Roasting system and method

Abstract

To provide a roasting system that uses biopellets to obtain stable combustion and control the hot air temperature to a target level. SOLUTION: This is a roasting system that burns biopellets in a pellet burner 2 to generate hot air, which is then sent to a roaster 3 to roast coffee beans. The pellet burner 2 is a hearth type that burns biopellets in a furnace body 2A. It is equipped with a first passage 4 that supplies hot air from the furnace body 2A of the pellet burner 2 to the roaster 3, a second passage 5 having one end connected to the first passage 4 and the other end open to the outside, and an open / close damper 6 provided in the second passage 5.

Description

[Technical field]

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

[0002] In recent years, the consumption of coffee drinks as a beverage of choice has increased significantly, and the consumption of coffee beans has also increased accordingly. As a result, a large amount of coffee extract residue is generated after coffee extraction. This is a similar problem to that of tea leaves, barley, and other food ingredients.

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

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

[0005] Such solid biofuels have poor ignition and combustion stability, making them difficult to use as a heat source for hot air roasting. In addition, their shape does not allow for continuous fuel supply, so only manual input is possible. For this reason, it has been considered to process them into small biofuels such as coffee pellets, which are easy to use as fuel, and use the coffee extract grounds as a heat source for hot air roasting. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-176933 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the inventors tried to use a small, integrated gun-type burner with solid biofuel such as coffee pellets as fuel for hot air roasting, but found that the combustion response was slower than when gas was used as fuel, and it was difficult to control stable combustion. This is thought to be because the gun-type burner does not have a starting flame, making the combustion unstable.

[0008] We then changed the burner from a gun type to a hearth type with a fire pit, and confirmed stable combustion. We also discovered that it was possible to control the hot air temperature by controlling the balance between exhausting some of the hot air and introducing cold air.

[0009] The present invention aims to provide a roasting system and a roasting method that can achieve stable combustion using biopellets and control the hot air temperature to a target value. [Means for solving the problem]

[0010] A roasting system according to one aspect of the present invention is a roasting system for roasting ingredients such as coffee beans and nuts, and includes a roaster for roasting ingredients, a hot air generating means for generating hot air to be supplied to the roaster, a first passage for supplying hot air from a 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 switch provided in the first passage, and a second switch provided in the second passage, wherein the hot air generating means generates hot air by burning solid biofuel in the furnace body, and the first switch and the second switch are opened and closed according to a temperature difference from a target temperature of the roaster, thereby adjusting 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 portion of the hot air can be discharged through the second passage, making it possible to control temperature with better responsiveness than controlling the temperature of the hot air by controlling the heat of the hot air generating means itself.

[0012] In addition, since hot air can be generated using solid biofuel, it contributes to energy saving. Also, while hot air generating means using solid biofuel has poor response compared to gas or burners, the above-mentioned configuration enables temperature control with excellent response.

[0013] In this case, it is preferable that the first passage is provided with an auxiliary air introduction means for introducing outside air into the first passage, and the amount of outside air introduced by the auxiliary air introduction means is controlled according to the temperature difference from the target temperature of the roaster, thereby further adjusting the temperature of the hot air supplied to the roaster. This makes it possible to introduce outside air (cold air) by the auxiliary air introduction means in addition to discharging a portion of the hot air through the second passage, enabling more responsive and precise temperature control.

[0014] An exhaust fan is provided in the second passage, and a third passage that exhausts hot air used in roasting to the outside of the roaster is connected to the roaster, and the third passage is connected to the second passage upstream of the exhaust fan. This allows hot air to be steadily drawn in from the first passage by the exhaust fan, stabilizing biocombustion, and allowing the exhaust air used in roasting to be discharged to the outside together with the exhaust air from the hot air generating means from the second passage.

[0015] Also, the first passage that supplies hot air from the hot air generating means to the roaster, the second passage connected to the first passage and equipped with an exhaust fan, and the third passage that sends exhaust air from the roaster to the second passage are connected in a passage from the hot air generating means to the exhaust fan via the roaster. This allows a one-to-one correspondence in which the hot air generated by the hot air generating means is pulled by one exhaust fan, so the amount of air introduced by the hot air generating means can be stabilized, and thus the combustion of the hot air generating means can be stabilized.

[0016] In addition, the high-temperature exhaust air from the hot air generating means and the exhaust air from the roaster after roasting are discharged through the same passage, so that the high-temperature exhaust air from the hot air generating means removes dirt such as oil that adheres to the inside of the passage and is caused by the exhaust air after roasting, providing the so-called thermal cleaning effect.

[0017] The other end of the second passage is open to the outside via a cyclone and a smoke suppressor, so that exhaust gas after roasting can be cleaned and discharged to the outside.

[0018] The roaster is preferably provided with an auxiliary hot air generating means for generating hot air by gas combustion. This allows the time required for warming up to be shortened by using the auxiliary hot air generating means, and allows for more precise temperature adjustment during roasting. It also allows roasting to continue in the event of an unexpected event, such as a malfunction of the hot air generating means.

[0019] It is preferable that the roaster is provided with a water supply means for supplying cooling water. This makes it easy to adjust the color of ingredients such as roasted coffee beans. It also makes it possible to cool the ingredients and the roaster.

[0020] It is preferable that a heat exchanger is provided in the second or third passage, so that the heat generated by the exhaust gas after roasting can be effectively utilized.

[0021] The solid biofuel is preferably coffee pellets, wood pellets, or a mixture of coffee pellets and wood pellets. This allows coffee grounds, which are usually discarded, to be effectively used as biopellets. In addition, by using wood pellets or mixing wood pellets, it is possible to improve ignition properties.

[0022] In addition, the roasting system uses an electric furnace instead of the hot air generating means that generates hot air by burning solid biofuel inside the furnace body, and the electric furnace is equipped with an electric heater and generates hot air using the electric heater as a heat source.

[0023] In this way, when the hot air from the electric furnace is supplied to the roaster, it can be partially exhausted through the second passage, enabling temperature control with better response than controlling the temperature of the hot air by controlling the heat of the electric furnace. Also, like the hot air generating means using the solid biofuel described above, electric heaters are very slow in response to controlling the amount of heat, unlike gas or oil, and are not good at fine control, so the above configuration enables temperature control with good response even when an electric heater is used.

[0024] A roasting method according to one aspect of the present invention is a method for roasting food materials using a roasting system including: a roaster for roasting food materials such as coffee beans and nuts; hot air generating means having a furnace body and 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 switches provided in the first passage and the second passage, The system comprises a hot air generating process of generating hot air by burning solid biofuel in the furnace body, a hot air supplying process of supplying the generated hot air to the roaster through the first passage, and a roasting process of roasting food materials in the roaster using the hot air, and is characterized in that the temperature of the hot air supplied to the roaster is adjusted by controlling the opening and closing of first and second switchgears depending on the temperature difference from a target temperature of the roaster.

[0025] In this way, when the hot air from the hot air generating means is supplied to the roaster, by opening and closing the first and second switches to exhaust a part of it through the second passage, it becomes possible to control the temperature with better response than controlling the temperature of the hot air by controlling the heat of the hot air generating means itself. Here, this switch includes, for example, an opening / closing damper, which can adjust the opening ratio in addition to completely opening / closing, and an adjustable one is preferable.

[0026] Here, when the inventors were developing a roasting method, they repeatedly tested various methods and felt that the flavor of the foodstuffs after roasting was being lost. After investigating the cause, they thought that the hot air sent from the hot air generating means to the roaster might contain soot, and after further testing various methods, they found a roasting method with the following configuration.

[0027] The roasting method is characterized in that it further comprises a warming process, prior to the hot air supplying process, in which the hot air generated within the furnace body is discharged to the outside through the second passage with the first switch closed and the second switch open.

[0028] The cause of the loss of flavor is that incomplete combustion occurs during the period from ignition of the solid biofuel in the hot air generating means to complete combustion, emitting a lot of soot. If the hot air is supplied to the roaster as is, soot will adhere to the piping, the inside of the cylinder, and even to the food being roasted, resulting in a loss of flavor.

[0029] In the roasting method having the above configuration, specifically, during the period from ignition of the solid biofuel to complete combustion, the first switch is closed and the second switch is open, and the hot air generated in the furnace body is discharged to the outside through the second passage, that is, a warm-up process is performed in which hot air containing soot is not supplied to the roaster, and then hot air is supplied to the roaster, thereby making it possible to prevent deterioration of flavor due to soot. Therefore, with this configuration, hot air can be supplied to the roaster after hot air of a desired temperature is generated, and there is no need to stop the hot air supply means that has started operating, making it safe and suppressing the adverse effects of soot on flavor.

[0030] In addition, the hot air generating means is not stopped from the start of hot air generation in the furnace body, including the warming process, until the end of roasting the ingredients. With this configuration, the hot air generating means can be operated safely from the start of operation of the hot air generating means to the end of roasting without being stopped.

[0031] This is because the hot air generating means burns biopellets to generate hot air, and if the hot air generating means is inadvertently stopped midway, there is a risk of backfire in the unburned biopellets, etc. Therefore, it is desirable to stop the combustion of the biopellets and stop the hot air generating means after the roasting is completed. It is more desirable not to stop the hot air generating means until the combustion of the biopellets remaining in the furnace body has subsided after the roasting of the coffee beans is completed.

[0032] In addition, the inside of the furnace is maintained at a negative pressure from the start of hot air generation in the furnace, including the warm-up process, until the hot air generating means is stopped after the roasting of the coffee beans is completed. With this configuration, if the inside of the furnace becomes positive pressure, there is a risk that heat will flow back into the fuel supply section where unused biopellets are present, causing a backfire. However, this can be prevented, enabling safe operation.

[0033] The roasting system also includes an auxiliary air introduction means for introducing outside air into the first passage, and in the hot air supplying step, the amount of outside air introduced by the auxiliary air introduction means is controlled according to the temperature difference from the target temperature of the roaster, and the hot air temperature is further adjusted by supplying it to the roaster. This allows outside air (cold air) to be introduced by the auxiliary air introduction means in addition to partial exhaust through the second passage, enabling more responsive and precise temperature control.

[0034] Moreover, in the roasting system, an exhaust fan is provided in the second passage, a third passage that exhausts hot air used for roasting to the outside of the roaster is connected to the roaster, and the third passage is connected to the second passage upstream of the exhaust fan, and in the roasting process, the hot air used for roasting is exhausted to the outside from the roaster through the third passage and the second passage.

[0035] This allows the exhaust fan to stably draw in hot air through the first passage, stabilizing combustion, and allows the exhaust air used for roasting to be discharged to the outside together with the exhaust air from the hot air generating means through the second passage.

[0036] In addition, the high-temperature exhaust air from the hot air generating means and the exhaust air from the roaster after roasting are discharged through the same passage, so that the high-temperature exhaust air from the hot air generating means removes dirt such as oil that adheres to the inside of the passage and is caused by the exhaust air after roasting, providing the so-called thermal cleaning effect.

[0037] The other end of the second passage is open to the outside through a cyclone and a smoke suppressor, and in the roasting process, 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 suppressor. This allows the hot air used for roasting to be released to the outside in a clean state, which is good for the environment.

[0038] In addition, the roasting system is provided with an auxiliary hot air generating means for generating hot air by gas combustion in the roaster, and in the hot air supplying step, the amount of hot air introduced by the auxiliary hot air generating means is controlled according to the temperature difference from the target temperature of the roaster, and the hot air is supplied to the roaster to further adjust the temperature of the hot air.

[0039] This allows the time required for warming up to be shortened by using the auxiliary hot air generating means, and allows for more precise temperature adjustment during roasting. It also allows roasting to continue in the event of an unexpected incident, such as a malfunction of the hot air generating means.

[0040] The roasting system is also provided with a water supplying means for supplying cooling water to the roaster, and further includes a water injection process using the water supplying means after the roasting process is completed. This makes it easy to adjust the color of the roasted coffee beans. Also, the coffee beans and the roaster can be cooled.

[0041] In addition, the roasting system is provided with a heat exchanger in the second or third passage, which recovers the thermal energy of the exhaust gas flowing through the second or third passage. This allows for effective use of the exhaust heat after roasting. For example, the heat exchanger may be disposed so as to straddle the second or third passage and a pipe leading to a hot air generating means, so that the thermal energy of the exhaust gas from the second or third passage is used to generate hot air.

[0042] In addition, the pellets burned in the furnace body in the hot air generating process are coffee pellets or biopellets, which are a mixture of coffee pellets and wood pellets. This allows coffee grounds, which are usually discarded, to be effectively used as biopellets. In addition, by mixing wood pellets, it is possible to improve ignition properties.

[0043] In addition, in the roasting system, 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 in the electric furnace using the electric heater as a heat source, instead of a step of generating hot air by burning biofuel in the furnace. According to the roasting method having this configuration, even when using an electric heater, which has a lower response than gas or a burner, it is possible to achieve temperature control with excellent response. Effect of the Invention

[0044] The present invention allows a portion of the hot air from the hot air generating means to be discharged through the second passage when it is supplied to the roaster, thereby enabling more responsive control of the hot air temperature than controlling the temperature of the hot air by controlling the heat of the hot air generating means itself, resulting in stable combustion. [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is an overall diagram showing a schematic configuration of a roasting system according to the present invention, in which a pellet burner (hot air generating means) is in a warm-up state. [Diagram 2] FIG. 13 is a diagram showing the state of the blades attached to the rotating cylinder of the roaster. [Diagram 3] FIG. 2 is an overall view showing the state of the roasting system during roasting (when heat is needed). [Figure 4] FIG. 2 is an overall view showing the state of the roasting system during roasting (when heating power is not required). [Diagram 5] FIG. 2 is an overall view showing the state during quenching in the roasting system. [Figure 6] FIG. 2 is an overall view showing the roasting system at the end of roasting (front lid open). [Figure 7] FIG. 2 is an overall view showing the state of the roasting system after roasting is finished (0 to 60 seconds after cooling starts). [Figure 8] FIG. 2 is an overall view showing the state of the roasting system during roasting (after 60 seconds from the start of cooling). [Figure 9]FIG. 2 is an overall view showing the state during suction in the roasting system. [Figure 10] FIG. 2 is a flow diagram showing a flow of roasting preparation in the roasting system. [Figure 11] FIG. 2 is a flow diagram showing a flow of a roasting process in the roasting system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall view showing the schematic configuration of a roasting system according to the present invention, in which a pellet burner (hot air generating means) is in a warm-up state.

[0047] In FIG. 1, reference numeral 1 denotes a roasting system that uses coffee pellets (biopellets) as fuel, and is equipped with 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 (roaster) 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 whose one end is connected to the first passage 4, and an opening / closing damper 6 provided in the second passage 5.

[0048] A third passage 7, which is upstream of the exhaust fan 8, is connected to the second passage 5, and the hot air used for roasting is exhausted through the third passage 7, via the exhaust fan 8, a cyclone 9, and a smoke suppression system 10, and released to the outside. An opening / closing damper 12 that is opened and closed by an actuator is provided in the first passage 4 downstream of the part where the second passage 5 branches off. The opening and closing of the opening / closing damper 6 is controlled according to the temperature difference with the target temperature of the roaster 3, to adjust the temperature of the hot air supplied to the roaster 3.

[0049] An exhaust fan 8 and a cyclone 9 are connected to the second passage 5 on the way to the exhaust port to the outside, and a deodorizing device fan (not shown) of a smoke elimination system 10 is connected downstream of the cyclone 9. In addition, a passage 11 connecting the cyclone 9 and the smoke elimination system 10 is provided with an opening / closing damper 11a that opens when the smoke elimination system 10 stops due to an abnormality, etc.

[0050] In addition, a passage 14 having an exhaust fan 13 is connected to the first passage 4 immediately downstream of the furnace body 2, and opening / closing dampers 15A and 15B are provided on the downstream side of each of the connections, which are opened and closed in conjunction with one actuator.Only during a power outage or cooling operation, the opening / closing damper 15A is opened and the opening / closing damper 15B is closed, and the exhaust fan 13 is driven to exhaust air.

[0051] 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.

[0052] 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.

[0053] The amount of air introduced can be controlled not only by the inverter but also by providing a motor damper at the air intake. Not using an inverter can reduce costs.

[0054] The auxiliary air introduction means 17 is also used for purposes other than those mentioned above. For example, in the latter finishing stage of roasting, if heat is blocked due to heat storage in the roaster or in the beans being roasted, the beans will continue to heat up even if no heat is 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.

[0055] 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.

[0056] In the roaster 3, a rotating cylinder 20 that houses and roasts coffee beans (green beans) is rotatably provided within a furnace body 19, and during roasting, the rotating cylinder 20 is rotated by a motor while hot air is introduced into it. The furnace body 19 is connected to the third passage 7 via a passage 22 having an exhaust bypass damper 21 that is opened and closed by an actuator.

[0057] An exhaust damper 23 that is opened and closed by an actuator is also provided on the upstream side of the third passage 7 of this connection portion. The exhaust damper 23 does not control the temperature of the hot air, and can be used to block leakage when the gas burner 18 is not in use.

[0058] Here, the uses of the exhaust damper 23 and the exhaust bypass damper 21 will be described. During roasting, the exhaust damper 23 is opened to exhaust the exhaust air from the roaster 3 through the third passage 7 and the second passage 5 to the outside. On the other hand, when the raw material hopper damper 26 is opened, the exhaust damper 23 is closed and the exhaust bypass damper 21 is opened to prevent the raw materials from being blown downstream (towards the third passage 7). Similarly, during quenching, in which the raw materials are cooled with water, the exhaust bypass damper 21 is opened to allow the hot air to escape, thereby preventing the raw materials from being blown away. This is because during quenching, the internal pressure in the rotating cylinder 20 increases due to the generated steam, and the raw materials are expelled to the outside.

[0059] In addition, with regard to the exhaust bypass damper 21, when the front cover 24 described later is open, cold air from the outside enters through the front cover 24 and attempts to flow into the third passage 7 through the exhaust damper 23, but by opening the exhaust bypass damper 21 at this time, it is possible to create a flow in which the inflow of cold air from the outside into the third passage 7 is suppressed and hot air from the hot air introduction section 16 by the gas burner 18 flows into the third passage 7 through the exhaust bypass damper 21. In this way, it is possible to suppress the combustibility of the gas burner 18 and the fuel consumption of the smoke suppression system 10 when cold air flows into the third passage 7.

[0060] Incidentally, when the exhaust damper 23 is closed, it is configured not to be fully closed. This is because if the timing is bad, such as when roasting using the gas burner 18, and the gas burner 18 goes off while the exhaust damper 23 is fully closed, there is a risk that the furnace body 19 will fill with combustion gas and ignite, so the exhaust damper 23 is not fully closed.

[0061] As shown in FIG. 2, the rotating cylinder 20 has stirring blades 20B randomly provided inside a cylindrical main body 20A.

[0062] 1, the rotating cylinder 20 is provided with a front cover 24 that is opened and closed by a sliding movement driven by an actuator, and the front cover 24 has a cylindrical input section 24a into which raw materials are input. The input section 24a is separably connected to the downstream end of the third passage 7, and a feed opening section 25a of a hopper section 25 that stores raw materials is provided near the downstream end of the third passage 7.

[0063] A raw material hopper damper 26 that is opened and closed by an actuator is provided at the inlet 25a, and is opened when raw materials are charged. A water supply means 27 is provided to supply cooling water to the rotating cylinder 20 to adjust the color of the coffee beans after roasting. It can also be used to deal with problems caused by warm-up or power outages on the roaster 3 side. It can also be used to suddenly lower the hot air temperature as a hot air control for the roaster 3.

[0064] According to the above system, by controlling the balance between the amount of hot air supplied to roaster 3 through first passage 4, the amount of air discharged through second passage 5, and further the amount of outside air (cold air) introduced by auxiliary air introduction means 17, it becomes possible to control the temperature of hot air with good responsiveness, and stable combustion is ensured once combustion starts. In other words, when heating power is required, the state shown in Figure 3 is established, while during roasting, the state shown in Figure 4 is established, and when heating power is not required, the state shown in Figure 5 is established.

[0065] However, when the pressure inside the furnace becomes positive in the pellet burner 2, heat flows back to the fuel supply section, while when the pressure inside the furnace becomes too negative, excessive air is supplied, the inside of the furnace is cooled, and combustion is hindered, so this point must be taken into consideration. In addition to the second passage 5, it is also possible to provide a passage 43 (circulation passage) having opening and closing dampers 41, 42 for more precise control. In the unlikely event that the pellet burner 2 becomes unusable, it is also possible to roast using only the gas burner 18, in which case roasting is performed using the opening and closing dampers 41, 42 and the passage 43 (circulation passage).

[0066] The combustion response is greatly affected by the control of the pellet supply amount, and there is a time lag of several minutes before this is reflected in the temperature. Therefore, the effect of the time lag can be minimized by performing balance control of whether to introduce all of the hot air into the roaster 3 or exhaust a portion of it through the second passage 5.

[0067] After roasting is completed, front cover 24 is opened (see FIG. 6), and holding frame 20a at the end of rotating cylinder 20 is moved by an actuator to move the roasted coffee beans to the top of cooling tank 28 next to roaster 3 (see FIG. 7). At this time, outside air (indoor air) is introduced through fourth passage 30 having introduction fan 29 to cool the beans (see FIG. 8).

[0068] The cooled air is exhausted through a fifth passage 34 having an open / close damper 31, an exhaust fan 32, and a cyclone 33. The raw material coffee beans (green beans) are added within, for example, 60 seconds after the start of cooling, and the next roasting starts 60 seconds after the start of cooling. Note that this 60-second period is an example and is not limited to this. Also, if the addition conditions are not met due to the supply of raw materials or the temperature inside the furnace body 19, the machine will wait.

[0069] After cooling, suction damper 35 is opened in cooling tank 28 (see FIG. 9), and the cooled roasted coffee beans are transported through suction passage 36 to storage tank 37 where they are stored. Storage tank 37 is provided with product discharge damper 37a and level gauge 37b. The suctioned air is then discharged to the downstream portion of exhaust fan 32 in fifth passage 34 through sixth passage 39 which has opening / closing damper 38 which is opened and closed by an actuator.

[0070] In addition to controlling the air volume (opening and closing control of the opening and closing damper 6) to decide whether the hot air from the pellet burner 2 is introduced directly into the roaster 3 or partially exhausted through the second passage 5, by controlling the amount of outside air (cold air) introduced by the auxiliary air introduction means 17, temperature control with better responsiveness than that achieved by controlling the flame power of a conventional gas burner is realized.

[0071] In addition, in the configuration of a gas burner and an auxiliary blower used in a conventional roaster, if you want to suddenly reduce the amount of hot air supplied to the roaster, you have to either reduce the burner output to the lowest level to increase the amount of air blown, or turn off the burner to blow only air. However, in the former case, it is not possible to reduce the output below the limit of the burner turndown ratio, so it is not possible to blow only cold air, and in the latter case, it is difficult to determine the timing of application because it takes time to reignite the burner. On the other hand, in the roasting system of this embodiment, a switch (opening / closing damper) is responsible for blocking the hot air and the blower is responsible for blowing air, so it is possible to solve the above-mentioned problems of the conventional system, and this improves safety even when roasting dark roasts.

[0072] In addition, since an exhaust fan 8 is provided in the second passage 5 for exhausting a portion of the hot air, the portion of the hot air can be smoothly exhausted without impairing stable combustion in the pellet burner 2.

[0073] Excess hot air supplied from the pellet burner 2 is exhausted through the second passage 5, so that it can be exhausted at a high temperature to the subsequent smoke suppression equipment 10, thereby reducing the fuel consumption of the smoke suppression equipment 10.

[0074] In addition, the excess hot air supplied from the pellet burner 2 is exhausted through the second passage 5, and the exhaust air from the roaster 3 is also exhausted through the second passage 5 via the third passage 7, so that the hot air from the pellet burner 2 burns and removes dirt containing coffee oil that adheres to the inside of the passage due to the exhaust air from the roaster 3, providing a so-called thermal cleaning effect. This also eliminates the risk of fires inside the duct.

[0075] Next, the basic control of the furnace temperature of the roaster 3 and the basic control of the exhaust bypass damper 21 will be described.

[0076] (Basic control of furnace temperature of Roaster 3) The furnace temperature setting 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 setting value, a certain amount of hot air generated by the pellet burner 2 is supplied to the first passage 4, and the hot air, which is appropriately distributed by controlling the open / close 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 by the auxiliary air introduction means 17, and the temperature of the hot air is controlled to an appropriate temperature.

[0077] The amount of air introduced through the auxiliary air introduction means 17 is set to the set temperature, and the opening of the opening / closing damper 17a of the auxiliary air introduction means 17 is PID controlled, thereby controlling the furnace temperature.

[0078] Then, as shown in Fig. 10, the operating power supply is turned on (step S1) to start. Then, the roaster button is turned on (step S2), the preheat button is turned on (step S3), the auxiliary hot air generating means (gas burner 18) is ignited (step S4), it is confirmed whether the preheat completion conditions are OK (step S5), and the process moves to the gas burner standby setting (step S6).

[0079] On the other hand, when the roaster button is turned ON, it is selected whether or not to automatically connect the coffee fuel burner (pellet burner 2) (step S7). If it is ON, the temperature inside the coffee fuel burner is set to be equal to or higher than the preset temperature (step S8). If it is OFF, the burner connection button is pressed and held (step S9), and a coffee fuel burner connection command is issued (step S10).

[0080] Then, the auxiliary hot air generating means (gas burner 18) is turned off (step S11), and the burner intake damper (opening / closing valve 18a) is closed (step S12). Meanwhile, the burner damper (opening / closing damper 12) is opened (step S13), the continuous operation button is turned on (step S14), and preparation is completed (step S15).

[0081] (Basic control of exhaust bypass damper 21) In addition to controlling the furnace temperature of the roaster 3, the exhaust bypass damper 21 is controlled to open and close depending on the state of the roaster 3. That is, (i) it is closed when waiting for the raw materials to be fed, (ii) it is open when the raw materials are fed, (iii) it is open before the finish temperature reaches 3°C, (iv) it is open when water is injected, (v) it is closed when the front cover is open, and (vi) it is closed during after-purging, but like other opening and closing dampers, it is driven to open and close by controlling the actuator.

[0082] 11, the process starts when the ready signal is ON (step S21), and it is determined whether the supply of raw beans is completed (step S22). If the signal is ON, the temperature rise starts (step S23), and if the signal is OFF, the process goes into a waiting state for supply (step S24). At this time, the exhaust bypass damper 21 is closed.

[0083] When the temperature rise starts, 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 input (roasting starts) begins (step S27). Here, the exhaust bypass damper 21 is opened and the exhaust damper 23 is closed.

[0084] The raw material hopper damper 26 is opened (step S28), the raw material hopper level gauge 25b is turned OFF (step S29), and the raw material hopper damper 26 is closed (step S30). At this time, 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.

[0085] When the temperature reaches minus 3° C. (finish temperature -3° C. achieved) (step S31), the exhaust bypass damper 21 opens, and then when the temperature reaches the finish temperature or the discharge button is turned on (step S32).

[0086] The exhaust bypass damper 21 is opened, and water injection by the water supply means 27 is started (step S33). When the amount of water injection is determined to be OK (step S34), the waiting time after water injection is increased (step S35), the exhaust bypass damper 21 is opened, the front lid 24 is opened, and the discharge of the roasted beans is started (step S36). The open time of the front lid 24 is increased (step S37), the exhaust bypass damper 21 is closed (step S38), and the front lid 24 is closed.

[0087] It is determined whether the roast cycle has stopped (Step S39). If it is ON, the cooling and suction process ends (Step S40), automatic operation ends (Step S41), the exhaust bypass damper 21 closes, and after-purging begins (Step S42). On the other hand, if it is OFF, the cycle does not stop and the process returns to the start of preparation complete ON (Step S21).

[0088] The pellet burner 2 is operated without stopping from the start of biopellet combustion to the end of roasting, and is controlled so that the inside of the furnace is always at negative pressure. When the pellet burner 2 is stopped after roasting is finished, the open / close damper 6 of the second passage 5 is opened so that hot air can be exhausted in order to maintain negative pressure inside the furnace until the biopellet combustion subsides.

[0089] It may also take several days to stop the combustion of the pellet burner 2. In that case, the opening and closing dampers 6 and 12 can be closed and cold outside air can be taken in through the auxiliary air introduction means 17 to cool the roaster 3 first.

[0090] As described above, the embodiment of the present invention has been described with reference to the drawings, but various additions, modifications, and omissions can be made without departing from the spirit of the present invention.

[0091] The opening / closing control of the opening / closing damper 6 and the amount of outside air introduced by the auxiliary air introduction means 17 can be performed by manually driving the actuator, but it is also possible to provide a temperature sensor in the roaster 3 to detect the temperature inside the furnace, and to control the opening / closing control of the opening / closing damper 6 and the amount of outside air introduced by the auxiliary air introduction means 17 based on the temperature difference between the temperature sensor signal and the set temperature set on the operation panel of the roaster 3.

[0092] In order to avoid the influence of fly ash from the pellet burner 2, a cyclone can be provided downstream of the pellet burner 2.

[0093] It is also possible to provide a heat exchanger in the second passage 5 or the third passage 7 to effectively utilize exhaust heat.

[0094] In Roaster 3, it is possible to recycle some of the exhaust hot air to improve fuel efficiency.

[0095] The hot air generating means that burns solid biofuel to generate hot air can be replaced with an electric furnace equipped with an electric heater instead of the pellet burner 2. Like the pellet burner using solid biofuel described above, electric heaters, unlike gas or oil, are very slow in their response to heat quantity control and are not good at fine control, but the configuration of the roasting system 1 described above makes it possible to control the temperature with excellent response even when an electric heater is used. [Explanation of symbols]

[0096] 1. Roasting System 2 Pellet burner 2A furnace body 3. Roaster 4 1st aisle 5 2nd aisle 6 Opening and closing damper 7 3rd aisle 8. Exhaust Fan 9. Cyclone 10 Smoke elimination equipment 11 Passage 11a Opening and closing damper 12 Opening and closing damper 13 Exhaust fan 14 Passage 15A, 15B Opening and closing damper 16 Hot air inlet 17 Auxiliary air introduction means 18 Gas burner (auxiliary hot air generating means) 20 Rotating Cylinder 21 Exhaust bypass damper 22 Passage 23 Exhaust damper 24 Front lid 25 Hopper section 26 Raw material hopper damper 27 Water supply means

Claims

1. A roasting method for roasting ingredients, such as coffee beans and nuts, using a roasting system including: a roaster for roasting ingredients such as coffee beans and nuts; hot air generating means having a furnace body and 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 a first switch and a second switch provided in the first passage and the second passage, 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; A roasting process for roasting coffee beans using hot air in the roaster, a first and a second switch are opened and closed in accordance with a temperature difference between the target temperature of the roaster and the temperature of the hot air supplied to the roaster, Furthermore, the roasting system is provided with an auxiliary hot air generating means for generating hot air by gas combustion in the roaster, In the hot air supplying step, the hot air introduction amount of the auxiliary hot air generating means is controlled according to the temperature difference with the target temperature of the roaster, and the hot air is supplied to the roaster to further adjust the temperature of the hot air. Roasting method.

2. The method further includes a warming process of discharging hot air generated in the furnace body to the outside through the second passage while closing the first switch and opening the second switch prior to the hot air supply process. The roasting method according to claim 1.

3. The hot air generating means is not stopped from the start of hot air generation in the furnace body, including the warming process, until the end of roasting the food material. The roasting method according to claim 1.

4. The furnace is maintained at a negative pressure from the start of hot air generation in the furnace, including a warm-up process, until the hot air generating means is stopped after the food roasting is completed. The roasting method according to claim 1.

5. The roasting system includes an auxiliary air introduction means for introducing outside air into the first passage, In the hot air supplying step, the amount of outside air introduced by the auxiliary air introduction means is controlled according to a temperature difference between the target temperature of the roaster and the outside air, 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.

6. The roasting system includes an exhaust fan provided in the second passage, a third passage connected to the roaster for exhausting hot air used in roasting to the outside of the roaster, and the third passage connected to the second passage upstream of the exhaust fan, In the roasting process, 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.

7. The other end of the second passage is open to the outside via a cyclone and a smoke suppressor, In the roasting process, 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 suppressor. The roasting method according to claim 6.

8. The roasting system includes a heat exchanger provided in the second passage or the third passage, The thermal energy of the exhaust gas flowing through the second passage or the third passage is recovered by a heat exchanger. The roasting method according to claim 6.

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

10. The hot air generating means is an electric furnace equipped with an electric heater, The hot air generating step is a step of generating hot air by using an electric heater as a heat source in the electric furnace instead of a step of burning biofuel in the furnace body to generate hot air.

10. The method of roasting coffee according to any one of claims 1 to 9.

11. This is a roasting system that roasts ingredients such as coffee beans and nuts. A roaster to roast ingredients, A hot air generating means for generating hot air to be supplied to the roaster; A first passage for supplying hot air from a 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 switch provided in the first passage; a second switch provided in the second passage, The hot air generating means generates hot air by burning solid biofuel in a furnace body, The first switch and the second switch are opened and closed in accordance with a temperature difference between the target temperature of the roaster and the temperature of the hot air supplied to the roaster, Furthermore, the roaster is characterized in that it is provided with an auxiliary hot air generating means for generating hot air by gas combustion. Roasting system.

12. The first passage includes an auxiliary air introduction means for introducing outside air into the first passage, The amount of outside air introduced by the auxiliary air introduction means is controlled according to a temperature difference between the target temperature of the roaster and the amount of outside air introduced by the auxiliary air introduction means, and the temperature of the hot air supplied to the roaster is further adjusted.

12. A roasting system according to claim 11.

13. An exhaust fan is provided in the second passage, A third passage is connected to the roaster to exhaust hot air used for roasting to the outside of the roaster, The third passage is connected to the second passage upstream of the exhaust fan.

13. A 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 suppressor.

12. A roasting system according to claim 11.

15. A heat exchanger is provided in the second passage or the third passage.

12. A roasting system according to claim 11.

16. The solid biofuel is coffee pellets or wood pellets or a mixture of coffee pellets and wood pellets.

12. A roasting system according to claim 11.

17. The hot air generating means uses an electric furnace instead of a means for burning solid biofuel in the furnace body to generate hot air, The electric furnace is equipped with an electric heater and generates hot air using the electric heater as a heat source.

17. A roasting system according to any one of claims 11 to 16.

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