Roasting system and roasting method

Abstract

To provide a roasting system using bio-pellets to acquire stable combustion and capable of controlling a hot air temperature to a target level.SOLUTION: There is provided a roasting system that burns bio-pellets in a pellet burner 2 to generate hot air, sends the hot air to a roaster 3 and roasts coffee beans. The pellet burner 2 is a hearth type that burns the bio-pellets in a furnace body 2A. The roasting system includes a first path 4 for supplying hot air from the furnace body 2A of the pellet burner 2 to the roaster 3, a second path 5 whose one end is connected to the first path 4 and whose other end is opened to the outside, and an opening / closing damper 6 provided in the second path 5.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a roasting system and a roasting method, and particularly to a roasting system and a roasting method using solid biofuel.

Background Art

[0002] In recent years, the consumption of coffee beverages has increased significantly as a favorite beverage, and accordingly, the consumption of coffee beans has also increased. Therefore, after coffee liquid extraction, a large amount of coffee liquid extraction residue is generated. This is also the case with tea leaves, wheat, and other food ingredients.

[0003] However, only a small part is being effectively utilized, and most of it is currently being discarded as general waste or industrial waste and incinerated.

[0004] In addition, in order to effectively utilize coffee liquid extraction residue, a coffee liquid extraction system has been proposed that uses the bio-coke technology to convert coffee liquid extraction residue into bio-coke and uses it as a heat source (see, for example, Patent Document 1).

[0005] Such solid biofuels have poor ignitability and combustion stability, and it is difficult to use them as a heat source for hot air roasting. Also, due to their shape, continuous fuel supply is not possible, so only manual feeding can be applied. Therefore, it has been considered to process it into small biofuels such as coffee pellets that are easy to use as fuel and use coffee liquid extraction residue as a heat source for hot air roasting.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, the inventors used a solid biofuel such as coffee pellets as fuel in hot air roasting and used an integrated and small gun-type burner. However, the combustion responsiveness was lower than when using gas as fuel, and it was difficult to control stable combustion. This is considered to be because in the case of a gun-type burner, there is no afterburner, so the combustion is unstable.

[0008] Therefore, when the burner was changed from a gun type to a hearth type with afterburner, stable combustion was confirmed, and it was found that the hot air temperature can be controlled by discharging a part of the hot air or introducing cold air and controlling their balance.

[0009] An object of the present invention is to provide a roasting system and a roasting method that can obtain stable combustion using bio-pellets and can control the hot air temperature to a target value.

Means for Solving the Problems

[0010] A roasting system according to an aspect of the present invention is a roasting system for roasting foodstuffs such as coffee beans and nuts, including a roaster for roasting foodstuffs, a hot air generating means for generating hot air to be supplied to the roaster, a first passage for supplying hot air from the furnace body of the hot air generating means to the roaster, a second passage having one end connected to the first passage or the hot air generating means and the other end open to the outside, a first on-off valve provided in the first passage, and a second on-off valve provided in the second passage. The hot air generating means generates hot air by burning solid biofuel in the furnace body, and controls the opening and closing of the first on-off valve and the second on-off valve according to the temperature difference from the target temperature of the roaster, and adjusts the temperature of the hot air supplied to the roaster.

[0011] In this way, when the hot air from the hot air generating means is supplied to the roaster, a part of it can be discharged through the second passage, so that temperature control with better responsiveness than controlling the hot air temperature by controlling the fire power in the hot air generating means itself becomes possible.

[0012] In addition, since hot air can be generated using solid biofuel, it contributes to energy conservation. Further, although the hot air generation means for solid biofuel is inferior in responsiveness compared to gas or a burner, by providing the above-described configuration, temperature control with excellent responsiveness is possible.

[0013] In addition, this roasting system is characterized in that, from the start of hot air generation in the furnace body until the end of roasting of the food material, without stopping the hot air generation means, the first opening / closing valve and the second opening / closing valve are controlled to open and close according to the temperature difference from the target temperature of the roaster, and the temperature of the hot air supplied to the roaster is adjusted. With this configuration, from the start of operation of the hot air generation means until the end of roasting, it can be operated without stopping the hot air generation means, which is safe.

[0014] This is because the hot air generation means burns bio-pellets to generate hot air, and if the hot air generation means is inadvertently stopped midway, there is a risk of backfiring into unburned bio-pellets or the like. Therefore, it is desirable to stop the combustion of bio-pellets and stop the hot air generation means after roasting is completed. Note that it is more desirable not to stop the hot air generation means until the combustion of the bio-pellets remaining in the furnace body subsides after the roasting of coffee beans is completed.

[0015] In addition, this roasting system can also be configured such that, from the start of hot air generation in the furnace body until the end of roasting of the food material, while maintaining the furnace body at a negative pressure, the first opening / closing valve and the second opening / closing valve are controlled to open and close according to the temperature difference from the target temperature of the roaster, and the temperature of the hot air supplied to the roaster is adjusted. Note that for maintaining the negative pressure in the furnace body, in addition to not stopping the above-described hot air generation means, known means for maintaining negative pressure can be used. According to this configuration, when the furnace body becomes positive pressure, there is a risk that heat may flow backward to the fuel supply section with unused bio-pellets and cause backfiring, but this can be prevented, enabling safe operation.

[0016] In this case, the first passage is provided with auxiliary air introduction means for introducing outside air into the first passage, and in accordance with the temperature difference from the target temperature of the roaster, the amount of outside air introduced by the auxiliary air introduction means is controlled to further adjust the temperature of the hot air supplied to the roaster. As a result, in addition to partial discharge through the second passage, outside air (cool air) can be introduced by the auxiliary air introduction means, enabling finer temperature control with better responsiveness.

[0017] An exhaust fan is provided in the second passage, and a third passage for exhausting the hot air used for roasting in the roaster to the outside of the roaster is connected. The third passage is connected to the second passage on the upstream side of the exhaust fan. As a result, the hot air can be stably drawn in from the first passage by the exhaust fan, the bio-combustion can be stabilized, and the exhaust used for roasting can be discharged to the outside together with the exhaust from the hot air generation means through the second passage.

[0018] Also, a first passage for supplying hot air from the hot air generation means to the roaster, a second passage connected thereto and provided with an exhaust fan, and a third passage for sending the exhaust from the roaster to the second passage are configured such that the passage from the hot air generation means through the roaster to the exhaust fan is connected. As a result, a one-to-one correspondence can be established in which the hot air generated by the hot air generation means is pulled by one exhaust fan, so that the intake air volume of the hot air generation means can be stabilized, and thus the combustion of the hot air generation means can be stabilized.

[0019] In addition, since the high-temperature exhaust from the hot air generation means and the exhaust from the roaster after roasting are discharged through the same passage, the so-called thermal cleaning effect can be obtained in which dirt such as oil adhering in the passage caused by the exhaust after roasting is removed by the high-temperature exhaust from the hot air generation means.

[0020] Also, the other end of the second passage is open to the outside through a cyclone and a smoke elimination device. As a result, the exhaust after roasting can be cleaned and discharged to the outside.

[0021] It is desirable that the roaster is provided with auxiliary hot air generating means for generating hot air by gas combustion. Thereby, during heating, by using the auxiliary hot air generating means, the time required for heating can be shortened, and finer temperature adjustment becomes possible during roasting. Also, in the event of an unexpected situation such as a malfunction occurring in the hot air generating means, for example, roasting can be continued.

[0022] It is desirable that the roaster is provided with water supply means for supplying cooling water. In this way, it is possible to easily adjust the color of ingredients such as coffee beans after roasting. Also, it becomes possible to cool the ingredients and the roaster.

[0023] It is desirable that a heat exchanger is provided in the middle of the second passage or the third passage. Thereby, the exhaust heat from the exhaust gas after roasting and the like can be effectively utilized.

[0024] It is desirable that the solid biofuel is coffee pellets, or wood pellets, or a mixture of coffee pellets and wood pellets. Thereby, coffee husks and the like that are usually discarded can be effectively utilized as bio-pellets. Also, by using wood pellets or mixing wood pellets, it is possible to improve the ignitability.

[0025] Further, in the roasting system, instead of the hot air generating means burning solid biofuel in the furnace body to generate hot air, an electric furnace is used, and the electric furnace is equipped with an electric heater and generates hot air using the electric heater as a heat source.

[0026] By doing so, when the hot air from the electric furnace is supplied to the roaster, a part of it can be discharged through the second passage, so that temperature control with better responsiveness than controlling the temperature of the hot air by controlling the firing in the electric furnace becomes possible. Further, unlike gas or oil, the electric heater has very slow responsiveness in controlling the amount of heat and is not good at fine control, similar to the hot air generating means using the above-described solid biofuel. Therefore, even when an electric heater is used, temperature control with excellent responsiveness becomes possible with the above-described configuration.

[0027] A roasting method according to one aspect of the present invention is a roasting method using a roasting system including a roaster for roasting foodstuffs such as coffee beans and nuts, a hot air generating means having a furnace body for generating hot air in the furnace body, a first passage connected to the hot air generating means and the roaster, a second passage having one end connected to the first passage or the hot air generating means and the other end open to the outside, and an opening / closing device provided in the first passage and the second passage, including a hot air generating step of burning solid biofuel in the furnace body to generate hot air, a hot air supplying step of supplying the generated hot air to the roaster through the first passage, and a roasting step of roasting the foodstuff using the hot air in the roaster, and characterized by controlling the opening and closing of the first and second opening / closing devices according to the temperature difference from the target temperature of the roaster to adjust the temperature of the hot air supplied to the roaster.

[0028] By doing so, when the hot air from the hot air generating means is supplied to the roaster, by opening and closing the first and second opening / closing devices to discharge a part through the second passage, etc., temperature control with better responsiveness than controlling the temperature of the hot air by controlling the firing in the hot air generating means itself becomes possible. Here, the opening / closing device includes, for example, an opening / closing damper, etc., and includes those whose opening ratio can be adjusted in addition to being fully opened / closed, and those whose opening ratio can be adjusted are preferred.

[0029] Here, when the inventors repeatedly tested various methods in developing the roasting method, they felt that the flavor of the ingredients after roasting was being impaired. When they investigated the cause, they considered the possibility that the hot air sent from the hot air generating means to the roaster contained soot, and they repeatedly tested various methods and found a roasting method having the following configuration.

[0030] The roasting method is further characterized in that, prior to the hot air supply step, in a state where the first switch is closed and the second switch is open, a warming step is provided in which the hot air generated in the furnace body is discharged to the outside through the second passage.

[0031] Here, regarding the cause of flavor impairment, incomplete combustion that emits a large amount of soot occurs from the ignition of the solid biofuel in the hot air generating means until complete combustion. And it was found that if the hot air is directly supplied to the roaster as it is, soot adheres to the piping, inside the cylinder, and ultimately to the ingredients to be roasted, impairing the flavor.

[0032] And the roasting method having the above configuration, specifically, from the ignition of the solid biofuel until complete combustion, with the first switch closed and the second switch open, the hot air generated in the furnace body is discharged to the outside through the second passage. That is, after going through a warming step of not supplying the hot air containing soot to the roaster and then supplying hot air to the roaster, it is possible to prevent flavor deterioration due to soot. Therefore, with this configuration, hot air at a desired temperature can be supplied to the roaster after it is generated, and it is not necessary to stop the hot air supply means that has been started, which is safe, and it is possible to suppress the adverse effect on the flavor due to soot.

[0033] Further, it is characterized in that the hot air generating means is not stopped from the start of generation of hot air in the furnace body until the end of roasting of the ingredients, including the warming step. With this configuration, it is safe to operate without stopping the hot air generating means from the start of operation to the end of roasting.

[0034] This is a device that generates hot air by burning bio - pellets in the hot - air generating means. If the hot - air generating means is inadvertently stopped midway, there is a risk of backfire onto unburned bio - pellets and the like. Therefore, after the roasting is completed, it is desirable to stop the combustion of the bio - pellets and then stop the hot - air generating means. Additionally, it is more desirable not to stop the hot - air generating means until the combustion of the bio - pellets remaining in the furnace body subsides after the roasting of the coffee beans is completed.

[0035] Also, it is characterized in that from the start of hot - air generation in the furnace body, including the warming process, until the hot - air generating means is stopped after the roasting of the coffee beans is completed, the inside of the furnace body is maintained at a negative pressure. According to this configuration, when the inside of the furnace body becomes positive pressure, there is a risk that heat will flow backward to the fuel supply part with unused bio - pellets and cause backfire, but this can be prevented, enabling safe operation.

[0036] Also, the roasting Method is provided with auxiliary air - introducing means for introducing outside air into the first passage. In the hot - air supply process, according to the temperature difference from the target temperature of the roaster, the amount of outside - air introduction of the auxiliary air - introducing means is controlled, and it is supplied to the roaster to further adjust the temperature of the hot air. As a result, in addition to partial discharge through the second passage, outside air (cold air) can be introduced by the auxiliary air - introducing means, enabling more responsive and precise temperature control.

[0037] Also, the roasting Method is provided with an exhaust fan in the second passage, and a third passage for exhausting the hot air used for roasting in the roaster to the outside of the roaster is connected. The third passage is connected to the second passage on the upstream side of the exhaust fan. In the roasting process, the hot air used for roasting is exhausted to the outside through the third passage and the second passage from the roaster.

[0038] As a result, hot air can be stably drawn in from the first passage by the exhaust fan, combustion can be stabilized, and the exhaust used for roasting can be discharged to the outside together with the exhaust from the hot air generation means from the second passage.

[0039] In addition, since the high-temperature exhaust from the hot air generation means and the exhaust from the roaster after roasting are discharged through the same passage, the so-called thermal cleaning effect of removing dirt such as oil adhering in the passage caused by the exhaust after roasting with the high-temperature exhaust from the hot air generation means can be obtained.

[0040] Also, the other end of the second passage is open to the outside via a cyclone and a smoke elimination device, and in the roasting process, the hot air used for roasting is exhausted to the outside from the roaster through the third passage, the second passage, the cyclone, and the smoke elimination device. As a result, the hot air after being used for roasting can be discharged to the outside in a clean state, which is good for the environment. The hot air after being used for roasting can be discharged to the outside in a clean state, which is good for the environment.

[0041] Also, in the roasting Method an auxiliary hot air generation means for generating hot air by gas combustion is provided in the roaster, and in the hot air supply process, the amount of hot air introduced by the auxiliary hot air generation means is controlled according to the temperature difference from the target temperature of the roaster, and is supplied to the roaster to further adjust the temperature of the hot air.

[0042] As a result, during heating, by using the auxiliary hot air generation means, the time required for heating can be shortened, and more precise temperature adjustment is possible during roasting. Also, for example, when an unexpected situation occurs such as a malfunction in the hot air generation means, it is possible to continue roasting.

[0043] Also, in the roasting Method a water supply means for supplying cooling water to the roaster is provided, and after the roasting process is completed, a water injection process is further provided by the water supply means. In this way, the color of the roasted coffee beans can be easily adjusted. Also, the coffee beans and the roaster can be cooled.

[0044] Also, in the roasting Method a heat exchanger is provided in the middle of the second passage or the third passage, and the heat energy of the exhaust gas flowing through the second passage or the third passage is recovered by the heat exchanger. Thereby, the exhaust heat due to the exhaust gas after roasting or the like can be effectively utilized. Further, this heat exchanger can be arranged, for example, so as to straddle the second passage or the third passage and a pipe leading to the hot air generating means, so that the heat energy of the exhaust gas in the second or third passage can be used for generating hot air.

[0045] Also, in the hot air generating step, the pellets burned in the furnace body are coffee pellets or bio-pellets which are a mixture of coffee pellets and wood pellets. Thereby, coffee grounds and the like which are usually discarded can be effectively utilized as bio-pellets. Further, by mixing wood pellets, it is possible to improve the ignitability.

[0046] Also, in the roasting Method the hot air generating means is an electric furnace equipped with an electric heater, and the hot air generating step is a step of generating hot air using the electric heater as a heat source by the electric furnace instead of a step of burning biofuel in the furnace body to generate hot air. According to the roasting method having this configuration, even when an electric heater having inferior responsiveness compared to a gas or a burner is used, temperature control with excellent responsiveness can be achieved.

Advantages of the Invention

[0047] In the present invention, when supplying hot air from the hot air generating means to the roaster, a part of the hot air can be discharged through the second passage, so that the temperature control of the hot air is more responsive than controlling the temperature of the hot air by the fire power control in the hot air generating means itself, enabling temperature control of the hot air and obtaining stable combustion.

Brief Description of the Drawings

[0048]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0049] Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 is an overall view showing the schematic configuration of the roasting system according to the present invention, showing the case where the pellet burner (hot air generating means) is in a warming state.

[0050] In FIG. 1, reference numeral 1 denotes a roasting system that uses coffee pellets (bio pellets) as fuel. The system includes a hearth-type pellet burner 2 (hot air generating means) that burns the coffee pellets in a furnace body 2A to generate hot air, a roaster 3 (roasting machine) that roasts coffee beans using the hot air, a first passage 4 that supplies hot air from the pellet burner 2 to the roaster 3, a second passage 5 having one end connected to the first passage 4, and an on-off damper 6 provided in the second passage 5.

[0051] A third passage 7 upstream of the exhaust fan 8 is connected to the second passage 5. The exhaust hot air used for roasting is discharged to the outside through the third passage 7, the exhaust fan 8, the cyclone 9, and the smoke elimination equipment 10. An on-off damper 12 that is opened and closed by an actuator is provided in the first passage 4 on the downstream side of the portion where the second passage 5 branches. The on-off damper 6 is controlled to be opened and closed according to the temperature difference from the target temperature of the roaster 3, so as to adjust the temperature of the hot air supplied to the roaster 3.

[0052] The second passage 5 has an exhaust fan 8 and a cyclone 9 connected thereto midway to the exhaust port to the outside. A deodorizing device fan (not shown) of the smoke elimination equipment 10 is connected to the downstream side of the cyclone 9. An on-off damper 11a that opens when the smoke elimination equipment 10 stops abnormally is provided in a passage 11 connecting the cyclone 9 and the smoke elimination equipment 10.

[0053] The first passage 4 has a passage 14 having an exhaust fan 13 connected immediately downstream of the furnace body 2A. On-off dampers 15A and 15B are provided on the downstream side of each of the connection portions. These are interlocked and opened and closed by one actuator. Only during a power failure or a cooling operation, the on-off damper 15A is opened and the on-off damper 15B is closed, and the exhaust fan 13 is driven to exhaust the air.

[0054] The first passage 4 is connected to the roaster 3 via a large-diameter hot air introduction section 16. The hot air introduction section 16 is provided with an auxiliary air introduction means 17 that introduces outside air to adjust the temperature of the hot air. As the auxiliary air introduction means 17 in this embodiment, an electric fan is used as an example.

[0055] The adjustment of the hot air temperature by auxiliary air introduction means 17 is performed by controlling the amount of outside air introduced by auxiliary air introduction means 17 according to the temperature difference from the target temperature of roaster 3, and adjusting to lower the temperature of the hot air supplied to roaster 3. The amount of air introduced by auxiliary air introduction means 17 is inverter controlled.

[0056] In addition, the control of the intake air volume is not limited to the inverter, but can be achieved by installing a motor damper at the intake port. It is also possible to adjust the power supply by controlling the power supply. By not using an inverter, costs can be reduced.

[0057] The auxiliary air introduction means 17 is also used for purposes other than those mentioned above. For example, in the latter half of the roasting process, when heat is blocked due to heat storage in the roaster or in the beans being roasted, the beans continue to heat up even without heat being added, making it difficult to brake the heating. In this case, the auxiliary air introduction means 17 takes in outside air to brake the heating.

[0058] The hot air introduction section 16 is also provided with an auxiliary hot air generating means for auxiliary generation of hot air by gas combustion during warming, etc. In this embodiment, as an example, a gas burner 18 is used as the auxiliary air introduction means. An opening / closing valve 18a is provided in the air introduction path of the gas burner 18 to shut off the cold air that leaks when the gas burner is not in use.

[0059] The roaster 3 is provided with a rotatable rotary cylinder 20 for accommodating and roasting green coffee beans inside the furnace body 19. During roasting, the rotary cylinder 20 is rotationally driven by a motor while hot air is introduced. The furnace body 19 is connected to the third passage 7 through a passage 22 having an exhaust bypass damper 21 that is opened and closed by an actuator.

[0060] An exhaust damper 23 that is opened and closed by an actuator is also provided on the upstream side of the third passage 7 at this connection part. The exhaust damper 23 can be used to block leakage when the gas burner 18 is not in use without controlling the temperature of the hot air.

[0061] Here, the uses of the exhaust damper 23 and the exhaust bypass damper 21 will be described. During roasting and the like, the exhaust damper 23 is opened, and the exhaust from the roaster 3 is exhausted to the outside through the second passage 5 via the third passage 7. On the other hand, when opening the raw material hopper damper 26, the exhaust damper 23 is closed and the exhaust bypass damper 21 is opened to prevent the raw material from being blown downstream (towards the third passage 7). Similarly, during quenching with water, the exhaust bypass damper 21 is opened to release the hot air so that the raw material is not blown away. This is because during quenching, the internal pressure inside the rotary cylinder 20 increases due to the generated water vapor, and the raw material tends to be expelled outside.

[0062] Regarding the exhaust bypass damper 21, when the front cover 24 described later is open and cold outside air tries to enter through the front cover 24 and flow into the third passage 7 through the exhaust damper 23, at this time, by opening the exhaust bypass damper 21, the inflow of cold outside air into the third passage 7 can be suppressed, and a flow can be created such that the hot air from the hot air introduction part 16 by the gas burner 18 flows into the third passage 7 from the exhaust bypass damper 21. By doing so, it is possible to suppress the combustibility of the gas burner 18 and the fuel consumption of the smoke elimination equipment 10 when cold air flows into the third passage 7.

[0063] When closing the exhaust damper 23 described above, it is configured not to be fully closed. This is because if the timing is poor when roasting using the gas burner 18, and the gas burner 18 misfires while the exhaust damper 23 is completely closed, there is a risk that the combustion gas will fill the furnace body 19 and cause ignition. Therefore, the exhaust damper 23 is not allowed to be fully closed.

[0064] Also, as shown in FIG. 2, the rotary cylinder 20 has stirring blades 20B irregularly provided inside a cylindrical main body 20A.

[0065] As shown in FIG. 1, the rotary cylinder 20 is provided with a front cover 24 that is opened and closed by a slide movement driven by an actuator. This front cover 24 has a cylindrical input portion 24a into which the raw material is input. This input portion 24a is separably connected to the downstream end of the third passage 7, and an input port 25a of a hopper portion 25 for storing the raw material is provided near the downstream end of the third passage 7. An input port 25a is provided with a raw material hopper damper 26 that is opened and closed by an actuator and is opened when the raw material is input. For the rotary cylinder 20, water supply means 27 for supplying cooling water is provided for adjusting the color of the roasted coffee beans and the like. It can also be used to deal with troubles such as during heating or a power failure on the roaster 3 side. Also, as the hot air control of the roaster 3, it can also be used to rapidly lower the hot air temperature.

[0066] By controlling the balance between the amount of hot air supplied to the roaster 3 through the first passage 4, the amount of air discharged through the second passage 5, and the amount of outside air (cool air) introduced by the auxiliary air introduction means 17, it is possible to control the temperature of the hot air with good responsiveness, and once combustion starts, stable combustion is ensured. That is, when fire power is required, it is in the state shown in FIG. 3, during roasting, it is in the state shown in FIG. 4, and when fire power is not required, it is in the state shown in FIG. 5.

[0067] According to the above system, by controlling the balance between the amount of hot air supplied to the roaster 3 through the first passage 4, the amount of air discharged through the second passage 5, and the amount of outside air (cool air) introduced by the auxiliary air introduction means 17, it is possible to control the temperature of the hot air with good responsiveness, and once combustion starts, stable combustion is ensured. That is, when fire power is required, it is in the state shown in FIG. 3, during roasting, it is in the state shown in FIG. 4, and when fire power is not required, it is in the state shown in FIG. 5.

[0068] By the way, in the pellet burner 2, when the pressure inside the furnace becomes positive pressure, heat flows backward to the fuel supply section. On the other hand, if the pressure inside the furnace is made too negative, the supply of air becomes excessive, the inside of the furnace is cooled, and this hinders combustion. Therefore, this point is taken into consideration. In addition, in order to enable more detailed control, in addition to the second passage 5, it is also possible to provide a passage 43 (circulation passage) having opening and closing dampers 41 and 42. In the unlikely event that the pellet burner 2 becomes unusable, it is also possible to roast using only the gas burner 18. In that case, roasting is performed using the opening and closing dampers 41 and 42 and the passage 43 (circulation passage).

[0069] The responsiveness of combustion is greatly affected by the control of the pellet supply amount, and a time lag of several minutes occurs before it is reflected in the temperature. Therefore, by performing balance control of whether to introduce all the hot air into the roaster 3 or exhaust a part of it through the second passage 5, the influence of the time lag can be minimized.

[0070] After roasting is completed, the front lid 24 is opened (see FIG. 6), and the holding frame 20a at the end of the rotary cylinder 20 is moved by an actuator, and the roasted coffee beans are moved to the upper part of the cooling tank 28 adjacent to the roaster 3 (see FIG. 7). At this time, outside air (indoor air) is introduced and cooled through the fourth passage 30 having the intake fan 29 (see FIG. 8).

[0071] This cooled air is exhausted through the fifth passage 34 having the opening and closing damper 31, the exhaust fan 32, and the cyclone 33. Coffee beans (raw beans) as raw materials are introduced, for example, within 60 seconds from the start of this cooling, and the next roasting is started after 60 seconds from the start of cooling. Note that this 60 - second time is an example and is not limited to this. Also, if the input conditions are not satisfied due to raw material supply, the temperature inside the furnace body 19, etc., it will be in a standby state.

[0072] After cooling, in the cooling tank 28, the suction damper 35 is opened (see Fig. 9), and the roasted coffee beans after cooling are conveyed through the suction passage 36 to the storage tank 37 and stored therein. The storage tank 37 is provided with a product discharge damper 37a and a level meter 37b. Then, the suction air is discharged to the downstream portion of the exhaust fan 32 in the fifth passage 34 through the sixth passage 39 having an opening / closing damper 38 that is opened and closed by an actuator.

[0073] In addition to the air volume control (opening / closing control of the opening / closing damper 6) of directly introducing the hot air from the pellet burner 2 into the roaster 3 or partially exhausting it through the second passage 5, by controlling the introduced air volume of outside air (cool air) by the auxiliary air introduction means 17, temperature control with excellent responsiveness is realized more than that controlled by the conventional gas burner's firepower control.

[0074] Also, in the configuration of a gas burner and an auxiliary blower used in a conventional general roaster, when it is desired to suddenly reduce the hot air supplied to the roaster, the method of increasing the blower volume with the burner output at the weakest or shutting off the burner and only blowing air has been adopted. However, in the former case, it is impossible to reduce the burner below the limit of the turndown ratio and only cold air can be blown, and in the latter case, it is difficult to apply the timing because it takes time to re-ignite the burner. On the other hand, in the roasting system of this embodiment, since the opening / closing device (opening / closing damper) is responsible for blocking the hot air and the blower is responsible for blowing air, the above-mentioned conventional problems can be solved, and thereby the safety is improved even when performing deep-roasted roasting.

[0075] Also, since the exhaust fan 8 is arranged in the second passage 5 for exhausting a part of the hot air, a part of the hot air can be exhausted smoothly without impairing the stable combustion of the pellet burner 2.

[0076] Since the excess hot air supplied from the pellet burner 2 is exhausted through the second passage 5, it is possible to exhaust it to the subsequent smoke elimination facility 10 while it is still hot, so that the fuel consumption of the smoke elimination facility 10 can also be suppressed.

[0077] Then, while the excess hot air supplied from the pellet burner 2 is exhausted through the second passage 5, the exhaust gas of the roaster 3 is also configured to be exhausted through the third passage 7 and then through the second passage 5. Therefore, the so-called thermal cleaning effect can be obtained, where the dirt containing the coffee oil adhering to the passage due to the exhaust gas of the roaster 3 is burned and removed by the hot air from the pellet burner 2. Also, this removes the risk of in-duct fire.

[0078] Subsequently, the basic control of the furnace temperature of the roaster 3 and the basic control of the exhaust bypass damper 21 will be described next.

[0079] (Basic control of the furnace temperature of the roaster 3) The furnace temperature set value of the pellet burner 2 is set on the operation panel on the roaster 3 side. After the temperature rises to the set temperature which is the furnace temperature set value, a certain amount of hot air generated by the pellet burner 2 is supplied to the first passage 4, and the hot air distributed to an appropriate air volume by the control of the opening and closing dampers 6 and 12 is supplied into the furnace of the roaster 3. At that time, the hot air is mixed with the air introduced from the auxiliary air introduction means 17, and the temperature of the hot air is controlled to an appropriate temperature.

[0080] The introduction amount from the auxiliary air introduction means 17 is targeted at the set temperature, and the opening degree of the opening and closing damper 17a of the auxiliary air introduction means 17 is PID-controlled to control the temperature of the furnace temperature.

[0081] Then, as shown in FIG. 10, the operation power supply is turned ON (step S1) and starts. Then, the roaster button is turned ON (step S2), the preheating button is turned ON (step S3), the auxiliary hot air generation means (gas burner 18) is ignited (step S4), it is confirmed whether the preheating completion condition is OK (step S5), and it shifts to the gas burner standby setting (step S6).

[0082] On the one hand, when the roaster button is turned ON, it is selected whether to automatically connect the coffee fuel burner (pellet burner 2) (step S7). If it is ON, the temperature inside the coffee fuel burner furnace is set to be equal to or higher than the set value (step S8). If it is OFF, the burner connection button is long-pressed (step S9), and a coffee fuel burner connection command is issued (step S10).

[0083] Then, the auxiliary hot air generation means (gas burner 18) is extinguished (step S11), and the burner intake damper (on-off valve 18a) is closed (step S12). On the other hand, the burner damper (on-off damper 12) is opened (step S13), the continuous operation button is turned ON (step S14), and the preparation is completed (step S15).

[0084] (Basic control of the exhaust bypass damper 21) In addition to the furnace temperature control of the roaster 3, the exhaust bypass damper 21 is opened and closed according to the state of the roaster 3. That is, (i) it is closed during the input standby, (ii) it is opened during the raw material input, (iii) it is opened 3 °C before the finish, (iv) it is opened during the water injection, (v) it is closed when the front cover is opened, and (vi) it is closed during the after purge. However, like the other on-off dampers, it is opened and closed by the control of the actuator.

[0085] Then, as shown in FIG. 11, when the preparation is completed and turned ON (step S21), it is determined whether the supply of green coffee is completed (step S22). If it is ON, the temperature rise is started (step S23). If it is OFF, the input standby state is set (step S24). At this time, the exhaust bypass damper 21 is closed.

[0086] When the temperature rise is started, the set furnace temperature is changed to the temperature rise set value (step S25), the input temperature is set to the appropriate temperature (step S26), and the input start (roasting start) is achieved (step S27). Here, the exhaust bypass damper 21 is opened and the exhaust damper 23 is closed.

[0087] The raw material hopper damper 26 is opened (step S28), the raw material hopper level meter 25b is turned off (step S29), and the raw material hopper damper 26 is closed (step S30). Here, the exhaust bypass damper 21 is closed and the exhaust damper 23 is opened. During roasting, the furnace temperature is controlled by the basic operation.

[0088] When the finished temperature reaches minus 3 °C (achieving the finished temperature - 3 °C) (step S31), the exhaust bypass damper 21 is opened, and then either the finished temperature is reached or the discharge button is turned ON (step S32).

[0089] With the exhaust bypass damper 21 open, water injection by the water supply means 27 is started (step S33). When the water injection amount is OK (step S34), the waiting time after water injection is increased (step S35). With the exhaust bypass damper 21 open and the front cover 24 open, the discharge of roasted beans is started (step S36). The opening time of the front cover 24 is increased (step S37), the exhaust bypass damper 21 is closed (step S38), and the front cover 24 is closed.

[0090] It is determined whether the roasting cycle is to be stopped (step S39). If it is ON, the cooling and suction process ends (step S40), the automatic operation ends (step S41), and the exhaust bypass damper 21 is closed and after-purge is started (step S42). On the other hand, if it is OFF, without stopping the cycle, it returns to the start of ready - on (step S21).

[0091] Note that the pellet burner 2 operates without stopping from the start of combustion of the bio - pellet until the end of roasting, and is always controlled so that the inside of the furnace is under negative pressure. Also, when stopping the pellet burner 2 after roasting, in order to keep the inside of the furnace under negative pressure until the combustion of the bio - pellet subsides, the opening and closing damper 6 of the second passage 5 is opened, etc., so that hot air is exhausted.

[0092] In addition, it is conceivable that it takes several days to stop the combustion of the pellet burner 2. In that case, the opening / closing dampers 6 and 12 can be closed, cold outside air can be introduced from the auxiliary air introduction means 17, and the roaster 3 can be cooled first.

[0093] As described above, the embodiments of the present invention have been described with reference to the drawings. However, various additions, changes, or deletions are possible without departing from the spirit of the present invention.

[0094] · The opening / closing control of the opening / closing damper 6 and the control of the outside air introduction amount of the auxiliary air introduction means 17 can be achieved by driving the actuator manually. However, a temperature sensor for detecting the furnace temperature is provided in the roaster 3. Receiving the signal from the temperature sensor, the opening / closing control of the opening / closing damper 6 and the control of the outside air introduction amount of the auxiliary air introduction means 17 can also be performed according to the temperature difference from the set temperature set on the operation panel on the roaster 3 side.

[0095] · In order to avoid the influence of fly ash from the pellet burner 2, it is possible to provide a cyclone downstream of the pellet burner 2.

[0096] · It is also possible to provide a heat exchanger in the middle of the second passage 5 or the third passage 7 to effectively utilize the exhaust heat.

[0097] · In the roaster 3, in order to improve the fuel efficiency, it is possible to circulate and use a part of the hot air to be exhausted.

[0098] · Instead of the hot air generation means for burning solid biofuel to generate hot air, an electric furnace equipped with an electric heater can be used in place of the pellet burner 2. Unlike the pellet burner using the above-mentioned solid biofuel, the electric heater has a very slow responsiveness in controlling the heat quantity and is not good at fine control. However, due to the configuration of the roasting system 1 described above, excellent temperature control with high responsiveness is possible even when an electric heater is used.

Explanation of reference numerals

[0099] 1 Roasting system 2 Pellet burner 2A Furnace body 3 Roaster 4 First passage 5 Second passage 6 On-off damper 7 Third passage 8 Exhaust fan 9 Cyclone 10 Smoke elimination equipment 11 Passage 11a On-off damper 12 On-off damper 13 Exhaust fan 14 Passage 15A, 15B On-off dampers 16 Hot air introduction part 17 Auxiliary air introduction means 18 Gas burner (auxiliary hot air generation means) 20 Rotary cylinder 21 Exhaust bypass damper 22 Passage 23 Exhaust damper 24 Front cover 25 Hopper part 26 Raw material hopper damper 27 Water supply means

Claims

1. Using a roasting system comprising a roaster for roasting ingredients such as coffee beans and nuts, a hot air generating means having a furnace body for generating hot air within the furnace body, a first passage connected to the hot air generating means and the roaster, a second passage having one end connected to the first passage or the hot air generating means and the other end open to the outside, and an opening / closing device provided in the first passage and the second passage, a roasting method for roasting ingredients, a hot air generating step of burning solid biofuel within the furnace body to generate hot air, a hot air supplying step of supplying the generated hot air to the roaster via the first passage, a roasting step of roasting coffee beans using hot air within the roaster, and comprising: characterized in that the opening and closing of the first and second opening / closing devices are controlled according to the temperature difference from the target temperature of the roaster to adjust the temperature of the hot air supplied to the roaster, A roasting method characterized in that the hot air generating means is not stopped from the start of hot air generation in the furnace body until the roasting of the ingredients is completed.

2. Using a roasting system comprising a roaster for roasting ingredients such as coffee beans and nuts, a hot air generating means having a furnace body for generating hot air within the furnace body, a first passage connected to the hot air generating means and the roaster, a second passage having one end connected to the first passage or the hot air generating means and the other end open to the outside, and an opening / closing device provided in the first passage and the second passage, a roasting method for roasting ingredients, a hot air generating step of burning solid biofuel within the furnace body to generate hot air, a hot air supplying step of supplying the generated hot air to the roaster via the first passage, a roasting step of roasting coffee beans using hot air within the roaster, and comprising: characterized in that the opening and closing of the first and second opening / closing devices are controlled according to the temperature difference from the target temperature of the roaster to adjust the temperature of the hot air supplied to the roaster, A roasting method characterized in that the inside of the furnace body is maintained at a negative pressure from the start of hot air generation in the furnace body until the roasting of the ingredients is completed.

3. Further comprising a warming step of discharging the hot air generated within the furnace body to the outside via the second passage with the first opening / closing device closed and the second opening / closing device open prior to the hot air supplying step. The roasting method according to Claim 1 or 2.

4. The roasting system is provided with auxiliary air introducing means for introducing outside air into the first passage. In the hot air supply step, according to the temperature difference from the target temperature of the roaster, the amount of outside air introduced by the auxiliary air introduction means is controlled, and the hot air is supplied to the roaster to further adjust the temperature of the hot air. The roasting method according to claim 1 or 2.

5. In the roasting system, an exhaust fan is provided in the second passage, a third passage for exhausting the hot air used for roasting from the roaster to the outside of the roaster is connected, and the third passage is connected to the second passage on the upstream side of the exhaust fan. In the roasting step, the hot air used for roasting is exhausted to the outside from the roaster through the third passage and the second passage. The roasting method according to claim 1 or 2.

6. The other end of the second passage is open to the outside through a cyclone and a smoke elimination device. In the roasting step, the hot air used for roasting is exhausted to the outside from the roaster through the third passage, the second passage, the cyclone, and the smoke elimination device. The roasting method according to claim 5.

7. The roasting system is provided with auxiliary hot air generation means for generating hot air by gas combustion in the roaster. In the hot air supply step, according to the temperature difference from the target temperature of the roaster, the amount of hot air introduced by the auxiliary hot air generation means is controlled, and the hot air is supplied to the roaster to further adjust the temperature of the hot air. The roasting method according to claim 1 or 2.

8. In the roasting system, a heat exchanger is provided in the middle of the second passage or the third passage. The heat energy of the exhaust flowing through the second passage or the third passage is recovered by the heat exchanger. The roasting method according to claim 7.

9. In the hot air generation step, the solid biofuel burned in the furnace body is coffee pellets, or wood pellets, or a mixture of coffee pellets and wood pellets. The roasting method according to claim 1 or 2.

10. A roasting system for roasting foodstuffs such as coffee beans and nuts. A roaster for roasting foodstuffs. Hot air generation means for generating hot air to be supplied to the roaster. A first passage for supplying hot air from the furnace body of the hot air generation means to the roaster. A second passage having one end connected to the first passage or the hot air generation means and the other end open to the outside. A first switch provided in the first passage. A second switch provided in the second passage. The hot air generation means generates hot air by burning solid biofuel in the furnace body. From the start of hot air generation in the furnace body until the roasting of the food ingredients is completed, without stopping the hot air generation means, the first opening / closing valve and the second opening / closing valve are controlled to open and close according to the temperature difference from the target temperature of the roaster, and the temperature of the hot air supplied to the roaster is adjusted. Roasting system.

11. A roasting system for roasting food ingredients such as coffee beans and nuts, A roaster for roasting food ingredients, Hot air generation means for generating hot air to be supplied to the roaster, A first passage for supplying hot air from the furnace body of the hot air generation means to the roaster, A second passage having one end connected to the first passage or the hot air generation means and the other end open to the outside, A first opening / closing valve provided in the first passage, A second opening / closing valve provided in the second passage, and comprising, The hot air generation means generates hot air by burning solid biofuel in the furnace body, From the start of hot air generation in the furnace body until the roasting of the food ingredients is completed, while maintaining a negative pressure in the furnace body, the first opening / closing valve and the second opening / closing valve are controlled to open and close according to the temperature difference from the target temperature of the roaster, and the temperature of the hot air supplied to the roaster is adjusted. Roasting system.

12. The first passage is provided with auxiliary air introduction means for introducing outside air into the first passage, According to the temperature difference from the target temperature of the roaster, the amount of outside air introduced by the auxiliary air introduction means is controlled to further adjust the temperature of the hot air supplied to the roaster. The roasting system according to claim 10 or 11.

13. An exhaust fan is provided in the second passage, A third passage for exhausting the hot air used for roasting to the outside of the roaster is connected to the roaster, The third passage is connected to the second passage on the upstream side of the exhaust fan. The roasting system according to claim 12.

14. The other end of the second passage is open to the outside via a cyclone and a smoke elimination device. The roasting system according to claim 11 or 12.

15. The roaster is provided with auxiliary hot air generation means for generating hot air by gas combustion. The roasting system according to claim 10 or 11.

16. A heat exchanger is provided in the middle of the second passage or the third passage. The roasting system according to claim 10 or 11.

17. The solid biofuel is coffee pellets, or wood pellets, or a mixture of coffee pellets and wood pellets. The roasting system according to claim 10 or 11.

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