FR2791227A1 - Roasting of small batches of coffee beans, in a cafe, using a compact device, which does not release unpleasant odors - Google Patents

Abstract

Raw coffee beans are roasted in a rotating drum (12) at 190 to 210 deg C. During roasting fumes and dust are sucked away (29, 31 and 55). After about 20 minutes a sample of beans is taken. If they are sufficiently roasted they are transferred to a cooling chamber (40) where they are gently agitated (46 to 50) and cooled.

Description

APPARATUS FOR ROASTING GREEN COFFEE

  The invention relates to an apparatus for roasting the

green coffee.

  At present, the ratio of the purchase price between a kilogram of roasted coffee and a kilogram of green coffee is around four. For this reason, and in particular for the purposes of use by sales professionals, many roasting devices of very different designs have been developed to enable these professionals

  to roast their coffee themselves.

  By way of example, such roasting devices are described in particular in patents US-5,387,256, US-5,322,005, US-3,153,377, EP-213,645, EP-41,082, FR-2,626,161 and GB-860894, and incorporate, in addition to means for roasting green coffee, means for grinding roasted coffee and percolation means, so that they have a chain of suitable elements

  to provide ready-to-drink coffee from green coffee.

  One of the drawbacks of such devices lies in the fact that green coffee is percolated almost immediately after being roasted. Indeed, and contrary to the assertions put forward in several of the aforementioned patents, this operating method does not make it possible to obtain a coffee having an optimal aroma and scent, because, contrary to these preconceived ideas, for that a coffee has an optimal flavor, on the contrary it should be left to rest the roasted coffee for a few hours while keeping it covered with a cloth or

  by enclosing it in a container, in order to avoid the dispersion of the aroma.

  Another drawback of the aforementioned current devices lies in the fact that they generally require being associated with various additional elements such as ventilation means, etc., allowing them to operate in compliance with safety standards and without the risk of inconvenience. users and

  consumers, in particular by smoke.

  The present invention relates to a different approach from the aim sought and has the essential objective of providing a fully autonomous roasting apparatus capable of operating without any nuisance for the

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  users and consumers, and designed to provide roasted coffee

  with optimal flavor characteristics.

  Another objective is to provide a compact roasting device capable of allowing it to be easily implanted, in particular on trolleys on which conventional percolators are installed. To this end, the invention relates to an apparatus for roasting green coffee comprising: - a rotary drum incorporating brewing means, and provided with an open front face, said drum being placed in a thermally insulated enclosure o0 provided with a fixed front wall for closing off the open front face of the latter, and incorporating electric heating means, - a container provided with a bottom wall closed by a valve with manual opening, arranged so as to allow feeding the rotary drum in green coffee by means of a conduit opening into a lumen formed in the front wall of the enclosure, facing the upper volume portion of said drum, - smoke extraction means comprising a conduit d extraction opening into the enclosure, and suction means able to allow the suction of fumes and films inside the duct through at least one passage formed between the drum r otative and said enclosure, - a filtration unit disposed at the outlet of the extraction duct and comprising a film deposition compartment and at least one filter capable of roasting the fumes, - a duct for emptying the rotary drum extending into the extension of a light provided in the fixed front wall of the enclosure, opposite the portion of lower volume of said drum, and closed by a shutter with manual opening, - means for receiving roasted coffee comprising a container disposed at the plumb with the emptying duct, said container having a bottom wall provided with perforations of dimensions smaller than those of the coffee beans,

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  means for cooling the roasted coffee contained in the container, comprising means for brewing said coffee and suction means capable of generating a circulation of air for cooling said coffee by sucking air through perforations made in the bottom wall of said container. Such an apparatus is designed in the first place to ensure the roasting of green coffee in a rotary drum brought to an adequate temperature by means of electric heating, roasting during which, on the one hand, the fumes are evacuated to a filtration unit o these last are "toasted"

  io before being released into the atmosphere, and on the other hand, the films are themselves

  same evacuated and recovered in the filtration unit.

  In this way, such a roasting apparatus operates completely independently without risk of harm to users and consumers. In addition, once roasted, the coffee is immediately cooled naturally by degasification in the open air so that this cooling does not in any way affect the aroma of the roasted coffee, which can then be kept for a few hours before being ground, to provide a coffee with an optimal flavor. Such a cooling mode also makes it possible to entrain any remaining dandruff so that the roasted coffee is cooled

presents an optimal cleanliness.

  It should also be noted that, according to the invention, the roasting and cooling operations are completely independent, so that the cooling of a quantity of previously roasted coffee can be carried out in masked time during the roasting of a new quantity of coffee. Furthermore, due to the arrangement of the various constituent elements arranged substantially one above the other, so as to obtain a path of gravity of the coffee between said elements, such a roasting apparatus has an optimal compactness making it possible for example to

  arrange on sideboards designed to support conventional percolators.

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  According to another characteristic of the invention, the suction means for cooling the roasted coffee comprise a duct connected to the filtration unit. Thus, the hot air resulting from the cooling of the roasted coffee

  it also passes through the filtration unit before being released into the atmosphere.

  In addition, and preferably, the respective suction means for extracting the fumes and cooling the roasted coffee comprise a single fan, to which the duct is connected, on the suction side.

  and the cooling duct.

  According to another characteristic of the invention, the receptacle io for receiving roasted coffee is able to slide horizontally between a position, called filling, where it extends at least partially in line with the rotary drum, and a position, called cooling, where it extends in position

  advanced with respect to said rotary drum.

  This arrangement has the essential advantage of allowing i5 to position the container in an advanced position where it is clear of the size of the device, so as to promote the cooling of the coffee and to facilitate the subsequent emptying of said container, without lead to an increase in the size of said device due to the possibility of moving the container back a

once it has been emptied.

  To this end, moreover, and advantageously, the container is carried by a drawer forming a closed enclosure into which the

cooling duct.

  According to another characteristic of the invention, the brewing means for cooling the roasted coffee comprise at least one scraper and means for moving each scraper on the bottom of the container.

  cooling along a circular path.

  In addition, the container advantageously has a cylindrical shape and has a drain hatch formed in a peripheral zone of its bottom wall. In addition, the brewing means then advantageously comprise at least two scrapers oriented so as to push the coffee towards the periphery of the container, said scrapers being offset.

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  radially so as to sweep concentric surface portions of the wall

bottom of said container.

  Such brewing means therefore make it possible, in addition to their function of helping to cool the coffee, to empty the container automatically once this cooling has taken place, after opening the hatch. According to another characteristic of the invention, the roasting apparatus comprises two scrapers each mounted towards one of the ends of a diametrical horizontal rod by means of adjusting the position along said rod and the orientation of said scraper, said rod being secured to an axial vertical shaft extending through the bottom wall of the

  container and carried by motor drive means for rotating said shaft.

  Furthermore, the enclosure advantageously has a film recovery volume disposed under the rotary drum at the rear of the fixed front wall, so as to receive said films through a space formed between said rotary drum and front wall, said volume containing a film reception drawer accessible from one of the

side walls of the enclosure.

  According to another characteristic of the invention, the roasting apparatus comprises a sample-taking chute extending in the rotary drum through an orifice formed in the front wall, so as to

  allow the control of the burning aspect of the coffee.

  Furthermore, the filtration unit advantageously comprises

  at least one electrostatic filter.

  Other characteristics, aims and advantages of the invention

  will emerge from the detailed description which follows with reference to the appended drawings

  which represent, by way of nonlimiting example, a preferred embodiment. In these drawings: FIG. 1 is a perspective view of a roasting apparatus according to the invention shown attached to a percolator of the conventional type,

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  - Figure 2 is a longitudinal section through a vertical plane A of this percolator, in the remote position of the container for receiving roasted coffee, - Figure 3 is a longitudinal section through the vertical plane A, in the advanced position of the container receiving the roasted coffee, - FIG. 4 is a partial longitudinal section through the vertical plane A, on an enlarged scale, of this roasting apparatus, - FIG. 5 is a partial cross-section thereof on an enlarged scale through a vertical plane B, - Figure 6 is a schematic longitudinal section through a vertical plane of the filtration unit of this roasting apparatus, - and Figure 7 is a top view of the container

  reception of roasted coffee from this roasting machine.

  The roasting apparatus according to the invention shown in FIGS. 1 to 7 constitutes a fully autonomous apparatus designed for roasting green coffee and then naturally cooling the roasted coffee, without causing any nuisance for the occupants of the premises in which said apparatus is installed. . In addition, as shown in Figure 1, its design leads to the production of a depth device combined with that of percolators 1 for conventional professional use, allowing it to be installed on worktops

  designed to receive such percolators.

  As shown in FIG. 1, this roasting apparatus comprises a main unit 2 for roasting and cooling the coffee, and a filtration unit 3, said units being of dimensions suitable for being installed, for example, respectively next to and above a percolator 1, from

  so as to form a compact whole.

  The roasting and cooling unit is first of all in the form of a casing 4 of generally rectangular parallelepiped shape, the front wall 4a of which is pierced by two superposed orifices: a circular upper orifice closed by a facade plate 5 , and an orifice

  lower housing the means for cooling roasted coffee.

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  This roasting and cooling unit further comprises a U-shaped duct 6 of section fixed to the front plate 5,

  intended for the transport of coffee to the various elements, as described below.

  The casing 4 contains, firstly, a thermally insulated cylindrical enclosure 7, having an open front face of combined dimensions of the circular orifice of the front wall 4a of said casing, adapted to be secured to said front wall so as to spread in

look of said circular orifice.

  The lower portion of the peripheral wall of this 0o enclosure 7 has, in addition, a cutout in which a tank 8 opens out secured to said peripheral wall, in the upper part of which are disposed

  electrical resistors such as 9.

  The enclosure 7 contains, moreover, an internal peripheral conduit 10 formed near its open face, in excess of its peripheral wall, said conduit extending between the tank 8 and the upper generator of

  said enclosure and opening through a mouth 11 at said generator.

  The roasting and cooling unit further comprises a rotary drum 12 housed in the enclosure 7 and secured by means of internal cross-pieces 13, 14 to a horizontal shaft 15 rotatably mounted in bearings 16, 17 positioned from on either side of said enclosure, and driven into

  rotation by an electric motor 18.

  As shown in Figures 1 to 3, one of the bearings 16 is disposed between the respective rear front walls of the enclosure 7 and the casing 4 and secured to the latter. The second bearing 17 is in turn secured to the

front plate 5.

  The rotary drum 12 has an open face opposite the front plate 5 and is arranged so that there remains a space between said open face and front plate. In addition, it has a

  rear front wall 19 having a mesh structure.

  This rotary drum 12 also incorporates three blades

  internal longitudinal ones such as 20 distributed around its longitudinal axis.

  Each of these blades 20 is secured to the peripheral wall of the rotary drum

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  12 so as to extend a short distance from the latter, and presents

  longitudinally the curved shape of a section of helical turn.

  The roasting and cooling unit also comprises a drawer 21 for recovering the films, arranged in an enclosed space 22 formed under the rotary drum 12 between the tank 8 and the front plate 5, said drawer being accessible at level '' an opening in one of the

  side walls 4b of the casing 4 and being provided with a handle 23 for handling.

  The routing of the green coffee to the rotary drum 12 is carried out, as mentioned above, by means of the conduit 6, from a bowl 24 for storing said coffee having the shape of a funnel fitted in a sleeve 25 extending projecting from the upper wall of said duct, said bowl being equipped with a shutter 26 consisting of a plate 27 for closing the neck of the funnel

  secured to a rod 28 for maneuvering said shutter.

  In view of this routing, and first of all, the front plate 5 is pierced with a rectangular opening 29 arranged opposite the upper volume portion of the rotary drum 12, and having a lower edge 29a with oblique profile inclined in the direction of said rotary drum. The duct 6 integrates, for its part, an inclined transverse wall 30 extending in the

  continuity of the lower edge 29a of the opening 29, and closing said conduit.

  For the evacuation of smoke and films by suction, as described below, the front plate 5 has, in addition, a second opening 31 formed above the opening 29 above, so as to be located substantially in the same horizontal plane as the mouth 1 of the conduit 10. In addition, a transverse partition 32 in the shape of a canopy is disposed above this opening 31 so as to prevent the green coffee from escaping through

the latter.

  The roasting and cooling unit also includes a dial pyrometer 33 arranged so that the end of its

  sensitive element extends in the rotary drum 12 through the opening 29.

  It further comprises a chute 34 for taking samples extended by a handle 35, and slidably mounted in a horizontal sleeve 36 integrated in the conduit 10, so as to open into the rotary drum 12 through

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  an orifice in the front plate 5, and to allow the appearance to be checked

of burning coffee.

  The roasting and cooling unit also comprises means for emptying the rotary drum 12 making it possible to evacuate the roasted coffee by rotation of said rotary drum, under the effect of the action of the blades 20. These emptying means comprise an opening 37 formed in the front plate 5 so that the lower edge of said opening coincides with the lower portion of the peripheral wall of the rotary 0o drum 12, in order to deliver the roasted coffee in the lower longitudinal section

of duct 6.

  This opening 37 is, moreover, closed by a flap 38 mounted pivoting about a horizontal axis extending laterally relative to

  to conduit 6 and secured to a lever 39 for manual actuation of said flap.

  Finally, the roasting and cooling unit includes a set for receiving and cooling the roasted coffee arranged

  to extend in line with the lower end of the duct 6.

  This assembly comprises, firstly, a cylindrical container 40 carried by a drawer 41 provided with a handle 41a and delimiting a closed enclosure, said drawer being mounted in horizontal slides such as 42 so as to allow the container 40 to be positioned, either in a retracted position, shown in FIG. 2, o said container is partially housed in the casing 4, or in an advanced position o this container 40 extends, for its

  most of it outside the housing 4.

  The container 40 furthermore comprises a hatch 43 for emptying formed in a peripheral zone of its bottom wall, and associated with an external handle 44 for operating said hatch. It also includes

  perforations defining a grid 45 formed in its bottom wall.

  The receiving and cooling assembly further comprises means for brewing the coffee in the container 40. These brewing means comprise two scrapers 46, 47 each mounted at one of the ends of a horizontal rod 48 arranged diametrically in the container o 2791227, and secured to an axial vertical shaft 49 extending through the bottom wall of said container, said shaft being driven in rotation by a motor 50 housed

in drawer 41.

  The two scrapers 46, 47 are, moreover, oriented so as to push the coffee in the direction of the hatch 43, and offset radially with respect to each other so as to sweep complementary concentric surfaces of the bottom wall of the container 40. In addition, these scrapers 46, 47 are mounted on the rod 48 by means of adjustment means 51 of a type known per se

  allowing to adjust their orientation and their position along said rod.

  The roasting and cooling unit finally comprises a fan 52, the suction of which is connected by two flexible pipes 53, 54 respectively at the end of the conduit 10 opposite the mouth 11, and to the drawer 41, so as to '' on the one hand, to evacuate the fumes and dandruff during roasting, and on the other hand, to generate an air circulation through the

  grid 45 of the container 40, during the cooling of the coffee.

  The discharge outlet of this fan 52 is

  it connected to the filtration unit 3 via a flexible pipe 55.

  As shown in FIG. 6, this filtration unit 3 comprises a volume 56 for recovering films and then two successive electrostatic filters 57, 58 for roasting the fumes which are then

  evacuated through a grid 59.

  Finally, and conventionally, the roasting device according to the invention comprises means for controlling the various aforementioned elements and for controlling the operation of the latter. As shown in FIG. 1, by way of example, these command and control means can integrate: - concerning the roasting unit 2: a thermostat 60 for adjusting the desired temperature inside the rotary drum 12 , 30. three on / off buttons 61, 62, 63 for controlling the electric motors 18 and the electric resistors 9, the electric motor 50 and the fan 52, ll 2791227

  two operation indicators 64, 65.

  - for the filtration unit 3, a control button

  for switching on the electrostatic filters 57, 58.

  The operation of the roasting device as described above is as follows: - firstly, the first operation consists in heating the rotary drum 12 by means of electrical resistors 9, operation during which said drum rotary 12 is driven in rotation by the electric motor 18. By way of example during this heating up, the 1st desired temperature obtained inside the rotary drum is between and 210. This temperature is adjusted by means of the thermostat 60 and can be checked by means of the pyrometer 33, - once the desired temperature inside the rotary drum 12 is obtained, a dose of green coffee contained in the bowl 24 is delivered by gravity to inside said rotary drum, by lifting the shutter 26. As an example, the roasting device is designed to roast doses of 1.5 to 2 kg of green coffee, - this dose of green coffee is then roasted by being simultaneously driven in rotation and stirred in the rotary drum 12. In addition, during this roasting, the fumes and films are sucked through orifices 29, 31 formed in the front plate 5 and from the mouth 11, and are conveyed to the filtration unit 3 by the conduit 10 and the flexible pipe 55. In addition, the films can also be recovered by gravity in the drawer 21. This roasting lasts on average d e the order of 20 minutes and requires, when approaching the expiration of this period, to check the appearance of the coffee by means of the chute 34 for taking the sample. For this purpose, a timer can be provided triggering an alarm signal a few minutes before the expiration of the twenty minutes, - once the coffee has been roasted, the flap 38 is opened by actuation of the lever 39, so as to transfer this coffee in the container 40 disposed in its advanced position. This transfer, and therefore the emptying of the drum

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  rotary 12, are obtained by rotation of said rotary drum, due to the action of the blades 20, - once this transfer has taken place, the coffee is naturally cooled by simultaneous brewing action by the scrapers 46, 47 and air circulation cooling aspirated through the grid 45 by the fan 52. For example, the cooling of the coffee according to this method requires a period of the order of five minutes, during which the roasting of a new one may possibly be started. dose of coffee, - the cooled coffee is then evacuated automatically after opening the hatch 43 under the effect of the action of the scrapers 46, 47. As shown in FIG. 3, it can then be recovered in a tank 75 positioned under the container 40 directly above the hatch 43, and for example, secured so

  removable from said container by any means known per se.

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Claims (7)

  1 / - Apparatus for roasting green coffee, characterized in that it comprises in combination: - a rotary drum (12) incorporating brewing means (20), and provided with an open front face, said drum being arranged in a thermally insulated enclosure (7) provided with a fixed front wall (5) for closing off the open front face of the latter, and incorporating electric heating means (9), - a container (24) provided with a bottom wall closed by a valve (26) with manual opening, arranged so as to allow the rotary drum (12) to be supplied with green coffee by means of a conduit (6) opening into a lumen (29) provided in the front wall (5) of the enclosure (7), facing the upper volume portion of said drum, - smoke extraction means comprising an extraction duct (10, 53, 55) opening into the enclosure (7), and suction means (52) capable of allowing the fumes and films to be sucked in the interior of the duct (10, 53, 55) through at least one passage (29, 31) formed between the rotary drum (12) and said enclosure, - a filtration unit (3) disposed at the outlet of the duct extraction (10, 53, 55) and comprising a compartment (56) for depositing films and at least one filter (57, 58) capable of roasting the fumes, - a duct (6) for emptying the rotary drum (12 ) extending in the extension of a lumen (37) formed in the fixed front wall (5) of the enclosure (7), facing the lower volume portion of said drum, and closed by a flap (38) with manual opening, - means for receiving roasted coffee comprising a container (40) disposed directly above the emptying duct (6), said container having a bottom wall provided with perforations (45) of dimensions smaller than those of coffee beans, - means for cooling the roasted coffee contained in the container (40), comprising brewing means e (46-51) of said coffee and suction means (52, 54, 55) capable of generating an air circulation of 14 2791227   cooling of said coffee by suction of air through the perforations (45)   formed in the bottom wall of said container.   2 / - Roasting apparatus according to claim 1, characterized in that the suction means (52, 54, 55) for cooling the roasted coffee comprise a conduit (54, 55) connected to the filtration unit (3) . 3 / - Roasting apparatus according to claim 2, characterized in that the respective suction means for extracting the fumes and cooling the roasted coffee comprises a single fan (52), to which are connected, suction side, the conduit d extraction (10, 53) and the cooling (54).   4 / - Roasting apparatus according to one of claims   1 to 3, characterized in that the receptacle (40) for receiving roasted coffee is able to slide horizontally between a position, called filling, where it extends at least partially in line with the rotary drum (12), and a so-called cooling position where it extends in an advanced position relative to said rotary drum.   / - Roasting apparatus according to one of claims   2 or 3, and claim 4 taken together, characterized in that the container (40) is carried by a drawer (41) forming a closed enclosure in which   opens the cooling duct (54).   6 / - Roasting apparatus according to one of claims   above, characterized in that the brewing means (46-51) for cooling the roasted coffee comprise at least one scraper (46, 47) and means (48-51) for moving each scraper (46, 47) on the bottom of   cooling container (40) along a circular path.   7 / - Roasting apparatus according to claim 6, characterized in that: - the container (40) has a cylindrical shape and comprises a drain flap (43) formed in a peripheral zone of its bottom wall, - the means of brewing comprises at least two scrapers (46, 47) oriented so as to push the coffee towards the periphery 2791227   of the container (40), said scrapers being offset radially so as to sweep   concentric surface portions of the bottom wall of said container.   8 / - Roasting apparatus according to claim 7, characterized in that it comprises two scrapers (46, 47) each mounted towards one of the ends of a diametrical horizontal rod (48) by means (51) of adjustment of the position along said rod and of the orientation of said scraper, said rod being secured to an axial vertical shaft (49) extending through the bottom wall of the container (40) and carried by motor means   (50) for driving said shaft in rotation.   9 / - Roasting apparatus according to one of claims   above, characterized in that the filtration unit (3) has at least one electrostatic filter (57, 58).   / - Roasting apparatus according to one of claims   previous, characterized in that the enclosure (7) has a volume (22) of i5 film recovery disposed under the rotary drum (12) behind the fixed front wall (5), so as to receive said films through a space provided between said rotary drum and front wall, said volume containing a drawer (21) for receiving films accessible from one of the   side walls (46) of the enclosure (7).   1 1 / - Roasting apparatus according to one of claims   previous, characterized in that it comprises a chute (34) for taking the sample extending in the rotary drum (12) through an orifice   formed in the front wall (5).