Method of roasting coffee beans

Abstract

The invention relates to a method of roasting coffee beans in a roasting system, said system comprising: - a roasting apparatus (1), and - a fume treatment unit (2) configured to treat fumes produced by the roasting apparatus, said fume treatment unit comprising at least one electrostatic precipitator (222) comprising at least one compartment comprising ionizing wires, a collection electrode and a repulsion electrode, and said compartment being supplied with electric power so as to apply a high voltage V to the ionizing wires, wherein during each roasting operation implemented in the roasting apparatus, the method comprises the steps of: - monitoring the voltage V at the ionizing wires and / or at the electrodes during the course of the roasting operation, - displaying a cleaning alert if, during a period of the roasting operation, the monitored voltage becomes lower than a predetermined voltage threshold V0, and - wherein said period during which the monitored voltage V is lower than said lower voltage threshold V0 is higher than a predetermined time threshold At.

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 coffee beans to the desired roast level, then cooling or quenching the heated beans to stop roasting. During heating, smoke is released. This smoke contains all the safe and desirable components, especially the common aromas of roasted coffee, but also contains less desirable and unsafe volatile organic compounds (VOCs) such as pyridine, 2-furanolol, caffeine furfural, formaldehyde, acetaldehyde… and particulate matter (PM2.5). 2.5 PM 10 )……

[0003] When roasting is carried out in manufacturing facilities that produce large quantities of roasted coffee beans, all conditions are typically provided to capture unsafe components.

[0004] However, a recent trend is to utilize small roasters for small-batch roasting in shops, restaurants, and cafes where customers can enjoy coffee brewed from freshly roasted beans. These roasters not only offer the advantages of freshness and a dramatic effect, but also distribute the pleasant aroma of roasted coffee throughout the shop or cafe.

[0005] However, as mentioned above, it also emits harmful components. When a baking machine is used in enclosed environments (such as shops, cafes, or restaurants), the emission of some components can become harmful depending on the size of the room and the room's ventilation... For people who work in the room for several hours, inhaling the fumes from a baking machine can cause health problems.

[0006] Therefore, in such an environment, it is recommended to stop emitting fumes from the baking machine to avoid any health problems for people present in the store. Existing solutions include destroying contaminants, such as afterburners or catalytic afterburners capable of thermally oxidizing contaminants, or retaining contaminants within the equipment, such as mechanical filters (metal sieves or paper filters), activated carbon filters, or electrostatic settlers, or combinations thereof.

[0007] Electrostatic precipitators capture PM particles typically ranging in size from 1.0 μm to 10 μm. The advantages of electrostatic precipitators include low purchase and operating costs and the absence of noise or heat generation during use. Because electrostatic precipitators capture contaminants that remain attached to the charged compartments of the device, the equipment must be cleaned regularly.

[0008] Cleaning warnings can be set based on the maximum number of hours the roaster can be operated or the maximum amount of coffee beans roasted. However, this alarm is not entirely accurate and may prompt the operator to clean the filter too late, resulting in insufficient filtration efficiency during the final roasting operation and compromising the safety of personnel around the roaster. Alternatively, the operator can ignore the alarm and continue roasting, as the roaster and filter system remains operational, albeit with reduced filtration efficiency.

[0009] Specifically, if cleaning operations are not performed on time, a problem unique to electrostatic precipitators is breakdown due to the presence of particles within the device. While these breakdowns may be brief, during the time they occur, the flue gas is not filtered, resulting in at least two undesirable effects:

[0010] - First, particulate matter may be emitted from the rooms of cafes, shops, or restaurants where people are present.

[0011] Secondly, some unfiltered particulate matter can clog other filters located downstream of the electrostatic precipitator, such as activated carbon filters. Therefore, VOCs are no longer filtered by these filters, increasing health problems in public indoor spaces.

[0012] Finally, the electrostatic settling device may be damaged.

[0013] These breakdowns could be due to the electrostatic precipitator reaching its particle collection limit, which occurs when the operator ignores early cleaning alarms. These failures could also be due to the abnormal presence of large particles, typically trapped upstream of the electrostatic precipitator, such as coffee bean bran, which flow abnormally within the precipitator, becoming blocked and causing breakdown. They could also be due to technical problems with the electrostatic precipitator itself. Summary of the Invention

[0014] The purpose of this invention is to solve the problems mentioned above.

[0015] Specifically, the purpose of this invention is to solve the maintenance problem of notifying the operator when a breakdown occurs and it is necessary to clean or operate the electrostatic precipitator flue gas filter, and to provide such information in an accurate manner.

[0016] It would be advantageous to distinguish between false breakdowns and faults that truly affect the filtration capacity of electrostatic precipitators.

[0017] In a first aspect of the invention, a method for roasting coffee beans in a roasting system is provided, the system comprising:

[0018] -Baking equipment, and

[0019] - A flue gas treatment unit configured to treat the flue gas generated by the baking equipment.

[0020] The flue gas treatment unit includes an electrostatic precipitator.

[0021] The electrostatic settler includes at least one compartment.

[0022] The compartment includes an electrical disconnect electrode, a collecting electrode, and a repulsive electrode, and

[0023] The compartment is supplied with electricity to apply a high voltage V to at least a portion of the electrical lines and electrodes.

[0024] During each baking operation performed in the baking equipment, the method includes the following steps:

[0025] - Monitor the voltage V at these electrical outlets and / or at these electrodes during the baking process.

[0026] - If, during the baking operation's time period Δt, the monitored voltage becomes lower than the predetermined voltage threshold V0, and

[0027] - If the time period Δt is higher than the predetermined time threshold Δt0, a cleaning alarm will be displayed.

[0028] The method involves roasting coffee beans using a system comprising two devices: a first, a roasting apparatus in which coffee beans are heated for roasting; and a second, a flue gas treatment unit configured to treat the fumes generated within the first roasting apparatus during the roasting of the coffee beans.

[0029] These two devices can be sub-components of a single main system, or alternatively, they can be considered as separate modules that work together during the baking process.

[0030] Any type of roasting equipment can be used. In the roasting equipment, the coffee beans are heated and preferably mixed to ensure that the heating of the coffee beans is uniform.

[0031] The heating source can be a burner (meaning combustion) fed by natural gas, liquefied petroleum gas (LPG), or even wood. Alternatively, the heat source can be a resistor, ceramic heater, halogen source, infrared source, or microwave source.

[0032] Preferably, the heating source is electric, so that the air pollutants generated during roasting are those produced solely by the heating of the coffee beans themselves, rather than by the combustion of gases that occur when the heating source is a gas burner using natural gas, propane, liquefied petroleum gas (LPG), or even wood.

[0033] During the roasting process, coffee beans can be mixed mechanically using a fluidized bed of hot air or by using stirring blades or a rotating drum.

[0034] Preferably, the roasting equipment is a hot air fluidized bed chamber. In such a chamber, heated air is forced with sufficient force through a screen or perforated plate beneath the coffee beans to elevate them. As the beans tumble and circulate within this fluidized bed, heat is transferred to them.

[0035] Alternatively, the roasting equipment may be a chamber in which coffee beans are tumbled in a heated environment. The chamber may consist of a cylinder that rotates along a horizontal axis, or it may include stirring blades to tumble the coffee beans in a heated environment.

[0036] The baking equipment includes an outlet from which fumes generated during the baking operation can be discharged.

[0037] Generally speaking, the flue gas treatment unit of the system includes a flue gas inlet, which is configured to cooperate with the flue gas outlet of the baking equipment and collect flue gas through the flue gas inlet.

[0038] Flue gas treatment units process flue gas to reduce or eliminate harmful pollutants contained in the flue gas, especially particulate matter such as PM1 and PM2.5. 2.5 and PM 10 .

[0039] This flue gas treatment unit includes at least one electrostatic precipitator.

[0040] An electrostatic settler is a particle collection device that filters flue gas by removing particles from the flue gas stream using electrostatic charges.

[0041] An electrostatic precipitator comprises one or more compartments. Each compartment is identical and includes:

[0042] - Off-line or corona metal wires in the upstream ionization region, and

[0043] - Collecting and repelling electrodes in the downstream collection zone. Typically, the electrodes are formed as plates. An electric field is generated through the electrodes and perpendicular to the flue gas flow. This electric field is generated by applying different voltages to the pair of electrodes or by applying a voltage to one electrode and grounding the other. Multiple pairs of spaced-apart collecting and repelling electrodes can be associated, allowing flue gas to flow in the space between the collecting and repelling electrodes.

[0044] Typically, the ionization line is supplied with electricity to apply a high voltage V. Particles in the flue gas flowing through the ionization zone are ionized, becoming either positively or negatively charged.

[0045] Then, as the flue gas flows through the downstream metal plate, the collecting electrode becomes a collector of ionized particles: charged particles are attracted to the plate and move toward it, forming a layer that remains on the plate. Thus, the discharged flue gas is cleaned from the charged particles already collected on the collecting electrode.

[0046] Electrostatic settlers can be used to capture particles that are present in sizes between 1.0 μm and 10 μm.

[0047] If the electrostatic precipitator comprises several compartments positioned sequentially in the flue gas flow, the first compartment filters most of the flue gas particles, and the second compartment filters the flue gas processed by the first compartment to achieve improved separation.

[0048] When performing a baking operation in a baking device, the method includes the following steps:

[0049] - Monitor the voltage V at these electrical outlets and / or at these electrodes during the baking process.

[0050] - If, during the baking operation's time period Δt, the monitored voltage becomes lower than the predetermined voltage threshold V0, and

[0051] - If the time period Δt is higher than the predetermined time threshold Δt0, a cleaning alarm will be displayed.

[0052] This voltage threshold V0 can be predefined such that when a baking operation is performed and the monitored voltage V falls below the lower voltage threshold for a period of time above a predetermined time threshold Δt0, this signifies an electrical breakdown. If this time period is short, the monitored low voltage is a false breakdown and must be disregarded.

[0053] Then, when, during a particular baking operation, the lower value of the monitored voltage falls below the lower limit voltage threshold V0 within a very short period of time, these values ​​are not taken into account.

[0054] Typically, a lower limit voltage threshold V0 is set considering the high voltage applied to the power line and based on experimental data as described below.

[0055] Typically, the voltage threshold V0 depends on the configuration of the electrostatic precipitator, especially the applied high voltage, and can be further determined experimentally.

[0056] Typically, this threshold is much lower than the high voltage applied to the electrical line and electrodes, preferably 10 times lower than the applied high voltage.

[0057] In a preferred embodiment, the lower limit predetermined voltage threshold V0 may be less than 100V.

[0058] Specifically, for high voltages above 5kV applied to the electrical line or electrodes, the lower limit predetermined voltage threshold V0 can be below 100V.

[0059] In one implementation, the length of the predetermined time threshold Δt0 may depend on the roasting level implemented during the roasting operation and / or the type of coffee beans roasted during the roasting operation.

[0060] In fact, it has been observed that different levels of roasting (light, medium, and dark) produce different amounts of PM for the same quantity of coffee beans. Specifically, it has been observed that dark roasting produces more emissions than light roasting.

[0061] Similarly, it has been observed that some types of coffee beans produce higher levels of PM than other types.

[0062] When roasting conditions (coffee bean level and type) produce more particles, the risk of particles temporarily clogging between electrodes and causing false breakdowns increases. To avoid these large or prolonged false breakdowns affecting the detection of conditions used to display cleanliness alarms, the predetermined time threshold Δt0 can be adjusted and increased during roasting operations at deep levels or during roasting operations of coffee bean types that produce a large amount of PM, compared to during roasting operations at light levels or during roasting operations of coffee bean types that produce less PM.

[0063] In another implementation, the length of the predetermined time threshold Δt0 may depend on the number of baking operations performed since the last cleaning operation of the electrostatic settler.

[0064] As electrostatic precipitators become increasingly dirty, the layer of particulate matter on the collecting electrodes becomes thicker, and the risk of particles temporarily blocking the electrodes and causing false breakdowns increases.

[0065] To avoid these large or prolonged false breakdowns affecting the detection of conditions used to display cleaning alarms, the predetermined time threshold Δt0 can be gradually or incrementally increased, depending on the number of baking operations performed since the last cleaning operation of the electrostatic settler.

[0066] In another implementation, the length of the predetermined time threshold Δt0 can vary with the baking operation.

[0067] It is known that PM generation is not constant during the baking process, and the peak occurs near the end of the baking process rather than at the beginning.

[0068] In a similar method as described above, in order to avoid a large number or longer false breakdowns affecting the detection of conditions used to indicate the cleanliness requirements, the predetermined time threshold Δt0 can be set longer at the end of the baking operation.

[0069] Typically, the predetermined time threshold Δt0 is about a few seconds, for example less than 10 seconds, and preferably less than 5 seconds.

[0070] Typically, the flue gas treatment unit includes a high-voltage process control panel configured to control the electrostatic precipitator and read the monitored voltage from the process control panel.

[0071] In a preferred embodiment, the electrostatic settler includes at least two compartments positioned sequentially one after another along the flue gas flow emitted by the baking machine, and the method is applied to each of these compartments.

[0072] Therefore, this method enables the detection of problematic breakdowns in each of these compartments.

[0073] Preferably, if, for both compartments, during the same time period Δt of the baking operation, the monitored voltage V is below the lower voltage threshold V0, and the time period is above the predetermined time threshold Δt0, an alarm for technical maintenance is displayed.

[0074] Preferably, the flue gas treatment unit includes at least one other filtration device besides an electrostatic precipitator. This other filtration device may include, in the following list: high-efficiency particulate filter, metal filter, activated carbon filter, paper filter, cotton, or cloth. Optionally, the flue gas treatment unit may include additional filtration devices such as a wet scrubber, catalytic converter, or afterburner.

[0075] The filter configured to capture VOCs is preferably an activated carbon filter or a charcoal filter.

[0076] Preferably, depending on the direction of the flue gas flow within the flue gas treatment unit, the flue gas filtration subunit successively includes at least one filter to remove particulate matter, followed by an electrostatic precipitator, and then an activated carbon filter. This sequence prevents the activated carbon filter from being clogged by particulate matter.

[0077] The flue gas is driven into the flue gas treatment unit and various filters by a flue gas actuator configured to circulate the flue gas from the inlet to the outlet of the flue gas treatment unit. At the outlet, since the flue gas and contaminants have been captured, the treated stream can be safely released into the atmosphere of the room.

[0078] A flue gas actuator is typically a fan that drives the flue gas to the outlet.

[0079] Preferably, the fan is positioned near the outlet of the flue gas treatment unit. Therefore, the fan is not contaminated by untreated flue gas and its maintenance is easier.

[0080] According to a preferred embodiment, the flue gas filtration subunit includes at least the following sequentially:

[0081] -Metal mesh, then

[0082] - Electrostatic settler, then

[0083] - Activated carbon filter based on the movement of flue gas flow within the flue gas treatment unit.

[0084] Preferably, in this embodiment, the activated carbon filter is physically positioned above the electrostatic precipitator. Therefore, the flue gas is introduced upwards through subsequent devices.

[0085] In a second aspect, a system for roasting coffee beans is provided, the system comprising:

[0086] -Baking equipment, and

[0087] - A flue gas treatment unit configured to treat the flue gas generated by the baking equipment.

[0088] The flue gas treatment unit includes at least one electrostatic precipitator.

[0089] The electrostatic settler includes at least one compartment.

[0090] The compartment includes an electrical disconnect electrode, a collecting electrode, and a repulsive electrode, and

[0091] The compartments are supplied with electricity to apply high voltage to at least a portion of the electrical wires and electrodes.

[0092] - A control system that is operable to control the baking process according to methods such as those described above.

[0093] Based on the integration of the baking equipment and the flue gas treatment unit, the control system can be shared between the two devices, and the steps of the method can be shared between the control units of at least these two devices.

[0094] In one implementation, the method can be executed by the control unit of the baking equipment and the control unit of the flue gas treatment unit, with the two control units communicating together. Specifically:

[0095] -The control unit of the flue gas treatment unit can perform the following steps:

[0096] Monitor voltage V,

[0097] The monitored voltage V is compared with a predetermined voltage threshold V0, and optionally the time period is compared with a predetermined time threshold Δt.

[0098] If necessary, transmit the cleaning requirement status to the baking equipment.

[0099] The control unit of the baking equipment can perform steps that display a cleaning alarm.

[0100] In another implementation scheme,

[0101] -The control unit of the flue gas treatment unit can perform the following steps:

[0102] Monitor voltage V, and

[0103] The monitored voltage V value is transmitted to the baking equipment, and

[0104] -The control unit of the baking equipment can perform the following steps:

[0105] The monitored voltage V is compared with a predetermined voltage threshold V0, and the time interval Δt is compared with a predetermined time threshold Δt0.

[0106] Display a cleaning alert if necessary.

[0107] In another implementation, the control unit of the flue gas treatment unit can perform all steps after receiving information from the baking equipment that the baking step has begun.

[0108] Preferably, the baking equipment may include a display unit to display a cleaning alarm.

[0109] Alternatively, the electrostatic settler may include a device for displaying a cleaning alarm, such as an illuminated button.

[0110] In another alternative, the control system can be configured to display cleaning alerts on mobile devices that communicate with the system.

[0111] In a third aspect, a computer program is provided, the computer program comprising instructions for causing the system described in the second aspect to perform the method described in the first aspect.

[0112] In one implementation, the computer program can be executed by the control unit of the baking equipment and the control unit of the flue gas treatment unit, with the two control units communicating together. Specifically:

[0113] -The control unit of the flue gas treatment unit can perform the following steps:

[0114] Monitor voltage V,

[0115] The monitored voltage V is compared with a predetermined voltage threshold V0, and the time interval Δt is compared with a predetermined time threshold Δt0.

[0116] If necessary, transmit the cleaning requirement status to the baking equipment.

[0117] The control unit of the baking equipment can perform steps that display a cleaning alarm.

[0118] In another implementation scheme,

[0119] -The control unit of the flue gas treatment unit can perform the following steps:

[0120] Monitor voltage V, and

[0121] The monitored voltage V value is transmitted to the baking equipment, and

[0122] -The control unit of the baking equipment can perform the following steps:

[0123] The monitored voltage V is compared with a predetermined voltage threshold V0, and the time interval Δt is compared with a predetermined time threshold Δt0.

[0124] Display a cleaning alert if necessary.

[0125] In another implementation, the control unit of the flue gas treatment unit can perform all steps after receiving information from the baking equipment that the baking step has begun.

[0126] In a fourth aspect, a computer-readable storage medium is provided having the aforementioned computer program according to the third aspect stored thereon.

[0127] The foregoing aspects of the invention can be combined in any suitable manner. Furthermore, various features herein can be combined with one or more of the foregoing aspects to provide combinations other than those specifically shown and described. Further objects and advantageous features of the invention will become apparent from the claims, detailed descriptions, and accompanying drawings. Attached Figure Description

[0128] Specific embodiments of the present invention will now be further described by way of example with reference to the following accompanying drawings:

[0129] - Figure 1 This is a view of a system according to the present invention, showing the path of flue gas through the system.

[0130] - Figure 2 It shows Figure 1 One of the compartments in the electrostatic precipitator section of the flue gas treatment unit.

[0131] - Figure 3 It shows that according to Figure 1 and Figure 2 A block diagram of the system's control system.

[0132] - Figure 4A and Figure 4B The voltage at the electrical line monitored during the baking process is described. Detailed Implementation

[0133] Systems for baking

[0134] Figure 1 A schematic diagram of a system including roasting equipment 1 and flue gas treatment unit 2 is shown. Functionally, the roasting equipment can be operated to roast coffee beans, and the flue gas treatment unit can be operated to treat the flue gas generated by the roasting equipment during roasting.

[0135] Baking equipment

[0136] The roasting equipment 1 is operable to receive and roast coffee beans within the roasting chamber 12.

[0137] Preferably, the roasting apparatus 1 includes a roasting chamber 12 into which a flow of hot air is introduced to agitate and heat the coffee beans. The hot air flow is typically generated by an airflow driver and a heater. These devices are positioned below the roasting chamber and introduce the hot air flow through the bottom of the chamber. In the accompanying drawings, the bottom of the chamber is configured to allow air to pass through; specifically, it may be a perforated plate on which coffee beans can be placed and through which air can flow upwards.

[0138] The airflow actuator can be operated to generate an upward airflow in the direction of the bottom of the container. The generated airflow is configured to heat, stir, and lift the beans. Therefore, the coffee beans are heated evenly. Specifically, the airflow actuator can be a motor-powered fan. An air inlet can be located within the base of the housing to feed air into the housing, and the airflow actuator blows this air in the direction of chamber 12.

[0139] The heater can be operated to heat the airflow generated by the airflow driver. Preferably, the heater is a resistor positioned between the fan and the perforated plate, resulting in the airflow being heated before entering chamber 12 to heat and lift the coffee beans.

[0140] Heaters and / or fans can be operated to apply a roasting profile to coffee beans, which is defined as a temperature versus time profile.

[0141] Preferably, the baking equipment includes a user interface 13, which is capable of:

[0142] - Input information about roasting (especially the amount of beans introduced into the roasting chamber and the desired roasting level) and output information about the roasting process (status, temperature, time).

[0143] and

[0144] - Preferably, the output of information concerning the flue gas treatment unit 2, particularly the output of information concerning the cleaning of the electrostatic precipitator 222.

[0145] The roasting of coffee beans generates smoke, which is driven to the top opening 121 of the roasting chamber by an airflow generated by an airflow driver. Figure 1 As shown by arrow S1 in the diagram.

[0146] Generally, the bran collector is in fluid communication with the top opening 121 of the chamber to receive the bran that gradually separates from the coffee beans during roasting and is blown into the bran collector due to its lighter density.

[0147] The remainder of the flue gas is discharged through the flue gas outlet 11 located at the top of the baking equipment.

[0148] Flue gas treatment unit

[0149] The flue gas treatment unit 2 can be operated to receive and treat the flue gas S1 emitted at the flue gas outlet 11 of the baking equipment.

[0150] First, the flue gas treatment unit 2 includes a flue gas collection device 21 suitable for collecting flue gas. The flue gas collection device 21 or collection device forms an internal void space or pipe that guides the flue gas from the outlet 11 of the baking equipment along the direction of the filter device of the flue gas filter subunit 22 (dashed lines S1, S2, S3).

[0151] The flue gas filtration subunit 22 includes components suitable for filtering small particulate matter, such as PM1 and PM2.5. 2.5 and PM 10 The electrostatic settling device 222 comprises two identical compartments 222a and 222b positioned one after another in the flue gas flow.

[0152] Figure 2 The main components of compartment 222a are shown. Compartment 222a is configured to be traversed by smoke and includes, sequentially according to the direction of smoke flow:

[0153] - Several electrical disconnections 2221, then

[0154] - Several collecting electrodes 2222 and repelling electrodes 2223, typically in the form of parallel plates, are positioned alternately at a distance of a few millimeters. These plates are oriented to create channels for generating flue gas flow.

[0155] A high voltage level (in the case of 8kV) is applied to the electrical line 2221 to generate a corona discharge that charges the flue gas particles entering the compartment.

[0156] An electric field is generated by the collecting electrode and the repulsive electrode by applying a voltage difference between them (e.g., in this case, applying 4 kV to the collecting electrode and fitting the repulsive electrode to the ground).

[0157] When charged particles flow in a channel defined by alternating collecting and repelling electrodes, these charged particles are attracted to the collecting electrode 2222 by an electric field perpendicular to the flow direction.

[0158] The cleaning operation of the electrostatic settler 222 includes removing the compartments 222a and 222b of the electrostatic settler from the flue gas filter unit and washing them with water and optionally with detergent, such as in a dishwasher.

[0159] Additionally, in the specifically illustrated embodiment, the flue gas filtration subunit 22 may include:

[0160] - Devices 223 suitable for filtering large particulate matter such as PM10, such as metal mesh and associated diffusers, which are typically metal grids located in front of (i.e., upstream of) the mesh.

[0161] - Activated carbon filter 221 suitable for removing VOCs from flue gas.

[0162] 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.

[0163] Physically, the electrostatic precipitator is positioned below the activated carbon filter to prevent particles from falling from the electrostatic precipitator onto the activated carbon filter when the electrostatic precipitator is de-energized.

[0164] The flue gas filtration subunit 22 includes a flue gas driver 23, typically a fan, for drawing contaminated flue gas from the inlet 211 of the collection device to the outlet 25 of the flue gas filtration subunit 22 (where the flue gas is safely distributed into the ambient atmosphere) through the flue gas filtration subunit 22 (where the flue gas is treated).

[0165] Control system of baking equipment and flue gas treatment unit

[0166] refer to Figure 1 , Figure 2 and Figure 3 Now consider control system 3: control system 3 can be operated to control flue gas filter unit 2, and in particular the electrostatic precipitator 222 of flue gas treatment unit.

[0167] Depending on the level of integration between baking equipment 1 and flue gas filtration unit 2, the control system can be shared between the control units of these two devices:

[0168] -If the flue gas treatment unit 2 is part of the baking equipment 1, the control unit of the baking equipment is usually the main unit, while the control unit of the filter is the slave unit.

[0169] -If the baking equipment 1 and the flue gas treatment unit 2 form two different devices (each of which has its own control unit), these control units can be configured to communicate to implement the method.

[0170] Communication can also be established between the systems of these two devices and mobile devices, especially for displaying information.

[0171] Figure 3 It shows Figure 1 The control system of the flue gas filtration unit 2.

[0172] The control system 3 typically includes, at the second level of the flue gas filtration unit 2: a processing or control unit 30, a power source 33, a memory unit 31, and a voltage sensor 34 for electrical disconnection.

[0173] The control unit 30 is configured to output feedback to the user interface 13 of the baking equipment, specifically displaying the cleaning requirement status of the electrostatic precipitator. In an alternative configuration, some processing units 2 may include their own user interface to display this status, such as an illuminated button that can be lit according to the status.

[0174] The control unit 30 can also display information about the following to the user interface 13:

[0175] - Cleaning instructions;

[0176] - Reset the alarm status.

[0177] The hardware of the user interface may include any suitable device, such as one or more of the following: buttons (such as joystick buttons, knobs, or push buttons), joysticks, LEDs, graphic or character LDCs, touch-sensitive graphical screens, and / or screen edge buttons. The user interface 20 may be formed as a single unit or multiple discrete units.

[0178] When the device is equipped with the communication interface 32 as described below, a portion of the user interface can also be located on the mobile application. In this case, at least a portion of the input and output can be transmitted to the mobile device via the communication interface 32.

[0179] Control unit 30 typically includes memory, input, and output system components arranged as integrated circuits (typically microprocessors or microcontrollers). Control unit 30 may include other suitable integrated circuits, such as ASICs, programmable logic devices (such as PALs, CPLDs, FPGAs, PSoCs), system-on-a-chip (SoCs), and analog integrated circuits (such as controllers). For such devices, the aforementioned program code can be considered programming logic or may additionally include programming logic, where appropriate. Control unit 30 may also include one or more of the aforementioned integrated circuits. An example of the latter is several integrated circuits arranged in a modular manner that communicate with each other, for example: a slave integrated circuit for controlling the flue gas treatment unit 2 communicates with a master integrated circuit for controlling the baking equipment 1, and a slave integrated circuit for controlling the user interface 13 communicates with the master integrated circuit for controlling the baking equipment 1.

[0180] The power source 33 can be operated to supply electrical energy to the controlled components and control unit 30. The power source 33 may include various devices, such as batteries or units for receiving and regulating mains power.

[0181] The control unit 30 typically includes a memory unit 31 for storing instructions as program code and optionally data. For this purpose, the memory unit typically includes: non-volatile memory, such as EPROM, EEPROM, or flash memory, for storing program code and operating parameters as instructions, and volatile memory (RAM) for temporary data storage. The memory unit may include separate and / or integrated (e.g., on a semiconductor die) memory. For programmable logic devices, instructions may be stored as programming logic.

[0182] The instructions stored in memory unit 31 can be idealized as a program that includes determining breakdown alarms and cleaning or maintenance requirements.

[0183] The control unit 30 is configured to output the value of the voltage V at the electrical line 2221, as measured by the sensor 34. In a preferred embodiment, the voltage can be read directly from the high-voltage PCB of the electrostatic precipitator.

[0184] During the baking process, control system 3 can operate as follows:

[0185] - Monitor the voltage V at power line 2221 during the baking process.

[0186] - If, during the baking operation period, the monitored voltage falls below the predetermined voltage threshold V0, and

[0187] - If the time period Δt is higher than the predetermined time threshold Δt0, a cleaning alarm will be displayed.

[0188] Figure 4A , Figure 4BThe diagram illustrates the evolution of monitored voltages in two compartments of an electrostatic precipitator during a portion of the baking operation. Curve A shows the evolution of the monitored voltage in the first compartment, and curve B shows the evolution of the monitored voltage in the second compartment. The voltage applied to the compartments is typically 8 kV. The predetermined threshold V0 is 100 V. The predetermined time threshold Δt0 is equal to 5 seconds.

[0189] exist Figure 4A During the exemplary portion of the baking operation, it was observed that during a time period Δt1 greater than Δt0, the voltage monitored in the first compartment became below 100V, thus triggering a cleaning alarm at this moment in the baking operation or at the end of the baking operation. Breakdown occurred during the period Δt1, and the flue gas was not filtered by the first compartment during this time.

[0190] Similarly, during another time period Δt2, which is greater than Δt0, the voltage monitored in the second compartment became below 100V, confirming that a cleaning alarm was displayed at this moment in the baking operation or at the end of the baking operation.

[0191] exist Figure 4B During the time period Δt1, which is greater than Δt0, the voltage monitored in the first compartment drops below 100V, thus triggering a cleaning alarm. Additionally, during time periods Δt1 and Δt2, the voltage monitored in both compartments drops below 100V; both of these time periods are greater than Δt0 and overlap. During the overlapping time periods, neither compartment is able to filter the flue gas, which can lead to harmful problems. New baking operations are not recommended, and it is preferable to check the operational status of the compartments. Therefore, a maintenance alarm is displayed at this point in the baking operation or at the end of the baking operation.

[0192] Although the invention has been described with reference to the embodiments shown above, it should be understood that the invention protected by the claims is not limited in any way to the embodiments shown.

[0193] Various changes and modifications may be made without departing from the scope of the invention as defined in the claims. Furthermore, if known equivalents exist for a particular feature, such equivalents should be incorporated as expressly mentioned in this specification.

[0194] As used in this specification, the words “including,” “contains,” and similar terms should not be construed as having an exclusive or exhaustive meaning. In other words, these terms are intended to mean “including but not limited to.”

[0195] The index list in the attached figure:

[0196] Baking equipment 1

[0197] Flue gas outlet 11

[0198] Baking Room 12

[0199] Top Exit 121

[0200] User Interface 13

[0201] Flue gas treatment unit 2

[0202] Flue gas collection device 21

[0203] Flue gas filter subunit 22

[0204] Activated carbon filter 221

[0205] Electrostatic settler 222

[0206] Compartments 222a, 222b

[0207] Electricity disconnection 2221

[0208] Collection electrode 2222

[0209] Repulsive electrode 2223

[0210] PM filter 223

[0211] Smoke drive 23

[0212] Exports 25

[0213] Control System 3

[0214] Control Unit 30

[0215] Memory unit 31

[0216] 32 compartment current source

[0217] Power source 33

[0218] Voltage sensor 34

Claims

1. A method for roasting coffee beans in a roasting system (10), said system comprising: -Baking equipment (1), and - A flue gas treatment unit (2), configured to treat the flue gas generated by the baking equipment, the flue gas treatment unit including at least one electrostatic precipitator (222). The electrostatic precipitator includes at least one compartment (222a, 222b), and The compartment includes an electrical disconnect electrode (2221), a collecting electrode (2222), and a repulsive electrode (2223), and The compartment is supplied with electricity to apply a high voltage to at least a portion of the electrical disconnect and the electrodes. During each baking operation performed in the baking equipment, the method includes the following steps: - Monitor the voltage V at the offline point and / or the electrode during the baking operation. - If, during the baking operation's time period Δt, the monitored voltage becomes lower than a predetermined voltage threshold V0, and - If the time period Δt is higher than the predetermined time threshold Δt0, a cleaning alarm is displayed.

2. The method according to claim 1, wherein the predetermined voltage threshold V0 is less than 100V.

3. The method according to claim 1 or 2, wherein the length of the predetermined time threshold Δt0 depends on the roasting level implemented during the roasting operation and / or the type of coffee beans roasted during the roasting operation.

4. The method according to claim 1 or 2, wherein the length of the predetermined time threshold Δt0 depends on the number of baking operations performed since the last cleaning operation of the electrostatic settler.

5. The method according to claim 1 or 2, wherein the length of the predetermined time threshold Δt0 varies with the baking operation.

6. The method according to claim 1 or 2, wherein the predetermined time threshold Δt0 is a few seconds.

7. The method of claim 1 or 2, wherein the flue gas treatment unit includes a high-voltage process control panel configured to control the electrostatic precipitator, and wherein the monitored voltage is read from the process control panel.

8. The method according to claim 1 or 2, wherein the electrostatic settler comprises at least two compartments (222a, 222b) sequentially positioned along the flue gas flow emitted by the baking machine, and wherein the method is applied to each compartment.

9. The method of claim 8, wherein if, for both compartments, during the same time period of the baking operation, the monitored voltage V at the offline point is below a lower voltage threshold V0, and the time period is above the predetermined time threshold Δt0, an alarm for technical maintenance is displayed.

10. The method according to claim 6, wherein, The predetermined time threshold Δt0 is less than 10 seconds.

11. The method according to claim 10, wherein, The predetermined time threshold Δt0 is less than 5 seconds.

12. A system for roasting coffee beans, the system comprising: -Baking equipment (1), and - A flue gas treatment unit (2), configured to treat the flue gas generated by the baking equipment, the flue gas treatment unit including at least one electrostatic precipitator (222). The electrostatic precipitator includes at least one compartment (222a, 222b), and The compartment includes an electrical disconnect electrode (2221), a collecting electrode (2222), and a repulsive electrode (2223), and The compartments are supplied with electricity to apply high voltage to at least a portion of the electrical wires and electrodes. - Control system (3), which is operable to control the baking process according to any one of claims 1 to 9.

13. A computer program product comprising instructions for causing the system of claim 12 to perform the method of any one of claims 1 to 11.

14. The computer program product according to claim 13, wherein the instructions are executed by the control unit (30) of the baking equipment and the control unit of the flue gas treatment unit, and the two control units communicate together.

15. A computer-readable storage medium having a computer program product according to claim 13 stored thereon.

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