Coffee Roaster

Abstract

Disclosed is a coffee bean roaster. The coffee bean roaster includes a roasting unit, a sensor arrangement, and a control unit. The roasting unit has a drum with a transparent and removable front wall. The roasting unit further has a hot air supply and a rear wall heater to heat a rear wall of the drum. The sensor arrangement includes a roasting bean temperature sensor. The control unit is configured to receive a control input signal as a function of time, wherein the control input signal includes the roasting bean temperature signal and the roasting bean color signal, and is further configured to automatically generate a control output signal as a function of time in dependence of the control input signal thereby controlling operation of the drum heater and the drum rotor drive to roast the coffee beans inside the drum according to a pre-determined selected roasting profile, wherein the selected roasting profile includes a desired roasting bean temperature as a function of time, a target roasting bean temperature and a target roasting bean color, wherein the control unit is configured to determine if an end-of-roasting-condition is met, wherein the end-of roasting condition includes the coffee beans inside the drum having the target roasting bean temperature.

Claims

1. A coffee roaster comprising: a) a roasting unit comprising: a drum, wherein the drum comprises a drum body with a thermal conductive rear wall, a drum inlet, a drum inlet, a drum outlet, and a removable front wall, a drum rotor,wherein the drum rotor is rotatable arranged inside the drum, a drum rotor drive in operative coupling with the drum rotor, a hot air supply comprising an air heater and a positive pressure device, the positive pressure device including a supply fan, to feed hot air into the drum, and a drum heater thermally coupled with the thermal conductive rear wall, b) a sensor arrangement comprising a roasting bean temperature sensor, wherein the roasting bean temperature sensor is configured to measure a roasting bean temperature of coffee beans positioned inside the drum and to provide a roasting bean temperature signal, c) a control unit for controlling execution of a coffee bean roasting process by the coffee roaster, wherein the control unit is configured to receive a control input signal as a function of time, wherein the control input signal includes the roasting bean temperature signal, wherein the control unit is further configured to automatically generate a control output signal as a function of time in dependence of the control input signal, wherein the control output signal includes a drum heater control signal, a drum rotor drive control signal, and at least one of an air heater control signal or a positive pressure device control signal, thereby controlling operation of the drum heater, the drum rotor drive,- and at least one of the air heater or of the positive pressure device, to roast the coffee beans inside the drum according to a pre-determined selected roasting profile, wherein the pre-determined selected roasting profile includes a desired roasting bean temperature as a function of time and a target roasting bean temperature, wherein the control unit is configured to determine if an end-of-roasting-condition is met, wherein the end-of roasting condition includes the coffee beans inside the drum having the target roasting bean temperature.

2. The coffee roaster according to claim 1, wherein the front wall is transparent.

3. The coffee roaster according to claim 1, wherein the sensor arrangement further includes at least one of: a roasting bean color sensor, wherein the roasting bean color sensor is configured to measure a roasting bean color of the coffee beans positioned inside the drum and to provide a roasting bean color signal, wherein the control input signal includes the roasting bean color signal, a rear wall temperature sensor, wherein the rear wall temperature sensor is configured to measure a rear wall temperature of the thermal conductive rear wall and to provide a rear wall temperature signal, wherein the control input signal includes the rear wall temperature signal, a drum air temperature sensor, wherein the drum air temperature sensor is configured to measure a drum air temperature inside the drum and to provide a drum air temperature signal, wherein the control input signal includes the drum air temperature signal, an inlet air temperature sensor, wherein the inlet air temperature sensor is configured to measure an inlet air temperature of hot air that is fed into the drum and to provide an inlet air temperature signal, wherein the control input signal includes the inlet air temperature signal, an air humidity sensor, wherein the air humidity sensor is configured to measure a withdrawn air humidity of air that is withdrawn from drum and to provide an air humidity signal, wherein the control input signal includes the air humidity signal, an air outlet pressure sensor, wherein the air outlet pressure sensor is configured to measure an air pressure of air that is withdrawn from the drum and to provide an outlet air pressure signal, wherein the control input signal includes the outlet air pressure signal, an air inlet pressure sensor, wherein the air inlet pressure sensor is configured to measure an air pressure of hot air that is fed into the drum and to provide an inlet air pressure signal, wherein the control input signal includes the inlet air pressure signal, or a crack detection sensor, wherein the crack detection sensor is configured to detect the occurrence of a crack of coffee beans during roasting, and provide a crack detection signal, wherein the control input signal includes the crack detection signal.

4. (canceled)

5. The coffee roaster according to claim 1, wherein the thermal conductive rear wall comprises an outer layer in thermal contact with the drum heater, a core layer of aluminum, and a food-grade inner layer.

6. The coffee roaster according to claim 1, further comprising a drum inlet shutter, wherein the drum inlet shutter is arranged to alternatively open or close the drum inlet, wherein the selected roasting profile includes a selected pre-roasting condition, wherein the control unit is configured: to generate a pre-roasting control output signal as part of the control output signal, and to determine, based on control input signal, if the selected pre-roasting condition is met and to control the drum inlet shutter to open the drum inlet upon the selected pre-roasting condition being met.

7. The coffee roaster according to claim 1, further comprising a drum outlet shutter, wherein the drum outlet shutter is arranged to alternatively open or close the drum outlet, wherein the control unit is configured to control the drum outlet shutter to open the drum outlet upon the end-of-roasting condition being met.

8. The coffee roaster according to claim 1, wherein the thermal conductive rear wall comprises an outer layer in thermal contact with the drum heater, a core layer, and a food-grade inner layer.

9. The coffee roaster according to claim 6, further comprising a cooling unit, wherein the cooling unit comprises: a) a cooling container with a cooling container inlet, wherein the cooling container inlet is coupled with the drum outlet via the drum outlet shutter, b) a cooling medium supply, wherein the cooling medium supply comprises at least one of: a cooling air supply fluidically coupled with an inner cooling container space to feed cooling air into the cooling container, or a cooling water supply including a nozzle arrangement configured for spraying cooling water onto coffee beans inside the cooling container.

10. The coffee roaster according to claim 7, wherein the cooling container is fluidically coupled with an inner drum space of the drum, thereby enabling a transfer of cooling air from the cooling container into the drum and a withdrawal of the cooling air from the drum by an exhaust air withdrawer.

11. (canceled)

12. The coffee roaster according to claim 1, further comprising an exhaust air treatment unit, wherein the exhaust air treatment unit includes a catalyzer configured to catalyze one or more components of the exhaust air that is withdrawn from the drum.

13. The coffee roaster according to claim 12, wherein the exhaust air treatment unit includes an exhaust air heater,the exhaust air heater being arranged fluidically upstream with respect to the catalyzer, and an exhaust air cooler, the exhaust air cooler being arranged fluidically downstream with respect to the catalyzer.

14. The coffee roaster according to claim 1, further comprising a chaff separator, the chaff separator including a cyclone separator.

15. The coffee roaster according to claim 14, further comprising a fire extinguisher configured to extinguish a fire in the chaff separator.

16. The coffee roaster according to claim 1, wherein the control unit is configured to control the positive pressure device to vary an airflow of the hot air in dependence of a progress of the roasting process.

17. The coffee roaster according to claim 1, wherein the control unit is configured for operatively coupling with a remote computer system and to receive the selected roasting profile from the remote computer system.

18. The coffee roaster according to claim 17, wherein the control unit is configured to acquire sensor data during coffee bean roasting process to transmit the acquired sensor data or data derived from the acquired sensor data to the remote computer system.

19. (canceled)

20. (canceled)

21. A coffee roasting system comprising: a) a roasting unit comprising: a drum, wherein the drum comprises a drum body with a thermal conductive rear wall, a drum inlet, a drum outlet, and a removable front wall, a drum rotor, wherein the drum rotor is rotatable arranged inside the drum, a drum rotor drive in operative coupling with the drum rotor, a hot air supply comprising an air heater and a positive pressure device, the positive pressure device including a supply fan, to feed hot air into the drum, and a drum heater thermally coupled with the thermal conductive rear wall, b) a sensor arrangement comprising a roasting bean temperature sensor, wherein the roasting bean temperature sensor is configured to measure a roasting bean temperature of coffee beans positioned inside the drum and to provide a roasting bean temperature signal, c) a control unit for controlling execution of a coffee bean roasting process by the coffee roaster, wherein the control unit is configured to receive a control input signal as a function of time, wherein the control input signal includes the roasting bean temperature signal, wherein the control unit is further configured to automatically generate a control output signal as a function of time in dependence of the control input signal, wherein the control output signal includes a drum heater control signal, a drum rotor drive control signal, and at least one of an air heater control signal or a positive pressure device control signal, thereby controlling operation of the drum heater, the drum rotor drive, and at least one of the air heater or the positive pressure device, to roast the coffee beans inside the drum according to a pre-determined selected roasting profile, wherein the pre-determined selected roasting profile includes a desired roasting bean temperature as a function of time and a target roasting bean temperature, wherein the control unit is configured to determine if an end-of-roasting-condition is met, wherein the end-of roasting condition includes the coffee beans inside the drum having the target roasting bean temperature; and a remote computer system configured to store a plurality of available roasting profiles, to receive a user input for selecting the selected roasting profile from the plurality of available roasting profiles, and to transmit the selected roasting profile to the control unit.

22. A method comprising: measuring a roasting bean temperature of coffee beans positioned inside a drum of a coffee roaster, the drum comprising a drum body with a thermal conductive rear wall, a drum inlet, a drum outlet, and a removable front wall; providing a roasting bean temperature signal; controlling, by a control unit, execution of a coffee bean roasting process by the coffee roaster; receiving a control input signal as a function of time, wherein the control input signal includes the roasting bean temperature signal; automatically generating a control output signal as a function of time in dependence of the control input signal, wherein the control output signal includes a drum heater control signal, a drum rotor drive control signal, and at least one of an air heater control signal or a positive pressure device control signal, thereby controlling operation of a drum heater, a drum rotor drive, and at least one of an air heater or a positive pressure device, to roast the coffee beans inside the drum according to a pre-determined selected roasting profile, wherein the pre-determined selected roasting profile includes a desired roasting bean temperature as a function of time and a target roasting bean temperature, wherein the drum heater, the drum rotor drive, and at least one of the air heater or the positive pressure device are within the coffee roaster; and determining if an end-of-roasting-condition is met, wherein the end-of roasting condition includes the coffee beans inside the drum having the target roasting bean temperature.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0132] FIG. 1 shows an exemplary embodiment of a coffee roaster in accordance with the present disclosure in a schematic side view;

[0133] FIG. 2 shows the arrangement of sensors in a coffee roaster as illustrated in FIG. 1;

[0134] FIG. 3 shows the control arrangement of coffee roaster as illustrated in FIG. 1;

[0135] FIG. 4 shows an embodiment of a coffee roasting system in accordance with the present disclosure;

[0136] FIG. 5 illustrates a coffee bean roasting process;

[0137] FIG. 6 shows a further exemplary embodiment of a coffee roaster in accordance with the present disclosure in a schematic side view;

[0138] FIG. 7 illustrates a further exemplary coffee bean roasting process.

DESCRIPTION OF THE EMBODIMENTS

[0139] In the following, reference is first made to FIG. 1, showing an exemplary embodiment of a coffee roaster 1 in accordance with the present disclosure in a schematic side view. The coffee roaster 1 includes a roasting unit 11, a cooling unit 14 and an exhaust air treatment unit 15. Further, the coffee roaster 1 includes a structurally separate respectively removable bean tray 17 with a drawer 18 and an integrated bean scale 16.

[0140] The roasting unit 11 includes drum 111 with drum body 1111 and front wall 1112 that result, in combination, in a generally cylindrical respectively disk-shaped overall shape of the drum 111. Favorably, the drum 111 has a filling volume respectively inner drum space that is suited for roasting about 1 kg of coffee beans. The drum has a horizontal drum axis A that coincides with the rotor axis of a rotor drum 112 that is rotatable arranged inside the drum 111. The drum is designed as explained in the general description, with the front wall 1112 being transparent and removable. The rear wall 11111 of the drum body 1111 is designed as sandwich in the interest of its thermal properties as explained above and is thermally coupled with an exemplarily resistive drum heater 116 that is arranged outside the drum 111. The drum heater 116 is arranged to ensure a substantially uniform heating of the rear wall 11111. In an upper area of the rear wall 11111 a drum inlet 11112 is arranged. Similarly, a drum outlet 11113 is arranged in a lower area of the rear wall 11111. A drum rotor 112 is connected to a drum rotor drive 113 which is realized as electric motor and is arranged outside the drum.

[0141] A hot air supply 114 is provided to supply hot air into the drum 111. arranged generally outside the drum and fluidically connected with the drum outlet 11113 via tubing (not referenced) to supply hot air into the drum. In the shown embodiment, the hot air supply 114 includes a resistive air heater 1141 and a positive pressure supply 1142 in form of a supply fan. In the shown embodiment, the hot air supply 114 is fluidically coupled via tubing with the drum outlet 1113, with the drum outlet 1113 simultaneously serving as hot air inlet. This, however, is not essential and a separate hot air supply opening may alternately be foreseen in the drum body 1111, in particular the rear wall 11111.

[0142] Via corresponding tubing, the drum inlet 1112 is connected with a hopper 1113 into which the raw beans to be roasted are filled. In the connection of the drum 111 respectively its inner space and the hopper 1111, a drum inlet shutter is arranged. Only if the drum inlet shutter 1114 is open, the raw beans that are present in the hopper 1113 may be transferred into the inner space of the drum 111 by way of gravity. The drum inlet shutter is generally open only for filling raw coffee beans into the drum 111, but is closed otherwise. For filling the drum with raw coffee beans, such beans are in this embodiment first filled into the bean tray 17 by a user, where the raw bean weight is automatically measured by bean scale 16. Subsequently, the user moves respectively lifts the bean tray 17 with the drawer 18 and the bean scale 16 to the hopper 1113 and fills the beans from the bean tray 17 into the hopper 1113.

[0143] In this embodiment, the bean tray 17, the drawer 18 and the bean scale 16 form an integral unit that is structurally separate from the further components and units of the coffee roaster 1 and is movable by a user.

[0144] Further, an exhaust air withdrawer 115 is provided to remove exhaust air from the inside of the drum. The exhaust air withdrawer 115 includes a negative pressure device 1151 that is fluidically coupled with an exhaust air withdraw opening 11114 in the upper area of the rear wall 11111 via corresponding tubing and, in this embodiment, an exhaust air treatment unit 15 as explained further below. The negative pressure device 115 includes in this design a withdrawer fan 1151 to generate a suction pressure. Further, the exhaust air withdrawer 1152 includes a chimney 1152 in fluidic coupling with the withdrawer fan 1151. In the exhaust air withdrawal opening 11114, a bean retainer 11115 in form of a perforated plate or a mesh is arranged to prevent coffee beans from leaving the inner space of the drum 111, while allowing air and chaff to pass.

[0145] The exhaust air treatment unit 15 is fluidically arranged between the exhaust air outlet 1114 of the drum 111 and the negative pressure device respectively withdrawer fan 1151 with chimney 1152. Thanks to the exhaust air treatment unit, the exhaust air that ultimately exits the chimney 1152 is cool and substantially free of undesired odorous substances, thereby allowing the coffee roaster 1 to be used within a generally closed room.

[0146] In the shown design, chaff separator unit 19 is fluidically arranged between the drum 111 and the exhaust air treatment unit 15. The chaff separator unit 19 may in particular include a cyclone separator and/or a mechanical chaff retainer filter according to the general description above.

[0147] The main element of the exhaust air treatment unit 15 is a water tank 151. In operation, the water tank 151 is filled to a filling level F with water, with the filling level F being below the exhaust air withdraw opening 11114 of the drum 11. In the shown embodiment, water tank 151 is fluidically coupled with a fresh water supply 152 via a fresh water supply valve 1521 for supplying fresh water into to the water tank 151 if the fresh water supply valve 1521 is open. Further, the water tank 151 is in this embodiment fluidic coupled with an exhaust water drain 151 via an exhaust water drain valve 1531 to remove exhaust water from the water tank 151 if the exhaust water drain valve 1531 is open.

[0148] Generally, the filling volume of the water tank 151 may be in a typical range of 0.5 to 2 liters, for example one liter and is favorably dimensioned sufficient to allow exhaust air treatment for a number of e. g,.one to three roasting operations. It is noted that an explicit fresh water supply 152 and exhaust water drain 153 as well the corresponding fresh water supply valve 1521 and drain exhaust water drain valve 1531 may in principle be omitted. In such embodiment, the water tank 151 may be filled and emptied manually by a user.

[0149] Below the filling level F, a water tank air inlet 1511 is arranged that is fluidically cooled via tubing with the exhaust air withdraw opening 1114 and accordingly the inner drum space.

[0150] Above the filling level F, a water tank air outlet 1512 couples the inner space of the water tank 151 via tubing with the negative pressure device respectively withdrawer fan 1151 via a condenser 155 and an exhaust air filter 154, such that air that leaves the water tank 151 first passes the condenser 155 and subsequently the exhaust air filter 154, typically an active carbon filter, before leaving the chimney 1152. Apart from the water tank air inlet 1511 and the water tank air outlet 1512, the water tank 151 is generally closed in operation.

[0151] Inside the water tank 115 and generally below the filling level F, a bubble enhancer r 156 in form of a perforated plate is arranged that substantially extends over the whole lateral surface area of the water tank 151. In embodiments without dedicated chaff separator unit, the bubble enhancer 156 may at the same time serve as chaff separator as explained above in the general description.

[0152] During the roasting process, the negative pressure device respectively withdrawer fan 1151 is generally active, thereby generating a negative pressure respectively under pressure in the air volume inside the water tank 115 above the filling level F, resulting in the water inside the water tank 151 being agitated and air bubbles being created. Exhaust air that enters the water tank 151 together with chaff comes into contact with the water and is accordingly cooled down, freed from chaff and at least partly from odorous substances and further contained associated material, in particular smoke. The exhaust air rises to the water surface at the filling level F and is withdrawn by the negative pressure device respectively withdrawer fan 1151 after passing the condenser 155 and the exhaust air filter 154 as explained before.

[0153] For cooling the roasted coffee beans at the end of the roasting process, a cooling unit 14 is present in this embodiment. The cooling unit 14 includes a cooling container 141 with a cooling container inlet 1411 and a cooling container opening 1412. The cooling container inlet 1411 is favorably arranged under the bean outlet opening 1113 of the drum 111, thereby allowing roasted coffee beans to be transferred from the inner space of the drum into the cooling container 141 by way of gravity. Between respectively at the connection of the drum outlet 1113 and the cooling container inlet 1411, a drum outlet shutter 1115 is present that allows the transfer of coffee beans into the cooling container 141 only in its open state. During the roasting of the coffee beans inside the drum 111, the drum outlet shutter 1115 is closed and is only opened at the end of the roasting.

[0154] The cooling unit 14 optionally includes a rotatory arranged cooling rotor 142 that is arranged inside the cooling container 141 and is operatively coupled with a cooling rotor drive 143 in form of an electric motor. In the shown embodiment, cooling of the coffee beans is obtained by way of cool air as well as an optional fog of water droplets, thereby allowing efficient cooling within short time, without wetting or otherwise negatively affecting the coffee beans.

[0155] For providing cool air, a cooling air supply 144 in form of a cooling fan 144 is provided that aspires respectively sucks cool air from the environment which is fed into the cooling container 141 and moves between and along the coffee beans. Favorably, the cool air enters the cooling container 141 at its bottom side.

[0156] For providing cooling water, an optional cooling water supply 145 is provided that includes a nozzle arrangement and a nozzle control valve. Via the nozzle arrangement, small water droplets respectively fog is created inside the cooling container 141. Via the cooling rotor rotating during the cooling, the coffee beans are continuously moved and exposed to cool air as well as the optional water droplets. At the end of the cooling process, a cooling container outlet shutter 146 is opened, thereby allowing the transfer of the cooled coffee beans into the bean tray 17 placed under the cooling container outlet 1412 by way of gravity. During the cooling, the cooling container outlet shutter is closed and is opened only at the end of the cooling. During the transfer of the coffee beans out of the cooling container 114 into the bean tray 17, the cooling rotor 141 favorably rotates to ensure that the coffee beans are actually transferred to the cooling container outlet 1412 and exit the cooling container 141.

[0157] In the following, reference is additionally made to FIG. 2, illustrating an exemplary embodiment for the arrangement of various sensors of the sensor arrangement of the coffee roaster 1. The sensors are used for controlling and supervising the coffee bean roasting process, in particular the roasting and the cooling of the coffee beans, as well as the operation of the exhaust air treatment unit 15.

[0158] Respectively inside the drum 11, a roasting bean temperature sensor 12a, a roasting bean color sensor 12b, a rear wall temperature sensor 12c, a drum air temperature sensor 12d as well as a crack detection sensor 12e, which may exemplarily be realized as microphone, are arranged. All of these sensors are, similar to the drum heater 116, arranged at the drum body 1111 and favorably at and/or in the rear wall 11111, in order to allow simple removal of the front wall 1112. At the drum outlet 11113, which also serves as hot air supply opening into the drum 111 in this embodiment as explained before, an inlet air temperature sensor 12f is arranged. Within the water tank 115 and below the filling level F, 15, a water temperature sensor 12j is arranged.

[0159] Further, an optional exhaust air temperature sensor 12k is arranged in this embodiment downstream of the negative pressure device respectively withdrawer fan 1151 that measure the air temperature of the exhaust air before leaving the chimney 1152. Between the drum outlet 1113 and the water tank air inlet 1511, an optional air outlet pressure sensor 12h, air inlet pressure sensor 12h2, and an optional air humidity sensor 12g are arranged that measures the exhaust air pressure and exhaust air humidity, respectively.

[0160] For monitoring the cooling of the coffee beans and detecting if the end-of-cooling condition is met, a cooling bean temperature sensor 12i is in this embodiment arranged inside the cooling container 141. As mentioned above, a cooling bean color sensor could be present additionally or alternatively.

[0161] The control unit 13 may further include sensor interface and/or evaluation circuitry for some or all of the various sensors as explained above and further below. However, such sensor interface and/or evaluation circuitry may also be part of and formed integral with some or all sensors. Similarly, the control unit 13 may include drive and/or control circuitry for the various motors and further actuators as well as the rear wall heater and the air heater and further actuators of valves and shutters. However, such drive and/or circuitry may also be part of and formed integral with some or all of these units or components. Generally, the control unit 13 is configured to evaluate the sensor signals and to control and monitor operation of the coffee roaster 1 as a whole, in particular the roasting unit 11, the cooling unit 14, and the exhaust air treatment unit 15.

[0162] The control unit 13 includes memory (not separately referenced) that stores the required program code that, when executed, instructs the more microcomputers and/or microcontrollers of the control unit 13 to control operation of the coffee roaster 1. Further, the control unit 13 includes memory for storing the selected roasting profile and optionally a plurality of available roasting profiles. Further, the control unit 13 further favorably includes memory for at least temporarily storing senor data that are acquired by the sensors and optionally the bean scale 16 during respectively in the context of one or more coffee bean roasting processes, as explained above in the general description.

[0163] In the shown embodiment, the control unit 13 receives input signals respectively sensor signals from roasting bean temperature sensor 12a, roasting bean color sensor 12b, rear wall temperature sensor 12c, drum air temperature sensor12d, crack detection sensor respectively microphone 12e, inlet air temperature sensor12f, air humidity sensor 12g, air outlet pressure sensor 12h, air inlet pressure sensor 12h2, cooling bean temperature sensor 12i, water temperature sensor 12j, exhaust air temperature sensor 12k, and filling level sensor respectively float gauge 12l as well as the bean scale 16. The sensors are operatively coupled to the control unit 13 in hardwired and/or wireless manner. While most sensors are typically hard-wired, especially the bean scale 16 may be coupled to the control unit 16 favorably wirelessly, e.g. via Bluetooth or WLAN. The sensor signals, in particular those sensor signals that are associated with the roasting and cooling of the coffee beans, form, in combination, the control input signal as explained before.

[0164] In the shown embodiment, the control unit 13 generates control signals for air heater 1141 positive pressure device respectively supply fan 1142, negative pressure device respectively withdrawer fan 1151, drum heater 116, drum rotor drive 113, cooling rotor drive 143, cooling air supply respectively cooling fan 1144 and cooling water supply 145 respectively its nozzle valve. Further, the control unit generates control signals for drum inlet shutter 1114, drum outlet shutter 1115, cooling container outlet shutter 146, as well as fresh water supply valve 1521 and waste water drain valve 1531. The different control signals may be analogue signals and/or binary signals. The control signals, in particular those control signals that are associated with the roasting and cooling of the coffee beans, form, in combination, the control output signal as explained before.

[0165] In the following, reference is made to FIG. 4, showing a coffee roasting system in accordance with the present disclosure. The coffee roasting system includes a number of coffee roasters 1a, 1b, 1c, 1d in accordance with the present disclosure as well as a remote computer system 2. Exemplarily, four coffee roasters are shown for illustrative purposes, while other numbers, including only one coffee roaster, may also be present. The coffee roasters 1a, 1b, 1c, 1d may for example coffee roasters 1 or 1′ as discussed above and further below.

[0166] The coffee roasters 1a, 1b, 1c, 1d are operatively coupled with the remote computer system 2 which is exemplarily sown as centralized computer system, but may also be a distributed, in particular cloud-based computer system.

[0167] The coffee roasters 1a, 1b, 1c, 1d and the remote computer system 2 are operatively coupled, exemplarily via an Internet-based connection.

[0168] Further, a number of user interface devices 3a, 3b are present that are exemplarily separate and distinct from the coffee roasters 1a, 1b, 1c, 1d and, e.g. be realized as tablet computers. In the shown configuration, user interface device 1a is operatively coupled with two of the coffee roasters 1a, 1b, while the other two coffee roasters 1c, 1d are each operatively coupled with a user interface device 3b respectively 3c, in a one-to-one relation. In this configuration, the coffee roasters 1a, 1b may be located close to each other, e.g. in one shop, while the coffee roasters 1c, 1d are located at different locations, in further shops.

[0169] In the shown configurations, the user interface devices communicate with the coffee roasters directly, e.g. via Bluetooth and may communicate with the remote computer device 2 via the coffee roasters. In alternatively configurations, however, the user interface devices 3a, 3b, 3c connect to the internet and communicate with the coffee roasters 1a, 1b, 1c, 1d and/or the remote computer device 2 via the Internet. In a further configuration, the user interface devices 3a, 3b, 3c as well as the coffee roasters 1a, 1b, ac, 1d only communicate with the remote computer device 2 as central instance, the user interface devices and coffee roasters communicate via the remote computer device.

[0170] In particular, if the user interface devices 3a, 3b, 3c are general-purpose-devices, they may store corresponding program code, in particular a suited software application respectively app. Alternatively or additionally, however, the control unit 13 of each coffee roaster 1 as well and/or the remote computer system 2 include an implemented Web server that is configured to generate and provide Web pages that are transmitted to and processed by the user interface devices.

[0171] In the following, reference is additionally made to FIG. 5, showing an example for roasting coffee beans and an example a selected roasting profile and/or target roasting profile. In the diagram of FIG. 5, the vertical axis (ordinate) shows the temperature inside the drum (as measured by drum air temperature sensor 12a, the rear wall temperature sensor 12c and/or the roasting bean temperature sensor 12d as a function of time.

[0172] At the beginning of a coffee bean roasting process, the control unit 13 generates a pre-roasting control output signal, thereby heating the drum and in particular the inner drum space until a selected pre-roasting condition is met. During the pre-heating, the hot air supply 114 in particular positive-pressure device respectively supply fan 1142 and air heater 1141, the drum heater 116 and the exhaust air withdrawer 115, in particular negative pressure device respectively withdrawer fan 1151 are operated. Further, the drum rotor drive 113 may optionally be activated to ensure that the hot air is equally distributed inside the inner drum space. During pre-heating, the shutters and in particular the drum inlet shutter 1114 and the drum outlet shutter 11115 are controlled by the control unit 13 to be closed. During the pre-heating, a user may fill the bean tray 17 with coffee beans that are weighted by bean scale 16 and the weight being transmitted as raw bean weight to the control unit 13. Subsequently, the user fills the raw coffee beans from the bean tray 17 into the hopper 1113 where they remain as long as the drum inlet shutter 1114 stays closed.

[0173] The pre-roasting condition is characterized by a pre-heat temperature. As the control unit 13 determines that the pre-roasting condition is met, the drum inlet shutter 1114 is controlled to temporarily open, thereby allowing the raw beans to be transferred respectively fall into the drum 111 and the drum inlet shutter is controlled to close again. During transferring of the raw coffee beans into the drum 111, the drum rotor drive 113 is favorably controlled to rotate the drum rotor 112 at an appropriate speed to ensure that the raw coffee beans are transported away from the drum inlet 1112.

[0174] Upon the coffee beans being filled into the drum 111, the temperature of the inner drum space decreases until a turning point temperature which is part of the selected roasting profile is reached at a turning point. However, while the actual temperature decreases, the control output signal is controlled to maintain the pre-heat temperature. Subsequent to the turning point, the temperature is again increased until the first crack is detected by the crack detection sensor respectively microphone. 112e. In a subsequent development phase, the temperature is controlled to slowly increase until the target roasting bean temperature and target roasting bean color according to the selected roasting profile are reached as indicated by the roasting bean temperature sensor signal and the roasting bean color signal. The target roasting bean temperature and the target roasting bean color being reached indicate the end-of-roasting condition.

[0175] During roasting, the temperature is controlled by appropriate control of the air heater 114, in particular hot air supply 1141 and positive pressure device respectively supply fan 1142, drum rotor drive, 113, drum heater 116, and negative pressure device respectively withdrawer fan 1151 via the control output signal as generated by the control unit 13. While in principle all of these units respectively elements may be controlled in a time-varying manner, some may also be controlled in a substantially steady manner and/or in an on/off manner.

[0176] As the end-of roasting condition is met, the control unit 13 controls the drum outlet shutter 1115 to open, thereby transferring the coffee beans from the drum 111 into the cooling container 141 of the cooling unit 14. During this transfer, the drum rotor drive 113 and the cooling rotor drive 143 are favorably controlled to operate the drum rotor 112 and the cooling rotor 141 at an appropriate speed to ensure that substantially all coffee beans are transferred into the cooling container 141. With the end-of-roasting condition being met, the hot air supply 114 with air heater 1141and positive pressure device respectively supply fan 1142, as well as the negative pressure device / withdrawer fan 1151 may be deactivated.

[0177] During the cooling, the cooling rotor drive 143 is activated to rotate the cooling rotor 142, and the cooling air supply respectively cooling fan 144 and the nozzle valve of the cooling water supply 145 are controlled by the control unit 13 to cool the beans until a target cooling bean temperature as part of the selected roasting profile is reached, thereby indicating an end-of-cooling condition. During cooling, the temperature of the beans is measured by the cooling bean temperature sensor 12i.

[0178] As the end-of-cooling condition is met, the control unit 13 controls the cooling container outlet shutter to open, thereby, transferring the cooled coffee beans into the bean tray 17 that is placed under the cooling container outlet 146.

[0179] Optionally, a tray sensor 12m, e.g. in form of an optical, capacitive or inductive sensor or a switch is arranged at the cooling unit outlet 1412 and is operatively coupled with the control unit 13. The control unit 13 may be configured to open the cooling container outlet shutter 146 only if the tray 17 is actually present and correctly positioned. Similarly, a drawer sensor 12n may be present to ensure that the drawer 18 is inserted when opening the cooling container outlet shutter 146.

[0180] The weight of the roasted coffee beans is weighted by bean scale 16 and the weight is transmitted as roasted bean weight to the control unit 13. Finally, the user may pull the drawer 18 and remove the roasted and cooled coffee beans.

[0181] In the following, reference is first made to FIG. 6, showing an exemplary embodiment of a coffee roaster 1′ in accordance with the present disclosure in a schematic side view, similar to FIG. 1. Since the coffee roaster 1′ is similar to the coffee roaster 1 regarding its fundamental design and operation and in a number of aspects regarding the device design, the following description is focused on the differences. It is noted that for the sake of clarity the various sensors, actuators and/or other components are not all shown in this embodiment. In principle, sensors, actuators and/or other components as shown in FIG. 2 may be present. Some sensors, actuators and/or other components, however, may also be omitted. The coffee roaster 1′ has a different design in particular regarding the cooling and further handling of the roasted coffee beans, as well as the exhaust air treatment.

[0182] In the embodiment as illustrated in FIG. 6, a user-removable cooling container 141′ is foreseen which also serves as a bean tray for removing the roasted coffee beans from the coffee roaster 1′. The cooling container 141′ is configured to rest on the bean scale 16. The cooling container 141′ has a perforated base allowing air to pass through, the perforations designed such that the beans however cannot pass through.

[0183] For cooling the roasted coffee beans, a cooling air supply respectively cooling fan 144 is foreseen similar to embodiments as illustrated in FIGS., 1, 2. For the coffee roaster 1′, however, only air is used for the cooling. During cooling, the cooling air that is supplied by the cooling fan 144 passes and thereby cools the coffee beans and exits the cooling container via the drum outlet 11113 into the drum. From the drum 111, the cooling air is removed respectively withdrawn by the negative pressure device respectively withdrawer fan 1151. The exhaust air withdrawer serves in this embodiment the double purpose of both withdrawing the exhaust air when roasting as well as the cooling air.

[0184] In an embodiment, the cyclone separator, the catalyzer and/or the exhaust air heater work during cooling such that the exhaust air is treated.

[0185] The cooling being complete respectively the end-of-cooling condition being met may be determined in the same ways as for the before-discussed embodiments and/or according to the general description. In a particular design, no dedicated cooling container outlet shutter under control of the control unit is present. The control unit may therefore optionally provide a user indication, in particular an optical and/or acoustic indication, upon the end-of-cooling condition being met.

[0186] The chaff separator 19′ of the coffee roaster 1′ includes a cyclone separator 191′ for separating the chaff from the exhaust air stream. The cyclone separator 191′ may be controlled by the control unit and activated during the roasting process. After leaving the drum outlet 11114, the exhaust air is fed into the cyclone separator 191′ in which the chaff is generally separated and moved to a chaff drawer 192′ for subsequent disposal. from the cyclone separator 191′ the exhaust air is fed to the particle filter which is exemplary realized as an electrostatic particle filter 159′. Prior to entering the electrostatic particle filter 158′, the exhaust air passes a chaff retainer filter 193′ which may be realized as mechanical filter, for example as perforated plate and prevents any residual chaff that may have passed the cyclone separator 191 from entering the further downstream components.

[0187] The chaff separator 191′ has attached thereto a fire extinguisher 194′ configured to extinguish a fire in the chaff separator 191′ and/or the chaff drawer 192′. The fire extinguisher 194′ is connected to the control unit 13 which controls its activation based on the control unit 13 detecting a condition indicative of a fire. The condition indicative of a fire may be determined using a fire detector. For example, the fire may be detected based on a temperature measured an additional fire temperature sensor, smoke detector, or any other type of fire detector arranged in the fire extinguisher 194′ itself, in the chaff separator 191′, in the chaff drawer 192′, or downstream from the chaff separator 191′.

[0188] The exhaust air treatment unit 15′ of the coffee roaster 1′ includes a catalyzer 157b′ for the removal of odorous, hazardous, toxic, and/or polluting substances, for example carbon monoxide. To ensure an appropriate temperature of the exhaust air for the catalyzer 157b′ to operate efficiently, an exhaust air heater 157a′ is arranged upstream of the catalyzer 157b′. Downstream of the catalyzer 157b′ an exhaust air cooler 157c′ is arranged to cool to the generally hot exhaust air exiting the catalyzer 157b′. The catalyzer may comprise a catalytic converter as known from vehicle exhaust systems.

[0189] In operation, the exhaust air heater 157a′ is favorably not operated continually but only in a phase, in particular a late phase of the roasting process as explained further below, when most smell occurs. Otherwise, odorous particles respectively substances are retained by the electrostatic particles filter 158′. Operation of the exhaust air heater 157a′ is controlled by the control unit of the coffee roaster. Typical heating temperatures may, e.g. be in a range of 200° C. to 400° C., in particular, 250° C. to 300° C., depending on the type and particular characteristics of the catalyzer 157b′.

[0190] From the exhaust air cooler 157c′ as downstream element of the exhaust air treatment unit 15′, the exhaust air passes the condenser/dehumidifier 155 and the exhaust air withdrawer 115 and exits the coffee roaster 1′ via chimney 1152 as explained before.

[0191] As explained before, the cooling air follows the same route as the exhaust air during roasting in the sown design.

[0192] In the following, reference is additionally made to FIG. 7, showing a further example for roasting coffee beans and an example a selected roasting profile and/or target roasting profile, generally similar to FIG. 5. The shown example is in this form based on a coffee roaster 1′ as shown in FIG. 6. Since the roasting process is generally carried out in a similar manner as discussed in context of FIG. 5 and the course of the roasting bean temperature is also similar, the following description is focused on particular aspects of the embodiment.

[0193] In FIG. 7, the bold line schematically shows the roasting bean temperature respectively the roasting bean temperature signal as determined by the roasting bean temperature sensor 12a, generally corresponding to or indicating the desired roasting bean temperature according to the selected roasting profile. The dashed-and-dotted line the rear wall 11111 temperature of the drum 111. Further, FIG. 7 shows supply air flow as a dashed line.

[0194] In a preparatory phase O, the weight of the coffee beans is determined by the bean scale 16 as explained before. Here, the cooling container 141′ serves as bean tray. Phase I is a pre-heating phase where the rear wall 11111 and the air inside the drum 111 are heated to desired target values according to the selected roasting profile. In the shown example, the rear wall temperature is kept substantially constant, which however may not be the case for another selected roasting profile. The pre-heating phase I is here two-parted and includes a pre-heating phase as such I-1 in which in particular the drum air temperature is heated to a desired value according to the selected roasting profile. As this temperature is reached, indicated with a dot as event E1, the drum air temperature is controlled to be kept generally constant respectively stabilizes in a pre-heating holding phase I-1. At the end of the pre-heating holding phase, the control unit controls the drum inlet shutter 1114 to temporarily open, thereby transferring the coffee beans that have by a user filled into the hopper 1113 after determining the weight into the drum 111. The course of the roasting bean temperature during roasting is in the shown example similar to the example of FIG. 5 as discussed before. The drum rotor drive 113 is controlled to rotate the drum rotor 112 in this example with a constant rotational speed, which, however is not mandatory. Instead, the selected roasting profile may include a time-variable profile.

[0195] The positive pressure device respectively supply fan 1142 and the air heater 1141, which both have major impact on the drum air temperature are in this example controlled as follows: The supply fan 1142 is controlled in a number of phases to a predetermined air flow and/or a pressure after the supply fan 1142 respectively at the inlet of the drum 111. The air heater 1141 is controlled such that the desired roasting bean temperature as a function of time is achieved. The different phases may be separated respectively a switching between the phases may be time controlled, occur upon the roasting bean temperature assuming a particular roasting bean temperature in accordance with the selected roasting profile and/or a roasting bean color assuming a particular roasting bean color in accordance with the selected roasting profile.

[0196] By way of example, at the end of Phase 1-b, the supply fan 1142 is set to 60% of a maximum air flow rate, and the temperature of the supply air is set to 450° C. The temperature as detected by the roasting bean temperature sensor 12a (as indicated by the solid line) drops upon the relatively cold beans entering the drum 111. This results in the temperature indicated by the roasting bean temperature sensor 12a dropping quickly until the temperature indicated by the roasting bean temperature sensor 12a matches a temperature of the beans (which is increasing due to the hot supply air and the hot drum 111). During phase II, the control unit 13 is configured to detect a minimum temperature as indicated by the roasting bean temperature sensor 12a. Upon the minimum having been detected, the supply fan 1142 is regulated to 65% of a maximum air flow rate and the temperature of the supply air set to 460° C. From approximately this point onwards, the temperature measured by the roasting bean temperature sensor 12a corresponds well to an actual temperature of the beans. Point E2 is reached once the roasting bean temperature sensor 12a indicates that the beans have reached 193° C. Then supply fan 1142 is set to 40% of a maximum air flow rate and the temperature of the supply air set to 430° C. The specific temperatures indicated in the example described depends on the roasting profile.

[0197] The negative pressure device respectively withdrawer fan 1151 is controlled as explained before to ensure a steady air low without back flow. The air flow and/or the pressure at the air inlet and/or the exhaust air withdraw opening 11114 may further be monitored for pre-defined threshold values which may, if exceeded, indicate a malfunction or defective, such as a blocked filter.

[0198] In the shown example, the roasting as such is two-parted with a first roasting phase II-1 and a subsequent second roasting phase II-2. In contrast to the first roasting phase II-1, the exhaust air heater 157a′ is activated to heat the exhaust air to a temperature of e.g. 300° C. to allow the catalyzer 157b′ to eliminate odorous, hazardous, toxic, and/or polluting substances as explained before in a catalytic process. The start of the second roasting phase II-2 may be initiated for example in dependence of the roasted bean temperature, exemplary at a value of 150° C.

[0199] The end of roasting condition, indicated as characteristic event E-3, is like in the example of FIG. 5, determined by the coffee bean temperature and optionally the coffee bean color assuming respective target values as defined by the selected roasting profile. Further, a time of roasting may define the end of roasting condition, in particular a time of roasting at and/or above a particular temperature. The subsequent steps of cooling, III, and determining the weight of the roasted coffee beans, IV, is carried out as explained before, considering, however, that different design and operation of the cooling unit 15′ as compared to the cooling unit 15 and the manual removal of the roasted coffee beans from the cooling container 141′.

TABLE-US-00001 REFERENCE SIGNS 1, 1′ 1a, 1b, 1c, 1d coffee roaster 11 roasting unit 111 drum 1111 drum body 11111 rear wall (drum body) 11112 drum inlet 11113 drum outlet 11114 exhaust air withdraw opening 11115 bean retainer / perforated plate 1112 front wall 1113 hopper 1114 drum inlet shutter 1115 drum outlet shutter 112 drum rotor 113 drum rotor drive 114 hot air supply 1141 air heater 1142 positive pressure device/supply fan 115 exhaust air withdrawer 1151 negative pressure device / withdrawer fan 1152 chimney 116 drum heater 12a roasting bean temperature sensor 12b roasting bean color sensor 12c rear wall temperature sensor 12d drum air temperature sensor 12e crack detection sensor / microphone 12f inlet air temperature sensor 12g air humidity sensor 12h air outlet pressure sensor 12h2 air inlet pressure sensor 12i cooling bean temperature sensor 12j water temperature sensor 12k exhaust air temperature sensor 121 filling level sensor/float gauge 12m tray sensor 12n drawer sensor 13 control unit 14′ cooling unit 141, 141′ cooling container 1411 cooling container inlet 1412 cooling container outlet 142 cooling rotor 143 cooling rotor drive 144 cooling air supply / cooling fan 145 cooling water supply/nozzle arrangement 146 cooling container outlet shutter 15, 15′ exhaust air treatment unit 151 water tank 1511 water tank air inlet 1512 water tank air outlet 152 fresh water supply 1521 fresh water supply valve 153 waste water drain 1531 waste water drain valve 154 exhaust air filter 155 condenser 156 bubble enhancer / chaff separator 157a′ exhaust air heater 157b′ catalyzer 157c′ exhaust air cooler 158′ (electrostatic) particle filter 16 bean scale 17 bean tray 18 drawer 19 chaff separator 191′ cyclone separator 192′ chaff drawer 193′ chaff retainer filter 194′ fire extinguisher 2 remote computer system 3a, 3b user interface device F filling level (water tank) A drum axis