DEVICE FOR PROCESSING USING PULSED ELECTRIC FIELDS
Patent Information
- Application Number
- DE112022007380
- Authority / Receiving Office
- DE · DE
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-06-15
- Publication Date
- 2025-03-27
Smart Images
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Abstract
Description
Technical area
[0001] The present disclosure relates to a pulsed electric field processing device that generates a pulsed electric field. background
[0002] As a technique capable of processing a processing target such as a food or a beverage at a temperature lower than that of heat processing, a pulsed electric field processing technique can be mentioned.
[0003] Patent Literature 1 discloses a liquid material sterilization device in which a required pulse voltage value for a pulse voltage applied to a sterilization processing unit is calculated based on a diameter and shape coefficient of a bacterial cell to be sterilized, a distance between electrodes in the sterilization processing unit, and a destruction threshold value. The destruction threshold value is a value required to adjust a voltage applied to the bacterial cell to a destruction reference value. The applied voltage to the bacterial cell refers to a voltage applied to the bacterial cell in the sterilization processing unit as a pulse voltage. The destruction reference value refers to a value of the voltage applied to the bacterial cell and is a value necessary for the destruction of the bacterial cell.An output of the pulse voltage from a pulse power supply is adjusted based on the calculation result and a measurement result of the pulse voltage. List of citationsPatent literature
[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2021-114943 Brief description of the inventionProblem to be solved by the invention
[0005] In Patent Literature 1, the pulse power supply is controlled using the resistivity of a liquid material before it flows into the sterilization processing unit. The resistivity is obtained by a resistivity measuring device arranged upstream of the sterilization processing unit. This results in a difference between the resistivity measured by the resistivity measuring device and the resistivity of the sterilization processing unit. As a result, there is a problem that the temperature of the liquid material cannot be accurately controlled, and the sterilization quality of the liquid material deteriorates.
[0006] The present disclosure has been developed in view of the foregoing, and an object of the present disclosure is to provide a pulsed electric field processing apparatus capable of controlling a temperature of a processing target with high accuracy and improving the processing quality of the processing target. Ways to solve the problem
[0007] To solve the above problem and achieve an object, a pulsed electric field processing apparatus according to the present disclosure includes: a pulse power supply for generating a pulse voltage; a pair of first electrodes for generating a pulse electric field by applying the pulse voltage thereto; a first processing chamber disposed between the pair of first electrodes for enclosing a space through which a processing target in a liquid state passes and in which the pulse electric field is generated;a temperature calculation unit for calculating a first processing temperature, which is a temperature of the processing target in the first processing chamber, based on a resistance value and a preset calibration value, the resistance value being obtained from the pulse voltage and a pulse current flowing through the processing target in the first processing chamber when the pulse voltage is applied to the first electrodes; and a power supply control unit for controlling the pulse power supply based on the first processing temperature and a preset target temperature. Effects of the invention
[0008] A pulsed electric field processing apparatus according to the present disclosure has an effect of controlling a temperature of a processing target with high accuracy and improving the processing quality of the processing target. Short description of the drawings Fig. 1 is a schematic diagram illustrating an exemplary configuration of a pulsed electric field processing apparatus according to a first embodiment. Fig. 2 is a cross-sectional view illustrating an exemplary configuration of a processing unit of the pulsed electric field processing device according to the first embodiment. Fig. 3 is a cross-sectional view illustrating another exemplary configuration of the processing unit of the pulsed electric field processing device according to the first embodiment. Fig. 4 is a circuit diagram illustrating an exemplary configuration of a pulse power supply of the pulsed electric field processing device according to the first embodiment. Fig. 5 is a timing chart illustrating examples of a pulse voltage waveform and a pulse current waveform of the pulse power supply of the pulsed electric field processing apparatus according to the first embodiment. Fig. 6 is a block diagram illustrating an exemplary configuration of a control system of the pulsed electric field processing device according to the first embodiment. Fig. 7 is a timing chart illustrating a temporal change of a processing temperature calculated by the pulsed electric field processing apparatus according to the first embodiment. Fig. 8 is a schematic diagram illustrating another exemplary configuration of the pulsed electric field processing apparatus according to the first embodiment. Fig. 9 is a schematic diagram illustrating an exemplary configuration of a pulsed electric field processing apparatus according to a second embodiment. Fig. 10 is a schematic diagram illustrating an example of a temperature distribution of the pulsed electric field processing apparatus according to the second embodiment. Fig. 11 is a block diagram illustrating an example of a hardware configuration implementing the control system of the first and second embodiments. Description of embodiments
[0009] In the following, a device for processing by means of pulsed electric fields according to embodiments is described in more detail in this document with reference to the drawings. First embodiment.
[0010] Fig. 1 is a schematic diagram illustrating an exemplary configuration of a pulsed electric field processing apparatus according to a first embodiment. The pulsed electric field processing apparatus includes a pulse power supply 10, a controller 40, a processing unit 50, an upstream pipe 70, and a downstream pipe 71. The pulsed electric field processing apparatus performs processing, including sterilization processing, on a processing target. The pulse power supply 10 outputs a pulse voltage having a voltage of 1 kV or more and a pulse width of 100 microseconds or less. The upstream pipe 70 and the processing unit 50 are connected to each other, and the processing unit 50 and the downstream pipe 71 are connected to each other.A processing target in a liquid state flows in the following order through the upstream pipe 70, the processing unit 50, and the downstream pipe 71. The processing target is, for example, a fluid such as juice or milk. The processing unit 50 is electrically connected to the pulse power supply 10 and has a function of repeatedly applying a pulse electric field to the processing target flowing in the processing unit 50 using the pulse voltage output from the pulse power supply 10. The control device 40 controls the pulse power supply 10.
[0011] Fig. 2 is a cross-sectional view illustrating an exemplary configuration of the processing unit 50 of the pulsed electric field processing device according to the first embodiment. The processing unit 50 includes an electrode 51 as a first electrode, insulating members 54, and a processing chamber 55. The electrode 51 includes a high-voltage electrode 52 and a low-voltage electrode 53 forming a pair. A pulse voltage is applied to the high-voltage electrode 52, and the low-voltage electrode 53 is maintained at ground potential. By using titanium, platinum, stainless steel, or the like as the material for the electrode 51, wear caused by the pulse voltage is mitigated.The high-voltage electrode 52 and the low-voltage electrode 53 each have a flat plate shape and are arranged to face each other, sandwiching the processing target. That is, the high-voltage electrode 52 and the low-voltage electrode 53 are arranged to generate an electric field in a direction substantially perpendicular to a flow direction W of the processing target.
[0012] The processing chamber 55 is a space in the processing unit 50 in which an electric field is generated by the electrode 51 and through which the processing target passes. When the high-voltage electrode 52 and the low-voltage electrode 53 are each in the shape of a flat plate and arranged to face each other, the processing chamber 55 thus has a rectangular parallelepiped shape. In order to be electrically insulated from the upstream pipe 70 and the downstream pipe 71, each of which has a tubular shape and is made of metal, the high-voltage electrode 52 is connected to the upstream pipe 70 and the downstream pipe 71 by means of insulating members 54, each of which is interposed between the high-voltage electrode 52 and a corresponding one of the upstream pipe 70 and the downstream pipe 71.The low-voltage electrode 53 may be connected to the upstream pipe 70 and the downstream pipe 71 by means of insulating members 54, each of which is interposed between the low-voltage electrode 53 and a corresponding one of the upstream pipe 70 and the downstream pipe 71, or it may be provided integrally with the upstream pipe 70 and the downstream pipe 71 without interposing the insulating members 54. In the former case, there is an effect of reducing electrical noise generated by the pulse voltage, and in the latter case, there is an advantage of miniaturizing the processing unit 50. By using a resin material containing fluorine or ceramics as the raw material for the insulating member 54, high heat resistance and high voltage resistance are achieved.
[0013] Fig. 3 is a cross-sectional view illustrating another exemplary configuration of the processing unit 50 of the pulsed electric field processing device according to the first embodiment. Fig. 3, the electrode 51, as the first electrode, includes the high-voltage electrode 52 and the low-voltage electrode 53, and has a ring-shaped structure with the flow direction W of the processing target as its axis. The upstream pipe 70, the insulating member 54, the low-voltage electrode 53, the insulating member 54, the high-voltage electrode 52, the insulating member 54, the low-voltage electrode 53, the insulating member 54, and the downstream pipe 71 are arranged in this order from the upstream side of the processing target. An electric field is generated in a direction substantially along the flow direction of the processing target.Therefore, when the high-voltage electrode 52, the low-voltage electrodes 53, and the insulating members 54 each have an annular structure, and the inner diameters of the high-voltage electrode 52, the low-voltage electrodes 53, and the insulating members 54 are substantially equal to each other, the processing chamber 55 has a columnar shape or a ring shape. Furthermore, since the low-voltage electrodes 53 are arranged at two locations in the flow direction W of the processing target object with the high-voltage electrode 52 interposed therebetween, a current path flowing from the high-voltage electrode 52 to the low-voltage electrodes 53 is divided into two. The insulating member 54 between the low-voltage electrode 53 and the upstream pipe 70 and the insulating member 54 between the low-voltage electrode 53 and the downstream pipe 71 are not necessarily provided.When these insulating members 54 are provided, there is an effect of reducing electrical noise, and when these insulating members 54 are not provided, there is an advantage of miniaturizing the processing unit 50.
[0014] As in Fig. As illustrated in Figure 2, when the high-voltage electrode 52 and the low-voltage electrode 53 are arranged to face each other, the electric field generated in the processing chamber 55 can be spatially uniform, and the effect of reducing the unevenness of processing can be achieved. As shown in Fig. 3, when the high-voltage electrode 52 and the low-voltage electrodes 53 are arranged along the flow direction W of the processing target object, the processing chamber 55 can have a columnar shape, and the processing target object can flow smoothly from the upstream pipe 70 to the downstream pipe 71 with a small pressure loss.
[0015] Fig. 4 is a circuit diagram illustrating an exemplary configuration of the pulse power supply 10 of the pulsed electric field processing device according to the first embodiment. In the pulse power supply 10, a switch 13, a capacitor 11, a switch 14, and a capacitor 12 are connected in series in this order from the ground side. The high-voltage electrode 52 of the processing unit 50 is connected to the capacitor 12 by a cable or the like. In the capacitor 11, a terminal on a side of the switch 13 is a charge-side terminal, and a terminal on a side of the switch 14 is a ground-side terminal. Further, in the capacitor 12, a terminal on a side of the switch 14 is a charge-side terminal, and a terminal on a side of the high-voltage electrode 52 is a ground-side terminal.
[0016] A DC power supply 15 generates a DC voltage that charges the capacitor 11 and the capacitor 12. The DC power supply 15 is connected to each of the charge-side terminal of the capacitor 11 and the charge-side terminal of the capacitor 12 via at least one current limiter 16. Furthermore, at least one current limiter 16 is further configured to be provided between the charge-side terminal of the capacitor 11 and the charge-side terminal of the capacitor 12. Likewise, the ground-side terminal of the capacitor 11 and the ground-side terminal of the capacitor 12 are grounded via at least one current limiter 16, and at least one current limiter 16 is provided between the ground-side terminal of the capacitor 11 and the ground-side terminal of the capacitor 12.
[0017] The pulse power supply 10 outputs a pulse voltage in two steps, including a charging step and a discharging step. In the charging step, the capacitor 11 and the capacitor 12 are charged by the DC power supply 15. In the discharging step, by turning on the switch 13 and the switch 14 almost simultaneously, a charging voltage of the capacitor 11 and a charging voltage of the capacitor 12 are superimposed and output. After the charging voltage is output, the switch 13 and the switch 14 are turned off to complete the discharging step. That is, a period in which the switch 13 and the switch 14 are turned on is a period of the discharging step and corresponds to a pulse width Tp of the pulse voltage output from the pulse power supply 10. The switching control of the switch 13 and the switch 14 is performed by the controller 40.
[0018] Semiconductor switches, such as metal oxide semiconductor field-effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBTs), are used as the switch 13 and the switch 14. Furthermore, resistors or reactors are used as the current limiters 16. Using resistors offers the advantage of charging the capacitor 11 and the capacitor 12 with a stable voltage, and using reactors reduces power consumption.
[0019] In the exemplary configuration of the pulse power supply 10 shown in Fig. As illustrated in Figure 4, two capacitors and two switches are used, but three or more capacitors and three or more switches with a similar configuration can be used. One advantage is that a higher pulse voltage can be achieved with an increasing number of capacitors and switches.
[0020] Fig. 5 is a timing chart illustrating examples of a pulse voltage Vp waveform and a pulse current Ip waveform of the pulse power supply 10 of the pulsed electric field processing device according to the first embodiment. In an upper diagram of Fig. 5, the pulse voltage Vp is a voltage that the pulse power supply 10 outputs to the high-voltage electrode 52 during the discharge step. The pulse voltage Vp has the pulse width Tp. In a lower diagram of Fig. 5, the pulse current Ip is a current flowing through the processing chamber 55 according to the pulse voltage Vp.
[0021] Fig. 6 is a block diagram illustrating an exemplary configuration of a control system of the pulsed electric field processing apparatus according to the first embodiment. The pulse power supply 10 includes a pulse voltage measuring device 22 that measures the pulse voltage Vp and a pulse current measuring device 23 that measures the pulse current Ip. The pulse current measuring device 23 measures the pulse current flowing through the processing target in the processing chamber 55 when the pulse voltage Vp is applied to the electrode 51. The pulse voltage measuring device 22 and the pulse current measuring device 23 repeatedly measure the pulse voltage Vp and the pulse current Ip, respectively, at intervals shorter than the pulse width Tp, and calculate the pulse voltage Vp and the pulse current Ip, respectively, using a plurality of acquired measurement values.Alternatively, by providing a capacitor for measurement, the pulse voltage Vp and pulse current Ip can be estimated using an integrated value for the pulse width Tp. In the former case, there is the advantage that the measurement can be performed with high accuracy, and in the latter case, the device can be downsized.
[0022] To further simplify the setup, the pulse voltage Vp and the pulse current Ip can be estimated from a voltage or current in the pulse power supply 10. The pulse voltage Vp can be calculated using a voltage charged in the capacitor 11 or the capacitor 12. Further, the pulse current Ip can be calculated from the pulse voltage Vp, the pulse width Tp, and a current flowing through the capacitor 11 or the capacitor 12 after the discharging step. The pulse power supply 10 has a function for optionally adjusting the pulse width Tp and the voltage output from the DC power supply 15. Therefore, the pulse voltage Vp and the pulse current Ip can be estimated by only measuring the current flowing through the capacitor 11 or the capacitor 12.
[0023] As in Fig. As illustrated in FIG. 6, the control device 40 includes a power supply control unit 41, a temperature calculation unit 42, a first abnormality detection unit 43, and a second abnormality detection unit 44. The temperature calculation unit 42 calculates a resistance value Rw (not illustrated) of the processing target object present in the processing chamber 55 using the pulse voltage Vp measured by the pulse voltage measuring device 22 and the pulse current Ip measured by the pulse current measuring device 23. Further, the temperature calculation unit 42 calculates a processing temperature tw as a first processing temperature, which is a temperature of the processing target object in the processing chamber 55, using a preset calibration value and the calculated resistance value Rw.The calibration value refers to a value based on the temperature dependence of the conductivity of the processing target object, and a value corresponding to the type of the processing target object is used for the calibration value. In addition, the temperature calculation unit 42 has a function of calculating the processing temperature tw in a first cycle Tc and storing the calculated processing temperature tw. The processing temperature tw may be calculated each time the pulse voltage Vp is output, or may be calculated each time the pulse voltage Vp is output twice or more. In the former case, the effect of improving the responsiveness can be achieved due to the short calculation cycle. In the latter case, the effect of reducing the calculation load and reducing the size of the device can be achieved.
[0024] The power supply control unit 41 controls the turning on and off of the switch 13 and the switch 14 based on the processing temperature tw calculated by the temperature calculation unit 42 and a preset target temperature to control the output from the pulse power supply 10. Specifically, at least one of an upper limit value and a lower limit value is preset as a target temperature for the processing temperature tw, and control to decrease the output from the pulse power supply 10 is performed when the processing temperature tw exceeds the upper limit value, and control to increase the output from the pulse power supply 10 is performed when the processing temperature tw falls below the lower limit value.When the processing temperature Tw is too high, there arises a problem that the taste, nutrients, and the like of the processing target object are impaired, whereas when the processing temperature Tw is too low, the sterilization effect, etc., is reduced. Therefore, by performing the above control, the processing target object can be maintained at an appropriate temperature and the quality of the processing target object can be improved.
[0025] The control of the output from the pulse power supply 10 is adjusted by changing at least one of the pulse voltage Vp, the pulse width Tp, and the pulse frequency fp (not illustrated). When the pulse voltage Vp is changed, it is necessary to control the DC power supply 15, and the responsiveness is low. Therefore, high responsiveness can be achieved by controlling the on / off of the switch 13 and the switch 14 so that the pulse voltage Vp is not changed and by changing at least one of the pulse width Tp and the pulse frequency fp.
[0026] The first anomaly detection unit 43 outputs a first anomaly signal when the processing temperature Tw calculated in the first cycle Tc exceeds a normal temperature range defined by a preset set value, or when a difference exceeding a set value Δtmx occurs between the processing temperature Tw and an average value of the past processing temperatures Tw stored in the temperature calculation unit 42. Fig. 7 is a timing chart illustrating a temporal change in the processing temperature tw calculated by the pulsed electric field processing device according to the first embodiment. Black dots indicate the processing temperatures tw calculated for each first cycle Tc. An average value tav is an average value of a plurality of past processing temperatures tw. When a difference Δta between the processing temperature tw calculated for the current time and the average value tav exceeds the target value Δtmx, the first anomaly detection unit 43 outputs a first anomaly signal.
[0027] The temperature calculation unit 42 can calculate a temperature rise Δt of the processing target object during a period in which the processing target object passes through the processing unit 50. In other words, the temperature calculation unit 42 can calculate the temperature rise Δt, which is a temperature difference between the temperature of the processing target object before passing through the processing unit 50 and the temperature of the processing target object after passing through the processing unit 50. That is, the temperature calculation unit 42 can calculate the temperature rise Δt of the processing target object during a period in which the processing target object passes through the processing unit 50 based on a relationship between a flow rate and a value of a physical property of the processing target object and the power output from the pulse power supply 10.The processing temperature tw calculated by the temperature calculation unit 42 represents the average temperature of the spatial temperature distribution in the processing chamber 55. Therefore, by adding approximately 1 / 2 of the temperature rise Δt to the processing temperature tw, a temperature twd of the processing target object downstream of the processing unit 50 can be estimated. The temperature calculation unit 42 transmits the estimated temperature twd of the processing target object downstream of the processing unit 50 to the second anomaly detection unit 44.
[0028] Furthermore, the temperature measuring device 24, which measures a temperature of the processing target object, is provided downstream of the processing unit 50. The temperature measuring device 24 is, for example, a thermocouple.
[0029] The second anomaly detection unit 44 periodically compares the temperature twd of the processing target object downstream of the processing unit 50, which is estimated by the temperature calculation unit 42, with the temperature of the processing target object downstream of the processing unit 50, which is measured by the temperature measuring device 24. The second anomaly detection unit 44 outputs a second anomaly signal when a difference exceeding a set value occurs between the compared temperatures. By providing the second anomaly detection unit 44, it is possible to constantly monitor whether the processing temperature tw calculated by the temperature calculation unit 42 is correct or not, and there is an advantage in that an anomaly can be detected when an anomaly occurs.
[0030] Note that the temperature measuring device 24 may be provided upstream of the processing unit 50, and the second anomaly signal may be output based on a comparison between the value measured by the temperature measuring device 24 provided upstream of the processing unit 50 and the temperature of the processing target object upstream of the processing unit 50 estimated by the temperature calculation unit 42. Furthermore, the second anomaly signal may be output based on a comparison between values measured by temperature measuring devices 24 provided downstream and upstream of the processing unit 50 and temperatures of the processing target object downstream and upstream of the processing unit 50 estimated by the temperature calculation unit 42.
[0031] The pulsed electric field processing device of the first embodiment includes a state observation unit 90 and a machine learning unit 91. The state observation unit 90 has a function of observing a charging voltage or a charging current in the capacitor 11 or the capacitor 12 as a state variable. The machine learning unit 91 learns a normal value of the charging voltage or the charging current using a training data set created based on the state variable and the value of the physical property of the processing target. By creating the training data set, wear of the electrode 51 caused by aging can be taken into account with respect to the normal value of the charging voltage or the charging current.Furthermore, the machine learning unit 91 has a function of transmitting an abnormality notification to the control device 40 when the value of the charging voltage or the charging current deviates from the normal value of the charging voltage or the charging current.
[0032] Fig. Fig. 8 is a schematic diagram illustrating another exemplary configuration of the pulsed electric field processing device according to the first embodiment. Fig. 8, heating units 72, which function to increase the temperature of the processing target, are provided upstream of the processing unit 50. A higher processing effect can be achieved by applying the pulse voltage Vp to the processing target in a state where the processing target has a higher temperature. The pulse power supply 10 can be downsized by using both the pulse power supply 10 and the heating unit 72, which is expected to lead to a downsizing and cost reduction of the pulsed electric field processing device.
[0033] As described above, according to the first embodiment, the temperature calculation unit 42 calculates the processing temperature tw, which is the temperature of the processing target in the processing chamber 55, based on the resistance value Rw and the preset calibration value. The resistance value Rw is obtained from the pulse voltage Vp and the pulse current Ip flowing through the processing target in the processing chamber 55 when the pulse voltage Vp is applied. In addition, the power supply control unit 41 controls the pulse power supply 10 based on the processing temperature tw and the preset target temperature. Therefore, the temperature of the processing target can be controlled with high accuracy, and the processing quality of the processing target can be improved. Second embodiment.
[0034] Fig. 9 is a schematic diagram illustrating an exemplary configuration of a pulsed electric field processing device according to a second embodiment. In the second embodiment, a processing unit 80 is added as a second processing unit downstream of the processing unit 50 of the electrolytic pulse processing device according to the first embodiment. Note that constituent elements that perform functions similar to those of constituent elements in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and redundant descriptions will be omitted.
[0035] The processing unit 80 has a configuration similar to that of the processing unit 50. That is, the processing unit 80 includes an electrode (not illustrated) that is a second electrode having a configuration similar to the electrode 51, an insulating member (not illustrated) that has a configuration similar to the insulating member 54, and a processing chamber (not illustrated) that is a second processing chamber having a configuration similar to the processing chamber 55. A second pulse voltage output from the pulse power supply 10 is applied to a high-voltage side electrode of the second electrode, and a second pulse current flows through the second processing chamber according to the second pulse voltage and a resistance value of the processing target in the second processing chamber.The temperature calculation unit 42 calculates a second processing temperature tw2, which is a temperature of the processing target object in the second processing chamber, based on the resistance value and a preset calibration value. The resistance value is obtained from the second pulse voltage and the second pulse current flowing through the processing target object in the second processing chamber when the second pulse voltage is applied. The power supply control unit 41 adjusts the output from the pulse power supply 10 based on at least two of the processing temperature tw of the processing target object in the processing unit 50, the second processing temperature tw2, and a target temperature set downstream of the processing unit 80.
[0036] Fig. Fig. 10 is a schematic diagram illustrating an example of a temperature distribution of the pulsed electric field processing device according to the second embodiment. Fig. 10, a horizontal axis represents the processing temperature and a vertical axis represents the position of the processing target object in the flow direction. The processing temperature of the processing target object increases as the processing target object passes through the processing unit 50, and the processing temperature of the processing target object continues to rise as the processing target object passes through the processing unit 80.
[0037] The power supply control unit 41 adjusts the output from the pulse power supply 10 according to a difference between the processing temperature tw and the second processing temperature tw2. At this time, by doubling the difference between the processing temperature tw and the second processing temperature tw2, the temperature rise of the processing target object while the processing target object passes through the processing unit 50 and the processing unit 80 can be calculated. As a result, the output from the pulse power supply 10 can be adjusted to achieve a desired temperature rise.Alternatively, the target temperature for the processing target object downstream of the processing unit 80 may be set to adjust the output from the pulse power supply 10 by comparing the target temperature with a value obtained by adding half of the power consumed by the processing unit 80 to the second processing temperature tw2. Therefore, by using at least two of the processing temperature tw, the second processing temperature tw2, and the target temperature set for the processing target object downstream of the processing unit 80, the output from the pulse power supply 10 can be controlled with respect to either the upper limit temperature or the temperature rise value of the processing target object.The pulse power supply 10 outputs different voltage waveforms to the processing unit 50 and the processing unit 80 based on independent control. With such control, the second processing temperature tw2 can be brought closer to the target temperature with greater accuracy. Alternatively, the pulse power supply 10 can output the same voltage waveforms to both the processing unit 50 and the processing unit 80. In this case, there is the advantage of simplifying the pulse power supply 10.
[0038] As described above, according to the second embodiment, the processing unit 80 is added downstream of the processing unit 50, and the temperature of the processing target object is controlled using at least two of the processing temperature tw, the second processing temperature tw2, and the target temperature set for the processing target object downstream of the processing unit 80. Therefore, the accuracy of temperature control on the processing target object is further improved, and the processing quality of the processing target object can be further improved.
[0039] Fig. Fig. 11 is a block diagram illustrating an example of a hardware configuration implementing the control system of the first and second embodiments. The components of the control device 40, the state observation unit 90, and the machine learning unit 91 shown in Fig.6 are implemented by a processor 93 and a memory 92.
[0040] The above configurations illustrated in the embodiments are examples of the contents of the present disclosure and may be combined with other known techniques, and the above configurations may be partially omitted or changed without departing from the gist of the present disclosure. List of reference symbols
[0041] 10 pulse power supply; 11, 12 capacitor; 13, 14 switch; 15 DC power supply; 16 current limiter; 22 pulse voltage measuring device; 23 pulse current measuring device; 24 temperature measuring device; 40 control device; 41 power supply control unit; 42 temperature calculation unit; 43 first anomaly detection unit; 44 second anomaly detection unit; 50, 80 processing unit; 51 electrode; 52 high-voltage electrode; 53 low-voltage electrode; 54 insulating member; 55 processing chamber; 70 upstream pipe; 71 downstream pipe; 72 heating unit; 90 state observation unit; 91 machine learning unit; 92 memory; 93 processor. QUOTES CONTAINED IN THE DESCRIPTION
[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature
[0000] JP 2021-114943
[0004]
Claims
[1] Device for processing by means of pulsed electric fields, comprising: a pulse power supply for generating a pulse voltage; a pair of first electrodes for generating a pulse electric field by applying the pulse voltage thereto; a first processing chamber disposed between the pair of first electrodes for enclosing a space through which a processing target in a liquid state passes and in which the pulse electric field is generated; a temperature calculation unit for calculating a first processing temperature, which is a temperature of the processing target object in the first processing chamber, based on a resistance value and a preset calibration value, the resistance value being obtained from the pulse voltage and a pulse current flowing through the processing target object in the first processing chamber when the pulse voltage is applied to the first electrodes; and a power supply control unit for controlling the pulse power supply based on the first processing temperature and a preset target temperature. [2] The pulsed electric field processing apparatus according to claim 1, further comprising a first anomaly detection unit for outputting a first anomaly signal based on a comparison between the first processing temperature calculated by the temperature calculation unit and a preset target value or an average value of the first processing temperature in the past. [3] Pulsed electric field processing device according to claim 1 or 2, wherein the power supply control unit performs control to change at least one of a pulse frequency and a pulse width of the pulse voltage without changing a voltage value of the pulse voltage. [4] Device for processing by means of pulsed electric fields according to one of claims 1 to 3, wherein the pulse power supply a circuit in which a capacitor and a switch are connected in series, wherein a charging voltage of the capacitor is discharged to apply a pulse voltage to the pair of first electrodes, and the temperature calculation unit calculates the pulse current based on a charging current of the capacitor. [5] Pulsed electric field processing device according to claim 4, comprising: a state observation unit for observing the charging voltage and the charging current of the capacitor as a state variable; and a machine learning unit for learning a normal value of the charging voltage or a normal value of the charging current using a training data set created based on the state variables and a value of the physical property of the processing target object. [6] Device for processing by means of pulsed electric fields according to one of claims 1 to 5, comprising a temperature measuring device for measuring a temperature of the processing target object, wherein the temperature measuring device is arranged at least either upstream or downstream of the first processing chamber, and the device for processing by means of pulsed electric fields further comprises a second anomaly detection unit for outputting a second anomaly signal based on a comparison between a temperature measured by the temperature measuring device and a temperature of the processing target object at least either upstream or downstream of the first processing chamber, which is calculated by the temperature calculation unit. [7] A pulsed electric field processing apparatus according to any one of claims 1 to 6, comprising a heating unit for heating the processing target object, the heating unit being provided upstream of the first processing chamber. [8] Pulsed electric field processing device according to one of claims 1 to 6, comprising: second electrodes for generating a pulsed electric field by applying the pulse voltage from the pulse power supply thereto, the second electrodes being arranged downstream of the first electrodes; and a second processing chamber arranged between a pair of second electrodes to enclose a space through which the processing target object passes and in which the electric pulse field is generated, wherein the temperature calculation unit a second processing temperature, which is a temperature of the processing target object in the second processing chamber, is calculated based on a resistance value and a preset calibration value, the resistance value being obtained from the pulse voltage and a pulse current flowing through the processing target object in the second processing chamber when the pulse voltage is applied to the second electrodes, and the power supply control unit controls the pulse power supply based on at least two of the first processing temperature, the second processing temperature, and a target temperature set for the processing target object downstream of the second processing chamber.
Citation Information
Patent Citations
Liquid material sterilizing device
JP2021114943A
2021-114943