FR3052024A3 - TORREFACTION MACHINE OF GRAIN MATERIAL, PARTICULARLY GRAIN COFFEE - Google Patents

Abstract

Roasting machine (100) of a granular material, in particular of coffee beans. The roasting machine (100) comprises the following devices: f1) a frame (100A); f2) a roasting drum (40) having an electrical heating device (20) for the granular material; f3) a cooling device (60) of the granular material at the outlet of the roasting drum (40); and f4) a film separator (80). In the roasting machine (100), the electric heater (20) is physically separate from the roasting drum (40) so that the hot air produced by the electric heater (20) is sent to the roasting drum. (40) by means of tubings and by means of a blower (30).

Description

TORREFACTION MACHINE OF GRAIN MATERIAL, PARTICULARLY GRAIN COFFEE

The present invention relates to a machine for roasting a granular material.

In particular, the present invention finds an advantageous, but not exclusive, application in the field of roasting coffee, to which the following description will make explicit reference without losing in generality.

As is known, "roasting" or "roasting" is a generic roasting process, which subjects a substance to a high temperature, so as to dehydrate, oxidize and in some cases burn it partially (depending on the degree). roasting).

Roasting is a widely used process for the preparation of coffee beans, barley, tea leaves or other plants.

In coffee roasting, the grains are subjected to a temperature of 200-220 ° C while being stirred.

The torrefaction processes are essentially two in number: 1) "fluid bed", wherein the raw coffee beans (green coffee) are struck by jets of hot air at a temperature of between 300 ° C and 400 ° C for a few minutes, remaining suspended in the roasting chamber (hence the name of the process); and 2) "rotating drum", in which a metal drum is used, inside which there are Archimedean screws or fins to continuously rotate the product and to uniformize the roasting thereof; and wherein a gas burner feeds the hot air required for the process, for a period of about 15-20 minutes depending on the type of coffee, the degree of moisture of the coffee, the capacity of the roasting machine and the taste of the roaster.

While in the first system, the coffee is roasted much more outside than inside, with taste and preparation abnormalities, the second method significantly improves the aromatic rendering of coffee, by standardizing roasting.

Normally, it is enough to open a grain in two, acting on the clear furrow and observe the interior to realize the quality or not the roasting process.

During such a process, the coffee bean undergoes some transformations such as caramelization of sugars and carbonization of cellulose, processes that give the grain not only its typical color, but also the formation of volatile compounds that confer the typical aroma roasted coffee.

At the same time, some of the caffeine is lost mainly because of high temperatures.

The roasted grain increases its volume by about 30%, while its weight decreases since a major part of the water that composes it, evaporates. An average weight reduction of 15-20% is expected.

The roasting degrees of the coffee have been normalized and starting from unroasted grain (green) unroasted, then to light, cinnamon, medium (medium), high (high), city, full city, French (black) and Italian (Italian).

The roasted coffee tastes slightly bitter, and becomes soluble in water, being more friable (remember that the raw grain is unusable for extraction with constant aromas), more easily reducible powder and therefore suitable for being ground into powder, whose particle size is established according to the process of extraction of liquid coffee.

Roasting is usually an industrial process, although more and more often small roasting facilities are spreading, eventually adopted by hotels, bars, restaurants, etc.

However, a hindrance to further diffusion micro-roasting facilities is constituted by the following disadvantages present in current roasting machines for domestic use: A) congestion and considerable weight of current machines; B) presence of at least one gas burner for producing hot water; this entails the need to comply with special safety standards to prevent fires, explosions, etc. ; (C) the actual dangers of setting the coffee mass on fire because loose films are flammable and if for whatever reason they come on the open flame of the gas burner, they may trigger a very dangerous combustion process for people and for appliances that become unusable; and D) the high costs of producing roasted coffee.

In addition, failed attempts have been made to use electrical resistors for torrefaction inside the roasting drum. The main danger of this type of installation consists in the fact that the films, in contact with the electric resistances, can easily ignite.

The object of the present invention is therefore to provide a machine for roasting a granular material which is free from the disadvantages described above.

Therefore, according to the present invention, there is provided a roasting machine of a granular material, in particular of coffee beans; the roasting machine comprises the following devices: fl) a frame; f2) a roasting drum provided with an electrical device for heating the granular material; f3) a device for cooling the granular material at the outlet of the roasting drum; and f4) a film separator of the roasted coffee beans; a roasting machine in which the electric heating device comprises an electric hot air generator physically separate from said roasting drum, so that the hot air produced by the electric generator is sent to the roasting drum by means of tubing and by through a blowing device.

For a better understanding of the present invention, a preferred embodiment will now be described, merely by way of nonlimiting example and with reference to the attached drawings, in which:

Figure 1 illustrates a three-dimensional overview of a roasting machine of a granular material object of the present invention;

Fig. 2 is an exploded view of the machine shown in Fig. 1;

Figure 3A illustrates a three-dimensional view of a detail of the roasting machine shown in Figures 1, 2; and

Figs. 3B and 3C show, respectively, a plan view and a cross section (section A-A) of the detail shown in Fig. 3A.

In Figures 1, 2, with reference numeral 100, there is shown, as a whole, a roasting machine of a granular material, in particular coffee beans, object of the present invention.

It should be noted that to facilitate the readability of the drawings, the connection pipes have been omitted in the roasting machine 100 shown in FIGS. 1, 2.

The roasting machine 100 comprises the following devices: fl) a frame 100A made with metal elements easily assembled together; f2) a loading hopper 10; f3) an electric hot air generator 20 having a plurality of ceramic electrical resistors (not shown); f4) a blower 30 (with an electric motor 30A) that turns the air in the roasting machine 100 itself (see below); f5) a roasting drum 40 (with horizontal axis (X)) comprising, in turn, a fixed outer sleeve 40A inside which there is a respective small roasting perforation 40B with a 40C electric motor respective suitable for rotating the small perforated basket 40B itself; said small perforated torrefaction basket 40B being provided with a plurality of coulters 40D suitable for stirring and for pushing the coffee beans in the roasting phase; it should be noted that the outer fixed jacket 4OA is provided with a front discharge opening 40E (with a hatch not shown) through which takes place, on demand, the passage of the roasted coffee in a transfer hopper 50 ( see below) ; the front discharge opening 40E is covered by a housing 41; f6) a cooling tank 60 (vertical axis (Y)) (with discharge chute 65 to the outside) of the roast coffee provided with a carousel 60A comprising a plurality of spatulas 60B suitable for mixing the coffee cooling phase; the cooling tank 60 provides the use of a bottom 60C made of metal mesh; as shown in FIGS. 3A, 3B, 3C, below the metal mesh, there is a toroidal element (torus) 67 provided with seven holes 68 (communicating with each other) through which forced suction of the cooling air, to which is attached a suction cooling fan (not shown); f7) a cyclone film separator 80 connected by means of a tubing (not shown) to the blower 30 which draws, from the roasting drum 40, the hot air mixed with the coffee films; in other words, the hot air, mixed with the coffee films, enters the film separator 80 through an opening 80A (arrow (F1)) and after the separation of the films in the cyclone, the air through an opening 80B (arrow (F2)) and is reintroduced into the electric generator 20 through an opening 20A (arrow (F3)); it should be noted, otherwise, that the hot air issuing through an opening 20B (arrow (F4)) is brought to the small perforated basket 40B by an opening 40F (arrow (F5)) made in the closed wall of the bottom of the small perforated basket 40B himself; it should also be noted that the films mixed with hot air leave the small perforated basket 40B through an opening 40G (arrow (F6)), to resume the cycle by entering the opening 80A (arrow (Fl)) the cyclone film separator 80 after passing through the blower 30 (arrows (F7) and (F8)); in other words, the path of the hot air inside the roasting machine 100 is indicated by the succession of arrows (F1), (F2), (F3), (F4), (F5), (F6), (F7), (F8); the film separating device 80 comprises an air discharge system provided with another filter for retaining any slag and volatile films; and f8) a protective casing 90 of an electrical panel and an electronic control unit (CC) suitable for controlling and controlling the various roasting and cooling phases of the coffee and the treatment air.

Of course, the roasting machine 100 is provided with a screen (not shown) and electronic controls (not shown) for controlling and controlling coffee roasting and cooling processes through the electronic control unit (CC) mentioned above. -above.

It should be noted that, for the sake of completeness, the roasting drum 40, in a known manner, is associated with a probe 95 by means of which the operator extracts, periodically, manually, a certain quantity of coffee, in order to verify the degree of roasting.

As mentioned above, an interesting detail is constituted by the toroidal element (torus) 67 provided with seven holes 68 (communicating with each other) through which the forced suction of the cooling air takes place, to which is attached a suction cooling fan (not shown), the suction mouth of which is in correspondence of a zone 69 without holes 68 (FIGS. 3A, 3B, 3C).

In the cooling tank 60, the coffee already previously roasted in the roasting drum 40 is agitated and pushed by spatulas 60B (rotation about the vertical axis (Y)) on the bottom 60C made of metal mesh; it should be noted that in use, the seven holes 68, through which the suction of the cooling air takes place, form types of cooling stations hot coffee, which is, so to speak "braked" and accumulated in correspondence of each hole 68, the time required to allow the arrival of a spatula 60B, which dissipates and pushes forward the small pile of coffee that had formed in the meantime on the hole 68 itself. In use, the green coffee is loaded in the roasting machine 100 by the hopper 10, from which it enters the roasting drum 40. Once roasted, the hatch that closes the front discharge opening 40E s opens, and the roasted coffee, pushed by coulters 40D, falls into the cooling tank 60 below, slipping into the transfer hopper 50.

After cooling, the roast and cooled coffee is discharged from the roasting machine 100 through the unloading chute 65.

The main advantages of the torrefaction machine, object of the present invention, are as follows: i) total dimensions comparable to those of a medium-large household appliance; (ii) absence of gas burners, and therefore the possibility of being installed in any location without the need to obtain specific authorizations from firefighters or other authorities; iii) total suppression of the fire hazards of coffee films as the electrical resistors are contained in a special device at a distance and away from the roasting drum; iv) halving the installed electrical power (7-8 KW against 15 KW of a conventional electric installation) by recycling a large part of the hot air with recovery of the latent heat contained in the hot air itself; v) complete combustion of fumes and absence of polluting substances dispersed in the atmosphere; vi) operation of the vacuum roasting drum and in an anaerobic atmosphere; this means that in case of lack of oxygen, the coffee bean increases by 50% with a complete extraction of moisture, exalting the taste of the other 800 elements included in the coffee, elements which give the coffee itself its special taste and aroma; and (vii) extremely limited roast coffee production costs.

Claims (5)

1. Roasting machine (100) of a granular material, in particular of coffee beans; the roasting machine (100) comprising the following devices: fl) a frame (100A); f2) a roasting drum (40) having electrical heating means (20) for the granular material; f3) a cooling device (60) of said granular material at the outlet of said roasting drum (40); and f4) a film separator (80) for roasting coffee beans; the roasting machine (100) wherein said electric heating means (20) comprises an electric hot air generator (20); said hot air generator (20) being physically separate from said roasting drum (40), whereby hot air produced by said electrical generator (20) is sent to said roasting drum (40) by means of tubings and through blowing means (30). The roasting machine (100) according to claim 1, wherein said blowing means (30) is adapted to circulate air between said hot air generator (20), said roasting drum (40) and a film separator (80). The roasting machine (100) according to claim 2, wherein the air path inside the roasting machine (100) is given by the succession of a plurality of arrows ((F1), ( F2), (F3), (F4), (F5), (F6), (F7), (F8)) of the air itself, from the film separator (80), the electric generator (20) and roasting drum (40). The roasting machine (100) according to any one of the preceding claims, wherein said cooling device (60) is tub-shaped having a carousel (60A) comprising a plurality of spatulas (60B) suitable for mixing coffee in the cooling phase; said cooling device (60) further having a perforated bottom (60C) above which there is a toroidal member (67) having a plurality of interconnecting holes (68) through which the Forced suction of the cooling air. The roasting machine (100) according to any one of the preceding claims, wherein said film separator (80) comprises an air discharge system provided with another filter for retaining any slag and volatile films.