WO2021234444A1 - Device to transport and mix a loose material, machine for the thermal treatment of a loose material and method for the thermal treatment of coffee - Google Patents

Abstract

A transport and mixing device (1) to transport and mix a loose material comprising: a helicoid (2) having a longitudinal extension and a plurality of helices (3); an inner chamber (4); a casing (5) that encloses the helicoid (2) and has an inner surface (6) delimiting the inner chamber (4); and a rotation device (9) to cause the helicoid (2) and the casing (5) to rotate around a rotation axis (A); the helicoid (2) and the casing (5) delimit a passage channel (7) configured to be crossed through by said loose material; at least a part of the inner chamber (4) has a cross-section substantially having the shape of a polygon; and the edges (8a) of the helices (3) are in contact with the inner surface (6).

Description

"DEVICE TO TRANSPORT AND MIX A LOOSE MATERIAL, MACHINE FOR THE THERMAL TREATMENT OF A LOOSE MATERIAL AND METHOD FOR THE THERMAL TREATMENT OF COFFEE"

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no. 102020000012115 filed on May 22, 2020, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a device to transport and mix a loose material, for example coffee, peanuts, dried fruit, pellets, granular construction material, etc., or a liquid material, or a muddy material, to a machine for the thermal treatment of a loose material and to a method for the thermal treatment of coffee.

BACKGROUND OF THE INVENTION

One of the most popular transport devices for loose materials is the so-called screw feed or Archimedean screw. It is a transport device which comprises: a helicoid having a plurality of helices, generally having a circular shape, arranged one after the other along a longitudinal axis of the helicoid; a casing, typically cylindrical-shaped, which encloses the helicoid, delimiting a transport channel together with the helicoid; and a rotation shaft that develops at the longitudinal axis of the helicoid and can be moved to rotate the helicoid and the casing so as to feed the loose material contained in the transport channel.

However, during said transport, the material present inside the transport channel moves while remaining substantially stacked. In other words, during transport, the loose material is substantially pushed forward along the transport channel while maintaining the reciprocal position between the various parts (i.e., between the various grains) of the loose material unaltered, therefore, without any mixing between the various parts (between the various grains) of the loose material.

This represents a problem particularly when said transport and mixing devices are used in processes of thermal treatment of loose material such as, for example, machines for roasting coffee, dried fruit, peanuts, machines for drying pellets, pasteurization machines, etc. In all these cases, the absence of reciprocal movement between the different parts (between the various grains) of the loose material causes the thermal treatment to affect the different parts of the loose material in a non-homogeneous way, with obvious disadvantages in terms of the final result of the process.

The object of the present invention is to propose a device to transport and mix loose material, a machine for the thermal treatment of a loose material and a method for the thermal treatment of coffee, which allow to overcome the drawbacks described above and which, at the same time, are easy and inexpensive to implement.

SUMMARY

According to the present invention, a device to transport and mix loose material, a machine for the thermal treatment of a loose material and a method for the thermal treatment of coffee are proposed, as set forth in the attached independent claims, and preferably, in any one of the claims directly or indirectly dependent on the aforementioned independent claims.

The claims describe preferred embodiments of the present invention forming an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the attached drawings, which illustrate a non-limiting embodiment, wherein: - Figure 1 illustrates a perspective view of a first embodiment of a device to transport and mix a loose material of the invention;

- Figure 2 illustrates a perspective view of a second embodiment of the device to transport and mix a loose material of the invention;

- Figure 3 illustrates an exploded perspective view of the transport and mixing device of Figure 2;

Figure 4 illustrates a perspective view of a part of a transport and mixing device of Figures 2 and 3;

- Figures 5 and 6 illustrate two perspective views of a part of a transport and mixing device made according to two further different embodiments.

DETAILED DESCRIPTION

In Figures 1 to 3, number 1 generally denotes, as a whole, a transport and mixing device to transport and mix a loose material (not illustrated).

In the present disclosure, with the expression "loose material" we intend to refer to any loose material that is not packaged such as coffee, peanuts, dried fruit, pellets, granular construction material, etc., or to a liquid material, or a muddy material .

Advantageously but not necessarily, the transport and mixing device 1 comprises a helicoid 2, which helicoid 2, in turn, has a longitudinal extension (i.e., it develops along a longitudinal axis Y) and a plurality of helices 3 arranged in succession along the longitudinal extension; an inner chamber 4, in which the helicoid 2 is arranged; and a casing 5, which encloses the helicoid 2 and has an inner surface 6 that delimits the inner chamber 4 (see Figures from 1 to 3).

Advantageously but not in a limitative way, the helicoid 2 and the casing 5 define a passage channel 7 (see Figures 1 and 2), which is configured to be crossed through said loose material. In particular, the passage channel 7 comprises (is formed by) the portion of the inner chamber 4 not occupied by the helicoid 2; in other words, the passage channel 7 comprises (is formed by) the space that remains defined between the casing 5 and the helicoid 2.

Advantageously but not in a limitative way (see for example the attached figures), the helicoid 2 has a defined pitch between the various helices 3 (i.e., a distance between one helix 3 and the next one), in particular fixed, and a defined cross-section which, advantageously but not in a limitative way, is repeated unchanged at each pitch. According to other embodiments not illustrated, the pitch between the various helices 3 is variable and/or the cross-section of the helicoid 2 is variable along the longitudinal extension, in particular along the longitudinal axis Y, for example the cross-section is increasing (or decreasing) along the longitudinal extension, in particular along the longitudinal axis Y.

Advantageously but not in a limitative way, the edges 8a of the helices 3 are in contact with the inner surface 6. Specifically, according to some non-limiting embodiments, the helicoid 2 has an outer side edge 8 (which comprises the edge 8a of each of the helices 3 and the edge of the surfaces that connect each helix 3 to the next one), which extends substantially completely in contact with the inner surface 6.

Advantageously but not in a limitative way, at least one part of the inner chamber 4 has a cross-section (in particular, perpendicular) relative to the aforementioned longitudinal extension (in particular, to the longitudinal axis Y) having substantially the shape of a polygon.

It follows that also the cross-section of at least part of the helicoid 2 has the shape of a polygon. Said configuration of the inner chamber 4, and therefore of the passage channel 7, guarantees, in use (i.e., when the transport and mixing device 1 is used to transport and mix loose material), a mixing between the various parts of the loose material. In fact, the conformation of the passage channel 7 (in particular the succession of broken lines which forms the cross-section of the inner chamber 6) induces, in use, a movement of the loose material inside the passage channel 7 also transversely (i.e., substantially perpendicular to the longitudinal axis Y). Said effect is even more felt when the passage channel 7 is filled at most about half of its volume, in particular filled at most about three quarters of its volume.

The polygon (which forms the shape of the cross-section of the inner chamber 4) is, advantageously but not in a limitative way, chosen from the group consisting of: triangle (see Figure 5), square (see Figures 1-4), pentagon (see Figure 6), hexagon, heptagon and octagon.

According to some non-limiting embodiments (such as that shown in Figure 5), the polygon has bevelled vertices. This is particularly advantageous when the inner angles of the polygon are acute angles. In this case, in fact, smoothing the corners avoids the risk of parts (grains) of loose material getting stuck at the vertices of the polygon.

Advantageously but not in a limitative way, the transport and mixing device 1 comprises a rotation device 9 (schematically represented with an arrow in Figures 1 to 3) configured to rotate the helicoid 2 and the casing 5 around a rotation axis A substantially longitudinal relative to the helicoid 2. According to some advantageous but non-limiting embodiments, the rotation axis A is substantially parallel to the longitudinal extension of the helicoid 2; more advantageously, the rotation axis A is an axis of symmetry of the helicoid 2. Even more specifically, according to some non-limiting embodiments (such as those illustrated in the attached figures), the rotation axis A coincides with the longitudinal axis Y of helicoid 2. It is understood that the rotation axis A could also be offset relative to the longitudinal axis Y, i.e., it could be parallel and at a distance defined by the longitudinal axis Y.

According to some non-limiting embodiments, the transport and mixing device 1 comprises, furthermore, a shaft 10 which extends inside the inner chamber 4; in particular according to some advantageous but non-limiting embodiments (such as those illustrated in the attached figures) said shaft 10 extends at the longitudinal axis Y of the helicoid 2 and is, advantageously but not necessarily, integral with the helicoid 2 and with the casing 5. In this case, advantageously but not necessarily, the rotation device 9 comprises an actuator (not illustrated in the attached figures and per se known, for example an electric motor) configured to cause the shaft 10 to rotate around the rotation axis A, so that (being the shaft 10 advantageously integral with the helicoid 2 and the casing 5) the rotation of the shaft 10 is, in use, transferred to the helicoid 2 and therefore to the casing 5.

Advantageously but not in a limitative way, the casing 5 has a plurality of walls 11, each defining one side of the polygon and being in contact with at least a part of the edge 8 of the helicoid 2. According to some advantageous but non-limiting embodiments (at least some of) the walls 11 of the plurality of walls 11 comprise (in particular, are formed by) continuous plates (see for example Figure 1), advantageously but not necessarily made of heat-conducting material, for example a metal material.

Alternatively, according to other advantageous but non-limiting embodiments, (at least some of) the walls 11 of the plurality of walls 11 comprise (in particular, are formed by) perforated plates (see for example Figures 2 and 3), they advantageously but not necessarily, are also made of a heat-conducting material, for example metal.

Said conformation of the walls 11 is particularly advantageous when the transport and mixing device 1 is used inside a machine for thermal treatment of loose material since the perforated walls 11 allow an exchange of heat and/or air between the inside and outside of the passage channel 7.

According to a further aspect of the present invention, a machine (not illustrated) is proposed for the thermal treatment of a loose material.

Said machine advantageously but not necessarily comprises a feeding device (not illustrated), for example a hopper, configured to feed a loose material; at least one transport and mixing device 1 (advantageously but not necessarily of the type described above) arranged and configured so as to receive the loose material from the feeding device and to transport and mix said loose material; and a thermal device configured to exchange heat with the passage channel 7 of the transport and mixing device 1.

The use of one or more transport and mixing devices 1 such as the one described above allows to obtain a more uniform thermal treatment of the loose material. Practically, the fact that the loose material is mixed as it is fed along the passage channel 7 causes the different parts of the loose material to be more uniformly involved in the thermal treatment than using the known transport devices of the known machines for the thermal treatment of loose material.

Advantageously but not necessarily, the feeding device comprises (in particular, is formed by) at least one hopper configured to load the loose material onto the transport and mixing device 1 through a suitable loading mouth.

According to some embodiments not illustrated, at least one of the walls 11 of the transport and mixing device 1 is movable relative to the other walls 11 to define an outlet opening or an inlet opening (for example the aforementioned loading mouth), through which the loose material can be fed or can exit from the transport and mixing device 1.

According to some advantageous but non-limiting embodiments, the machine comprises a plurality of transport and mixing devices 1 (advantageously of the type described above) connected one to the other so as to arrange the respective passage channels 7 in fluidic connection.

In this case, advantageously, during the thermal treatment, the loose material is transported from one transport and mixing device 1 to the next one. For example, the different transport and mixing devices 1 could be characterized by a different feeding speed of the loose material (obtained by varying the speed imparted to each helicoid 2 and to each casing 5 by the respective rotation device 9). This would allow, for example, to feed the loose material more slowly when performing thermal treatments that require a given time (for example during cooking) and to feed the same loose material faster in other sections of the same machine, allowing the optimization of machine operation. Alternatively or in combination, according to other advantageous embodiments, the machine for the thermal treatment of a loose material could comprise a plurality of thermal devices each arranged to exchange heat with a respective transport and mixing device 1, this would allow to perform subsequent thermal treatments (for example heating, cooking, and subsequent cooling) and/or to perform different steps of a same thermal treatment characterized by different temperatures, in a simple and fast way. This allows, furthermore, to create a machine for the thermal treatment of a loose material that works continuously and guarantees better results in terms of homogeneity in the treatment of the material than known machines, with times up to 10 times faster than the times required by the known machines for the thermal treatment of a loose material.

Advantageously but not in a limitative way, the machine for the thermal treatment of a loose material can be a coffee or peanut or dried fruit roasting machine, or a pasteurizing machine for milk or a machine for drying pellets, etc.

In this regard, according to a still further aspect of the present invention a method for the thermal treatment of coffee is proposed, advantageously but not necessarily implemented with a machine for the thermal treatment of a loose material such as the one described above.

In particular, this method comprises an at least partial roasting step, during which a thermal device supplies heat to the coffee beans while they are conveyed along the passage channel 7 of a transport and mixing device 1 made according to any of the embodiments described above. Advantageously but not necessarily, during this roasting step, the thermal device supplies heat to the coffee until reaching (inside the passage channel 7) a temperature of at least 150° C, in particular of at least 200° C, more particularly of at least 250° C.

Advantageously but not in a limitative way, the method comprises a cooling step, at least partially subsequent to the roasting step, during which the coffee beans (after being roasted) are cooled while they are conveyed along the passage channel 7 of a transport and mixing device 1, which can be the same along which the roasting takes place or another transport and mixing device 1 which is arranged in fluidic connection with the transport and mixing device 1 at which the roasting takes place. Advantageously but not necessarily, the method also comprises a feeding step, at least partially prior to the roasting step, during which the coffee is fed to the transport and mixing device 1 (to one of the transport and mixing devices 1, in particular to the one between the transport and mixing devices 1 closest to the feeding device).

It is understood that the transport and mixing device 1 of the invention, as well as the machine for the thermal treatment of a loose material, can be used in various fields of application (other than that of coffee roasting) such as, for example, in the food industry in the cooking processes of peanuts and dried fruit etc., in pasteurization processes, in meat processing plants, for water treatment, in the pharmaceutical industry, in the construction sector for transport and possibly the thermal treatment of granular materials such as cement, bitumen, etc.

The present invention has numerous advantages, among which we mention the following.

Thanks to its particular shape, the transport and mixing device 1 allows, at the same time, to transport and mix loose material; in particular, with respect to known devices to transport loose material, it allows to mix loose material as it advances along the passage channel 7, i.e., to obtain a variation of the reciprocal position of the different parts (of the different grains) that make up the loose material while maintaining similar transport times.

Claims

1. A transport and mixing device (1) to transport and mix a loose material; the transport and mixing device (1) comprises: a helicoid (2) having a longitudinal extension and a plurality of helices (3) arranged in succession along the longitudinal extension; an inner chamber (4), in which said helicoid (2) is arranged; a casing (5), which encloses said helicoid (2) and has an inner surface (6) delimiting said inner chamber (4); and a rotation device (9), which is configured to cause the helicoid (2) and the casing (5) to rotate around a rotation axis (A), which is substantially longitudinal relative to said helicoid (2); said helicoid (2) and said casing (5) delimit a passage channel (7), which is configured to be crossed through by said loose material; the transport and mixing device (1) being characterized in that: at least part of said inner chamber (4) has a cross-section substantially having the shape of a polygon; the edges (8a) of the helices (3) are in contact with the inner surface (6).

2 . The transport and mixing device (1) according to claim 1 and comprising a shaft (10), which extends inside said inner chamber (4).

3. The transport and mixing device (1) according to claim 2, wherein said rotation device (9) comprises an actuator, which is configured to cause said shaft (10) to rotate around said rotation axis (A); the shaft (10) being integral to said helicoid (2) and to said casing (5).

4 . The transport and mixing device (1) according to any one of the preceding claims, wherein said helicoid (2) has an outer side edge (8), said casing (5) has a plurality of walls (11), each defining a side of said polygon and being in contact with part of said outer side edge (8) of the helicoid (2).

5. The transport and mixing device (1) according to claim 4, wherein said outer side edge (8) substantially extends completely in contact with the inner surface (6).

6. The transport and mixing device (1) according to any one of the preceding claims, wherein said helicoid (2) has a defined pitch and a defined cross-section.

7. The transport and mixing device (1) according to any one of the preceding claims, wherein said polygon has a plurality of bevelled vertices.

8. The transport and mixing device (1) according to claim 7, wherein said polygon is chosen from the group consisting of: triangle, square, pentagon, hexagon, heptagon and octagon.

9. The transport and mixing device (1) according to any one of the preceding claims, wherein the casing (5) has a plurality of walls (11), which comprise (in particular, consist of) perforated plates.

10. A machine for the thermal treatment of a loose material comprising: a feeding device, which is configured to feed a loose material; at least one transport and mixing device (1) according to any one of the preceding claims, which is arranged and configured so as to receive said loose material from said feeding device; and a thermal device, which is configured to exchange heat with said passage channel (7).

11. A method for the thermal treatment of coffee; the method is implemented by a machine according to claim 10 and comprises a step of at least partial roasting, during which the thermal device supplies heat to the coffee beans while they are conveyed along said passage channel (7).