METHOD AND DEVICE FOR CONTINUOUS MONITORING AND IMPROVED AUTOMATIC CONTROL OF TEMPERATURE, AND OF AERATION-OXYGENATION, OF THE PROCESS OF ALCOHOLIC FERMENTATION IN WINE BY MEANS OF ACOUSTIC EMISSION TECHNIQUES

Abstract

The present invention relates to a device for continuous monitoring and improved automatic control of temperature, and of aeration-oxygenation, of the process of alcoholic fermentation in wine by means of acoustic emission techniques (D1), of the type of devices that incorporate means for tracking and controlling alcoholic fermentation in a self-emptying fermentation tank (0), and that mainly consists of: a. an instrumentation subsystem (1); b. an acoustic emission instrumentation subsystem (2); c. a gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2 or O.sub.2 (3); d. a control subsystem (4); and a method (P1) that uses the system (D1).

Claims

1. Device for continuous monitoring and improved automatic control of temperature, and of aeration-oxygenation, of the process of alcoholic fermentation in wine by means of acoustic emission techniques (D1), of the type of devices that incorporate means for tracking and controlling alcoholic fermentation in a self-emptying fermentation tank (0), and that is characterized in that the means for tracking and controlling comprise: a. an instrumentation subsystem (1) which, by means of a plurality of sensors, measures and calculates a series of parameters in the fermentation must, containing: a set of sensors arranged in the self-emptying fermentation tank (0) in the torispherical head, these sensors being: a torispherical head pressure sensor (10) that measures the pressure (P) of CO.sub.2 or other gases: air or N.sub.2, and it is combined with sensors (13, 15) to eliminate calculation error of the density (D) of the fermentation must; a torispherical head temperature sensor (11) that measures the temperature (T) of CO.sub.2 or other gases: air or N.sub.2; a torispherical head flowmeter sensor (12) that measures the flow rate (F) of suctioned CO.sub.2 or of other gases: injected air or N.sub.2. a set of sensors arranged in the self-emptying fermentation tank (0) in the upper cylindrical body, these sensors being: an upper cylindrical body pressure sensor (13) that measures the pressure (P) in the liquid phase of the fermentation must below the area of the cap combined with the sensor (15) and, by eliminating error by means of the sensor (10), the density (D) of the must and the level of the free surface are calculated; an upper cylindrical body temperature sensor (14) that measures the temperature (T) in the fermentation must below the area of the cap. a set of sensors arranged in the self-emptying fermentation tank (0) in the lower cylindrical body, these sensors being: a lower cylindrical body pressure sensor (15) that measures the pressure (P) in the liquid phase of the fermentation must above the area of solids sunken to the bottom combined with the sensor (13) and, by eliminating error by means of the sensor (10), the density (D) of the must and the level of the free surface are calculated; a lower cylindrical body temperature sensor (16) that measures the temperature (T) in the liquid phase of the fermentation must above the area of solids sunken to the bottom; an aeration or oxygenation flowmeter sensor (18) that measures the flow rate (F) of injected air or O.sub.2. a CO.sub.2 or N.sub.2 injection flowmeter sensor (17) that measures the flow rate (F) of injected CO.sub.2 or N.sub.2, arranged in the self-emptying fermentation tank (0) in the toriconical end. b. an acoustic emission instrumentation subsystem (2) that measures the acoustic emission caused by the CO.sub.2 generated during respiration and alcoholic fermentation in the fermentation must, containing: an omnidirectional-type hydrophone sensor (20) that measures the acoustic emission (A) produced within the fermentation must; an analog signal conditioner (21) that pre-amplifies (AS) the voltage of the hydrophone (20). c. a gas processing and storage subsystem for the gases of air, CO.sub.2 N.sub.2 or O.sub.2 (3) which, by means of a plurality of devices and actuators, interacts in the fermentation must, containing in a preferred embodiment an inerting control valve (32), a valve located in the upper part of the tank in the dome element (010) which allows the action of pressurizing the tank (0), incompatible with the vent valve (011), so valve (32) replaces valve (011); and which is supplied from the CO.sub.2 tank (0) by means of a suction pipe (33), controlled by an outlet or injection valve (31), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, the function of which is to allow capturing of CO.sub.2 or injecting same or other gases: air or N.sub.2; and which, by means of a delivery pipe (34) through which pressurized CO.sub.2 or other gases: air or N.sub.2, are conducted, controlled by an injection control valve (35), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing the entry of CO.sub.2 or other gases: air or N.sub.2 to the CO.sub.2 injection collector (36), a pipe external to the tank (0) which connects all the CO.sub.2 injection elements with the inlet valve (35); and which, by means of an aeration or oxygenation control valve (111), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing CO.sub.2 or air injection into the tank (0); and which, by means of a cooling control valve (113), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing or preventing the passage of liquid coolant to the jackets (05) of the fermentation tank (0). the subsystem (3) further contains a plurality of valves, these valves being: a selector valve for the capturing of CO.sub.2 or air (310), a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4), and having the function of selecting the capturing of CO.sub.2 or air; a selector valve for the delivery of CO.sub.2 or air (311), a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4), and having the function of selecting the delivery of CO.sub.2 or air; a selector valve for the delivery of air (312), a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4), and having the function of selecting the delivery of air; a selector valve for the delivery of air or O.sub.2 (313), a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4), and having the function of selecting the delivery of air or O.sub.2; the subsystem (3) further contains a plurality of tanks, these tanks being: trap filter tank (314) which prevents the entry of condensate into the compressors, protecting them from said condensate; pressurized CO.sub.2 or N.sub.2 tank (316), which is a pressurized buffer tank with a design pressure of 10 bar; pressurized air tank (317), which is a pressurized buffer tank with a design pressure of 10 bar; pressurized N.sub.2 tank (319), which is a pressurized buffer tank with a design pressure of 10 bar; compressed O.sub.2 cylinder (320). the subsystem (3) further comprises a compressor (315) with a design pressure of 10 bar, suitable for the food industry, and an N.sub.2 generator (318) which is an N.sub.2 generator for inerting the fermentation tank (0). d. a control subsystem (4), containing: a main control panel (40), containing a programmable logic controller (PLC) (401) which incorporates means for communicating with a human machine interface (HMI) device (402); a slave panel (41), which incorporates decentralized periphery modules that collect input signals of the instrumentation subsystems for sending data to the panel (40) by means of a single communications bus; a secondary panel (42), which incorporates solenoid valve modules that collect control data of the panel (40) by means of a single communications bus in order to act on the valves of the instrumentation subsystems.

2. Device according to claim 1, characterized by the fact that the omnidirectional-type hydrophone sensor (20) has a range of 1 Hz to 140 kHZ, of horizontal positioning and ?2 dB omnidirectional type with an operating temperature range of ?2? C. to +80? C., of the type that is submersible and resistant to wine must and acetic acid, and is arranged submerged in the fermentation must contained in the self-emptying fermentation tank (0).

3. Method for continuous monitoring and improved automatic control of temperature, and of aeration-oxygenation, of the process of alcoholic fermentation in wine by means of acoustic emission techniques (P1) by means of using a system (D1) for the implementation thereof, of the type of methods which interact with means for tracking and controlling alcoholic fermentation in a self-emptying fermentation tank (0), comprising a method module implemented in a PLC program (P0), installed in a PLC (401) which incorporates means for communicating with an HMI device (402), wherein if the hardware (HW) of the PLC (401) is correct (OK), a start block is cyclically executed which, by means of the interaction of a user in the HMI (402), only calls one of the selected steps a-f but with the user being able to activate steps g, h, i simultaneously, characterized in that the method module implemented in the PLC program (P0) for the purpose of interacting with the means for tracking and controlling comprises at least the following steps: STEP a (P10): Providing, in a controlled manner, by means of acoustic emission techniques, a fermentation tank (0, D1) with a gas mixture (air+CO.sub.2), allowing yeasts to perform respiration exclusively when the passage of air to the fermentation tank (0, D1) is allowed or prevented to perform aeration by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35), in this step a (P10), the naturally present or artificially inoculated yeast performs, by means of the supply of gas (air and CO.sub.2), respiration controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented. In this optional step a (P10), the probable alcoholic strength of the wine is reduced, causing the yeast to perform respiration by providing it with the required air (of which the yeast will use oxygen), such that a part of the sugars in the must undergoes respiration instead of fermentation, subsequently, the air supply must be stopped in order to continue with the conventional process of fermentation, since an excess presence of oxygen causes a reduced quality of the wine. The CO.sub.2 (gas) generated during respiration remains in dissolution until it is released once the fermentation must (liquid) becomes saturated, whereas the water (liquid) remains in dissolution (three times as much CO.sub.2 is produced in respiration compared to fermentation), the CO.sub.2 is suctioned for subsequent injection into the fermentation must for the purpose of achieving homogenization, avoiding the performance of pumping over, STEP a (P10) of respiration with air comprises at least the following sub-steps: injecting air in the fermentation tank (0, D1) (P11); suctioning CO.sub.2+injecting air in the fermentation tank (0, D1) (P12); suctioning CO.sub.2+injecting air and CO.sub.2 in the fermentation tank (0, D1) (P13), the following can be selected simultaneously along with STEP a (P10): STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques; STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques, STEP b (P20): providing, in a controlled manner, by means of acoustic emission techniques, a fermentation tank (0, D1) with a gas mixture (O.sub.2+CO.sub.2), allowing yeasts to perform respiration exclusively, the passage of O.sub.2 to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35), in this STEP b (P20), the naturally present or artificially inoculated yeast performs, by means of the supply of gas (O.sub.2 and CO.sub.2), respiration controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented, STEP b is similar to STEP a but with the difference that a gas mixture containing O.sub.2 instead of air is provided, STEP b (P20) of respiration with O.sub.2 comprises at least the following sub-steps: injecting O.sub.2 in the fermentation tank (0, D1) (P21); suctioning CO.sub.2+injecting O.sub.2 in the fermentation tank (0, D1) (P22); suctioning CO.sub.2+injecting O.sub.2 and CO.sub.2 in the fermentation tank (0, D1) (P23), the following can be selected simultaneously along with STEP b (P20): STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques; STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques, STEP c (P30): providing a fermentation tank (0, D1) with a gas mixture (CO.sub.2+air), allowing yeasts to perform combined alcoholic fermentation and respiration monitored and controlled by means of acoustic emission techniques, the passage of air to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35). In this STEP c (P30), the naturally present or artificially inoculated yeast performs, by means of the supply of gas (CO.sub.2 and air), alcoholic fermentation monitored and controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented, the CO.sub.2 (gas) generated during alcoholic fermentation remains in dissolution until it is released once the fermentation must (liquid) becomes saturated, whereas ethanol (liquid) remains in dissolution, although a small fraction of ethanol is lost through evaporation, The CO.sub.2 is suctioned for subsequent injection in the fermentation must for the purpose of achieving homogenization, avoiding the performance of pumping over, The aeration in this STEP c allows the yeast to also perform respiration for the purpose of facilitating its growth and reproduction by providing it with the required air (of which the yeast will use oxygen), such that a part of the sugars in the must undergoes respiration instead of fermentation, STEP c differs from STEP a in that in STEP a respiration is performed continuously for some time, whereas in this STEP c respiration can be performed discontinuously or continuously together with fermentation, producing wines with more color that is fixed by the oxygen from aeration, in addition to achieving a greater disassociation of tannins and anthocyanins, STEP c (P30) of alcoholic fermentation plus aeration is characterized in that it comprises at least the following sub-steps: injecting air in the fermentation tank (0, D1) (P11); suctioning CO.sub.2+injecting air in the fermentation tank (0, D1) (P12); suctioning CO.sub.2+injecting air and CO.sub.2 in the fermentation tank (0, D1) (P13); suctioning CO.sub.2+injecting CO.sub.2 in the fermentation tank (0, D1) (P31); suctioning CO.sub.2 in the fermentation tank (0, D1) (P32), the following can be selected simultaneously along with STEP c (P30): STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques; STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques, STEP d (P40): providing a fermentation tank (0, D1) with a gas mixture (CO.sub.2+O.sub.2), allowing yeasts to perform combined alcoholic fermentation and respiration monitored and controlled by means of acoustic emission techniques, the passage of O.sub.2 to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35). In this STEP d (P40), the naturally present or artificially inoculated yeast mainly performs, by means of the supply of gas (CO.sub.2 and O.sub.2), alcoholic fermentation monitored and controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented. STEP d is similar to STEP c but with the difference that a gas mixture containing O.sub.2 instead of air is provided. The oxygenation of this STEP d allows the yeast to also perform respiration for the purpose of facilitating its growth and reproduction by providing it with the required oxygen, such that a part of the sugars in the must undergoes respiration instead of fermentation. STEP d differs from STEP b in that in STEP b respiration is performed continuously for some time, whereas in this STEP d respiration can be performed discontinuously or continuously together with fermentation, producing, like in the preceding step, wines with more color that is fixed by the oxygen from oxygenation, in addition to achieving a greater disassociation of tannins and anthocyanins. STEP d (P40) of alcoholic fermentation plus oxygenation is characterized in that it comprises at least the following sub-steps: injecting O.sub.2 in the fermentation tank (0, D1) (P13); suctioning CO.sub.2+injecting O.sub.2 in the fermentation tank (0, D1) (P22); suctioning CO.sub.2+injecting O.sub.2 and CO.sub.2 in the fermentation tank (0, D1); suctioning CO.sub.2+injecting CO.sub.2 in the fermentation tank (0, D1) (P31); suctioning CO.sub.2 in the fermentation tank (0, D1) (P32). the following can be selected simultaneously along with STEP d (P40): STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques; STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques. STEP g (P70): monitoring and controlling the temperature in a fermentation tank (0, D1) by means of acoustic emission techniques. since alcoholic fermentation is an exothermic reaction, the heat generated during the process of fermentation must be removed in order to maintain the optimal temperature. To that end, a cooling system of any of the state of the art is used which, by means of a cooling control valve (113), allows or prevents the passage of the liquid coolant to the jackets (05) of the fermentation tank (0, D1). The acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation is measured and the acoustic emission speed (dACO.sub.2/dt) is calculated for the early detection of the fermentation speed (g of CO.sub.2/l/h) (amount, by weight or by volume, of CO.sub.2 produced per unit of time), and therefore the activity of the yeasts. The analog signal of the omnidirectional hydrophone sensor (20) is collected in the slave panel (41), being sent to the main control panel (40) and reaching the programmable logic controller (401) where it is internally converted to a digitalized signal, first being processed in a calibration module (P101) of the program (P0) to obtain the basic amplitude, frequency, and spectral descriptors thereof by applying fast Fourier transform (FFT); with the correct frequency range, the digitalized signal passes to the filtration module (P102) where a digital filter is applied to the signal to discriminate frequencies not related with the process of fermentation, finally obtaining the real-time value of the acoustic emission (ACO.sub.2). when the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, exceeds a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the cooling control valve (113) is opened to keep the temperature within compatible winemaking limits to stabilize alcoholic fermentation, according to the following simple conditional logic equation: $\mathrm{If}113=0\mathrm{AND}T?\left(T_{\mathrm{setpoint}}+?T\right)O$ $\left(T_{\mathrm{setpoint}}-?T\right)<T<\left(T_{\mathrm{setpoint}}+?T\right)$ $\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}+?\left({A\mathrm{CO}}_2\right)\right)\right)$ $\mathrm{then}\left\{113=1\right\}$ when the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, is below a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the cooling control valve (113) is closed allowing the temperature to rise to within compatible winemaking limits in order to reactivate alcoholic fermentation, according to the following simple conditional logic equation: $\mathrm{If}113=1\mathrm{AND}T?\left(T_{\mathrm{setpoint}}-?T\right)O$ $\left(T_{\mathrm{setpoint}}-?T\right)<T<\left(T_{\mathrm{setpoint}}+?T\right)$ $\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}-?\left({A\mathrm{CO}}_2\right)\right)\right)$ $\mathrm{then}\left\{113=0\right\}$ STEP h (P80): monitoring and controlling the aeration or oxygenation of a fermentation tank (0, D1) by means of acoustic emission techniques. the passage of air or oxygen to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111). The acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation is measured and the acoustic emission speed (dACO.sub.2/dt) is calculated for the early detection of the fermentation speed (g of CO.sub.2/l/h), and therefore the activity of the yeasts. The analog signal of the omnidirectional hydrophone sensor (20) is collected in the slave panel (41), being sent to the main control panel (40) and reaching the programmable logic controller (401) where it is internally converted to a digitalized signal, first being processed in a calibration module (P101) of the program (P0) to obtain the basic amplitude, frequency, and spectral descriptors thereof by applying fast Fourier transform (FFT); with the correct frequency range, the digitalized signal passes to the filtration module (P102) where a digital filter is applied to the signal to discriminate frequencies not related with the process of fermentation, finally obtaining the real-time value of the acoustic emission (ACO.sub.2), when the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, is below a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the aeration or oxygenation control valve (111) is opened in order to reactivate the activity of the yeasts, according to the following simple conditional logic equation: $\mathrm{If}111=0\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}-?\left({A\mathrm{CO}}_2\right)\right)\right)$ $\mathrm{then}\left\{111=1\right\}$ when the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, exceeds a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the aeration or oxygenation control valve (111) is closed in order to deactivate the excessive activity of the yeasts, according to the following simple conditional logic equation: $\mathrm{If}111=1\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}+?\left({A\mathrm{CO}}_2\right)\right)\right)$ $\mathrm{then}\left\{111=0\right\}$

4. Method according to claim 3, characterized by the fact that noise from aeration, oxygenation, CO.sub.2 injection, cooling water recirculation through the jackets, and any other desired noise is eliminated to obtain the acoustic emission (ACO.sub.2); to that end, before the start of alcoholic fermentation the acoustic emission of aeration (AAera), of oxygenation (AO.sub.2), of CO.sub.2 injection (AICO.sub.2), of cooling (AR), and of any other desired noise (AO) is recorded; then, noise is eliminated from the acoustic emission measured in the fermentation must (AMF) by means of the following equation:
ACO.sub.2=AM?AAera?AG.sub.2?AICO.sub.2?AR?AO since the PLC program (P0), installed in the PLC (401), has at all times the state of the aeration, oxygenation, CO.sub.2 injection, and cooling sub-steps so that in the case where one or more of them are activated, the corresponding noise from the active sub-steps can be subtracted by means of the preceding equation; that which is indicated above is performed if a noise emitting source is detected for the purpose of obtaining only the acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation.

5. The method according to claim 3, characterized by the fact that the maximum aeration conditions which maintain the level of dissolved oxygen close to zero from the start and the levels of acetic acid at the end of the process at 0.3 g/l are: Airflow (l/h)=5-volume (l) of fermentation must; Time (h)=48, counted in a continuous regimen or accumulated in a discontinuous regimen.

6. Method according to claim 3, characterized by the fact that the maximum oxygenation conditions which maintain the level of dissolved oxygen close to zero from the start and the levels of acetic acid at the end of the process at 0.3 g/l are: Oxygen flow (l/h)=l.Math.volume (l) of fermentation must; Time (h)=48, counted in a continuous regimen or accumulated in a discontinuous regimen.

7. Method according to claim 3, characterized by the fact that the calculation error of the density (D) of the fermentation must is obtained from measurements given by the pressure sensor (10) combined with the pressure sensors (13, 15) by means of an initial calibration before starting alcoholic fermentation which consists of performing a first measurement by means of the three pressure sensors (13, 15, and 10) when there is still no CO.sub.2 dissolved in the fermentation must, an error-free measurement, and a second measurement by injecting CO.sub.2, opening the injection control valve (35) of the gas processing and storage subsystem (3) until the pressure sensor (10) indicates the same CO.sub.2 pressure as the working pressure marked by the inerting control valve (32), a measurement with error; the error produced in the pressure sensors (13, 15) for said CO.sub.2 pressure is obtained with both measurements, subtracting the value of the measurement with error from the error-free measurement.

Description

[0215] FIG. 1 shows a 3D computer graphic of a fermentation tank (0), any one from the prior art, which incorporates a device for continuous monitoring and improved automatic control of temperature of the process of alcoholic fermentation in wine by means of acoustic emission techniques (D1), object of the invention, in which the implementation of the subsystems (1, 2, 3, and 4) comprised in same can be observed.

[0216] FIG. 2 shows an elevational view of a self-emptying fermentation tank (0), any one from the prior art; in which the elements comprised in same can be observed.

[0217] FIG. 3 shows a schematic view of the instrumentation subsystem (1) of the device (D1), object of the invention; in which the elements comprised in same can be observed.

[0218] FIG. 4 shows a schematic view of the acoustic emission instrumentation subsystem (2) of the device (D1), object of the invention; in which the elements comprised in same can be observed.

[0219] FIG. 5 shows an elevational view of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1), object of the invention; in which the interconnecting elements with a self-emptying fermentation tank (0) can be observed.

[0220] FIG. 6 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: REFILLING AIR TANK (317).

[0221] FIG. 7 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: REFILLING N.sub.2 TANK (318).

[0222] FIG. 8 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: INJECTING AIR IN THE FERMENTATION TANK (0, D1).

[0223] FIG. 9 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2+INJECTING AIR IN THE FERMENTATION TANK (0, D1).

[0224] FIG. 10 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2+INJECTING AIR and CO.sub.2 IN THE FERMENTATION TANK (0, D1).

[0225] FIG. 11 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2+INJECTING CO.sub.2 IN FERMENTATION TANK (0, D1).

[0226] FIG. 12 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2 IN THE FERMENTATION TANK (0, D1).

[0227] FIG. 13 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: INJECTING O.sub.2 IN THE FERMENTATION TANK (0, D1).

[0228] FIG. 14 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2+INJECTING O.sub.2 IN THE FERMENTATION TANK (0, D1).

[0229] FIG. 15 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: SUCTIONING CO.sub.2+INJECTING O.sub.2 and CO.sub.2 IN THE FERMENTATION TANK (0, D1).

[0230] FIG. 16 shows a P&ID diagram of the gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2, or O.sub.2 (3) of the device (D1) in the operating mode: INERTING BY MEANS OF N.sub.2 IN THE FERMENTATION TANK (0, D1).

[0231] FIG. 17 shows a GRAFCET diagram with the start block, which is cyclically executed, implemented in a PLC program (P0), installed in a PLC (401).

[0232] FIG. 18 shows a GRAFCET diagram with STEP a.0 of refilling the air tank (317) (P100) and STEP a of respiration with air (P10), implemented in a PLC program (P0), installed in a PLC (401).

[0233] FIG. 19 shows a GRAFCET diagram with STEP b of respiration with O.sub.2 (P20), implemented in a PLC program (P0), installed in a PLC (401).

[0234] FIG. 20 shows a GRAFCET diagram with STEP a.0 of refilling the air tank (317) (P100) and STEP c of alcoholic fermentation plus aeration (P30), implemented in a PLC program (P0), installed in a PLC (401).

[0235] FIG. 21 shows a GRAFCET diagram with STEP d of alcoholic fermentation plus oxygenation (P40), implemented in a PLC program (P0), installed in a PLC (401).

[0236] FIG. 22 shows a GRAFCET diagram with STEP g of optimized control of temperature (P70), implemented in a PLC program (P0), installed in a PLC (401).

[0237] FIG. 23 shows a GRAFCET diagram with STEP h of optimized control of aeration or oxygenation (P80), implemented in a PLC program (P0), installed in a PLC (401).

DETAILED DESCRIPTION OF THE INVENTION AND DETAILED DISCLOSURE OF A PREFERRED EMBODIMENT OF THE INVENTION

[0238] A preferred embodiment of the invention, from among different possible alternatives, is described in detail by means of listing the components of the embodiment, as well as their functional relationship based on references to the figures, which have been included, in an illustrative and non-limiting manner, according to the principles of the claims. Reference is made to the figures, where necessary, in order to better understand what is shown therein.

[0239] Once the bunches of grape are destemmed (with the stem removed), the dense must (pulp or mesocarp, seeds, skins, and bloom) coming from the red grape, although it can also be ros? or even white, is sent to the self-emptying fermentation tank (0) provided with a device for continuous monitoring and improved automatic control of temperature, and of aeration-oxygenation, of the process of alcoholic fermentation in wine by means of acoustic emission techniques (D1), in order to proceed with alcoholic fermentation.

[0240] The invention proposes, with respect to and controls of temperature of AF, of aeration or oxygenation known in the state of the art, measuring the acoustic emission of CO.sub.2 in dissolution and in a released CO.sub.2 flow which allows knowing at an early time the evolution of fermentation kinetics (speed) as it is proportional to the CO.sub.2 generation speed, implementing an optimal control of temperature, aeration or oxygenation by means of acoustic emission techniques which have been found to achieve, for a maximum generated CO.sub.2 speed of 0.81 g of CO.sub.2/l/h, a reduction of 16.25%*(3.25% per degree of hysteresis) in the duration of fermentation with respect to the mean of isothermal controls of temperature in red wine (22? C.-26? C.), simultaneously obtaining an increase in wine quality of 5-10%* in the total polyphenol index (TPI) which causes a qualitative leap in terms of organoleptic parameters (proven in tasting sessions by means of sensory analysis).

[0241] (*) Results obtained by UNIVERSIDAD DE LA RIOJA during the 2018 and 2019 grape harvests. A campaign of in situ measurements in the must obtained in six conventional red wine fermentation tanks and in six tanks with the system claimed in the present invention was carried out in each grape harvest.

[0242] Therefore, the invention seeks to perform continuous tracking of alcoholic fermentation in wine by means of acoustic emission techniques using the following subsystems comprised in the invention: an instrumentation subsystem (1); an acoustic emission instrumentation subsystem (2); a gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2 or O.sub.2 (3); anda control subsystem (4).

[0243] The invention proposes a device for continuous monitoring and improved automatic control of temperature of the process of alcoholic fermentation in wine by means of acoustic emission techniques (D1), of the type of devices that incorporate means for tracking and controlling alcoholic fermentation in a self-emptying fermentation tank (0), and is characterized in that the means for tracking and controlling comprise: [0244] a. an instrumentation subsystem (1) (FIG. 03) which, by means of a plurality of sensors, measures and calculates a series of parameters in the fermentation must, containing in a non-limiting preferred embodiment:

[0245] A set of sensors arranged in the self-emptying fermentation tank (0) in the torispherical head, these sensors being: [0246] a torispherical head pressure sensor (10); this sensor measures the pressure (P) of CO.sub.2 or other gases: air or N.sub.2; it is combined with sensors (13, 15) to eliminate calculation error of the density (D) of the fermentation must; being of a flush membrane-type pressure sensor for red wines having a range of 0-160 mbar and for white wines having a range of 0-250 mbar; [0247] a torispherical head temperature sensor (11); this sensor measures the temperature (T) of CO.sub.2 or other gases: air or N.sub.2; being of a PT100 probe type for measuring from 10 to 40? C.; [0248] a torispherical head flowmeter sensor (12); this sensor measures the flow rate (F) of suctioned CO.sub.2 or other gases: injected air or N.sub.2; having a range of 10-1000 l/min or for installations with many compressors and suctions of 10-2000 l/min.

[0249] A set of sensors arranged in the self-emptying fermentation tank (0) in the upper cylindrical body, these sensors being: [0250] an upper cylindrical body pressure sensor (13); this sensor measures the pressure (P) in the liquid phase of the fermentation must below the area of the cap; combined with the sensor (15) and, by eliminating error by means of the sensor (10), the density (D) of the must and the level of the free surface are calculated; being of a flush membrane-type pressure sensor having a range of 0-400 mbar for tanks up to 4 m in height and of 0-1 bar for tanks up to 10 m in height; [0251] an upper cylindrical body temperature sensor (14); this sensor measures the temperature (T) in the fermentation must below the area of the cap; being of a PT100 probe type for measuring from 10 to 40? C.;

[0252] A set of sensors arranged in the self-emptying fermentation tank (0) in the lower cylindrical body, these sensors being: [0253] a lower cylindrical body pressure sensor (15); this sensor measures the pressure (P) in the liquid phase of the fermentation must above the area of solids sunken to the bottom; combined with the sensor (13) and, by eliminating error by means of the sensor (10), the density (D) of the must and the level of the free surface are calculated; being of a flush membrane-type pressure sensor having a range of 0-400 mbar for tanks up to 4 m in height and of 0-1 bar for tanks up to 10 m in height; [0254] a lower cylindrical body temperature sensor (16); this sensor measures the temperature (T) in the liquid phase of the fermentation must above the area of solids sunken to the bottom; being of a PT100 probe type for measuring from 10 to 40? C.; [0255] an aeration or oxygenation flowmeter sensor (18); this sensor measures the flow rate (F) of injected air or O.sub.2; having a range of 0-3000 l/min for CO.sub.2 injection and a range of 0-10 l/min for O.sub.2 injection.

[0256] Therefore, calculation of the density (D) of the fermentation must is performed based on measurements given by pressure sensors (13, 15). Since the tank is closed, the CO.sub.2 released in the upper part thereof causes a pressure in the fermentation must which causes a calculation error of the density (D) of the fermentation must; this is due to the fact that Pascal's principle which states that pressure applied to a point of a static incompressible fluid confined in a container is transmitted entirely to all the points of the fluid is not complied with given that the fermentation must contains a fraction of CO.sub.2 in dissolution, which is a compressible gas; error elimination is carried out based on the measurement given by the pressure sensor (10) which measures the pressure (P) of CO.sub.2 or other gases. To that end, the invention proposes performing an initial calibration before starting alcoholic fermentation which consists of performing a first measurement by means of the three pressure sensors (13, 15, and 10) when there is still no CO.sub.2 dissolved in the fermentation must (error-free measurement) and a second measurement by injecting CO.sub.2 (measurement with error), opening the injection control valve (35) of the gas processing and storage subsystem (3) until the pressure sensor (10) indicates the same CO.sub.2 pressure as the working pressure marked by the inerting control valve (32); the error produced in the pressure sensors (13, 15) (error=measurement with error?error-free measurement) is obtained with both measurements. In general, the pressure of the inerting control valve (32) is fixed for each type of tank, so calibration only needs to be performed once. [0257] b. acoustic emission instrumentation subsystem (2) (FIG. 04) which, by means of a set of sensors, measures the acoustic emission caused by the CO.sub.2 generated during respiration and alcoholic fermentation in the fermentation must, containing in a non-limiting preferred embodiment: [0258] an omnidirectional-type hydrophone sensor (20); this sensor measures the acoustic emission (A) produced within the fermentation must; having a range of 1 Hz to 140 kHZ, of horizontal positioning and ?2 dB omnidirectional type with an operating temperature range of ?2? C. to +80? C., of the type that is submersible and resistant to wine must and acetic acid, and is arranged submerged in the fermentation must contained in the self-emptying fermentation tank (0); [0259] an analog signal conditioner (21); this conditioner preamplifies (AS) the voltage of the hydrophone (20); having an output DC voltage range of 0-10 V;

[0260] In this case, ultrasound signals are not processed, rather the vibro-acoustic emission (below the ultrasonic frequency range) generated by the carbon dioxide gas resulting from respiration and alcoholic fermentation is captured. The effects of temperature on the alcoholic fermentation range do not significantly affect measurements. [0261] c. a gas processing and storage subsystem for the gases of air, CO.sub.2, N.sub.2 or O.sub.2 (3) (FIGS. 03-16) which, by means of a plurality of devices and actuators, interacts in the fermentation must, containing in a preferred embodiment an inerting control valve (32), a valve located in the upper part of the tank in the dome element (010) which allows the action of pressurizing the tank (0), incompatible with the vent valve (011), so valve (32) replaces valve (011); and which is supplied from the CO.sub.2 tank (0) by means of a suction pipe (33), controlled by an outlet or injection valve (31), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, the function of which is to allow capturing of CO.sub.2 or injecting same or other gases: air or N.sub.2; and which, by means of a delivery pipe (34) through which pressurized CO.sub.2 or other gases: air or N.sub.2, are conducted, controlled by an injection control valve (35), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing the entry of CO.sub.2 or other gases: air or N.sub.2 to the CO.sub.2 injection collector (3, 6), a pipe external to the tank (0) which connects all the CO.sub.2 injection elements with the inlet valve (35); and which, by means of an aeration or oxygenation control valve (111), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing the O.sub.2 or air injection into the tank (0); and which, by means of a cooling control valve (113), a 2-way type seated globe valve having 2 positions that is pneumatically or electrically operated and controlled within the control of the system, has the function of allowing or preventing the passage of liquid coolant to the jackets (05) of the fermentation tank (0).

[0262] The subsystem (3) further contains in a preferred embodiment a plurality of valves, these valves being: [0263] a selector valve for the capturing of CO.sub.2 or air (310); being a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4); having the function of selecting the capturing of CO.sub.2 or air; [0264] a selector valve for the delivery of CO.sub.2 or air (311); being a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4); having the function of selecting the delivery of CO.sub.2 or air; [0265] a selector valve for the delivery of air (312); being a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4); having the function of selecting the delivery of air; [0266] a selector valve for the delivery of air or O.sub.2 (313); being a 3-way type seated globe valve with 3 positions that is pneumatically or electrically operated and controlled within the control subsystem (4); having the function of selecting the delivery of air or O.sub.2.

[0267] The subsystem (3) further contains in a preferred embodiment a plurality of tanks, these tanks being: [0268] trap filter tank (314); this tank prevents the entry of condensate into the compressors, protecting them from said condensate; [0269] pressurized CO.sub.2 or N.sub.2 tank (316); being a pressurized buffer tank with a design pressure of 10 bar; [0270] pressurized air tank (317); being a pressurized buffer tank with a design pressure of 10 bar; [0271] pressurized N.sub.2 tank (319); being a pressurized buffer tank with a design pressure of 10 bar; [0272] compressed O.sub.2 cylinder (320).

[0273] The subsystem (3) further contains in a preferred embodiment a compressor (315) with a design pressure of 10 bar according to ISO 8573-1 standard, class 0, in terms of the quality of air suitable for the food industry; and an N.sub.2 generator (318); being an N.sub.2 generator for inerting the fermentation tank (0).

[0274] In a preferred embodiment, the inerting control valve (32) will allow pressurizing in a range of minimum 5 mbar and maximum 40 mbar for large tanks (0) and minimum 5 mbar and maximum 120 mbar for other tanks (0). [0275] d. a control subsystem (4) (FIG. 01) containing in a preferred embodiment: [0276] a main control panel (40), containing a programmable logic controller (PLC) (401) which incorporates means for communicating with a human machine interface (HMI) device (402); [0277] a slave panel (41), which incorporates decentralized periphery modules that collect input signals of the instrumentation subsystems for sending data to the panel (40) by means of a single communications bus; [0278] a secondary panel (42), which incorporates solenoid valve modules that collect control data of the panel (40) by means of a single communications bus in order to act on the valves of the instrumentation subsystems.

Method for Continuous Monitoring and Improved Automatic Control of Temperature, and of Aeration-Oxygenation, of the Process of Alcoholic Fermentation in Wine by Means of Acoustic Emission Techniques (P1) Using a System (D1) for the Implementation Thereof.

[0279] A method for continuous monitoring and improved automatic control of temperature of the process of alcoholic fermentation in wine by means of acoustic emission techniques (P1) using a system (D1) for the implementation thereof is described in detail by means of listing the steps to be executed according to the indicated order.

[0280] In order to improve understanding and clarity, the operation of each step and sub-step is graphically described by means of Graphs of Control by Steps and Transitions (GRAFCET) and Piping and Instrumentation Diagrams (P&IDs), mentioning in each of them the corresponding figure in each case, avoiding textual description as it is less clear. The P&IDs show the active element in grey and passage through the pipes in black. In the GRAFCET: in selected steps a-f, the equations of transition of each sub-step, as well as the actuators activated in each of them, are indicated; in steps that are likely to work simultaneously, i.e., steps g, h, i, the equations of transition of each sub-step, as well as the actuators activated and deactivated in each of them, are indicated. The invention proposes a method for continuous monitoring and improved automatic control of temperature of the process of alcoholic fermentation in wine by means of acoustic emission techniques (PI) using a system (D1) for the implementation thereof, of the type of methods which interact with means for tracking and controlling alcoholic fermentation in a self-emptying fermentation tank (0), comprising a method module implemented in a PLC program (P0), installed in a PLC (401) which incorporates means for communicating with an HMI device (402); wherein if the hardware (HW) of the PLC (401) is correct (OK), a start block is cyclically executed (FIG. 17: GRAFCET) which, by means of the interaction of a user in the HMI (402), only calls one of the selected steps a-f but with the user being able to activate steps g, h, i simultaneously, characterized in that the method module implemented in the PLC program (P0) for the purpose of interacting with the means for tracking and controlling comprises at least the following steps:

STEP a (P10): Providing, in a Controlled Manner, by Means of Acoustic Emission Techniques, a Fermentation Tank (0, D1) with a Gas Mixture (Air+CO.sub.2), Allowing Yeasts to Perform Respiration Exclusively.

[0281] The passage of air to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35).

[0282] In this step a (P10), it is proposed that the yeast (naturally present or artificially inoculated) mainly performs, by means of the supply of gas (air and CO.sub.2), respiration controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented.

[0283] In this optional step a (P10), the object is to reduce the probable alcoholic strength of the wine, causing the yeast to perform respiration by providing it with the required air (of which the yeast will use oxygen), such that a part of the sugars in the must undergoes respiration instead of fermentation. Subsequently, the air supply must be stopped in order to continue with the conventional process of fermentation, since an excess presence of oxygen causes a reduced quality of the wine (Gonzalez et al., 2013).

[0284] The chemical equation (symbolic description) of the chemical reaction of respiration is as follows:

C.sub.6H.sub.12O.sub.6(glucose/fructose)+6.Math.O.sub.2.fwdarw.6.Math.H.sub.2O(water)+6.Math.CO.sub.2+Q(kJ)RESPIRATION

[0285] With the following stoichiometry: [0286] Molecular weight (g/mol): [0287] 180+192 (6-32).fwdarw.108 (6.Math.18)+264 (6.Math.44) [0288] Proportion (%): [0289] 100%.fwdarw.29.03%+70.97%

[0290] The CO.sub.2 (gas) generated during respiration remains in dissolution until it is released once the fermentation must (liquid) becomes saturated, whereas the water (liquid) remains in dissolution (three times as much CO.sub.2 is produced in respiration compared to fermentation).

[0291] The CO.sub.2 is suctioned for subsequent injection into the fermentation must for the purpose of achieving homogenization, avoiding the performance of pumping over.

[0292] During an exhaustive experimentation campaign, it has been found that, in a preferred embodiment, the maximum aeration conditions which maintain the quality of the wine since the level of dissolved oxygen is kept close to zero from the start and the levels of acetic acid at the end of the process are similar to those obtained in an anaerobic process of alcoholic fermentation (0.3 g/I) are: [0293] Airflow (l/h)=5-volume (I) of fermentation must; [0294] Time (h)=48; [0295] Ethanol reduction=2% (v/v); [0296] Combined with a discontinuous homogenization cycle by means of CO.sub.2 injection.

[0297] Lower aeration conditions may arise maintaining the quality of the wine, but with an ethanol reduction of less than 2% (v/v).

[0298] STEP a (P10) comprises a prior routine sub-step, STEP a.0 (P100), of refilling the air tank (317) which is implemented, by way of illustration, in a preferred embodiment of the invention, for the purpose of refilling the air tank (317) within operating limits according to the pressure thereof (FIG. 18: GRAFCET; FIG. 06: P&ID).

[0299] STEP a (P10) of respiration with air is characterized in that it comprises at least the following sub-steps (FIG. 18: GRAFCET): [0300] injecting air in the fermentation tank (0, D1) (P11) (FIG. 08: P&ID). [0301] suctioning CO.sub.2+injecting air in the fermentation tank (0, D1) (P12) (FIG. 09: P&ID). [0302] suctioning CO.sub.2+injecting air and CO.sub.2 in the fermentation tank (0, D1) (P13) (FIG. 10: P&ID).

[0303] The following can be selected simultaneously along with STEP a (P10): [0304] STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 22: GRAFCET). [0305] STEP h (P80) of optimized control of aeration or oxygenation in a fermentation
tank (0, D1) by means of acoustic emission techniques (FIG. 23: GRAFCET).

[0306] STEP b (P20): Providing, in a Controlled Manner, by Means of Acoustic Emission Techniques, a Fermentation Tank (0, D1) with a Qas Mixture (O.sub.2+CO.sub.2), Allowing Yeasts to Perform Respiration Exclusively.

[0307] The passage of O.sub.2 to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35).

[0308] In this STEP b (P20), it is proposed that the yeast (naturally present or artificially inoculated) mainly performs, by means of the supply of gas (O.sub.2 and CO.sub.2), respiration controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented.

[0309] STEP b is similar to STEP a but with the difference that a gas mixture containing O.sub.2 instead of air is provided.

[0310] During an exhaustive experimentation campaign, it has been found that, in a preferred embodiment, the maximum oxygenation conditions which maintain the quality of the wine since the level of dissolved oxygen is kept close to zero from the start and the levels of acetic acid at the end of the process are similar to those obtained in an anaerobic process of alcoholic fermentation (0.3 g/l) are: [0311] Oxygen flow (l/h)=1-volume (I) of fermentation must; [0312] Time (h)=48; [0313] Ethanol reduction=2% (v/v); [0314] Combined with a discontinuous homogenization cycle by means of CO.sub.2 injection.

[0315] Lower oxygenation conditions can arise maintaining the quality of the wine, but with an ethanol reduction of less than 2% (v/v).

[0316] STEP b (P20) of respiration with O.sub.2 is characterized in that it comprises at least the following sub-steps (FIG. 19: GRAFCET): [0317] injecting O.sub.2 in the fermentation tank (0, D1) (P21) (FIG. 13: P&ID). [0318] suctioning CO.sub.2+injecting O.sub.2 in the fermentation tank (0, D1) (P22) (FIG. 14: P&ID). [0319] suctioning CO.sub.2+injecting O.sub.2 and CO.sub.2 in the fermentation tank (0, D1) (P23) (FIG. 15: P&ID).

[0320] The following can be selected simultaneously along with STEP b (P20): [0321] STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 22: GRAFCET). [0322] STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 23: GRAFCET).
STEP c (P30): Providing a Fermentation Tank (0, D1) with a Gas Mixture (CO.sub.2+Air), Allowing Yeasts to Perform Combined Alcoholic Fermentation and Respiration Monitored and Controlled by Means of Acoustic Emission Techniques.

[0323] The passage of air to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35).

[0324] In this STEP c (P30), it is proposed that the yeast (naturally present or artificially inoculated) mainly performs, by means of the supply of gas (CO.sub.2 and air), alcoholic fermentation monitored and controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented.

[0325] The chemical equation (symbolic description) of the chemical reaction of alcoholic fermentation is as follows:

C.sub.6H.sub.12O.sub.6(glucose/fructose).fwdarw.2.Math.C.sub.2H.sub.5OH(ethanol)+2.Math.CO.sub.2+Q(kJ)FERMENTATION

[0326] With the following stoichiometry: [0327] Molecular weight (g/mol); energy (kcal/mol of sugar consumed): [0328] 180.fwdarw.92 (2.Math.46)+88 (2.Math.44)+23.5 kcal [0329] Proportion (%): [0330] 100%.fwdarw.51.11%+48.89%

[0331] The CO.sub.2 (gas) generated during alcoholic fermentation remains in dissolution until it is released once the fermentation must (liquid) becomes saturated, whereas ethanol (liquid) remains in dissolution, although a small fraction of ethanol is lost through evaporation.

[0332] The CO.sub.2 is suctioned for subsequent injection into the fermentation must for the purpose of achieving homogenization, avoiding the performance of pumping over.

[0333] The aeration in this STEP c allows the yeast to also perform respiration for the purpose of facilitating its growth and reproduction by providing it with the required air (of which the yeast will use oxygen), such that a part of the sugars in the must undergoes respiration instead of fermentation. STEP c differs from STEP a in that in STEP a respiration is performed continuously for some time, whereas in this STEP c respiration can be performed discontinuously or continuously together with fermentation, producing wines with more color that is fixed by the oxygen from aeration, in addition to achieving a greater disassociation of tannins and anthocyanins.

[0334] The maximum aeration conditions which maintain the quality of the wine since the level of dissolved oxygen is kept close to zero from the start and the levels of acetic acid at the end of the process are similar to those obtained in an anaerobic process of alcoholic fermentation (0.3 g/l) are the same as those found during the experimentation campaign described in STEP a, these conditions being: [0335] Airflow (l/h)=5-volume (I) of fermentation must; [0336] Time (h)=48 (counted in a continuous regimen or accumulated in a discontinuous regimen); [0337] Ethanol reduction=2% (v/v); [0338] Combined with a discontinuous homogenization cycle by means of CO.sub.2 injection.

[0339] Lower aeration conditions can arise maintaining the quality of the wine, but with an ethanol reduction of less than 2% (v/v).

[0340] This step comprises a prior routine sub-step, STEP a.0 (P100), of refilling the air tank (317) which is implemented, by way of illustration, in a preferred embodiment of the invention, for the purpose of refilling the air tank (317) within operating limits according to the pressure thereof (FIG. 20: GRAFCET; FIG. 06: P&ID).

[0341] STEP c (P30) of alcoholic fermentation plus aeration is characterized in that it comprises at least the following sub-steps (FIG. 20: GRAFCET): [0342] injecting air in the fermentation tank (0, D1) (P11) (FIG. 08: P&ID). [0343] suctioning CO.sub.2+injecting air in the fermentation tank (0, D1) (P12) (FIG. 09: P&ID). [0344] suctioning CO.sub.2+injecting air and CO.sub.2 in the fermentation tank (0, D1) (P13) (FIG. 10: P&ID). [0345] suctioning CO.sub.2+injecting CO.sub.2 in the fermentation tank (0, D1) (P31) (FIG. 11: P&ID). [0346] suctioning CO.sub.2 in the fermentation tank (0, D1) (P32) (FIG. 12: P&ID).

[0347] The following can be selected simultaneously along with STEP c (P30): [0348] STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 22: GRAFCET). [0349] STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 23: GRAFCET).
STEP d (P40): Providing a Fermentation Tank (0, D1) with a Gas Mixture (CO.sub.2+O.sub.2), Allowing Yeasts to Perform Combined Alcoholic Fermentation and Respiration Monitored and Controlled by Means of Acoustic Emission Techniques.

[0350] The passage of O.sub.2 to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111), and the passage of CO.sub.2 to said fermentation tank (0, D1) is allowed or prevented by means of an injection control valve (35).

[0351] In this STEP d (P40), it is proposed that the yeast (naturally present or artificially inoculated) mainly performs, by means of the supply of gas (CO.sub.2 and O.sub.2), alcoholic fermentation monitored and controlled by means of acoustic emission techniques in a fermentation tank (0) in which a device (D1) object of the invention has been implemented.

[0352] STEP d is similar to STEP c but with the difference that a gas mixture containing O.sub.2 instead of air is provided.

[0353] The oxygenation of this STEP d allows the yeast to also perform respiration for the purpose of facilitating its growth and reproduction by providing it with the required oxygen, such that a part of the sugars in the must undergoes respiration instead of fermentation. STEP d differs from STEP b in that in STEP b respiration is performed continuously for some time, whereas in this STEP d respiration can be performed discontinuously or continuously together with fermentation, producing, like in the preceding step, wines with more color that is fixed by the oxygen from oxygenation, in addition to achieving a greater disassociation of tannins and anthocyanins.

[0354] The maximum oxygenation conditions which maintain the quality of the wine since the level of dissolved oxygen is kept close to zero from the start and the levels of acetic acid at the end of the process are similar to those obtained in an anaerobic process of alcoholic fermentation (0.3 g/I) are the same as those found during the experimentation campaign described in STEP b, these conditions being: [0355] Oxygen flow (l/h)=1.Math.V (I) of fermentation must; [0356] Time (h)=48 (counted in a continuous regimen or accumulated in a discontinuous regimen); [0357] Ethanol reduction=2% (v/v); [0358] Combined with a discontinuous homogenization cycle by means of CO.sub.2 injection.

[0359] Lower oxygenation conditions may arise maintaining the quality of the wine, but with an ethanol reduction of less than 2% (v/v).

[0360] STEP d (P40) of alcoholic fermentation plus oxygenation is characterized in that it comprises at least the following sub-steps (FIG. 21: GRAFCET): [0361] injecting O.sub.2 in the fermentation tank (0, D1) (P13) (FIG. 13: P&ID). [0362] suctioning CO.sub.2+injecting O.sub.2 in the fermentation tank (0, D1) (P22) (FIG. 14: P&ID). [0363] suctioning CO.sub.2+injecting O.sub.2 and CO.sub.2 in the fermentation tank (0, D1) (P23) (FIG. 15: P&ID). [0364] suctioning CO.sub.2+injecting of CO.sub.2 in the fermentation tank (0, D1) (P31) (FIG. 11: P&ID). [0365] suctioning CO.sub.2 in the fermentation tank (0, D1) (P32) (FIG. 12: P&ID).

[0366] The following can be selected simultaneously along with STEP d (P40): [0367] STEP g (P70) of optimized control of temperature in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 22: GRAFCET). [0368] STEP h (P80) of optimized control of aeration or oxygenation in a fermentation tank (0, D1) by means of acoustic emission techniques (FIG. 23: GRAFCET).
STEP e (P50): Providinq a Fermentation Tank (0, D1) with Qas (N.sub.2) for the Purpose of Inerting the Tank.

[0369] A routine step which is implemented, by way of illustration, in a preferred embodiment of the invention (FIG. 21: GRAFCET) (FIG. 16: P&ID).

STEP f (P60): Performina a Normal Stop in the Control of a Fermentation Tank (0. D1).

[0370] A routine step which is implemented, by way of illustration, in a preferred embodiment of the invention (FIG. 21: GRAFCET). By selecting STEP f (P60) any of steps a-f that was selected is deselected, so the actuations of steps a-f transition to the logic state=0. In a preferred embodiment, simultaneous STEPS g-h are kept in operation.

STEP g (P70): Monitoring and Controlling the Temperature in a Fermentation Tank (0, D1) by Means of Acoustic Emission Techniques.

[0371] Since alcoholic fermentation is an exothermic reaction, the heat generated during the process of fermentation must be removed in order to maintain the optimal temperature. To that end, a cooling system of any of the state of the art is used which, by means of a cooling control valve (113), allows or prevents the passage of the liquid coolant to the jackets (05) of the fermentation tank (0, D1).

[0372] One of the parameters having the most influence on the evolution of the process of alcoholic fermentation is temperature which, in addition to an optimum temperature, contributes to obtaining wine with the typical characteristics of its denomination. In general, wines prepared at low temperature are more aromatic and better valued in the organoleptic analysis but, on the other hand, their fermentation can be incomplete.

[0373] The acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation is measured and the acoustic emission speed (dACO.sub.2/dt) is calculated for the early detection of the fermentation speed (g of CO.sub.2/l/h) (amount, by weight or by volume, of CO.sub.2 produced per unit of time), and therefore the activity of the yeasts.

[0374] In a preferred embodiment, the analog signal of the omnidirectional hydrophone sensor (20) is collected in the slave panel (41), being sent to the main control panel (40) and reaching the programmable logic controller (401) where it is internally converted to a digitalized signal, first being processed in a calibration module (P101) of the program (P0) to obtain the basic amplitude, frequency, and spectral descriptors thereof by applying fast Fourier transform (FFT); with the correct frequency range, the digitalized signal passes to the filtration module (P102) where a digital filter is applied to the signal to discriminate frequencies not related with the process of fermentation, finally obtaining the real-time value of the acoustic emission (ACO.sub.2).

[0375] According to another configuration for obtaining acoustic emission (ACO.sub.2), noise from aeration, oxygenation, CO.sub.2 injection recirculation of cooling water through the jackets, and any other desired noise is eliminated; to that end, before the start of alcoholic fermentation the acoustic emission of aeration (AAera), of oxygenation (AO.sub.2), of CO.sub.2 injection (AICO.sub.2), of cooling (AR), and of any other desired noise (AO) is recorded, then, noise is eliminated from the acoustic emission measured in the fermentation must (AMF) by means of the following equation:

ACO.sub.2=AMF?AAera?AO.sub.2?AICO.sub.2?AR?AO

since the PLC program (P0), installed in the PLC (401), has at all times the state of the aeration, oxygenation, CO.sub.2 injection, and cooling sub-steps so that in the case where one or more of them are activated, the corresponding noise from the active sub-steps can be subtracted by means of the preceding equation; that which is indicated above is performed if a noise emitting source is detected for the purpose of obtaining only the acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation.

[0376] When the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, exceeds a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the cooling control valve (113) is opened to keep the temperature within compatible winemaking limits to stabilize alcoholic fermentation, as shown in the following simple conditional logic equation (FIG. 22: GRAFCET):

[00001]$\mathrm{If}113=0\mathrm{AND}T?\left(T_{\mathrm{setpoint}}+?T\right)O$$\left(T_{\mathrm{setpoint}}-?T\right)<T<\left(T_{\mathrm{setpoint}}+?T\right)$$\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}+?\left({A\mathrm{CO}}_2\right)\right)\right)$$\mathrm{then}\left\{113=1\right\}$

[0377] When the acoustic emission speed (dACO.sub.2/dt), i.e. production of CO.sub.2, is below a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the cooling control valve (113) is closed allowing the temperature to rise to within compatible winemaking limits in order to reactivate alcoholic fermentation, as shown in the following simple conditional logic equation (FIG. 22: GRAFCET):

[00002]$\mathrm{If}113=1\mathrm{AND}T?\left(T_{\mathrm{setpoint}}-?T\right)O$$\left(T_{\mathrm{setpoint}}-?T\right)<T<\left(T_{\mathrm{setpoint}}+?T\right)$$\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}-?\left({A\mathrm{CO}}_2\right)\right)\right)$$\mathrm{then}\left\{113=0\right\}$

[0378] This set of indicated operations allows an optimum alcoholic fermentation kinetics (speed), as well as a quicker completion of fermentation.

STEP h (P80): Monitoring and Controlling the Aeration or Oxygenation of a Fermentation Tank (0, D1) by Means of Acoustic Emission Techniques.

[0379] The passage of air or oxygen to the fermentation tank (0, D1) is allowed or prevented to perform aeration or oxygenation by means of an aeration or oxygenation control valve (111).

[0380] The acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation is measured and the acoustic emission speed (dACO.sub.2/dt) is calculated for the early detection of the fermentation speed (g of CO.sub.2/l/h), and therefore the activity of the yeasts.

[0381] In a preferred embodiment, the analog signal of the omnidirectional hydrophone sensor (20) is collected in the slave panel (41), being sent to the main control panel (40) and reaching the programmable logic controller (401) where it is internally converted to a digitalized signal, first being processed in a calibration module (P101) of the program (P0) to obtain the basic amplitude, frequency, and spectral descriptors thereof by applying fast Fourier transform (FFT); with the correct frequency range, the digitalized signal passes to the filtration module (P102) where a digital filter is applied to the signal to discriminate frequencies not related with the process of fermentation, finally obtaining the real-time value of the acoustic emission (ACO.sub.2).

[0382] According to another configuration for obtaining acoustic emission (ACO.sub.2), noise from aeration, oxygenation, CO.sub.2 injection recirculation of cooling water through the jackets, and of any other desired noise is eliminated; to that end, before the start of alcoholic fermentation the acoustic emission of aeration (AAera), of oxygenation (AO.sub.2), of CO.sub.2 injection (AICO.sub.2), of cooling (AR), and any other desired noise (AO) is recorded, then, noise is eliminated from the acoustic emission measured in the fermentation must (AMF) by means of the following equation:

ACO.sub.2=AMF?AAera?AO.sub.2?AICO.sub.2?AR?AO

[0383] since the PLC program (P0), installed in the PLC (401), has at all times the state of the aeration, oxygenation, CO.sub.2 injection, and cooling sub-steps so that in the case where one or more of them are activated, the corresponding noise from the active sub-steps can be subtracted by means of the preceding equation; that which is indicated above is performed if a noise emitting source is detected for the purpose of obtaining only the acoustic emission (ACO.sub.2) caused by the CO.sub.2 generated during respiration and alcoholic fermentation.

[0384] When the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, is below a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the aeration or oxygenation control valve (111) is opened in order to reactivate the activity of the yeasts, as shown in the following simple conditional logic equation (FIG. 23: GRAFCET):

[00003]$\mathrm{If}111=0\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}-?\left({A\mathrm{CO}}_2\right)\right)\right)$$\mathrm{then}\left\{111=1\right\}$

[0385] When the acoustic emission speed (dACO.sub.2/dt), i.e., CO.sub.2 production, exceeds a previously established limit ((ACO.sub.2)setpoint), taking into account a preestablished hysteresis value (?(ACO.sub.2)), the aeration or oxygenation control valve (111) is closed in order to deactivate the excessive activity of the yeasts, as shown in the following simple conditional logic equation (FIG. 23: GRAFCET):

[00004]$\mathrm{If}111=1\mathrm{AND}\left(\frac{{\mathrm{dA}\mathrm{CO}}_2}{\mathrm{dt}}?\left(\left({A\mathrm{CO}}_2\right)\mathrm{setpoint}+?\left({A\mathrm{CO}}_2\right)\right)\right)$$\mathrm{then}\left\{111=0\right\}$

[0386] This operation allows aeration or oxygenation metering to be optimized, as required, until the accumulated flow (f18), measured by the aeration or oxygenation flowmeter sensor (18), reaches the setpoint value (fsetpoint), obtaining an increase in wine quality in the Total Polyphenol Index (TPI) which causes a qualitative leap in terms of organoleptic parameters.

STEP i (P90): Performing an Emergency Stop in the Control of a Fermentation Tank (0, D1).

[0387] A routine step which is implemented, by way of illustration, in a preferred embodiment of the invention (FIG. 21: GRAFCET). By actuating the NC emergency push button (PE), STEP i (P90) which will reset all the actuations is selected.