coffee roaster

Abstract

The coffee roaster (1) includes a roasting unit (11) having a drum (111) with a front wall (1112), a hot air supply (114) for heating a rear wall (11111) of the drum (111), and a drum heater (116); a sensor device including a roasted bean temperature sensor (12a); and a control unit (13) that automatically generates control output signals as a function of time depending on received control input signals and controls the operation of the drum heater (116) and the drum rotor drive (113) to roast the coffee beans inside the drum (111) according to a predetermined selected roasting profile, the selected roasting profile including a desired roasted bean temperature as a function of time, a target roasted bean temperature, and a target roasted bean color, and the control unit (13) determines whether a roasting end condition is satisfied based on whether the coffee beans inside the drum (111) have the target roasted bean temperature.

Description

[Technical Field]

[0001] The present invention relates to the field of coffee roasters and to the roasting of coffee beans. [Background technology]

[0002] Roasting coffee beans is known to be a highly complex process that depends on multiple parameters and influencing factors, and generally requires considerable skill and experience. Large industrial coffee roasters are known and widely used for roasting coffee beans. Smaller coffee roasters are also available for roasting small amounts of coffee beans, for example, up to 1 kg or a few kilograms, and are used in shops and some private homes. However, these smaller coffee roasters still tend to require substantial skill from the user, which is often not present, and further require substantial attention from the user or operator to provide satisfactory results.

[0003] Furthermore, coffee roasters generally produce hot, smelly exhaust, requiring operation in a well-ventilated environment and / or expensive and costly exhaust treatment. Furthermore, cooling of the coffee beans after roasting is often unsatisfactory, resulting in suboptimal roasting results. Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, the overall objective is to improve the state of the art in coffee roasting with small coffee roasters suitable for use in, for example, shops, cafeterias, etc., while still producing high quality roasted coffee beans.

[0005] Preferably, some or more of the aforementioned problems and drawbacks are at least partially overcome. Further specific advantages present in some embodiments are discussed in their respective contexts. [Means for solving the problem]

[0006] In one aspect, the overall objective is achieved by a coffee roaster for carrying out a coffee bean roasting process. The expression "coffee bean roasting process" may include, in addition to the roasting process itself, further processes or methods, in particular cooling of the coffee beans after the roasting process, in particular post-treatment such as by a cooling unit, and / or treatment of the exhaust air, as well as removal of chaff, in particular by an exhaust air treatment unit, and the filling of green coffee beans and removal of roasted coffee beans. The expression "roasting process itself" directly refers to roasting the coffee beans in the drum, as will be further explained below.

[0007] It should be noted that the cooling unit and exhaust treatment unit described further below are described herein in the context of a particular embodiment and overall design of a coffee roaster. However, they may also be used in the context of coffee roasters of different designs. Separate implementation of the corresponding subject matter is expressly reserved.

[0008] In a further aspect, the general object is achieved by a coffee roasting system, the coffee roasting system including one or more coffee roasters configured to be operatively coupled to a remote computer system.

[0009] In a further aspect, the general object is achieved by a method of roasting coffee beans and / or a method of brewing coffee, the method comprising using a coffee roaster and / or a coffee roasting system according to an embodiment of the present disclosure.

[0010] A coffee roaster according to the present disclosure may include a roasting unit. The roasting unit may include a drum, the drum comprising a drum body having a thermally conductive rear wall, the drum body further comprising a drum inlet and a drum outlet. The drum further comprises a removable front wall. An inner drum space is defined by the rear wall portion, the front wall portion, and the peripheral wall portion. The roasting unit may further include a drum rotor, the drum rotor being rotatably disposed inside the drum and comprising a drum rotor drive operatively coupled to the drum rotor to rotate the drum rotor. In the recessed configuration, the front wall is transparent.

[0011] Depending on the embodiment, the drive is fixedly attached to and / or is part of the drum, or the drive is separate from the drum. The drive can comprise an electric motor.

[0012] It should be noted that the designs described herein, and in particular the removable and optionally transparent front wall, introduce many constraints and limitations into the overall design of the coffee roaster that are not present in typical prior art features. In particular, the front wall is transparent (typically from glass, as explained further below) and / or removable, such that, as explained in more detail below, the front wall is required to accommodate heaters, sensors, and openings / openings for loading and unloading coffee beans. Instead, all such features generally need to be located in the drum body, and in particular in the rear wall of the drum.

[0013] The roasting unit may further include a hot air supply unit including an air heater and a positive pressure device for supplying hot air into the drum. The roasting unit may further include an exhaust air extraction device for extracting exhaust air from the drum. The exhaust air extraction device may include a negative pressure device.

[0014] The roasting unit may further include a drum heater, the drum heater thermally coupled to the rear wall for heating the rear wall.

[0015] The coffee roaster further includes a sensor device. The sensor device may include a roasted bean temperature sensor configured to measure a roasted bean temperature of the coffee beans disposed inside the drum and provide a roasted bean temperature signal. The roasted bean temperature sensor may be embodied as, for example, a PT100 temperature sensor or an infrared temperature sensor.

[0016] The coffee roaster further includes a controller that controls execution of the coffee bean roasting process by the coffee roaster. The control unit is configured to receive control input signals as a function of time, where the control input signals may include a roasted bean temperature signal. The control unit is further configured to automatically generate control output signals as a function of time in response to the control input signals. The control output signals include at least one of a drum heater control signal, a drum rotor drive control signal, and an air heater control signal and / or a positive pressure function control signal, thereby controlling operation of at least one of the drum heater, the drum rotor drive function, and the air heater and / or the positive pressure function to roast the coffee beans inside the drum according to a predetermined selected roasting profile. The selected roasting profile may include a desired roasted bean temperature as a function of time and a target roasted bean temperature.

[0017] The operation of the drum heater can be controlled via a drum heater control signal. The operation of the drum rotor drive can be controlled via a drum rotor drive control system. The operation of the air heater can be controlled via an air heater control signal. The operation of the positive pressure device, particularly the supply fan as further described below, can be controlled via a positive pressure device control signal.

[0018] The control unit is further configured to determine whether an end-of-roast condition is met, the end-of-roast condition may include the coffee beans in the drum having a target roasted bean temperature.

[0019] Roasting of the coffee beans is achieved by a combination of direct heat transferred to the beans through the rear wall and, particularly preferred, hot air. During roasting, the drum rotor drive is generally activated, causing the drum rotor to rotate and continuously mix the coffee beans within the drum, resulting in a uniform roast.

[0020] Controlling the operation of the drum heater may include, in particular, controlling the heating power of the drum heater. Preferably, the heating power of the drum heater may be controlled substantially continuously. However, in further embodiments, the heating power may be controlled in several discrete steps and / or may be switched on and off only via the drum heater control signal.

[0021] Controlling the operation of the drum rotor drive may include, inter alia, controlling the rotational speed of the drum rotor drive, and thus the rotational speed of the drum rotor. Preferably, the rotational speed of the drum rotor drive may be controlled substantially continuously. However, in further embodiments, the rotational speed of the drum rotor drive may be controlled in several discrete steps and / or may be switched on and off only via the drum heater control signal. In general, the drum rotor drive may be turned off via the drum rotor drive control signal.

[0022] Controlling the operation of the air heater may in particular include controlling the heating power of the air heater, for example by switching the heating power on / off and / or adjusting it continuously or in several discrete steps.

[0023] As described further below, controlling the operation of the positive pressure supply and optionally the negative pressure device generally relates to controlling the pressure difference between the inlet and outlet sides and / or airflow through the positive pressure device and negative pressure device, respectively. In embodiments where the positive pressure device includes a supply fan, controlling the operation of the positive pressure supply may include, among other things, controlling the rotational speed of the supply fan. Similarly, in embodiments where the negative pressure device includes an extraction fan, controlling the operation of the negative pressure device may include, among other things, controlling the rotational speed of the extraction fan. The operation of each of the positive pressure supply or negative pressure device is preferably controlled substantially continuously, for example, by continuously controlling the rotational speed of the supply fan or extraction fan, respectively. In further embodiments, the positive pressure supply and / or negative pressure supply may be switched on and off only via corresponding control signals, without continuous adjustment, without adjustment of rotational speed, or may be controlled in several discrete steps.

[0024] The coffee roaster according to the present disclosure has a number of desirable characteristics that make it particularly suitable for direct use in stores, cafeterias, and the like, as well as for on-demand roasting for end users or consumers in general. While the coffee roaster according to the present disclosure may be designed to handle and roast different quantities of coffee beans, it may typically be designed to roast approximately 0.5 kg to 1.5 kg of coffee beans, and the inner drum space may therefore be designed to accommodate approximately 0.5 kg to 1.5 kg of coffee beans. In contrast to the roasting equipment typically used by commercial coffee roasters, which are designed to efficiently roast large quantities of coffee beans uniformly and generally in a time-efficient manner, the coffee roaster according to the present disclosure can be advantageously used to roast substantially smaller quantities of coffee beans in a flexible manner. The type of coffee beans and the roasting process and its parameters are preferably easily changeable from batch to batch. Furthermore, the coffee roaster according to the present disclosure is suitable for direct use in stores and cafeterias, ensuring no issues from a health and safety perspective, since the exhaust air is cooled, filtered, and / or passed through a catalyst. Furthermore, the coffee roaster is designed to operate within acceptable noise limits.

[0025] Since the coffee bean roasting process is carried out automatically under the control of the control unit, little (if any) experience and coffee roasting skill is required to obtain the desired result defined by the predetermined selected roasting profile. Also, substantially no manual observation and handling is required during roasting, which is particularly preferable for use in, for example, a shop or cafeteria. Further advantageous features and embodiments in the context of types of application are further described below in the context of the general description and the description of the drawings, respectively.

[0026] It has been found that measuring coffee bean temperature (potentially together with other properties and characteristics as further described below) is particularly suitable for controlling the roasting process and automatically determining when a desired state has been reached and the roasting process is complete.

[0027] In the context of control, the desired roasted bean temperature as a function of time provided as part of the selected roast profile can each be considered a time-dependent setpoint as a reference variable. Each component of the control output signal can be considered as a correction to a respective operating variable. The target roasted bean temperature, as well as one or more optional further target values, in particular the target roasted bean color as further described below, define the end of the roasting conditions as a stop criterion for terminating the roasting process.

[0028] In addition to the rear wall, the drum body includes a peripheral wall connecting the rear wall to the front wall. The peripheral wall may optionally be integrally formed with the rear wall or may be formed separately. Preferably, the peripheral wall is also thermally conductive and may be made from the same material as the rear wall, each designed to be the same, but this is not required.

[0029] The drums have longitudinal drum axes that are symmetrical about the central axis and extend through the centers of the rear and front walls. In the operating configuration of the coffee roaster, the longitudinal drum axes are horizontal and perpendicularly transverse to the direction of gravity. The drum rotors have rotor axes that are coincident with the longitudinal drum axes as a common axis.

[0030] Furthermore, the drum preferably has a drum diameter that is substantially greater than the distance between the parallel rear and front walls of each extension of the drum length along the drum axis, so that the drum is preferably disk-shaped.

[0031] All parts of a coffee roaster that come into contact with the coffee beans before, during, and after the roasting process are made from food-grade materials. This is especially true for the drum and drum rotor, which must also be designed to withstand the temperatures typically in excess of 400°C that occur during roasting.

[0032] In one embodiment, the rear wall is realized as a sandwich comprising an inductively heatable outer layer in thermal contact with the drum heater, an aluminum core layer, and a food-grade inner layer (on the coffee bean-contacting side opposite the outer layer). This design is particularly preferred in designs where the drum heater is designed as an inductive heater in thermal contact with the outer layer. The core layer distributes heat substantially uniformly and with low losses. Instead of aluminum, other suitable materials with high thermal conductivity, such as copper, can be used for the core layer. The food-grade inner layer may be made of, for example, chromium steel or stainless steel, each of which may be relatively thin and realized as a coating. The peripheral walls of the drum rotor and drum body are also coated or minimally coated with food-grade material. In particular, the peripheral wall portion may have the same design as the rear wall portion and may be realized as a sandwich as described above. Typical thicknesses of each layer may be, for example, 1 mm to 5 mm. The expression "outer layer" refers to the outer side of the rear wall facing away from the inner drum space, while the inner layer defines the defining surface of the inner drum space.

[0033] The front wall is preferably made of inert glass and food-grade glass. The front wall is generally removably attached to the drum body in a manner that allows for easy removal by an operator, optionally without the need for tools, thereby allowing for easy removal for cleaning and maintenance purposes. Optionally, the inner surface of the front wall may be coated with a heat-reflective and transparent coating, as commonly known in the art, to reduce unwanted heat radiation and limit the temperature of the front wall's generally user-accessible outer surface. In an operational state in which the front wall is attached to the drum bay, the connection between the drum bay and the front wall is preferably both airtight and / or odor-tight.

[0034] In embodiments where the front wall is not transparent, the front wall may be made from substantially the same material as the rear and / or peripheral walls, for example food grade stainless steel.

[0035] In a further design, the drum heater is not designed as an induction heater, but rather as a resistance heater, Peltier element heater, or infrared heater, for example. Such a design allows for a modification of the sandwich structure described above, which does not require an outer layer, a core layer, and an inner layer. In particular, in embodiments in which the drum heater is a resistance heater, the rear wall may be realized as a sandwich including two layers. One layer is an outer layer of aluminum or other material with high thermal conductivity, within which the heating element is embedded. The other layer is an inner layer of food-grade material, as described above.

[0036] The drum inlet is arranged above the longitudinal drum axis. Typically, the drum inlet is arranged on the rear wall close to the connection to the peripheral wall. However, alternatively, the drum inlet may also be arranged in the upper region of the peripheral wall. The drum inlet is or includes an opening through which green coffee beans can be introduced into the drum for subsequent roasting. Preferably, the inlet opening is connected to or connectable to a hopper, which can be filled with coffee beans to be roasted, typically manually. Such a hopper may be part of a coffee roaster. In a particularly preferred embodiment, the drum inlet is connected to the hopper via a drum inlet shutter, which may be arranged between the hopper and the drum inlet, or which may be arranged at the drum inlet. The hopper is preferably arranged above the drum inlet so that the coffee beans can be transferred from the hopper into the drum by gravity.

[0037] The drum outlet is located below the longitudinal drum axis. Typically, the drum outlet is located on the rear wall near the connection to the peripheral wall. However, alternatively, the drum outlet may be located in a lower region of the peripheral wall. The drum outlet is or includes an opening through which roasted coffee beans can be removed from the drum. In a particularly preferred embodiment, a drum outlet shutter is located at the drum outlet, as described further below. In an embodiment described in more detail below, the drum outlet is further configured to receive cooling air from a cooling vessel when cooling the roasted coffee beans. In such a design, the drum outlet is preferably designed to be airtightly coupled to the cooling vessel, in particular the cooling vessel inlet. Thus, the drum is rapidly cooled as the coffee beans are cooled, allowing the drum to return to a temperature at which it can be safely handled and / or to receive additional unroasted beans for a subsequent roasting process.

[0038] To supply hot air into the drum, the drum body, preferably the rear wall, is provided with hot air supply openings as interfaces between the hot air supply sections and the internal drum space, respectively establishing fluid communication between the hot air supply sections and the internal drum space. In some specific embodiments, the hot air supply openings are respectively identical to the drum outlets.

[0039] The heating element of the hot air supply is typically realized as a resistive heating element, but in principle may also be realized differently, in particular as an induction heating element or gas heating element, a Peltier element, etc. The hot air is actively forced into the drum via a positive pressure device. In a typical embodiment, the positive pressure device is realized as a supply fan, respectively a supply blower. However, in alternative embodiments, the positive pressure device is realized as or includes, for example, a pressurized air tank, a compressor, etc. In some embodiments, one or more flow control elements, such as valves, throttles, etc., may be present. The positive pressure device may generally be coupled to the internal drum space via a suitable tube for connecting with the hot air supply opening.

[0040] To draw exhaust air from the internal drum space, the drum body, preferably the rear wall, is provided with an exhaust air drawer opening as an interface between the internal drum space and the exhaust air drawer, establishing fluid communication between the exhaust air drawer and the internal drum space. Similar to the inlet opening, the exhaust air vent opening is preferably arranged in an upper region of the drum body above the longitudinal drum axis. Preferably, a coffee bean retaining element, particularly in the form of a perforated plate or mesh, is arranged at the exhaust vent opening. The openings of the coffee bean retaining element are dimensioned such that the exhaust air can pass through without substantial resistance, and also allow chaff that is separated from the coffee beans during roasting to pass through, while the coffee beans are retained within the drum.

[0041] The exhaust air extraction device includes a negative pressure device for actively extracting the exhaust air by suction. In a typical embodiment, the negative pressure device is realized as an extraction fan, respectively an extraction blower. However, in an alternative embodiment, the negative pressure device is realized by a vacuum pump, such as a water jet pump. In principle, the negative pressure device may be directly coupled to the internal drum space, for example, using a suitable tube for connecting with the exhaust vent opening. However, in other particularly preferred embodiments, the negative pressure device is fluidically coupled to the internal drum space via an exhaust treatment unit as an intermediate element, as will be described in more detail below. Furthermore, the exhaust air collector may include, in particular, a chimney, e.g., an extraction fan, which may be fluidically arranged downstream of the negative pressure device. It should be noted that the negative pressure device may also be considered part of the exhaust treatment unit, as will be further described below in the context of specific embodiments.

[0042] In embodiments described further below, the exhaust air extractors are further configured and used during operation to extract cooling air used to cool the roasted coffee beans within the cooling unit, respectively.

[0043] In one embodiment, the sensor device further includes one or more additional sensors, as described below:

[0044] The sensor device may include a roasted bean color sensor configured to measure the roasted bean color of coffee beans placed inside the drum and provide a roasted bean color signal, and the control input signal includes the roasted bean color signal. The roasted bean color sensor is typically an optical sensor as known in the art, or may be realized, for example, by a camera combined with corresponding image processing logic and / or image processing firmware / software code. The roasted bean color sensor may be particularly located on the peripheral wall or rear wall, respectively. Such a roasted bean color sensor is not preferably located inside the drum, but is configured to measure the roasted bean color of the coffee beans through a window or opening in the peripheral wall or rear wall. In embodiments including a roasted bean color sensor, the end-of-roasting condition may include coffee beans inside the drum having a target roasted bean color.

[0045] The sensor device may include a backwall temperature sensor configured to measure a backwall temperature of the backwall and provide a backwall temperature signal, and the control input signal includes the backwall temperature signal.

[0046] The sensor device may include a drum air temperature sensor configured to measure a drum air temperature inside the drum and provide a drum air temperature signal, and the control input signal includes the drum air temperature signal.

[0047] The sensor device may include an inlet air temperature sensor configured to measure an inlet air temperature of the hot air supplied to the drum and provide an inlet air temperature signal, and the control input signal includes the inlet air temperature signal.

[0048] The sensor device may include an air humidity sensor configured to measure drawn air humidity of air drawn from the drum and provide an air humidity signal, and the control input signal includes the air humidity signal.

[0049] The sensor device may include an airflow sensor configured to measure an extracted air flow rate of air drawn from the drum and provide an airflow signal, and the control input signal includes the airflow signal.

[0050] The sensor device may include a crack detection sensor configured to detect the occurrence of first and / or second cracks in the coffee beans during roasting and provide a crack detection signal, and the control input signal may include the crack detection signal. The crack detection sensor is configured and arranged to detect the occurrence of the first and / or second cracks based on mechanical waves resulting from the cracks. The detected mechanical waves may be acoustic waves, and the crack detection sensor may be a microphone. Alternatively, or additionally, the mechanical waves may be structurally generated and detected in the drum body, particularly the rear wall and / or peripheral wall. In such an embodiment, the crack detection sensor may be, for example, a piezo-resistive or capacitance-based acceleration or vibration sensor.

[0051] The sensors described herein have been found to provide particularly useful information for monitoring and / or supervising the roasting process in the context of an automated setting, and some or all of them may be used accordingly. Additional sensors that may be present in some embodiments are discussed further below in their respective contexts.

[0052] In one embodiment, the sensor comprises one or more pressure sensors, including, for example, an air outlet pressure sensor and / or an air inlet pressure sensor. A given pressure sensor can measure absolute pressure, relative pressure, and / or differential pressure. The one or more pressure sensors are configured to measure air pressure at one or more locations within the coffee roaster, particularly the air pressure of air entering and / or exiting the drum. For example, the sensor comprises a pressure sensor located upstream of the drum configured to measure the relative pressure of the inlet air relative to ambient pressure. Additionally, the sensor may comprise a pressure sensor located downstream of the drum configured to measure the relative pressure of the outlet air relative to ambient pressure. Each of the one or more pressure sensors is configured to provide a control signal indicative of the measured pressure.

[0053] A control signal indicative of a pressure sensor can be used to determine the temperature difference between two or more locations, which indicates, for example, the rate of air flow between the two locations.

[0054] In one embodiment, the control output signal includes a negative pressure device control signal, which controls the operation of the negative pressure device of the exhaust air vent. During roasting, the positive pressure device and the negative pressure device may be coordinated so that the hot air flow respectively supplied to the drum corresponds to the exhaust air flow respectively discharged from the drum. In this way, a continuous flow is achieved and any backlash is prevented. In an embodiment including a cooling unit in which cooled air is respectively supplied into the drum and after cooling the roasted coffee beans collected by the exhaust air collector, the exhaust air collector, e.g., the collector fan, may be controlled to operate at a generally high, potentially maximum, power. In this way, it is ensured that air is safely collected from the drum via the air collector and no backlash occurs.

[0055] In one embodiment, the coffee roaster includes a drum inlet shutter, the drum inlet shutter arranged to alternately open and close the drum inlet. In such an embodiment, the selected roast profile can include a selected pre-roast condition, and the control unit can be configured to generate a pre-roast control output signal as part of the control output signal, determine based on the control input signal when the selected pre-roast condition is met, and control the drum inlet shutter to open the drum inlet when the selected pre-roast condition is met. The control unit is further configured to control the drum inlet shutter to close the drum inlet when coffee beans are respectively loaded into the drum and to maintain the drum inlet shutter closed during roasting. Thus, the drum inlet shutter is controlled to only temporarily open the drum inlet for loading to respectively transfer coffee beans into the drum, but to maintain the drum inlet closed otherwise.

[0056] The drum inlet shutter is disposed at the drum inlet or between the hopper and the drum inlet, so that coffee beans can be filled into each drum space within the drum when the coffee bean inlet shutter is open. When the inlet shutter is closed, the passage from the hopper to the drum is blocked. The inlet shutter is preferably designed to hermetically seal the passage from the internal drum space to the hopper. This prevents exhaust air from leaving the internal drum space through the inlet opening during roasting, but only through the opening through which the exhaust air is extracted. The inlet shutter further includes a control unit and an inlet shutter actuator, such as an electromagnet or a motor, in an operationally cooled state.

[0057] The pre-roast conditions typically include the drum air temperature and drum body temperature, particularly the back wall temperature, present at the start of the roast depending on the desired roast, or in another embodiment, only the drum body temperature present at the start of the roast.

[0058] The embodiment with the controlled inlet shutter is preferred for both convenience and quality of the roasting process. A user can fill the hopper with green coffee beans at virtually any time, for example after turning on the coffee roaster. The coffee beans in the hopper are transferred into the drum by automatically opening the drum and the respective inlet shutter when the pre-roasting condition is met. The time until the pre-roasting condition is met is also called pre-heating.

[0059] During preheating, the drum rotor drive and the drum rotor are generally controlled to operate in a manner that ensures uniform temperature distribution within the drum. Furthermore, the control unit is configured to control the drum rotor drive during each transfer of coffee beans from the hopper to the drum while the drum inlet opening is open to rotate at a generally reduced speed, so that the drum rotor transfers the coffee from the drum inlet opening to the inner drum space and ensures that the drum inlet opening is not blocked. When the drum inlet opening is closed again by the drum inlet shutter, roasting begins, and the drum rotor drive is controlled according to a selected roasting profile. Preheating can include a holding phase after the pre-roast conditions are met, during which relevant parameters, particularly the back wall temperature and the drum air temperature, are maintained constant before opening the inlet shutter and starting roasting.

[0060] In one embodiment, the coffee roaster includes a drum exit shutter arranged to alternately open and close the drum exit, In such an embodiment, the control unit may be configured to control the drum exit shutter to open the drum exit when an end-of-roast condition is met.

[0061] This type of embodiment has the particular advantage that the coffee beans automatically leave the drum once the roast end conditions are met, and in particular that the coffee beans have a target roast bean temperature and are not further roasted in an uncontrolled and undesirable manner due to the hot back wall and hot air within the drum.

[0062] The drum exit shutter may include a flap similar to the drum inlet shutter described above, but may also be, for example, a movable perforated plate or slide. The drum exit shutter further includes a control unit and an exit shutter actuator, such as an electromagnet or motor, in an operationally cooled state.

[0063] In the drum outlet open configuration, the roasted coffee beans are removed from the inner drum and can suitably fall out of the drum by gravity. During this process, the drum rotor drive is preferably controlled to be active, rotating the drum rotor which pushes the coffee beans out of the inner drum space.

[0064] In one embodiment, a coffee roaster includes the cooling unit, although it should be noted that a cooling unit according to the present disclosure may also be implemented and used in the context of other types of coffee roasters.

[0065] The cooling unit includes a cooling vessel having a cooling vessel inlet, which may be coupled to the drum outlet via a drum outlet shutter.

[0066] The cooling unit may further include a cooling medium supply. The cooling medium supply may include a cooling air supply, the cooling air supply fluidly coupled to the interior cooling vessel space for supplying cooling air into the cooling vessel. Alternatively or additionally, the cooling medium supply may include a cooling water supply.

[0067] The cooling water supply may include a nozzle arrangement configured to spray cooling water onto the coffee beans in the cooling vessel.

[0068] Via the cooling unit, the coffee beans can be cooled in a well-defined and controlled manner. In particular, it is generally desirable to cool the coffee beans rapidly without moistening them. This can be achieved in embodiments that include both a cooling air supply and a cooling water supply. However, in some designs, either may be sufficient.

[0069] In one embodiment, the cooling unit may further include a cooling rotor drive operatively coupled to the cooling rotor to rotate the drum rotor. Further, in one embodiment, the cooling vessel may include a cooling vessel outlet. In alternative embodiments, there may be no dedicated cooling vessel outlet, and / or there may be no cooling rotor and cooling rotor drive.

[0070] The cooling unit may in particular be coupled to the drum outlet opening via a drum outlet shutter which alternatively connects the cooling unit to the drum space when the drum outlet opening is open, or which decouples the cooling unit from the drum space when the drum outlet opening is closed and accordingly the drum outlet shutter can also be considered to function as a cooling vessel inlet shutter, respectively, so that the roasted coffee beans can be removed from the drum and transferred to the cooling vessel only when the drum outlet shutter is open.

[0071] The cooled air supply source can include, among other things, a cooling fan and a cooling blower coupled to the cooling vessel interior space to actively force air into the cooling vessel interior space, respectively. Rather than a cooling fan, the cooled air supply source can include, for example, an air pump or compressor to force air into the cooling vessel interior space. In typical embodiments, the cooled air temperature is generally the ambient air temperature. However, if desired, the cooled air supply source can include a dedicated cooling device to cool the cooled air.

[0072] The coffee beans should not actually be wetted by the supply of cooling water. Therefore, the nozzle device preferably includes multiple nozzles that create a mist atmosphere within the cooling container. Each nozzle device is preferably located at the top of the cooling container. The cooling water supply unit may include a cooling water pump to supply cooling water to the nozzle device and / or may operate at the line pressure of a common water supply. Alternatively, the cooling water supply unit may include a cooling water tank located above the cooling container, so that water is forced from the cooling water tank to the nozzle by gravity. The cooling water supply unit may include a nozzle control valve operably coupled to the control unit via a nozzle control valve control signal and controlled by the control unit. The nozzle control valve control signal may be part of the control output signal, as described above. Such a nozzle control valve may be a shut-off valve or a continuous control valve for continuously controlling the supply of water to the nozzle device. To prevent the coffee beans from actually getting wet, the cooling water supply is preferably controlled so that it is only activated when the coffee bean temperature exceeds a wetting temperature threshold, in particular 100°C, and is switched off when the coffee bean temperature falls below the wetting temperature threshold as indicated by the cooling bean temperature sensor, in particular by completely closing the nozzle control valve.

[0073] In certain embodiments including a cooling unit, the cooling unit can further include a cooling vessel outlet shutter configured to alternatively open and close the cooling vessel outlet. The control unit of such embodiments can be configured to control the cooling vessel outlet shutter to close the cooling vessel outlet during cooling, and to open the cooling vessel outlet when cooling is complete.

[0074] The cooling vessel outlet shutter may include a flap and a control unit and a cooling vessel outlet shutter actuator, such as an electromagnet or a motor, in an operational cooling state. When the outlet shutter opens, coffee beans may fall into the outlet vessel. The control unit is preferably designed to control the cooling vessel outlet shutter to open the cooling vessel outlet only for removing coffee beans from the cooling vessel, but otherwise to close it, especially during cooling.

[0075] During cooling of the coffee beans, the coffee beans may be continuously moved by the cooling rotor to ensure uniform exposure of the coffee beans to the cooling medium and / or cooling medium, in particular the above-mentioned cooling air and / or cooling water.

[0076] The operation of the cooling rotor drive and the cooling water supply and / or cooling air supply may be controlled by a control unit that may be configured to generate a cooling rotor drive control signal and a cooling air supply control signal and / or a cooling water supply control signal. During cooling, the cooling air supply and / or the cooling water supply may be controlled to operate continuously and in a constant manner. Advantageously, however, the cooling air supply and / or the cooling water supply are controlled to vary as a function of time via time-varying control signals, thereby varying the cooling by the air and / or the cooling water over time during cooling. The control parameters for generating the cooling rotor drive control signal and the cooling air supply and / or the cooling water supply as a function of time may be stored as fixed parameters by the control unit. Preferably, however, the control parameters for generating the cooling rotor drive control signal and one or more of the cooling air supply and / or the cooling water supply may be part of a selected roast profile and may therefore vary depending on a selected target roast profile. The cooling rotor drive control signal and the cooling air supply control signal and / or the cooling water supply control signal may be part of a control output signal generated by the control unit.

[0077] Additionally, the control unit may be configured to switch the cooled rotor drives on and off in a binary manner. In an alternative embodiment, the control unit may be configured to control operation of the cooling air supply and / or cooling water supply to vary as a function of time during cooling, thereby varying cooling by the air and / or cooling water over time during cooling.

[0078] When the optional cooling vessel outlet shutter opens to remove the coffee beans from the cooling vessel and transfer them to the outlet vessel, as described above, the cooling rotor drive is advantageously activated to rotate the cooling rotor, thereby ensuring that all the coffee beans are transferred to the cooling vessel outlet.

[0079] In a further embodiment of the cooling unit having a cooling rotor and a cooling rotor drive, the cooling rotor is not disposed inside the cooling vessel. Instead, the cooling rotor may be integrally formed with the cooling vessel. In such an embodiment, the cooling vessel is rotatable and is coupled to the cooling drive for rotating the cooling vessel. In such an embodiment, the cooling vessel may comprise stirring elements, such as lamellae or ribs, disposed within the interior space of the cooling vessel and stirring the coffee beans as the cooling vessel rotates.

[0080] In one embodiment, cooling is considered complete when a cooling termination condition is satisfied. A satisfied cooling termination condition can be detected, in particular, based on one or more cooling sensor signals, which are generated by one or more corresponding cooling sensors of the cooling unit. In particular, the cooling unit can include a cooled bean temperature sensor configured to measure the cooled bean temperature of the coffee beans in the cooling container and provide a corresponding cooled bean temperature signal, and the cooling termination criteria include a cooled bean temperature reaching or falling below a predetermined target cooled bean temperature. Furthermore, the cooling unit may additionally or alternatively include a cooled bean color sensor configured to measure the cooled bean color of the coffee beans in the cooling container and provide a corresponding cooled bean color signal, and the cooling termination criteria include a cooled bean color assuming a predetermined target cooled bean color. The cooling termination conditions, in particular the target cooled bean temperature and / or the target cooled bean color, can be fixed in some embodiments. However, they are advantageously part of the selected roast profile. One or more cooling sensor signals, in particular a cooled bean temperature signal and / or a cooled bean color signal, may be part of the control input signal, and one or more cooling sensors, in particular a cooled bean temperature sensor and / or a cooled bean color sensor, may be part of the sensor arrangement. In a further embodiment, the cooling of the coffee beans is time-controlled, and the cooling end criterion is the lapse of a predetermined cooling time span after the start of cooling. When cooling is complete, the control unit can provide a corresponding indication and / or control the cooling container outlet shutter to release the coffee beans.

[0081] In certain embodiments including a cooling unit, the cooling vessel is fluidly coupled to the interior drum space of the drum, thereby enabling the transfer of cooling air from the cooling vessel to the drum and the extraction of cooling air from the drum by the exhaust extractor. Such a design is particularly advantageous when cooling air alone is not foreseen as a cooling medium. In such a design, the exhaust extractor serves the additional purpose of extracting cooling air during cooling in a controlled manner.

[0082] The fluid connection between the cooling vessel and the drum space can be achieved in particular via the drum outlet. In such a design, the drum outlet serves to remove the roasted coffee beans from the drum and transfer them into the cooling vessel, and then to remove the cooling air from the cooling vessel and transfer it respectively into the drum, without any coffee beans being present in the drum at this stage. In such an embodiment, the outlet shutter is generally controlled to open during cooling. However, in another variant, a separate fluid coupling is foreseen between the drum and the cooling vessel for removing the cooling air from the cooling vessel and feeding it respectively into the drum.

[0083] In one embodiment, the cooling container may be a removable tray configured to be removed once cooling of the beans is complete, with the beans remaining in the tray. The cooling container may be located inside a drawer. In such a design, a dedicated cooling container outlet shutter may be omitted. The tray may be open, particularly at the top, and / or have a removable or openable cover. Such a cover may be provided with an opening for coupling with the drum outlet. Alternatively, the tray is open at its top. Such a fluid-tight coupling may be achieved by a seal, which may be part of the cooling container, e.g., the tray, and / or the housing of the coffee roaster. The sides and / or bottom of the tray are perforated with air holes dimensioned to prevent the passage of beans. The tray is configured so that the perforated sides and / or bottom of the tray do not fully contact adjacent surfaces, respectively, thereby allowing unimpeded passage of air into the tray through at least some of the air holes. In one embodiment, the cooling container is a bean tray, as further described below. The drawer may include a scale configured to measure the weight of the tray so that the weight of the beans in the tray can be determined. Furthermore, the drawer may comprise an insert configured to receive cooling air from a cooling air source and direct the cooling air into the trays. In particular, the insert is configured to direct the cooling air so that it flows through the perforations into the trays, thereby cooling the beans. In a preferred example, the cooling vessel, in particular the insert, comprises a seal configured to achieve a fluid-tight connection to the cooling air source.

[0084] In one embodiment, a coffee roaster includes an air exhaust treatment unit. However, it should be noted that an air exhaust treatment unit according to the present disclosure may also be implemented and used in the context of other types of roasters. In a particular embodiment, the air exhaust treatment unit may include a water tank, the water tank designed to be filled with water up to a fill level, the water tank having a water tank air inlet and a water tank air outlet. The water tank air inlet is fluidly coupled to the exhaust air extraction opening and, therefore, to the interior drum space. The water tank air inlet is located below the fill level of the water tank. The water tank air outlet is located above the fill level. The air exhaust treatment unit may further include a fresh water supply for supplying fresh water into the water tank and a waste water drain for draining waste water from the water tank.

[0085] Preferably, the extraction fan as described above is fluidly disposed downstream of the water tank and fluidly coupled to the water tank air outlet, such that the water tank is fluidly disposed between the drum and the extraction fan.

[0086] During operation, the extraction fan generates a negative suction pressure in the air volume above the filling level, respectively, and simultaneously agitates the water. Through the connection with the internal drum space, exhaust air is drawn into the water tank by the arrangement of the water tank air inlet and enters the water tank below the filling level, where the water dissolves and thus removes smoke and its components from the exhaust air, simultaneously cooling the exhaust air. The cooled exhaust air rises to the water surface (defined by the filling level) in the formation of bubbles and is sucked out by the extraction fan. A bubble enhancer may be arranged inside the water tank, generally below the filling level. The bubble enhancer may be realized by a perforated plate extending substantially over the entire lateral surface area of ​​the water tank. The bubble enhancer breaks up larger bubbles into smaller ones, respectively, thereby increasing smoke removal and cooling efficiency.

[0087] In some embodiments, the coffee roaster includes a chaff separator, which generally serves the purpose of separating chaff from the exhaust air. In certain embodiments including an exhaust air treatment unit having a water tank and a foam enhancer as described above, the holes in the perforated plate that serves as the foam enhancer are sized small enough to prevent the passage of chaff. In such embodiments, the chaff enters the water tank along with the exhaust air and remains in the water tank below the foam enhancer until it is removed manually or by cleaning the water tank. In such embodiments, the foam enhancer also functions as a chaff separator.

[0088] In a further embodiment, a chaff separator may be disposed between the drum and the water tank, particularly between the exhaust outlet and the water tank air inlet. The chaff separator may include a mechanical chaff-retaining filter, such as a mesh or perforated plate, that is passed by the exhaust air and prevents chaff from passing through. The chaff may be removed from the water tank with the drainage water during flushing and / or may be removed manually.

[0089] In one embodiment, a bypass line is arranged so that cooling air exiting the drum during cooling bypasses the chaff separator. For example, a first end of the bypass line is connected upstream of the chaff separator, e.g., between the exhaust outlet and the chaff separator. The first end of the bypass line is connected at a first junction, which may include one or more valves configured to direct cooling air through the bypass line during cooling. A second end of the bypass line is connected downstream of the chaff separator, e.g., between the chaff separator and a catalyst, which will be described in more detail below. In particular, the second end of the bypass line is connected at a second junction between the chaff separator and a filter, as will be described in more detail below.

[0090] In one embodiment, a water temperature sensor can be positioned within the water tank below the fill level to monitor the water temperature. The water temperature sensor is operably coupled to the control unit. The water temperature sensor provides a water temperature sensor signal that can be part of the input control signal. The control unit may be configured to determine when the water tank should be cleaned and the water replaced based on the water temperature control signal. The control unit may be particularly configured to substantially continuously compare the water temperature with a water temperature threshold, for example, 70 degrees Celsius. A water temperature that reaches or exceeds the water temperature threshold indicates that the water tank should be flushed and the water in the water tank should be replaced.

[0091] To clean the water tank and change the water, there may be a fresh water inlet supply and a waste water drain, as described above, which are connected to the internal volume of the water tank via a fresh water supply valve and a waste water drain valve, which may be controlled by a control unit, thereby allowing automatic cleaning and water change of the water tank as needed.

[0092] To ensure that the water tank is filled to the desired fill level initially and after cleaning, a fill level sensor may be provided in operative communication with the control unit. The fill level sensor may, in particular, be a float gauge. Alternatively, the fill level sensor may be realized differently, for example, by one or more electrical resistance-based sensors, capacitive sensors, optical sensors, etc. The control unit may be configured to control the fresh water supply valve and / or the drain discharge valve according to the signal provided by the fill level sensor. In particular, the control unit may be configured to control the fresh water inlet valve to open after completely emptying the water tank until the fill level sensor indicates that the desired fill level has been reached. In a further embodiment, the fill level sensor is a water flow sensor located in or at the fresh water supply, and the control unit is configured to determine the fill level from the amount of water supplied to the water tank.

[0093] In alternative embodiments, flushing of the water tank and changing of the water may be performed manually, for example, when a user instruction is provided, for example, when the water temperature reaches or exceeds a water temperature threshold. Although manual water changes are required between each roast of a batch of coffee beans when the coffee roaster is not running, automatic flushing and water changes under the control of the control unit, as previously mentioned, can also be performed during an ongoing roasting process.

[0094] Exhaust air is drawn from the water tank via the water tank air outlet. In embodiments where a condenser and an exhaust filter are present, the exhaust filter is preferably fluidly located downstream of the condenser, so that the air after leaving the water tank is first dried and then filtered. Undesirable odors and / or odours are removed from the exhaust air via the filter. In this way, the coffee roaster can be operated indoors without the generation of undesirable odors or odours and without the need for additional exhaust treatment equipment.

[0095] In some embodiments of the exhaust air treatment unit, the exhaust air treatment unit includes a condenser that is fluidly coupled to the water tank air outlet such that air drawn from the water tank passes through the condenser. As the exhaust air exits the water tank, it is generally saturated with humidity, which is removed by the condenser, thereby drying the exhaust air. The condenser therefore functions as a dehumidifier. Furthermore, the condenser is preferably fluidly disposed between the water tank air outlet and the extraction fan such that the exhaust air passes through the condenser before the extraction fan.

[0096] In one embodiment of the exhaust air treatment unit, the exhaust air treatment unit includes an exhaust filter. The exhaust air filter is fluidly coupled to the water tank air outlet such that air drawn from the water tank passes through the exhaust air filter. The exhaust air filter removes unwanted odorous substances from the exhaust air. Furthermore, the exhaust air filter is preferably fluidly positioned between the water tank air outlet and the extraction fan such that the exhaust air passes through the exhaust air filter before the extraction fan.

[0097] In embodiments where both a condenser and an exhaust filter are present, the condenser and exhaust filter may be arranged in fluid series between the water tank air outlet and the extraction fan, particularly such that the exhaust air first passes through the condenser after leaving the water tank, and then through the exhaust filter.

[0098] In embodiments including a chaff separator, the chaff separator may include a cyclone separator for separating the chaff and a chaff collector, e.g., in the form of a drawer. The cyclone separator may be controlled by the control unit via a corresponding cyclone control signal. The cyclone separator may be a passive cyclone separator such that the air entering the cyclone circulates and maintains a spiral air vortex (i.e., cyclone). Particles in the air exit the cyclone separator through an opening at the bottom of the cyclone separator, while air exits the cyclone separator through an opening at the top. Such a passive cyclone separator does not require any active elements to start or maintain the cyclone.

[0099] In one embodiment, the coffee roaster includes a chaff separator temperature sensor configured to directly or indirectly measure the air temperature inside the chaff separator. The chaff separator temperature sensor can be located in the chaff separator, for example, attached to a housing of the chaff separator, with the temperature of the housing indicating the air temperature inside the chaff separator. The chaff separator temperature sensor can be located inside the chaff separator, thereby directly measuring the air temperature inside the chaff separator. The chaff separator temperature sensor can be fluidly located downstream of the chaff separator, thereby measuring the air temperature of the air exiting the chaff separator. The chaff separator temperature sensor provides a control signal to the control unit. The control unit is configured to determine whether a fire exists in the coffee roaster depending on the temperature measured by the chaff separator temperature sensor. In particular, a temperature measured by the chaff separator temperature sensor that exceeds a fire temperature threshold is considered to be indicative of a fire. Additionally, if the temperature measured by the chaff separator temperature sensor increases faster than a predetermined temperature increase rate, this is considered to be indicative of a fire. The fire typically burns the chaff in the chaff drawer.

[0100] In one embodiment, the coffee roasting machine includes a fire extinguisher. The fire extinguisher is preferably positioned to extinguish a fire in the chaff separator, including the chaff drawer. The fire extinguisher may be attached to or connected to the chaff separator and / or the chaff drawer. When the control unit detects a fire, the fire extinguisher is activated. The fire extinguisher may use water, CO2, foam, or other extinguishing means to extinguish the fire. Furthermore, the control unit may be configured to generate an alarm to alert a user of the coffee roasting machine of the fire, for example, by generating an alarm signal that is transmitted to an acoustic transducer to alert the user. Furthermore, the alarm signal may be connected to a lighting element of the coffee roasting machine to visually indicate a fire condition. Furthermore, the control unit may be configured to turn off all heating elements and reduce airflow through the coffee roasting machine to a minimum level, the minimum level being determined so as not to damage the heating elements.

[0101] In embodiments including an exhaust gas treatment unit, the exhaust gas treatment unit includes a catalyst configured to remove odorous substances from the exhaust gas drawn from the drum. The catalyst and advantageous auxiliary components, as described further below, can be provided in addition to, and particularly in series with, the water-based exhaust gas treatment described above. Typically, however, an exhaust gas treatment unit including a catalyst can be envisioned as an alternative. This has the particular advantage of being able to remove odorous substances from the exhaust gas without the typically complex and cumbersome handling of cooling water. In particular, the catalyst can be configured to remove carbon monoxide from the exhaust gas.

[0102] In certain embodiments including an exhaust gas treatment unit with a catalytic device, the exhaust gas treatment unit includes an exhaust gas heater, the exhaust gas heater being fluidly upstream of the catalytic device, and an exhaust gas cooler being fluidly downstream of the catalytic device. The exhaust gas heater, catalyst, and exhaust gas cooler are generally fluidly arranged in series. The exhaust gas heater is activated during the roasting process, particularly during the final stages of the roasting process, and is used to heat the exhaust gas leaving the drum to an optimal temperature for catalytic cleaning via the catalyst, which removes odorous substances. The exhaust gas heater can heat the exhaust gas to a temperature of 200°-400°C, preferably 250°-300°C. During earlier stages of the roasting process, the exhaust gas heater is typically deactivated and switched off.

[0103] The exhaust heater can be controlled by the control unit via an exhaust heater control signal. The exhaust heater control signal may be part of the control output signal. Controlling the operation of the exhaust heater can include, among other things, controlling the heating power of the exhaust heater, for example, by switching it on / off and / or adjusting it continuously or in several discrete steps. Furthermore, an exhaust air temperature sensor can be disposed in the exhaust heater or downstream from the exhaust heater to measure the temperature of the heated exhaust air. An exhaust cooler can be provided to cool the significantly heated exhaust air exiting the catalytic device. The exhaust cooler can, for example, include a gas cooler through which the exhaust passes, heats up, and then dissipates heat to the environment via convection and radiation. Furthermore, one or more fans can be disposed in the coffee roaster and configured to blow and / or suck air over the exhaust cooler, particularly the gas cooler's piping, to increase the rate of heat dissipation and thus reduce the temperature of the exhaust air exiting the coffee roaster.

[0104] In addition to or instead of the aforementioned configurations, the exhaust treatment unit may include further odor and / or harmful substance removal devices. In particular, a mechanical particle filter through which the exhaust gas passes may be envisaged. In addition to or instead of the mechanical filter, the particle filter may include an electrostatic particle filter. The electrostatic particle filter may be configured to retain particles by electrostatic attraction and repulsion. The particle filter may also be or include an activated carbon filter. In one example, the electrostatic particle filter includes a glass fiber filter. In one embodiment, the exhaust treatment unit is configured so that the removal devices, in particular the mechanical particle filter, are accessible and removable, and therefore easily replaceable.

[0105] The chaff separator and exhaust treatment unit are generally fluidly disposed between the drum outlet and the exhaust collector. Preferably, the chaff separator is fluidly disposed upstream of the exhaust treatment unit so that the exhaust gas is free or substantially free of chaff when it enters the exhaust treatment unit.

[0106] In one embodiment, the coffee roaster includes a green bean scale for measuring the weight of the green coffee beans before they are filled into the drum. Further, in one embodiment, the coffee roaster includes a roasted bean scale for measuring the roasted weight of the roasted coffee beans. In one embodiment, the coffee roaster includes a bean scale that functions as both a green bean scale and a roasted bean scale. The bean scale may be integrated into a collector or container. The collector or container may be used to fill the hoppers of each of the drums with the green coffee beans, as described above. The collector or container, as well as the box and bean scale, may be configured to measure the weight of the green coffee beans before they are filled into each of the drum hoppers. After roasting, the collector or container may be positioned at or below the cooling vessel outlet so that the roasted and optionally dried coffee beans are each discharged into the collector or container, where the roasted bean weight of the roasted, cooled, and optionally dried coffee beans is measured.

[0107] Preferably, as a combined green bean scale and roasted bean scale, the green bean scale and roasted bean scale are operably coupled to a control unit for transmitting the measured green bean weight and roasted bean weight, respectively, to the control unit. The control unit may, in some embodiments, be configured to store and / or process the green bean weight and roasted bean weight. Optionally, the control unit may be configured to transmit the green bean weight and / or roasted bean weight to a remote computer system, as described further below. The control unit and / or remote computer system may, where applicable, be further configured to determine whether the roasting and drying of the coffee beans was successful based on the difference and / or ratio between the green bean weight and the roasted bean weight. If so, the weight of the roasted beans is more than 10% greater than the weight of the green beans.

[0108] The control unit may include a user interface unit and / or be designed to be operatively coupled to a user interface unit to control the operation of the coffee roasting machine and provide information to a user, such as status information, alerts, and / or warnings. The user interface unit may be part of the coffee roasting machine or may be provided, in whole or in part, as a separate user interface device. In certain embodiments, the user interface device is a general-purpose computing device, such as a smartphone, a tablet computer, or a laptop or desktop computer. In one embodiment, the control unit may be realized in whole or in part by such a general-purpose computing device.

[0109] In one embodiment, the user interface device and the control unit may be configured to communicate via a wireless communication interface, e.g., a Bluetooth and / or Wi-Fi interface, and / or an interface for communication via a mobile communication network, e.g., according to the 5G standard. Alternatively, or in addition, the user interface device and the control unit may be configured to communicate via a wired interface, e.g., one or more USB buses (e.g., mini-US, micro-US, US-B, US-C) or a wired LAN interface. Furthermore, in some embodiments, the control unit and the user interface device may be configured to communicate via the Internet. To this end, the user interface device and the control unit may be configured for wired and / or wireless Internet access. The user interface device may further be configured to communicate with a remote computer system via the Internet.

[0110] Controlling the execution of the roasting process according to the selected roast profile is generally a closed-loop control in which control output signals are generated substantially in real time based on the control input signals as feedback signals and the selected roast profile, respectively. In a typical embodiment, the closed-loop control is a multi-input multi-output control with signals provided by sensors of the sensor device combining to form the control input signals.

[0111] A roast profile, particularly a selected roast profile, may include the desired roasted bean temperature as a function of time, for example in the form of one or more interpolating functions, such as splines, respective parameters, and / or a look-up table of time-temperature pairs. Additionally, the roast profile may include only the temperatures to be approached one after the other.

[0112] The generation of the output control signals by the respective control units may be based on classical controller designs, for example PID controllers, and / or may be based on, for example, fuzzy control algorithms and / or neuron networks.

[0113] The control parameters do not necessarily have to remain constant over time during the roasting process, but may for example be changed or modified in a predetermined manner as a function of time and / or may be changed in response to the occurrence of characteristic events, as explained below, according to one or more rules which form part of the roast profile, in particular the selected roast profile.

[0114] The control input signals may include one or more sensor signals directly and / or indirectly indicating the temperature conditions inside the drum, in particular the roasted bean temperature signal, the back wall temperature signal, the inlet air temperature signal, and the air flow signal. Furthermore, the control input signals may include one or more sensor signals indicating the phase of the roasting process and / or a particular characteristic event during the roasting process, in particular the aforementioned roasted bean color signal and / or crack detection signal. Such characteristic events may also be derived from sensor signals indicating temperatures, such as the roasted bean temperature signal. For example, the bean temperature determined by the roasted bean temperature sensor may assume a predetermined characteristic value according to a selected roasting profile and serve as a characteristic event. Upon the occurrence of a characteristic event, the control unit may be configured to modify or change the generation of a control output signal, respectively, for one or more of its components. For example, the roasted bean temperature, the back wall temperature, the drum air temperature, the heating power of the air heater, and / or the setpoints of the positive and / or negative pressure devices, e.g., the rotation speed of the supply fan and / or the extraction fan, may be changed upon the occurrence of a characteristic event.

[0115] However, not all sensor signals are directly used to control the roasting process. Certain sensor signals may be used to manage and monitor the roasting process without affecting the control output signal. By way of example, the air humidity signal generated by any air humidity sensor may be evaluated by the control unit to monitor the coffee bean roasting process, and in particular the progress of the roasting process as a whole. Furthermore, air humidity is an indicator of the taste that can be expected from the roasted coffee beans. Furthermore, an exhaust air temperature sensor may optionally be configured to measure the exhaust air temperature, for example in the chimney or chimney. The exhaust air temperature signal may generally be evaluated by the control unit for safety reasons.

[0116] The control output signal may include one or more control signals that can affect the temperature conditions inside the drum, particularly the back wall temperature, drum air temperature, and / or bean temperature, by controlling the operation of one or more of the air heater, drum heater, positive pressure device, and negative pressure device. Generally, increasing the heating power of the drum heater and / or air heater results in an increase in the temperature inside the drum, and vice versa. Similarly, increasing the operation of the positive pressure device, particularly an increase in the rotation speed of the supply fan, results in an increase in the temperature inside the drum, and vice versa. Increasing the operation of the negative pressure device, particularly an increase in the operation of the extraction fan, results in a decrease in the temperature inside the drum, and vice versa. As previously mentioned, the hot air flow entering the drum should generally correspond to the exhaust air flow exiting the drum during roasting.

[0117] In a typical embodiment, the back wall temperature can be controlled in a range from ambient to about 300°C, the hot air temperature can be controlled in a range from ambient to about 550°C, the drum rotor rotation speed can be controlled when operated in a range from, for example, 50 RPM (Rounds per minute) to 90 RPM, and the extraction and supply fans can be controlled at air flow rates in a range from, for example, 10 liters / minute to 350 liters / minute.

[0118] Controlling the execution of the cooling process via the cooling unit as described above may be a closed-loop control in which corresponding control signals, in particular at least one of the cooling rotor drive control signal, the cooling air supply control signal, and / or the cooling water supply control signal, are each generated substantially in real time based on control input signals, in particular signals provided by one or more cooling sensors, feedback signals, and the selected roast profile. In an alternative embodiment, the aforementioned control signals are generated at least in part according to open-loop control during cooling. In particular, the cooling water supply is preferably stopped at the humidity temperature threshold as previously described, while the cooling air supply, in particular the supply fan, may be timed or continue to operate until manually switched off and / or the next batch of coffee beans has to be roasted.

[0119] In some embodiments, the control unit may be configured to further modify or change the generation of the control output signal in response to the control input signal upon the occurrence of one or more limiting events. Such limiting events may be, for example, the roasted bean temperature, the hot air temperature inside the drum, or the exhaust air temperature assuming or exceeding the respective limiting temperatures. In such cases, the control unit may be configured, for example, to reduce the heating power of the drum heater, the amount of hot air supplied via the positive pressure device, and / or the heating power of the hot air supply. The limiting values, in particular the limiting temperatures, may be fixed and / or part of the roasting profile.

[0120] The control algorithms and / or control parameters that generate the control output signals in response to the control input signals may be permanently stored by the control unit. Alternatively, or additionally, the control unit may be configured to receive the control algorithms and / or control parameters from a remote computer system for an individual or several roasting procedures, store the control algorithms and / or control parameters, and generate the control output signals in accordance with the stored control algorithms and / or control parameters. In such embodiments, the control algorithms and / or control parameters may be modified as needed via the remote computer system.

[0121] According to a preferred embodiment, a coffee roaster, particularly one according to the present disclosure, may have a modular design and may include a coffee roaster frame or base that may include, for example, a control unit and potentially auxiliary functions such as a power supply. The roasting unit, cooling unit, and exhaust treatment unit may generally be designed as self-contained units, e.g., plug-in units designed to be attached to or plugged into the frame or base, with the base or frame and the individual modules preferably equipped with corresponding electrical and fluid couplers, with the modules being coupled via the base or frame. However, some or all couplings, particularly fluid couplings, may be direct between the modules, and optionally, some or all of the modules may be divided into sub-modules designed to be separately attached to or plugged into the frame or base. In particular, the drum heater and the drum with the hot air supply may be provided as separate sub-modules. Similarly, an inlet module, which may include a hopper and a drum inlet shutter as described above, may be provided with a chaff separator module and be attached to or plugged into the frame or base. In some embodiments, the aforementioned control unit and / or auxiliary further devices are not included in the coffee roaster frame or base, but are also designed as self-contained modules. Furthermore, as will be further explained below in the context of exemplary embodiments, the combination of the bean scale, bean tray and drawer may be provided as a separate, structurally distinct unit.

[0122] Such a modular design greatly simplifies the maintenance and cleaning of the coffee roaster, especially by non-technical users, and it also simplifies the repair and replacement of defective modules.

[0123] In one embodiment, the control unit is operatively coupled to a remote computer system and configured to receive the selected roasting profile from the remote computer system. The remote computer system may be a centralized and / or cloud-based remote computing system. Preferably, the remote computing system and the respective control units of the coffee roasting machine are configured to communicate via the Internet as described above. Furthermore, in such an embodiment, the user interface device and the remote computing device as described above may be configured to communicate via the Internet. In such an embodiment, the user interface device typically communicates with the coffee roasting machine via the remote computer system as an intermediate element. However, alternatively or additionally, the user interface device and the coffee roasting machine may be configured for direct wired and / or wireless communication. This is particularly preferred, for example, for providing a command to the coffee roasting machine to start the coffee roasting process, as well as for displaying information such as warnings and alerts, and information about the roasting process, e.g., sensor signals, to a user.

[0124] A coffee roasting system according to the present disclosure includes a coffee roaster and a control unit configured to operably couple with a remote computer as described above. The coffee roasting system may also include several such coffee roasters. The coffee roasting system further includes a remote computer system configured to store a plurality of available roast profiles, receive user input for selecting a selected roast profile from the plurality of available roast profiles, and transmit the selected roast profile to the control unit. In such an embodiment, a user generally selects a roast profile on a user interface device as described above, and the selection is communicated to the remote computer device.

[0125] In some embodiments in which the control unit is configured to be operatively coupled to a remote computer system, the control unit is configured to acquire sensor data during the coffee bean roasting process and to transmit the acquired sensor data and / or data derived from the acquired sensor data to the remote computer system.

[0126] The acquired data may include, among other things, one or more of the following: a roasted bean temperature signal, a roasted bean temperature signal, a cooled bean temperature signal, a cooled bean color signal, a back wall temperature signal, a drum air temperature signal, an inlet air temperature signal, an air humidity signal, an air flow signal, a crack detection signal, and / or a water temperature sensor signal, as previously described. Additionally, the acquired sensor data may include green bean weight, roasted bean weight, and / or the respective ratios therebetween.

[0127] Additionally, the control unit may be configured to transmit the control output signals and / or data derived from the control output signals to a remote computer system.

[0128] Data derived from the acquired sensor data may be, for example, average values, extreme values, smoothed values, or filtered values, as well as characteristic durations or time points, such as the time from the start of the coffee bean roasting process to the first crack detected by the crack detection sensor, the roasted bean temperature at the end of the roasting process (before cooling), the cooled bean temperature at the end of the cooling process, the roasted bean color at the end of the roasting process (before cooling), the cooled bean color at the end of the cooling process, etc.

[0129] The remote computer system may be configured to store and / or further evaluate and / or process data received from the one or more coffee roasters, particularly for quality control purposes.

[0130] Furthermore, in one embodiment, the remote computer system is configured to evaluate the acquired sensor data and / or acquired sensor-derived data to determine whether the coffee bean roasting process was successful, and to send corresponding feedback information to the coffee roasting machine, in particular its control unit, and / or user interface device.

[0131] Furthermore, the control unit and the user interface or user interface device may be configured to display certain characteristic events or milestones, particularly characteristic events of the coffee bean roasting process, on the display of the user interface or user interface device. Such characteristic events may include one or more of a pre-roasting condition where pre-heating is completed, the start of the roasting process, the occurrence of a first crack, the end of roasting, the start of cooling, and the end of cooling, each of which is met. Furthermore, the control unit and the user interface or user interface device may be configured to display sensor data in real time on the display of the user interface or user interface device. [Brief explanation of the drawings]

[0132] [Figure 1] 1 shows a schematic side view of an exemplary embodiment of a coffee roaster according to the present disclosure; [Figure 2] The arrangement of sensors within the coffee roaster shown in Figure 1 is shown. [Figure 3] The control configuration of the coffee roaster shown in Figure 1 is shown. [Figure 4] 1 illustrates an embodiment of a coffee roasting system according to the present disclosure. [Figure 5] 1 illustrates a coffee bean roasting process. [Figure 6] 1 shows a further exemplary embodiment of a coffee roaster according to the present disclosure in a schematic side view; [Figure 7] 1 illustrates a further exemplary coffee bean roasting process. DETAILED DESCRIPTION OF THE INVENTION

[0133] In the following, referring first to Figure 1, an exemplary embodiment of a coffee roaster 1 according to the present disclosure is shown in a schematic side view. The coffee roaster 1 comprises a roasting unit 11, a cooling unit 14, and an exhaust air treatment unit 15. Furthermore, the coffee roaster 1 includes a structurally separate and respectively removable bean tray 17 with a drawer 18 and an integrated bean scale 16.

[0134] The roasting unit 11 includes a drum 111 having a drum body 1111 and a front wall 1112, each of which has a generally cylindrical disk-like overall shape. Preferably, the drums 111 each have an internal drum space fill volume suitable for roasting approximately 1 kg of coffee beans. The drum has a horizontal drum axis A that coincides with the rotor axis of a drum rotor 112 rotatably disposed inside the drum 111. The drum is designed as described in the general description, and the front wall 1112 is transparent and removable. The rear wall 11111 of the drum body 1111 is designed as a sandwich due to its thermal properties as described above and is thermally coupled to an exemplary resistive drum heater 116 disposed outside the drum 111. The drum heater 116 is positioned to ensure substantially uniform heating of the rear wall 11111. A drum inlet 11112 is located in the upper region of the rear wall 11111. Likewise, the drum outlet 11113 is arranged in the lower region of the rear wall 11111. The drum rotor 112 is realized as an electric motor and is connected to a drum rotor drive 113 arranged outside the drum.

[0135] The hot air supply 114 is provided for supplying hot air into the drum 111. The hot air supply 114 is disposed generally outside the drum and is fluidly connected to the drum outlet 11113 via piping (not shown) for supplying hot air into the drum. In the illustrated embodiment, the hot air supply 114 includes a resistance air heater 1141 and a positive pressure supply 1142 in the form of a supply fan. In the illustrated embodiment, the hot air supply 114 is fluidly coupled to the drum outlet 11113 via a tube, which simultaneously functions as a hot air inlet. However, this is not required, and separate hot air supply openings may be alternately foreseen in the drum body 1111, particularly the rear wall 11111.

[0136] Via a corresponding tube, the drum inlet 11112 is connected to a hopper 1113 into which green beans to be roasted are filled. A drum inlet shutter 1114 is arranged at the connection between the internal space of the drum 111 and the hopper 1113. Only when the drum inlet shutter 1114 is open can the green beans present in the hopper 1113 be transferred into the internal space of the drum 111 by gravity. The drum inlet shutter 1114 is generally only open for filling the drum 111 with green coffee beans, but is otherwise closed. To fill the drum with green coffee beans, in this embodiment, such beans are first filled into the bean tray 17 by a user, whereupon the weight of the green beans is automatically measured by the bean scale 16. Subsequently, the user moves the bean tray 17 equipped with the drawer 18 and the bean scale 16 to the hopper 1113, respectively, and fills the beans from the bean tray 17 into the hopper 1113.

[0137] In this embodiment, the bean tray 17, drawer 18 and bean scale 16 are structurally separated from the further components and units of the coffee roaster 1 and form an integral unit that is movable by the user.

[0138] Furthermore, an exhaust air vent device 115 is provided to remove exhaust air from the interior of the drum. The exhaust air vent device 115 includes a negative pressure device 1151 that is fluidly coupled to an exhaust air vent opening 11114 in the upper region of the rear wall 11111 via corresponding piping and, in this embodiment, to the exhaust air treatment unit 15, as further explained below. In this design, the negative pressure device 115 includes an extraction fan 1151 for generating suction pressure. Furthermore, the exhaust air vent device 115 includes a chimney 1152 that is fluidly coupled to the extraction fan 1151. A perforated plate or mesh-like bean retainer 11115 is arranged at the exhaust air vent opening 11114 to prevent coffee beans from escaping the interior space of the drum 111 while allowing air and chaff to pass through.

[0139] The exhaust air treatment unit 15 is fluidly disposed between the exhaust air outlet 11114 of the drum 111 and the extraction fan 1151 of each negative pressure device having a chimney 1152. By virtue of the exhaust air treatment unit, the exhaust air that eventually leaves the chimney 1152 is cool and substantially free of undesirable odorants, thereby allowing the coffee roaster 1 to be used in a generally closed room.

[0140] In the illustrated design, the chaff separator 19 is fluidly disposed between the drum 111 and the exhaust treatment unit 15. The chaff separator 19 may include, among other things, a cyclone separator and / or a mechanical chaff retainer filter in accordance with the general description above.

[0141] A key element of the exhaust treatment unit 15 is a water tank 151. During operation, the water tank 151 is filled with water to a fill level F, with the fill level F being below the exhaust air vent opening 11114 of the drum 111. In the illustrated embodiment, the water tank 151 is fluidly coupled to a fresh water supply 152 via a fresh water supply valve 1521 for supplying fresh water to the water tank 151 when the fresh water supply valve 1521 is open. Additionally, the water tank 151 is fluidly coupled to a waste water drain 153 via a waste water drain valve 1531 in this embodiment for removing waste water from the water tank 151 when the waste water drain valve 1531 is open.

[0142] In general, the fill volume of the water tank 151 may be in the typical range of 0.5 to 2 liters, e.g., 1 liter, and is preferably sized sufficiently to allow exhaust processing for a number of roasting operations, e.g., 1 to 3. Note that the explicit fresh water supply 152 and waste water drain 153, and the corresponding fresh water supply valve 1521 and waste water drain valve 1531, may in principle be omitted. In such an embodiment, the water tank 151 may be filled and emptied manually by the user.

[0143] Below the fill level F is arranged the water tank air inlet 1511, which is fluidly cooled via a tube with exhaust air vent openings 11114 and thus via the internal drum space. Apart from the water tank air inlet 1511 and the water tank air outlet 1512, the water tank 151 is generally closed during operation.

[0144] Inside the water tank 151, generally below the fill level F, there is arranged a bubble enhancer 156 in the form of a perforated plate extending substantially over the entire lateral surface area of ​​the water tank 151. In embodiments without a dedicated chaff separator unit, the bubble enhancer 156 can simultaneously function as a chaff separator, as described above in the general description.

[0145] During the roasting process, the extraction fan 1151 of each negative pressure device is generally active, thereby generating a negative pressure in the air volume in the water tank 151 above the fill level F, which in turn agitates the water in the water tank 151 and generates air bubbles. The exhaust air, which enters the water tank 151 together with the chaff, comes into contact with the water and is accordingly cooled, freed from the chaff and at least partially freed from odoriferous substances and further related substances, in particular smoke. The exhaust air rises to the water surface at the fill level F and, after passing through the condenser 155 and the exhaust air filter 154 as described above, is collected by the extraction fan 1151 of each negative pressure device.

[0146] To cool the roasted coffee beans at the end of the roasting process, a cooling unit 14 is present in this embodiment. The cooling unit 14 comprises a cooling vessel 141 having a cooling vessel inlet 1411 and a cooling vessel opening 1412. The cooling vessel inlet 1411 is preferably positioned below the bean outlet opening 11113 of the drum 111, thereby allowing the roasted coffee beans to be transferred by gravity from the interior space of the drum into the cooling vessel 141. Between the respective connections of the drum outlet 11113 and the cooling vessel inlet 1411, there is a drum outlet shutter 1115 which can only be opened to allow the coffee beans to be transferred into the cooling vessel 141. During roasting of the coffee beans in the drum 111, the drum outlet shutter 1115 is closed and is only opened at the end of the roast.

[0147] The cooling unit 14 is disposed within a cooling vessel 141 and optionally includes a rotatably arranged cooling rotor 142 operatively coupled to a cooling rotor drive 143 in the form of an electric motor. In the illustrated embodiment, cooling of the coffee beans is obtained by cool air as well as an optional mist of water droplets, thereby allowing efficient cooling within a short period of time without wetting or otherwise adversely affecting the coffee beans.

[0148] To supply the cool air, a cool air supply 144 in the form of a cooling fan 144 is provided, which respectively draws cool air from the environment which is supplied into the cooling vessel 141 and moves along and between the coffee beans. Preferably, the cool air enters the cooling vessel 141 at its bottom side.

[0149] An optional cooling water supply 145 including a nozzle device and a nozzle control valve is provided to supply cooling water. Through the nozzle device, a small mist of water droplets is generated inside the cooling vessel 141. The rotating cooling rotor continuously moves the coffee beans during cooling, exposing them to cool air and any water droplets. At the end of the cooling process, the cooling vessel outlet shutter 146 opens, allowing the cooled coffee beans to be transferred by gravity to the bean tray 17 located below the cooling vessel outlet 1412. The cooling vessel outlet shutter is closed during cooling and is only opened at the end of cooling. While transferring the coffee beans from the cooling vessel 141 to the bean tray 17, the cooling rotor 142 rotates appropriately to ensure that the coffee beans are actually transferred to the cooling vessel outlet 1412 and exit the cooling vessel 141.

[0150] In the following, further reference is made to Figure 2 which shows an exemplary embodiment of various sensor arrangements of the coffee roasting machine 1. The sensors are used to control and monitor the coffee bean roasting process, in particular the roasting and cooling of the coffee beans, as well as the operation of the exhaust gas treatment unit 15.

[0151] Inside the drum 111, there are arranged a roasted bean temperature sensor 12a, a roasted bean color sensor 12b, a rear wall temperature sensor 12c, a drum air temperature sensor 12d, and a crack detection sensor 12e, which may be exemplarily realized as a microphone. All of these sensors, as well as the drum heater 116, are arranged on and / or in the drum body 1111, preferably on the rear wall 11111, to allow for easy removal of the front wall 1112. The drum outlet 11113, which in this embodiment also functions as a hot air supply opening to the drum 111 as described above, is also equipped with an inlet air temperature sensor 12f. A water temperature sensor 12j is arranged in the water tank 151 below the fill level F.

[0152] Additionally, optional exhaust air temperature sensors 12k are located downstream of each of the negative pressure device and extraction fan 1151, in this embodiment measuring the temperature of the exhaust air before it leaves the chimney 1152. Optional air outlet pressure sensor 12h, air inlet pressure sensor 12h2, and optional air humidity sensor 12g are located between the drum outlet 11113 and the water tank air inlet 1511, measuring the exhaust air pressure and exhaust humidity, respectively.

[0153] To monitor the cooling of the coffee beans and detect whether the cooling termination condition is met, in this embodiment a cooled bean temperature sensor 12i is arranged inside the cooling vessel 141. As mentioned above, a cooled bean color sensor can additionally or alternatively be present.

[0154] Reference is further made below to FIG. 3 , which shows the control architecture of coffee roasting machine 1 in a schematic functional diagram. Coffee roasting machine 1 typically includes a control unit 13 based on one or more microcomputers and / or microcontrollers executing corresponding software code, but may also include further electronics and circuits. Control unit 13 may further include sensor interfaces and / or evaluation circuits for some or all of the various sensors, as described above and further below. However, such sensor interfaces and / or evaluation circuits may also be part of, or integrally formed with, some or all of the sensors. Similarly, control unit 13 may include drive and / or control circuits for the various motors and further actuators, as well as further actuators for the backwall heaters and air heaters and valves and shutters. However, such drive and / or circuits may also be part of, or integrally formed with, some or all of these units or components. In general, control unit 13 is configured to evaluate sensor signals and control and monitor the operation of coffee roasting machine 1 as a whole, in particular roasting unit 11, cooling unit 14, and exhaust treatment unit 15.

[0155] The control unit 13 includes a memory (not separately referenced) that stores necessary program code that, when executed, instructs more microcomputers and / or microcontrollers of the control unit 13 to control the operation of the coffee roaster 1. Furthermore, the control unit 13 includes a memory for storing a selected roast profile and optionally a plurality of available roast profiles. Furthermore, the control unit 13 preferably further includes a memory for at least temporarily storing sensor data acquired by the sensors and optionally bean scale 16 during each, in the context of one or more coffee bean roasting processes, as described above in the general description.

[0156] In the illustrated embodiment, the control unit 13 receives input signals from a roasted bean temperature sensor 12a, a roasted bean color sensor 12b, a back wall temperature sensor 12c, a drum air temperature sensor 12d, a crack detection sensor microphone 12e, an inlet air temperature sensor 12f, an air humidity sensor 12g, an air outlet pressure sensor 12h, an air inlet pressure sensor 12h2, a cooled bean temperature sensor 12i, a water temperature sensor 12j, an exhaust air temperature sensor 12k, and a fill level sensor float gauge 12l, as well as a bean scale 16. The sensors are operably coupled to the control unit 13 in a hardwired and / or wireless manner. While most sensors are typically hardwired, the bean scale 16, in particular, may preferably be coupled to the control unit 13 wirelessly, for example via Bluetooth or WLAN. The sensor signals, particularly those related to roasting and cooling of coffee beans, are formed by combining the control input signals as described above.

[0157] In the illustrated embodiment, the control unit 13 generates control signals for the air heater 1141, the positive pressure device supply fan 1142, the negative pressure device extraction fan 1151, the drum heater 116, the drum rotor drive 113, the cooling rotor drive 143, the cooling air supply fan 144, and the nozzle valves of the cooling water supply 145. Furthermore, the control unit generates control signals for the drum inlet shutter 1114, the drum outlet shutter 1115, the cooling vessel outlet shutter 146, as well as the fresh water supply valve 1521 and the waste water drain valve 1531. The different control signals may be analog and / or binary signals. The control signals, particularly those related to roasting and cooling the coffee beans, are formed by combining the control output signals as described above.

[0158] Reference is now made to Figure 4, which illustrates a coffee roasting system according to the present disclosure. The coffee roasting system includes several coffee roasters 1a, 1b, 1c, 1d according to the present disclosure and a remote computer system 2. Illustratively, four coffee roasters are shown for illustrative purposes, although other numbers including only one coffee roaster may also exist. Coffee roasters 1a, 1b, 1c, 1d may, for example, be coffee roaster 1 or 1', as discussed above and further below.

[0159] The coffee roasters 1a, 1b, 1c, 1d are exemplarily interspersed as a centralized computer system and operatively coupled to a remote computer system 2, but may also be a distributed, in particular cloud-based, computer system.

[0160] The coffee roasters 1a, 1b, 1c, 1d and the remote computer system 2 are illustratively operably coupled via an internet-based connection.

[0161] Furthermore, there are several user interface devices 3a, 3b that are illustratively separate from the coffee roasters 1a, 1b, 1c, 1d and are realized, for example, as tablet computers. In the configuration shown, user interface device 3a is operably coupled to two of the coffee roasters 1a, 1b, while the other two coffee roasters 1c, 1d are operably coupled in a one-to-one relationship to user interface devices 3b, 3c, respectively. In this configuration, coffee roasters 1a, 1b may be located close to each other, for example in one store, while coffee roasters 1c, 1d are located in different locations in another store.

[0162] In the illustrated configuration, the user interface devices may communicate directly with the coffee roasters, for example via Bluetooth, and communicate via the coffee roasters with the remote computing device 2. However, in an alternative configuration, the user interface devices 3a, 3b, 3c connect to the internet and communicate via the internet with the coffee roasters 1a, 1b, 1c, 1d and / or the remote computing device 2. In a further configuration, the user interface devices 3a, 3b, 3c and the coffee roasters 1a, 1b, 1c, 1d only communicate with the remote computing device 2 as a central instance, and the user interface devices and the coffee roasters communicate via the remote computing device.

[0163] In particular, if the user interface devices 3a, 3b, 3c are general-purpose devices, they may store corresponding program code, in particular appropriate software applications, respectively apps. However, alternatively or additionally, the control unit 13 of each coffee roasting machine 1 and / or remote computer system 2 comprises an implemented web server configured to generate and serve web pages that are transmitted to and processed by the user interface devices.

[0164] In the following, further reference is made to Figure 5, which shows an example of roasting coffee beans and an example of a selected roast profile and / or a target roast profile. In the diagram of Figure 5, the vertical axis (ordinate) shows the temperature inside the drum (measured by the drum air temperature sensor 12d, the back wall temperature sensor 12c and / or the roasted bean temperature sensor 12a) as a function of time.

[0165] At the start of the coffee bean roasting process, the control unit 13 generates a pre-roast control output signal, thereby heating the drum, particularly the inner drum space, until the selected pre-roast conditions are met. During pre-heating, the hot air supply unit 114, particularly the positive pressure device (supply fan 1142 and air heater 1141), the drum heater 116, and the exhaust air vent device 115, particularly the negative pressure device (extraction fan 1151), are activated. Furthermore, the drum rotor drive 113 can optionally be activated to ensure that the hot air is evenly distributed within the inner drum space. During pre-heating, the shutters, particularly the drum inlet shutter 1114 and drum outlet shutter 1115, are controlled by the control unit 13 to close. During pre-heating, the user can fill the bean tray 17 with coffee beans weighted by the bean scale 16, and the weight is transmitted to the control unit 13 as the raw bean weight. The user then loads green coffee beans from the bean tray 17 into the hopper 1113, where they remain as long as the drum entrance shutter 1114 remains closed.

[0166] The pre-roasting conditions are characterized by a preheat temperature. When the control unit 13 determines that the pre-roasting conditions are met, it controls the drum inlet shutter 1114 to temporarily open, thereby allowing the green coffee beans to fall into the drum 111, and controls the drum inlet shutter to close again. During the transfer of the green coffee beans into the drum 111, the drum rotor drive 113 is preferably controlled to rotate the drum rotor 112 at an appropriate speed to ensure that the green coffee beans are carried away from the drum inlet 11112. Finish Color

[0167] Once the coffee beans are loaded into the drum 111, the temperature of the inner drum space drops until it reaches a turning point temperature that is part of the selected roasting profile. However, while the actual temperature drops, the control output signal is controlled to maintain the preheat temperature. Following the turning point, the temperature rises again until the first crack is detected by the microphone of the crack detection sensor 12e. In the next progression phase, the temperature is controlled to gradually increase until the target roasted bean temperature and color are reached according to the selected roasting profile, as indicated by the roasted bean temperature sensor signal and roasted bean color signal. Reaching the target roasted bean temperature and color indicates the end-of-roast condition.

[0168] During roasting, the temperature is controlled via control output signals generated by the control unit 13 by appropriate control of the air heater 114, in particular the hot air supply 1141 and the positive pressure device, respectively the supply fan 1142, the drum rotor drive 113, the drum heater 116, and the negative pressure device, respectively the extraction fan 1151. In principle, all of the elements of each of these units may be controlled in a time-varying manner, although some may be controlled in a substantially steady-state manner and / or in an on / off manner.

[0169] When the roast end 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 vessel 141 of the cooling unit 14. During this transfer, the drum rotor drive 113 and the cooling rotor drive 143 are suitably controlled to operate the drum rotor 112 and the cooling rotor 142 at appropriate speeds to ensure that substantially all of the coffee beans are transferred into the cooling vessel 141. When the roast end condition is met, the hot air supply unit 114, which comprises the air heater 1141 and the positive pressure device, respectively, the supply fan 1142, and the negative pressure device / extraction fan 1151, may be deactivated.

[0170] During cooling, the cooling rotor drive 143 is actuated to rotate the cooling rotor 142, and the nozzle valves of the cooling air supply cooling fan 144 and cooling water supply 145 are controlled by the control unit 13 to cool the beans until they reach the target cooled bean temperature as part of the selected roast profile, thereby indicating an end-of-cooling condition. During cooling, the temperature of the beans is measured by the cooled bean temperature sensor 12i.

[0171] When the cooling end condition is met, the control unit 13 controls the cooling container outlet shutter to open, thereby transferring the cooled coffee beans to the bean tray 17 arranged below the cooling container outlet 1412.

[0172] Optionally, a tray sensor 12m, for example in the form of an optical, capacitive or inductive sensor or switch, is located at the outlet 1412 of the cooling unit and is operatively coupled to the control unit 13. The control unit 13 may be configured to open the cooling bin outlet shutter 146 only if a tray 17 is actually present and correctly positioned. Similarly, a drawer sensor 12n may be present to ensure that a drawer 18 is inserted when opening the cooling bin outlet shutter 146.

[0173] The weight of the roasted coffee beans is weighed by the bean scale 16 and the weight is transmitted as the roasted bean weight to the control unit 13. Finally, the user can pull out the drawer 18 to remove the roasted and cooled coffee beans.

[0174] In the following, first referring to FIG. 6, an exemplary embodiment of a coffee roaster 1' according to the present disclosure is shown in a schematic side view similar to FIG. 1. Because coffee roaster 1' is similar to coffee roaster 1 in terms of the basic design and operation of coffee roaster 1, as well as in some aspects related to device design, the following description will focus on the differences. Note that for clarity, 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. However, some sensors, actuators, and / or other components may be omitted. Coffee roaster 1' has a different design, particularly with regard to the cooling and further handling of the roasted coffee beans, as well as the exhaust treatment.

[0175] 6 foresees a user-removable cooling container 141' that also functions as a bean tray for removing 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 that allows air to pass through, while the perforations are designed so that beans cannot pass through.

[0176] 1 and 2, a cooling air supply and cooling fan 144 are foreseen for cooling the roasted coffee beans. However, for coffee roaster 1', only air is used for cooling. During cooling, the cooling air supplied by cooling fan 144 passes through, thereby cooling the coffee beans, and exits the cooling vessel into the drum via drum outlet 11113. From the drum 111, the cooling air is removed by extraction fans 1151 of each of the negative pressure devices, respectively. The exhaust air extraction devices serve a dual purpose in this embodiment, both to extract exhaust air during roasting and to extract cooling air.

[0177] In one embodiment, the cyclone separator, catalyst and / or exhaust heater are activated during cooling so that the exhaust is treated.

[0178] When cooling is complete, the respective cooling termination condition that is satisfied may be determined in the same manner as in the previous embodiment and / or according to the general description. In certain designs, there is no dedicated cooling vessel exit shutter under the control of the control unit. Thus, the control unit may optionally provide a user indication, particularly an optical and / or acoustic indication, when the cooling termination condition is satisfied.

[0179] The chaff separator 19' of the coffee roaster 1' includes a cyclone separator 191' for separating chaff from the exhaust airflow. The cyclone separator 191' is controlled by the control unit and may be operated during the roasting process. After leaving the drum outlet 11114, the exhaust air is fed to the cyclone separator 191', where the chaff is generally separated and moved to a chaff drawer 192' for subsequent disposal, from which the exhaust air is fed to a particle filter, illustratively realized as an electrostatic particle filter 158'. Before entering the electrostatic particle filter 158', the exhaust air passes through a chaff-retaining filter 193', which may be realized as a mechanical filter, for example as a perforated plate, to prevent any residual chaff that may have passed through the cyclone separator 191' from entering further downstream components.

[0180] The chaff separator 19' is fitted with a fire extinguisher 194' for extinguishing a fire in the cyclone separator 191' and / or the chaff drawer 192'. The fire extinguisher 194' is connected to the control unit 13 which controls its operation based on the control unit 13 detecting conditions indicative of a fire. Conditions indicative of a fire can be determined using a fire detector. For example, a fire can be detected based on temperatures measured by an additional fire temperature sensor, a smoke detector, or any other type of fire detector located downstream of the fire extinguisher 194' itself, the cyclone separator 191', the chaff drawer 192', or the chaff separator 19'.

[0181] The exhaust gas treatment unit 15' of the coffee roaster 1' includes a catalytic device 157b' for removing odorous, harmful, toxic and / or polluting substances, such as carbon monoxide. To ensure an appropriate temperature of the exhaust gas for the catalytic device 157b' to operate efficiently, an exhaust gas heater 157a' is arranged upstream of the catalytic device 157b'. Downstream of the catalytic device 157b', an exhaust gas cooler 157c' is arranged to cool the substantially hot exhaust air leaving the catalytic device 157b'. The catalytic device may comprise a catalytic converter as known from vehicle exhaust systems.

[0182] In operation, the exhaust heater 157a' is preferably operated only during certain phases, particularly later phases of the roasting process as explained further below, when most of the odors are generated, rather than continuously. Otherwise, each odorous particle would be retained by the electrostatic particle filter 158'. The operation of the exhaust heater 157a' is controlled by the coffee roaster's control unit. Typical heating temperatures may range, for example, from 200°C to 400°C, particularly from 250°C to 300°C, depending on the type and specific characteristics of the catalytic device 157b'.

[0183] From the exhaust air cooler 157c' as a downstream element of the exhaust air treatment unit 15', the exhaust air passes through the condenser / dehumidifier 155 and the exhaust air extractor 115 as previously described and exits the coffee roaster 1' via the chimney 1152.

[0184] As previously mentioned, the cooling air follows the same path as the exhaust air during roasting in the studded design.

[0185] In the following, further reference is made to Figure 7, which shows an example of roasting coffee beans and an example of a selected roast profile and / or target roast profile, generally similar to Figure 5. The example is shown in this formulation based on the coffee roaster 1' shown in Figure 6. Since the roasting process is generally carried out in a similar manner, and the temperature profile of the roasted beans is also similar, as discussed in the context of Figure 5, the following description will focus on specific aspects of the implementation formulation.

[0186] In Figure 7, the bold lines indicate the roasted bean temperature signal determined by the roasted bean temperature sensor 12a, which generally corresponds to or indicates the desired roasted bean temperature according to the selected roasting profile. The dashed-dotted line indicates the temperature of the rear wall 11111 of the drum 111. Also shown in Figure 7 is the supply air flow, indicated by the dashed lines.

[0187] In the preparation phase O, the weight of the coffee beans is determined by the bean scale 16 as described above. Here, the cooling container 141' functions as a bean tray. Phase I is a preheating phase in which the back wall 11111 and the air in the drum 111 are heated to a desired target value according to a selected roasting profile. In the illustrated example, the back wall temperature is kept substantially constant, but this may not be the case for a different selected roasting profile. Preheating phase I is divided into two, and specifically includes a preheating phase Ia in which the drum air temperature is heated to a desired value according to the selected roasting profile. Once this temperature is reached, the drum air temperature is controlled to remain generally constant in a preheating hold phase Ib, as indicated by a dot as event E1. At the end of the preheating hold phase, the control unit controls the drum inlet shutter 1114 to temporarily open, thereby transferring the coffee beans loaded by the user into the hopper 1113 after determining their weight into the drum 111. The progression of roasted bean temperature during roasting is an illustrated example similar to the example of Figure 5 discussed above. The drum rotor drive 113 is controlled to rotate the drum rotor 112 at a constant rotational speed in this example, although this is not required. Alternatively, the selected roast profile can include a time-varying profile.

[0188] The positive pressure devices, supply fan 1142 and air heater 1141, both of which have a significant effect on the drum air temperature, are controlled in this example as follows: supply fan 1142 is controlled in stages to a predetermined air flow and / or pressure at the inlet of drum 111 and after supply fan 1142, respectively. Air heater 1141 is controlled to achieve a desired roasted bean temperature as a function of time. The different phases may each be time-controlled and may occur based on roasted bean temperature, assuming a specific roasted bean temperature according to a selected roasting profile, and / or based on roasted bean color, assuming a specific roasted bean color according to a selected roasting profile.

[0189] As an example, at the end of Phase Ib, the supply fan 1142 is set to 60% of the maximum air flow rate, and the supply air temperature is set to 450°C. The temperature detected by the roasted bean temperature sensor 12a (shown by the solid line) drops above the relatively cool beans entering the drum 111. This causes the temperature indicated by the roasted bean temperature sensor 12a to drop rapidly until it matches the temperature of the beans (which has been increased by the hot supply air and the hot drum 111). During Phase II, the control unit 13 is configured to detect the minimum temperature indicated by the roasted bean temperature sensor 12a. When this minimum is detected, the supply fan 1142 is adjusted to 65% of the maximum air flow rate, and the supply air temperature is set to 460°C. From approximately this point on, the temperature measured by the roasted bean temperature sensor 12a corresponds closely to the actual temperature of the beans. Point E2 is reached when the roasted bean temperature sensor 12a indicates that the beans have reached 193°C. The supply fan 1142 is then set to 40% of maximum air flow and the supply air temperature is set to 430° C. The specific temperatures shown in the illustrated examples depend on the roast profile.

[0190] Each extraction fan 1151 of the negative pressure device is controlled as described above to ensure a steady airflow without backflow. The airflow and / or pressure at the air inlet and / or exhaust air vent openings 11114 may further be monitored for predefined thresholds, which, if exceeded, may indicate a fault or defect, such as a blocked filter.

[0191] In the example shown, the roasting itself is divided into a first roasting phase II-1 followed by a 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, for example, 300°C, allowing the catalytic device 157b' to remove odorous, harmful, toxic and / or polluting substances, as described above in the catalytic process. The start of the second roasting phase II-2 can be initiated, for example, depending on the temperature of the roasted beans, for example, a value of 150°C.

[0192] The end of the roasting condition, indicated as characteristic event E3, is similar to the example of Figure 5 and is determined by the coffee bean temperature and, optionally, coffee bean color, assuming the respective target values ​​defined by the selected roast profile. Furthermore, the duration of the roast may define the end condition of the roast, in particular the duration of the roast at and / or above a specific temperature. The subsequent cooling step III and roasted coffee bean weight determination step IV are performed as described above, taking into account the different design and operation of cooling unit 15' compared to cooling unit 15, and the manual removal of the roasted coffee beans from cooling vessel 141'. [Explanation of symbols]

[0193] 1, 1', 1a, 1b, 1c, 1d Coffee roaster 11 Roasting unit 111 Drums 1111 Drum body 11111 Rear wall (drum body) 11112 Drum entrance 11113 Drum outlet 11114 Exhaust air vent opening 11115 Bean holder / perforated board 1112 Front wall 1113 Hopper 1114 Drum entrance shutter 1115 Drum exit shutter 112 Drum rotor 113 Drum rotor drive unit 114 Hot air supply section 1141 Air heater 1142 Positive pressure device / supply fan 115 Exhaust air vent device 1151 Negative pressure device / extraction fan 1152 Chimney 116 Drum heater 12a Roasted bean temperature sensor 12b Roasted 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 temperature sensor 12L Fill Level Sensor / Float Gauge 12m tray sensor 12n pull-out sensor 13 Control Unit 14' Refrigeration Unit 141, 141' Cooling vessel 1411 Cooling vessel inlet 1412 Cooling vessel outlet 142 Cooling rotor 143 Cooling rotor drive unit 144 Cooling air supply unit / cooling fan 145 Cooling water supply unit / nozzle device 146 Cooling vessel exit shutter 15, 15' Exhaust 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 Drain 1531 Drain valve 154 Exhaust air filter 155 Condenser 156 Bubble Enhancer / Chaff Separator 157a' Exhaust Gas Heater 157b' Catalyst device 157c' Exhaust Cooler 158' (electrostatic) particle filter 16 Bean Scale 17 Bean Tray 18 Drawers 19 Chaff separator 191' Cyclone Separator 192' Chaff Drawer 193' Chaff Retaining Filter 194' Fire extinguisher 2. Remote Computer Systems 3a, 3b User Interface Devices F Fill level (water tank) A Drum shaft

Claims

1. A coffee roaster (1) for carrying out a coffee bean roasting process, a) - a drum body (1111) with a thermally conductive rear wall (11111), a drum inlet (11112) and a drum outlet (11113), the drum (111) further comprising a removable front wall (1112); a drum rotor (112) rotatably arranged inside the drum (111); - a drum rotor drive (113) operatively connected to said drum rotor (112); a hot air supply unit (114) including an air heater (1141) and a positive pressure device (1142) for supplying hot air into the drum (111); a roasting unit (11) including a drum heater (116) thermally coupled to said rear wall (11111); b) a sensor device including a roasted bean temperature sensor (12a) configured to measure the roasted bean temperature of coffee beans placed inside said drum (111) and to provide a roasted bean temperature signal; c) a control unit (13) for controlling the execution of the coffee bean roasting process by the coffee roaster (1), the control unit (13) is configured to receive control input signals as a function of time, the control input signals including the roasted bean temperature signal; the control unit (13) is further configured to automatically generate control output signals as a function of time in response to the control input signals, the control output signals comprising one of a drum heater control signal, a drum rotor drive control signal, an air heater control signal, and a positive pressure device control signal, thereby controlling operation of at least one of the drum heater (116), the drum rotor drive (113), the air heater (1141), and the positive pressure device (1142) to roast the coffee beans inside the drum (111) according to a predetermined selected roasting profile; Coffee roaster (1), wherein the selected roast profile comprises a desired roasted bean temperature as a function of time and a target roasted bean temperature, and wherein the control unit (13) is configured to determine whether a roast end condition is met, the roast end condition comprising the coffee beans in the drum (111) having the target roasted bean temperature.

2. Coffee roaster (1) according to claim 1, wherein the front wall (1112) is transparent.

3. The sensor device a roasted bean color sensor (12b) configured to measure the roasted bean color of the coffee beans placed in the drum and to provide a roasted bean color signal, the control input signal comprising the roasted bean color signal; - a back wall temperature sensor (12c) configured to measure a back wall temperature of said back wall (11111) and provide a back wall temperature signal, said control input signal comprising said back wall temperature signal; - a drum air temperature sensor (12d) configured to measure a drum air temperature inside the drum (111) and provide a drum air temperature signal, the control input signal comprising the drum air temperature signal; an inlet air temperature sensor (12f) configured to measure an inlet air temperature of the hot air supplied to the drum (111) and to provide an inlet air temperature signal, the control input signal comprising the inlet air temperature signal; - an air humidity sensor (12g) configured to measure the extracted air humidity of air extracted from said drum (111) and to provide an air humidity signal, said control input signal comprising said air humidity signal; - an air outlet pressure sensor (12h) configured to measure the air pressure of the air extracted from said drum (111) and to provide an air outlet pressure signal, said control input signal comprising said air outlet pressure signal; an air inlet pressure sensor (12h2) configured to measure the air pressure of the hot air supplied to the drum (111) and to provide an inlet air pressure signal, the control input signal comprising the inlet air pressure signal; a crack detection sensor (12e) configured to detect the occurrence of first and / or second cracks in the coffee beans during roasting and to provide a crack detection signal, the control input signal comprising the crack detection signal.

4. 4. The coffee roasting machine (1) according to any one of claims 1 to 3, wherein the rear wall (11111) is realized as a sandwich comprising an outer layer in thermal contact with the drum heater (116), an aluminum core layer and a food-grade inner layer.

5. Further comprising a drum inlet shutter (1114) arranged to alternately open and close the drum inlet (11112), The selected roast profile includes selected pre-roasting conditions, and the control unit (13) - generating a pre-roast control output signal as part of said control output signal; - determining whether a selected pre-roasting condition is met based on the control input signal, and controlling the drum inlet shutter (1114) to open the drum inlet (11112) when the selected pre-roasting condition is met; Coffee roasting machine (1) according to any one of claims 1 to 4, configured as follows:

6. Further comprising a drum outlet shutter (1115) arranged to alternately open and close the drum outlet (11113), 6. A coffee roaster (1) according to any one of claims 1 to 5, wherein the control unit (13) is configured to control the drum outlet shutter (1115) to open the drum outlet (11113) when the roast end condition is met.

7. a) a cooling vessel (141) having a cooling vessel inlet (1411) and connected to the drum outlet (11113) via the drum outlet shutter (1115); 7. The coffee roasting machine (1) of claim 6, further comprising a cooling unit (14) including: b) a cooling medium supply source, the cooling medium supply source including a cooling air supply (144) fluidly coupled to the interior cooling vessel space to supply cooling air into the cooling vessel (141), and / or a cooling water supply (145) including a nozzle arrangement configured to spray cooling water onto the coffee beans in the cooling vessel (141).

8. 8. The coffee roasting machine (1) of claim 7, wherein the cooling vessel (141) is fluidly coupled to an interior drum space of the drum (111), thereby enabling the transfer of cooling air from the cooling vessel (141) to the drum (111) and the recovery of the cooling air from the drum.

9. 9. A coffee roasting machine (1) according to any one of the preceding claims, further comprising an exhaust gas treatment unit (15, 15') including a catalytic device (157b') configured to catalytically react one or more components of the exhaust gas drawn from the drum.

10. 10. The coffee roaster (1) of claim 9, wherein the exhaust gas treatment unit (15, 15') comprises an exhaust gas heater (157a') arranged fluidly upstream of the catalytic device (157b') and an exhaust gas cooler (157c') arranged fluidly downstream of the catalytic device (157b').

11. Coffee roasting machine (1) according to any of the preceding claims, further comprising a chaff separator (156, 19).

12. Coffee roasting machine (1) according to claim 11, further comprising a fire extinguisher (194') configured to extinguish a fire in the chaff separator (156, 19).

13. Coffee roaster (1) according to any one of the preceding claims, wherein the control unit (13) is configured to control the positive pressure device (1142) so as to vary the hot air flow as the roasting process progresses.

14. 14. A coffee roaster (1) according to any one of the preceding claims, wherein the control unit (13) is operatively coupled to a remote computer system (2) and configured to receive the selected roast profile from the remote computer system (2).

15. 15. The coffee roasting machine (1) according to claim 14, wherein the control unit (13) is configured to acquire sensor data during the coffee bean roasting process and to transmit the acquired sensor data and / or data derived from the acquired sensor data to the remote computer system (2).

16. a) a coffee roaster (1) according to any one of claims 14 or 15; b) a remote computer system (2) configured to store a plurality of available roast profiles, receive a user input for selecting said selected roast profile from the plurality of available roast profiles, and transmit said selected roast profile to said control unit (13); Coffee roasting system, including:

17. 17. A method for roasting coffee beans or a method for brewing coffee, comprising using a coffee roaster (1) according to any one of claims 1 to 15 or a coffee roasting system according to claim 16.

Images