How to roast coffee beans

Abstract

The present invention relates to a method for roasting coffee beans in a roasting system (10), the system comprising a roaster (2) and a smoke treatment unit (3) configured to treat smoke produced by the roaster, the smoke treatment unit comprising at least an electrostatic precipitator (222), the method comprising the steps of: during each roasting operation performed in the roaster, monitoring the voltage at the ionization wire and / or the voltage at the electrodes over the time of the roasting operation; comparing the monitored voltage with a predetermined upper voltage threshold V1 and one predetermined lower voltage threshold V2; and indicating a cleaning status request if, during a period Δt of the roasting operation, the monitored voltage is below the predetermined upper voltage threshold V1 but above the predetermined lower voltage threshold V2.

Description

[Technical Field]

[0001] This invention relates to an apparatus for roasting coffee beans in a safe environment. [Background technology]

[0002] Roasting coffee beans is a well-known process. The main steps involve heating the beans to the desired roast level, and then cooling or quenching the heated beans to stop the roasting. During heating, smoke is released. This smoke contains not only safe and desirable components, especially the aroma of normal roasted coffee, but also undesirable and unsafe volatile organic compounds (VOCs) such as pyridine, 2-furan methanol, caffeine furfural, formaldehyde, acetaldehyde, and particulate matter (PM). 2.5 PM 10 ) is also included.

[0003] When roasting is carried out in a manufacturing facility that produces significant quantities of roasted beans, all conditions are generally in place to capture any unsafe components.

[0004] However, recently, there is a trend towards small-batch roasting by small roasters in stores, restaurants, and coffee shops where customers can consume coffee brewed with freshly roasted beans. These roasters not only provide freshness and on-site advantages, but also release a pleasant aroma of roasted coffee into the store or coffee shop.

[0005] However, as mentioned above, harmful components are also released. When a roaster is used in an enclosed environment such as a shop, coffee shop, or restaurant, the release of some components can be harmful depending on the size and ventilation of the room. For people working in that room for several hours, inhaling the smoke from the roaster can lead to health problems.

[0006] As a result, in such environments, it is recommended to stop the emission of smoke from roasters to avoid health problems for people inside the store. Existing solutions consist of eliminating contaminants with afterburners or catalytic afterburners that allow for thermal oxidation of contaminants, or retaining contaminants inside devices such as mechanical filters (metal sieves or paper filters), activated carbon filters, electrostatic precipitators, or combinations thereof.

[0007] Electrostatic precipitators capture some PM particles, typically having a size of 1.0–10 μm. The advantages of electrostatic precipitators are their low cost of purchase and use, and the absence of noise and heat during operation. Because electrostatic precipitators capture contaminants that remain attached to the precipitator's charging cells, the devices must be cleaned regularly.

[0008] Cleaning warnings can be set based on the maximum number of hours the roaster has been operated or the maximum amount of coffee beans roasted. However, these warnings are merely estimates and not entirely accurate, and may prompt the operator to clean the filters too late, resulting in inefficient filtering during the final roasting cycle and potentially compromising the safety of those around the roaster. In addition, the roaster and filter systems may still be functional, albeit inefficiently, so the operator may ignore this alarm and continue roasting.

[0009] In particular, if the cleaning operation is not performed on time, a problem specific to electrostatic precipitators is the occurrence of dielectric breakdown due to the presence of particles inside the device. These dielectric breakdowns can be very short, but while they occur, the smoke is not filtered, resulting in at least two undesirable consequences. Firstly, particulate matter may be released into rooms in cafes, shops, or restaurants where people are present. Secondly, some unfiltered particulate matter can clog other filters located downstream of the electrostatic precipitator, such as activated carbon filters. As a result, VOCs are no longer filtered out by these filters, increasing health problems in public rooms. Finally, the electrostatic precipitator device may be damaged.

[0010] In particular, the risk of such dielectric breakdown increases when the electrostatic precipitator has reached its particle collection limit, which can occur if the operator ignores previous cleaning alarms. [Overview of the project]

[0011] The objective of this invention is to address the aforementioned existing problems.

[0012] In particular, the objective of the present invention is to address the problem of informing the operator of the moment when cleaning of the smoke filter of an electrostatic precipitator is absolutely necessary, and to provide that information accurately.

[0013] It would be advantageous to avoid electrical breakdowns caused by increased pollution and to predict the moment of their occurrence.

[0014] In a first aspect of the present invention, a method for roasting coffee beans in a roasting system is provided, the system is Roasting equipment and A smoke treatment unit configured to process smoke generated by a roasting device, wherein the smoke treatment unit includes an electrostatic precipitator, The above electrostatic precipitator comprises at least one cell, The above cell comprises an ionization beam, a collection electrode, and a repulsion electrode. The above cell is supplied with power to apply an ionization beam and a high voltage to at least a portion of the electrodes. Equipped with a smoke treatment unit, During each roasting operation performed within the roasting apparatus, this method Monitoring the voltage in the ionization line and / or the voltage at the electrode over time during the roasting operation; Comparing the monitored voltage with at least one predetermined upper voltage threshold V1 and one predetermined lower voltage threshold V2; During the roasting operation period Δt, if the monitored voltage is below the at least one predetermined upper voltage threshold V1 and above the predetermined lower voltage threshold V2, displaying a cleaning state requirement; Including.

[0015] This method relates to the roasting of coffee beans by a system comprising two devices: firstly, a roasting device for heating and roasting the beans, and secondly, a smoke treatment unit configured to treat the smoke generated inside the first roasting device during the roasting of the coffee beans.

[0016] These two devices can be sub-parts of a single main system or can be considered as separate modules that cooperate during the roasting process.

[0017] Any type of roasting device can be used. Inside the roasting device, the coffee beans are heated and preferably mixed to homogenize the heating of the entire beans.

[0018] The heating source may be a burner (meaning combustion) supplied with natural gas, liquefied petroleum gas (LPG), or even wood. Alternatively, the heat source may be an electric resistor, a ceramic heater, a halogen source, an infrared source, or a microwave source.

[0019] Preferably, the heating source is electrically operated, so that the air pollutants generated during roasting are only those resulting from the heating of the coffee beans themselves and not those resulting from the combustion of gas as would occur if the heating source were a gas burner using natural gas, propane, liquefied petroleum gas (LPG), or even wood.

[0020] Mixing of the beans during roasting can be obtained mechanically using a hot air fluidized bed or using a stirring blade or a rotating drum.

[0021] Preferably, the roasting apparatus is a hot air fluidized bed chamber. In such a chamber, heated air is fed through a screen or perforated plate under the coffee beans with sufficient force to lift the beans. In this fluidized bed, heat is transferred to the beans as they roll and circulate.

[0022] Alternatively, the roasting apparatus may be a drum chamber in which the coffee beans are tumbled in a heated environment. The drum chamber can consist of a drum rotating along a horizontal axis, or the drum chamber can be equipped with stirring blades for rolling the coffee beans in a heated environment.

[0023] The roasting apparatus includes an outlet capable of discharging the smoke generated during the roasting operation.

[0024] Generally, the smoke treatment unit of the system has a smoke inlet configured to cooperate with the smoke outlet of the roasting apparatus and collect the smoke through the smoke inlet.

[0025] The smoke treatment unit treats the smoke to reduce or remove harmful pollutants contained in the smoke, particularly particulate matter such as PM1, PM 2.5 , and PM 10 .

[0026] This smoke treatment unit includes at least an electrostatic precipitator.

[0027] The electrostatic precipitator is a particle collection device that filters the smoke by removing particles from the smoke stream using electrostatic charges.

[0028] The electrostatic precipitator includes one or more cells. Each cell is identical and ionization wires or corona metal wires in the upstream ionization region, and The system comprises a collection electrode and a repulsion electrode in a downstream collection area. Typically, the electrodes are in the form of plates. An electric field is generated through the electrodes and is perpendicular to the smoke flow. This electric field is generated by applying different voltages to a pair of electrodes, or by applying a voltage to one electrode and grounding the other electrode. By associating several pairs of collection plates and repulsion plates spaced apart from each other, smoke can be directed into the space between the collection plates and repulsion plates.

[0029] Typically, an ionization beam is powered to apply a high voltage V to it. Smoke particles flowing through the ionization region are ionized to either a positive or negative charge.

[0030] Next, as the smoke stream passes the downstream metal plate, the collection electrode acts as a collector for ionized particles, attracting the charged particles to the plate, moving toward it, and forming a layer that remains on the plate. Thus, the escaping smoke stream is removed from the charged particles collected on the collection electrode.

[0031] Using an electrostatic precipitator, particles with a size of 1.0 to 10 μm can be captured.

[0032] If the electrostatic precipitator has several cells, these cells are arranged in sequence in the smoke stream, with the first cell filtering out most of the smoke particles, and the second cell filtering the smoke processed by the first cell to achieve improved separation.

[0033] When roasting is performed inside the roasting apparatus, this method A step of monitoring the voltage in the ionization line and / or the voltage in the electrode along the time of the roasting operation, The steps include comparing the monitored voltage with at least one predetermined upper voltage threshold V1 and one predetermined lower voltage threshold V2, If, during the roasting operation period Δt, the monitored voltage falls below at least one predetermined upper voltage threshold V1 while exceeding the predetermined lower voltage threshold V2, the step of displaying a cleaning state request, Includes.

[0034] During the roasting operation, the voltage V monitored at the ionization line or electrode changes, generally showing a pattern of decreasing from an initial voltage V0 (corresponding to the high voltage applied to the line or electrode), then reaching a minimum voltage Vlow, and finally rising from that minimum to the initial voltage V0 at the end of the roasting operation. Starting with a recently cleaned electrostatic precipitator, it has been observed that after several roasting operations, the minimum voltage Vlow decreases with each operation. In fact, this minimum value is a measurable parameter that provides information about the level of particle collection on the collection electrode.

[0035] If any of the monitored voltages, especially the lowest value, falls below the voltage threshold, an alarm is displayed to draw the operator's attention to the fact that a cleaning operation is required.

[0036] Different upper voltage thresholds can be set, which provides the operator with incremental information regarding cleaning requests, particularly regarding the urgency of the cleaning.

[0037] The upper voltage threshold V1 can be predefined so that the roasting operation can be carried out without any alarms being triggered when the monitored voltage exceeds the upper voltage threshold during the roasting operation. However, if the monitored voltage falls below the upper voltage threshold during a particular operation, it means that there is a nearly certain risk of dielectric breakdown occurring during the subsequent roasting operation, and that the subsequent operation cannot be carried out while achieving efficient filtering of the smoke. Therefore, this method detects the moment when cleaning of the electrostatic precipitator is necessary.

[0038] The cleaning status request can provide different types of information, ranging from a simple suggestion to clean before a certain number of operations occur, depending on the setting of a predetermined upper voltage threshold V1, to emergency cleaning at the end of the current roasting operation, as described below.

[0039] Typically, the upper voltage threshold V1 is determined by considering the high voltage applied to the ionization beam or electrode, and further by experiments described later.

[0040] In one preferred embodiment, this upper threshold V1 represents more than 50% of the value of the high voltage V0 applied to the ionization beam or electrode.

[0041] During the operation of an electrostatic precipitator, the voltage periodically drops to very low levels due to the momentary presence of particles that establish contact between the repulsive electrode and the collecting electrode. The voltage drops extremely low at this moment and then rises to normal levels as the particles are carried away by the smoke stream.

[0042] These very low voltage values ​​over very short periods of time are not considered for analyzing the state of cell contamination. For this reason, according to this method, the monitored voltage is also compared to a predetermined lower voltage threshold V2, and if the monitored voltage falls below the predetermined lower voltage threshold V2, there is no need to display a cleaning status request.

[0043] This predetermined lower voltage threshold V2 can be set to eliminate false dielectric breakdown, and the lower values ​​of the monitored voltage during this phenomenon should not be taken into consideration.

[0044] Typically, the lower voltage threshold V2 depends on the configuration of the electrostatic precipitator, particularly the high voltage applied, and can be further determined by experiment.

[0045] Typically, this lower threshold is far below the high voltage applied to the ionization beam and electrodes, as well as the upper voltage threshold V1. The V1 / V2 ratio is usually greater than 10.

[0046] In one preferred embodiment, the lower predetermined voltage threshold V0 may be less than 100V.

[0047] In particular, for high voltages exceeding 5kV applied to the ionization beam or electrode, the lower predetermined voltage threshold V0 may be less than 100V.

[0048] Preferably, a cleaning status request is displayed in the following cases: If the monitored voltage falls below at least one predetermined upper voltage threshold V1, while exceeding a predetermined lower voltage threshold V2, and When the period Δt exceeds a predetermined time threshold Δt1.

[0049] By introducing a second condition regarding the length of the period Δt during which the monitored voltage is below a predetermined upper voltage threshold V1, instantaneous abnormally low voltage values ​​are not considered, and even if they exceed a predetermined lower voltage threshold V2, no cleaning state request is displayed.

[0050] Typically, time Δt1 is approximately a few seconds, for example, about 5 seconds.

[0051] In one embodiment, a cleaning state request may be displayed if, during a period Δt exceeding one of the roasting operations, the monitored voltage falls below at least one predetermined upper voltage threshold V1 while exceeding a predetermined lower voltage threshold.

[0052] In one embodiment, the steps of monitoring the voltage and comparing the monitored voltage are performed only during a portion of the roasting operation time, preferably during the last 20% of the roasting operation time, or during a portion of the roasting operation when the bean temperature exceeds 150°C.

[0053] As mentioned above, during the roasting process, the voltage V at the ionization line and electrodes changes, generally showing a pattern of decreasing from the initial voltage V0, then reaching a minimum voltage Vlow, and then rising from that minimum to the initial voltage V0 at the end of the roasting process. (As shown in the figure below) It has also been observed that the voltage reaches its minimum value during the final part of the roasting process. Therefore, monitoring and comparing the voltage during the final part of the roasting process is sufficient to analyze the cleaning state requirements. This final part of the roasting process can also correspond to bean temperatures exceeding 150°C.

[0054] Typically, a fume treatment unit includes a high-voltage process control board configured to control an electrostatic precipitator. Preferably, the monitored voltage can be read from the process control board.

[0055] In one preferred embodiment, the electrostatic precipitator comprises at least two cells, the cells arranged successively along the flow of smoke emitted by the roaster, and the method is applied to at least the first cell along the flow of smoke, preferably to each cell.

[0056] In this preferred embodiment, the first cell has been observed to capture about 90% of the smoke particulate matter that the cell is configured to capture, meaning that subsequent cells capture 90% of the remaining 10% of particulate matter. As a result, applying the method of the present invention to the first cell may be sufficient to detect the risk of contamination and dielectric breakdown of that cell.

[0057] Preferably, this method is applied to each cell, meaning that the voltage is monitored in each cell.

[0058] Preferably, the fume treatment unit comprises at least one other filtering device in addition to the electrostatic precipitator. This other filtering device may include, but is not limited to, high-efficiency particle accumulation filters, metal filters, activated carbon filters, paper filters, cotton, and cloth. Optionally, the fume treatment unit may also comprise additional filtering devices such as a wet scrubber, catalytic converter, or afterburner.

[0059] The filter configured to capture VOCs is preferably an activated carbon filter or a charcoal filter.

[0060] Preferably, the smoke filtering subunit comprises, in accordance with the direction of smoke flow within the smoke treatment unit, at least one filter for removing particulate matter, followed by an electrostatic precipitator, and then an activated carbon filter, in a sequence. This sequence prevents the activated carbon filter from becoming clogged with particulate matter.

[0061] Smoke is propelled through the smoke treatment unit and different filters by a smoke driver configured to circulate the smoke through the smoke treatment unit from the inlet to the outlet. At the outlet, the smoke and contaminants are captured, so that a safely treated flow can be released into the room atmosphere.

[0062] A smoke driver is generally a fan that pushes smoke towards an outlet.

[0063] Preferably, the fan is positioned adjacent to the outlet of the smoke treatment unit. As a result, the fan is not contaminated by untreated smoke, and its maintenance becomes easier.

[0064] According to one preferred embodiment, the smoke filtering subunit comprises, in sequence, at least the following: Metal mesh, then Electrostatic precipitator, then An activated carbon filter that responds to the movement of smoke flow inside the smoke treatment unit.

[0065] Preferably, in this embodiment, the activated carbon filter is physically positioned above the electrostatic precipitator. Thus, the smoke is introduced upward through the continuous device.

[0066] In one embodiment, the value of a predetermined upper voltage threshold V1 changes according to the number of roasting operations performed since the last cleaning operation of the electrostatic operator, and preferably, the value decreases as the number of roasting operations increases.

[0067] Since the cell becomes increasingly contaminated with each roasting operation, a high level of estimation of its contamination can be provided by counting the number of operations since the last cleaning operation of the cell. Based on experiments, the maximum number of roasting operations before the cell requires cleaning can be estimated.

[0068] Based on this estimation, the value of a predetermined upper voltage threshold V1 can be gradually decreased, and when the number of roasting operations reaches the corresponding predetermined number of roasting operations N1, N2, and N3, the upper voltage threshold can be set to values ​​V11, V12, and V13, respectively.

[0069] The value can be decreased in steps, and at each step, the value can correspond to a percentage of a predetermined maximum upper voltage threshold.

[0070] In another embodiment, the system may include a meter configured to estimate the number of roasting operations that are still operational before a cleaning operation of the electrostatic precipitator is required, and a predetermined upper voltage threshold V1 changes according to the estimated number, preferably decreasing as the estimated number of roasting operations decreases.

[0071] Such a meter can be configured to estimate the contamination level of the cells in an electrostatic precipitator and to estimate the number of roasting operations that can still be performed before cleaning is required. This estimate can be based on the number of roasting operations already performed, and / or the type of roasting operations already performed, and / or the type of beans roasted during those operations.

[0072] In particular, when the estimated number of roasting operations that can still be performed, after being gradually reduced, reaches the corresponding predetermined number of roasting operations N1, N2, and N3, respectively, the predetermined upper voltage threshold values ​​can be set to values ​​V11, V12, and V13, respectively.

[0073] When the value of a predetermined upper voltage threshold V1 changes, preferably, a corresponding type of cleaning status request is displayed according to the value of the predetermined upper voltage threshold V1.

[0074] Specifically, as the value of a predetermined upper voltage threshold V1 decreases, the cleaning status may progress from simple information or a pre-warning to an emergency cleaning request alarm.

[0075] In one embodiment, the system includes a sensor configured to measure particulate matter in smoke processed by an electrostatic precipitator, and the method includes the following steps: A step of measuring the concentration of particulate matter during the roasting process. A step to compare the cleaning request status with a measured value.

[0076] The sensor allows for verification that the displayed cleaning request status is correct based on an analysis of the monitored voltage.

[0077] In a second embodiment, a system for roasting coffee beans is provided, and the system is Roasting equipment and A smoke treatment unit configured to process smoke generated by a roasting apparatus, wherein the smoke treatment unit comprises at least an electrostatic precipitator, The above electrostatic precipitator comprises at least one cell, The above cell comprises an ionization beam, a collection electrode, and a repulsion electrode. The above cell is supplied with power to apply an ionization beam and a high voltage to at least a portion of the electrodes. Smoke treatment unit, A control system capable of operating to control the roasting process according to the roasting method described above, It is equipped with.

[0078] Depending on the integration of the roasting apparatus and the smoke treatment unit, the control system can be shared between both apparatuses, and the steps of the method can be shared between the control units of at least these two apparatuses.

[0079] In one embodiment, the method can be carried out by the control unit of the roasting apparatus and the control unit of the smoke treatment unit, and both treatment units communicate with each other. Specifically, it is as follows: The control unit for the smoke treatment unit is, The steps include monitoring the voltage V, The steps include comparing the monitored voltage V with the upper and lower voltage thresholds, If necessary, the following steps can be taken: communicate the status of the cleaning request to the roasting machine. The control unit of the roasting machine can perform the step of displaying the status of the cleaning request.

[0080] In another embodiment, The control unit for the smoke treatment unit is, The steps include monitoring the voltage V, The steps of communicating the monitored voltage V value to the roasting device can be performed. The control unit of the roasting machine is The steps include comparing the monitored voltage V with the upper and lower voltage thresholds, If necessary, the following steps can be taken: displaying the status of the cleaning request.

[0081] In another embodiment, the control unit of the smoke treatment unit can perform all steps after receiving information from the roasting device that the roasting step has started.

[0082] Preferably, the roasting apparatus may be equipped with a display unit to indicate the status of cleaning requests.

[0083] Alternatively, the electrostatic precipitator may be equipped with a device for indicating the status of the cleaning request, such as an indicator light button.

[0084] In another alternative configuration, the control system may be configured to display the status of cleaning requests on a mobile device communicating with the system.

[0085] In a third aspect, a computer program is provided which includes instructions causing the system according to the second aspect to perform the method according to the first aspect.

[0086] In one embodiment, the computer program can be executed by the processing unit of the roasting apparatus and the control unit of the smoke processing unit, and both processing units communicate with each other. Specifically, this is as follows: The control unit for the smoke treatment unit is, The steps include monitoring the voltage V, The steps include comparing the monitored voltage V with the upper and lower voltage thresholds, If necessary, the following steps can be taken: communicate the status of the cleaning request to the roasting machine. The control unit of the roasting machine can perform the step of displaying the status of the cleaning request.

[0087] In another embodiment, The control unit for the smoke treatment unit is, The steps include monitoring the voltage V, The steps of communicating the monitored voltage V value to the roasting device can be performed. The control unit of the roasting machine is The steps include comparing the monitored voltage V with the upper and lower voltage thresholds, If necessary, the following steps can be taken: displaying the status of the cleaning request.

[0088] In another embodiment, the control unit of the smoke treatment unit can perform all steps after receiving information from the roasting device that the roasting step has started.

[0089] In a fourth aspect, a computer-readable storage medium is provided that stores the computer program according to the third aspect.

[0090] The above embodiments of the present invention can be combined in any preferred combination. Furthermore, by combining various features described herein with one or more of the above embodiments, combinations other than those specifically illustrated and described can be provided. Further objects and advantageous features of the present invention will become apparent from the "Claims," ​​"Modes for Carrying Out the Invention," and the accompanying drawings. [Brief explanation of the drawing]

[0091] Specific embodiments of the present invention are further described herein by reference to the following drawings. [Figure 1] This is a diagram of the system according to the present invention, showing the path of smoke passing through the system. [Figure 2] Figure 1 shows one of the cells in the electrostatic precipitator section of the smoke treatment unit. [Figure 3] Figures 1 and 2 show block diagrams of the control system of the system. [Figure 4] This shows the changes in monitored voltage and emitted particles during the roasting operation under two different contamination conditions of the collection electrode. [Figure 5] This shows the changes in monitored voltage and emitted particles during the roasting operation under two different contamination conditions of the collection electrode. [Figure 6] Figure 4 is a magnified view of one roasting operation. [Modes for carrying out the invention]

[0092] A system for roasting coffee beans Figure 1 shows an exemplary diagram of the system comprising a roasting apparatus 1 and a smoke treatment unit 2. Functionally, the roasting apparatus is capable of operating to roast coffee beans, and the smoke treatment unit is capable of processing the smoke generated during roasting by the roasting apparatus.

[0093] Roasting equipment The roasting device 1 is operable to receive coffee beans into the roasting chamber 12 and roast them.

[0094] Preferably, the roasting apparatus 1 includes a roasting chamber 12 into which a hot air flow is introduced to agitate and heat the beans. The hot air flow is usually generated by an airflow driver and a heater. These devices are located below the roasting chamber and introduce a flow of hot air through the bottom of the chamber. In the diagram shown, the bottom of the chamber is configured to allow air to pass through, and specifically, it may be a perforated plate through which beans are placed and air can flow upward.

[0095] The airflow driver is operable to generate an upward airflow towards the bottom of the container. The generated flow is configured to heat and agitate the beans, lifting them up. As a result, the beans are heated uniformly. Specifically, the airflow driver may be a motor-powered fan. An air inlet may be located in the base of the housing to supply air into the housing, and the airflow driver blows this air towards the chamber 12.

[0096] The heater is operable to heat the airflow generated by the airflow driver. Preferably, the heater is an electrical resistor placed between the fan and the perforated plate, so that the airflow is heated before it enters the chamber 12 to heat and lift the beans.

[0097] The heater and / or fan can be operated to apply a roasting profile to the beans, which is defined as a temperature curve over time.

[0098] Preferably, the roasting apparatus includes a user interface 13 that enables the following: Input of information regarding roasting, specifically the amount of beans introduced into the roasting chamber and the desired roasting level, and output of information regarding the roasting operation (state, temperature, time), and Preferably, the output relates to the output of information concerning the smoke treatment unit 2, specifically, information concerning the cleaning of the electrostatic precipitator 222.

[0099] Bean roasting generates smoke that is sent to the upper opening 121 of the roasting chamber by an airflow generated by an airflow driver, as shown by arrow S1 in Figure 1.

[0100] Generally, the chaff collector is in flow communication with the upper opening 121 of the chamber and catches the chaff that gradually separates from the beans during roasting and is blown into the chaff collector by its light density.

[0101] The remaining smoke is discharged through the smoke outlet 11 at the top of the roasting device.

[0102] Smoke treatment unit The smoke processing unit 2 is operable to receive and process the smoke S1 emitted from the smoke outlet 11 of the roasting apparatus.

[0103] Firstly, the smoke treatment unit 2 includes a smoke collection device 21 adapted to collect smoke. This smoke collection device 21 or collection device forms an internal void space or duct that guides smoke (dotted lines S1, S2, S3) from the outlet 11 of the roasting apparatus toward the filtering device of the smoke filtering subunit 22.

[0104] The smoke filtering subunit 22 filters PM1, PM 2.5 , and PM 10 The system includes an electrostatic precipitator 222 adapted to filter out small particulate matter such as smoke. The electrostatic precipitator 222 comprises two identical cells 222a and 222b arranged in succession in the smoke stream.

[0105] Figure 2 shows the main components of cell 222a. Cell 222a is configured to be traversed by smoke and is continuously configured as follows, according to the direction of the smoke flow. Several ionization lines 2221, then Several collection electrodes 2222 and repulsion electrodes 2223 are arranged alternately at a distance of a few millimeters, usually in the form of parallel plates. The plates are oriented to form channels for smoke flow.

[0106] A high voltage level (in this case, in the range of 8kV) is applied to the ionization line 2221, generating a corona discharge that charges the smoke particles entering the cell.

[0107] By applying a voltage difference between the collecting electrode and the repulsive electrode (for example, in this case, applying 4kV to the collecting electrode and connecting the repulsive electrode to ground), an electric field is generated by the collecting electrode and the repulsive electrode.

[0108] When charged particles flow through a channel defined by alternating collecting and repulsive electrodes, these charged particles are attracted to the collecting electrode 2222 by an electric field perpendicular to the direction of flow.

[0109] The cleaning operation of the electrostatic precipitator 222 consists of removing the cells 222a and 222b of the electrostatic precipitator from the smoke filtering unit and washing the cells with water and optionally with detergent, for example, in a dishwasher.

[0110] In addition, in this particular exemplary embodiment, the smoke filtering subunit 22 may include the following: PM 10 A device 223 adapted to filter large particulate matter such as a metal mesh and associated diffuser, generally a metal grid placed in front of (i.e., upstream of) the mesh. Activated carbon filter 221 adapted to remove VOCs from smoke.

[0111] Preferably, the device for removing particulate matter is positioned upstream of the activated carbon filter. This upstream position ensures that particulate matter does not contaminate the activated carbon filter.

[0112] The electrostatic precipitator is physically positioned beneath the activated carbon filter to prevent particles from falling onto the activated carbon filter when the electrostatic precipitator is switched off.

[0113] The smoke filtering subunit 22 is equipped with a smoke driver 23, typically a fan, for drawing in contaminated smoke from the inlet 211 of the collection device through the smoke filtering subunit 22 where the contaminated smoke is processed, to the outlet 25 of the smoke filtering subunit 22, where it is safely discharged into the ambient atmosphere.

[0114] Control system for roasting equipment and smoke treatment unit Referring to Figures 1, 2, and 3, we will now consider the control system 3. The control system 3 is operable to control the smoke filtering unit 2, and in particular the electrostatic precipitator 222 of the smoke treatment unit.

[0115] Depending on the level of integration between the roasting apparatus 1 and the smoke filtering unit 2, the control system can be shared between the control units of these two devices. If the smoke treatment unit 2 is part of the roasting apparatus 1, typically the control unit of the roasting apparatus is the master and the control unit of the filter is the slave. If the roasting apparatus 1 and the smoke processing unit 2 form two different apparatuses, each having its own independent control unit, these control units may be configured to communicate in order to carry out the method.

[0116] In particular, it may be possible to establish communication between the systems of these two devices and a mobile device in order to display information.

[0117] Figure 3 shows the control system for the smoke filtering unit 2 in Figure 1.

[0118] The control system 3 typically includes a processing or control unit 30, a power supply 33, a memory unit 31, and a voltage sensor 34 for the ionization electrode, all located at a second level of the smoke filtering unit 2.

[0119] The control unit 30 is configured to output feedback to the user interface 13 of the roasting apparatus, in particular, to display the status of the electrostatic precipitator cleaning request. In an alternative configuration, some processing units 2 may have their own user interface for displaying this status, such as a light button that can be illuminated according to the status.

[0120] The control unit 30 may also output the following information to the user interface 13: Cleaning instructions like those in tutorials, historical data on cleaning operations, etc. Reset alarm status.

[0121] The user interface hardware may include any suitable device(s), for example, one or more of the following: buttons such as joystick buttons, knobs or push buttons, a joystick, LEDs, a graphic LCD or character LCD, a graphic screen having touch-sensitive buttons and / or screen edge buttons. The user interface 20 can be formed as one unit or multiple separate units.

[0122] Part of the user interface may also be located on the mobile app if the device is provided with a communication interface 32, as described below. In that case, at least part of the inputs and outputs can be transmitted to the mobile device through the communication interface 32.

[0123] The control unit 30 generally comprises memory and input / output system components, typically configured as integrated circuits such as a microprocessor or microcontroller. The control unit 30 may also comprise other suitable integrated circuits, such as programmable logic devices like ASICs, PALs, CPLDs, and FPGAs, and analog integrated circuits such as PSoCs, system-on-a-chip (SoCs), and controllers. With respect to such devices, where appropriate, the aforementioned program code can be considered as programmed logic, or can be considered to additionally include programmed logic. The control unit 30 may also comprise one or more of the aforementioned integrated circuits. In the latter example, several integrated circuits are configured to communicate with each other modularly, for example, a slave integrated circuit for controlling the smoke processing unit 2 communicates with a master integrated circuit for controlling the roasting apparatus 10.

[0124] The power supply 33 is operable to supply electrical energy to the controlled components and the control unit 30. The power supply 33 may include various means, such as a battery or a unit for receiving and regulating the main power supply.

[0125] The control unit 30 generally includes a memory unit 31 for storing instructions as program code and optionally for storing data. For this purpose, the memory unit typically includes non-volatile memory such as EPROM, EEPROM, or Flash for storing program code and operating parameters as instructions, and volatile memory (RAM) for temporarily storing data. The memory unit may include separate and / or integrated memory (e.g., on a semiconductor die). For programmable logic devices, instructions can be stored as programmed logic.

[0126] The instructions stored in the memory unit 31 can be ideally configured to include a program for determining the level of contamination of the system's smoke treatment unit, specifically, a cleaning status request (no cleaning required, emergency cleaning at the end of the current roasting operation, etc.).

[0127] The control unit 30 is configured to output a voltage V value at the ionization line 2221, which is measured by the sensor 34. In a preferred embodiment, the voltage can be read directly from the high-voltage PCB of the electrostatic precipitator.

[0128] During the roasting process, the control system 3 can operate as follows: Monitor the voltage at the ionization line and / or the voltage at the electrodes along the time of the roasting operation. The monitored voltage is compared with a predetermined upper voltage threshold V1 and a predetermined lower voltage threshold V2, and, If, during the roasting operation period Δt, the monitored voltage falls below the predetermined upper voltage threshold V1 while exceeding the predetermined lower voltage threshold V2, a cleaning state request is displayed.

[0129] Figure 4 shows the changes in emitted PM and monitored voltage during a series of roasting operations (n°1-6).

[0130] Curve C represents the amount of PM released during the roasting process and measured upstream of the electrostatic precipitator (i.e., before processing by this filtering device). 2.5 The measured values ​​are shown.

[0131] The voltages at the ionization line 2221 of the upstream cell 222a and the downstream cell 222b during these roasting operations are represented by curves A and B, respectively.

[0132] During the roasting operation, the voltage V at the ionization line changes, decreasing from an initial voltage V0 (approximately 7kV), then reaching a minimum voltage Vlow (indicated by black dots), and finally rising from this minimum voltage back to the initial voltage V0 at the end of the roasting operation. Starting with a recently cleaned electrostatic precipitator, several roasting operations are performed, and it is observed that the minimum voltage Vlow decreases with each operation, as shown by the dotted line. This minimum value is a measurable parameter that provides information about the particle collection level on the collection electrode.

[0133] When a portion of the monitored voltage, such as the minimum value Vlow, is set to 4.5kV and falls below the upper voltage threshold V1 shown in Figure 4, an alarm is displayed to draw the operator's attention to the fact that a cleaning operation is required.

[0134] Through curve B, we can see that the monitored voltage of the other cell 222b does not decrease significantly. This is because the upstream cell 222a captures approximately 90% of the PM. As a result, the downstream cell 222b is not rapidly contaminated.

[0135] The upper voltage threshold V1 can be defined in advance by a durability test in which the roasting operation that emits the highest level of PM (preferably beans roasted to the dark roast level) is repeated and the voltage is monitored. As the operation is repeated and the minimum value of the voltage decreases, the first insulation breakdown appears, revealing that a very high level of PM has accumulated on the plate. Since these insulation breakdowns (where PM scatters into the room or clogs the activated carbon filter downstream if there is one) are undesirable, the upper voltage threshold V1 is defined so that no insulation breakdown occurs during the operation even when this threshold is reached during the roasting operation.

[0136] Figure 5 shows the change in PM emitted and the monitored voltage during consecutive roasting operations identified as n°x to n°x + 5, where operation n°x + 1 is the first operation while the monitored voltage is below the voltage threshold V1 set at 4.5 kV.

[0137] Similar to Figure 4, curve C shows the PM emitted during the roasting operation and measured upstream of the electrostatic precipitator 2.5 and the measured values, and the voltages at the ionization lines 2221 of the upstream cell 222a and the downstream cell 222b respectively during these roasting operations are represented by curve A and curve B respectively.

[0138] Curve A shows the situation where the monitored voltage of cell 222a is below V1 during each roasting operation between roasting operation n°x and the two subsequent operations n°x + 1 and n°x + 2. During both of these operations, no insulation breakdown occurs and the filtering operation remains safe, but if a further operation occurs after roasting operation n°x + 2, it is noticed that during all subsequent roasting operations n°x + 3 to n°x + 5, the monitored voltage drops extremely to a value below V1. This means that insulation breakdowns systematically occur during the operation. Therefore, in a safe manner, the upper threshold V1 is set to a voltage higher than the first minimum voltage observed in the insulation breakdown (3.2 kV during operation n°x + 3).

[0139] Through the analysis of curve B, it can be observed that while the second downstream cell still efficiently captures PM during roasting operations n°x+1 to n°x+3, this second cell also rapidly becomes contaminated and suffers dielectric breakdown without the ability to filter smoke. Therefore, it is highly preferable to display an alarm prompting the operator to clean the electrostatic precipitator immediately after roasting operation n°x+1 is completed and the problem with the first upstream cell is detected.

[0140] Figure 6 is a magnified view of roasting operation n°6 extracted from Figure 4, showing that at time t1, the monitored voltage drops to almost zero in a very short time. The value falls below 100V, and the duration is less than 5 seconds. Such a low voltage corresponds to a false dielectric breakdown. This may be due to a brief contact established by particles between the two electrodes, and the particles being carried away by the smoke flow and disappearing almost immediately. This false dielectric breakdown does not provide any information about contamination of the electrostatic precipitator cell. Therefore, if the monitored voltage falls below the lower threshold V2, which itself falls below the upper threshold V1, no cleaning state request is displayed. The lower voltage threshold V2 can be set to approximately 100V.

[0141] By conducting experiments on roasting operations using the electrostatic precipitator and roasting apparatus systems shown in Figures 4 and 5, the value of the upper threshold V1 can be predetermined.

[0142] In addition, the lowest voltages of curves A and B gradually decrease, so as shown by the dotted line in Figure 4, V 11 >V 12 >At V1, a predetermined upper voltage threshold V 11 , V 12 By defining multiple conditions such as the above, it is also possible to progressively warn the operator by gradually triggering alarms for different cleaning state requests. For example, if the monitored voltage reaches the upper threshold V 11If the value remains above the threshold, a message may be displayed indicating that more than N1 roasting operations can be performed before cleaning is required, where N1 corresponds to 2 / 3 of the normal total number of operations possible with a cleaned cell. Then, if the monitored voltage is between the upper thresholds V12 and V11, a message may be displayed indicating that N1 to N2 roasting operations can be performed before cleaning is required, where N2 corresponds to 1 / 3 of the normal total number of operations possible with a cleaned cell.

[0143] Next, if the monitored voltage is between the upper thresholds V1 and V12, a message can be displayed indicating that fewer than N2 roasting operations can be performed before cleaning is required.

[0144] Finally, if the monitored voltage falls below the upper threshold V1, a message will be displayed indicating that cleaning must be performed before operating a new roast.

[0145] Typically, the upper threshold V1 (or optionally, predetermined voltage thresholds V11, V12, etc.) is set in the roasting system's settings menu based on these predetermined experiments. This threshold is stored in the control unit 30's memory 31. Based on this threshold, if the monitored items approach this threshold during a single roasting operation, an alarm for cleaning is displayed.

[0146] Generally, if the monitored voltage during roasting reaches the upper threshold V1, a systematic dielectric breakdown will occur in the next roasting operation, resulting in unfiltered PM. Therefore, an alarm prompts the operator to clean the electrostatic precipitator before performing a new roasting operation.

[0147] This method is particularly useful when the operator forgets to clean the electrostatic precipitator despite having already been notified through another alarm for cleaning, such as an alarm based on the number of hours of roasting operation. A new indicator prompts the operator to take action by prompting them to perform emergency cleaning before the next roasting operation. This new indicator ensures that if the operator follows the cleaning recommendation, dielectric breakdown of the electrostatic precipitator will not occur during the next operation, and the public will maintain a safe environment around the roasting system.

[0148] Preferably, during the roasting operation, the control system 3 is operable to display a cleaning state request in the following cases: During the roasting operation period Δt, if the monitored voltage falls below at least one predetermined upper voltage threshold V1 while exceeding the predetermined lower voltage threshold V2, and This occurs when the period Δt exceeds a predetermined time threshold Δt1. Preferably, this predetermined time threshold Δt1 is about 5 seconds.

[0149] In Figure 5, it can be observed that during roasting operation n°x+1, the monitored voltage of cell 222a remains below the threshold V1 for a time Δt exceeding 1 minute (in fact, the time scale in Figure 5 is such that one roasting operation lasts at least 15 minutes in Figure 5). Such low voltage over such a long period cannot be considered an isolated low value of voltage, and therefore this measured voltage is held to initiate the display of a cleaning alarm.

[0150] If this period Δt is very short, for example less than 5 seconds, this measured voltage will not be held in order to trigger the display of the cleaning alarm.

[0151] Taking the length of the period Δt into account provides a more accurate indication of the cleaning request status.

[0152] In alternative or complementary ways, the control system may operate as follows: Monitor the voltage at the ionization line and / or the voltage at the electrodes along the time of the roasting operation. Calculate the moving average of the voltage monitored throughout the roasting process. The above-calculated moving average is compared with a predetermined lower voltage threshold V1. If the moving average falls below the predetermined upper voltage threshold V1 during the roasting operation period Δt, a cleaning status request is displayed.

[0153] Calculating voltage values ​​using a moving average has the advantage of smoothing out fluctuations and eliminating outliers across many measurement points, particularly false dielectric breakdowns or abnormally low voltage values ​​(below V1) that occur over very short periods.

[0154] Although the present invention has been described with reference to the embodiments illustrated above, it will be understood that the claimed invention is by no means limited to these illustrated embodiments.

[0155] Modifications and alterations can be made without departing from the scope of the present invention as defined in the claims. Furthermore, where known equivalents exist for a particular feature, such equivalents are incorporated as specifically referred to herein.

[0156] When used herein, the terms “equipped,” “equipped,” and similar terms should not be interpreted as exclusive or exhaustive. In other words, they shall mean “including, but not limited to, ~.” [Explanation of symbols]

[0157] 1. Roasting equipment 11 Smoke outlet 12 roasting chambers 121 Upper exit 13 User Interface 2. Smoke treatment unit 21 Smoke collection device 22 Smoke Filtering Subunit 221 Activated carbon filter 222 Electrostatic precipitator Cells 222a and 222b 2221 Ionization electrode 2222 Collecting electrodes 2223 Repulsive electrode 223 PM filter 23 Smoke Driver 25 Exit 3. Control System 30 Control Units 31 memory units 32-cell current supply source 33 Power supply 34 Ionization electrode voltage sensor

Claims

1. A method for roasting coffee beans in a roasting system (10), Roasting apparatus (1), A smoke treatment unit (2) configured to process smoke generated by the roasting apparatus, wherein the smoke treatment unit comprises at least one electrostatic precipitator (222), The electrostatic precipitator comprises at least one cell (222a, 222b), The cell comprises an ionization beam (2221), a collection electrode (2222), and a repulsion electrode (2223), The cell is supplied with power to apply a high voltage to the ionization beam and at least a portion of the electrodes. It comprises a smoke treatment unit (2) and, During each roasting operation performed in the roasting apparatus, the method A step of monitoring the voltage in the ionization line and / or the voltage in the electrode along the time of the roasting operation, The steps include comparing the monitored voltage with a predetermined upper voltage threshold V1 and a predetermined lower voltage threshold V2, If, during the roasting operation period Δt, the monitored voltage falls below the predetermined upper voltage threshold V1 while exceeding the predetermined lower voltage threshold V2, a cleaning state request is displayed. Methods that include...

2. The method according to claim 1, wherein the ratio V1 / V2 is greater than 10.

3. The method according to claim 1 or 2, wherein the cleaning state request is displayed when the monitored voltage falls below at least one predetermined upper voltage threshold V1, while exceeding a predetermined lower voltage threshold V2, and the period Δt exceeds a predetermined time threshold Δt1.

4. The method according to claim 3, wherein the predetermined time threshold Δt1 is less than 10 seconds.

5. The method according to claim 1 or 2, wherein during a period Δt exceeding one of the roasting operations, if the monitored voltage falls below at least one predetermined upper voltage threshold V1 while exceeding a predetermined lower voltage threshold, the cleaning state request is displayed.

6. The method according to any one of claims 1 to 5, wherein the step of monitoring the voltage and the step of comparing the monitored voltage are performed only during a portion of the time of the roasting operation.

7. The method according to any one of claims 1 to 6, wherein the smoke treatment unit comprises a high-voltage process control board configured to control the electrostatic precipitator, and the monitored voltage is read from the process control board.

8. The method according to any one of claims 1 to 7, wherein the electrostatic precipitator comprises at least two cells (222a, 222b), the cells are arranged in a continuous line along the flow of smoke emitted by the roasting apparatus, and the method is applied to at least the first cell (222a) along the flow of smoke.

9. The method according to any one of claims 1 to 8, wherein the value of the predetermined upper voltage threshold V1 changes according to the number of roasting operations performed since the last cleaning operation of the electrostatic precipitator.

10. The method according to any one of claims 1 to 9, wherein the roasting system includes a meter configured to estimate the number of roasting operations that can still be performed before a cleaning operation of the electrostatic precipitator is required, and the value of a predetermined upper voltage threshold V1 changes according to the estimated number.

11. The method according to claim 9 or 10, wherein a corresponding type of cleaning state request can be displayed according to the value of the predetermined upper voltage threshold V1.

12. The roasting system includes a sensor configured to measure particulate matter in smoke processed by the electrostatic precipitator, and the method is A step of measuring the concentration of particulate matter during the roasting process, A step of comparing the cleaning request status with the measured concentration, A method according to any one of claims 1 to 11, including the method described in any one of claims 1 to 11.

13. A system (10) for roasting coffee beans, wherein the system is Roasting apparatus (1), A smoke treatment unit (2) configured to process smoke generated by the roasting apparatus, wherein the smoke treatment unit comprises at least one electrostatic precipitator (222), The electrostatic precipitator comprises at least one cell (222a, 222b), The cell comprises an ionization beam (2221), a collection electrode (2222), and a repulsion electrode (2223), The cell is supplied with power to apply a high voltage to the ionization beam and at least a portion of the electrodes. Smoke treatment unit, A control system (3) that is operable to control the roasting process according to the method of any one of claims 1 to 12, A system that includes these features.

14. A computer program comprising an instruction causing the system described in claim 13 to perform the method described in any one of claims 1 to 12.

15. The computer program according to claim 14, wherein the computer program is executed by the control unit (30) of the roasting apparatus and the control unit of the smoke processing unit, and both control units communicate with each other.

16. A computer-readable storage medium storing the computer program described in claim 14.

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