JP2000166523A - Sterilizer for liquid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of a pulse power source for applying a pulse voltage having both a low-electric field long pulse region and a high-electric field short pulse region to a liquid material in a sterilization treating part. SOLUTION: This sterilizer for a liquid material 2 is equipped with a sterilization treating part 10 and a pulse power source 20b for applying a pulse electric field EP having both a low-electric field long pulse region and a high-electric field short pulse region to the liquid material 2. The pulse power source 20b is provided with one pulse voltage generating circuit 54 for generating the pulse voltage, a charging power source 52 for charging the pulse voltage generating circuit 54 and a magnetic switch 58 connected to the pulse voltage generating circuit 54 and the sterilization treating part 10. The magnetic switch 58 provides a relatively high inductance at the time of unsaturation, is capable of applying a pulse voltage forming the low-electric field long pulse region of the pulse electric field EP in cooperation with the pulse voltage generating circuit 54 to the sterilization treating part 10, provides a relatively low inductance at the time of saturation and is capable of applying a pulse voltage forming the high-electric field short pulse region of the pulse electric field EP in cooperation with the pulse voltage generating circuit 54 to the sterilization treating part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse of a high electric field on liquids (including liquids) such as beverages (juice, milk, etc.), liquid eggs, water, lotion, liquid medicines, hydroponic liquids, culture liquids and the like. The present invention relates to a sterilization apparatus for performing a sterilization treatment by applying an electric field, and more specifically, to an improvement in a pulse power supply of a sterilization apparatus that enables energy saving and low-temperature processing while maintaining a sterilization effect.

[0002]

2. Description of the Related Art A technique for applying a pulse electric field of a high electric field (also referred to as an electric field pulse; the same applies hereinafter) to a liquid material as described above to perform a sterilization treatment is known. For example, Tokiko 3-11
See No. 755. In principle, this technology has advantages such as energy saving, low-temperature sterilization, no alteration of the liquid material, and physical sterilization with no danger of remaining toxic chemicals.

[0003] Further, a sterilizer which improves a known sterilizer and enables energy saving and low-temperature treatment while maintaining a sterilizing effect has been previously proposed by the same applicant (Japanese Patent Application No. 10-314645). issue). One example of the sterilizer will be described below with reference to FIGS.

The sterilization apparatus shown in FIG. 9 has two electrodes 12 and 14 facing each other, and a sterilization process in which the liquid material 2 to be sterilized is filled (for example, flowed) between the two electrodes 12 and 14. Part 10 and two electrodes 1 of this sterilization processing part 10
Supplying a pulse voltage V _P between 2 and 14 and the electrodes 12, 1
It comprises a liquid material 2 between 4 and a pulse power source 20a that applies a pulsed electric field E _P. In this example, the two electrodes 12 and 14 have a parallel plate shape as an example, but may have a coaxial cylindrical shape or the like. Reference numeral 16 denotes an insulator.

The two electrodes 12, 14 of the sterilizing section 10
And the pulse voltage V _P supplied between both electrodes 12,1
Between the pulsed electric field E _P applied to the liquid product 2 between 4, if the distance between the electrodes 12 and 14 is d, the relation of the following equation is established, and the pulse voltage V _P waveform of the pulse electric field E _P are substantially equal to each other.

[0006]

## EQU1 ## E _P = V _P / d

[0007] In the sterilizing section 10, the liquid 2 is applied.
Pulse electric field E_PIs, for example, as shown in FIG.
Low electric field long pulse area with relatively low electric field strength and long pulse width
Area E _LHigh electric field with relatively high electric field strength and short pulse width
Short pulse region E_HIt has a waveform that combines this
Pulse electric field E having such a waveform_PIs applied to the liquid material 2.
Are the features of this prior art. The example of FIG.
Long pulse area E_LHigh electric field short pulse region E_HSuperimpose
FIG._LAnd E_HPulse width
And an example of the electric field strength.

[0008] The pulsed electric field E _P, for explaining the mechanism of bacterial cell killing in the liquid product 2 at the time of applying the liquid material 2 of the sterilization unit 10 with reference to FIG. 11.

[0009] (1) Step 1 (FIG. 11A, B) in this process, by the electric field of the pulse electric field E _P, fungal cell 4
The positive ions 44 and the negative ions 45 in 0 move in the opposite directions to each other up to the vicinity of the cell membrane 42, and become polarized (FIG. 11).
B).

[0010] (2) Step 2 (FIG. 11C) In this process, the electric field of the pulse electric field E _P, membrane 4
A small hole 46 is opened in 2. The mechanism by which the small holes 46 are opened is considered to be due to the electrical breakdown of the cell membrane 42 due to the application of a strong electric field to the inside and outside of the cell membrane 42. A higher electric field is required than in the process.

[0011] (3) Step 3 (FIG. 11D) in this process, by the electric field of the pulse electric field E _P, fungal cell 4
The ions 44 and 45 in 0 flow out of the cell. In this ion outflow process, the ion balance in the bacterial cells 40 is disturbed, and the ions pass through the small holes 46 of the cell membrane 42, so that the small holes 46 are expanded and become irreversible. .

In such a mechanism of electric field sterilization, a low electric field long pulse area E _L and a high electric field short pulse area E _H
By applying a pulsed electric field E _P as described above having both bets on liquid material 2, an electric field is applied (Step 1 and Step 3) The role of low field length pulse area E _L of for migration of ions bacterial cell is shared, it is possible to share the role of applying a high electric field for cell membrane disruption (step 2) a high field short pulse region E _H. As a result, unlike the case of the known techniques for applying a pulsed electric field of a single waveforms (i.e. two regions E _L and E _H and the waveform without having both the above-mentioned), extra energy to the liquid substance 2 An effective sterilization treatment can be performed while preventing the introduction. Therefore, energy saving and low-temperature treatment can be realized while maintaining the sterilizing effect.

[0013] low field length pulse area E _L of the pulse electric field E _P is the electric field strength E 1 kV / cm or more 15kV /
cm and a pulse width τ of 2 μs or more and 100 μs
It is preferable to set the following. The high electric field short pulse region E _H is
When the electric field strength E is 15 kV / cm or more and 100 kV / cm
And the pulse width τ is preferably set to 0.05 μs or more and less than 2 μs. By doing so, it is possible to more reliably realize energy saving and low-temperature treatment while maintaining the sterilization effect, and to prevent the electrode constituent substance ions from being mixed into the liquid material 2 and to prevent the sterilization processing unit 10 from performing the process. The insulation design can be facilitated.

[0014] The typical configuration example of the pulse power source 20a, which can realize the application of pulsed electric field E _P as described above is shown in FIG. 12. The pulse power source 20a is a predetermined time difference from the two pulse voltage generating circuit 24 and 34, the pulse voltage V corresponding respectively to the low field length pulse area E _L and high field short pulse region E _H of pulsed electric field E _P described above _L and V _H are generated, respectively, and these are connected to the protection circuits 28, 3
8 sterilization section 1 as a pulse voltage V _P superimposed over the
0 is supplied. Each pulse voltage generation circuit 2
4 and 34 have capacitors 25 and 35 and discharge start switches 26 and 36, respectively, in this example. Each of the pulse voltage generation circuits 24 and 34 (more specifically, each of the capacitors 25 and 35) It is charged by charging power supplies 22 and 32, respectively. After charging, discharge start switch 26
And 36 are closed (turned on) with a predetermined time difference, the pulse voltages _VL and _VH are generated with a predetermined time difference.

Since the pulse voltage generation circuits 24 and 34 utilize the discharge of the capacitors 25 and 35,
Pulse voltage V _P that combines a pulse voltage V _L and V _H of the exponential decay waveform (CR discharge waveform) is obtained. Instead of capacitors 25 and 35, a pulse shaping network (PF
The use of N) or Blumlein, it is possible to obtain a pulse voltage V _P that combines a pulse voltage V _L and V _H of the rectangular waveform. FIG. 10 shows the pulse voltage V of this rectangular waveform.
Shows an example of a pulsed electric field E _P wave upon application of a _P.

[0016]

[SUMMARY OF THE INVENTION In order to apply a pulsed electric field E _P having both a low field length pulse area E _L as described above in the liquid substance 2 in sterilization section 10 and the high-field short pulse area E _H Normally switches the pulse power supply 20a to the following (1)
It is necessary to have the configuration of (4).

(1) In order to generate two pulse voltages of a long pulse and a short pulse, two pulse voltage generation circuits for generating pulse voltages having different pulse widths from each other are used.
FIG. 12 shows an example of such a configuration.

(2) In order to set the long pulse side to a relatively low voltage and the short pulse side to a relatively high voltage, the two pulse voltages are generated using two charging power supplies having different ratings. Instead of making the charging voltages for the circuits different from each other or using only one charging power supply, the output voltage of one pulse voltage generating circuit is increased by using a booster circuit such as a pulse transformer or a voltage doubler circuit. FIG. 12 shows an example as described above.

(3) In order to apply the high voltage short pulse width voltage to the sterilization processing unit 10 later than the low voltage long pulse width voltage (for example, by delaying about several μs), the two pulse voltage generation circuits start discharging. A switch is provided to turn on these two discharge start switches with a time difference or to simultaneously discharge two pulse voltage generating circuits (that is, output pulse voltages simultaneously), and output a high voltage short pulse width voltage. A delay circuit such as a delay line is provided on the side,
The high voltage short pulse width voltage is delayed and applied to the sterilization processing unit 10. FIG. 12 shows an example as described above.

(4) The output units of the two pulse voltage generating circuits are connected before the sterilization processing unit 10 to superimpose the two pulse voltages. In that case, a protection circuit such as a diode or a reactor is provided to protect each pulse voltage generation circuit from the other side. FIG. 12 shows an example of such a configuration.

As described above, the liquid material 2 in the sterilizing section 10
In order to apply a pulsed electric field E _P having both a low field length pulse area E _L and the high electric field short pulse area E _H as described above, the pulse power source 20a, it (1) two pulse voltage generating circuit Required, (2) two charging power supplies or boosting circuits are required for boosting, (3) two discharge start switches or delay circuits are required to delay one pulse voltage, and (4) two pulse voltage generations A charging power supply, such as a protection circuit is needed to protect the circuits from each other,
Compared with a normal pulse power supply having one pulse voltage generation circuit and one discharge start switch,
There is room for improvement in that the configuration of “a” becomes considerably complicated (approximately two normal pulse power supplies).

Accordingly, the present invention simplifies the structure of a pulse power supply for applying a pulse electric field having both a low electric field length pulse region and a high electric field short pulse region to a liquid material in a sterilization section. Main purpose.

[0023]

According to the present invention, there is provided a sterilization apparatus comprising:
The pulse power supply is one pulse voltage generation circuit that generates a pulse voltage, one charging power supply that charges the pulse voltage generation circuit, and is connected in series between the pulse voltage generation circuit and the sterilization processing unit. It has a relatively high inductance when not saturated, and in cooperation with the pulse voltage generation circuit, applies a pulse voltage forming the low electric field length pulse region of the pulse electric field to the sterilization processing unit, A magnetic switch for applying a pulse voltage that forms the high electric field short pulse region of the pulse electric field to the sterilization processing unit in cooperation with the pulse voltage generation circuit, having a relatively low inductance when saturated. It is characterized by:

The pulse voltage generating circuit can be charged by the charging power supply, and a pulse voltage can be generated from the pulse voltage generating circuit. This pulse voltage is applied to the sterilization section via the magnetic switch.

Since a normal magnetic switch has a very large inductance when it is not saturated, it is almost off with respect to the pulse voltage when it is not saturated. However, the magnetic switch constituting the present invention has a smaller inductance than that of a normal magnetic switch and is appropriately conducting, so that the pulse voltage generated by the pulse voltage generating circuit can be passed. It can be applied to the sterilization section. At this time, the inductance of the magnetic switch is
Since the pulse voltage is larger than that at the time of saturation, the pulse voltage applied to the sterilization unit via this magnetic switch has a relatively low voltage and a long pulse width due to the influence of the inductance. This makes it possible to apply a pulse voltage for forming the above-described low electric field length pulse region of the pulse electric field to the sterilization processing unit.

When the pulse voltage is supplied to the magnetic switch for a predetermined time, the magnetic switch is saturated. When the magnetic switch saturates, its inductance becomes smaller than that when it is not saturated, and the magnetic switch is turned on. Therefore, the pulse voltage applied to the sterilizing section via the magnetic switch is relatively unaffected by the inductance of the magnetic switch, and therefore has a relatively high voltage and a short pulse width. This makes it possible to apply a pulse voltage for forming the high electric field short pulse region of the pulse electric field to the sterilization processing unit.

Therefore, according to the present invention, only one pulse voltage generating circuit and one charging power supply are required, and the booster circuit, the delay circuit, and the protection circuit are not required, so that the configuration of the pulse power supply is greatly simplified. Can be.

[0028]

FIG. 1 is a view mainly showing a pulse power source of an example of a sterilizing apparatus according to the present invention. FIG. 9-
Parts that are the same as or correspond to those of the preceding example shown in FIG. 12 are denoted by the same reference numerals, and differences from the preceding example will be mainly described below.

In this sterilizing apparatus, the two electrodes 12 of the sterilizing section 10 as described above are supplied from the pulse power source 20b.
A pulse voltage _VP is applied between the two electrodes 12 and 14.
In the liquid material 2 in between, the low electric field length pulse region E as described above
Pulse electric field E having both _L and high electric field short pulse region E _H
It is configured to apply _P. The sterilization processing unit 10
For example, since it is as shown in FIG. 9 described above and the description thereof, the description is omitted here.

The pulse power supply 20b includes one pulse voltage generation circuit 54 for generating a pulse voltage, and a pulse voltage generation circuit 54 (more specifically, a capacitor 55).
It has one charging power supply 52 for charging, and a magnetic switch 58 connected in series between the pulse voltage generating circuit 54 and the sterilization processing unit 10. The magnetic switch 58 is also called a saturable reactor.

The charging power supply 52 normally outputs a direct current or a current having a long pulse width to charge the capacitor 55. A pulse voltage V having a positive polarity on the magnetic switch 58 side
_{When P} is output, the capacitor 55 is charged so that the magnetic switch 58 side of the capacitor 55 has a positive polarity as in this example.

In this example, the pulse voltage generation circuit 54
It includes a capacitor 55 charged by the charging power source 52 and a discharge start switch 56 for discharging the charge. When the discharge start switch 56 is closed (turned on) after charging the capacitor 55, the charge of the capacitor 55 is rapidly discharged, and in this example, a positive pulse voltage is generated. The discharge start switch 56 includes, for example, a thyratron, a semiconductor switch, and the like.

The magnetic switch 58 is relatively unsaturated.
With high inductance, the pulse voltage generation circuit 54
In cooperation, the aforementioned pulsed electric field E_PLow electric field length pulse area
Area E _L(In other words, the low electric field length pulse region E_L
Pulse voltage V_L(See Fig. 2 etc.)
Applied to the part 10 and has a relatively low inductance when saturated.
In cooperation with the pulse voltage generation circuit 54,
Pulse electric field E_PHigh electric field short pulse region E_HForm
(In other words, the high electric field short pulse region E_HPal)
Voltage V_H(See FIG. 2 and the like) to the sterilizing section 10.
You.

In order to perform a switching (on / off) operation, the magnetic switch usually has a very large inductance when it is not saturated (for example, about several hundred times to several thousand times the inductance when it is saturated). Designed. Therefore, when it is not saturated, it is almost off with respect to the pulse voltage.

On the other hand, in the magnetic switch 58, the inductance at the time of saturation is made smaller than the inductance of the normal magnetic switch, that is, the inductance at the time of saturation is appropriately increased. It is made conductive. In other words, it is in an intermediate state between off and on.

Since the inductance of the magnetic switch 58 at the time of saturation is set to be sufficiently small similarly to a normal magnetic switch, the magnetic switch 58 is in an on state with respect to the pulse voltage at the time of saturation.

More specifically, the magnetic switch
Unsaturated inductance L_USAnd inductance at saturation
L_SIs simply expressed by the following equation. here
And S ₁Is the cross-sectional area of the core (assuming the space factor is 1), S_TwoIs
Area enclosed by winding, μ_rUSIs the relative permeability when the core is unsaturated,
μ_rSIs the relative magnetic permeability when the core is saturated.

[0038]

L _S / L _US = (S ₂ / S ₁ ) × (μ _rS / μ _rUS )

In a normal magnetic switch, S ₂ / S ₁ is almost 1 because the winding is wound on the core almost in close contact. Further, the relative magnetic permeability μ _rUS of the core used in the ordinary magnetic switch when the core is not saturated is about several hundreds to several thousands, and the relative magnetic permeability μ _rS when the core is saturated is almost 1, so the above ratio L _S / L
_US is on the order of several hundredths (ie, 10 ⁻² to 10 ⁻³ units) to several thousandths (ie, 10 ⁻³ to 10 ⁻⁴ units).

On the other hand, in the magnetic switch 58,
The inductance L _US at the time of non-saturation is appropriately increased to make the ratio L _S / L _US larger than that of a normal magnetic switch. For example, the ratio L _S / L _US is set to 10 ⁻¹ to 10 ⁻²
I am on a table.

In order to appropriately increase the inductance L _US of the magnetic switch 58 when it is not saturated, for example, the relative permeability μ _rUS of the core when it is not saturated is not so large (that is, the relative permeability μ _rUS when it is not saturated). using a core material not so large in _rUS), winding moderately increase the area S ₂ which surrounds, may be employed either or both means of.

[0042] In operation example of the sterilizing apparatus shown in FIG. 1, leave charged to the capacitor 55 of the pulse voltage generation circuit 54 by the charging power supply 52 to turn on the discharge start switch 56 at time t ₁ shown in FIG. 2 At this time, although the magnetic switch 58 is in an unsaturated state, as described above, its inductance is moderately large and conducts appropriately, so that the pulse voltage generated by the pulse voltage generating circuit 54 passes through the magnetic switch 58. Then, it can be applied to the sterilization processing unit 10. At this time, the inductance of the magnetic switch 58 is larger than that at saturation, pulse voltage V _P applied to the sterilization unit 10 through the magnetic switch 58, the influence of the inductance, relative (i.e. A lower voltage and longer pulse width (compared to when the magnetic switch 58 is saturated). That is, the aforementioned pulse electric field E
Pulse voltage V _L to form a low field length pulse area E _L of the _P
Can be applied to the sterilization processing unit 10. The waveform of the pulse voltage _VL is the pulse voltage generation circuit 54 in the example of FIG.
Since the capacitor 55 is used, the waveform becomes substantially sinusoidal as shown in FIG.

When the pulse voltage V _L is supplied to the magnetic switch 58 for a predetermined time, the magnetic switch 58 is saturated at a time t ₂ shown in FIG. 2, for example. The time difference (t ₂ −t ₁ ) from the energization start time t ₁ to the saturation time t ₂ can be determined according to a known saturation condition of the magnetic switch. This time difference may be, for example, about several μs to about 10 μs as described above.

When the magnetic switch 58 saturates, its inductance becomes very small.
Is turned on. Therefore, the pulse voltage V _P applied to the sterilization unit 10 through the magnetic switch 58,
Since it is hardly affected by the inductance of the magnetic switch 58, it has a relatively high voltage and a short pulse width. Thereby, it is possible to apply a pulse voltage V _H to form a high-field short pulse region E _H of pulsed electric field E _P described above in sterilized unit 10. The waveform of this pulse voltage V _H is shown in FIG.
Since the capacitor 55 is used in the pulse voltage generation circuit 54 in the example of FIG. 2, an exponential decay waveform (CR discharge waveform) is obtained as shown in FIG.

[0045] In this way, the sterilization unit 10 from the pulse power supply 20b, relatively a pulse voltage V _L of the low voltage and long pulse width, a relatively high voltage and short pulse width of the pulse voltage V _H it is possible to apply the pulse voltage V _P that combines. As a result, the liquid substance 2 in sterilized unit 10, it is possible to apply a pulsed electric field E _P having both a low field length pulse area E _L as described above and a high electric field short pulse region E _H.

Therefore, as in the case of the preceding example, the liquid 2
Thus, effective sterilization can be performed while preventing unnecessary energy input, so that energy saving and low-temperature processing can be realized while maintaining the sterilization effect.

Further, according to the pulse power supply 20b, the number of components is almost half as compared with the pulse power supply 20a shown in FIG. In other words, only one pulse voltage generation circuit and one charging power supply are required, and the booster circuit, the delay circuit, and the protection circuit are not required, so that the configuration of the pulse power supply can be greatly simplified.

The pulse voltage generating circuit 54 generates a pulse voltage having an exponentially attenuated waveform by utilizing the discharge of the capacitor 55 as described above, as well as a pulse forming network (PFN) and a pulse forming line (PFL). Alternatively, a pulse voltage having a rectangular waveform may be generated using a bloom line or the like. That is, instead of the capacitor 55,
A pulse shaping network, a bloom line, or the like may be used. The same applies to the cases shown in FIGS. 5 to 8 described later.

In this case, the pulse shaping network, the bloom line, and the like are designed so as to generate a pulse voltage V _H having a high voltage short pulse width corresponding to the high electric field short pulse region E _H described above. good. Magnetic switch 5
Before the saturation of the magnetic switch 5, the pulse voltage _VL having a low voltage and a long pulse width is applied to the sterilization processing unit 10 as described above.
After the saturation of 8, a rectangular pulse voltage V _H having a high voltage short pulse width is applied to the sterilization processing unit 10. An example of the thus waveform of the pulse voltage V _P applied to the sterilization unit 10 shown in FIG.

The waveform of the pulse voltage V _P shown in FIG. 3, the impedance of the pulse forming network and Blumlein constituting the pulse voltage generation circuit 54, when substantially equal to the impedance of the sterilization unit 10 is a load (i.e. impedance Although the waveform is obtained when matching is performed, a mismatch may be intentionally performed. That is, the impedance of the pulse forming network or the bloom line may be lower than the impedance of the sterilization processing unit 10. An example of a waveform of the pulse voltage V _P applied to the sterilization unit 10 in such a case shown in FIG.

In the case of this example, before the saturation of the magnetic switch 58, the pulse voltage V _L having a low voltage and a long pulse width as described above.
Occurs. After saturation of the magnetic switch 58, a rectangular pulse voltage _VH having a high voltage and a short pulse width is output. However, due to mismatching in the sterilization processing unit 10, a reflected wave having the same polarity as the incident wave is generated. pulse voltage V _H of a voltage higher than the pulse voltage V _H during the matching shown occurs.
Furthermore, it becomes a pulse that draws a tail due to the influence of the reflected wave,
After the pulse voltage V _H, the pulse voltage V having a low-voltage long pulse width
_The waveform follows _L2 .

[0052] Therefore, in this case, as compared to the matching state, it is possible to apply a high electric field short pulse region E _H of high electric field by the liquid substance 2 in sterilized unit 10, the cell membranes in the mechanism of electric field sterilization described above By drilling holes (see step 2 shown in FIG. 11), a high effect can be obtained. Furthermore, by the pulse voltage V _L2, even after the liquid material 2 of a high-field short pulse area E _H it is possible to apply a low field length pulse area E _L, in the mechanism of electric field sterilization after drilling of the cell membrane cells (See step 3 shown in FIG. 11). A higher bactericidal effect can be obtained by both of the above actions.

At the time of mismatching, the relationship of impedance is reversed in the opposite manner, that is, the pulse voltage generation circuit 54
When the impedance of the pulse shaping network or the bloom line constituting the above is higher than the impedance of the sterilization processing unit 10, a reflected wave having a polarity opposite to that of the incident wave is generated in the sterilization processing unit 10, the pulse voltage _VH decreases, and the This is not preferable because the pulse voltage V _L2 becomes negative.

The magnetic switch 5 having the above characteristics
8 is realized, depending on the magnetic material used for the core,
If an attempt is made to secure the time required for saturation only for a necessary time (for example, about several μs to ten μs as described above), the inductance at the time of non-saturation may become too large.
In addition, if an attempt is made to increase the inductance at the time of non-saturation appropriately, the inductance at the time of saturation may be too large than a predetermined value.

Therefore, as shown in FIG. 5, an auxiliary reactor 60 having an appropriate inductance may be connected in parallel to the magnetic switch 58. This auxiliary reactor 60 has a smaller inductance than the magnetic switch 58 when it is not saturated and a larger (preferably sufficiently larger) than the inductance when the magnetic switch 58 is saturated.
It is preferable to use one having inductance.

By providing the auxiliary reactor 60 as described above, when the magnetic switch 58 is not saturated, the combined inductance of the inductance of the magnetic switch 58 and the inductance of the auxiliary reactor 60 can be easily made appropriate. Become. When the magnetic switch 58 is saturated, its inductance becomes very small, so that the influence of the inductance of the auxiliary reactor 60 is small, and it can be almost ignored.

Thus, the desired inductance (synthetic inductance) of the magnetic switch 58 when it is not saturated, and
A desired inductance at saturation of the magnetic switch 58, it becomes possible to realize substantially independently of each other, it is easy to obtain a pulse voltage V _P of the desired waveform. For example, in the design of the magnetic switch 58, it is possible to mainly design the time until saturation and the inductance after saturation, so that the design of the magnetic switch 58 is facilitated.

In the case of the example shown in FIG. 1, the pulse voltage generation circuit 54 (more specifically, the capacitor 5
5), the charging current is applied to the sterilizing section 10
Flows through. At this time, if a device that outputs a direct current or a current having a long pulse width is used as the charging power supply 52, electrolysis of the liquid material 2 in the sterilization processing unit 10 may occur.

Therefore, as shown in FIG. 6, a charging reactor 62 for passing a charging current from the charging power supply 52 may be connected in parallel with the sterilizing section 10. This allows the charging current from the charging power supply 52 to flow while bypassing the sterilization processing unit 10, so that the electrolysis in the sterilization processing unit 10 can be prevented.

The impedance of the charging reactor 62 is smaller than the impedance of the sterilizing section 10 with respect to the charging current from the charging power supply 52, and is preferably set sufficiently small. By doing so, almost all of the charging current from the charging power supply 52 is transferred to the charging reactor 6.
2, the effect of preventing the electrolysis in the sterilizing section 10 is further enhanced. And the impedance of the charging reactor 62, for the pulse voltage V _P applied to the sterilization unit 10, greater than the impedance of the sterilization unit 10, preferably from idea to sufficiently large. By doing so, the pulse current is nearly all sterilization unit 1 during application of the pulse voltage V _P
Since it flows through 0, it is possible to prevent a decrease in the sterilizing action in the sterilizing section 10.

The charging reactor 62 may be connected upstream of the magnetic switch 58, that is, in parallel with the output of the pulse voltage generating circuit 54, as in the example shown in FIG. By doing so, the charging current from the charging power supply 52 does not flow not only to the sterilization processing unit 10 but also to the magnetic switch 58, so that the inductance in the charging path can be further reduced. As a result, the pulse voltage generation circuit 54 can be charged at a higher speed, and a high repetition operation can be performed, and the processing capacity of the apparatus (that is, the amount of the liquid material 2 that can be sterilized per unit time) is further increased. It becomes possible.

As shown in FIG. 8, the provision of the auxiliary reactor 60 and the provision of the charging reactor 62 may be used in combination. By doing so, both of the above-described effects can be achieved. In that case,
The charging reactor 62 may be provided on the upstream side of the magnetic switch 58, or may be provided in parallel with the sterilization processing unit 10 as shown in the illustrated example because it can be charged at a high speed through the auxiliary reactor 60.

[0063]

Since the present invention is configured as described above, it has the following effects.

According to the first or second aspect of the present invention, only one pulse voltage generating circuit and one charging power supply are required, and a booster circuit, a delay circuit, and a protection circuit are not required. Can be simplified.

Further, as in the case of the prior art, the porosity generation process of the electric field sterilization mechanism is performed in a high electric field short pulse region.
Since the ion transfer / outflow process of the same mechanism can be shared in the low electric field length pulse region, effective sterilization can be performed while preventing unnecessary energy input to the liquid material. Therefore, energy saving and low-temperature treatment can be realized while maintaining the sterilizing effect.

According to the third aspect of the present invention, the desired inductance when the magnetic switch is not saturated and the desired inductance when the magnetic switch is saturated can be realized almost independently of each other. Thus, it becomes easy to obtain a pulse voltage having a desired waveform, and the design of the magnetic switch becomes easy.

According to the fourth or fifth aspect of the present invention, the charging current from the charging power supply can be caused to flow by bypassing the sterilizing section, so that occurrence of electrolysis in the sterilizing section can be prevented. .

[Brief description of the drawings]

FIG. 1 is a diagram mainly showing a pulse power supply of an example of a sterilization apparatus according to the present invention.

FIG. 2 is a diagram illustrating an example of a waveform of a pulse voltage.

FIG. 3 is a diagram showing another example of a waveform of a pulse voltage.

FIG. 4 is a diagram showing still another example of the waveform of the pulse voltage.

FIG. 5 is a diagram mainly showing a pulse power supply of another example of the sterilizing apparatus according to the present invention.

FIG. 6 is a view mainly showing a pulse power supply of still another example of the sterilizing apparatus according to the present invention.

FIG. 7 is a diagram mainly showing a pulse power supply of still another example of the sterilizing apparatus according to the present invention.

FIG. 8 is a diagram mainly showing a pulse power source of still another example of the sterilizing apparatus according to the present invention.

FIG. 9 is a diagram mainly showing a sterilizing section of an example of a sterilizing apparatus according to the prior art.

FIG. 10 is a diagram illustrating an example of a waveform of a pulse electric field.

FIG. 11 is a diagram schematically showing a mechanism of electric field sterilization.

12 is a diagram illustrating a configuration example of a pulse power supply in FIG. 9;

[Explanation of symbols]

2 liquid material 10 sterilized section 12, 14 electrodes 20b pulsed power supply 52 charges the power supply 54 pulse voltage generating circuit 58 the magnetic switch 60 auxiliary reactor 62 charged reactor V _P, V _L, V _H pulse voltage E _P pulsed electric field E _L low field Long pulse area E _H High electric field short pulse area

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeru Kato 47-47 Umezu Takaune-cho, Ukyo-ku, Kyoto-shi, Kyoto (72) Inventor Kawakita Yes 47-47 Umezu-Takaune-cho, Ukyo-ku, Kyoto, Kyoto Nissin Electric F term in reference (reference) 4B021 LA42 LP10 LT03 LW06 4C058 AA20 AA21 AA22 AA30 BB06 KK06 KK42 KK46

Claims (5)

[Claims] 1. A sterilizing section having two electrodes facing each other and filled with a liquid material between the two electrodes, and supplying a pulse voltage between the two electrodes of the sterilizing section to supply a pulse voltage between the two electrodes. A pulse power supply for applying a pulse electric field having both a low electric field length pulse region having a relatively low electric field strength and a long pulse width and a high electric field short pulse region having a relatively high electric field intensity and a short pulse width to a liquid material; In the sterilization apparatus, the pulse power supply may include one pulse voltage generation circuit that generates a pulse voltage, one charge power supply that charges the pulse voltage generation circuit, and between the pulse voltage generation circuit and the sterilization processing unit. The pulse voltage that is connected in series and has a relatively high inductance when not saturated and cooperates with the pulse voltage generating circuit to form the low electric field pulse region of the pulse electric field is sterilized. The pulse voltage is applied to the sterilization processing unit by applying a pulse voltage that forms the high electric field short pulse region of the pulse electric field in cooperation with the pulse voltage generation circuit. A sterilizer for a liquid material, comprising: 2. The electric field intensity of a low electric field pulse region of a pulse electric field applied to the liquid material is 1 kV / cm or more and 15 kV.
The liquid material according to claim 1, wherein the pulse width is less than 2 μs / cm, the pulse width is 2 μs or more and 100 μs or less, the electric field intensity in the high electric field short pulse region is 15 kV / cm or more and 100 kV / cm or less, and the pulse width is 0.05 μs or more and less than 2 μs. Sterilization equipment. 3. An auxiliary reactor having an inductance smaller than an inductance of the magnetic switch when it is not saturated and larger than an inductance of the magnetic switch when it is saturated is connected in parallel with the magnetic switch. 3. An apparatus for sterilizing liquid substances according to 2. 4. The apparatus for sterilizing a liquid material according to claim 1, wherein a charging reactor for flowing a charging current from the charging power supply is connected in parallel with the sterilizing section. 5. The apparatus for sterilizing a liquid material according to claim 1, wherein a charging reactor for flowing a charging current from the charging power supply is connected in parallel with an output section of the pulse voltage generating circuit.