios on total solids and extraction yield were investigated with and without sonication. The brew ratio is the ratio of the brewed coffee produced to dry coffee used. In these experiments, brewed coffee was prepared using a 25 g VST triple basket with a basket loading percentage of 50%, sonicated for 1 minute at ambient temperature with 100 W of ultrasonic power at 38.8 kHz.

[0127] As demonstrated by Figures 26 and 27, the presently disclosed methods and devices can operate across brew ratios from 1 to 20 and can be used to produce concentrated coffee brews with total solids above 5%, like espressos, by reducing the brew ratio (brew ratios from 1 to 3), as well as diluted beverages with about 1-2% of solids, like filtered coffee or cold brew, by increasing the brew ratio.

[0128] Referring to Figure 28, the effect of sonication time on extraction yield was investigated. For these experiments, brewed coffee was prepared using a 25 g VST triple basket with a basket loading percentage of 50% and a brew ratio of 10, sonicated at ambient temperature with 100 W of ultrasonic power at 38.8 kHz for varying lengths of time.

[0129] Referring to Figure 29, the effect of temperature on extraction yield was investigated. For these experiments, brewed coffee was prepared using a 25 g VST triple basket with a basket loading percentage of 50% and a brew ratio of 10, sonicated for 30 seconds with 100 W of ultrasonic power at 38.8 kHz at varying temperatures.

[0130] The results of the varying preparation temperatures and times demonstrate that methods and devices according to the present disclosure can be operated with times ranging from 5 seconds to 5 minutes and with temperatures ranging from ambient to95°C. That is, the application of sonication as described herein can be used to accelerate the production of espresso- and cold brew-style coffees.EXAMPLES - APPLE DRYING

[0131] A method of drying apples was formed using a plate and transducer-horn assemblies as shown in Figures 21A-21D, and the validation of the resonant patterns on the flat plate surface using sand as shown in Figure 22, with the pattern formed by the sand due to the ultrasonic vibrations moving the sand particles toward the nodal regions of the surface.

[0132] In the following examples, the apples were dried operating the transducer-horn assemblies at 28.88 kHz. Power loading analysis indicated that the ultrasound generator achieved a peak power transmission efficiency of 93.5%, which is significantly higher than previously reported efficiencies of airborne or indirect ultrasound applications, typically below 20%.

[0133] Figure 30 shows the effects of varying ultrasound power levels (0, 50, and 100 W) on the drying kinetics of apple slices of 2 mm thickness using dry air at 0° C. The drying experiments were conducted at low temperatures to protect the quality of the apples by reducing thermal effects, however it will be appreciated that higher temperatures may be used. The total drying time was assessed to achieve a target moisture content of 20%, which corresponds to a water activity level below 0.6, ensuring safe, long-term storage of dried fruits and vegetables.

[0134] As can be seen from Figure 30, ultrasound application at 50 W and 100 W reduced the total drying time by 20.86% and 36.15%, respectively, in 2 mm thick slices, demonstrating a significant decrease in drying time compared to the control samples.

[0135] Figure 27 shows the effect of varying temperatures (-5, 0, and 5°C) on the drying rate. Results indicated that higher temperatures positively influenced the drying rate, leading to a decrease in drying time with increased temperature.

Claims

1. A coffee brewing device comprising:a coffee brewing vessel configured for receiving ground coffee beans and water; anda transducer-horn assembly comprising:a transducer; anda horn comprising:a base portion; andan engagement portion comprising a brewing vessel engaging edge configured for engaging the brewing vessel.

2. The device according to claim 1, wherein the horn further comprises a transition portion connecting the base portion to the engagement portion.

3. The device according to claim 2, wherein the transition portion is sloped from the base portion to the engagement portion.

4. The device according to claim 3, wherein the transition portion is hexahedral or conical.

5. The device according to claim 2, wherein the engagement portion is stepped from the base portion.

6. The device according to any one of the preceding claims, wherein the engaging edge has a complimentary shape to an outer surface of the brewing vessel.

7. The device according to any one of the preceding claims, wherein the engaging edge is concave, plane or convex.

8. The device according to any one of claims 1 to 7, wherein the horn is connected to the transducer.

9. The device according to any one of claims 1 to 7, wherein the horn is integrally formed with the transducer.

10. The device according to any one of the preceding claims, wherein the transducer comprises a front driver clamped to a back driver.

11. The device according to claim 10, wherein the front driver defines the horn.

12. The device according to claim 10 or claim 11, further comprising a secondaryback mass.

13. The device according to claim 12, wherein the secondary back mass clamps the front driver to the back driver.

14. The device according to claim 12, wherein the front driver is clamped to the back driver via a bolt passing through the back mass.

15. The device according to any one of claims 12 to 14, wherein a gap is provided between the secondary back mass and the back driver.

16. The device according to any one of the preceding claims, further comprising:a portafilter comprising:a portafilter head configured to receive and carry the brewing vessel in the form of a coffee filter basket, the portafilter head comprising a side wall having one or more windows for receiving a horn therethrough for contact with the filter basket carried therein; anda handle extending from the portafilter head, anda housing comprising:a group head for selectively securing the portafilter head; anda water source.

17. The device according to claim 16, wherein the transducer-horn assembly is movable between:a brewing position in which the horn extends through the window of the portafilter positioned in the group head such that the engaging edge of the horn contacts an outer surface of the filter basket; anda storage position in which the horn is withdrawn from the window, allowing movement of the portafilter head into and out of engagement with the group head.

18. The device according to claim 17, further comprising a locking mechanism for locking the transducer-horn assembly in the brewing position.

19. The device according to claim 17 or claim 18, further comprising a biasing means for applying pressure of the horn on the filter basket in the brewing position.

20. The device according to any one of claims 16 to 19, wherein the transducerhorn assembly is movably mounted to the housing.

21. The device according to any one of the preceding claims, comprising two or more transducer-horn assemblies.

22. The device according to claim 18, wherein each transducer-horn assembly is configured to contact the filter basket at the same longitudinal position.

23. An extraction device comprising for the extraction of at least one component of a first phase into a second phase:a holding device formed of a sheet material, the holding device configured for receiving and holding the phases such that at least one phase contacts one side of the sheet material;a transducer-horn assembly comprising:a transducer; anda horn comprising:a base portion; andan engagement portion comprising a holding device engaging edge configured for engaging the holding device;wherein the transducer-horn is positioned on the other side of the sheet material in a region of maximal acoustic displacement to reinforce the resonance of the holding device.

24. The extraction device according to claim 23, wherein the extraction device comprises two or more transducer-horn assemblies, wherein each transducer-horn assembly is positioned on the other side of the sheet material in regions of maximal acoustic displacement to reinforce the resonance of the holding device.

25. The extraction device according to claim 23 or claim 24, wherein the holding device comprises an extraction vessel formed of the sheet material.

26. An extraction device according to claim 25, wherein the extraction vessel is a cylindrical extraction vessel formed of the sheet material.

27. An extraction device according to claim 23 or claim 24, wherein the holding device comprises an extraction plate formed of the sheet material.

28. The device according to any one of claims 23 to 27, wherein the horn is connected to the transducer.

29. The device according to any one of claims 23 to 28, wherein the horn further comprises a transition portion connecting the base portion to the engagement portion.

30. The device according to claim 29, wherein the transition portion is sloped from the base portion to the engagement portion.

31. The device according to claim 30, wherein the transition portion is hexahedral or conical.

32. The device according to claim 29, wherein the engagement portion is stepped from the base portion.

33. The device according to any one of claims 23 to 32, wherein the engaging edge has a complimentary shape to an outer surface of the brewing vessel.

34. The device according to any one of claims 23 to 33, wherein the engaging edge is concave, plane or convex.

35. The device according to any one of claims 23 to 34, wherein the horn is integrally formed with the transducer.

36. The device according to any one of claims 23 to 35, wherein the transducer comprises a front driver clamped to a back driver.

37. The device according to claim 36, wherein the front driver defines the horn.

38. The device according to claim 36 or claim 37, further comprising a secondaryback mass.

39. The device according to claim 38, wherein the secondary back mass clamps the front driver to the back driver.

40. The device according to claim 38, wherein the front driver is clamped to the back driver via a bolt passing through the back mass.

41. The device according to any one of claims 38 to 40, wherein a gap is provided between the secondary back mass and the back driver.

42. A brewing device comprising:a brewing vessel; anda transducer-horn assembly comprising:a transducer; anda horn comprising:a base portion; andan engagement portion comprising a brewing vessel engaging edge configured for engaging the brewing vessel.

43. A drying device for reducing the moisture content in solid materials, a drying plate configured for receiving the solid materials to be dried; and a transducer-horn assembly comprising:a transducer; anda horn comprising:a base portion; andan engagement portion comprising a drying plate engaging edge configured for engaging the drying plate.

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