JPH056792Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an apparatus for roasting coffee beans, and particularly to a mounting structure for a temperature sensor that detects the temperature of coffee beans.

(Prior Art) When cooking coffee beans, the coffee beans are cooled quickly after roasting to bring out the flavor, aroma, etc. of the coffee beans.
In this case, how to set the roasting temperature, roasting time, cooling temperature drop characteristics after roasting, etc. is an important factor in improving the flavor and quality of coffee beans.

Conventional coffee bean roasting devices detect the completion of roasting of coffee beans using a temperature sensor and then block the progress of roasting by cutting off the heat source (Japanese Patent Application Laid-open No. 72678/1999, 1977-
No. 72679) is known.

(Problem that the invention aims to solve) However, in such conventional coffee bean roasting machines, a temperature sensor to detect the temperature of the coffee beans is placed inside the coffee beans collected at the bottom of the rotating drum. Therefore, there is a problem that the temperature detected by the temperature sensor varies widely, making it difficult to accurately detect the temperature of coffee beans.

The present invention was developed to solve these problems, and the coffee beans are roasted by making them less susceptible to the direct effects of both radiant and convective heat generated within the rotating drum and by making the coffee beans flow. To provide a coffee bean roasting device that can accurately detect the temperature of coffee beans inside.

(Means for Solving the Problems) Therefore, the coffee bean roasting device of the present invention includes a heating furnace formed of a heat insulating material, and a rotatable rotatable furnace that stores coffee beans and stirs them. a bottomed cylindrical rotating drum; a heating means fixed to the inner wall of the heating furnace for heating the rotating drum; a basin member that temporarily receives the coffee beans that fall along with the basin; a temperature sensor that is inserted into the coffee beans received by the basin member; and a water sprayer that sprays water into the rotating drum from the opening of the rotating drum. It is characterized by being equipped with a nozzle.

(Function) According to the coffee bean roasting device of the present invention, as shown in FIG. 6, a part of the coffee beans that are stirred and mixed by the rotation of the rotating drum are attached to the inner circumferential wall of the rotating drum due to centrifugal force. A portion of the coffee beans that are lifted upward and then fall due to gravity are received by the square member. As shown in FIG. 7, the coffee beans received in this cell fall from the bottom hole of the cell onto the inner circumferential wall of the rotating drum due to gravity. At this time, a temperature sensor surrounded by flowing coffee beans in the square member detects the temperature of the coffee beans, so it is possible to accurately detect the temperature of the coffee beans while blocking radiant heat and convection heat. .

Therefore, the roasting temperature of the coffee beans is accurately measured using a temperature sensor within the square member to detect the end of roasting. By spraying water from the water spray nozzle to the coffee beans based on the detected set temperature, the roasted coffee beans in the rotating drum are cooled uniformly and quickly. This primary cooling tightens the epidermis of the coffee beans, maintains the quality of the coffee beans, such as their flavor and aroma, and improves the external color and gloss of the coffee beans.

(Example) Embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, an input port 2 for inputting coffee beans is provided at the top of a frame 1 of the coffee bean roasting device, and this input port 2 is connected to a passage 3 extending vertically downward. be done. The inclined passage 3b is bent and inclined from the middle of the passage 3,
It opens to a hearth opening surface 10a of a heating furnace 10, which will be described later. On the other hand, an exhaust passage 5 is branched from the upper end of the passage 3 and extends horizontally backward (leftward in FIG. 1).
A shutter 6 for selectively switching between inputting coffee beans and discharging coffee beans is attached to the branch portion so as to be able to swing freely around a fulcrum 7.

A bottomed cylindrical rotary drum 13 provided in the heating furnace 10 is arranged so that its axis of rotation is in the horizontal direction, and its opening surface 14 faces parallel to the above-mentioned hearth opening surface 10a to form a gap. provided through. This gap is adjusted to, for example, 1 to 2 mm. Thereby, the coffee beans from the inclined passage 3b are taken into the rotary drum 13 from the hearth opening surface 10a through the opening surface 14, and at this time, the coffee beans are prevented from falling through the gap.

The cylindrical body 15 of the rotating drum 13 is made of punched metal, and has a large number of small holes, such as round holes, which communicate between the inside and outside of the drum. The bottomed disc portion 16 of the rotating drum 13 is formed into a disc shape by punching metal, and has a large number of small holes communicating between the inside and outside of the drum. The aperture ratio of the large number of small holes formed in the cylindrical body 15 and the bottomed disc part 16 is 20.
It is set to ~70%. These small holes play the role of effectively transmitting radiant heat from an infrared heater 12 (described later) to the coffee beans in the drum.

On the inner circumferential wall of the cylindrical body 15, thin plate band-shaped feed vanes 30a and 30b, which feed the coffee beans taken into the drum from the opening surface 14 into the bottomed disk part 16 side during rotation, are offset by 180 degrees from each other with respect to the cylindrical axis. They are arranged in a spiral pattern at different positions. Thin band-shaped return vanes 31a and 31b for taking out the coffee beans taken into the drum 13 to the outside from the opening surface 14 are attached to the inner circumferential wall of the cylindrical body 15 in a direction intersecting the aforementioned sending vanes 30a and 30b. These sending blades 30a, 30b and returning blades 31a, 31b
is a thin plate strip having a predetermined width, and a large number of small holes are set in this strip so that the aperture ratio is in the range of 20 to 70%. This is to promote roasting through rotational agitation by the rotating drum 13 and transmission of radiant heat.

The rotating drum 13 is driven by a drive shaft 17, spokes 18 extend radially from a boss portion 16 fixed to the drive shaft 17, and the other end 18a is fixed to the inner circumferential wall of the cylindrical body 15. The rotating drum 13 is supported by the drive shaft 17 by the spokes 18 .

The drive shaft 17 extending toward the outside of the rotating drum 13 is inserted into the insertion hole 10c of the hearth end closing surface 10b.
The shaft is rotatably supported by bearings 19 and 20 through the shaft, and the shaft end 17a is fitted into the sprocket 21. This sprocket 21 is connected to the drive motor 2
It is driven by a chain 22 wrapped around a sprocket 23 driven by a sprocket 4.

A large number of ceramic infrared heaters 12 are provided on the inner peripheral wall surface 10b of the bottomed cylindrical heating furnace 10 so as to surround the rotating drum 13 and extend in the front-rear direction of the heating furnace 10. The infrared heater 12 is
For example, a heating resistor such as a nichrome wire is embedded in a ceramic radiation plate such as cordierite porcelain, and is attached to the inner peripheral wall surface 10b. When the infrared heater 12 is energized, infrared rays having a wavelength of 3 to 7 μm are emitted. When the infrared heater 12 generates heat, radiant heat is radiated into the drum through small holes in the rotating drum 13.

A cell member 80 is provided near the bearing 20 of the drive shaft 17 located below the end opening surface 10a of the heating furnace 10. As shown in FIGS. 2 to 5, the cell member 80 is eccentrically fixed to the furnace wall 10d by a distance X horizontally to the left and a distance Y vertically downward from the mounting position of the boss 20 in FIG. ing. The attachment position of this square member is not limited to the above-mentioned position, but may be any position that can accurately receive the coffee beans lifted along with the rotating drum 13, as shown in FIG. Square member 80
consists of flat plates 82 and 83, and these flat plates 8
2 and 83 are trapezoidally shaped, and as they go downward, the passage 84 becomes narrower and has a bottom hole 85. Also,
The shape of the cell member is not limited to the above shape,
For example, any shape such as a cylindrical funnel shape can be adopted, but it is necessary to make the lower end narrower than the upper end so that the coffee beans can be received and dropped while flowing.

A temperature sensor 35 is provided on the hearth inner wall 10d facing the opening surface 14 of the rotating drum 13 directly below the hearth opening surface 10a of the heating furnace 10. The tip of the temperature sensor 35 is surrounded by a protective tube 35a.
The heat retaining tube 35a is inserted horizontally into approximately the center of the passage 84, as shown in FIGS. 3, 4, and 5.

The temperature sensor 35 detects the roasting temperature of the coffee beans in the rotating drum 13 and adjusts the timing of water spraying, and uses, for example, a sheathed thermocouple of chromel-alumel wire. The tip of this protection tube 35a is formed into a round shape so as not to damage the coffee beans when it comes into contact with the coffee beans.

In addition, in the present invention, the temperature sensor attached to the hearth is not limited to a thermocouple, and other types of temperature sensors may of course be used. It may be set at an appropriate position depending on the diameter, amount of food, drum rotation speed, coffee bean agitation status, etc., but a position where the coffee beans are scattered in the air and can receive both radiant heat and convection heat is desirable.

As shown in FIG. 8, the hearth inner wall 1 of the heating furnace 10
The water injection nozzle 36 installed at 0d is connected at its upstream end to a water tank 46 via a pipe 45,
A water pipe 47 and an air pipe 50 are connected to the upstream side of this water tank 46, respectively. When a solenoid valve 49 provided in the middle of the water pipe 47 is opened, water is injected into the water tank 46. Solenoid valve 4
9 is closed and the air solenoid valve 50 is opened, the water tank 46 becomes high pressure due to the pressure from the air pipe 48, and this pressure rise causes mist water to flow from the water spray nozzle 36 into the rotating drum 13 via the pipe 45. Sprayed. The nozzle direction, nozzle mounting position, and spray pressure are set so that the water sprayed from the water spray nozzle 36 becomes a mist and is uniformly applied to the coffee beans in the rotating drum 13. The air pressure from the air solenoid valve 50 is preferably in the range of 4 to 6 kg/cm ² . This is to uniformly cool the coffee beans by making the spray water into a sufficiently atomized form so as to disperse the coffee beans, which is combined with the stirring by the rotating drum.

At the hearth 10d of the heating furnace 10, a rotating drum 13 is installed.
A sampler mounting hole 55 is opened, into which a sampler for visually observing the degree of roasting progress of coffee beans is mounted, and a sampler main body 56 is detachably mounted to this mounting hole 55. Note that an air inlet 70 for introducing air into the furnace is provided on the inner circumferential wall surface 10b of the heating furnace.

Exhaust gas generated in the rotating drum 13 during roasting ascends through the inclined passage 3b and the passage 3 from the opening surface 14, passes through the exhaust passage 5 connected to the passage 3, and
It is sucked in by an exhaust blower 52 provided on the downstream side of the exhaust passage 5 and discharged to the outside. During exhaust, the shutter 6 switches the communication between the passage 3 and the exhaust passage 5 to an open state as shown in FIG.

As shown in FIG. 1, an opening surface 10 of a heating furnace 10
At the hearth 10d located below a, there is a half-moon-shaped outlet 60 from which roasted coffee beans are taken out.
is opened, and a discharge door 6 opens and closes this discharge port 60.
1 is rotatably attached around a rotation shaft 61a. A thin plate-like curved discharge shutter 65 having an arcuate cross section is attached to the outside of the discharge port 60 so as to be inclined diagonally downward.

Next, the operation of the embodiment of the present invention will be explained.

The coffee beans input from Hotsupa 2 are placed in aisle 3.
It flows from the inclined passage 3b into the rotating drum 13 through the opening surface 10a. When the rotating drum 13 is rotated, the coffee beans that have flowed into the rotating drum 13 are heated (roasted) by radiant heat from the infrared heater 12 while being stirred by the sending blades 30a, 30b and return blades 31a, 31b. Ru.

That is, the coffee beans in the rotating drum 13 are
Due to its gravity, it accumulates on the bottom side of the drum, and as the drum rotates, it is pushed toward the bottomed disc portion 16 side by the sending blades 30a and 30b, and pushed toward the opening surface 14 side by the returning blades 31a and 31b. Therefore, the coffee beans are evenly reciprocated in the direction of the drum axis and are agitated and distributed, while being roasted uniformly by the radiant heat from the infrared heater 12.

In this case, the radiant heat from the infrared heater 12 is transmitted through a large number of small holes in the rotating drum 13. In this example, the coffee beans in the drum are uniformly stirred,
Moreover, since a portion of the coffee beans are continuously scattered within the drum, the radiant heat from the heater can be efficiently and continuously received, so that the radiant heat is transmitted from the surface layer of the coffee beans to the inside. Further, since the coffee beans in the rotating drum are agitated by the sending blades 30a, 30b and return blades 31a, 31b in the rotating drum 13, close contact between the coffee beans can be avoided. For this reason, the contact area between the coffee beans and the convective heat is increased, promoting convective heating, and since the inside of the drum is under negative pressure, forced convection heat is generated, which causes the steam generated from the surface of the coffee beans to It is quickly blown away, promoting convective heating within the drum. That is, inside the rotating drum, the coffee beans are uniformly heated to the core by a combination of radiant heat and convection heat.

As the rotary drum rotates, the coffee beans are lifted above the rotary drum, and then fall due to gravity, and some of the falling coffee beans are caught by the square member 80. The coffee beans received by the square member 80 pass around the temperature sensor protection tube 35a at a substantially constant speed. At this time, the temperature of the coffee beans that have been roasted evenly to the core is reliably measured in order to prevent the effects of radiant heat and convection heat described above due to the flat plates 82 and 83 and the piled-up coffee beans. Therefore, the roasted quality of the coffee beans becomes uniform. It is preferable that the coffee beans be set so that they are slightly piled up on the square member 80 so that they can quickly pass through the passage 84.

Furthermore, the coffee beans are fed by the feed blades 30a, 30.
Since the coffee beans are stirred uniformly along the longitudinal direction of the drum by the return blades 31a and 31b, the roasted coffee beans are It is possible to accurately detect the temperature of

Next, when the temperature sensor 35 detects that the roasting temperature of the coffee beans has reached, for example, 210°C, the air solenoid valve 50 is activated based on the detection signal of the temperature sensor 35.
is opened, and air at an air pressure of 4 to 6 kg/cm ² instantly flows into the water tank 46 from the air passage 48.
A mixture of water and air in the water tank 46 is atomized from the water spray nozzle 36 from the pipe 45 and sprayed onto the coffee beans in the rotating drum 13.

By this water spray, the temperature of the coffee beans in the heating furnace 13 is lowered to, for example, 160° C., and the temperature of the coffee beans is rapidly lowered to prevent roasting from proceeding more than necessary. The temperature change detected by the temperature sensor in this case is as shown in FIG.

The steam generated in the rotating drum 13 during water spraying rises from the opening surface 14 through the inclined passage 3b and the passage 3 when the shutter 6 is opened, passes through the exhaust passage 5 connected to the passage 3, and is discharged to the downstream side. The air is sucked in by the air blower 52 and discharged to the outside.

Next, when the handle 61 is opened, the rotating drum 1
After roasting, the coffee beans in the cup 3 slide through the discharge port 60 and the discharge shutter 65, and are transferred to a cooler (not shown).

In this way, according to this embodiment, in the apparatus of this embodiment that uses both the radiant heat and convection heat of the infrared heater, a portion of the coffee beans are scattered in the air in the drum, and are roasted uniformly with thermal efficiency and then dropped. In order to achieve stable roasting, a temperature sensor detects the temperature of the coffee beans passing through the square member 80. Because it detects temperature, there is little variation in detected temperature.
Therefore, cooling is performed by water spray from the water spray nozzle 35 based on the accurately detected coffee bean temperature, so that the quality of the roasted coffee beans is uniform and stabilized.

(Effects of the invention) As explained above, according to the coffee bean roasting apparatus of the invention, the temperature of the coffee beans sufficiently stirred and mixed in the rotating drum is detected with radiant heat and convection heat blocked. It is possible to extract a detection signal with high accuracy and little variation from coffee beans using a temperature sensor. Based on this highly reliable detection signal, the appropriate amount of water is sprayed from the water spray nozzle to quickly cool the coffee beans, which tightens the outer skin of the coffee beans and improves their color, luster, etc. This has the effect of further improving the quality of the coffee beans, such as their flavor and aroma.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a coffee bean roasting device according to an embodiment of the present invention, FIG. 2 is a partial front view of the coffee bean roasting device viewed from the direction of the arrow shown in FIG. 1, and FIG. FIG. 4 is a side view showing the cell member, FIG. 5 is a front view showing the cell member, and FIG. 6 is an enlarged partial sectional view showing the cell member and temperature sensor shown in the figure. A schematic explanatory diagram; FIG. 7 is a schematic explanatory diagram showing the action of the cell member shown in FIG. 6; FIG. 8 is a schematic diagram showing the system for supplying water to the water spray nozzle; FIG. 9 is a diagram showing the temperature of coffee beans. It is a graph showing changes. 10... Heating furnace, 12... Infrared heater (heating means), 13... Rotating drum, 14... Opening surface,
35... thermocouple (temperature sensor), 36... water spray nozzle, 80... cell member.

Claims (1)

[Scope of Claim for Utility Model Registration] A heating furnace formed of a heat insulating material; a bottomed cylindrical rotary drum rotatably provided within the heating furnace for storing and stirring coffee beans; and the heating furnace. heating means fixed to the inner wall of the heating furnace to heat the rotating drum; and a basin member attached to the inner wall of the heating furnace at the opening of the rotating drum to temporarily receive coffee beans that fall as the rotating drum rotates. A temperature sensor inserted into the coffee beans received in the cup member, and a water spray nozzle that sprays water into the rotating drum from the opening of the rotating drum. Roasting equipment.